Thermal enhancement and reliability of 40 mm EPBGA packages with interface materials

Increasing power requirements for Plastic Ball Grid Array (PBGA) packages demand better thermal management for increased performance and reliability. One of the important parameters that affect the rate of thermal dissipation is the thermal resistance between the package surface and the heat sink. An Enhanced PBGA package of 40 mm /spl times/40 mm body size with an Intricast plate fin heat sink was used to evaluate commercially available interface materials. Junction-to-ambient resistance of the package and the base temperature at the center of the heat sink was measured with respect to air velocity. Thermal cycling was carried out to determine the long term effects on the the thermal performance. In addition to experiments, a computational model was also used. Relative performance of interface materials was determined.