Power semiconductor device internal contact thermal resistance measurement method and measurement clamp

Abstract

The invention provides a power semiconductor device internal contact thermal resistance measurement method and measurement clamp. The measurement method comprises the steps that a relation curve of device electrical parameters and junction temperature is drawn; a transient thermal impedance curve when liquid metal is coated between the surface of a device shell and a heat radiator is drawn; numeric calculation is performed on the transient thermal impedance curve so that the integral structure function and the differential structure function of the device are obtained; and a contact thermal resistance value is solved through reference to the integral structure function and the differential structure function. The measurement clamp is composed of three substrates arranged in a horizontal direction and two columns arranged in a vertical direction. An insulated plate and a heat radiation substrate are longitudinally and symmetrically arranged between the upper substrate and the intermediate substrate. A pressure uniform distribution device, a sensor, a pressure maintaining plate and a pressure applying device are installed between the intermediate substrate and the lower substrate in turn. According to the measurement method, measurement error caused by a thermocouple can be eliminated, the measurement result is real and reliable and the measurement method is simple and efficient.

Description

technical field [0001] The invention relates to the field of thermal resistance measurement of power semiconductor devices, in particular to a method for measuring internal contact thermal resistance of power semiconductor devices and a test fixture thereof. Background technique [0002] Compression-type power semiconductor devices such as transistors, IGBTs, IGCTs, and GTOs have been gradually applied to high-voltage direct current transmission (HVDC) in power systems due to their advantages such as high power density, double-sided heat dissipation, easy series connection, and high reliability. , electric locomotives and other high-voltage, high-power applications. [0003] Thermal resistance, which is an important standard for measuring the heat dissipation performance of semiconductor devices, is the most important parameter of semiconductor devices. The thermal resistance value of a device reflects the increase in power density and compact structure of semiconductor devi...

AI Technical Summary

Problems solved by technology

Conventional contact thermal resistance measurement methods include steady-state method and transient method. In the typical steady-state method, the temperature difference data of the contact surface is linearly extrapolated to obtain the contact thermal resistance. The data is reliable when it is large, and it is very difficult to accurately measure the temperature difference between the semiconductor device and the contact surface

The most widely used photothermal method in the transient method is to obtain the contact thermal resistance by measuring the phase difference (attenuation of wave amplitude) between the thermal wave (deformation wave) and the modulating wave after encountering the interface. The diffusion that causes the thermal wave to occur at the contact destroys its phase relationship, skewing the measurement

[0005] There are a large number of internal components of the press-fit IGBT device, and each component has a large area and thin thickness. It is not feasible to measure the temperature difference between the interfaces by the traditional thermocouple method: on the one hand, because the component thickness is very thin, the thermocouple cannot be placed; On the other hand, the area of ​​the component is relatively large, and it is difficult to ensure that the measured temperature is the maximum temperature. The most important thing is that the contact thermal resistance between the interfaces is not only related to pressure, but also related to temperature, surface roughness, etc., and through the same material, etc. Effective measurement is difficult to meet the requirements of roughness and actual working conditions, and the measurement results have large errors

The transient method will also produce errors in the measurement accuracy of the contact thermal resistance of the internal components of the press-fit IGBT device, because the large current passing through the contact interface between the internal components of the device will have an impact on the deformation wave

Images