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How to create DRC marker to find overlapped via on Though pad?

ichliebedich over 4 years ago

Hi All

sometime I make mistake creating via like below

I want to create DRC marker to find out the via which overlapped on Throuh pin pad

how can I find out them?

regard

RFinley over 4 years ago

Same net spacing in constraint manager is going to help you with this.

Do you have this DRC turned off already? >CM >Spacing Modes >Pins [ ] SMD pin to thru via...

The cool thing is you can set for an acceptable via to pad overlap by using a negative clearance on via to SMD pad.
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ichliebedich over 4 years ago in reply to RFinley

thank you, it work well with same net spacing rule I forgot to on of Mode
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ichliebedich over 4 years ago in reply to RFinley

oh well... I try again it was not work ...

I set like below

I turn on the mode, and set the negative value of same net spacing at the +12V net

but although I refreshed the DRC, I created the overlapped via with pad, the DRC marker was not occurred..
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jc teyssier over 4 years ago in reply to ichliebedich

Why a negative value? This is the way to tell to the tool to NOT check; so the behavior is correct. If you whish are DC use a non negative value
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RFinley over 4 years ago in reply to jc teyssier

negative clearance for same-net via to device pad allows you to place a via that overlaps a device pad, same net.. Even with bubble mode set to hug.

My workplace avoids laser drills as much as possible.

We overlap mechanical vias with drills as small as 0.15mm/6mil up to 0.5mm into the SMD pad.

We need to make sure mask is not opened over the hole (which would draw solder away from the device pad during reflow).
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