Improved thermal management for GaN power electronics: Silver diamond composite packages

A novel packaging solution for GaN power electronics for efficient heat extraction in high power devices is presented. The benefits of using silver diamond composites as base plate in packages for GaN power bars are demonstrated. Micro-Raman thermography measurements were carried out to probe the device temperature for devices mounted on different base plates, silver diamond composites and standard CuW, at a range of operating power levels. A significant improvement in terms of thermal management, achieving a reduction in GaN power electronics temperature by up to a factor of two, was obtained when using silver diamond composites base plates with respect to the existing packaging technologies such as of CuW. Bare silver diamond and Cu-plated silver diamond base plates were compared. The influence of die attach to the base plates on thermal performance of GaN power electronics is also discussed. Finite element thermal model was built to correlate to the experiments, and good agreement was achieved.