Failure analysis of the first wire’s bond

Wire bonding was an important process in electronics packaging technology. The bonding quality had a great influence on the performance of integrated circuit. In this paper, the first golden wire’s bond failure was analyzed in detail. It was found that the results of the destructive bond pull test were in accordance with the failure criteria specified in the MIL-STD-883G Method 2011.7 after 150 °C high temperature stability baking for 24 hours. But the first wire’s bond peeled between the bond and the pad interfaces when the circuits were in use. Material and structure of the pad were analyzed and the bonding parameters’ window was tested. The results showed that the thickness of the pad was three times as thick as conventional one, so the power used conventionally became the power limit for the circuit. This could not even be detected in the on-line bond pull testing. Finally, the defect was eliminated by adding golden ball peeling test and improving the bonding parameters. The bonding reliability was improved remarkably.