Circuit board and preparation method therefor

An electronic device, comprising a circuit board;

• wherein the circuit board comprises:
• a base layer;
• a transmission wire layer, comprising a plurality of conductor tabs;
• wherein a gap is defined between each adjacent two of the plurality of conductor tabs to expose at least a portion of the base layer;
• and
• an insulating and thermally conductive layer, comprising a plurality of insulating and thermally conductive portions;
• wherein each gap is filled with a corresponding insulating and thermally conductive portion, and a height of the corresponding thermally conductive portion is greater than heights of the each adjacent two of the plurality of conductor tabs to define a connection groove,
• wherein thermally conductive portion comprises:
• a first sub thermally conductive portion, wherein the first gap is filled with the first sub thermally conductive portion;
• and a second sub thermally conductive portion, wherein the second gap is filled with the second sub thermally conductive portion,
• wherein a height of the first sub thermally conductive portion is greater than heights of each two adjacent corresponding first portions to define a part of a corresponding connection groove on a first side of the connection portion while a height of the second sub thermally conductive portion is greater than heights of each two adjacent corresponding second portions to define a part of another corresponding connection groove on a second side of the connection portion.