Stress and strain analysis of solder joints of gull wing lead in the cooling process of reflow

The finite element analysis model of solder joints of gull wing lead was established and the stress-strain simulation analysis of the cooling process of reflow was carried out, the stress-strain distribution of the SAC305 solder joints of gull wing lead in the cooling process of reflow was obtained.The QFP solder joint length,space height and solder joint pitch were used as the key factors and the solder joints of 9 different structural parameters were designed by orthogonal array,the influence of these three factors on the stress of QFP solder joints in the cooling process of reflow was analyzed, the difference degree is the solder joint space height, solder joint pitch and solder joint length from the largest to the smallest;With 95% confidence, solder joint space height and solder joint pitch have significant effect on the stress of solder joints in the cooling process of reflow.