毕业论文移动版

摘要PLCC焊点尺寸用有限元方法进行优化仿真。随着电子行业的快速发展，也让我们更加注意到焊点的可靠性能。研究表明，最大的应力汇集在焊点的角上，有可能会是焊点裂纹的初始。这篇论文利用ANSYS对模型进行分析,利用ANSYS强大的功能建模。通过改变焊点高度和焊点和基板相交处的直径，还有改变基板的高度然后对焊点可靠性分析。采用二维模型对焊点进行力学性能分析，最终能找到芯片模块产生焊点最容易发生裂纹的部位。当温度有规律的变化的时候，焊点应力分布随之发生改变。在电子封装中，热负载会使焊点可靠性发生变化，所以目前的封装它已经成为最热门的话题和最值得讨论的问题。由于焊点太小，在任何时候找到焊点的应变都很难。通过使用有限元法，在各种负载条件下的焊点的应力和应变分布可以充分表达，并详细描述了焊点的分布。其中最有效的方法是有限元分析方法，通过不间断的实验证实，在电子封装的有限元法具有较高的效果，从而提供了理论基础，以提高设备的可靠性和优化。81058

论文有图25幅，表3个，参考文献40篇。

毕业论文关键词：电子封装  有限元分析   焊点可靠性

Optimization design of lead free solder joint size for PLCC device

Abstract Finite element method for PLCC solder joint size optimization and simulation。 With the rapid development of the electronics industry, it also allows us to pay more attention to the reliability of solder joints。 The study shows that the maximum stress is gathered in the corner of the solder joint, and it is likely to be the initial crack of the solder joint。 This paper uses ANSYS to analyze the model, using the powerful function of ANSYS modeling。 By changing the solder joint height and the diameter of the solder joint and the base plate, the height of the base plate is changed and the reliability of the solder joint is analyzed。 Using two dimensional model to analyze the mechanical properties of the solder joint, the chip module can be found to be the most prone to crack。 When the temperature changes regularly, the stress distribution of the solder joint is changed。 In electronic packaging, thermal load will make the solder joint reliability change, so the current package it has become the most popular topic and the most worthy of discussion。 As the solder joints are too small, it is difficult to find the strain of the solder joints at any time。 By using the finite element method, the stress and strain distribution of the solder joints under various loading conditions can be fully expressed, and the distribution of the solder joints is described in detail。 The most effective method is finite element analysis method, confirmed by the uninterrupted experiment, in electronic packaging of the finite element method has a higher effect, thus providing theoretical basis, in order to improve the reliability and optimization of equipment。

Key Words: Electronic packaging  Finite element analysis  Solder joint reliability

目  录

摘要 Ⅰ

Abstract Ⅱ

图清单 V

表清单 V

变量注释表 VI

1绪论 1

1。1 前言 1

1。2 电子封装简介 1

1。3 电子封装的发展历程与趋势 2

1。4电子封装的可靠性问题 3

1。5 本课题的研究意义及主要研究内容 (责任编辑：qin)