#1421

[@andymouse]

During design I route critical grounds directly even if I know they will be swallowed up by the pour at the end, you can say with certainty that the ground path is good. I think that etching your own boards is a dying art nowadays (sort of sad ?) and double sided boards are the same price so you can stick a full ground pour on the bottom and use 'Vias' but even then care must be taken.I loved your last example as that really is a "Trap for young players" and you had to be careful when just having one side of copper to play with and no DRC ! I enjoy any stuff others have to say on this subject and I hope you will do more sometime in the future as It's always a 'hot' subject...cheers.

[@ats89117]

Unless you are building a really low budget board, you should have a non-routed ground plane which is well connected by non-thermal vias to the surface ground, poured or not. Four layer boards are pretty inexpensive today, and for many applications, the additional planes and the ability to have impedance controlled traces justifies the extra few dollars to get the boards built.

[@olavodias]

I hate to disagree with you, but I did a simple calculation in one of those famous websites for making PCBs. 10 EA with 2 layers costs 5 bucks... 10 EA with 4 layers costed 50. It's a 10x price increase, so it's far being pretty inexpensive.

[@Rotwold]

⁠​⁠@@olavodias i checked jlcpcb and they quoted me: 2 Layer = $5 4 Layer = $13 10 boards / 100x100mm

[@davidharms3562]

I really enjoy these PCB design videos! Thanks!

[@curtkeisler7623]

Thank you so much for sharing this. I literally ordered boards the night before I saw this video they had the very problem that you talked about. I wish I had seen this before I ordered those boards. It's just on a decoupling capacitor that I have before a rotary encoder so I can jump over a wire from the ground on encoder to the ground on the capacitor and not have a problem but dang it I hate that I missed it. It's the first PCB I've ever created. Anyway love you videos thank you so much please keep doing this I have learned so much from you!

[@DustinWatts]

The last trick you could also do with the ground pin of resistor above. And of course, a ground plain on the bottom would solve a lot of problems! But thanks for the video.

[@steves7189]

I didn’t think about those thermal reliefs when I designed my lpf boards. Thanks for the info! …back to KiCad…

[@JenkinsUSA]

Thank you @1:40 for thermal vias. 💪

[@foogod4237]

A couple of additional notes: If you're doing all through-hole stuff, it doesn't matter as much, but if you're working with any SMD components, it is much better to do your ground plane on the back side (non-component side) instead of the front side of the board. This is because all of your component pads and the traces between them will be on the front side, and will interrupt the pour everywhere, but on the back side the whole pad can be mostly undisturbed. Also, for a similar reason, when making a two-layer board (even for through-hole stuff), I always try to dedicate one side of the board to just the fill, and put as many of the traces as possible on the _other_ side of the board (don't try to do your fill and your traces on the same side). You can run some traces on the filled side if it's just not really feasible to do them on the main side, but the fewer of those you do, the easier it is to keep the ground pad contiguous, so you don't have to worry about issues like islands or long convoluted return paths, etc. (This also has the advantage that the return ground current for a trace can often flow along the ground plane directly under that trace (without having to go off on some other completely different route to get back to ground), which can be significantly better for protecting against crosstalk and interference.)

[@tvelektron]

One more detail: If You have several stages on one board it may be a good idea to create separate groundplanes. Otherwise it is so easy to get noise from the digital part right into the analog input stage for example. Or you can easy end up with positive feedback and oszillation if you have an loudspeaker power amp and a input stage sharing the same ground plane for example 🙂

[@sebastian_harnisch]

Most of the time this would be bad advise. What you really don't want to happen is having a large the loop area. Use a single ground plane, but place the different circuits far enough apart and don't let currents flow where they shouldn't (both DC and AC). But don't just break the ground plane in order to separate circuits. And most importantly, don't route signal accross different ground planes, except you want to create an antenna.

[@ArjanvanVught]

5:54 a DRC check would tell that there are errors. At least Eagle does.

[@andymouse]

Kicad does too but the point is the last example where up close examination the route is just nuts but electrically sound, this is useful for beginners.

[@blazini]

Not sure if he mentioned that he's using KiCAD. I think he said "DRC won't always catch it"...that's absolutely not the case KiCAD might miss a small floating island but it will never miss an unconnected net. He also had the rats nest turned off, otherwise it a white line would have been making it obvious that the pad was not connected to it's net

[@TheElectronicDilettante]

Thanks for the video. I just watched a video presentation from Altium Design featuring an engineer named Rick Hartley on the importance of grounding. You guys raise the same issues. On a completely different topic, as I continue down the rabbit learning RF and everything that goes with it, I’ve been getting into Software Defined Radio. Just last night , I ran into a few scholarly papers on Software Defined Antennae. I could get my head around SDR but antennae configured by software is a bit bizarre. It seems like it’s not brand new but I can’t find much outside Academia on the topic. If you have any info you can share or a direction I can be pointed, I’d appreciate it. Thanks for your time- Jason Burchell

[@JenkinsUSA]

@0:14 Your grounded 😊 - ok let’s see how this plays out…

[@ivolol]

Given the modern possibility of chinese board manufacturing, where 2-layer and now even 4-layer boards are super cheap, (heck even western PCB prototyping isn't that bad if you don't mind) although a lot of the advice in here is valid, I am puzzled that you never gave the context of the availability of avoiding 75% of the problems presented here with a bottom-layer ground pour. Indeed I'd thought that the most appropriate advice for beginners laying out a board nowadays would be to start off with a 2-layer, bottom-layer ground pour design and route from there. Maybe this stems from the days when a single-layer home-manufactured PCB prototype was the most common, but nowadays ordering them is far easier for me than getting a hold of ferric chloride. I don't mean to be negative just would love to see that possibility mentioned if it makes sense for someone learning from these. Still love the series.

[@anameisrequired3729]

I agree. A good default strategy is a solid ground plane on the second layer, without any traces. That way you don't have to think about the return path (as long as you're routing on an adjacent layer). I don't know how to approach routing if a solid ground pour on layer 2 is not an option: probably first route ground? Given that the (ground) return path should be close and contiguous to every (fast edge/high speed) signal, it seems that manually routing the (ground) return path at the same time would be quite a lot of effort.

[@RechargeableLithium]

Super easy to get muriatic ("pool") acid and hydrogen peroxide these days. I suspect part of the reason for not jumping to the bottom layer for ground by default is because it's not a universal solution. It can be useful for an RF amplifier with plenty of vias. One must omit bottom copper for oscillators and any other circuit where the capacitance between the layers will disrupt the circuit. I look forward to seeing how this series unfolds!

[@Edisson.]

I really like the series, in the research labs I was the one who made the PCB and everything that was said here is true. It's also true that it's easier to order a board these days (I make small boards myself and when I'm super lazy I build it on a prototype board), but in order to order it, I have to be able to design it. The layout of the paths and the placement of the components is not so simple, we must always remember that the circuits affect each other and a wrongly designed PCB can have functional problems even if it is connected correctly. Nice day 🙂Tom

[@pedrova8058]

but ground is ground! as long as it's connected to the chassis it's fine lol In school I built a lot of guitar pedals and amplifiers of various sizes, shapes and forms (nothing of big power really). For the most part, the ground schemes worked fine (just by chance), but in things with low signal (high amplification with low noise), very high/very low impedance, or in circuits carrying digital and analog components, the correct ground routing it's an art. I only learned many years later, after several headaches xD

[@VoltageNostalgia]

I still don't understand ground in circuits, ive watched many videos. If I take a circuit diagram and try to build it, its very hard to understand where the grounds are supposed to go. They just end abruptly with the little symbol, how are you supposed to know where that connects to in reality?

[@IMSAIGuy]

yes, it is not obvious. you need to mentally think about all the current flows. it's like knowing where something is located on the map but finding the best way to get there the map doesn't tell you.

[@dekutree64]

You can do it fairly literally on a 4 layer board where 1 or more layers are completely filled with ground, so vias placed anywhere can connect straight to it like the symbols in the schematic. On 1-2 layer boards or point-to-point construction, you have to route it like any other net (optionally using copper fill to save time, with caveats explained in the video). Ground and power are almost always the most complicated nets in a circuit since most components connect to one or both of them.

[@mejoe444]

Does KiCad warn about floating ground planes?

[@IMSAIGuy]

No. It will show a non-route trace, but that is very easy to not see and miss. and it does not show up when you do a error check. So, it is up to you. I like to click on a ground trace and then the ~/` key. this will highlight all grounds

[@mejoe444]

@@IMSAIGuy ~Thanks ~ didnt work for me but I had to select and right click a trace and theres net inspection there where it has highlight net option.

[@foogod4237]

@@IMSAIGuy That's definitely not correct. All versions of KiCAD I've used will identify floating fill islands by default (and will highlight the unconnected net as well) if you run the DRC (which you always should be doing anyway). Maybe you just manually disabled those checks somehow?