Thermal Resistance Calculation For Heat Sink

Contrary to heat exchangers it is impossible to calculate the efficiency of a heat sink without comparing it to another design.

Thermal resistance calculation for heat sink.

By calculating the thermal resistance of two different heat sinks the thermal efficiency gain between them can be measured. This tool is designed to calculate the heat dissipation and the heatsink thermal resistance required given four parameters. The calculator computes the total thermal resistance due to the conduction through and convection and radiation from the pcb. Calculate the thermal resistance and pressure drop of a plate fin heat sink and study how individual parameters affect the heat sink performance.

How does the heat sink calculator work. You can choose to include figures for the thermal interface material in addition to the junction to case thermal resistance if desired. This calculator uses the calculation methodology explained in the blog posts how to design a flat plate heat sink and performance of a led flat plate heat sink in multiple orientations the heat sink thermal resistance and temperature of the heat source are calculated by the calculator. Note that the heat sinks in question must be designed to cool the same heat source.

The resistance to heat flow from the junction of the heat generating component through the casing thermal interface material heat sink and finally to environment is represented by the thermal resistance circuit shown in the diagram below. When choosing heat sinks you want the smallest thermal resistance possible which means that the heat will be more easily dissipated. Thermal resistance calculator calculate the heat sink thermal resistance required to maintain a specified component junction temperature using the thermal resistance calculator below. The maximum ambient temperature the device s junction to package thermal resistance the thermal resistance of the heat sink and the power applied.

For surface mount smt parts where the pcb copper is used as a heat sink for 1 ounce copper the heat dissipation asymptotically approaches 1 square inch in other words having a pcb heat sink greater than 1. This calculation is for a heat source that is the same size as the base of the heat sink therefore no spreading resistance is included in the calculation. Pcb thermal resistance calculator. Reference the blog post how to design a flat plate heat sink to learn about how to calculate the thermal spreading resistance.

The following equation is used to calculate r hs the thermal resistance of the heat sink. This tool is designed to calculate junction temperature of an electronic device typically power devices given four parameters.