At 09:25 14.03.02 +0000, you wrote: >Quoting Brad Velander <[EMAIL PROTECTED]>: > > > Kiernan, > > Ian's explanation below is correct. What you're seeing are drawn > > pads rather then flashed rectangular pads. A major shortcoming of Protel > > if > > you are doing very fine or finicky work. As for your soldermask > > encroachment, that will not be an issue because the soldermask pad will > > be > > drawn similarly and won't encroach. > >Thanks guys. We're using FPC connectors with an 0.3mm pitch. I've got the >pads >designed so that there's virtually no visible land after soldering, so I will >get soldermask encroachment under the pad even though the soldermask lines up >with the copper because the pad that I'm getting out of the gerber is smaller >than the one on the screen (ie smaller than the pin). At the very least, I'll >get severe solderballing. > >I've put a sample of the gerber output for a couple of pads below and I >wonder >whether anyone knows enough about gerber to see if there's a quick fix that >will produce the correct result. One of the pads is supposed to be a >rectangle >and the other actually uses the octagonal option. > >Are there any other Non-WYSIWYG features that I should know about before I >spend too many hours on this?? I thought gerber output was the gold standard >for PCB packages.
Yes, if you use soft-arcs. They are made from small track segments. If you have a polygon arround a round pad, the clearence from the poly to the pad is slightly smaller as expected. The smaller the pad (radius) the larger the error. Workaround: Use arcs in the gerbers. Edi >Cheers > > >Kiernan Fitzpatrick > > >%ADD10C,0.0600*% >%ADD11C,0.0150*% >D10* >X102723Y83933D02* >X102879Y83353D01* >D11* >X101100Y83387D02* >X101268Y84015D01* >X101702Y83899D01* >X101534Y83271D01* >X101100Y83387D01* >X101253Y83476D02* >X101356Y83862D01* >X101549Y83810D01* >X101446Y83424D01* >X101253Y83476D01* > > > >------------------------------------------------- >Join IrishCircle - IrishAbroad's premium service >http://www.irishabroad.com/circle/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + IH electronic + Phone: ++41 52 320 90 00 + + Edi Im Hof + Fax: ++41 52 320 90 04 + + Doernlerstrasse 1, Sulz + URL: http://www.ihe.ch + + CH-8544 Rickenbach-Attikon + E-Mail: [EMAIL PROTECTED] + + Switzerland + + ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
