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khsaleh@gmail.com , 03-21-2022, 04:04 PM

Hi @@phils-lab, In lesson 13 of Mixed-Signal Hardware Design with KiCad, ground vias are throuhole, which option do you use for Annular rings, (All copper layers ... etc)

phils-lab , 03-28-2022, 03:46 AM

Hi there,

If you're talking about stitching vias (+ 'ground return' vias), I'll usually go with something that's easily manufacturable. For example, 0.7mm pad with 0.3mm drill.

If you have space constraints then of course something smaller, such as 0.6mm pad with 0.2mm drill.

Phil

khsaleh@gmail.com , 03-28-2022, 04:35 AM

Hi @@phils-lab, I apologize for not making the question clear. The ground connected to the decoupling capacitors on the front layer: which layers do the vias start and end, do you start on the front and end at innerlayer1 or do you use throuhole? If the latter, which annular ring param you use? Same goes for the stitching groung vias.

Ant1882 , 04-04-2022, 06:49 AM

I'm pretty sure all the VIAS are through hole, as JLCPCB (used in this instance) won't do internal / blind VIAs, it's just that on each layer of the PCB you specify the connection to the VIA, for instance if you place a VIA and go directly to the back copper, only the top and bottom layers will be connected by the VIA.

When placing a GND VIA, because you have already specified L2, L3 as GND planes this will make a through hole VIA with a connection between only these two planes (which are separated by the core).

Hope that makes sense, that's how I understood it anyway... anyone can feel free to correct me if need be, I'm still learning myself :-)

Phil mentioned the following sizes for VIAS, personally if I have lots of space, when adding the stitching VIAs for example I would just go with the larger size (easier for manufacturing- the smaller the drill size the more often they break).

• Small - 0.45mm pad, 0.25mm drill
• Medium - 0.7mm pad, 0.3mm drill
• Large - 0.8mm pad, 0.4mm drill

Anthony