While many people have never heard of the printed circuit board (PCB), these little circuit boards make all of our electronic devices possible. The current methods of PCB fabrication are responsible for all of the advancements in our electronic technology.
To understand the importance of the PCB fabrication process, you need to understand what PCBs are. Printed circuit boards provide the electrical connection and mechanical support for the electronic devices and appliances we all use. The board components are connected with electrically conductive tracks made from copper that has been attached to a non-conductive material. They can be single or double sided. There are even multi layer PCBs.
While PCBS do require a bit of extra design at the outset to correctly lay out the full circuit, this time is more than made up in the PCB fabrication process, which is an automated one. Circuits that are made with PCBs are much cheaper and easier to manufacture. The development of this process is what made the mass production of electronic devices and appliances possible.
How were PCBs invented?
Prior to the advent of the PCB, point to point construction was used to make electronic products. This was extremely clumsy and bulky. The designs that were used were not very reliable. They needed to large sockets and they needed near constant repairs and replacements be made. When this was the main way electronic circuits were made, the idea of mass production and use of electronic products was a far fetched idea. Modern PCB fabrication techniques eliminated many of these problems.
Paul Eisler, an Austrian engineer, has been credited with inventing the modern PCB. He was working on radios in England. He had begin working on his design before he escaped Austria. In the early 1940s, the United States military started using Eisler’s PCB for parts in its weapons systems for the end of World War II.
While the technology was made available for commercial use after the war ended, it took more work from the U.S. Army to get the technology off of the ground. In 1956, Moe Abramson and Stanislaus F. Danko from the Army Signal Corps were granted a patent for the andldquo;Process of Assembling Electrical Circuits.andrdquo; This established the basics for modern day PCB fabrication. The actual patent went to the Army, not the scientists who developed the PCB fabrication process.
In the beginning the electronic components on circuits had wire leads. Holes were drilled in each PCB for where each component would be placed. The wires were then passed through the holes and attached, by solder, to the PCB trace. This method was referred to as “through-hole construction.” The PCB fabrication process developed by the Army scientists was automated. They developed a process by which the leads were inserted into a copper foil interconnection pattern. The board was then dipped into a zinc soldering bath. This was the direct precursor of the methods used today for PCB fabrication.
This represented a major advancement in the development of the PCB. The new process made it easier to develop prototype PCBs, which led to newer electronic products that could be more efficiently produced.
In the 1970s, surface mounted parts started to be added to the PCBs, this greatly increased the number of components that could be attached. These added components are the reason we have some features such as touch screens, WiFi connections and cameras and all of the other features that we depend on and cannot imagine life without.
What does does the future hold for PCBc?
It is hard to say where engineers will take PCBs from here. Today, the PCB fabrication process is a multi-step one. It uses photolithographic patterning and conventional vacuum deposition. There are drawbacks to these newer techniques and processes.
The good news is that the next revolution in the PCB fabrication and manufacturing process has already begun. The advent of three dimensional printing means printing these circuit boards is becoming easier than ever. Engineers are even working on PCBs that are made from paper.
Over the past century, electronic products have changed dramatically and they have changed the world at the same time. Most of us cannot imagine life without our mobile devices. It is not too much to say that PCBs were and are revolutionary.