Simulation Study on Thermal Mechanical Properties of Different Embedded Packaging Structures and Materials of GaN Devices

With the advent of wide-band gap (WBG) semiconductors such as SiC and GaN, it is believed that the Si-based semiconductors will be replaced in high-frequency and high-power application fields soon. At the same time, it calls for better electronic packaging technologies and packaging materials which can ensure devices survive at higher power density. Embedded packaging and metal-based sintering die attachment technologies are recently the most advanced ideas. It can not only minimize the packaging volume to increase power density but also enhance thermal conductivity to lower down thermal stress for the device. In this paper, we conducted a comparative study by finite element method (FEM) simulation to reveal the advancement of such techniques. First, four different packaging structures are considered, including the traditional surface mounted packaging method, the embedded packaging design, embedded thick copper design and the double-sided cooling design. Second, study on thermal dissipation properties of different die-attachment (DA) material have been carried out. The results show that the last two designs significantly reduce the service temperature of the packaging, and both the silver and copper sintering technologies can provide good DA layer without high thermal stress.