SiC is an extremely hard, synthetically produced crystalline compound of silicon and carbon that has long been utilized as an abrasive in grinding wheels, abrasive paper and cloth, as well as in industrial furnaces and rocket engines.
ROHM is committed to using wide bandgap materials in power devices, such as SiC MOSFETs. These devices offer much lower series resistance compared with conventional planar power MOSFETs.
High-performance power devices
Power semiconductor devices form the core of power systems, and progress in power electronics relies heavily on their performance. SiC devices offer higher switching frequencies with lower losses compared to conventional silicon (Si, bandgap 1.1eV) power semiconductors for creating more compact and efficient systems.
ROHM recently unveiled their 4th generation of SiC MOSFETs featuring double trench structures to reduce parasitic capacitance and provide the industry’s lowest specific ON resistance.
The company has also achieved low leakage current and temperature dependence with these new devices, making them suitable for high-speed switching applications like electric vehicle inverters as well as power factor correction circuits and rectifier bridges – enabling faster charging times with increased efficiency for electric vehicle battery packs.
SiC Schottky barrier diodes reduce the rise voltage by over half when compared with conventional Silicon FRDs while maintaining similar leakage current and recovery characteristics, which allows faster operation of high-speed devices like MOSFETs. Furthermore, their lower drift layer resistance enables higher than 600V withstand voltage configuration and smaller passive components that contribute significantly towards smaller power systems with reduced size, weight and energy costs.
Energy-efficient power modules
Silicon has long been the go-to material for power semiconductor devices used across a range of electronic circuits, but recently silicon carbide (SiC) offers an attractive alternative with wider bandgap that permits lower resistance, switching losses, and leakage current compared to conventional silicon (Si) chips.
ROHM has developed SiC molded-type modules designed to reduce both size and weight for more compact electric vehicle (EV) inverter drives and power supplies. Their 4th Generation SiC MOSFETs boast lower ON resistance than general purpose silicon (Si) modules while their innovative trench structure significantly enhances short circuit robustness.
SiC power modules maximize high-speed performance through a combination of MOSFETs and SBDs made entirely from SiC material, offering higher switching frequencies than comparable silicon-based IGBTs and supporting wider input voltage ranges for more energy efficient use.
Silicon carbide (SiC) is a dense solid black crystal with an hexagonal close-packed structure made up of carbon and silicon atoms bonded together at temperatures above 1,700 degC through chemical reactions between carbon and silicon atoms, producing two primary polymorphs: alpha and beta. Moistanite occurs naturally in certain meteorites and kimberlite while beta forms can be found in diamonds to produce silicon carbide powder.
EcoSiCTM brand
Silicon Carbide (SiC) devices feature higher switching frequencies and reduced losses compared to silicon devices, creating more energy-efficient and compact systems. Furthermore, SiC power semiconductors are carbon neutral and help lower energy consumption in electric vehicles and renewable energy systems. ROHM has introduced its EcoSiC brand for products which incorporate this advanced technology.
EcoSiC’s logo features hexagonal crystal structures which represent circuit patterns, symbolizing its precision and innovation. Its color scheme was chosen as an ode to Venturi’s Formula E racing car in red – which ROHM developed alongside them as part of its high performance electric vehicle technology collaboration project.
Edward Acheson first discovered SiC in 1891. Today it’s an industrial ceramic material used as an abrasive, steel additive and structural component – as well as being one of the primary raw materials for producing semiconductor devices. Although SiC is generally colorless to black in its native state, its hue can be changed through doping with phosphorus, nitrogen or aluminium.
ROHM SiC power devices have been featured in traction inverters of Chinese carmaker Zhejiang Geely Holding Group (Geely). ROHM also produced and shipped power modules utilizing its 4th Generation SiC MOSFET bare chips to GEEKR powertrain modules – further expanding production capacities to meet rising demand for these products.
Collaboration with SEMIKRON
Silicon carbide is an extremely hard and rigid material with hardness rivaling diamond. With a low thermal expansion coefficient and high electrical conductivity, silicon carbide makes an excellent material choice for applications requiring components that must remain accurate over a wide temperature range, such as telescope mirrors. Furthermore, its stability of frame makes silicon carbide an excellent material to use in high-speed power semiconductor devices.
ROHM has responded to the rapid expansion of the electric vehicle (EV) industry with a 1200V RGA IGBT with improved performance and reliability that addresses this shortcoming by offering optimized products with low switching losses, thermal characteristics that increase power density while remaining compatible with existing IGBT solutions.
SEMIKRON and ROHM Semiconductor have collaborated to produce the world’s first complete EV inverter solution with silicon carbide (SiC). Their integrated power module contains a ROHM SiC MOSFET in a SEMIKRON eMPackTM module designed for automotive applications, coupled with the National Instruments LabVIEW programming environment and support for selecting full-qualified, ready-to-use power assemblies; control algorithm development; real-time Hardware-In-Loop testing (HIL); electric power analysis; and power grid communication protocols.
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