【摘要】陶瓷球栅阵列(Ceramic Ball Grid Array简称CBGA)是表面封装技术的一种,它有自己的优缺点,优点就是:它拥有优异的热性能和电性能;与其他表面封装类型相比,它很少受到机械损伤;当装备到有大量I/O接口的PCB上时,具有很高的产量。缺点就是:陶瓷封装与电路板之间的热膨胀系数不一样,这会导致封装的可靠性问题。在实际应用中,严重时,可靠性问题甚至会在热循环期间导致封装器件焊点失效。本次的课题就是研究CBGA封装阵列的可靠性问题。在导师的指导下,我们确定了研究方案:就是采用ANSYS建立实体模型,对实体模型进行拉伸后可以得到球栅阵列;通过对球栅阵列的有限元分析来确定阵列的受力情况。这里使用的方法不是GUI方法,而是程序命令法,用到的是一段蠕变程序,研究的是阵列在蠕变的情况下,应力的变化。输入程序后,我们可以得到阵列的应力分布图,根据对应力图的分析,我们才能得到最终想要的结论。33225
【毕业论文关键词】ANSYS建模;蠕变分析;焊点可靠性;结构优化
CBGA device structure optimization design
【Abstract】Ceramic Ball Grid Array is one kind of Surface Mounting Technology.It has its own advantages and disadvantages.Advantage is:it has excellent thermal and electrical properties;Compared with other surface mount type,it is rarely subjected to mechanical damage;When there is a lot of I/O interface equipment to the PCB , when, with a high yield.Disadvantage is:the coefficient of thermal expansion between the ceramic package and the circuit board are not the same, this will lead to reliability problems of package.In practice, serious reliability problems during thermal cycling even cause package device solder joint failure.The issue is to study the reliability of an array of CBGA package.Under the guidance of instructors, we identified research programs:building a solid model with ANSYS, you can get the ball grid array of solid model after stretching;through the ball grid array finite element analysis to determine the forces array.GUI method is not used here, but the program command method,what used in the program is a creep, research in the case of creeping, the stress changes in an array.After entering the program, we can get an array of stress distribution, according to the analysis of the corresponding trying, we will get a final conclusion we want.
【Keyword】ANSYS Modeling;Creep Analysis;Solder Joint Reliability;Optimization
目 录 1
第1章 绪 论 4
1.1选题背景 4
1.1.1电子封装发展史 4
1.1.2陶瓷球栅阵列(CBGA) 4
1.2 SMT焊点可靠性 4
1.2.1 SMT焊点可靠性的概念 4
1.2.2 SMT研究现状 5
1.3研究内容 5
1.4研究意义 6
第2章 基本理论介绍 7
2.1有限元法基本原理 7
2.1.1简介 7
2.1.2基本思想 7
2.1.3分析过程 7
2.2求解步骤 7
2.2.1求解步骤(GUI方法) 7
2.2.2求解步骤(命令流方法) 8
2.3结构优化 9
第3章 分析软件ANSYS介绍 10
3.1简介 10
3.2ANSYS工作流程简介 10
第4章 CBGA器件模型创建 11
4.1问题描述 11
4.2问题分析 11
4.3具体操作步骤 11
4.3.1创建几何模型 11
4.3.3划分网格 26
4.3.4添加载荷 27
第5章 结果分析与优化设计 29 ANSYS的CBGA器件结构优化设计:http://www.youerw.com/zidonghua/lunwen_30187.html