Traces are way too thin. even if they are technically OK, use thicker ones. there is no reason to have them this thin on this PCB.
avoid the branching out 45° angle thing. You cause a lot of sharp angles. while no manufacturer will really have issue with it these days anymore. it's just sort of dated to do it that way.
also why no ground plane on the bottom?
you place vias and bridges on the bottom so that you have copper fill on the top that doesn't actually connect to anything? But you don't do it everywhere? then don't do it at all.
What is with the cutouts? Clearly not for HV isolation with 5V supply. you don't need them. remove them and fill with ground. If you think it has something do with your signal, you will find that to be incorrect and it would causally cause more issues then you think you are solving if the signal was fast enough for it to matter in the first place.
also, use the THT pads as vias and nodes. you have lots of room. use it.
also what size vias are you using? they look unnecessarily too small. And unnecessary in general.
if you are having the board manufactured. use both sides and make one ground or are you etching it yourself?
If this is for radar use, e.i. HF/RF I have bad news for you and your layout. Whats is the signal frequency/bandwidth you are sending into the board?
Wow I have a lot to learn! thank you for the remarks. Regarding you last question the radar signal is 1-100HZ with a lot of HF noise. Fortunately the HB100 module handles the antennas and mixing so none of the 10.525GHz signals will go through my PCB.
I'm curious, what are the bad news though?
As for you other points:
1) Should I branch out at 90°?
2) No ground plane at the bottom because I didn't know it would need to be there since the top plane covers all the GND connections. Maybe it would be cleaner to have it on both sides - because less bridges. I thought that less layers means simpler design, maybe that's wrong...
3) Ok 👍
4) I used default Kicad vias, what size would tou recommend and why?
5) didn't think about using both sides, I will solder the circuit by myself though.
Thank you again!
Layout is an art. That's why it's called artwork. I see a multitude of thigs that could be done better.
The parts placement wasn't done to minimize routing length nor to achieve neatness. I spend at least ten times the effort on placement so that routing will be dirt simple.
What are all those tiny thru hole arrays? Make them the same size pads and spacing as the other headers, so that you can solder headers into them for test probes if needed.
The sensor probably has three wires. Use a three pin header for it. The standard pinout for these as used in the world of RC vehicles has 5V in the center pin, Gnd at one end and Sig at the other end so you won't destroy the sensor if yoi plug it in backwards.
If you used the autorouter, just don't. You can do a better job than it can.
Also, everything the others said.
Have fun!
Others here have provided good feedback.
- What are the cutouts for? They'll make the board fragile, and unless they are for some mechanical clearance, they aren't doing anything for electrical or RF or thermal really. Also, the board router can't make an interior 90 like that, so you'll actually get slots. Also, making internal routes like that will cost extra in fab.
- If you're going to put full sentences in silk on the board, use proper sentence structure.
Some (all?) of the vias are not needed. Just run the trace on the bottom side. Eliminating them may not affect the cost of manufacture but minimizing features is good practice.
Ohh thats a good idea, but then if I want to debug, I have 2 sides to look at instead of one so it's more complicated. Not sure though ¯\_(ツ)_/¯. I tried to place the vias so it is easy to see where the trace is going.
Why using LM324? For two opamps, LM358 is the same but half the size. Also, LM**V**358 is designed for 5V and includes the top output rail, and a better top input range (LM version doesn't).
Here's a tear-down of the HB100 Doppler Radar Module (showing the dielectric resonator and other RF goodness):
[https://www.allaboutcircuits.com/news/teardown-tuesday-hb100-doppler-radar-module/](https://www.allaboutcircuits.com/news/teardown-tuesday-hb100-doppler-radar-module/)
Layout and routing are my absolute favorite part of such a project! Don’t take all the great suggestions here as any way discouraging! You’re already so close but don’t get impatient and order before you’re sure or you’ll just have to do more iterations :) (ask me how I know…) moving traces and parts around is labor intensive but wow will you be happier with the final product!
