Circuit board and preparation method therefor

Disclosed are a circuit board and its preparation method. The circuit board includes a base layer, a transmission wire layer including multiple conductor tabs, and an insulating and thermally conductive layer including multiple thermally conductive portions. A gap is defined between each adjacent two of the multiple conductor tabs to expose at least a portion of the base layer, and the gap is filled with a corresponding thermally conductive portion. A height of the thermally conductive portion is larger than heights of each adjacent two of the multiple conductor tabs to define a connection groove. The circuit board the disclosure providing enhances heat dissipation performance of circuit boards.