US5077889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating a positive-temperature-coefficient heating device
Assignee: ADO ELECTRONIC INDUSTRIAL Co Ltd A CORP OF JAPAN
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Filing: 1990-12-14
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Granted: 1992-01-07
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Expires: 2010-12-14
Abstract
Abstract A process for fabricating a PTC thermistor device. A pair of opposing electrodes are formed on either major surface of a ceramic plate PTC thermistor element. Metallic plate heat radiation fins are secured to the opposing electrodes by brazing in a non-oxidizing environment. The PTC thermistor element is then heat treated in an oxidizing environment. Optionally, the opposing electrodes may include shield layers for preventing emission of gas from the PTC thermistor element during brazing.
Inventors
- 👤 Yasuaki Matsuda
- 👤 Daisuke Takahata
- 👤 Mitsuo Aoki
- 👤 Hiroshi Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:32
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/141; H05B3/40; H05B3/42; H05B3/48; H05B3/50; H05B2203/00; H05B2203/02; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49085
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
75 words
A process for fabricating a PTC thermistor device, comprising the steps of: forming a pair of opposing electrodes on either major surface of a PTC thermistor element consisting of a ceramic plate; securing heat radiation fins formed of metallic plates to said opposing electrodes in a non-oxidizing environment by brazing; and exposing said PTC thermistor element to an oxidizing environment of a temperature higher than 480 degrees C. after securing said heat radiation fins thereto.
Claim 2
Dependent Claim
75 words
A process for fabricating a PTC thermistor device, comprising the steps of: forming a pair of opposing electrodes on either major surface of a PTC thermistor element consisting of a ceramic plate; securing heat radiation fins formed of metallic plates to said opposing electrodes in a non-oxidizing environment by brazing; and exposing said PTC thermistor element to an oxidizing environment of a temperature higher than 480 degrees C. after securing said heat radiation fins thereto.
Claim 3
Dependent Claim
47 words
A process according to claim 1, wherein said heat radiation fins are formed by bending metallic heat radiation fin plates so as to define a plurality of peaks, and said securing step consists of brazing said peaks of said heat radiation fin plates to said opposing electrodes.
Claim 4
Dependent Claim
18 words
A process according to claim 2, wherein said opposing electrodes have a thickness of 50 to 300 micrometers.
Claim 5
Dependent Claim
117 words
A process for fabricating a PTC thermistor device, comprising the steps of: forming metallic films on either major surface of a PTC thermistor element essentially consisting of a ceramic plate; overlaying electroconductive shield layers on said metallic films to prevent emission of gas from said PTC thermistor element and metallic fin plates having a plurality of metallic fins defined therein on said shield layers, with peaks of said fins abutting said shield layers; integrally joining the assembly consisting of said PTC thermistor element, said metallic films, said shield layers and said metallic fin plates by brazing them in a non-oxidizing environment; and placing said assembly in an oxidizing environment at a temperature higher than 480 degrees C.
Claim 6
Dependent Claim
117 words
A process for fabricating a PTC thermistor device, comprising the steps of: forming metallic films on either major surface of a PTC thermistor element essentially consisting of a ceramic plate; overlaying electroconductive shield layers on said metallic films to prevent emission of gas from said PTC thermistor element and metallic fin plates having a plurality of metallic fins defined therein on said shield layers, with peaks of said fins abutting said shield layers; integrally joining the assembly consisting of said PTC thermistor element, said metallic films, said shield layers and said metallic fin plates by brazing them in a non-oxidizing environment; and placing said assembly in an oxidizing environment at a temperature higher than 480 degrees C.
Claim 7
Dependent Claim
23 words
A process according to claim 4, wherein said metallic film and said shield layer have a combined thickness of 50 to 300 micrometers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |