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Printed Circuit boards and their explanation.

In this post today, I’ll walk you through PCB (Printed Circuit Boards) in detail.

PCBs are commonly used in computers, smartphones, digital cameras, and other electronic devices. PCB is a circuit board that connects different electrical components. It provides both mechanical support and a conductive path for the components mounted on the board. Using PCBs, designers can make compact, simple, and less expensive designs, setting you free from the point-to-point construction in electronic devices.

Different types of PCB include single layer, double layer, multiple layers, rigid, rigid-flex, flexible, and aluminium circuit boards.

Read this post all the way through as I’ll cover each and everything related to PCB including what is PCB, its components, mounting technologies, types, and applications.

Let’s get started.

What is PCB (Printed Circuit Boards)?

A PCB (Printed Circuit Board) is an electronic circuit board that provides both mechanical support and electrical connection for the electronic components using conductive signal traces or pathways made up of copper material laminated on a non-conductive substrate usually consists of fibreglass.

Image of a PCB with components

The PCB is known as an etched wiring board or printed wiring board when the board only contains copper traces and no electronic components like resistors, capacitors, transistors or active electronic devices have been mounted on the board.

A PCB stuffed with several electronic components is called printed circuit assembly, however, we commonly use the term PCB for both bare and assembled circuit boards.

Before PCBs were introduced, designers used to connect electronic components using end-to-end wiring which leads to erratic and complicated designs.

PCB designs, however, have revitalized the electronic industry with simple, compact, and sophisticated circuit boards that cover less space and are easier to manufacture, and can rest on hard-to-reach places.

From using single-layer PCB in old 1990s TV sets to 60-layer PCB in supercomputers, PCB designs have come a long way. Recent versions of electronic circuit boards offer better solutions for increased demand of smaller size, greater functionality, and added utility.

PCB Components

The PCB consists of six components.

  • Prepreg
  • Laminate
  • Copper foil
  • Solder mask
  • Nomenclature
  • Final finish

Prepreg is a substrate material usually composed of fibreglass that is coated with resin. The FR4 is the most common resin used as a substrate. Laminates, also known as copper-clad laminates, are made of sheets of substrate that are laminated together with pressure and heat. Next, copper foil is laminated on the board that provides a conductive path for the components mounted on the board.

Image showing the structure of a PCB

The soldier mask rests on the copper foil. This layer is used to insulate the copper layer. Nomenclature, also known as silkscreen, is the white letters that stand on the top of the solder mask. The silkscreen is used to add labels and numbering for each component on the board. To protect the exposed copper holes and to provide a smooth solderable finish, a metallic coating of silver, nickel, or gold is normally used.

Through-Hole vs Surface Mount Technology

There are two ways to mount components on the circuit boards during a PCB Manufacturing Process.

Through-Hole Mounting

This method was a common practice to mount components on the board before Surface Mount Technology was introduced in the 1980s. In through-hole mounting, the leads of electronic components are placed into a drilled hole of the PCB that is then soldered from the other side of the board. This type of mounting is a good fit for designs that need a stronger connection between the layers. Though drilling the holes is expensive and time-consuming, the leads passing through the drilled holes offer strength and can withstand extreme environmental stress.

PCB showing through hole technology

Surface Mount Technology

SMT is a process by which electrical components are directly mounted on the circuit boards, offering a more compact and concise design compared to through-hole mounting. When you require a smaller PCB size, more component density, and less expensive design, SMT is always preferred over through-hole mounting.

PCB showing surface mount technology

Types of PCBs

Different types of printed circuit boards include:

Single Layer PCB:

Single-layer PCB, also known as single-sided PCB, is a type of circuit board where conductive copper is applied on the single side of the board. It is widely used in digital cameras, calculators, printers, power supplies, and other electronic devices.

Double Layer PCB:

Double Layer PCB, also known as double-sided PCB, is a type of circuit board where the copper layer is applied on both sides of the circuit board. This board is less thin compared to a single-sided board. It is used in automotive dashboards, HVAC systems, and LED lighting and vending machines.

Multiple Layer PCB:

Multi-layer PCB is a type of circuit board that contains three or more double-sided boards. Based on the requirement you can add as many layers as you want, however, the maximum number of layers you can include is 129.

Rigid PCB:

A rigid PCB is a type of circuit board that consists of a solid substrate material that prevents the board from folding. The computer motherboard is composed of rigid circuit boards.

Flexible PCB:

This type of circuit board is composed of flexible substrate material like fibreglass. You can fold and twist this board as per the requirement. Due to the presence of soft substrate material, the Flexible PCB is costly to manufacture compared to other circuit boards.

Rigid-Flex PCB:

This type of PCB is a combination of both rigid and flexible boards. Rigid-Flex PCB is commonly used in digital cameras, cell phones, and automobiles.

Aluminum PCB:

Aluminum PCB is a type of circuit board that contains the Aluminum metal substrate. The board comes with a thermally conductive and electrically insulated dielectric material that stands between the copper clad and Aluminum metal.

Applications of PCB

The following are the main applications of PCB.

  • High current battery chargers
  • Industrial load testers
  • Motor controllers
  • Medical and Military
  • LED-based lighting systems
  • Automotive and aerospace industry

That’s all for today. Hope you’ve found this article useful. If you have any questions, you can pop your comment in the section below, I’d love to help you the best way I can. Thank you for reading this article.

HI, I am a student of Electrical Engineering. I am currently working for an electronic store. I work at the electrical components there. I am learning many useful practical concepts there. On the other hand, I give online tuitions to some students of high school I love electrical and electronics devices and have a plan to have a Master's Degree in Electronics.
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