Comparing Heat Sink Aluminium Extrusions vs. Copper

Heat sinks, critical components in electronics cooling, dissipate heat from devices to maintain optimal temperatures. The choice between aluminium extrusions and copper extrusions for heat sinks is a crucial decision with significant implications for performance and cost. This article presents a comprehensive comparison of these materials to guide readers in making informed choices.

Thermal Conductivity

The primary consideration is thermal conductivity, which measures a material’s ability to transfer heat. Copper has a significantly higher thermal conductivity (401 W/m·K) than aluminium (237 W/m·K), making it a better heat conductor. This translates into more efficient heat dissipation for copper heat sinks.

Weight and Cost

Aluminium is less dense than copper, resulting in lighter heat sinks. This advantage is crucial for applications where weight is a concern, such as aerospace and portable electronics. However, copper’s lower electrical resistance and higher thermal conductivity often allow for smaller heat sinks, which can offset the weight difference. Aluminium is also significantly less expensive than copper, making it more economical for large-volume applications.

Corrosion Resistance

Copper is more corrosion-resistant than aluminium, providing longer service life in harsh environments. Aluminium extrusions require additional surface treatments to enhance corrosion resistance, increasing manufacturing costs. In applications exposed to moisture, salt spray, or chemicals, copper heat sinks are a preferred choice.

Formability and Machinability

Aluminium extrusions are highly formable, allowing manufacturers to create complex shapes with ease. Copper, on the other hand, is more rigid and less easily deformed. This makes intricate designs more challenging and expensive to produce. However, copper exhibits excellent machinability, enabling precision machining of features such as fins and channels.

Applications

Aluminium heat sinks are widely used in electronics, automotive, and industrial applications where cost, weight, and formability are priorities. They are particularly suitable for large, complex, or lightweight heat sinks. Copper heat sinks are ideal for applications demanding high thermal performance, corrosion resistance, and durability. They are commonly found in high-power electronics, aerospace, and medical devices.

Conclusion

The choice between aluminium extrusions and copper for heat sinks depends on specific application requirements. Aluminium offers advantages in weight, cost, and formability, while copper excels in thermal performance, corrosion resistance, and machinability. By carefully considering these factors, engineers can optimize heat sink design for maximum efficiency and reliability.