PLANAR MAGNETIC DEVICE AND POWER SUPPLY IC PACKAGE USING SAME

• US 20090045905A1
• Filed: 10/26/2006
• Published: 02/19/2009
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Inventors: Nakagawa, Katsutoshi, Sato, Akira, Inoue, Tetsuo
• Granted Patent: US 7,920,043 B2
• Time in Patent Office: Days
• US Class Current: 336/232
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 1/37 in a bonding agent
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/0066 with a magnetic layer
• CPC Class Codes: H01F 2017/0073 with a special conductive pattern, e.g. flat spiral
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 23/495 Lead-frames or other flat leads H01L23/498 takes precedence; lead frame interconnections between components H01L23/52
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/07802 not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: Y10T 29/4902 : Electromagnet, transformer or inductor

Abstract

A planar magnetic device 1 includes a first magnetic layer 3 and a second magnetic layer 5 that are made of a mixture of a magnetic powder 7 and a resin, and a planar coil 4 disposed between the magnetic layers. When the planar coil 4 has an adjacent winding interval W between the potions 4c of the coil and the magnetic powder 7 has a maximum particle size L, planar magnetic device 1 satisfies the relationship W>L. In the planar magnetic device 1 having the above structure, fine magnetic powder that can produce a high inductance fills the spaces between the adjacent windings. Thus, the invention can achieve a high-performance planar magnetic device, such as a thin inductor.

Claims

1. A planar magnetic device comprising a first magnetic layer and a second magnetic layer that are made of a mixture of a magnetic powder and a resin, and a planar coil disposed between the first magnetic layer and the second magnetic layer, wherein the planar coil and the magnetic powder satisfy the relationship W>

L, where w represents the intervals between adjacent windings of the planar coil and L represents the maximum particle size of the magnetic powder.

2. The planar magnetic device according to claim 1, wherein the magnetic powder contained in the magnetic layer is close to the planar coil at a distance of 1 μ

m or less or is in contact with the planar coil.

3. The planar magnetic device according to claim 1, wherein the planar coil and the magnetic powder satisfy the relationship W>

2L, where W represents the interval of the adjacent windings of the planar coil and L represents the maximum particle size of the magnetic powder.

4. The planar magnetic device according to claim 2, wherein at least three particles of the magnetic powder are disposed in a segment having a length W defined by the adjacent winding interval W of the planar coil.

5. The planar magnetic device according to claim 4, wherein at least five particles of the magnetic powder are disposed in the segment having the length W defined by the adjacent winding interval W.

6. The planar magnetic device according to any one of claims 1 to 4, wherein the magnetic powder contains at least one selected from the group consisting of amorphous alloys, fine crystal alloys, pure iron, sendust, Fe—

Ni alloys, Fe—

Si alloys, and ferrites.

7. The planar magnetic device according to claim 1, wherein the magnetic powder has an average particle size of 80 μ

m or less.

8. The planar magnetic device according to any one of claims 1 to 7, wherein the planar magnetic device has a thickness of 0.4 mm or less.

9. The planar magnetic device according to any one of claims 1 to 8, wherein the planar coil is made of a sintered body of metal powder.

10. The planar magnetic device according to any one of claims 1 to 8, wherein the planar coil is formed by etching a metal foil.

11. A power IC package comprising the planar magnetic device as set forth in any one of claims 1 to 10.

12. The power IC package according to claim 11, wherein the power IC package is integrated with an IC.