Electronics manufacturers employ a variety of methods to manage thermal energy in electronics. One of the most common types of thermal management involves heat sinks. If you're looking for the right heat sink for your application, you should consider several important heat sink design factors before you buy. We'll cover five important heat sink parameters to keep in mind as you select an appropriate component.
1. Heat Sink Materials
One of the most critical parameters of a heat sink is the material from which it is constructed. To efficiently move thermal energy away from a heat-generating component, the heat sink must have high thermal conductivity. Some of the more common construction materials for heat sinks are aluminum and copper. Lower-grade heat sinks can also be made out of stainless steel or other metal alloys, and these materials are also significantly more cost effective at large sizes.
2. Thermal Conductivity of Heat Sinks
You'll commonly find metal alloys at use in heat sinks because they have high thermal conductivity (which equals low thermal resistance). Thermal conductivity is a material's ability to move heat through itself, which makes it efficient at moving heat from a low surface area to a high surface area environment. Copper has a thermal conductivity of 388 W/m-C, while the "best" aluminum alloy, 6061, has a thermal conductivity of 180 W/m-C. Copper is therefore over two times more efficient at moving thermal energy through itself.
Thermal conductivity rates depend on the construction material as well as the coating and finish on the heat sink's surface. This coating allows the total thermal conductivity to vary across different heat sink models. If you're choosing a heat sink, be sure to specify not only the material but also the thermal conductivity as well.
3. Heat Sink Fins: Types and Impacts on Efficiency Style
A heat sink's fin style can significantly influence its ability to release thermal energy into the environment. However, fin style is generally subject to the shape of the heat-generating component. For example, a proper design would utilize a radial fin style when cooling a cylindrical shape, as opposed to a flat straight-fin heat sink.
4. Standard Heat Sink Components
Some common component styles produce high amounts of excess heat―such as Ball Grid Array (BGA) chips―and require the use of heat sinks. Heat sinks therefore come in similar standard sizes that will match those common component standard sizes. For example, a 23mm x 23mm BGA can be supplemented by a heat sink that is perfectly sized for a 23mm x 23mm BGA package, such as this heat sink.
5. Heat Sink Attachment Methods
Placing a heat sink on a component won't be enough to properly connect the component to the heat sink. You'll need an adhesive method to create a solid thermal connection between the heating component and the heat sink. You can use a thermal paste, thermal grease, or another thermally conductive adhesive.
To shop popular heat sinks, such as the heat sink for Raspberry Pi and more thermal management devices, visit our thermal management category page.