Last Updated on October 23, 2023 by Kevin Chen
Printed circuit boards are integral components in the modern electronics. They define what an electronic device should do and how it should operate. Copper coating is one of the crucial activities that are undertaken during the PCB manufacturing process. The coating entails spreading a thin layer of copper material on the surface of a printed circuit board. The layer is used for various purposes that we are going to discuss in this article.
What is PCB coating?
As the name suggests, PCB coating entails applying copper coating on the surface of a printed circuit board. It often results in the formation of a thin layer of copper on the PCB surface. The copper coating can be applied to any part of the PCB. It can be on the top, in the middle, or on the bottom side of the PCB.
In most PCBs, you are likely to discover that some sections have the copper coating and others don’t. In such cases, the coating may be done to isolate components of the PCB. It all depends on the requirement specifications of the PCB.
Not all types of PCB copper coatings are the same. They tend to differ on various factors such as the grade of copper material that is used or the technique of applying the coating on the PCB surface. Additionally, the whole coating process is done by specialists using special technologies.
Reasons for PCB copper coating
Here are some of the key reasons and as well as the benefits of PCB copper coating:
We all know that copper material is an excellent conductor of electric signals. When the coating is included in a printed circuit board, it can play the role of grounding. This means that it will provide a route through which the electrons on a PCB can flow to the ground. Proper grounding helps to protect the PCB and its components from the effects of the current surge. By using copper coating, it means that your grounding is achieved without the need to install other physical interconnects or external wiring.
Other than being a good electric conductor, copper is also an excellent heat conductor. When coated on the surface of a PCB it can help to dissipate heat away from the printed circuit board. Manufacturers implement this functionality by including heat vias on the copper coating. The result is proper thermal management in the PCB.
Electromagnetic interference is one of the main concerns that should be addressed during PCB manufacturing. It is usually generated by different electronic components on the PCB. Copper coating can be used as a protective mechanism against the impact of EMI. It achieves this by shielding sensitive components from being exposed to the magnetic waves generated by other components. This way, components can function smoothly and accurately.
Used for trace routing
Copper coating is also used for determining the direction of the current flow on the printed circuit board. Since it is also an excellent conductor of electric current, it can dictate where and how the signals should glow on the circuit board.
The fact that copper traces in this case exist in the form of coating means that you can be sure about the integrity of the signal flow. There will be minimal signal loss due to heat or even external noise. Additionally, it is easy to design accurate copper traces when applying the copper coating on the PCB surface. The result is having a large circuit path, especially for high-current applications.
Copper coating helps to achieve copper balancing on the printed circuit board. The main purpose of copper balancing is to achieve a symmetric distribution of copper traces on the circuit board. It helps to minimize the impact of warpage and even twisting when the PCB is finally deployed in an electronic device.
The coating ensures that a perfect balance is achieved since it entails an equal distribution of copper on the PCB layer. Balancing also helps to achieve the stability of copper especially when the coating is done on both sides of the PCB.
Better PCB manufacturing
Copper coating provides a convenient way of manufacturing PCBs. Any PCB manufacturing will entail the placement of copper traces. Coating is a better alternative since it can be easily done without having to undertake any complex procedures.
How is copper coated on PCB?
There are two main methods of PCB copper coating. These are large-area copper coating and pure copper-clad coating.
Large area copper coating technique increases the surface area through which electric signals can flow. It is done using a wave soldering tool. The pure copper-clad coating helps to provide an electric shield from different types of noise. It also provides a better heat dissipation solution.
How do you protect the copper coating on the PCB?
Applying the copper coating on the PCB is not enough. The state of the coating will determine the durability and even the performance of the PCB in general. The easiest way of protecting the coating is to keep the PCB away from toxic environments and materials. For example, it should be kept in rooms that have moderate temperature conditions.
Otherwise, the most effective method is by using conformal coating. Here, you will use aerosol spray coatings and epoxy coatings. They are good at shielding the copper coatings from rust, dust, and chemical damage.
Copper coating is an important aspect of PCB manufacturing It enhances the reliability, functionality, and performance of a printed circuit board. As a PCB manufacturer, you should include copper coating as part of your production process. It is considered among the mandatory industry standards that all manufacturers should follow.
On the client side, buyers should ensure that the PCBs that they want to buy feature high-quality copper coating. But, how will I know that it has the right copper coating? Having a PCB sourcing agent will be the easiest way to handle the process. They have skills and expertise in analyzing printed circuit boards and will tell you whether it has the right copper coating.
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