MARCH/APRIL 2011
OLED Goes Roll-to-Roll Printed Memory The Influence of Stencil Exposure
www.industrial-printing.net
Processes for Dials and Gauges P. 18
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CONTENTS
INDUSTRIAL + SPECIALTY PRINTING March/APril 2011 • Volume 2/Issue 2
FEATURES
COLUMNS 12 Business Management
14 Pursuing the Printed OLED
Riikka Suhonen and Markus Tuomikoski, VTT Technical Research Centre of Finland This article provides an in-depth look at what it takes to print light-emitting diodes successfully.
18 Specialty Printing of Dials and Gauges
Benjamin Gorenberg for GM Nameplate Discover some of the processes for making dials and gauges and the markets for which they are designed.
22 Making Memories with Specialty Printing Randall Sherman, New Venture Research
Find out what progress has been made in printing memory devices on polymer.
26 Determining Optimum Exposure
Wim Zoomer, Technical Language This article examines the influence of stencil exposure on print quality and productivity.
Marcia Y. Kinter, Specialty Graphic Imaging Association Review the safety, health, and environmental regulations that affect industrial printers.
34 Printing Methods
John Corrall, Industrial Inkjet Ltd. This article addresses roll-toroll inkjet printing and how to overcome challenges in using single-pass technology for flexible applications.
38 Industry Insider
Stephan Raithel, SEMI PV Group Learn the latest information on the roadmap for manufacturing photovoltaics by reading this association-written commentary.
DEPARTMENTS 4 Editorial Response 6 Advisory Board 8 Product Focus 30 Industry News 33 Upcoming Events 39 Advertising Index 40 Shop Tour ON THE COVER
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INDUSTRIAL + SPECIALTY PRINTING, (ISSN 2125-9469) is published bi-monthly by ST Media Group International Inc., 11262 Cornell Park Dr., Cincinnati, OH 45242-1812. Telephone: (513) 421-2050, Fax: (513) 362-0317. No charge for subscriptions to qualified individuals. Annual rate for subscriptions to non-qualified individuals in the U.S.A.: $42 USD. Annual rate for subscriptions in Canada: $70 USD (includes GST & postage); all other countries: $92 (Int’l mail) payable in U.S. funds. Printed in the U.S.A. Copyright 2011, by ST Media Group International Inc. All rights reserved. The contents of this publication may not be reproduced in whole or in part without the consent of the publisher. The publisher is not responsible for product claims and representations. POSTMASTER: Send address changes to: Industrial + Specialty Printing, P.O. Box 1060, Skokie, IL 60076. Change of address: Send old address label along with new address to Industrial + Specialty Printing, P.O. Box 1060, Skokie, IL 60076. For single copies or back issues: contact Debbie Reed at (513) 421-9356 or Debbie.Reed@STMediaGroup.com. Subscription Services: ISP@halldata.com, Fax: (847) 763-9030, Phone: (847) 763-4938, New Subscriptions: www.industrial-printing.net/subscribe.
Specialty printing is a key part of the manufacturing processes used to create dials and gauges. Turn to page 18 to read about the imaging techniques and markets associated with these components. Cover design by Keri Harper.
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EDITORIAL RESPONSE
Backing the Right Technology Is Essential GAIL FLOWER Editor
Picture this, a gathering of about 450 serious experts in printed electronics at the 10th Annual Flexible Electronics & Displays Conference in Phoenix this February, all prepared to present their capabilities to a seriously learned audience. Attendees came from high-tech companies, the U.S. Army, NIST, universities, and manufacturers. The first presentation was Delivering Capabilities to the Warfighter by David Honey, Ph.D., Office of the Director of Defense Research & Engineering. According to Honey, there’s a shift in the technical talent base from U.S. builds to more foreign builds of weapons systems. The Quadrennial Defense Review (QDR) Mission Set is to defend the U.S., succeed in counterinsurgency, build the security of partner states, and deter and defeat aggression. As such, the QDR is involved in ubiquitous autonomous robots, superfast computers, ultra-secure communications, precise navigation and detection, and novel materials with strange properties—metamaterials that bend light backwards, have invisibility properties, materials morphing, and artificial muscles. The Army’s booth had camo uniforms with printed electronics built into the fabric. Printed batteries have made progress in the past year. Gary Johnson, president of Westlake, OH-based Blue Spark Technologies, handed out samples of his company’s printed batteries, no larger than a large Band-Aid patch. Yet the Blue Spark UT is a thin, flexible battery that is designed for transit tickets, powered display cards, and battery-assisted RFID. The Blue Spark HD (high-drain) Series is designed for applications that require an extra boost of power, such as musical greeting cards, promotional toys, and transdermal patches. Enfucell Oy, based in Vantaa, Finland, has also developed a SoftBattery, a thin, flexible, environmentally friendly power source.
Tim Bradow of Infinite Power Solutions talked about THINERGY Micro-Energy that provides energy storage with power density and extended, rechargeable service life. These can be combined with solar cells and power-management ICs for constant, maintenance-free power supplies. James Stasiak of Hewlett-Packard presented information on digital printing, flexible electronics, and smart packaging. Although the industry remains years away from fabricating a low-cost Pentium-class processor on plastic, there has been steady progress towards realizing this vision with the latest in electronic materials, devices and circuits, low-temp fabrication process, and roll-to-roll manufacturing. HP’s laboratories address smart-packaging efforts to meet the needs of industrial and commercial printing markets by using the HP Scitex and Indigo platforms. Soon, Stasiak stated, HP will print RFID labels along with other visible and invisible deterrents. A digitally fabricated, flexible package will be a backplane where high-performance analog and digital circuitry and MEMS devices will be located in the smart drug, blister-package foil. The competition to keep costs low, have a visible display—even in sunshine—and producing color provides a race for most e-book manufacturers. Nam-Seok Roh of Samsung Electronics talked about plastic LCD technologies for thin and light tablets. Many presenters had adhesives, coatings, flexible substrates, and conductive inks for low-cost production of solar panels. But the PV market as it stands today depends on policies, not markets or materials. As I drove from the airport in Kentucky to Cincinnati’s sparkling city by the river, I thought about the note in my e-mail from Obama that said, “That’s why we must invest in innovation, to ensure that the jobs and industries of the future are built....” It will be an exciting future.
4 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net
Industrial + Specialty Printing www.industrial-printing.net
STEVE DUCCILLI Group Publisher steve.duccilli@stmediagroup.com GREGORY SHARPLESS Associate Publisher gregory.sharpless@stmediagroup.com GAIL FLOWER Editor gail.flower@stmediagroup.com BEN P. ROSENFIELD Managing Editor ben.rosenfield@stmediagroup.com KERI HARPER Art Director keri.harper@stmediagroup.com LINDA VOLZ Production Coordinator linda.volz@stmediagroup.com BUSINESS DEVELOPMENT MANAGERS Lou Arneberg – Midwest lou.arneberg@stmediagroup.com Lisa Zurick – East US, East Canada, Europe lisa.zurick@stmediagroup.com Ben Stauss – West US, West Canada, Asia ben.stauss@stmediagroup.com EDITORIAL ADVISORY BOARD Joe Fjelstad, Dolf Kahle, Bruce Kahn, Ph.D., Rita Mohanty, Ph.D., Randall Sherman, Mike Young, Wim Zoomer
JERRY SWORMSTEDT Chairman of the Board TEDD SWORMSTEDT President JOHN TYMOSKI Associate Director/Online
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advisory board
Joe Fjelstad
Joseph Fjelstad (josephfjelstad@aol.com) is a 34-year veteran of the electronics-interconnection industry and is an international authority, author, columnist, lecturer, and innovator who holds more than 150 issued and pending US patents in the field. He is the founder and president of Verdant Electronics, a firm dedicated to environmentally friendly electronics assembly. He is co-founder and CEO of SiliconPipe, a specialist in highspeed interconnection-architecture design, much of which is based on flexible-circuit technology. Prior to founding SiliconPipe, he worked with IC-package-technology developer Tessera Technologies, where he was appointed the company’s first fellow. Fjelstad and his innovations have received many industry awards and accolades. Verdant Electronics
Dolf Kahle (rkahle@vmsinc.com) is the CEO of Twinsburg, OH-based Visual Marking Systems, Inc., (VMS), a company that specializes in the OEM durableproduct-identification market and manufactures overlays, decals, and decorative trim for Fortune 1000 companies. Beyond the OEM market, VMS also produces fleet graphics, P-O-P products, and durable signage for the public-transportation market. VMS is an ISO 9000- certified company that enjoys statewide recognition as a Lean Enterprise. Kahle is an active member of SGIA, SPIRE, and GPI. He served on the SGIA board for more than 10 years and was its chairman in 1999. He is currently the chairman of SPIRE. He holds a bachelor’s degree in mechanical engineering from the University of Michigan and an MBA from Arizona State University.
Dolf Kahle
Visual Marking Systems, Inc.
Bruce kahn, ph.d.
Bruce Kahn (bkahn@electronicsprinting.com) is a consultant who specializes in the multidisciplinary fields of printable electronics, nanotechnology, RFID, and smart packaging. Kahn holds a Ph.D. in chemistry from the University of Nebraska and is the author of more than 75 publications, including the recently published “Developments in Printable Organic Transistors,” “Printed and Thin Film Photovoltaics and Batteries,” and “Displays and Lighting: OLED, e-paper, electroluminescent and beyond.” He is a frequent lecturer and author, and he regularly teaches workshops in the U.S. and abroad. Printed Electronics Consulting
rita mohanty, ph.d.
Rita Mohanty (rmohanty@speedlinetech.com) is the director of advanced development at Speedline Technology and a certified Six Sigma Master Black Belt instructor. She has more than 15 years of experience in industries and academics relating to engineering and electronic polymers, electronic packaging, and board assembly. She is a patent holder and has authored and edited books on electronics and numerous technical papers. Mohanty is active in and holds various leadership positions with IMAPS, SMTA, IPC, iNEME, and SGIA. She received her Ph.D. in chemical engineering from the University of Rhode Island. Speedline Technology
Randall Sherman (rsherman@newventureresearch. com) is the president and CEO of New Venture Research, a technology market research firm. He holds a B.S. in astrophysics, an M.S. in electrical engineering from the University of Colorado, and an M.B.A. from Edinburgh School of Business. Visit www.newventureresearch.com for more information.
RANDALL SHERMAN New Venture Research
Mike Young (mikeyyoung@aol.com) has spent 40 years as a specialist in high-definition graphic and industrial screen printing. He is an SGIA Fellow, a member of the Academy of Screen Printing Technology, and a recipient of the prestigious Swormstedt Award for technical writing. He frequently writes for industry trade publications and speaks at international industry events. Young has published several technical books on advanced screen-printing techniques and frequently conducts seminars for high-profile screen-printing companies worldwide. Young is a consultant with Imagetek Consulting Int’l.
mike young
Imagetek Consulting Int’l.
Wim Zoomer (wimzoomer@planet.nl) is owner of Nijmegen, Netherlands-based Technical Language, a consulting and communication business that focuses on flatbed and reel-to-reel rotary screen printing and other printing processes. He has written numerous articles for international screen-printing, art, and glass-processing magazines and is frequently called on to translate technical documents, manuals, books, advertisements, and other materials in English, French, German, Spanish, and Dutch. He is also the author of the book, “Printing Flat Glass,” as well as several case studies that appear online. He holds a degree in chemical engineering. You can visit his Website at www.technicallanguage.eu.
wim zoomer
Technical Language
| Industrial + Specialty Printing www.industrial-printing.net
Mimaki_UJF3042_iSP1110.qxd:Layout 1 10/8/10 3:57 PM Page 1
• Industrial apps • Packaging proofs • Prototypes & comps • Membrane switches • Labels, stickers, decals
UV LED PRINTER
Effective print area: 11.8"W x 16.5"L Maximum media thickness: Up to 2"
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PRODUCT FOCUS
The latest equipment and materials for industrial printing
Digital Label Press Epson (www.epson.com) say its new SurePress L-4033A is designed for label converters, large-scale product manufacturers, and commercial printers and notes that the SurePress fits easily into existing digital workflows and prints on a range of off-the-shelf substrates with no pre-coating required. The system prints up to 13 in. (330 mm) wide at speeds up to 16 ft/min (5 m/min) and uses Epson’s MicroPiezo inkjet technology and newly developed SurePress AQ six-color (CMYKOG), water-based, resin-coated pigment ink.
Web-Cleaning System Meech Int’l (www.meech.com) introduces ShearClean, a web-cleaning system that is compatible with litho, gravure, and flexo, as well as converting, food-packaging, and pharmaceutical applications. According to Meech, acceptable substrates include those with surfaces that are prone to scratching or have special coatings, including papers and films. ShearClean can be supplied for use with reel widths up to 60 in. (1524 mm) and web speeds of up to 1500 ft/min (458 m/min). Meech says faster speeds may be achieved by adjusting factory settings. Those who want to remove debris from the web prior to printing may position ShearClean before the first unit, and pre-printed reels can be cleaned before packaging. Meech says it offers a variety of control upgrades to create a fully programmable unit. 8 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net
Carbon-Nanotube Inks
SouthWest NanoTechnologies, Inc. (SWeNT, www.swentnano. com) recently introduced its V-Series of carbon-nanotube inks. They’re formulated for printing with commercial, high-volume methods and equipment, including flexo, gravure, and screen printing. SWeNT says the ink technology eliminates the need for subtractive patterning and post-production processes used to remove ink dispersants and surfactants. The company also notes that the inks facilitate printing large-area, low-cost devices for photovoltaics, printed electronics, displays, and more.
Project-Management Solution
Inkjet Printheads
FUJIFILM Dimatix (www.dimatix.com) says its new Emerald QE-256/30 AAA and QE-256/80 AAA inkjet printheads are engineered to combine precise jetting and versatile grayscale operation with a durable, field-proven metal nozzle plate to support aqueous, UV-curable, and solvent ink formulations. The Emerald QE-256/30 is designed to eject adjustable 30- to 80-pl drops in binary mode or a 30-pl fundamental drop in grayscale mode. The Emerald QE-256/80 is designed to eject adjustable 80- to 200-pl drops in binary mode or an 80-picoliter fundamental drop in grayscale mode. FUJIFILM Dimatix reports that operating at a nominal 8-m/second drop velocity when jetting fluids in the 10- to 14-cPs range, the Emerald QE-256/30 operates at firing frequencies up to 33 kHz and the Emerald QE-256/80 has a maximum operating frequency of 20 kHz. Grayscale operation is made possible with Dimatix’s VersaDrop technology.
Energy and Resource Calculator
The Ecometer from manroland (www.manroland.com) is designed to calculate required energy and resources based on customer-specific information such as machine type, production volume, and media consumption and offer specific suggestions for improving printing processes sustainably. In addition, it reveals the total savings that are possible over a year or over the total service life of a press. Ecometer is configured to represent energy efficiency, reduced emissions, and resource savings; provide an ecological assessment for predefined press configurations; and indicate savings for carbon dioxide, energy, and the cost of materials. Ecometer is available in German and English and can be used worldwide.
Copper-Nanoparticle-Based Ink Intrinsiq CI, the newest copper-nanoparticle-based ink for printed electronics applications from Intrinsiq Materials (www. intrinsiqmaterials.com), is a 12%-by-weight formulation designed for photonic curing at room temperature in air. Intrinsiq says the ink is the first product in a range of ink formulations for use with industry-standard commercial inkjet systems on a variety of substrates including paper, polyimide, and FR4 that produces conductivities typically comparable to commercial silver inks with significantly higher metal loadings. Pack sizes start at 50 ml.
EskoArtwork’s (www.esko.com) WebCenter 10 is the latest version of its online collaboration and approval tool for the packaging and print-supply chain. The company says the solution offers a straightforward user interface, staged approval support, and management tools; helps securely manage and automate approval cycles; and comes with a fast and accurate online viewing tool with features focused on the needs of the packaging and print industry. WebCenter 10 includes a briefing module and task-management system that enable it to function as a lifecycle-management tool. According to EskoArtwork, WebCenter 10’s document-management capabilities turn it into a centralized and secure, Web-based warehouse for all project related digital assets, including technical drawings, artwork, text, logos, images, and other elements. WebCenter also supports version tracking and metadata-based search tools for finding projects and documents. Its new approval module allows customers to design and automate multilevel approval cycles with support for both parallel and sequential parts in one approval cycle.
UHF RFID Module
Trimble’s ThingMagic Division (www. thingmagic.com) announces the availability of the Mercury6e (M6e) UHF RFID module. According to Trimble, M6e offers world leading performance, form factor, and time-to-market advantages to OEMs, value-added resellers, and others looking to add RFID to existing product lines or design and build new solutions from the ground up. M6e features include: multiprotocol support, including EPCglobal Gen 2 (ISO 18000-6C) with DRM, ISO 18000-6B (optional), and IP-X (optional); four 50-Ohm MMCX connectors supporting four monostatic antennas; separate read and write levels, command-adjustable from 5-31.5 dBm (1.4W) with +/0.5 dBm accuracy above +15 dBm; support for full 860- to 960-MHz UHF RFID carrier frequency range to accommodate worldwide regulations; USB 2.0 port (up to 12 Mbps); maximum tag-read rate of more than 400 tags/sec; maximum tag-read distance of more than 30 ft (9 m) with 6-dBi antenna; and four GPIO lines controlled through data interface.
MARCH/APRIL 2011 | 9
Barcode Reader and Inspection Solution
Topcoat for Label Media
MACtac (www.mactac.com) reports that is has enhanced its Vivid line of label materials with a new topcoat formulated to enhance print receptivity. The topcoat is available on two Vivid 3.4-mil white vinyl stocks and is the same topcoat used on several of the company’s film products recognized by Underwriters Laboratories and Canadian Standards Association. According to MACtac, the topcoat offers a matte finish and improved printability for a variety of prime film applications, including labels for health and beauty products, food and beverages, chemical and cleaner containers, and more. Cognex Corp. (www.cognex.com) recently unveiled DataMan 500, an image-based barcode reader. DataMan 500 is designed to achieve higher read rates, offer improved online visualization, and have higher reliability than laser scanners. It uses Cognex’s IDMax code-reading software, processes images at up to 1000 frames/sec, and can read codes in any orientation, 2D codes such as Data Matrix and QR, and multiple codes in the same image. The company also released VisionPro 7.0 Inspection Designer, designed to simplify development and field maintenance of inspection applications. Cognex says Inspection Designer provides vision-systems integrators and end users with the functionality to simplify the specification, development, and maintenance of inspection applications. A new image-grading utility allows integrators and end users to grade product images and specify different defect types within each image. It creates a library of graded images for the next step of the process. The verification tool helps developers confirm that the vision system is producing the desired results by comparing the grades of the inspection results with stored and graded images. The verification tool also allows the end user to re-test the inspection tools against the library of graded images at any time and add new images to the library of graded parts.
Primer for Indigo Presses
Michelman (www.michelman.com) has introduced DigiPrime 6029, the newest addition to its line of primers and overprint varnishes for use with HP Indigo presses. This primer is designed specifically for the demands of high-speed printing on the HP Indigo WS6000 label- and package-printing system. Michelman says DigiPrime 6029 is an HPapproved solution that produces superior ink transfer, ink adhesion, and rub resistance on embossed and heavily textured, pressure-sensitive paper label stock. According to Michelman, it’s non-blocking, moisture resistant, and backward-compatible with older model Indigo presses. The company explains that DigiPrime 6029 comes from renewable sources and is solvent-free, odorless, and repulpable.
Mild-Solvent Inkjet Ink
INX Digital (www.inxdigital.com) recently debuted PDQ, a multipurpose, mild-solvent, pigmented ink (CMYK) for wide-format inkjet printers. It’s designed for use in high-resolution printers that have 32- to 42-pl printheads, such as those manufactured by Spectra, Xaar, and Ricoh, with a drop volume between 9-25 pl. PDQ inks are cycloxehanone free.
10 | Industrial + Specialty Printing www.industrial-printing.net
Wide-Format Flatbed UV Inkjet Printer CET Color (www.cetcolor.com) recently announced the release the FK512-X, a 4 x 8-ft (1.2 x 2.4-m) flatbed UV inkjet printer that features 14-pl drop size, white ink and varnish capabilities, a scalable platform that allows expansion from six to 16 heads, 3-l ink tanks, and field upgradability. The printer supports media up to 3 in. (76 mm) thick and images at speeds up to 800 sq ft/hr (74 sq m/hr) and resolutions up to 720 x 1440 dpi.
Inkjet Modules
Industrial Inkjet Ltd (www.industrialij. com) introduces two MonoPrint modules to its range of print engines. They facilitate printing with varnish and white inks. The company says the modules, designed with Konica Minolta printheads, are designed to complement and be integrated into existing analog and digital printing technologies. They support full-color, spot, and variabledata printing.
Send us your product news! Email ben.rosenfield@stmediagroup.com
Backlit Films
Labeling Products
MACtac (www.mactac.com) developed its TORQ line of high-tack-adhesive labeling solutions for adhesion to rough, textured surfaces and to withstand damaging environmental conditions and chemical exposure. The product line includes solutions for flexo and variable-data printing with paper and film facestocks and features three adhesive technologies: high-tack rubber-based, acrylic permanent, and solvent-based. End applications include tires, lumber, carpet backing, Styrofoam, drums, tools, construction materials, waxy and corrugated materials, packaging materials, various metals, and a variety of plastics.
Roland DGA Corp. (www.roalnddga.com) recently added two new media products to its line of eco-solvent-compatible media for wide-format inkjet printers: Glossy Backlit Film (ESM-GBF) and Matte Backlit Film (ESM-MBF). Both are 8-mil products engineered for dimensional stability and designed to support high-density backlit images with a Dmax rating of 2.2. Glossy and Matte Backlit Films are certified for Roland’s VersaCAMM, VersaArt, and SOLJET PRO III inkjet printers.
Copper-Based Screen Ink NovaCentrix (www.novacentrix.com) announces the availability of Metalon ICI-020, a copper-based screen ink the company says is based on the same functional principles as its Metalon ICI-003 inkjet ink. Copper oxide particles are formulated with a reduction agent. After the ink is printed, a NovaCentrix PulseForge tool is used to modulate a reduction reaction, thereby converting the copper oxide into a thin film of highly conductive copper. According to NovaCentrix, this process is performed in ambient air on low-temperature substrates at speeds exceeding 328 ft/min (100 m/min).
Modular Flatbed UV Inkjet Printer The :Jeti 3020 Titan from Agfa Graphics (www.agfa.com) is a wide-format flatbed UV inkjet printer designed in a modular format that allows users to extend the unit’s color and speed capabilities. The standard version features 16 Ricoh Gen 4 grayscale printheads for CMYK output at resolutions up to 1200 dpi. The system supports a maximum print area of 9.8 x 6.6 ft (3 x 2 m) and print speeds up to 1216 sq ft/ hr (113 square m/hour). Modular upgrades are available for up to 48 printheads and a maximum print speed of 2432 sq ft/hr (226 sq m/hr). Additional ink choices for the :Jeti 3020 Titan include light cyan and light magenta, double white, white and clear varnish, or orange and green. Titan’s vacuum table accommodated flexible and rigid materials up to 1.9 in. (50 mm) in thickness. Agfa says the Titan, even in its initial, four-color configuration, performs flawlessly on photographic and solid colors with no banding and with crisp, clear text output in sizes as small as 4 pt.
Protective Overlays for Printed Electronics
Polyonics (www.polyonics.com) recently introduced a line of films engineered to encapsulate and protect printed circuits from harsh environments. The protective overlays use either a PEN or polyimide film along with a pressure-sensitive adhesive that can be cold laminated to a printed circuit to guard it from abrasion, chemical exposure, and high temperatures. Polyonics says the overlays are a good match for polyimide substrates and notes that it has partnered with ink suppliers to ensure that the substrates are printable and have good ink anchorage. According to Polyonics, the protective overlays can also be provided with static-dissipation and flame-retardant features. The company reports that the overlays comply with the requirements of RoHS and REACH and are certified to be halogen free to IEC 61249-2-21 levels.
march/april 2011 | 11
business management
A Look at the Regulatory Landscape for Industrial Facilities Marcia Y. Kinter
Specialty Graphic Imaging Association
Safety, health, and environmental regulations impact all types and sizes of printing operations. This is a very basic tenet. If you’re in the industrial marketplace, the issues that in your own backyard are often compounded by those on an international level. Rather than provide you with the basic regulatory primer, let’s just be realistic and state that all safety and health regulations impact your facility, regardless of product specialty or size of facility. The regulations issued by the Occupational Safety and Health Administration (OSHA) do not exempt any manufacturing facility based on size of operation. Environmental regulations are a bit different. Your obligation does differ based on location, size of facility, type of chemicals used, and other factors. While attention generally focuses on air emissions, environmental regulations do not just focus on air, but waste and water as well. The following offers highlights of the most often missed regulatory standards for safety, health, and environment, as well as a few insights regarding upcoming regulatory initiatives. Hazard-communication standard Even well into its third decade, OSHA’s Hazard Communication (HazComm) Standard remains in the top ten OSHA violations year after year. The required elements are rather straightforward: compile and maintain copies of Material Safety Data Sheets (MSDSs) of those hazardous substances used in the workplace; train employees regarding the use and handling of these substances on a regular basis; maintain an in-plant labeling system; develop a written hazard-communication program; and maintain a list of all hazardous substances found in your facility. If
you have hazardous chemicals in the workplace and are a manufacturing facility, then you are required to have the elements of a Hazard Communication Program in place. OSHA has proposed changes to this standard to align more closely with the Global Harmonization System. Under the proposed changes, all MSDSs would be required to follow the same format, and labels would also be required to use pictograms in addition to words. The majority of the proposed changes would impact the chemicalsupply community; however, there will be new requirements for in-plant labeling systems and training components. It is anticipated that the new regulation will be issued at some point in 2011. Lockout/tagout standard This, too, continues to fall within the top ten violated safety and health regulations. If you operate machinery, then you must have a lockout/tagout program in place. Similar to the HazComm standard, there are no exemptions based on size of facility or type of manufacturing operation. This regulation requires facilities to ensure that all stored energy is released from machinery prior to repair and maintenance
12 | Industrial + Specialty Printing www.industrial-printing.net
An MSDS station (top) and a lockout device (bottom).
activities. As with most OSHA standards, there are elements of training and written programs. The standard requires the development of specific lockout/ tagout (LOTO) procedures for each machine. These procedures must describe the department or location, the machine, the equipment ID number, employees authorized to lock out the machine, employees affected by locking out the machine, energy sources in the machine, energy controls/isolation devices on the machine, shutdown procedures for the machine, release and restart procedures, date written or revision, and review and approval signatures. All employees must be trained in these procedures, and the level of training coincides with the interaction with the machinery during repair and servicing. Ideally, all employees should recognize the lockout/tagout device used and that only the authorized employee may attach or remove the device. Required OSHA forms and posters Paperwork violations still make up a large portion of OSHA violations. First, ensure that you have the required employment posters available and in a conspicuous location. This includes any employment posters as required by law, such as minimum wage, anti-discrimination statements, as well as the required OSHA posting indicating that all employees have a right to a safe workplace. The other paperwork to maintain are your OSHA logs, Form 300 and 300A. A critical piece of recordkeeping is the annual posting of the OSHA Summary Log, 300A, each year from February to April. Even if your facility was fortunate to not suffer any accidents, lost time injuries, or illnesses, you still need to post this summary form. Environmental programs While safety and health regulations apply to all facilities, environmental regulations have different applicability thresholds that not only differ by location, but often by media as well. For example, if your facility were fortunate to operate in the Los Angeles area, then your air-pollution-control requirements would be much more stringent and complex than if you were to operate in the state of Ohio. However, regardless of where you operate, your requirements
regarding storage and handling of hazardous waste are the same. Air issues are often the most misunderstood regulatory program. Facilities need to be aware that all screen-printing and digital-imaging facilities are regulated by state environmental agencies. These agencies are not only concerned with the amount of volatile-organic-compound emissions, but often emissions of hazardous air pollutants as well. Programs to focus on include air permitting and specific or general air-pollution-control standards. Often, conductive-ink technology is exempt from a state’s graphic-arts rule; however, this does not mean that the facility is exempt from all air-pollution-control standards. It is crucial that you determine your air-permitting threshold, as well as any other general airpollution-control standard that may impact your operation. This holds especially true for digital operations. State graphic-arts airpollution-control standards often exempt digital printing from coverage; however, all states do have a general solvent-usage rule that may impact digital printing. Hazardous-waste issues are another commonly overlooked regulatory program. All facilities do generate some level of hazardous waste, and this waste must be handled and disposed properly. Spent solvent is the major waste stream for many facilities. Used shop towels that are contaminated with spent solvent may also be a possible waste stream, depending on the state in which you operate. It is never an acceptable practice to dispose of solvent waste with reusable shop towels. Your regulatory responsibilities regarding the disposal of hazardous waste directly correlates to the amount you generate. Those generating less than 25 gallons per calendar month have significantly fewer requirements than those generating more than 25 and less than 200 gallons, or more than 200 gallons per calendar month. Regardless of amount generated, remember that all must be properly labeled and disposed. International issues As mentioned at the outset, industrial applications also need to be aware of international developments. Well known is the European Directive, Restriction of Hazardous Substances, or RoHS. Though RoHS is
called the lead-free directive, there are six hazardous substances whose presence is restricted by RoHS: lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers. Similarly, REACH, which stands for Registration, Evaluation, and Authorization of Chemicals, has also had an impact within the industrial community. Under REACH, producers and importers of certain chemicals have to register them with the EU Chemicals Agency. While these regulations have origins in Europe, many other nations are moving forward with their own versions. China, South Korea, India, and Japan all have their own aggressive environmental manufacturing and recycling laws. And, as with U.S. laws and regulations, these international directives are updated and revised on a regular basis. Looking ahead As mentioned earlier, OSHA seeks to amend the Hazard Communication Standard, and it is expected that the Agency will release a proposed rule mandating that all companies develop and adopt an Injury Illness and Prevention Program. This farreaching safety and health system seeks to require all employers to formally adopt a safety and health program that includes elements of job and hazard analysis for any and all possible safety and health issues. On the environmental front, state environmental agencies continue to develop and adopt air-pollution-control strategies that have direct impact on both screen and digital printers. Most notable is the flurry of state regulations that govern the use of cleaning solvents by both screen and digital operations. The safety, health, and environmental landscape in which your facility operates will change over time. It is critical that your facility institute strategies and programs that allow them to proactively integrate changes into their company’s operations.
marcia y. kinter SGIA
Marcia Y. Kinter is vice president of government and business information for the Specialty Graphic Imaging Association (SGIA), Fairfax, VA. march/april 2011 | 13
FEATURE STORY
Pursuing the Printed OLED This article provides an in-depth look at what it takes to print organic light-emitting diodes successfully. Riikka Suhonen, Markus Tuomikoski VTT Technical Research Centre of Finland
T
he successful launch of OLED flat-panel displays into the high-end market is a reality, and companies involved in solid-state lighting are now releasing their first OLED-based products. Both of these applications benefit from the unique properties of the technology as a thin, flat, area source of diffuse light. Concurrently, both of these applications also envision using the most appealing feature of OLEDs: their flexibility. Organic light-emitting diodes (OLEDs) traditionally are divided into two classes: small-molecule and polymer-based OLEDs, according to the active materials used in the OLED stack. Commercially available products are based mostly on small-molecule materials because of their enhanced performance, stability, and luminous efficiency. Vacuum-based deposition techniques are used in current manufacturing processes, with glass as a substrate, to ensure adequate product life. Even though a rigid glass substrate functions as an excellent barrier and protects the organic materials from degradation, it also inhibits the flexibility of the organic materials. Vacuum-based techniques currently used in the deposition of small-molecule-based OLEDs require high investments and, therefore, high throughput to decrease the share of manufacturing cost in the final product. Thus, vacuum evaporation can be seen as a transitional deposition technique that will be partly or totally replaced by more cost-efficient, solution-based deposition techniques such as printing. The potential for lowered fabrication costs that result from the solubility of polymer-based OLED materials in common solvents has been the motivation for their use. Suppliers of small-molecule materials have recently indicated interest in the development of soluble small-molecule materials, and many research projects have been launched focusing on the solubility of and ability to process smallmolecule-based materials via solution-based deposition techniques. Fabrication processes The main advantages of printing as a deposition method include the high speed of fabrication, low material wastage, well established 14 | Industrial + Specialty Printing www.industrial-printing.net
deposition techniques, possibility for direct patterning of the printed films, and the low processing temperatures that enable the use of flexible substrates. The most commonly used printing-deposition techniques in OLED processing to date include gravure, flexo, screen, and inkjet printing, as well as slot die coating. This article emphasizes the use of gravure printing for producing OLED devices. The gravure process involves a metallic gravure roll, the surface of which carries engraved printing patterns. As shown in Figure 1A, these patterns are filled with ink gathered from an ink fountain, the excess ink being subsequently wiped off using a doctor blade that is pressed tightly against the gravure roll. The patterns filled with ink then come into contact with the substrate, which is pressed against the gravure roll using an imprint roll, and the ink is transferred from the patterns to the substrate, completing the print. The use of a metallic printing roll that does not suffer from solvent swelling or deformation facilitates high resolution and pattern fidelity in gravure printing. The ink is also transferred directly to the substrate, avoiding the need for a secondary transfer process that is commonly used in many other traditional printing techniques. The metallic printing roll allows very high printing speeds and thus high throughput. The drawback, however, is that gravure rolls are rather expensive and slow to pattern, making gravure less ideal for printing patterns that vary frequently. A schematic description of the layers used in a polymer-based, printed OLED device is shown in Figure 1B. The device consists of thin organic films deposited between two electrodes. For such a simple device structure the processing flow can be described as follows. Barrier layers are initially deposited to reduce the oxygen and moisture absorption into the organic OLED films. The barrier substrate is then coated with a transparent anode. The barrier substrate coated with transparent anode is cleaned, its charges removed, and its surface energy adjusted by means of washing, deionization, and plasma or corona treatment. The pre-treatment of the substrate is essential because the thickness of the following layers is in the order of sub-micrometers.
Impression Roll The hole-injection layer and the emissive layer and cathode are then printed on the pre-treated barrier-anode substrate. Each of the layers is dried directly after printing to minimize the dissolution and interfacial mixing of the underlying layer during deposition of the following active layer. Finally, the OLED elements on the substrate are encapsulated by laminating a foil containing barrier layers and an adhesive layer onto the substrate. Patterning of the electrodes is needed because the light-emissive area of an OLED is formed on the location where anode and cathode overlap. FLEXIBLE BARRIER MATERIALS Application of a flexible substrate in OLEDs requires development of a new class of transparent materials with low water-vapor- and oxygen-transmission rates (WVTR and OTR, respectively). The purpose of the barrier substrate is to protect the sensitive organic materials from environmental conditions such as moisture, oxygen, and mobileion contaminants, as well as temperature changes, radiation, and mechanical and physical damage. As shown in Figure 1B, light is emitted through the transparent anode and barrier substrate from the OLED. It is, therefore, essential to have a transparent frontside barrier. The backside barrier layer may be opaque. Whereas thin, opaque barrier materials are easily found, transparent thin layers with barrier properties suitable for OLED purposes, have needed to be developed. The VWTR for a common plastic film such as PET is around 0.1 g/m2/day but the requirement for OLED applications is in the range of 10 -6 g/m2/day. Thus, development of substrates with the special features has been extensive and still ongoing because it is the key element in increasing the operative and shelf lifetime of printed OLEDs. Currently, the most common method that is used in processing of transparent barrier substrates is a multilayer structure with alternating polymer and ceramic (e.g. oxide) layers as shown in Figure 2A. The number of the polymer and ceramic layers defines the barrier properties of the film. VWTR values as low as 1Ă—10 -6 g/m2/day have been reported for such multilayer films. The key challenges of this approach are the brittle nature of the ceramic layers reducing the full flexibility of
1A 1B Printed Substrate
g
Doctor Blade
Printing Roll
Figure 1 Shown here are (A) the gravure printing process and (B) traditional stack architecture used in polymerbased OLEDs.
Ink Fountain
2A
Oxide Barrier Layers Polymer Polymer Polymer Polymer Substrate
2B
Al(CH3)3(g) Pulse
1 micron
Figure 2 Shown here are (A) a SEM cross-section of the Barix stack approach (source: Vitex Systems, Inc.) and (B) a description of an ALD approach for transparent barrier substrates (source: Beneq).
Al(CH3)2(S) H20(g) Purge Pulse Repeat ALD cycle N times
the substrates and the high cost of manufacturing by vacuum-deposition methods. The relatively low throughput in fabrication of the layers also leads into an increased price of the films. Atomic layer deposition, ALD, is a novel, innovative method of fabricating transparent barrier substrates. This method uses chemical bonding of a single molecule layer per one deposition cycle on the surface of the substrate (Figure 2B). The deposition cycles can be repeated as many times as necessary, resulting in to a fully covered, pin-hole-free barrier substrate with excellent barrier prop-
Al2O3(S) Purge
erties. Due to the relatively new application in OLED applications, ALD is still mostly in the research and development phase, and barrier-substrate rolls are not yet commercially available in large quantities. Even though many companies have announced their efforts in developing transparent barrier substrates in a roll form, the availability of high-performance barrier rolls with VWTR below 1Ă—10 -4 g/m2/day is still limited. The low availability, as well as the high purchase price of the barrier substrates, can be seen as one of the major factors delaying the market entry of printed, flexible OLEDs. MARCH/APRIL 2011 | 15
3A Traditional inks
3B
Functional inks
Ink Modification
Inks tailored for printed OLEDs
Printing Quality
3C Commercial ink
OLEDs
Modified ink
Figure 3 Shown here are (A) a comparison of the behavior of traditional inks used in conventional graphics and the functional inks used in OLEDs, (B) the ink-modification cycle, and (C) an example of a commercial PEDOT:PSS ink that is modified to yield a homogenous film (source: VTT Technical Research Centre of Finland).
