PCB, short for Printed Circuit Board, is playing increasing important role during our daily life. It makes the circuit miniaturize and visualize, and it’s essential role of fixing batch production and optimizing the layout of electrical equipment can never be ignored.
The circuit boards is generally composed of the following parts:
Pattern
Pattern mainly refers to the line on the surface. The line is the connective tool between the components. And another copper surface will be designed as the ground and power layer.
Dielectric
It is used to keep the insulativity of the layers and commonly known as the base material.
Through hole/via
The hole can make two or more layers to conduct to each other. Usually, the larger holes are used as parts plug-in, while the NPTH is used to do surface-mount positioning, helping to fix screws when doing assembly.
Solder Mask
Not all the copper surface needs to solder on the parts. So for the area which soldering is not necessary, we will print a kind of material, usually known as epoxy resin, to prevent the copper surface from short circuit between the lines. According to different process, the solder mask can be divided into green oil, red oil and blue oil.
Legend/Silk Screen
This is not a necessary composition. The main function of it is to mark the name and location of the components, and to convenience the repair work after assembly.
Surface Finish/Treatment
Due to the copper surface is easy to oxidize during the general environment, causing poor solder ability. So there is usually a protection layer on the copper surface. And the methods of protection include Hot Air Solder Leveling (HASL), Immersion Gold (ENIG), Immersion Silver, Immersion Tin and OSP.
Circuit board is one of the most active industries in modern electronic components industry. The growth rate of the industry is generally higher than the electronic components industry by 3%. For the wide range of the application of printed circuit board, there must be wider market for it.
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