PCB Basics

Sep 15th 2015 at 6:07 AM

If you’ve ever seen a broken or an opened electronic gadget, then it is highly probably that you might have seen a printed circuit board inside it. It is something that is primarily used to connect electronic components inside the gadget, and also supports the device. This board consists of copper sheets which are laminated onto a non-conductive substrate. Connection features such as conductive tracks, pads, etc. are etched on the copper sheet. There can be PCB boards with a single copper sheet to make them one-sided, or have two copper sheets to make them double-sided. There are also boards with multi-layers. These multi-layers boards can accommodate a much higher component density. Connections on different layers are established through holes called “vias”. Advanced technology allows for embedding devices in the board – capacitors, resistors, etc.

The most common material used as the non-conducting layer is the FR-4 glass epoxy. It is used by printed circuit board manufacturers to produce rigid PCBs. These boards can be used for simple gadgets or for complicated electronics. Multi-layered PCBs are preferred for complicated electronics because of the reason that they can accommodate complicated circuit designs. Printed circuit board manufacturing is a relatively cheap process. Practically every part can be automated except for the designing aspect for which extra effort will need to be expended. However, automation does reduce operator wiring errors.

These days, a printed circuit board is referred to as a printed circuit assembly. The word “board” has fallen into disuse, although the acronym still carries its initial. When there is nothing etched on or embedded in the board, it is called a PCB. When it consists of resistors, capacitors and other devices on it, it is called a printed circuit assembly, or PCA.

Until not too long ago, the PCBs used to be designed manually. This was done through a mylar sheet with a photomask of the design on it, usually blown up in proportions by two to four times. After the circuit was completely and clearly laid out like this, using the photolithography technique, this design was transferred onto the copper layer on the PCBs. Although this technique is hardly in use today, it was what constituted the first steps in PCB design and production. Nowadays, everything is done by computers, and very little human input is required, if at all. Similarly, in this field also, printed circuit board design software has taken over the conventional processes of old. This software is capable of designing circuit boards across a range of one to tens of layers, depending on complexity of the circuit. An electronic design automation tool takes a schematic capture, and based on the requirements of the circuit, card dimensions and templates are decide on. Then the software determines placement of all the components and heat sinks on the board, the layers stacks of the PCB and the ground and power planes. Signalling and line impedance constitute the next steps. Finally, the components are placed and signal traces are routed. Designing and manufacturing a PCA has become fairly easy.

To know more about PCB boards, visit PCBCart.com.

About The Author

James Whitehall is an expert when it comes to printed circuit board manufacturing and design. He loves writing interesting articles and blogs about the topic and recommends PCBCart.com as the name to trust if you are looking printed circuit board fabrication services and support.

Please to comment

sign in

Remember Me

New to IM faceplate? join free!

Lost Password? click here