文章基本信息

标题：Analysis of Die Tilt Effect on the Stress Distribution in a Small Outline Transistor Using Finite Element Method
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作者：Jennifer J. Fabular ; Hannah Erika R. Ducusin ; Manolo G. Mena 等
期刊名称：Lecture Notes in Engineering and Computer Science
印刷版ISSN：2078-0958
电子版ISSN：2078-0966
出版年度：2018
卷号：2235&2236
页码：662-666
出版社：Newswood and International Association of Engineers
摘要：The increasing demand for miniaturization and high function integration in today’s microelectronic industry poses a big challenge in maintaining the reliability of the package. Majority of the reliability problems can be attributed to thermal and mechanical loadings during manufacturing and assembly process. One of the most common defects originating from these processes is die tilting. In this study, the behavior of a Small Outline Transistor (SOT) when exposed to thermal loads was analyzed using finite element method. This work also investigated the effect of varying solder tilt angle configurations on the stresses experienced by the package. A 5-layer, multimaterial, non-symmetric SOT package was modeled in detail to determine the interlayer stresses caused upon by the CTE mismatched between each material. Three different tilt angle configurations for both upper and bottom solder were simulated using ANSYS software. The 3D model of the package was exposed to temperature load of 370˚C and cooled down to room temperature. Material modeling and mesh sensitivity analysis were also conducted in this research to determine the most appropriate material type and mesh density to be used for the simulation. The maximum principal stress distribution, taken after the cooling stage of die bonding process, was used as a criterion to determine the location of the maximum stress on the silicon die. Results from the simulation have shown that the maximum principal stress distribution shifted to the area of thinner solder as the tilt angle is increased. The results holds true for both upper and bottom solder tilting. In addition, the results show that the magnitude of the stresses in the area where the solder becomes the thinnest also increases. This study presents a clear relationship between the thermo-mechanical response of the silicon die and changing die tilt angles. These observations can be helpful in detecting and locating the possible site of failure and can be used to develop more reliable microelectronic packages.
关键词：ANSYS; Die Tilt; Small Outline Transistor;; Thermo-mechanical