The effect of mold compounds on warpage in LOC package

This paper describes a warpage study on LOC-TSOP memory devices. The main objectives of this study are to evaluate the impact of the mold compound on the package warpage with different sized dies. It was found that the balance of the bending between at the edge side region and at the die attach region controls the package warpage. The package tends to bend convex upward at the edge side region and concave downward at the die attach region. The various mold compounds were prepared to study the effect of the components, particularly resin and filler. It has shown that the optimum mold compound can be changed according to the inner structure of the LOC-TSOP. The effect of post mold cure on package warpage was also examined based on the cure rate.