US4512917A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hexaboride resistor composition
Assignee: EIDP Inc
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Filing: 1984-02-21
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Granted: 1985-04-23
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Expires: 2004-02-21
Abstract
Abstract A composition for the preparation of thick film resistors comprising an admixture of finely divided particles of a conductive metal hexaboride and a crystallizable glass frit which is irreducible by the metal hexaboride containing at least 5 mole % of Ta 2 O 5 which is reducible by the metal hexaboride under normal firing conditions.
Inventors
- 👤 Paul C. Donohue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:00
CPC Classifications
H; H01; H01C; H01C7/00; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06513; H01C17/06566; H01C7/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
A composition for the preparation of thick film resistors comprising an admixture of finely divided particles of: A. 2-70% by weight, basis total solids, of conductive metal hexaboride selected from the group consisting of LaB 6 , YB 6 , rare earth hexaboride, CaB 6 , SrB 6 and mixtures thereof; and B. 98-30% by weight, basis total solids, of an alkali metal or alkaline earth metal aluminosilicate crystallizable glass comprising 70-95 mole % components which are irreducible by the conductive metal hexaboride having dissolved therein 30-5 mole % Ta 2 O 5 .
Claim 2
Dependent Claim
94 words
A composition for the preparation of thick film resistors comprising an admixture of finely divided particles of: A. 2-70% by weight, basis total solids, of conductive metal hexaboride selected from the group consisting of LaB 6 , YB 6 , rare earth hexaboride, CaB 6 , SrB 6 and mixtures thereof; and B. 98-30% by weight, basis total solids, of an alkali metal or alkaline earth metal aluminosilicate crystallizable glass comprising 70-95 mole % components which are irreducible by the conductive metal hexaboride having dissolved therein 30-5 mole % Ta 2 O 5 .
Claim 3
Dependent Claim
16 words
The composition of claim 1 in which the crystallizable glass is an alkaline earth metal boroaluminosilicate.
Claim 4
Dependent Claim
16 words
The composition of claim 1 in which the glass contains 5-10% Ta 2 O 5 .
Claim 5
Dependent Claim
15 words
The composition of claim 1 in which the conductive metal hexaboride is LaB 6 .
Claim 6
Dependent Claim
20 words
The composition of claim 1 in which the particle size of the conductive metal hexaboride is less than one micron.
Claim 7
Dependent Claim
14 words
A screen printable composition comprising the composition of claim 1 dispersed in organic medium.
Claim 8
Dependent Claim
79 words
The method of making a resistor element comprising the sequential steps of (a) forming a dispersion in organic medium of the composition of claim 1; (b) forming a patterned thin layer of the dispersion of step (a); (c) drying the layer of step (b); and (d) firing the dried layer of step (c) in a nonoxidizing atmosphere to effect reduction of the Ta 2 O 5 , volatilization of the organic medium, and liquid phase sintering of the glass.
Claim 9
Dependent Claim
45 words
A resistor comprising a patterned thin layer of the dispersion of claim 6 which has been dried and fired in a nonoxidizing atmosphere to effect reduction of the Ta 2 O 5 , volatilization of the organic medium and liquid phase sintering of the glass.
References Cited (Backward Citations)
GB1282023A
Cited
FR2397704A1
Cited
US4225468A
Cited
EP0008437B1
Cited
US4260525A
Cited
US4237084A
Cited
US4420338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |