● Dielectric layer
● Solder Mask
● Surface Finishing
● Trace & Holes
Printed circuit boards run through our lives and enjoy a great amount of users and related products. But how many people know what the PCB construction is and how parts of a PCB function individually? In fact, the PCB is mainly composed of several parts: dielectric layer, solder mask, surface finishing, trace, silkscreen, holes and other components.
1. Dielectric layer: It is the main part of a printed circuit board, which keeps the insulation between the patterns and layers, commonly known as substrate.
2. Solder mask: Not all the copper surface of a printed circuit board will be pasted with tin. So the un-pasted part of copper surface will be printed on insulating substance, avoiding short-circuit between traces. This is called solder mask. Usually, solder mask can be divided into green, red, black and blue solder mask.
3. Surface finishing: Among the normal environment, copper surface is easily oxidized, resulting in the bad result of tin pasting. Therefore, it will be protect the copper surface. Conventionally, protection methods are immersion tin, immersion gold, immersion silver, OSP and so on. They all share some advantages and disadvantages, but they collectively referred to surface finishing.
4. Trace: PCB traces play a role of tool to connect electronic component. And in the designing, a large copper surface is designed as the grounding and power layer. Traces and the copper surface are made simultaneously.
5. Silkscreen: This is not the necessary component for manufacture a printed circuit board. The main function of silkscreen is that it marks the name of components and location of SMD, for the repair and identification after assembly with identification.
6. Holes: Through holes make the electronic connection between two layers possible. The larger one is used for electronic components assembly. Besides, other non-conductive holes are usually used to fix a position for assembly.
The PCB construction is not as simple as its look. Every part of it plays a particularly important role. For the different use of PCB, the materials of its components are different. So, in general, before the mass production of PCB, customers will turn to PCB prototype to guarantee the quality.