PCB (Printed Circuit Board) is no longer unfamiliar to us, it is the core component of electronic devices such as mobile phones, computers, radios, and lamps. Without the development of PCB, we will not be able to enjoy the convenience brought by these electronic devices. Then, I A question comes to mind: what is the history of PCB development? Excellent, let's discuss it in this article.

A milestone in the history of PCB

We can understand the PCB development process by dividing it into several important stages listed below:

In 1903, the famous German inventor Albert Hansen applied for a British patent, he pioneered the concept of using "wires" for telephone switching systems, metal foils were used to cut line conductors, and paraffin paper was then glued on top of the line conductors And the bottom, and set up vias at the intersection of the lines to realize the electrical interconnection between different layers. This is different from our modern PCB manufacturing method, because phenolic resin was not invented at that time, and chemical etching technology was not mature. Invented by Albert Hansen The method can be said to be the prototype of modern PCB manufacturing, which is the basis for the following development.

Development stage (1920s-1940s):

In 1925, Charles Ducas came from the United States and he had an innovative idea of printing circuit patterns on insulating substrates. , and then electroplating to make conductors for wiring. The term "PCB" came into existence at this time. This method made it easy to make electrical appliances.

In 1936, Austrian Dr. Paul Eisler, as. . While known as the "Father of Printed Circuits", Foil Technology was published in the UK and he developed the first printed circuit boards for radios. Paul Eisler used a method very similar to what we use for printed circuit boards today. This method is called subtraction, and it removes unnecessary metal parts.

Around 1943, Paul Eisler's technological invention was used on a large scale by the United States to manufacture proximity fuzes used in World War II. At the same time, the technology was widely used in military radios.

turning point(1948):

The year 1948 was a turning point in the development of PCB history, as the invention of the printed circuit board officially recognized by the United States for commercial use. Although there was little history of using PCBs in electronic devices at the time, this decision largely contributed to PCBs development and application.

Boom stage (1950s-1990s):

From the 1950s to the 1990s, the PCB industry formed and grew rapidly, that is, the early stage of PCB industrialization, when PCB had become an industry.
1950s, transistors Used in the electronics market, which helps to effectively reduce the size of electronic products and makes it easier to integrate PCBs, in addition, the electronic reliability is significantly improved.

In 1953, Motorola developed a double-sided board with plated vias. Around 1955, Toshiba of Japan introduced the technology to generate copper oxide on the surface of copper foil, and copper clad laminates (CCLs) appeared. Thanks to these two technologies, multi-layer printing The circuit board was invented successfully and has been applied on a large scale.
In the 1960s, printed circuit boards were widely used at this time, PCB technology became more and more advanced, and due to the many The extensive use of layered printed circuit boards effectively increases the ratio of wiring to substrate area.

In the 1970s, multi-layer PCBs developed rapidly, pursuing higher precision and density, fine-line holes, high reliability, lower cost, and automated production. At that time, PCB design work was still done by hand. PCB Layout engineers use colored pencils and a ruler to draw circuits on clear mylar. To improve drawing efficiency, they made several packaging templates and circuit templates for some common devices.

In the 1980s, surface mount technology (SMT) began to gradually replace through-hole mounting technology as the mainstream at that time. It also entered the digital era.

Mature Stage (1990 Snow):

With the development of electronic devices such as personal computers, CDs, cameras, game consoles, etc. , correspondingly have changed considerably. The size of the PCB must be reduced to accommodate these small electronic devices.

Computerized design automates multiple steps of PCB design and makes the design of small and light components easier. Regarding component suppliers, they also need to improve their equipment by reducing power consumption, but at the same time, they need to consider the issue of cost reduction .

In the 2000s, PCBs became more complex, more functional, and smaller in size. Especially multilayer and flexible circuit PCB designs made these electronic devices more maneuverable and functional, with small size and low cost PCB.

In the early 2000s, the advent of smartphones drove the development of HDI PCB technology. While retaining laser-drilled microvias, stacked vias began to replace interleaved vias, and combined with “any layer” construction techniques, HDI boards resulted in final line widths/lines The distance reaches 40μm.

This arbitrary-layer approach is still based on a subtractive process, and it is certain that for mobile electronics, most high-end HDIs are still using this technology. However, in 2017, HDI began to enter a new phase of development, starting to shift from subtractive processes to Process based on pattern plating.

Main trends will affect the PCB industry

Today, various types of printed circuit boards including rigid PCBs, rigid-flex boards, multilayer printed circuit boards, and HDI PCBs are widely used in the market, undergoing many evolutions. What we can confirm is that as people With ever-increasing demands, this evolution will continue in the future.