US5045637A
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Magnetic shielding material
Assignee: Nippon Steel Corp
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Filing: 1990-07-17
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Granted: 1991-09-03
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Expires: 2010-07-17
Abstract
Abstract A magnetic shielding material is described which has a laminate structure comprising a ferromagnetic sheet having a high saturation magnetic flux density, a ferromagnetic sheet having a high magnetic permeability and a non-magnetic sheet. The high saturation magnetic flux density sheet includes a sheet of mold steel, silicon steel or an iron-cobalt alloy. The high magnetic permeability sheet includes an amorphous alloy foil or a laminate thereof. The magnetic shielding material may further have at least one foil of an electromagnetic wave-shielding material.
Inventors
- 👤 Takashi Sato
- 👤 Toshio Yamada
- 👤 Masami Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:55
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0075; B; B32; B32B; B32B15/00; B32B15/01; B32B15/011
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
184 words
A magnetic shielding material having a laminate structure comprising a basic laminate comprised of (a) a ferromagnetic sheet having a high saturation magnetic flux density, (b) a non-magnetic sheet and (c) an amorphous ferromagnetic sheet having a high magnetic permeability, said sheets (a), (b) and (c) in the basic laminate being superposed in this order and so that the ferromagnetic sheet (a) confronts a magnetic field-generating source; the ferromagnetic sheet (a) having a saturation magnetic flux density of at least 1.5 Tesla, and the amorphous ferromagnetic sheet (c) having a specific initial permeability of at least 1,000 and composed of an alloy having a composition represented by the formula: FE.sub.a --X.sub.b --M.sub.c wherein X represents at least one metal selected from the group consisting of Co, Ni, Cr, Mo, Nb, V and Mn, M represents at least one metalloid element selected from the group consisting of B, Si, C, P and Ge; when X is Co or Ni, b is 0 to 40 atomic % and is not larger than a, and c is 10 to 30 atomic %, (a+b+c) is 100 atomic %.
Claim 2
Dependent Claim
184 words
A magnetic shielding material having a laminate structure comprising a basic laminate comprised of (a) a ferromagnetic sheet having a high saturation magnetic flux density, (b) a non-magnetic sheet and (c) an amorphous ferromagnetic sheet having a high magnetic permeability, said sheets (a), (b) and (c) in the basic laminate being superposed in this order and so that the ferromagnetic sheet (a) confronts a magnetic field-generating source; the ferromagnetic sheet (a) having a saturation magnetic flux density of at least 1.5 Tesla, and the amorphous ferromagnetic sheet (c) having a specific initial permeability of at least 1,000 and composed of an alloy having a composition represented by the formula: FE.sub.a --X.sub.b --M.sub.c wherein X represents at least one metal selected from the group consisting of Co, Ni, Cr, Mo, Nb, V and Mn, M represents at least one metalloid element selected from the group consisting of B, Si, C, P and Ge; when X is Co or Ni, b is 0 to 40 atomic % and is not larger than a, and c is 10 to 30 atomic %, (a+b+c) is 100 atomic %.
Claim 3
Dependent Claim
42 words
A magnetic shield material as set forth in claim 1, wherein the ferromagnet sheet having a high saturation magnetic flux density comprises a layer of at least one member selected from the group consisting of mild steels, silicon steels and iron-cobalt alloys.
Claim 4
Dependent Claim
36 words
A magnetic shielding material as set forth in claim 1 wherein the ferromagnetic sheet having a high magnetic permeability is an amorphous alloy foil, a laminate thereof, an annealed amorphous alloy foil or a laminate thereof.
Claim 5
Dependent Claim
42 words
A magnetic shielding material as set forth in claim 3 wherein the total thicknness of the amorphous alloy foil or foils or annealed amorphous alloy fill or foils of the ferromagnetic sheet having a high magnetic permeabilty is 50 to 1,000 μm.
Claim 6
Dependent Claim
35 words
A magnetic shielding material as set forth in wherein the ferromagnetic sheet having a high magnetic permeability is an amorphous alloy foil or a laminate thereof, which has a thickness of at least 50 μm.
Claim 7
Dependent Claim
35 words
A magnetic shielding material as set forth in wherein the ferromagnetic sheet having a high magnetic permeability is an amorphous alloy foil or a laminate thereof, which has a thickness of at least 50 μm.
Claim 8
Dependent Claim
29 words
A magnetic shielding material as set forth in claim 1, wherein the ferromagnetic sheet having a high saturation magnetic flux density has a thickness of 0.1 to 5 mm.
Claim 9
Dependent Claim
32 words
A magnetic shielding material as set forth in claim 1, wherein the thickness of the ferromagnetic sheet having a high saturation magnetic flux density has a thickness of 0.3 to 3 mm.
Claim 10
Dependent Claim
23 words
A magnetic shielding material as set forth in claim 1, which is in the form of an enclosure structure having rounded corner portions.
Claim 11
Dependent Claim
25 words
A magnetic shielding material as set forth in claim 1, wherein the laminate structure further comprises at least one foil of an electromagnetic wave-shielding material.
Claim 12
Dependent Claim
18 words
A magnetic shielding material as set forth in claim 9, which is in the form of a panel.
Claim 13
Dependent Claim
34 words
A magnetic shielding material as set forth in claim 10, wherein the foil or foils of the electromagnetic wave-shielding material have a size larger than that of the other constituents of the laminate structure.
Claim 14
Dependent Claim
41 words
A magnetic shielding material as set forth in claim 1, herein the laminate structure is secured by non-magnetic bolts, and the side end portions of the laminate structure, the bolts and the bolt holes are coated and sealed with a sealant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |