What are Printed Circuit Boards?
A printed circuit board, also called a circuit board or PCB, is a non-conductive board utilized for placing or mounting the different electrical components that comprise a working circuit or assembly. All the components mounted on the board will have traces that will serve as interconnections that make electronic gadgets and equipment work.
A PCB can be one-sided, two-sided, or even multi-layer. When you view it from the side, it will look like a sandwich with different layers of conductors. The layers are separated with insulation.
There are many materials used for fabricating circuit boards, but the most common materials used are plastic, glass-fiber or resin. The tracks are usually made from copper. However, with technology improving year after year, many other materials are being used. There are both rigid and flexible PCBs being manufactured today. Flexible PCBs allow them to fit into uneven spaces.
PCBs are made by fabrication and assembly companies. One such company is Imagineering Inc. Their website pcbnet highlights its history and achievements, as well as a comprehensive list of their services.
What is PCB Fabrication?
PCB Fabrication is the actual process of building a printed circuit board. The process varies slightly based on whether the board that will be made has a single layer, double layers or multiple layers.
Regardless of the number of layers, there are two basic processes that the PCB goes through. The first part is where solder is used to assemble and place components on the board. This is usually done with special equipment. A varnish called solder mask is applied on both surfaces of the assembled board. The application prevents the solder from short-circuit accidents. The solder mask is usually green in color.
The next part of the process is silk screening or overlay. When PCB manufacturers do silk-screening, the manufacturer prints information on the solder mask. The information will help facilitate assembly, verification, and repair services. Silk screening can be placed on just one side of the board, or even on both sides of the board, depending on client specifications.
The next part of the process is stacking the layers. Now this depends on how many layers are specified by the client.
Companies such as Imagineering Inc. fabricates high quality customized PCBs. Their clients are some of the top corporations of America such as NASA, Whirlpool, Motorola, Boeing, and many others. Customers can get a free quotation on www.pcbnet.com. They just need to fill in their PCB specifications.
What are the Different PCB layers and their properties?
Any type, property, or function of layer stack may be used in PCBs. Multi-layer PCBs can have as many layers as possible, depending on the capability of the manufacturer. An average layer is around 14, and that is the maximum number that www.pcbnet.com offers their clients.
Each layer should be specified by the client. The instructions have to be very specific, down to its material, mechanical requirements, thickness, and dimensions. All these choices are presented to the client when you get a quote from Imagineering Inc.’s website, www.pcbnet.com.
Here are some common layer types and properties:
The first layer type is the signal layer. It is a layer made from copper, and it is used to define signal routing. It also serves as the carrier of electrical signals and circuit supply.
Another layer type is the internal plane. It is also made of solid copper. Its main purpose is to distribute power within the board.
A layer made from a variety of materials including FR4 or polymide is the insulating dielectric layer. This layer is crucial so it should have dimensional stability, flexibility, and tear resistance.
What are the Different Component Packages?
There are three main electronic component packages for PCBs. The three packages are thru-hole, surface mount technology, and ball grid array.
Thru-hole comprises of components soldered to the opposite side of the board from which the component was originally inserted. The components are mounted on only one surface of the board.
Surface mount technology has components that can be mounted on both sides of the board. The components are significantly smaller than thru-hole package type. This can be used when denser and smaller circuit boards are required.
The ball grid array is used for integrated circuits that have unusually high density. Special machinery is used to solder them to the PCBs.