Regarding PCBs, two commonly used materials are aluminum and copper.
Both have unique properties that affect their suitability for specific applications.
This blog post will compare aluminum vs. copper for superior PCB performance and help determine which material best fits your project.
Aluminum vs. Copper
Influence of Metal Cores in Revolutionizing PCBs
Metal-core printed circuit boards are becoming increasingly popular in PCB manufacturing due to their improved thermal conductivity.
Traditional PCBs are typically made using a fiberglass substrate, which is ineffective at dissipating heat.
This means that in high-power applications, the components on the board can quickly overheat, causing damage and reducing the lifespan of the PCB.
On the other hand, metal-core printed circuit boards use a metal core as their base, offering much better thermal conductivity.
The metal core helps to absorb and dissipate heat away from the components, preventing them from overheating and improving the overall reliability of the PCB.
The choice of metal used for the core is critical and will depend on the specific application and performance requirements.
Two of the most commonly used metals for metal cores are aluminum and copper, each with unique advantages and disadvantages.
Metal Cores in PCB
Aluminum Features and Characteristics
Aluminum is a widely used metal in various industries, including electronics. Its unique features and characteristics make it an ideal choice for certain applications.
One of the key features of aluminum in PCB manufacturing is its non-magnetic properties.
This makes it ideal for use in electronic applications where magnetism could interfere with the performance of the circuitry.
For example, in high-frequency applications, the magnetic field created by the flow of current through copper can cause interference with nearby components.
Using aluminum instead can minimize this interference, resulting in improved overall performance and reliability of the PCB.
Its ability to be easily drawn out into thin wires or rolled into sheets allows it to be formed into different shapes and sizes, which is crucial in manufacturing PCBs.
For example, aluminum can be used as a substrate in metal core PCBs, providing improved thermal conductivity compared to traditional fiberglass substrates.
Its ductility also makes it easier to bond with other materials. This bonding process ensures the final product’s good electrical connectivity and thermal management.
Aluminum’s silvery-white color and reflective surface make it an attractive choice in visible applications, such as LED lighting fixtures or displays.
In PCB manufacturing, aluminum’s reflective properties can also be utilized to improve the circuitry performance.
For example, aluminum can be used as a reflector in LED PCBs, which helps redirect and amplify the light output of the LEDs.
Aluminum’s high reflectivity is desirable in PCB manufacturing, particularly in high-frequency applications with critical signal loss and noise reduction.
The reflective surface of aluminum can be used as a ground plane or shield to protect sensitive components from electromagnetic interference.
For example, aluminum is commonly used as a ground plane in RF PCBs to reduce signal loss and improve signal quality.
660.3 °C Melting Point
Aluminum’s high melting point of 660.3 °C makes it a suitable material for PCB manufacturing, where high temperatures can be generated during manufacturing.
For example, temperatures of up to 250 °C are typically used to melt the solder and create electrical connections between components during the soldering process.
The high melting point of aluminum ensures that it remains stable and does not deform or melt during this process.
2,470 °C Boiling Point
Aluminum’s high boiling point of 2,470 °C is not a critical factor in PCB manufacturing, as the temperatures used during the manufacturing process do not typically reach this level.
However, the high boiling point of aluminum can be advantageous in high-temperature applications, such as power electronics or industrial applications, where it provides improved thermal management compared to other materials.
Copper Features and Characteristics
Copper‘s features and characteristics make it a desirable material for PCB manufacturing, ranging from low-power circuits to high-power applications.
Copper’s malleability is a desirable property in PCB manufacturing, where it can be easily formed into different shapes and sizes to suit the application’s specific requirements.
It also allows for the creation complex shapes and patterns, such as those found in high-density interconnect (HDI) PCBs.
Its malleability makes it suitable for applications where the PCB must conform to non-planar surfaces, such as in wearable technology or medical devices.
Copper is generally considered more malleable than aluminum, allowing for greater flexibility and customization in PCB design.
This property is particularly important in producing conductive traces, where thin wires or sheets are required to create complex electrical connections.
Copper’s flexibility also makes it suitable for applications where the PCB must withstand repeated bending or flexing, such as in flexible PCBs.
Compared to aluminum, copper is generally considered more malleable, making it a better choice for applications where the material will undergo repeated stress or flexing.
High Thermal and Electrical Conductivity
Copper’s high electrical conductivity allows for the efficient flow of electricity throughout the PCB, while its high thermal conductivity allows for the dissipation of heat generated by the circuit.
These properties are particularly important in high-power applications, where the circuit must handle large amounts of electricity and dissipate significant amounts of heat.
Compared to aluminum, copper is generally considered a better conductor of both heat and electricity, making it a better choice for high-power applications.
Copper’s reddish-orange color is not typically a significant factor in its usage in PCB manufacturing, as a layer of solder mask or another protective coating typically covers the material.
The reddish-orange color can be used as a visual indicator of the presence of copper in the circuit, which can be helpful in troubleshooting or repair situations.
1,085 °C Melting Point
Compared to aluminum, copper has a higher melting point of 1,085 °C, an important consideration in PCB manufacturing.
Aluminum has a lower melting point of 660.3 °C, which means it is more prone to melting or deforming during the high-temperature soldering process used in PCB assembly. This can lead to defects or failures in the circuit, affecting the overall functionality of the PCB.
Copper’s higher melting point means it is more resistant to the high temperatures used in soldering and less likely to melt or deform.
2,562 °C Boiling Point
The higher boiling point of copper means it is more resistant to thermal stress and less likely to degrade or fail due to exposure to high temperatures.
In contrast, aluminum’s lower boiling point of 2,470 °C means it is more likely to experience thermal stress and degradation under high-temperature conditions.
While copper’s higher boiling point does not provide a significant advantage in most PCB manufacturing processes, it is desirable for applications where the PCB must operate in high-temperature environments.
Pros and Cons of Aluminum vs. Copper
- Costs Less Than Copper – Aluminum is cheaper than copper, making it an attractive option for mass-produced PCBs.
- Resistant to Corrosion – Aluminum is resistant to corrosion, making it suitable for use in PCBs exposed to harsh environments.
- More Effective Conductor – Aluminum is a more effective conductor of electricity than copper, so it can transmit electrical signals more efficiently.
- More Flexible – Aluminum is more flexible than copper, which allows it to bend and conform to various shapes without cracking or breaking. This flexibility is particularly useful in PCBs that require complex designs or intricate shapes.
- Susceptible to Oxidation – Aluminum is susceptible to oxidation, which can cause its surface to become dull or discolored over time. This can be a problem in PCBs that require long-term reliability or resistance to environmental factors, such as moisture or humidity.
- Needs More Aluminum to Carry Current – Aluminum has a lower conductivity than copper, meaning it needs more material to carry the same amount of current. This can be an issue in PCBs that require high levels of current, as they may need to be larger or thicker to accommodate the necessary amount of aluminum.
Characteristics of Aluminum PCB
- Stronger than Aluminum – Copper is a stronger metal than aluminum, making it a better choice for applications where structural integrity is important.
- Can Carry Almost Twice the Current Capacity – This material has a higher electrical conductivity than aluminum. It can carry more current without heating up or losing energy.
- Exceptional Electrical and Thermal Characteristics – This material can transfer heat and electricity more efficiently than most other metals. This makes it ideal for electronic devices and other applications where efficient heat dissipation is important.
- Expands Less and Does Not Flow at Terminations – Copper has a low coefficient of thermal expansion. It expands and contracts less than other metals when exposed to temperature changes. This makes it a good choice for applications where stability and reliability are important, such as PCBs, where components are soldered onto the copper traces.
- More Expensive than Aluminum – This is generally more expensive than aluminum, making it less cost-effective for some applications. This can make it less attractive for certain applications, especially those that require a large amount of material.
- More Difficult to Manufacture than Aluminum – Copper is also more difficult to manufacture than aluminum, which can add to the overall cost and time of producing copper-based PCBs. The manufacturing process for copper involves more steps and is generally more complex than aluminum.
Characteristics of Copper PCB
Aluminum vs. Copper: Which is Better for PCB?
When choosing between aluminum and copper for PCB manufacturing, the decision largely depends on the specific needs and requirements of the project.
While aluminum is often the more cost-effective option, copper offers several advantages, making it a more reliable choice for many applications.
Copper is stronger than aluminum and can carry almost twice the current capacity of aluminum, making it an excellent choice for high-power applications.
Additionally, copper has exceptional electrical and thermal characteristics, which can help to ensure the reliability and longevity of a PCB.
One of the key benefits of copper over aluminum is its oxidation resistance, which can help to prevent the build-up of corrosion that can degrade the performance of a PCB over time.
Copper also expands less and does not flow at terminations, which can help to ensure that connections remain stable and reliable over time.
While copper is a more reliable choice for many applications, it is also more expensive and difficult to manufacture than aluminum.
Ultimately, the decision between aluminum and copper for PCB manufacturing will depend on the specific needs and requirements of the project, as well as the budget and resources available.
In conclusion, choosing between aluminum and copper for PCB manufacturing depends on various factors, including cost, performance requirements, and the intended application.
While aluminum may be a more cost-effective option, copper offers superior electrical and thermal conductivity, greater strength, and a longer lifespan, making it a more reliable choice for high-performance applications.
Ultimately, it is important to consider all these factors when selecting the appropriate metal core for your PCB, ensuring that your design meets your performance, durability, and cost-effectiveness requirements.