A doctoral student at NC State University’s Department of Mechanical and Aerospace Engineering recently received the ASME MEMS Divison’s Student Innovative Paper Award at the annual International Mechanical Engineering Congress and Exposition (IMECE).
Pouria Zaghari received the prestigious award late last month for his paper “Finite Element Analysis and Fatigue Life Prediction of a Laterally Conducting Gan-Based Power Package Under Thermal Cycling.”
Zaghari works under MAE Assistant Professor Jong Eun Ryu, whose research group focuses on creating multifunctional composite materials with unique characteristics and functionalities in order to apply them to different engineering problems.
Zaghari’s paper addresses thermal fatigue life analysis of GaN packages, which is an important consideration that affects the reliability and durability of electronic devices.
“The fatigue life assessment of a GaN laterally conducting power packaging, including SAC305 and Sn63/Pb37 solders was conducted using the finite element analysis (FEA) method,” the abstract states. “The thermal cycling loading was chosen based on JEDEC Standard JESD22-A104D condition M. With temperature cycling from -40℃ to 150℃. To simulate the viscoplastic behavior of solder materials under thermal cycling, the Anand constitutive model was adopted. Coffin-Manson, Engelmaier, and Solomon empirical models were utilized to predict the cyclic life of the package based on stress and strain distribution in the solder layers.”
Zaghari and his team’s results showed that the critical solder joint location of the failure was in the SAC305 solder and the maximum inelastic strain range of SAC305 solder was calculated to be 0.023697. In conclusion, the fatigue life prediction of the module showed that the Engelmaier model was the most conservative model resulting in a fatigue life of 136 cycles.
On this paper, Zaghari worked alongside Dr. Ryu as well as ECE student Sourish S. Sinha, and ECE professors Paul D. Franzon and Douglas C. Hopkins.