Mechanical fatigue of a lead-free solder alloy

无铅焊料合金的机械疲劳

• 批准号: 474836-2014
• 负责人: Weck, Arnaud
• 金额: $ 1.82万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=565105
• 关键词: Mechanical; fatigue; lead; free; solder

In microelectronic packages, solder joints ensure both electrical and mechanical connections between the printed circuit board (PCB) and the chip. During in service use, local operating temperatures increase and decrease repeatedly, exposing components of the package to thermo-mechanical strains arising from different coefficients of thermal expansion of the materials involved including the solder joints. These cyclic mechanical strains in the solder lead to thermo-mechanical fatigue crack initiation and propagation that can lead to solder joint failure. In addition to thermomechanical fatigue, solder joints can also be subjected to mechanical fatigue when the board or substrate is bent during mechanical handling or from vibration forces.

在微电子封装中，焊点确保了印刷电路板(PCB)和芯片之间的电气和机械连接。在使用过程中，局部工作温度反复上升和下降，使封装组件暴露在热机械应变下，这些应变是由于所涉及的材料(包括焊点)的热膨胀系数不同而引起的。焊料中的这些循环机械应变导致热机械疲劳裂纹的萌生和扩展，从而导致焊点失效。除了热机械疲劳外，当电路板或基板在机械处理或振动力作用下弯曲时，焊点也会受到机械疲劳。