| Summary: | 碩士 === 國立清華大學 === 動力機械工程學系 === 101 === With regards to the multi-layer structure such as solar cell chip module and insulated gate bipolar transistor (IGBT) power module, it is an important issue to estimate its reliability effectively, and apply to the development of actual production. Compare to the traditional accelerated failure experiment, using simulation analysis in research shall save a lot of time and outlay, and the physical behavior of the structure under periodical loading shall be understood. The methodology is progressively, widely used in recent years. However, the life-estimating model should be proposed according to the result of simulation and the verification of applicable experiment. A 3-D finite element model (FEM)was established based on test samples i.e. High Concentrated Photovoltaic (HCPV) module, in this study. The model was subjected to thermal cycling test to analyze the mechanical behavior of solder, and the life prediction model was further validated by the experiment from the literature.
First, the transient heat transfer analysis of HCPV module was conducted, and the result was compared to the temperature distribution of the experiment in order to verify the rationality of the FE model. Then the thermal-mechanical analysis of HCPV was performed, and the results reveal that the stress levels at the solder expect for the boundary is very low. Another model was established from the literature to analyze the stress/strain distribution, and the tendency resembles to the prior one. The maximum equivalent strain could be substituted into life prediction model to afford the prediction life, which is smaller than the experimental value. It is inferred that the uniformity of solder thickness will cause larger strain, so the predicted lifetime is smaller than the experiment.
The crack front could be estimated by the distribution of the equivalent plastic strain of the solder, then the loading and forced convective condition was given to observe the affection of the delaminating area on the temperature distribution of the whole packaging. The analytical result points out that when the delaminating occurs, the property of conduction will be affected, and the temperature of the whole packaging rises.
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