Experimental Analysis for Bump Shear Method of BSOB Wire Bonding Process

The ball stitch on ball(BSOB) bonding mode is very common in wire bond, which greatly enhances the strength of the 2nd bonding and provides well support for the wire heel. The bump that is directly torn off by the wedge will leave a tail wire which will reduce the bonding strength. Seriously, it will lead to bonding failure or flying wire. Therefore, the wire tearing off method of bump needs to be improved. There are four bump shear methods: (a) horizontal bump shear; (b) horizontal reverse bump shear; (c) horizontal reciprocating bump shear; (d) diagonal bump shear. This paper gets well consistency bumps through the parameter optimization test of different shear modes about 25um gold wire bonding. Secondly, the paper analyzes the bond strength about four bump shear modes combining the relevant parameters obtained from the above experiments.