微电子表面组装焊点二维形态预测研究

A Forecasting Study of Two-dimensional Solder Joint Formation in Microelectronic Surface Mount Technology

微电子表面组装（ＳｕｒｆａｃｅＭｏｕｎｔＴｅｃｈｎｏｌｏｇｙ，简称ＳＭＴ）焊点形态的预测和控制研究对提高ＳＭＴ工艺设计水平和决策效率，保证焊点和组件的可靠性有重要意义。本文基于焊点二维形态预测的Ｈｅｉｎｒｉｃｈ模型，考虑元件与基板的高度间隙对焊点形态的影响，建立了进一步完善的ＳＭＴ片式元件焊点形态预测模型，考察了熔融钎料性质、钎料量对焊点形态的影响。结果表明，焊点钎料量对焊点上、下圆角形态有不同程度的影响，元件与基板的高度间隙对焊点形态有显著影响。

A more perfect two-dimensional model for the solder joint formation of chip components in SMT has been developed, in which the stand off height(SOH) between chip component and substrate pad has been considered. The critical parameters that influence the geometry of fillets such as molten solder properties (density ρ,surface tension γ),solder volume and SOH were investigated. The results show that the shape of upper fillet varies obviously with change of solder volume, whereas the shape of lower fillet is nearly a straight line; the stand off height has a great effect on solder joint formation.