Spacers for stacked PCBs

Thread Starter

clangray

Joined Nov 4, 2018
227
I'm considering stacking a few very small boards with some M1.6 brass standoffs (the smallest standoffs I could find). To decrease the space between them even more, I could instead make a custom space with some M1.6 screws and hex nuts between the boards or even shorter like M1.4. However would the brass spacers be more suitable because they are "anti-short" and are more electrically friendly? Am I risking the circuit with the custom version?
 

Boggart

Joined Jan 31, 2022
67
You can buy nylon screws, nuts, washers, and spacers just as if they were made of metal.

View attachment 282571
Yes, this. I use black nylon spacers with nylon bolts on some of the kits I sell, no worries about shorts between boards and the spacers can even sit on top of tracks without issue, so you don't have to worry about exclusion zones around the holes, although it is preferred to avoid spacers sitting on tracks if possible.

Also, nylon spacers are a lot cheaper than brass, a big plus when doing lots of boards, I buy them in 1000qtys for a $20 to $60, depending on length.
 

Thread Starter

clangray

Joined Nov 4, 2018
227
Yes, this. I use black nylon spacers with nylon bolts on some of the kits I sell, no worries about shorts between boards and the spacers can even sit on top of tracks without issue, so you don't have to worry about exclusion zones around the holes, although it is preferred to avoid spacers sitting on tracks if possible.

Also, nylon spacers are a lot cheaper than brass, a big plus when doing lots of boards, I buy them in 1000qtys for a $20 to $60, depending on length.
Hi, this makes very good sense. However I can't find Nylon standoffs < M2 size. That's my reason to try to customize with the small screws M1.6, 1.4 or less. It makes a big impact on the profile of my board. Now if the possibility of shorts between the board and standoffs are reduced by nylon I can ditch the customized plan, increase the profile of the board to accommodate the nylon screws. Or I can go with brass that I found on EBay for M1.6.
 

Lo_volt

Joined Apr 3, 2014
280
Brass spacers should be fine if you don't connect the mounting holes to any nets. Isolate the holes from your circuit and the brass won't affect your circuit.
 

Thread Starter

clangray

Joined Nov 4, 2018
227
What if instead I used very small screws, stainless steel/brass and anchored it by passing through both boards and arranged one end with two hex nuts to keep it from sliding. I've attached a rudimentary illustration to demonstrate how this would work. 0 Nets touching the screw; exclusion zones necessary?double_deck illustration.png
 
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ericgibbs

Joined Jan 29, 2010
16,792
Hi clang.
I added a missing Nut under the top PCB.
Also, I would extend the holes to the edge of the PCB, using a round needle file, you will find it easier to disassemble/reassemble as required
E
Added image,
Image1.gif
 
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