US4232214A
Expired / Lapsed
US
⏱️ 0.0 years remaining
PTC Honeycomb heating element with multiple electrode layers
Assignee: TDK Corp
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Filing: 1979-02-22
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Granted: 1980-11-04
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Expires: 1999-02-22
Abstract
Abstract In a honeycomb heating element comprising a PTC thermister body, a single electrode layer composed of a silver paste was conventionally used for applying power to the body. In the present invention, two or three electrode layers with improved electrical and chemical properties are used to provide the heating element with a long service life, improved reliability and a high heat generation.
Inventors
- 👤 Ryoichi Shioi
- 👤 Tamotu Yamauchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:33
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/141; H01; H01C; H01C1/00; H01C1/14; H01C1/1406; H01C7/00; H01C7/02; H01C7/022
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
102 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate, wherein a pair of inner electric conductive layers comprising mainly silver are provided on both end surfaces of said semiconductor ceramic body, electrically connected to a source for supplying power to said semiconductor ceramic body, and wherein an outer electric conductive layer consisting of at least one metal selected from the group, which consists of nickel, zinc and chromium is provided on each of the inner layers.
Claim 2
Dependent Claim
102 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate, wherein a pair of inner electric conductive layers comprising mainly silver are provided on both end surfaces of said semiconductor ceramic body, electrically connected to a source for supplying power to said semiconductor ceramic body, and wherein an outer electric conductive layer consisting of at least one metal selected from the group, which consists of nickel, zinc and chromium is provided on each of the inner layers.
Claim 3
Dependent Claim
123 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate, wherein a pair of inner electric conductive layers are provided on both end surfaces of said semiconductor ceramic body, electrically connected to a source for supplying power to said semiconductor ceramic body, and wherein an intermediate layer consisting of at least one metal selected from the group, which consists of silver, gold and copper is provided on each of said inner layers, and an outer layer consisting of at least one metal selected from the group consisting of nickel, zinc and chromium is provided on each intermediate layer.
Claim 4
Dependent Claim
123 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate, wherein a pair of inner electric conductive layers are provided on both end surfaces of said semiconductor ceramic body, electrically connected to a source for supplying power to said semiconductor ceramic body, and wherein an intermediate layer consisting of at least one metal selected from the group, which consists of silver, gold and copper is provided on each of said inner layers, and an outer layer consisting of at least one metal selected from the group consisting of nickel, zinc and chromium is provided on each intermediate layer.
Claim 5
Dependent Claim
27 words
A heating element according to claim 1, wherein the total thickness of said inner and outer, layers is in the range of from 10 to 35 microns.
Claim 6
Dependent Claim
28 words
A heating element according to claim 2, wherein the total thickness of said inner, intermediate and outer, layers is in the range of from 15 to 40 microns.
Claim 7
Dependent Claim
28 words
A heating element according to claim 3 or 4, wherein the thickness of each of the inner layers is in the range of from 5 to 10 microns.
Claim 8
Dependent Claim
40 words
A heating element according to claim 4, wherein the thickness of the intermediate layer is in the range of from 5 to 20 microns, and the thickness of outer layer is in the range of from 3 to 7 microns.
Claim 9
Dependent Claim
30 words
A heating element according to claim 5 or 6, wherein the thickness of the partition wall of said honeycomb structure is in the range of from 0.15 to 3 mm.
Claim 10
Dependent Claim
25 words
A heating element according to claim 7, wherein the thickness of said semiconductor ceramic body of a honeycomb structure is from 3.5 to 6 mm.
Claim 11
Dependent Claim
134 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate having electrical conductive terminal layers attached by a process comprising a step of screen printing a pair of inner electric conductive layers comprising mainly silver on both end surfaces of said semiconductor ceramic body, wherein said process further comprises the steps of: electrolytically depositing an intermediate electric conductive layer, consisting of at least one metal selected from the group which consists of silver, gold and copper, on each of said inner layers, and plating on each intermediate layer an outer electric layer consisting of at least one metal selected from the group which consists of nickel, zinc and chromium.
Claim 12
Dependent Claim
134 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate having electrical conductive terminal layers attached by a process comprising a step of screen printing a pair of inner electric conductive layers comprising mainly silver on both end surfaces of said semiconductor ceramic body, wherein said process further comprises the steps of: electrolytically depositing an intermediate electric conductive layer, consisting of at least one metal selected from the group which consists of silver, gold and copper, on each of said inner layers, and plating on each intermediate layer an outer electric layer consisting of at least one metal selected from the group which consists of nickel, zinc and chromium.
Claim 13
Dependent Claim
135 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate having electrically conductive terminal layers attached by a process comprising a step of screen printing a pair of inner electric conductive layers comprising mainly silver on both end surfaces of said semiconductor ceramic body, wherein said process further comprises the steps of: screen printing an intermediate electric conductive layer, consisting of at least one metal selected from the group which consists of silver, gold and copper, on each of said inner layers, and plating on each intermediate layer an outer electric conductive layer consisting of at least one metal selected from the group which consists of nickel, zinc and chromium.
Claim 14
Dependent Claim
135 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate having electrically conductive terminal layers attached by a process comprising a step of screen printing a pair of inner electric conductive layers comprising mainly silver on both end surfaces of said semiconductor ceramic body, wherein said process further comprises the steps of: screen printing an intermediate electric conductive layer, consisting of at least one metal selected from the group which consists of silver, gold and copper, on each of said inner layers, and plating on each intermediate layer an outer electric conductive layer consisting of at least one metal selected from the group which consists of nickel, zinc and chromium.
Claim 15
Dependent Claim
30 words
A heating element according to claim 9 or 10 wherein the total thickness of said inner, intermediate and outer layers is in the range of from 15 to 40 microns.
Claim 16
Dependent Claim
41 words
A heating element according to claim 11, wherein the thickness of the intermediate layer is in the range of from 5 to 20 microns, and the thickness of the outer layer is in the range of from 3 to 7 microns.
Claim 17
Dependent Claim
103 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate having electrically conductive terminal layers attached by a process comprising a step of screen printing a pair of inner electric conductive layers on both end surfaces of said semiconductor ceramic body, wherein said process further comprises a step of: plating an outer electrically conductive layer consisting of at least one metal selected from the group which consists of nickel, zinc and chromium, on each of said inner layers.
Claim 18
Dependent Claim
103 words
A heating element comprising a semiconductor ceramic body of a honeycomb structure, the material of said semiconductor ceramic body having a positive temperature coefficient of resistance over a Curie point and composed of barium titanate having electrically conductive terminal layers attached by a process comprising a step of screen printing a pair of inner electric conductive layers on both end surfaces of said semiconductor ceramic body, wherein said process further comprises a step of: plating an outer electrically conductive layer consisting of at least one metal selected from the group which consists of nickel, zinc and chromium, on each of said inner layers.
Claim 19
Dependent Claim
24 words
A heating element according to claim 13, wherein the thickness of the inner layers is in the range of from 5 to 10 microns.
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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) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |