JP2007198799A - Method for measuring frequency of piezoelectric vibration component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a stable frequency measurement by suppressing trouble in a frequency measuring method of a piezoelectric vibration component. <P>SOLUTION: This frequency measuring method of the piezoelectric vibration component includes a step for setting a frequency zone to be measured and a plurality of frequency measurement points, a step for performing weighting according to weighting conditions of which a reference measurement point and an adjoining measurement point are set, and a step for measuring the gain of the reference measurement point. In the weighting conditions, the gain of the reference measurement point is constituted from the gains of the reference measurement point and the adjoining measurement point, the rate of the gains of the reference measurement point and the adjoining measurement point is set, and the rate of the gain of the reference measurement point is increased comparing to the rate of the gain of the adjoining measurement point. When measurement is performed between the low frequency side and the high frequency side while sweeping in one direction, a measurement point at which the gain increases steeply to the adjoining measurement point and makes a first projection top is set to be a temporary resonance point, an approximation of the gain is derived from the temporary resonance point and its adjoining measurement point, and a true resonance point is derived from the approximation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a frequency measurement method for a piezoelectric vibration component.

  Currently, examples of the piezoelectric vibration component include a piezoelectric vibration device and a piezoelectric vibration piece provided in the piezoelectric vibration device. In this piezoelectric vibrating device, the piezoelectric vibrating piece is hermetically sealed by the base and the cap.

  The above-described piezoelectric vibration device performs frequency measurement a plurality of times in the manufacturing process, and adjusts the frequency of the piezoelectric vibration piece of the piezoelectric vibration device (see, for example, Patent Document 1 below).

The frequency measurement of the piezoelectric vibrating piece of Patent Document 1 described below is an air gap type non-contact frequency measurement for a piezoelectric vibrating piece on which no electrode is formed.
Japanese Patent Laid-Open No. 11-142456

  By the way, when the frequency measurement of the piezoelectric vibration component such as the frequency measurement disclosed in Patent Document 1 described above is performed, the frequency measurement result fluctuates due to problems such as poor maintenance of the frequency measurement device itself or low resolution. May occur.

  Accordingly, in order to solve the above-described problems, an object of the present invention is to provide a frequency measurement method for a piezoelectric vibration component that suppresses problems caused by the frequency measurement method for the piezoelectric vibration component and stabilizes frequency measurement.

  In order to achieve the above object, the frequency measurement method for a piezoelectric vibration component according to the present invention measures the gain at each frequency of the piezoelectric vibration component while sweeping in one direction between the low frequency side and the high frequency side. In the frequency measurement method of the piezoelectric vibration component, a setting step of setting a frequency band to be measured, setting a plurality of measurement points of the frequency to be measured within the band, a measurement step of sequentially measuring the gain of the measurement point, About the gain data of each measurement point by the measurement step, a correction data acquisition step for obtaining gain data of the measurement point by weighting the measurement point and the adjacent measurement point according to a preset weighting condition; In the weighting condition, the gain of the measurement point is set to the gain of the measurement point and its adjacent Set the gain ratio of the measurement point and the gain ratio of the adjacent measurement point, and set the gain ratio of the measurement point to the adjacent measurement point gain. It is characterized in that it is increased with respect to the ratio of the gain of the measurement point.

  According to the present invention described above, the method includes the setting step, the measurement step, and the correction data acquisition step. Under the weighting condition, the gain of the measurement point is set to the gain of the measurement point and the adjacent measurement point. The gain ratio of the measurement point and the gain ratio of the adjacent measurement point are set out of the gains of the measurement point, and the gain ratio of the measurement point is set to the gain of the measurement point. Since the gain is increased with respect to the ratio of the gain, it is possible to suppress the frequency measurement inconvenience of the piezoelectric vibration component and stabilize the frequency measurement. That is, according to the present invention described above, since the setting step, the measurement step, and the correction data acquisition step are included, the difference between the measurement point and the adjacent measurement point is clarified, and the measurement point and the adjacent Thus, it is possible to make associations with measurement points to be measured, and it becomes possible to clarify the measurement points at which the gain has increased sharply at all measurement points. As a result, it is possible to easily find the resonance point of the piezoelectric vibration component in a short time. In addition, according to the present invention, since the setting step, the measurement step, and the correction data acquisition step are included, the measurement points are related even in the case of a frequency measurement method for an air gap type piezoelectric vibration component. In addition, it is possible to suppress fluctuations in frequency measurement due to changes in the gap amount during frequency measurement.

  In the method, the range of the measurement points adjacent to the reference measurement point may be one point adjacent or two points adjacent to the low frequency side and the high frequency side of the measurement point, respectively.

  In this case, the range of the measurement point adjacent to the reference measurement point is one point or two points adjacent to the low frequency side and the high frequency side of the measurement point, for example, measurement related to the measurement point. By making the points within 5 points in total, it is preferable to make the association with the adjacent points when viewed from all the measurement points while clarifying the difference between the adjacent measurement points when viewed from all the measurement points. That is, when the measurement point range related to the measurement point is widened (for example, the measurement point range is set to 5 points), the frequency measurement is performed with high accuracy in consideration of the value (gain data) of the measurement point adjacent to the measurement point. Can be corrected. It is also preferable that there are a total of three measurement points related to the measurement point. That is, if the measurement point range related to the measurement point is narrowed (for example, the measurement point range is set to three points), it is possible to perform high-speed frequency measurement correction with practical accuracy. Therefore, it is possible to shorten the frequency measurement time.

  In the method, when measuring while sweeping in one direction between the low frequency side and the high frequency side, the gain is steeply increased with respect to the gain of the adjacent measurement point on the lowest frequency side. The measurement point that is the apex of the first convex point may be the resonance point of the piezoelectric vibration component.

  In this case, when measuring while sweeping in one direction between the low frequency side and the high frequency side, the gain is steeply increased with respect to the gain of the adjacent measurement point on the lowest frequency side. By making the measurement point that is the apex of the first convex point (peak gain) as the resonance point of the piezoelectric vibration component, it is possible to prevent erroneous measurement using the excitation point (peak gain) due to spurious generated thereafter as the resonance point. Is possible.

