JP2002026672A - Resonance frequency measurement device for piezoelectric material, resonance frequency measurement method for piezoelectric material, foreign material eliminating device for piezoelectric material, foreign material eliminating method for piezoelectric material, device for manufacturing piezoelectric material and method for manufacturing piezoelectric material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resonance frequency measurement device for a piezoelectric material that can accurately measure a resonance frequency of a piezoelectric material with a simple operation without being affected by a gap caused between the piezoelectric material and an electrode and to provide a foreign material eliminating device for a piezoelectric material that can obtain sufficient eliminating performance of a foreign material deposited on the surface of the piezoelectric material through a comparatively simple configuration. SOLUTION: While a blank B is placed between a couple of electrodes 11, 12 arranged opposite to each other, a high frequency signal is swept onto the blank B between the electrodes 11 and 12. A waveform detection circuit 4 detects a voltage waveform on the electrode 11, 12 in the case of applying the high frequency signal between the electrodes 11, 12. By recognizing the presence of a piezoelectric material resonance wave on the voltage waveform, whether or not the blank B is resonated, that is, whether or not the sweep frequency reaches the resonance frequency is discriminated so as to obtain the resonance frequency of the blank B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the resonance frequency of a piezoelectric body represented by a quartz oscillator, a method of measuring the resonance frequency thereof, an apparatus for removing foreign matter from a piezoelectric body, an apparatus for removing such foreign matter, an apparatus for manufacturing a piezoelectric body and Related to the manufacturing method. In particular, the present invention relates to an improvement for accurately measuring the resonance frequency of a piezoelectric body and for reliably removing foreign substances adhering to the surface of a piezoelectric body.

[0002]

2. Description of the Related Art Conventionally, it has been known that the resonance frequency of a piezoelectric body represented by a quartz resonator depends on its thickness. For this reason, in the manufacturing process of this kind of piezoelectric body, the surface of a crystal blank (hereinafter referred to as a blank) cut out at a predetermined cutting angle with respect to the crystal axis of the crystal ingot is used. Polishing is performed to a predetermined thickness to obtain a desired frequency characteristic. Also,
After this polishing, the resonance frequency of the blank is measured by a frequency measuring device to check whether desired frequency characteristics are obtained.

[0003] As a method of measuring the resonance frequency, an oscillation method and a transmission method are generally known. In the oscillation method, a blank is incorporated in an oscillation circuit by arranging electrodes facing both sides of the blank. Then, a voltage is applied to the blank to vibrate, and the frequency of the vibration is detected by a detector such as a network analyzer, so that the frequency characteristics of the blank can be confirmed (for example, Japanese Patent Application Laid-Open No. 5-187896). . On the other hand, in the transmission method, an impedance matching circuit is provided in the measurement circuit, and an impedance matching operation is performed so that the input voltage and the output voltage of the blank to be excited become a predetermined value set in advance. The resonance frequency of the blank is obtained based on the blank (for example, Japanese Patent Laid-Open No.
No. 1368).

In this type of quartz oscillator, after the above-described polishing of the blank, a cleaning operation for removing foreign substances such as an abrasive adhered to the surface is performed.
Until now, this cleaning work has generally been performed by cleaning with a cleaning liquid or removing foreign matter by irradiating electron particle energy.

[0005]

However, as described above, the conventional method for manufacturing a crystal resonator has the following problems.

First, regarding the measurement of the resonance frequency, the gap formed between the blank and each electrode becomes a capacitance component in any of the above measuring methods, and the resonance frequency is accurately determined by the influence of the gap. Measurement may not be possible. FIG. 8 is an equivalent circuit of a measuring instrument for measuring the resonance frequency of the crystal unit in the above-described oscillation method. In the figure, C1 and C2 are capacitances corresponding to the gaps connected in series to the blank B. This C
Since the values of C1 and C2 greatly change depending on the gap size, the resonance frequency cannot be measured stably unless the values of C1 and C2 are always kept constant. Note that NA in FIG. 8 is a network analyzer for detecting a resonance frequency.

Therefore, in order to improve the reliability of resonance frequency measurement, it is necessary to manage the gap with extremely high accuracy. However, for that purpose, it is necessary to control the positioning of the blank with respect to each electrode in units of several microns,
Not only is the work of installing the blank between the electrodes complicated, but also the cost of the frequency measuring device is increased, which is not practical.

On the other hand, with respect to the removal of foreign matter adhering to the blank surface, the conventional techniques have been insufficient to reliably remove foreign matter. In other words, it is not possible to obtain sufficient removal performance with respect to foreign substances that are firmly attached,
There is a possibility that the process may be shifted to the step of measuring the resonance frequency while the foreign matter remains on the blank surface. In such a situation, as in the case described above, the resonance frequency cannot be measured accurately due to the influence of the capacitance component of the foreign matter.

The inventors of the present invention have considered the cause of the inability to sufficiently obtain the foreign matter removing performance. Then, they have found that there is a limit to the removal performance in a method of removing foreign matter by an externally added element such as a cleaning liquid or electron particle energy.

The present invention has been made in view of the above point, and one of its objects is to measure the resonance frequency of a piezoelectric body without being affected by a gap generated between the piezoelectric body and an electrode. Another object of the present invention is to enable accurate measurement of the resonance frequency with a simple operation. It is another object of the present invention to remove foreign substances adhering to the surface of a piezoelectric body and to obtain sufficient removal performance with a relatively simple configuration.

[0011]

Means for Solving the Problems-Summary of the Invention-In order to achieve the above object, the present invention places a piezoelectric body between the electrodes, sweeps (sweeps) a high-frequency voltage signal applied between the electrodes, and The resonance frequency of the piezoelectric body can be measured by detecting the voltage waveform at that time. In addition, by providing a main part similar to the configuration for measuring the resonance frequency, it is possible to remove foreign substances adhering to the piezoelectric body.

-Solution Means- Specifically, in a first solution means relating to a resonance frequency measuring device for a piezoelectric material, a pair of electrodes disposed opposite to each other with respect to the resonance frequency measuring device, and a piezoelectric material is provided between the electrodes. Sweep means for sweeping a high-frequency voltage signal applied between the electrodes while the body is positioned, and a voltage waveform on the electrodes when the high-frequency voltage signal swept by the sweep means is applied between the electrodes. Accordingly, a waveform detecting means is provided for making it possible to recognize the presence or absence of the piezoelectric resonance waveform on the voltage waveform.

In a second solution according to the method for measuring the resonance frequency of a piezoelectric material, a sweeping device for sweeping a high-frequency voltage signal applied between the electrodes while the piezoelectric material is positioned between a pair of electrodes arranged opposite to each other. Detecting the voltage waveform on the electrode when the high-frequency voltage signal swept by the sweeping step is applied between the electrodes, thereby enabling the presence or absence of the presence of the piezoelectric resonance waveform on the voltage waveform. And a waveform detecting step.

According to these specific items, when a high-frequency voltage signal is swept between the electrodes, the detected voltage waveform is only the applied voltage waveform until the sweep frequency matches the resonance frequency of the piezoelectric body. Then, when the sweep frequency coincides with the resonance frequency of the piezoelectric body due to the frequency sweep operation,
The voltage waveform is detected as a waveform obtained by adding the resonance waveform of the piezoelectric body to the applied voltage waveform. That is, by recognizing the detected waveform, it is possible to determine whether the piezoelectric body is resonating, that is, whether the sweep frequency has reached the resonance frequency.

According to a third aspect of the present invention, there is provided a piezoelectric solution removing apparatus comprising: a pair of electrodes opposed to each other; And a means for applying a predetermined high-frequency voltage signal to the piezoelectric material to excite the piezoelectric body to remove foreign matter.

According to a fourth aspect of the present invention, in the above third aspect, a sweeping means for sweeping a high-frequency voltage signal applied between the electrodes by the applying means is provided.

In a fifth solution according to the method for removing foreign matter from a piezoelectric body, a predetermined high-frequency voltage signal is applied between a pair of electrodes arranged opposite to each other while the piezoelectric body is positioned between the electrodes. An application step of exciting the piezoelectric body to remove foreign matter is provided.

According to a sixth aspect, in the fifth aspect, the high frequency voltage signal applied between the electrodes in the applying step is swept.

According to these specific items, when a high-frequency voltage signal is applied between the electrodes while the piezoelectric body is positioned between the electrodes, when the high-frequency voltage signal matches the resonance frequency of the piezoelectric body, The body excites. By this excitation, foreign matter adhering to the surface of the piezoelectric body is removed. If the resonance frequency of the piezoelectric body is measured in advance, foreign matter is effectively removed by applying a high-frequency voltage signal having a frequency corresponding to the resonance frequency between the electrodes. On the other hand, when the resonance frequency of the piezoelectric body is not measured, the high frequency voltage signal is swept as in the fourth and sixth solutions. When the sweep frequency coincides with the resonance frequency of the piezoelectric body in accordance with the frequency sweeping operation, the piezoelectric body is excited to remove foreign matter.

According to a seventh aspect of the present invention, a foreign matter removing stage for removing foreign matter adhering to the surface of the piezoelectric body, and a piezoelectric material having the foreign matter removed by the foreign matter removing stage. It is assumed that an apparatus for manufacturing a piezoelectric body includes a measurement stage for measuring a resonance frequency.
By applying a high-frequency voltage signal between the pair of electrodes disposed opposite to each other on the foreign matter removing stage and the piezoelectric body between the electrodes, and applying a high-frequency voltage signal between the electrodes. There is provided an application unit that excites and removes foreign matter, and a sweep unit that sweeps a high-frequency voltage signal applied between the electrodes. On the other hand, a pair of electrodes arranged opposite to each other on the measurement stage, a sweeping means for sweeping a high-frequency voltage signal applied between the electrodes in a state where the piezoelectric body is positioned between the electrodes, Waveform detection means is provided for detecting a voltage waveform on the electrode when the high-frequency voltage signal is applied between the electrodes, thereby enabling the presence or absence of a piezoelectric resonance waveform on the voltage waveform to be recognized.

According to an eighth aspect of the present invention, there is provided a piezoelectric body manufacturing method comprising: a foreign matter removing step for removing foreign matter adhering to the surface of the piezoelectric body; and a piezoelectric material having the foreign matter removed in the foreign matter removing step. A method for manufacturing a piezoelectric body including a measurement step for measuring a resonance frequency is assumed. In contrast to the method for manufacturing a piezoelectric body, in the foreign matter removing step, a high-frequency voltage signal is applied between the electrodes while the piezoelectric body is positioned between a pair of electrodes arranged opposite to each other, and the voltage is applied between the electrodes. By sweeping a high-frequency voltage signal, the piezoelectric body is excited to remove foreign matter. On the other hand, in the measurement step, in a state where the piezoelectric body is positioned between a pair of electrodes arranged opposite to each other,
The high-frequency voltage signal applied between the electrodes is swept, and the voltage waveform on the electrodes when the swept high-frequency voltage signal is applied between the electrodes is detected.

By these specific items, the functions according to the first to sixth solving means can be obtained together, and the foreign matter adhering to the piezoelectric body can be removed, and the resonance of the piezoelectric body from which the foreign matter has been removed can be achieved. The measurement of the frequency can be performed continuously. In particular, the measurement of the resonance frequency can be performed in a state where no foreign matter is attached to the piezoelectric body. For this reason, it is possible to avoid a situation in which the resonance frequency cannot be measured accurately due to the influence of the capacitance component of the foreign matter, and the accurate measurement of the resonance frequency becomes possible.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a description will be given by taking, as an example, an elementary plate of a quartz oscillator (one on which electrodes are not formed, hereinafter referred to as a blank) as a piezoelectric body.

(First Embodiment) First, an embodiment of a blank (piezoelectric) resonance frequency measuring apparatus according to the present invention will be described.

-Description of Configuration of Resonance Frequency Measuring Device- FIG. 1 is a block diagram showing a resonance frequency measuring device according to the present embodiment. This resonance frequency measuring device includes a pair of electrodes 11 and 12 that are arranged to face each other. These electrodes 1
The reference numerals 1 and 12 are arranged with an interval slightly larger than the thickness of the blank B. Specifically, when the blank B is arranged between the electrodes 11 and 12, a gap of less than 1 mm is generated between the blank B and the electrodes 11 and 12, or the blank B and the electrodes 11 and 12 are separated from each other. Set to touch.

The present resonance frequency measuring apparatus includes a frequency sweep oscillator 2 for oscillating a sweep frequency signal for applying a frequency-swept voltage to the electrodes 11 and 12, and an oscillation signal from the frequency sweep oscillator 2. A high-frequency signal generator 3, a waveform detection circuit 4, a frequency counter 5, and a comparator 6.

The frequency sweeping oscillator 2 is composed of a voltage-capacitance conversion element (for example, an oscillation circuit that oscillates at a tuning frequency of a tuning circuit combining a varicap and a coil), and a voltage applied to the electrodes 11 and 12. The frequency is swept between “f−Δf to f + Δf”. The frequency “f” is the target resonance frequency of the blank B, and the voltage frequency is changed with a sweep width of ± Δf.

The high-frequency signal generator 3 receives the sweep frequency signal from the frequency sweep oscillator 2 and applies a high-frequency signal of a predetermined high-frequency power (for example, 0.5 W) based on the swept frequency signal to the electrodes 11 and 12. It has become. The power value is not limited to this.

