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Patent US4612140A successfully refreshed from Google Patents.
US4612140A
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Non-linear electrical resistor having varistor characteristics
Assignee: Murata Manufacturing Co Ltd
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Filing: 1984-04-06
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Granted: 1986-09-16
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Expires: 2004-04-06
Abstract
Abstract A ceramic composition for use in production of non-linear resistors. This composition comprises strontium titanate (or a mixture containing strontium titanate as a major ingredient) and 0.1 to 1.0 mol % of Er 2 O 3 , Ho 2 O 3 or mixtures thereof. In a preferred composition 0.02 to 0.2 mol % of at least one of MnO 2 , Co 2 O 3 or mixtures thereof are included. Non-linear resistors produced using the composition are comparable to those produced from conventional ceramic compositions in the threshold level voltage and non-linear factor but have greatly improved flexural strength.
Inventors
- 👤 Haruhumi Mandai
- 👤 Kazutaka Nakamura
- 👤 Yasuyuki Naito
- 👤 Kiyoshi Iwai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:23
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/105; H01C7/108; H01C7/115; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/47
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
64 words
A non-linear electrical resistor consisting essentially of strontium titanate and 0.1 to 1.0 mol % of Er 2 O 3 , Ho 2 O 3 or mixtures thereof, said non-linear electrical resistor having varistor characteristics and having a granular crystalline structure wherein the grains of said structure are semiconductors and the grain boundaries of said structure have a higher electrical resistance than said grains.
Claim 2
Dependent Claim
64 words
A non-linear electrical resistor consisting essentially of strontium titanate and 0.1 to 1.0 mol % of Er 2 O 3 , Ho 2 O 3 or mixtures thereof, said non-linear electrical resistor having varistor characteristics and having a granular crystalline structure wherein the grains of said structure are semiconductors and the grain boundaries of said structure have a higher electrical resistance than said grains.
Claim 3
Dependent Claim
31 words
The non-linear resistor of claim 1 wherein said resistor includes, in addition to said strontium titanate, a member selected from the group consisting of: titanates other than strontium, zirconates or stannates.
Claim 4
Dependent Claim
19 words
The non-linear resistor of claim 1 wherein said resistor is comprised of over about 98 mol % strontium titanate.
Claim 5
Dependent Claim
20 words
The non-linear resistor of claim 1 wherein said resistor includes MnO 2 , Co 2 O 3 or mixtures thereof.
Claim 6
Dependent Claim
80 words
A ceramic non-linear resistor consisting essentially of strontium titanate, 0.1 to 1.0 mol % of Er 2 O 3 , Ho 2 O 3 or mixtures thereof and 0.02 to 0.2 mol % of MnO 2 , Co 2 O 3 or mixtures thereof, said ceramic non-linear resistor having varistor characteristics and having a granular crystalline structure wherein the grains of said structure are semiconductors and the grain boundaries of said structure have a higher electrical resistance than said grains.
Claim 7
Dependent Claim
80 words
A ceramic non-linear resistor consisting essentially of strontium titanate, 0.1 to 1.0 mol % of Er 2 O 3 , Ho 2 O 3 or mixtures thereof and 0.02 to 0.2 mol % of MnO 2 , Co 2 O 3 or mixtures thereof, said ceramic non-linear resistor having varistor characteristics and having a granular crystalline structure wherein the grains of said structure are semiconductors and the grain boundaries of said structure have a higher electrical resistance than said grains.
Claim 8
Dependent Claim
31 words
The non-linear resistor of claim 5 wherein said resistor includes, in addition to said strontium titanate, a member selected from the group consisting of: titanates other than strontium, zirconates and stannates.
Claim 9
Dependent Claim
17 words
The non-linear resistor of claim 6 wherein said resistor is more than 60 mol % strontium titanate.
Claim 10
Dependent Claim
39 words
The non-linear resistor of claim 6 wherein said resistor comprises from 98.80 to 99.88 mol % of a material selected from the group consisting of strontium titanate mixtures of strontium titanate and titanates other than strontium, zirconates or stannates.
Claim 11
Dependent Claim
59 words
A ceramic material consisting essentially of strontium titanate with minor amounts of ErO 3 , Ho 2 O 3 or mixtures thereof, said material having a granular crystalline structure wherein the grains in said structure are a semiconductor material consisting essentially of strontium titanate and the grain boundaries of said structure have a higher electrical resistance than said grains.
Claim 12
Dependent Claim
59 words
A ceramic material consisting essentially of strontium titanate with minor amounts of ErO 3 , Ho 2 O 3 or mixtures thereof, said material having a granular crystalline structure wherein the grains in said structure are a semiconductor material consisting essentially of strontium titanate and the grain boundaries of said structure have a higher electrical resistance than said grains.
Claim 13
Dependent Claim
28 words
The material of claim 9 wherein said material contains from 0.1 to 1.0 mol %, of Er 2 O 3 , Ho 2 O 3 or mixtures thereof.
Claim 14
Dependent Claim
17 words
The ceramic material of claim 9 wherein said material contains over about 98 mol % strontium titanate.
Claim 15
Dependent Claim
28 words
The ceramic material of claim 9 wherein said material further includes from 0.02 to 0.2 mol % of MnO 2 , Co 2 O 3 or mixtures thereof.
Claim 16
Dependent Claim
21 words
The ceramic material of claim 9 wherein other titanates, zirconates or stannates are substituted for a portion of said strontium titanate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |