NTC thermistor chip for IGBT developed and produced by EXSENSE Electronic Technology Co., Ltd., plays the role of temperature monitoring and temperature control in IGBT due to its resistance value varies with temperature. As an ideal switching device in the field of power electronics, IGBT technology continues to develop with the emergence of various new structures, new processes and new material technology. The power consumption is decreasing and the actual operating temperature is constantly increasing.
By isolating the edge structure of IGBT chip, IGBT (RB-IGBT) with bidirectional blocking ability can be formed. In bidirectional switching applications, there is no need to in series diodes in bidirectional switching applications, and less leakage current and lower loss can be achieved. Super Junction technology breaks the limit relationship between the on-off voltage drop and the withstand voltage of traditional silicon devices, and can greatly reduce the device power consumption. It has been successfully applied in MOSFET. The application of this technology in IGBT can further reduce power consumption, which has been widely concerned by the industry.
The main difficulty of IGBT of super junction is the realization of technology. In order to reduce the process difficulty, various "semi-super-junction" structures are proposed to achieve the compromise between performance and process. At the same time, the technology level of IGBT is constantly improving, many advanced technology, such as ion implantation, fine lithography, etc. has been applied to the manufacture of IGBT. The minimum characteristic sizes of IGBT chips have ranged from 5μm to 3μm and then to 1μm, and even up to the sub-micron level. The use of precision manufacturing process can greatly increase the power density, at the same time reduce the junction depth, and reduce the high temperature diffusion process, thus making it possible to manufacture IGBT using 12-inch or larger silicon wafers. In addition, new materials, such as the development of wide bandgap semiconductor material technology, can realize more low power dissipation, larger power capacity, higher working temperature. Among them, silicon carbide (SiC) has become the main research direction of high-power semiconductor at present, and has been commercialized in unipolar devices, making progress in the research of IGBT and other bipolar devices. At present, IGBT is mainly limited by the defects of manufacturing process and substrate material, such as channel mobility and reliability, smaller current gain, and the growth of highly doped P-type substrate, etc. In the future, with the development of material epitaxial technology, silicon carbide (SiC) IGBT will achieve breakthroughs.
With the continuous development of IGBT chip technology, the highest working temperature and power density of the chip are constantly improving, and IGBT module technology should also be adapted to it. In the future, IGBT module technology will also continue to improve to surround two aspects of the back of the chip fixed by welding and frontal electrode interconnection. It is expected to combine advanced encapsulating concepts and technologies such as free weldless, leadless bonding and liner/substrate free, etc., make upper and lower surfaces of the chip sintered or pressure welded to achieve fixed and electrode interconnections, while more functional elements are integrated into the module, such as temperature sensors, current sensors and drive circuit, etc., continuously improve the power density, integration level and intelligence of IGBT module.
At present, in the common process technology, IGBT chip generally adopts planar gate or groove gate structure, and uses soft penetration structure and transparent collector area structure technology, as well as various of enhanced technology, in order to improve the comprehensive performance and long-term reliability of IGBT. The high pressure IGBT module technology is still based on the standard welding encapsulation, while the middle and low pressure IGBT module products have a lot of new technologies, such as sintering instead of welding, pressure contact instead of wire bonding, liner/substrate free encapsulation and so on. In the future IGBT will continue to develop towards integration, intelligence and miniaturization.