Copper vs. Aluminium Heat Sinks: Which is Better?

This article compares copper and aluminium heat sinks, highlighting the key differences between them. A heat sink is a crucial component used to transfer heat away from electronic devices (like CPUs and GPUs) to the surrounding air or liquid. This helps maintain the device at an optimal operating temperature, preventing overheating and ensuring stable performance.

Heat sinks are commonly made from either copper or aluminium. Let’s delve into the properties of each material.

Copper Heat Sink

Figure 1: A typical copper heat sink.

Here are some typical thermal and mechanical properties of copper used in heat sinks:

• Bulk Thermal Conductivity (W/m*K): 391
• Specific Thermal Conductivity (W/m*K)/(g/cm³): 45
• Density (g/cm³): 8.9
• Tensile Strength (MPa): 270

Aluminium Heat Sink

Figure 2: A common aluminium heat sink design.

Here are the thermal and mechanical properties of aluminium commonly used in heat sink construction:

• Bulk Thermal Conductivity (W/m*K): 180
• Specific Thermal Conductivity (W/m*K)/(g/cm³): 63
• Density (g/cm³): 2.8
• Tensile Strength (MPa): 180

Key Differences: Copper vs. Aluminium Heat Sinks

Here’s a breakdown of the key differences between copper and aluminium heat sinks:

• Thermal Conductivity: Copper’s thermal conductivity is roughly double that of aluminium. This means copper conducts heat more efficiently. While copper is better at conducting heat, aluminium is generally considered to radiate heat better.

• Size: Due to its superior thermal conductivity, a copper heat sink can be about half the size of an aluminium heat sink to achieve similar performance.

• Cost: Copper is significantly more expensive than aluminium.

• Fabrication: Aluminium is easier to fabricate and machine than copper.

• Weight: Aluminium heat sinks are considerably lighter than copper heat sinks.