Session 22: Direct Write
Breakthrough dielectric and conductive materials combinations for inkjet-printed multi-layer circuits
Thursday, June 22, 2017
11:00 AM - 11:20 AM
Despite decade-old industry forecasts, directly printing multi-layer structures of conductive and dielectric inks has been a challenge until very recently. Conductive inks that can be applied reliably, sinter at temperatures compatible with polymer substrates and exhibit sufficient conductivity have developed to a point where they are fit for many applications. Similarly, inks of polyimide, acrylates and epoxies are applied in numerous applications. However, the combination of inkjet printed conductive and dielectric materials has suffered from incompatible material properties. One can think of different shrinkage rates during processing of the materials, incompatible sintering and curing requirements, adhesion issues and even chemically incompatibilities between the two material sets.
By doing extensive research into the properties of the both material categories, trying many combinations of (commercially available) materials, analysing the results and possible failure modes, and by working together with material suppliers, we have identified combinations of dielectric and conductive inks that perform well enough to enable a variety of printed circuit applications. In this paper we will present an overview of the issue we have overcome, will quantify the results of the work and show-case various circuits produced thus far.