| Summary: | 碩士 === 中華大學 === 機械與航太工程研究所 === 94 === Nonlinear finite element method was employed in the study to analyze the deformation and stress distribution of a new type of flexible flip chip packages under service conditions. Four procedures were simulated in the finite element analysis. Firstly, the package was attached on a surface by a rigid concave mask with a curvature radius of 30 mm. Secondly, the contact condition of the upper surface was relieved to simulate the removing of the compressive force. Thirdly, the temperature of environment was cooled down to -55℃. Finally, the temperature of environment was raised to 125℃. Three different materials of the bump core were considered in the numerical analysis to study the material effect on the stress behavior. Furthermore, the D. O. E. method were used to study the influence of the bump polymer core width, the bump sidewall thickness and the bump core material on the stress distribution. The analysis results show that higher Young’s modulus will induce the lower stress during the step 1 and 2, but higher Young’s modulus and lower CTE will induce higher stress level during TCT (Thermal cycle test) process.
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