Thermal Analysis of Electronic Components
The electrical analogy is straightforward:
The sum of the three series resistors must not exceed:
Suppose the semiconductor package and joint interface resistors are as follows:
This implies the heatsink used must have a maximum thermal resistance of:
The designer must select a heatsink which has a thermal resistance of less than Otherwise, the juncture temperature will exceed 120 degrees C.
Liquid Cold Plate
An analysis of liquid cold plates uses the same basic principles as air cooling, however in this case the waste energy is transferred to a liquid stream which flows through a cold plate heat exchanger. Since the liquid temperature will rise as the flow stream picks up the heat, one can calculate the rise using the energy equation. That is:
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