Practical Application of Liquid Compression Mold Underfill

Abstract

In recent years, the technical advancement of semiconductor packages has driven a shift to larger die sizes and narrower bump pitches for high performance. The challenge is to develop both encapsulation materials and encapsulation processes suitable for such complicated semiconductor packages for higher performance.

In this study, we developed a Liquid Compression Mold Underfill (LCMUF) which can simultaneously fill and encapsulate the gap between an interposer and chips, as well as the peripheral parts of the chips, in a single step using compression molding equipment. Our LCMUF is well balanced between warpage reduction and high flowability thanks to the design optimization of resin and filler. As a result, we have been able to commercialize our LCMUF for mass production.