摘要由于社会经济和生活质量的快速发展，计算机手机等电子产品开始普及，带动了电子产业以及与电子产业息息相关的电子封装产业的发展。科技的进步使得人们生活的追求开始不断提高，电子产品趋于小型化发展，使得电子封装产业逐渐成为微电子封装来满足社会的发展需求。由于目前，球栅阵列封装(BGA)在微电子封装领域中的普及运用，而PBGA是BGA中应用范围最广的一种，所以本文主要研究的是PBGA封装。77651

    通过翻阅大量的有关文献发现焊点是影响微电子封装的最大因素，所以想要提高PBGA器件的寿命，研究出最可靠的封装结构，必须要研究焊点的可靠性。通常，我们基本都是用Sn-Pb共晶焊料作为焊点的材料，而随着人们对保护环境的意识越来越强，无铅焊点发展的趋势是势在必行。通常焊点失效的原因大部分是因为电子器件各部分组成材料的线膨胀系数不同，焊点收到持续热应力所导致。由于实际操作测试过程复杂且费时费力，所以本文利用ANSYS有限元分析软件建立PBGA三维模型，进行网格划分并施加载荷约束，对焊点进行仿真模拟分析，分析其在蠕变应变的服役过程中，焊点的应力分布，得到数据。通过改变焊点直径的大小，改变焊点的材料进行对比分析得到结论，从而达到提高PBGA封装可靠性的目的。

毕业论文关键词： 微电子封装  有限元分析  无铅焊点 蠕变应变 

The optimal design of lead-free solder joint for Plastic Ball Gird Array

Abstract According to the development of social economy and living quality，the computer and smart phone become famous in our daily life，the development of the electronic products lead to the development of electronics industry progress in science and technology has promoted our daily life greatly，electronic products tend to be miniaturization lead to the electronic packaging industry pass into microelectronic packaging to meet the development requests of social。 the Ball Gird Array as the main stream is famous used in the microelectronics packaging field，and the Plastic Ball Gird Array is most widely used in Ball Gird Array，so，in this paper，we major research focused on Plastic Ball Gird Array。 We find the solder is biggest influence factors in microelectronic packaging。 So，if we want increase the service life of PBGA，we must to research the surest package structure，and must to research the reliability of solder ，in the long time，we also use the Sn-Pb to the solder material，with the call of people for the protect of environment more and more high，it’s imperative to lead-free solder joints。 Most often the cause of the solder joint failure because electronic different  linear expansion coefficient of each part of material received continuous thermal stress caused by solder joint。 Because the practical experimental process is complex ，waste time and energy，so，in this paper，we use ANSYS to build 3D modeling，gird mesh in manual mode，then do some simulation analysis on the spot，we analyze the creep strain of the service process，solder joints stress distribution then get the data。 Though change the size of solder diameter and change the material to contrast the date and get the result。

Key Words: Microelectronic packaging   Finite element analysis  Lead-free solder Joint creep strain   

目  录

摘 要 I

Abstract II

图清单 Ⅴ

表清单 Ⅵ

1 绪论 1

1。1 前言 1

1。2微电子封装技术