The manufacturing process of PCB (printed circuit board) is a complex and delicate process, which involves multiple key steps to ensure the quality and performance of the final product. The following are the main steps of the PCB manufacturing process, and each paragraph is elaborated in detail:
1. Design stage
PCB manufacturing begins with the design stage, which is the most basic link in the entire process. At this stage, engineers use CAD (computer-aided design) software to create circuit schematics and PCB layouts. These design files specify key information such as the size, wiring method, pad size, component location, etc. of the PCB. After the design is completed, engineers need to convert the circuit schematics and PCB layouts into Gerber files, which is a standardized file format used to guide the subsequent manufacturing process.
2. Graphic conversion and plate making
Graphic conversion is the process of converting Gerber files into graphic information that can be used for plate making. Plate making is the core link in PCB manufacturing, which uses high-precision plate making equipment to transfer graphic information to copper foil. This process usually includes steps such as exposure and development, and the required lines and graphics are formed on the copper foil through photochemical reactions. The accuracy and quality of plate making directly affect the subsequent process and the performance of the final product.
3. Etching and Drilling
Etching is the process of removing the unwanted parts of the copper foil after plate making. By soaking the copper foil in etching solution and controlling the appropriate etching time and temperature, the excess copper foil can be etched away, leaving the required circuits and graphics. Drilling is to drill various holes on the PCB board, including pad holes, positioning holes, mounting holes, etc. These holes are essential for subsequent component installation and circuit connection. Drilling requires the use of a high-precision drill press or drilling machine to ensure the accuracy and consistency of the hole positions.
4. Coating and Welding
Coating is the process of covering a layer of solder film on the PCB board. The solder film is used to protect the circuits and pads of the PCB board and provide the necessary conductivity and wettability in the subsequent welding process. Welding is the process of mounting components on the PCB board and connecting them. This usually involves using a soldering iron or welding equipment to solder the pins of the component to the pads on the PCB board. During the welding process, it is necessary to control appropriate parameters such as temperature, time and pressure to ensure the quality and reliability of welding.
5. Inspection and Cleaning
Inspection is the process of quality inspection of the PCB board after welding. This includes the use of AOI (automatic optical inspection), X-ray inspection, ICT (in-circuit testing) and other means to check whether there are defects or problems in the circuits, solder joints, components, etc. on the PCB board. Cleaning is the process of cleaning the residues and solder slag generated during the welding process. The cleaned PCB board is more neat and beautiful, and is conducive to subsequent packaging and assembly operations.
6. Post-processing and finished product inspection
Post-processing includes steps such as silk screen printing and surface treatment, which are used to add logos, text or other surface treatments on the PCB board to improve its appearance and durability. Finished product inspection is a comprehensive inspection and test of the PCB board that has completed all manufacturing steps to ensure that it meets the design requirements and quality standards. This includes functional testing, performance testing, appearance inspection and other aspects.
In summary, the manufacturing process of PCB is a complex and delicate process, which involves multiple key steps such as design, graphic conversion, plate making, etching, drilling, coating, welding, testing, cleaning, post-processing and finished product inspection. Each step requires strict control of process parameters and quality standards to ensure that the quality and performance of the final product meet the design requirements.
