Introduction
The contrast is striking. A calculator PCB in the 1960s had just 30 transistors. Today’s computer PCBs pack over a million transistors on a single chip. This progress marks one of the biggest technological leaps in modern history.
PCBs have come a long way. German inventor Albert Hanson got the ball rolling with the first PCB-like patent in 1903. The first working circuit boards didn’t show up until 1943, when Dr. Paul Eisler developed them in Australia. Things moved faster after that. By 1947, engineers could use both sides of the board with double-sided circuits, which led to more efficient designs.
The 1980s brought a game-changer: surface-mount technology. This made manufacturing cheaper and designs more compact. The numbers tell an impressive story. The global PCB market grew from $7.1 billion in 1995 to $60.2 billion by 2014. Experts predict it will reach $96.57 billion by 2029.
In this piece, we’ll look at how PCBs transformed from their basic beginnings to today’s innovations. We’ll explore how these advances revolutionized electronics and peek into what’s next for PCB design.
From Point-to-Point Wiring to the First PCB (1900–1940s)
“A precursor to modern PCBs, in 1927 Charles Ducas patented a method for printing electronic pathways onto a board.” — United Pacific Electronics, Electronics manufacturing company
Electronics relied completely on point-to-point wiring before printed circuit boards came along. Workers had to connect components manually with individual wires. This method took too much time and led to mistakes, especially with complex devices. The move from these basic methods to organized circuit boards became one of the biggest changes in electronics history.
Albert Hanson’s 1903 Patent for Multi-layer Boards
Modern PCBs took their first documented step in 1903. German inventor Albert Hanson filed a British patent that would change everything. He created flat foil conductors attached to an insulating board in multiple layers for telephone exchange systems. His design was way ahead of its time and shared many features with today’s PCBs.
These early circuit boards had through-hole construction and conductors on both sides of paraffin paper insulation. The conductors formed a rectangular grid in alternate layers that connected through holes in the paper. Hanson had given us the blueprint for both double-sided and multi-layer boards long before they became common.
The technology world wasn’t ready for Hanson’s state-of-the-art ideas. Manufacturing capabilities in the early 1900s couldn’t bring his vision to life, and his designs stayed mostly on paper for many years.
Charles Ducas and the 1927 Printed Wiring Concept
American inventor Charles Ducas pushed circuit technology forward in 1927. He patented a method that created the term “printed circuit.” His technique involved putting conductive materials directly onto wooden boards to create electronic pathways without manual wiring.
Ducas employed electroplating techniques in his work. He printed circuit patterns on insulated surfaces with electrically conductive inks. This let him print wires through a stencil right onto the board. His process included several ways to create conductive pathways:
- Electroplating copper, silver, or gold patterns through contact masks
- Creating grooves in dielectric materials like wax and filling them with conductive paste
- Printing or stenciling conductive paste onto dielectric materials
Ducas could also foresee multilayer circuits and ways to connect layers – ideas that wouldn’t work commercially for decades. The Great Depression hit in 1929 and limited the practical use of his ideas.
Paul Eisler’s 1943 Copper Foil PCB Design
PCB development made its real breakthrough with Austrian engineer Paul Eisler, known as the “father of printed circuits.” He escaped Nazi persecution to England in the 1930s. His engineering background and printing industry experience helped him create the first working printed circuit board around 1941.
Eisler’s design used copper foil attached to non-conductive glass base, much like modern PCB manufacturing. He showed off a radio with this PCB by 1943 to prove it worked. His method removed unnecessary metal instead of adding materials like earlier inventors had done.
World War II created perfect timing for Eisler’s innovation. The U.S. Army Signal Corps quickly started using PCB technology in anti-aircraft shell proximity fuses. This became the first large-scale use of printed circuit boards.
Electronic tubes back then created lots of heat and took up space, which made mounting them on early PCBs tough. Eisler’s invention still laid the groundwork for all future PCB development. He made things even better by 1942 with the world’s first practical double-sided PCB, getting the patent in 1943.
Post-War Innovations and the Rise of Mass Production (1950s–1970s)
“This recognition drove investment in research and development, leading to the creation of more sophisticated and reliable PCBs.” — United Pacific Electronics, Electronics manufacturing company
World War II’s aftermath brought a revolutionary period in circuit board progress. Military technology found its way into commercial products. PCBs evolved from simple lab experiments into mass-produced components that revolutionized electronics manufacturing.
Auto-Sembly Process by U.S. Army Signal Corps
Researchers at Fort Monmouth, New Jersey made a breakthrough in 1949. They created the first auto-assembly process for printed circuits. Moe Abramson and Stanislaus F. Danko of the U.S. Army Signal Corps reshaped manufacturing with their systematic approach to PCB production.
Their process combined copper foil interconnection patterns with base materials like melamine and used dip soldering technology to insert component leads onto boards. The developers drew wiring patterns and photographed them onto zinc plates to create printing plates for offset printing presses. Manufacturers could deposit acid-resistant ink patterns through stencils, screening, and rubber stamping.
The U.S. Patent Office recognized this breakthrough in 1956 with a patent for the “Process of Assembling Electrical Circuits”. Components could now be inserted through non-plated holes in the laminate material. The board was then dipped or floated on molten solder to create reliable connections between components and traces.
Introduction of Double-Sided and Multi-layer Boards
The first double-sided PCB went into production in 1947. It featured through-hole plating that let developers use both sides of the printed circuit board. The design used copper plating on the through-holes to enable electrical conductivity throughout the board.
PCB construction materials changed from common materials to specialized resins and industrial compounds during the 1950s and 1960s. By 1960, manufacturers created PCBs with four or more layers of conductive material. This offered better space savings and design flexibility.
PCB manufacturers adopted hot-air soldering methods in the 1970s for faster soldering and better repair processes. Complex applications needed double-sided PCBs more than ever. Wave soldering techniques improved to handle components on both sides without damaging delicate parts during the second soldering pass.
Bell Labs and the Commercialization of PCBs
Bell Laboratories led PCB commercialization efforts. Electrical engineer Jack Morton’s team at Bell Labs ran a “fundamental development” program in semiconductor technology that encouraged many manufacturing advances.
Bell Labs hosted the nine-day Transistor Technology Symposium in 1952. Over 100 representatives from 40 companies attended after paying a $25,000 patent-licensing fee to learn semiconductor technology firsthand. Electronics giants like GE and RCA participated along with smaller companies like Texas Instruments and Sony.
The symposium produced “The Transistor,” which became known as “Ma Bell’s Cookbook.” This publication became the bible for the new semiconductor industry. Bell Labs benefited from this knowledge-sharing approach as they could use advances made by others.
Western Electric started manufacturing transistors in 1950. The first commercial use appeared in tone generators for toll-call signaling. Morton’s team moved fast when Bell Labs announced their successful junction transistor fabrication in mid-1951. They got the device into production within a year.
Morton’s technology transfer approach worked well. He set up semiconductor development groups at Western Electric plants with Bell Labs employees. These employees connected with their colleagues at the main research facilities. This strategy helped bridge research innovation and practical manufacturing gaps, which sped up PCB adoption in commercial applications.
The Digital Boom and Surface Mount Revolution (1980s–1990s)
The 1980s brought a dramatic transformation to printed circuit board technology. This change came with the digital revolution and widespread use of personal computers. These changes shaped manufacturing approaches, design methods, and ways to integrate components that still influence PCB development today.
Surface Mount Technology (SMT) vs Through-Hole
Surface Mount Technology emerged in the 1980s and became the industry standard faster than expected. It changed how components connected to circuit boards. Through-hole mounting needed drilled holes and inserted component leads. SMT let components be soldered right onto the board’s surface. This breakthrough created several benefits:
- Space efficiency: SMT components were just one-third the size and one-tenth the weight of through-hole equivalents
- Manufacturing speed: Pick-and-place machines and reflow ovens made assembly automatic
- Cost reduction: Less drilling and using both sides of boards cut waste and lead times
Through-hole technology still worked well for specific uses that needed mechanical strength, especially in aerospace and military products in extreme conditions. In spite of that, SMT’s space-saving features became essential to make consumer electronics smaller.
EDA Software and Computer-Aided PCB Design
Boards grew more complex and manual design methods no longer worked well. The 1990s saw widespread use of computer-aided design and manufacturing software that cut many steps in PCB development. Australian engineer Nicholas Martin saw this need and founded Protel in 1985 to create electronic design automation (EDA) software.
The software brought these breakthroughs:
- Integrated schematic capture and PCB layout in unified environments
- Component libraries with predefined models to ensure consistency
- Up-to-the-minute 3D PCB visualization for better accuracy
These tools made complex designs with smaller, lighter components possible while cutting production costs.
Ball Grid Array (BGA) and Silicon Integration
Ball Grid Array technology became the most important advancement in the 1990s. Unlike connections only around the edges, BGAs used the entire bottom surface of integrated circuits with an array of solder balls. This approach offered vital benefits:
- Higher pin density for more complex chips
- Shorter electrical paths cut signal distortion at high frequencies
- Better thermal management stopped overheating
BGAs had early challenges with solder joint fractures from thermal stress and inspection problems after soldering. The technology ended up enabling the massive silicon integration needed for modern computing devices.
Modern PCB Technologies and Manufacturing (2000s–Present)
The year 2000 marked a new chapter in PCB manufacturing. Technologies that experts once called experimental became industry standards, ushering in an era of ultra-miniaturization in printed circuit boards.
High-Density Interconnect (HDI) and Microvias
HDI circuit boards changed electronics forever by packing more wiring into the same space than conventional PCBs. These boards employ laser-drilled microvias—tiny holes as small as 75 microns—to connect different layers. IPC-2226 states that true HDI boards must have finer lines and spaces (≤100 μm), smaller vias (<150 μm), and higher connection pad density (>20 pads/cm2).
The conical frustum shape of microvias changed PCB design. These holes slope inward between layers, and modern laser drilling can create openings as tiny as 15 μm. This breakthrough significantly expanded routing options. Microvias also deliver better signal integrity because they have smaller parasitic capacitance and inductance.
Flexible and Rigid-Flex PCB Adoption
Flexible PCB technology took off after 2000. The market grew to $21.80 billion by 2023, making up 30% of the entire PCB industry. These versatile circuits work reliably even when bent, folded, or twisted.
Rigid-flex PCBs combine rigid and flexible substrates. They proved crucial for space-limited applications, reaching $22.1 billion in market value by 2023. Experts predict 10.9% annual growth through 2032. The benefits include:
- 75% weight reduction with fewer connector requirements
- Better reliability from reduced mechanical connections
- Design flexibility that allows complex 3D shapes
These features made rigid-flex PCBs vital in smartphones, medical implants, automotive electronics, and aerospace systems.
Machine Assembly and Miniaturization Trends
Today’s PCB manufacturing runs mostly on automation. High-end facilities use Japanese Fuji pick-and-place machines, 3D X-RAY inspection, and 3D Solder Paste Inspection (SPI) systems. These systems maintain consistent quality through immediate production monitoring.
Every Layer Interconnect (ELIC) technology arrived in 2006 and pushed miniaturization further. This method connects any two PCB layers using stacked copper-filled microvias, maximizing connection density. By 2017, the mSAP (modified Semi-Additive Process) technique achieved line width/spacing of just 30μm. This advancement made 0.3mm pitch BGAs possible in modern smartphones.
PCB manufacturers continue to push the boundaries of miniaturization. They work hard to pack more functions into increasingly smaller spaces.
The Future of PCB Design and Emerging Trends
The next decade of PCB development promises several innovative technologies that will transform circuit board design and manufacturing practices.
AI-Driven PCB Layout Optimization
AI technology is transforming PCB design by automating complex tasks that engineers traditionally handled. AI algorithms now optimize component placement to reduce signal interference, minimize electromagnetic interference, and improve heat dissipation across the board. These tools significantly cut design time. Allegro X AI reduces placement and power plane generation from days to minutes. AI enables generative design that goes beyond simple automation. It tests thousands of layout combinations based on specified constraints and creates optimized PCB configurations that human designers might not imagine.
Biodegradable and Eco-Friendly PCB Materials
Jiva Materials created Soluboard, the world’s first recyclable and biodegradable PCB substrate made from natural fibers and a halogen-free polymer. This breakthrough dissolves in hot water and leaves only compostable organic material while preserving electronic components. These materials could reduce carbon emissions by 60% compared to traditional FR-4 boards. The savings amount to 10.5 kg of carbon and 620g of plastic per square meter of PCB. The biodegradable PCB market now uses materials like polylactic acid (PLA) and cellulose nanofibers from agricultural waste.
Wearable Tech and Embedded Camera Modules
PCB innovations drive the future of wearable technology. Stretchable PCB meshes with serpentine copper traces can withstand ±25% strain, which enables electronic tattoos and smart compression garments. Materials with lower dielectric constants (Dk) such as polyimide films (Dk of 3.76 versus FR4’s 4.5) serve as ideal substrates for high-frequency wearable applications.
PCB Trends 2025: Smart Homes and Autonomous Systems
Autonomous vehicles will need specialized PCBs with neuromorphic computing chips and in-memory computing by 2025. The global PCB market value stands at $70 billion in 2023 and should reach $85 billion by 2025. Higher-frequency PCBs that support millimeter wave (mmWave) communications will enable ultra-low-latency vehicle-to-everything (V2X) connectivity. Bio-based resins and carbon fiber-reinforced substrates will help reduce environmental impact.
Conclusion
Looking Back and Forward: The Remarkable Trip of Circuit Boards
This piece traces printed circuit boards’ remarkable progress from basic concepts to advanced technologies that shape our digital world. Albert Hanson’s 1903 patent marked the first step, but Paul Eisler’s functional design forty years later launched the PCB revolution. Manufacturing innovations in post-war years turned these specialized components into mass-produced necessities.
The digital boom of the 1980s and 1990s brought a fundamental change. Surface mount technology changed how components connected to boards and reduced size requirements. Computer-aided design software reshaped the development process. Engineers could now create complex circuits with better precision.
Modern PCB technologies like high-density interconnects, microvias, and flexible substrates have made portable electronics possible. Your smartphone exists because of these innovations.
AI-driven design optimization will reshape how engineers approach PCB layout. New environmentally conscious materials help address electronic waste concerns. Ground applications in wearable technology, autonomous vehicles, and smart home systems will challenge circuit board capabilities.
The progress from hand-wired circuits to sophisticated multi-layer designs stands as one of technology’s greatest engineering achievements. PCBs have evolved from room-sized systems to microscopic components. They are more powerful, reliable, and available. This progress continues as newer, innovative technologies expand what circuit boards can do.
