Heat Sink Design Basics for Aluminium Enclosures

Fin pitch, thickness and height limits for extruded aluminium heat sinks — and how to integrate the mount into the profile.

When the enclosure is also the heat sink, the profile design decides the thermal budget. Extrusion is ideal here because the fin and the wall are one piece of aluminium — no bolted seam in the heat path.

The three numbers that matter

• Fin thickness: extruded fins typically run 0.3–1.2 mm thick.
• Fin height: up to about 60 mm in stable production.
• Fin pitch: tight enough for area, open enough for air and for the die to fill.

Integrate the mount, do not bolt it on

Where the design allows, we integrate the mounting pad into the profile so the interface face is CNC-milled rather than left as-extruded. That removes a thermal joint and lets us hold the flatness the device needs. Send the target thermal resistance and the available envelope and our engineers propose a fin geometry the press can actually hold in volume.

See a real result in our heat-sink fin redesign case, where a fin change dropped temperature by 8°C.