EP0166408A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Gas sensor and method of producing the same
Assignee: Hitachi Ltd
•
Filing: 1985-06-24
•
Granted: —
•
Expires: 2005-06-24
Abstract
Abstract In a gas sensor consisting of a pair of electrodes (3a, 3b) juxtaposed with each other on an electrically insulating substrate (1), a sensitive member film (4) interposed electrically between one end each of the electrodes (3a, 3b) and a protective film (5) covering a part on the sensitive member film (4) and on the other portions of the electrodes (3a, 3b), the present invention provides a gas sensor characterized in that the sensitive member film (4) consists of plasma- sprayed titanium oxide layer which has a diffusion reactive layer (8) between it and the substrate (1), and fine grooves are formed in the surface portion of the sensitive member film (4). The gas sensor is improved on the response and durability.
Inventors
- 👤 Naomasa Sunano
- 👤 Naotatsu Asahi
- 👤 Toshio Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 11:40
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/06; G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; H10P72/04; H10P72/0402; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
A gas sensor comprising a pair of electrodes (3a, 3b) juxtaposed with each other on an electrically insulating substrate (1), a sensitive layer (4) interposed electrically between said electrodes (3a, 3b) at their one ends, and a protective film (5) covering a part of said sensitive layer (4) and a part of each of said electrodes (3a, 3b), the improvement wherein said sensitive layer is a thermally sprayed titanium oxide layer (4) which has a diffusion reactive layer (8) between said layer (4) and said substrate (1) and has fine groove or pores in its surface portion. -
Claim 2
Dependent Claim
98 words
A gas sensor comprising a pair of electrodes (3a, 3b) juxtaposed with each other on an electrically insulating substrate (1), a sensitive layer (4) interposed electrically between said electrodes (3a, 3b) at their one ends, and a protective film (5) covering a part of said sensitive layer (4) and a part of each of said electrodes (3a, 3b), the improvement wherein said sensitive layer is a thermally sprayed titanium oxide layer (4) which has a diffusion reactive layer (8) between said layer (4) and said substrate (1) and has fine groove or pores in its surface portion. -
Claim 3
Dependent Claim
20 words
The gas sensor as defined in claim 1 wherein said diffusion reactive layer (8) is 0.1 - 5 µm thick.
Claim 4
Dependent Claim
19 words
The gas sensor as defined in claim 1 wherein said sensitive layer (4) is 10 - 100 µm thick.
Claim 5
Dependent Claim
23 words
The gas sensor as defined in claim 1 wherein said sensitive layer (4) has resistance of at least 100 M11 in the atmosphere.
Claim 6
Dependent Claim
61 words
The gas sensor as defined in claim 1 wherein said protective film (5) is heat-resistant and electrically insulating, and is deposited both on a part of said sensitive layer (4) so that said part of said sensitive layer (4) free of the deposition be wider than the gap between said electrodes (3a, 3b) and on a part of said each electrode.
Claim 7
Dependent Claim
47 words
The gas sensor as defined in claim 1, wherein said protective film (5) is deposited on said electrodes (3a, 3b) so that a part of one end of said each electrode (3a, 3b) covered with said sensitive layer (4) is free of the deposited protective film (5).
Claim 8
Independent Claim
144 words
A method of producing a gas sensor by forming at least two electrodes (3a, 3b) on an electrically insulating substrate (1) by printing, depositing a sensitive layer (4) to the tip portion of each of said electrodes (3a, 3b) and depositing a heat-resistant and electrically insulating protective film (5) on a part of said sensitive layer (4) and on' a part of said each electrode (3a, 3b), the improvement wherein said sensitive layer (4) is formed by a method comprising the steps of forming a stoichiometrically metastable TiO 2-x layer by plasma spraying on said electrically insulating substrate (1), and then heat-treating said TiO 2-x film to form a diffusion reactive layer (8) with said substrate and to form dispersedly fine grooves on the surface while at least the surface portion of said layer (8) is converted to stable titanium oxide (Ti0 2 ).
Claim 9
Independent Claim
144 words
A method of producing a gas sensor by forming at least two electrodes (3a, 3b) on an electrically insulating substrate (1) by printing, depositing a sensitive layer (4) to the tip portion of each of said electrodes (3a, 3b) and depositing a heat-resistant and electrically insulating protective film (5) on a part of said sensitive layer (4) and on' a part of said each electrode (3a, 3b), the improvement wherein said sensitive layer (4) is formed by a method comprising the steps of forming a stoichiometrically metastable TiO 2-x layer by plasma spraying on said electrically insulating substrate (1), and then heat-treating said TiO 2-x film to form a diffusion reactive layer (8) with said substrate and to form dispersedly fine grooves on the surface while at least the surface portion of said layer (8) is converted to stable titanium oxide (Ti0 2 ).
Claim 10
Dependent Claim
37 words
The method of producing a gas sensor as defined in claim 7, wherein said TiO 2-x layer (4) is formed by plasma spraying titanium oxid on said substrate (1) in an athmosphere of hydrogen and argon gas.
Claim 11
Dependent Claim
24 words
The method of producing a gas sensor as defined in claim 7, wherein said heat treating is effected in an athmosphere including oxygen gas.
Claim 12
Dependent Claim
42 words
The method of producing a gas sensor as defined in claim 7, wherein said heat treating is effected at a temperature of at least 1.000°C and less than a melting point of said titanium oxide and the material of said substrate (1).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.