RESISTANCE-FORMED SUBSTRATE AND METHOD FOR MANUFACTURING SAME

1 . A resistance-formed substrate comprising:

a first insulating layer;

a first wiring formed on a first surface of the first insulating layer;

a thin-film resistance layer formed on a second surface of the first insulating layer and including nickel as a main component; and

a first via-hole conductor penetrating through the first insulating layer, and electrically connected to the first wiring and the thin-film resistance layer,

wherein the first via-hole conductor includes:

a metal part including

a low-melting point metal including tin and bismuth and having a melting point of 300° C. or lower, and

a high-melting point metal including at least one of copper and silver and having a melting point of 900° C. or higher; and

a paste resin part, and

wherein the first via-hole conductor is brought into contact with the thin-film resistance layer at both the paste resin part and the metal part.

2 . The resistance-formed substrate of claim 1 , further comprising:

a second wiring coupled to the first via-hole conductor via the thin-film resistance layer on the second surface of the insulating layer.

3 . The resistance-formed substrate of claim 2 ,

wherein the thin-film resistance layer is integrated with the second wiring.

4 . The resistance-formed substrate of claim 3 ,

wherein the thin-film resistance layer is brought into surface contact with a surface of the second wiring.

5 . The resistance-formed substrate of claim 2 ,

wherein the thin-film resistance layer has a different shape from that of the second wiring.

6 . The resistance-formed substrate of claim 1 , further comprising:

a diffusion portion in which nickel included in the thin-film resistance layer diffuses into the metal part, and

wherein the metal part and the thin-film resistance layer are coupled to each other through the diffusion portion.

7 . The resistance-formed substrate of claim 1 ,

wherein the thin-film resistance layer includes phosphorus.

8 . The resistance-formed substrate of claim 1 ,

wherein the paste resin part is scattered in a contact portion between the thin-film resistance layer and the first via-hole conductor.

9 . The resistance-formed substrate of claim 1 , further comprising:

a second insulating layer laminated on the second surface of the first insulating layer.

10 . The resistance-formed substrate of claim 9 , further comprising:

a second via-hole conductor penetrating through the second insulating layer and connected to the thin-film resistance layer.

11 . The resistance-formed substrate of claim 1 , further comprising:

a third insulating layer laminated on the first surface of the first insulating layer.

12 . A method for manufacturing a resistance-formed substrate, the method comprising:

bonding a protective film to at least one surface of prepreg;

forming through-holes by perforating the prepreg covered with the protective film from an outer side of the protective film;

filling the through-holes with conductive paste including

a low-melting point metal powder including tin and bismuth, and having a melting point of 300° C. or lower,

a high-melting point metal powder including at least one of copper and silver, and having a melting point of 900° C. or higher, and

uncured resin;

forming protruding portions by peeling off the protective film such that a part of the conductive paste protrudes from each of the through-holes;

disposing and pressure-laminating composite foil formed by laminating a thin-film resistance layer including nickel as a main component and copper foil onto each other on the protruding portion, such that the thin-film resistance layer is disposed to a conductive paste side; and

heating the conductive paste to a temperature not lower than a melting point of the low-melting point metal powder.

13 . The method for manufacturing a resistance-formed substrate of claim 12 ,

wherein further heating at a temperature of 200° C. or higher is carried out after the heating of the conductive paste.