Thermal Resistance Measurement

Thermal Resistance MeasurementMeasuring the thermal resistance of high performance cold plates is a delicate operation because the thermal resistance of most common interface materials is often higher than the resistance of the cold plate.

To eliminate the interface resistance, the NCP test articles are fabricated with an integral heat flux probe, as shown in the photograph.   Thermocouples soldered into the heat flux probe are used to measure the temperature gradient in the heat flux probe.   From the gradient, one can calculate the heat flux and from the temperature closest to the cold plate and the gradient one can calculate the temperature at the position of the nominal cold plate surface.

The cold plate resistivity R* is then calculated from:

Thermal Resistance Calculation