Thermal management of heat spreader materials for flip chip type package

The heat spreader for the organic package in a flip chip assembly was investigated. The thermal management analysis, which is based on thermal simulation techniques and an experimental database, was applied to find suitable materials for the heat spreader. We successfully accomplished the simulation technique for the thermal management, which is consistent with the experimental results. We revealed that the critical stress in the die attach resin should be less than 2 kgf/mm/sup 2/ through this technique. We also revealed that the CTE of the heat spreader material should range from 8 to 16 ppm/K. This value of CTE supports the proposal that sintered Al-SiC is suitable as a heat spreader material for an organic package with flip chip assembly. Furthermore, the adhesive strength of Al-SiC with the resin is strong enough to be used as the heat spreader material.