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Guild: wafer.space Community
Channel: ℹ️ - Information / ⁉️-questions / Metal Fill
After: 2025-10-31 11:59 p.m.
Before: 2025-12-01 12:00 a.m.
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[2025-11-30 3:31 a.m.] buck_042
When I use LibreLane to generate a small digital module, everything looks normal but there is no metal fill, whereas I noticed that the top design in the template does have metal fill. What is causing this difference?

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[2025-11-30 3:46 a.m.] bigturtle8
First thought would be different hardening strategies in the config.json, but could be wrong (https://librelane.readthedocs.io/en/latest/usage/caravel/index.html)


[2025-11-30 3:52 a.m.] buck_042
I don't know, I don't see any configuration related to metal fill in template's config.yaml. And the fillers are successfully inserted, but no metal fill.


[2025-11-30 4:57 a.m.] buck_042
I see, the template uses the chip flow, which calls some KLayout scripts to insert metal fill. In my case, I didn’t explicitly set any flow, so I assume it’s using the default classic flow, which doesn’t seem to run the KLayout density/metal-fill steps.

If I want to add metal fill for a small standalone digital block, what is the recommended approach?

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[2025-11-30 7:35 a.m.] mole99
Normally, you wouldn't run metal fill for a standalone block.

One way to do that, however, is to add the `KLayout.Filler` step after one the StreamOut steps in the Classic flow. You can do this directly in the config.


[2025-11-30 7:48 a.m.] buck_042
Thanks! May I ask how to do that directly in the config?


[2025-11-30 9:37 a.m.] mole99
You can find the relevant docs here: https://librelane.readthedocs.io/en/latest/usage/writing_custom_flows.html
By using `substituting_steps` and placing a "+" before the step ID. You're welcome!


[2025-11-30 5:26 p.m.] buck_042
Thank you!


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Exported 8 message(s)
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