PCB, otherwise known as printed circuit board is used to connect by way of electricity the electric components with the use of conductive pathways and signal traces. These will go through etching from copper sheets which have been laminated to become non-conductive substrate. A certain PCB filled with electronic components is called a printed circuit board assembly or in short, PCB assembly. Printed circuit boards are usually present in almost all the simplest electronic devices which are commercially produced.
The development of PCB assembly started during the twentieth century. In 1903, Albert Hanson who was a German inventor gave a description regarding flat foil conductors being laminated to an insulating board in numerous layers. Also in 1904, Thomas Edison made an experiment with the chemical processes of plating conductors on a linen paper.
Furthermore, in 1913, Arthur Berry made a patent of a print-and-etch technique in Britain of which Max Schoop acquired a patent in America. It was also in 1927 that Charles Durcase obtained a patent regarding the method of electroplating circuit patterns.
Once the PCB is finished, the electric components should be attached so that a functional PCB assembly is formed. There are two construction processes which can be used in order to form the PCB assembly. One is the through-hole construction in which the component leads are inserted in the holes while the other one is the surface-mount construction wherein the components are situated on pads located on the external surfaces of the PCB. Both types of construction have component leads which are fixed mechanically as well as electrically to the board through a metal solder which has melted.
Moreover, there are various soldering methods to be used in order to connect the PCB components so that PCB assembly can be possible. Production that is of high volume must be done through machine placement and bulk wave type of soldering. However, expert technicians have the ability to solder very minute parts by the hand under a microscope. This is usually done with the use of tweezers and a soldering iron with a fine tip which is designed for small volume prototypes. Yet, there are parts that are impossible to solder with the hands just like the ball grid array.
PCB's which would make up the PCB assembly have conformal coating that is applied by way of dipping or spraying once the components are done soldering. This coat will basically prevent corrosion and the leaking of current or possible shorting because of condensation. PCB assembly is static sensitive, thus; it should be placed inside antistatic bags while it is being transported. Improper techniques in handling could transmit static charge through the board and as a result may damage the components.