无钯镀镍碳纤维增强Sn-3.0Ag-0.5Cu复合钎料的制备

Fabrication of Palladium-Free Nickel-Coated Carbon Fiber Reinforced Sn-3.0Ag-0.5Cu Composite Solder

摘要:

采用化学镀法在碳纤维表面制备无钯镍镀层,用粉末冶金法制备了以镀镍碳纤维为增强相的Sn-3.0Ag-0.5Cu 复合钎料,借助于SEM、EDS、OM等检测手段对其微观组织进行分析,研究镀镍碳纤维含量对复合钎料微观组织和基本性能的影响。结果表明：镀镍碳纤维主要分布在复合钎料的晶界处；随着复合钎料中镀镍碳纤维含量的增加,其弥散度逐渐降低,熔点变化不大；当镀镍碳纤维含量大于1wt%时,镀镍碳纤维在晶界处的团聚现象严重,复合钎料的电阻率显著升高。添加1wt%的镀镍碳纤维有助于减小液态复合钎料在助焊剂界面和Cu基板处的表面张力,降低钎料基体的电流密度,使得复合钎料的润湿性提高,电阻率有所降低。

Abstract:

Palladium-free Nickel coating was deposited on the surface of carbon fibers by electroless plating method. Nickel coated carbon fibers reinforced Sn-3.0Ag-0.5Cu composite solder was made using the powder metallurgy technique. Microstructure of composite solder was observed and analyzed with the help of SEM, EDS and OM. The effect of Nickel coated carbon fibers contents on the microstructure and properties of composites solder was studied. The results showed that nickel plated carbon fiber was mainly distributed in the grain boundary of the composite solder. The dispersity of coated carbon fiber decreased with its content increasing, while the melting point of composite solder changed little. When the coated carbon fiber content was greater than 1wt%, the reinforced phase appeared obvious agglomeration, which led to the higher electrical resistivity. The added 1wt% coated carbon fiber will be helpful to decrease the surface tension of liquid composite solder between the flux and Copper substrate, which caused the excellent wetting effect. At the same time, the current density of solder matrix was decreased, which resulted in the lower electrical resistivity of composite solder.