FlexTech Alliance hosted a workshop focused on ink and substrate interactions on August 1-2, 2012 at Western Michigan University’s Center for the Advancement of Printed Electronics. The workshop examined the unique challenges of printing electronics on paper, plastic, glass, textiles, foil and other substrates. Perspectives from material suppliers, equipment manufacturers, and university research labs were presented.
“One of the most critical issues facing printed electronics is the interaction of ink and flexible substrates,” stated Dr. Malcolm J. Thompson, Chief Technical Advisor to FlexTech Alliance. “Understanding these interactions is key to resolving performance challenges and providing the low-cost, conformable products made possible with printed electronics.”
Dr. Margaret Joyce from Western Michigan’s Center for the Advancement of Printed Electronics (CAPE) launched the morning’s session with a discussion of coated paper technologies for printed electronic applications. Technical reviews followed from Corning and DuPont Teijin Films about manufacturing on glass and plastic substrates respectively. The presentations gave detailed accounts of fabrication process advancements, case studies of devices designed and fabricated for specific application needs, and new applications and processes under development to take advantage of the unique properties of paper, glass and plastic. Several process challenges were examined including surface smoothness, solvent resistance and commercial availability of the substrate materials.
Experts from the University of Texas at Dallas and Arizona State University discussed the challenges of printing electronics on textiles with flexible CMOS, CBD CdS, and TFT processes. That was followed by a presentation by Dr. Nackbong Choi, Lehigh University, on flexible, printable electronics on metal foil substrates with offset roll printing technology. Several advantages were reviewed, including low CTE, high process temperature, strong resistance to chemicals, impermeability, and heat sink.
The afternoon session reported on current manufacturing capabilities and trends. Kevin Manes of Mark Andy began with a practical, hands-on discussion of current roll-to-roll printing equipment and the intricacies of the process tools. Next, Tim Luong of FUJIFILM Dimatix examined in detail inkjet printhead deposition technology. Bob Praino of Chasm Technologies delivered a tutorial on the printing and coating ecosystem with a special emphasis on the rheology and drying of the inks and their importance on the overall success of the process.
The workshop concluded with presentations focused on printing devices: Dania Alsaid of CAPE (capacitors), UC Berkeley (high performance printed transistors), PARC (printed field-effect transistors) and HP (paper-based devices, sensors and MEMS). Workshop participants agreed that to ensure progress continues the industry should leverage design flows of conventional printing, incorporate multi-layer processes, deliver high quality patterns and uniformity, and evolve EDA tools.