Realization of Ultra Fine Pitch Traces on LCP Substrates

Abstract

Liquid crystal polymer (LCP) is being utilized in a variety of applications that could benefit from the realization of ultra fine pitch conductive traces on the surface of the LCP substrate. LCP has unique chemical properties that not only benefit the intended application, but can also be exploited to realize ultra fine pitch traces. Through a series of experiments, it was discovered that a thin film of Ti can form TiC with the surface of an Ar ion ablated LCP substrate. This layer then provides sufficient adhesion for other metals to be deposited so that ultra fine pitch traces can be patterned. Using this process, 10 mum wide traces on a 20 mum pitch with high yield were demonstrated and analyzed. Smaller feature size test structures were also demonstrated.