Sn-Ag-Cu表面贴装元件的水清洗技术

Water cleaning technology for surface mounted components soldered with Sn-Ag-Cu solder

摘要: 采用SMT450-LD全自动SMT水清洗系统对模拟试件和贴装有片式电阻的PCB板表面残留物采用水基清洗剂清洗。结果表明,用Sn-Ag-Cu免清洗焊膏贴装在FR4基板上的片式电阻,焊后采用水基清洗剂清洗,表面残留物离子浓度为1.9μg/cm₂,达到美国军用标准MIL-STD-2000小于5.7μg/cm₂的规定。清洗过程中参数的设置,如清洗温度,清洗时间会对清洗效果产生较大影响。

Abstract: Simulative specimens and SMC soldered with layer resistances were cleaned by SMT450-LD SMT water-cleaning system and the results indicate that the layer resistance mounted on FR4 by Sn-Ag-Cu no-cleaning solder paste is clean and the residua concentrateion on PCB surface is about 1.9μg/cm²,which met the requirement of MIL-STD-2000(the residua concentrateion on PCB surface should be less than 5.7μg/cm²).Cleaning parameters such as cleaning temperature and cleaning time have great effects on the cleaning result.