Failure Analysis of Foreign Materials in Electronic Packaging Assembly

Failure analysis on FM in electronic packaging assembly has always been a very challenging job. In this paper, various analysis methods including composition identification, configuration imaging and commonality study were applied to FM characterization. Several real cases were discussed in terms of FM sources. For instance, a short failure in flip chip package was found to be induced by Sn bridge along Si dust that contaminated bump array during wafer saw process; and a typical case of FM left by human contacting showed spots containing high C, O around Na, K, Cl crystals, with special FM location and pattern being observed