Conceptual Development Using 3D Printing Technologies for 8kV SiC Power Module Package

Abstract

Post-silicon power devices, SiC or GaN for example, have many advantages over traditional silicon devices, particularly for smaller size and higher thermal densities. Although these devices are in the early stage of development, many applications have been identified, such as hybrid vehicles and the smart grid. For power packaging, there is now a greater challenge of much higher voltage, faster switching speed and much smaller package size (higher density). All of these issues call for newer approaches in power packaging. The microelectronics area has been developing stacked 3D technology along with printed 3D circuit technologies. Of been interested are the 3D printing technologies that can implement complicated structures, such as multilevel interconnects and selective dielectric field enhancements, besides introducing rapid prototyping in the early power stage design cycle. The 3D printing technology, introduced in the late 1980's, is now becoming prevalent. Commercial printers can create high-resolution structures in ceramic, metals (e.g. titanium, copper and aluminum) and polymers. The conceptual design proposed in this paper will incorporate a hybrid approach of traditional structures over-printed with polymers, or more advanced structures over-printed with metal and ceramic. The design focuses on packaging 1 cm × 1 cm SiC Schottky diode, which has a blocking capability of 8kV with a final target at 15kV. Early use of the package, in keeping with rapid prototyping, is to provide a test vehicle for the device, and prove the application of 3D printed material to high voltage power modules. This paper will present the necessity for packaging new SiC devices, review device characteristics, introduce the use of extruded 3D printing materials for a hybrid structure, and use of jetted/extruded layer-by-layer buildup for total, direct structure creation. Characterization of some available dielectric and metal printable materials, and a test methodology for electrical, thermal and mechanical performance will be discussed. An early-stage example will be shown and extrapolated to higher-level conceptual designs.