Static Protection Design for Printed Electronics

Presented by Kelly Robinson, Electrostatic Answers LLC

Electrostatic Discharges (ESD) or sparks can damage electronic devices. An energetic spark can cause thermal damage (burn components). And, the current surge from the spark can damage conductive traces and cause momentary high voltages that damage insulating layers. Static control for traditional semiconductor fabs is well developed. The Electrostatic Discharge Association (ESDA) is a professional organization dedicated to static control for electronic manufacturing and devices. Printed electronics introduces exciting new manufacturing methods, capabilities, and challenges. One challenge is that electrostatic charges on insulating webs can cause highly energetic sparks. I briefly review best-practice static control for printed electronic manufacturing lines. In addition, the printed devices should be designed to minimize static problems. For example, designs should include grounding busses along the edges of web so that printed patterns have continuous contacts with grounded metal idler rollers. These grounding busses may in edge-trim areas on the web that are removed before final inspection and assemble. Special attention is also needed at splices between rolls to ensure that the trailing edge of the expired roll remains well grounded knowing that the splice prevents electrical contact between the tail of the expired roll and the leading edge of the new roll.