High Thermal-Transient Packaging for a SiC-Based Solid State Circuit Breaker

摘要

Solid-State Circuit Breakers (SSCBs), or Contactors, are critical components in next generation electric aircraft, andmust be small in size, fast in response, and have high reliability. Silicon Carbide (SiC) semiconductor switchesprovide a series of improvements over traditional silicon-based breakers in both electrical and thermalperformances. The reported SSCB uses SiC MOSFETs mounted on cast-aluminum traces, cast onto an aluminumnitride (AlN) ceramic co-captured in an aluminum composite baseplate. The system is similar to an AlSiC and Direct-Bonded-Aluminum (DBA) approach.This presentation details the transient thermal characterizations of an SSCB having the highest density indevelopment. Previous work focused on a 30A SSCB that was constructed and tested to show a 300A, 500ns circuitbreaking capability. The high density comes from allowing the SiC junctions to pulse to ~350°C (in 5ms) from a105°C ambient baseplate. The 30A/300A module was reported in IMAPS HiTEC’10 “Development of a SiC SSPCModule with Advanced High Temperature Packaging,” This paper builds on that paper adding the mechanicalresults and all new data on the larger, high energy density module with larger die. The objective of the presentationis to introduce (or update) the use of cast composite metal-ceramic structures for high thermal transientapplications and document the mechanical stress/strain performance through simulations. The module is indevelopment for military applications and has not been field-tested. This is also developed for Smart-Gridapplications in local distribution systems.