The waveform detection circuit 4 receives the oscillation signal from the frequency sweep oscillator 2 and the output signal from the high frequency signal generator 3. Thereby, the voltage waveform on the electrodes 11 and 12 can be sensed. In this sensing, when the sweep frequency of the high-frequency signal applied to the electrodes 11 and 12 matches the resonance frequency of the blank B, as the voltage waveform to be sensed, the resonance waveform of the blank B is added to the applied voltage waveform. It will be obtained as a waveform.

The voltage waveform detected by the waveform detection circuit 4 is frequency-counted by a frequency counter 5 and a count signal is transmitted to a comparator 6.

The comparator 6 compares the blank B resonance frequency obtained from the count signal received from the frequency counter 5 with a predetermined desired resonance frequency (target resonance frequency), and outputs the comparison result to an output terminal. It outputs from 61. The output from the output terminal 61 is transmitted to, for example, a display panel (not shown) on the device, and the detection result of the resonance frequency is displayed on the display panel.

Description of Operation of Resonance Frequency Measuring Apparatus Next, the operation of measuring the resonance frequency of the blank B by the present resonance frequency measuring apparatus will be described. First, a blank B polished to a predetermined thickness in advance is placed between the electrodes 11 and 12. In this state, the resonance frequency measuring device is activated, and the frequency sweep oscillator 2 oscillates a sweep frequency signal. High frequency signal generator 3 receiving this swept frequency signal
Applies the frequency-swept high-frequency signal to the electrodes 11 and 12. For example, as shown by the arrow in FIG.
A high frequency signal of −Δf is applied, and the frequency is gradually increased toward “f + Δf”. At this time, the waveform detection circuit 4 senses the voltage waveform on the electrodes 11 and 12.

During the rise of the frequency, the electrodes 11, 12
When the sweep frequency of the blank B matches the resonance frequency of the blank B, the sensed voltage waveform is obtained as a waveform obtained by adding the resonance waveform of the blank B to the applied voltage waveform. Specifically, assuming now that the resonance frequency of the blank B is “f”, at point a in FIG. 2, the sweep frequency does not match the resonance frequency of the blank B, and therefore, sensing is performed. The voltage waveform is only the applied voltage waveform as shown in FIG. On the other hand, at the point b in FIG. 2 where the frequency is increased and the sweep frequency becomes “f”, the sweep frequency matches the resonance frequency of the blank B, and thus the frequency is shown in FIG. Thus, a waveform obtained by adding the resonance waveform of the blank B to the applied voltage waveform is obtained. When this waveform is sensed by the waveform detection circuit 4, the frequency counter 5 counts the frequency,
Comparator 6 compares the resonance frequency with a preset desired resonance frequency, and outputs the comparison result from output terminal 61. Then, selection of the blank B with respect to the frequency and the quality determination are performed. That is, the blank B is selected according to the frequency as the measurement result, or in the above comparison, if the resonance frequency is a desired value, the non-defective judgment of the blank B is performed, and if the resonance frequency is not the desired value. , A pass / fail judgment such as a defective judgment of the blank B is performed.

As described above, in this embodiment, the voltage waveform on the electrodes 11 and 12 is detected while applying the frequency-swept high-frequency signal to the electrodes 11 and 12, and the waveform of the blank B is applied to the waveform. The resonance frequency of the blank B can be measured by determining whether or not a resonance waveform is applied. For this reason, it is possible to measure the resonance frequency of the blank B irrespective of the size of the gap generated between the blank B and the electrodes 11 and 12. That is, regarding the sensing of the voltage waveform by the waveform detection circuit 4, the frequency detection degree is affected to some extent by the effect of the gap generated between the blank B and the electrodes 11 and 12. However, the presence of this gap has no effect on the frequency value. Therefore, the resonance frequency of the blank B can be accurately measured by directly recognizing the voltage waveform on which the frequency value is reflected. As a result, it is not necessary to manage the gap between the blank B and the electrodes 11 and 12 with extremely high accuracy, and the work of installing the blank B between the electrodes 11 and 12 is simplified, and the workability is improved. . In addition, the number of blanks B capable of measuring the resonance frequency per unit time increases, so that the production cost can be reduced, and the cost of the frequency measurement device can be reduced.

(Second Embodiment) Next, an embodiment of a blank foreign matter removing apparatus according to the present invention will be described.

FIG. 4 is a block diagram showing a foreign matter removing apparatus according to the present embodiment. This foreign matter removing device also has a pair of electrodes 11 and 12 arranged opposite to each other, similarly to the above-described resonance frequency measuring device. These electrodes 11 and 12 are also arranged with an interval slightly larger than the thickness of the blank B.
Also in this case, specifically, when the blank B is disposed between the electrodes 11 and 12, the blank B and the electrodes 11 and 12 are used.
Are set so that a gap of less than 1 mm is generated between them, or the blank B and the electrodes 11 and 12 are in contact with each other.

