PCB History and Development
Sat, Oct 12, 2019
A brief history of PCB and how SMT originated
The early days of electronic components are a mess of wires connecting each component terminal by individual wires.
This leads to bulky and untidy devices and the manufacturing was error-prone and needed manual skilled labor.
Austrian engineer Dr. Paul Eisler had an idea to eliminate those bundles of wiring by printing the wires onto the boards, as a result, the first operational PCB (Printed Circuit Board) was developed by Dr. Paul Eisler in 1943.
By the year 1947 PCB manufacturing matured into double-sided PCB design.
The technique of through-hole(TH) copper plating allowed designers to use both sides of the PCB.
The next turning point was the invention of the dip soldering process by the U.S. Army in 1949.
This speeds up the manufacturing process of PCBs significantly by that time.
In the following decade, PCBs advanced into multilayer designs.
From the 1960s Surface-mount technologies(SMT) were emerging as a method to build PCBs more compactly, it replaced through-hole(TH) components with surface mount devices(SMD).
Other benefits of SMT include reduced process and handling costs and higher product quality and reliability.
Pcb is an important piece of technological hardware, they make their presence felt in almost every aspect of our modern world.
While their use is widespread and generally noticed by the average population, there is another aspect to it, which is not so well known; its history and development.
Not many people know the history and development of PCBs, and it is indeed an interesting story unto itself. The history and development of PCBs go back several decades, to the age of modern technological computing.
To start off, there was a time when there were no PCBs, and instead, were what wired point-to-point circuits on a chassis were.
These chassis, in turn, were usually designed using a sheet metal frame, and which sometimes came with a wooden bottom.
The various components of this primitive circuit were attached with the help of metal fixtures, soldering, and crimp connections, and so on.
As much as it was effective in getting the job done, the technology proved to be very rudimentary, large, bulky, and heavy.
In addition to this, it was also very fragile and could easily be damaged. It was partly for this reason that a newer form of circuitry was envisioned.
One of the earliest developments of PCBs came about when a German inventor, Albert Hanson, in 1903, described a flat foil conductor laminated to an insulating board, in several layers.
On the other side of the Atlantic in the United States, Thomas Edison worked on chemical-based platings to create a conducting layer on linen paper in 1904.Similar experiments were carried out in other parts of the world as well. All of these served as the basis on which to build the modern PCB.
The modern PCB started to take form when an Austrian engineer named Paul Eisler invented a printed board as part of a larger radio set project in the UK.The first large scale use of this PCB technology came about during World War II when the US military started using it to create proximity fuses in warfare.
It should be noted that the technology was still in military hands at the time, with the commercial use of the technology being kept beyond the reach of this technology.
After the war, the technology was released for civilian use, from when it started to really become commercialized.
At first, they didn't seem like much, given that the technology was still in its infancy.
With the passage of time, however, things started to take off regarding PCBs, particularly with the rise of consumer electronics.
Although they had widespread applications, some of the most common places where they found adoption were in the manufacture of televisions and radios.
It should be noted that even during this time, there was large scale use of the more rudimentary point-to-point chassis.
The technology underwent several different changes during this stage.
For example, originally, all of the electronic components used to have wire leads in the design, with the PCBs having holes drilled in them for each of the wire leads used in the circuit assembly, which in turn was inserted through the holes and then soldered to copper PCB traces.
This technology eventually gave way to the one where lamination and etching would be used to create the circuits, similar to the technology used today.
The technological evolution remained largely the same at the foundational level, albeit with some minor changes in the manufacturing process.
The next real change came about with the rise of multi-level circuits, wherein there were several different circuits combined and compressed on top of each other.
This process began around the 1990s and became an industry standard with the passage of time. In fact, the modern multi-layer circuits which are used in the world are very much similar to the designs of these early chips, albeit with the many improvements that have been made over the years.
One of the most iconic developments of this era was that of HDI or ‘High-Density Interconnect’ chips, using ‘Microvia’ technology, which allowed for the creation of high-density circuits in a much smaller area.
In simple words, this technology allowed for the circuit chips to be created in a way that allowed for a greater number of circuits per unit area, thereby allowing the circuits to have a higher capacity than their predecessors.
Today, the same HDI technology is in use, in combination with ‘multi-level’ designs to create circuits that are extremely dense, fast, and efficient.Today, the technology is still evolving, with large scale investment and research into the advancement of this circuitry technology. Among the many trends that have emerged include, among others, the adoption of artificial intelligence, automation, better materials, and improvements in manufacturing processes, and so on.
And then there is the use of 3D printing, which has greatly reduced the price of the chips, while at the same time allowing for large scale production of high-quality circuitry.
This is one of the technologies that have been of significant interest to manufacturers and researchers, given the potential of this new emerging technology.
These are just some of the technologies that are currently being tested out, with many more in the works as well.
All of these are still technologies still in the works, and which are certainly promising.
To sum up, the above is just a general idea of the way PCBs evolved in society, in terms of their general history and development.
It is a brief read that should give an idea of how this iconic modern-day technology came about, from its early days to its present form.
In addition to this, it should be added here that many finer and ‘not so important’ details have been eliminated along the way, so as to create a brief ‘summary’ of how the technology emerged.
It is in no way a conclusive and complete report, but rather an introduction to the subject.
Feel free to do your own research, if you would like to know more about how the story of this technology played out in recent times.