Ferrite magnetic film structure having magnetic anisotropy, method of manufacturing the same, and planar magnetic device employing ferrite magnetic film structure having magenetic anisotropy

• US 6,611,035 B2
• Filed: 11/06/2001
• Issued: 08/26/2003
• Est. Priority Date: 09/13/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Inoue, Tetsuo
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): NGUYEN, THINH T
• Application Number:
  US09/985,760
• Publication Number:
  US 20020048668A1
• Time in Patent Office: 658 Days
• Field of Search: 257/421, 257/258, 257/275, 257/351, 257/528, 428/693, 427/116, 427/129, 427/275
• US Class Current: 257/421
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 41/043 by thick film techniques
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

A ferrite magnetic film structure exhibiting a magnetic anisotropy, the ferrite magnetic film structure comprising, a substrate provided on one main surface thereof with a groove-like recessed portion and with a ridge-like projected portion located neighboring to the groove-like recessed portion, and a ferrite magnetic film constituted by a continuous film having a substantially flat upper surface and formed on one main surface of the substrate, wherein the ferrite magnetic film structure meets the following conditions:

(a/(a+b))(h/(t−h))≧0.047

1≧(a+b)

where “a” is a width of the ridge-like projected portion, b is a width of the groove-like recessed portion, h is a height of step between the groove-like recessed portion and the ridge-like projected portion, t is a thickness of the ferrite magnetic film at the recessed portion, and 1 is a length of the recessed portion and of the projected portion.

Claims

1. A planar magnetic device comprising:

a substrate provided on one main surface thereof with a groove-like recessed portion and with a ridge-like projected portion located neighboring to said groove-like recessed portion;

a first ferrite magnetic film formed on one main surface of the substrate and exhibiting a magnetic anisotropy; and

a planar coil conductor formed on the ferrite magnetic film.

2. The planar magnetic device according to claim 1, which further comprises a second ferrite magnetic film formed on the planar coil conductor and exhibiting a magnetic anisotropy.

3. The planar magnetic device according to claim 1, wherein said first ferrite magnetic film has a substantially flat upper surface.

4. The planar magnetic device according to claim 1, wherein said groove-like recessed portion and said ridge-like projected portion are both spiral in shape.

5. The planar magnetic device according to claim 1, wherein said groove-like recessed portion and said ridge-like projected portion are both concentric in shape.

6. The planar magnetic device according to claim 1, wherein at least surface portion of said substrate is formed of a metal selected from the group consisting of zirconium, copper and aluminum, and one main surface of said substrate is covered with a metal diffusion preventive film.

7. The planar magnetic device according to claim 1, wherein said substrate is formed of insulating substance selected from the group consisting of SiN and SiO₂.

8. A planar magnetic device comprising:

a substrate;

a magnetic film formed on one main surface of the substrate and exhibiting a magnetic anisotropy; and

a planar coil conductor formed on said magnetic film,

wherein said magnetic film is provided with uniaxial magnetic anisotropy in an inline direction of said substrate so as to allow an extending direction of said planar coil conductor to be maintained parallel with easy direction of magnetization.

9. A hybrid integrated circuit comprising:

a circuit board;

a semiconductor chip mounted on said circuit board; and

an inductor mounted on said circuit board and including

a substrate provided on one main surface thereof with a groove-like recessed portion and with a ridge-like projected portion located neighboring to said groove-like recessed portion;

a ferrite magnetic film formed on one main surface of the substrate and exhibiting a magnetic anisotropy; and

a planar coil conductor formed on the ferrite magnetic film,

wherein said semiconductor chip and said inductor constitute an integrated circuit.

10. The hybrid integrated circuit according to claim 9, wherein said ferrite magnetic film has a substantially flat upper surface.

11. A hybrid integrated circuit comprising:

a circuit board;

a semiconductor chip mounted on said circuit board; and

an inductor mounted on said circuit board and including

a substrate;

a magnetic film formed on one main surface of the substrate and exhibiting a magnetic anisotropy; and

a planar coil conductor formed on said magnetic film,

wherein said magnetic film is provided with uniaxial magnetic anisotropy in an in-line direction of said substrate so as to allow an extending direction of said planar coil conductor to be maintained parallel with easy direction of magnetization, and said semiconductor chip and said inductor constitute an integrated circuit.

12. The planar magnetic device according to claim 11, wherein said ferrite magnetic film has a substantially flat upper surface.

13. A hybrid integrated circuit comprising:

a circuit board;

a semiconductor chip mounted on a first portion of said circuit board; and

an inductor mounted on a second portion of said circuit board,

wherein said second portion of said substrate is provided on one main surface thereof with a groove-like recessed portion and with a ridge-like projected portion located neighboring to said groove-like recessed portion, and

said inductor includes a ferrite magnetic film formed on said second portion of said substrate and exhibiting a magnetic anisotropy, and a planar coil conductor formed on the ferrite magnetic film.

14. A hybrid integrated circuit comprising:

a circuit board;

a semiconductor chip mounted on a first portion of said circuit board; and

and inductor mounted on a second portion of said circuit board and including a ferrite magnetic film formed on said second portion of said substrate and exhibiting a magnetic anisotrophy, and a planar coil conductor formed on the ferrite magnetic film.