Inventory summary of commonly used power semiconductor devices
Power electronic devices, also known as power semiconductor devices, are used for high-power (usually tens to thousands of amps of current and hundreds of volts or more) electronic devices in power conversion and power control circuits. It can be divided into half-controlled devices, fully-controlled devices and uncontrollable devices, among which thyristors are half-controlled devices, with the highest withstand voltage and current capacity among all devices; power diodes are uncontrollable devices, with simple structure and principle, work Reliable; it can also be divided into voltage-driven devices and current-driven devices, among which GTO and GTR are current-driven devices, and IGBT and power MOSFET are voltage-driven devices.
1.MOS Control led Thyristor
Equivalent circuit diagram of MCT
MCT is a new type of MOS and bipolar device. As shown in FIG. MCT is a combination of high impedance, low driving pattern, power and fast switching speed of MOSFET and high voltage and high current characteristics of thyristor to form a high-power, high-voltage, fast full-control device. Essentially the MCT is a MOS gate controlled thyristor. It can be turned on or off by adding a narrow pulse to the gate, which is formed by paralleling countless unit cells. Compared with GTR, MOSFET, IGBT, GTO and other devices, it has the following advantages:
(1) High voltage and large current capacity, the blocking voltage has reached 3 000V, the peak current has reached 1 000 A, and the maximum current density that can be turned off is 6 000kA/m2;
(2) The on-state voltage drop is small and the loss is small, and the on-state voltage drop is about 11V;
(3) Extremely high dv/dt and di/dt tolerance, dv/dt has reached 20 kV/s, and di/dt is 2 kA/s;
(4) The switching speed is fast, the switching loss is small, the turn-on time is about 200ns, and the 1 000 V device can be turned off within 2 s;
2. Intergrated Gate Commutated Thyristors
IGCT is a new type of device developed on the basis of thyristor technology and combined with IGBT and GTO technologies. It is suitable for high-voltage and large-capacity frequency conversion systems. It is a new type of power semiconductor device used in giant power electronic complete sets. IGCT integrates GTO chip with anti-parallel diode and gate driver circuit, and then connects with its gate driver in a low-inductance manner at the periphery, which combines the advantages of stable turn-off capability of transistor and low on-state loss of thyristor. The performance of a thyristor is exerted in the on-phase, and the characteristics of a transistor are exhibited in the off-phase. The IGCT chip is not connected in series or in parallel, the power of the two-level inverter is 0.5~3 MW, and the power of the three-level inverter is 1~6 MW; if the reverse diode is separated, it is not integrated with the IGCT, and the two-level inverter The inverter power can be expanded to 4/5 MW, and the three-level can be expanded to 9 MW. At present, IGCT has been commercialized, the highest performance parameter of IGCT products manufactured by ABB is 4 5kV/4kA, and the highest development level is 6kV/4kA. In 1998, Japan's Mitsubishi Corporation also developed a GCT thyristor with a diameter of 88 mm. The advantages of low loss, fast switching, etc. ensure that it can be used in 300 kW~10 MW converters reliably and efficiently, without the need for series and in parallel.
3. Injection Enhanced Gate Transistor
IEGT is an IGBT series power electronic device with a withstand voltage of more than 4 kV. It realizes a low on-state voltage by adopting a structure of enhanced injection, which has made a leap in the development of large-capacity power electronic devices. IEGT has a potential development prospect as a MOS series power electronic device. It has the characteristics of low loss, high-speed operation, high withstand voltage, intelligent active gate drive, etc., as well as the characteristics of using trench structure and multi-chip paralleling and self-current sharing. It has the potential to further expand the current capacity. In addition, many derivative products can also be provided through module packaging, which are highly expected in the application of large and medium-capacity converters. The IECT developed by Japan's Toshiba takes advantage of the electron injection enhancement effect, so that it has the advantages of both IGBT and GTO: low saturation voltage drop, safe operating area (the capacity of the absorption circuit is only about one tenth of that of GTO), low gate Drive power (two orders of magnitude lower than GT O) and higher operating frequency. The device adopts a flat-plate crimping motor lead-out structure, with high reliability, and its performance has reached the level of 4.5 kV/1 500A.
4. Intergrated Power Elactronics Mod ules
IPEM is a module that integrates many components of a power electronic device. It firstly encapsulates semiconductor devices MOSFET, IGBT or MCT and diode chips together to form a building block unit, and then stacks these building block units on an open-hole high-conductivity insulating ceramic substrate, and below it is sequentially Copper substrate, beryllium oxide ceramic and heat sink. On the upper part of the building block, the control circuit, gate drive, current and temperature sensors, and protection circuit are integrated on a thin insulating layer by surface mounting. IPEM realizes the intelligence and modularization of power electronic technology, greatly reduces circuit wiring inductance, system noise and parasitic oscillation, and improves system efficiency and reliability.
5. Power Electric Building Block
Power Electric Building Block is a device or module developed on the basis of IPEM that can handle power integration. PEBB is not a specific semiconductor device, it is the integration of different devices and technologies designed according to the optimal circuit structure and system structure. A typical PEBB is shown above. Although it looks a lot like a power semiconductor module, PEBB includes gate driver circuits, level shifting, sensors, protection circuits, power supplies, and passive devices in addition to power semiconductor devices. PEBB has energy interface and communication interface. Through these two interfaces, several PEBBs can form a power electronic system. These systems can be as simple as small DC-DC converters or as complex as large distributed power systems. In a system, the number of PEBBs can vary from one to any number. Multiple PEBB modules work together to complete system-level functions such as voltage conversion, energy storage and conversion, and cathodic impedance matching. The most important feature of PEBB is its versatility.
6. Ultra-high power thyristor
The thyristor (SCR) has increased its power capacity by a factor of nearly 3000 since its inception. Now many countries have been able to stably produce 8kV / 4kA thyristors. Light-triggered thyristors (LTTs) of 8kV/4kA and 6kV/6kA are now in production in Japan. The United States and Europe mainly produce electrically-triggered thyristors. In the past ten years, due to the rapid development of self-shutdown devices, the application field of thyristor has been reduced. However, due to its high voltage and high current characteristics, it is widely used in HVDC, static var compensation (SVC), high-power DC It still occupies a very important position in the application of super power and high voltage frequency conversion speed regulation. It is expected that in the next few years, thyristors will continue to develop in high-voltage, high-current applications. Many manufacturers now offer high-voltage, high-current GTOs with a rated switching power of 36MVA (6kV/6kA). Typical turn-off increments for conventional GTOs are only 3 to 5. The "squeeze effect" caused by the inhomogeneity during the turn-off of the GTO makes it necessary to limit the dv/dt to 500-1kV/μs during the turn-off. For this reason, one has to use bulky and expensive absorption circuits. In addition, its gate drive circuit is more complicated and requires larger drive power. So far, gated power semiconductor devices are the most commonly used in high voltage (VBR > 3.3kV), high power (0.5 to 20 MVA) traction, industrial and power inverters. At present, the highest research level of GTO is 6in, 6kV/6kA and 9kV/10kA. In order to meet the needs of the power system for a three-phase inverter power voltage source of more than 1GVA, it is very likely to develop a 10kA/12kV GTO in the near future, and it is possible to solve the technology of connecting more than 30 high-voltage GTOs in series. A new level of application in power systems.
7. Pulse power closing switching thyristor
The device is particularly suitable for delivering extremely high peak power (several MW), extremely short duration (several ns) discharge closure switch applications such as: lasers, high intensity lighting, discharge ignition, electromagnetic transmitters and radar modulators Wait. The device can be turned on quickly under a high voltage of several kV, does not require a discharge electrode, has a long service life, is small in size, and has a relatively low price. It is expected to replace the high-voltage ion thyratron, ignition tube, spark, Gap switch or vacuum switch, etc. The unique structure and process characteristics of the device are: the gate-cathode perimeter is very long and forms a highly interwoven structure, the gate area accounts for 90% of the total chip area, while the cathode area only accounts for 10%; the base hole-electron lifetime Very long, the horizontal distance between gate-cathode is less than one diffusion length. The above two structural features ensure that the device can get 100% application of the cathode area when the device is turned on. In addition, the device's cathode electrode uses a thicker metal layer to withstand transient peak currents.
8. New GTO device - integrated gate commutated thyristor
There are currently two alternatives to conventional GTOs: high-power IGBT modules, and new GTO-derived devices - integrated gate-commutated IGCT thyristors. IGCT thyristor is a new type of high-power device. Compared with conventional GTO thyristor, it has many excellent characteristics, such as reliable turn-off without snubber circuit, short storage time, strong turn-on capability, and turn-off gate charge. The total power loss of the application system (including all devices and peripheral components such as anode reactors and snubber capacitors, etc.) is low.
