US4603372A
Expired / Lapsed
US
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Method of fabricating a temperature or humidity sensor of the thin film type, and sensors obtained thereby
Assignee: Météo-France
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Filing: 1984-11-05
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Granted: 1986-07-29
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Expires: 2004-11-05
Abstract
Abstract A printed circuit type of substrate (1) has a conductive film (2) on one face which is etched to constitute a first electrode (3) shaped as a printed circuit resistance between two connection tabs (4A, 4B) and a second electrode (5) having a connection tab (6), both electrodes are covered in a film of polymer and points (12) of the second electrode (6) are bared of polymer to put it into direct contact with a porous metal film covering the polymer film which serves as a dielectric between the said porous metal film and the first electrode (3).
Inventors
- 👤 Gabriel Abadie
- 👤 Bernard Loitiere
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:46
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/16; G01K7/18; G01K7/183; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01N27/225
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
249 words
A method of fabricating a thin film sensor comprising a support, a first film of metal constituting a first capacitor plate, a polymer-based dielectric film, and a second film of metal constituting a second capacitor plate, wherein: the dielectric film is deposited as at least a first film of polymer which is hydrophobic and a second film of polymer which is sensitive to humidity, these polymer films being made from solutions based on different specific solvents, with the first polymer film being suitable for spreading well and ensuring good adherence, and with the second polymer film being chosen for its dielectric qualities; the support being made from a printed circuit type of substrate having a conductive film on at least one face; first and second distinct electrodes with respective connection tabs being made in said conductive film by etching; a first film of hydrophobic polymer being deposited thereon; a second film of humidity sensitive polymer being deposited on the first film of polymer; both films of polymer being removed at a plurality of points over the second electrode, to bare the second electrode; a porous film of metal being deposited on the assembly, thereby making electrical contact with the second electrode via said bared points and thus constituting a second capacitor plate, suitable for co-operating via the dielectric constituted by the films of polymer with the first electrode constituting the first capacitor plate; and the said tabs being reserved as terminals for connecting the sensor to an electrical circuit.
Claim 2
Independent Claim
249 words
A method of fabricating a thin film sensor comprising a support, a first film of metal constituting a first capacitor plate, a polymer-based dielectric film, and a second film of metal constituting a second capacitor plate, wherein: the dielectric film is deposited as at least a first film of polymer which is hydrophobic and a second film of polymer which is sensitive to humidity, these polymer films being made from solutions based on different specific solvents, with the first polymer film being suitable for spreading well and ensuring good adherence, and with the second polymer film being chosen for its dielectric qualities; the support being made from a printed circuit type of substrate having a conductive film on at least one face; first and second distinct electrodes with respective connection tabs being made in said conductive film by etching; a first film of hydrophobic polymer being deposited thereon; a second film of humidity sensitive polymer being deposited on the first film of polymer; both films of polymer being removed at a plurality of points over the second electrode, to bare the second electrode; a porous film of metal being deposited on the assembly, thereby making electrical contact with the second electrode via said bared points and thus constituting a second capacitor plate, suitable for co-operating via the dielectric constituted by the films of polymer with the first electrode constituting the first capacitor plate; and the said tabs being reserved as terminals for connecting the sensor to an electrical circuit.
Claim 3
Dependent Claim
67 words
A method according to claim 1, wherein the first electrode is made in the shape of a printed circuit resistor extending between two separate tabs for connection to an electrical circuit, thereby obtaining a two-function sensor comprising a hygrometer for connection between the second electrode tab and the tabs of the first electrode taken together, and a thermometer for connection between the tabs of the first electrode.
Claim 4
Dependent Claim
53 words
A method according to claim 1, wherein the substrate used has a thin conductive film on both of its opposite faces, and wherein a hygrometer according to claim 1 is made on one of said faces and an independent printed circuit resistance is made on the other face to constitute a temperature sensor.
Claim 5
Dependent Claim
44 words
A method according to claim 1, wherein a final film of hydrophilic polymer is deposited over the film of metal to a thickness of a few microns to several tens of microns using a solution whose solvent is different from the second film solvent.
Claim 6
Dependent Claim
16 words
A method according to claim 4, wherein the final film uses a 10% solution of polyurethane.
Claim 7
Dependent Claim
127 words
A thin film sensor comprising a support, a first film of metal constituting a first capacitor plate, a polymer based dielectric, and a second film of metal constituting a second capacitor plate, the sensor including the improvements wherein the support is a printed circuit type of substrate having a conductive film on at least one face, which film is shaped to constitute a first electrode connected to a first connection tab and a second electrode connected to a second connection tab, the dielectric comprises at least one film of polymer spread over the two electrodes, and the second film of metal is porous, is deposited on the polymer film, and makes electrical contact with the second electrode at bare points thereon where the polymer film is absent.
Claim 8
Dependent Claim
127 words
A thin film sensor comprising a support, a first film of metal constituting a first capacitor plate, a polymer based dielectric, and a second film of metal constituting a second capacitor plate, the sensor including the improvements wherein the support is a printed circuit type of substrate having a conductive film on at least one face, which film is shaped to constitute a first electrode connected to a first connection tab and a second electrode connected to a second connection tab, the dielectric comprises at least one film of polymer spread over the two electrodes, and the second film of metal is porous, is deposited on the polymer film, and makes electrical contact with the second electrode at bare points thereon where the polymer film is absent.
Claim 9
Dependent Claim
24 words
A sensor according to claim 6, wherein the first electrode has the shape of a printed circuit resistance extending between two separate connection tabs.
Claim 10
Dependent Claim
31 words
A sensor according to claim 6, wherein the polymer film comprises at least a first hydrophobic film deposited on the electrodes and a second hydrophilic film deposited on the first film.
Claim 11
Dependent Claim
49 words
A thin film sensor wherein the support is a substrate of the printed circuit type having a conductive film on both large faces, one of the faces constituting a sensor according to claim 6 and the other face having a printed circuit type resistance extending between two connection tabs.
Claim 12
Dependent Claim
25 words
A sensor according to claim 6 including a final film of hydrophilic polymer having a thickness of a few microns to several tens of microns.
Claim 13
Independent Claim
100 words
A method for fabricating a thin film sensor, comprising the steps of: depositing a first film of hydrophobic polymer on a printed circuit-type substrate having a conductive film on at least one face; depositing on said first film a second film of polymer sensitive to humidity; said polymer films being made from solutions based on different specific solvents, said first polymer film being suitable for spreading well and ensuring good adherence with said substrate and said second polymer film, said second polymer film being chosen for its dielectric quality; and depositing a porous film of metal on said second film.
Claim 14
Independent Claim
100 words
A method for fabricating a thin film sensor, comprising the steps of: depositing a first film of hydrophobic polymer on a printed circuit-type substrate having a conductive film on at least one face; depositing on said first film a second film of polymer sensitive to humidity; said polymer films being made from solutions based on different specific solvents, said first polymer film being suitable for spreading well and ensuring good adherence with said substrate and said second polymer film, said second polymer film being chosen for its dielectric quality; and depositing a porous film of metal on said second film.
Claim 15
Dependent Claim
22 words
A method according to claim 11, wherein the first polymer film is given a thickness of a few tenths of a micron.
Claim 16
Dependent Claim
23 words
A method according to claim 12, wherein the second film of polymer is spread by centrifuging with the substrate in a vertical position.
Claim 17
Dependent Claim
20 words
A method according to claim 11, wherein the second polymer film is given a thickness of one to several microns.
References Cited (Backward Citations)
US3138747A
Cited
US3273033A
Cited
US3323027A
Cited
US3359467A
Cited
US3381255A
Cited
US3615913A
Cited
US3802268A
Cited
US3798145A
Cited
US4393434A
Cited
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