Low Temperature Curable Low Dk & Df Polyimide for Redistribution Layer

Abstract

In this paper, we report low temperature curable (around 200～250℃), low Dk (2.7) and low Df (0.007) negative tone type photo-definable polyimides. Those materials, which were in states of liquid or B-stage sheet, were able to be patterned by photolithography process. Our novel polyimides showed excellent dielectric and mechanical properties, and good results on reliability tests. Our developed polyimides kept enough insulating performance after a biased HAST (High Accelerated Stress Test). Finally, in collaboration with IME, a test package which mounted our novel polyimide as redistribution layers was fabricated.