Printed circuit boards, or PCBs, are essential to many modern day electronics. These boards can be found in everything from smartphones and LED lights to televisions and cars. In fact, almost any electronic device you can think of likely uses at least one PCB to function.
So, how do printed circuit boards work? Today, we’ll take a closer look at the basics of PCBs.
Mounting Components on a Board
At the heart of every PCB is the board itself. The board holds everything a circuit needs to function, including components and wiring.
When a PCB is built, all the components that it houses are mounted directly on the board. For example, if you want to include a microchip that has five tiny connection points, the board will be drilled with five precise holes that align with the microchip’s dimensions. During assembly, the microchip is placed into the pre-drilled holes and soldered in place.
By mounting components on the board in this way, it is possible to fit a surprising number of chips, diodes, switches, and other electronic components on a single small PCB.
Etching Copper Traces
The surface of a PCB board is coated with a non-conductive material to prevent electricity from flowing freely between all the components on your board. Underneath the non-conductive surface is a layer of highly conductive copper foil.
With etching, it is possible to leave behind a thin line of copper connecting any two components on your board. These thin copper lines are known as traces, and they are responsible for carrying power and electrical signals in a defined path across your PCB.
Traces are key to PCBs because they replace traditional wiring. Instead of having a three-dimensional mass of wires surrounding your board, components are connected to each other directly through traces etched into the surface of your board.
Designing and Building a PCB
Most PCBs are designed on a computer using purpose-built software. By using software, it is easy to play around with different layouts for the components or paths for the traces. Some design software will automatically lay out traces for you, making it quicker and easier to complete your circuit.
Another advantage of using software is that it will enable you to visualize how your PCB will work before you manufacture it. In addition, you’ll be able to confirm that all the components needed are present and properly connected with traces.
Designing a PCB takes time and practice. Most PCBs go through several iterations of prototyping before they are optimized. When building your first printed circuit board, start with a simple design and use software to make the process easier.