Thanks to all that responded, now things are clear. Globally thinking, most assemblers do not pay for gerber editors and rely on free viewers for reading the files. Quite often we need to measure things in order to figure out editing of paste files (especially when using intrusive soldering), or if the fiducials are not in the CAD file and we need to figure out their position, etc. So, to answer Robert, yes you are right, the fab does not need them, but the assemblers do. And mainly because we need to stuff boards from many various designers, with different design styles and conventions and with many gray spots in documentation. Regards Ioan Tempea, ing. t : 450-967-7100 ext : 244 [log in to unmask] <mailto:[log in to unmask]> www.digico.cc <http://www.digico.cc/> P N'imprimer que si nécessaire - Print only if you must ________________________________ De : DesignerCouncil [mailto:[log in to unmask]] De la part de Robert Pellerin - Paradox Innovation Envoyé : 30 janvier 2009 10:23 À : [log in to unmask] Objet : Re: [DC] Aperture generation in gerber files The FLASH or DRAW selection is controled by the software and we have no real control over that. In the past with few softwares, like PCAD for DOS, it was possible, but now, it seems useless for PCB fabrication to specify on instead of the other. Robert Pellerin, B.A.A., C.I.D. PCB Designer / Paradox Innovation Ltd. ________________________________ De : DesignerCouncil [mailto:[log in to unmask]] De la part de Ioan Tempea Envoyé : 29 janvier 2009 22:42 À : [log in to unmask] Objet : [DC] Aperture generation in gerber files Dear Colleagues, The many gerber files I have seen can be divided into two categories, according to how the geometrical figures (apertures) of the land patterns are generated: o Apertures declared as stand alone geometrical figures (e.g. a rectangular 100x200 pad is declared as a 100x200 rectangle) o Apertures generated by successive positions of a smaller element (e.g. 100x200 rectangle generated by adjoining twenty 100x10 lines) The second version does not come handy at all when trying to measure the center of an aperture with a gerber viewer. Questions: o How is each of them generated? o Are there CAD systems that can only generate the latter? o Any precautions that can be taken by the designer so that only the first one be generated? o If I want to call each method by its technical name, what would that be? Thank you, Ioan Tempea, ing. Ingénieur Principal Fabrication / Sr. Manufacturing Engineer 30 ans déjà! - Already 30 years! 950 rue Bergar, Laval, Québec, H7L 5A1 t : 450-967-7100 ext : 244 Mtl : 514-990-5762 f : 450-967-7444 [log in to unmask] www.digico.cc <http://www.digico.cc/> P N'imprimer que si nécessaire - Print only if you must ------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil To temporarily stop/(start) delivery of DesignerCouncil for vacation breaks send: SET DesignerCouncil NOMAIL/(MAIL) Search previous postings at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext. 2815 ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil To temporarily stop/(start) delivery of DesignerCouncil for vacation breaks send: SET DesignerCouncil NOMAIL/(MAIL) Search previous postings at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext. 2815 ------------------------------------------------------------------------------- --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL) Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ---------------------------------------------------------------------------------