How Do Circuit Boards Work?

Circuit boards are integral to the functionality of any electronic product. They support the product mechanically while connecting its electrical components throughout. 

But how do they work?

 PCBs are made up of a variety of different electrical components, produced in the manufacturing process and each is vital to the functionality of the device to which it will belong. 

A standard PCB in its most basic form is a plastic board covered in fibreglass. Components are mounted on a non-conductive board and connected with small pathways, called traces. These traces allow the electrical components across the board to function by passing electricity through. PCBs also have small holes which are drilled where each component needs to be placed.

The circuit board (if a single-sided board) has one layer of conducting material, copper, on one side of the board and another side that’s used for incorporating different electronic components on the board. 

Double-sided PCBs can mount the conductive copper and components on both sides of the board, as opposed to just the one, which allows for closer routing traces as they can alternate between the top and bottom layers using vias. This can be very useful in many electronic products as the circuits on one side of the board can be connected to the other with the help of holes drilled onto the board. 


The components themselves on each individual board are essential to making these boards work and passing through electricity or energy. There are a number of different components that work together to ensure their functionality such as resistors, transistors and capacitors, for example.

  • Resistors are one of the most crucial components to making a circuit board work, as they transmit an electric current in order to produce a voltage and dissipate electric power as heat. 
  • Similarly, transistors are used to switch or control the electronic signals in the board. There will be times during a circuit board’s lifespan where more energy or electrical charge will be needed in other parts of the board.
  • This is where capacitors come into action as they hold an electric charge within the board and release it whenever this power is needed elsewhere. 
  • Inductors also store energy within the board in the form of a magnetic field when current flows through them. They are often used to block signals within the board, such as interference from another electronic device or piece of equipment.
  • Another important component of a circuit board are diodes, which are devices that allow the electrical current to flow in one direction, but not the other, which can be useful in blocking currents from flowing through the board in the wrong direction, which could cause damage.

If you’d like to find out more about how circuit boards work, what is a circuit board made of, or how ABL Circuits can help you with your project, get in touch for more information.



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