US4078284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric substrate fabrication process
Assignee: Zenith Electronics LLC
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Filing: 1977-04-04
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Granted: 1978-03-14
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Expires: 1997-04-04
Abstract
Abstract A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprises combining lead oxide, titanium tetra-n-butoxide, lanthanum oxide, and manganese dioxide, with a hydrocarbon solvent and adding water to the combination to form a slurry in which titanium polyester is precipitated unto the lead oxide and lanthanum and manganese oxides. The slurry is dried by heating to a temperature sufficient to remove the liquids therefrom but below the temperature at which an exothermic reaction between the included hydrogen, oxygen and carbon occurs. A first calcining operation produces the exothermic reaction and forms lead titanate after which the lead titanate is heated to and maintained at a temperature above that produced by the exothermic reaction. The lead titanate is then ground to produce powdered lead titanate and a second calcining is carried out to produce structural annealing of the powdered lead titantate. Binder materials are added and the combination of powdered lead titanate and binder materials is cold-pressed into substantially planar substrates. After removal of the binders by heating, the substrates are fired to reduce porosity and poled to impart a piezoelectric characteristic.
Inventors
- 👤 Raymond G. Capek
- 👤 Ann A. Koss
- 👤 Frank T. Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:29
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/01; H10N30/09; H10N30/093; H10N30/80; H10N30/85; H10N30/853; H10N30/8548; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
164 words
A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprising the steps of: combining an inorganic lead compound, a titanium alkoxide, a lanthanide series metal compound, and a compound formed of a metal selected from vanadium, manganese, niobium and tantalum; adding a hydrocarbon solvent and water to the combination formed in said combining step to form a slurry in which titanium polyester is precipitated unto said lead compound; drying said slurry by heating to a temperature sufficient to remove the liquid therefrom but below the self-calcining temperature of said slurry; first calcining the dried slurry to produce lead titanate; grinding said lead titanate to produce powdered lead titanate; second calcining said powdered lead titanate to produce structural annealing; adding binder materials; cold pressing the combination of said powdered lead titanate and said binder materials into substantially planar substrates; removing said binders by heating said substrates; firing said substrates to reduce porosity thereof; and poling said substrates to impart piezoelectric characteristic thereto.
Claim 2
Independent Claim
164 words
A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprising the steps of: combining an inorganic lead compound, a titanium alkoxide, a lanthanide series metal compound, and a compound formed of a metal selected from vanadium, manganese, niobium and tantalum; adding a hydrocarbon solvent and water to the combination formed in said combining step to form a slurry in which titanium polyester is precipitated unto said lead compound; drying said slurry by heating to a temperature sufficient to remove the liquid therefrom but below the self-calcining temperature of said slurry; first calcining the dried slurry to produce lead titanate; grinding said lead titanate to produce powdered lead titanate; second calcining said powdered lead titanate to produce structural annealing; adding binder materials; cold pressing the combination of said powdered lead titanate and said binder materials into substantially planar substrates; removing said binders by heating said substrates; firing said substrates to reduce porosity thereof; and poling said substrates to impart piezoelectric characteristic thereto.
Claim 3
Dependent Claim
128 words
The method set forth in claim 1 wherein the dried slurry produces an exothermic reaction of the included hydrogen, carbon, and oxygen at or above said self-calcining temperature and wherein said step of first calcining includes the steps of: initially heating said dried slurry to produce said exothermic reaction; reaction heating said dried slurry during said exothermic reaction such that the combined effect of said exothermic reaction and said reaction heating raises the temperature of said dried slurry to a reaction temperature at which said titanium polyester and said lead compound react to form lead titanate; final heating said lead titanate after the termination of said exothermic reaction to a predetermined elevated temperature to produce a substantially uniform crystal structure; and cooling said material at a predetermined rate.
Claim 4
Dependent Claim
14 words
The method set forth in claim 2 wherein said titanium alkoxide comprises titanium tetra-n-butoxide.
Claim 5
Dependent Claim
26 words
The method set forth in claim 3 wherein said metal compound formed of a metal selected from vanadium, manganese, niobium and tantalum comprises a manganese oxide.
Claim 6
Dependent Claim
14 words
The method set forth in claim 4 wherein said manganese oxide comprises manganese dioxide.
Claim 7
Dependent Claim
15 words
The method set forth in claim 3 wherein said inorganic lead compound comprises lead oxide.
