Selected Problems of Power MOSFETs Thermal Parameters Measurements

Abstract

In the paper, selected problems that are related to the measurements of thermal parameters of power MOSFETs that are placed on a common heat sink are analysed. The application of the indirect electrical method, the contact method, and the optical method in measuring self and mutual transient thermal impedances of these transistors is presented. The circuits that are required to perform measurements are presented and described. The errors of measurements are assessed for each of the considered methods. In the case of the indirect electrical method, an additional influence of the selection of a thermo-sensitive parameter and the function approximating thermometric characteristics on the measurement error are taken into consideration. The measurement results of the thermal parameters of the investigated transistors that were obtained using the considered measurement methods in various supply conditions are presented and discussed.

Cooling Systems of Power Semiconductor Devices—A Review

“…The problem of the effective cooling of electronic devices is a subject of the investigations of packaging constructors [6,7], as well as designers and constructors of electronic circuits containing these devices [8][9][10]. This paper [6] proves that the size of voids in the soldering joint practically has no influence on the efficiency of heat removal from a power semiconductor device.…”

“…In turn, active systems need the external energy to supply fans, pumps or thermoelectric modules, being parts of these cooling systems. Some active cooling systems can work in a passive mode; however, their ability to dissipate heat in this mode is significantly lowered [8]. The passive operation of a cooling system is desired in the case when a high level of reliability is needed, e.g., in automotive applications.…”

“…The previous papers by the authors [8,11] presented the results of the investigations on cooling systems for selected electronic components. These papers show that through the appropriate selection of a cooling system, it is possible to improve the efficiency of the heat removal from a semiconductor device even several dozen times.…”

“…These papers show that through the appropriate selection of a cooling system, it is possible to improve the efficiency of the heat removal from a semiconductor device even several dozen times. Figure 17 shows the measured dependences of thermal resistance on the dissipated power for power MOSFETs with the TO-220 type case operating in different cooling systems marked successively with letters from A to H. The investigations were carried out using the following cooling systems described in [8]:…”

“…This paper [6] proves that the size of voids in the soldering joint practically has no influence on the efficiency of heat removal from a power semiconductor device. In turn, the paper [8] presents the results of the measurements, which show that an increase in the dissipated power and the air flow speed led to an improvement in the efficiency of cooling of such devices. Special components of cooling systems, such as ultra-thin micro heat pipes and vapor chambers, are described and analyzed in detail in the papers [9,10].…”