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A 2N3055 silicon NPN power transistor transistor mounted on an aluminum heat sink. A mica insulator electrically isolates the transistor case from the heat sink.


A heat sink (also commonly spelled heatsink or heat-sink) is a passive heat exchanger, such as a bent peace of aluminium, 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 at optimal levels.




In computers, heat sinks are used to cool central processing units or graphics processors. Heat sinks are used with high-power semiconductor devices such as power transistors and optoelectronics such as lasers and light emitting diodes (LEDs), where the heat dissipation ability of the component itself is insufficient to moderate its temperature.

A heat sink is designed to maximize its surface area in contact with the cooling medium surrounding it, such as the air. Air velocity, choice of material, metal protrusion design and surface treatments like silicone jell are factors that affect the performance of a heat sink. Heat sink attachment methods and thermal interface materials also affect the die temperature of the integrated circuit.

Mostly silicone based thermal adhesives or thermal greases improve the heat sink's performance by filling air gaps between the heat sink and the heat spreader on the device. A heat sink is usually made out of copper and/or aluminium. Copper is used because it has many desirable properties for thermally efficient and durable heat exchangers. First and foremost, copper is an excellent conductor of heat. This means that copper's high thermal conductivity allows heat to pass through it quickly. Aluminum is used in applications where weight is a big concern, if it is not an issue, copper and steel are used.

Metal tabs[]

A LM317 adjustable linear voltage regulator with heat sink.

Power transistors, voltage regulators and hot-running (as far as the tiny die is concerned) microchips have metal tabs on them to help dissipate the heat Many have a hole cut in the tab so they can be screwed to a bigger metal plate or a metal part of the appliance's casing. thermal adhesives or thermal greases the go between the tab and what it links to.

Metal plates[]

Fans on top[]

Air holes in cases[]

'Siberian' and 'Alaskan' fingers[]

Also see[]

  1. Science
  2. Transistors
  3. Useful metals
  4. Integrated circuits
  5. Transistor and IC packages


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  6. https://www.wikiwand.com/en/Heat_sink_(disambiguation)
  7. http://callofduty.wikia.com/wiki/Heat_Sink
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  12. http://www.ebay.com/itm/3x-2N2905-GOLD-TUNGSRAM-JAN2N2905-Si-PNP-60V-600mA-TO5-Transistors-BFX30/310843933529?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3Df72c7009504b4e24ae56755385a0930c%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D322264308797
  13. http://www.ebay.com/itm/1Pair-NEW-ORIGINAL-2SC3280-2SA1301-C3280-A1301-x2PCS/170817399727?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3Df72c7009504b4e24ae56755385a0930c%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D322264308797
  14. http://www.ebay.com/itm/2SC3280-Original-New-Toshiba-Transistor-C3280/121155903361?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3D2eb393f248ec4def8ddd19145fbcb93f%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D170817399727
  15. http://www.ebay.com/itm/50pairs-New-2SA1145-2SC2705-Transistor/271582771034?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20131003132420%26meid%3Df72c7009504b4e24ae56755385a0930c%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D322264308797