JP2001196882A - Frequency adjustment device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MCF adjustment device easy in maintenance and capable of speedily adjusting a passing band frequency without causing any particle in a vacuum vessel. SOLUTION: The vacuum vessel is provide with deflection coils 73a, 73b that generate a magnetic field to deflect an orbit of an ion beam 68 for ion etching toward a target electrode 51a on a monolithic crystal filter 51 with piezoid 51k at least on one side of which a plurality of resonance electrodes 51a, 51b is placed and on the other side of which a ground electrode 51c is placed, and the frequency adjustment device is provided with a magnetic field control circuit 71 that controls the strength of the magnetic field generated by the deflection coils 73a, 73b to apply ion etching to the resonance electrodes 51a, 51b on the piezoid 51k.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency of a monolithic crystal filter (MCF) having a plurality of electrodes on at least one surface of a piezoelectric crystal plate such as a quartz plate and a ground electrode on the other surface. More particularly, the present invention relates to a frequency adjusting device for a monolithic crystal filter that adjusts a pass band frequency by ion-etching each of the electrodes.

[0002]

2. Description of the Related Art A monolithic crystal filter (hereinafter, referred to as MCF) utilizes the energy trapping effect of a piezoelectric crystal plate such as a quartz plate, and is widely used as a small, narrow band bandpass filter. .
In a basic MCF configuration, a ground electrode is formed on one surface of a piezoelectric crystal plate, and two resonance electrodes are formed on the other surface. As a method of using the MCF, the ground electrode is grounded, one of the other two resonance electrodes is connected to the input terminal, and the other is connected to the output terminal. The passband frequency characteristic of the MCF is determined by the thickness of the piezoelectric crystal plate, the size and thickness of each electrode, the distance between two resonance electrodes, and the like. Since the thickness of the piezoelectric crystal plate is determined at the time of manufacturing the piezoelectric crystal plate and cannot be changed, the final adjustment of the pass band frequency of the MCF is performed by adjusting the size and thickness of each electrode. The size and thickness of each electrode can be adjusted by vapor deposition of a metal film and ion etching after vapor deposition. This can be adjusted because there is a close relationship between the thickness of the piezoelectric crystal plate including the electrodes and the resonance frequency.In general, when the thickness of the piezoelectric crystal plate including the electrodes is reduced, There is a relationship that the resonance frequency increases. For example, when the resonance frequency corresponding to each resonance electrode obtained when a voltage is applied between each of two resonance electrodes and the ground electrode and excited is f1 and f2, the pass band width of the MCF is widened. If desired, the passband can be widened by ion-etching the resonance electrode having the higher resonance frequency to widen the difference between the resonance frequencies f1 and f2. In order to shift the pass band frequency of the MCF to a higher frequency side, both the resonance electrodes are subjected to ion etching, or the ground electrode is subjected to ion etching to obtain a piezoelectric crystal including the electrodes. The passband frequency can be shifted to a higher frequency side by reducing the thickness of the plate. Conversely, when it is desired to shift the pass band frequency of the MCF to a lower frequency side, a metal film of a required thickness is deposited on both resonance electrodes, or a metal film of a required thickness is deposited on a ground electrode. By increasing the thickness of the piezoelectric crystal plate including the electrodes, the passband frequency can be shifted to a lower frequency side. Hereinafter, an adjusting device and an adjusting method for adjusting a pass band frequency of a conventional MCF will be described with reference to the drawings.

FIG. 6 is a diagram showing a configuration of an example of a conventional MCF adjustment device. The conventional frequency adjusting device 1 of the MCF 51 shown in FIG.
A configuration is provided for adjusting the frequency by depositing a and 51b or ion etching. MCF51
Is arranged in the vacuum vessel 11. The air in the vacuum vessel 11 is exhausted by a vacuum pump (not shown) or the like, and the vapor deposition or ion etching is performed in the same high vacuum state during vapor deposition and ion etching. In addition,
At the time of ion etching, argon gas or the like is slightly filled, and etching is performed using molecules such as argon gas. M
Each wiring connection part 51at, 51bt, 51ct of each electrode 51a, 51b, 51c of the CF 51 is connected to an oscillation circuit outside the vacuum vessel 11. The oscillating circuit 21 includes the electrodes 51a
To 51c, a voltage is applied between the electrodes 51a to 51c.
The resonance frequency generated during the period c is detected and sent to the main control unit 23. In the main control unit 23, for example, the monitor 2 as a display unit of the network analyzer
4 is displayed. The operator (adjustment operator) who has recognized each resonance frequency on the monitor 24 inputs an instruction for the next process from the input unit 26. The main control unit 23 that has received the instruction from the input unit 26 outputs an instruction of a process to be executed next to the motor control unit 27 and the vapor deposition control unit 25. Motor control unit 27
Rotates the motor 29 in accordance with an instruction from the main control unit 23. The vapor deposition control unit 25 receives a deposit 58 a from the vapor deposition source 57 in the vacuum vessel 11 according to an instruction from the main control unit 23.
Release 58b. The rotational driving force of the motor 29 is converted into linear motion by the mask driving unit 55, and
3 is moved linearly. Further, the above-described vapor deposition source 57 and vapor deposition control unit 25 are used when the metal films of the electrodes 51a, 51b, and 51c are formed on the front and back surfaces of the piezoelectric crystal plate 51k of the MCF 51 to have a required thickness by vapor deposition. Are the respective electrodes 51a, 51b, 51 of the metal film once formed.
When adjusting the resonance frequency by reducing the thickness of c by etching, the above-described evaporation source 57 and evaporation control unit 25 are used.
, An ion beam control unit 35 and an ion beam gun 67 are used. The ion beam control unit 35 causes the ion beam gun 67 to emit ion beams 68a and 68b according to an instruction from the main control unit 23. The emitted ion beams 68a and 68b collide with the molecules of the argon gas filled in the vacuum vessel 11 to emit electrons of the argon gas.
Etching is performed by colliding with 1a, 51b and the like. However, in the following description, the ion beams 68a and 68b emitted from the ion beam gun 67 are directly
Etching is performed by colliding with a, 51b, and the like. Here, the movable mask 53 is arranged at a certain distance from the surface of the MCF 51 so as not to damage the surface of the MCF 51.

[0004] The frequency adjustment device 1 shown in FIG.
The method for adjusting the passband frequency of the CF 51 is as follows. When the operator inputs a vapor deposition instruction from the input unit 26, the main control unit 23 having received the vapor deposition instruction outputs the instruction to the motor control unit 27, and the position of the window 53a provided in the movable mask 53 is The movable mask 5 is positioned so as to be located on a straight line connecting the resonance electrodes 51a and 51b and the evaporation source 57.
Slide 3 in the direction of the arrow. Each resonance electrode 51
When the position of the movable mask 53 is determined such that the window 53a provided in the movable mask 53 is located on each straight line connecting the a and 51b and the evaporation source 57, the main control unit 23 An instruction to start deposition by outputting the deposition materials 58a and 58b from the deposition source 57 is output. Two resonance electrodes 51a and 51b are provided on one surface of the piezoelectric crystal plate 51k.
A deposit such as silver is deposited so as to be thicker than required so that the (metal film) is formed at intervals. Also,
A ground electrode 5 is formed on the other surface of the piezoelectric crystal plate 51k in advance.
1c is formed thicker than required thickness by vapor deposition. After the electrodes 51a to 51c on both sides of the piezoelectric crystal plate 51k are formed by vapor deposition, the vapor deposition source 57 provided in the vacuum vessel 11 and the vapor deposition control unit 25 provided outside the vacuum vessel 11
To the ion beam gun 67 and the ion beam controller 3 respectively.
Replace with 5. A monolithic crystal filter is obtained by reducing the thickness of each electrode 51a to 51c (metal film such as silver) formed on the quartz plate 51k by ion etching using the ion beam gun 67 and the ion beam control unit 35. Adjustment of the pass band frequency of 51 is performed. That is, at the time of adjusting the pass band frequency of the conventional monolithic crystal filter 51, the movable mask 53 is used not only at the time of vapor deposition but also at the time of ion etching.
The ion beam hits the target electrode by moving 3a to an appropriate position.

