PCB
PCBs are the foundation of modern electronic devices. They mechanically support and electrically connect electronic components and allow signals to be routed between them. These circuit boards contain conductive pathways, called traces, that are printed or inscribed on them according to predetermined designs. They also contain other important electrical components, such as capacitors, diodes, and resistors.
Printed circuit board fabrication and assembly are exacting and complex processes that rely on precise design data. As the industry evolves to accommodate advances in miniaturization, high-speed data, and sustainability, it’s vital that engineers understand the fundamentals of these technologies. This guide offers an in-depth look at the technology behind these essential pieces of hardware.
A pcb is like a layer cake or lasagna in that it has alternating layers of different materials, referred to as substrates, cores, and conductors. A single-layer PCB has one substrate and a single layer of copper; double-layer circuit boards have two substrates but only a single layer of copper. Multilayer PCBs have more than two copper layers.
What is a PCB?
The bare substrate, also known as the core or build layer, is made from fiberglass, composite epoxy, or another laminate material. The core layer is then coated with a dielectric material, such as solder mask or a HASL (high-area soldering) finish. This is followed by a layer of copper and finally, a silkscreen print of essential information.
This information is then sent to a fab house that will create the bare circuit board for assembly. The bare board is then loaded with all of the necessary components and run through different soldering processes, depending on the type of component. Once the board is assembled, it’s tested and ready for shipping. After etching, the PCB goes through a series of drilling and milling processes to create holes for component mounting and to refine the board’s dimensions. Surface finishes, such as solder mask and silk screen, are then applied to protect the traces and provide labeling for components. Finally, the assembled PCB undergoes testing to verify its functionality and adherence to specifications.
Capacitors, for example, hold an electric charge and then release it when this power is needed elsewhere on the circuit board. They can also block currents flowing in the wrong direction, protecting the rest of the board from damage. Diodes, on the other hand, let current flow in one direction but not the other, allowing it to pass through the board without interruption.
Whether you’re a seasoned engineer, an aspiring student preparing to enter the field, or simply a tech-savvy individual curious about the inner workings of your gadgets, this guide will provide an essential overview of the fundamentals of PCB technology. Mastering the basics will help you appreciate the challenges and opportunities of this dynamic industry. Best of all, it will enable you to contribute your skills to a world that’s continually evolving.