In computers, the heatsink clip is the connector that holds the heatsink in place. The heatsink is the unit that cools computer hardware and is usually used on the main processing chip, which is located on the motherboard. A heatsink often has its base situated flush with the processing chip in the computer processing unit (CPU) socket. The clip connects the heatsink to the CPU by fastening to a screwed-in base frame around the processor chip bed. Usually, the heatsink clip is made of carbon steel.
A heatsink can most often be found attached to a motherboard. How a heatsink connects to a motherboard depends upon the heatsink and motherboard manufacturers. To reduce the temperature of the CPU, the heatsink is attached to the CPU so that it makes contact with the chip and conducts heat away from it. Most CPU heatsinks are connected to a fan that helps move hot air away from the computer hardware.
Heatsinks that use a fan to move air are called active heatsinks. Active heatsinks are the most common type of heatsink. Some heatsinks do not use a fan, but instead have large metal coils to help conduct and redistribute the heat from the hardware. These types of heatsinks are called passive heatsinks. Because passive heatsinks rely solely on heat conduction through metal to cool the hardware, they tend to have more metal than active heatsinks, making them much larger and heavier.
Large heatsinks, usually passive, weigh much more and can put stress on a standard heatsink clip base. Too much weight on the motherboard can cause the motherboard to break. In some cases, the heatsink can break the heatsink clip, become detached from the motherboard and fall, damaging other nearby hardware. This can be a particular problem when the heatsink is left to hang its weight on the heatsink clip, either upside-down or to the side.
Heatsinks that are inordinately heavy often have retention bed designs that differ from the standard heatsink clip. These heavier heatsinks may have aluminum bars securing them in place of a heatsink clip. Using passive heatsinks with an upgraded retention method can help prevent motherboard damage and heatsink clip breakage.
Because passive heatsinks lack a fan, they can cool a computer silently, eliminating fan whirring, but their size and weight can make them an unwise choice for some computer users. Smaller computer cases may not have the room for a passive heatsink system. Active heatsinks are usually smaller in size and more likely to accommodate case size and cooling capacity needs.
Most heatsinks work better if a thermal paste is applied at the point where the heatsink and CPU chip touch. The paste helps facilitate the transfer of thermal energy to the heatsink. Thermal paste can also be called heatsink compound or heatsink paste.