Hi! I'm a biomedical engineering student, 2nd year, very passionate about electronic. I have developed an EEG theoretically, but to make it real (pcb) i first need to practice. So i decided to make a very simple EMG (electromyography). End decided that if it will work, maybe, i will try to make a little business out of that (I have quite a lot of ideas with emgs). But first I need very solid PCB design knowledge. How does it look to you? If it is shitty, just say it XD. I haven't placed the 1 uF capacitor after the LDO nor the 10nF in parallel with the 1uF decoupling capacitors of the other ICs (called Cu1,Cu2..). I tried to make everything not compact because I will have to hand-solder it (it's 3something cm wide, so it's already pretty tiny). I also tried to not place any components on the bottom layer. Is my ground plate ok? Are the connection ok? Specifically, is the via under the "very important opamp" (an ina) ok? I think it's one of the most messy part of the pcb. I used the same trace width for simplicity: should i make the gnd and supply/reference traces bigger even if the pcb is so small? Do not hesitate if it completely sucks, I'm a very beginner and thirsty of knowledge. Thank you again!

ps: i have just noticed i accidentally let the white connection lines (ratlines). I didn't follow them as I found easier to arrange the components in different ways from the schematic.

 

Delete the cutsie text.

Some components do not have reference designators. That will be a serious problem during debugging.

For the 5-oin connector (reference designators!), it looks like you have obround holes in the board. This will be an unnecessary cost increase.

Also, the diameter of the pads is very close to the axis length of the pin holes. A small misalignment in production will cause a breakout - the copper pad sill not be continuous all the way around the pin. You've got plenty of room to increase the diameter of the pads so there is at least 20 mils of copper all the way around. Since it is a connector, and things tug on connectors, bigger fatter pads will increase mechanical strength.

There are many places on the board where one trace joins another at an acute angle. This creates a "flux trap", and should be avoided. Adjust the traces such that they meet at 90 degrees.

I'm not a big fan of daisy-chain connections. Example, the left side of R2. If you determine that you need to disconnect R2 from that net for some reason, you have to make 2 trace cuts to isolate the pad, and add a jumper to reconnect the net around the pad. Better to run the trace near the pad and connect it with a spur. Now you can isolate the pad with a single cut and no jumper. This isn't critical (and in RF work it sometimes is avoided), but over the decades it has saved me a lot of surgery. Daisy-chaining is fast and convenient, but as a personal design rule I think it should be done only when justified.

ak

 

What program are you using,? I find the free Kicad works for me, right up to the files for production company.

 

What program are you using,? I find the free Kicad works for me, right up to the files for production company.

altium