METHOD TO MEASURE THERMAL JUNCTION-TO-CASE RESISTANCE OF HIGH-CAPACITY MIS TRANSISTORS Russian patent published in 2016 - IPC G01R31/26 

FIELD: measurement equipment.

SUBSTANCE: heating of a powerful MIS transistor is carried out with heating capacity modulated according to harmonic law, for this purpose they send a sequence of heating current pulses of permanent amplitude via the transistor, with the permanent repetition period and duration that varied according to the harmonic law. Pulses are sent via the anti-parallel diode built into high-capacity MIS transistor with the closed transistor channel, diode voltage is measured and saved for each heating pulse, and time dependence is calculated for the average heating power in the repetition period. In pauses between pulses of heating current they measure and save values of temperature-sensitive parameter - direct voltage on diode at low permanent measurement current, and calculate the time dependence of crystal temperature in process of transistor heating, afterwards with the help of Fourier transform they calculate amplitude of main harmonic of crystal temperature and amplitude of main harmonic of heating power, ratio of which is equal to module of thermal impedance of the transistor at the frequency of heating power modulation. Then the process of measurement is repeated at other frequencies of modulation, the frequency dependence of the transistor thermal impedance module is produced, which comprises a section with permanent value of thermal impedance module, which is accepted as equal to thermal junction-to-case resistance of the high-capacity MIS transistor.

EFFECT: increased accuracy of measurements.

4 dwg