PBGA Solder Stress Development Mechanism Analyses Under Random Vibration

Large size commercially available plastic ball grid array chip packaging was tested and analyzed under random vibration to assess its application feasibility on satellite electronics. Two types of the PBGA were chosen, and the chips were surface mounted without underfill on a daisy chained polyimide printed circuit boards. Two strong levels of the random vibrations were applied sequentially to investigate the sustainability of the PBGA chips mounted on the polyimide PCB with aluminum frame. It was found that the test results did not show any solder failure under the test conditions, indicating the robust structural integrity and providing the evidences justifying the PBGA packaging application to the aerospace applications. Numerical analyses were also performed for the solder stress development mechanism. The results demonstrated that the first natural mode was not necessarily the dominant source for the maximum solder stress, and higher stress could be induced at higher natural modes depending on the chip size and its location.