Transparent anode: materials and patterning methods The requirements for the anode in OLEDs include high transparency in the visible range, high conductivity, and high work function. The most commonly used anode material is indium tin oxide (ITO), which has established its status by filling all the previously mentioned requirements. The drawbacks of ITO include the increasing price of indium, the high cost of vacuum-based manufacturing (sputtering), and the brittleness of the films. Additionally, the layers need to be patterned prior to the processing of the OLED stack on top. The patterning of the sputtered ITO layers is traditionally done via lithographic methods, where fine patterns are achieved, but the process includes multiple, time-consuming steps. Alternative routes for ITO patterning have also been reported and include methods such as hot-embossing, laser ablation, gel etching, and printing of an ITO nanocomposite ink. 16 | Industrial + Specialty Printing www.industrial-printing.net
Prior to printing of the hole-injection layer on top of the ITO, the substrate is cleaned, its charges removed, and its surface energy adjusted by means of washing, deionization, and plasma or corona treatment. The plasma treatment increases both the surface energy and the work function of the ITO, thereby increasing the wetting of the HIL ink on top of it and aligning the energy levels of the ITO and HIL. Due to the drawbacks already described for ITO, alternative solutions with lowered production cost have recently been developed and introduced. These alternatives include other transparent conductive oxides, such as aluminum-doped zinc oxide (AZO), semitransparent metal or metal grid layers, carbon-nanotube coatings, conductive polymers, and metallic-nanowire coatings. Thanks to their flexibility and solution-based fabrication techniques, the alternative materials are especially tempting for flexible-OLED applications and are already partly used as replacement for the sputtered ITO. Gravure printing of hole-injection and emissive layers Traditionally, gravure printing is used in graphic arts to print halftone dots. When gravure printing is applied as a deposition method in printed OLEDs, instead of dots, homogenous films of active materials are desired (Figure 3A). To achieve homogenous films, some key aspects need to be considered. From the ink point of view, the printing process can be divided in two parts, emptying of the engraved cell and the subsequent spreading of the printed drop. The cell is never completely emptied, and the exact amount of ink that is transferred from the cell onto the substrate depends on the rheology of the ink, the shape (width, depth, sidewall angle, and aspect ratio), the surface energy and roughness of the cell, and the ink-surface interactions. The spreading of the printed drop is determined by the surface energies of the three intersecting phases, the solid and liquid, the solid and air, and the liquid and air. If the substrate has a higher surface energy with the ink than with the air, the ink will tend to wet the substrate. The spreading of the drop can thus be controlled by either modifying the surface or the ink. Ink properties such as viscosity, surface tension, and adhesion can be controlled by a proper choice of solvents, solids content, geometry of the engraved cells, use of additives, and surface pre-treatments. A typical test cycle on modification of functional materials to printable inks is depicted in Figure 3B. When the ink is modified to increase the homogeneity of the printed film, its properties in an OLED device should also be tested. The printed film should always retain its original properties, such as charge transport, charge blocking, or light emission. These properties are best retained when the printed film is smooth, homogenous in thickness, and free of any materials that could deteriorate the original behavior of the ink. The most commonly used material as a hole-injection layer in polymer-based OLEDs is PEDOT:PSS, which consists of poly(3,4ethylenedioxythiophene) (PEDOT) polymer doped with a certain amount of poly(styrenesulfonate) (PSS). PEDOT:PSS has reached its status as the standard hole-injection layer in polymer OLEDs because of its high conductivity, suitable work function, high transparency, ITO-smoothing properties, and ability to process from polar aqueous dispersion, thereby ensuring the possibility to stack organic layers via solution processing without dissolution of the PEDOT:PSS layer. Despite of all these outstanding properties of PEDOT:PSS, it still
4A
Figure 4 Shown here are (A) a SEM image of the surface of screen-printed aluminum ink and (B) photographs of printed OLEDs with aluminum ink cathode (source: VTT Technical Research Centre of Finland).
4B Vac-Low PC-Std. 10kV x300 Sample 6 Al
100 µm
suffers from a few disadvantages, such as high acidity and the instability of the interface between HIL and emissive layer. Other novel, solution-based, hole-injection-layer materials with similarly doped systems—but with reduced acidity and increased stability—have since been introduced. When the commercially available OLEDgrade aqueous PEDOT:PSS dispersion is gravure printed on top of pre-treated ITO as received, the quality of the printed films is poor (Figure 3C). The main reason for the non-uniformity is the poor wetting of the printed PEDOT:PSS drops on the surface of the ITO. Because the surface energy of ITO is already increased by plasma pre-treatment, the only way to increase the wetting is to decrease the surface tension of the PEDOT: PSS ink. Much better wetting properties are achieved by adding a surfactant and wetting agents to the standard PEDOT:PSS formulation (Figure 3C). The uniformity of the gravure-printed films is in the same range as the films that were spin coated with standard PEDOT:PSS. Additionally, the current-voltage-luminescence behavior of OLEDs containing the printed PEDOT:PSS as a hole-injection layer show no significant difference compared to a standard, spincoated OLED. Similarly to the modification of the PEDOT:PSS ink, light emitting polymer inks are modified to fit the surface energy of the underlying hole-injection layer. Because any foreign additive remaining in the film has the potential to act as a non-emissive decay route, the main way to modify the emitter inks is to vary the solvents and the solids content of the ink. Several polymer emitting materials in variable colors can be deposited via printing technologies such as gravure and inkjet and reach performance similar to the spin-coated OLEDs.
Printed cathode In the polymer-based OLED structure, the cathode layer traditionally consists of vacuum-evaporated, low- and high-work-function metals such as barium and aluminum, respectively. The development of a cathode ink is needed to realize a fully printed OLED structure. Conductive silver inks are commercially available in a range of products but result in poor OLED performance when used without an additional electron-injection layer. From the electron- injection point of view, lower-work-function metal such as aluminum is expected to result in to higher OLED performance than silver. Ball milling is used to process aluminum for cathode ink. The resulting metal flakes are dispersed in a solvent/binder mixture to provide an ink of the required viscosity. The surface of a screen-printed layer of aluminum is shown in Figure 4A. The metal flakes, approximately 5 µm in diameter, can be seen in the SEM image. The disadvantage of using low-work-function metal like aluminum is its reactivity to the atmosphere. The metal flakes oxidize readily when in contact with air. Additionally, a good contact between the underlying organic layer and the cathode is crucial (Figure 4B). Therefore, the solvent of the cathode ink has to be chosen carefully so that it does not dissolve the underlying emissive layer. Also, the curing temperature of the cathode ink has to be lower than the glass-transition temperatures of the organic materials and the substrate. In the case of aluminum ink, the intrinsic oxide layer can also act as a protective layer and prevent further oxidation of the cathode layer. However, for the printed cathode to be conductive, the preparation and printing of the ink have to be done in inert atmosphere, which adds cost because of specialized equipment required for the process.
First applications for printed OLEDs While most of the attention on printed-OLED technology comes from the lighting and display industry’s perspective, the first applications for high-volume, low-cost, and relatively low-performance printed OLEDs could be in signage. Market research indicates that signage products manufactured using printed and organic electronics are expected to generate a $2.5 billion worldwide market within the next five years. As the efficiency and lifetime continues to develop in the direction required for displays and lighting, a low-end application would open up a window of opportunity for creating new business from novel products that are based on the competitive strengths of high-volume and cost-efficient printed OLED technology.
Riikka Suhonen, Ph.D.
VTT Technical Research Centre of Finland
Riikka Suhonen, Ph.D., is a research scientist at VTT Technical Research Centre of Finland. She focuses on the printability of organic photovoltaic and light-emitting materials. Suhonen holds an M.Sc. degree in organic chemistry from the University of Oulu, Finland, and finished her Ph.D. studies in Germany at Siemens AG.
Markus Tuomikoski
VTT Technical Research Centre of Finland
Markus Tuomikoski is senior research scientist at VTT Technical Research Centre of Finland and team manager of the prototype manufacturing at the printable-optics and electronics knowledge center. He holds an M.Sc. degree in inorganic chemistry from the University of Oulu, Finland, and was technical manager of the EU-funded ROLLED project, which developed the world’s first fully roll-to-roll-printed OLEDs. march/april 2011 | 17
COVER STORY
Specialty Printing of Dials and Gauges
This article examines the printing processes and production methods that are suitable for the manufacture of information-display applications.
Benjamin Gorenberg For GM Nameplate
Figure 1 Traditional dials used in medical and marine industries
18 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net
al and
T
he modern world could not function without the devices, vehicles, and machinery that require instrument panels, gauges, and dials. From power plants to planes, trains, and automobiles, our world needs an interface that communicates information to a user. That interface is most likely a dial, gauge, or instrument-panel cluster (Figure 1). What qualifies as a dial or gauge? All sorts of products, from single-purpose instruments to complex machines, require interfaces that quickly and efficiently convey information from the device to the user or operator. This information runs the gamut from internal data, such as power level or engine temperature, to external data, such as positioning, speed, or temperature. Manufacturers create metal dials or gauges—or their more modern equivalents, such as an instrument-panel (IP) cluster—to convey this information In addition to mechanical options, like metal dials and gauges, newer digital display alternatives, such as touchscreens, are gaining popularity. An industrial printer needs to offer wide-ranging capabilities for both analog and digital displays to match manufacturing options for form and functionality needed for each part. Industries, especially those that require precise measurement for high performance, require reliability. And when it comes to gauge, dial, or IP cluster production, this demands precision with tight tolerances and repeatable manufacturing processes. Many product uses require specialized capabilities for their instrumentation, including the durability to work in unfavorable environmental conditions or to withstand harsh chemicals or the possibility of physical damage, like abrasions. Who uses instrumentation? The changing demographics in the industrialized world are a driving factor in the growth of the healthcare industry, and there are many medical products that require gauges and dials. From familiar devices, such as the thermometer, bloodpressure gauge, and syringe, to more advanced devices, including infusion pumps, defibrillators, and diabetic-monitoring devices, all require precise indicators to deliver data to the end user.
Figure 2 IP clusters showcase current backlit technology in the automotive industry.
Private aviation, commercial air travel, airfreight, and military aviation all require complex machinery. The support staffs on the ground that prepare a plane, drone, or rocket and monitor its progress to ensure a safe and successful flight or mission rely on instrumentation to perform their jobs. The cockpit of a modern airplane is filled with displays, dials, and levers, which all have an impact on the plane’s flight. All of these devices require precision-crafted instrumentation. The Army, Air Force, Navy, Marines, and Coast Guard use tools and equipment for communication between units and troops. Instruments aid in the detection of chemical agents, locate targets or potential threats, and aid in the planning and execution of successful operations. Many of these tools are held to an extremely high standard due to the adverse environmental conditions in which they must function. When it comes to the automotive industry, the entire display of a modern dashboard is effectively a collection of gauges. From the speedometer and oilpressure gauge to the engine-temperature or external thermometer, the instrumentpanel cluster provides important information to the driver regarding the vehicle’s operation or its surroundings (Figure 2). A mechanic who inspects and repairs a vehicle relies on many different instruments with dials and gauges to verify how the vehicle is performing or what needs to be fixed.
Processes used to produce dials and gauges Gauges, dials, and IP clusters can be made using a variety of production processes and materials, depending on the industry’s requirements. The main processes used to create instrumentation currently include graphic overlays, direct printing onto metal or plastic substrates, and dimensional forming or molding. The IP cluster in most modern vehicles is usually a graphic overlay printed on a plastic substrate using a digital, screen, or lithographic press. Direct printing onto metal or plastic creates a dial or gauge like the ones seen on the meters that measure power consumption in homes and businesses. These are produced using screen, litho, digital, and pad printing, as well as processes such as hot stamping. A dimensional process is appropriate to use when a gauge needs to be created to fit in or around an instrument, like the gauge wrapped around a weather thermometer. Dimensional processes include the forming of metal or the molding or in-mold decoration of plastics. Graphic overlays vs. direct printing There are advantages and disadvantages to each printing method. Creating a graphic overlay by printing a gauge or an IP cluster onto a plastic substrate allows for back lighting of the indicator through a display window, dead-front graphics panel, or a light-emitting diode (LED). The ink can march/april 2011 | 19
Figure 3 These gauges are currently used in the automotive industry.
be second-surface printed (printed on the backside of the substrate), increasing the indicator’s durability so that the ink cannot be worn away by touching the gauge. Graphic overlays allow for the use of unique textures that offer visual or tactile advantages. These textures can be added either through the selection of a textured substrate or through the use of specialized inks and finishing processes. This method of printing also offers enhanced flexibility in the choice of color palette or pattern design. Graphic overlays generally require mounting or installation, which often means looser tolerances in print and installation can be expected. Additional material costs need to be factored into a product’s design for the overlay material and required adhesive layer. Direct printing onto a dial or gauge can support tight tolerances because the number of processes required during production is reduced. This can be accomplished through screen printing, pad printing,
or injection-mold design. Design options increase with the ability to add a threedimensional appearance by using forming or injection molding during the printing process. Direct printing is often a less costly option, as it can be performed on an existing product or product casing. Printing directly onto an indicator, product housing, or first-surface printing is generally a less durable option because cleaning or abrasions, which occur in dayto-day use, may erode or degrade inks over time. Adding processes to the production, like hard coating, counter this limitation but add time and expense to the process. Additionally, direct printing usually offers limited backlighting options and provides less overall flexibility in terms of the printing process. Fabrication and forming options Multiple options exist for forming and fabricating dials and gauges. The indicator can be embossed, formed, molded,
20 | Industrial + Specialty Printing www.industrial-printing.net
die cut, or fabricated. Embossing is an excellent option for creating a functional, three-dimensional product. Either Class-A or magnesium embossing provide height or depth to an indicator, which adds a visual and tactile dimension to a product. Another option is thermoforming. This is used primarily when manufacturing an in-mold-decorated overlay that requires a deeper draw. Plastic sheets are printed prior to exposure (Figure 3) to heat; a vacuum and a male tool are used to create the final form. A thermoformed part can then be moved to an injection-molding tool for the creation of a custom printed part, which is then back printed for durability. The injection-molding process adds a wide range of design options, allowing for curves, textures, or well-defined edges and shapes, if needed. Another molding option is silicon-compression molding—best used when the durability of rubber is required. Other fabrication options for stamping or cutting an indicator include the use of a
Figure 4 (left) This part showcases digital technology used in the medical area for testing and measurement. Figure 5 (top) This is instrument technology used in high-end controls designed for durability in harsh industrial environments.
Class-A tool, a steel-rule die, plotter router, or even a laser. Class-A tools are often used when a part requires very tight tolerances or for extremely high-volume production runs. A steel-rule die is one of the most commonly used fabrication methods. It produces good tolerances, offers longevity, and is less expensive than the Class-A tool. The plotter router and laser are appropriate fabrication options for low volumes and thinner materials and substrates. Impact of digital printing Digital printing allows for lower production volumes and provides the opportunity to make a product with a high mix of design variables, thereby allowing for mass customization of parts within a single production run. Preparing for a production run on a modern digital printer is a faster process than setting up a traditional screen-printing press. The time required is considerably shorter, even when adding multiple colors or other custom options within a single run, which provides significant cost savings when this option is available. Digital printing (Figure 4) can support tight tolerances in print-to-print
registration and repeatability, comparable and sometimes superior to that of traditional screen and lithographic presses or pad-printing and hot-stamping methods. This makes digital printing a good option for designers seeking to create a highly customized instrument with a high-end appearance. Digital equipment that is able to print on metal surfaces is beginning to become available. This added option provides the same flexibility to designers who seek a part with unique colors and patterns but require that the design be applied directly to the surface. And a modern digital press can handle objects that are formed to provide a third dimension for custom applications. This combination of faster setup times, mass customization, and tight tolerances with a low-cost direct printing method provides an excellent option that can rival traditional printing methods. Demanding applications Some industries, such as the military and medical-device manufacturers, have very demanding requirements. Whether this is due to harsh environments, strict regula-
tions, or simply because of mission-critical reliability, some parts need to be manufactured to a higher standard (Figure 5). Metal-photo and anodized-aluminum printing are popular choices for military and aerospace manufacturing. Sealing open-pore anodized aluminum after decorating creates an extremely durable dial or gauge. Metal-photo parts typically survive more than 20 years of outdoor use and are resistant to many harsh chemicals. Custom manufacturing Acquiring the appropriate equipment and developing the kind of experience necessary to custom manufacture industrial and specialty printed parts such as dials, gauges, instrument-panel clusters, and touchscreens is a challenge. Mastering the processes required for tight-tolerances and extremely demanding performance requirements isn’t something everyone can accomplish. However, the markets for the applications discussed here are so vast that you’re bound to be able to find a compatible niche for your business.
Benjamin gORenberg For GM Nameplate
Benjamin Gorenberg is a freelance writer and editor based in Seattle, WA. He can be reached at www.gorenberg.net. He wrote this article for GM Nameplate of Seattle, WA. march/april 2011 | 21
FEATURE STORY
MAKING MEMORIES Randall Sherman
New Venture Research
P
This article highlights the progress made in printed memory and details the challenges that await this emerging manufacturing process.
rinted electronics (PE) is an emerging field in which specialized printing methods are used to create electrically functional devices. PE is not a replacement for conventional electronics, but its main advantages lie in its extremely low fabrication costs, accommodation of large areas of coverage, and compatibility with a variety of substrates (increasingly flexible). It suffers from long switching times and low integration density, while conventional electronics has extremely short switching times and high integration density, but requires rigid substrates and expensive and sophisticated fabrication techniques. Printed electronics today is essentially a coatings business, although many applications still involve the deposition of fine layers of conductive organic and inorganic compounds. More precisely, printed electronics is a set of printing methods used to create electrically functional devices. A wide variety of materials is used in the coatings for devices, including inks, polymers, and organic and inorganic materials; substrate surfaces can consist of glass, paper, plastic, ceramics, and inert compounds. Nearly all industrial printing methods are used in the production of PE. Similar to conventional printing, printed electronics applies ink layers one on top of another so that the coherent
22 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net
development of printing methods and ink materials are the field’s essential tasks. The attraction of printing technology for the fabrication of electronics mainly results from the opportunity to prepare stacks of micro-structured layers (thin-film devices) in a much more simple and cost-effective way compared to conventional electronics. In addition to this, there is the possibility to implement new or improved functionalities, such as mechanical flexibility or curved surfaces, into a device. ORGANIC ELECTRONICS AND THIN-FILM TECHNOLOGY Organic electronics (OE), plastic electronics, and polymer electronics technologies all use conductive polymers, plastics, or small molecules. These technologies are called organic because the polymers and small molecules are carbon based, much like living organisms. Traditional electronics relies on inorganic conductors such as copper and doped silicon, which are electrically more efficient. Conductive polymers have a higher resistance and, therefore, conduct electricity slowly and inefficiently when compared to inorganic conductors. Yet for simple applications that involve the use of logic and memory, OE printed circuits are all that is needed and remain the only viable option today. Thin-film polymers have emerged as an alternative material for next-generation devices because of two distinguishing properties. First, polymers are solution process able—that is, they have rheological properties that make them behave like liquids. Second, polymers are non-rigid materials that can be applied to almost
any surface, limited only by practical restrictions regarding the size of the active area. In contrast, silicon is rigid, brittle, and still restricted by a maximum wafer diameter of 12 in. Organic transistors The first organic transistor was demonstrated in 1986, and as performance steadily increased throughout the 1980s and 1990s, integrated circuits were eventually fabricated. Organic complementary circuits, which are characterized by greater speed and lower power consumption compared to the first organic transistors, were first developed at Lucent Technologies (Bell Laboratories) in 1996. Since that time, organic systems have been developed with deliberate semiconducting properties. This innovation immediately opened up a range of technology applications for conducting, insulating, and semiconducting polymers and organic transistors. The primary goal of making organic transistors and integrated devices is to create circuits that are functional, inexpensive, and printable on demand. Organic thin-film circuits can take the place of silicon circuits in applications that require short turnaround times, flexibility (not only for non-brittle materials, but also for variable configurations), and simple performance. Perhaps of more interest is that organic materials can be rendered into a liquid form and applied at room temperature and atmospheric pressure, and thus are ideal for printable formats. A new breed of low-cost electronics is emerging that can easily and quickly be applied via conventional inkjet technologies at minimal cost. The starting point for the development of printable, organic, functional materials was the discovery of conjugated polymers (earning the Nobel Prize in chemistry, 2000) and their development into soluble materials. This has led to the availability of many polymer materials in liquid form—that is, as solution, dispersion, or suspension. Polymers today have varying electrical properties depending on their molecular structure. The material with the highest electrical conductivity is polymer PEDT (or PEDOT, polyethylenedioxythiophene). It is the basis for millions of polymer capacitors used in electronics today. More recently, nanoparticulate inorganic
semiconductors or hybrid organic-inorganic semiconductor materials have been introduced that promise both the superior carrier mobility of inorganic semiconductors and the process ability of organic materials. Polymer electronics Thin-film-electronics innovators have developed polymers that are bistable and can be used as the active material in a nonvolatile memory application. In other words, they can be switched from one state to the other and maintain that state even when the electrical field is turned off. This type of polymer is smart to the extent that functionality is built into the material itself, including switchability, addressability, and charge storage. This is different from silicon and other electronic materials, in which such functions typically are only achieved by complex circuitry. Smart materials can be produced from scratch, molecule by molecule, allowing them to be built according to a specific design. By combining different print and production techniques, polymer electronics can be engineered in conductor paths of any desired length, with printed layers 0.001 mm thick. As the process technology evolves, polymer electronics will be able to integrate hybrid designs so that transistors, diodes, memory, and displays can be produced in a continuous and mass-printed form. To date, polymer electronics have produced touch-sensitive sensors (keys), digital memory (16-96 bits, depending on the available surface area on the substrate), processor logic, photovoltaic batteries, and color displays. In 2009, inorganic semiconductors were being sold by Kovio for RFID tags due to their much higher mobility than is found in organic semiconductors. Similarly, companies such as Pelikon and elumin8 have applied inorganic materials to flexible electroluminescent displays that involve six to eight layers, including a copper-doped phosphor. In 2009, PolyIC and Thin Film Electronics ASA jointly manufactured fully functional, rewritable polymer memory products in a high-volume, roll-to-roll printing process. Thin-film memory In December, 2010, ThinFilm Electronics announced the first commercially available
rewriteable memory device produced using roll-to-roll printing processes. The 20-bit device can be read and re-written indefinitely using a hand-held reader/writer, a design of which is offered to customers through a development kit. ThinFilm received its first order through one of the ten largest toy manufacturers out of Japan and hopes to apply its technology to interactive games, collector cards, RFID, and biometric applications. The company is targeting addressable applications of 40- to 128-bit memories and hopes soon to merge printed transistors together through an alliance with Xerox PARC. Other partners include Inktec (a publicly listed company in Korea and a qualified partner of display manufacturers Samsung and LG), and also development agreements with PolyIC and Soligie. While it may seem that 20 bits appears like very little information, ThinFilm has an algorithm that can represent 220 permutations—that is, the table can have 1,048,576 different permutations or states. For an interactive games (their primary target market), this means that avatars can achieve various skill levels, carry a list of items, wield particular weapons, and that this personalization can be placed on a card showing the particular character that the child selects. Obviously, the success of PE memory devices depends significantly on the cost. ThinFilm CEO Davor Sutija is keenly aware of this and indicates that current prices are around five cents a device for orders more than 1 million. Costs will naturally come down with volume, yet rather than see the unit cost drop, Sutija expects the performance to increase proportionately. ThinFilm’s competition is not believed to be with read-only devices, but rather addressable solutions. The combination of “logic and memory is truly revolutionary ... and the applications are numerous,” Sutija says. It seems that addressable memories will open up the opportunity for creating all-printed devices for the first time by combining logic and memory with other elements, such as sensors and printed power sources or disposable displays. By storing user and game-flow information, ThinFilm’s memory enables interactive experiences and makes cards and toys intelligent. The company is focused on march/april 2011 | 23
providing low-power, non-volatile, rewritable polymer memory technology and products in the PE market. Using printing to manufacture electronic memory makes it possible to reduce the number of process steps, manufacturing costs, and environmental impact as compared to traditional semiconductor processes. Memory is an essential part of most electronics. Memory is required for identification, tracking status and history, and any other application that requires information storage. ThinFilm’s non-volatile, ferroelectric polymer memory technology is suited for applications with other PE devices because power consumption during read and write is negligible, and as it is permanent, so no connection to external power is required for data detainment. Commercial applications of PE include e-paper, electronic readers, and organic light-emitting displays (OLED). Sensors, batteries, and photovoltaic energy sources are also in development, and together with technologies such as ThinFilm’s memory, they will open the door to many new products and applications. ThinFilm and Inktec were the first companies to announce successful highvolume, roll-to-roll production of rewritable ferroelectric memories in April 2009. An additional announcement with PolyIC in September of the same year demonstrated that they had additional printing partners. ThinFilm acquired the ferro-electric-polymer patents held by Opticom, a company that together with its partner, Intel Corp., developed the methodologies and design of memory arrays that they use in their devices. Intel and Opticom were aiming to displace the use of silicon in high-density applications as an alternative to NAND Flash memories. While this work was discontinued in 2005 (Intel left the memory business), the patents are the basis for ThinFilm’s position in printed memories. ThinFilm does not see conventional, silicon-based chips as the competitor to using printed memories. EEPROMs and Flash are cheap enough that the first generation of RFID chips incorporate these technologies. For wide-scale adoption, however, numbering in the hundreds of billions of rewritable tags (as predicted by other market-research firms), one may not be able to use existing semiconductor technologies at marginal cost, but will need
Memory reel: These reels of plastic are printed with 20-bit memory devices. Photo cour tesy of Poly IC
to invest in new facilities under which printed electronics has a real chance to compete and win. Getting organic- and inorganic-transistor electronics to work as efficiently as integrated semiconductor electronics will be the major challenge of the next decade. In terms of cost, performance, and size, silicon semiconductors have a 40-year head start and fantastic R&D investment. What printed electronics cannot achieve in largescale integration, it can achieve in smaller scale batches and flexibility. Because of the continuous-process-manufacturing technology of printed electronics, the ability to integrate printed circuits through repetitive layers will create a sustainable competitive advantage in time—in certain applications. Although integrated logic, memory, and sensor applications were demonstrated re-
24 | Industrial + Specialty Printing www.industrial-printing.net
cently, the interface electronics—including power conversion and modulation, drivers and clocking mechanisms, amplifiers, electromechanical integration, and any number of monitoring and self-checking/correction designs that make a completed system— remain undeveloped at this point in time. The result is an embryonic and incipient market, yet one that could ultimately be truly disruptive.
RANDALL SHERMAN New Venture Research
Randall Sherman is the president and CEO of New Venture Research, a technology market research firm. He holds a B.S. in astrophysics, an M.S. in electrical engineering from the University of Colorado, and an M.B.A. from Edinburgh School of Business. Visit www.newventureresearch.com for more information.
June 14-16, 2011
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San Jose Convention Center, San Jose, California Register now for the best production-focused educational program in the printed electronics industry, featuring a wide range of market segments: • Printed photovoltaic and electroluminescent technology • Membrane switch production • LED, OLED surface mount technologies • Printed medical sensors and instrumentation • Flexible electronics • RFID and high speed production technologies
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FEATURE STORY
Determining Optimum Exposure
Read on to discover how proper stencil exposure influences quality and productivity throughout the screen-printing workflow. Wim Zoomer
Technical Language
S
tencil life and print quality are directly related to a screen printer’s ability to determine optimum exposure time in prepress. Fortunately, calculating proper exposure time can be a simple process. It starts with mesh selection. The mesh count and the mesh type the screenmaker chooses depend on the image. An image with large solid areas calls for a coarse mesh that will allow more ink to transfer to the substrate. The screenmaker would choose a fi ner mesh for a highly detailed image or one composed of halftones. Inks also influence mesh selection. UV-curable, solvent, water-based, conductive, and other inks have their own requirements. For example, UV-curable inks contain 100% solid matter, so the wet ink deposit and post-cure ink deposit after are practically the same—practically, because UV-ink shows some shrinkage during curing. Solvent-based ink may contain 70% solvent, for example. In other words, 30% of ink in its solid state remains on the substrate after printing and drying using high temperature. Obviously, these properties affect mesh selection. 26 | INDUSTRIAL + SPECIALTY PRINTING www.industrial-printing.net
Once the appropriate mesh and ink are selected, correct stencil-exposure time will keep required print quality consistent until the end of the print run. However, incorrect exposure is one of the primary and most frequent causes of stencil failure. Let’s look at the screenmaking process and related parameters that affect print quality before we discuss how to determine correct exposure time. EMULSION Many screenmakers use direct emulsions based on hybrid (dualcure) systems or capillary film. These two-pot emulsions contain the diazo sensitizer. Some screenmakers use emulsions based on photopolymer systems. The exposure time of photopolymer emulsions is shorter compared to hybrids. It is not surprising that the exposure latitude of photopolymer systems is quite small. The light-sensitive components in the emulsion relate to a certain wavelength range in the ultraviolet light spectrum. In general, the light sensitivity of direct emulsions and capillary films is in the range of 350-500 nm. The emulsion will start to polymerize upon exposure to light in this wavelength range.
Light source The emulsion is susceptible to a certain UV-wavelength range. The bulb that is used to expose the emulsion emits light within this wavelength range (emission spectrum). Metal-halide bulbs are common in exposure units. These high-intensity-discharge bulbs produce UV and blue light and contain mercury vapor and metal (iron or gallium) halide to adjust the emission spectrum. These bulbs produce emission peaks at 385 and 420 nm. Light energy The power of the lamp, such as 1 or 5 kW, affects exposure time. More power shortens the exposure time. The bulb’s intensity reduces gradually as it ages. To compensate, some exposure systems come standard with a light integrator that measures the amount of light energy. The light integrator ensures that a screen is exposed to the same amount of light energy, regardless of the bulb’s age. Distance The distance between the lamp and screen affects exposure time as well. If we decrease the distance between the lamp and the screen, the UV light will concentrate in the center of the print area. The light intensity decreases toward the sides of the screen. We will observe a loss of fine details due to undercutting of the light. Increasing the distance between the screen and lamp improves the light distribution across print area on the screen and, on the other hand, increases exposure time. The exposure time is proportional to the distance square. In other words: Exposure time new = Exposure time old x (Distance new)2 (Distance old)2 Example: Old distance: 60 cm New distance: 120 cm Old exposure time: 25 seconds
Figure 1 Light reflection during exposure of emulsion on white fabric
Optimum exposure 1,2 1
Relative quality
Mesh fabric Mesh fabric is commonly woven of polyester threads and is available in numerous mesh counts and thread diameters. Screenmakers use relatively fine fabrics when printing fine text, halftones, linework, or thin ink deposits. They apply a thin coat of emulsion (or a thin capillary film) onto the fabric. Emulsion thickness after drying is often approximately 5 μm. Coarse fabrics allow printing thick ink deposits, high-viscosity inks, or inks containing pigments. The corresponding images are coarse as well. Emulsion thickness increases as the mesh becomes coarser. Mesh is commonly white, yellow, or orange. White threads reflect UV light and, therefore, may cause undercutting during exposure (Figure 1). Dyed mesh absorbs UV light during exposure and, consequently, cause less reflection. Dyed mesh causes less undercutting and produces an image that is more open with a much better edge sharpness. Dyed mesh is more expensive than white and is therefore used most often for printing very fine details or images with high quality requirements.
Resistance
0,8 0,6 0,4
Image quality
0,2 0
2
4
6
8
10
Exposure time (units) Figure 2 Exposure time vs. stencil quality
The new exposure time is 100 seconds. Doubling the lamp distance quadruples the exposure time. Standardization Standardization is a very important part of managing the large number of variables in the exposure process. In this context, standardization means limiting the number of variables. Reduce the number of mesh fabrics from which to choose. Use one type of direct emulsion or capillary film. Use the same mesh color each time. Duplicate exposure conditions, including the exposure system and lamp distance. A light integrator is a very important part of standardization. If a light integrator is not available, its absence will add a continuous variable to the process. Standardization reduces the risk of making mistakes. Understanding how exposure time affects the most relevant characteristics of the emulsion we use allows us to accept the remaining process variables: image quality and emulsion resistance. In exposure, there are just three possibilities: too short, too long, or optimum. To avoid getting lost in the number of process variables available, I recommend using a log book in the screenmaking department. A log book allows the screenmaker to find the conditions under which the screen was coated, which mesh was used for the job, the exposure time applied for the job, and the lamp’s age. march/april 2011 | 27
12
A
B
C
D
E
Figure 3 The basics of step exposure
Figure 4 Examples of exposure calculators from Ulano and MacDermid Autotype
Polymerization Using the correct exposure time is essential to ensuring long stencil life and high image quality. UV light causes a chemical reaction between the emulsion’s monomers, pre-polymers, and other chemical substances that change into a strong and stable grid of polymers to eventually create a stencil. The emulsion’s color will darken. Unexposed emulsion is soluble in water and is removed from the mesh during washout. On the other hand, exposed (polymerized) emulsion is only moderately soluble in water and, therefore, remains
affixed to the mesh during washout. Exposure time affects a number of the stencil’s characteristics, such as resolution, edge sharpness, stencil thickness, chemical and mechanical resistance, and useful life. Proper exposure polymerizes the emulsion completely, leaving an exact copy of the image on the mesh. The emulsion’s adhesion is excellent during washout and printing. The chemical and mechanical resistance and lifetime of a properly exposed stencil are good, whereas the emulsion’s reclaimability leaves nothing to be desired.
28 | Industrial + Specialty Printing www.industrial-printing.net
Exposure time too short Polymerization starts at the top of the emulsion (the print side) and proceeds through the emulsion coat towards the bottom (squeegee side), where the emulsion is connected to the fabric. Underexposed emulsion fails to polymerize completely, and the adhesion between the emulsion and mesh is reduced. The resulting thickness of the emulsion coat on the mesh declines, and edge sharpness deteriorates. Reduced stencil life, a result of the stencil’s decreased chemical and mechanical resistance, will affect the length of the print run. Should the exposure time decrease even more, the emulsion will separate from the mesh completely during washout. Chemical and mechanical resistance will drop, as will the chances for reclamation. Exposure time too long Is exposing too long perhaps a better option than exposing too short? After all, exposing too long does not create adhesion problems between emulsion and fabric. Additionally, the overexposed stencil will be strong enough to finish the print job. However, overexposure causes image quality to decline. Overexposing the emulsion through the film positive causes UV-light refraction, which leads to exposure of the emulsion underneath the black part of the film positive. This undercutting effect, particularly when combined with the reflection caused by white mesh, reduces edge sharpness. Longer exposure times increase undercutting, causing narrower open lines in the stencil. This means that the line width (resolution) is affected negatively as well. The very fine open details will be blocked first and will not appear during printing. Quality of the line (width) is strongly influenced by exposure time. This undercutting effect does not appear, or is hardly visible, when the correct exposure time is used. Exposed correctly The graph shown in (Figure 2) represents relative exposure time as it related to stencil quality. Relative quality is expressed as 0 = very bad to 1.0 = excellent. The green curve represents the emulsion’s strength
(chemical and mechanical resistance). We see that the emulsion’s resistance improves as exposure time increases. Resistance hardly increases when exposure time reaches 7 units and stabilizes at an optimum level. Polymerization (cure) is complete, and the emulsion has hardened out completely. The image-quality curve, shown in red, shows that applying an exposure time longer or shorter than 4.5 units means a decrease in image quality (edge sharpness, definition, or resolution). The optimum exposure time is the intersection of both curves, representing the compromise between resistance and image quality, resulting in an optimum exposure time of 6 units. Exposure tools We can use two simple methods to determine the optimum exposure time: step exposure and an exposure calculator. Step exposure means to vary the exposure time of different image areas: much too short, too short, as expected, too long, and much too long. We cover successive areas with black film during each exposure step. This experiment requires a film positive with images we intend to expose on a screen (line work, halftones, type, or solids) and a piece of black film. Divide the film into equal parts, and call them area A, B, C, D, and E. Indicate these characters on the film positive. Mount the film on the print side of the coated screen. If we anticipate using an exposure time of 20 seconds, then we’d use area C to represent that time in our test. We expose the test areas as follows: A 10 seconds, B 15 seconds, C 20 seconds, D 25 seconds, and E 30 seconds. First, we expose the complete film positive (areas A, B, C, D, and E) for 5 seconds. Next we cover areas A, B, C, and D and expose again for 5 seconds. Before exposure, we cover areas A, B, and C, and expose for 5 seconds. We move the black film to the left after each exposure step until we reach the last area. After exposure, we remove the film positive, perform the washout as usual, and dry the end result. We observe a gradual color change. The longer the exposure time, the darker the emulsion. The
emulsion’s color does not change after being fully cured (complete polymerization). No more monomers or pre-polymers remain in the emulsion to react chemically. The emulsion’s chemical and mechanical resistance is at its peak. Finding the area where the emulsion’s color change stops gives us a general idea of where optimum exposure occurs. Figure 3 shows that the color change stops at area D, which was exposed for 25 seconds. Next, we compare the edge sharpness and resolution of the test sections next to area D. We observe area C complies with the edge sharpness and resolution requirement. In this example, the exposure steps are 25% of the resulting rough exposure time of 20 seconds. We can repeat this test with smaller steps to fine-tune the optimum exposure time. Most emulsion manufacturers supply exposure calculators (Figure 4). These very convenient tools help us determine correct exposure time, and they require only one exposure. The exposure calculator consists of two parts: a film positive, often with five of the same images, and a film that carries filters with different grayscales (often five). The size of the grayscales corresponds with the size of the images on the other film. These different grayscales transmit different amounts of light. The factors indicating each individual area represents the relative amount of light transmitted. Factor 1 area transmits 100% incident light. Factor 0.25 is the darkest filter. This grayscale transmits only 25% of the incident light. The calculator uses a succession of areas of increasing light transmission factors, such as 0.25, 0.33, 0.5, 0.7, and 1.0. Suppose we expect an exposure time of 100 units. Double it, and conduct the exposure test with the doubled value (200 units). The different areas on the exposure calculator are now being exposed by 50, 66.5, 100, 140, and 200 units, respectively. The expected exposure time is in the middle of the range, allowing the screenmaker to compare the different areas. After development (washout) and drying we first determine the emulsion’s color change. The factor where the color change stops represents optimum expo-
sure. Different elements on the exposure calculator, such as text, linework, and halftones, enable the screenmaker to finetune the exposure time. The criteria are resolution and edge sharpness. Suppose area Factor 0.6 provides the best result. The resulting optimum exposure time is 0.6 x 200 units = 120 units. Exposure calculators are provided with separate number of test images and the corresponding number of light-transmission filters. Most common ones have factor 0.5 in the middle of the range. Some exposure calculators are equipped with extra tools, such as halftone-reproduction targets or definition targets to assess print resolution and edge definition. Expose yourself to quality Calculating optimum exposure time is a critical part of overall quality. Taking the time necessary in prepress to manage this essential process will yield benefits in image resolution, stencil longevity, production efficiency, and, ultimately, client satisfaction.
