Printed Circuit Board---history

After Gustav Tauschek, another Viennese engineer and inventor—Paul Eisler, made a significant contribution in the modern electronics industry with the invention of printed circuit board (PCB) in 1936.

The Austrian Jew Paul Eisler was born in Vienna in 1907. After graduating with an engineering degree from Technische Universität Wien (Vienna University of Technology) in 1930, already a budding inventor, he didn’t manage to find a proper job in Austria. In 1934, Eisler accepted a workplace in Belgrade, Yugoslavia, to design a radio-electronic system for a train, but that job ended when the customer offered payment in grain instead of currency:-)

Back in Austria, Eisler wrote for newspapers and founded a radio journal, and began to learn about printing technology. Printing was a fairly robust technology by the 1930s, and Eisler started to imagine how the printing process could be used to lay down electronic circuits on an insulating base, and do so in volume. At the time, it was usual to interconnect all components in electronic devices with hand-soldered wires, an error-prone method of manufacture, which did not lend itself to any high degree of automation. Eisler wanted to eliminate these problems, printing the wires on a board, and mounting the elements over it.

In 1936 Eisler decided to leave Austria, in order to escape persecution from Nazists. He secured an invitation to work in England based on two patent applications he had already filed: One for a graphical sound recording and one for a stereoscopic television with vertical resolution lines.

In London he managed to sold the TV patent for ₤250, enough money to live for a while in a Hampstead boarding house, which was a good thing, because he couldn’t find a job. He proceed to develop his printed circuit board idea, and one telephone company really liked it, at least initially, because it would have eliminated those bundles of wiring used for phone systems back then. But then the big boss told him that the manual wiring work was being done by “girls” and “girls are cheaper and more flexible.” That’s is the holy truth, the girls are always much more flexible, than a circuit board;-)

Eisler didn’t found a piece of good fortune in England though. As WWII loomed, he worked at getting his family out of Austria. His sister committed suicide and when the war began, in 1940 the British interned him as an illegal alien. Even locked up, this brilliant engineer began to fabricate a radio using a printed circuit board (see the nearby photo).

After being released in 1941, Eisler was able to find a work in a music printing company—Henderson and Spalding. Originally, his objective was to perfect the company’s unworkable Technograph music typewriter, operating out of a laboratory in a bombed-out building. Later, Technograph invested in his printed circuit idea (the concept of using etched foil to lay down traces on a substrate). Unfortunately, Eisler forfeited rights to his invention when he neglected to read the contract before signing it, but it wasn’t the first or last time Eisler would be taken advantage of. It was a pretty standard employment contract in that he agreed to submit any patent right during his employment for a nominal fee (one pound sterling) but it also gave him 16.5 percent ownership of Technograph.

Eisler first boards look much like plates of spaghetti, with almost no straight traces. He filed a patent application in 1943.

Technograph drew no interest until the United States incorporated the technology into work on the proximity fuzes of shells, which was vital to counter the German V-1 flying bomb.

After that, Eisler had a job and some small amount of fame. After the war, the technology spread. The U.S. mandated in 1948 that all airborne instrument circuitry was to be printed.

Eisler’s 1943 patent application was eventually split into three separate patents: 639111 (Three-Dimensional Printed Circuits), 639178 (Foil Technique of Printed Circuits), and 639179 (Powder Printing). These three were published on June 21, 1950, but very few companies actually licensed the patents, and Technograph had financial difficulties. Eisler resigned from Technograph in 1957, to work as a freelancer.

Among his projects as a freelancer, were films to heat “floor and wall coverings” and food, the foil battery, concrete molds, the pizza warmer and rear window defroster, and more, but Eisler was not so successful in their commercialization. Later he found success in the medical field, and died with dozens of patents to his name.

Eisler’s invention of the etched foil printed circuit, whilst being of enormous benefit to the world-wide electronics industry, brought him little personal financial return. Eisler died in London on 26th of October, 1992. He had just received the Institution of Electrical Engineers’ Nuffield Silver Medal.