Inductor and electric power supply using it

• US 7,868,728 B2
• Filed: 01/25/2010
• Issued: 01/11/2011
• Est. Priority Date: 05/08/2006
• Status: Active Grant

• Current Assignee: Ibiden Co., Ltd.
• Original Assignee: Ibiden Co., Ltd.
• Inventors: Kato, Shinobu, Kariya, Takashi, Mano, Yasuhiko
• Primary Examiner(s): NGUYEN, TUYEN T
• Application Number:
  US12/692,907
• Publication Number:
  US 20100117779A1
• Time in Patent Office: 351 Days
• Field of Search: 336/65, 336/83, 336/200, 336232-234, 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

An inductor embedded in a printed wiring board includes a conductor extending in the thickness direction of a printed circuit board and a magnetic body that is in contact with the conductor with no gap therebetween. For example, the magnetic body is composed of ferrite having a cylindrical tubular shape. The conductor is composed of a copper film formed by plating on an inner peripheral surface of the cylindrical tubular ferrite. The inductor is inserted in the thickness direction of the printed wiring board.

Claims

1. A printed wiring board comprising:

a core substrate;

a plurality of conductive circuits formed on top and bottom surfaces of the core substrate, respectively;

a through-hole conductor formed in the core substrate and electrically connecting the conductive circuits;

an inductor formed in the core substrate; and

a build-up layer formed on the core substrate and comprising a plurality of insulating layers and a plurality of conductive circuits, the insulating layers and conductive circuits of the build-up layer being alternately laminated, the conductive circuits in the build-up layer provided on different layers being electrically connected each other through at least one via hole conductor;

wherein said inductor includes a magnetic body that extends in the thickness direction of the core substrate and that has a through-hole and a conductor provided on an inner surface of the through-hole.

2. The printed wiring according to claim 1, further comprising a via conductor provided on the inductor.

3. The printed wiring board according to claim 1, wherein the conductor comprises copper.

4. The printed wiring board according to claim 1, wherein the conductor comprises copper and has a substantially cylindrical shape.

5. The printed wiring board according to claim 1, wherein the conductor comprises copper and has a substantially hollow cylindrical shape.

6. The printed wiring board according to claim 1, wherein the magnetic body is surrounding a side face of the conductor.

7. The printed wiring board according to claim 1, wherein the magnetic body comprises ferrite.

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

9. The printed wiring board according to claim 1, wherein the magnetic body comprises a composite material containing a magnetic powder and a resin.

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

11. The printed wiring board according to claim 1, further comprising a dielectric material surrounding a side face of the magnetic body.

12. The printed wiring board according to claim 1, further comprising a dielectric material comprising an under-fill material having low thermal expansion characteristics.