关键词: 高密度封装, 翘曲, 收缩

Abstract: With the improvement of semiconductor package density, single-sided packages such as FBGA are widely used. In these packages, warpage is easy to occur due to their asymmetric structures, and the substrate of large-area package is thinner and thinner, so the requirement to reduce warpage is higher and higher. In order to reduce the warpage of single-sided package, it has been reported that it is effective to reduce the molding shrinkage rate by increasing the glass transition temperature (T_g) and reducing the linear expansion coefficient of package materials. However, it is difficult to maintain the high flowability of epoxy molding compound (EMC) and significantly reduce molding shrinkage rate. The curing shrinkage rate is introduced into the thermal viscoelasticity analysis technology, the mechanism of ball grid array (BGA) package warpage is clarified, and the EMC with low viscosity, high flowability and low warpage is designed by reducing the high temperature flexural modulus.

Key words: high-density package, warpage, shrinkage