PCBStandards PadStacks

[Denisl]

I understand and agree with the reasoning behind including Solder/Paste Masks data in the pad stacks for a pattern. I have encountered what appears to be a bug... and wondered how others have overcome this.

Regarding a card-edge pattern or a part with pads on both sides w/o a hole. Part is mounted on layer TOP. Pads are defined for "mounted side" and "opposite side" Also, pads are defined for SolderMask-TOP and Soldermask-BOT. When I set my CAM document for the Bottom mask I select PADS from the SM layer and not the bottom layer... however, for these particular components the mask opening does not appear (in preview) on the bottom layer even though a pad is defined. They show as expected on the TOP (mounted) side.

The only way I have been able to get the bottom soldermask openings to appear in preview is to select PADS from layer BOTTOM.

Seems like a bug to me... your thoughts?

[randychase]

Sounds like a bug.

Denis, what part are you using?

[Denisl]

The part in question is not from the PCBStandards Library. It is one that we use for Gigabit GBIC's. The similarity is in the padstack structure and the intended use of seperate pads for the soldermask. It is in essence, a card-edge connector.

I reported this to Mentor and just learned that it is, in fact, a bug. So far there are only two reports of this defect. I would encourage others to test this and report it to Mentor as well.

[randychase]

Got it. I didn't think it was our part.

Interesting bug. Good to know about it also.