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Printed circuit boards are pieces of electronic equipment which hold the components together to make it run. It is usually etched, or “printed,” with a pattern made from a conductive material underneath or within the middle of the board; sometimes it is etched on both ends. It connects each component together to create a circuit that makes the electronic equipment work. The board itself is usually made from a material that doesn’t get affected by electricity.
Printed circuit boards are widely used for assembling electronic devices. It helps in making the device more compact and easier to manage. If printed circuit board was not created, each electronic component inside a device would have been tied together with a massive amount of cables connecting one component to another. Very old electronic devices like computers with vacuum tubes had used this setup but as time goes by, the wires are known to experience wear and tear, affecting the efficiency of the devices. The circuit boards were able to reduce the sizes of the computers along with the introduction of the integrated circuit, reducing the computer sizes to the ones that we are able to use today.
Printed circuit boards also have different names, but all refer to the same item. They can be also called “printed wiring boards” or “printed wiring cards.”
With designing printed circuit boards, the designer would start by selecting the material to use with it. The base material which will be used is called a substrate, where the circuit is “printed” onto. The substrate is usually made out of fibreglass. Making sure that the board is made with a substance that is of an insulated substance is vital in setting up a circuit board. Once the pattern is finalized, places where each electrical component will go through the board are punctured in order for it to be prepared with the other steps in making the circuit board.
Once the pattern for the circuit board is finalized, choosing the conductive material to create the circuit is the next step. The common material used with circuit boards is copper. Once the pattern is set in place, the copper is then “printed” onto the board. A thin copper foil is used here and it will be etched onto the board, connecting the holes that were previously created on it. Each line on a circuit board is carefully designed so that the components which will need to meet in a circuit will be the only ones in the circuit and no other components will go across that path. A typical circuit board will have the pattern printed on both the top and bottom of the board, but with the cheaper ones, it is only printed at the bottom.
The colour of the board that you may see is commonly green and in some cases they are red. This is the soldermark of the circuit board. The soldermark protects the patterns that are etched onto the circuit board and at the same time, it protects the patterns from touching each other or getting scratched which can interrupt the electric circuits created on the board. There are cases when the copper paths on a circuit board would get shorted by an accidental solder mark placed between two circuit paths that are not supposed to go together. This is called a solder jump and soldermasks can prevent this from occurring.
When the electric components are placed onto the circuit board, placing each piece is easy with the help of an additional layer called a silkscreen layer. This gives a label telling which component must be soldered onto a certain area of the board. For easy identification, these marks and codes are white in color so they can stand out from the green soldermark.