Development of Positive Working Photosensitive Polyimide Coatings for Semiconductor Packages

Abstract

This paper describes an approach to develop a positive working photosensitive polyimide coating (positive-PSPI) for semiconductor packages. We designed a new polyimide back-bone for positive-PSPI from a point of solubility, adhesion to molding compound and copper migration. In addition, we found effective adhesion improvers for Cu. From these experimental results, we succeed to develop new positive-PSPI coatings which are suitable for wafer level chip size packaging, bumping protection, as well as buffer coating.