What Is a Printed Circuit Board? The Basics Explained

You can’t imagine our current world without printed circuit boards (PCBs). That’s because anything remotely electronic in nature has a circuit board to give it life. Whether the device is loud and flamboyant, or even subtle. At its core, you’ll find a printed circuit board. 

This amazing piece of technology isn’t young. It has been around since World War II, as they were intended to be implemented in military applications and machines.

Yet, the moment these circuits hit the commercial market, a boom in electronics occurred, due to electronic manufacturers developing cost-effective solutions and ushering in the new age. Interestingly enough, there’s another electronics boom predicted to happen between now and 2026. 

If you’re completely unfamiliar with printed circuit boards, no worries. We’ve got you covered. Keep on reading for our full breakdown of printed circuit boards, answering questions like “what is a printed circuit board?” as well as covering the different types of PCBs, and their most common uses. 

What Is a Printed Circuit Board?

Let’s start with covering our basics. 

In the simplest of terms, a printed circuit board (PCB) is a thin board, usually made from an insulating material with a metal-covered surface, either on the top or bottom or even on both sides. 

By taking a quick look at a PCB, you’ll notice that there are etches made in the metal coating. These patterns are created using acid to allow electricity to move amongst the different components, basically creating pathways on the board. Besides, these other components are mounted on the board using solder. 

The Main Material Types of Printed Circuit Boards

The different types of PCBs all depend on the primary materials that have been used in manufacturing the boards.

So, if you’re interested in using a PCB board printer, you’ll want to have a solid understanding of what type of PCB you’re looking for and the appropriate materials you’ll want to use.  

Plastic and Fiberglass Substrates

Generally speaking, a PCB can be constructed using flexible or rigid-base materials. This decision depends on the final intended PCB design. 

When it comes to rigid PCBs, they use materials like FR4 or polyimide fiberglass. On the other end of the spectrum, flexible circuits and rigid-flex layers would go for high-temperature polyimide films. The plastic substrate come in for flexible circuits, which includes  liquid crystal polymer (LCP), polyimide (PI), polyethylene naphthalate (PEN), and polyester (PET)

Using Copper

When searching for materials with high electrical conductivity, copper is king. That’s why it’s the most used material for circuitry in PCBs. The laminates usually come with very thin sheets of copper foil laminated on either one or both sides of the plastic.

Then, the fabricator uses gerber files, which are supplied by the designer, so it can itch and image the circuits to meet the requirements set by the customer. 

The Soldermask

This epoxy material, coming in liquid form, will be applied to the outer layers of rigid PCBs. Also, you can find them used on the rigid parts of a rigid-flex PCB. 

This material is designed to insulate the copper circuits on the outer layer from reacting (and oxidizing) due to exposure to the environment. Moreover, soldermask is responsible for controlling and retaining the flow of solder, specifically during the assembling process.

The Nomenclature

At this point, the PCB needs identifying information, bar codes, and other marks.

These are printed onto the soldermask of the PCB, and they’re known as nomenclature. Besides, the nomenclature will be defined by the files that are included with other gerber layers. 

Uses and Applications of Printed Circuit Boards

We’ve talked about the materials used in the assembly of PCBs. Yet, what makes PCBs so important and beneficial? Let’s take a look at their uses and applications. 

In comparison to traditional wired circuits, the PCBs are rather small and lightweight, as well as easy to maintain and reliable when it comes to integration in complex systems. In addition to all of those benefits, they’re actually cost-effective to produce. 

Medical Field

Whether you’re looking at imaging systems, MRI machines, and radiation equipment, all of those machines are evidence of the advancement of technology, thanks to PCB’s electronic capability. 

As you get thinner and smaller PCBs that are flexible or rigid-flex, medical engineers were able to create compact devices like pacemakers, hearing aids, implantable devices, and even minuscule cameras to conduct minimally invasive procedures. 

Aerospace Field

The aerospace industry is filled with instrument panels, flight controls, dashboards, safety and flight management systems. All of those devices use a plethora of PCBs, whether rigid, flexible, or rigid-flex.

As the advances in aerospace technology increase, the need for more complex PCBs that can be used in different aircraft, and aerospace electronics rises. 

The Military Sector

Can’t really talk about PCBs and not mention the military sector. 

PCBs are used in numerous equipment that is exposed to heavy impact, as well as shock and vibration applications. Those can be ruggedized computers, modern weapons, and military vehicles, and other robotics. 

The Industrial and Commercial Sectors

Looking at a simple example of complex processes in business, like supply chain management. PCBs were able to help manufacturers increase automation, information gathering, and work efficiency. If you’re looking for a reliable way to direct heavy equipment in an automated facility, then look no further than PCBs. 

Basically, both flexible and rigid-flex PCBs help manufacturers create lighter (and smaller) products that come with better functionality, better reliability, like mobile electronics and cameras. 

PCB: The Building Cell of Technology

We know that learning about PCBs might seem a bit complicated or overwhelming at first. However, by going through our thorough breakdown of the key elements of PCBs, their applications, uses, and even the materials used in creating them, you’re in a much better place to conduct more research. 

This definitely answered the question: “what is a printed circuit board?” Yet, we hope that it also gave you a solid foundational understanding of the sheer importance of PCBs in our modern age, and how it’s going to stay the gift that keeps on giving.