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
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
P
N'imprimer
que si nécessaire - Print only if you must
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