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Reply To: | TechNet E-Mail Forum. |
Date: | Fri, 18 Jan 2002 11:11:00 EST |
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Hi Charlie,
The optimuization needs to be done from a systems point-of-view, not just a
pcb manufacture point-of-view. Just because some internal pads are
electricelly non-functional does not make them non-functional in other
respects.
Hi Peter,
You are right on the money.
Hi MoonCaveMan,
You are too categorical.
IMHO:
1. 'Non-functional' lands can make pcb manufacture slightly more
difficult--depending on complexity and process controls;
2. 'Non-functional' lands do provide a 'wall achor' [as Peter terms them]
reducing the possibility of hole wall separation and innerlayer separation
after solder temperature excursions;
3. 'Non-functional' lands for many less complex PCBs make no measurable
reliability impact; for thicker MLBs with larger diameter holes they do.
Back to skiing,
Werner Engelmaier
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