1.Temperature and humidity control failure
2.Exposure temperature rise too high
1.Under normal circumstances, temperature control at 22 ± 2 ℃, humidity at 55% ± 5% RH.
2.The use of cold light source or cooling device exposure and constantly replace the backup film.
Second, the film deformation correction process
Change the hole method
In mastering the operation of the digital programming instrument technology, the first film and drilling test plate mounted control, measured the length and width of the two deformations, in the digital programming instrument in accordance with the deformation amount of the size of the hole to extend or shorten the use of Long holes or holes to shorten the drilling test board to meet the deformation of the film, eliminating the cumbersome splicing film work to ensure the integrity and accuracy of graphics. Call this method "change hole method".
Hang hanging law
Aiming at the physical phenomenon that the film changes with the change of the temperature and the humidity of the environment, the negative film in the sealed bag should be taken out before the copying of the negative film, hanging for 4-8 hours under the working environment, so that the negative film is deformed before being copied, After the copy of the deformation of the film is very small, saying that this Act "hanging hanging law."
For the line is simple, line width and spacing larger, irregular deformation of the graphics, the film can be deformed part of the cut open control hole test plate hole re-splicing and then go to copy, called the "splicing method."
Pad overlap method
Adopt the hole in the test board to amplify into a pad to re-deform the circuit board to ensure minimum ring width technical requirements, calling this method "pad overlap method."
The deformation of the negative on the graphics enlarged scale, re-mapping plate, saying that this method is "mapping method."
Use the camera to zoom in or out of the graphic, saying that this method is "camera method."
Third, the relevant method Notes
For: the line is not too dense, the deformation of the film negative film; film and multi-layer resistance of the formation of film deformation is particularly applicable.
Not applicable: Films with high wire density, line width and spacing of less than 0.2 mm.
Note: splicing should be minimal injury wire, not to hurt the pad. Stitching a copy of the revised version, we should pay attention to the correctness of the connection.
Change the hole method:
Applicable: All layers of film deformation consistent. Line-intensive film also applies this method;
Not applicable: Film deformation is not uniform, the local deformation is particularly serious.
Note: After using the programming instrument to extend or shorten the hole, the hole should be set on the ultra-poor.
Application: The film has not been deformed and prevent deformation after copying.
Not applicable: Deformed film.
Note: In the ventilation and darkness (with security can) hanging hanging film, avoid and pollution. Make sure the temperature and humidity of the hanging place and work place are the same.
Pad overlap method:
Applicable: Graphic lines are not too dense, line width and spacing greater than 0.30mm.
Not applicable: In particular, users have strict requirements on the appearance of printed circuit boards.
Note: Due to overlapping copies, the pad is oval. After overlapping copies, the halo and distortion on the edge of the line, disk.
Applicable: the deformation of the length and width of the film the same proportion of the inconvenience to re-drill test plate, only for silver film.
Not applicable: The length and width of the film deformation is inconsistent.
Matters needing attention: Photographic focus should be accurate, to prevent line deformation. More negative film, under normal circumstances, the need to have many times after debugging to obtain satisfactory circuit graphics.
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