Why no routing on TopMetal 1&2 ?

[maliberty]

@KrzysztofHerman in https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/blob/7e8900be6942b8f67e67211f84a24089fde3b690/flow/platforms/ihp-sg13g2/config.mk#L94 you set the max routing layer to Metal5. I'm wondering why you excluded TopMetal 1&2? There is a fair amount of routing resource on those layers even with pdn stripes.

[KrzysztofHerman]

@maliberty TopMetal1 and TopMetal2 are thick (3 um) aluminum metals typically used for power grid and for redistribution layer routing. Anyway if someone needs these layers for routing it can be easily changed in the configuration.

[maliberty]

Do you use bumps for packing at IHP? I was aware of the need for RDL. The power grid doesn't use all the resources and routers can avoid it.