EP0125831A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Ag/Pd electroding powder and preparation thereof
Assignee: MRA Laboratories Inc
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Filing: 1984-05-01
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Granted: —
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Expires: 2004-05-01
Abstract
Abstract A metal electroding powder for use in making monolithic ceramic capacitors comprises a silver-palladium alloy powder having a composition, by weight, of 90Ag/10Pd and having palladium oxide on the surface of the alloy particles. The powder is made by heating a silver-palladium alloy powder containing less than 90% by weight of silver, in air at about 500°C so as to oxidise a portion of the palladium to form palladium oxide at the surface of the alloy particles and to increase the silver content of the alloy until it has a composition, by weight, of 90Ag/10Pd.
Inventors
- 👤 Galeb Hamid Maher
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:09
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/005; H01G4/008; H01G4/0085; C; C22; C22C; C22C32/00; C22C32/001; C22C32/0015; C22C32/0021; Y; Y10; Y10S; Y10S75/00; Y10S75/95; Y10S75/951; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
36 words
A metal electroding powder for use in making monolithic ceramic capacitors, which powder comprises a silver-palladium alloy powder having a composition, by weight, of 90Ag/10Pd and having palladium oxide on the surface of the alloy particles.
Claim 2
Dependent Claim
36 words
A metal electroding powder for use in making monolithic ceramic capacitors, which powder comprises a silver-palladium alloy powder having a composition, by weight, of 90Ag/10Pd and having palladium oxide on the surface of the alloy particles.
Claim 3
Dependent Claim
30 words
A powder according to claim 1, in which the weight ratio of the total silver to the total palladium (including that present in said oxide) is from 30Ag/70Pd and 90Ag/10Pd.
Claim 4
Dependent Claim
21 words
A powder according to claim 1 or 2, which has a surface area from 0.5 to 2. O m 2 /gm.
Claim 5
Dependent Claim
22 words
A powder according to any of claims 1 to 3, which has an average particle size of from 0.1 to 2 microns.
Claim 6
Independent Claim
74 words
A method of making a metal electroding powder for use in monolithic ceramic capacitors, which comprises heating in air at about 500 0 C, a silver-palladium alloy powder containing less than 90% by weight of silver so as to oxidize a portion of the palladium to form palladium oxide at the surface of the alloy particles and to increase the silver content of the alloy until it has a composition, by weight, of 90Ag/10Pd.
Claim 7
Independent Claim
74 words
A method of making a metal electroding powder for use in monolithic ceramic capacitors, which comprises heating in air at about 500 0 C, a silver-palladium alloy powder containing less than 90% by weight of silver so as to oxidize a portion of the palladium to form palladium oxide at the surface of the alloy particles and to increase the silver content of the alloy until it has a composition, by weight, of 90Ag/10Pd.
Claim 8
Dependent Claim
26 words
A method according to claim 5, which comprises the further step of mixing the oxidized alloy with an organic liquid vehicle to form an electroding paste.
Claim 9
Dependent Claim
48 words
A method according to claim 5 or 6, in which said heating is preceded by mixing a silver powder with a palladium powder and thoroughly dispersing the two metal powders to form a homogenous mixture, and heating the mixture to about 300°C to form the silver-palladium alloy powder.
Claim 10
Dependent Claim
25 words
A method according to claim 7, in which the silver powder has a surface area which is substantially less than that of the palladium powder.
Claim 11
Dependent Claim
37 words
A method according to claim 8, in which the surface area of the silver powder is less than 6m /gm and the surface area of the palladium powder is from 8 to 12 m 2 /g m.
Claim 12
Independent Claim
36 words
A method according to any of claims 7 to 9, in which the alloy powder is comminuted after said heating to about 300°C until its surface area is from 0.5 to 5. Om 2 /g m.
Claim 13
Independent Claim
42 words
A method according to any of claims 7 to 10, in which the dispersing of the silver and palladium powders is effected by milling the powders in a liquid vehicle containing a dissolved cationic dispersant that begins to decompose at above 350°C.
Claim 14
Independent Claim
26 words
A method according to any of claims 7 to 9, in which the weight ratio of silver powder to palladium powder is from 30/70 to 90/10.
Claim 15
Dependent Claim
96 words
A method of making a monolithic ceramic capacitor, which comprises: (a) forming a plurality of layers of a green ceramic composition comprising a mixture of a high- firing-temperature ceramic powder and a low-melting- temperature sintering flux; (b) depositing a layer of an electroding paste as obtained by the method of claim 6 on all but one of the green ceramic layers; (c) stacking the green ceramic layers to form a green monolithic ceramic capacitor body having electroding paste between each adjacent pair of ceramic layers; and (d) sintering the green ceramic body at less than 1200°C.
References Cited (Backward Citations)
No citation records indexed.
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