Throughout the 50s and 60s, the substrates used to make circuit boards changed from common materials we know to resins and other rare materials. The new materials enabled developers to create more boards quickly and on a large scale. Though printing was limited to one side, these PCBs were more efficient than the early wiring approaches.
In the 60s, developers began making PCBs with more than three layers of connective materials. These PCBs were more space-intensive and flexible. In the 70s, PCBs reduced in size further. Developers started applying hot-air soldering techniques for more effective soldering and better repair processes.
PCB evolution timeline
- 1925: Charles Ducas, an American inventor, patents the first circuit board design when he stencils conductive materials onto a flat wooden board.
- 1936: Paul Eisler develops the first printed circuit board for use in a radio set.
- 1943: Eisler patents a more advanced PCB design that involves etching the circuits onto copper foil on glass-reinforced, non-conductive substrate.
- 1944: The United States and Britain work together to develop proximity fuses for use in mines, bombs, and artillery shells during WWII.
- 1948: The United States Army releases PCB technology to the public, prompting widespread development.
- 1950s: Transistors are introduced to the electronics market, reducing the overall size of electronics, and making it easier to incorporate PCBs and dramatically improving electronics reliability.
- 1950s-1960s: PCBs evolve into double-sided boards with electrical components on one side and identification printing on the other. Zinc plates are incorporated into PCB designs and corrosion-resistant materials and coatings are implemented to prevent degradation.
- 1960s: The integrated circuit – IC or silicon chip – is introduced into electronic designs, putting thousands and even tens of thousands of components on a single chip – significantly improving the power, speed, and reliability of electronics that incorporate these devices. To accommodate the new IC’s the number of conductors in a PCB had to increase dramatically, resulting in more layers within the average PCB. And at the same time, because the IC chips are so small, the PCBs begin to grow smaller, and soldering connections reliably becomes more difficult.
- 1970s: Printed circuit boards are incorrectly associated with the environmentally harmful chemical polychlorinated biphenyl, which was also abbreviated as PCB at the time. This confusion results in public confusion and community health concerns. To reduce confusion, printed circuit boards (PCBs) are renamed printed wiring boards (PWB) until chemical PCBs are phased out in the 1990s.
What is the development of 90s?
Even with the density and functionality of PCBs improving, production costs reduced significantly in the 90s. This enabled manufacturers to make various electronics to sustain the swelling demand. In the 90s, silicon use became more familiar with the invention of the Ball Grid Array (BGA) method. This packaging technique offers more interlinking pins than the flat packaging method. Instead of just the edges, the whole lower part of the PCB becomes functional.
While no significant improvements were made on circuit boards in the 90s, the design procedure became a change on its own. Designers embraced Design for Test (DFT) techniques in their work. Instead of concentrating on solving the present needs, they considered future reworks in their designs.
The Roaring Twenties of PCB
With World War I coming to a close we’re now in the Roaring Twenties and seeing a giant economic boom in the United States. This was the first time in history that more people lived in cities than in farms. We’re also starting to see the introduction of chain stores and brands throughout the United States. You might have had one or two family-owned shops in two different towns, but now we have major brands and stores going national.
The greatest invention during this period was the automobile by Henry Ford and its required infrastructure. This situation is similar to the 1990s, where we had to build a major infrastructure to handle the internet and our information age by building switches, routers, and fiber optic cables. The automobile was no different.