Significance of Copper Coating in PCB Design

Printed circuit boards have a certain unused area, which is coated with copper known as copper coating or filling. There are several benefits of copper coating and one of them is to minimize the impedance of ground wire, as well as enhance the anti-interference and power supply, and minimize the voltage droppings.
The copper coating also helps prevent the deformation of a PCB during soldering. However, you have to manage copper coating properly to avoid certain issues that we will discuss here and find ways to resolve.

PCB has wirings distributed capacitance regarding high frequencies. The designer knows that when the length is higher than 1/20 of the corresponding wavelength of the noise frequency, it will cause the antenna effect causing the noise emission through wiring. Poor grounding of copper results in noise, so the ground line should have a hole with a pitch that is lower than λ/20 to have a good grounding on a multi-layered Printed Circuit Board.

The grid has traces in multiple directions and the trace width comes up with a corresponding electrical length to help a PCB operate. If the operating frequency is low, the gridline becomes less effective. But, the electrical length compatible with a PCB’s operating frequency causes bad effects and the PCB stops working transmitting the signals somewhere else.

High-frequency PCB resists a multi-purpose grid having high-interference requirements. On the other hand, the low-frequency PCB comes up with a wide current circuit and the designers use it for copper plating.
The grid should be compatible with the PC design, otherwise, the signals get scattered interfering with the entire system. The high-frequency PCB should have a high multi-purpose grid, and low-frequency PCB involves copper laying.

There are two methods of copper coating known as grid copper and large-area coating. In a large-area copper coating, bubbles develop due to wave soldering. In large-area coating, some slots are opened and the foaming of the copper foil is alleviated. Whereas the grid coating provides shielding to reduce heat dissipation, and it also provides electromagnetic shielding.

• Sometimes the PCB has several grounds, including GND, AGND, and SGND. The main surface of a circuit board becomes a reference to use copper plating, or as a digital or analog ground. However, copper pouring does not need to be separated. Moreover, the designer has to increase the thickness of the power connections, such as 3.3V and 5.0V which helps make different deformed surfaces having different shapes.
• When it is about different grounds single-point connection, the process involves a connection through magnetic beads or 0-ohm resistors.
• You also have to take care of copper coating in areas adjacent to the crystal oscillator, which is a source of high-frequency emission. The basic technique is to shield a copper coating of the crystal oscillator and ground it separately.
• There is another issue of a dead zone, also known as the Island. However, you can reduce it by defining a hole.
• PCB ground should have equal treatment while wiring. You can’t depend on copper coating by adding a hole to remove a pin’s connection, as it would affect the signals badly.
• The PCB design should not have sharp angles, such as 180 degrees, because they cause a transmitting effect in terms of electromagnetism.
• The multi-layered PCB’s middle layer has open wiring that should not have copper as it is harder to manage and keep it grounded.
• You should also properly ground the metal reinforcement and a metal heat sink.
• You should also properly ground the metal block that causes heat dissipation regarding a three-terminal regulator. The isolation belt of the crystal oscillator should also be grounded properly.

So, you can make a copper coating significant by managing the grounding issues. Such management can reduce the signal path’s backflow issue and also reduce electromagnetic interference.

Many unused surfaces in a PCB are coated with copper known as copper coating or filling. There are several benefits of copper coating and one of them is to minimize the impedance of ground wire, as well as enhance the anti-interference and power supply, and minimize the voltage droppings.

The copper coating also helps prevent the deformation of a PCB during soldering. However, you have to manage copper coating properly to avoid certain issues that we will discuss here and find ways to resolve. PCB has wirings distributed capacitance regarding high frequencies. The designer knows that when the length is higher than 1/20 of the corresponding wavelength of the noise frequency, it will cause the antenna effect causing the noise emission through wiring. Poor grounding of copper results in noise, so the ground line should have a hole with a pitch that is lower than λ/20 to have a good grounding on a multi-layered PCB.

Moreover, the grid has traces in multiple directions and the trace width comes up with a corresponding electrical length to help a PCB operate. If the operating frequency is low, the gridline becomes less effective. But, the electrical length compatible with a PCB’s operating frequency causes bad effects and the PCB stops working transmitting the signals somewhere else.

As you know that high-frequency PCB resists a multi-purpose grid having high-interference requirements. On the other hand, the low-frequency PCB comes up with a wide current circuit and the designers use it for copper plating. The grid should be compatible with the PC design, otherwise, the signals get scattered interfering with the entire system. The high-frequency PC Board should have a high multi-purpose grid, and low-frequency PCB involves copper laying.
There are two methods of copper coating known as grid copper and large-area coating. In a large-area copper coating, bubbles develop due to wave soldering. In large-area coating, some slots are opened and the foaming of the copper foil is alleviated. Whereas the grid coating provides shielding to reduce heat dissipation, and it also provides electromagnetic shielding.

Also, PCB has several grounds, including GND, AGND, and SGND. The main surface of a circuit board becomes a reference to use copper plating, or as a digital or analog ground. However, copper pouring does not need to be separated. Moreover, the designer has to increase the thickness of the power connections, such as 3.3V and 5.0V which helps make different deformed surfaces having different shapes. When it is about different grounds single-point connection, the process involves a connection through magnetic beads or 0-ohm resistors.
Similarly, you must take care of copper coating in areas adjacent to the crystal oscillator, which is a source of high-frequency emission. The basic technique is to shield a copper coating of the crystal oscillator and ground it separately. There is another issue of a dead zone, also known as the Island. However, you can reduce it by defining a hole.

Moreover, the PCB ground should have equal treatment while wiring. You can’t depend on copper coating by adding a hole to remove a pin’s connection, as it would affect the signals badly. The PCB design should not have sharp angles, such as 180 degrees, because they cause a transmitting effect in terms of electromagnetism.
The multi-layered PCB’s middle layer has open wiring that should not have copper as it is harder to manage and keep it grounded. You should also properly ground the metal reinforcement and a metal heat sink. You should also properly ground the metal block that causes heat dissipation regarding a three-terminal regulator. The isolation belt of the crystal oscillator should also be grounded properly.

You can make PCB more effective by applying copper plating the right way. The design of the PCB matters a lot in this case because you need the right tools. Lots of software are there that designers use according to their requirements. You can also get customized PCBs through online platforms by giving your requirements.

At the same time, you need to follow specific design rules, and the fabrication should also be of high quality. Both designer and manufacturer should be experienced to provide the best PCB with correct copper coatings.

Wrap Up

PCB has wirings distributed capacitance regarding high frequencies. The designer knows that when the length is higher than 1/20 of the corresponding wavelength of the noise frequency, it will cause the antenna effect causing the noise emission through wiring. Poor grounding of copper results in noise, so the ground line should have a hole with a pitch that is lower than λ/20 to have a good grounding on a multi-layered PCB. The grid has traces in multiple directions and the trace width comes up with a corresponding electrical length to help a PCB operate. If the operating frequency is low, the gridline becomes less effective. But, the electrical length compatible with a PCB’s operating frequency causes bad effects and the PCB stops working transmitting the signals somewhere else.

High-frequency PCB resists a multi-purpose grid having high-interference requirements. On the other hand, the low-frequency PCB comes up with a wide current circuit and the designers use it for copper plating. The grid should be compatible with the PC design, otherwise, the signals get scattered interfering with the entire system. The high-frequency PCB should have a high multi-purpose grid, and low-frequency PCB involves copper laying.

Would like to know more about the Copper coating in PC design or pcb fabrication? Write us at sales@pnconline.com

Written by Sam Sangani

Sam Sangani is the President & CEO of PNC Inc., a Nutley, NJ based Printed Circuit Board manufacturer. Sam graduated from L. D. Engineering College with a BS Degree in Mechanical Engineering. He also continued his education and graduated from Steven’s Institute of Technology where he acquired a Master’s degree in Computer Science.

After completion of his BS, Sam worked as a QC Manager, for Xerox, Romania and London. He was responsible for the Quality Control of Cable and Wire Harness imports from Romania. After completing his Master’s Degree, he worked as a Senior Programmer with IBM, Tucson, Arizona. Sam was responsible for leading the Mainframe System Programming Team.

In 1997, Sam acquired PNC INC., a Nutley, NJ based PC Board fabrication Shop. From 1997-2013, Sam has made tremendous improvements and changes within PNC INC., as he added many new Products and Technologies in PNC’s portfolio. With his proven track record and leadership, PNC has never had an unprofitable year and has continued its growth yearly since 1997.

His current responsibilities are Strategic Planning, Corporate Management, New Business Ventures, Sales & Marketing, Trade Shows, Professional Services and leading productive teams to achieve peak potential. He has also utilized Lean Management techniques which have built a foundation for PNC’s high-paced growth. Sam also enjoys real-estate investing, web design & SEO, trading stocks, options, futures and Forex markets.