Heatsink

Heatsinks are normally metal objects used to dissipate heat away from a component or device that is temperature sensitive or is structurally degraded by the presence of heat. Heatsinks are usually made of Copper, Aluminum or another material with high heat conductivity (k). Their theory of operation is the more surface area, the more heat is dissipated to the surrounding medium, usually air or water. Heatsinks can also be used to radiate cold temperatures away from a device, such as on the cold side of a Peltier Cooler, though this is not common.

Heatsinks come in a large variety of sizes and shapes, from CPU coolers commonly found in computers, which are moderately sized and are designed to be as efficient as possible given the small area available in a PC case, to massive aluminum heat sinks welded or integrated into a case of a transformer.

When there is a larger heat load than a heatsink can handle, liquid cooling is used, by attaching a metal block to the heat load and passing water or another coolant through the block, with the water transferring heat to an external radiator away from the heat source.