What are the Screen Printing Specifications and Requirements for PCB?
PCB screen printing is an important process in PCB production, and it also determines the quality of the finished PCB board. So, what are the screen printing specifications and requirements for PCB circuit boards?
1. All components, mounting holes and positioning holes have corresponding silk screen labels. In order to facilitate the installation of the finished board, the screen printing of the mounting holes on the PCB electronic board is marked with H1, H2…Hn.
2. The silk-screen characters should follow the principle from left to right and bottom to top as far as possible; for electrolytic capacitors, diodes and other polar devices, try to keep the same direction in each functional unit.
3. There is no silk screen on the device pad and the tin track that needs to be tinned, and the device number should not be blocked by the device after installation; the silk screen should not be pressed on the via hole and the pad, so as to avoid part of the silk screen being lost when the resistance soldering window is opened; The screen spacing is greater than 5mil.
4. For components with polarity, the polarity is clearly indicated on the silk screen, and the polarity direction marking is easy to identify.
5. For directional connectors, the direction is clearly indicated on the silk screen.
6. When the space of the custom pcb printing board allows, there should be a bar code silk screen frame on the PCB, and the position of the bar code should be considered for easy scanning.
7. The printed board information such as board name, date, version number, etc. should be printed on the PCB file, and the position should be clear and eye-catching.
8. There should be complete relevant information of the manufacturer and anti-static logo on the fr4 circuit board.
9. The number of sheets of the PCB light drawing file is correct, each layer should have the correct output, and there should be a complete number of layers output.
10. The identifier of the device on the integrated circuit board must be consistent with the identifier in the BOM list.