A Performance & Manufacturability Evaluation of Bump Chip Carrier Packages

Abstract

Bump Chip Carrier® (BCC) is an attractive solution to the demand of high packaging density of low I/O-count packages. It offers low cost, high performance, and much smaller package size than Quad Flat Packages (QFP). Electrically, BCC offers significant performance advantage as a function of frequency. It also has customizable configurations. In this paper, an extensive finite element thermomechanical analysis has been conducted to evaluate the reliability of BCC packages during thermal cycling. The effect of a variety of parameters on package reliability was evaluated, including board thickness, package size mold material, solder paste thickness, and terminal height. The solder reliability of corner leads vs. inner leads, as well as square leads vs. rectangular leads was also investigated. Then some manufacturing issues were studied. During manufacturing, molded panels for BCC packages are undergoing significant warpage. Two types of mold designs were compared through 3D finite element analysis. A variety of mold compound materials were evaluated. The most effective way to reduce warpage was suggested.