Novel interconnection processes for low cost PEN/PET substrates

Recently a new class of flexible electronics is starting to emerge which is most effectively termed dasiaprinted electronicspsila. This term often refers to all-printed, cost effective, smart electronic products that will find a wide range of applications in large quantities in our society. The substrate material for these applications will be low cost materials like PEN or PET. Because of their lower thermal stability, novel interconnection technologies need to be developed. The current paper describes research into two of these interconnection technologies. The first one is dasiaembedded circuitrypsila. It will be shown that with this low cost technology it is possible to make conducting lines with widths down to 10 mum in foil and specific resistances down to 3.10^-7 Omega.m based on conductive pastes. The second topic is about filling of through-vias for the purpose of front-to-backside electrical contacting. Both inkjet printing and a combination of stencil and screen printing were investigated. The best results were obtained using a combination of stencil and screen printing. Through-vias with a diameter of 100 and 200 mum could be filled with a high yield, a good resistance and good mechanical and thermal stability.