Multilayer wiring plate and method for fabricating same

1. A multilayer wiring plate, wherein a coaxial wire including a signal line, an insulation coating around the signal line, and an outer peripheral conductor arranged on the insulation coating, is arranged in an inner layer of the multilayer wiring plate, a metal film circuit formed by circuit-processing metal foil or a plated layer is separated from the coaxial wire by the intermediary of an insulating layer, and the metal film circuit and the outer peripheral conductor are connected, and the metal film circuit and the signal line of the coaxial wire are connected,

wherein a signal line connection part that connects the signal line of the coaxial wire to the metal film circuit, includes:

a penetration hole A that passes through the insulating layer and the outer peripheral conductor of the coaxial wire;

the coaxial wire arranged inside the penetration hole A in a state in which the outer peripheral conductor and the insulation coating are removed from the signal line of the coaxial wire;

a hole filling resin filled inside the penetration hole A;

a penetration hole B that passes through the hole filling resin and the signal line of the coaxial wire; and

a plated layer arranged on an inner wall of the penetration hole B.

2. The multilayer wiring plate according to claim 1 , wherein the metal film circuit is a ground, and the outer peripheral conductor of the coaxial wire is connected to the ground through a surface layer circuit.

3. The multilayer wiring plate according to claim 2 , wherein the surface layer circuit and the ground are connected through a non-penetration through-hole or a penetration through-hole.

4. The method for fabricating the multilayer wiring plate according to claim 3 , the method comprising:

a step of forming a non-penetration hole of a depth such that the non-penetration hole does not reach the outer peripheral conductor of the coaxial wire from each of front and back surfaces of the multilayer wiring plate;

a step of laser-processing a bottom part of the non-penetration hole, removing the outer peripheral conductor of the coaxial wire, leaving the signal line, and forming the penetration hole A;

a step of filling the hole filling resin inside the penetration hole A;

a step of forming the penetration hole B of a diameter smaller than a diameter of the penetration hole A in the hole filling resin filled inside the penetration hole A, and exposing a cross section of the signal line of the coaxial wire to an inner wall of the penetration hole B;

a step of forming the plated layer inside the penetration hole B where the cross section of the signal line of the coaxial wire is exposed;

a step of forming a non-penetration hole reaching the outer peripheral conductor of the coaxial wire from the surface layer circuit, and exposing the outer peripheral conductor of the coaxial wire to a bottom part of the non-penetration hole; and

a step of forming the plated layer inside the non-penetration hole where the outer peripheral conductor of the coaxial wire is exposed.

5. A method for fabricating the multilayer wiring plate according to claim 1 , the method comprising:

a step of forming a non-penetration hole of a depth such that the non-penetration hole does not reach the outer peripheral conductor of the coaxial wire from each of front and back surfaces of the multilayer wiring plate;

a step of laser-processing a bottom part of the non-penetration hole, removing the outer peripheral conductor of the coaxial wire, leaving the signal line, and forming the penetration hole A;

a step of filling the hole filling resin inside the penetration hole A;

a step of forming the penetration hole B of a diameter smaller than a diameter of the penetration hole A in the hole filling resin filled inside the penetration hole A, and exposing a cross section of the signal line of the coaxial wire to an inner wall of the penetration hole B; and

a step of forming the plated layer inside the penetration hole B where the cross section of the signal line of the coaxial wire is exposed.

6. A multilayer wiring plate, comprising:

a coaxial wire including a signal line, an insulation coating around the signal line, and an outer peripheral conductor arranged on the insulation coating;

a metal film circuit;

an insulating layer provided between the coaxial wire and the metal film circuit;

a signal line connection part connecting the signal line of the coaxial wire to the metal film circuit, the signal line connection part comprising:

a penetration hole A that passes through the insulating layer and the outer peripheral conductor of the coaxial wire;

a first portion of the signal line of the coaxial wire arranged inside the penetration hole A in a state in which the outer peripheral conductor and the insulation coating are removed;

a hole filling resin filling an outer peripheral portion of the penetration hole A;

a penetration hole B that passes through the hole filling resin and another portion of the first portion of the signal line of the coaxial wire; and

a plated layer arranged on an inner wall of the penetration hole B,

wherein the metal film circuit and the outer peripheral conductor and the signal line of the coaxial wire are connected.

