Patent ID: 11744004

Abstract:
A circuit board includes a first outer wiring layer, a circuit substrate, and a second outer wiring layer stacked. The circuit substrate includes a first inner wiring layer, an insulating layer, and a second inner wiring layer stacked. A plurality of thermally conductive pillars is arranged at intervals on the first inner wiring layer, a liquid storage space is formed between every two adjacent thermally conductive pillars, and a thermally conductive agent is received in the liquid storage space. The first outer wiring layer is formed on the plurality of thermally conductive pillars. The second outer wiring layer is formed the second inner wiring layer. A first groove penetrates the second outer wiring layer, the second inner wiring layer and the insulating layer, exposes a portion of the first inner wiring layer, and corresponds to the thermally conductive pillars. At least one heating element is installed in the first groove.