role of copper in a PCB
Copper is a vital component in a PCB. It creates the conductive pathways that channel electric charges between all of the different components in a circuit board. Though dozens of substances can transmit electrical signals, copper is usually the preferred choice because it has the highest level of conductivity, which means it transfers charges with little to no loss or interference in the signal.
It is also a very thermally conductive metal and can transfer heat across the surface of the PCB more effectively than other materials. This helps to prevent excessive heating of the PCB, which can lead to micro-fracturing and other structural problems. Normally, there are six layers of copper in a PCB, with four of these used for the core and two to enhance panels inside the panel.
In PCB Fabrication, if the copper layer or layers in a pcb are unevenly distributed, there can be mechanical alignment issues. This can cause the PCB to twist. The twist is the vertical displacement of one corner that is not aligned symmetrically with other corners. It occurs when pressure is applied in asymmetric ways on the board. This causes the surface that has thin copper deposition ooze out resins, forming voids in that area.
What is the role of copper in a PCB?
When PCBs are made, the first layer that is affixed to the substrate is called the base copper. This is the foundation of the entire circuit board. The base copper layer is a thin sheet that serves as the underlying platform for all the other layers to build upon.
The base copper also provides a strong connection to the conductive paths on the top and bottom layers of the board. This is necessary because the traces in a circuit board can have a huge impact on its performance. If they are not connected correctly, the traces will lose power due to resistance and other issues. The connection is made through plated through holes, which are metal structures in the PCB that connect one layer to another.
A thicker base copper can help to reduce the resistance of the traces, which is important for efficient electricity flow. This is because thicker copper can provide more surface area for electrons to move through, so the traces will not have as much resistance.
However, a thicker copper can make it more difficult for the etching process to remove all of the excess material. To avoid this issue, it is recommended that the thickness of the copper be carefully selected to ensure it meets all the requirements for a specific design. In addition, the traces should be evenly distributed to prevent “copper nests” from forming. This can be achieved by using a grid pattern in the layout program. This will also reduce the difficulty of the etching process. If you have any questions regarding the thickness of your PCB’s copper, contact your fabrication manufacturer. They will be able to offer advice on the best stack-up for your design.