Every electronic component has over a hundred to three hundred meters of wires. Today, electronic components are multi-functional, and they can operate many components at once. For electronics to work, each component needs to be interconnected, and they need to have all components work seamlessly together. A single wire in a smartphone can cover a football field. However, you cannot see these wires even if you open up the smartphone.
This is because they are inside the Printed Circuit board. A printed circuit board or PCB is the green board that you find inside electronics. This circuit board has multiple layers with hundreds of different copper wires. A PCB gives all the components inside the PCB structure and organization. The wires that run in between the PCB component allow all the components to be interconnected with one another.
How do PCBs Function?
Before you learn how Printed Circuit Boards function, you need to realize that there is a difference between components and PCBs. The components of the Printed Circuit Board include Microchips, Capacitors, Resistors, and Connectors. You can find these components mounted on top of the PCB with the help of a solder mask. A PCB without the components is simply a flat board without anything mounted on it.
You can also find other components with the PCB, however, they are not mounted on the board, but rather attached on it. If you take an X-ray picture of a PCB, you will find conductive wires clumped up inside, and you will also find light shades that are non-conductive insulator material. The dark shades will present multiple layers of wires that are aligned on top of each other.
Even though they are layered, they do not come in contact. Microchips are mounted on the PCB on a grid of connection points or pads known as the ball grid array. Microchips are like the central functioning units of any highly specialized component. There are many pads and compartments on the printed circuit board for other microchips.
Conductive Layers of the PCB
The PCB consists of multiple conductive layers. The top and bottom layers are the ones where you mount the components. Each of the components on the circuit board requires power to function. This is why the printed circuit board has layers that are only responsible for providing power.
They are called power planes and ground planes. Additional ground planes are used for heat dissipation and electromagnetic shielding. Other layers carry signal wires which help in communication. Each of the conductive layers has copper, insulating fiber glass, and epoxy resin that shuts down the flow of electricity. PCBs can have anywhere from 2 to 50 layers depending on their application. However, most of them will have a total of ten layers.
On the top and bottom is a colored solder mask that is covered. This not only keeps the mounting pads intact, but also provides insulation. On top of that you have silkscreen, which is ink that provides markings for where you need to store the components.
As you can see, printed circuit boards play an integral role in the majority of the electronics you see today. Years of careful engineering and evolution have led to the printed circuit boards you see today, which is why they have been perfected to the core.