Study On Heat Dissipation Characteristics Of Silicon-based GaN Power Devices Packing

In recent years,due to the characteristics of high electron mobility,high electron saturation rate,wide band gap(about 3.4e V),and high breakdown electric field of gallium nitride materials,AlGaN/GaN HEMT devices have great application prospects in the field of electronic devices.With the upgrading of application requirements,the size of the device is smaller and smaller,and the power density is larger and larger,which leads to a significant increase in the channel temperature of the device,which poses a serious challenge to the device packaging.Therefore,in order to improve the stability,reliability and service life of the device,it is very important to study the thermal characteristics of AlGaN / GaN HEMT device.This paper studies the temperature characteristics of two devices,cascaded power devices and normally closed power devices.The specific research work is as follows:A three dimensional thermal simulation model of multi grid connected cascaded power devices and groove power devices is established.The influence of material temperature on the thermal conductivity is considered,and the temperature distribution of the device under different conditions is obtained by Ansys simulation.By discussing the transverse and longitudinal temperature distribution in AlGaN/GaN HEMT devices,it helps to understand the ways and means of heat transfer.In this paper,the effects of different plastic packaging materials,device layout,packaging frame materials,packaging structure,gate structure of AlGaN/GaN HEMT devices,substrate materials and thickness on the temperature characteristics of devices are studied,which is helpful to optimize the device structure and packaging structure,and is of great significance to alleviate the self heating effect of power devices.In this paper,a cascaded power device with thermal resistance of 6.89℃/W and a groove power device with thermal resistance of 26.90℃/W are obtained through simulation.Finally,the factors affecting the temperature characteristics of the device are analyzed,the effective measures to reduce the temperature of the device are summarized,and the ideal design model is given.The temperature measurement of cascaded power devices and groove power devices is realized.The infrared imager is used to measure the temperature of the two devices under different conditions,analyze them and calculate the thermal resistance.Finally,the cascaded power device with thermal resistance of 5.45℃/W and the groove power device with thermal resistance of 24.71℃/W are obtained.The thermal resistance of the cascaded power device in this paper is similar to that reported at home and abroad.The package structure and process used in this paper are relatively simple and easy to realize,and the temperature distribution of the device is more uniform to avoid local heat accumulation.The experimental results are consistent with the simulation results,and the error is less than 10%,which verifies the rationality of the simulation model and has a certain guiding significance.This paper realizes the electrical test of cascaded power devices and groove power devices,and obtain the output characteristic curve and transfer characteristic curve of the device.Both devices are normally closed devices,in which the threshold voltage of the cascaded power device is 2.3V,and the threshold voltage of the grooved power device is 2.1V.