Printed circuit boards (PCBs) are the smallest yet the most reliable wiring solution today. All the important electric components needed for the functionality of any machine today can be collected in a single 3-inch printed circuit board. The small size of this kind of integrated circuitry has the benefit of speed and electrical efficiency.
The term “printed circuit board” may refer to either the board alone or the board together with the components mounted on it. It is correctly called “printed wiring board,” when referring to the board alone. If it refers to the entire unit, including the board and components, “printed circuit assembly” is the appropriate term.
The printed circuit board industry uses many terms to refer to the various aspects of PCB manufacturing. Some of them are listed and explained below.
1.Board. It is the flat material on which holes are drilled :
copper foils are etched, and components are mounted. It is also known as laminate. Boards or laminates may be composed of four layering materials. The innermost material which constitutes most of the laminate is called substrate. On top of substrates is a copper sheet covered by solder mask. On top of solder mask are silkscreen labels.
In a printed circuit assembly, these are the things mounted on one or both surfaces of printed circuit boards. Components include transistors, resistors, diodes, conductors, etc.
This is the innermost part of printed circuit boards. It could be made of glass fiber, plastic, epoxy, or cotton paper. It constitutes the largest part of the circuit board. Durability lies in the type of material used for making the substrate. Woven glass fiber is the most rigid, followed by plastic and cotton paper.
This metal is important for the electric connections of various components mounted on a printed circuit board. It is etched on the surface of the bare substrate and acts as a wire.
Initially, a thin sheet of copper, known as copper foil is layered on top of the substrate. Parts of this copper foil must be removed to leave only lines and few planes of copper foil.
5.Solder mask :
It is a protective layer of covering that insulates the copper. Accidental contact of live copper traces may cause short circuits and other circuit problems, hence a cover is needed. The solder mask is usually green but other colors are also available.
6.Silkscreen label :
This refers to the symbols painted on top of solder mask, serving as a guide. It helps assemblers locate where components are to be soldered.
It is one of the stages of making a large-scale manufacturing printed circuit board. Printed circuit boards are created in one large piece of board called panel. Once the panel is copper-printed and drilled, it is ready to be “de-paneled” or divided into smaller individual PCBs. Sometimes, the mounting of the components is done before de-paneling.
8.Chemical etching :
It is one of the methods of removing the unwanted copper foil. It includes exposing the unwanted copper while protecting the necessary copper against a chemical, usually ferric chloride. The chemical could etch away the unwanted copper, leaving the necessary copper to form traces.
9.Copper traces :
These are copper lines left after unwanted copper is removed from the substrate. These are the wires or electric pathways that connect the components.
10.Through-hole mounting :
It is the process of mounting the components by inserting the leads of the components in the plated-through holes of the board. The leads then can be soldered on the other side of the board.
11.Surface mounting :
This is a way of mounting the components directly on the surface of the board without inserting leads on the holes. Metal tabs or end caps of components are directly soldered on the same side of the board.
Now that you’re aware of what those terms mean, you should be a bit more ready to tinker with your very own projects – particularly those that involve the need to handle PCBs.