thermal vias

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cchamilt
Posts: 10
Joined: 23 Feb 2014, 23:35

thermal vias

#1 Post by cchamilt » 11 Aug 2014, 21:17

Hi, OSHPark says they support tenting on thermal vias. So how would I go about tenting with solder mask over the vias in a thermal pad? Since vias are not supported as part of the pattern, I add static vias in the pad and connect them to the pad. This results in the bottom layer tented, but leaves the pad surface open. Is there anyway I can specify a circle of mask over the center of the via?

Thanks!

-- 11 Aug 2014, 20:06 --

Oh and just another note. I tried making overlaying through hole pads on the thermal pad to create vias. It complains about them having the same number, but is is similar to static vias. It seems all mask options are mask additive, there is no way to subtract the through-hole pin mask.

Tony Philipsson
Posts: 32
Joined: 11 Jul 2011, 19:27

Re: thermal vias

#2 Post by Tony Philipsson » 27 Jun 2015, 23:21

Tenting the bottom is not recommended as gas-out can happen, though not tenting bottom and it can create a wicking effect.
Tenting the top layer of the via is hard, as even if you disable soldermask for the via, the soldermask for the pad itself will override it.

So somehow the custom made pad with open circles where the via's goes needs to be made, but how?

Techno Tronix
Posts: 188
Joined: 10 Jan 2015, 02:00
Location: Anaheim, CA 92806
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Re: thermal vias

#3 Post by Techno Tronix » 30 Oct 2015, 07:40

Solder going though the holes and causing voids (not shorts) is said to not be a problem if the via hole diameter is kept to 0.3mm or less. Spacing of 1mm is suggested, and of course the vias should not have thermal reliefs.

roseibarry
Posts: 10
Joined: 08 Oct 2015, 08:06
Location: San Diego, CA

Re: thermal vias

#4 Post by roseibarry » 30 Oct 2015, 07:56

Open copper pour properties, go to connectivity tab and verify thermal settings.

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