(国防科技大学 机电工程与自动化学院, 长沙 410073)
摘 要: 基于能量最小原理对装配后的EBGA焊点形态进行了预测。 采用统一型粘塑性Anand本构方程描述了Sn63Pb37合金的粘塑性力学行为, 采用非线性有限元方法研究了EBGA焊点在热循环条件下的应力应变过程及其特殊性, 应用基于能量和损伤累积的Darveaux方法预测了EBGA焊点的热循环寿命。
关键字: 可靠性; 焊点; 形态预测; 热疲劳寿命; 非线性有限元分析;粘塑性
of EBGA solder joint
(College of Mechatronic Engineering and Automation,
National University of Defense Technology, Changsha 410073, China)
Abstract:Based on the principle of the minimum energy, the energy control equation for solder joint geometry was presented and three-dimensional geometry of the solder joint mounted on the PCB was predicted by using Surface Evolver program. The unified viscoplastic Anand constitutive equation was employed to represent the viscoplastic deformation behavior of Sn63Pb37 alloy, nonlinear finite element method was applied to study the accumulation of inelastic strain and the feature of stress—strain distribution in the solder joints under thermal cycling. At last, the thermal cycle life of EBGA solder was predicted using the energy-based and damage-based Darveaux method.
Key words: reliability; solder joint; thermal fatigue life; nonlinear finite element analysis; viscoplasticity