When it comes to thermal management, heat sinks are the most prevalent method. Even individuals knowledgeable about the technology can easily overlook these components.
This post defines what a heat sink is and covers the fundamental operating principles of heat sinks.
What is a Heat Sink?
If you have a device that produces heat, and you want to regulate the device's temperature by dissipating that heat into a fluid medium such as air or a liquid coolant, you need a heat sink.
A heat sink works by increasing the working area of the device and increasing the amount of low-temperature fluid that flows through.
Heat sinks come in various shapes and sizes, and even within the same model, there can be significant visual differences. Each type indeed has its unique features.
How Does a Heat Sink Work?
A heat sink moves heat away from a critical component by directing it elsewhere. Almost all heat sinks follow the four steps below to complete their function.
Source of Heat
Any system that generates heat and necessitates the removal of that heat can serve as this source. Examples of heat sources include chemical, solar, mechanical, friction, and electrical.
Heat Radiates Away from the Source
It is also possible to use heat pipes to help in this process. When a heat sink is directly in contact with the heat source, it is directed into the heat sink and away from the source through natural conduction.
The thermal conductivity of the heat sink material directly affects this process. As a result, heat sinks are typically constructed from copper and aluminum, which have excellent thermal conductivity.
Dissipates the Heat Evenly
Natural conduction will allow heat to flow through the heat sink from a high temperature to a lower temperature environment without a fan. There will be inconsistencies in the heat sink's thermal profile due to this. Hence, heat sinks tend to be hotter near the source and cooler at the sink's extremities. For a very challenging application, a custom heatsink is applied.
Direct Heat Away from the Heat Sink
This process is dependent on the temperature gradient of the heat sink and its working fluid, which is often air or a non-electrically conducting liquid. Flowing through the machine is working fluid utilizing thermal conduction and convection to cool a warm heat sink's surface removing heat from the surface.
Like the previous one, this stage depends on a temperature gradient to draw heat away from the heat sink. As a result, if the temperature outside is not lower than the temperature of the heat sink, there will be no convection and no subsequent evacuation of heat. This is also the stage at which the entire surface area of the heat sink becomes most beneficial. A wide surface area increases the space available for thermal diffusion and convection.
Final Thoughts
A heat sink plays a vital role in keeping a device performing well. Most consumers are not aware such a part exists. Understanding how heat sink functions will give you an idea on how vital it is.