Public information shows that power devices are an important branch of discrete devices, which can be divided into three categories: power discrete devices, power modules and power ICs. It is understood that the power device is the core device for electric energy (power) processing, which is used to change the voltage and frequency in electronic devices, DC-AC conversion, etc. Its application fields are extremely wide, almost covering automotive electronics, industrial control, consumer electronics, solar energy, wind power, data center, computer, lighting, rail transit and other industries.





Metal oxide semiconductor field effect transistor (MOSFET) is one of the main parts of power discrete devices, which can be traced back to 1960. It has the advantages of high input impedance, low driving power, fast switching speed, no secondary breakdown, wide safe working area and good thermal stability. It is widely used in IC design and board level circuit. Especially in the field of high-power semiconductors, MOSFETs with various structures play an irreplaceable role.





It is reported that the application of power devices represented by MOSFET in the automotive field mainly assists in driving various electric motors, including ventilation system, wiper, electric window, etc; At the same time, it also plays a key role in power control systems such as electric power steering system and electric braking system, as well as power conversion modules such as DC / DC converter and battery management system.





In addition to MOSFET, power discrete devices also include IGBT, power diode, power bipolar transistor and thyristor. In fact, the development history of power discrete devices is as long as half a century, and its application history can be traced back to the 1950s. There is no more detail here.





In terms of development, the earliest power devices were mainly uncontrollable diodes / triodes, which were mainly used in industry and power system; Followed by semi controlled thyristors, which are mainly used to improve controllability; Furthermore, fully controlled MOSFET and IGBT are mainly used to realize high frequency and greatly improve low loss performance; Since then, superjunction MOSFETs with smaller on resistance, smaller volume and lower loss than ordinary mosfefs have appeared, meeting the application requirements of high power and high frequency in the market.





After half a century of development, because the performance development of semiconductor material silicon (SI) has approached the physical limit, the development of third-generation semiconductor materials such as silicon carbide (SIC) and gallium nitride (GAN) began to receive attention.