Leonard I had a case a few months ago that seems might be related to this unit conversion problem. I had created a donut shaped fine pitch shield made up of concentric 4mil arcs, each 8 mil radius larger than the previous arc. The two sides of the PCB had traces lined up with the spaces on the opposite side. Each side had about 80 concentric arcs. About 30 arcs into the structure an error occurred. An arc was skewed. It crossed other arcs. The matter was not noticed until the board house examined the files with an independent gerber viewer. Protel 99SE and Camastic both showed this arc in the proper position while Gcprevue showed it crossing other arcs. To fix it I drew the arcs in metric units and the arcs appeared properly in both Camtastic and GCPrevue. It would seem that Protel 9SE and Camtastic must share some unit conversion code that has a bug. Dave Eloranta [EMAIL PROTECTED]
-----Original Message----- From: Leonard Fischer [mailto:[EMAIL PROTECTED]] Sent: Monday, December 17, 2001 5:13 PM To: 'Protel EDA Forum' Subject: Re: [PEDA] bug plotting rotated fill Wow. That is interesting and kind of amazing that it is workable. And the first paragraph where you just said it was a board with submicron precision really threw me for a loop. Question/Suggestion/Possibility: It seems to me that part of the issue here is that Protel and Camtastic are both designed for larger physical boards. Ideally of course Altium would fix the precision issues. If they don't, or don't quickly enough to do what you need, could you work at some multiplication/magnification of the final scale, say 10x, then just "photographically" reduce the Gerbers? I'm assuming there is some way to do that (Camtastic?), not that I know how. This could help with the precision issue in Protel and the magnification in Camtastic. Just like working with 4x decals and tape! I'm also assuming that the ceramic module is relatively small compared to a PC Board - I'd be interested in hearing more about the ceramic module, like how big it is and what kind of components you put on it, if that's not proprietary. Len Fischer Trax Softworks -----Original Message----- From: Abd ul-Rahman Lomax [mailto:[EMAIL PROTECTED]] Sent: Monday, December 17, 2001 11:10 AM To: Protel EDA Forum Subject: [PEDA] bug plotting rotated fill I'm working on a board which requires high precision, in the submicron range. Theoretically, Protel supports photoplotting with four-place decimal metric, i.e., one-tenth micron resolution; however, I ran into some problems with PCB and with CAMtastic. Rotated fills, which are not flashed but which are drawn, were seen to have some stray draws. I've sent files to [EMAIL PROTECTED], but for our bug list, I am also reporting the matter here. That rotated fills (and pads, I expect) are drawn instead of being flashed is a bit distressing; this board already generates a lot of data and drawing those fills will make the gerber files huge. Rectangles (and other shapes) can be created with RS-274X Aperture Macros, which include a rotation parameter. They would then also be importable as single primitives (with appropriately modified gerber import routines.) Fortunately the fills only occur on one layer which will not be fabricated with the "PCB" (it is a multilayer co-fired ceramic module) but will be added later as a separate metalization on the top of the module. Then, looking at the files in CAMtastic, the aperture tables did not properly import, there were errors in aperture creation on the order of 1.5 microns. This is a bit hard to fathom; a metric 150 micron draw embedded in RS-274X should become, one would think, a 150 micron aperture in the CAMtastic aperture table, but it doesn't, instead it is 149.9 microns. (Some other apertures had higher deviations.) I'd guess that metric apertures are being translated to inches on creation, then displayed back as metric. But the aperture tables were editable to the correct values, so it is not that the database does not support sufficient precisions. However, the maximum zoom level in CAMtastic does not provide as high a magnification as does PCB, it was barely adequate, if cramped, for working in the micron range. PCB provides plenty of magnification before it refuses to zoom in further, it looks to me like roughly 0.1 micron per pixel. [EMAIL PROTECTED] Abdulrahman Lomax Easthampton, Massachusetts USA * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
