Some special problems in the process of PCB light painting process
1) Gerber file to generate the center hole of the pad: When processing the Gerber file to generate the center hole in the ordinary method, there are two dangers: 1. When the D code does not match, there should be no hole in the hole, causing the hole to be lost . 2. Some flashes that shouldn't have holes have a center hole and cause disconnection. These problems are determined by the characteristics of Gerber data. Unless the D code that the light plotter can hold is unlimited, it is impossible to achieve a complete D code match. As long as the D code does not match, there is the first danger. When some CAD software generates Gerber files, Flash is added to both ends of a certain line, so the second danger is inevitable. Because of these two factors, to accurately generate the center hole, the center hole must be generated according to the drilling file, and the circular center hole is formed with the drilling file, so as to erase the circuit graphics, and then the completely correct graphics can be generated (2 ) AutoCAD designed PCB files are converted to Gerber files. AutoCAD is a general-purpose CAD software, not a professional PCB-CAD software, so it cannot generate Gerber files. To solve the special requirements of a few users, some CAM software provides a bridge for transition. The file can be converted into a plotter file in AutoCAD, and the plotter file is a standard format, which can be accepted by many software. 1. Convert AutoCAD files to Gerber files through View2001. View2001 is just such a software, it can accept HPGL file format. As a result, the following ways to convert AutoCAD files into Gerber files are produced: (1) Output the files in AutoCAD to generate HPGL files; (2) Read in HPGL files in View2001; (3) Modify the D code in View2001 to make the graphics Achieve satisfactory results; (4) Save the file as Gerber format in View2001 and generate the D code table. 2. Convert AutoCAD files to Protel files through PCBTools: (1) In AutoCAD, output the files to generate HPGL files. (2) Use PCBTOOLS to convert HPGL files into Protel PCB files. 3. Convert AutoCAD files to Gerber files through CAM350. (1) Export the file as DXF format in AutoCAD; (2) Read in DXF file in CAM350; (3) Modify related parameters in CAM350; (4) Export the file in CAM350 as Gerber format and D code table .