A Complete PCB Introduction It’s Here

Published on June 29, 2021 , Last modified on July 26, 2024
by Hommer Zhao

Contents1 Abstract2 Complete PCB–Content Abstract PCB stands for Printed Circuit Board, a copper etched board that keeps printed the laid copper tracks. These tracks connect the components in most electronics items. The board is stiff enough so that it can mechanically support components mounted over it. The panels are designed on computer-aided design software in everyday practice, and then the design is transferred over the PCB material for etching. The etching is a chemical process where the necessary copper is saved, which removes extra copper. The printed paths after etching are known as tracks. Over-etching obliterates the traces or breaks the […]

Abstract

PCB stands for Printed Circuit Board, a copper etched board that keeps printed the laid copper tracks. These tracks connect the components in most electronics items. The board is stiff enough so that it can mechanically support components mounted over it. The panels are designed on computer-aided design software in everyday practice, and then the design is transferred over the PCB material for etching.

The etching is a chemical process where the necessary copper is saved, which removes extra copper. The printed paths after etching are known as tracks. Over-etching obliterates the traces or breaks the connections, resulting in an open circuit. The unnecessary open circuit or short circuit of two conductive paths results in partial or complete board failure. On the other hand, insufficient etching results in minor hair-like copper shortages from one track to another.  

This is why the precision processing machines perform the board etching under controlled pressure, time, and chemical composition. Most PCBs are manufactured by fiberglass or glass-reinforced plastic materials with a copper sheet on one side. The conductive paths, i.e., tracks, are made on the copper sheet side. The components are also soldered on the copper sheet side.

PCB Assembly Services

Kickstart Your Projects with Precision! Get PCB Assembly for Only $99—Limited Time Offer!

ORDER NOW

Complete PCB–Content

The PCBs in the current electronic products market range from single-layer, double-layer, and multilayer formats. In a multilayer PCB, multiple copper conductive layers are stacked and glued over each other to enhance the signal density and reduce the PCB size. The different layers are etched and separated by the prepreg material and then joined together. The PCB sheet is an insulating sheet of 1 to 2mm thickness coated with copper on one or both sides in the raw form.

The copper is coated over the entire insulator sheet in a small quantity, like 1 to 2 ounces per square foot. In common, the copper thickness varies from 17 to 70µm. The high current sink or source circuits, like power supply circuits, need thicker and wider copper tracks, whereas low-power but high-frequency signals need thinner copper tracks. Therefore, the magnitude of the current flow is determined by the thickness of the board and the width of the copper track.

Complete PCB3

In the electronics market, various PCBs are produced, categorized by performance, availability, manufacturing facility cost, etc. The insulator material of the PCB, although not conducting, also affects signal health. This is why, for higher frequencies, unique PCB materials are used. For higher frequencies, specially developed low-absorption materials are used.

, Other readily available materials are CEM-3, CEM-4, CEM-5, FR-1, FR-5, Teflon, and the Roger material. In common, FR-4 is used for single, double, and multilayer PCB manufacturing. After manufacturing, an essential qualification phase, the PCBs are inspected for surface-level finishing, solder mask coating, top overlay printing, etc…

Figures 1 and 2 show different types of PCBs.

PCB1.png
Complete PCB4

PCB manufactured for high pin-density components

Complete PCB
Complete PCB5

PCB tracks and vias after etching and finishing of a manufactured PCB

PCB Assembly Services

Kickstart Your Projects with Precision! Get PCB Assembly for Only $99—Limited Time Offer!

ORDER NOW
Avatar photo
Hommer Zhao
Hi, I'm Hommer Zhao, the founder and Chief Editor at WellPCB. With extensive experience in the PCB industry, I oversee all content to ensure it meets the highest standards of accuracy and insight. We proudly serve over 4,000 customers globally. For inquiries or more information, don't hesitate to reach out. Your satisfaction is my top priority!