The Science of Aluminium Heat Sinks
Heat sinks work by increasing the surface area in contact with air, allowing heat to move from a component into the surrounding environment through conduction and convection. Aluminium is the material of choice because it offers an excellent balance of thermal conductivity (around 200 W/m·K for 6063 alloy), light weight, and corrosion resistance.
Why Extruded Profiles Win
Extrusion allows manufacturers to create complex fin geometries in a single pass — sunflower-type, plate-fin, and pin-fin designs all start as a die. Unlike die-cast or machined parts, extruded profiles offer consistent material properties, tight tolerances, and cost efficiency at medium to high volumes.
Surface Treatment Matters
Anodizing not only protects the surface from corrosion but also increases emissivity, helping the heat sink radiate heat more effectively. Powder coating adds durability for harsh environments, though it slightly reduces thermal performance compared to bare or anodized aluminium.
How to Specify
Tell your supplier the heat load (W), the maximum allowable temperature rise, the available airflow, and the mounting method. From these, we can recommend a standard profile or design a custom die to match your exact geometry and budget.
Frequently Asked Questions
How does an aluminium heat sink actually remove heat?
Heat conducts from the component into the heat sink base, spreads through the metal, and is carried away from the fins by air (or liquid) through convection, while the surface also radiates heat. Larger surface area and better airflow speed up this removal.
Why does the thermal interface matter as much as the heat sink?
Microscopic air gaps between component and heat sink block heat flow. Thermal paste, pads or phase-change materials fill those gaps and can cut contact resistance dramatically – sometimes more than upgrading the heat sink itself.
What is the simplest way to improve an existing heat sink?
Increase airflow first (better fan, ducting), improve the interface material, and check mounting pressure. If those are exhausted, move to a longer or denser extrusion – often the cheapest upgrade since the die already exists.