PCB Technical - PCB screen printing specifications and requirements

In the following circuit boarddesign, the PCB screen layer is the text layer. Its function is to facilitate the installation and maintenance of the circuit. The upper and lower surfaces of the PCB are printed with the required logo patterns and text codes, such as component numbers. And nominal value, component outline shape and manufacturer's logo, production date, etc. So what are the specifications and requirements for the silk screen of the PCB board?

PCB screen printing

1. All components, mounting holes, and positioning holes have corresponding silk-screen marks. In order to facilitate the installation of the PCB board, all components, mounting holes, and positioning holes have corresponding silk-screen marks. The mounting holes on the PCB board use H1. H2……Hn for identification.

2. The silk-screened characters follow the principle of left to right and bottom-up. The silk-screened characters should follow the principle of left-to-right and bottom-up as far as possible. For electrolytic capacitors, diodes and other polar devices, try to keep them in each functional unit. The direction is the same.

3. There is no silk screen on the device pad and the tin track that needs to be tinned, and the device position number should not be blocked by the device after installation. (The density is higher, except for those that do not need to be silk-screened on the PCB)

In order to ensure the reliability of the soldering of the device, it is required that there is no silk screen on the device pad; in order to ensure the continuity of the tin channel, it is required that there is no silk screen on the tin channel; The device is blocked after installation; the silk screen should not be pressed on the vias and pads, so as not to cause part of the silk screen to be lost when the solder mask is opened, which will affect the training. The silk screen spacing is greater than 5mil.

4. The polarity of the components with polarity is clearly indicated on the silk screen, and the polarity direction mark is easy to identify.

5. The direction of the directional connector is clearly indicated on the silk screen.

6. There should be a barcode position mark on the PCB board. When the PCB board space permits, there should be a 42*6 barcode silk screen frame on the PCB board. The position of the barcode should be considered for easy scanning.

7. PCB board name, date, version number and other information silk screen position of the finished board should be clear. The PCB board file should have the board name, date, version number and other finished board information silk screen, the location is clear and eye-catching.

8. The PCB board should have the manufacturer's complete relevant information and anti-static signs.

9. The number of light drawing files on the PCB board is correct, each layer should have the correct output, and there should be a complete output of the number of layers.

10. The identifier of the device on the PCB circuit board must be consistent with the identification symbol in the BOM list.