What is a heat sink?



A technician says that your laptop is running slowly because your heat sink may have come loose. What is a heat sink?

A) A heat sink uses cool water to lower the temperature of motherboard components.

B) A heat sink is a fan that sits directly on processors to provide additional cooling.

C) A heat sink is used to pull cool air through computer cases to lower the overall case temperature.

D) A heat sink dissipates heat from computer components through thermal conduction.


Answer: D) A heat sink dissipates heat from computer components through thermal conduction.

Heat sinks are slabs of copper or aluminum alloy that have fins or grids that extend upwards. Cool air passes through the fins, where the heat is transferred from the metal to the air and carried out of the computer case. If a heat sink comes loose inside of a laptop, the inside of the system will become very hot and the system will automatically throttle down the speed of the system to prevent any permanent damage.


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The incorrect answers:

A) A heat sink uses cool water to lower the temperature of motherboard components.
Liquid cooling systems are designed to lower the temperature of the motherboard components using liquid chemical coolants.

B) A heat sink is a fan that sits directly on processors to provide additional cooling.
Although there are fans that work in conjunction with heat sinks to cool processors, the fans themselves aren’t considered heat sinks.

C) A heat sink is used to pull cool air through computer cases to lower the overall case temperature.
Case fans are used to pull cool air through a computer case. Heat sinks use this cool air to transfer the heat away from the computer components.

Want to know more? Watch “Cooling System Overview.”


Personal computers must be constantly cooled to ensure the system runs at peak efficiency. Without appropriate cooling in place, the computer’s life expectancy is shortened and in extreme cases the computer will halt due to overheating of the components. In this video, you’ll learn how computers are cooled through heat sinks, on-board fans, computer case fans, and liquid cooling systems.