@golkit1 don’t take this too harshly. Many of us here have decades of experience, are professional designers or both.
As I said, post your design here and ask for a layout review. Worst thing that can happen is that the thread is locked for being off-topic (this forum is not intended to teach electronics).
I probably agree with that. My comments (criticism) is often interpreted more negatively then it’s meant.
But I also agree with RaptorUK & Eelik here. There are already plenty of PCB reviews here, and the suggestions for improvements are very much the same each time. Adding more reviews is not going to improve that.
I think the TO would definitely learn something from a review.
Should that be here? I don’t know. It’s partially basic PCB design and partially how to use KiCad.
For example let’s adress those microscopic tracks and vias. Just guessing, we might suggest 0.4 mm tracks and 0.6/1 mm vias. This leads to board setup, setting rules for the default class and so on. Maybe adding a power class with 1 mm tracks just for practise. Those are already a number of nontrivial KiCad specific tasks (where, when asked in the eevblog/beginner forum I might think: Why does this guy not ask in the KiCad forum?)
As to “we had this 100 times already”: How often do we see questions like “I put this connector on the board and the pin spacing is slightly off”? Look at it from the positive side: Those are all new users we can help with moderate effort, so why not do it? Or, what is the percentage of forum users that can benefit from yet another explanation of default netclass setup compared to those requiring via backdrilling?
Sorry, already too much OT…
He would learn most from starting from an interest and willingness to learn.
Dumping parts on a PCB and letting an autorouter rip does not show such interest.
I did not read your post beyond that line.
Thanks for all the answers so far!
I understand there’s some debate about whether this forum is meant for PCB design questions — but I’ll go ahead and share my schematic and basic PCB layout here in case anyone’s open to giving feedback. If not, no harm done.
schematics:
I’m using global labels (net ports?) so I can divide the schematic between two PCBs:
- The bottom board holds only components.
- The top board includes mostly front-panel elements — jacks and pots — along with a few regular components (resistors, capacitors) that fit closely around them.
here is the two pcbs with the way I placed the components:
bottom board:
top board:
bottom and top board close to each other (for better seeing the whole design):
You’ll really have to show you’ve put in some effort from integrating the tips already given before I would be inclined to give any further advise.
At the moment I’m more inclined to closing the thread as “off topic” then to making any other contribution.
more changes made regarding bottom board:
edit: regarding ground connection - if I get it right - No need to route tracks between ground pads because I should make ground pouring on both side of pcbs? this will ‘save’ me plenty of routing(?)
so I start again to route my pcb, I feel it is going much better. I use bottom track (blue) for vertical routing and top tack for horizontal routing.
in this scenario:
R3 lug 2 should be connected to R4 lug 2. they are much close apart. should I continue this connection ob the bottom part (blue line) or switch to the red line (top part) ? what would be a better choice in that case?
edit:
Here is my try to better routing the bottom board:
here is it with hiding the copper zone area for better seeing my routing:
Nope. Still garbage.
Throw away the auto router, do the routing manually on one layer and keep the other layer intact for the GND plane.
Also, the amount of screen posts you make does not help your cause. Sit back for a while, do some real studying and then create and post a proper PCB layout. I guess that for your first PCB this will take one or two days of work. After you’ve done a handful, you can do a PCB of this complexity in an hour or two. (Including footprint placement, which takes more time then the routing on itself).
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There is no debate, this forum is for KiCad specific issues/questions. We try to be helpful as much as possible but our free time is not endless . . .
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You can have some tips on routing here.
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I think you are being unnecessarily harsh and over critical for no reason!
Th OP was asking a perfectly reasonable question for a beginner (and to Kicad) and was being polite. There are better ways to convey criticism which is not belittling.
I found your wording quite rude surely impacting their confidence - why would they return here after your comment.
Because the OP found Paul’s answer helpful . . .
Okay, so the reason auto routing does not solve your pcb design problems is simply that the routing is not the hard part, it is often pretty straight forward thing once you get the component laid out in a sane way its usually pretty easy to do the routing.
Let’s take some examples on your board. Look at R2 and R1. Consider what would happen:
- If R1 would be above R2
- and R and R2 would be rotated 180 degrees.
Now do this for all components. The trick is to postpone routing a bit longer until the layout is easier. Work form most important to least important…
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what is most important and what is less important?
usually you start with closer components tracks then farther once?
For some circuits, track length and loop area can be extremely important. (SMPS circuits is a good example).
For other circuits, (High impedance stuff) guard rings may be a necessity.
For other circuits, track resistance, and even minute voltage drops over tracks can be extremely important. A good example of this is PCB design for an audio amplifier. With a 120dB or more range between the output and the noise floor, and the presence of tracks that carry several amperes these things need special considerations.
For high speed logic, you get things like differential pairs and delay matching.
And of course, decoupling and their capacitors. And not only digital circuits need decoupling, it improves performance of analog circuits just as well.
And any PCB should at least give some consideration to EMC issues, and by far the simplest and straight forward method to do this is to design a proper GND plane into the circuit, especially because you get the 2nd layer for free with the cheap PCB pooling services. Rick Hartley has made an excellent (2h and 10 minute) video about “how to design a proper ground plane”. The video is worth the time, but I guess you’re not ready for it yet. But it does indicate the importance of this part of PCB design.
Yes. Already mentioned a few times in this thread, but still worth repeating. It is also one of the reasons why many people do not use an autorouter in the first place. Figuring out a good footprint placement needs a lot of attention to the details of which pins of your footprint connect together. And often you draw a few PCB tracks, then saw you made a mistake, move a few footprints and redo a few tracks. This is an interactive process by switching between a bit of track layout and footprint placement. An autorouter can not help here.
High impedance stuff and signals are the most obvious. Keep sensitive parts physically separated from “noise generating” parts. Building circuits on breadboards is a good way to get an idea of the importance of signal integrity.
And overall, the big picture… You need to build up some experience, and to gain that experience you need to invest time. Autorouters can be a useful tool, but they are certainly not a magic tool that designs the PCB for you. This is a common misconception for beginners. And you do not gain much experience by using an autorouter either. It’s probably best to not even attempt to use an autorouter before you have routed around 20 or so PCB’s manually.
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Having a GND plane is not about making routing easier (although it does). More on that here:
Most designs will benefit from a ground plane because individual tracks have non-negligible resistance and thus (by Ohm’s law, V = IR) voltage drops between the different points. You want all GND connections to have the same potential and that is easier to achieve if there is a single ground plane with as few interruptions as possible.
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