The present disclosure provides a circuit board. The circuit board may include a number of stacked core boards each having a top surface. At least part core boards of the number of stacked core boards may include circuit layers at top surfaces thereof. A groove may be defined through the at least part core boards. A conductive material may be received in the groove configured to couple to the circuit layers of at least two core boards. A cross section of the groove may include a length in a first direction and a length in a second direction, and the length in the first direction may be greater than the length in the second direction. Electroplating solution may capable of contacting any portions of the groove to electroplate, to form the conductive material.