Inductor built-in substrate
An inductor built-in substrate includes a core substrate having openings and first through holes, a magnetic resin filled in the openings and having second through holes, first through-hole conductors formed in the first through holes respectively such that each of the first through-hole conductors includes a metal film, second through-hole conductors formed in the second through holes respectively such that each of the second through-hole conductors includes a metal film, first through-hole lands formed on the core substrate such that each of the first through-hole lands includes a lowermost layer including a metal foil and that the first through-hole lands are connected to the first through-hole conductors respectively, and second through-hole lands formed on the magnetic resin such that each of the second through-hole lands includes a lowermost layer including a plating film and that the second through-hole lands are connected to the second through-hole conductors respectively.
1. An inductor built-in substrate, comprising:
a core substrate having a plurality of openings and a plurality of first through holes;
a magnetic resin filled in the openings and having a plurality of second through holes;
a plurality of first through-hole conductors formed in the plurality of first through holes respectively such that each of the first through-hole conductors comprises a metal film;
a plurality of second through-hole conductors formed in the plurality of second through holes respectively such that each of the second through-hole conductors comprises a metal film;
a plurality of first through-hole lands formed on the core substrate such that each of the first through-hole lands includes a lowermost layer comprising a metal foil and that the plurality of first through-hole lands is connected to the plurality of first through-hole conductors respectively; and
a plurality of second through-hole lands formed on the magnetic resin such that each of the second through-hole lands includes a lowermost layer comprising a plating film and that the plurality of second through-hole lands is connected to the plurality of second through-hole conductors respectively.
2. The inductor built-in substrate according to claim 1 , wherein the plurality of first through-hole lands is formed such that each of the first through-hole lands includes the metal film extending from a respective one of the first through-hole conductors, and a shield layer formed on a core substrate side of the metal film, and the plurality of second through-hole lands is formed such that each of the second through-hole lands includes the metal film extending from a respective one of the second through-hole conductors, and a shield layer formed on a magnetic resin side of the metal film.
3. The inductor built-in substrate according to claim 2 , wherein the plurality of first through-hole lands is formed such that each of the first through-hole lands includes the shield layer comprising an electroless plating film and an electrolytic plating film, and the plurality of second through-hole lands is formed such that each of the second through-hole lands includes the shield layer comprising an electroless plating film and an electrolytic plating film.
4. The inductor built-in substrate according to claim 3 , wherein the magnetic resin includes an iron oxide filler in an amount of 60% by weight or more.
5. The inductor built-in substrate according to claim 4 , wherein the plurality of first through-hole conductors is formed such that each of the first through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film, and the plurality of second through-hole conductors is formed such that each of the second through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film.
6. The inductor built-in substrate according to claim 4 , wherein the plurality of first through-hole conductors and the plurality of second through-hole conductors are formed such that the metal film in each of the first through-hole conductors has a thickness that is greater than a thickness of the metal film in each of the second through-hole conductors.
7. The inductor built-in substrate according to claim 3 , wherein the plurality of first through-hole conductors is formed such that each of the first through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film, and the plurality of second through-hole conductors is formed such that each of the second through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film.
8. The inductor built-in substrate according to claim 3 , wherein the plurality of first through-hole conductors and the plurality of second through-hole conductors are formed such that the metal film in each of the first through-hole conductors has a thickness that is greater than a thickness of the metal film in each of the second through-hole conductors.
9. The inductor built-in substrate according to claim 2 , wherein the magnetic resin includes an iron oxide filler in an amount of 60% by weight or more.
10. The inductor built-in substrate according to claim 2 , wherein the plurality of first through-hole conductors is formed such that each of the first through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film, and the plurality of second through-hole conductors is formed such that each of the second through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film.
11. The inductor built-in substrate according to claim 2 , wherein the plurality of first through-hole conductors and the plurality of second through-hole conductors are formed such that the metal film in each of the first through-hole conductors has a thickness that is greater than a thickness of the metal film in each of the second through-hole conductors.
12. The inductor built-in substrate according to claim 1 , wherein the magnetic resin includes an iron oxide filler in an amount of 60% by weight or more.
13. The inductor built-in substrate according to claim 12 , wherein the plurality of first through-hole conductors is formed such that each of the first through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film, and the plurality of second through-hole conductors is formed such that each of the second through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film.
14. The inductor built-in substrate according to claim 12 , wherein the plurality of first through-hole conductors and the plurality of second through-hole conductors are formed such that the metal film in each of the first through-hole conductors has a thickness that is greater than a thickness of the metal film in each of the second through-hole conductors.
15. The inductor built-in substrate according to claim 1 , wherein the plurality of first through-hole conductors is formed such that each of the first through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film, and the plurality of second through-hole conductors is formed such that each of the second through-hole conductors includes the metal film comprising an electroless plating film and an electrolytic plating film.
16. The inductor built-in substrate according to claim 15 , wherein the plurality of first through-hole conductors and the plurality of second through-hole conductors are formed such that the metal film in each of the first through-hole conductors has a thickness that is greater than a thickness of the metal film in each of the second through-hole conductors.
17. The inductor built-in substrate according to claim 1 , wherein the plurality of first through-hole conductors and the plurality of second through-hole conductors are formed such that the metal film in each of the first through-hole conductors has a thickness that is greater than a thickness of the metal film in each of the second through-hole conductors.
18. The inductor built-in substrate according to claim 1 , wherein the plurality of first through holes and the plurality of second through holes are formed such that a diameter of each of the first through holes is substantially equal to a diameter of each of the second through holes.
19. The inductor built-in substrate according to claim 1 , wherein the plurality of first through-hole lands and the plurality of second through-hole lands are formed such that a diameter of each of the first through-hole lands is substantially equal to a diameter of each of the second through-hole lands.
20. The inductor built-in substrate according to claim 1 , wherein the plurality of second through-hole lands is formed such that a diameter of each of the second through-hole lands is smaller than a diameter of each of the openings in which the magnetic resin is filled.