New high-power density SiC power modules set a new standard for OBCs

ROHM has developed the new 4-in-1 and 6-in-1 SiC moulded modules in the HSDIP20 package optimised for PFC and LLC converters in OBC for xEVs. The lineup includes six models rated at 750V (BSTxxx1P4K01) and seven products rated at 1200V (BSTxxx2P4K01). All basic circuits needed for power conversion in various high-power applications are integrated into a compact module package, lowering the design workload for manufacturers and facilitating the miniaturisation of power conversion circuits in OBCs and other applications.

In recent years, the rapid electrification of cars has been driving efforts to attain a decarbonised society. EVs are seeing higher battery voltages to extend the cruising range and enhance charging speed, creating a demand for higher output from OBCs and DC-DC converters. At the same time, there is a growing need in the market for greater miniaturisation and lighter weight for these applications, necessitating technological breakthroughs to improve power density – a key factor – while enhancing heat dissipation characteristics that could otherwise hinder progress. The company's HSDIP20 package addresses these technical challenges that were previously difficult to overcome with discrete configurations, contributing to higher output and the downsizing of electric powertrains.

The HSDIP20 features an insulating substrate with outstanding heat dissipation properties, suppressing the chip temperature rise even during high-power operation. When comparing a typical OBC PFC circuit using six discrete SiC MOSFETs with top-side heat dissipation to its 6-in-1 module under the same conditions, the package was verified to be approximately 38C cooler (at 25W operation). This high heat dissipation performance supports high currents even in a compact package, gaining industry-leading power density more than three times higher than top-side cooled discretes and over 1.4 times that of similar DIP-type modules. As a result, in the PFC circuit mentioned above, the HSDIP20 can lower mounting area by approximately 52% compared to top-side cooled discrete configurations, greatly contributing to the miniaturisation of power conversion circuits in applications such as OBCs.

Application examples include power conversion circuits like PFC and LLC converters, commonly used in industrial equipment's primary side circuits. This allows the HSDIP20 to contribute to miniaturising industrial and consumer electronics applications. Automotive systems: Onboard chargers, electric compressors and more. Industrial equipment: EV charging stations, V2X systems, AC servos, server power supplies, PV inverters, power conditioners, etc.