Circuit boards or Printed circuit board or Printed Wiring Board (PCB / PWB), is board made out of non-insulating and highly heat-resistant insulating material such as fiberglass. These boards are also called substrates. A substrate or board may have only one single layer (Single-Layer Circuit Board) or more than one layer (Multilayer Circuit Board). A conductive metal such as copper is used to make conductive pathway or traces to facilitate flow of electricity. Once these conductive traces are etched on the substrate, it is termed as “Printed Circuit Board”.

These circuit boards are of no good use until Electronic Components are mounted on it. Electronic components can be either through- hole components or SMD Components. Again the technology used to Solder these components on the circuit board can be through-hole technology or Surface Mount Technology. Soldering material may include Solder in the form of Solder Wire, Solder Paste, Solder Balls for BGA (Ball Grid Array) and Solder Flux.

As explained above, a Printed circuit board (PCB) is a board made of one or more layers of insulating material (Fiberglass, Ceramic, Highly Heat-Resistant Plastic or any other dielectric material) with conductive pathways etched with metal such as copper. During the manufacturing process of the circuit board, traces of copper or any other conductor is etched off the board leaving only traces that are needed to mount / solder electronic components. Once all electronic components are mounted / soldered / assembled on the circuit board and the board is ready for use, it is called Printed Circuit Assembly (PCA) or Printed Circuit Board Assembly (PCBA).

A circuit diagram is a diagram showing and explaining how and where electronic components will be mounted to achieve the target product. Each component on a circuit board diagram is represented by a symbol. (Have a look at the pictures on the right for more information).

How to draw a circuit diagram?

Drawing a circuit diagram is not that difficult if you know the basics. Here are some tips and guidelines:

3. For complex circuit diagrams, start from left to right. so that signals flow from left to right (inputs and controls should be on the left, outputs on the right).

Mounting electronic components on the circuit board and getting it ready for use is what is called circuit board assembly.

A Circuit board assembly process may use through-hole assembly technology or Surface Mount Technology (SMT) or a mix to both. Once the circuit board is assembled with components it is ready for testing and finally to be assembled with the product. But it is not guaranteed that a circuit board assembly will give 100% zero defect production. There will be defects and these defect need to be reworked / repaired.

Go through following Circuit Board Assembly Articles:

• Surface Mount Technology (SMT): Tutorial

• SMT Equipments

• SMD Soldering - An Illustrated Guide

• EMI and layout fundamentals: Switched-mode circuits

• Layout guidelines: for switching power supplies and regulators

• Printed circuit board: Designing and manufacturing overview of PCB

• Circuit board: Design rules (size, trace width, SMT footprints and more)

• PCB Design: Tutorial on Circuit Design including base materials, calculators, guidelines

• PC trace: Fusing current

• Schematics capture & free PCB design software (working evaluation for small designs)

• Free CAD: Program with PSPICE

• Free printed circuit board: Layout Software Download (GNU/Linux).

• GERBV: Free Gerber file viewer

• Merlin PCB Designer: Freeware for CorelDraw

• PC-A-610D: Preview- Acceptability of Printed Circuit Board Assembly (PCBA)

• Circuit Board Repair: PCB Repairing and Rework Guide

• Trace width: Calculator for external and internal layers

• PCB Calculator and Designing: A collection of calculators and PCB design tools

• IPC-7351: Land Pattern viewer and tools (replaced IPC-SM-782)

• IPC-7351A: SMT (Surface Mount Technology) land pattern calculator