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Silkscreen Over Vias?
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Silkscreen Over Vias?

by DJDevon3 on Wed Aug 14, 2019 5:47 pm

Is it ok to have silkscreen printed on through hole layer vias? I'm not dumb enough to silkscreen on solder pasted areas for SMD or SMT components. Just wondering about those tiny through hole vias. Obviously it would be best not to but sometimes I run into situations where I can't avoid it. Just wondering about the implications if any.
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Re: Silkscreen Over Vias?

by westfw on Wed Aug 14, 2019 7:20 pm

Most board houses seem to "mask" the silkscreen layer with the soldermask layer, so nothing will get printed on any "exposed copper" - you don't have any choice.

To intentionally get silkscreen over vias, you have modify the board format so that the vias are also covered with soldermask.

EAGLE has a feature where you can tell it to "tent" all vias below a certain size, which means that they'll get covered, and then the silkscreen (if any) as well.
You can see this in action on something like the Adafruit Playground Express board, where they have the "This board belongs to" section of silkscreen for people to write on:
There are a lot of vias under that!

I'm not sure how to do this in the CAD package you're using...

(Note that if your tented vias are small, they will likely fill with the soldermask compound, and it will look pretty good. If your vias are larger, they may still end up hole-like, and it won't be as nice.
And of course, you shouldn't do this if you want the vias to get filled with solder for thermal or electrical conductivity reasons.)

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Re: Silkscreen Over Vias?

by adafruit_support_mike on Thu Aug 15, 2019 12:28 am

Most board houses can do tented vias (vias with soldermask over them), but it's usually an extra step that will increase the cost of production a bit.

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