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What are some common power semiconductor devices?
We know that power devices are the core of power conversion and circuit control in electronic devices. They use the unidirectional conductivity of semiconductors to change the voltage, frequency, phase, DC/AC conversion and other functions in electronic devices. According to controllability and other use factors, power devices are divided into many categories, including:
MOS Controlled Thyristor
MCT is a new type of MOS bipolar composite device. MCT combines the characteristics of MOSFET such as high impedance, low driving diagram, power and fast switching speed with the high-voltage and large current characteristics of thyristor to form a high-power, high-voltage and fast fully controlled device. In essence, MCT is a MOS gate controlled thyristor. It can add a narrow pulse on the gate pole to make it turn on or off. It is composed of countless cells in parallel.
IGCT Integrated Gate Commutated Thyristors
IGCT is a new device developed on the basis of thyristor technology and GTO technology. It has the characteristics of large current, high blocking voltage, high switching frequency, high reliability, compact structure, low conduction loss, etc. It is a new type of power semiconductor device used in giant power electronic complete sets, which is suitable for high-voltage and high-capacity frequency conversion systems, and has a good application prospect due to its low manufacturing cost and high yield.
IGCT integrates GTO chip with anti parallel diode and gate drive circuit, and then connects with its gate driver in a low inductance mode. It combines the advantages of stable turning off capability of transistor and low on state loss of thyristor. In the conduction stage, the performance of the thyristor is displayed, and in the turn off stage, the characteristics of the transistor are displayed.
Integrated Power Electronics Modules (IPEM)
IPEM is a module that integrates many devices of power electronic devices. It first encapsulates the semiconductor device MOSFET, IGBT or MCT and its chips together to form a building block unit, and then stacks these building block units onto the high conductivity insulating ceramic substrate with holes. Below it are copper substrate, beryllium oxide ceramic chip and heat sink. On the upper part of the building block unit, the control circuit, gate drive, current and temperature sensors and protection circuit are integrated on a thin insulating layer through surface mounting.
PEM realizes the intellectualization and modularization of power electronics technology, greatly reduces circuit wiring inductance, system noise and parasitic oscillation, and improves system efficiency and reliability.
Power Electronic Building Block
PEBB 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 excellent circuit structure and system structure.
In addition to power semiconductor devices, it also includes gate drive circuit, level conversion, sensor, protection circuit, power supply and passive devices. PEBB has energy interface and communication interface, through which several PEBBs can form 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 range from one to any number. Multiple PEBB modules can work together to complete system level functions such as voltage conversion, energy storage and conversion, cathodic impedance matching, etc. The important feature of PEBB is its universality.
Electron Injection Enhanced Gate Transistor (IEGT)
IEGT is a series of IGBT power electronic devices with withstand voltage of more than 4kV. By adopting the structure of enhanced injection, the low on state voltage is realized, which makes the large capacity power electronic devices achieve a leap forward development. IEGT has the potential development prospect as a MOS series power electronic device. It has the characteristics of low loss, high speed operation, high voltage withstand, intelligent active gate drive, etc., as well as the characteristics of groove structure and multi chip parallel and self current sharing, which makes it quite potential in further expanding the current capacity. In addition, many derivative products can also be provided through module packaging, which is expected in large and medium capacity converter applications.
Super power thyristor
Since the advent of SCR, its power capacity has increased nearly 3000 times. In recent ten years, due to the rapid development of self turning off devices, the application field of thyristor has shrunk. However, due to its high voltage and large current characteristics, it still occupies a very important position in the application of HVDC, static var compensation (SVC), high-power DC power supply and ultra large power and high-voltage variable frequency speed regulation.
IGBT (TrenchIGBT) module with high power trench grid structure
Nowadays, IGBT cells in high power IGBT modules usually use grooved gate IGBTs. Compared with the plane gate structure, the grooved gate structure usually adopts 1 μ M machining accuracy, thus greatly improving the cell density. Due to the existence of gate channel, the junction field-effect transistor effect between adjacent cells in the planar gate structure device is eliminated, and a certain electron injection effect is introduced, which makes the on resistance decrease. It creates conditions for increasing the thickness of long base region and improving the withstand voltage of devices. Therefore, IGBT devices with high voltage withstand and high current appeared in recent years all adopt this structure.
And silicon carbide (SiC) power devices
Among the power devices made of new semiconductor materials, silicon carbide (SiC) power devices are promising. 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 bandgap width, high saturated electron drift speed, high breakdown strength, low dielectric constant and high thermal conductivity. These excellent physical properties determine that silicon carbide is an ideal semiconductor material for high temperature, high frequency and high power applications.
Under the same withstand voltage and current conditions, the drift resistance of SiC devices is 200 times lower than that of silicon. Even the conduction voltage drop of high withstand voltage SiC FETs is much lower than that of unipolar and bipolar silicon devices. Moreover, the switching time of SiC devices can reach the order of 10nS, and it has a very superior FBSOA. SiC can be used to manufacture RF and microwave power devices, various high-frequency rectifiers, MESFETS, MOSFETS, JFETS, etc.
These are common power semiconductor devices. The power level of power electronic converter covers a wide range, including small power range, such as notebook computers, refrigerators, washing machines, air conditioners, etc; Medium power range electric drive, new energy power generation, etc; High power range: such as HVDC transmission system. The development of science and technology also puts forward more and more requirements for high performance of power semiconductor devices.