Further, the present foreign matter removing apparatus includes the above-mentioned electrodes 11,
12, a frequency sweep oscillator 2 for oscillating a sweep frequency signal for applying a frequency-swept voltage, a high-frequency signal generator 3 receiving an oscillation signal from the frequency sweep oscillator 2, and a signal from the high-frequency signal generator 3. An amplifier 7 for amplifying a high-frequency signal is provided. The frequency sweeping oscillator 2 and the high-frequency signal generator 3 are the same as those of the resonance frequency measuring device according to the first embodiment described above, and the description is omitted.

The amplifier 7 applies a high-frequency signal of a relatively high output (for example, 5 W) between the electrodes 11 and 12. Note that the output value is not limited to this value. In particular, the output of the high-frequency signal amplified by the amplifier 7 generates the excitation of the blank B to such an extent that foreign substances adhering to the blank B can be sufficiently removed. And an arbitrary value within a range of 0.05 to 10 W, for example.

Next, the operation of the present foreign matter removing apparatus for removing foreign matter from the blank B will be described. First, a blank B polished to a predetermined thickness in advance is placed between the electrodes 11 and 12. In this state, the foreign matter removing device is activated, and the frequency sweep oscillator 2 oscillates a sweep frequency signal. The high-frequency signal generator 3 that has received the sweep frequency signal outputs a high-frequency signal whose frequency has been swept, and this output is amplified by the amplifier 7 to become a relatively high-output high-frequency signal, and the electrodes 11, 1 are output.
Applied between the two.

Thus, when the sweep frequency matches the resonance frequency of the blank B, the blank B is greatly excited,
Foreign matter such as an abrasive adhered to the surface is effectively removed.

-Effects of Embodiment- As described above, in this embodiment, it is possible to remove the adhered foreign matter by exciting the blank B with a relatively high-output high-frequency signal. For this reason, it is possible to dramatically improve the foreign matter removal performance, which has been limited by the conventional method of removing foreign matter using an external additional element such as a cleaning liquid or electron particle energy. That is, when the blank B is excited by a high-output high-frequency signal, the blank B
Is always excited within the destruction limit, so that it is possible to remove foreign matters with unprecedentedly high performance and without adversely affecting the blank B itself. Further, in the present embodiment, by sweeping the frequency of the high-frequency signal, even when the resonance frequency of the blank B is not measured, it is possible to reliably excite the blank B and remove foreign substances, thereby improving reliability. It is expensive.

In this embodiment, the blank B is applied by applying a frequency-swept high-frequency signal between the electrodes 11 and 12.
The foreign matter on the surface of is removed. This is because the frequency characteristics (resonance frequency) of the blank B have not been measured. Therefore, if the resonance frequency of the blank B has been previously confirmed by the resonance frequency measuring device, the electrodes 11 and
It is not necessary to sweep the frequency of the high-frequency signal applied between the electrodes 12, and a high-frequency signal having a frequency matching this resonance frequency may be applied between the electrodes 11 and 12.

(Third Embodiment) Next, a description will be given of a production line as a piezoelectric production apparatus incorporating the above-described resonance frequency measuring device and foreign matter removing device.

FIG. 5 is a block diagram showing a foreign matter removing stage S1 in which a foreign matter removing device is installed and a resonance frequency measuring stage S2 in which a resonant frequency measuring device is installed in a production line of the crystal resonator according to the present embodiment. . The foreign matter removal stage S1 is a blank B polished to a predetermined thickness in the previous process.
This is a stage for removing foreign substances such as abrasives attached to the surface of the substrate. On the other hand, the resonance frequency measurement stage S2
Is a stage for measuring the resonance frequency of the blank B from which foreign matter has been removed in the foreign matter removing stage S1. Hereinafter, each of the stages S1 and S2 will be described.

In the foreign matter removing stage S 1 and the resonance frequency measuring stage S 2, a pair of electrodes 11, 12, 13, and 14 are opposed to each other on the transport line of the blank B. These electrodes 11, 12, 13, and 14 are arranged in a direction (vertical direction in FIG. 5) orthogonal to the transport direction of the blank B (indicated by a dashed line arrow in FIG.
Are arranged with an interval slightly larger than the thickness dimension.

Further, the present production line includes the stages S1,
A frequency-swept oscillator 2 similar to that described above for applying a frequency-swept voltage to the electrodes 11, 12, 13, and 14 of S2 is provided.

Each of the stages S 1 and S 2 has a high-frequency signal generator 3 that receives an oscillation signal from the frequency sweep oscillator 2.
1, 32 are provided. Resonance frequency measurement stage S
2, the high frequency signal generator 32 uses the electrodes 13 and
A high-frequency signal of a predetermined high-frequency power (for example, 0.5 W) is applied between the fourteen. On the other hand, in the foreign matter removal stage S1, an amplifier 7 receiving the output of the high frequency signal generator 31 is provided, and a relatively high output (for example, 5 W) high frequency signal amplified by the amplifier 7 is supplied to the electrodes 11, 1.
The voltage is applied between the two. Note that the above output values are not limited to these values. In particular, the output of the high-frequency signal amplified by the amplifier 7 is a value at which excitation of the blank B is generated to such an extent that foreign substances on the blank B can be sufficiently removed. And is set, for example, in the range of 0.05 to 10 W.
In this way, the frequency of the high-frequency voltage applied to the electrodes 11, 12, 13, 14 is changed within a predetermined range according to the oscillation signal from the frequency sweep oscillator 2.

Further, the resonance frequency measuring stage S2 includes:
A waveform detection circuit 4, a frequency counter 5, and a comparator 6 are provided. Each of these devices has the same configuration as that of the above-described first embodiment, and a description thereof will be omitted.

In the foreign matter removing stage S1, the same operation as in the above-described second embodiment is performed while the blank B is being transported on the line, so that the foreign matter adhering to the blank B is effectively removed. That is, when the blank B passes between the electrodes 11 and 12, the frequency sweeping oscillator 2 oscillates the sweeping frequency signal, and the high frequency signal from the high frequency signal generator 3 receiving this sweeping frequency signal is amplified by the amplifier 7. The electrode 1
Applied between 1 and 12. Thus, when the sweep frequency matches the resonance frequency of the blank B, the blank B is excited while being conveyed, and foreign substances such as abrasives attached to the surface thereof are effectively removed.

On the other hand, in the resonance frequency measuring stage S2,
While the blank B from which the foreign matter has been removed is conveyed on the line, the same operation as in the above-described first embodiment is performed, and the resonance frequency is measured. That is, when the sweep frequency to the electrodes 13 and 14 matches the resonance frequency of the blank B, the waveform detection circuit 4 senses the waveform to which the resonance waveform of the blank B is added, and at that time, the frequency counter 5 counts the frequency. , Comparator 6 compares the resonance frequency with a preset desired resonance frequency, and outputs the comparison result from output terminal 61. Then, selection of the blank B with respect to the frequency and the quality determination are performed.

-Effects of Embodiment- In this embodiment, the effects of the above-described first embodiment can be obtained in the foreign matter removing stage S1, and the effects of the above-described second embodiment can be obtained in the resonance frequency measurement stage S2. Can be played. For this reason, it is possible to continuously perform the reliable removal of the foreign matter adhering to the blank B and the accurate measurement of the resonance frequency of the blank B from which the foreign matter has been removed. In particular, the resonance frequency measurement stage S
The measurement of the resonance frequency in 2 can be performed in a state where no foreign matter is attached to the blank B, so that it is possible to avoid a situation in which the resonance frequency cannot be measured accurately due to the adverse effect of the presence of the foreign matter. As a result, accurate measurement of the resonance frequency becomes possible.

(Fourth Embodiment) The fourth embodiment is a modification of the above-described third embodiment. Therefore, only the differences from the third embodiment will be described here. FIG.
FIG. 3 is a block diagram showing a foreign matter removing stage S1 and a resonance frequency measuring stage S2 in the production line of the crystal unit according to the embodiment.

As shown in this figure, in the manufacturing line according to the present embodiment, the high-frequency signal generator 3 in each of the stages S1 and S2 is also used. That is, in the present embodiment, the high-frequency signal generator 3 receives the oscillation signal from the frequency sweep oscillator 2, applies the high-frequency signal of a predetermined high-frequency power between the electrodes 13 and 14 of the resonance frequency measurement stage S2, and A high-frequency signal is output, and a relatively high-output high-frequency signal amplified by the amplifier 7 is applied between the electrodes 11 and 12 of the foreign matter removal stage S1.

According to this configuration, a single high-frequency signal generator 3 can output a high-frequency signal to each of the stages S1 and S2, so that the configuration of the entire apparatus can be simplified.

(Fifth Embodiment) The fifth embodiment is a modification of the above-described fourth embodiment. Therefore, only differences from the fourth embodiment will be described here. FIG.
FIG. 3 is a block diagram showing a foreign matter removing stage S1 and a resonance frequency measuring stage S2 in the production line of the crystal unit according to the embodiment.

