Heat Sink Buying Guide

Heat sinks are essential cooling devices widely used in electronics and machinery to dissipate heat generated during operation. They help components run efficiently and extend their lifespan by transferring heat away from the source. Heat sinks prevent overheating, which can lead to system failures or damage. In practice, the term ‘heat sink’ typically refers to various kinds ofelectronic cooling, where it might also be referred to as a heat spreader or simply a cooler. Coolers of this type are a form of radiator because they radiate the heat they collect out into the atmosphere and away from the source. While heat sinks come in various types and designs, they all serve the same purpose of cooling critical components.

Heat sinks, typically made from metals like copper or aluminium, come in various designs such as the common 'fin' layout or alternative versions with pins or stamping techniques to enhance surface area and heat transfer rates. Most heat sinks are passive, naturally conducting heat away from the source when in direct contact with the component. However, active heat sinks, which incorporate powered fans for improved dissipation, are also available. For a comparison of widely used heat sink types, refer to the following sections.

As noted above, there is a wide variety of constructions, designs and manufacturing techniques used in making heatsinks for computers, motherboards and other devices. Common options include:

• Extruded heat sinks - the metal is simply forced into the required shape, extremely common in a wide range of applications.
• Forged heat sinks - relies on a die or mould to set the metal in the form needed, often cheaper for mass production.
• Bonded heat sinks - fins are individually attached to the base in a dense array, ideal for bespoke or space-limited applications.
• Stamped heat sinks - among the cheapest to mass-produce but generally less powerful and effective as coolers.
• **CNC machined heat sinks **- often among the more expensive options as the metal is precision-cut from a solid block, meaning much more material goes to waste.
• Skived or zipper fin heat sinks - a highly effective (and, again, typically more expensive) manufacturing process, using a dedicated machine to cut the fins and then push them up into position; identified by a slight curve at the fin base.

Most of these techniques offer alternate ways of achieving the classic finned or pinned heatsink layout. Typically, the choice will come down to striking the best balance for an individual supplier between quality, performance, cost, and sales volume.

We’ve already touched on the importance of heatsinks for cooling vital PC components such as CPUs and GPUs. Some other examples of everyday heat sink uses include:

• Motherboard heatsinks
• Solid-state and relayheat sinks
• Power transistor heat sink
• PCB heat sinks
• External/internal laptop heatsinks
• Heat sinks for amplifiers

When asking yourself ‘What type of heat sink should I buy?’, the answer will almost always come down to the specifics of your setup and cooling needs. Identifying some basic details about your intended application is the first step in knowing how to choose heat sinks.

Key considerations for the best choice of heat sink include:

• What sort of power draw will the component in question be using? This is often referred to as the TDP (thermal design power, or thermal design profile). TDP is often used as a basic indication of a component’s power consumption, especially with CPUs (processors) and GPUs (video cards). TDP ratings specify the maximum heat a component can use in watts. It’s typically a good indicator of how hot a particular part has the potential to get under load.
• How cool the component ideally needs to be kept in order to perform optimally?
• How much space is available to install a cooler, heat spreader, or heat sink - they’re available in a wide variety of sizes, from tiny module heat sinks to much larger installations.
• Which type of heat sink design or layout will give you the best thermal performance for your system specs?
• Whether you need an active heat sink or a passive radiator.
• How much you’re willing to spend on a cooler?

To fit a heat sink, attach the base plate tightly to the component using manual clamping or screw-down assembly. Various mounting accessories like spring clips, spring mount rivets, screws, and adhesive tapes are available. Applythermal paste between the component and the heat plate to enhance thermal transfer and fill in small gaps. Thermal paste improves cooling performance but may require periodic reapplication as it can dry and crack over time.

You can find some typical applications of the various types of heat sink materials in the table below.