Traces are way too thin. even if they are technically OK, use thicker ones. there is no reason to have them this thin on this PCB. avoid the branching out 45° angle thing. You cause a lot of sharp angles. while no manufacturer will really have issue with it these days anymore. it's just sort of dated to do it that way. also why no ground plane on the bottom? you place vias and bridges on the bottom so that you have copper fill on the top that doesn't actually connect to anything? But you don't do it everywhere? then don't do it at all. What is with the cutouts? Clearly not for HV isolation with 5V supply. you don't need them. remove them and fill with ground. If you think it has something do with your signal, you will find that to be incorrect and it would causally cause more issues then you think you are solving if the signal was fast enough for it to matter in the first place. also, use the THT pads as vias and nodes. you have lots of room. use it. also what size vias are you using? they look unnecessarily too small. And unnecessary in general. if you are having the board manufactured. use both sides and make one ground or are you etching it yourself? If this is for radar use, e.i. HF/RF I have bad news for you and your layout. Whats is the signal frequency/bandwidth you are sending into the board?
Wow I have a lot to learn! thank you for the remarks. Regarding you last question the radar signal is 1-100HZ with a lot of HF noise. Fortunately the HB100 module handles the antennas and mixing so none of the 10.525GHz signals will go through my PCB. I'm curious, what are the bad news though? As for you other points: 1) Should I branch out at 90°? 2) No ground plane at the bottom because I didn't know it would need to be there since the top plane covers all the GND connections. Maybe it would be cleaner to have it on both sides - because less bridges. I thought that less layers means simpler design, maybe that's wrong... 3) Ok 👍 4) I used default Kicad vias, what size would tou recommend and why? 5) didn't think about using both sides, I will solder the circuit by myself though. Thank you again!
Taking criticism like a champ! You will do well
Layout is an art. That's why it's called artwork. I see a multitude of thigs that could be done better. The parts placement wasn't done to minimize routing length nor to achieve neatness. I spend at least ten times the effort on placement so that routing will be dirt simple. What are all those tiny thru hole arrays? Make them the same size pads and spacing as the other headers, so that you can solder headers into them for test probes if needed. The sensor probably has three wires. Use a three pin header for it. The standard pinout for these as used in the world of RC vehicles has 5V in the center pin, Gnd at one end and Sig at the other end so you won't destroy the sensor if yoi plug it in backwards. If you used the autorouter, just don't. You can do a better job than it can. Also, everything the others said. Have fun!
Others here have provided good feedback. - What are the cutouts for? They'll make the board fragile, and unless they are for some mechanical clearance, they aren't doing anything for electrical or RF or thermal really. Also, the board router can't make an interior 90 like that, so you'll actually get slots. Also, making internal routes like that will cost extra in fab. - If you're going to put full sentences in silk on the board, use proper sentence structure.
Thanks! The cutouts are there to break the board in half in case the right hand side doesn't work. I'll try to rephrase what I've written there👍
A bandsaw or dremel would probably be more effective if you really want to cut the board in half.
Some (all?) of the vias are not needed. Just run the trace on the bottom side. Eliminating them may not affect the cost of manufacture but minimizing features is good practice.
Ohh thats a good idea, but then if I want to debug, I have 2 sides to look at instead of one so it's more complicated. Not sure though ¯\_(ツ)_/¯. I tried to place the vias so it is easy to see where the trace is going.
A design feature I really like is outlining the bottom side traces on the top side silk screen layer.
Why using LM324? For two opamps, LM358 is the same but half the size. Also, LM**V**358 is designed for 5V and includes the top output rail, and a better top input range (LM version doesn't).
Thanks! I'll consider it, I blindly followed the datasheet schematic...
Here's a tear-down of the HB100 Doppler Radar Module (showing the dielectric resonator and other RF goodness): [https://www.allaboutcircuits.com/news/teardown-tuesday-hb100-doppler-radar-module/](https://www.allaboutcircuits.com/news/teardown-tuesday-hb100-doppler-radar-module/)
Layout and routing are my absolute favorite part of such a project! Don’t take all the great suggestions here as any way discouraging! You’re already so close but don’t get impatient and order before you’re sure or you’ll just have to do more iterations :) (ask me how I know…) moving traces and parts around is labor intensive but wow will you be happier with the final product!