A Study on the Improvement of Solder Joint Reliability of Module Products by IPL Soldering Method

In recent years, the demand for performance of modules and solid state devices (SSDs) in areas such as artificial intelligence (AI), electric vehicles, and data centers has increased rapidly, leading to an increase in heat generation from modules and SSDs. Due to the difference in thermal expansion coefficients between BGA packages and PCBs, repeated heating and cooling of the products cause cracks in the solder joints between them, which significantly affects the product's lifespan. Therefore, this study applied an intense pulsed light (IPL) soldering process to increase the product's lifespan. Unlike reflow, which utilizes conventional convection methods, IPL soldering uses white light to induce radiant heat and perform soldering with low power in a short time. In this study, we performed soldering of SAC305/SAC305 + LTS hybrid/full LTS solder joints using IPL soldering and confirmed that reliability was improved through thermal cycle tests. In addition, cross-sectional microstructure analysis was used to identify the mechanism of improved reliability.