PCBs are currently found in virtually every electrical product, large to small. However, one must consider just how remarkable and groundbreaking the innovation of the PCB was.
Prior to the invention of PCBs, electronic devices contained a multitude of wires, occupied plenty of space, and had an intrinsic ability to get tangled up. Short circuits were the norm.
The first PCB concept was invented at the beginning of the 20th century by German inventor Albert Hanson, who filed a patent for a flat conductor for a multi-layer insulating board, but the technology world was not yet ready to welcome this new electrical component and it did not catch on. In time, Paul Eisler, an Austrian inventor, located in England, took the PCB idea to another level.
Eisler developed a copper foil placed on a non-conductive glass base, similar to the PCB of current days. The Austrian-born inventor conceived this brilliant idea, one of the most important inventions of this century, but unfortunately had major challenges gaining acceptance.
Although he developed what has become the backbone for today's mass production of computers, televisions, cars, and virtually everything electronic, he dealt with significant rejection of innovation,.
Eisler experimented continuously and filed his first patent in 1936, a forerunner to his main patent, which outlines the Printed Circuit Board. He offered it to British radio fabricator Plessey. The firm said “our women workers are cheaper”, and his idea was ignored.
Wealthy printing house owner Harold Strong recognized Eisler's invention could possibly assist a growing arms industry. Strong bought the rights from Eisler for one British pound. At least Eisler was invited to join the Board of the new company.
The British Ministry of Defense said “no thanks”, however the British routinely reported every innovation to the American Bureau of Standards at that time. The Americans said “yes please” and a printed circuit board was developed as a proximity fuse for air defense projectiles.
Neither Eisler nor Strong had the financial success they envisioned. Their company, Technograph, marketed licenses for printed circuit boards however a monopoly for printed circuit boards could never be achieved.
In 1948 the PCB was released by the United States for commercial use. Then, during the 1950s, the US army developed an automatic assembly process, leading to mass production and bringing the PCB to much broader use among electronics consumers.
During the cold war, the USA and Soviet Union struggled to improve their communications capabilities. A decade later a patent was filed by Hazeltine Corporation for the first plated through-hole technology, which allowed the PCB components to be placed together without crossover connections in a much more reliable way. At the same time surface mount technology was developed by IBM.
In the 1970s another massively important invention emerged, the Integrated Circuit (IC). The first microprocessor was invented in the late 1950s by Jack Kilby. It then took Kilby more than a decade to share it with his colleagues at Texas Instruments, which led to the development of the first IC. Following the birth of the IC , the world of electronics manufacturing was forced to utilize the PCB.
Up until the 1980s, PCBs were still drawn by hand, which allowed for saving and transferring of the designs only with photographs. Computers and EDA (Electronic Design Automation) software emerged, making PCB designs dynamic and easily integrated into PCB manufacturing machinery. At the same time, innovations such as the Walkman and cordless phones, mandatory items for Boomers and Gen X's , burst onto the scene utilizing small PCBs as their bases.
During the 1990s. electronic devices continued to shrink and this made manual PCB manufacturing impractical. The internet was launched and started a revolution, turning the personal computer into a must-have. Cell Phones were introduced, a technological jump which could not have happened without the progress in the PCB technology and micro-technologies.
Developers no longer design the PCB for a single purpose. Design for Test (DFT) strategies have evolved, always considering the possibility of future adaptations and edge cases.
Today, countless quantities of printed circuit boards are produced all over the world and are getting smaller and more complex. Modern mass production of electronic devices would be unthinkable without the printed circuit board.
