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Solder Mask Opening Rule for VIAs to the selected Nets/Net Class.

anish , 10-16-2015, 01:12 AM
How to set the Soldermask opening rule for VIAs to the selected Nets/Net Class on PCB? Presently I have requirement to setup all the VIAs as test points. Please Help.
robertferanec , 10-16-2015, 01:35 AM
Hi @anish. I am not sure if setting up a solder mask rule is what you are looking for (I guess, solder mask rule will only cause DRC, but it will not automatically open the mask). Also, even if it was possible to set this kind of rule, it will unmask all the VIAS on the net - and again, I am not sure if that is what you are looking for. Also, in Altium there is something called Testpoints, but we don't use it (I think, some time ago I had a look at it, but it was not what I needed).

In our designs, we use a special component in schematic - Testpoint (it is standard component with 1 pin only and special footprint). In your case, you can make tespoint footprint to look as a VIA (or you can create a component called TestVIA). In the schematic, place it on the net where you would like to have it and then use it in your PCB.
anish , 10-16-2015, 03:30 AM
Hi Robert,
I just referred to this Altium LInk, http://techdocs.altium.com/display/A...n+Enhancements
Here it says by selecting nets it is applicable. Kindly refer,
"To apply specific top and bottom expansion rules for a particular Net for example, define the applicable Net in the query match (upper section of dialog), check the Use Separate Solder Mask Expansion option and enter the desired expansion distances for the Top and Bottom layers. The rule will apply where pad and via expansion settings for that net have not been individually overridden."
Hope the same can be applied using net class as well.
robertferanec , 10-16-2015, 04:52 AM
We tested it. It really does work and Altium automatically adjusts the mask based on the rules. You just may need to play with it. Here are some screenshots from our testing.

anish , 10-18-2015, 04:13 AM
Thank you ...
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