Die Bond Failure Modes

Die bond failures are of particular concern because of their impact on the stability of device electrical performance over a period of time in use, during which the device may be subjected to elevated temperatures, thermal cycling, and hostile ambients. The ultimate failure of a die bond comes when the device fails either to block voltage, or to conduct current because either the semiconducting element has cracked, or the solder bond has ruptured. Earlier, before such catastrophic happenings, it is possible to find indications of trouble in developing trends toward increased junction leakage currents, or decreased power handling capability when heat can no longer be dissipated fast ecx nough to dat nough to prevent the device from going into secondary breakdown.