摘要
以热弹塑性理论为基础,建立无铅BGA焊点在回流焊工艺中的残余应力有限元模型,采用ANSYS进行热结构耦合分析,得到Sn3.5Ag0.75焊点回流冷却结晶后的残余应力分布规律。并针对焊点的直径、焊点的高度、PCB板的厚度和对流系数四个因素建立正交试验表,分析这四个因素对BGA冷却过程中残余应力影响规律,通过极差分析得出影响程度由大到小分别为对流系数、焊点高度、焊点直径、PCB板厚度,对控制BGA回流冷却残余应力提供理论指导。
In the thermal elastoplastic theory as the foundation, the residual establishment of lead-free BGA solder joint in reflow process stress finite element model, uses ANSYS to carry on the thermal structure coupling analysis, get the Sn3.5Ag0.75 solder reflow cooling crystallization of residual stress distribution after. And according to the diameter of the solder joint, solder joint height, the thickness of the PCB plate and the convection coefficient of four factors of orthogonal test table is established, the analysis of the four factors on the residual BGA in the cooling process of stress distribution by range analysis, the degree of influence from large to small respectively the convection coefficient, weld- ing point height, diameter, PCB solder joint plate thickness, to control the BGA recirculation cooling residual stresses and provide theoretical guidance.
出处
《装备制造技术》
2014年第10期44-46,共3页
Equipment Manufacturing Technology
关键词
回流焊
残余应力
正交试验
reflux welding
residual stress
orthogonal test
