It is shown that the thermal resistance of the junction-case is determined through a partial heat flux and is some characteristic of the crystal fastening in the case of high-frequency pulse voltage converters. It is practically impossible to measure this resistance in mass production because of the high complexity and low accuracy, although this resistance is indicated in the reference data sheet for each IC. To exclude the possibility of hidden defects that are not detected during the control of electrical parameters, it is proposed to use one hundred percent control of thermal parameters by way of comparison with a standard.
The transient thermal characteristic can be determined experimentally for a specific IC and specific cooling conditions. After approximation by its exponents, it is possible to construct a thermoelectric model and use it to study the change in the temperature of the IC chip with changing various parameters (supply voltage, load power, etc.).
Dual Quasi-Resonant Controller Position Observer Based on High Frequency Pulse Voltage Injection Method