Because optimum thickness aluminium heat sink fins are too soft and fragile.
Heat sink fin thickness.
A simple plate fin heatsink has seven independent geometric parameters that can be varied in any design.
Finally the total resistance of the optimized variable thickness fin heat sink is lower than that of the optimized uniform thickness fin heat sink.
The convection heat dissipation q c1 from area a 1 the external side surfaces of the heat sink shown figure 2 is first calculated.
Even though the thermal conduction is worse the toughness of steel allows thinner fins.
Aluminium heat sinks are always made with the fins too thick.
A heat sink with high aspect ratio will have either a greater density of fins in a specific footprint tall fins compared to heat sinks with less aspect ratio.
Fin thickness fin height fin length fin spacing base length base width and thickness of the base plate.
A heat sink also commonly spelled heatsink is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium often air or a liquid coolant where it is dissipated away from the device thereby allowing regulation of the device s temperature.
A heat sink s aspect ratio is the comparison between the fin height.
In the case presented in table 2 the total thermal resistance shows a decrease of about 15 after allowing the fin thickness to vary in the direction normal to the fluid flow.
A variation of the straight fin heat sink is a cross cut heat sink where the straight fin heat sink is cut at regular intervals.
Notice that any old steel heat sink you see will have thinner fins than any new aluminium heat sink.
In computers heat sinks are used to cool cpus gpus and some chipsets and ram modules.
Calculate the thermal resistance and pressure drop of a plate fin heat sink and study how individual parameters affect the heat sink performance.