  In the method, among the measurement points, the measurement point on the lowest frequency side and the measurement point on the highest frequency side may be excluded from the measurement points in the weighting condition.

  In this case, among the measurement points, the measurement point on the lowest frequency side and the measurement point on the highest frequency side are excluded from the measurement points in the weighting condition, and thus are out of the band of the frequency before the first measurement point. It is not necessary to set a temporary measurement point as the adjacent measurement point that is outside the frequency band after the previous measurement point and the last measurement point, and prevent erroneous measurement by setting the temporary measurement point. Is possible.

  In the method, a correction data acquisition step may be further performed on each correction gain data obtained by the correction data acquisition step. That is, the correction data acquisition process may be performed a plurality of times.

  In this case, since the correction data acquisition process is further performed for each correction gain data in the correction data acquisition process, it is possible to remove noise generated during frequency measurement, and the correction data acquisition process is performed once. It is preferable to stabilize the measured value as compared with the above. Specifically, in the present invention, since the second correction data acquisition step uses the data of each correction gain obtained in the first correction data acquisition step, the second correction data acquisition step is used as the first correction data acquisition step. It is possible to perform the overall correction for the process. In other words, by performing the correction data acquisition process (correction process) a plurality of times, the measurement point range to be corrected is expanded.

  In the above method, the gain at each frequency of the piezoelectric vibration component may be measured while sweeping in one direction between the low frequency side and the high frequency side by an air gap method.

  In this case, since the frequency measurement method of the piezoelectric vibration part of the air gap method is used, the frequency measurement is not stable because the gap amount is likely to change during frequency measurement. However, according to the configuration of the present invention, the air gap It is possible to stabilize the frequency measurement while suppressing problems caused by the frequency measurement method of the piezoelectric vibration component of the type. In the air gap measurement, a quartz crystal vibrating piece is used as an example of a piezoelectric vibrating part. The quartz vibrating piece is mounted on the lower electrode body, and an AC voltage is applied in a state of being close to the upper electrode body. It is to measure the frequency of the resonator element. In this air gap measurement, the measurement becomes unstable due to external factors, such as the proximity distance (air gap) between the quartz crystal vibrating piece and the upper electrode body slightly fluctuating due to the vibration of the adjacent transfer device. Although it causes noise, correction of frequency measurement, which is a characteristic effect of the present invention, is particularly effective in this case.

  In the method, the frequency band is divided into a band on the low frequency side from the center frequency of the band and a band on the high frequency side from the center frequency, and a low frequency specific band is divided from the band on the low frequency side. Setting and setting a high frequency specific band from within the high frequency side band, calculating an average value of gain at each measurement point in the low frequency specific band, and each measurement in the high frequency specific band From the calculation step of calculating the average value of the gain at the point, the average value of the gain in the low frequency specific band, and the average value of the gain in the high frequency specific band, the fluctuation of the gain due to the frequency level is calculated. And a correction step of correcting the fluctuation of the gain due to the frequency level.

  In this case, since there are a division process, a calculation process, and a correction process, even if there is a variation in gain at each measurement point due to poor maintenance of the measurement apparatus itself that performs frequency measurement of the piezoelectric vibration component, that is, When the entire gain waveform at each measurement point is inclined obliquely, this variation (inclination) can be corrected, and the maximum gain point (resonance point) can be reliably extracted. As a result, it is possible to improve the accuracy of the gain characteristic of each frequency. Note that if the instrument is fully calibrated, the measurement waveform will not be tilted. For example, in the case of the air gap method, the measurement electrode (upper electrode body and lower electrode body) is short-circuited in the calibration operation. The body may be deformed or the like, which may result in poor maintenance. However, according to the present invention, this problem can be avoided.

  In the method, the low frequency specific band is a band of about ¼ of the frequency band from the lowest frequency measurement point to the high frequency side of the low frequency side band, and the high frequency The specific band may be about a quarter of the frequency band from the highest frequency measurement point to the low frequency side of the high frequency side band.

  In this case, the low frequency specific band is a band of about ¼ of the frequency band from the lowest frequency measurement point to the high frequency side of the low frequency side band, and the high frequency specific band Since the band is about ¼ of the frequency band from the highest frequency measurement point to the lower frequency side of the high frequency side band, resonance points are included in these measurement points. However, the gain fluctuation at each measurement point due to poor maintenance of the measurement apparatus itself (the slope of the entire gain waveform at each measurement point) can be accurately calculated.

  In the method, a provisional resonance point setting step in which the measurement point in the vicinity of the resonance point of the piezoelectric vibration component obtained by performing the measurement step is a temporary resonance point, a measurement point of the temporary resonance point, A true resonance point deriving step of deriving an approximate expression of gain at each measurement point in the vicinity including the temporary resonance point from a measurement point adjacent to the measurement point of the temporary resonance point, and deriving the true resonance point by the approximate expression; You may have.

  In this case, a resonance point by frequency measurement in an unstable state is set as the temporary resonance point, an approximate equation of gain is derived using the temporary resonance point, and the true resonance point is measured from this approximate equation. Even if the measurement point that is a point deviates from the true resonance point, this resonance point is set as a temporary resonance point, and the temporary resonance point is not set as the true resonance point, and the true resonance point deriving step accurately The true resonance point can be obtained. As a result, the approximation formula near the resonance point makes it easy to obtain the true resonance point even if the measurement point is rough. Specifically, for example, the present invention is a case of a frequency measurement method of an air gap type piezoelectric vibration part, and the true resonance point even if the frequency measurement is not stable due to a change in the gap amount during frequency measurement. Therefore, it is possible to stabilize frequency measurement. Further, in the frequency measurement method of the air-gap type piezoelectric vibration component, any one of the measurement points may be the true resonance point, but the measurement points themselves may be out of the true resonance point. . In this case, the frequency in the vicinity of the true resonance point can be derived as the approximate true resonance point, but the true resonance point cannot be derived from any of the measurement points. However, according to the present invention, since the provisional resonance point setting step and the true resonance point deriving step are included, the true resonance point can be derived from any one of the measurement points.

  In addition, in order to achieve the above object, the frequency measurement method for a piezoelectric vibration component according to the present invention sweeps the gain at each frequency of the piezoelectric vibration component in one direction between the low frequency side and the high frequency side. In the frequency measurement method of the piezoelectric vibration component to be measured, a setting step of setting a frequency band to be measured and setting a plurality of measurement points of the frequency to be measured within the band; a measurement step of sequentially measuring the gain of the measurement point; , A provisional resonance point setting step in which a measurement point in the vicinity of the resonance point of the piezoelectric vibration component obtained by performing the measurement step is a temporary resonance point, a measurement point of the temporary resonance point, and the temporary resonance point An approximate expression of gain at each measurement point in the vicinity including the temporary resonance point is derived from the measurement points adjacent to the measurement point, and the true resonance point is determined by the approximate expression. Ku the true resonance point deriving step, characterized by having a.

  According to the above-described present invention, since there are a setting step, a measurement step, a temporary resonance point setting step, and a true resonance point derivation step, it is possible to suppress the frequency measurement inconvenience of the piezoelectric vibration component and stabilize the frequency measurement. It becomes. That is, according to the present invention described above, a resonance point obtained by frequency measurement in an unstable state is set as the temporary resonance point, and an approximate expression of gain is derived using the temporary resonance point, and the true resonance is derived from the approximate expression. Since the point is measured, even if the measurement point that is the resonance point is deviated from the true resonance point, this resonance point is set as the temporary resonance point, and the temporary resonance point is not set as the true resonance point. The true resonance point can be accurately obtained by the point deriving step. As a result, the approximation formula near the resonance point makes it easy to obtain the true resonance point even if the measurement point is rough. Specifically, the present invention is a case of a frequency measurement method of an air gap type piezoelectric vibration component, and the true resonance point is derived even when the frequency measurement is not stable due to a change in the gap amount during frequency measurement. This makes it possible to stabilize the frequency measurement. Further, in the frequency measurement method of the air-gap type piezoelectric vibration component, any one of the measurement points may be the true resonance point, but the measurement points themselves may be out of the true resonance point. . In this case, the frequency in the vicinity of the true resonance point can be derived as the approximate true resonance point, but the true resonance point cannot be derived from any of the measurement points. However, according to the present invention, since there are a setting step, a measurement step, a temporary resonance point setting step, and a true resonance point derivation step, the true resonance point can be derived from any of the measurement points.

  ADVANTAGE OF THE INVENTION According to this invention, the frequency measurement method of the piezoelectric vibration component which suppresses the malfunction by the frequency measurement method of a piezoelectric vibration component and stabilizes frequency measurement is attained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a case where the present invention is applied to an AT-cut quartz resonator as a piezoelectric vibration device is shown.

  As shown in FIG. 1, an AT-cut crystal resonator 1 (hereinafter referred to as a crystal resonator) according to the present embodiment includes an AT-cut crystal resonator piece 2 (hereinafter referred to as a crystal resonator piece) and a crystal resonator piece 2. It consists of a base 31 to be held and a cap 32 for hermetically sealing the quartz crystal vibrating piece 2 held on the base 31.

  In this crystal resonator 1, a base 31 and a cap 32 are joined to form a package 3 that is a casing thereof, and an internal space 4 is formed in the package 3. The crystal vibrating piece 2 is held on the base 31 of the internal space 4 and the internal space 4 of the package 3 is hermetically sealed. As shown in FIG. 1, the base 31 and the crystal vibrating piece 2 are bonded using a bonding material 5. Next, each configuration of the crystal resonator 1 will be described.

  As shown in FIG. 1, the base 31 is formed in a box-like body composed of a bottom portion and a wall portion extending upward from the bottom portion. The base 31 is integrally fired in a concave shape by laminating a rectangular parallelepiped wall portion of a ceramic material on the bottom of a rectangular plate in a plan view made of a ceramic material. Moreover, the wall part is shape | molded along the surface outer periphery of a bottom part. The upper surface of the wall portion is a bonding region with the cap 32, and a metallized portion 39 for bonding with the cap 32 is provided in the bonding region.

  Further, electrode pads 34 and 35 that are electrically connected to the excitation electrodes 24 and 25 of the crystal vibrating piece 2 are formed on the surface 33 of the base 31 in the internal space 4. These electrode pads 34 and 35 are electrically connected to terminal electrodes 37 and 38 formed on the back surface 36 of the base 31, and these terminal electrodes 37 and 38 are connected to external electrodes of external components and external devices. The electrode pads 34 and 35 and the terminal electrodes 37 and 38 are formed by printing integrally with the base 31 after printing a metallized material such as tungsten or molybdenum.

  The cap 32 is made of a metal material and is formed into a single plate having a rectangular shape in plan view as shown in FIG. The cap 32 is joined to the metallized portion 39 of the base 31 by a technique such as seam welding or beam welding, so that the package 3 of the crystal unit 1 is configured by the cap 32 and the base 31. The cap 32 may be made of a ceramic material and hermetically sealed using a glass material instead of the metallized portion 39.

  As the material of the bonding material 5, a conductive adhesive made of silicon containing a plurality of silver fillers is used. By curing the bonding material 5, the plurality of silver fillers are combined to become a conductive substance.

  As shown in FIG. 1, the crystal vibrating piece 2 disposed in the internal space 4 of the package 3 is made of an AT-cut crystal piece (not shown) and is formed into a single-plate rectangular parallelepiped. Further, excitation electrodes 24 and 25 and excitation electrodes 24 and 25 are external electrodes (in this embodiment, the electrode pads 34 and 24 of the base 31 described above) on both main surfaces 21 and 22 of the crystal vibrating piece 2. 35) and extraction electrodes 26 and 27 drawn from the excitation electrodes 24 and 25 for electrical connection.

