US4154025A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing oxide piezoelectric material wafers
Assignee: Toshiba Corp
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Filing: 1977-10-03
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Granted: 1979-05-15
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Expires: 1997-10-03
Abstract
Abstract A method for preparing oxide piezoelectric material wafers from a rhombohedral single crystal of an oxide piezoelectric material as-grown cylindrically in the X-axis direction includes linearly rubbing-off at least one side portion of such as-grown cylindrical single crystal facing to a specified direction along the longitudinal direction of such single crystal before cutting X-cut wafers from such single crystal thereby to provide a corresponding flat portion.
Inventors
- 👤 Tsuguo Fukuda
- 👤 Hitoshi Hirano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:34
CPC Classifications
B; B28; B28D; B28D5/00; B28D5/0005; B28D5/0011; H; H10; H10N; H10N30/00; H10N30/01; H10N30/08; H10N30/085; H10N30/088; H10N30/09; H10N30/093; H10N30/095; H10N30/80; H10N30/85; H10N30/853; H10N30/8542
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
A method for preparing oxide piezoelectric material wafers by cutting an anisotropic rhombohedral cylindrical single crystal of an oxide piezoelectric material with the longitudinal direction conincident with the X-axis thereof, comprising rubbing-off at least one side portion of said rhombohedral cylindrical single srystal as-grown facing to at least one direction among a direction <102>, a direction perpendicular to said direction <102>, and directions involved in a range within ±15° from said two directions to form a strip-shaped flat portion along the longitudinal direction of said cylindrical single crystal, and thereafter cutting an X-cut wafer from said single crystal.
Claim 2
Independent Claim
98 words
A method for preparing oxide piezoelectric material wafers by cutting an anisotropic rhombohedral cylindrical single crystal of an oxide piezoelectric material with the longitudinal direction conincident with the X-axis thereof, comprising rubbing-off at least one side portion of said rhombohedral cylindrical single srystal as-grown facing to at least one direction among a direction <102>, a direction perpendicular to said direction <102>, and directions involved in a range within ±15° from said two directions to form a strip-shaped flat portion along the longitudinal direction of said cylindrical single crystal, and thereafter cutting an X-cut wafer from said single crystal.
Claim 3
Dependent Claim
28 words
A method according to claim 1, wherein the ratio (w/R) of a rubbing-off width w to the diameter R of said single crystal ranges from 0.2 to 0.5.
Claim 4
Dependent Claim
15 words
A method according to claim 2, wherein said ratio (w/R) ranges from 0.3 to 0.4.
Claim 5
Dependent Claim
31 words
A method according to claim 1, wherein said single crystal with a part of said side portion rubbed off is subsequently annealed at a temperature of approximately 1,000° C. and above.
Claim 6
Dependent Claim
29 words
A method according to claim 1, wherein said oxide piezoelectric material is at least one among lithium tantalate, lithium niobate, and materials including said compounds with impurities added thereto.
Claim 7
Dependent Claim
30 words
A method according to claim 1, wherein said step of rubbing-off comprises polishing said at least one side surface of said cylindrical single crystal to form said strip-shaped flat portion.
Claim 8
Dependent Claim
30 words
A method according to claim 1, wherein said step of rubbing-off comprises grinding said at least one side portion of said cylindrical single crystal to form said strip-shaped flat portion.
References Cited (Backward Citations)
US2487091A
Cited
US3078549A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |