A synthetic criterion for level-1 crack-free package-proposal of a superior package structure

A synthetic criterion to provide guidance for the high-reliability structure design for the level-1 crack-free package is introduced. The criterion reflects a consideration of both delamination and package cracking. According to the criterion, to prevent delamination is the most effective means to realize the level-1 crack-free package for large chips (ex. 15 mm square). Therefore, a new package structure, a chip side support (CSS) structure which eliminates a die-pad is proposed and reliability tests are carried out. The CSS package realizes the level-1 crack-free package without moisture-proof packing.