The History of PCBA

By: Jason Smith

Before we talk about PCBA, we should understand what PCB is.

What is PCB

The PCB, a definition from Wikipedia, is a short name of Printed Circuit Board, sometimes called PWB(Printed Wiring Board), which a medium used to connect electronic components to one another in a controlled manner. It is a layered sandwich structure composed of alternating conductive layers and insulating layers. Each conductive layer has an specific pattern depicting wires, planes, and other features (similar to wires on a plane) etched from one or more layers of copper foil, which Layers are attached to or sandwiched between one or more non-conductive substrate layers.

a classic PCB

a construction figure of PCB

The PCBA technology

PCBA stand for Printed Circuit Board Assembly, that is to say, the empty PCB board passes through the SMT upper part, or the whole process of DIP plug-in, referred to as PCBA most of the time, but the standard method in Europe and America should be PCB’A, adding a mark ” ‘ “, which is called the official language.

The history of PCBA

The history of PCBA can be traced back to the 1940s, when electronic products mainly used vacuum tubes and point-to-point soldering technology, which were bulky, heavy, and unreliable.

Handmade vacuum tubes circuits

With the invention and application of transistors in 1947 by John Bardeen, Walter Brattain, and William Shockley at Bell Labs, electronic products began to develop towards miniaturization, lightweight, and high performance. To solve the complexity and instability of circuit connections, people began to use printed circuit boards (PCBs) to replace traditional wire boards. PCB is a technology that uses chemical or physical methods to make conductive patterns on an insulating substrate, which can greatly simplify circuit connections, improve reliability and production efficiency. The first patent for a PCB was filed by German inventor Albert Hanson in 1903, but it was not until 1943 that Paul Eisler, an Austrian engineer, made the first operational PCB for a radio set.

John Bardeen, Walter Brattain and William Shockley (left to right)

The foundation of PCBA technology

In the period, The emergence of PCB built the foundation for the development of PCBA, but PCBAPCBA technology as we knew doesn’t appear yet. In the early days, PCBs assemble still using manual plug-in and soldering methods, which were inefficient and difficult to guarantee quality. With the emergence and popularization of integrated circuits (ICs) in 1958 by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor(a legend company of Silicon Valley, actually, she made the present Silicon Valley), the number and density of electronic components increased rapidly and significantly, and manual plug-in and soldering have been becoming a big barrier to meet the increasing demand. Therefore, people began to study automated PCBA technologies, including automatic plug-in machines (AI), surface mount technology (SMT), reflow soldering technology (Reflow), wave soldering technology (Wave Soldering), etc. Therefore, it is the time that the modern PCBA technology was to come into being. The four parts of PCBA was appearing.

Automatic plug-in machine

Automatic plug-in machine is a device that automatically inserts components into PCB holes and fixes them by wave soldering or other methods. Automatic plug-in machine can improve plug-in speed and accuracy, reduce labor cost and error rate. Automatic plug-in machine first appeared in the late 1950s by Universal Instruments Corporation, initially only capable of handling single-sided boards and simple components, later gradually developed into devices that can handle double-sided boards and complex components.

STM technology

Surface mount technology (SMT), it is another Indispensable part of PCBA, which is a technique of mounting electronic components directly on the surface of printed circuit boards (PCBs) and securing them by reflow soldering or other methods. SMT has many advantages over the previous technique of inserting component leads into holes on the PCBs, such as saving space, improving density and performance, reducing cost and weight. SMT was first developed in the 1960s by IBM for their mainframe computers, but it was initially only used for military and high-end products. Later, it became widely used for consumer and various products.

Reflow soldering technology

This technology is a technology that puts PCBs with mounted components into a heating furnace, melts and solidifies the solder between the components and PCBs. Reflow soldering technology can achieve high-speed, high-quality, high-reliability soldering, suitable for various surface mount components. Reflow soldering technology first appeared in the early 1970s by IBM for their surface mount devices, initially using infrared heating method, later developed into using hot air heating method.

Wave soldering technology

Wave soldering technology is a technology that immerses PCBs with inserted components in a wave-shaped molten solder, forming solder joints between the components and PCBs. Wave soldering technology can achieve fast, uniform, complete soldering, suitable for various plug-in components. Wave soldering technology first appeared in the early 1960s by Western Electric for their telephone equipment, initially using tin-lead alloy as solder, later developed into using lead-free solder.


Therefore, the above four technologies are the main technologies of PCBA. Their changes redefine and establish modern PCBA technology. However, with the continuous innovation and join-in new development of electronic products, PCBA is also constantly improving and improving. Some new technologies and Methods continue to emerge, such as lead-free soldering, optical inspection, X-ray inspection, laser welding, flexible circuit boards, etc. This is a history of PCBA, which also is a history of the development of the electronics industry, as well as a history of human wisdom and creativity. PCBA has evolved from the early days of point-to-point wiring and through-hole mounting to the modern techniques of surface mount technology and high-density interconnect. PCBA has enabled the creation of various electronic devices that have improved the quality of life and productivity of human society. The future of PCBA will continue to keep pace with the times and bring more convenience and value to human society. It will also face new challenges and opportunities in terms of design, manufacturing, testing, and application. Some of the emerging trends in PCBA include board cameras, flexible PCBs, 3D printing, artificial intelligence, and new energy vehicles.


  • What’s the full name of PCB and PCBA?
  • When can the PCBA’s history date back to?
  • Which company created the wave soldering technology?

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