At 06:36 AM 3/13/2002 -0500, [EMAIL PROTECTED] wrote: >Ah, but the radius of curvature at the "corners" is much smaller, leading to >a stress point for peel to start, which is what started this discussion. >Protel's version of rounded pads are actually better in that respect.
For a pad with x > y, the radius of curvature of the ends is y/2. For a rounded rectangle as Tango defined it, the radius of curvature is y/4. This is not enough difference, I suspect, to cause a significant increase in peelability. A square pad has a radius of curvature of the process resolution. Say 1 mil. That -- for normal sized pads -- is a big difference. Regardless, this is a design decision the outcome of which may vary from designer to designer even with the same design situation, and there are many situations. The software should not force the designer's choice. Protel should really support complex and off-center pad shapes directly. But short of that, allowing true hexagons (unambiguous in the gerber), rounded rectangles, and ellipses (maybe), would be a small step in the right direction. Likewise allowing square draws in the gerber would allow drawing true squares. But that is another topic. 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] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
