US4912450A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermistor and method of producing the same
Assignee: Murata Manufacturing Co Ltd
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Filing: 1988-08-25
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Granted: 1990-03-27
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Expires: 2008-08-25
Abstract
Abstract A method for producing negative temperature coefficient thermistor units, comprising the steps of forming a pair of green sheets of insulating ceramic material, stacking the green sheets interposing therebetween in predetermined areas a layer of paste for thermistor elements; providing for each thermistor unit a coating of paste to be formed into internal electrodes; cutting the stacked sheets into individual thermistor units; co-firing the thermistor units whereby the thermistor element is enclosed in an envelope of sintered ceramic material or sandwiched between two layers of sintered ceramic material. A pair of external electrodes is then provided on each thermistor unit.
Inventors
- 👤 Yasunobu Yoneda
- 👤 Michihiro Murata
- 👤 Harufumi Mandai
- 👤 Yukio Sakabe
- 👤 Yukio Banba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:57
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49087; Y10T29/49092
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
168 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element enclosed in an envelope of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of green sheets wherein each green sheet comprises said insulating ceramic material; (b) coating predetermined areas of the surfaces of said green sheets with paste to be formed into internal electrodes for said thermistor units; (c) stacking said green sheets, interposing therebetween in predetermined areas a non-continuous layer of paste for thermistor elements for said thermistor units; (d) cutting said stacked green sheets into individual thermistor units in such a manner that the cuts do not go through the paste for the thermistor elements; (e) co-firing each obtained thermistor unit so as to form a sintered body, wherein the thermistor element in each thermistor unit is enclosed in an envelope of sintered insulating ceramic material; and (f) forming a pair of external electrodes on the surfaces of each thermistor unit.
Claim 2
Independent Claim
168 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element enclosed in an envelope of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of green sheets wherein each green sheet comprises said insulating ceramic material; (b) coating predetermined areas of the surfaces of said green sheets with paste to be formed into internal electrodes for said thermistor units; (c) stacking said green sheets, interposing therebetween in predetermined areas a non-continuous layer of paste for thermistor elements for said thermistor units; (d) cutting said stacked green sheets into individual thermistor units in such a manner that the cuts do not go through the paste for the thermistor elements; (e) co-firing each obtained thermistor unit so as to form a sintered body, wherein the thermistor element in each thermistor unit is enclosed in an envelope of sintered insulating ceramic material; and (f) forming a pair of external electrodes on the surfaces of each thermistor unit.
Claim 3
Dependent Claim
48 words
A method according to claim 1, wherein the step of forming said pair of green sheets further comprises the step of forming for each thermistor unit a pair of through holes, each of which is filled with the same electrically conductive material as that of the external electrodes.
Claim 4
Dependent Claim
55 words
A method according to claim 1, wherein the step of stacking said green sheets interposing therebetween a layer of paste for thermistor elements further comprises the step of forming for each thermistor unit a pair of through holes, each of which is filled with the same electrically conductive material as that of the external electrode.
Claim 5
Independent Claim
187 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element enclosed in an envelope of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of first green sheets of said insulating ceramic material; (b) coating predetermined areas of the surfaces of said first green sheets with paste to be formed into external electrodes; (c) preparing a second green sheet made of the same material as said first green sheets and formed with a number of openings arranged at predetermined positions thereof; (d) filling up each of said openings with paste for thermistor elements; (e) stacking said first green sheet interposing therebetween said second green sheet; (f) cutting said stacked sheets into individual thermistor units in such a manner that the cuts do not go through the paste for the thermistor elements; (g) co-firing each obtained thermistor unit as to form a sintered body wherein the thermistor element in each thermistor unit is enclosed in an envelope of sintered insulating ceramic material; and (h) forming a pair of external electrodes on each thermistor unit.
