PCBs are considered among the most significant inventions that came out from the last 100 years, as virtually every gadget and electronic device contains at least one of them. PCBs are printed circuit boards which connect electrical or electronic components using pads, conductive tracks, and other features. Usually, components get soldered onto the board in order to connect them electrically and fasten them to it mechanically.
PCBs are instantly recognizable due to their iconic green color. In reality, the green color is the color of the solder mask which is showing through the glass. There are many theories about why the color green is being used. Speculations are that it was a regulation standard set by the American military, and the use of it spread from that point on. Other theories state that green is the color of the solder mask resins, and that despite the fact that the materials are no longer in use the color has been kept as a convention.
An Austrian inventor, Paul Eisler, is usually credited with the invention of PCBs, but the development which led to their invention can be traced as far back as the 1890s. Paul Eisler developed the PCB in 1936 while working on a radio set. He was working for a music printing company and decided to share the idea that he worked on for years. Despite them being created in the 1930s they became a matter of mass usage only after the 1950s, their popularity increasing dramatically from there.
Despite the fact that devices usually use wires in order to transmit energy, PCBs are an exception, as instead of wires they employ the use of copper traces which helps transport electrons. The copper traces used instead of wires allow the boards to be small, as the traces do not take a lot of space. The boards can include many components, each with their own properties. It can include resistors, capacitors, relays, inductors, potentiometers, batteries, transformers, fuses, diodes and transistors.
The Army Signal Corps is credited with the development of the auto-assembly process, something that allows for a fast creation of PCBs. This stream-lined production helped increased the amount of consumer products that we have today. PCBs have even been used for NASA’s space program, as the boards helped with the Apollo 11 mission which sent astronauts to the moon and back. Due to the fact that they are lightweight and have small electricity requirements, they allowed for complicated electronics in the small area of the spacecraft.
Since 1936, PCBs have changed drastically, nowadays being faster, smaller, and efficient to build. The technology is constantly evolving, scientists currently working on creating PCBs which are biodegradable. As some electronic devices became smaller and smaller, PCBs had to adapt. There are many companies which make circuit boards to order, meaning the customer can customize them in order to meet their specifications. Custom PCBs are not cheap however, but 99% of the PCBs bought fall within the parameters of 14 services available. The standardized specifications allow manufacturers to lower the costs.