As shown in this figure, in the manufacturing line according to the present embodiment, the foreign matter removing stage S1 and the resonance frequency measuring stage S2 are shared on one stage S. In other words, a pair of electrodes 11 and 12 are opposed to each other at one position on the production line of the quartz oscillator, and the high-frequency signal generator 3
The high frequency signal from the
It is configured to be applied between 1 and 12.

The foreign matter removing operation and the resonance frequency measuring operation in this embodiment are performed by applying a high-frequency signal between the electrodes 11 and 12 with the blank B positioned between the electrodes 11 and 12. More specifically, the above-described resonance frequency measuring operation of the first embodiment and the foreign substance removing operation of the second embodiment are performed simultaneously, or the foreign substance removing operation is performed with the blank B held at this position. After that, the resonance frequency measuring operation is performed. In the latter case, for example, a sweep (f-Δf
To f + Δf) to perform the foreign matter removing operation, and then sweep (f +
An operation such as performing a resonance frequency measurement operation by sweeping from Δf toward f−Δf) is performed. Further, the amplification by the amplifier 7 may not be performed during the resonance frequency measuring operation.

According to this configuration, the production line can be simplified by making one stage S on the production line have both the function as the foreign matter removal stage S1 and the function as the resonance frequency measurement stage S2. The installation space of the production line can be reduced.

-Other Embodiments- In each of the above-described embodiments, a description has been given by taking as an example a blank plate of a quartz oscillator as the piezoelectric body. The present invention is not limited to this, and can be applied to a case where foreign substances are removed or a resonance frequency is measured with respect to a crystal resonator having electrodes formed on a blank. Further, the present invention can be applied to piezoelectric bodies other than quartz.

In each of the above embodiments, the frequency is gradually increased in the frequency sweeping operation, but the frequency may be swept so as to gradually decrease.

[0061]

As described above, according to the present invention, the following effects are exhibited.

First, in the resonance frequency measuring apparatus according to the first aspect and the resonance frequency measuring method according to the second aspect, a voltage waveform on an electrode is detected while applying a frequency-swept high-frequency voltage signal between the electrodes. By determining whether or not a piezoelectric resonance waveform exists on the waveform, the resonance frequency of the piezoelectric body can be measured. For this reason, it is possible to measure the resonance frequency of the piezoelectric body regardless of the size of the gap generated between the piezoelectric body and the electrode. Therefore, it is not necessary to manage the gap between the piezoelectric body and the electrode with extremely high accuracy, and the work of installing the piezoelectric body between the electrodes is simplified, and the workability is improved. Further, the number of piezoelectric bodies capable of measuring the resonance frequency per unit time is increased, so that the production cost can be reduced, and the cost of the frequency measurement device can be reduced.

Further, in the foreign matter removing device according to the third and fourth aspects and the foreign matter removing method according to the fifth and sixth aspects, it is possible to remove the attached foreign matter by exciting the piezoelectric body with a high frequency voltage signal. I have. For this reason, it is possible to dramatically improve the foreign matter removal performance, which has been limited by the conventional method of removing foreign matter using an external additional element such as a cleaning liquid or electron particle energy. According to the fourth and sixth aspects of the present invention, by sweeping the frequency of the high-frequency voltage signal, even when the resonance frequency of the piezoelectric body is not measured, the excitation is reliably performed and the foreign substance removing operation is performed. Thus, the reliability of foreign matter removal can be improved.

According to the seventh and eighth aspects of the invention, the effects according to the third to sixth aspects can be achieved in the foreign matter removing stage, and the first and second aspects in the measurement stage. The effects according to the described invention can be obtained. For this reason, it is possible to continuously perform the reliable removal of the foreign matter attached to the piezoelectric body and the accurate measurement of the resonance frequency of the piezoelectric body from which the foreign matter has been removed. In particular, since the measurement of the resonance frequency in the measurement stage can be performed in a state where no foreign matter is attached to the piezoelectric body, it is possible to avoid a situation where the resonance frequency cannot be accurately measured due to the adverse effect of the presence of the foreign matter. This allows more accurate measurement of the resonance frequency.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a resonance frequency measuring device according to a first embodiment.

FIG. 2 is a diagram for explaining an operation of changing a sweep frequency when measuring a resonance frequency.

3A is a diagram showing a sensing waveform when the sweep frequency and the blank resonance frequency do not match, and FIG. 3B is a diagram showing sensing when the sweep frequency and the blank resonance frequency match. It is a figure showing a waveform.

FIG. 4 is a block diagram showing a foreign matter removing device according to a second embodiment.

FIG. 5 is a block diagram illustrating a foreign matter removal stage and a resonance frequency measurement stage according to a third embodiment.

