Thermal and Warpage Analysis of IC Packages

• Main Authors: Chih-Wei Cheng, 鄭世偉
• Other Authors: Chia-Lung Chang
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/75243117341647603561

碩士 === 國立雲林科技大學 === 機械工程技術研究所 === 87 === In this study, the thermal performance and warpage of IC packages are studied by finite element method(FEM). Both the thermally enhanced PQFP and high power dissipation PBGA are studied. The temperature distribution of both PQFP and PBGA under nominal power dissipation is predicted by FEM. Then the thermal resistance is calculated by the maximum junction temperature. The simulated thermal resistance is verified by experimental measurement to check the validity of the simulation. The effects of design parameters on the thermal resistance are based on the verified model of packages. The results show that there are two important factors of the thermal performance. One is heat transfer path, the other is the conduction coefficients of the heat dissipation mechanism. An equation for thermal resistance of important parameters of heat spreader is formulated by linear regression, it provides a useful reference for thermal design. The warpage of PQFP is studied by experimental measurement. The results show that the lowest location is not always near the center of the packages, the warpage profile of package with heat spreader is more complicated, also the warpage of package without heat spreader is improved after post mold curing. Compared with the simulation results, the warpage trend of both results is similar, but the warpage magnitudes at different locations are not matched so well. The reason may be the major concern of the simulation is temperature change during the molding, non-uniform temperature distribution inside the package, and real material properties of components during temperature change are not taken into consideration in the simulation.