Thermal stress analysis of tape automated bonding packages and interconnections

A study of the stresses and strains in tape-automated-bonding (TAB) assemblies using a nonlinear three-dimensional finite-element method is discussed. Emphasis is placed on the thermomechanical behavior of TAB assembly beam leads, polyimide rings, gold bumps, silicon chips, and solder joints. It is found that the TAB beam leads are more likely to fail than the solder joints in conventional surface-mount-technology packages. Furthermore, the analytical results agree with the observed failure mechanisms of the beam leads. The results should be useful in understanding and designing more reliable advanced surface mount assemblies.<>