Circuit board and electronic device

A circuit board, comprising a first wiring board, wherein the first wiring board comprises a first substrate and a first wiring layer disposed on a first side surface of the first substrate, and the first wiring layer comprises a first ground wiring;

• the circuit board further comprises a first protective layer and a first electromagnetic interference shielding layer which are sequentially stacked on a side of the first wiring layer away from the first substrate;
• and the first protective layer is provided with a first opening, wherein the first opening exposes at least a portion of the first ground wiring and is filled with a first conductive material, and a height difference between a surface of the first conductive material and a surface of the first protective layer away from the first substrate is from 0 micron to 2 microns, and the first conductive material connects the first electromagnetic interference shielding layer to the first ground wiring;
• and wherein the first wiring board further comprises a second wiring layer disposed on a second side surface of the first substrate, and the second wiring layer comprises a second ground wiring;
• the circuit board further comprises a first insulating layer, a second electromagnetic interference shielding layer and a conductive layer which are sequentially stacked on a side of the second wiring layer away from the first substrate;
• and the first insulating layer and the second electromagnetic interference shielding layer are provided with a second opening, wherein the second opening exposes at least a portion of the second ground wiring and is filled with a second conductive material, wherein a height difference between a surface of the second conductive material and a surface of the second electromagnetic interference shielding layer away from the first substrate is from 0 micron to 2 microns, and the second conductive material connects the conductive layer to the second ground wiring.