Study On Related Technology Of Reliability Growth Of Infrared Detector Assembly

Infrared detector assembly is the core component of infrared imaging system. It’s performance and reliability plays a decisive role in the whole system. With the further application of the infrared technology and the increase of the assembly dimension the user put forward higher requirements on the reliability and life of the infrared detector. The reliability problem has become one of the key factors to promote the application of the infrared assembly deeper and wider. The area of this paper focuses on the reliability of the infrared assembly including mainly thermal stress and it’s effects on the photoelectric properties of components, the optimization design of thermal stress, reliability design of packaging, the key technology of reliability such as selective remelting of the indium bump and low temperature deformation test technology, the numerical method of the measurement of the cold loss, the reliability of the test process of the assembly etc. The goal is to realize the reliability growth of infrared detector assembly finally.Reliability is a systemic problem, in general each process of the whole life cycle of the product including the principle of mechanism, design, process, testing, application, etc. will have an impact on the reliability of the product. The research method of this paper is guided by the systematic principle.Starting from the common failure mode and failure mechanism of infrared component the failure mechanism of the component under thermal stress has been studied. Based on this the package structure has further optimized by the method of FEM and experimental verification and a new package structure, the space limit namely, has been put forward. The structure breaks through the contradiction between thermology and mechanics in the Dewar design. The reliability design of infrared detector has been realized.In the respect of technics a deep study has been carried on such as the realization of the space limit structure, the selective remelting of indium bump and the measurement of low temperature deformation. The space limit structure has been realized innovatively. Induction heating method not only remelts the indium bump but also avoids the high temperature process. a non-contact measurement method of The low temperature deformation has been presented. The error analysis of this method is also discussed. All these make the experimental verification of packaging design possible.To overcome the difficulty of the online measurement of dewar cold loss by use of traditional method this paper study the online-geeting temperature curve fitting of the cold head based on the properly simplifying of the heat environment of dewar. A cold loss to temperature cure is got by fitting.The assembly reliability test is an indispensable link of the production process, the reliability of the test process is related to the success of the product. so the large scale reliability test which is aging test of the infrared component is studied which guaranteed the reliability of the test.So, this paper studies respectively the mechanism, design, process, testing, inspection etc finally achieving the reliability growth of the infrared detector products.