PCB Vias 101 - Phil's Lab #77

Basics, guidelines, and best practices for vias in PCB designs. From sizing, to placement, to transfer and stitching vias, and more!
[SUPPORT]
Free trial of Altium Designer: www.altium.com/yt/philslab
PCBA from $0 (Free Setup, Free Stencil): jlcpcb.com/RHS
Patreon: / phils94
Mixed-signal hardware design course: phils-lab-shop.fedevel.education
[GIT]
github.com/pms67
[TIMESTAMPS]
00:00 Introduction
00:44 Altium Designer Free Trial
01:00 Via Basics
01:53 Via Parameters
04:50 Recommended Parameters
05:56 Via Current Handling
07:45 Via Placement
09:42 Voiding
11:16 Transfer Vias
13:07 Stitching Vias #1 (Tying Pours Together)
14:12 Stitching Vias #2 (Shielding)
14:42 Stitching Via Spacing
16:38 Outro

[@imagiro1]

Darn - every time a new video comes out I have to redo all my boards...

[@hagalazmultiverze3411]

There's a reason why, the sub title of our High Speed Digital Design textbook is "Handbook of Black Magic "

[@PhilsLab]

Haha glad to hear the videos are helpful in some way!

[@imagiro1]

@@PhilsLab Hehe... They are, most definitely! Just imagine, I did my last PCB maybe 30 years ago with a sharpie, and nearly causing a chemical spill in my parent's backyard :) You are providing a level of expert details, that is hard to come by for an amateur like me. So yes, I will have to check my little project once more, before ordering prototypes. But who knows, maybe I should better wait for the next video before I do so... ;)

[@10356665]

Same story !!

[@kmacademy6742]

Excellent video as usual. Vias are at the heart of many manufacturability and reliability issues. During a course, our instructor mentioned this story. A company had issues with this military grade PCB having an intermittent issue that only happens in the field but not during lab testing. It turned out that some of their vias weren't sized properly for their intended environment. The via walls would crack due to thermal expansion after being exposed to the sun but as soon as the board cools down, the issue disappears.

[@PhilsLab]

Thank you! Was that per chance a course by Rick Hartley? I think I heard that story from him as well during a seminar.

[@kmacademy6742]

@@PhilsLab No, the course was "Certified Printed Circuits Designer" from PCEA and taught by Mike Creeden. The two are friends so probably one of them heard it from the other.

[@reidt9155]

Your videos are the reason I managed to create my senior capstone project successfully. Thanks so much for what you do!

[@PhilsLab]

Very glad to hear that - thank you, Reid!

[@7alfatech860]

Everything you always wanted to know about vias (but were afraid to ask)! 😁

[@myetis1990]

seriously this guy is gifted. thank you Phil. great content as ever. If you mentioned back-drilling, microvia and etc. a bit then it would be a Bootcamp of vias :)

[@micheleabolaffio7527]

Top notch content! You are able to extract the best recommendations and communicate them very effectively! Keep them coming!

[@PhilsLab]

Thank you very much, Michele!

[@happyhippr]

imo, maybe one of the most valuable electronics channel on youtubKZbin... for continuing education at that intermediate electronics level

[@andershestad284]

All practical information presented very concisely! Fantastic video, I'll probably show it to some friends in my student Org. 🚀

[@PhilsLab]

Thanks a lot, Anders - glad to hear you'll be sharing it with some friends!

[@ZozoleonLego]

Highly informative as always!

[@PhilsLab]

Thank you!

[@DustinWill]

Well Phil, I am an amateur at most everything, but after watching your vids I am reminded I am a baby EE. I always learn something new. Thanks for all you do.

[@PhilsLab]

Thank you very much, Dustin - glad to hear the videos are useful!

[@Coolman6564]

This is "grail" type info... the stuff you've always wanted to ask someone, but never did and never dug down to find the answer to. Thank you for this!

[@PhilsLab]

Thank you for watching!

[@kiprof4350]

Nice Video! Thank you, Phil! 😊

[@miore580]

Amazing content. Thank you!

[@hubercats]

Great video! Thank you.

[@PhilsLab]

Thanks for watching!

[@embeddedduniya7774]

Absolutely brilliant

[@PhilsLab]

Thanks!

[@Bianchi77]

Nice info, thanks for sharing :)

[@byll4831]

thank you Phil.

[@Mr8GBMonkey]

Absolutely brilliant as always Phil. Could you give any recommendations for other sources that continue on this topic and go into some of the further details you mentioned, please?

[@oscarpeters1351]

You can search on youtube for Eric Bogatin or Rick Hartley

[@Graham_Wideman]

You might like Robert Feranec's channel. Also FesZ.

[@ZebbeBa]

Fantastik and so helpfull👍🏻

[@Ghost572]

You're explenation on the stitching via equation is so well done, was the explenation from a book or you just figuring it out over time because most of the time we are given equations without proper explenations to what the components actually do either individually or in smaller groups. I think it would be quite a useful skill to have. I suppose one way I could of figured that out would be to keep an eye on the units when multiplying the different factors together to see if there is anything that stands out to me, since that is the only way I could see my self figuring this stuff out. Real cool video though thanks for sharing your knowlege

[@nightdew4934]

Great video! Would not mind something similar for other basics such as traces, ground planes, etc.

