Did you know?… 10 Facts about PCBs

12 July 2021

  1. PCBs are everywhere.

In today’s world, printed circuit boards (PCBs) are everywhere. You can find them in many devices like smartphones, tablets, and computers. They are also in radios, medical devices, smoke detectors, and security cameras. Additionally, you’ll see them in LEDs and parts for cars and planes, along with many other electronics. We use electronic devices every day. Still, we often overlook how vital these boards are to today’s technology.

  1. Who invented PCBs?

The PCB’s history goes back to the 1890s. However, people credit Paul Eisler, an Austrian inventor, with its invention. He created the printed circuit board in 1936 while working on a radio set. PCBs didn’t see mass usage until after the 1950s, and their popularity surged from that point onward.

  1. Why they are green?

Green is the colour of the solder mask. It protects the copper circuits on the fiber glass core. This helps prevent short circuits and soldering errors.  There are a few theories about why PCBs are green; the most common are:

  • Glass epoxy, originally used to make PCB solder masks, has a green colour. Today, green remains the most common colour. It is also the cheapest to produce. That is why it is still the default colour for printed circuit boards.

  • In the early days, workers had to inspect boards by hand. They used only their eyes, which was tough. Green is the best colour for checking printed circuit boards. This is because green light can help reduce fatigue and relax the body.

  1. Space Travel made possible the PCBs.

PCBs were an integral part of NASA’s space programme. They helped send the Apollo 11 astronauts to the moon and ensured their safe return home. PCBs are lightweight and need little electricity. This allows for more complex electronics in the tight space of a spacecraft.

  1. They are getting smaller.

Developers are making PCBs smaller over time. This is because manufacturing is getting more precise. Smaller PCBs also save space.  This is also because the electronics we use today are smaller, too.

  1. They have lots of components.

Circuit boards are complex electronics with lots of components and they all have their own individual properties and serve different purposes on the board.  The list of components you can expect to find on a PCB includes (but not limited to): capacitors, resistors, inductors, diodes, batteries, fuses and transistors.

  1. Traces not wires.

Circuit boards are intricate electronic devices. They have many components, each with unique properties. These parts serve different purposes on the board.

You can find many components on a PCB, such as:

  • capacitors

  • resistors

  • inductors

PCBs are completely wire-free – circuit boards utilise copper traces to transport electrons. These traces are much smaller than traditional wires. They are flat, so they take up less space. Copper traces connect small parts on a circuit board more efficiently than wires do.

  1. They are subject to Ohm’s Law.

The rules of physics impose strict regulations on printed circuit boards.  The most famous of these among electrical engineers is Ohm’s Law. Ohm’s Law explains how current, resistance, and voltage relate. Current has a direct relationship with voltage and an inverse relationship with resistance.

  1. Main manufacturing techniques

There are two main methods of mounting components onto a circuit board; through hole technology and surface mount technology.

  • Through hole was developed in the 1940s and it had become a very popular method of mounting components.  Essentially through hole utilises holes that are drilled into the PCB and then leads of components are fed through and soldered onto the pads on the opposite side.
  • Surface mount technology was then developed in the 1960s which is a technique that allows components to be placed directly onto the surface of the board.  This eliminated the need  to drill holes through the PCB which meant that the mounting and soldering of the components can be automated which saves time which then saves money.

  1. There are a variety of PCB types

Not all PCBs are the same. Many types of circuit boards exist. Each one has unique features for specific tasks. Some designs fit low-performance devices better. This makes the PCB cheaper and easier to make. Other boards might work better for high-power devices, but they cost more to make.  For example, single-sided, double-sided, multi-layered PCBs, flexible, rigid, and flex-rigid.