Patent US3905883A successfully refreshed from Google Patents.
US3905883A
Expired / Lapsed
US
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Electrolytic etching method
Assignee: Hitachi Ltd
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Filing: 1974-06-18
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Granted: 1975-09-16
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Expires: 1994-06-18
Abstract
Abstract A precise pattern figure can be formed on a thin film of permalloy, iron, nickel, cobalt and copper through an electrolysis with a mixture of ammonium persulfate and nitric acid electrolyte under control of the electrode potential. Particularly, a desired part of an electrode whose surface is in coexistence with aluminum can be electrolytically etched without damaging the aluminum.
Inventors
- 👤 Masanobu Hanazono
- 👤 Osamu Asai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:26
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/66; H10P50/663; H10P50/667; C; C25; C25F; C25F3/00; C25F3/02; C25F3/14; G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3163; H01; H01F; H01F41/00; H01F41/14; H10P95/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
76 words
AN ELECTROLYTIC ETCHING METHOD FOR ETCHING PRESICE ELECTRICAL PARTS, WHEREIN A 0.1 TO 2.5 MOL/L CONCENTRATION AMMONIUM PERSULFATE - 0.02 TO 10 MOL/L CONCENTRATION NITRIC ACID ELECTROLYTE IS USED AND A DC VOLTAGE IS APPLIED BETWEEN A CATHODE ELECTRODE OF INSOLUBLE METAL AND AN ANODE ELECTRODE INCLUDING A METAL OBJECT TO BE ETCHED, SAID METAL OBJECT BEING MADE FROM A MEMBER SELECTED FROM THE GROUP CONSISTING OF IRON, NICKEL, COBALT, COPPER AND ALLOYS THEREOF, WHEREBY A
Claim 2
Dependent Claim
76 words
AN ELECTROLYTIC ETCHING METHOD FOR ETCHING PRESICE ELECTRICAL PARTS, WHEREIN A 0.1 TO 2.5 MOL/L CONCENTRATION AMMONIUM PERSULFATE - 0.02 TO 10 MOL/L CONCENTRATION NITRIC ACID ELECTROLYTE IS USED AND A DC VOLTAGE IS APPLIED BETWEEN A CATHODE ELECTRODE OF INSOLUBLE METAL AND AN ANODE ELECTRODE INCLUDING A METAL OBJECT TO BE ETCHED, SAID METAL OBJECT BEING MADE FROM A MEMBER SELECTED FROM THE GROUP CONSISTING OF IRON, NICKEL, COBALT, COPPER AND ALLOYS THEREOF, WHEREBY A
Claim 3
Dependent Claim
29 words
An electrolytic etching method according to claim 1 wherein said electrolyte comprises a 0.8 to 1.5 mol/l concentration ammonium persulfate - 0.5 to 8 mol/l concentration nitric acid solution.
Claim 4
Dependent Claim
39 words
An electrolytic etching method according to claim 1, wherein said anode electrode including said metal objects to be etched is covered with isobutylene rubber, polycinamic vinyle, diazo compound photoresist films at a part other than that to be etched.
Claim 5
Dependent Claim
34 words
An electrolytic etching method according to claim 1, wherein said anode electrode including said metal objects to be etched is covered with an aluminum film at a part other than that to be etched.
Claim 6
Dependent Claim
145 words
An electrolytic etching method for etching precise electrical parts wherein one end of an anode electrode including an object to be etched is connected to a potentiostat, said object being constituted by an electrically insulative substrate or aluminum layer provided thereon with a thin film made from a member selected from the group consisting of iron, nickel, cobalt and alloys thereof said thin film being coated with a photoresist or aluminum pattern, one end of a cathode electrode including an insoluble metal is connected to said potentiostat, and the other ends of said anode electrode and said cathode electrode are immersed in a 0.8 to 1.5 mol/l concentration ammonium persulfate 0.5 to 8 mol/l nitric acid electrolyte, whereby a constant potential electrolytic etching is performed by maintaining the anode electrode potential between thE natural electrode potential and the oxygen creation potential of said anode electrode.
Claim 7
Dependent Claim
145 words
An electrolytic etching method for etching precise electrical parts wherein one end of an anode electrode including an object to be etched is connected to a potentiostat, said object being constituted by an electrically insulative substrate or aluminum layer provided thereon with a thin film made from a member selected from the group consisting of iron, nickel, cobalt and alloys thereof said thin film being coated with a photoresist or aluminum pattern, one end of a cathode electrode including an insoluble metal is connected to said potentiostat, and the other ends of said anode electrode and said cathode electrode are immersed in a 0.8 to 1.5 mol/l concentration ammonium persulfate 0.5 to 8 mol/l nitric acid electrolyte, whereby a constant potential electrolytic etching is performed by maintaining the anode electrode potential between thE natural electrode potential and the oxygen creation potential of said anode electrode.
Claim 8
Dependent Claim
71 words
An electrolytic etching method according to claim 5, wherein after a constant potential electrolysis is performed by maintaining the anode electrode potential between the natural electrode potential of said anode metal and 1.2 volts (relative to SCE), a noble potential than said natural electrode potential is applied to said anode electrode immersed in said electrolyte, whereby a remaining part of metal to be etched which has been electrically insulated is dissolved.
Claim 9
Dependent Claim
21 words
An electrolytic etching method according to claim 1, wherein said anode electrode including a metal object to be etched comprises aluminum.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |