Pcb fabrication Printed circuit boards (PCB circuit boards), also known as printed circuit boards, are providers of electrical connections for electronic components. Its development has a history of more than 100 years; its design is mainly layout design; the main advantage of using circuit boards is to greatly reduce wiring and assembly errors, and increase the level of automation and production labor.
PCB fabrication PCB circuit board composition
1. Circuit and pattern (Pattern): The circuit is used as a tool for conduction between the originals. In the design, a large copper surface will be designed as a grounding and power layer. The lines and drawings are made at the same time.
2. Dielectric layer (Dielectric): Used to maintain the insulation between the circuit and each layer, commonly known as the substrate.
3. Hole (Through hole / via): The through hole can make the lines of more than two levels connect to each other, the larger through hole is used as a part plug-in, and there are non-through holes (nPTH) usually used as Surface mount positioning, for fixing screws during assembly.
4. Solder resistant /Solder Mask: Not all copper surfaces need to be tinned parts, so the non-tin area will be printed with a layer of material that isolates the copper surface from eating tin (usually epoxy resin) , To avoid short circuits between non-tinned circuits. According to different processes, it is divided into green oil, red oil and blue oil.
5. Silk screen (Legend /Marking/Silk screen): This is a non-essential composition. The main function is to mark the name and position frame of each part on the circuit board to facilitate maintenance and identification after assembly.
6. Surface Finish: Because the copper surface is easily oxidized in the general environment, it can not be tinned (poor solderability), so it will be protected on the copper surface that needs to be tinned. The protection methods include HASL, ENIG, Immersion Silver, Immersion TIn, and Organic Solder Preservative (OSP). Each method has its advantages and disadvantages, collectively referred to as surface treatment.