Where do currents flow on a rough conductor surface

Do they travel over the bumps or between them? To explore this, I conducted a numerical experiment using the Simbeor 3DTF solver, which employs Trefftz finite elements—ideal for examining the interiors of conductive materials. This video demonstrates the plane quasi-TEM wave current density on a solid copper surface covered with 1 µm tall and 0.5 µm by 0.5 µm wide copper posts (with a skin depth of about µm). While the geometry is simplified and doesn't perfectly mimic a real rough surface, it might challenge your assumptions about current flow. Could you imagine how currents behave in this scenario? What do you think they would look like at 100 GHz? Find out more in this video: • How Interconnects Work™: Rough conduc... #simbeor #electromagnetics #signal_integrity #conductor_roughness