Thermal management and design aspects of high performance plastic quad flat packages for smart-power ICs

This paper investigates the influence of the design and physical limitations on the performance of thin quad flat packages (TQFIPs). In particular, the evaluation and implementation methodology for low profile 48-lead TQFPs is outlined. A 3-D finite element scheme to simulate the thermal effects of different design configurations and material properties has been developed. Thermal design guidelines which provide quantitative understanding for package thermal management will be summarized. Also, this paper highlights the qualification test results which have proven that this package has an excellent reliability performance when compared to the current industry standards. An improvement by a factor of 6 in die attach shear strength has been achieved. In addition, C-SAM analysis of parts exposed to pre-conditioning and HAST tests revealed that these new packages have very high cracking and moisture penetration resistance characteristics.