微电子封装低温Sn-xBi-yM合金钎料研究现状与展望

小型化、多功能电子产品的发展使器件在封装和组装过程中面临热损伤和基板翘曲等问题。为了减小电子封装和组装过程对芯片和器件的热影响，需要研究和开发低熔点的互连材料。锡铋（Sn-Bi）合金钎料由于低熔点、低成本、良好的润湿性和机械强度等特性受到了广泛关注，但是其中脆性Bi相的偏析却不利于器件的长期服役可靠性。通过在Sn-Bi钎料中添加合金元素构成Sn-xBi-yM形式的合金钎料可以有效改善Sn-Bi合金钎料及其焊点的服役可靠性。本文从钎料合金化的角度出发，分析并总结了不同合金元素对Sn-Bi钎料的熔点、润湿性、微观组织、机械性能、界面反应及可靠性的影响。并根据现有的研究成果，展望了锡铋合金钎料未来的发展方向。

Research advances and prospect of low temperature Sn-xBi-yM alloy solders for microelectronic packaging

The development of miniaturized and multifunctional electronic products makes the devices face problems such as thermal damage and substrate warpage during the packaging and assembly process. In order to reduce the thermal impact of electronic packaging and assembly processes on chips and devices, low melting point interconnect materials need to be researched and developed. Tin-bismuth (Sn-Bi) alloy solder has received considerable attention due to its low melting point, low cost, good wettability and mechanical strength, but the segregation of the brittle Bi phase is detrimental to the long-term service reliability of the devices. By adding alloying elements to the Sn-Bi solder to form a Sn-xBi-yM alloy solder, the service reliability of the Sn-Bi alloy solder and its solder joints can be effectively improved. This paper analyzes and summarizes the effects of different alloying elements on the melting point, wettability, microstructure, mechanical properties, interfacial reaction and reliability of Sn-Bi solder from the perspective of solder alloying. And based on the existing research results, the future development direction of Sn-Bi alloy solder is prospected.