Lead Bonding Techniques and Physics of Failure Considerations

The areas in which perhaps most is at stake concerning economy and reliability of semiconductor components is that of attaching devices and integrated circuits into packages. The most common situation involves a single component, per package, although multi-component encapsulation and hybrid integrated circuits represent rapidly growing fields. A great many bonding techniques and geometries have evolved and are in use today--thermocompression and ultrasonic wire bonding (wedge and ball), welding, soldering, eutectic brazing, organic adhesion, flip chip bonding (solder and ultrasonic), beam lead, and spider. From the standpoint of reliability physics, the number of problems inherent in this multiplicity of bonding techniques is considerably expanded by the number of materials commonly utilized with each technique, and by the variety of package environments that are in use. All of this is further modified by the controls exercised on bonding and packaging during manufacture.