US3594616A
Expired / Lapsed
US
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Ceramic capacitor comprising semiconductive barium titanate body and silver alloy electrodes containing minor amounts of lead oxide and bismuth oxide
Assignee: Panasonic Holdings Corp
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Filing: 1969-06-05
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Granted: 1971-07-20
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Expires: 1989-06-05
Abstract
Abstract A ceramic voltage dependent resistor made up of a semiconductive titanate (e.g. barium titanate) plate having a nonohmic electrode on one surface thereof and an ohmic electrode on the other surface. The nonohmic electrode consists essentially of 93-55 percent by weight of silver component, 6.5-25 percent by weight of lead oxide and bismuth oxide and 0.5-38.5 percent by weight of at least one metal oxide selected from the group consisting of boron, copper, cadmium, zinc, nickel, cobalt, iron, titanium, niobium and tantalum. The thickness of the nonohmic electrode after firing it onto the titanate plate is 40-250 microns. The titanate plate comprises barium titanate of a means grain size of 5 to 50 microns and has an electrical resistivity less than 10 ohm-cm. Such voltage dependent resistors are suitable for use in varistors.
Inventors
- 👤 Tsuneharu Nitta
- 👤 Hiromitsu Taki
- 👤 Kaneomi Nagase
- 👤 Shigeru Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:28
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/4684; H; H01; H01C; H01C17/00; H01C17/28; H01C17/281; H01C17/283; H01C17/285; H01C17/286; H01C7/00; H01C7/10; H01C7/105; H01C7/108; H01C7/115
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
70 words
A ceramic voltage dependent resistor according to claim 1, wherein said nonohmic electrode consists essentially of, as solid ingredients, 80-60 percent weight of silver component, 14-24 percent by weight of a combined addition of lead oxide and bismuth oxide and 6-26 percent by weight of a further addition of at least one metal oxide from the group consisting of boron, copper, cadmium, zinc, nickel, cobalt, iron, titanium, niobium and tantalum.
Claim 2
Dependent Claim
30 words
A ceramic voltage dependent resistor according to claim 2, wherein said silver component consists essentially of 10-80 percent by weight of silver and 20-90 percent by weight of silver oxide.
Claim 3
Dependent Claim
18 words
A ceramic voltage dependent resistor according to claim 2, wherein said further addition consists essentially of boron oxide.
Claim 4
Dependent Claim
31 words
A ceramic voltage dependent resistor according to claim 2, wherein said further addition consists essentially of 20-80 percent by weight of cadmium oxide and 80-20 percent by weight of copper oxide.
Claim 5
Dependent Claim
38 words
A ceramic voltage dependent resistor according to claim 2, wherein said further addition consists essentially of 20-50 percent by weight of cadmium oxide, 20-40 percent by weight of copper oxide and 10-60 percent by weight of niobium oxide.
Claim 6
Dependent Claim
15 words
A ceramic voltage dependent resistor according to claim 2, wherein said ohmic electrode comprises aluminum.
Claim 7
Dependent Claim
36 words
A ceramic voltage dependent resistor according to claim 3, wherein said semiconductive titanate plate is comprised of titanate having a mean grain size of 5 to 50 microns and an electrical resistivity less than 10 ohm-cm.
Claim 8
Dependent Claim
32 words
A ceramic voltage dependent resistor according to claim 2, wherein said combined addition consists essentially of 40 -60 percent by weight of lead oxide and 60-40 percent by weight of bismuth oxide.
Claim 9
Dependent Claim
19 words
A ceramic voltage dependent resistor according to claim 9, wherein said semiconductive titanate plate consists essentially of barium titanate.
Claim 10
Dependent Claim
23 words
A ceramic voltage dependent resistor according to claim 2, wherein the said nonohmic electrode has a thickness of from 40 to 250 microns.
Claim 11
Independent Claim
141 words
A method of making a ceramic voltage dependent resistor comprising providing a semiconductive titanate ceramic body; applying to one surface of said ceramic body, an electrode pigment consisting essentially of, as solid ingredients, 93-55 percent by weight of silver component, 6.5- 25 percent by weight oF a combined addition of lead oxide and bismuth oxide and 0.5-38.5 percent by weight of a further addition of at least one metal oxide selected from the group consisting of boron, copper, cadmium, zinc, nickel, cobalt, iron, titanium, niobium and tantalum; firing said electrode pigment at 600* C to 920* C in an oxidizing atmosphere having an oxygen content ranging from 2 to 100 percent by volume; cooling said fired body having said electrode pigment thereon to room temperature in said oxidizing atmosphere; and applying to another surface of said ceramic body an aluminum electrode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |