People have always been tinkering with technology. Since ancient times, people have been experimenting with new and better tools for the jobs they need to do. As technology grows, mankind’s capacity to create even more technology increases. This is readily apparent in the printed circuit board, arguably one of the most important inventions of mankind.
In truth, a printed circuit board and a bunch of electrical components connected by wires are not really that different. Both group components together to form one functioning unit. Both contain circuits capable of doing computations necessary for the functioning of most gadgets.
Their main differences lie in two things: power and size. Printed circuit boards are made up of superior materials, making them faster and more powerful than their counterparts. They are also smaller, making it possible to produce powerful but compact gadgets like pacemakers and smart phones.
Printed circuit boards have two main components:
A layer of substrate with one or more layers of copper attached to it. Copper is used in the majority of circuit boards for their low cost, high corrosion resistance, and high electrical conductivity. During manufacturing, they various parts of the copper are removed. This leaves behind numerous lines of copper on the surface; these act as circuits by letting electricity flow through them to various components attached on the circuit board. These copper paths are generally very narrow in order to maximize the available surface on the circuit board, although higher voltages necessitate the use of wider copper paths. A thin layer of tin-lead is electroplated on the copper for added protection.
Some of the copper traces extend to the borders of the circuit board. Commonly called contact fingers, they make it possible to connect circuit boards to each other or even to other electrical components. Various layers of tin-lead, nickel, and gold are applied to them to increase their ability to conduct electricity.
The substrate, on the other hand, is composed of an insulating material, such as fiberglass or plastic. They prevent electric current from escaping from the copper circuits and causing short circuits, which may damage the printed circuit board and possibly the whole electric device.
People who design circuit boards spend a considerable amount of time planning the circuit layout so that they can fit as many circuits on the board as they can. Generally, increasing the number of circuits on the board also increases the computational power of the printed circuit board.
Other components are present on the circuit board. For example, resistors, which have a higher resistance than the copper circuits, may be placed to limit the amount of electricity passing through a specific circuit. Various diodes, which limit the flow of electricity to one direction only, may also be used to control the flow of electricity. Integrated circuits, which are more complex and compact versions of printed circuit boards, may also be attached to make the printed circuit boards even more powerful.
These components must be attached firmly to the circuit board. Otherwise, electric currents will fail to flow and broken circuits will occur. Material called solders are used to attach these components. Solders are made up of metals, typically tin-lead alloys, which have low melting points. This property allows them to melt during the attachment process without destroying the surrounding material. Once cooled, they form a bond between the component and the circuit board which provides support and allows electricity to flow.
There are two main methods by which components are attached on the circuit board. In “through hole technology”, holes are drilled through the board. The components, which have long metal wires called leads, are then attached on the board. The leads, after being inserted into the holes, are then soldered in place on the other side of the board. In “surface mount technology”, solder is applied on places where the components are to be attached. Once the components are in place, heat is applied in order to seal the bond.
There is little doubt that the invention of the printed circuit board has revolutionized the world. They have made it possible to create small but powerful devices. They have helped significantly in increasing the rate at which human technology develops.