How to improve the strength of PCB board?

I need to install a 20inx12in PCB board on a vehicle. How can I improve the strength of the board so that it won't bend?

Make it thicker!

For illustration purposes I found two (blank) PCBs of differing thicknesses - one is (tinned) double sided 1.6mm thick and the other a 4 layer board (from an old project) that is 4.0mm thick. Both boards are approximately 300mm wide. Clamping both in the vice, I pulled...
(and what you can't see is that I'm pulling *much* harder on the 4.0mm board!)

And a picture tells a 1000 words...


(I'm sure beam deflection formulae (https://en.wikipedia.org/wiki/Deflection_(engineering)) would yield a far superior scientific approach to deciding how thick a PCB you need, but you get the idea

Essentially, the bending stiffness is proportional to board thickness raised to the square. And it's slightly increased by continuous power planes and copper pours.

For the said board size, a metallic frame might be appropriate.

Vibrations must be expected on a vehicle. At worst case hitting the self resonance frequency of your board...

Google "board stiffener". There are various ways to do this.

thylacine1975 said:

Make it thicker!

For illustration purposes I found two (blank) PCBs of differing thicknesses - one is (tinned) double sided 1.6mm thick and the other a 4 layer board (from an old project) that is 4.0mm thick. Both boards are approximately 300mm wide. Clamping both in the vice, I pulled...
(and what you can't see is that I'm pulling *much* harder on the 4.0mm board!)

And a picture tells a 1000 words...

(I'm sure beam deflection formulae (https://en.wikipedia.org/wiki/Deflection_(engineering)) would yield a far superior scientific approach to deciding how thick a PCB you need, but you get the idea

Click to expand...

Thank you thylacine1975 for the input. 4mm looks really strong:lol: My board is now 3mm thick and I can't increase it because of some through hole connectors...

FvM said:

Essentially, the bending stiffness is proportional to board thickness raised to the square. And it's slightly increased by continuous power planes and copper pours.

For the said board size, a metallic frame might be appropriate.

Vibrations must be expected on a vehicle. At worst case hitting the self resonance frequency of your board...

Click to expand...

Thank you FvM. My board has several pwr/gnd planes. Hope they will help. Resonance frequency... Is there any way to change it, if it happen to be the worst case?

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spudboy488 said:

Google "board stiffener". There are various ways to do this.

Click to expand...

This should help. Thanks. It reminds me of the stiffener I used on my speakers.:lol: