Originally metal boards and strips were used to connect electrical components which were perched on the wooden base. Gradually this device evolved into modern day printed circuit boards. It was somewhere between 1960?s and 1970?s that these boards became the necessity. But astonishingly there is no particular thing as a standard printed circuit board.
Printed circuit board manufacturers design each board for a unique purpose for different products. Special software and design systems are used to lay out the circuit pattern for the board. Often 0.04 inches (1.0mm) or smaller spaces are present between the electrical conducting paths. Holes for component leads or contact points? location are laid. All of this information is transferred as instructions for a drilling machine that is controlled by the computer numerical. Sometimes the instructions are for automatic solder pastor which is used in the process of production.
Fiberglass is mostly used by the printed circuit board manufacturers with the copper wire on single or both sides for substrates. The circuits themselves are made up of copper and layered with tin-lead which prevents oxidation. Whereas contact fingers are layered with tin-lead, then nickel, and lastly with gold to ensure undisturbed conductivity.
Printed circuit board supplier should check some random circuit boards manually from the whole consignment to be sure of the quality and functionality of the boards before delivering to the customers. They should check that each circuit board is plugged in tightly. Check the cards by pushing them to make sure they are securely attached.
Every plug-in component should be checked. Every chip and daughter board must be in place, and there should be no loose connection. Make sure there is no foreign object on the board as it may hinder the working of the circuit. All secondary wiring plugs must be looked at properly.
It is important that the board doesn?t have any cracks because even a hairline crack can break the circuit traces. Boards can possibly be damaged during transportation which makes it imperative for the printed circuit board supplier to check carefully and thoroughly. These are the basic steps to evaluate the circuit boards physically.
It is highly unlikely to find blackened components in an unused device or to find broken leads, but it must be looked out for nevertheless. Tiny wire leads must be jiggled slightly to make sure there is no broken wire, and everything is well-connected and intact.