In a first step, referring to FIG. 1, a substrate 10 is provided, and a hole is formed in the substrate 10 to form a through hole 11.

In this embodiment, one side of the substrate 10 is connected to a carrier board 102 through a separable film 101 to facilitate processing, but it is not limited to this.

In other embodiments, the separable film 101 and the carrier board 102 may be omitted. The substrate 10 is a low dielectric resin material, preferably a polyester polymer base material or a polyether polymer base material, such as polyether ether ketone (PEEK), liquid crystal polymer (LCP), etc.

In this embodiment, the through hole 11 is formed by laser processing. It can be understood that, in other examples, the through hole 11 may also be formed by mechanical processing.

In a second step, referring to FIG. 2, the through hole 11 is filled with a conductor 111 to form a conductive hole 12.

The conductor 111 is a conductive material such as conductive paste.

In a third step, referring to FIG. 3, a peelable film 13 is provided for covering one side of the substrate 10.

In this embodiment, the peelable film 13 covers the side of the substrate 10 facing away from the carrier board 102.

The peelable film 13 is a resin material such as polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.