摘要如今电子工业迅速发展，电子封装作为电子工业最重要的一项越来越受到重视，FCBGA作为电子封装的极具前景的技术 手段，具有许多优越性，构造是否合理是影响该器件修寿命的一个重要因素的可靠性，决定了电子产品的质量。本篇文章通过建立有限元模型，对不同尺寸、不同位置的焊点进行模拟，绘制出了焊点在工作状态下的应力 应变分布图。对在热循环下的焊点进行分析，我们应在分析塑性和蠕变的同时，还要注意到塑性和蠕变的交互影响，这种情况下很难对其进行精准地描述，于是本文采取有限元数值模拟来对FCBGA器件结构进行剖析。
本课题焊点采用Sn63Pb37焊料来模拟FCBGA器件中的焊球，由于在常温下就处于蠕变变形控制阶段,所以在有限元的分析过程中不但需要考虑可能会发生的弹性变形,而且要注意到它还具有粘塑性特征,本文采用对焊点在热循环下应力、应变分布表特征比较理想的 Anand 本构模型。通过分析该本构模型，得出了粘塑性问题的基本解题思路，并一步步推出其求解过程。 选用有限元方法及Anand 本构模型不仅能对焊点粘塑性的力学行为进行分析，而且能够得到了在热循环下焊点的应力、应变分布特行，确定在FCBGA最危险的焊点与焊点区域风险的位置。然后通过改变焊点的大小参数、形状和位置，对其热疲劳寿命进行对比，选择最合适的器件结构。31945
毕业论文关键词：电子封装   FCBGA  有限元分析  结构  优化  蠕变
Structural optimization design of FCBGA device
Abstract
  Now the rapid development of electronic industry, electronic packaging as one of the most important electronic industry more and more attention,FCBGA as a technical means of electronic packaging promising, has many advantages,reasonable structure of solder joints is an important factor affecting the life of the device,reliability, determines the quality of electronic products.This article through the establishment of finite element model, the solder joint with different dimensions, different positions of simulation, draw the solder joint under the working state of stress and strain distribution.The solder joint not only to plastic, considering creep under thermal cycling, but also consider the interaction of plasticity and creep, it is difficult to accurately describe in theory, this paperadopts the finite element numerical simulation to analyze the structure of FCBGA device.
The project uses Sn63Pb37 as solder solder material to simulate FCBGA solder joint,because in normal temperature creep deformation in the control stage, so in the process of finite element analysis not only needs to consider the elastic deformation, but also to take into account the viscoplastic properties, this paper used for solder joint stress and strain distribution characteristics comparison table the ideal under thermal cycle Anand constitutive model.Through the analysis of the constitutive model, the basic way of solving visco plastic problem,and a step by step to launch its solving process. By using the finite element method andAnand constitutive model analysis not only on joint viscoplastic mechanical properties, at the same time, the stress and strain distribution of solder joints under thermal cycle,To determine the position of the most dangerous solder joint in FCBGA and the risk of the solder joint area. Then the size parameters of solder joints and position, and compares the thermal fatigue life of device structure, choose the most suitable.
Keywords: electronic packaging  FCBGA  finite element analysis  structure  optimization   creep
目录
摘要    II
Abstract    III
第一章 绪论    1
1.1课题综述    1
1.2电子封装技术的发展历程    1 FCBGA器件结构优化设计+文献综述:http://www.751com.cn/tongxin/lunwen_28278.html