Circuit board, light-emitting substrate, backlight module, display panel and display device

A circuit board, comprising:

• a substrate;
• and
• a stress neutral layer disposed on a side of the substrate;
• wherein
• the stress neutral layer includes:
• one or more first metal layers;
• one or more second metal layers;
• wherein the one or more second metal layers and the one or more first metal layers are stacked;
• and at least one of the one or more first metal layers is made of a material for generating a tensile stress, and at least one of the one or more second metal layers is made of a material for generating a compressive stress;
• and
• a plurality of patterns, and each pattern of the plurality of patterns includes sub-patterns respectively formed by stacked layers;
• in a case where the stress neutral layer includes a plurality of first metal layers and the at least one second metal layer, in the pattern, a slope angle of a sub-pattern formed by a stacked layer farther from the substrate is less than a slope angle of a sub-pattern formed by a stacked layer closer to the substrate;
• wherein a stacked layer in the stacked layers is any one of a portion of a first metal layer, a portion of a second metal layer, or a portion of a combination film layer of a first metal layer and a second metal layer that are adjacent to each other.