Heavy Copper PCB Manufacturing

Designing Heavy Copper PCBs involves quite a few important considerations to keep in mind. This is to make sure that the boards meet the required performance standards while maintaining reliability and manufacturability. Here are the most important design considerations for a heavy copper PCB prototype.

Copper Thickness and Width

The dimensions of your thick copper plate impact current-carrying capacity and heat dissipation. Designers need to choose the right copper weight based on the application’s power requirement.

If you increase the copper thickness, the PCB can handle more current, but it might need more layer adjustments to accommodate the increased width of traces and pads.

These are the ideal dimensions for the baseline thickness of copper foil.

Thermal Management

A board with increased copper thickness is often used in high-power applications, so you need to be able to manage heat dissipation. Designers should consider the integration of heat sinks, thermal VIAs, and potentially using thermal interface materials.

With proper thermal management when producing heavy copper PCBs, you can ensure the longevity and reliability of your PCB. You will also be able to prevent a decrease in performance due to overheating.

Copper Trace and Space Width

The heavy copper layers make it so that the spacing trace width needs to be adjusted during the copper etching and plating process. Wider traces can carry more current but require more space. With enough spacing, you can prevent short circuits and etching issues.

Etching Considerations

It’s more challenging to etch thick copper layers than thin copper layers. You need to be able to carefully control your etching to achieve accurate circuit patterns without under-etching or over-etching. Poor etching can cause faults in your circuit.

Current Carrying Capacity

When current goes through a trace, its resistance becomes heated. It’s important for the designer to accurately calculate the maximum current a trace can carry before it reaches an appropriate temperature rise. Copper layers on the inner PCB can only handle around half of the current carrying capacity of exposed traces.

Layer Count and PCB Stackup

The number of layers on a standard printed circuit board with copper and the way they are arranged (stackup) must be planned in advanced. This will balance the electrical, thermal, and mechanical requirements of the application. If your stackup is designed well, it can improve PCB performance and thermal distribution, and reduce electromagnetic interference.

Substrate Material

There are many different materials one can choose for the substrate of a PCB, the most common of which is FR-4 material. It’s important to note the glass transition temperature of both your copper and your substrate, as higher currents can result in cracks.

Mechanical Strength and Board Rigidity

Because heavy copper standard circuits have increased weight and thickness, it can affect its mechanical strength and rigidity. It’s important to keep this in mind when you design enclosures and supports. PCBs need to be mechanically stable, especially if the application involves vibration or mechanical stress.

Heavy copper printed circuit boards (PCBs) are essentially printed circuit boards with thick copper, usually 3 ounces (≈ 113 grams) per square foot. If you’re looking for a great electric conductor, a thick copper PCB is a great choice. It can handle high-current or high-power circuits and control circuits on the same board.

Types of Heavy Copper PCBs

• Single-Sided: These PCBs only have copper on one side of the substrate. They are much simpler for a PCB manufacturer to make. Single-sided PCBs are usually used in small and simple electronic devices, such as LED lighting systems.
• Double-Sided: This is when there are thicker copper layers on both sides of the substrate, which allows for a higher density of circuits and connectivity. It’s often used in more complicated devices than single-layer copper PCBs, like power supplies.
• Multilayer: These PCBs have a much higher layer count. With multiple heavy copper layers separated by insulation, they can handle more complicated circuits with high connectivity density. You might see these PCBs in aerospace devices.
• Extreme Copper PCB: These are specialized PCBs when extreme performance and higher current carrying capacity are required. There is increased thickness of the copper, which can be thicker than 20 oz per square foot. They are typically used in industrial transformers.
• Flexible: This is a combination of the flexibility of heavy copper PCB technology with other materials that allow it to bend. These PCBs are used in situations where the board needs to fit a specific shape, like in wearable electronics.
• Hybrid: This heavy copper PCB design uses different technologies and materials, like standard copper with high-frequency materials, to tailor to multiple functionality requirements. It’s used in more advanced communication devices.
• High-Density Interconnect (HDI): HDI heavy copper PCBs offer the integration of HDI technology; it’s used in high-density components for a PCB with heavy copper. These are usually used for high-power requirements and thermal loads, such as in military electronics.

Benefits of Heavy Copper PCBs