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Guild: wafer.space Community
Channel: ℹ️ - Information / ⁉️-questions / Is there a DRC violation waiver system?
After: 2026-03-31 11:59 p.m.
Before: 2026-05-01 12:00 a.m.
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[2026-04-01 12:40 a.m.] mithro_
@Leo Moser (mole99) - I'm not sure they do any planarization of the last layers?


[2026-04-01 7:32 a.m.] mole99
Neither am I, but I'm also not sure that a chip-sized hole in the passivation layer won't cause problems.


[2026-04-01 7:43 a.m.] 246tnt
That's what nmz said above, PM.4 ?  You need a 2um overlap of TopMetal for any passivation opening.


[2026-04-01 9:08 a.m.] mole99
Right. Technically, you could cover the entire chip with TopMetal (no upper density limit?) and open up almost the entire inside area. However, this would be pretty useless since you would then have TopMetal everywhere. Even then, I don't think it would be accepted for manufacture. The rules seem targeted at "normal" bonding applications.

So I guess it's fair to say the min. pad opening is 40x40um, and there's no way around this by opening up the whole chip.


[2026-04-01 10:57 a.m.] nmz787
Assuming this is "bond pad" rules, then I think each pad would also need to meet "PAD.5 MetalTop (2) overlap of Top_Via (3)" which just says 0.5... not > or <= etc... so I feel they must mean 'exactly 0.5'.


[2026-04-01 10:58 a.m.] nmz787
Which then cascades to via size rules


[2026-04-01 10:58 a.m.] nmz787
And presumably they aren't letting topvia be some wild numbers???


[2026-04-01 10:58 a.m.] nmz787
(i am used to a big CSV file with all the Design Rules, so these multiple webpages and clicking around isn't easy for me)


[2026-04-01 11:02 a.m.] nmz787
I guess these are the via size rules? https://gf180mcu-pdk.readthedocs.io/en/latest/physical_verification/design_manual/drm_07_15.html


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