摘要
在125℃下对96.5Sn-3Ag-0.5Cu无铅焊点进行3种应变幅值(0.4%,0.5%,0.6%)和3种频率(0.05,0.10,1.00 Hz)条件下的低周疲劳试验,利用光学显微镜和电子显微镜对3种频率下焊点的断裂路径和断口形貌进行分析。结果表明,不同应变条件下无铅焊点的疲劳寿命符合Coffin-Manson模型。焊点的疲劳破坏过程主要分为应变强化阶段、稳定变形阶段和加速破坏阶段。疲劳裂纹主要在焊点端部的钎料与基体之间的界面处萌生,并沿一定角度向钎料内部扩展。不同频率下焊点的断口主要分为韧断区和脆断区,失效模式为韧-脆混合断裂。
Low cycle fatigue tests on 96.5Sn-3Ag-0.5Cu solder joints were carried out at 125℃ with three different strain magnitudes（0.4%, 0.5%, 0.6%） and three different frequencies（0.05, 0.10, 1.00 Hz）. The crack propagation path and the fracture morphologies with the three frequencies were analyzed using optical microscope, scanning electron microscope The results show that the fatigue life of lead-free solder joints in different strain conditions follows the Coffin-Manson equation. The fatigue failure process of the solder joints can be divided into three stages： strain hardening stage, stable deformation stage and accelerated failure stage. Cracks predominantly nucleate at the interface between the solder and the matrix from the corner of the solder joint and propagate into the solder along a certain angle. The fracture of solder joints with different frequencies is mainly divided into two characteristic regions： ductile fracture zone and brittle fracture zone. The failure modes of the solder joints arebrittle-ductile fracture.
出处
《电子元件与材料》
CAS
CSCD
北大核心
2013年第12期73-78,共6页
Electronic Components And Materials
基金
国家自然科学基金资助项目(No.51275007)
北京市自然科学基金资助项目(No.2112005)
关键词
低周疲劳
无铅焊点
高温
可靠性
裂纹萌生
裂纹扩展
low cycle fatigue
lead-free solder joint
high temperature
reliability
crack initiation
crack propagation
