Modified single cantilever adhesion test for EMC/PSR interface in thin semiconductor packages

We propose and implement an adhesion test configuration called “modified single cantilever adhesion test” (M-SCAT) that can be employed to determine the adhesion strength of epoxy molding compound (EMC) and photo solder resist (PSR) interface in thin semiconductor packages. The proposed M-SCAT method is optimal for quick and quantitative in-situ testing of the interface with strong adhesion as sample preparation and testing are simple while maintaining a low mode mixity at the crack tip. Detailed sample preparation and experimental testing to determine the critical load required for delamination are presented. A numerical procedure is followed to assess the stress and strain fields around the crack tip at the point of delamination, thus allowing for the J-integral method to be employed to determine the critical energy release rate. The proposed approach is carried out for two different EMC/PSR interfaces. The results show excellent repeatability, which allows for the test method to be used effectively to select the most ideal material set for given applications.