| |July 20219high-power modules play an important role in the success of electric, hybrid fuel cell vehicles ­ a change from other conventional electric vehicles designed in the initial adoption stage.But a few concerns continue to be the impediments in the growth of the semiconductor modules. The develop-ment of automotive power module is facing comprehensive challenges in de-signing the structure, material, and as-sembly technology. On the material, the year 2020 has been a tough year, when supplies remained a problem. Strong pi-oneers like the Mitsubishi Electric were prepared for situations like this. Despite odds, the Company continued supplying the latest tech-enabled J1-series power semiconductor modules for hybrid ve-hicles. Mitsubishi Electric pioneered the mass-production of power semiconduc-tor modules for hybrid vehicles in 1997.The new J1-Series, a direct water-cooling (pin-fin) structure, mainly for motor drive applications in electric and hybrid vehicles, is known to meet stringent safety standards and provides greater reliability.Semiconductor modules offer special features. Some like the J1-Series contribute to further compactness, weight reduction and reduced power consumption in inverters for electric and hybrid vehicles.It has cutting-edge features like re-duced inverter size and weight, achieved through the extra compact package with high integration. The compact power semiconductor module features a high-ly integrated seventh generation IGBT with a carrier-stored trench-gate bi-polar transistor (CSTBTTM) structure and seventh generation diodes. The di-rect cooling pin-fin structure achieves 30% lower thermal resistance and 40% smaller footprint.Another important feature is that each IGBT chip is provided with a current sensor for short -circuit protection as well as an on-chip temperature sensing for over-temperature protection, which can directly monitor the chip temperature.The new design adds to the efficiency: J1-series of Mitsubishi Electric, for instance, no longer uses heatsink grease as required by the previous formats; instead, it is equipped with a cooling fin integrated with the module to allow direct cooling and improve the cooling performance.Also, by optimizing the shape and layout of the fin, and eliminating the solder layer beneath the isolation layer, the thermal resistance between the chip and the cooling water, Rth(j-w), is reduced by more than 30% from the level of the conventional product that consists of three J-series transfer-moulded power modules(T-PMs) mounted on the copper cooling fin with the heatsink grease between them.The J1-series uses Aluminium as the cooling fin material to provide high corrosion resistance against water cooling & reduces the assembly weight significantly from the conventional product.The new module is automo-tive-grade high quality and adopts Mit-subishi Electric's original Direct Lead Bonding (DLB) structure. The DLB structure ensures power-cycle and temperature-cycle life spans 30 times longer than those of typical industrial power semiconductor modules.The outlookExtensive research and development are being undertaken to make EVs the main focus of the automotive industry. Furthermore, the development of HEV/EV is becoming the main policy of most governments and automotive industry, leading to worldwide adoption. This will increase the consumption and demand for high-powered semiconductors like the J1-Series.The technology mentioned above is going to be adopted by most EV manufacturers. Going forward, technological advancements, along with a reduction in cost and size of components and systems, are expected to play a pivotal role in the growth of the automotive power electronics in the electric vehicles market. The popularity of EVs will grow and EVs will become the need of the masses.
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