How you can design better aluminium heat sinks to improve thermal performance
Improving the thermal performance of a heat sink depends on the design of the solution and on a handful of other factors. They tie together. Let us go through these factors, which might enable you to improve the design of your heat sink and achieve the performance you need.
Designing heat sinks is about optimizing the surface area that is in contact with the coolant fluid, or with the air around it. This sounds simple in theory, and when you have experts working on the design, the task absolutely becomes easier. It will wind up saving you money, too.
Why? Because the design phase is the phase in which you can achieve significant cost reductions. Once the design is locked in, the most significant cost-saving possibilities will be behind you. My advice then is to go out and find the expertise you need – expertise in areas such as:
- Aluminium design
- Extrusion technology
- Product design
Yes, you can find sophisticated software in the market for performing Computational Fluid Dynamics (CFD). This can help you design a heat sink. But I am convinced that getting what you need requires more.
Involving expertise early means getting alternatives for alloy selection, advice for surface treatment and advice in the overall design. For example, integrating functionalities such as screw ports, cable channels, and features for fastening other parts to the heat sink.
These are going to be pros who understand your industry and know that improved thermal performance using aluminium extrusions tends to lead to less weight, higher efficiency and a lower overall cost.
Factors that improve thermal performance of aluminium heat sinks
Aluminium heat sinks are usually air-cooled or liquid-cooled. Regardless of whether yours uses liquid or air cooling, the main factors that impact its thermal performance include air or liquid flow and fin/channel design. Other factors to consider in the design phase:
- Surface treatment
- Thermal resistance
- Joining methods
- Materials, including the thermal interface material
The most common heat sink materials are aluminium alloys in the 6000-series, primarily the 6060, 6061 and 6063 alloys. The thermal conductivity values of these alloys are solid. Their thermal properties are not as good as those of copper, but an extruded aluminium heat sink weighs about half as much as a copper conductor having the same conductivity, and the aluminium solution does not cost as much, either.
This article was first published December 2020.