IGBT Thermal Management system
The sales growth trend of new energy vehicles and the current situation of chip shortage, coupled with the uncertainty of the future epidemic trend, the market supply of IGBT is still in a relatively tight state. Similar to other power devices, in order to ensure its efficient, safe and stable operation, the thermal management technology for IGBT module is the most important link in the design and application of new products.
What is IGBT:
IGBT (insulated gate bipolar transistor) is a kind of power semiconductor device. Its Chinese name is "insulated gate bipolar transistor", which is composed of BJT (bipolar junction transistor) and MOSFET (insulated gate field effect transistor). As the core power device of energy conversion and power control, IGBT is called "CPU" in power electronics industry.
Thermal management for IGBT Modules:
The failure causes of most IGBT power semiconductor modules are related to heat. Therefore, the reliability of IGBT has also been widely concerned by the industry and academia, and has become a research hotspot at present. The thermal management methods for IGBT modules can be divided into internal thermal management and external thermal management. In specific applications, due to the large heat capacity between the cooling system and the semiconductor device substrate, only the slowly changing temperature can be compensated, so the external thermal management is suitable for low-frequency junction temperature fluctuations. For the rapid temperature change, it is considered to adjust the electrical parameters related to temperature in the system, that is, internal thermal management, to directly affect the junction temperature.
Internal thermal management:
The main idea of internal thermal management is to change the loss of IGBT module to smooth the junction temperature fluctuation caused by load power fluctuation. So far, scholars have explored many active thermal management strategies, including adjusting switching frequency, grid resistance, duty cycle, cyclic reactive power and power router, and proved their feasibility theoretically and experimentally.
External thermal management:
The external thermal management methods of IGBT module are mostly used to compensate the change of ambient temperature or control the average junction temperature, while the research on smooth junction temperature change is relatively few.
Similar to other power devices, an efficient, stable, convenient and compact cooling system is of great significance to the design of IGBT devices to ensure their safe and stable operation. Especially with the increase of IGBT module power density, the harsh application environment, and the improvement of reliability and life requirements, for IGBT module, its thermal design and thermal management technology is the most important link in the design and application of new products.
