Study on IMC Growth Law of Solder Joints in Aerospace Electronic Products and Its Influence on Reliability

Abstract

In order to better understand the influence degree of temperature curve parameters on the growth characteristics of intermetallic compounds (IMC) in solder joints during reflux welding, the influence of different temperature curve parameters on the thickness of IMC in Sn63Pb37 solder joints was explored based on the orthogonal test method. A multiple regression model was established for each parameter and the thickness of IMC. In addition, the results show that: (1) The influence degree of temperature curve parameters on IMC thickness in descending order is the highest temperature, liquidus time, cooling time and cooling rate. (2) The coefficient of the established multiple regression model is R2=0.70391. In this model, the IMC thickness increases with the increase of the maximum reflow temperature and liquidus time and decreases with the increase of the cooling time. (3) When the thickness of IMC is 1 μm- 4 μm, the thermal shock reliability of solder joints decreases with the increase of IMC thickness.