US4785375A
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Temperature stable dielectric composition at high and low frequencies
Assignee: Tam Ceramics LLC
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Filing: 1987-06-11
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Granted: 1988-11-15
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Expires: 2007-06-11
Abstract
Abstract The invention is directed to a dielectric ceramic having a dielectric constant K, greater than 35, a quality factor, Q, greater than 9,000 at 4 GH z and a reduction of the firing temperature to less than about 1350° C. The dielectric ceramic consists essentially of a sintered mixture of about 35 to 55 mole percent ZrO 2 , about 30 to 50 mole percent TiO 2 , 5 to about 22.5 mole percent SnO 2 , about 0.5 to 10 mole percent ZnO, and 0.3 to about 2.5 mole percent CuO.
Inventors
- 👤 Scott S. Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:24
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; H01P; H01P7/00; H01P7/10
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
84 words
A dielectric ceramic having a K value in the range of about 25 to 40, Q greater than about 9000 at 4 GH z consisting essentially of a mixture of about 35 to 55 mole percent of ZrO 2 , about 30 to 50 mole percent of TiO 2 , about 5 to 22.5 mole percent of SnO 2 , about 0.5 to 10 mole percent of ZnO, and about 0.3 to 2.5 mole percent of CuO; sintered at less than about 1350° C.
Claim 2
Dependent Claim
84 words
A dielectric ceramic having a K value in the range of about 25 to 40, Q greater than about 9000 at 4 GH z consisting essentially of a mixture of about 35 to 55 mole percent of ZrO 2 , about 30 to 50 mole percent of TiO 2 , about 5 to 22.5 mole percent of SnO 2 , about 0.5 to 10 mole percent of ZnO, and about 0.3 to 2.5 mole percent of CuO; sintered at less than about 1350° C.
Claim 3
Dependent Claim
10 words
A dielectric resonator comprising said sintered mixture of claim 1.
Claim 4
Dependent Claim
11 words
A multilayer ceramic capacitor comprising said sintered mixture of claim 1.
Claim 5
Dependent Claim
9 words
A substrate comprising said sintered mixture of claim 1.
Claim 6
Dependent Claim
53 words
A multilayer ceramic capacitor consisting essentially of a sintered mixture of about 35 to 55 mole percent ZrO 2 , about 30 to 50 mole percent TiO 2 , about 5 to 22.5 mole percent SnO 2 , about 0.5 to 10 mole percent ZnO, and about 0.3 to 2.5 mole percent CuO.
Claim 7
Dependent Claim
53 words
A multilayer ceramic capacitor consisting essentially of a sintered mixture of about 35 to 55 mole percent ZrO 2 , about 30 to 50 mole percent TiO 2 , about 5 to 22.5 mole percent SnO 2 , about 0.5 to 10 mole percent ZnO, and about 0.3 to 2.5 mole percent CuO.
Claim 8
Dependent Claim
37 words
A multilayer ceramic capacitor according to claim 5 which comprises 44 mole percent ZrO 2 , 12 mole percent SnO 2 , 44 mole percent TiO 2 , 2.0 mole percent ZnO and 1.0 mole percent CuO.
Claim 9
Dependent Claim
65 words
A composition for making dielectric ceramics useful at about 1 KHz to about 15 GHz consisting essentially of about 35 to 55 mole percent of ZrO 2 , about 30 to 50 mole percent of TiO 2 , about 5 to 22.5 mole percent of SnO 2 , about 0.5 to 10 mole percent of ZnO, and about 0.3 to 2.5 mole percent of CuO.
Claim 10
Dependent Claim
65 words
A composition for making dielectric ceramics useful at about 1 KHz to about 15 GHz consisting essentially of about 35 to 55 mole percent of ZrO 2 , about 30 to 50 mole percent of TiO 2 , about 5 to 22.5 mole percent of SnO 2 , about 0.5 to 10 mole percent of ZnO, and about 0.3 to 2.5 mole percent of CuO.
Claim 11
Dependent Claim
11 words
A dielectric resonator comprising said dielectric ceramic composition of claim 7.
Claim 12
Dependent Claim
10 words
A substrate comprising said dielectric ceramic composition of claim 7.
Claim 13
Dependent Claim
12 words
A multilayer ceramic capacitor comprising said dielectric ceramic composition of claim 7.
Claim 14
Independent Claim
144 words
A method of manufacturing a dielectric ceramic having a K value in the range of about 25 to 40, a Q greater than about 9,000 at 4 GHz comprising the steps of: (a) preparing a mixture of high purity oxides consisting essentially of about 35 to 55 mole percent of ZrO 2 , about 30 to 50 mole percent of TiO 2 , about 5 to 22.5 mole percent of SnO 2 , about 0.5 to 10 mole percent ZnO, and about 0.3 to 2.5 mole percent CuO; (b) calcining said mixture at a temperature to initiate formation of a base ceramic solid solution phase; (c) reducing the particle size of the calcined mixture; (d) pulverizing said powdered composition; (e) compressing said calcined mixture in a mold; and (f) firing said compressed powdered composition in air at a temperature less than about 1350° C.
Claim 15
Independent Claim
144 words
A method of manufacturing a dielectric ceramic having a K value in the range of about 25 to 40, a Q greater than about 9,000 at 4 GHz comprising the steps of: (a) preparing a mixture of high purity oxides consisting essentially of about 35 to 55 mole percent of ZrO 2 , about 30 to 50 mole percent of TiO 2 , about 5 to 22.5 mole percent of SnO 2 , about 0.5 to 10 mole percent ZnO, and about 0.3 to 2.5 mole percent CuO; (b) calcining said mixture at a temperature to initiate formation of a base ceramic solid solution phase; (c) reducing the particle size of the calcined mixture; (d) pulverizing said powdered composition; (e) compressing said calcined mixture in a mold; and (f) firing said compressed powdered composition in air at a temperature less than about 1350° C.
Claim 16
Dependent Claim
20 words
A method of manufacture according to claim 11 wherein the particle size of said calcined mixture is reduced by milling.
Claim 17
Dependent Claim
32 words
A method of manufacture according to claim 11 wherein said mixture is calcined at a temperature within the range of about 800° C. to 1300° C. for about 3 to 6 hours.
Claim 18
Dependent Claim
32 words
A method of manufacture according to claim 13, wherein the base ceramic solid solution phase of the calcined mixture includes more than about 90% of the (Zr, Sn) TiO 2 orthorhombic phase.
Claim 19
Dependent Claim
43 words
A method of manufacture according to claim 13, wherein the calcined mixture is ball milled in water with ZrO 2 media for about 8 hours to a surface area of about 3.0 m 2 /g and a particle size of about 1.2 microns.
Claim 20
Dependent Claim
20 words
A method of manufacture according to claim 11, wherein the mixture of high purity oxides is ball milled in water.
Claim 21
Dependent Claim
41 words
A method of manufacture according to claim 11, wherein said powdered composition is compressed into cylinders at a pressure of about 55 MPa and fired at temperatures between 1200° C. and 1350° C. in air for about 4 to 6 hours.
Claim 22
Dependent Claim
36 words
A method of manufacture according to claim 11, wherein said compressed powdered composition is tape cast into multilayer capacitors and fired at temperatures between about 1200° C. and 1350° C. in air for about 3 hours.
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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |