US4224547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjusting the frequency of piezoelectric crystal devices via fracturing the crystal surface
Assignee: AT&T Inc
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Filing: 1979-02-28
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Granted: 1980-09-23
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Expires: 1999-02-28
Abstract
Abstract A method which permits highly stable frequency adjustment of piezoelectric crystal devices to tight tolerances. Small fragments of the crystal (10) which resemble conchoidal shells (18) are removed from at least one surface (11) of the crystal plate by fracturing. In one example, this is accomplished by applying pressure from a sharp-pointed stylus (20) near the edge of the plate.
Inventors
- 👤 Anton J. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:28
CPC Classifications
H; H03; H03H; H03H3/00; H03H3/007; H03H3/02; H03H3/04; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
67 words
In a method for fabricating piezoelectric devices, a method for adjusting the resonant frequency of a single crystal piezoelectric plate (10) having major (12,13) and minor (11) surfaces comprising the step of removing a selected amount of material from said plate, CHARACTERIZED IN THAT material is removed in the form of a localized chip by fracturing the crystal near the edge between the major and minor surfaces.
Claim 2
Dependent Claim
67 words
In a method for fabricating piezoelectric devices, a method for adjusting the resonant frequency of a single crystal piezoelectric plate (10) having major (12,13) and minor (11) surfaces comprising the step of removing a selected amount of material from said plate, CHARACTERIZED IN THAT material is removed in the form of a localized chip by fracturing the crystal near the edge between the major and minor surfaces.
Claim 3
Dependent Claim
45 words
The method according to claim 1 wherein the chip is removed substantially from a minor surface (11) of the crystal by applying pressure at a point on the adjacent major surface (13) a predetermined distance (d) from the edge between the major and minor surfaces.
Claim 4
Dependent Claim
16 words
The method according to claim 2 wherein the pressure is applied by a sharp-pointed instrument (20).
Claim 5
Dependent Claim
23 words
The method according to claim 1 wherein the chip is removed from an area of the crystal so as to decrease the frequency.
Claim 6
Dependent Claim
11 words
The method according to claim 1 wherein the crystal comprises quartz.
Claim 7
Dependent Claim
30 words
The method according to claim 1 wherein the crystal vibrates in the fundamental extensional mode and has a final resonant frequency in the range of 40 KHz to 500 KHz.
Claim 8
Dependent Claim
30 words
The method according to claim 1 wherein the crystal vibrates in the fundamental face-shear mode and has a final resonant frequency in the range of 50 KHz to 3 MHz.
Claim 9
Dependent Claim
29 words
The method according to claim 1 wherein the crystal vibrates in the fundamental flexure mode and has a final resonant frequency in the range 1 KHz to 150 KHz.
Claim 10
Dependent Claim
32 words
The method according to claim 6 wherein a plurality of chips are removed to bring the final resonant frequency within the range of ±35 parts per million of a predetermined desired frequency.
Claim 11
Dependent Claim
32 words
The method according to claim 7 wherein a plurality of chips are removed to bring the final resonant frequency within the range of ±12 parts per million of a predetermined desired frequency.
Claim 12
Independent Claim
86 words
A method of adjusting the resonant frequency of a piezoelectric quartz crystal plate (10) having major (12,13) and minor (11) surfaces comprising the step of removing a selected amount of material from said plate CHARACTERIZED IN THAT the material is removed in the form of a localized chip from a selected area substantially at a minor surface (11) of the plate by applying pressure at a point on the adjacent major surface (13) a predetermined distance (d) from the edge between the major and minor surfaces.
Claim 13
Independent Claim
86 words
A method of adjusting the resonant frequency of a piezoelectric quartz crystal plate (10) having major (12,13) and minor (11) surfaces comprising the step of removing a selected amount of material from said plate CHARACTERIZED IN THAT the material is removed in the form of a localized chip from a selected area substantially at a minor surface (11) of the plate by applying pressure at a point on the adjacent major surface (13) a predetermined distance (d) from the edge between the major and minor surfaces.
Claim 14
Dependent Claim
16 words
The method according to claim 11 wherein the pressure is applied by a sharp-pointed instrument (20).
Claim 15
Dependent Claim
41 words
The method according to claim 11 wherein the crystal vibrates in the extensional mode and a plurality of chips are removed from the minor surface so as to adjust the final resonant frequency within ±35 ppm of a predetermined desired frequency.
Claim 16
Dependent Claim
40 words
The method according to claim 11 wherein the crystal vibrates in the face-shear mode and a plurality of chips are removed along the minor surface so as to adjust the frequency to within ±12 ppm of a predetermined desired frequency.
Claim 17
Dependent Claim
28 words
The method according to claim 11 wherein the chip is removed from an area of the minor surface so as to decrease the frequency of the crystal plate.
Claim 18
Dependent Claim
62 words
A piezoelectric device comprising a single crystal piezoelectric plate (10) having major (12,13) and minor (11) surfaces, and at least one pair of electrodes (14,15) disposed on opposite major surfaces of said plate, CHARACTERIZED IN THAT there is included on at least one surface of the crystal at least one localized area of fractured material in the shape of a conchoidal shell.
Claim 19
Dependent Claim
62 words
A piezoelectric device comprising a single crystal piezoelectric plate (10) having major (12,13) and minor (11) surfaces, and at least one pair of electrodes (14,15) disposed on opposite major surfaces of said plate, CHARACTERIZED IN THAT there is included on at least one surface of the crystal at least one localized area of fractured material in the shape of a conchoidal shell.
Claim 20
Dependent Claim
17 words
The device according to claim 16 wherein the fractured area is formed substantially in a minor surface.
Claim 21
Dependent Claim
11 words
The device according to claim 16 wherein the crystal comprises quartz.
Claim 22
Dependent Claim
28 words
The device according to claim 16 wherein the crystal vibrates in a fundamental extensional mode with a resonant frequency in the range of 40 KHz to 500 KHz.
Claim 23
Dependent Claim
28 words
The device according to claim 16 wherein the crystal vibrates in the fundamental face-shear mode with a resonant frequency in the range of 50 KHz to 3 MHz.
Claim 24
Dependent Claim
28 words
The device according to claim 16 wherein the crystal vibrates in the fundamental flexure mode with a resonant frequency in the range of 1 KHz to 150 KHz.
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) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |