Stress Singularity and Fracture Analyses in the FlipChip Assembly

• Main Authors: Ho-wei Hsu, 許鶴威
• Other Authors: Ching-Hwei Chue
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/42419115993005909654

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 92 === 　In this paper, we analyze the behavior of stress singularities and obtain numerically the stress intensity factors near the geometric and material discontinuities of the flip chip assembly. The governing factors that affect the failure probability include the material properties, geometry, and the applied thermal loads. All materials are assumed to be linear elastic, isotropic and temperature independent. 　In the stress singularity analyses, we only change the material properties and assembling angles of underfill. After employing the eigenfunction expansion method on the complex potential function, the singularity orders at the wedge or junction tips in the assembly are computed numerically. From the results, the conditions for weak singularities can be obtained. 　In the second part, we focus on the determination of the stress intensity factors at chip-solder joints interface and the global warping of the integrated structure. The parameters, such as chip and substrate thickness, chip overhang, solder joints pitch, solder joint geometry, stiffness and thermal expansion coefficient of substrate, are subjected to be changed. The results provide us useful guidance for design.