A heat sink may be found located above the cpu on a computer motherboard. It's a helpful guide to where the cpu< is located, and requires removal to access the cpu. It works in a similar fashion to a radiator in a car, drawing heat away from the engine: rapidly distributing heat from the cpu to a much larger volume and surface area. Just like the car radiator, the heat sink depends on airflow (air from a computer fan). With no moving air, a heat sink is incapable of radiating the heat away. The fan included in the power supply may be enough, or an additional fan is added to the case, or directly over the processor to provide the necessary cooling. Beryllia is a compound of Beryllium which transmits heat very efficiently and is used in heat sinks. Beryllia heat sinks have been used in specific designed parts, which are attached to a heat source, and have also been built into specific microelectronic devices as integral parts of the substrates of those devices.

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