Printed circuit boards are so common in electronics that people in the industry often forget that not everyone knows what they are. They simple assume it is common knowledge because they use them so frequently. For the average person, however, a printed circuit board often remains a great mystery, yet this doesn’t have to be the case. With some basic knowledge, anyone can understand what a board of this type, often referred to as a PCB, is and what it can do.
Printed circuit boards may be referred to as printed wiring cards or printed wiring boards, yet they are all the same thing. Circuits, before these boards were invented, were constructed via point to point wiring. Wire junction failures and/or short circuits were not uncommon with this method of wiring, as the insulation of the wires often cracked as it aged. Wire wrapping, or the wrapping of small gauge wire at connection points, reduced the risk of this problem, yet more needed to be done. This is where the printed circuit board comes in.
Printed circuit boards use pads and lines to connect different points on the board. Through these connections, power and signals may be conducted between physical components. Solder is used to make the connections because it is a powerful mechanical adhesive. The board consists of various layers of different materials. These materials are then laminated together using adhesive and heat to create one item. FR4 is the base material and is usually made with fiberglass. On this board, copper foil is laminated and then a solder mask is placed on top of this. The solder mask is the green material seen on a circuit board. Finally, silkscreen is added to the board and contains any symbols, letters and numbers needed for assembly.
Most electronics today make use of printed circuit boards. A board of this type will be found in computers and cell phone devices. Televisions typically have circuit boards, and the same is true of household appliances with digital control panels. If you use exercise equipment with a digital readout, the machine also contains one or more boards. Everywhere you look you’ll find boards of this type. They are working in the background, even when you don’t know they are there.