SnAgCu-<i>x</i>Pr钎料组织及性能

SnAgCu-xPr钎料组织及性能

摘要: 研究了不同含量Pr元素(质量分数分别为0,0.05%,0.5%)对Sn-3.8Ag-0.7Cu无铅钎料凝固特性、润湿铺展性能以及微观组织的影响.结果表明,SAC,SAC-0.05Pr以及SAC-0.5Pr的凝固所需过冷度分别为20.6,5.0,5.1℃,说明适量Pr元素的加入能够显著降低SnAgCu钎料凝固所需的过冷度;同时,Pr元素的加入细化了钎料组织,降低钎料组织中初晶β-Sn的尺寸,抑制了SnAgCu/Cu焊点内部不同形貌大块化合物Ag₃Sn初晶的形成;当Pr元素的添加量为0.05%时,钎料润湿性能最优、组织最佳;0.5%Pr元素的添加会在钎料以及焊点内部形成PrSn₃相,对焊点的性能造成不利的影响.

Abstract: The effect of different Pr additions(0,0.05,0.5wt.%) on the solidification behavior,spreading property and microstructures of Sn-3.8Ag-0.7Cu(SAC) solder were investigated.The results showed that the undercooling of SAC,SAC-0.05Pr and SAC-0.5Pr solder in solidification were 23.2,7 and 8.6℃ respectively which indicated that the proper content of Pr addition could obviously decrease the undercooling of SAC solder.Meanwhile,with Pr addition,the microstructure of SAC solder was improved and the primary Ag₃Sn plate in SAC/Cu solder joint was restrained.Moreover,the SAC-0.05Pr solder has the best wetting property and microstructure;when the Pr addition was up to 0.5 wt%,PrSn₃ phase with large size formed in solder would deteriorate the property of SAC solder joint.