| Summary: | 碩士 === 國立中正大學 === 機械工程研究所 === 86 === The thermal failure of a Plastic Quad Flat Package (PQEP) could depend on a number of parameters that related to material, configuration, and manufacturing. One of the main factor led to failure is the coefficient of thermal expansion (CTE) mismatch between two levels of packageing which will cause notably shear stresses in their interconnections. Therefore, it is important to establish the experimental method to examine the thermal strain distribution inside packaging. It is also important to develop numerial analysis model to predict the thermal strain and stress during the structure change of the packaging. The aim of this research is to develop the research is to develop the experimental methods and computational models that can be use as design tools to study the thermal deformation of a PQEP. In this research, a whole field optical testing method Moire'' Interferometry were applied first to detect thermal strain within the packages cut plane with high sensitivity 2400 lines / mm and the effects of temperature change in the range from 80 up to 120 degree ℃. Full field strain maps were measured and the effective CTE properties of the materials used in PQFP can also be obtained from the thermal detormations. Next, a three dimension finite element model of PQFP was built and analyzed with the material constitutive law and the CTE properties of the materials used in PQFP can also be obtained from the thermal deformations. Next, a three dimension finite element model of PQFP was built and analyzed with the material constitutive law and the CTE values found by Moire''. The thermal deformation predict by this hybrid FE model was re - compared with Moire'' testing data validate the accuracy of the FE model. Once the FE Model that compare well with Moire'' testing data then it can be used for further structural modification studies.
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