内生无铅复合钎料在不同工艺条件下的制备及性能研究

Preparation and properties study of lead-free in-situ composite solder under different conditions

通过采用不同工艺的内生法在Sn-3.5Ag共晶钎料基体中引入弥散分布的Cu6Sn5颗粒,制得了内生无铅复合钎料。研究了不同工艺条件对该钎料力学性能及电迁移行为的影响。结果表明,在冷却速度(0.1℃/s)较慢时制备的钎料,其内生Cu6Sn5颗粒细小,分布最均匀,且团聚程度较轻,另外,其钎焊接头力学性能最好;通5 A电流384 h后,其正负极金属间化合物层厚度的差异保持在约1.2μm,说明Cu6Sn5颗粒的引入提高了钎料的抗电迁移性能。

Lead-free in-situ composite solders were prepared by introducing Cu6Sn5 grain reinforcements into the Sn-3.5Ag eutectic solder using in-situ methods with different processes. The effects of preparation condition on the mechanical and electromigration properties of the solder were studied. The results show that, for the solder prepared at a relatively low cooling rate （0.1 ℃/s）, its endogenous Cu6Sn5 grains show small size, the most uniform distribution and less agglomeration, and its joint shows the best mechanical performance; After applying 5 A current for 384 h, the difference in the thickness of intermetallic compound between positive and negative poles of the solder keeps at about 1.2 μm, indicating that introduction of Cu6Sn5 reinforcements enhances the anti-electromigration ability of the solder.