In situ ball bond shear measurement using wire bonder bond head

Abstract

A novel ball bond quality evaluation method is reported using bond head motion to shear the ball bond with the capillary directly after bonding. The bond head motor controller's force signal is used to obtain a value that correlates to the ball bond's shear force as measured on conventional shear test equipment. This new method performs well over a wide range of bonding conditions when using a shear speed of 100 /spl mu/m/ms and a normal force of 50 mN during shearing. For a 60 /spl mu/m ball pitch process bonded at ambient temperature, the correlation coefficient is greater than 0.95. Post-bond heating and its effect on this method have also been investigated.