PCB News - PCB screen printing specification and requirements

The screen printing layer is the text layer, which belongs to the top layer of PCB board and is generally used for annotation. The correct layout principle of screen printing layer characters is: "no ambiguity, stitching, beautiful and generous", which is to facilitate the installation and maintenance of the circuit, in the upper and lower surface of the printing board printing on the required logo pattern and word code special layer. PCB screen printing specification and requirements

1. All components, mounting holes and positioning holes have corresponding silk screen labels. In order to facilitate the installation of the board, all components, mounting holes and positioning holes have corresponding silk screen labels. Hn for identification.

2. Silk screen characters follow the principles of from left to right and from bottom to top. For polar devices such as electrolytic capacitors and diodes, keep the same direction in each functional unit.

3. The solder pad of the device and the tin channel to be lined with tin have no silk screen, and the position number of the device shall not be blocked by the device after installation. (Except for those with high density that do not need screen printing on PCB) To ensure the welding reliability of the device, no screen printing is required on the welding pad of the device; In order to ensure the continuity of tin lining, tin lining is required to have no silk screen; In order to facilitate device installation and maintenance, the device position number should not be blocked by the device after installation. Screen printing can not be pressed on the through-hole, pad, so as to avoid the loss of part of screen printing when opening resistance welding window, affecting identification. The silkscreen spacing is greater than 5mil.

4. The polarity of the polar components is clearly shown on the screen printing diagram, and the polarity direction mark is easy to identify.

5. The direction of the connector is clearly shown on the screen.

6. There should be bar code location mark on the PCB. If the PCB board space allows, there should be 42*6mm bar code screen printing frame on the PCB.

7. The screen printing position of PCB board name, date, version number and other information shall be clear. PCB file should be board name, date, version number and other board information screen printing, clear position, eye-catching.

8.PCB should have complete related information and anti-static label of PCB manufacturer.

9.PCB light drawing file number is correct, each layer should be correct output, and have a complete layer output.

10. The identifiers of the components on the PCB board must be consistent with those in the BOM list.