  Then, the extraction electrodes 26 and 27 of the crystal vibrating piece 2 and the electrode pads 34 and 35 of the base 31 are bonded by the bonding material 5, and as shown in FIG. 1, the crystal vibrating piece 2 has one end portion 28. In FIG.

  By the way, in the above-described crystal resonator 1, one step of the manufacturing process includes a step of performing frequency measurement and adjusting the frequency of the crystal resonator 1. Therefore, as a frequency measurement step of the above-described crystal resonator 1, for example, a crystal vibrating piece in a blank state (state when no electrode is formed) formed from a single AT-cut crystal piece into a rectangular solid plate. 2 frequency measurement process (hereinafter referred to as the first frequency measurement process), or the frequency measurement process of the crystal resonator 1 when the crystal resonator element 2 is bonded to the base 31 by the bonding material 5 (hereinafter referred to as the second frequency measurement process). Or a frequency measurement step (hereinafter referred to as third frequency measurement) when the frequency of the crystal resonator 1 after the crystal resonator element 2 is joined to the base 31 is adjusted to a predetermined frequency. The frequency measurement process (hereinafter referred to as fourth frequency measurement) of the crystal unit 1 when the cap 32 is joined to the package 3 and the frequency measurement process of the crystal unit 1 before shipment (hereinafter referred to as the fifth frequency measurement). Frequency measurement) And the like.

  The first frequency measurement step described above is performed using an air gap type frequency measurement device (not shown). In this air gap type frequency measuring apparatus, upper and lower electrodes having opposite electrode surfaces are used, and a blank crystal vibrating piece 2 is arranged in a space facing these upper and lower electrodes to measure the frequency of the blank crystal vibrating piece 2. Is. In this air gap type frequency measurement method, one electrode (for example, the lower electrode) is brought into contact with the blank crystal vibrating piece 2 and the other electrode (for example, the upper electrode) is not connected to the blank crystal vibrating piece 2. A gap (air gap) is formed between the other electrode as a contact state and the quartz crystal vibrating piece 2 in a blank state. In this state, an AC voltage is applied to the blank crystal vibrating piece 2 by the upper electrode and the lower electrode using a network analyzer to measure the frequency of the blank crystal vibrating piece 2 (gain (output signal at each frequency) ) Characteristic measurement). In addition, although this 1st frequency measurement process is used in many cases, the frequency adjustment after that is a process performed arbitrarily as needed.

  The second to fifth frequency measurement steps described above are performed using a contact-type frequency measurement device (not shown) using a probe pin. In this frequency measurement method apparatus, a pair of probe pins is used, and the pair of probe pins are brought into contact with the input / output electrodes (terminal electrodes 37 and 38) of the crystal unit 1. In this state, a network analyzer is used to apply an AC voltage to the crystal unit 1 with a pair of probe pins to measure the frequency of the crystal unit 1 (measurement of gain (output signal) characteristics at each frequency).

  In the first to fifth frequency measurement steps described above, the frequency measurement of the piezoelectric vibrating parts (quartz crystal vibrator 1, quartz crystal vibrating piece 2) is performed using a network analyzer. Therefore, the frequency measurement of the piezoelectric vibrating parts (quartz crystal resonator 1, quartz crystal vibrating piece 2) using this network analyzer will be described below with reference to the drawings. In the first to fifth frequency measurements of the present embodiment, the frequency measurement ranges have different scales. Therefore, the frequency measurement devices used in the first to fifth frequency measurements of the present embodiment may be different from each other. Since the basic frequency measurement process of the first to fifth frequency measurement of the embodiment is common, it is treated as the same process in this embodiment, but from the above, the first to fifth frequency measurement is limited to this embodiment. There is nothing. In addition, the frequency measurement according to the present embodiment includes frequency measurements that are three characteristics, and these frequency measurements are referred to as first to third frequency measurements (see below) for convenience. Moreover, the frequency measurement (1st-3rd frequency measurement) concerning a present Example makes the gain (output signal) in each frequency of a piezoelectric vibration component (quartz crystal vibrator 1, quartz crystal vibrating piece 2) high frequency from the low frequency side. Measure while sweeping to the side. As described above, the first frequency measurement is an air gap type non-contact frequency measurement, and the second to fifth frequency measurements are frequency measurements by probe pin contact.

  In the first frequency measurement, first, a frequency band to be measured is set, and a plurality of measurement points of the frequency to be measured within this band are set (setting step in the present invention). In the present embodiment, the frequency band to be measured is set to 45.535 to 47.865 MHz, the measurement point is set to 1600 points, and a piezoelectric vibrator (crystal resonator 1, crystal resonator piece 2 is set by a network analyzer. ) Is measured while sweeping from the low frequency side to the high frequency side. The data shown in FIG. 2 indicates that the gain at each frequency of the piezoelectric vibrating parts (quartz crystal resonator 1, quartz crystal vibrating piece 2) is reduced by a network analyzer by frequency measurement according to the conventional method without performing the first frequency measurement. It is data measured while sweeping from the frequency side to the high frequency side. As shown in FIG. 2, it can be seen that the entire gain waveform is inclined upward from the low frequency side to the high frequency side. This indicates that the frequency measurement result is fluctuated due to a problem caused by poor maintenance of the frequency measurement device itself.

  After the setting step, measurement is performed by sequentially measuring the gain of the measurement point at each measurement point of 1600 points (measurement step referred to in the present invention), and the gain data of each measurement point in the measurement step is measured and adjacent to each measurement point. The measurement points (hereinafter also referred to as adjacent measurement points) are weighted according to preset weighting conditions to obtain gain data of each measurement point (correction data acquisition step referred to in the present invention).

