Research on Vibration Reliability of DIP Surface-Mounted Solder Joint after Pin Bend

In order to facilitate the entire board reflow process, the pin of a DIP(Dual In-line Package) component is bent into a gull-wing type pin. However, after a short period of service, the failure of the Dual Inline Package surface-mounted solder joints of this type of product has occurred. In order to analyze the causes of failures, the DIP surface-mount solder joints were synthesized by means of metallographic sectioning, SEM (scanning electron microscope) analysis and numerical simulation analysis.After metallographic sectioning and SEM&EDS analysis, it is found that due to the possible poor coplanarity of the bent DIP pin array, some of the pins are deficient in solder under the reflow soldering, resulting in a solder joint with the effective connection area too small, so that it is cracked by environmental vibration stress during the service process. The main objective of the work is to evaluate the long-term reliability of DIP surface mounted solder joints, this study mainly used reliability simulation techniques to perform random vibration simulations on module components, and conducted stress analysis on the vibration response of solder joints to verify the location of solder joint cracking under the vibration load. The vibration responses of bent gull-wing solder joints and normal plug-in type solder joints were compared and analyzed through simulation techniques. The vibration reliability of plug-in solder joints was found to be significantly higher than that of gull-wing solder joints after design changes. As a result, for long-term reliability considerations, this design change is not recommended.