Method for quickly detecting temperature of power device

Abstract

The invention discloses a method for quickly detecting the temperature of a power device. The method comprises the steps of enabling a 0402 packaged temperature sensor to be welded on a flexible printed circuit (FPC), forming a very narrow groove in a radiator under a heat dissipation substrate of the power device, enabling the size of the flexible printed circuit to be equivalent to the size of the groove during the design of the flexible printed circuit, coating the flexible circuit board welded with the temperature sensor with heat conduction silicone grease and then extending into the groove, then covering the flexible circuit board with the ceramic chip with the two sides coated with the heat conduction silicone grease, and finally attaching the power device to the ceramic chip and locking through the elastic piece. The temperature change of the power device can be followed very quickly and accurately; strong and weak electricity isolation is realized between the temperature sensor and high voltage; the thermal resistance between the heat dissipation substrate of the power device and the radiator is not influenced; and the method is low in cost, convenient to install and rapidand accurate in detection.

Description

technical field [0001] The invention relates to a temperature detection method, in particular to a fast and accurate method for detecting the temperature of a power device. Background technique [0002] With the development of power electronics technology, the power density of power electronic devices is getting higher and higher. Compared with air-cooled or self-cooled radiators, water-cooled radiators have the advantages of small size, high heat dissipation efficiency, and large heat capacity. Lots of applications. At the same time, IGBT single tubes have great advantages over IGBT modules in terms of cost and system power density improvement, and are widely used in electric vehicle motor controllers, general-purpose inverters, photovoltaic inverters, UPS and other fields. [0003] When packaging the IGBT module, in order to facilitate the application, one or more NTCs will be embedded on the DCB substrate inside the IGBT module to detect the temperature of the module. N...

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Problems solved by technology

[0004] However, when the above method is installed on a water-cooled radiator with a single-tube IGBT, there is a fatal flaw: there is water or coolant in the water channel of the water-cooled radiator, and the water or coolant will dissipate heat through a cooling system such as a fan, which makes The heat capacity of the entire water-cooled radiator is very large

In the experiment, it was found that if the temperature of the cooling medium is low, such as 10°C, and the IGBT loss is high, until the IGBT wafer is damaged due to overheating (over 150°C), the temperature detected by the NTC is still low, and the overheating cannot be achieved. Protection point, unable to effectively achieve overheating protection

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