How Does A Circuit Board Work

One very profound invention of humankind is transforming the existence of all aspects of our life. From history, we have surely come a very long way. The evolution of technology is known as the journey of cultural and social growth right from fire discovery and this has been a very important catalyst shaping how we think, act, and live. In the technological evolution of today, there are many stages. This has led us to our current state of convenience and comfort.

However, this very comfortable lifestyle won’t have been realistic without the use of electronic circuit boards. This means that, with circuit boards absent in our lives, we would have lived in a very different world. Considering all aspects and areas of our lives, including education, health, transport, defense, entertainment, and communication, the electronic circuit boards are known to play a significant role in our modern life.

This small bare board doesn’t just form the hearts of all electronic devices; they have also played a very important role in all technology-defined industries or are relying on technology. Before we understand how a printed circuit board assembly works, let first understand what it is.

What is a Printed Circuit Board (PCB)?

Speaking simply, a printed circuit board features conductive pathways that are referred to as traces. These traces help in connecting the electronic components together. Furthermore, the circuit boards are very important inventions which formed the basis of electronic technology. Also, with technology evolution, these boards’ complexity has evolved as well. However, one thing that doesn’t change is the underlying concept.

A circuit board exists due to many discoveries, inventions, as well as improvements that have marked the modern technology course.

Simplification of the Process

Generally, printed circuit boards help in simplifying the electrical wiring. This they achieve by replacing the majority of the electronic components, that at one point in time was wired via cable or solder mask with printed circuit board that is easier and simpler to assemble.

Furthermore, circuit boards are manufactured from many components. They have now become sophisticated and complex, and at times they feature at least 30 layers. The layers of a printed circuit board are usually linked together with the help of traces. Some of the layers are designed to provide power, while others enhance electronic signals.

Also, all the components can serve as a transistor. It can also serve as components that are as complex as the microprocessor. This is a complex IC (integrated circuit) that features about billions of transistors. There is a need for the circuit board traces to be built on any flat surface that is coated with copper foil and copper layers to ensure conductive pathways. In addition these pathways can either be on the board’s top or bottom. This depends on the extent to which the length of that trace must be shortened.

In addition, a significant asset of the circuit boards is their provision of easy pathway to replace and add components without stress or hassle. You achieve this by using the headers on the printed circuit boards providing environments whereby you can plug the printed circuit cards in the mainboard. The same way, printed circuit boards may feature many printed circuit cards that are plugged in.

For all electronics, circuit boards are known as the foundation. The functioning of power supply, load balancers, phones, elevators, printers, lights, and the majority of electronic equipment, works with circuit boards.

History of the Printed Circuit Board

The circuit boards having fixed contacts can be traced back to the 1800s. Included among the earliest printed circuit boards was manufactured by Vladimir K. Zworykin back in 1924. Back then, he failed to patent it, therefore it was subjected to the public domain. There are other inventors that have helped in developing printed circuit boards as well as printed circuit board fabrication.

How does Circuit Boards Work?

The circuit board technology came to be during the steam, and since then it has had a very big impact, even till today.

Integrated circuits may sound very complex; however, taking simply, a circuit translates electronic instructions to mechanical action. During the earlier stages of our existence, the printed circuits were known to be very simple.

Due to inventions and advancement in science, everything changed. There was also an increase in the technological vocabulary we use and also we learned the use of other worlds like analog, cache memory, software, hardware, and electronics.

Electronics has a major job, which is the translation of information between different forms. It also helps in simplifying the process of making use of many different points at once when performing a function. With time, circuit boards helped in achieving that.

What Electronic Circuits are

In order to really comprehend what electronic circuits are, there is a need to comprehend how they function. All electricians know that their rules are broken down into the four major laws regarding charge transfer.

  • The first of all is the continuity principle. This is the energy flow between two main points
  • Second, is the charge conservation principle. This refers to the constant electric quantity as a whole.
  • Third, is the freedom of charge principle. Here, you can add electric charges as well as remove them from materials.
  • Fourth and lastly, is the energy transfer principle. Here electric charges have the ability to transfer energy.

The basic laws outlined below are for all circuits. It also explains the principles that we explained earlier.

All circuits are composed of three main parts. A power source has two wires. When you follow these wires, you will see a resistive load. The load is what circuits usually perform like lights, motors, etc. Importantly., circuits are composed of conductors that can be wire for copper cases and plastic when we refer to printed circuit board, a switch, and a load. Furthermore, there is a switch in all power circuits.

Continuity Principle

The continuity principle is the first electricity law. Electricity walks through the path having the least resistance. When the wire is single, then electricity will not find an easier oath to take. What this means is that electricity will move via the whole wire and then leave at the extreme other end. We refer to this as a ‘fixed’ or ‘continuous’ circuit.

For circuits that are more complex, the electricity will have at least two paths to pass or move through. This is where the electricity laws come in. You can restrict the electricity flow in all circuits to ensure the heat transfer of just a specific quantity.

Conservation Principle

This conservation principle reveals the answer to this. Now, the wire must carry this amount to create the continuous short circuit. We refer to this as voltage division. Also, we can place some impurities into the metal. This serves as resistors.

Also, this allows the passage of the voltage up to a particular point. When these impurities stop that electricity from getting to the wire end, it results to a ‘closed’ circuit. For closed circuits, there is a change in direction of the current. However, the voltage remains the same.

You can use the bare circuits in carrying large quantities of power. Furthermore, the process involved in the dividing of the voltage ensures that it is safe and just a fraction of this power acts via the wire at a specific and given time. Furthermore, if the circuit has any breaks, then power will not reach the load.

Also, it is very important to know that in all circuit types, there is a specific current. This helps in limiting the length of time that the circuit is connected as well as circuits designed in order to be hard-wired so as to possess a maximum length, which can be connected.

Gathering the Closed-loop

Furthermore, the final process is generating the closed-loop. We refer to this as the energy transfer principle. This is a little variation when it comes to the continuity principle. When you form a wire loop correctly, then there will be a continuous flow via the loop. Converting energy into heat as well as other utilities such as electric toasters is possible. This ensures that the wire can retain large amounts of energy.

In addition, this principle explains the reason behind the ability of transferring energy through the wire. This process happens in a similar way as that of the continuity principle. For now, we have explained the metal wire resistance.

However, it is possible there are resistors that are made of some solid materials such as glass. Each has a different resistance, and working with the continuity principle, this current will be able to move via the wire. Though the wire may fail to conduct the required task, it could cause a different effect. Inventing carbon and graphite filters transformed the way of transporting energy between different locations and are now useful in the computer circuit boards.

What are the Applications of a Printed Circuit Board?

PCBs deliver some benefits, in contrast to the wired circuits. Their lightweight and small pcb design is useful in the majority of modern devices. Also, their maintenance ease and reliability allows them to be integrated in different complex systems. In addition, their low production cost ensures that they are a very cost-effective option.

Below are the applications of circuit boards


All medical electronics have benefited greatly from the presence of PCBs. Electronics present in MRI machines, imaging systems, radiation equipment, and computers, all keeps advancing in technology via the PCB’s electronic capability.

The smaller and thinner size of rigid flex PCBs and flexible PCBs ensure the manufacturing of more lightweight and compact devices like pacemakers, hearing aids, implantable devices, etc.


The circuit board used in the military is usually exposed to vibration and shock applications and heavy impact like modern weapons, ruggedized computers, military vehicles, and other electronics systems like targeting systems, guidance, and robotics.


The aerospace industry is known to make use of rigid flex PCBs, flexible PCBs, and rigid PCBs in dashboards, instrument panels, safety systems, flight management, and flight controls. The rigid flex circuits and flexible circuits offer mission survivability and great durability because connectors are eliminated.

This is why they are useful for high-vibration applications. For applications that dependability is important, this is a very important solution.

Commercial and Industrial

Using PCBs for commercial and industrial electronics have helped in the revolutionizing of everything that involves manufacturing and supply chain management. This involves increasing efficiency, automation, and information.

What are the Types of PCBs?

Though any circuit board feature similar fundamental objective and goal, they come in different configurations and pcb design to ensure they meet the needs and requirements of different applications. The available ones include

  • Single sided rigid
  • Multi-layered rigid
  • Double sided rigid
  • Double sided flexible circuits
  • Rigid-flex
  • Multiple layers flexible circuits or multi layer pcbs
  • Single-layer flexible circuits
  • Aluminum-backed
  • High frequency

Let’s consider the most common of them all.

Most Common Types of PCBs

Flexible PCBs

This features relatively great folding and bending capabilities. This helps it to fit in oddly shaped and confined spaces. With this quality, it ensures they are very versatile and are useful in packaging small electronic devices. They provide greater heat resistance compared to the rigid PCBs.

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