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simeon , 03-03-2025, 02:30 PM

Hello,

Does anyone know which rule needs to be used to modify the solder mask expansion for pads and for through holes?
In my footprint library I have the pads/holes as rule based for solder mask expansion. I received my PCB in without this solder mask and have to fix that right now in my PCB file. I just can't find which rule is responsible for this expansion...
Hopefully, someone will now. Thanks in advance!

QDrives , 03-03-2025, 07:13 PM

I am trying to think what your actual question is, as there are multiple parts that point in different directions.
"*I received my PCB in without this solder mask...*" -- A board without solder mask is rare. But this could be a language issue.
"*...and have to fix that right now in my PCB file.*" -- The expansion, solder mask, export, or what do you need to fix?
"*I just can't find which rule is responsible for this expansion... *" -- Design / Rules and then see screenshot.

As for the values to use....
https://www.eurocircuits.com/technical-guidelines/pcb-design-guidelines/soldermask/
That depends on the technology used.
For LDI (Laser Direct Imaging) this can be 30um.
With PI (Photo Imaging) it is 100um.
The color of the solder mask determines which technology can be used.
For vias, you can use 50um from hole edge as setting.

simeon , 03-04-2025, 10:58 AM

yeah it wasn't showing up but the I had isvia instead isVia unforutnately. And well, I don't know what you mean but all the pads were covered with soldermask because of this. In order to solder them, I'd have to scratch off the solder from each pin which is quite a lot of work.

QDrives , 03-04-2025, 04:29 PM

Always check your board in 3D. Your pads should have a different color than the traces due to solder resist (solder mask).