Electrical – Is solder mask expansion overlap legal

pcbpcb-designsolder-mask

I used the component wizard in Altium to automatically create a footprint but it decided to overlap the solder mask expansion with neighboring pads. Is this ok or should I change it such that there is a gap between each pad.

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Best Answer

The overlap is not a problem as far as having the PCB green-board made. There will just be no soldermask everywhere you see the purple.

This could be a problem when you have the boards populated, because solder bridging is more likely.

The real answer here is that you should work with your board house and determine what the solder mask expansion and minimum sliver size should be (the smallest sliver between pads).

soldermask expansion rule

minimum soldermask sliver

Also, check your part to make sure the rule isn't overridden:

pad properties