← Back to team overview

kicad-developers team mailing list archive

Re: Trapeziodal pads are buggy

 

> In fact, this is not really a bug, but an inconsistency in pad editor, due to the way Pcbnew handles modules on back side.
> When a footprint is flipped, the footprint is mirrored and some Y coordinates are negated.
> So m_DeltaSize.y is negated by the mirroring transform and become negative if it was set to a positive value in module editor.
> This is also true for m_Offset.y and m_Pos0.y
> Sizes are always >0 and therefore are not modified.
>
> The inconsistency is the fact the dialog uses values for m_DeltaSize.y and m_Offset.y
> which are modified by the side where the footprint is,  but which are not modifed by its orientation.
> (i.e. module orientation does not change the displayed values, but flipping this module change these values)
>
> I am working on a dialog pad editor enhancement to avoid this inconsistency,
> and also avoid mistakes in parameters edition.
> (I think just modifying the way Delta Y size or Offset Y value is displayed is not enough)
>
> Note also trapezoidal pads are mainly for microwaves applications and others issues (clearance area shape, DRC...) are more a "not 
> finished work" problem than a bug.
> DRC using microwaves constraints is a lot more tricky than usual DRC
>
>   

Thanks Jean-Pierre for looking into this for me.

I have re-opened the original bug report which was basically a two part
report.

    https://bugs.launchpad.net/bugs/632355

The specctra export part has been fixed.  For this to be fully usable:

1) Alfons needs to fix the bug in freerouter for back side of the board
support.

2) We still have some more work on the DRC distance calculations WRT to
trapezoidal pads.  The re-opened bug report is a reminder of such.


Dick




References