To be fair, the actual development of the first PCB was preceded by a series of major and minor breakthroughs. As early as the turn of the 19th century, German inventor Albert Hanson used flat foil conductors laminated on an insulating board in several layers. The famous Thomas Alva Edison also experimented with chemical methods of coating conductors on insulating paper. Arthur Berry then patented a method of printing and etching joints before World War I. On the other side of the ocean, in the United States, Max Schoop applied for a patent for hot metal spraying on a plate through a mask. Charles Ducas thus more or less combined their ideas into one solution using electroplating circuits. The first truly commercial application was then discovered a decade later by Austrian developer Paul Eisler, who used the first classic PCB in a radio set - and in the following years continually improved the technology until he created a circuit board design that involved etching circuits onto copper foil on a non-conductive glass-reinforced substrate.

Downsizing and refinement

The potential of PCBs was quickly realized by the military during World War II. The United States and Britain had already come out with non-contact fuses in 1944 for use in mines, but especially in bombs and artillery shells. Then, in 1948, the United States Army released circuit board technology to the public and started a real boom in commercial exploitation.

Shortly thereafter, transistors were introduced to the market, dramatically reducing the overall size of electronics while improving their reliability. In the 1960s, the silicon chip integrated circuit was discovered, which made it possible to transfer thousands and often tens of thousands of components onto a single board, greatly improving not only the performance but also the speed and reliability of the electronics these devices contain. The number of wires in a printed circuit board has increased dramatically, and there has also been a lot of work on multiple layers on each board. But related to this, PCBs are also starting to get smaller and soldering connections is becoming more difficult.

In the late seventies and early eighties, the military companies accelerated the development of boards again. Military masks made of thin polymer materials were developed to facilitate easier application of solder to copper circuits without bridging adjacent circuits. A photographic polymer coating has also been developed that can be applied directly to the circuits, then dried, and then photo exposure adjusted. It is this method that will become the basis of future printed circuit board production for many years to come. Since the 1980s, we have also known about SMT surface mount technology. While previously all PCB components had wire leads, these have now been replaced by soldering directly onto small pads without the need for additional holes.

The 1990s brought, above all, the incredible boom of home computers and a wave of various software solutions. This was also reflected in the PCB manufacturing itself, as programs like CAD/CAM were able to automate many different manufacturing steps. Along with this, they also replace heavier components with lighter and smaller ones. And miniaturization and automation are two major trends we've seen ever since.

Boards are getting smaller, allowing for the simple addition of more layers, and new flexible materials are increasingly being added. "In general, electronics is moving towards complexity, which is also linked to miniaturisation. This is an undeniable trend of recent years. If you remember what the first mobile phones from the 1990s looked like, they were a bulky 'brick' with a charger. Yes, you could carry it around, but it made you sweat. Yet, what could it do then and what can cell phones do today - when we carry small and lightweight devices in our pockets, stuffed with high-tech gadgets, cameras, apps, fast internet connections? Now, on top of that, comes flexible technology. I'm convinced that in the next few years, the biggest interest will be in complex and complicated boards, whether they are rigid-flex or, in quotes, standard multilayer boards, high-frequency boards, impedance-controlled boards. For us manufacturers, it is necessary to move in this direction, because the financial effect associated with speed and complexity can be very attractive," confirms František Vlk, who has been manufacturing printed circuit boards since the early 1990s and is co-owner of Gatema PCB, which supplies boards to most EU markets.

And what's next? The year of the pandemic brought two crises - first a market freeze and then a raw materials war. As a result, the forecast that the entire market would reach the fabled $100 billion mark by the centenary began to be adjusted. According to Global Industry Analysts, it is more realistic that it will grow more slowly. Even so, it should reach $76 billion in 2027. And that's a fascinating number for an idea to attach a circuit board to a solid board.