为了获得低热阻和解决不同焊接材料之间的热应力匹配问题,大功率DC-DC模块电源产品广泛采用了载体组件作为功率元器件热沉的散热方法。载体组件由金属基板和陶瓷基板焊接而成,为了得到无空洞的焊接界面,载体组件采用了真空再流焊工艺技术。文中从焊料形态、焊接表面处理、真空度等几个方面介绍了载体组件的Sn-3.0Ag-0.5Cu真空再流焊工艺过程,载体组件完成真空再流焊接以后,通过焊点X光无损检测、焊接界面微观组织结构分析、焊点剪切强度测试及温循试验对载体组件真空再流焊工艺的可靠性进行了验证。试验结果表明,载体组件真空再流焊可以保证大功率模块电源长期使用的可靠性。%In order to obtain low thermal resistance and solve the thermal stress question of different materials,high-power DC-DC converter extensively use substrate-heat sink as the means of power devices cooling.The substrate-heat sink is consists of metal substrate and ceramic substrate.In order to get void-free interface,the substrate-heat sink is soldered with vacuum reflow soldering technology.This paper introduces the process of vacuum reflow soldering technology with Sn-3.0Ag-0.5Cu solder,which is described mainly from solder form,superficial treatment of solder surfaces,vacuum level and the otherwise.After reflowing the Sn-3.0Ag-0.5Cu solder,the substrate-heat sink solder joint is inspected by X-ray,the quality of the solder interface is evaluated by SEM images,soldering strength and a temperature cycling is performed.The results show that the substrate-heat sink attached by vaccum reflow soldering can meet the high-power DC-DC converter＇s long-term reliability.
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