冷却速率对无铅再流焊焊点质量的影响（待续）

摘要

Cooling rate affects mechanic property and reliability of solder joint markedly in lead-free reflow soldering.Rapid cooling rate can fine structure,control indirectly thickness and modality of intermetallic compound,affect failure style and reinforce performance of solder joint,but stress induced by mismatching between components and PCB materials brings about invalidation of produce.Summarize the work of documents and projects a experiment of oven cooling,air cooling and water cooling for reflow soldering,test solder joints strength and analyze metallograph of interface compound as well.The optimums cooling rate is 3 to 6 Celsius per seconds in electronic industry.%无铅再流焊中冷却速率影响焊点力学性能及可靠性。快速冷却可以细化组织,间接控制金属间化合物厚度和形态,影响焊点断裂模式,提高焊点综合性能。但是由于元件与PCB等材料的热不匹配性而造成的较大应力,易造成元件或焊点失效等。通过对文献中研究结果的总结,设计了炉冷、空冷和水冷等几种再流焊冷却方式,并对焊点进行了强度测试和组织成分分析,建议工业用最佳冷却斜率控制在3℃/s～6℃/s。