Towards Low Cost High Density Bumping

Abstract

A chemical batch bumping method is suggested both for Flip-Chip and TAB (tape automated bonding) appli- cations Several suggestions from earlier studies by other authors are referred and commented. Experiments with a selective Ni/Au bump structure have been carried out in a prototype processing line. The initial results confirm that this method has low capital, material and labor cost As no die specific tooling is required the process will have fast tum-around time and potential even for low vol- ume low cost wafer bumping, as well as for mass production.