Claim 6
Independent Claim
187 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element enclosed in an envelope of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of first green sheets of said insulating ceramic material; (b) coating predetermined areas of the surfaces of said first green sheets with paste to be formed into external electrodes; (c) preparing a second green sheet made of the same material as said first green sheets and formed with a number of openings arranged at predetermined positions thereof; (d) filling up each of said openings with paste for thermistor elements; (e) stacking said first green sheet interposing therebetween said second green sheet; (f) cutting said stacked sheets into individual thermistor units in such a manner that the cuts do not go through the paste for the thermistor elements; (g) co-firing each obtained thermistor unit as to form a sintered body wherein the thermistor element in each thermistor unit is enclosed in an envelope of sintered insulating ceramic material; and (h) forming a pair of external electrodes on each thermistor unit.
Claim 7
Independent Claim
169 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element enclosed in an envelope of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of green sheets wherein each green sheet comprises said insulating ceramic material; (b) coating predetermined areas of the surfaces of said green sheets with paste to be formed into diffusion preventing layers; (c) providing over said paste for the diffusion preventing layers a coating of a paste to be formed into internal electrodes; (d) stacking said green sheets, interposing therebetween in predetermined areas a non-continuous layer of paste for thermistor elements for said thermistor units; (e) cutting said stacked green sheets into individual thermistor units in such a manner that the cuts do not go through the paste for the thermistor elements; (f) firing said thermistor unit so as to form a sintered body, wherein the thermistor element in each thermistor unit is enclosed in an envelope of sintered ceramic material.
Claim 8
Independent Claim
169 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element enclosed in an envelope of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of green sheets wherein each green sheet comprises said insulating ceramic material; (b) coating predetermined areas of the surfaces of said green sheets with paste to be formed into diffusion preventing layers; (c) providing over said paste for the diffusion preventing layers a coating of a paste to be formed into internal electrodes; (d) stacking said green sheets, interposing therebetween in predetermined areas a non-continuous layer of paste for thermistor elements for said thermistor units; (e) cutting said stacked green sheets into individual thermistor units in such a manner that the cuts do not go through the paste for the thermistor elements; (f) firing said thermistor unit so as to form a sintered body, wherein the thermistor element in each thermistor unit is enclosed in an envelope of sintered ceramic material.
Claim 9
Dependent Claim
28 words
A method according to claim 5, wherein each diffusion preventing layer comprises a powdered material of the Y 2 O 3 -ZrO 2 -Al 2 O 3 system.
Claim 10
Independent Claim
189 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element sandwiched between two layers of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of green sheets wherein each green sheet comprises said insulating ceramic material; (b) coating predetermined areas of the surfaces of said green sheets with paste to be formed into internal electrodes in such a manner that the area of one green sheet extends to the position corresponding to one side of the thermistor unit and the area of the other green sheet extends to the position corresponding to the other side of the thermistor unit; (c) stacking said green sheets, interposing therebetween in predetermined areas a layer of paste for thermistor elements for said thermistor units; (d) cutting said stacked green sheets into individual thermistor units; (e) coating both ends of each of said thermistor units with paste for external electrodes; and (f) firing said thermistor unit so as to form a sintered body, wherein the thermistor element in each thermistor unit is sandwiched between two layers of sintered ceramic material.
Claim 11
Independent Claim
189 words
A method of producing negative temperature coefficient thermistor units, wherein each thermistor unit comprises a thermistor element sandwiched between two layers of insulating ceramic material, internal electrodes, and external electrodes, comprising the steps of: (a) forming a pair of green sheets wherein each green sheet comprises said insulating ceramic material; (b) coating predetermined areas of the surfaces of said green sheets with paste to be formed into internal electrodes in such a manner that the area of one green sheet extends to the position corresponding to one side of the thermistor unit and the area of the other green sheet extends to the position corresponding to the other side of the thermistor unit; (c) stacking said green sheets, interposing therebetween in predetermined areas a layer of paste for thermistor elements for said thermistor units; (d) cutting said stacked green sheets into individual thermistor units; (e) coating both ends of each of said thermistor units with paste for external electrodes; and (f) firing said thermistor unit so as to form a sintered body, wherein the thermistor element in each thermistor unit is sandwiched between two layers of sintered ceramic material.
References Cited (Backward Citations)
US3493913A
Cited
US3634840A
Cited
JPS527535A
Cited
US4445026A
Cited
US4395623A
Cited
US4431983A
Cited
US4550301A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |