hobbss
Member level 2
My board house is complaining that I do not have enough clearance on a few holes on internal [plane] layers. This is an issue because although the holes are supposed to be non-plated, the board house claims to not be able to guarantee that (quick-turn house that does all drilling at the beginning and uses resist on the non-plated holes). Besides, with a power and a ground plane, for a board mounting hole with metal hardware, if the clearance isn't sufficient, the hardware would short out the board...
I have a four layer board, with power and ground as two internal planes, defined by dynamic shapes. Because the holes in question are non-plated holes, it seems like OrCAD is not using the anti-pad specified in the padstack for the hole. It is instead using some number in the constraint editor for shape to through hole pin (I think). However, whenever I attempt to edit the constraint manager values, all holes get flooded in the shape, no matter what value I put in the constraint field. I have also tried making the holes plated (less desirable) with large antipads, but the clearance around the hole doesn't change on the internal plane layers. I suspect this has something to do with the fact that the hole is not tied to a net, so the software doesn't recognize it as needing an antipad in the plane layer.
Question number 1: is there a better way to do this, not involving the constraint manager? One of these holes is for a plastic pin in a molex connector; it would be nice if this clearance "property" were associated either with the pad or the part, so that the designer wouldn't need to edit the constraint editor in the project every time they use this part on a multilayer board with planes. The other is for a board mounting hole.
Question 2: if I need to use the constraint editor, is there a way to specify a minimum clearance ONLY around particular holes/pins? I don't want a 150 mil clearance around ALL holes in the board, just the mounting holes.
I have a four layer board, with power and ground as two internal planes, defined by dynamic shapes. Because the holes in question are non-plated holes, it seems like OrCAD is not using the anti-pad specified in the padstack for the hole. It is instead using some number in the constraint editor for shape to through hole pin (I think). However, whenever I attempt to edit the constraint manager values, all holes get flooded in the shape, no matter what value I put in the constraint field. I have also tried making the holes plated (less desirable) with large antipads, but the clearance around the hole doesn't change on the internal plane layers. I suspect this has something to do with the fact that the hole is not tied to a net, so the software doesn't recognize it as needing an antipad in the plane layer.
Question number 1: is there a better way to do this, not involving the constraint manager? One of these holes is for a plastic pin in a molex connector; it would be nice if this clearance "property" were associated either with the pad or the part, so that the designer wouldn't need to edit the constraint editor in the project every time they use this part on a multilayer board with planes. The other is for a board mounting hole.
Question 2: if I need to use the constraint editor, is there a way to specify a minimum clearance ONLY around particular holes/pins? I don't want a 150 mil clearance around ALL holes in the board, just the mounting holes.
