Introduction
Heat sinks are essential components in electronic devices that help dissipate heat generated by the components. They are commonly used in computers, smartphones, and other electronic gadgets. The two most common materials used for heat sink manufacturing are aluminum and copper. In this article, we will explore why heat sinks are made of aluminum and not copper.
The Properties of Aluminum and Copper
Aluminum and copper are both excellent thermal conductors, which is the most important property for heat sink materials. However, copper has a thermal conductivity of 401 W/mK while aluminum has a thermal conductivity of 237 W/mK. This means that copper is a better conductor of heat than aluminum. Moreover, both aluminum and copper have high heat capacity, meaning they can absorb and hold large amounts of heat energy.
Cost and Availability
Despite being a better thermal conductor than aluminum, copper is significantly more expensive than aluminum. Copper is also less abundant than aluminum, which makes it less accessible. Due to these factors, heat sinks made of copper are more expensive than those made of aluminum.
Weight and Density
Another important factor to consider when manufacturing heat sinks is weight and density. Aluminum is significantly lighter and less dense than copper, which makes it easier to manufacture. Heat sinks made of aluminum are lighter and less bulky, which makes them ideal for use in small electronic devices.
Corrosion Resistance
Aluminum has excellent corrosion resistance. It forms a thin, protective layer of oxide on its surface, which prevents it from further oxidation. Copper, on the other hand, is prone to corrosion and oxidizes more easily than aluminum. This makes heat sinks made of aluminum more durable and long-lasting than those made of copper.
Performance
When it comes to heat sink performance, the choice of material is critical. Heat sinks made of aluminum are best suited for cooling applications where the ambient temperature is below 120°C. On the other hand, copper heat sinks are better suited for high-temperature applications above 150°C. This is because copper has a higher melting point than aluminum.
Manufacturability
Aluminum is easier to machine and manipulate than copper due to its lower density and hardness. Heat sinks made of aluminum can be stamped, extruded, or cast easily, making them cost-effective to manufacture. Copper, on the other hand, requires more energy and specialized tools to be manipulated.
Toxicity
Aluminum is a non-toxic and non-hazardous metal, making it safe to use in electronic devices. Copper, on the other hand, can be toxic in high concentrations. As such, using copper heat sinks in electronic devices may present a health risk to users.
Recyclability
Aluminum is a highly recyclable material and can be reused in the production of other products. Copper is also recyclable but requires more energy to process than aluminum. This makes aluminum heat sinks a more environmentally friendly option than copper heat sinks.
Conclusion
While copper is a better thermal conductor than aluminum, heat sinks are primarily made of aluminum due to its low cost, availability, light weight, corrosion resistance, and manufacturability. Aluminum heat sinks are better suited for cooling applications where the ambient temperature is below 120°C. Nevertheless, copper heat sinks are better suited for high-temperature applications above 150°C.