Thermal numerical simulation for advanced package development

In recent years, NFME has been developing advanced packages such as QFN, BGA, LGA, and SiP. In the new product development stage, thermal design needs to be taken into consideration to assess its thermal reliability. So, the accurate junction temperature prediction for the package is critical to electronic packaging design. In the industry, numerical models are often utilized to predict package thermal performance. In this paper, detailed HLQFP and BGA models were created, and a series of computational studies were conducted to obtain junction temperature and thermal resistance under JEDEC standards for natural and forced air convection conditions. In order to reduce computation time, model simplification was made from package geometry to the attached PCB test board. The simulated junction temperature values can also be used to estimate the maximum power dissipation allowed for the specific package. Thermal analysis helps determine whether the package will dissipate a sufficient amount of heat, or if it is still necessary to apply an external heat sink. Validated with experimental measurements, effective simulation can greatly help optimize advanced package structure design and material selection, and minimize the working temperature of packages to meet application requirements.