Light Drawing Process In PCB Clone Manufacturing
The general process for the PCB Clone Light Drawing Process is to examine the file-a CAD file to determine the process parameters-a Gerber file for a CAM process and an output.
1. Check the file
(1) check the user's file The user to the file, first of all to conduct the following checks.
① Check the disk file is intact.
② check whether the file with a virus, a virus must first antivirus.
Check the user data format.
④ If it is a Gerber file, check whether there is D code table or D code (RS274-X format).
User-supplied raw data, usually in the following format.
HPGL1 / 2 (HP Graphic Layer);
Dxf & Dwg (Autocad for Windows);
Protel format (DDB \ pcb \ sch \ prj);
Oi5000 (Orbotech output format);
Excellon1 / 2 (drill \ rot);
So to be able to correctly analyze the data format of a data. Especially in Gerber RS274D in the format to get to know, to analyze and understand the right, the standard Aperture, the relationship between them for a detailed analysis. It is very important to read the Apeture file carefully, because sometimes there are some special circumstances, for example, sometimes the user will put an Aperture from circular into rectangular, rectangular from the heat into the plate. If you open the original Gerber file, you will find that its data only D code and coordinates, because the graphics file consists of three parts: coordinates, size, shape, and Gerber file only coordinates, so the other two conditions, if received Apertuer file in the file, then open it, you will find the necessary data, if it can be a good combination, then the user will be able to read the original data.
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(2) check whether the design meets the factory process level
① Check the customer files designed to meet the spacing of the factory process, the line between the spacing between the lines, the distance between the line and the pad, pad and pad spacing, the above spacing should be greater than the Plant production process can achieve the minimum spacing.
② Check the width of the wire, the width of the wire should be greater than the factory production process can achieve the minimum line width.
③ check the size of vias to ensure that the factory production process of the smallest aperture.
④ Check the pad size and its internal aperture to ensure that the edge of the pad after drilling a certain width.
In this case,
2. Determine PCB Clone process parameters
According to user requirements to determine the various process parameters. Process parameters may have the following situations.
(1) according to the requirements of post-process technology to determine whether the mirror-like photographic film
① the principle of negative film In order to reduce the error, film surface (that is, latex surface) must be directly attached to the surface of the plastic film.
② negative mirror image of the decisive factor if it is screen printing process or dry film process, the substrate surface film substrate attached to the copper surface shall prevail. If it is exposed with diazo film, due to diazo film copy of the mirror, so the image should be negative film surface is not attached to the substrate copper surface. If the photomicrography is a cell negative, rather than imposition on a photomask, an additional mirror is required.
(2) to determine the parameters of solder mask expansion
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① determine the principle of increase in solder resist pattern to not reveal the wire next to the solder pad shall prevail; solder mask to reduce the graphics do not cover the principle of the pad. Due to the error in operation, the solder resist pattern may deviate from the line. If the solder mask pattern is too small, the result of the deviation may mask the edge of the pad, thus requiring a larger solder mask pattern; but if the solder mask pattern expands too much, the next wire may be exposed due to the bias.
② solder resist pattern expansion of the determinants of solder resistance of the factory location of the deviation values, solder resist pattern deviation. Due to a variety of processes caused by the deviation is not the same, so corresponding to a variety of processes to increase the value of solder mask graphics are also different. Large deviation of the solder mask to enlarge the value should be selected bigger. Board conductor density, solder pad and the distance between the wire from the small, solder resist pattern should be selected to expand the value of smaller; board wire density is small, widen the value of solder mask optional larger.
(3) According to whether the need for plug gold-plated board (commonly known as Goldfinger) to determine whether to increase the process wire.
(4) According to the plating process requirements to determine whether to increase the plating used conductive frame.
(5) according to the hot air leveling (commonly known as spray tin) process requirements to determine whether to add conductive process line.
(6) According to the drilling process to determine whether to add pad center hole.
(7) According to the sequence process to determine whether to add process positioning holes.
(8) According to the board shape to determine whether to add shape lines.
(9) when the user requires high precision board precision line width, according to the factory PCB Clone production level, to determine whether the line width correction to adjust the impact of side erosion.