subject: Main Role Of Pcb [print this page] A PCB is a printed circuit board, also known as a printed wiring board. It is used in electronics to build electronic devices. A PCB serves two purposes in the construction of an electronic device. It is a place to increase the components and it provides the way of electrical connection between the machinery.
A PCB starts out as a thin, non-conducting sheet of material. The most common material used is a glass fiber epoxy cover material. A thin layer of copper is then chemically deposited on each side of this material.
The next step is to "print" the connection diagram onto the PCB. The connection diagram is the wiring required to connect the components. In the very early days of electronics, these connections were in fact done with wires. This is the reason PCBs are also sometimes referred as printed wiring boards. The "printing" is usually done by photographically transferring the image to the PCB. This image is "printed" with an acid resistant material.
Next, the PCB is put into an acid bath. The acid bath removes the copper from the board, excluding the areas protected by the resistant material. This process leaves the connections or wiring "printed" on the PCB. Next, holes are drilled in the panel to allow the components to be mounting to the PCB and the PCB itself to be mounted to the case protecting the electronics. Finally, a protective coating is useful to the board to prevent rust of the copper traces.
The above process describes what is referred to as a doubled sided or two layer PCB. It is possible to make PCBs nearly any number of layer may repeat the process above and laminating the resulting PCBs into a particular PCB. The PCB inside of the computer on which you are reading this document is a smallest four layer PCB and more likely to be an eight or even 12 layer PCB.
It is also most common way for parts to be soldered directly to the board, eliminating the need for holes into which leads (wires) from the components must be inserted. A component soldered to the board is logically called a surface mount component, and the PCB is a surface mount PCB. This method allows a large amplify in the number of components to be mounted on the same PCB, or the same number of components to be mounted on a much smaller PCB. However, surface increases also require better quality control on the manufacture of the PCB.
A PCB is now used in almost every electronic manufactured goods available. It is by far the most common way which at present used to connect and assemble the components of almost any electronic device.
