PLCC电子元器件结构优化设计
人们对电子元件需求日益增加故而对焊点的可靠性这一问题表现得更为关注。但鉴于在整个封装结构中焊点的几何尺寸比较小，所以通过物理实验方法去测试焊点在热循环过程中产生的应力、应变会比较吃力。在这种情况下，限元分析方法则可以大显身手，可以不进行实际实验而是在虚拟的环境中较为准确地得出估测结果，从而在评价焊点可靠性的问题上占据举重若轻的地位。
本文的主要是探究当材料属性和几何结构等参数发生变化时会对PLCC封装结构的热疲劳寿命产生怎样的影响，为了得到性能更为优化的结果并且提高热疲劳寿命，需反复调整改变各种参数进行试验。建立三文有限元模型并模拟PLCC封装实际工作状态，得到数值模拟结果并进行分析，并利用有限元分析方法对结果进行验证。
[毕业论文关键词]：plcc封装 有限元分析 可靠性 焊点
PLCC Electronic Component Optimization design [Abstract]: In modern microelectronic industries, first of all, how to make it lignter, better, smaller in size is the developing direction of the microelectronic packaging technology today ; besides ,the microelectronic products have been expected to more reliable when their working environment is in bad situation.Thus,the reliability of the microelectronic packaging has been given so much concern, which decides that the reliability research of the microelectronic packaging will hold an significant part in the future life of human beings.
People are in need of microelectronic devices for a queite long time so the reliability of solder joint problem which is of great importance in research have been the hot issue among the public . Because the geometric scale of grid in the whole structure is small, the general experimental method is adopted to the stress and strain of solder joint in the process of thermal cycling track observation will be difficult,and limited element analysis method can play its advantage in this case, which can be found out clearly in the solder joints under long-time loading condition and in this condition its evolution could be described in detail directly by this software as well as the evaluation of the ease with which position on the issue of solder joint reliability .
This paper mainly aims to find out the best combination of design factors to improve thermal fatigue reliability through the impact study material properties and geometry of multi PLCC package thermal fatigue life.creating dimensional finite element model of solder joints during temperature cycling stress and strain will aid finite element analysis on the optimal combination of factors to verify the results.
[KEY WORDS]：Finite Element Analysis PLCC Package reliability solder joints
目录
摘要 1
第一章 绪论 3
1.1课题的背景及意义 3
1.2 电子封装及PLCC概述 3
1.3 研究现状 6
1.4 本文研究内容 7
第二章 可靠性热设计方法的研究 8
2.1 电子封装的可靠性 8
2.2电子元器件可靠性的研究过程 10
第三章 有限元分析技术 11
3.1 有限元法的基本思想 11
3.2 有限元法的特点 12