Inductor and electric power supply using it

• US 8,207,811 B2
• Filed: 01/06/2011
• Issued: 06/26/2012
• Est. Priority Date: 05/08/2006
• Status: Active Grant

• Current Assignee: Ibiden Co., Ltd.
• Original Assignee: Ibiden Co., Ltd.
• Inventors: Mano, Yasuhiko, Kariya, Takashi, Kato, Shinobu
• Primary Examiner(s): Nguyen, Tuyen
• Application Number:
  US12/985,475
• Publication Number:
  US 20110102122A1
• Time in Patent Office: 537 Days
• Field of Search: 336/65, 336/83, 336/200, 336/232, 257/531, 361760-766
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 17/06 with core substantially closed in itself, e.g. toroid
• CPC Class Codes: H01F 2017/002 Details of via holes for interconnecting the layers
• CPC Class Codes: H01F 2017/065 Core mounted around conductor to absorb noise, e.g. EMI filter
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16235 the bump connector connecting to a via metallisation of the item
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15312 being a pin array, e.g. PGA
• CPC Class Codes: H01L 2924/1532 the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H05K 1/0233 : Filters, inductors or a magnetic substance
• CPC Class Codes: H05K 1/115 : Via connections; Lands around holes or via connections H05K1/112 takes precedence
• CPC Class Codes: H05K 1/185 : Components encapsulated in the insulating substrate of the printed circuit or incorporated in internal layers of a multilayer circuit semiconductor chips encapsulated by interconnect and support structures H01L23/5389, H01L24/00
• CPC Class Codes: H05K 2201/086 : for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/09581 : Applying an insulating coating on the walls of holes
• CPC Class Codes: H05K 3/4046 : using auxiliary conductive elements, e.g. metallic spheres, eyelets, pieces of wire
• CPC Class Codes: H05K 3/42 : Plated through-holes or plated via connections
• CPC Class Codes: H05K 3/4602 : characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated
• CPC Class Codes: Y10T 29/4902 : Electromagnet, transformer or inductor

Abstract

A printed wiring board including a substrate having a first surface and a second surface on the opposite side of the second surface, a first conductive circuit formed on the first surface of the substrate, a second conductive circuit formed on the second surface of the substrate, a magnetic body embedded in the substrate and extending in a thickness direction of the substrate, the magnetic body having a through-hole formed through the magnetic body and extending in the thickness direction of the substrate, and a through-hole conductor formed on an inner surface of the through-hole of the magnetic body such that the first and second conductive circuits are electrically connected to each other through the through-hole conductor.

Claims

1. A printed wiring board, comprising:

a substrate having a first surface and a second surface on an opposite side of the second surface;

a first conductive circuit formed on the first surface of the substrate;

a second conductive circuit formed on the second surface of the substrate;

a magnetic body embedded in the substrate and extending in a thickness direction of the substrate, the magnetic body having a through-hole formed through the magnetic body and extending in the thickness direction of the substrate; and

a through-hole conductor formed on an inner surface of the through-hole of the magnetic body such that the first and second conductive circuits are electrically connected to each other through the through-hole conductor.

2. The printed wiring board according to claim 1, wherein the through-hole conductor comprises a plating film.

3. The printed wiring board according to claim 2, wherein the through-hole conductor comprises copper.

4. The printed wiring board according to claim 2, wherein the through-hole conductor forms a part of an inductor element of a power supply circuit formed in the printed wiring board.

5. The printed wiring board according to claim 2, wherein the magnetic body is positioned in the substrate such that a semiconductor is mounted over the magnetic body.

6. The printed wiring board according to claim 2, wherein the magnetic body is made of a ferric bulk material.

7. The printed wiring board according to claim 1, wherein the magnetic body comprises a composite material comprising a magnetic material and a nonmagnetic material.

8. The printed wiring board according to claim 1, wherein the magnetic body comprises a composite material comprising a magnetic material and a nonmagnetic material, the magnetic material comprises a carbonyl iron powder, and the nonmagnetic material comprises a resin.

9. The printed wiring board according to claim 1, wherein the magnetic body has a cylindrical shape.

10. The printed wiring board according to claim 1, further comprising:

a conductive pad formed at an end portion of the through-hole conductor such that the conductive pad covers the through-hole of the substrate.

11. A method of manufacturing a printed wiring board, comprising:

preparing an inductor comprising a magnetic body and a through-hole conductor, the magnetic body having a cylindrical shape and a through-hole, the through-hole conductor being formed on an inner surface of the through-hole of the magnetic body;

forming a through-hole through a core substrate;

embedding the inductor into the through-hole of the core substrate;

forming first copper plating layers on first and second surfaces of the core substrate, respectively;

patterning the first copper plating layers such that first conductive circuits are formed, respectively;

forming insulating layers on the first conductive circuits and the first and second surfaces of the core substrate, respectively;

forming via holes in the insulating layers, respectively;

forming second copper plating layers on the insulating layers and the via holes, respectively; and

patterning the second copper plating layers such that second conductive circuits are formed, respectively.

12. The method of manufacturing a printed wiring board according to claim 11, wherein the embedding of the inductor includes inserting the inductor into the through-hole of the core substrate and filling a space between the inductor and the through-hole with a resign material.

13. The method of manufacturing a printed wiring board according to claim 11, wherein the preparing the inductor comprises preparing a magnetic material, shaping the magnetic material into a cylindrical shape having a through-hole, sintering the magnetic material shaped into the cylindrical shape;

and copper plating on an inner surface of the through-hole of the magnetic body such that the through-hole conductor is formed.

14. The method of manufacturing a printed wiring board according to claim 13, further comprising removing a projecting portion of the magnetic body when the through-hole conductor projects from an end portion of the magnetic body.

15. The method of manufacturing a printed wiring board according to claim 11, further comprising plating an end portion of the magnetic body such that a conductive pad covering the end portion of the magnetic body is formed.

16. A method of manufacturing a printed wiring board, comprising:

preparing an inductor comprising a magnetic body which has a cylindrical shape and a through-hole;

forming a through-hole through a core substrate;

embedding the inductor into the through-hole of the core substrate;

copper-plating an inner surface of the through-hole of the magnetic body and first and second surfaces of the core substrate, respectively, such that a through-hole conductor is formed on the inner surface of the through-hole of the magnetic body and that first copper plating layers are formed on the first and second surfaces of the core substrate, respectively;

patterning the through-hole conductor on the inner surface of the through-hole of the magnetic body and the first copper plating layers such that first conductive circuits are formed, respectively;

forming insulating layers on the first conductive circuits and the first and second surfaces of the core substrate, respectively;

forming via holes in the insulating layers, respectively;

forming second copper plating layers on the first and second surfaces of the insulating layers and the via holes, respectively; and

patterning the second copper plating layers such that second conductive circuits are formed, respectively.

17. The method of manufacturing a printed wiring board according to claim 16, wherein the embedding of the inductor comprises inserting the inductor into the through-hole of the core substrate and filling a space between the inductor and the through-hole with a resign material.

18. The method of manufacturing a printed wiring board according to claim 16, further comprising plating an end portion of the magnetic body such that a conductive pad covering the end portion of the magnetic body is formed.