[0005]

However, in the above configuration, since the movable portion such as the movable mask is provided in the vacuum container, the mechanism of the frequency adjusting device becomes complicated, and furthermore,
The shape of the window provided on the movable mask is vapor deposition (metal adhesion)
In addition, because of deformation due to ion etching, much time and man-hours were required for maintenance. Further, even when the movable mask is properly arranged, since the gap exists between the MCF 51 and the movable mask 53, the ions spread around so as to go around after passing through the window 53a, and the resonance electrodes 51a, The surface of the piezoelectric crystal plate 51k in the vicinity of 51b is etched and roughened, or
In the case where only a is etched, in the case of a small MCF, the distance between the two resonance electrodes 51a and 51b is narrow.
There has also been a problem that the surface of the electrode 106 that does not require etching is also etched. Therefore, as a means for preventing etching of portions other than the electrodes, there is a method described in Japanese Patent Application No. 11-177082, for example. In this method, the thickness of the front electrode on the back surface facing the resonance electrode is adjusted instead of the resonance electrode which needs to adjust the film thickness for frequency adjustment. Are prevented from being unintentionally etched. However, in such a method, M
When the resonance electrode becomes smaller due to the higher frequency and smaller size of CF, strict alignment is required to make the position of the front electrode facing the resonance electrode the etching area, but the alignment accuracy is strict. However, there is a limit in performing this method, and the ratio of the deviation of the etching position to the size of the resonance electrode increases as the MCF becomes smaller. In addition, since there is a limit to the operating speed of the movable part, the work of adjusting the passband frequency of the MCF cannot be completed in a short time. In addition, since the movable portion has the movable portion, fine particles (particles) are generated in the vacuum vessel 11 by sliding between the movable portion and its support portion, or by fitting of the movable portion and its drive portion. And the particles floating in the vacuum vessel 11 obstruct the path on the trajectory of the ion beam. The present invention has been made in order to solve the conventional problems as described above, is easy to maintain, can reduce the time required for adjusting the passband frequency, and can be used in a vacuum vessel. An object of the present invention is to provide an MCF adjustment device that does not generate particles.

[0006]

According to a first aspect of the present invention, there is provided a frequency adjusting apparatus for a piezoelectric vibrating element having electrodes on both main surfaces of a piezoelectric crystal plate. A frequency adjusting device for adjusting a frequency by ion-etching each electrode, wherein a deflection coil for generating a magnetic field for deflecting a trajectory of an ion beam used for the ion etching toward a target electrode is provided. In addition, a magnetic field control circuit for controlling the intensity of the magnetic field generated by the deflection coil is provided. The frequency adjusting device of the present invention according to claim 2 is a frequency adjusting device that adjusts a frequency by ion-etching each of the electrodes on a piezoelectric vibrating element having electrodes on both main surfaces of a piezoelectric crystal plate. And an electric field control circuit for providing a deflection electrode for generating an electric field for deflecting the trajectory of the ion beam used for the ion etching toward a target electrode, and for controlling the intensity of the electric field generated by the deflection electrode. Is provided. Claim 3
According to the frequency adjusting apparatus of the present invention, in addition to the first or second aspect, the piezoelectric vibration element has a plurality of resonance electrodes on at least one surface of a piezoelectric crystal plate and a ground electrode on the other surface. A monolithic crystal filter having a negative electrode, a voltage having a polarity opposite to the potential of ions is applied to a resonance electrode serving as a target on the piezoelectric crystal plate, and a potential of ions is applied to a resonance electrode not serving as a target. It is characterized in that potentials of the same polarity are applied. The frequency adjustment method according to claim 4, wherein the electrode is etched by colliding ions with the electrode of the piezoelectric element, thereby adjusting the frequency of the piezoelectric element. By applying a bias to the electrode requiring etching so as to have a potential having a polarity opposite to that of the ions, the collision of ions is concentrated on the surface of the electrode. 6. The frequency adjusting method according to claim 5, wherein the piezoelectric element includes an electrode that does not require etching in addition to the electrode, and the electrode that does not require etching has a potential of the same polarity as the potential of ions. By applying a bias so as to satisfy the following condition, ions are prevented from colliding with the surface of the electrode. According to a sixth aspect of the present invention, in addition to the first to fifth aspects, one of the electrodes provided on both main surfaces of the piezoelectric substrate is a ground electrode covering substantially one surface of the piezoelectric substrate, and the other is provided with another electrode. An electrode provided on one main surface is a resonance electrode, and the ground electrode is divided into a portion facing the resonance electrode and another portion.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on illustrated embodiments. FIG. 1 is a block diagram showing the configuration of the MCF adjustment device according to the first embodiment of the present invention. still,
1 and 2, the same reference numerals are given to portions having the same functions as those of the conventional MCF adjustment device shown in FIG. 6, and redundant description will be omitted. As shown in FIG.
In the CF adjusting device 70, the ion beam gun 67 and the MCF
Deflection coils 73a and 73b for generating a magnetic field for deflecting the trajectory of the ion beam for ion etching toward the resonance electrode 51a or 51b serving as a target are provided between the deflection coils 73a and 51b. Furthermore, the MCF adjustment device 70 of the present embodiment
A magnetic field control circuit 71 is provided for controlling the intensity of the magnetic field generated by the deflection coils 73a and 73b to control the trajectory of the ion beam and ion-etch the respective resonance electrodes 51a and 51b on the piezoelectric crystal plate 51k. The magnetic field control circuit 71 controls the strength of the magnetic field by controlling the current flowing through the deflection coils 73a and 73b. And
Thus, in the magnetic field due to the so-called Lorentz force, a force acts in a direction perpendicular to the radiation direction of the ion beam and perpendicular to the magnetic field in accordance with Fleming's left-hand rule in a magnetic field, so that the irradiation direction can be deflected. In FIG. 1, only one set of the deflection coils 73a and 73b is described at the upper and lower positions of the ion beam as the deflection coils. However, two sets of the actual deflection coils are provided in the vertical and horizontal directions of the ion beam. Or two in the vertical and horizontal directions
Four sets of deflection coils or two or more sets of deflecting coils are provided by adding two sets of diagonally right-up and diagonally left-up directions. Therefore, in this embodiment, by providing two or more sets of deflection coils and controlling the magnetic field in multiple directions as described above,
The trajectory of the ion beam can be controlled in any direction.

In this embodiment, each of the electrodes 51a, 51b
When ion etching is performed, the magnetic field generated by the deflection coils 73a, 73b and the like is controlled by the magnetic field control circuit 71 so that the trajectory of the ion beam
a, 51b. For example, when etching the resonance electrode 51a, the magnetic field control circuit 71 controls the deflection coil 7a.
The magnetic field generated by 3a, 73b or the like is controlled so that the ion beam is deflected and strikes the resonance electrode 51a.
That is, the magnetic field generated by the deflection coils 73a and 73b is controlled so that the target of the ion beam becomes the resonance electrode 51a. If the ion beam is likely to diffuse, for example, a deflection coil group may be provided so as to surround the ion beam separately from the deflection coil, and the direction of the magnetic field generated by each deflection coil may be changed. By turning inward, the ion beam can be narrowed down. In the present embodiment, as described above, the deflection coils 73a, 73b
Since the trajectory of the ion beam is controlled in an arbitrary direction by the above-described method, it is not necessary to provide a movable portion and a sliding portion such as the movable mask 53 in the vacuum chamber 11. Therefore, the vacuum container 11
The ion beam can be deflected toward the target electrode without generating particles therein, and maintenance becomes easy because there is no movable part having a complicated configuration. Further, in the present embodiment, there is no need to mechanically slide the movable mask 53 and the like, so that the tact time before starting the adjustment work by ion etching is shortened, the adjustment work is speeded up, and the work efficiency is improved. be able to.

Further, in the MCF adjusting apparatus 70 of the present embodiment, when the ions irradiated from the ion beam gun 67 are negative ions by the oscillation circuit 21 at the time of ion etching, for example, a target electrode on the piezoelectric crystal plate 51k is formed. A positive voltage is applied to the electrode 51a, and a negative voltage is applied to the electrode 51b that is not a target. As described above, by applying a voltage having a polarity attracting ions to an electrode serving as a target and applying a voltage having a polarity repelling ions to an electrode not serving as a target,
Even if the ion beam emitted from the ion beam gun 67 deviates from the trajectory to the electrode 51a, it does not collide with the non-target electrode 51b, so that the electrode 51b is not etched. Therefore, in the present embodiment, for example, only the electrode 51a serving as a target, which is performed in order to increase the difference in thickness between the electrode 51a and the electrode 51b, can be efficiently performed. Further, in the conventional frequency adjustment device 1, the same vacuum vessel 11 is used for vapor deposition and ion etching, but in the present embodiment,
For example, the vacuum vessel 11 used for vapor deposition and the vacuum vessel 11 used for ion etching are separately installed, and the MCF deposited in the vacuum vessel 11 used for vapor deposition is transferred to the vacuum vessel 11 used for ion etching. You may change it. In the present embodiment, for example, the same vacuum vessel 11 is used for the vapor deposition process and the ion etching process,
It is possible to replace the vapor deposition source 57 with the ion beam gun 67, but in this case, if the movable mask 53 used for vapor deposition is moved to a position outside the trajectory of the ion beams 68a, 68b, etc. Particles can be prevented from being generated during ion etching of the form.

