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Questions relating to designing PCBs
By RonnyM
#31348
Is there a way in Eagle, to create a via without the stop layer opening? It would make it easier to solder down modules with exposed pads that may be grounded without insulating.
Thanks,
Ron
By bkgoodman
#31619
I don't know if you can - but I wouldn't

You're never going to get it totally covered, because the soldermask will fall through the hole in the via.

If you really want this done, tell your board house that you want the via's "plugged and tented".

What you could also do, is create a "special" via size - for example - if your using all 16mil vias, use 17mil vias for ones you want plugged and tented, and then put a note (and tell your board house) stating that you want the 17's plugged and tented, (and they can actually be drilled as 16's).

-BKG
By busonerd
#31622
If you just want it so its less likely to short - theres a minimum mask size opening setting in the drc options of eagle - set that just above your via size - and they'll all have soldermask covering the exposed ring of the via.

Cheers,

--David Carne
User avatar
By bigglez
#31634
bkgoodman wrote:I don't know if you can - but I wouldn't
Greetings BKG,

New to this forum? The board house that SFE uses (via BatchPCB) is a special hobby level service for low cost, low options, and long delivery. (Which is great for my hobby needs!).
bkgoodman wrote:You're never going to get it totally covered, because the soldermask will fall through the hole in the via.
The OP wants to expose the vias, not cover them.
RonnyM wrote:Is there a way in Eagle, to create a via without the stop layer opening? It would make it easier to solder down modules with exposed pads that may be grounded without insulating.
I haven't done this (yet) but any custom designed EAGLE library part could be made non-insulating by removing the stop layers. My concern is that the solder mask and silk screen have a finite thickness, and soldering modules to the top (or bottom) layer foil would require solder to fill this void. Probably not an issue if the area is open to one edge of the device (or module). TO-262 devices can be soldered this way.

Another issue would be how much heat is required to bring the entire contact area up to temp for good soldering? I've reported earlier about my hot-air PCB assembly, where large parts (SMT inductors and SMT electrolytics) are best soldered by hand (and not by a hot air gun).

Comments Welcome!
By busonerd
#31664
The Stop layer is negative - aka, the presence of an area indicates that there is an opening in the solder stop.

Removing the stop areas will give you an insulating area over the pad.
Cheers,

--David Carne
User avatar
By phalanx
#31666
Simply draw a polygon around the via in the t_stop layer. There will be no soldermask where that polygon resides. You will have to do it on the bottom side as well. I think that layer is b_stop.

-Bill
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