The first printed circuit boards (PCBs) can be traced all the back to the early 1900s and a patent for “printed wire.” It was in 1925 that Charles Ducas first submitted a patent that involved creating an electrical path directly on an insulated surface. It was a revolutionary idea because it could eliminate complex wiring and provide consistent results. Still, they didn’t really catch on until after WWII, when Dr. Paul Eisler in Austria began making the first real operational printed circuit boards in 1943.
Before printed circuits became the common component used in electronics, point to point construction was used. This meant some extremely bulky and unreliable designs that required large sockets and regular replacement. Most of these issues were directly addressed when PCBs went into regular production.
1920s – The early PCB material could be almost anything, from Bakelite and Masonite to plain old thin pieces of wood. Holes could be drilled into the material and flat brass wires would be riveted onto it. It may not have been pretty, but the concept was there, and it worked. It was often used in radios and gramophones at the time.
1950s – 60s – The types of materials used for the board was shifting to different resins and other materials, but they could still only be printed on a single side. The wiring would be printed on one side and the electrical components would be on the other. Still, it was a much more efficient option than bulky wiring, so it was starting to see a wider adoption.
One of the biggest steps forward came in 1956 when the U.S. Patent Office granted a patent to a small group of scientists representing the U.S. Army for the “Process of Assembling Electrical Circuits.” At the time, the process involved drawing the wiring pattern and then photographing it onto a zinc plate. This plate could then be used to create a printing plate for an offset printing press. This is what was used to print the wire in acid resistant ink on the copper foil, which could then be etched by an acid solution.
1957 – IPC (The Institute of Printed Circuits) formed and hold first meeting in Chicago IL.
1960 – Multilayer (4+ layer count) PCB’s begin production.
1960s -70’s – Boards were designed using 4:1, red-and-blue line vellum method for hand-taping components and tracks. A precision camera then produced the 1:1 negative manufacturing film. An experienced designer could layout and tape a board at the rate of about two hours for each equivalent 14-pin IC on the board.
1970s – The circuitry and overall size of the boards were starting to get a lot smaller by the 70s, and hot air soldering methods began to be used. This is also when the Japanese developers began to create screen processes that used various aqueous developed LPIs (liquid photo imageable masks). This became the industry standard over the years.
Gerber Scientific introduces RS-274-D as a machine-based format for vector photoplotters.
1980s – Surface mount parts became the preferred option over through-hole components,
which led to further size reductions while maintaining the same level of functionality.
1986 – RS-274X released as an enhancement to RS-274-D data format. New version supports embedded aperture information relieving the need for external aperture definition files.
1992 – Valor Computerized Systems founded introducing Genesis 2000 software for PCB CAM and DFM.
1990s– While the complexity of modern circuit boards continues to go up, the size of the boards and costs of materials has generally been able to go down. Once developers were able to start using multi-layer circuit boards
they were able to minimize the size and incorporate combinations of rigid and flexible PCBs in a range of devices. Going forward, new developments will continue to produce more efficient circuits that can effectively meet the needs of rapidly growing technology.
1995 -US PCB production
reaches $7.1 billion, topping $7 billion for first time.
1995 – Use of micro-via technology in PCB production starts, ushering in the era of HDI (High Density Interconnect) PCB’s.
1997 – Valor Computerized Systems releases ODB ++ printed circuit board manufacturing data format into public domain.
2000- US PCB fabrication market peaks at more than $10 billion.
2000s – PCB Real Estate becomes even tighter with 5-6mil trace & space becoming commonplace. Hi-tech shops fabricating boards with 3.5 to 4.5mil trace & space in production quantities. Flex and Rigid –Flex PCBs become an affordable option and widely used.
2010s – ELIC (Every Layer Interconnect) production begins.
Miniaturization of electronic products continue to drive printed circuit board manufacturing technology and design towards smaller and more densely packed boards with increased electronic capabilities. Future advancements may include three-dimensional molded plastic boards and the increased use of integrated circuit chips, POP (package on package) as well as embedded components. These and other advancements will keep the design and manufacture of printed circuit boards a dynamic and constantly evolving industry for many years to come.
Statement: This post is only the personal view of the author and does not represent the opinions of ALLPCB.com.