Why having via holes in mounting holes

[peranders]

Any idea why some people have lots of via holes in screw holes? The picture shows a double sided board with no ground planes.

 

[Mark Johnson]

The vias give a more textured surface for toothed lockwashers* to bite and grab. Picture attached.


* (US name, I don't know European name)

 

[peranders]

Ok, could be an idea but I have never seen a pcb mounted with toothed washers... BTW: taggbricka in swedish

 

[Refugee1]

Star washer in UK.
The solder on the via hole spreads the load from the screw head. Imperfections in the screw head can sometimes crack the board if it is not protected.

 

[JonSnell Electronic]

Makes a good earth bond as it keeps the tension under compression of the conductors. Otherwise known as a 'shakeproof' washer.

 

[bwaslo]

If there are any plated through holes needed, it is cheaper to make them all plated, it saves a processing step.