Solder mask keepout issues


#1

Fritzing doesn’t seem to be using a consistent keepout distance around my SMD pads. In the attached image, you can see that some pads have no keepout, some have a small keepout of around 2 mils, and some have the “normal” keepout of 6 mils. Even within identical pads on the QFN part, some pads have no keepout and some have alarge keepout that bleeds together. Any ideas what is causing this? Does inconsistency in SVGs for parts influence this somehow (maybe strike width??)

Thanks!

What I expected should have happened instead:

Consistent mask keepout around pads

My version of Fritzing and my operating system:

Windows 10, Fritzing 0.9.3

Please also attach any files that help explaining this problem


#2

I have seen similar issues with parts i’ve edited. It has to do with the way the pads are written in the svg file. I am not sure exactly the why but I do know for me I had to remove the pads from their svg group and delete all the extra attributes in the xml and then resize the entire thing before regrouping and renaming the group.

Now with that said it looks like it is only the paste mask layer with the issue so if you are not getting a stencil cut I wouldn’t worry about it.


#3

Thanks—I did make those parts, so I’ll try messing with the SVGs to see if I can get it worked out. I am getting a stencil made, but if I need to I can edit the Gerber file for the paste layer to clean it up.