FIG. 2 shows an MCF according to a second embodiment of the present invention.
It is a block diagram showing composition of an adjustment device. In the MCF adjustment device 80 of the present embodiment shown in FIG.
Deflection coils 73a and 73b provided in the embodiment
Are replaced by deflection electrodes 51b3a and 83b, and accordingly, the magnetic field control device 71 used in the first embodiment is replaced by an electric field control device 81. The electric field control circuit 81 controls the intensity of the electric field by controlling the voltage applied to the deflection electrodes 51b3a and 83b. Therefore, the magnetic field that deflects the ion beam generated in the first embodiment is
In this embodiment, the electric field deflects the ion beam.
Other configurations of the second embodiment are the same as those of the first embodiment. Since the ion beam is charged to one of the positive and negative potentials as described above, for example, if the ion is an anion, it is attracted to the plus side of the electric field in an electric field and changes its course. In FIG. 2, the deflecting electrodes 51b are provided at upper and lower positions of the ion beam as deflecting electrodes.
Although only one set of 3a and 83b is described, as an actual deflection electrode, two sets of vertical and horizontal directions of the ion beam, or two sets of upper and lower sides and right and left diagonally rising directions are used. Add two sets of diagonally up left and add four sets, or
By providing many more sets of deflection electrodes, the trajectory of the ion beam is controlled in an arbitrary direction. In this embodiment, when the electrodes 51a and 51b are ion-etched, the trajectory of the ion beam is changed by the electric field generated by the deflection electrodes 51b3a and 83b controlled by the electric field control circuit 81 as described above. 51a, 51b
Can be deflected toward In the case where the ion beam is likely to be diffused, instead of the deflection coil used in the first embodiment, for example, the ion beam is deflected so as to surround the ion beam separately from the deflection electrode. An ion group can be narrowed down by providing an electrode group and directing all directions of the electric field generated by each deflection electrode inward. As described above, also in the present embodiment, the trajectory of the ion beam is controlled in an arbitrary direction by the deflection electrodes 51b3a, 83b and the like as in the first embodiment. There is no need to provide a sliding portion, the ion beam can be deflected toward the target electrode without generating particles in the vacuum vessel 11, and maintenance is facilitated because there is no complicated movable portion. Also, in this embodiment,
Since there is no need to mechanically slide the movable mask 53 and the like, it is possible to shorten the tact time and the like before starting the adjustment work by ion etching, to speed up the adjustment work, and to improve the work efficiency.

Also, in the MCF adjusting apparatus 80 of the present embodiment, the oscillation circuit 21 uses the oscillation circuit 21 during ion etching.
For example, the target electrode 5 on the piezoelectric crystal plate 51k
Since a positive voltage is applied to 1a and a negative voltage is applied to the electrode 51b which is not a target,
The etching process of only the electrode 51a serving as a target can be efficiently performed. Further, in the above description, since the etching is performed by using anions, the resonance electrode to be etched is set to a positive potential, and the resonance electrode which does not need to be etched is charged to a negative potential. In the case of etching using positive ions such as ions, etching may be performed by charging a resonance electrode to be etched to a negative potential and charging a resonance electrode that does not require etching to a positive potential. Further, the method of biasing the resonance electrode can be applied to an etching method using a plasma atmosphere as shown in FIG. That is, FIG. 3 shows a conceptual diagram of an etching apparatus for realizing another dry etching method of the quartz filter according to the present invention. As shown in the drawing, a filament 91 for emitting electrons and a filament 91 are provided in a vacuum vessel 11 where dry etching is performed.
A grid electrode 92, which is arranged in front of the substrate and biased to a positive potential, and an etching mask 93 are provided.

An argon gas 94 is introduced into the vacuum vessel 11 so as to be supplied between the filament 91 and the grid electrode 92. And the piezoelectric crystal plate 51k
For example, a crystal filter 96 having input / output electrodes 51a and 51b made of a metal film on the surface of a crystal substrate 95 is set behind the etching mask 93.
Here, the etching mask 93 does not completely cover the front surface of the quartz filter 96, and when a portion requiring etching is, for example, the electrode 51a, a through hole is provided to expose the electrode surface. And a crystal filter 9 so that the crystal filter 96 is not damaged.
6 is arranged at a position separated by a certain distance from the surface. The feature of the apparatus having the above-described configuration is that the electrode 51a requiring etching is biased to a negative potential and the electrode 51b not requiring etching is biased to a positive potential. Therefore, the electrode 51
a is connected to a negative power supply 99 via an AC blocking resistor 97 and a switch 98, and the electrode 51b is connected to a positive power supply 102 via an AC blocking resistor 100 and a switch 101. In consideration of the case where only the electrode 51b is etched, the switch 98 is switched to connect the electrode 51a to the positive power supply 103.
The switch 51 is switched so that the electrode 51b can be connected to the negative power supply 104.

Next, a process until the electrode 51a of the crystal filter 96 is etched in the vacuum vessel 11 installed as described above will be described. The electrons emitted from the filament 91 pass through the atmosphere of the argon gas 94 in the course of reaching the grid electrode 92, and at this time, the plasma is generated by colliding with the argon molecules 105. At this time, the potential of the plasma space is kept neutral as a whole, but the argon molecules 105 are scattered in the space by collision between the argon molecules 105 and electrons or collision between the argon molecules 105. The constituent electrons jump out, and the argon ions 106 generated thereby and the jumped out electrons are mixed. Since the argon ions 106 are positive ions, they are forcibly attracted to the electrode 51a biased to a negative potential. As a result, the electrode 51a is actively etched by the argon ions 106 concentrated on the surface thereof. . Further, when a displacement occurs in the arrangement position of the etching mask 93, the negative potential draws the argon ions 106 into the electrode surface covered with the etching mask 93 and, of course, the quartz substrate 95 exposed by the displacement of the etching mask 93. The argon ions 106 to be irradiated on the surface of the electrode 51 and the argon ions 106 diffused and scattered around the etching mask 93 are also applied to the electrode 51.
In such a case, only the surface of the electrode 51a is uniformly etched without etching the surface of the quartz substrate 95 near the electrode 51a.

On the other hand, on the surface of the electrode 51b which does not need to be etched, in addition to the mask effect of the etching mask 93, since this electrode is biased to a positive potential, etching of the electrode surface due to diffusion and scattering of argon ions 106 is performed. Can also be more actively prevented. The reason why the above-mentioned etching mask is required is to prevent the etching of the surface of the quartz substrate by argon molecules in an active state existing in the plasma atmosphere. Next, a method of inspecting the resonance frequency of the crystal filter 96 in a vacuum vessel will be described. FIG. 4 is a circuit diagram for explaining a method of inspecting a resonance frequency when performing a frequency adjustment method of a crystal filter according to the present invention. As shown in the figure, the inspection circuit connects the electrode 51a of the crystal filter 96 and the capacitor 107, connects the other end of the capacitor 107 to the collector of the switch transistor 108, and further connects the emitter of the transistor 108 to the AC block. Connected to the input signal supply terminal fIN via the capacitor 109 for switching, and the base of the transistor 108 is connected to the voltage terminal V1 for switch control by the resistor 1
Connect via 10. A switch transistor 111 is connected to the connection point between the capacitor 107 and the collector of the transistor 108, and the transistor 111
Are grounded, and the base of the transistor 111 is connected to the switch control terminal V2. Further, the electrode 5
1b, a capacitor 112 for blocking direct current is connected, the other end of the capacitor 112 is connected to the collector of the switch transistor 113, the emitter of the transistor 113 is grounded, and the base of the transistor 113 is connected to the resistor 1b.
14 to the output terminal of the switch control voltage terminal V2. Further, the collector of the transistor 113 is connected to the collector of the switch transistor 115 and the emitter of the transistor 115 is connected to the transistor 10.
8 and the base of the transistor 115 and the output terminal of the switch control voltage terminal V2 are connected to a resistor 1
16 is connected. The emitter of the transistor 115 and the signal output terminal fOUT are connected via a capacitor 117 and grounded via a resistor 118.

