There are various kinds of chips. Today, I would like to introduce a kind of IGBT (Insulated Gate Bipolar Transistor), which is closely related to our life. This chip is widely used in electric vehicles. 
   
IGBT is a chip used for AC motor output control of electric vehicles, railway locomotives and multiple units. IGBT directly controls the conversion between direct current and alternating current, which determines the torque of the driving system and the maximum output power. So, your car's acceleration ability, top speed and energy efficiency all depend on it. IGBT accounts for about half of the cost of motor drive system, accounting for 5% of the whole vehicle cost, and it is the second most expensive component of the whole electric vehicle (the first highest cost is battery). It is no exaggeration to say that this is the "core technology" in the field of electric vehicles. Structurally, IGBT has three main development directions: 1. Vertical structure of IGBT: NPT type with non-transparent collector, PT type with buffer layer, NPT type with transparent collector and FS electric field cutoff type; 2. IGBT gate structure: planar gate mechanism and Trench structure; 3. Silicon wafer processing technology: epitaxial growth technology, zone melting silicon single crystal; According to the packaging technology, IGBT modules can be divided into two types: welding type and crimping type. Generally, high-voltage IGBT modules are mainly packaged by standard soldering, while middle and low-voltage IGBT modules have many new technologies, such as soldering by sintering and wire bonding by pressure contact. With the continuous development of IGBT chip technology, the highest working junction temperature and power density of the chip are constantly increasing, and IGBT module technology should also adapt to it. In the future, IGBT module technology will be improved around "welding and fixing the back of the chip" and "interconnection of front electrodes". Main Application Fields of IGBT As the mainstream device of new power semiconductor devices, IGBT has been widely used in traditional industrial fields such as industry, 4C (communication, computer, consumer electronics, automotive electronics), aerospace, as well as strategic emerging industrial fields such as rail transit, new energy, smart grid and new energy vehicles. 1. IGBT module of new energy vehicle plays a vital role in electric vehicle, and is the core technical component of electric vehicle and charging pile. IGBT modules account for nearly 10% of the cost of electric vehicles and about 20% of the cost of charging piles. IGBT is mainly used in the following aspects in the field of electric vehicles: a) the electric control system drives the automobile motor after high-power DC/AC inverter; B) Low-power direct current/alternating current (DC/AC) inverter of vehicle-mounted air conditioning control system, using IGBT and FRD； with low current; C) IGBT module in intelligent charging pile of charging pile is used as switching element; 2. Smart grid IGBT is widely used in the power generation end, transmission end, transformation end and power consumption end of smart grid. From the power generation end, IGBT modules are required for rectifiers and inverters in wind power generation and photovoltaic power generation. From the transmission side, FACTS flexible transmission technology in UHVDC transmission needs a large number of power devices such as IGBT. From the substation side, IGBT is the key device of power electronic transformer (PET). From the power consumption side, there is a large demand for IGBT for household white electricity, microwave ovens, LED lighting drivers, etc. 3. Rail TransitIGBT devices have become the mainstream power electronic devices for traction converters and various auxiliary converters of rail transit vehicles. AC drive technology is one of the core technologies of modern rail transit. In AC drive system, traction converter is the key component, and IGBT is one of the core components of traction converter.