Simulation Assessment On Transistor Temperature Testing

With the rapid development of power electronic technology, the applications of transistor devices have become very popular. However, some transistor devices can not work because of its high temperature in power electronic products. Transistor devices are very sensitive to temperature. In the case of high temperature, the Transistor devices will have several bad problems, such as working point drifting, generating higher noise, signal distortion, Gain Value instability and even causing thermal breakdown. At present, the transistor's problem of temperature has become the key of electronic product development.In this graduation thesis, the accuracy of junction temperature'measurement of transistor will be evaluated and researched to the question of SANTAK Corporation. The transistor's junction temperature is an very important index of its application and selection. So, the accuracy of measurement of Transistor'junction temperature is a key. At present, the staff measure the junction temperature through measuring plastic package, which will be inaccurate. Because different transistors have different structure of encapsulation and material, different size and location of junction, different amount of base pin and different loss of Working state. Therefore, it is necessary to evaluate the methods of measurement. In this paper, the diode of TO247 in encapsulation type will be studied as the research object to discussing the different parameters'effect of the temperature measurement to diode mainly through the way of simulation. It is necessary to establish a reliable simulation model before the simulation analysis. Therefore, in order to ensure the reliability of the model, the first step is to get experiment date through the experiment testing, the second step is to revise and check simulation model based on the experimental data, then the parameters which have influence in the accuracy of transistor temperature testing will be analyzed according to the reliable simulation model.In this graduation thesis, three main parameters will be analyzed:λp (thermal conductivity of Plastic packaging), Rjc (thermal resistance from junction to the outside surface of Copper matrix) and P (the loss of transistor).then finding out the rule of the temperature measurement effect of three main parameters according to the simulation data.