US4411731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of contouring crystal plates
Assignee: AT&T Inc
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Filing: 1982-12-27
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Granted: 1983-10-25
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Expires: 2002-12-27
Abstract
Abstract A method of contouring crystal plates for frequency control. After plate dimensions are established, the plates are kept in a stack separated by a bonding material. The stack is immersed in an etchant which etches the exposed crystal edges in a manner which undercuts the bonding material, thus batch forming bevel contours on at least the outer portions of the major faces of each plate in the stack.
Inventors
- 👤 Anton J. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:19
CPC Classifications
C; C30; C30B; C30B33/00; H; H03; H03H; H03H3/00; H03H3/007; H03H3/02; H10; H10W; H10W46/00; H10W46/201
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
49 words
A method of fabricating piezoelectric devices which include crystal plates comprising the steps of providing a stack of such plates separated by a bonding material, and contouring such plates by immersing the stack in an etchant which dissolves the bonding material and etches the exposed portions of the plates.
Claim 2
Independent Claim
49 words
A method of fabricating piezoelectric devices which include crystal plates comprising the steps of providing a stack of such plates separated by a bonding material, and contouring such plates by immersing the stack in an etchant which dissolves the bonding material and etches the exposed portions of the plates.
Claim 3
Dependent Claim
12 words
The method according to claim 1 wherein the bonding material comprises beeswax.
Claim 4
Dependent Claim
12 words
The method accordig to claim 1 wherein the etchant comprises a fluoride.
Claim 5
Dependent Claim
12 words
The method according to claim 3 wherein the etchant comprises hydrofluoric acid.
Claim 6
Dependent Claim
24 words
The method according to claim 1 wherein the etchant produces a bevel contour on the outer portions of both major surfaces of the plates.
Claim 7
Dependent Claim
17 words
The method according to claim 1 wherein the aspect ratio of the plates is less than 50.
Claim 8
Dependent Claim
21 words
The method according to claim 1 wherein the etchant produces a bevel contour over the entire major surfaces of the plates.
Claim 9
Dependent Claim
20 words
The method according to claim 1 wherein the stack is immersed in the etchant for a time of 3-25 hours.
Claim 10
Dependent Claim
40 words
The method according to claim 1 where the major surfaces of the plates are rectangular and the etchant produces a multi-bevel contour on at least one outer portion of both major surfaces and a sharp edge between the major surfaces.
Claim 11
Independent Claim
86 words
A method of adjusting the frequency response of piezoelectric crystal plates having an aspect ratio less than 50 comprising the steps of providing a stack of such plates separated by a bonding material comprising beeswax, and contouring outer portions of the major surfaces of such plates by immersing the stack in an etchant comprising hydrofluoric acid which slowly dissolves the bonding material and etches the exposed portions of the plates to produce a bevel contour at an outer portion of the major surfaces of each plate.
Claim 12
Independent Claim
86 words
A method of adjusting the frequency response of piezoelectric crystal plates having an aspect ratio less than 50 comprising the steps of providing a stack of such plates separated by a bonding material comprising beeswax, and contouring outer portions of the major surfaces of such plates by immersing the stack in an etchant comprising hydrofluoric acid which slowly dissolves the bonding material and etches the exposed portions of the plates to produce a bevel contour at an outer portion of the major surfaces of each plate.
References Cited (Backward Citations)
US3864111A
Cited
US3951728A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |