Heat Sink

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What is a Heat Sink?

A heat sink is a hardware component that is attached to a critical digital or electromechanical component to prevent it from overheating. The primary purpose of a heat sink is to absorb the heat the critical component generates and disperse it.


In computing, heat sinks prevent processors from reaching temperatures that could cause malfunctions or physical damage. Most of the time, heat sinks are installed during the manufacturing process.

However, if you are building a computer from scratch or are installing a more powerful central processing unit (CPU) or graphics processing unit (GPU) on a gaming PC or crypto mining rig, you will need to purchase a heat sink and install it yourself.

Techopedia Explains the Heat Sink Meaning

Techopedia Explains the Heat Sink Meaning

Heat sink definitions often make a distinction between active and passive heat sinks.

Passive heat sinks do not have moving parts. They rely on the properties of thermodynamics to dissipate heat naturally. This type of heat sink is often pre-installed and used to keep tablets and smartphones from overheating.

In contrast, active heat sinks include a fan or pump that moves air or liquid across the heat sink’s surface to dissipate heat. This type of heat sink is used more often to keep desktop computers, servers, gaming PCs, and electromechanical devices used in manufacturing from overheating.

How Heat Sinks Work

Technically, heat sinks use conduction to absorb heat and convection to dispense the heat into the surrounding environment.

Essentially, the base plate absorbs heat from the component it is attached to through conduction, and the fins dissipate the heat into the surrounding air through convection.

Active heat sinks include a fan to move more air through the heat sink’s fins and increase the heat dissipation rate.

Key Components of a Heat Sink

Key Components of a Heat Sink

Base plates, fins, and mounting mechanisms are the three key components of both passive and active heat sinks.

Base Plate
The base plate is the part of the heat sink that makes direct contact with the heat-generating component.

Fins are thin protrusions that are added to the base plate to increase the heat sink’s surface area and facilitate ambient airflow.

Mounting Mechanisms
Mounting mechanisms are the screws, clips, or thermal compounds that are used to connect heat sinks with heat-generating components.

Types of Heat Sinks

While most passive and active heat sinks use air to dissipate heat, some types of more sophisticated (and expensive) heat sink designs use liquid cooling and heat pipes.

This type of heat sink is more expensive, but it offers several advantages over air cooling, including higher thermal conductivity, more efficient heat transfer, and the ability to dissipate heat over a larger area.

Liquid-cooled heat sinks are typically used to improve heat dissipation for high-performance computing applications and overclocked operating systems (OS).

Essentially, a liquid coolant (such as water) absorbs heat from the heat sink’s base plate and is passed through a radiator. The radiator functions much like a traditional air-cooled heat sink, using extensive fins to increase the surface area and dissipate heat into the air.

Some types of liquid-cooled heat sink designs also include heat pipes.

Heat pipes are sealed, hollow tubes filled with fluid. One end of a heat pipe is located near the heat sink’s base, and the other end is located near the heat radiator’s fins.

As heat from the source comes into contact with a heat pipe, the fluid absorbs the heat and turns to vapor. The hot vapor rises in the tube until it reaches the fins, where condensation turns it back into a liquid. The liquid then flows back towards the warmer end of the heat pipe and begins the cooling process again.

Factors to Consider When Choosing a Heat Sink

The choice of heat sink depends on factors such as the required level of thermal conductivity and heat load management.

Thermal conductivity describes a material’s ability to conduct heat. Most heat sinks use aluminum or copper, both of which have relatively high thermal conductivity compared to other materials.

Aluminum is commonly used for passive heat sinks. It is inexpensive, readily available, and can be easily manipulated to accommodate different types of fin structures.

Copper is also easy to use, but it’s more expensive. Copper has higher thermal conductivity and is a better choice for applications that need to maximize heat transfer efficiency.

Many heat sinks use a combination of copper and aluminum components to obtain the benefits of copper at a lower cost. For example, the base plate may be made of copper for its superior thermal conductivity, while the fins are made of aluminum for cost savings and weight reduction.

What Affects Heat Sink Performance

The heat sink’s surface area and the spacing between fins will affect its ability to dissipate heat into the surrounding environment.

Too much spacing will allow heated air to bypass the heat sink, while too little spacing can impede airflow and hinder heat dissipation.

Ventilation and airflow management within the heat sink’s housing can also impact performance. Factors such as airflow direction, obstructions in the airflow path, and fan speed can affect cooling effectiveness.

How to Install a Heat Sink

  1. When you are installing an aftermarket heat sink on a CPU or GPU, the first thing you will need to do is apply a thin layer of thermal compound (also called thermal paste) on top of the processor. This will allow the heat sink to absorb heat.
  2. The next step is to attach the heat sink to the processor and secure it with mounting mechanisms. Heat sinks require close contact, so proper alignment with the heat-producing component is important.

If you are installing an active heat sink, you will also need to connect the heat sink’s fan with the CPU fan header on the computer’s motherboard. This will allow the motherboard to monitor temperatures and adjust fan speeds accordingly for optimal cooling and noise management.

Applications of Heat Sinks

Applications of Heat Sinks

Heat sinks are often used in computing to reduce the heat generated by processors, but the principles of heat transfer can be applied to many other applications.

Here are some other ways heat sinks are used:

Heat sinks are often used to regulate internal combustion engine temperatures and prevent overheating.

LED lighting
Heat sinks are used to keep LED lights cool and extend their lifespan.

Solar Panels
Solar panels often incorporate heat sinks to prevent overheating and improve performance.
Industrial Machinery
Various industrial machines can generate excess heat and require heat sinks to maintain ideal temperatures.

Heat Sink Pros and Cons

Like any engineering solution, heat sinks have both pros and cons.

For example, aftermarket heat sinks are highly effective at dissipating heat away from electronic or mechanical components, but they need to be installed properly to prevent overheating.

Here are some of the other pros and cons of purchasing and installing aftermarket heat sinks:

CustomizationNoiseOverclocking PotentialAestheticsPricePerformance

Pros: Allows users to choose a heat sink that best fits their needs.

Cons: Requires careful consideration of compatibility with the CPU socket, motherboard layout, and case dimensions.

Pros: Some aftermarket fans for active heat sinks are designed to operate quietly.

Cons: Higher fan speeds may be necessary for optimal cooling, which can lead to increased noise levels.

Pros: Better thermal performance and stability for higher CPU frequencies.

Cons: Overclocking may void the computer’s warranty.

Pros: Some aftermarket heat sinks come with RGB lighting options for added visual appeal.

Cons: RGB lighting can increase power consumption and add complexity to installation and setup.

Pros: Can provide options for users with different budgets.

Cons: Higher-performance aftermarket heat sinks tend to be more expensive than stock coolers.

Pros: Can provide better heat dissipation.

Cons: Performance gains may vary depending on the quality of installation.

The Bottom Line

Heat sinks prevent processors on electronic devices and components in many electromechanical devices from overheating. They use conduction to absorb heat and convection to dissipate it into the surrounding environment.


What is a heat sink in simple terms?

Can I use multiple heat sinks on a computer?

What are the 2 types of heat sink?

Do all components in a computer require a heat sink?


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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.