The IGBT cells in today's high-power IGBT modules usually use trench gate IGBTs. Compared with the planar gate structure, the trench gate structure is usually processed with a precision of 1 μm, which greatly improves the cell density. Due to the existence of the gate trench, the junction field effect transistor effect formed between the adjacent cells in the planar gate structure device is eliminated, and a certain electron injection effect is introduced at the same time, which reduces the on-resistance. The conditions are created for increasing the thickness of the long base region and improving the withstand voltage of the device. Therefore, the high-voltage and high-current IGBT devices that have appeared in recent years all adopt this structure. In 1996, Japan's Mitsubishi and Hitachi respectively successfully developed IGBT modules with huge capacity of 3.3kV/1.2kA. Compared with conventional GTO, their switching time is shortened by 20%, and the gate drive power is only 1/1000 of that of GTO. In 1997, Fuji Electric successfully developed 1kA/2.5kV flat-panel IGBT. The flat-plate crimping structure similar to GTO adopts a more efficient heat dissipation method at both ends of the chip. It is particularly meaningful to avoid a large number of electrode lead-out lines inside the high-current IGBT module, improve reliability and reduce lead inductance, but the disadvantage is that the utilization rate of chip area decreases. Therefore, the high-voltage and high-current IGBT module with the flat-plate crimping structure is also expected to become the preferred power device for high-power and high-voltage converters.
10.Injection Enhanced Gate Trangistor
In recent years, Toshiba Corporation of Japan has developed IEGT. Like IGBT, it also has two structures, plane gate and trench gate. The former product is about to come out, and the latter is still under development. IEGT has some advantages of both IGBT and GTO: low saturation voltage drop, wide safe operating area (suction loop capacity is only about 1/10 of GTO), low gate drive power (2 lower than GTO) order of magnitude) and higher operating frequencies. In addition, the device adopts a flat-plate crimping electrode lead-out structure, which is expected to have higher reliability. Compared with the IGBT, the main features of the IEGT structure are that the gate length Lg is longer, and the lateral resistance value of the N-long base region near the gate side is higher, so holes are injected into the N-long base region from the collector, unlike in IGBTs. As in the case, the lateral flow into the emitter through the P region smoothly, but a hole accumulation layer is formed in this region. To keep this region electrically neutral, the emitter must inject a large amount of electrons into the N-long base region through the N-channel. In this way, high-concentration carrier accumulation is also formed on the emitter side of the N-long base region, and a carrier distribution similar to that in GTO is formed in the N-long base region, thereby better solving the problem of high current and high withstand voltage. contradiction. At present, the device has reached the level of 4.5kV/1kA.
11.MOS gated thyristor
The MOS gate-controlled thyristor makes full use of the good on-state characteristics, excellent turn-on and turn-off characteristics of thyristors, and is expected to have excellent self-turn-off dynamic characteristics, very low on-state voltage drop and high voltage resistance. And there are promising high-voltage and high-power devices in the power system. At present, more than a dozen companies in the world are actively conducting research on MCT. There are three main structures of MOS gated thyristor: MOS field controlled thyristor (MCT), base resistance controlled thyristor (BRT) and emitter switch thyristor (EST). Among them, EST may be the most promising structure among MOS gated thyristors. However, it will take a considerable period of time for this kind of device to become a commercialized practical device and reach the level of replacing GTO.
The pressure is low, and the practical application is limited. In order to meet the needs of high-voltage, high-speed, high-efficiency and low-EMI applications, high-voltage GaAs high-frequency rectifier diodes have been successfully developed in Motorola. Compared with silicon fast recovery diodes, this new type of diode has the following remarkable features: small reverse leakage current changes with temperature, low switching losses, and good reverse recovery characteristics.
13.Silicon Carbide and Silicon Carbide (SiC) Power Devices
Among the power devices made with new semiconductor materials, the most promising are silicon carbide (SiC) power devices. Its performance index is an order of magnitude higher than that of gallium arsenide devices. Compared with other semiconductor materials, silicon carbide has the following excellent physical characteristics: high forbidden band width, high saturation electron drift speed, high breakdown strength, Low dielectric constant and high thermal conductivity. The above-mentioned excellent physical properties determine that silicon carbide is an extremely ideal semiconductor material in high temperature, high frequency, and high power applications. Under the same withstand voltage and current conditions, the drift region resistance of SiC devices is 200 times lower than that of silicon. much lower. Moreover, the switching time of SiC devices can reach the order of 10nS, and it has a very good FBSOA. SiC can be used to manufacture RF and microwave power devices, various high frequency rectifiers, MESFETS, MOSFETS and JFETS, etc. SiC high frequency power devices have been successfully developed at Motorola and are used in microwave and radio frequency devices. GE is developing SiC power devices and high-temperature devices, including sensors for jet engines. Westinghouse has produced very high frequency MESFETs operating at 26GHz. ABB is developing high-power, high-voltage SiC rectifiers and other SiC low-frequency power devices for industrial and power systems.
Scan to visit the mobile website and follow the official WeChat account of Kingser Electronics