片式电容Sn96.5/Ag3/Cu0.5焊点热疲劳性能比较

以0805封装片式电容器件焊点为研究对象，建立了多周期温度冲击下Sn96.5/Ag3/Cu0.5的焊点有限元分析模型，开展了多周期温度冲击条件下焊点剪切力测试工作，获得了Sn96.5/Ag3/Cu0.5和Sn63/Pb37两种焊点的周期-剪切力测试数据，并利用非线性最小二乘法得到了1 500个周期内的焊点热疲劳状态拟合曲线.结果表明，在规定试验条件下，在有限的1 500个周期内0805封装电容的Sn96.5/Ag3/Cu0.5焊点的热疲劳劣化速率略慢于Sn63/Pb37焊点.

Comparative studies on thermal fatigue performance to Sn96.5/Ag3/Cu0.5 solder joints of chip capacitor

With the use of Pb in a variety of occasions prohibited, Lead-free technology becomes one of important research direction. For understanding the fatigue properties of lead-free solder, there is important significance to analyse fanalyse state of lead-free solders and to research on the method of testing. With the 0805 chip capacitor device package solder joints as the research object, Sn96.5/Ag3/Cu0.5 solder joints finite element model is established for multi period under temperature cycles. And shearing test is carried out. The value of Period-shearing stress to Sn96.5/Ag3/Cu0.5 and Sn63/Pb37 solders is obtained. Thermal fatigue fitting curves of solder in 1 500 periods is acquired, by using nonlinear least square method to fit curves. The results indicates that under the stipulated test condition, in limited 1 500 periods, thermal fatigue performance of Sn96.5/Ag₃/Cu0.5 solder joints'' rate of thermal fatigue deterioration to 0805 capacitance is slightly slower than that of Sn63/Pb37 solder joints.