Alfonso,
A PCB file is likely to have part numbers and component values - this makes
the reverse engineering a little easier. It may also contain descriptive
net labels that may aid understanding of the designers intent.
If all such IP is stripped from a PCB file I really don't see a great deal
of difference between a PCB and a full gerber/drill manufacturing pack (in
terms of either IP or ease of a PCB maker making modifications). So given
the removal of as much IP as possible I would agree with you.
Also, thinking about the original issue. Gerber can be misinterpreted
(metric/imperial, 2.4, 2.3, 2.5), NC data may be in different format to the
gerbers, apertures may be rendered differently by the manufacturers
aperture generation - so there is lots that can go wrong (but usually it
would be obvious). If you are *really* confident that the PCB maker has
the same version of program, providing the data in a native format where
all the data is fully contained and all units are defined in the file
*could* be argued as being more reliable but a little more IP is
released). The biggest problem comes in when they *don't* have the same
version and you precious solid polygon just doesn't show up in their system
(or whatever). But this problem is so big in my mind that I prefer the
risk of specifying incorrect units where the problem should be obvious to
the potentially very silent problems of sending out native files.
Ian
On 12:31 PM 6/09/2005 +1000, Alfonso Baz said:
I am a little confused and concerned.
If you send just the PCB file how is your IP in danger.
Unless you send the PCB file with a name like
"DirtToGoldConverterModule.pcb"
How would they know what the board does, let alone undergo the massive task
of reverse engineering the PCB to come up with a schematic, and if you have
programmable parts...
Alfonso
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> On Behalf Of Ian Wilson
> Sent: Tuesday, 6 September 2005 8:43 AM
> To: Protel EDA Discussion List
> Subject: RE: [PEDA] Protel2004 into 99SE
>
> Brad is right. In Oz and NZ and possibly some other places there are many
> PCB makers that are happy to receive PCB files. Some of them take it in a
> number of formats (not just Protel, but this is the dominant one).
>
> In some cases the PCB makers prefer it in the native format as they can
> then optimise for their process, thought patterns and phase of moon.
>
> I am always nervous about doing it and usually send gerbers. I have
> heard,
> though, that many gerbers that PCB makers receive are pretty poorly
> generated and this step is a source of confusion and bad boards for those
> new to this game. So the PCB makers here feel they can give better boards
> to their clients by accepting PCB files.
>
> Users then have to trust that the PCB maker doesn't make changes that
> affect the working of the design (which they can do with gerber anyway)
> and
> that they are comfortable with releasing all that IP. (This is one of the
> reasons I wrote my little IP stripping script.).
>
> Seems like reasonable service to me - offer something extra to the client
> so they don't have to do a step that many find fraught with problems. In
> my
> case though I don't like releasing all that IP and I am pretty comfortable
> with releasing and checking gerbers so I almost always go this path - the
> last time I released a native PCB file would have been years ago -
> certainly when P99SE was pervasive.
>
> With the newer file formats, with their non-backwards compatible features,
> it is a risk I certainly no longer take. I would hate to try to manage
> the
> risk of a critical entity being dropped.
>
> I have been on a bit of a one man crusade to try to get the PCB makers
> here
> to support some more intelligent formats like ODB++ for some time now.
>
> The difference between a native file fully supported by a PCB maker and an
> intelligent interchange format (ODB++) or even a full set of gerbers,
> netlist and drill file is pretty small really in terms of their ability to
> be messed up by a poor PCB maker. Or their IP content for that matter.
> (Reduced releases like just gerber and drill do provide some masking but
> hands up those that have *not* reverse engineered a design from
> gerber/actual PCB?)
>
> I think the issue of PCB file being more dangerous in terms of being
> hacked/edited by the PCB maker is a little wide of the mark. Most CAM
> systems these days effectively reconstruct the full board and changes can
> just as easily be done within them (make traces smaller, move this, add
> copper balancing ...). The bigger issue for me is controlling the release
> of the IP - which will become an increasing issue with things like ODB++
> where descriptive net names can add quite a bit of intelligence to a
> manufacturing pack. I will be continuing to update my IP removal script
> (not for P99SE though I am afraid) to try to balance the manufacturing
> pack
> intelligence at different points of release with the benefits in providing
> smarter export files (a PCB maker can use a netlist for electrical check
> but the net names can be NET1, NET2, .....). A contract board assembler
> doesn't need the netlist but does require (effectively) the parts list
> (possibly somewhat masked if you provide the kit) but they have so much IP
> at this point that you will have to be operating on a trust basis anyway -
> so the release of a native file at this point of the process is something
> of a moot point IMO.
>
> Certainly if you are chasing cheapest PCB pricing by regularly changing
> PCB
> makers, then some industry standard manufacturing pack is the only way to
> go practically.
>
> Ian
>
> On 06:09 AM 6/09/2005, Brad Velander said:
> >Terry (?),
> > From what we have heard over the years, this is an Oz
> phenomenon.
> >
> > Seems in Oz most of the fabricators have Protel in-house and can
> > tweak things themselves. Maybe historically they have had too many
> > designers that were screwing up the Gerber/Drill fab output so the
> > fabricators started doing it themselves. Or was it actual
> > design/fabrication issues that they needed to tweak, who knows?
> >
> > Recently, this seems to be becoming more of an issue. Since by
> > the number of posts there seems to be one or more of these fabricators
> > that are not upgrading their software to DXP. Thus the slow but steady
> > flow of questions about converting back to P99Se for their fabricators.
> > Hope the designers aren't using any of the new features that don't
> > transfer back to 99SE. That could be a disaster.
> >
> > I am with you though Tony, all other issues considered, once you
> > turn over the database you have no control over what you are actually
> > getting. The board may be great one time from one fabricator, turn it
> > over to another fabricator and get a different flavour altogether.
> >
> >Sincerely,
> >Brad Velander
> >Senior PCB Designer
> >Northern Airborne Technology
> >#14 - 1925 Kirschner Road,
> >Kelowna, BC, V1Y 4N7.
> >tel (250) 763-2329 ext. 225
> >fax (250) 762-3374
> >
> >
> >
> >-----Original Message-----
> >From: TDK [mailto:[EMAIL PROTECTED]
> >Sent: Monday, September 05, 2005 7:16 AM
> >To: [EMAIL PROTECTED]; 'Protel EDA Discussion List'
> >Subject: RE: [PEDA] Protel2004 into 99SE
> >
> >
> >You are right. They don't need the native data base.
> >
> >Regards
> >TDK
> >
> >
> >-----Original Message-----
> >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> On
> >Behalf Of Tony Karavidas
> >Sent: Monday, September 05, 2005 1:05 AM
> >To: 'Protel EDA Discussion List'
> >Subject: RE: [PEDA] Protel2004 into 99SE
> >
> >What is with people using fabricators who require the native database?
> Why
> >do they need anything besides the gerber files and a drill file?? I've
> asked
> >this question before, but I don't recall anyone giving a reasonable
> >explanation. I would never use a fabricator who requires my Altium files.
> I
> >actually don't even give my assembly house access to the programmable
> >devices. If I did, I would probably be selling more stuff in China and
> not
> >even getting any money for it.
> >
> >Tony
> >
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