Electronics > Beginners
PCB design
(1/4) > >>
r4r:
Hi, everyone!

Here is my first PCB design, I've spent many time. Should I fix something?

Heard about GND loops that is bad, but what about power loop?
And I doubt about copper pour. How do you think, in this particular situation this is good or not?

RobBarter:
Nice.   Also a novice like you, however I think your thru holes are too close to the pads of the components near the top?
mariush:
any reason you can't place u4 on top , let's say near u2 or between connectors?
would help with all those traces cutting the copper fill on bottom
can you replace c2 with ceramic capacitor (or several in parallel) or a surface mount capacitor?
This and battery are the only through hole parts.

if possible consider movng the battery holder below chip, near connectors.
Would allow you to shift the main chip up and shorten and reduce all those traces going to left i/o pins leaving you loads of room to move at least the capacitors for oscillator on top.
move RESET button on left side above the io pins ?
move 3.3v and ground on left as well so you don't need that long trace on bottom going to both sides of board.
Maybe if possible, have the whole row of pins a few mm to the right, leaving more room for that 3.3v trace to go between edge of board and pins.

are those r5,r6,r8 same value? maybe you can replace with single part with multiple resistors in parallel to reduce space used.

Here's a very crude mockup i made in ms paint, shifting some components a bit



and loads of room on back side for ceramic capacitors and resistors under where u3 used to be and under the battery holder... your only issue is gonna be where the 3v from battery lands right in the center of the board, but you can route that trace to where it's needed easily

you could also get those 4 traces on the bottom going down to the connector closer together so they don't break that ground fill so much

r4r:

--- Quote from: RobBarter on May 09, 2019, 10:03:24 am ---Also a novice like you, however I think your thru holes are too close to the pads of the components near the top?

--- End quote ---
About 2.5mm from edge to edge. Arduino nano has roughly the same distance between chip pads and IO holes. But you're right, I think I'll put capacitors horizontally.

mariush, thanks! Will try to modify PCB like you suggested.
akowalczyk:
Looks great for a first PCB  :)

As a recommendation, I'd avoid going with 45 degree components unless the datasheet specifically calls it out. If those are the caps for the crystal, I'd suggest rotating them around so that the grounds are closer together, it may get you a bit less noise on the clock line if you're lucky

For your through-hole mounts, make sure you have a decent amount of distance between the copper surrounding the hole and the hole itself. 20 thou (roughly 0.5mm) should do. The rest of your electrical rules look good.

Is there any reason C2 is electrolytic here? What value is it? You may be able to downsize to either a few larger SMDs or a tantalum, but either way it'll be shorter than what you have there and easier to build a case around. If it's going to a SD card holder (which it looks like it is) I don't think you need all that much capacitance

Overall this is a great start, I'd agree with everyone else to see if you can get more parts on the top, but I see nothing that would prevent the board from working


Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod