MEMS封装中全Cu3Sn焊点组织演变及剪切性能

Microstructure Evolution and Shear Performance of Full Cu3Sn Solder Joints in MEMS Packaging

中文关键词:  MEMS封装  全Cu₃Sn焊点  组织演变  剪切性能

英文关键词:MEMS packaging  full Cu₃Sn joints  microstructural evolution  shear performance

中文摘要:

      对Cu/Sn+Sn/Cu结构进行了低温键合，在不同的键合时间下制备焊点，分析了键合时间对焊点界面组织演变的影响和全Cu₃Sn焊点制备过程中界面反应机理，对焊点的剪切性能进行了分析和研究。结果表明，随着键合时间的增加，Cu₆Sn₅逐渐变成扇贝状并不断长大。键合时间达到90 min时，Sn完全被消耗，继续增加键合时间，Cu₃Sn以Cu₆Sn₅的消耗为代价不断长大，最终全部转变成Cu₃Sn。随着加载速率的增加，全Cu₃Sn焊点的抗剪切强度值逐渐减小，焊点界面两侧Cu₃Sn界面处沿晶断裂占焊点断裂模式的比例越来越大，因为这种沿晶断裂的抗剪切能力较小，所以焊点的抗剪切强度随着加载速率的增加而下降。

英文摘要:

      The Cu/Sn+Sn/Cu structure is soldered in low temperature and joints are fabricated under different bonding time.The effects of different bonding time on the microstructure evolution at the interface and the interfacial reaction mechanism in the process of full IMC joints fabrication are analyzed.The shear performance of full Cu₃Sn joined is studied.The results indicate that Sn is totally consumed with the bonding time reached 90 min.Continue to increase the soldering time,Cu₃Sn generally increases at the expense of Cu₆Sn₅ consumption and Cu₆Sn₅ totally transforms into Cu₃Sn eventually.With the increase of loading rate,the shear strength of full Cu₃Sn joints decreases gradually.The proportion of the intergranular fracture of Cu₃Sn boundary at both sides of joints is bigger and bigger with the increase of loading rate and the shear resistance of this intergranular fracture is low.Therefore,the shear strength of full Cu₃Sn joints decreases gradually with the increase of loading rate.