FIG. 6 is a diagram corresponding to FIG. 1 in a fourth embodiment.

FIG. 7 is a diagram corresponding to FIG. 1 in a fifth embodiment.

FIG. 8 is a diagram showing an equivalent circuit of a resonance frequency measuring device according to a conventional oscillation method.

[Explanation of symbols]

 11 to 14 electrodes 2 frequency sweep oscillator (sweep means) 3, 31, 32 high-frequency signal generator (application means) 4 waveform detection circuit (waveform detection means) B blank (piezoelectric body) S1 foreign matter removal stage S2 resonance frequency measurement stage

Claims (8)

[Claims] 1. A resonance frequency measuring device for measuring a resonance frequency of a piezoelectric body, comprising: a pair of electrodes arranged opposite to each other; and a high-frequency voltage applied between the electrodes while the piezoelectric body is positioned between the electrodes. Sweep means for sweeping the voltage signal, and detecting the voltage waveform on the electrode when the high-frequency voltage signal swept by the sweep means is applied between the electrodes, thereby detecting the presence of the piezoelectric resonance waveform on this voltage waveform. A resonance frequency measuring apparatus for a piezoelectric body, comprising: a waveform detecting means for recognizing presence / absence. 2. A resonance frequency measuring method for measuring a resonance frequency of a piezoelectric body, wherein the piezoelectric body is positioned between a pair of electrodes arranged opposite to each other and a high frequency voltage signal applied between the electrodes is swept. Detecting the voltage waveform on the electrodes when the high-frequency voltage signal swept by the sweeping step is applied between the electrodes, so that the presence or absence of the piezoelectric resonance waveform on the voltage waveform can be recognized. A method for measuring a resonance frequency of a piezoelectric body, comprising: a waveform detecting step. 3. A foreign matter removing device for removing foreign matter adhering to a surface of a piezoelectric body, comprising: a pair of electrodes arranged opposite to each other; Applying means for applying a predetermined high-frequency voltage signal to the piezoelectric material to excite the piezoelectric material to remove the foreign material. 4. An apparatus according to claim 3, further comprising a sweeping means for sweeping a high-frequency voltage signal applied between the electrodes by the applying means. . 5. A foreign matter removing method for removing foreign matter adhering to the surface of a piezoelectric body, wherein a predetermined high frequency is applied between the pair of opposed electrodes while the piezoelectric body is positioned between the electrodes. A method for removing foreign matter from a piezoelectric body, comprising an application step of exciting a piezoelectric body by applying a voltage signal to remove foreign matter. 6. The method according to claim 5, wherein a high-frequency voltage signal applied between the electrodes in the applying step is swept. 7. A foreign matter removing stage for removing foreign matter adhering to the surface of a piezoelectric body, and a measuring stage for measuring a resonance frequency of the piezoelectric body from which foreign matter has been removed in the foreign matter removing stage. In the apparatus for manufacturing a piezoelectric body, the foreign matter removing stage includes a pair of electrodes arranged opposite to each other, and a piezoelectric body positioned between the electrodes, and a high-frequency voltage signal applied between the electrodes to apply a piezoelectric signal. An application unit that excites the body to remove foreign matter, and a sweep unit that sweeps a high-frequency voltage signal applied between the electrodes are provided, while the measurement stage includes a pair of electrodes that are opposed to each other. ,
Sweep means for sweeping a high-frequency voltage signal applied between the electrodes while the piezoelectric body is positioned between the electrodes, and a high-frequency voltage signal swept by the sweep means on the electrodes when the high-frequency voltage signal is applied between the electrodes. An apparatus for manufacturing a piezoelectric material, comprising: a waveform detecting means for detecting the presence of a piezoelectric resonance waveform on the voltage waveform by detecting the voltage waveform. 8. A foreign matter removing step for removing foreign matter adhering to the surface of the piezoelectric body, and a measuring step for measuring a resonance frequency of the piezoelectric body from which foreign matter has been removed in the foreign matter removing step. In the method of manufacturing a piezoelectric body, in the foreign matter removing step, a high-frequency voltage signal is applied between the electrodes while the piezoelectric body is positioned between a pair of electrodes arranged opposite to each other, and the high-frequency voltage signal is applied between the electrodes. The high-frequency voltage signal is swept to excite the piezoelectric body to remove foreign matter. In the measurement step, the piezoelectric body is applied between a pair of electrodes disposed opposite to each other. A method for manufacturing a piezoelectric body, comprising: sweeping a high-frequency voltage signal; and detecting a voltage waveform on the electrode when the swept high-frequency voltage signal is applied between the electrodes.