Flip-chip solder joint interconnections and encapsulants in silicon-on-silicon MCM technology: thermally induced stresses and mechanical reliability

The results of theoretical and experimental investigation of the thermally induced stresses in, and mechanical reliability of, flip chip solder joint interconnections used in Si-on-Si MCM designs are presented. The mechanical behavior of encapsulants in such interconnections and their effect on the stresses in solder joints are also briefly discussed. It is concluded that matched thermal expansion between the chip and the substrate leads to a more reliable interconnection. However, application of thermally matched materials should not be regarded as a panacea which puts right all the mechanical troubles