What is a Printed Circuit: Detailed Guide to PCBs, Types, and More!

The PCB industry first developed in the 20th century and is constantly evolving. PCBs hugely contribute to the growth of the electronics industry. For example, it led to the emergence and development of smaller electrical components with very high performance, like resistors.

We will discuss the printed circuit board, its uses, and the step-by-step process of making one. Also, it will help you learn and find the correct PCB for your needs!

 1. What is a Printed Circuit?

A printed circuit is the foundation of many electronic devices. These PCBs are mount surfaces for other essential equipment, whether it's a simple printed circuit or the most complex circuit.

For example, resistors, capacitors, semiconductors, transistors, and diodes need PCBs to function. 

(A photo of a PCB)

2. Why are Printed Circuit Boards Used?

PCBs are standard since they have lots of advantages. These boards are usually compact and have a lightweight design; therefore used in many modern electrical devices. Also, for very complex systems, PCBs are essential. It is because the boards are elementary to work with and maintain. In addition, these boards are cost-effective since they cost a lot less in terms of production.

Some of the common markets in which you will find a PCB include;

• Aerospace

The continuous advancement in aerospace technology demands the use of compact but complex circuit boards. Flexible and rigid-flex circuits offer excellent durability and survivability due to the lack of connectors. 

• Medical

The minute size of workable PCBs makes it easier to use the best medical devices. For example, the medical hearing aid uses PCB technology.

Mainly, rigid-flex boards are essential when there is a need to reduce the complexity of devices. These circuit boards often don't require flex cables and connectors that utilize more space. 

(a printed circuit board of a laptop)

• Industrial and commercial

In the industrial and commercial market, PCB technology is revolutionary. The boards have changed everything from manufacturing to supply chain management. Also, the use of these boards makes it easy to direct equipment using automated devices. This method enhances production at the same time reducing the labor cost.

• Military

Most military equipment and machinery experience a lot of heavy impacts and banging. Just like any other market sector, military equipment has integrated PCB technology. These devices require both mechanical and electrical performances. For example, flex and rigid-flex packaging need modifications. These two package types can withstand continuous pounding and vibration without damage.

(electronic printed circuit board.)

3. What are PCBs Made of?

Printed Circuit Board materials are the fiberglass/plastic substrates, solder mask, copper, and nomenclature ink.

• Plastic substrates/fiberglass

A manufacturer can use either a flexible or a rigid surface when making a PCB. These two surfaces depend entirely on the PCB design a project requires. Importantly, tough surfaces require polyamide fiberglass or FR4. At the same time, flexible surfaces use flexible materials like high-temperature polyamide films. Some of the common non-conductive substrates to use for flexible boards include polyamide, liquid crystal polymer, polyethylene, and polyester. Also, these substrates provide a non-conductive surface where all the conductive circuits go on.

• Copper

Copper wires have very high electrical conductivity. The plastic substrates used have been laminated with thin copper traces on all plastic sides. However, for multi-layer PCBs, the construction is different. Multi-layers have an alternated arrangement of a layer of copper which acts as a conductive material to the insulating materials.

• Solder mask

Solder mask is a fluid usually applied to the outer layers of the rigid Printed Circuit Board. Importantly, its work is to cover the copper sheets preventing them from oxidation. Also, when all the components are on the board, the fluid retains and controls the flow of molten solder. When a liquid solder flows out of the surface, it risks connecting two adjacent circuits, forming a short circuit. Notably, solder mask liquid has a typical green color. However, other colors such as blue, white, red, clear are also available.

Once you apply the solder mask layer, the next step is to print barcodes, identifying information and marks. These marks are nomenclature. Crucially, jargon helps to achieve accurate PCB assembly.

(a photo of a PCB with markings.)

4. Types of Printed Circuit Boards.

Below are the three most common types of PCBs with different material properties.

• What is a Printed Circuit: Rigid PCBs

The rigid PCB type consists of a rigid fiberglass substrate. This property makes the PCB inexpensive and practical. However, it is not flexible. The rigid PCB costs less to produce, unlike the flexible PCBs. But, they are less versatile thus can be challenging to fit in certain device design practices.

• What is a Printed Circuit: Flexible PCBs

This PCB has excellent flexible substrates. Importantly, this feature makes them versatile and can fit in oddly shaped devices. These circuit boards are highly adaptable, and there is no specific shape for them. Also, the flexible PCB has higher heat resistance, unlike the rigid PCBs.

• What is a Printed Circuit: Rigid-flex PCBs

The rigid-flex PCB reduces the board's weight and size by compactly containing the electronic interconnectivity within the board. Also, this PCB type is long-lasting, strong, and flexible, combining notable qualities of both the rigid PCB and flexible PCB.

(An empty circuit board.)

5. What is a Printed Circuit: PCB Design Factors and Processes.

There are many different design types of PCB. Importantly, understanding the design process is vital.

• The environment in which the PCB will work.
• A PCB's flexibility.
• The assembly and installation of the PCB.
• Amount of configuration and technique the PCB will need.
• The type of application in which the PCB will operate.

(a high frequency printed circuit board.)

6. What is a Printed Circuit: How to Make a PCB Step by Step?

The following steps help guide you in developing a proper PCB.

• First, chemically image and etch the layers of copper with the small paths to connect electronic components.
• Second, laminate the copper layers with bonding material that can also serve as insulation.
• Next, plate and drill holes in the PCB to electrically join all the copper layers.
• Then, image and plate the pathways on the outside layers of the board.
• Coat the board outline with a solder mask, then print the nomenclature marks.
• Finally, machine the board according to the dimension in the perimeter file.

Once you complete these steps, you can mount components onto the PCB.

(a microchip on a PCB)

Summary

There are several rapidly emerging and advanced PCB technologies today due to the emerging development in technology. Therefore, investing in small and efficient technology is the only way to make a long-lasting and durable device.

We've given information on what PCBs do and how they work in this article. If you're interested in learning more about your PCB-related projects, contact us! Our team is always happy to answer any questions from you.