Circuit board, preparation method thereof, and electronic device

A circuit board preparation method, comprising:

• preparing a substrate, wherein the substrate defines a first through-hole;
• embedding a metal block in the first through-hole for fixedly connecting the metal block and an inner wall of the first through-hole;
• arranging a conductive line layer on at least one side surface of the substrate, wherein the conductive line layer partially covers an opening of the first through-hole on a corresponding side surface of the substrate;
• and
• arranging a conductive channel connected to the metal block in a side of the conductive line layer back to the substrate, such that the conductive line layer is electrically connected to the metal block through the conductive channel, and at least one third through-hole corresponding to the conductive channel is defined in the conductive line laver.

An electronic device, comprising:

• a circuit board and a functional component;
• wherein the circuit board comprises:
• a substrate, defining a first through-hole;
• a metal block, embedded in the first through-hole and fixedly connected to the substrate;
• a conductive line layer, arranged on at least one side surface of the substrate;
• wherein the conductive line layer partially covers an opening of the first through-hole on a corresponding side surface of the substrate;
• and
• a conductive channel, penetrating the conductive line layer and extending to the metal block;
• wherein the conductive line layer defines at least one third through-hole corresponding to the conductive channel;
• the conductive channel comprises a second through-hole and a conductive medium plated on a wall of the second through-hole;
• and an end of the conductive medium is connected to the conductive line layer, and another end of the conductive medium is connected to the metal block;
• wherein the functional component is arranged on the conductive line layer on a side of the substrate.