Why don't you use a layer specific keep-out track? Place a skinny track 1 mil or so between the pads and when you pour the polygon, it will avoid the area between the two SMD pads.
Tony > -----Original Message----- > From: Jenkins, Charlie [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, November 21, 2001 10:35 AM > To: 'Protel Users Mailing List' > Subject: [PEDA] How to use objects as keepouts? > > > I noticed at some point that a keepout check box was added to the fill > properties. I have long wanted to place a top or bottom only keepout in > between certain surface mount pads such that copper pours were prevented > from filling in between pads that had a layer specific keepout. > > Unfortunately to make the keepout layer-specific the fill that will be > turned into a keepout must be on a single side layer, like Toplayer or > Topoverlay. Unfortunately the fill must be associated with a conductive > layer to prevent polygons on that layer from over-running the > fill-made-keepout. This now leaves a chunk of copper in between > the pads in > place of the pour. Better but not what is needed. > > I thought of using very thin traces in the form of a rectangle with no net > to block the migration of the pour. Of course there would have to be a set > of rules written to keep the DRC happy. > > Ideally we could make an all-sides keepout fill be layer specific by > selecting the desired layer in a "Constrain Keepout to a Specific Layer" > pull down but that does not exist yet. > > Does anyone have any better ideas how to keep pours on a given layer from > passing through certain pads. The solution should be able to be > saved with > the footprint and should not involve using larger clearance rules. > > The reason for this requirement is to keep the copper from between surface > mount pads when using circuit board routers to prototype SMT boards. Since > solder masking is typically not used with this type of prototype, copper > under components like caps and resistors can lead to shorts from paste > reflow. The selective keepout would prevent the polygon from > getting under > some of these small components. > > Charlie Jenkins, Pioneer * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