  Here, the weighting means that the normal distribution state in which the positive and negative frequencies of the center value are spread to the same extent, or the weighting and adding the value of the reference range to obtain a correction value. Therefore, in the weighting condition according to the present embodiment, the gain of each measurement point is composed of the gain of the reference measurement point (hereinafter also referred to as the reference measurement point) and the gain of the adjacent measurement point. Among the gains, the ratio of the gain of the reference measurement point and the ratio of the gain of the adjacent measurement point are set. Here, as the set ratio condition, it is possible to increase the gain ratio of the reference measurement point relative to the gain ratio of the adjacent measurement point. Specifically, the range of the adjacent measurement points in the present embodiment is a measurement point adjacent to one point on the low frequency side and the high frequency side of the reference measurement point, respectively. Therefore, the reference measurement points are weighted by a total of 3 points. Further, about 1/2 of the gain of the reference measurement point is set as the ratio of the gain of the reference measurement point, and about 1/4 is set as the ratio of the gain of two adjacent measurement points.

  Also, when measuring while sweeping the frequency from the low frequency side to the high frequency side, the gain increases sharply relative to the gain of the adjacent measurement point on the lowest frequency side, and the first convex point (peak The measurement point that is the apex of the gain is defined as the resonance point of the piezoelectric vibration component (the crystal resonator 1 and the crystal resonator element 2).

  Of the measurement points, the measurement point on the lowest frequency side (first point from the lowest frequency side in the set frequency band) and the measurement point on the highest frequency side (from the lowest frequency side in the set frequency band) The 1600th point) is excluded from the measurement points in the weighting condition.

  In this first frequency measurement, the number of times of sweeping and measuring from the low frequency side to the high frequency side (frequency measurement number) is usually one time, but frequency measurement is performed multiple times and the average value is set as measurement data. May be. For example, if the electric power (drive level) applied to the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) is reduced during frequency measurement, the measurement result (waveform) becomes small, so noise components from the surroundings cannot be ignored. In some cases, noise components can be reduced by performing frequency measurement a plurality of times and using the average value as measurement data.

  Moreover, although the correction data acquisition process by weighting is performed with respect to the gain data (measurement data measurement data) of each measurement point by the measurement process, this correction data acquisition process may be repeated a plurality of times. For example, the primary correction data is acquired in the correction data acquisition step by weighting with respect to the measurement data, and the correction data acquisition step by weighting is further executed on the primary correction data to thereby obtain the secondary correction data. To get. In this way, by repeating the correction data acquisition process a plurality of times (for example, 5 times), the noise component can be further suppressed.

  Therefore, when the frequency of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) was measured by the first frequency measurement based on the above-described setting conditions, the piezoelectric vibration component (crystal) as shown in FIG. Gain characteristics at each frequency of the vibrator 1 and the crystal vibrating piece 2) were obtained.

  According to the gain characteristics at each frequency of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) shown in FIG. 3 (a), the fluctuation of the gain at each frequency is suppressed as compared with the data shown in FIG. I understand that. Therefore, it can be seen that the resonance point is a peak gain between 46.700 and 46.846 MHz as compared with the data shown in FIG.

  Next, in the second frequency measurement, first, a frequency band to be measured is set, and a plurality of measurement points of the frequency to be measured within this band are set (setting step referred to in the present invention). In this embodiment, the frequency band to be measured is set to 45.535 to 47.865 MHz similarly to the first frequency measurement described above, the measurement point is set to 1600 points, and the piezoelectric vibration component ( The gain at each frequency of the crystal resonator 1 and the crystal resonator element 2) is measured while sweeping from the low frequency side to the high frequency side.

  In this second frequency measurement, the frequency band is divided into a band from the center frequency to the low frequency side and a band from the center frequency to the high frequency side, and a low frequency specific band is set from the low frequency side band. At the same time, a high frequency specific band is set from the high frequency side band (a classification step in the present invention). In this embodiment, the low frequency specific band is the frequency band from the lowest frequency measurement point (first point from the lowest frequency side of the set frequency band) to the high frequency side of the low frequency side band. The high frequency specific band is the low frequency from the highest frequency measurement point (first point from the highest frequency side of the set frequency band) in the high frequency side band. The frequency band is set to about 1/4 of the frequency band. Note that the approximately ¼ band here includes not only a strict ¼ band but also a substantially ¼ band.

  And while calculating the average value of the gain in each measurement point in the low frequency specific band set in the classification process, the average value of the gain in each measurement point in the high frequency specific band is calculated (calculation process referred to in the present invention).

  From the average gain value in the low frequency specific band calculated in the calculation process and the average gain value in the high frequency specific band, calculate the gain fluctuation due to the high and low frequencies, and correct the gain fluctuation due to the high and low frequencies. (Correction process as used in the present invention).

  Therefore, when the frequency of the piezoelectric vibration component (quartz crystal resonator 1, crystal vibration piece 2) was measured by the second frequency measurement based on the above-described setting conditions, the piezoelectric vibration component (quartz crystal) as shown in FIG. Gain characteristics at each frequency of the vibrator 1 and the crystal vibrating piece 2) were obtained. That is, here, the gain waveform at each frequency (measurement point) is linearly approximated, and the gain data for each measurement point is corrected based on the inclination (amount).

  According to the gain characteristics at each frequency of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) shown in FIG. 3B, the gain inclination at each frequency is suppressed as compared with the data shown in FIG. I understand that.

  The first and second frequency measurements described above may be used not only independently but also simultaneously. Therefore, FIG. 3C shows frequency measurement data obtained by actually using the first and second frequency measurements.

  According to the gain characteristics at each frequency of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) shown in FIG. 3 (c), the fluctuation and inclination of the gain at each frequency are compared with the data shown in FIG. I understand that it suppresses. From this, it can be seen that the frequency measurement using the first and second frequency measurements described above is a more accurate frequency measurement than the frequency measurement using the first and second frequency measurements alone.

  Next, in the third frequency measurement, first, a frequency band to be measured is set, and a plurality of measurement points of the frequency to be measured within this band are set (setting step referred to in the present invention). In this embodiment, the frequency band to be measured is set to 45.535 to 47.865 MHz as in the first and second frequency measurements, the measurement point is set to 1600 points, and the piezoelectric vibration is detected by the network analyzer. The gain at each frequency of the component (crystal resonator 1, crystal resonator element 2) is measured while sweeping from the low frequency side to the high frequency side.

  Further, the resonance point of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) obtained by performing the measurement process or a measurement point near the resonance point is set as a temporary resonance point (temporary resonance point setting step in the present invention). ). For example, in this embodiment, when measuring while sweeping the frequency from the low frequency side to the high frequency side, the gain increases sharply with respect to the adjacent measurement points and becomes the apex of the first convex point (peak gain). The measurement point is set as a temporary resonance point of the piezoelectric vibrating component (quartz crystal resonator 1, quartz crystal vibrating piece 2).

  Then, from the measurement point of the temporary resonance point set in the temporary resonance point setting step and the measurement point adjacent to the measurement point of the temporary resonance point, an approximate equation of gain at each measurement point in the vicinity including the temporary resonance point is derived. Then, the true resonance point is derived by the approximate expression (true resonance point deriving step in the present invention).

  In the third frequency measurement, the frequency of the piezoelectric vibration component is measured based on the above set conditions.

  Therefore, when the frequency of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) was measured by the third frequency measurement based on the above-described setting conditions, the piezoelectric vibration component (crystal) as shown in FIG. The approximate expression of the gain at each frequency of the vibrator 1 and the crystal vibrating piece 2) was derived. As shown in FIG. 3D, when the measured resonance point is a temporary resonance point, it is understood that this resonance point is not a true resonance point. However, since the approximate expression (approximate line) of the gain is derived in the third frequency measurement, the true resonance point can be easily derived from the approximate expression (approximate line) of the gain.

  The third frequency measurement can be used not only alone but also in combination with the first and second frequency measurements described above. Further, it is preferable to determine whether the first to third frequency measurements are merged depending on whether or not the accuracy of the frequency measurement is important in the manufacturing process of the piezoelectric vibration component (the crystal resonator 1 and the crystal resonator element 2).

  In addition, as described above, in the first to fifth frequency measurement processes described above, the frequency measurement with higher accuracy is required as it becomes a subsequent process of the manufacturing process of the crystal unit 1. Therefore, in each of the first to fifth frequency measurement steps, the above first to third frequency measurements are used alone, or a combination of these first to third frequency measurements is arbitrarily set according to the accuracy of the frequency measurement. Is preferred.

  As described above, according to the frequency measurement method of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) according to the present embodiment, the setting step, the measurement step, and the correction data acquisition step are included. The gain of the measurement point is composed of the gain of the measurement point and the gain of the adjacent measurement point, and the ratio of the gain of the measurement point and the ratio of the gain of the adjacent measurement point of the gain of the measurement point And increase the ratio of the gain of the measurement point relative to the ratio of the gain of the adjacent measurement point, so that the frequency measurement failure of the piezoelectric vibrating parts (quartz crystal unit 1, crystal unit 2) is suppressed. Frequency measurement can be stabilized.

  That is, according to the frequency measurement method of the piezoelectric vibration component (quartz crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, since the setting step, the measurement step, and the correction data acquisition step are included, the measurement point ( The reference measurement point and the adjacent measurement point can be associated with each other while clarifying the difference between the reference measurement point and the adjacent measurement point (adjacent measurement point), and the gain at all the measurement points has increased sharply. Can be clarified. As a result, it is possible to easily find the resonance point of the piezoelectric vibration component (the crystal resonator 1 and the crystal resonator element 2) in a short time.

  Further, according to the frequency measuring method of the piezoelectric vibrating component (quartz crystal resonator 1, quartz crystal vibrating piece 2) according to the above-described embodiment, the setting process, the measuring process, and the correction data acquiring process are included. Even in the case of the frequency measurement method of the piezoelectric vibrating parts (quartz crystal vibrator 1, quartz crystal vibrating piece 2), it is possible to suppress the variation in frequency measurement due to the change in the gap amount at the time of frequency measurement by relating each measurement point. .

  Further, according to the frequency measurement method of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, the range of the adjacent measurement points is the low frequency side and the high frequency side of the reference measurement point, respectively. Therefore, it is preferable to perform the association with the adjacent points when viewed from all the measurement points while clarifying the difference between the adjacent measurement points when viewed from all the measurement points. In particular, as in the present embodiment, it is preferable that there are a total of three measurement points related to the reference measurement point. That is, if the measurement point range related to the measurement point is narrowed (for example, the measurement point range is set to three points), it is possible to perform high-speed frequency measurement correction with practical accuracy. Therefore, it is possible to shorten the frequency measurement time. In the present embodiment, the measurement point range is set to three points, but this is a preferred example and is not limited to this. That is, when the measurement point range related to the measurement point is widened (for example, the measurement point range is set to 5 points), the frequency measurement is performed with high accuracy in consideration of the value (gain data) of the measurement point adjacent to the measurement point. Can be corrected.

  Further, according to the frequency measurement method of the piezoelectric vibration component (quartz crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, when measuring while sweeping the frequency from the low frequency side to the high frequency side, On the low frequency side, the gain increases sharply relative to the gain of the adjacent measurement point, and the measurement point that becomes the peak of the first convex point (peak gain) is set as the resonance point of the piezoelectric vibration component. Incorrect measurement using an excitation point (peak gain) due to a spurious generated at the resonance point can be prevented.

  In addition, according to the frequency measurement method of the piezoelectric vibration component (quartz crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, the measurement point on the lowest frequency side and the measurement on the highest frequency side among the measurement points. Since the point is excluded from the measurement point in the weighting condition, the previous point outside the frequency band before the first measurement point and the subsequent point outside the frequency band after the last measurement point are used as adjacent measurement points. It is not necessary to set temporary measurement points, and erroneous measurement due to setting temporary measurement points can be prevented.

  In addition, according to the frequency measurement method of the piezoelectric vibration component (quartz crystal resonator 1, quartz crystal resonator element 2) according to the above-described embodiment, the correction data acquisition step is further performed for each correction gain data in the correction data acquisition step. Therefore, it is possible to remove noise generated during frequency measurement, which is preferable for stabilizing the measurement value as compared with the case where the correction data acquisition process is performed once. Specifically, in this embodiment, since the correction data obtained in the first correction data acquisition step is used in the second correction data acquisition step, the second correction data acquisition step is used as the first correction data acquisition step. This can be done as an overall correction to the acquisition process. In other words, by performing the correction data acquisition process (correction process) a plurality of times, the measurement point range to be corrected is expanded.

  In addition, the frequency measurement method of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) according to this embodiment described above is the frequency measurement of the air gap type piezoelectric vibration component (crystal resonator 1, crystal resonator element 2). Since this method is likely to cause a change in the gap amount during frequency measurement, the frequency measurement is not stable. However, according to the configuration of the present embodiment, the air-gap type piezoelectric vibration component (crystal resonator 1, crystal vibration) It is possible to stabilize the frequency measurement while suppressing problems caused by the frequency measurement method of the piece 2). Note that the air gap type measurement uses a crystal vibrating piece as an example of a piezoelectric vibrating part. The crystal vibrating piece is mounted on the lower electrode body, and an AC voltage is applied in a state of being close to the upper electrode body to vibrate the crystal vibration. The frequency of the piece is to be measured. In this air gap measurement, the measurement becomes unstable due to external factors, such as the proximity distance (air gap) between the quartz crystal vibrating piece and the upper electrode body slightly fluctuating due to the vibration of the adjacent transfer device. Although this causes noise, correction of frequency measurement, which is a characteristic effect of the present embodiment, is particularly effective in this case.

  Further, according to the frequency measuring method of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, the piezoelectric vibration component includes the setting step, the division step, the calculation step, and the correction step. Even if there is a variation in gain at each measurement point due to poor maintenance of the measuring device itself that measures the frequency of the (crystal resonator 1, crystal resonator element 2), that is, the entire gain waveform at each measurement point is diagonal. When tilted, the fluctuation (slope) can be corrected, and the maximum gain point (resonance point) can be reliably extracted. As a result, the accuracy of the gain characteristic of each frequency can be improved. Note that if the instrument is fully calibrated, the measurement waveform will not be tilted. For example, in the case of the air gap method, the measurement electrode (upper electrode body and lower electrode body) is short-circuited in the calibration operation. The body may be deformed or the like, which may result in poor maintenance. However, according to this embodiment, this problem can be avoided. The accuracy of gain characteristics at each frequency can be increased.

  Further, according to the frequency measurement method of the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, the low frequency specific band is the lowest frequency measurement point in the low frequency side band. The frequency band is about 1/4 of the frequency band from the high frequency side to the high frequency side, and the high frequency specific band is the frequency band from the highest frequency measurement point to the low frequency side of the high frequency side band. Therefore, these measurement points rarely contain resonance points, and gain fluctuations at each measurement point due to poor maintenance of the measurement device itself (the entire gain waveform at each measurement point). (Tilt) can be calculated accurately.

  In addition, according to the frequency measurement method for the piezoelectric vibration component (crystal resonator 1, crystal resonator element 2) according to the above-described embodiment, the setting step, the measurement step, the temporary resonance point setting step, and the true resonance point deriving step are performed. Therefore, it is possible to stabilize the frequency measurement by suppressing the problem of the frequency measurement of the piezoelectric vibration component (the crystal resonator 1 and the crystal resonator element 2). That is, according to the above-described embodiment, a resonance point obtained by frequency measurement in an unstable state is set as a temporary resonance point, and an approximate equation of gain is derived using the temporary resonance point, and the true resonance point is derived from this approximation equation. Therefore, even if the measurement point, which is the resonance point, deviates from the true resonance point, this resonance point is set as a temporary resonance point, and the temporary resonance point is not set as the true resonance point, and the true resonance point derivation process is performed accurately. The true resonance point can be obtained. As a result, the approximation formula near the resonance point makes it easy to obtain the true resonance point even if the measurement point is rough. Specifically, for example, this embodiment is a case of a frequency measurement method of an air gap type piezoelectric vibration part, and even if the frequency measurement is not stable due to a change in the gap amount at the time of frequency measurement, A point can be derived, and frequency measurement can be stabilized. In the frequency measurement method of the air gap type piezoelectric vibration component, any of the measurement points may be a true resonance point, but each measurement point itself may be out of the true resonance point. In this case, the frequency near the true resonance point can be derived as an approximate true resonance point, but the true resonance point cannot be derived from any of the measurement points. However, according to the present embodiment, since the setting process, the measurement process, the temporary resonance point setting process, and the true resonance point deriving process are included, the true resonance point can be derived from any of the measurement points.

  In this embodiment, an AT-cut quartz crystal resonator is used as the piezoelectric vibration device, but the present invention is not limited to this, and other types of crystal resonators may be used as long as the thickness-slip system is used.

  Further, in this embodiment, the crystal vibrating piece 2 is formed into a single plate rectangular parallelepiped, but the present invention is not limited to this, and concave portions are formed on both main surfaces 21 and 22 of the crystal vibrating piece 2 ( Inverse mesa formation), and the higher frequency of the crystal unit 1 may be supported.

  In this embodiment, a conductive adhesive is used as the bonding material 5. However, the present invention is not limited to this, and connection bumps may be used. In this case, the package 3 is useful for downsizing.

  In this embodiment, the frequency is measured while sweeping from the low frequency side to the high frequency side, but the present invention is not limited to this, and the frequency is measured while sweeping from the high frequency side to the low frequency side. May be.

  In the present embodiment, the adjacent measurement points are adjacent to the reference measurement point by one point on the low frequency side and one on the high frequency side, respectively. However, the present invention is not limited to this. It may be. Even in this case, it is possible to associate the points adjacent to each other when viewed from all the measurement points while clarifying the difference between the measurement points adjacent to each other from all the measurement points.

  In this embodiment, the number of correction data acquisition steps is, for example, five. However, the number of correction data acquisition steps is not limited to this. For example, the correction data acquisition step may be set to any number such as once, three, or seven times. Note that increasing the number of steps of the correction data acquisition step is preferable for stabilizing the measured value as compared with the case where the number of steps of the correction data acquisition step is one.

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit, gist, or main features. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention is suitable for frequency measurement of a piezoelectric vibration component, particularly a crystal resonator or a crystal resonator element.

FIG. 1 is a schematic configuration diagram of a crystal resonator according to the present embodiment. FIG. 1A is a schematic plan view of the crystal resonator according to the present embodiment with the cap removed. FIG.1 (b) is the sectional view on the AA line of Fig.1 (a). FIG. 2 is a data diagram showing the gain of each frequency obtained by measuring the frequency of a conventional piezoelectric vibration component. FIG. 3 is a data diagram showing the gain of each frequency obtained by measuring the frequency of the piezoelectric vibrating component according to this example. FIG. 3A is a data diagram showing the gain of each frequency by the first frequency measurement according to the present embodiment. FIG. 3B is a data diagram showing the gain of each frequency by the second frequency measurement according to the present embodiment. FIG. 3C is a data diagram showing the gain of each frequency by the first and second frequency measurements according to the present embodiment. FIG. 3D is a data diagram showing the gain of each frequency by the third frequency measurement according to the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crystal resonator 2 Crystal vibrating pieces 24 and 25 Excitation electrode 3 Package 31 Base 32 Cap 4 Internal space

Claims (10)

In the frequency measurement method of the piezoelectric vibration component, the gain at each frequency of the piezoelectric vibration component is measured while sweeping in one direction between the low frequency side and the high frequency side.
A setting step of setting a frequency band to be measured and setting a plurality of measurement points of the frequency to be measured within the band;
A measurement step of sequentially measuring the gain of the measurement points;
A correction data acquisition step of obtaining gain data of the measurement point by weighting the measurement point and the gain data of each measurement point according to a predetermined weighting condition with respect to the measurement point and its adjacent measurement points; Have
In the weighting condition, the gain of the measurement point is composed of the gain of the measurement point and the gain of the adjacent measurement point, and the ratio of the gain of the measurement point and the adjacent measurement of the gain of the measurement point. A method for measuring a frequency of a piezoelectric vibration component, characterized in that a gain ratio of a point is set and a gain ratio of the measurement point is increased with respect to a gain ratio of an adjacent measurement point.   2. The piezoelectric vibration component according to claim 1, wherein ranges of measurement points adjacent to the reference measurement point are adjacent to one point or two points on the low frequency side and the high frequency side of the measurement point, respectively. Frequency measurement method.   When measuring while sweeping in one direction between the low frequency side and the high frequency side, the gain increases sharply with respect to the gain of the adjacent measurement point on the lowest frequency side. 3. The method of measuring a frequency of a piezoelectric vibration component according to claim 1, wherein a measurement point that is a vertex of the point is a resonance point of the piezoelectric vibration component.   The measurement point on the lowest frequency side and the measurement point on the highest frequency side among the measurement points are excluded from the measurement points in the weighting condition. Frequency measurement method for piezoelectric vibration parts.   5. The method of measuring a frequency of a piezoelectric vibration component according to claim 1, wherein a correction data acquisition step is further performed for each correction gain data in the correction data acquisition step.   The gain at each frequency of the piezoelectric vibration component is measured while sweeping in one direction between the low frequency side and the high frequency side by an air gap method. The frequency measuring method of the piezoelectric vibration component as described. The frequency band is divided into a band on the low frequency side from the center frequency of the band and a band on the high frequency side from the center frequency, and a low frequency specific band is set from the band on the low frequency side, A step of setting a high frequency specific band from within the high frequency side band; and
Calculating an average value of gain at each measurement point in the low frequency specific band, and calculating an average value of gain at each measurement point in the high frequency specific band; and
A correction step of calculating the gain fluctuation due to the frequency level from the average gain value in the low frequency specific band and the average gain value in the high frequency specific band and correcting the gain fluctuation due to the frequency level The frequency measurement method for a piezoelectric vibration component according to claim 1, wherein: The low frequency specific band is a band of about ¼ of the frequency band from the lowest frequency measurement point of the low frequency side band toward the high frequency side,
8. The high frequency specific band is a band that is about ¼ of the frequency band from the highest frequency measurement point to the low frequency side of the high frequency side band. A method for measuring the frequency of the piezoelectric vibration component according to claim 1. A temporary resonance point setting step in which the measurement point in the vicinity of the resonance point or the resonance point of the piezoelectric vibration component obtained by performing the measurement step is a temporary resonance point;
From the measurement point of the temporary resonance point and the measurement point adjacent to the measurement point of the temporary resonance point, an approximate expression of the gain at each measurement point in the vicinity including the temporary resonance point is derived, and true resonance is obtained by the approximate expression. A method for measuring a frequency of a piezoelectric vibration component according to claim 1, further comprising: a true resonance point deriving step for deriving a point. In the frequency measurement method of the piezoelectric vibration component, the gain at each frequency of the piezoelectric vibration component is measured while sweeping in one direction between the low frequency side and the high frequency side.
A setting step of setting a frequency band to be measured and setting a plurality of measurement points of the frequency to be measured within the band;
A measurement step of sequentially measuring the gain of the measurement points;
A temporary resonance point setting step in which the measurement point in the vicinity of the resonance point or the resonance point of the piezoelectric vibration component obtained by performing the measurement step is a temporary resonance point;
From the measurement point of the temporary resonance point and the measurement point adjacent to the measurement point of the temporary resonance point, an approximate expression of the gain at each measurement point in the vicinity including the temporary resonance point is derived, and true resonance is obtained by the approximate expression. A method for deriving a true resonance point for deriving a point, and a method for measuring a frequency of a piezoelectric vibration component.

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