The evolution of technology has been phenomenal. The devices that people now use and take for granted are several orders of magnitude more powerful and more compact than those used by people a few decades ago. If these devices existed during those times, they would have been considered technological miracles. Modern technology owes it all to a simple but ingenious device: the printed circuit board.
What really makes printed circuit boards so special? These devices are able to fit a very large number of electric circuits into a compact space. Circuits do the majority of the work done by most electric devices, enabling them to respond to input, do some processing, and produce output. Putting more circuits enables devices to carry out more complicated work.
Printed circuit boards contain a substrate on which some layers of conducting material are printed, hence their name. Various electrical components, which form part of the circuits, are also attached on the circuit boards.
Copper is used often in the conducting layers –
This metal conducts electricity well and does not corrode easily. It is also abundant and cheap, making them a good choice among manufacturers. The copper layer forms the circuits present on the board. During the manufacturing process, some copper is removed, leaving only narrow copper pathways on the board. Once operational, electricity will flow through these pathways, powering the different electrical components on the board.
A thin protective layer of tin-lead is applied on the copper to help it resist any corrosion. A printed circuit board can be easily destroyed by short circuits. As a precaution, many circuit boards have an additional layer, called the solder mask, which protects the circuit board from short circuits. Another layer called the silkscreen layer may also be present. It marks symbols and text on the surface, enabling people to understand the different parts of the board.
Conversely, the substrate contains non-conducting material. Usually, fiberglass or plastic is used for this purpose. The main purpose of the substrate is to attach all of the other components of the printed circuit board firmly, especially the conductive layers. The substrate also provides some protection from mechanical shocks, usually caused by rough handling.
Since fiberglass is comparatively expensive, lower-end models primarily use plastic. Although both are acceptable substrates, plastic is inferior to fiberglass due to its lower thermal tolerance. When soldering components, the heat may cause the plastic to deform or release noxious fumes.
There are roughly three types of printed circuit boards, classified by increasing complexity: single-layered boards, double-layered boards, and multi-sided boards.
The first type has only one layer of conductive material –
Typically, the components are attached on the side opposite the conductive layer. The second type has two layers of conductive material, which cover both sides of the board. Double-layered boards are inherently more difficult to manufacture, but can handle more complicated circuits. The two conductive layers are connected by special holes lined with a conductive material. These holes enable circuits on one side to interact with circuits on the other side. The third type has multiple conductive layers. These layers are placed between substrate layers to prevent any short circuits. The conductive layers are connected to each other using the holes described earlier. The depth of the holes determines which layers are connected. Multi-layered boards are harder to manufacture and cost more, but they provide more computing power than other types.
Other components may also be present on the printed circuit board. These components, ranging from light-emitting diodes to integrated circuits, actually do most of the work of the circuit board. The circuit board functions as a medium by which these components can interact. This does not mean though that circuit boards are useless. Without them, manufacturers would have had to use traditional wiring to connect the electrical components together. Aside from being time-consuming and resource-draining, this process also makes the device clunkier and more likely to malfunction.
The use of printed circuit boards has made it possible to create more powerful and more compact devices. As technology continues to improve, people can expect to see more powerful versions of the printed circuit board to emerge.
Any printed circuit boards is probably the fundamental elements of electronic apparatus. It is necessary since it will serve since the coronary heart with the consumer electronics, generating everything function.