US4699702A
Expired / Lapsed
US
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Process for preparing soft magnetic film of Permalloy
Assignee: Sharp Corp
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Filing: 1986-09-12
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Granted: 1987-10-13
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Expires: 2006-09-12
Abstract
Abstract A process for preparing a soft magnetic film of Permalloy on a rugged substrate in an inert gas atmosphere by a multielectrode sputtering method wherein the target voltage and the target current are independently controllable, the Permalloy film being prepared by: (a) setting the inert gas pressure and the target voltage at values below the critical values where the coercive force of the Permalloy film abruptly increases when the film is formed on a flat substrate, and (b) applying to the rugged substrate during film formation a negative bias voltage not lower than a specific value determined by an angle of inclination formed by a stepped portion in the rugged substrate.
Inventors
- 👤 Ryoji Minakata
- 👤 Toru Kira
- 👤 Mitsuhiko Yoshikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:56
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/34; C23C14/35; C23C14/354; C23C14/355; H; H01; H01F; H01F41/00; H01F41/14; H01F41/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A process for preparing a soft magnetic film of Permalloy on a rugged substrate in an inert gas atmosphere by a multielectrode sputtering method wherein the target voltage and the target current are independently controllable, the Permalloy film being prepared by: (a) setting the inert gas pressure and the target voltage at values below the critical values where the coercive force of the Permalloy film abruptly increases when the film is formed on a flat substrate, and (b) applying to the rugged substrate during film formation a negative bias voltage not lower than a specific value determined by an angle of inclination formed by a stepped portion in the rugged substrate.
Claim 2
Dependent Claim
111 words
A process for preparing a soft magnetic film of Permalloy on a rugged substrate in an inert gas atmosphere by a multielectrode sputtering method wherein the target voltage and the target current are independently controllable, the Permalloy film being prepared by: (a) setting the inert gas pressure and the target voltage at values below the critical values where the coercive force of the Permalloy film abruptly increases when the film is formed on a flat substrate, and (b) applying to the rugged substrate during film formation a negative bias voltage not lower than a specific value determined by an angle of inclination formed by a stepped portion in the rugged substrate.
Claim 3
Dependent Claim
30 words
A process as defined in claim 1 wherein the inert gas pressure is set to not higher than 6 mtorr, and the target voltage to not higher than 500 V.
Claim 4
Dependent Claim
28 words
A process as defined in claim 1 wherein the inert gas pressure is set to 2 to 4 mtorr, and the target voltage to 200 to 400 V.
Claim 5
Dependent Claim
17 words
A process as defined in claim 1 wherein the negative bias voltage is 60 to 100 V.
Claim 6
Dependent Claim
23 words
A process as defined in claim 1 wherein the multielectrode sputtering method is a d.c. triode sputtering method or d.c. tetrode sputtering method.
Claim 7
Dependent Claim
14 words
A process as defined in claim 1 wherein the inert gas is argon gas.
Claim 8
Dependent Claim
33 words
A process as defined in claim 1 wherein the Permalloy is Ni-Fe two-element Permalloy or a multi-element Permalloy prepared by adding the third element of Mo, Ti, Cr, V or Nb to Ni-Fe.
Claim 9
Dependent Claim
31 words
A process as defined in claim 1 wherein the rugged substrate is a magnetic substrate of Ni-Fe ferrite or Mn-Zn ferrite or a nonmagnetic substrate having a Permalloy or Sendust layer.
References Cited (Backward Citations)
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Cited
US3361659A
Cited
US3625849A
Cited
US4159909A
Cited
US4487675A
Cited
US4484995A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-12 | 1991-04-13 | 1991-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-12 | 1995-04-13 | 1995-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-12 | 1999-04-13 | 1999-10-13 | $7700.00 | Window Closed / Lapsed |