IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

288 / 2017-12-07 16:20:11

Three dimensional integration of GaN-HEMT-based DC-DC converter using planar inductor as a substrate

three dimensional integration,Finite Element Analysis,gallium ntride,synchronous buck converter

Plenary track > Very high efficiency and compact converters

The three dimensional(3D) integration technology using planar inductor as a substrate for power converter is a promising method to improve the power density. But it introduces additional parasitic inductance, not good for the application of GaN semiconductor devices. So a conductive shield layer was introduced between the magnetic substrate and GaN-based 12V/3.3V synchronous buck converter circuit to reduce loop inductance. Then the effect of shield layer thickness, insulator thickness and inductor current on parasitic inductance was investigated. And the influence of different parasitic inductance caused by different integrating structures on voltage overshoot across switches and switches’ power loss was analyzed by simulation. The results show that 3D integrated split-capacitor layout with shied layer can realize the parasitic loop inductance of 0.27nH when inductor current is 8A, which is much smaller than 1nH of the conventional structure. Heat distribution of 3D integrated structure of split-capacitor layout with shield was obtained by multi-physics coupling simulation, showing acceptable operating temperature. At last, prototypes for experiment were built to demonstrate the feasibility of 3D integrated structure using planar inductor as a substrate for power converter.