Step S1-4: as shown in FIG. 5, cutting the inner layer conductive component 110 along the pre-cutting slit 29 to form a first slot 27 penetrating the inner layer conductive component 110. The first slot 27 completely penetrates the inner layer conductive component 110.

Step S2: as shown in FIG. 6, provide a first insulating layer 113, a second insulating layer 114, a first conductive material layer 25, and a second conductive material layer 26. Second slot 28 is formed on the first insulating layer 113 to correspond to the first slot 27. The second insulating layer 114 is arranged on the side of the inner layer conductive component 110 away from the first insulating layer 113. The first conductive material 25 is arranged on the side of the first insulating layer 113 away from the inner layer conductive component 110. The second conductive material 26 is arranged on the side of the second insulating layer 114 away from the inner layer conductive element 110.

Step S3: pressing the first insulating layer 113, the second insulating layer 114, the first conductive material layer 25, the second conductive material layer 26, and the inner layer conductive component 110 to form a first groove 103;

In one embodiment, the materials of the first insulating layer 113 and the second insulating layer 114 are semi-fluid materials.