Next, the operation of the inspection circuit having such a configuration will be described. First, a predetermined voltage is applied to the switch control voltage terminal V1, and a 0 V voltage is applied to the switch control voltage terminal V2. Then, with the above configuration, the transistors 113 and 108 are activated by the bias voltage from the switch control voltage terminal V1, and the switch control voltage terminal V1 is turned on.
2, the transistor 115
As a result, the electrode 51b of the crystal filter 96 is
13 and the electrode 5 of the crystal filter 96.
1a is the signal input side terminal fIN via the transistor 108
And the receiving-side terminal fOUT. The signal input end fIN of the circuit thus connected
Is supplied with an input frequency including a plurality of frequency components, the crystal filter 96 has a low impedance at the resonance frequency f1, and the frequency characteristic appearing at the output receiving terminal fOUT is a peak signal only at the frequency component f1 (this If so, a level drop) appears. Further, when the electrode 51b is connected to the signal conducting path side, the electrode 51a is connected to be grounded, and the frequency characteristics are checked, a voltage of 0V is applied to the terminal of the switch control voltage V1 and the terminal of the switch control voltage V2 is connected. May be applied with a predetermined voltage. Therefore, only by controlling the switch circuit as described above from the outside of the vacuum vessel, while the quartz filter is arranged in the vacuum vessel,
The value of the resonance frequency of the crystal filter 96 can be confirmed. Note that the electrodes 51a, 8
Although the frequency measurement may be performed with the bias voltage applied to the DC voltage applied, it is desirable to stop the supply in consideration of the possibility that noise from the DC voltage may affect the inspection result. Furthermore, although the present invention has been described above using the method of etching the resonance electrode,

The present invention is not limited to this,
The ground electrode disposed on the back surface of the piezoelectric substrate on which the resonance electrode is disposed may be configured as shown in FIG. 5 and may be etched while applying a required voltage to each electrode. That is,
FIG. 5 shows a surface of the crystal filter 96 on the ground electrode side. As shown in the figure, the crystal filter 96 includes resonance electrodes 51a and 51b on one surface of a piezoelectric crystal substrate 51k, and a ground electrode 51c on the other surface, and further connects the ground electrode to the resonance electrode 51a. It is configured to be divided into the ground electrodes 51ca and 51cb opposed to 51b and other parts. For example, when it is desired to perform etching so as to reduce the electrode mass of the portion of the resonance electrode 51b, a voltage having a polarity opposite to that of the ion is applied to the ground electrode 51cb facing the resonance electrode 51b, and the other ground electrodes are May be applied to the ground electrode side while applying a voltage having the same polarity as the ion potential. In such a configuration, the surface of the piezoelectric substrate is less exposed, and the surface of the piezoelectric substrate can be completely divided into an etched surface and a non-etched surface by a bias. Etching can be performed with high precision without the need for a mask. Further, the present invention has been described using a quartz crystal filter as the piezoelectric element. However, the present invention is not limited to this, and a piezoelectric filter using another piezoelectric substrate, or any other quartz oscillator, etc. It goes without saying that the present invention can be applied to a piezoelectric element.
As described above, in each of the above embodiments, the structure can be simplified by eliminating the need for a movable mask, a mask driving unit, a motor, and the like used in the conventional monolithic crystal filter adjustment device, and further, an etching mask is used. Even in this case, since it is not necessary to strictly set the arrangement position of the mask, the size of the apparatus can be reduced and the manufacturing cost can be reduced. In the above embodiments, the resonance electrodes 51a, 51b and the like are formed by vapor deposition. However, when forming the resonance electrodes 51a, 51b and the like, the films may be formed by sputtering. In addition, the deposited material for forming the resonance electrodes 51a and 51b is not limited to silver, but may be gold or the like. Further, it is needless to say that the present invention can be applied to not only the monolithic crystal filter but also the frequency adjustment of a piezoelectric vibrating element having an electrode on a piezoelectric substrate.

[0017]

As described above, according to the present invention, it is not necessary to provide a movable part, so that the ion beam can be deflected toward the electrode of the target without generating particles in the vacuum vessel. Since there are no parts, maintenance becomes easy. Further, since it is not necessary to mechanically slide the movable mask or the like, it is possible to shorten the tact time and the like before starting the adjustment work by ion etching, to speed up the adjustment work, and to improve the work efficiency. Further, in the present invention, a positive voltage is applied to the target electrode on the piezoelectric crystal plate and a negative voltage is applied to the non-target electrode, so that only the target electrode is efficiently etched. be able to. Furthermore, even when an etching mask is used, it is not necessary to set the position of the etching mask with high accuracy, so that high productivity can be obtained, and the cost of the piezoelectric element can be reduced. Also, in the present invention, monolithic
Since the structure of the crystal filter adjustment device is simplified, the size of the device can be reduced and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an MCF adjustment device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an MCF adjustment device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a conceptual diagram of a frequency adjustment method according to a third embodiment of the present invention.

FIG. 4 is a circuit diagram illustrating a frequency checking method according to the present invention.

FIG. 5 is a diagram showing a configuration diagram of a crystal filter for explaining another embodiment of the frequency adjusting method according to the present invention.

FIG. 6 is a diagram illustrating a configuration of an example of a conventional MCF adjustment device.

[Explanation of symbols]

1, 70, 80: MCF adjustment device, 11: vacuum vessel, 21: oscillation circuit, 23: main control unit, 24
... Monitor, 26 ... Input unit, 25 ... Evaporation control unit, 27 ... Motor control unit, 29 ... Motor, 35
... Ion beam controller, 51 ... MCF, 51
a, 51b: Resonant electrode, 51c, 51ca, 51c
b: ground electrode, 51k: piezoelectric crystal plate, 51a
t, 51bt, 51ct ... wiring connection part, 67 ...
Ion beam gun, 68 ... ion beam, 71 ...
.Magnetic field control circuits 73a, 73b... Deflection coils, 8
DESCRIPTION OF SYMBOLS 1 ... Electric field control circuit, 83a, 83b ... Deflection electrode, 91 ... Filament, 92 ... Grid electrode, 93 ... Etching mask, 94 ... Argon gas, 95 ... Quartz substrate , 96 ... crystal filter,
97, 100, 110, 114, 116, 118 ...
Resistance, 98, 101 ... switch, 99, 102,
103, 104: power supply, 105: argon molecule, argon ion: 106, 107, 109, 1
12, 117... Capacity, 108, 111, 113, 1
15 ... transistor

Claims (6)

[Claims] 1. A frequency adjustment device for adjusting the frequency of a piezoelectric vibrating element having electrodes on both main surfaces of a piezoelectric crystal plate by ion-etching each of the electrodes. A deflecting coil for generating a magnetic field for deflecting the trajectory of the used ion beam toward a target electrode is provided, and a magnetic field control circuit for controlling the intensity of the magnetic field generated by the deflecting coil is provided. Frequency adjustment device. 2. A frequency adjustment device for adjusting a frequency of a piezoelectric vibrating element having electrodes on both main surfaces of a piezoelectric crystal plate by ion-etching the electrodes, wherein the frequency adjustment device is used for the ion etching. A frequency, wherein a deflection electrode for generating an electric field for deflecting the trajectory of the ion beam toward a target electrode is provided, and an electric field control circuit for controlling the intensity of the electric field generated by the deflection electrode is provided. Adjustment device. 3. The monolithic crystal filter, wherein the piezoelectric vibrating element has a plurality of resonance electrodes on at least one surface of a piezoelectric crystal plate and a ground electrode on the other surface. 2. The method according to claim 1, wherein a voltage having a polarity opposite to the potential of the ions is applied to the resonance electrode serving as a target, and a potential having the same polarity as the potential of the ions is applied to the resonance electrodes not serving as the target. Item 3. A frequency adjusting device for a monolithic crystal filter according to Item 2. 4. A frequency adjusting method using a dry etching method for etching an electrode of a piezoelectric element by colliding ions with the electrode, thereby adjusting the frequency of the piezoelectric element, requires etching. A method for adjusting the frequency of a piezoelectric element, comprising: applying a bias to the electrode so as to have a potential having a polarity opposite to that of the ions to thereby focus the collision of ions on the surface of the electrode. 5. The piezoelectric element further includes an electrode that does not require etching in addition to the electrode, and biases the electrode that does not require etching so that the electrode has the same polarity as the potential of ions. 5. The method according to claim 4, wherein the application prevents ions from colliding with the surface of the electrode. 6. One of the electrodes provided on both main surfaces of the piezoelectric substrate is a ground electrode covering substantially one surface of the piezoelectric substrate,
The electrode provided on the other main surface is a resonance electrode, and further,
The frequency adjustment device or the frequency adjustment method according to claim 1, wherein the ground electrode is configured to be divided into a portion facing the resonance electrode and another portion.