PCB Manufacturing Process
PCB manufacturing process contains a series of steps. This process requires advanced high-precision machines and is only cost-effective when daily PCB fabrication volume is large.
The manufacturing process begins with specifying a PCB development software. The fully designed PCB is saved in Gerber format and converted into a film negative using a plotter. Place the film on a board made of plastic with copper layers on both sides. The film is placed on the copper layer and then radiated by UV light. The film layer is UV-sensitive in places where copper connection lines go through, but is UV-resistant in other parts, so the film in connection area can only adhere to the copper layer.
The sequential process is an optical check of all plates for errors, and then layers are aligned on the same machine in the correct order. Fiberglass with glue is placed on each copper plate and plates are attached to each other in an aligned order. The entire board is heat-pressed by a mechanical control to bond the boards together with high precision.
After that is the process of drilling holes, copper is placed into the holes and the whole structure is cleaned up. The outer layers are prepared after finishing the inner layer process. To protect the copper in the outer layer from corrosion, a solder mask is applied and then cured under UV light, often, the surface color of PCB board is green.
To make the process of components soldering easier, gold or silver is sometimes applied over the outer layer. Finally, the PCB board is cut, shaped, electrically tested, documented and packaged, thus the whole PCB manufacturing process is completed.