Patent EP0431531A2 successfully refreshed from Google Patents.
EP0431531A2
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Solid dielectric capacitor and method of manufacture
Assignee: Taiyo Yuden Co Ltd
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Filing: 1990-12-03
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Granted: —
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Expires: 2010-12-03
Abstract
Abstract A monolithic capacitor having a dielectric ceramic body cosintered with at least two base metal electrodes. The ceramic body is composed of a major ingredient expressed by the formula, where M is either or both of magnesium and zinc,L is either or both of calcium and magnesium, R is a rare earth element or elements, and a , k, x, z and y are numerals in specified ranges. To this major ingredient is added a minor proportion of a first additive ingredient and a second additive ingredient. The first additive ingredient is at least either of chromium oxide and aluminum oxide. The second additive ingredient is a mixture of boric oxide or lithium oxide, silicon dioxide and at least one metal oxide selected from among barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide. For the fabrication of capacitors the mixture of the above major ingredient and additives in finely divided form are formed into moldings of desired shape and size, each with at least two electrodes buried therein. The moldings and electrodes are cosintered in a reductive or neutral atmosphere at temperatures of less than 1200 degrees C. and then are heated at a lower temperature in an oxidative atmosphere.
Inventors
- 👤 Hiroshi Saito
- 👤 Mutsumi Honda
- 👤 Hiroshi Kishi
- 👤 Hisamitsu Shizuno
- 👤 Hirokazu Chazono
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 17:33
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1209; H01G4/1236; H01G4/1245; C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/49
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
230 words
A solid dielectric capacitor comprising a dielectric ceramic body and at least two electrodes in contact therewith, the dielectric ceramic body consisting essentially of: (a) 100 parts by weight of a major ingredient expressed by the formula, where M is either or both of magnesium and zinc; L is either or both of calcium and strontium; R is at least one metal selected from scandium, yttrium, gadolinium, dysprosium, holmium, erbium, ytterbium, terbium, thulium and lutetium; a is a numeral in the range of 0.005 to 0.040; k is a numeral not less than 1.00 and not more than 1.05; x is a numeral greater than 0 and less than 0.10; z is a numeral greater than 0 and not greater than 0.05; the sum of x and z is a numeral not less than 0.01 and not greater than 0.10; and y is a numeral greater than 0 and not greater than 0.04; (b) greater than 0 and not greater than 3.00 parts by weight of at least either of chromium oxide and aluminum oxide ; and (c) from 0.2 to 5.0 parts by weight of an additive mixture of at least two members selected from the group consisting of boric oxide or lithium oxide, silicon oxide and at least one metal oxide selected form the group consisting of barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide.
Claim 2
Dependent Claim
230 words
A solid dielectric capacitor comprising a dielectric ceramic body and at least two electrodes in contact therewith, the dielectric ceramic body consisting essentially of: (a) 100 parts by weight of a major ingredient expressed by the formula, where M is either or both of magnesium and zinc; L is either or both of calcium and strontium; R is at least one metal selected from scandium, yttrium, gadolinium, dysprosium, holmium, erbium, ytterbium, terbium, thulium and lutetium; a is a numeral in the range of 0.005 to 0.040; k is a numeral not less than 1.00 and not more than 1.05; x is a numeral greater than 0 and less than 0.10; z is a numeral greater than 0 and not greater than 0.05; the sum of x and z is a numeral not less than 0.01 and not greater than 0.10; and y is a numeral greater than 0 and not greater than 0.04; (b) greater than 0 and not greater than 3.00 parts by weight of at least either of chromium oxide and aluminum oxide ; and (c) from 0.2 to 5.0 parts by weight of an additive mixture of at least two members selected from the group consisting of boric oxide or lithium oxide, silicon oxide and at least one metal oxide selected form the group consisting of barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide.
Claim 3
Dependent Claim
208 words
The solid dielectric capacitor of claim 1 wherein the additive mixture is an additive mixture of lithium oxide, silicon dioxide and at least one metal oxide selected from the group consisting of barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide, the relative proportions of lithium oxide, silicon dioxide and at least one selected metal oxide constituting the additive mixture being in that region of the ternary diagram of FIG. 2 attached hereto which is bounded by lines sequentially connecting: the point A where the additive mixture consists of one mole percent lithium oxide, 80 mole percent silicon dioxide, and 19 mole percent metal oxide; the point B where the additive mixture consists of one mole percent lithium oxide, 39 mole percent silicon dioxide, and 60 mole percent metal oxide; the point C where the additive mixture consists of 30 mole percent lithium oxide, 30 mole percent silicon dioxide, and 40 mole percent metal oxide; the point D where the additive mixture consists of 50 mole percent lithium oxide, 50 mole percent silicon dioxide, and 0 mole percent metal oxide; and the point E where the additive mixture consists of 20 mole percent boric oxide, 80 mole percent silicon dioxide, and 0 mole percent metal oxide.
Claim 4
Dependent Claim
233 words
The solid dielectric capacitor of claim 1 wherein the additive mixture is an additive mixture of boric oxide, silicon dioxide and at least one metal oxide selected from the group consisting of barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide, the relative proportions of boric oxide, silicon dioxide and at least one selected metal oxide constituting the additive mixture being in that rigion of the ternary diagram of FIG. 3 attached hereto which is bounded by lines sequentially connecting: the point A where the additive mixture consists of one mole percent boric oxide, 80 mole percent silicon dioxide, and 19 mole percent metal oxide; the point B where the additive mixture consists of one mole percent boric oxide, 39 mole percent silicon dioxide, and 60 mole percent metal oxide; the point C where the additive mixture consists of 30 mole percent boric oxide, 0 mole percent silicon dioxide, and 70 mole percent metal oxide; the point D where the additive mixture consists of 90 mole percent boric oxide, 0 mole percent silicon dioxide, and 10 mole percent metal oxide; the point E where the additive mixture consists of 90 mole percent boric oxide, 10 mole percent silicon dioxide, and 0 mole percent metal oxide; and the point F where the additive mixture consists of 20 mole percent boric oxide, 80 mole percent silicon dioxide, and 0 mole percent metal oxide.
Claim 5
Dependent Claim
20 words
The solid dielectric capacitor of claims 1, 2 or 3 wherein the electrodes are buried in the dielectric ceramic body.
Claim 6
Dependent Claim
18 words
The solid dielectric capacitor of claims 1, 2 or 3 wherein the electrodes are of a base metal.
Claim 7
Dependent Claim
13 words
The solid dielectric capacitor of claim 5 wherein the base metal is nickel.
Claim 8
Dependent Claim
271 words
A process for the manufacture of a solid dielectric capacitor which comprises: (a) providing in finely divided form a mixture of: 100 parts by weight of a major ingredient expressed by the formula, where M is either or both of magnesium and zinc; L is either or both of calcium and strontium; R is at least one metal selected from scandium, yttrium, gadolinium, dysprosium, holmium, erbium, ytterbium, terbium, thulium and lutetium; a is a numeral in the range of 0.005 to 0.040; k is a numeral not less than 1.00 and not more than 1.05; x is a numeral greater than 0 and less than 0.10; z is a numeral greater than 0 and not greater than 0.05; the sum of x and z is a numeral not less than 0.01 and not greater than 0.10; and y is a numeral greater than 0 and not greater than 0.04; greater than 0 and not greater that 3.00 parts by weight of at least either of chromium oxide and aluminum oxide; and from 0.2 to 5.0 parts by weight of an additive mixture of at least two members selected from the group consisting of boric oxide or lithium oxide, silicon oxide and at least one metal oxide selected form the group consisting of barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide; (b) molding the mixture into desired shape and size, the molding having at least two electrode portions of an electroconductive material; (c) cosintering the molding and the electrode portions to maturity in a nonoxidative atmosphere; and (d) heating the cosintered molding and electrode portions in an oxidative atmosphere.
Claim 9
Dependent Claim
271 words
A process for the manufacture of a solid dielectric capacitor which comprises: (a) providing in finely divided form a mixture of: 100 parts by weight of a major ingredient expressed by the formula, where M is either or both of magnesium and zinc; L is either or both of calcium and strontium; R is at least one metal selected from scandium, yttrium, gadolinium, dysprosium, holmium, erbium, ytterbium, terbium, thulium and lutetium; a is a numeral in the range of 0.005 to 0.040; k is a numeral not less than 1.00 and not more than 1.05; x is a numeral greater than 0 and less than 0.10; z is a numeral greater than 0 and not greater than 0.05; the sum of x and z is a numeral not less than 0.01 and not greater than 0.10; and y is a numeral greater than 0 and not greater than 0.04; greater than 0 and not greater that 3.00 parts by weight of at least either of chromium oxide and aluminum oxide; and from 0.2 to 5.0 parts by weight of an additive mixture of at least two members selected from the group consisting of boric oxide or lithium oxide, silicon oxide and at least one metal oxide selected form the group consisting of barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide; (b) molding the mixture into desired shape and size, the molding having at least two electrode portions of an electroconductive material; (c) cosintering the molding and the electrode portions to maturity in a nonoxidative atmosphere; and (d) heating the cosintered molding and electrode portions in an oxidative atmosphere.
Claim 10
Dependent Claim
28 words
The process of claim 7 wherein the electrode portions are formed on the molding by coating the same with an electroconductive paste composed principally of a base metal.
Claim 11
Dependent Claim
11 words
The process of claim 8 wherein the base metal is nickel.
Claim 12
Dependent Claim
25 words
The process of claim 7 whrein the molding and the electrode portions are cosintered in a temperature range of 1050 degrees to 1200 degrees C.
Claim 13
Dependent Claim
25 words
The process of claim 7 wherein the cosintered molding and electrode portions are heated in a temperature range of 500 degrees to 1000 degrees C.
References Cited (Backward Citations)
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