Claim 8
Dependent Claim
14 words
The method set forth in claim 3 wherein said lanthanide series metal comprises lanthanum.
Claim 9
Dependent Claim
14 words
The method set forth in claim 7 wherein said rare-earth compound comprises lanthanum oxide.
Claim 10
Dependent Claim
15 words
The method set forth in claim 3 wherein said hydrocarbon solvent comprises an alcohol solution.
Claim 11
Dependent Claim
14 words
The method set forth in claim 9 wherein said alcohol solution includes isopropyl alcohol.
Claim 12
Independent Claim
163 words
A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprising the steps of: combining an inorganic lead compound, a titanium alkoxide, a thorium metal compound, and a compound formed of a metal selected from vanadium, manganese, niobium and tantalum; adding a hydrocarbon solvent and water to the combination formed in said combining step to form a slurry in which titanium polyester is precipitated unto said lead compound; drying said slurry by heating to a temperature sufficient to remove the liquid therefrom but below the self-calcining temperature of said slurry; first calcining said dried slurry to produce lead titanate; grinding said lead titanate to produce powdered lead titanate; second calcining said powdered lead titanate to produce structural annealing; adding binder materials; cold pressing the combination of said powdered lead titanate and said binder materials into substantially planar substrates; removing said binders by heating said substrates; firing said substrates to reduce porosity thereof; and poling said substrates to impart piezoelectric characteristic thereto.
Claim 13
Independent Claim
163 words
A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprising the steps of: combining an inorganic lead compound, a titanium alkoxide, a thorium metal compound, and a compound formed of a metal selected from vanadium, manganese, niobium and tantalum; adding a hydrocarbon solvent and water to the combination formed in said combining step to form a slurry in which titanium polyester is precipitated unto said lead compound; drying said slurry by heating to a temperature sufficient to remove the liquid therefrom but below the self-calcining temperature of said slurry; first calcining said dried slurry to produce lead titanate; grinding said lead titanate to produce powdered lead titanate; second calcining said powdered lead titanate to produce structural annealing; adding binder materials; cold pressing the combination of said powdered lead titanate and said binder materials into substantially planar substrates; removing said binders by heating said substrates; firing said substrates to reduce porosity thereof; and poling said substrates to impart piezoelectric characteristic thereto.
Claim 14
Independent Claim
179 words
A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprising the steps of: combining lead oxide, titanium tetra-n-butoxide, lanthanum oxide, and manganese dioxide; adding a hydrocarbon solvent and water to the mixture formed in said combining step to form a slurry in which titanium polyester is precipitated unto said lead oxide; drying said slurry by heating to a temperature sufficient to remove the liquid therefrom but below the temperature at which an exothermic reaction occurs between the hydrogen, oxygen and carbon within the constituents of said slurry; first calcining said slurry to produce said exothermic reaction and form lead titanate; heating said lead titanate at a predetermined temperature to insure proper crystal structure; grinding said lead titanate to produce powdered lead titanate; second calcining said powdered lead titanate to produce structural annealing thereof; adding binder materials; cold pressing the combination of said powdered lead titanate and said binder materials into substantially planar substrates; removing said binders by heating said substrates; firing said substrates to reduce porosity thereof; and poling said substrates to impart piezoelectric characteristic thereto.
Claim 15
Independent Claim
179 words
A method of fabricating a lead titanate piezoelectric surface acoustic wave substrate comprising the steps of: combining lead oxide, titanium tetra-n-butoxide, lanthanum oxide, and manganese dioxide; adding a hydrocarbon solvent and water to the mixture formed in said combining step to form a slurry in which titanium polyester is precipitated unto said lead oxide; drying said slurry by heating to a temperature sufficient to remove the liquid therefrom but below the temperature at which an exothermic reaction occurs between the hydrogen, oxygen and carbon within the constituents of said slurry; first calcining said slurry to produce said exothermic reaction and form lead titanate; heating said lead titanate at a predetermined temperature to insure proper crystal structure; grinding said lead titanate to produce powdered lead titanate; second calcining said powdered lead titanate to produce structural annealing thereof; adding binder materials; cold pressing the combination of said powdered lead titanate and said binder materials into substantially planar substrates; removing said binders by heating said substrates; firing said substrates to reduce porosity thereof; and poling said substrates to impart piezoelectric characteristic thereto.
References Cited (Backward Citations)
US3642637A
Cited
US3917780A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |