Would like to have some feedback on my Trezor One Layout (pretty Newbie)

[M_a-r_k-u_s]

Hi together,

I'm quite new to PCB-Layout and would be thankful if you could give me some feedback on this PCB-design. I pretty much used the exact schematic of the Trezor One, which can be found on Github [1] and then only did the PCB-layout myself to practice PCB layouting. SMD parts I changed to 1206 for easier hand soldering.

I'm particular unsure in my layout about the tracks underneath the STM32 on the bottom, if this could cause signal integrity issues because the bottom is otherwise a solid GND-plane. You can also comment on other things if you want to. I'm also not completely sure if the oscillator placement and routing is ok or could be done better.

Thanks,
Markus

[1]: https://github.com/trezor/trezor-hardware/tree/master/electronics/trezor_one

Edit: The stackup is 2-layer board with 1,6mm

[jwet]

I think its looks very good especially for someone new at this.  The tracks under the STM32 are no problem.  Your use of a ground plane is a good choice, the circuit will be pretty quiet but this isn't really necessary- lots of microcontroller boards like this were made double sided without any planes.  You have to take some care with bypassing and routing grounds well with fat traces.  I love the test points- nice job.  With boards being so cheap and quick these days, I'd check it over one more time and send it out for fab.  It will work even if there is a little rework.  You'll probably have a final cleanup pass anyway for little things or parts availability, etc.

I noticed a few small things that are mostly just comments-

1. Those two USB traces going through R3 and R4 are routed awfully close together- as long as your board vendor can do the line widths and and the spaces, its no problem but I don't think there is a good technical reason for this.   These are USB D- and D+ and while they have to be matched, etc, they don't require this level of effort.

2.  All the traces on the board are pretty small, they look like 6 or 8 mil.  If you're hand soldering, you might want to make all the traces 10 or 12 mils where they'll fit.  Tiny traces are easy to overheat, lift pads, etc.  Use the most conservative design rules that will work- its easier for everyone and improves yields.

3.  I don't see any mounting holes, this can be easy to overlook when you get buried in the routing.

[M_a-r_k-u_s]

Hi jwet,

thanks for your commenting I appreciate it.

Unfortunately I can't get the board assembled b/c you don't get any STM32 uCs these days - but that's another issue.