ROHM Develops World's First Transfer-molded SiC Power Module Capable of Operating at High Temperatures (225ºC)


Kyoto, Japan – Semiconductor manufacturer ROHM Co., Ltd., has developed a SiC power module capable of operating at high temperatures in line with SiC device temperature characteristics for driving inverters in electric vehicle (EV) and hybrid electric vehicle (HEV) applications and industrial equipment. The module—the first of its kind to use a newly developed high-heat-resistance resin and achieve high-temperature operation at 225ºC with a transfer-molded design—can take advantage of the same compact, low-cost packaging as modules utilizing existing Si devices, making it likely that the product will help spur widespread use of SiC modules.

The module's ability to drive a 3-phase, 600 V/100 A inverter at temperatures of up to 225ºC with six ROHM SiC-SBDs and six SiC-trench MOSFETs at 600 V/100 A has been confirmed. Additionally, the module can be used in 1,200 V class inverters. This capability enables not only dramatically lower loss and more compact designs than were possible with previous Si-IGBT modules, but also significant cost reductions compared to previous case-type SiC modules. ROHM aims to commercialize the product after three to four years. ROHM also plans to use the technology in IPMs with gate driver ICs by developing IPMs with SiCs of up to 600 V/50 A that are capable of operating at high temperatures in a transfer-molded DIP-type design.

Faced with demand for higher-power, higher-efficiency designs capable of operating at high temperatures in the power electronics field, which is typified by fast-moving developments in product segments such as EVs and HEVs, manufacturers developing SiC devices are simultaneously working to develop SiC modules capable of high-efficiency, high-temperature operation. In October 2010, ROHM became the first manufacturer to successfully integrate a module (600 V/450 A) with SiC-trench MOSFETs and a diode module (600 V/450 A) with SiC-SBDs (Schottky barrier diodes) into a motor and then use them to drive the motor.

Since conventional transfer-molded modules were unable to withstand high temperatures of 200ºC and higher, manufacturers had been using case-type designs made with materials capable of withstanding temperatures of up to 250ºC. However ROHM chose to focus on developing transfer-molded designs due to their more compact size, lower cost, and superior suitability for mass production. It proved difficult to develop a transfer-molded design capable of withstanding temperatures in excess of 200ºC due to a number of issues, including the fact that most encapsulation resins that could be used at temperatures of 200ºC and above were hard and prone to cracking in high-temperature environments. Nonetheless, ROHM was able to reach heat resistance of 225ºC in a compact design thanks to optimization of resin properties and the module structure, making the company the first manufacturer to achieve high-power operation at 225ºC with a transfer-molded design.

Leveraging the characteristics of SiC devices in combination with the new package, it is possible to shrink modules by a factor of 50:1 by volume compared to a conventional Si-IGBT module with the same functionality while implementing a full SiC design (with trench MOSFETs and SBDs). In terms of electrical characteristics, switching time is halved and operation dramatically accelerated.

ROHM will continue to focus its resources on developing SiC devices and SiC modules for the automotive and other markets.

ROHM plans to exhibit the results of this development effort at CEATEC Japan 2011 from October 4 to 8 at Makuhari Messe in Chiba, Japan.

■Principal features

  1. High-temperature operation at 225ºC
  2. 6-in-1 package, capable of driving 600 V/100 A class inverters
  3. Compact, transfer-molded design
  4. Full SiC design (with trench MOSFETs and SBDs) for high-speed, high-efficiency operation

■Principal specifications

Dimensions 32 (L) x 48 (W) x 3 (H) mm (4.608 cm3)
Circuit architecture 3-phase inverter (6-in-1)
Rated voltage 600 V
Rated current 100 A
Heat-resistant temperature (drive) Tjmax 225ºC
Package type Transfer-molded
Switching time Turn-on: 76 ns; turn-off: 96 ns

■Module static characteristics

Module static characteristics

■Module switching waveforms

(Measurement conditions: Ids=100 A, Vds=300 V; load: L=200 ºCH, Rg=3.2Ω, Rgs=15 kΩ)
Module switching waveforms

■Transfer-molded SiC power module

Transfer-molded SiC power module


  • Transfer-molded design
    A type of package formed by placing a bonded frame in a die and filling it with thermosetting resin.
  • Case-type design
    A type of package formed by assembling molded components.