Thin PoP: Warpage Control for Thinner PoP Package in Mobile Applications

Abstract

In order to significantly improve warpage of a PoP bottom package, Shinko developed an enhanced PoP structure. The inclusion of a support material attached to the backside of the flip chip die and over molded resin is the structure's key attribute. By adjusting the balance of each material (mold resin, substrate and support material thickness), we can better control warpage at both room temperature and reflow temperature. This enhanced thin PoP structure can be easily incorporated into a standard assembly process with existing equipment sets. This paper describes simulation results, along with measured warpage characteristics of the new package.