Influence of Stress-free Temperature and Model Simplification in Life Evaluation of CCGA Packages

Finite element analysis can be used to evaluate the thermal cycle fatigue life of ceramic column grid array (CCGA) packages, there are different opinions on the value of stress-free temperature and model simplification methods in relevant researches at home and abroad. Finite element analysis and Darveaux model are used to calculate the thermal cycle fatigue life of chosen CCGA package with different stress-free temperature and model simplification methods. The results show that the difference in the fatigue life calculation results is less than 0.1% when stress-free temperature equal to room temperature and the maximum temperature in thermal cycle test. Thermal cycle fatigue life is slightly underestimated when stress-free temperature equal to solder solidification temperature. Similar fatigue life calculation results can be obtained by omitting plating and copper foil, omitting part of printed circuit board, slice model and sub-model. The slice model performs best in reducing the amount of computer calculation. The number of model grid elements is reduced by 95% using slice model compared with initial model, and the deviation of the fatigue life calculation result is less than 10%. © 2024 Chinese Mechanical Engineering Society. All rights reserved.