Ultrasonic Evaluation of Wire Bonded Areas in Semiconductor Devices

Abstract

In this study, a ultrasonic evaluation was performed on the bonded areas in the semiconductor devices. The capillary or bonding tool fixed with epoxy resin holder was used for the transmission of ultrasound from the probe to wire bonded area and for the reception of reflected wave from bonded area. The ball shear test and EPMA analysis were also carried out for the evaluation of strength and wire boded area.
The comparison between the ultrasonic test and shear test showed that the amplitude change from the wire bonded area is related with the very short time range and is small. The wave analyses of reflected wave proposed a available parameter for the nondestructive evaluation of wire bonded area, which showed good relation with the shear strength. It was also shown that this parameter depends upon the length of epoxy resin holder and was deeply related to the transmission of the ultrasound from capillary to holder in the measurement.