FlexTech Alliance, Cal Poly Complete Screen Printing Study for Printed Electronics Applications

FlexTech Alliance announced the completion of a one year, $40,000 study to explore the capabilities of screen printing electronics with the Graphic Communication Department at the California Polytechnic State University at San Luis Obispo (Cal Poly). The partnership, which was launched in late 2012, investigated low viscosity inks to produce thin ink films and fine features with the intent to help the printing industry better understand and adopt printed electronics technologies.

The study, which was titled “Characterizations of Screen Printing Low Viscosity Ink, Thin Film and Small Features for Printed Electronics Applications,” explored the capabilities of screen printing in producing fine features (30 microns or less), and thin ink films (a few microns to submicron), all while using inks having much lower viscosity (a few thousands to a few hundreds centipoises) than typical screen printing inks. This study also investigated the impact of mesh technologies, ink rheology, and printing conditions on feature quality measured in width, thickness and electrical resistance.

“Screen printing is a widely used process for the electronics industry. If screen printing can produce finer features and utilize thinner ink films, it will help the industry replace more expensive processes and expand existing screen printing lines for new printed electronics products. We support Cal Poly’s efforts to dive in and explore the available options for the electronics industry,” said Michael Ciesinski, CEO of FlexTech Alliance.

The project provided systematical analysis of the impacts of printing and material characteristics to print quality while screen printing fine features. The results of the study concluded that ink rheological properties play a significant role in printing fine features. And, while substrates and printing conditions had an impact on printing fine features, their bearing was not nearly as substantial as ink rheological properties. Under the optimized conditions, screen printing can print fine features around 40 microns. However, the study did conclude that it is difficult to print fine features with low viscosity inks.

The project team included Drs. Xiaoying Rong and Malcom Keif in the Graphic Communication Department Cal Poly State University at San Luis Obispo.

“With optimized printing parameters, fine features can be screen printed with commercially available inks, mesh, and emulsion. The conclusions of this study support screen printing as a cost-effective production method that can simplify the fabrication processes while utilizing existing technology and equipment to serve the printed electronics industry,” added Dr. Rong.