Discover the intricate process of manufacturing printed circuit boards (PCBs), the backbone of modern electronic devices. Learn about PCB evolution, manufacturing steps, and quality control measures.
A printed circuit board (PCB) serves as the fundamental infrastructure for all modern electronic devices. Let's delve into what PCBs are and unravel the intricacies of their manufacturing process.
In the early days, electronic components were manually assembled and interconnected using wires, leading to errors and scalability challenges. Repairing complex circuits was cumbersome and unreliable. In 1936, Paul Eisler, an ingenious engineer, revolutionized the industry by introducing the concept of printing copper circuits on non-conductive boards, marking the inception of PCBs.
Modern-day PCBs have evolved into sophisticated, intricate structures. Manufacturing begins with a simple copper flat sheet, which undergoes a meticulous transformation into an advanced electronic device. Initially, a layer of copper foil is laminated onto an insulating glass fiber sheet, providing mechanical support throughout the manufacturing process.


Subsequently, the sheet is drilled, with registration holes serving as reference points for alignment processes. Engineers design circuits using computer-aided simulations and generate design files known as Gerber files. These files guide the drilling machine to create holes for component attachment.

After drilling, thorough cleaning ensures the removal of any residue. The crucial step of producing tiny copper traces involves chemical etching, wherein a resistive mask is applied to the copper plate. Submerging the arrangement in an alkaline solution dissolves the exposed copper, leaving behind the required traces.

Quality inspection is paramount, with optical machines scrutinizing printed boards for defects. Solder mask resin, applied to protect against oxidation and dust exposure, imparts the characteristic green hue to PCBs. However, this resin can hinder connections between copper traces and components.

To mitigate this issue, a UV process removes the mask from the hole edges. Silk screen printing adds visible ink traces for component identification, completing the manufacturing process.

Once manufactured, components are soldered onto the PCB using liquid tin, and final flying probe testing ensures connectivity between components, traces, and pads.

While through-hole technology (THT) was prevalent, surface-mount technology (SMT) now dominates. Though THT remains relevant for educational purposes, SMT represents the latest advancement in PCB technology.

In conclusion, from a simple copper plate to a fully functional electronic device, the journey of PCB manufacturing is intricate yet indispensable in the realm of modern electronics.