In modern computers, you can find millions of transistors or more on a single computer motherboard. The high-density, tiny manufacturing concept has become the mainstream of the times, which has also consolidated the position of PCB in the electronics manufacturing industry.
Development conditions of PCB
Like all great inventions, the printed circuit board didn’t come out of nowhere, it was built on the foundations of progress throughout history. Let’s go back in time to 140 years ago when there were no circuit boards.
The power system developed from urban to rural from 1880 to 1900, coal, wood, and oil were gradually replaced, and electricity entered the home. During this period, there were many inventions about electromagnetism and motor. Because of the influence of this era, PCB has been enduring for a long time in history and has become an indispensable part of the electronics manufacturing industry.
- Edison invented the light bulb in 1879 and is known as the world’s greatest inventor.
- Nikola Tesla invented the motor and AC power supply in 1888 and 1895, respectively.
- Alexander Graham Bell invented the telephone in 1876.
- Kodak invented the first camera in 1884.
- Herman Hollerith invented the tabulating machine in 1890 and would go on to create IBM.
Note: PCB did not originate from this era, but benefited from this era. Printed circuit boards would not exist without the manufacturing advancements of the Gilded Age, and the spreading effects of electricity.
History of PCB
Printed circuit boards were developed at the beginning of the 20th century and waited until electricity became widespread. With the continuous upgrading of PCB manufacturing technology, semiconductor packaging technology is widely used in PCB factories, which makes PCBs become lower-cost, more efficient, and electronic products suitable for investment. In 2014, the global PCB bare board market exceeded US$60.2 billion and is expected to reach US$79 billion by 2024.
The development starting point of PCB
Albert Hanson applied for a British patent in 1903 for a device that was a flat foil conductor on a multilayer insulation board. In Albert Hanson’s patent he describes the concept hole application for us. This is the first time that humans have made electrical connections through perforations.
Charles Ducasse patented “Method of Adding Conductive Ink to Insulating Materials” in 1925. Although this patent does not realize the electrical connection between the circuit and the components, it is only used as a flat heating coil. But it laid the foundation for how to produce printed circuit boards.
In 1943 Paul Eisler produced the world’s first simple Rigid PCB board, replacing the traditional way of relying on wires to achieve electrical connections. This PCB design involves etching circuits on copper foil that is bonded to a glass-reinforced non-conductive substrate.
The first application of PCB
The PCB invented by Paul Eisler was affirmed by the US military and applied to military radios. During World War II, the US government and the British government reached a cooperation to jointly develop circuit boards, and used PCB technology in military weapons during World War II.
The technology has been recognized by both the United Kingdom and the United States, and for this reason, the United States secretly assembles printed circuit boards at military bases. In order to improve efficiency, the U.S. side specializes in researching assembly methods and develops a one-stop automatic assembly line. The PCB assembly technology used by the US military was the most advanced in the world at the time. The double-sided circuit they designed was designed with through-hole plating and copper-coated vias to carry electrical signals across the board. In addition, in order to prevent moisture and increase the utilization rate of PCBs, the United States uses zinc plates with corrosion-resistant coatings in the design. Second, transistors significantly increase the utilization of printed circuit boards, while also improving circuit reliability.
The popularity of PCB
Due to the excellent performance of PCB boards during World War II, the United States officially recognized this technology in 1956, and the U.S. Army first published a patent for the “circuit assembly process”. This also provided great help for the subsequent development of circuit boards. As of today in 2022, PCB manufacturers have a wide variety of assembly techniques for both securing electronics and making electrical connections between components with copper traces.
Hazeltine Corporation patented plated through-hole technology in 1963. This technology allows the otherwise independent electronic components to be closely arranged on the PCB board, and most importantly, we do not need to worry about cross-connection. This patent makes the connection of the components clearer so far, allowing the circuit board to be used in real family life.
Evolutionary stages of PCBs
In the 1970s, printed circuit boards ushered in earth-shaking changes, with the introduction of ICs (integrated circuits—microprocessors) that revolutionized printed circuit boards. This is the reason for the aforementioned “millions of transistors can be found on a motherboard.” With the introduction of integrated circuits, the number of conductor layers in the PCB stack-up has increased. Although the volume of the circuit board becomes smaller, the function is more powerful, of course, the increase in the difficulty of PCB soldering.
To break this situation, PCB manufacturing companies have introduced solder masks made of thin polymer materials. This move reduces bridge formation between adjacent pins or discrete components. The photopolymer coating is applied to the circuit and imaged in a dry and exposed environment. FS Technology believes that this method will become a standard procedure in the PCB manufacturing process.
PCBs dominate in electronics
With the popularity of surface mount technology (PCB SMT) in 1980, PCBA factories have realized the automated assembly production process. Through PCB SMT technology, the performance of circuit boards has been significantly improved while reducing power consumption. Compared with traditional through-hole technology, the cost of SMT assembly has dropped significantly.
With the change of consumption patterns, many household devices appeared in 1980, such as: TVs, computers, game consoles, headphones and so on. The popularity of these household appliances has greatly promoted the development of electronic components, and the demand for SMD (If you are not clear about the concept of SMD and SMT, you can read the article “SMD vs SMT”) components and integrated circuits has reached an unprecedented height at this time. These electronic components provide more powerful functions for PCBA, making the PCB industry an indispensable part of electronic consumer products.
Future trends of printed circuit boards
The 2021 PCBA exhibition noted that with the proliferation of artificial intelligence, health monitoring and implantable devices are becoming more common in everyday life. Advances in CCTV and fire alarm safety equipment that are needed in life rely on tiny high-density PCBs. On the other hand, in order to achieve safe and powerful performance, aerospace, telecommunications and military equipment have become more and more demanding on PCBs, and advanced application equipment is completely inseparable from more complex PCB boards.
In addition, waste from the electronics manufacturing industry causes serious damage to the environment, which reflects that the technological development of PCBs is as important as other industries. To give a simple example: the artificial intelligence industry—vacuum cleaners—sweeping robots—is exactly the benefit brought about by the qualitative leap of PCB.
The hottest metaverse concept in 2022 also needs to rely on high-performance flexible PCBs to realize. Probably the only way to reduce the number of components in circuit designs in the future is to convert PCBs to source files.
Through the evolution of history, PCB can conform to the trend of the times. Take turnkey PCB assembly as an example, it reduces the time cost of manufacturing, assembly, and procurement for customers, and only the final mechanical assembly can realize the sale and purchase of products. There will be more such progress in the PCB industry in the future.
The above is the whole content of “history of printed circuit boards”, more related articles can be found in the PCB Knowledge Blog.
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