通过扫描电镜(SEM)等手段研究了Sn-9Zn/Cu在不同浸焊时间与时效时间等条件下的界面反应及其金属间化合物(IMC)生长行为.结果表明:在浸焊后,Sn-9Zn/Cu钎焊接头界面形成了扇贝状的界面化合物Cu 5 Zn 8,IMC层厚度随着浸焊时间与时效处理时间的增加而增加,未时效处理的焊点界面IMC与铜基板接触的一面较为平直,而与钎料接触的一侧呈现出锯齿状,随着时效时间的增加,界面变得越来越不平整;另外在IMC层与焊料之间产生裂缝现象,分析认为是由于钎料与IMC之间的热膨胀系数差异导致热应力形成裂缝.浸焊600 s后的试样在时效15 d后IMC层与Cu基板接触侧产生了与初始金属间化合物Cu5Zn8不同的三元化合物Cu6(Sn,Zn)5.%Interfacial reaction and the growth behavior of intermetallic compound (IMC) between Sn-9Zn solder and Cu substrate interface under different dipping time and aging conditions were investigated by SEM, etc. Experiment proves that the scallop-shaped Cu5Zn8layer is formed at the interface and the IMC layer is thickened with increasing dip-soldering time and aging time. The interfacial IMC of solder joint closes to the Cu substrate without aging treatment, is relatively flat. But on the solder side, the IMC becomes serrated, and the interface is becoming more and more uneven with the increase of aging time. In addition, the crack between the IMC layer and the solder is formed, which is attributed to the thermal stress resulted from the difference of thermal expansion coefficient between the solder and the IMC. After 600 seconds dip-soldering and 15 days aging, the ternary compound Cu6(Sn, Zn)5is formed between the IMC layer and Cu substrate.
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