|
О сайте:
|
What is Printed Circuit Board?
A Printed Circuit Board (PCB) is a Sheet of Insulating Material such as Fiberglass, with Metallic Circuit or Track Printed or Etched on it for Electrical Conductivity. A PCB is found in almost all electronic products that we use in our daily life – Mobile Phone, Tablet, TV, Computer, Laptop, Keyboard, Mouse, Military Weapons, Airplane, Satellite etc.
In applications where fine conductive traces are needed, such as computers, PCBs are made by a photolithographic process, in a larger scale version of the way conductive paths in processors are made.
Electronic components are typically placed by machine onto a finished PCB that has solder dabs in place. The PCB bakes in an industrial oven to melt the solder, which joins the connections. Most PCBs are made from fiberglass or glass-reinforced plastics with copper traces. PCBs can be single-layer for simple electronic devices. Printed circuit boards for complex hardware, such as computer graphics cards and motherboards, may have up to twelve layers. PCBs are most often green but they can come in any color.
Other methods of PCB manufacturing include silk-screening and CNC-milling.
Different types of printed circuit boards
The most basic type of PCB is the original single-layer board which, as the name suggests, involves mounting one layer of copper on a substrate. Later developments led to double-layer and multi-layer PCBs, which saw multiple copper layers applied to two or more substrate layers. This made it possible to add a much higher density of components to the PCB and use them to create more powerful devices. While multi-layer boards did make maintenance more difficult, they soon became so cheap to make that it is now often more cost-effective to replace an entire board than to repair it.
Today, the most common substrate is FR-4 glass epoxy, though new materials have emerged as the popularity of PCBs has grown. Examples of PCB configurations include rigid PCBs, flexible PCBs, rigid-flex PCBs, and high-frequency PCBs. The different configurations often use different substrates. And there are many different types of PCB such as Flexible PCB, Rigid-Flex PCB, HDI PCB Board, High Frequency PCB, Aluminum PCB, Ceramic PCB, Multilayer PCB, etc.
What is PCB Assembly?
Well, a PCB is of No use unless we solder some Active and Passive Electronic Components on to the Board. These Electronic Components can be either Thru-Hole of SMD (Surface Mount Components). Once all the Electronic Components are Soldered (Assembled) on to the Board, it is Termed as Printed Circuit Board Assembly or PCB Assembly. The assembly can be also divided into Aerospace PCB Assembly and Automotive PCB Assembly.
|