wim zoomer
Technical Language Wim Zoomer (wimzoomer@planet.nl) is owner of Nijmegen, Netherlands-based Technical Language, a consulting and communication business that focuses on flatbed and reel-to-reel rotary screen printing and other printing processes. He has written numerous articles for international screen-printing, art, and glass-processing magazines and is frequently called on to translate technical documents, manuals, books, advertisements, and other materials in English, French, German, Spanish, and Dutch. He is also the author of the book, “Printing Flat Glass,” as well as several case studies that appear online. He holds a degree in chemical engineering. You can visit his Website at www.technicallanguage.eu. march/april 2011 | 29
Market movements and association updates
INDUSTRY NEWS
Market Forecasts Predict Solid Recovery
60%
Signs of economic improvement abound. According to recent reports, the job market looks stronger in 2011. For example, private employers added 187,000 jobs in January according to payroll processor ADP. In the manufacturing sector, economic activity expanded in January for the 18th consecutive month, and the overall economy grew for the 20th consecutive month said supply managers in the Manufacturing ISM Report on Business. “The manufacturing sector grew at a faster rate in January as the PMI [Purchasing Managers Index] registered 60.8%, which is its highest level since May 2004 when the index registered 61.4%. The continuing strong performance is highlighted as January is also the sixth consecutive month of month-over-month growth in the sector. New orders and production continue to be strong, and employment rose above 60% for the first time since May 2004. Global demand is driving commodity prices higher, particularly for energy, metals, and chemicals,” says Norbert J. Ore, chair of the Institute for Supply Management Manufacturing Business Survey Committee. Bannockburn, IL-based IPC (Association Connecting Electronics Industries) announced an improved picture for future growth. In the printed circuit board industry, rigid board shipments were up 10.6% and bookings decreased 0.8% in December 2010 from December 2009. Year to date, rigid PCB shipments were up 17.8%, and bookings have grown 20.9%. Flexible-circuit shipments in December were up a whopping 50.9%, and bookings grew 65.3% compared to December 2009. Year to date, flexible-circuit shipments increased 16.0%, and bookings were up 22.3%. The North American flexible-circuit book-to-bill ratio in December climbed back to 0.97%. At the Signage and Graphics Summit (www.signageandgraphics. com) in January 2011, market forecaster Brian Beaulieu of ITR (www. itreconomics.com) presented a positive outlook in his keynote, Business Strategies for Tomorrow’s Economy, during which he noted that corporate profits are growing and that “it’s a good time to buy someFlexible Rigid Shipments Rigidand and Flexible PCBPCB Shipments Year-on-Year Growth Rates Rates Year-on-Year Growth thing.” Many types of businesses go through predictable cyclical growth and expansion to decline stages, he explained. For each phase, he gave management objectives as to how to handle recessions, early recovery cycles, late recovery, and growth periods. 35.7%
40%
0%
3.6% -14.2%
-20% -17.1%
-40% -60%
-18.9%
25.3%
19.6%
16.6%
20%
1.0%
-2.1% -3.0% -3.1%
9.4%
7.9% 4.3%
-13.7%
-3.5%
-0.4%
-14.9% -23.2%
-15.9%
-11.3%
-3.4%
-4.1%
14.8%
10.5%
-2.1% -1.3%
-14.9%
-34.2%
-30.8%
Rigid Shipments
Flex Shipments
30 | Industrial + Specialty Printing www.industrial-printing.net
35.7%
38.8%
21.0%
23.9%
-2.0%
-26.2% -27.4%
-30.5% -37.1%
-14.0%
38.2%
31.4%
24.3% 18.3%
14.7%
9.7%
13.6%
50.9%
10.6%
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TECHNIQUES, TIPS & APPLICATIONS
Sutija Now CEO of Thin Film Electronics
Material Shortages Hike Ink Prices
Heraeus Buys Clevios
Avery Dennison and GE Collaborate on RF
Davor Sutija, Ph.D., has been promoted to CEO of Thin Film Electronics ASA. He takes over from Roff Aberg, who continues as an executive board member. Thin Film claims to be the first company to produce polymer memories in large scale using roll-toroll printing. “My main task is the successful commercialization of [our] technology. We have unique and proven technology, we are ready for volume production, and we have product with excellent commercial prospects,” Sutija says. “We experience strong interest both in the printed electronics market in general and in specific markets such as toys and games.”
By acquiring H.C. Starck’s Conductive Polymers Business Group, Heraeus is engaging in targeted expansion of its product portfolio of coating materials in the electronics industry. The Clevios product line includes liquid polymer chemicals for anti-static and conductive coatings, screen coatings, plastics, and conductive polymer coatings, each tailored to specific applications, such as organic LEDs or as electrodes in capacitors. The transfer was completed early in December of 2010. Clevios is being integrated into the Heraeus Precious Metals Business Group as the Conductive Polymers Division.
Apple Dedicates $3.9B to LCD Displays
Apple Inc. is investing billions of dollars amid the intense demand for supplies of small and medium displays used by smart phones and tablets to guarantee availability of advanced liquid-crystal display (LCD) panels for its iPad and iPhone lines, IHS iSuppli research indicates. Tim Cook, acting CEO at Apple, states that the company has executed long-term supply agreements with three vendors. The agreements are expected to involve approximately $3.9 billion in inventory component prepayments and capital expenditures during a two-year period. iSuppli speculates that the companies in question may be LG Display, Sharp Corp., and Toshiba Mobile Display. The agreements would involve the supply of Apple’s retina display, used in the iPhone and iPad. The retina display uses in-plane switching and low-temperature polysilicon technology for high resolutions in small displays by using pixels that are smaller than the human eye can perceive.
The National Association of Printing Ink Manufacturers, Inc. issued a bulletin that provides insight into the current volatility facing the supply of raw materials to the printing-ink market. It states that rosin, a major ingredient in resin production, has experienced a nearly threefold increase in price in 2010, and supply remains constrained with low inventories. Lead times for carbon black have increased, and it’s rumored that two major suppliers are for sale. Suppliers of titanium dioxide are not taking on any new business because supply remains tight and inventory levels are low. Capacity for colored organic pigment has decreased during the last few years, and there’s no indication that this will change.
GE’s Technology Ventures unit will work on the commercialization of its Radio Frequency Sensing Technology (RFS) through a commercial license to the RFID division of Avery Dennison. The partnership is designed to facilitate a wide range of low-cost, wireless sensing products for industrial applications. “Through our technology development with GE, we have successfully demonstrated that RF sensors can be manufactured using a standard roll-to-roll process,” says Jack Farrell, VP and general manager at Avery Dennison RFID. These particular sensor tags contain GE sensors for detecting toxic industrial chemicals, volatile organic compounds, and biological agents for use in many applications rather than the just the basic information for inventory control monitoring as used in many RFID applications. As such, the RFID tags are laminated with specialized films and require a specific reader to identify and measure both RF-waveform data and information regarding chemical information.
Nazdar Announces New Product Sustainability Shawnee, KS-based Nazdar has begun sustainability drives in its Lyson wide-format solvent, cartridge-based ink line. The company now uses solvent-ink cartridges marked with Society of the Plastics Industry (SPI) recycling codes. Users can disassemble empty cartridges, remove the ink bladder for proper disposal, and recycle the remaining three pieces of plastic. In addition to the new recyclable cartridge shell, the company will discontinue use of an outer cardboard box for each individual cartridge. This is designed to reduce waste and reduce the harmful environmental effects associated with the cardboard-bleaching process.
Send us your news! Email gail.flower@stmediagroup.com 32 | Industrial + Specialty Printing www.industrial-printing.net
Narrow-Bezel LCD Displays to Grow in 2011 Advancements in liquid-crystal displays (LCDs) are now allowing for commercial-grade products with thin bezels (the visible rim or edge of the display), making them suitable for videowall applications, DisplaySearch reports, noting that four of the top-selling brands in the U.S. (Samsung, NEC, LG Electronics, and Sharp) offer commercial-grade LCD flat-panel displays in the U.S. and are now competing to offer the thinnest form bezel, from 15 mm to smaller than 5 mm.
Cymbet Plans SolidState-Battery Facility Cymbet Corp. and X-FAB Texas Inc. have agreed to open a largevolume, solid-state-battery facility in Lubbock, TX. The move is attributed to global demand for Cymbet’s EnerChip’s solid-stage battery. Cymbet is also expanding its Elk River, MN, staff by more than 20%, reports Cymbet CEO Bill Priesmeyer.
FLEXcon to Purchase Graphics Division of Arlon Inc. Spencer, MA-based FLEXcon, manufacturer of pressure-sensitive films and adhesives, is in the process of acquiring the business assets of the Graphics Division of Arlon, Inc. of Santa Ana, CA, to form a company to be named Arlon Graphics, LLC, a new, wholly owned subsidiary of FLEXcon. This purchase is aimed at strengthening FLEXcon’s market position by expanding its product portfolio in advertising and promotional products, as well as extending its sales channel and global market presence. When the acquisition is complete, the company will also have the option to purchase Arlon Engineered Coated Products and Arlon SignTech Ltd. of San Antonio, TX. The Graphics Division of Arlon, Inc. manufactures pressuresensitive cast vinyl, flexible substrates, and print media for digital imaging, signage, vehicle graphics, and industrial printing. The company has distribution centers in six continents. FLEXcon is a family owned, privately held business formed in 1956 with 1200 employees. The firm coats, laminates, and finishes wide-web roll-to-roll polymeric materials for graphics and label applications, as well as bonding, barrier, optical, and electronics applications.
Ulvac Concentrates on Small Displays
Chigasaki, Japan-based Ulvac competes with Tokyo Electron and Applied Materials in equipment for making chips, flat-panel displays, and solar cells. Lately Ulvac is focusing on gear used in making small, next-generation liquid-crystal (LCD) equipment. Hidenori Suwa, Ulvac’s president has stated recently that his firm is aiming to make more small panels for use in smart phones. In solar-cell technology, Suwa sees potential for thin-film silicon panels, according to industry sources. In January, however, Ulvac revised its forecast for orders for flat-panel displays in June 2011 to 77.6 billion yen from 84.5 billion yen. “At the start of the financial year, we were anticipating a lot of investment from China. It turned out that we couldn’t bank on investment in China and other foreign companies, so we revised our forecast,” he says.
Samsung Acquires Liquavista
Samsung bought all shares of Liquavista stock from former share holders. The plan is for Liquavista to keep the name and brand intact and for the company to become a high-class R&D center for Samsung. John Feenstra, Liquavista’s founder and newly appointed CEO, says, “The outright acquisition of Liquavista by the largest electronics company in the world is the fulfillment of a strategy dating back to the original spin-out. In the future, consumers will need products that not only support full color and video, but also offer readability in all lighting conditions and give them ultimate freedom and portability. Being part of Samsung, we can all be sure that electrowetting display technology will find its way to the market in the fastest possible time.”
upcoming events APR 3-7 IDTechEx Printed Electronics & Photovoltaics Europe.
APR 12-14 IPC APEX Expo,
Dussledorf, Germany www.idtechex.com
May 24-27 FESPA
Las Vegas, NV www.ipc.org
June 14-16 SGIA Printed Electronics & Membrane Switch Symposium San Jose, CA www.sgia.org
July 12-14 SEMICON West IPC San Francisco, CA www.ipc.org
SEPTEMBER 22-23 International Conference on Flexible and Printed Electronics Tokyo, Japan www.icfpe2011.org
September 27-28 RFID Europe IdTechEx Cambridge, UK www.idtechex.com
Hamburg, Germany www.fespa.com
march/april 2011 | 33
printing methods
Challenges in Single-Pass, Roll-to-Roll Inkjet Printing John Corrall
Industrial Inkjet Ltd. Single-pass printing is gaining in popularity in the manufacture of labels and other flexible applications, and more inkjet-based systems are available today than ever before to facilitate high-speed, short-run production. However, roll-to-roll inkjet printing differs from conventional methods used for label decoration. This article addresses these differences and describes some important features that will help label producers integrate digital imaging technology successfully. Inks and substrates Almost all inks for inkjet printing in the label industry are UV curable. The ideal UV inkjet ink for roll-to-roll applications of any kind is one that will wet out properly and adhere to a wide range of materials. For this to work, the ink must exhibit low surface tension, and the substrates must exhibit high surface energy. With flexo, and almost all conventional printing technologies, mechanical pressure forces the ink out into a smooth film. With inkjet, that force only comes from the difference between the surface tension of the ink and the surface energy of the media. There is no roller pressing down the ink. Typical surface tension of UV ink is approximately 28-32 mNm-1; however, this is really too high for printing on popular materials used in roll-to-roll production. Materials such as PE or PP, originally designed for conventional, contact-based printing have energies of approximately 38 mN/m-1. Testing reveals that, with most inks available today, optimum results are realized when a substrate’s surface energy is 52-56 mN/m-1. The lowest level ink that can still work well in the printheads is usually around 21 mNm-1. Such an ink might work with a roll-to-roll material of perhaps 44 or 48mNm-1. If you cannot specify a material that has an inherently high surface energy, such as
PET or BOPP, then you can either pre-treat the substrate with a corona or flame unit or prime the substrate with a specially formulated coating before printing. Keep in mind that some substrates, such as coated papers designed for offset printing, often exhibit inconsistent surface energy. Therefore, the quality of the results you obtain with a single-pass inkjet system will be equally inconsistent. Print may be fine in one area but terrible nearby. A measurement of the Dyne level (surface energy) of these materials will show that surface energy may vary over distances as small as a few millimeters. Printing an ink that has high surface tension onto a substrate that has low surface energy almost always yields very poor results (Figure 1). Inks fail to wet out completely and do not form a smooth film. Ink wet-out is maximized by combining an ink that has low surface tension and substrates that have high surface energy. Incompatible surface tension and surface energy can create a phenomenon called ink
reticulation. This occurs when ink drops fail to merge to form a contiguous ink film. Instead, they join randomly and leave gaps before reaching the UV lamp, thereby leaving areas of the substrate’s surface visible, which makes the image look grainy and makes colors look dull. Scratching the three-dimensional ink drops on the media’s surface easily tears the drops free, so abrasion resistance is poor. Similarly if the media were required to stretch or shrink, then the reticulated or three-dimensional drops would easily pop off the media. However, the ink forms a thin, contiguous film where the ink wet-out is good. Colors look bright, abrasion and stretch resistance is good, and the smooth ink film looks glossy without varnish. Curing systems An adjustable or moveable UV-curing system is a necessity in roll-to-roll inkjet printing. The ability to change the position of the UV unit in relation to the printhead
Figure 1 Inadequate ink wet-out and adhesion are problems associated with printing ink that has high surface tension onto a substrate that has low surface energy.
