(1) Check the user’s files
The files brought by the user must be routinely checked first:
1. Check whether the disk file is intact;
2. Check whether the file contains a virus. If there is a virus, you must first kill the virus;
3. If it is a Gerber file, check for D code table or D code inside.
(2) Check whether the design meets the technical level of our factory
1. Check whether the various spacings designed in the customer files conform to the factory’s process: the spacing between the lines, the spacing between the lines and the pads, the spacing between the pads and the pads. The above various spacings should be greater than the minimum spacing that can be achieved by our production process.
2. Check the width of the wire, the width of the wire should be greater than the minimum that can be achieved by the factory’s production process
Line width.
3. Check the size of the via hole to ensure the smallest diameter of the factory’s production process.
4. Check the size of the pad and its internal aperture to ensure that the edge of the pad after drilling has a certain width.
(3) Determine the process requirements
Various process parameters are determined according to user requirements.
Process requirements:
1. Different requirements of the subsequent process, determine whether the light painting negative (commonly known as film) is mirrored. The principle of negative film mirroring: the drug film surface (that is, the latex surface) is attached to the drug film surface to reduce errors. The determinant of the mirror image of the film: the craft. If it is a screen printing process or a dry film process, the copper surface of the substrate on the film side of the film shall prevail. If it is exposed with a diazo film, since the diazo film is a mirror image when copied, the mirror image should be the film surface of the negative film without the copper surface of the substrate. If the light-painting is a unit film, instead of imposition on the light-painting film, you need to add another mirror image.
2. Determine the parameters for solder mask expansion.
Determination principle:
① Do not expose the wire next to the pad.
②Small can not cover the pad.
Due to errors in operation, the solder mask may have deviations on the circuit. If the solder mask is too small, the result of the deviation may cover the edge of the pad. Therefore, the solder mask should be larger. But if the solder mask is enlarged too much, the wires next to it may be exposed due to the influence of deviation.
From the above requirements, it can be seen that the determinants of solder mask expansion are:
①The deviation value of the solder mask process position of our factory, the deviation value of the solder mask pattern.
Due to the different deviations caused by various processes, the solder mask enlargement value corresponding to various processes is also
different. The enlargement value of the solder mask with large deviation should be selected larger.
②The board wire density is large, the distance between the pad and the wire is small, and the solder mask expansion value should be smaller;
The sub-wire density is small, and the solder mask expansion value can be selected larger.
3. According to whether there is a printed plug (commonly known as golden finger) on the board to determine whether to add a process line.
4. Determine whether to add a conductive frame for electroplating according to the requirements of the electroplating process.
5. Determine whether to add a conductive process line according to the requirements of the hot air leveling (commonly known as tin spraying) process.
6. Determine whether to add the center hole of the pad according to the drilling process.
7. Determine whether to add process positioning holes according to the subsequent process.
8. Determine whether to add an outline angle according to the board shape.
9. When the user’s high-precision board requires high line width accuracy, it is necessary to determine whether to perform line width correction according to the factory’s production level to adjust the influence of side erosion.