Displaying backplane and fabricating method thereof, and displaying device

A displaying backplane, a displaying region of the displaying backplane being delimited into a first displaying region and a second displaying region, a light transmittance of the first displaying region being less than a light transmittance of the second displaying region, and the displaying backplane having a metal signal line in a trace region, wherein a plurality of sub-pixels located within the first displaying region are connected to a common cathode, and the common cathode is connected to the metal signal line;

• at least some of the plurality of sub-pixels located within the second displaying region are connected to independent cathodes, a plurality of the independent cathodes within the second displaying region are separate from each other, the displaying backplane further comprises a first electrically conductive layer, and the independent cathodes are connected to the metal signal line via the first electrically conductive layer;
• and
• the first electrically conductive layer is a planar electrode, and an orthographic projection of the planar electrode on a substrate base plate covers the second displaying region;
• or
• the first electrically conductive layer has a plurality of electrically conductive traces, and the plurality of electrically conductive traces are connected to the common cathode.