7. The multilayer wiring plate according to claim 6 , wherein the metal film circuit is a ground, and the outer peripheral conductor of the coaxial wire is connected to the ground through a surface layer circuit.

8. The multilayer wiring plate according to claim 7 , wherein the surface layer circuit and the ground are connected through a non-penetration through-hole.

9. The multilayer wiring plate according to claim 7 , wherein the surface layer circuit and the ground are connected through a penetration through-hole.

10. A method for fabricating the multilayer wiring plate according to claim 6 , the method comprising:

forming a non-penetration hole of a depth such that the non-penetration hole does not reach the outer peripheral conductor of the coaxial wire from each of front and back surfaces of the multilayer wiring plate;

laser-processing a bottom part of the non-penetration hole, removing the outer peripheral conductor of the coaxial wire, leaving the first portion of the signal line, and forming the penetration hole A;

the hole filling resin inside the penetration hole A;

forming the penetration hole B of a diameter smaller than a diameter of the penetration hole A in the hole filling resin filled inside the penetration hole A, and exposing a cross section of the signal line of the coaxial wire to an inner wall of the penetration hole B; and

forming the plated layer inside the penetration hole B and in contact with the cross section of the signal line of the coaxial wire exposed to the inner wall of the penetration hole B.

11. The method for fabricating the multilayer wiring plate according to claim 8 , the method comprising:

forming a non-penetration hole of a depth such that the non-penetration hole does not reach the outer peripheral conductor of the coaxial wire from each of front and back surfaces of the multilayer wiring plate;

laser-processing a bottom part of the non-penetration hole, removing the outer peripheral conductor of the coaxial wire, leaving the first portion of the signal line, and forming the penetration hole A;

filling the hole filling resin inside the penetration hole A;

forming the penetration hole B of a diameter smaller than a diameter of the penetration hole A in the hole filling resin filled inside the penetration hole A, and exposing a cross section of the signal line of the coaxial wire to an inner wall of the penetration hole B;

forming the plated layer inside the penetration hole B and in contact with the cross section of the signal line of the coaxial wire exposed to the inner wall of the penetration hole B;

forming a non-penetration hole reaching the outer peripheral conductor of the coaxial wire from the surface layer circuit, and exposing the outer peripheral conductor of the coaxial wire to a bottom part of the non-penetration hole; and

forming the plated layer inside the non-penetration hole and in contact with the cross section of the signal line of the coaxial wire exposed to the inner wall of the penetration hole B.

12. A method for fabricating a multilayer wiring plate, comprising:

providing a multilayer wiring plate comprising a coaxial wire including a signal line, an insulation coating around the signal line, and an outer peripheral conductor arranged on the insulation coating; a metal film circuit; and an insulating layer provided between the coaxial wire and the metal film circuit;

forming non-penetration holes from each of front and back surfaces of the multilayer wiring plate to depths such that each of the non-penetration holes does not reach the outer peripheral conductor of the coaxial wire;

laser-processing a bottom part of each of the non-penetration holes to remove the outer peripheral conductor of the coaxial wire, leaving a first portion of the signal line, and forming a penetration hole A;

filling a hole filling resin inside the penetration hole A;

forming a penetration hole B of a diameter smaller than a diameter of the penetration hole A in the hole filling resin filled inside the penetration hole A, and exposing a cross section of the signal line of the coaxial wire to an inner wall of the penetration hole B; and

forming a plated layer inside the penetration hole B and in contact with the cross section of the signal line of the coaxial wire exposed to the inner wall of the penetration hole B.