34 | Industrial + Specialty Printing www.industrial-printing.net
array will allow you to print a wider variety of materials. Some materials, particularly absorbent ones, require you to have the UV lamp right behind the inkjet printhead to prevent ink drops from spreading too much or too quickly. Others may require more time for the ink to spread before it is cured. Changing the distance between the UV lamp and the printhead is an effective way to delay ink curing without compromising the speed at which materials are fed and printed (Figure 2). Modifying the position of the UV lamp, while keeping all other print parameters the same, also minimizes the variables in the printing process. Fine tuning UV-lamp placement is an important part of quality management. Producing a print on typically good material with high surface energy, but with one second of delay between the printhead and UV lamp, may yield barely acceptable results, while the same job printed and cured with two seconds of delay between the printhead and UV lamp may be perfect. Widening the gap further to create five seconds of delay is very likely to produce entirely unacceptable results. Ink reticulation, as described earlier, can also occur with a long delay in UV curing—even when using the best materials. There is a window in time for optimum results. Optimum cure-delay time actually changes with a material’s surface energy. For example, a substrate that has a low surface energy requires a longer cure delay. Remember that the force causing the ink drops to form a film on the substrate is the difference between the ink’s surface tension and the material’s surface energy. If the difference between these numbers is small, then the force is small and the ink takes longer to form a film. Many wide-format UV inkjet printers used to produce display graphics are engineered to cure inks 100-200 milliseconds after the inks are jetted (the UV lamps are fitted very close to the inkjet printheads). This extremely short span of time between printing and curing means the ink drops are still three dimensional on the material’s surface and do not have a chance to flow together. As a result, the underlying material is still visible between the drops. To get good ink coverage, the printer needs to increase the amount of ink used, perhaps by having the printhead make more passes over the media. Typical ink consumption per square
meter in a wide-format printer is two to three times that of a properly configured single-pass system. Single-pass inkjets that are designed to UV cure, or pin, each color before the next also consume more ink than necessary for the same reason. Print resolution Printed graphics can sometimes appear less appealing than expected, even when you’ve selected the right materials and inks, have the ink’s surface tension and material’s surface energy at optimum levels, and have the UV unit’s position set properly. The ability to modify print resolution via the software interface can remedy the problem.
Selecting the correct ink-drop size for the specific application is an effective way to maximize print quality. Using the largest ink drop possible is often recommended for label applications. For example, a 6-pl drop size might be required for the smallest two-dimensional barcodes, while a 14-pl drop size is acceptable for most traditional label graphics and for text down to 4 pt. There are two benefits of using slightly larger drops. First their extra mass means they can fly further through the air, which means the inkjet can be safely further away from materials that might flap and hit the printheads. Secondly, printheads that fire larger drops jet more ink per second, which means speeds
march/april 2011 | 35
Figure 2 (above) The ability to reposition a printer’s UV-curing assembly allows operators to adjust the time that elapses between printing and curing without modifying other print parameters. Figure 3 (right) This comparison shows the difference between using binary (top) and greyscale (botom) printing to produce an image.
can be higher. But even after the drop size has been selected, how it is to be used can have a big effect on print quality. In inkjet, grayscale printing means changing the amount of ink fired into each pixel, depending on image data. In theory, grayscale technology should be preferable to asymmetric resolution binary technology, but tests indicate this is not really true. In many cases, binary technology yields faster speeds, uses less ink, and delivers better printing results. However, the ability to select in software either binary or grayscale printing enables printers to accommodate all requirements for image resolution. Grayscale printing relies on image data to dictate the size of printed ink drops used in each pixel. Ink-drop sizes are variable, and in most inkjet systems, the final ink drop is created from a string of small drops jetted together. As its name suggests, a binary printer will either jet an ink drop of a particular size or none at all. Drop sizes are constant. Typically, in binary printing, we use only one ink drop per pixel, but we print at a higher resolution in dots per inch than with grayscale printing. Grayscale printing typically involves jetting drops of variable size at a lower resolution. To achieve good print quality, inks must spread evenly along two axes at once to form a continuous layer. Errors in ink-drop placement, even the smallest misalignment, will
cause an ink drop to spread to a neighboring drop out of sequence. The end result is reticulation. Binary printing is typically more regimented and less susceptible to problems created by errors in initial drop placement or local changes in ink-flow rate caused by variations in surface energy or defects in substrate surface or composition. The following is a test example for comparison. The test used the same material and ink, the same printhead (it produces a 6-pl drop), but different imaging resolutions. The first image was printed at 360 x 360 dpi in grayscale mode, which used up to 7 dpd— that is, up to seven sub-droplets for a total of 42 pl—to make up the final ink drop. The second image was printed at 360 x 1440 dpi in binary mode or one 6-pl drop per pixel. There might be little difference in print quality between these two modes on good material, but on poor material (maybe with low surface energy) the print quality differs notably (Figure 3). Binary printing at 360 x 1440 dpi is thought to win out because the ink drops land much closer together along the substrate than across it. The ink drops almost overlap along the substrate and join together quickly along the substrate to create parallel rows of ink. These rows then interlock, much like a zipper, to create a smooth and continuous ink film. In addition, the binary print is faster and can use less
36 | Industrial + Specialty Printing www.industrial-printing.net
ink. The printhead had to print seven drops of ink into a 360 x 360-dpi space in the first example (grayscale), but only four drops in the binary case. It therefore prints roughly 75% faster! The challenges ahead Single-pass inkjet printing—whether in a roll-to-roll format as highlighted here for labels and other flexible graphics applications or a flatbed configuration for plastics, glass, ceramics, and other rigid media—is a challenging proposition. However, advancements in printing technologies and related consumables are making this emerging technology an attractive reality for printers who wish to complement their conventional printing assets with solutions that can accommodate short and medium runs lengths effectively.
John Corrall
Industrial Inkjet Ltd. John Corrall is managing director of Industrial Inkjet Ltd. He has more than 20 years of experience in industrial inkjet technology, including product ,design, manufacturing, and technical support for Domino, Elmjet, Videojet, and Xaar.
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industry insider
Building a Technology Roadmap for Photovoltaics Stephan Raithel SEMI PV Group
The photovoltaics industry fared well in 2010 compared to other industries. However, looking forward, the solar industry may be faced with business cycles similar to those in the semiconductor industry. To get prepared for this boom-and-bust type of cycle, it’s important to engage in continuous pre-competitive discussions about critical issues and challenges in the manufacturing process. As Gerhard Rauter, COO of QCells, said recently, “The battle will be won on the manufacturing floor.” Searching for a common denominator like Moore’s Law in the semiconductor industry seems to have come to an end. It is not only the cost per Wp, but it will also become the cost per kWh where all of the important production parameters, such as as cost per piece, efficiency, and system costs, are included. The reduction of the cost per piece at increased efficiencies will be the main driver for the speed and importance of any future technology development. For the last 12 months or so, SEMI PV Group has been facilitating the early roadmapping steps initiated by the European special interest group for crystalline-cellmanufacturing technology (CTM). One of the group’s main goals is to establish an International Technology Roadmap for PV (ITRPV, www.itrpv.net) comparable to what was done in the semiconductor industry with the well-known ITRS. The first official publication was presented in March 2010 during PV Group’s annual PV Fab Managers Forum (www.pvgroup.org/pvvfmf), and the leading European solar cell manufacturers became SEMI PV Group members and the CTM efforts folded in. Additionally, various PV players from research and academia, equipment and material suppliers, wafer manufacturers, and cell and module manufacturers have
weighed in on the roadmap process, and now it’s time for an update. During this year’s Photovoltaic Fab Managers Forum (March 20-22, Berlin, Germany, www. pvgroup.org/pvfmf), the 2011 roadmap edition will be presented and discussed in detail during sessions about advance crystalline-cell technology and various manufacturing standards presentations. Ralf Lüdemann, SolarWorld Innovation’s managing director and chair of the CTM group, says that the global infrastructure of an association like SEMI PV Group is essential to reaching the goals we have in mind with this special-interest group. Lüdemann realizes the complexity of such a roadmap approach. To further increase the value and consistency of the ITRPV, everyone is constantly considering how to involve other industry stakeholders to provide input. Including the input of non-European PV players in the publication is a viable option. SEMI’s experience in coordinating technology developments on a global basis—SEMI Standards, for example—will certainly be of great help to achieve this goal. It is not easy to establish a truly accepted and global roadmap. One basic, but necessary, condition is to have the leading industry experts in the working groups. One of the chairs of the ITRPV roadmap group—Markus Fischer, director of R&D processes at Q-Cells Technology—has been involved in the road mapping process from the beginning. We started the discussions with just nine different cell-manufacturing companies a year and a half ago. In the last 12 months, we have had about 35 meetings, talks, and teleconferences with experts from all along the supply chain. The 2011 edition of the International Technology
38 | Industrial + Specialty Printing www.industrial-printing.net
Roadmap is written based on the input from approximately 40 companies and institutes. This is huge progress. There is a huge list of areas identified for potential standardization—for and from the industry. One of the upcoming tasks for SEMI PV Group is to bring together the roadmap experts with the professionals in the different standards committees and working groups. In addition to being presented at the next Fab Managers Forum in Berlin, the roadmap will be featured at Intersolar Europe (June 8-10, Munich, Germany, www. pvgroup.org/intersolareu) and SEMICON West and Intersolar North America (July 12-14, San Francisco, CA, www.semiconwest.org) in various formats. SEMI PV Group is partnering with Intersolar exclusively to focus on PV-manufacturing technology. This range of activities includes workshops and information sessions, executive conferences, networking events, and full exhibition areas. And for a last word to the PV-industry leaders, we invite you to join us. Let your voices be heard. Whether you join one of our standards committees, task forces, or special-interest groups, your input for roadmapping, standards, market data, and other valuable advice is needed. The only way to reach sustainable success for the global industry is to be open for pre-competitive collaboration.
Stephan Raithel SEMI PV Group
Stephan Raithel joined SEMI Europe in 2007 as operations manager in the Brussels Office. Starting December 2009, he has become the head of the European office in Berlin. Since January 2011, he also functions as director Photovoltaics Europe.
ADVERTISING INDEX
March/April 2011
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Nazdar
Franmar Chemical Inc.
IBC
Schober Technologies
7
Graphic Parts International
37
Specialty Graphic Imaging Assn.
25
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Hallmark Nameplate, Inc. location Mount
Dora, FL other info Hallmark Nameplate’s experience in engineering and design spans more than 50 years and thousands of custom-designed products for the medical, computer, telecommunications, OEM, and other industries. In addition to product-identification services, Hallmark Nameplate also offers complete electronic assembly. For more information, visit www.hallmarknameplate.com.
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The art and engineering department offers all the services to take all products from concept to completed product.
are measured on the Nameplate recently 5 Hallmark 3 Parts comparator, which allows for purchased new screen-printexact measurement of the final part down to 0.001 in. to ensure specifications are met.
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art department specializtwo digital presses, HallElectronic assemblies are 4 With 2 The es in process-color matching mark Nameplate has the abil- 6 tested to assure product and spot-color matching.
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inspects products 7 Hallmark multiple times before shipping them to customers.
40 | Industrial + Specialty Printing www.industrial-printing.net