【摘要】 研究了功率模块芯片在 ＤＣＢ基板上 ９２．５Ｐｂ５Ｓｎ２．５Ａｇ钎料焊层的热循环可靠性和裂纹扩展，应用超声波显微镜对裂纹扩展过程进行检测，得到了热循环失效的裂纹扩展数据，采用统一型粘塑性 Ａｎａｎｄ方程描述了 ９２．５Ｐｂ５Ｓｎ２．５Ａｇ的力学本构，模拟了焊层在热循环条件下的应力应变过程．基于裂纹扩展的实验数据和等效塑性应变增量△εｉｎｅｑ，提出了一种描述热循环裂纹扩展速率的经验方程更多还原

【Abstract】 In electronic packaging technology, the SnPb solder joint reliability of die attachment for power module under thermal cycling attracts the attention in this field. This paper investigated the reliability and crack propagation of 92.5Pb5Sn2.5Ag solder layer, with which the chips of power module were mounted on A12O3 DCB substrate, under thermal cycling. The crack propagation process in solder layer was inspected with C-mode scanning acoustic microscope (CSAM) and the crack propagation data were also measured. The stress/strain responses of the solder layer under thermal cycling were simulated by employing the unified viscoplastic Anand constitutive equation with which the deformation behavior of 92.5Pb5Sn2.5Ag solder was represented. Based on the experimental data of crack propagation and the calculated equivalent plastic strain amplitude △εineq, an empirical equation was put forward to describe the crack propagation rate of PbSnAg solder layer under thermal cycling.更多还原