Circuit board, light-emitting substrate, backlight module, and display apparatus

A circuit board, comprising:

• a substrate;
• a first conductive layer disposed on a side of the substrate;
• the first conductive layer including a plurality of signal lines and a plurality of first conductive portions;
• a first insulating layer disposed on a side of the first conductive layer away from the substrate;
• the first insulating layer being provided with first via holes extending through the first insulating layer;
• and
• a second conductive layer disposed on a side of the first insulating layer away from the substrate;
• the second conductive layer including a plurality of second conductive portions;
• a second conductive portion passing through a first via hole to be in electrical contact with a first conductive portion;
• wherein
• the first conductive layer and the second conductive layer each include at least one main conductive layer;
• at least one of the first conductive layer and the second conductive layer further includes a stop layer, and the stop layer is disposed between two adjacent main conductive layers;
• a material of the stop layer includes nickel or a nickel alloy with a nickel atomic percentage greater than 40%, and a content of nickel atoms in a portion of the stop layer proximate to the substrate is less than a content of nickel atoms in a portion of the stop layer away from the substrate 11.