Circuit board and display module

The utility model discloses a circuit board and a display module. The circuit board in one embodiment comprises a substrate layer, a plurality of wiring layers, a pin layer and a heat dissipation structure, wherein the substrate layer, the wiring layers and the pin layer are sequentially stacked. The heat dissipation structure comprises a heat dissipation cavity which at least penetrates through part of the wiring layers in the plurality of wiring layers, and a first guide hole which penetrates through the pin layer and extends to be conducted with the first end of the heat dissipation cavity in the direction deviating from the stacking direction; the second guide hole penetrates through the pin layer and extends to be conducted with the second end of the heat dissipation cavity in the direction away from the stacking direction, and the orthographic projection of the first end of the heat dissipation cavity and the orthographic projection of the second end of the heat dissipation cavity on the substrate layer are oppositely arranged. Based on the heat dissipation structure provided by the embodiment of the utility model, the heat dissipation cavity, the first guide hole and the second guide hole form a heat dissipation channel capable of carrying out air flow exchange with external air, so that heat dissipation of the heat dissipation structure is realized, and the poor display of the display panel caused by heat conduction from a heating electronic component to the display panel is improved.