A History of Printed Circuit Board Assemblies
Though Printed Circuit Board Assemblies, or PCB Assemblies, have been around since the 1920’s, when rudimentary Printed Circuit Boards were created from layered Masonite, the development of modern PCB Assemblies really began in the 1950’s.
1950’s – Single Sided, New Materials
Though still single sided at the time, PCB Assemblies evolved in the 1950’s to include new materials being used in the assembly process. New types of resins were combined with different materials to create a more efficient circuit board. These circuit boards found new uses and applications in the rapidly expanding industrial-based economy in North America, as Printed Circuit Boards were far superior to bulky wiring and cables that were used previously.
The communications and defense industries fueled much of the growth in demand for PCB Assemblies in the 1950’s, as new technologies emerged that utilized the advantages offered by the assemblies over the traditional wiring.
1960’s – Double Sided, Longer Lasting, More Efficient
The 1960’s saw the development of more advanced plating processes that allowed hole walls in the board assemblies to be plated. This led to the first double-sided assemblies. Double sided PCB Assemblies held a distinct advantage over single sided, as they could meet greater circuit density requirements. The development of solder masks also advanced during this time, which helped improve manufacturability.
All of this development combined made PCB Assemblies the ‘go-to technology’ in the 1960’s for the communications and defense industries, as well as other industries needing advanced circuitry.
1970’s – 1990’s – Smaller and Smaller – Multi-Layer PCB Assemblies
Advancements in the 1970’s allowed circuitry and spacing on the boards to become smaller, which increased the applications for PCB Assemblies. Hot air soldering also began in the 1970’s, and the first surface mount component was also used around this time. These advances led to smaller, more efficient assemblies that could handle greater design demands.
Between the 1970’s – 1990’s, technologies developed that lead to the development of multilayer PCB board assemblies. Multilayer PCBs are made up of two or more thin circuit layers which are bonded together and connected with thru-hole plated vias and typically have at least 4 conductive layers.
Multilayer PCB boards are used in applications that need high-speed circuitry, making them perfect for professional electronic equipment, such as military equipment, telecommunications, and computers.
PCB Assemblies have advanced significantly since then, as assemblies have grown to include even more demanding applications. The aerospace, defense and telecommunication industries have driven this growth, but other industries – such as the medical and industrial sectors – are finding new applications for Printed Circuit Boards.
In our next article, we’ll discuss some of the primary uses of PCB assemblies in various industries.