Summary: | 碩士 === 義守大學 === 機械與自動化工程學系碩士班 === 94 === Due to huge demand for optical mouse, digital cameras, photo-mobile phones, web-cam and optoelectronic devices in home entertainment in recent years, the production and packaging techniques for CMOS image sensor (CIS) have been rapidly developed and improved. The CIS will gradually become main product to take over CCD camera for its low price and high performance.
The reliability and thermal design for CMOS image sensor has been fully studied in this paper. It has been found that uv glue and solder paste are much easiest to failure in thermal fatigue for CIS structure. Therefore, it would be an important issue to choose suitable materials for CIS package. The thermal and moisture-absorption characteristic of uv glue and molding compound (Dam) for CIS have been studied in this paper. In addition, the predicted thermal fatigue life for different series of lead-free SnAgCu solder paste has been conducted in this research.
Because the coefficient of thermal expansion (CTE) of the air is much greater than other materials and the rate of absorbed moisture is faster than other polymer materials, it is important to develop an effective moisture-resistant mechanism for CIS package, which has been carefully studied in this paper.
A three-dimensional solid model of CMOS image sensor based on finite element ANSYS software is developed to predict the thermal-induced strain, stress distributions, and the hygroscopic swelling strain. The predicted thermal-induced displacements were found to be excellent agreement with the Moir? Interferometry experimental in-plane deformation. In this paper, the application of sub-model scheme in thermal cycle test prediction was also studied for its efficiency and interesting in recent years.
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