stempialdo

plane to mounting hole clearance

Discussion created by stempialdo on Aug 28, 2019

Hi there,

 

In Xpedition PCB V.X2.5 (and also in earlier 2.xx), I have noted that the plane-to-mounting hole clearance is defined by the minimum value between: 

 1) the plane to mounting hole clearance in Plane Classes and Parameters 

 2) Pad-to-Plane clearance in the Constraint Manager

 

It's straight forward to adjust the distance by setting 1); but I am not sure why setting 2) also applies.

 

A mounting hole generally doesn't have pads in the padstack and it's non-plated (or at least those I use), however the Pad-to-Plane clearance in the Constraint Manger applies to a mounting hole even with no pads.

Actually the Pad-to-Plane clearance applies to the actual hole and not to the pads in the padstack (if any).
To prove it I tried the clearance on a mounting hole with pads in the padstack smaller than the hole: the Pad-to-Plane clearance applies to the actual hole, not the pads (that's why it applies to mounting holes with no pads, like mines).

 

This is not an issue once known, but I don't find it very intuitive. Any thoughts?

 

Cheers

Flavio

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