微量Ag、Bi、Ni对无铅微焊点固-液界面扩散的影响

摘要

In order to study the influence of trace elements on the solid-liquid interfacial diffusion behavior of lead-free solder joints, the Cu/SAC0705+Bi+Ni/Cu solder joints were chose as the main research objects. In costrast with Cu/SAC305/Cu and the Cu/SAC0705/Cu solder joints, the growth and evolution behaviors of interface IMC in three kinds of solder joints were studied after solid-liquid diffusion, and the effects of trace elements Ag, Bi, Ni on the solid-liquid interface diffusion were analyzed. The results show the trace elements Ag, Bi, Ni in the solder can refine the grain size after reflow, which can improve the strength of the interface. The growth rate of interface IMC depends on the grain of interface IMC during a long period of solid-liquid aging. The Cu/SAC0705+Bi+Ni/Cu solder joints have the smallest interface IMC grain size, so its interface IMC has the maximum growth rate of 11.74 μm/h. The Cu/SAC0705/Cu solder joints have the biggest interface IMC grain size, so its interface IMC has the minimum growth rate of 1.24 μm/h.%为了获得微量元素 Ag、Bi、Ni 对无铅微焊点固-液界面扩散行为的影响规律,以低银无铅微焊点Cu/SAC0705+Bi+Ni/Cu为主要研究对象,并与Cu/SAC0705/Cu及高银钎料Cu/SAC305/Cu进行对比.研究了三种成分焊点固-液扩散后界面IMC的生长演变行为,并分析了Ag、Bi、Ni对微焊点固-液扩散的影响.研究结果表明:钎料中微量元素Ag、Bi、Ni添加可细化界面IMC晶粒,对提高界面强度有利.长时间的固-液时效过程中,界面IMC的生长速率主要取决于界面IMC的晶粒尺寸.Cu/SAC0705+Bi+Ni/Cu焊点界面IMC晶粒尺寸最小,界面IMC生长速率最大,为11.74 μm/h.Cu/SAC0705/Cu焊点界面IMC晶粒尺寸最大,界面IMC生长速率最慢,其数值为1.24 μm/h.