Precautions for correcting FPC film deformation related methods
1, the splicing method:
Applicable: the film with less dense lines and inconsistent deformation of the film layers; it is especially suitable for the deformation of the solder mask and multilayer power supply ground film;
Not applicable: negative film with high wire density, line width and spacing less than 0.2mm;
Note: When cutting, try to minimize the damage to the wire and not damage the pad. When splicing and copying, you should pay attention to the correctness of the connection relationship.
2，Change the hole position method:
Applicable: The deformation of each layer is consistent. Line-intensive negatives are also suitable for this method;
Not applicable: The film is not uniformly deformed, and the local deformation is particularly serious.
Note: After using the programmer to lengthen or shorten the hole position, the hole position of the tolerance should be reset.
3, hanging method:
Applicable; a film that has not been deformed and prevented from being deformed after copying;
Not applicable: Deformed negatives.
Note: Dry the film in a ventilated and dark (safe and okay) environment to avoid contamination. Make sure that the air temperature is the same as the temperature and humidity at the work place.
4, the pad overlap method:
Applicable: The graphics lines are not dense, and the line width and spacing are greater than 0.30mm;
Not applicable: In particular, the user has strict requirements on the appearance of the printed circuit board;
Note: The pad is elliptical due to overlapping copies. After overlapping copies, the halo and deformation of the lines and disc edges.
5, photo method:
Applicable: The deformation ratio of the film in the length and width directions is the same. When it is inconvenient to re-drill the test plate, only the silver salt film is applicable.
Not applicable: The film has different length and width deformation.
Note: Focus should be accurate when shooting, to prevent line distortion. The loss of the negative film is large. Under normal circumstances, it is necessary to have multiple adjustments to obtain a satisfactory circuit pattern.