Thermal performance of tape based ball grid array over molded packages

A near chip scale package based on area array technology with a tape interposer is thermally evaluated using both computer models and measurement techniques. The package is described and compared to the thermal performance of QFPs with comparable physical dimensions. The thermal performance of the package has been found to be highly dependent upon the arrangement of the solder balls on the interposer and on the die size. The impact of thermal solder balls and underfill is investigated, the contribution of a heat spreader is described, and thermal variation with material composition is studied.