Like other revolutionary inventions in history, the Printed Circuit Boards (PCBs) we have today were laid on a foundation of advancements throughout history. This article traces the history of PCBs back to the 1920s when the great industrial machine was invented. What we will be covering in this article is not a complete history but rather the sweeping moments that transformed circuit boards into what we have today.
Before we dive into that, let’s briefly look at why PCBs have advanced at a tremendous speed.
What Has Led to the High Advancement in PCBs?
Over time, circuit boards have evolved as a tool for optimizing the production of electronic devices. Once manually assembled, what was once manually assembled soon paved the way for microscopic parts that required the accuracy and efficiency of machines. For example, let’s consider the diagram below. To the left is an older PCB for a calculator manufactured in the 1960s. To the right is a high-density motherboard used in modern computers.
PCB comparison between a 1968 PCB for a calculator and a modern motherboard for computers. (Image source left, right)
The calculator PCB probably contains about 30 transistors, but there are more than one million transistors on one chip on the computer motherboard. The outstanding point from this comparison is that the rate at which technology and circuit board design itself has evolved is remarkable. Everything on the left image can now be accommodated by one chip on the right image.
PCB advancements are being driven majorly by the super speed and functionality of electronics. Electronic consumers expect devices, especially hand appliances and computers, to respond rapidly – a few seconds delay sends users into fury. For functionality, consider video games. In the 80s, our predecessors were probably playing Pacman at the arcade. Nowadays, we are experiencing photorealistic representations of reality – virtual games. The evolution is simply amazing.
It is evident that PCB evolution is directly related to consumer expectations. Modern electronic users want faster, cost-effective, more powerful products, and the best method of meeting these expectations is miniaturizing and making the production process more efficient.
When did this crazy for electronic devices and printed circuit boards begin?
The Promising 20s
In 1925, Charles Ducas patented the “Printed Wire,” which entailed an electrical connection creation on an insulated flat material. Although this idea eliminated the requirements for complicated connections, the first functional circuit boards were developed in 1943 in Australia by Dr. Paul Eisler.
Throughout the 20s, developers worldwide made PCBs from ordinary materials, such as Bakelite, and wood. They bored holes and fastened wires into the materials. The developers then created connections to different components by inserting traces into the void rivet while placing the component’s leads into the rivet end. While this didn’t create the sleek, appealing, and complex PCBs we have nowadays, the technique offered reliable results.
As electricity was made available for home use, the transformation from the use of coal, wood, and oil presented matchless possibilities. To make matters better, people worldwide embraced these changes readily since they were more comfortable carrying out home improvement activities and chores using electricity.
World War II
The production of the first double-sided circuits started in 1947. The design applied through-hole plating, allowing designers to use the two PCB sides. Besides, copper coating on the vias facilitated electrical transmission across the board.
Two years later, Moe Abraham and Stanislaus Danko from the U.S Army Signal Corps came up with the first circuit board automatic assembling process and transformed the production of circuit boards. They used a copper interlinking design and dip soldering technique to mount leads into boards. Besides, they sketched the wiring design and snapped it into a zinc plate to make boards. In 1956, Moe and his colleague patented their concept.
The Invention of Multi-Layered Boards (the 1950s-1970s)
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.
The Digital Era
The 80s, better referred to as the Digital Era, presented significant changes in how people viewed electronics. The demand for electronic gadgets increased significantly, and electronic shops struggled to meet the high demand for electronics.
In the 80s, circuit boards underwent a further decrease in size due to the invention of surface-mount technology (SMT). Due to lower manufacturing costs and high functionality, developers preferred SMT to the through-hole method, even with miniaturized board sizes.
By then, designers were still sketching circuits manually using light boards and stencils. But when the Computers and Electronic Design Automation (EDA) software was introduced in the 80s, developers quickly shifted to computer designing.
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.
During this period, electronics became more complicated, and consumers and businesses worldwide became more reliant on them. The global PCB manufacturing industry hit a market valuation of $7.1 billion in 1995. In the same year, developers started leveraging the micro-via technique to manufacture circuit boards.
The Internet Age
During this period, circuit boards became even smaller and denser. While five to six mil trace and space were assumed standard during this period, some high-tech companies fabricated PCBs with 3.5-4.5 mil traces and space. Elastic boards became more popular because they were a bit cost-effective; hence, more suitable for designs that required compact sizes.
In 2006, the Every Layer Interconnect (ELIC) process was introduced. It allowed developers to create links between stacked board layers. While this process raised the flexibility level and enabled designers to make maximum use of interlink density, ELIC boards were not widely applied until the beginning of the 2010s.
Modern Day PCBs
Though a PCB in the 60s might have contained almost 30 transistors, one chip on a contemporary motherboard can house over one million components. This has been enabled by cutting-edge technology, and electronic companies can effectively integrate high functionality into their PCB products.
As electronics have become more miniaturized and complex, manual assembling has almost become a thing of the past. Currently, circuit boards contain multiple microscopic parts, and assembly calls for super accuracy and efficiency associated with machine assembling. This complexity transformation has made way for advanced electronic production.
The Future of Printed Circuit Boards
The PCB manufacturing process presents adequate room for growth. Manufacturers worldwide are faced with various challenges in their daily activities. The following trends will shape the future of PCB:
1. Wearable Tech
Currently, wearable gadgets are widely used and are expected to hit new levels soon. These gadgets seem to be shifting towards smaller, more powerful equipment every year. They are mostly implanted into clothing and other flexible accessories, like smart shoes and wristbands.
2. High-Speed Capacities
The digital society has become used to fast-paced technology and the demand for fast-paced functionality in everything. This applies to circuit boards since they act as the integral elements of electronic devices. Therefore, the demand for high-speed capacities will continue to push developers to increase the capacity of the current PCBs.
3. Camera Technology
Tiny cameras that are mounted into PCBs are transforming the way people use electronics. Equipped to capture high-resolution images and videos, these cameras are found in smartphones and medical equipment. The technology behind them is continually tweaked to make them smaller, more powerful, and efficient.
4. Eco-Friendly Materials
Climate change is a trending topic globally, and the amount of electronic waste is a matter of concern. Most PCB materials are non-degradable and contribute to vast hips of the chunk in landfills. Bearing this in mind, environmentalists have recommended significant changes to PCB manufacturing – using biodegradable laminates and assembling with less harmful chemicals. Furthermore, authorities worldwide want the precious metals in electronic waste to be extracted and recycled for use.
The history of PCBs from the 1920s is fascinating, as demonstrated in the above discussion. The ancient PCB design techniques of the 60s to the modern-day EDA design tools were laid on multiple inventions and technology setups. While circuit boards have undergone numerous changes, we will continue to experience more inventions and changes as technology advances.
MKTPCB is the leading PCB manufacturer based in Shenzhen, China. We help businesses with everything – from component sourcing to PCB assembly. We will walk with you through the manufacturing and assembling process. Kindly contact us today to learn more about our products and services.