[@PhilsLab]

Thanks! That's a good idea.

[@danieleottorogo2898]

@@PhilsLab +1 on that, it will be amazing

[@tharukanayanajith3510]

Thank you🙏

[@mursalaboobacker3593]

great video thanks ❤❤

[@PhilsLab]

Thanks, Mursal!

[@omkarbansode6305]

thanks man

[@yaseentwati7737]

quick question, i know there isn't a 'standard via size' but since there isn't much current difference between them, what are the downsides of sticking to the smallest viable size ?

[@victorgallegos6590]

Great ideas and tips in all your videos!! Congratulations!! may be you could talk about the interconection between analog/digital ground planes with a net tie, resistor, ferrite...or with only one big plane for all....thanks for your videos!!!! :)

[@PhilsLab]

Thanks, Victor! I do in some of my mixed-signal videos. In general, and for 99% of cases, a solid, single GND is what I use.

[@user-ww2lc1yo9c]

Are you going to make a video on the topic of using vias for high speed signals?

[@andyschnoebelen4279]

Why do you need any annular ring on the top and bottom plane with transfer or stand alone stitching via? Making the hole size equal the pad size would allow the transfer via to be closer to the signal via and save routing space. The plating is in the hole and connects only to the inner ground planes. Is the annular ring required for the plating?

[@peterhall8797]

Do you still want to sufficiently space ground and signal vias to avoid voiding?

[@douggale5962]

Is it okay to put vias under ICs? How much margin do I need to make sure i won't get solder wicking? I am probably being too careful.

[@kadirozdinc6065]

Hi Phils Great content again as always of course :) I have a question about via impedance. To provide controlled impedance, Should we calculate via impedance ?

[@PhilsLab]

Thanks, Kadir. For most systems (unless you're working with several GHz++) it's not important - however, I try to minimise via usage on high-speed lines.

[@nhlakaniphombatha5769]

THANKS ALOT PHIL 👍

[@PhilsLab]

Thanks for watching :)

[@danielbilodeau4701]

Great video, as always. I have a question. Does adding in-pad vias to component such as QFN packages and such add cost to the manufacturing?

[@jakobhalskov]

To my understanding I do not see why this should increase PCB cost, but it can cause "solder wicking", where the via will drag the molten solder from the pad down into the hole and can cause bad joints as not enough solder is left to connect the pin to the pad.

[@zachbrown7272]

only if you choose to fill and plate over them.

[@ruben.w]

Hi Phil, just a quick question about the stitching vias for shielding. You mention "spacing the vias apart by L" and you give this nice drawing where L is the distance between the via centers. Is this correct, or should L be the distance between the outer points of two contiguous vias, since the radius of the vias might have effect?

[@PhilsLab]

Hi Ruben, As shown in the drawing, the distance should be measured from the via centers. The main 'via connection' is along the 'barrel' - not the pads. The pads typically will not extend down or be placed on inner layers (in Altium, the function 'removed unused pads' can be used).

[@bharathk8841]

For High Speed what is the drill and pad size

[@chrisvidal1683]

Does anyone know if Phil has released a video where he shows how to wire a USB C type connector to an STM32? Or if there's a video on YT for that?

[@PhilsLab]

Not yet I'm afraid but a video on USB C is something I have planned!

[@davidliddelow5704]

Would be good to cover via types ie tented, plugged and capped.

[@sc0or]

Isn't a GSSPSG layout is better for 6-layers PCB, than SGSPGS? Signal to power has a same return path as signal to ground. And considering a core between layers 2 and 3, and x3 thicker outer planes than inner ones.

[@ramimehyar481]

So my understanding is that any board of more than 2 layers cannot be manufactred by JLCPCB because they do not support blind vias! Am I right or am I missing something?

[@VIPINSAINI_20]

Can you please share the SaturnPCB Toolkit files with me I tried searching on official website and other sources but didn't find it anywhere Please

[@dewmithfernando1503]

did you make pcb and code for money i have a paper drew and i wont it to pcb can you do it

[@notheoryplease]

Dummy question… but how do you get the Dimensions tool there 😅😅

[@PhilsLab]

Ctrl + M

[@tamaseduard5145]

👍🙏❤

[@jameslmorehead]

If a manufacturer offers via in pad as a standard option, why not take advantage of that option? The solder screen will need to be modified for the volume of solder wicked into the via, but that's not an insurmountable problem.

[@yudianimations]

viaoooo

[@carrefamily01]

You should offer consultation services @$200 hour. It seems it would be worth it.

[@remy-]

Hi so practically you design 20 via’s (if the design permits) in a wavelength? This week I saw a video with Eric Bogatin (kzbin.info/www/bejne/oZWme6uah5x_lasm35s) who advised to put at least 6 via’s in a wavelength. What’s your thought about that?

[@t.p.2305]

9:15 regardind differential pairs this may also be a very insightful video: kzbin.info/www/bejne/h3iTcqOloZKioJI kzbin.info/www/bejne/h3iTcqOloZKioJI