BGA焊点的形态预测及可靠性优化设计

Shape Prediction of BGA Solder Joint and Its Reliability Optimization Design

制定了BGA(球栅阵列)焊点的形态预测以及可靠性分析优化设计方案,对完全分布和四边分布的两种BGA元件,通过改变下焊盘的尺寸得到不同钎料量的焊点,并对其形态进行了预测,建立了可靠性分析的三维力学模型。采用有限元方法分析了元件和焊点在热循环条件下的应力应变分布特征,预测了不同种类和不同形态的BGA焊点的热疲劳寿命,由此给出了最佳的上下焊盘比例范围。

A scheme for predicting and analyzing solder interconnection joint shape and reliability was proposed.Through the variations of lower pads' diameters, the shapes of full array and peripheral array of BGA solder joints with different solder volumes were predicted,and 3-D finite element models were established.Using finite element method,the distribution characteristics of the stress and strain in solder joints under thermal cycle load were analyzed.Based on this, fatigue lives of solder joints with different solder volumes were predicted, and the optimum diameter ratios of lower pad to upper pad for these two kinds of BGA assemblies were suggested.