METHOD MEASURING THERMAL RESISTANCE OF TWO-TERMINAL NETWORKS WITH WELL-KNOWN TEMPERATURE COEFFICIENT OF RESISTANCE

摘要

electronics, inspection of quality of electron articles, evaluation of their temperature margin. SUBSTANCE: method measuring thermal resistance of two-terminal networks with well-known temperature coefficient of resistance consists in transmission through tested two-terminal network of heating current whose value changes by harmonic law with fixed amplitude and period one order higher than thermal constant of time of two-terminal network. Change of voltage drop across two-terminal network is measured on two frequencies: on measurement frequency of heating current and on frequency thrice as much as measurement frequency of heating current. Value of thermal resistance of tested two-terminal network is found by amplitudes of first Um1 and third Um3 harmonics of change of voltage by formula Zt= (1/alpha.Im).[Ua/(Ub-Ua)2], where alpha is temperature coefficient of resistance; Im is amplitude of heating current; Ua= 4Um3, Ub= Um1+Um3. EFFECT: raised precision of measurement of thermal resistance of two-terminal networks and reduced expenses. 1 dwg