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Translated by: Jo Stans
Author/Editor: Reinhard Kluger / Kristin Rinortner

Progress came in print: the history of printed circuit boards

The printed circuit board (PCB) is probably one of the most important inventions of the 20th century. The intellectual father of the printed circuit board was Paul Eisler.

If he had only asked for a few pennies for each copy of his invention, he would have amassed a fortune greater than that of Bill Gates however, he did not.

Although the Austrian-born inventor came up with the brilliant idea for the most important invention of this century, he had to fight for recognition for many years.

What he developed at the end of the 1930s is considered a milestone for today’s mass production of radios, televisions, washing machines and computers, cars etc., in fact anything that contains a PCB derives from Paul Eisler invention.

Focus on mass production

Eisler, who studied engineering, had worked as an editor of a magazine during his studies. Even then, printing on paper gave him the idea that this process should enable more than just the mass production of newspapers. In his cramped one-room flat in the London suburb of Hampstead, he had his first idea.

The construction of the radios of that time used tubes, resistors and coils that were still connected with individual wires. A tangled mass of wires (something called “bird’s nests”) was created in the radios of that time, which was complex and confusing to follow. Eisler, on the other hand, wanted a clean system of conductor lines on one level. Something that could be printed, something that would be the basis for a mass production process.

Signing the contract in the taxi

Eisler experimented vigorously and registered his first patent in 1936, a precursor to his main patent that describes the first real printed circuit board. He presented his idea to the English radio manufacturer Plessey. Countless women worked there to connect the complicated wire bundles. Their opinion was “Our girls are cheaper and more flexible” and so they rejected him and his idea.

In 1939, at the beginning of the war, he found a patron in the wealthy owner of a printing house named Harold V. Strong. In Eisler’s idea of the printed circuit board he recognized the possibility of making the transition from a printing industry, suffering from a shortage of paper, to a flourishing arms industry. During a taxi ride, Eisler confidently signed the contract and transferred the rights to his invention to Strong for one English pound sterling.

The idea remained under lock and key

As obvious as the military use of the invention was, the British Ministry of Defence at the time was opposed to its use. The consequence: no private company dared to take up the idea and develop it further. The Americans were different. At that time, the British routinely reported every invention to the American Bureau of Standards.

There, they developed a printed circuit board as a proximity fuse for air defence projectiles. Now electronics could be produced in large quantities at low cost. Before the end of the war, the first mass deployment took place in the Far East.

The printed circuit board became public in 1948

In 1948, the public also learned about the idea of the printed circuit. The triumphant march of the printed circuit board began, especially since the principle of mass soldering by solder wave was developed at that time. This was another important prerequisite for low-cost mass production of electronics.

But Eisler did not achieve much and nor did Harold V. Strong have the financial success he had hoped for at the beginning. His company Technograph marketed the licences for printed circuit boards. Eisler, although being a member of the board of the company, did not become a rich man, because a monopoly for printed circuit boards could never be achieved.

Today, countless quantities of printed circuit boards are produced all over the world. Even though they are getting smaller and smaller, a modern mass production of electronic devices would be unthinkable without the printed circuit board.

Eisler was not recognised as the Inventor until over 35 years

The American electronics industry took up the idea of the printed circuit board in the 1950s and rapidly developed it further. In the mid-1950s the invention returned to Europe as German companies also began producing printed circuit boards in 1957.

Eisler, initially still on the board of Technograph, left the company in 1957. He was less bitter about the lack of financial success than he was about the fact that he was not given the honour he deserved: to be the creator of one of the most important inventions of the century.

It was not until 1971 that he was recognised as the inventor of the printed circuit board. The last significant honour was bestowed on him even later. It was only in 1992 that the Institute of Electrical Engineers awarded him the Nuffield Silver Medal, shortly before Eisler died on 26 October 1992 at the age of 85 in a suburb of London.

Other important inventions Eisler also conceived

What is little known to the public: In addition to his world-famous invention of the printed circuit, Paul Eisler invented other important products for electrical engineering. Among other things, he applied for patents for electrical fuses, for multilayer materials or for a foil battery.

Without printed circuitry we would not be able to communicate with mobile phones, have television reception, play on the computer or surf the Internet. Cheap and affordable electronics are now available thanks to Paul Eisler’s invention.