A Highly Integrated PCB Embedded GaN Full-Bridge Module With Ultralow Parasitic Inductance

Abstract

To fully take the high-frequency advantage of gallium nitride (GaN) devices, this article presents a face-up integrated power module based on the printed circuit board embedding technology to tackle the challenges caused by the conventional discrete solutions. The proposed GaN module highly integrates a GaN-bare-dies-based full bridge, driving circuits, and decoupling capacitors, in which the advanced bismaleimide-triazine material is used as the packaging material and the copper-filled laser microvias are used for low-parasitic-inductance and high-thermal-conductivity interconnection. Careful electro-thermal codesign and optimization of power loop is conducted to make the tradeoff between power loop inductance and thermal performance. The proposed full bridge power module achieves the lowest power loop inductance of about 0.305 nH in power modules with the same power level. The maximum thermal resistances from the embedded GaN bare dies to top and bottom surface are 3.39 and 0.42 °C/W, respectively. Benefitting from the ultralow power loop parasitic inductances, the switching speed of GaN devices reaches to 57.5 V/ns, while the voltage overshoot is not higher than 5.35% of the dc bus voltage. The superior performance of the proposed integrated GaN module makes it a promising application prospect in high frequency high power density converters.