As one of the most ideal switching devices in the field of power electronics, IGBT has three characteristics of high voltage, high speed and high current. It is widely used in the field of household appliances, transportation, power engineering, renewable energy and smart grid. At present, IGBT devices have been developed from the first generation to the fourth generation, its operating frequency can reach 200KHz. The power capacity has grown from a single tube of low power (80-300A/ 500-1200V) to ultra-high power (1000-1200A/ 4500V) module, formed a series of products.
IGBT module is a modular semiconductor product which is encapsulated by IGBT (Insulated Gate Bipolar Transistor Chip) and FWD (Diode Chip) through a specific circuit bridge. It has the characteristics of energy saving, convenient installation and maintenance, and stable heat dissipation. The encapsulated IGBT Module can be directly applied to the inverter, UPS uninterruptible power supply and other equipment. However, due to the ability of the IGBT to withstand over-current and over-voltage, it can cause damage in the event of an accident. Therefore, IGBT must be protected.
NTC is a negative temperature coefficient thermistor, which is a high technology semiconductor functional ceramic material with barium titanate as the main component. The main features of NTC thermistor in the operating temperature range of resistance decreases with increasing temperature in order to achieve automatic gain adjustment, overload protection, temperature control, temperature compensation, stable voltage regulator and so on.
IGBT module overheating protection is generally adopted by the radiator (including ordinary radiator and heat tube radiator), and can be forced air cooling. Installing the NTC thermal chip in the IGBT module can effectively detect the steady-state shell temperature (Tc) of the power module. IGBT NTC thermistor parameters of IGBT module encapsulation are exactly the same. According to different IGBT modules, the IGBT NTC temperature sensor and IGBT NTC thermistor chip which can be used to measure the temperature of IGBT module are directly encapsulated in the same ceramic substrate (DCB). Or the NTC thermistor is installed on a separate ceramic substrate to make the measurement process of IGBT module shell temperature more efficient and convenient.