US4439294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reactive ion etching of soft-magnetic substrates
Assignee: US Philips Corp
•
Filing: 1983-02-02
•
Granted: 1984-03-27
•
Expires: 2003-02-02
Abstract
Abstract A method of providing grooves in a body of a soft-magnetic, iron-containing material. The method includes reactive ion etching the body in a chlorine-containing or bromine-containing plasma after providing the body areas not to be etched with a mask of an inorganic material such as Al 2 O 3 .
Inventors
- 👤 Thijs W. Bril
- 👤 Willibrordus G. M. van den Hoek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:32
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/193; C; C04; C04B; C04B41/00; C04B41/53; C04B41/5338; C04B41/5346; C23; C23F; C23F4/00; H; H01; H01F; H01F41/00; H01F41/32; H01F41/34
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
65 words
A method of providing grooves in a substrate of a soft-magnetic, iron-containing material selected from the group consisting of ferrites, Ni-Fe alloys and Al-Fe-Si alloys, comprising reactive ion etching the substrate in a chlorine-containing or bromine-containing plasma, the substrate areas not to be etched being covered by a mask of an inorganic material which is not substantially more rapidly etched than the soft-magnetic, iron-containing material.
Claim 2
Independent Claim
65 words
A method of providing grooves in a substrate of a soft-magnetic, iron-containing material selected from the group consisting of ferrites, Ni-Fe alloys and Al-Fe-Si alloys, comprising reactive ion etching the substrate in a chlorine-containing or bromine-containing plasma, the substrate areas not to be etched being covered by a mask of an inorganic material which is not substantially more rapidly etched than the soft-magnetic, iron-containing material.
Claim 3
Dependent Claim
48 words
A method as claimed in claim 1, characterized in that the substrate is Mn-Zn-ferrous ferrite or Ni-Zn ferrite and is provided, prior to the etching step with a mask of a material selected from the group of materials consisting of Ni, alloys of Ni and Fe, and Al.
Claim 4
Dependent Claim
31 words
A method as claimed in claim 2, characterized in that the Ni and the alloys of Ni and Fe, respectively, are grown on the substrate by electrodeposition through a lacquer pattern.
Claim 5
Dependent Claim
36 words
A method as claimed in claim 1, characterized in that the substrate consists of Mn-Zn-ferrous ferrite or Ni-Zn ferrite and is coated, prior to the etching step with a mask of Al 2 O 3 .
Claim 6
Dependent Claim
37 words
A method as claimed in claim 4, characterized in that the Al 2 O 3 mask is formed by making a pattern in an Al 2 O 3 layer by means of a reactive ion etching process.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1, characterized in that the reactive ion etching step is carried out with powers from 0.5-2.5 W/cm 2 .
Claim 8
Dependent Claim
33 words
A method as claimed in claim 6, characterized in that the reactive ion etching step is carried out in a chlorine-containing or bromine-containing plasma having a partial pressure of approximately 10 -2 Torr.
References Cited (Backward Citations)
US4016062A
Cited
US4238277A
Cited
US4226691A
Cited
US4295924A
Cited
US4299680A
Cited
US4375390A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |