JP2016178602A - Method of manufacturing oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an oscillator capable of reducing an adjustment error of a frequency at a frequency adjustment step compared with the conventional art.SOLUTION: A method of manufacturing an oscillator 1 that comprises a vibrator 3 and an integrated circuit (IC) 2 for making the vibrator 3 oscillate, the integrated circuit 2 having a storage unit 70 and a temperature compensation circuit 40, includes: a step (S10) of mounting the integrated circuit 2 on a package (a container) 4; a step (S20) of mounting the vibrator 3 on the package 4; a step (S30) of storing in the storage unit 70 temperature compensation data for bringing a primary component of frequency temperature characteristics of the oscillator 1 close to zero by the temperature compensation circuit 40; and a frequency adjustment step (S40) of making the vibrator 3 oscillate to measure a frequency and adjusting the frequency, in a state where the integrated circuit 2 and the vibrator 3 are electrically connected with each other.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an oscillator manufacturing method.

  Patent Document 1 discloses a method of adjusting the frequency by reducing the mass by irradiating the excitation electrode of the vibrator piece with laser light to evaporate the metal component in the piezoelectric device.

JP 2003-198312 A

  By the way, the temperature of the resonator element rises when irradiated with laser light, and a temperature difference occurs at the start and end of the frequency adjustment process. Therefore, even if the target frequency is adjusted, When the temperature returns, the frequency deviates from the target frequency. That is, the frequency is adjusted to a frequency different from the target frequency depending on the frequency temperature characteristics of the resonator element. Conventionally, the frequency adjustment error in the frequency adjustment process can be corrected by a frequency adjustment function of an integrated circuit (IC) that oscillates the resonator element, and thus is not a big problem. However, in recent years, there has been a demand for higher accuracy in the frequency of the oscillator, which cannot be corrected within the frequency adjustment range of the conventional IC, resulting in poor yield, or the circuit area of the IC increases when the frequency adjustment range of the IC is expanded. However, both have the problem of increasing costs.

  The present invention has been made in view of the above problems, and according to some aspects of the present invention, an oscillator capable of reducing the frequency adjustment error in the frequency adjustment step as compared with the prior art. A manufacturing method can be provided.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
An oscillator manufacturing method according to this application example includes an oscillator and an integrated circuit for causing the oscillator to oscillate, and the integrated circuit includes a storage unit and a temperature compensation circuit. The temperature compensation circuit brings the first-order component of the frequency temperature characteristic of the oscillator close to 0 in the step of mounting the integrated circuit in the container, the step of mounting the vibrator in the container, and the storage unit. Storing the temperature compensation data, and in a state where the integrated circuit and the vibrator are electrically connected, oscillating the vibrator, measuring the frequency, and adjusting the frequency. Including.

  Various oscillator circuits such as a Pierce oscillation circuit, an inverter type oscillation circuit, a Colpitts oscillation circuit, a Hartley oscillation circuit, and the like may be configured by the vibrator and the integrated circuit.

According to the method for manufacturing an oscillator according to this application example, in the frequency adjustment process, the temperature compensation function of the integrated circuit is used to change the temperature component of the oscillator by bringing the primary component of the frequency temperature characteristic of the oscillator closer to 0. The amount of change in the frequency of the oscillator can be reduced. Therefore, even if it adjusts so that it may approach a target frequency in a frequency adjustment process, the adjustment error of a frequency can be made smaller than before.

[Application Example 2]
In the method of manufacturing an oscillator according to the application example, the temperature compensation circuit includes a primary voltage generation circuit that generates a primary voltage with respect to temperature, and the temperature compensation data includes the primary voltage generation circuit. It may be data for control.

[Application Example 3]
In the method of manufacturing an oscillator according to the application example, the frequency adjustment step may be performed at a temperature of 15 ° C. or more and 35 ° C. or less.

  According to the method for manufacturing an oscillator according to this application example, a vibrator whose frequency changes substantially linearly with respect to a temperature change in a range of 15 ° C. or more and 35 ° C. or less (for example, a vibrator whose frequency temperature characteristic exhibits a cubic curve) ) Can be adjusted with high accuracy.

[Application Example 4]
In the oscillator manufacturing method according to the application example, the temperature compensation data may be data calculated based on measurement results of frequency temperature characteristics of a plurality of vibrators of the same type as the vibrator.

  According to the method for manufacturing an oscillator according to this application example, the primary component of the frequency temperature characteristic of the oscillator can be brought close to 0 using the temperature compensation data (fixed value) calculated in advance in the frequency adjustment step. Prior to the frequency adjustment step, it is not necessary to measure the frequency temperature characteristics of the vibrator.

[Application Example 5]
The method for manufacturing an oscillator according to the application example may include a step of measuring a frequency temperature characteristic of the oscillator and calculating the temperature compensation data based on a measurement result.

  According to the method for manufacturing an oscillator according to this application example, the primary component of the frequency temperature characteristic of the oscillator can be made substantially zero by using temperature compensation data suitable for the frequency temperature characteristic of the oscillator in the frequency adjustment step. Therefore, the frequency adjustment error can be further reduced.

[Application Example 6]
In the method for manufacturing an oscillator according to the application example described above, in the frequency adjustment step, the frequency may be adjusted by irradiating the vibrator with laser light.

  According to the method for manufacturing an oscillator according to this application example, the frequency of the oscillator can be adjusted with high accuracy even if the temperature of the vibrator rises due to laser light irradiation in the frequency adjustment step.

[Application Example 7]
In the oscillator manufacturing method according to the application example described above, the vibrator may be an AT-cut quartz crystal vibrator.

The AT-cut vibrator has a cubic curve of frequency-temperature characteristics, and generally the frequency changes linearly with respect to the temperature change near room temperature where the frequency adjustment is performed. Therefore, according to the method of manufacturing an oscillator according to this application example, In the frequency adjustment step, the frequency of the oscillator can be adjusted with high accuracy.

The perspective view of an oscillator. 2A is a cross-sectional view of the oscillator, and FIG. 2B is a bottom view of the oscillator. The functional block diagram of an oscillator. Explanatory drawing of frequency adjustment. Explanatory drawing of general frequency adjustment. The figure which shows the individual difference of the frequency temperature characteristic of a vibrator | oscillator. Explanatory drawing of the adjustment variation of a frequency. The figure which shows the relationship between the adjustment dispersion | variation at the time of frequency adjustment, and the adjustment dispersion | variation after lid sealing and heat processing. The flowchart figure which shows an example of the procedure of the manufacturing method of the oscillator of this embodiment. The flowchart figure which shows an example of the procedure of a frequency adjustment process. Explanatory drawing of the frequency adjustment in this embodiment. The figure which shows the individual difference of the frequency temperature characteristic at the time of the frequency adjustment of the manufacturing method of FIG. Explanatory drawing of the effect of the manufacturing method of the oscillator of this embodiment. The flowchart figure which shows another example of the procedure of the manufacturing method of the oscillator of this embodiment. The figure which shows the individual difference of the frequency temperature characteristic at the time of the frequency adjustment of the manufacturing method of FIG. Sectional drawing of the oscillator of another structure. FIG. 3 is a functional block diagram illustrating an example of a configuration of an electronic apparatus according to the embodiment. 1 is a diagram illustrating an example of an appearance of an electronic apparatus according to an embodiment. The figure which shows an example of the mobile body of this embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

1. Oscillator [Configuration of oscillator]
1 and 2 are diagrams showing an example of the structure of an oscillator to which the manufacturing method of the present embodiment described later is applied. FIG. 1 is a perspective view of the oscillator, and FIG. 2A is a cross-sectional view taken along the line AA ′ of FIG. FIG. 2B is a bottom view of the oscillator.

  As shown in FIGS. 1 and 2A, the oscillator 1 according to the present embodiment includes an integrated circuit (IC) 2, a vibrator 3, a package 4, a lid (lid) 5, and an external device shown in FIG. A terminal (external electrode) 6 is included.

  As the vibrator 3, for example, a crystal vibrator, a SAW (Surface Acoustic Wave) resonator, another piezoelectric vibrator, a MEMS (Micro Electro Mechanical Systems) vibrator, or the like can be used. As a substrate material of the vibrator 3, a piezoelectric single crystal such as crystal, lithium tantalate, or lithium niobate, a piezoelectric material such as piezoelectric ceramics such as lead zirconate titanate, or a silicon semiconductor material can be used. As the excitation means of the vibrator 3, one using a piezoelectric effect may be used, or electrostatic driving using a Coulomb force may be used.

The package 4 accommodates the integrated circuit (IC) 2 and the vibrator 3 in the same space. More specifically, the package 4 is provided with a recess, and the recess 5 is covered with the lid 5 to form the accommodation chamber 7. To electrically connect two terminals (an XO terminal and an XI terminal in FIG. 3 described later) of the integrated circuit (IC) 2 and two terminals of the vibrator 3 to the inside of the package 4 or the surface of the recess. (Not shown) is provided. In addition, wiring (not shown) for electrically connecting each terminal of the integrated circuit (IC) 2 and each corresponding external terminal 6 is provided inside the package 4 or on the surface of the recess.

  As shown in FIG. 2B, the oscillator 1 of the present embodiment has an external terminal VDD1 as a power supply terminal 1, an external terminal VSS1 as a ground terminal, and a frequency control signal input to the bottom surface (the back surface of the package 4). There are provided four external terminals 6 which are an external terminal VC1 which is a terminal and an external terminal OUT1 which is an output terminal. A power supply voltage is supplied to the external terminal VDD1, and the external terminal VSS1 is grounded.

  The vibrator 3 has metal excitation electrodes 3a and 3b on its front surface (upper side of FIG. 2A) and rear surface (upper side of FIG. 2A), respectively, and changes the mass of the excitation electrode 3a. Thus, the oscillation frequency of the vibrator 3 can be changed. In the present embodiment, when the vibrator 3 is manufactured (before being mounted on the package 4), the excitation electrode 3a is set so that the oscillation frequency of the vibrator 3 is lower than a desired frequency (frequency required for the oscillator 1). Before the package 4 is sealed with the lid 5, the excitation electrode 3 a is cut (polished) by irradiating laser light to reduce the mass of the vibrator 3, and as a result, vibration The oscillation frequency of the child 3 is increased and adjusted to a desired frequency.

  FIG. 3 is a functional block diagram of the oscillator 1. As shown in FIG. 3, the oscillator 1 is an oscillator including an oscillator 3 and an integrated circuit (IC) 2 for causing the oscillator 3 to oscillate. The integrated circuit (IC) 2 and the oscillator 3 are included in a package 4. Contained.

  The integrated circuit (IC) 2 is connected to a power supply terminal VDD terminal, a ground terminal VSS terminal, an output terminal OUT terminal, a frequency input signal VC terminal, and a vibrator 3 connection. Terminals XI terminal and XO terminal are provided. The VDD terminal, the VSS terminal, the OUT terminal, and the VC terminal are exposed on the surface of the integrated circuit (IC) 2, and are connected to external terminals VDD1, VSS1, OUT1, and VC1 provided in the package 4, respectively. The XI terminal is connected to one end (one terminal) of the vibrator 3, and the XO terminal is connected to the other end (the other terminal) of the vibrator 3.

  In the present embodiment, the integrated circuit (IC) 2 includes an oscillation circuit 10, an output circuit 20, a frequency adjustment circuit 30, an AFC (Automatic Frequency Control) circuit 32, a temperature compensation circuit 40, a temperature sensor 50, a regulator circuit 60, and a storage unit. 70 and a serial interface (I / F) circuit 80. Note that the integrated circuit (IC) 2 of the present embodiment may have a configuration in which some of these elements are omitted or changed, or other elements are added.

  The regulator circuit 60 is based on the power supply voltage VDD (positive voltage) supplied from the VDD terminal, and a part or all of the power supplies of the oscillation circuit 10, the frequency adjustment circuit 30, the AFC circuit 32, the temperature compensation circuit 40, and the output circuit 20. A constant voltage that is a voltage or a reference voltage is generated.

The storage unit 70 includes a nonvolatile memory 72 and a register 74, and is configured to be able to read / write the nonvolatile memory 72 or the register 74 from an external terminal via the serial interface circuit 80. In the present embodiment, the integrated circuit (IC) 2 connected to the external terminal of the oscillator 1 has only four terminals, VDD, VSS, OUT, and VC. Therefore, the serial interface circuit 80 has, for example, a voltage at the VDD terminal. When the value is higher than the threshold value, a clock signal input from the VC terminal and a data signal input from the OUT terminal are received, and data is read / written from / to the nonvolatile memory 72 or the register 74.

  The nonvolatile memory 72 is a storage unit for storing various control data, and may be various rewritable nonvolatile memories such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) and a flash memory, for example. However, various non-rewritable nonvolatile memories such as a one-time PROM (One Time Programmable Read Only Memory) may be used.

  The nonvolatile memory 72 stores frequency adjustment data for controlling the frequency adjustment circuit 30 and temperature compensation data (primary compensation data,..., N-order compensation data) for controlling the temperature compensation circuit 40. Is done. Further, the non-volatile memory 72 stores data (not shown) for controlling the output circuit 20 and the AFC circuit 32, respectively.

  The frequency adjustment data is data for adjusting the frequency of the oscillator 1. After adjusting the oscillation frequency of the oscillator 1 with the frequency adjustment data set to the initial value in the frequency adjustment process of the oscillator 1, the oscillator 1 is normally set. When the oscillation frequency at the time of operation deviates from a desired frequency, it is possible to finely adjust the oscillation frequency to approach the desired frequency by rewriting the frequency adjustment data.

  The temperature compensation data (primary compensation data,..., Nth compensation data) is data for correcting the frequency temperature characteristic of the oscillator 1 calculated in the temperature compensation adjustment process of the oscillator 1. It may be a first-order to n-th order coefficient value corresponding to each order component of the frequency temperature characteristic of 3. For example, if the vibrator 3 is an AT cut quartz crystal vibrator, the frequency temperature characteristic exhibits a cubic curve, and therefore an integer value of 3 or more is selected as n. The temperature compensation data may include compensation data of all orders from the first order to the nth order, or may include only compensation data of a part of the orders from the first order to the nth order.

  Each data stored in the nonvolatile memory 72 is transferred from the nonvolatile memory 72 to the register 74 when the integrated circuit (IC) 2 is turned on (when the voltage at the VDD terminal rises from 0 V to a desired voltage). It is held in the register 74. The frequency adjustment data held in the register 74 is input to the frequency adjustment circuit 30, and the temperature compensation data (primary compensation data,..., N-order compensation data) held in the register 74 is input to the temperature compensation circuit 40. ) Is input, and the control data held in the register 74 is also input to the output circuit 20 and the AFC circuit 32.

  When the non-volatile memory 72 is not rewritable, each of the registers 74 holding each data transferred from the non-volatile memory 72 from the external terminal via the serial interface circuit 80 when the oscillator 1 is inspected. Each piece of data is directly written into the bit, and the oscillator 1 is adjusted and selected so as to satisfy desired characteristics, and each adjusted and selected data is finally written in the nonvolatile memory 72. When the nonvolatile memory 72 is rewritable, each data may be written to the nonvolatile memory 72 from the external terminal via the serial interface circuit 80 when the oscillator 1 is inspected. However, since writing to the non-volatile memory 72 generally takes time, when the oscillator 1 is inspected, each data is directly input to each bit of the register 74 from the external terminal via the serial interface circuit 80 in order to shorten the inspection time. Each data that has been written and adjusted / selected may be finally written in the nonvolatile memory 72.

The oscillation circuit 10 amplifies the output signal of the vibrator 3 and feeds it back to the vibrator 3 to oscillate the vibrator 3 and output an oscillation signal based on the oscillation of the vibrator 3. For example, the oscillation stage current of the oscillation circuit 10 may be controlled by control data held in the register 74.

  The frequency adjustment circuit 30 generates a voltage corresponding to the frequency adjustment data held in the register 74 and applies it to one end of a variable capacitance element (not shown) that functions as a load capacitance of the oscillation circuit 10. As a result, the oscillation frequency (reference frequency) of the oscillation circuit 10 under the condition that the predetermined temperature (for example, 25 ° C.) and the voltage at the VC terminal are the predetermined voltage (for example, VDD / 2) is substantially the desired frequency. Control (fine adjustment) is performed.

  The AFC circuit 32 generates a voltage corresponding to the voltage at the VC terminal and applies it to one end of a variable capacitance element (not shown) that functions as a load capacitance of the oscillation circuit 10. Thereby, the oscillation frequency of the oscillation circuit 10 (oscillation frequency of the vibrator 3) is controlled based on the voltage value of the VC terminal. For example, the gain of the AFC circuit 32 may be controlled by control data held in the register 74.

  The temperature sensor 50 is a temperature-sensitive element that outputs a signal (for example, a voltage corresponding to the temperature) corresponding to the temperature around the temperature sensor 50. The temperature sensor 50 may have a positive polarity with a higher output voltage as the temperature is higher, or may have a negative polarity with a lower output voltage as the temperature is higher. As the temperature sensor 50, it is desirable that the output voltage changes as linearly as possible with respect to a temperature change in a desired temperature range in which the operation of the oscillator 1 is guaranteed.

  The temperature compensation circuit 40 receives an output signal from the temperature sensor 50, generates a voltage (temperature compensation voltage) for compensating the frequency temperature characteristic of the vibrator 3, and functions as a load capacitance of the oscillation circuit 10. Applied to one end of a capacitive element (not shown). As a result, the oscillation frequency of the oscillation circuit 10 is controlled to be substantially constant regardless of the temperature. In the present embodiment, the temperature compensation circuit 40 includes a primary voltage generation circuit 41-1 to an n-order voltage generation circuit 41-n and an addition circuit 42.

  The primary voltage generation circuit 41-1 to n-th order voltage generation circuit 41-n receives an output signal from the temperature sensor 50, respectively, and corresponds to the primary compensation data to n-order compensation data held in the register 74. The primary compensation voltage to the n-order compensation voltage for compensating the n-order component from the primary component of the frequency temperature characteristic of the vibrator 3 are generated.

  The adder circuit 42 adds and outputs the primary compensation voltage to the n-order compensation voltage generated by the primary voltage generation circuit 41-1 to the n-order voltage generation circuit 41-n, respectively. The output voltage of the adder circuit 42 becomes the output voltage (temperature compensation voltage) of the temperature compensation circuit 40.

  The output circuit 20 receives the oscillation signal output from the oscillation circuit 10, generates an oscillation signal for external output, and outputs it to the outside via the OUT terminal. For example, the frequency division ratio and output level of the oscillation signal in the output circuit 20 may be controlled by control data held in the register 74.

  The oscillator 1 according to the first embodiment configured as described above is a voltage control type temperature compensation type that outputs an oscillation signal having a constant frequency according to the voltage of the external terminal VC1 regardless of the temperature in a desired temperature range. It functions as an oscillator (VC-TCXO (Voltage Controlled Temperature Compensated Crystal Oscillator) if the vibrator 3 is a crystal vibrator).

[Problems with frequency adjustment]
As shown in FIG. 4, in this embodiment, in the oscillator 1 before the package 4 is sealed by the lid 5, the oscillator 3 is oscillated by the integrated circuit (IC) 2 at about 25 ° C. to 30 ° C., for example. The frequency (oscillation frequency) of the oscillation signal output from the external terminal 6 corresponding to the external terminal OUT1 is measured, and the excitation electrode 3a on the surface of the vibrator 3 is irradiated with the laser light emitted from the laser light source 9 according to the measurement result. The frequency is adjusted by shaving. For example, at the start of the frequency adjustment, the frequency deviation Δf / f of the oscillation frequency of the oscillator 1 is about −1000 ppm, and the oscillation frequency so that the frequency deviation approaches 0 ppm (so that the measured frequency approaches the desired frequency). Adjust. However, since the temperature of the vibrator 3 is increased by irradiating the excitation electrode 3a of the vibrator 3 with the laser beam, the temperature of the vibrator 3 when the frequency is measured is the temperature at the start of frequency adjustment ( Therefore, even if the measured frequency is adjusted to match the desired frequency, the oscillation frequency at 25 ° C. of the oscillator 1 has an error depending on the frequency temperature characteristic of the vibrator 3. It will be.

  Here, for example, when the vibrator 3 is an AT-cut quartz crystal vibrator, the frequency temperature characteristic exhibits a cubic curve. Therefore, as shown in FIG. 5, the oscillation frequency of the oscillator 1 is adjusted to 25 ° C. In the vicinity, the oscillation frequency decreases almost linearly with increasing temperature. Then, since the temperature of the vibrator 3 is higher at the end of the frequency adjustment at which the frequency deviation is close to 0 ppm than at the start of the frequency deviation being about −1000 ppm, the oscillation frequency of the oscillator 1 is shown in FIG. In a state having such a temperature characteristic, an adjustment error occurs unless the frequency is adjusted to be lower than a desired frequency.

  Further, for example, as shown in FIG. 6A, there is an individual difference in the frequency temperature characteristics of the vibrator 3, and as shown in FIG. 6B in which the vicinity of 25 ° C. in FIG. The degree of frequency decrease with respect to a temperature increase near 25 ° C. is also different. Further, the vibrator at the time of frequency adjustment is based on the difference in temperature at the time of frequency adjustment for each oscillator 1 or the difference in the amount of heat generated by the vibrator 3 due to the difference in the laser irradiation time corresponding to the difference in the initial frequency for each vibrator 3. There is also a difference in the temperature of 3. Then, as shown in FIG. 7, when the horizontal axis is the frequency deviation (Δf / f) and the vertical axis is the number of the oscillators 1, the frequency of the oscillator 1 adjusted at 25 ° C. or 30 ° C. is normally distributed. Thus, the difference between the maximum frequency adjusted at 25 ° C. and the minimum frequency adjusted at 30 ° C. becomes obvious as adjustment variation A.

  Furthermore, after the frequency is adjusted, the package 4 is sealed with the lid 5 and the state of the oscillator 1 is changed in the process of performing heat treatment to adhere the lid 5 to the package 4. As a result, the oscillation frequency of the oscillator 1 is changed. It is possible to take measures to offset the target frequency at the time of frequency adjustment in consideration of the change amount of the oscillation frequency. However, even if such measures are taken, there is an individual difference in the amount of change in the oscillation frequency. Therefore, as shown in FIG. 8, the adjustment variation B after sealing and heat treatment by the lid 5 is an adjustment variation at the time of frequency adjustment. It becomes larger than A.

  As described above, the frequency of the oscillator 1 can be finely adjusted by the frequency adjustment circuit 30 by rewriting the frequency adjustment data. However, when a high frequency accuracy of 1 ppm or less is required, the adjustment variation B is the frequency adjustment data. Since it becomes larger than the adjustable range by rewriting and the number of oscillators 1 that cannot be adjusted increases, the yield decreases. Although it is possible to improve the yield by widening the adjustable range by the frequency adjustment circuit 30, if the adjustable range is widened while maintaining the adjustment resolution, the number of bits of the frequency adjustment data increases and the cost increases. If the adjustable range is widened while maintaining the number of bits of the frequency adjustment data, the adjustment resolution is lowered and the frequency accuracy of the oscillator 1 is deteriorated.

  As described below, the manufacturing method of the present embodiment reduces the adjustment variation B by reducing the adjustment variation A at the time of frequency adjustment, and maintains the yield without expanding the adjustable range by the frequency adjustment circuit 30. It is to improve.

[Oscillator manufacturing method]
FIG. 9 is a flowchart showing an example of the procedure of the method for manufacturing an oscillator according to the present embodiment (the method for manufacturing the oscillator 1 described above). Part of steps S10 to S100 in FIG. 9 may be omitted or changed, or other steps may be added. Prior to the flowchart of FIG. 9, it is assumed that the initial value of the frequency adjustment data (for example, the intermediate value of the adjustable range) is written in the nonvolatile memory 72 or the register 74.

  In the example of FIG. 9, first, the integrated circuit (IC) 2 is mounted on the package 4 (S10), and then the vibrator 3 is mounted on the package 4 (S20). By the steps S10 and S20, the integrated circuit (IC) 2 and the vibrator 3 are connected by wiring provided in the package 4 or on the surface of the recess, and when the power is supplied to the integrated circuit (IC) 2, the integrated circuit (IC) 2 is connected. IC) 2 and vibrator 3 are electrically connected.

  Next, the temperature compensation data (fixed value) for the temperature compensation circuit 40 to bring the primary component of the frequency temperature characteristic of the oscillator 1 close to 0 is stored in the storage unit 70 of the integrated circuit (IC) 2 (S30). This temperature compensation data is data calculated in advance based on the measurement results of frequency temperature characteristics of a plurality of vibrators of the same type (model number) as that of the vibrator 3, and for example, the frequency of the plurality of vibrators. This is primary compensation data for compensating the average value of the slope (primary component) around 25 ° C. of the temperature characteristics. In step S30, the primary compensation data is written to the nonvolatile memory 72 or the register 74 from the external terminal via the serial interface circuit 80.

  Next, in a state where the integrated circuit (IC) 2 and the vibrator 3 are electrically connected, the vibrator 3 is oscillated to measure the frequency and adjust the frequency (S40). In this frequency adjustment step S40, the primary voltage of the temperature compensation circuit 40 is changed according to the primary compensation data transferred from the nonvolatile memory 72 to the register 74 and held, or the primary compensation data written in the register 74. The frequency is adjusted while the generation circuit 41-1 is generating the primary compensation voltage.

  Next, the package 4 is sealed with the lid 5, and heat treatment is performed to adhere the lid 5 to the package 4 (S50).

  Next, for example, the frequency of the oscillator 1 is measured at 25 ° C. (S60), and when the frequency deviation of the measured frequency (deviation from a desired frequency) is within a predetermined range (Y in S70), other adjustments and inspections ( For example, temperature compensation adjustment is performed (S100), and the process ends.

  If the frequency deviation of the measured frequency (deviation from the desired frequency) is not within the predetermined range (N in S70), if the frequency deviation is within the adjustable range (Y in S80), the frequency adjustment data is rewritten. (S90), Step S60 and subsequent steps are performed again. On the other hand, if the frequency deviation of the measured frequency is not within the adjustable range (N in S80), the process may be terminated without performing step S100, and for example, the oscillator 1 may be discarded as a rejected product.

  In the flowchart of FIG. 9, the order of the steps may be changed as appropriate within a possible range. For example, step S30 may be performed before step S10. In this case, the temperature compensation data (fixed value) may be stored in the nonvolatile memory 72 of the storage unit 70.

  FIG. 10 is a flowchart showing an example of the procedure of the frequency adjustment step (step S40 in FIG. 9).

  First, a target frequency is set (S41).

  Next, laser light is irradiated from the laser light source 9, and the excitation electrode 3a of the vibrator 3 is polished and shaved (S42). By this step S42, the mass of the vibrator 3 decreases and the frequency of the oscillator 1 increases.

  Next, the frequency of the oscillator 1 is measured (S43), and if the deviation of the measured frequency from the target frequency is not within a predetermined range (N in S44), the processes after step S42 are performed again. If the deviation of the measured frequency with respect to the target frequency is within a predetermined range (Y in S44), the frequency adjustment process is terminated. In step S43, the frequency is measured in a state where a desired voltage, for example, a voltage (for example, VDD / 2) corresponding to the intermediate frequency in the frequency variable range is applied to the external terminal VC1.

  Here, at step S30 in FIG. 9, as shown in FIG. 11, at the start of the frequency adjustment step S40 (when the frequency deviation with respect to the target frequency is about −1000 ppm), the frequency temperature characteristic of the oscillator 1 is about 25 ° C. The oscillation frequency is almost flat with respect to the temperature rise. Therefore, at the end of the frequency adjustment step S40 in which the frequency deviation with respect to the target frequency is close to 0 ppm, the temperature of the vibrator 3 rises by several degrees due to the laser light irradiation, but the oscillation frequency of the oscillator 1 due to the temperature rise of the vibrator 3 Therefore, even if the frequency is adjusted so as to be the target frequency at 25 ° C., for example, the adjustment error is small.

  Actually, for example, as shown in FIG. 12A, there is an individual difference in the frequency temperature characteristics of the vibrator 3, and the fixed value of the primary compensation data is stored in the storage unit 70 in step S30 of FIG. Therefore, as shown in FIG. 12B, a difference also occurs in the slope (first-order component) around 25 ° C. of the frequency temperature characteristic of the oscillator 1 in the frequency adjustment step S40. For this reason, the frequency adjustment error varies to some extent, but as shown in FIG. 13A, as compared with the case where step S30 in FIG. 9 is not performed (broken line in FIG. 13A), FIG. When step S30 is performed (solid line in FIG. 13A), the adjustment variation A during frequency adjustment is reduced. As a result, as shown in FIG. 13B, the case where step S30 of FIG. 9 is performed (FIG. 13B) as compared to the case where step S30 of FIG. 9 is not performed (broken line in FIG. 13B). ) (Solid line) also reduces the adjustment variation B after sealing by the lid 5 and heat treatment.

  Therefore, even with respect to the oscillator 1 having a relatively large frequency adjustment error, the difference from the target frequency can be set within a predetermined range by performing fine adjustment of the frequency in steps S60 to S90 in FIG. Can be maintained or improved.

  According to the flowchart of FIG. 9, the frequency temperature characteristics of a plurality of vibrators of the same type (model number) as the vibrator 3 are measured in advance, and data (fixed values) calculated based on the measurement results are used. Since the primary component of the frequency temperature characteristic of the oscillator 1 can be brought close to 0, it is not necessary to measure the frequency temperature characteristic of the vibrator 3 prior to the frequency adjustment step S40. However, in order to further improve the yield, it is also possible to perform frequency adjustment by storing more appropriate primary compensation data corresponding to the frequency temperature characteristics of each oscillator 1 as described below.

  FIG. 14 is a flowchart showing another example of the procedure of the method for manufacturing an oscillator according to the present embodiment (the method for manufacturing the oscillator 1 described above). Part of steps S10 to S100 in FIG. 14 may be omitted or changed, or other steps may be added. Prior to the flowchart of FIG. 14, it is assumed that the initial value of the frequency adjustment data (for example, the intermediate value of the adjustable range) is written in the nonvolatile memory 72 or the register 74.

  In the example of FIG. 14, similarly to FIG. 9, first, the integrated circuit (IC) 2 is mounted on the package 4 (S10), and then the vibrator 3 is mounted on the package 4 (S20).

  Next, the frequency temperature characteristic of the oscillator 1 is measured, and temperature compensation data for approximating the primary component of the frequency temperature characteristic of the oscillator 1 to 0 based on the measurement result is calculated (S32). For example, by measuring the frequency at a plurality of temperatures near 25 ° C., the primary component of the frequency temperature characteristic of the oscillator 1 can be measured. For example, the frequency is measured at 25 ° C. and 30 ° C., respectively, and primary compensation data for correcting the slope (primary component) of the straight line connecting the two points is calculated.

  Next, the temperature compensation data calculated in step S32 is stored in the storage unit 70 of the integrated circuit (IC) 2 (S34).

  Next, in a state where the integrated circuit (IC) 2 and the vibrator 3 are electrically connected, the vibrator 3 is oscillated to measure the frequency and adjust the frequency (S40). The detailed procedure of this frequency adjustment process S40 is the same as that of FIG.

  Next, as in FIG. 9, after the package 4 is sealed with the lid 5, heat treatment is performed to bond the lid 5 to the package 4 (S50), and then the frequency of the oscillator 1 is measured at 25 ° C., for example ( If the frequency deviation of the measured frequency (deviation from the desired frequency) is within a predetermined range (Y in S70), other adjustments and inspections (for example, temperature compensation adjustment) are performed (S100), and the process is terminated.

  If the frequency deviation of the measured frequency (deviation from the desired frequency) is not within the predetermined range (N in S70), if the frequency deviation is within the adjustable range (Y in S80), the frequency adjustment data is rewritten. (S90), Step S60 and subsequent steps are performed again. On the other hand, if the frequency deviation of the measured frequency is not within the adjustable range (N in S80), the process may be terminated without performing step S100, and for example, the oscillator 1 may be discarded as a rejected product.

  In the flowchart of FIG. 14, the order of the steps may be changed as appropriate within the possible range. For example, step S32 and step S34 may be performed before step S10. In this case, the calculated temperature compensation data may be stored in the nonvolatile memory 72 of the storage unit 70.

  Here, for example, as shown in FIG. 15A, there are individual differences in the frequency temperature characteristics of the vibrator 3, but in step S34 of FIG. Therefore, as shown in FIG. 15B, the slope (primary component) of the frequency temperature characteristic of the oscillator 1 in the frequency adjustment step S40 in the vicinity of 25 ° C. is stored in the oscillator 1 as shown in FIG. Regardless, it can be almost zero. Therefore, the adjustment variation A at the time of frequency adjustment becomes extremely small, and as a result, the adjustment variation B after sealing by the lid 5 and heat treatment can be further reduced.

  Therefore, for most oscillators 1, by performing fine adjustment of the frequency in steps S60 to S90 in FIG. 14, the difference from the target frequency can be within a predetermined range, and the yield can be further improved. .

  As described above, according to the method for manufacturing an oscillator of the present embodiment, in the frequency adjustment step, the temperature compensation function of the integrated circuit (IC) 2 is used, and the primary component of the frequency temperature characteristic of the oscillator 1 is obtained. By approaching 0, the amount of change in the frequency of the oscillator 1 due to the change in the temperature of the vibrator 3 can be reduced. Therefore, even if it adjusts so that it may approach a target frequency in a frequency adjustment process, the adjustment error of a frequency can be made smaller than before.

In particular, according to the method for manufacturing an oscillator of this embodiment, the integrated circuit (IC) 2 controls the primary compensation voltage of the temperature compensation circuit 40 to reduce the adjustment variation A during frequency adjustment, thereby reducing the lid 5. The adjustment variation B after sealing by heat treatment and heat treatment is reduced, and the frequency adjustment circuit 30 is reduced.
It is possible to maintain or improve the yield without expanding the adjustable range.

  The method for manufacturing an oscillator according to the present embodiment is effective when the frequency changes substantially linearly with respect to a temperature change near the temperature at which the frequency adjustment step (step S40) is performed. For example, the frequency temperature The present invention can be widely applied to the oscillator 1 having the vibrator 3 whose characteristic exhibits a cubic curve. As such a vibrator 3, in addition to the above-described AT-cut quartz crystal vibrator, for example, a surface acoustic wave (SAW: Surface Acoustic Wave) whose frequency temperature characteristic exhibits a cubic curve by improving the ST cut. ) A resonator or the like. Also in this surface acoustic wave (SAW) resonator, the frequency can be adjusted by irradiating a laser beam and removing a part of an IDT (InterDigital Transducer) electrode and a reflector.

  When the frequency temperature characteristic of the vibrator 3 exhibits a cubic curve, it is desirable that the frequency adjustment step (step S40 in FIGS. 9 and 14) is performed at a temperature of 15 ° C. or higher and 35 ° C. or lower. In this temperature range, the frequency of the vibrator 3 changes substantially linearly with respect to the temperature change. Therefore, by storing the primary compensation data for making the primary component of the frequency temperature characteristic of the oscillator 1 close to 0, the frequency The adjustment error can be reduced.

  The oscillator 1 described above is an oscillator having a temperature compensation function and a voltage control function (frequency control function) (VC-TCXO (Voltage Controlled Temperature Compensated Crystal Oscillator, etc.)). The present invention can also be applied to a temperature compensated oscillator (TCXO (Temperature Compensated Crystal Oscillator), etc.) that does not have a voltage control function (frequency control function).

  The oscillator manufacturing method of the present embodiment is widely applied to the oscillator 1 that can measure the frequency by oscillating the vibrator 3 by the integrated circuit (IC) 2 and adjust the frequency according to the measurement result. be able to. Such an oscillator 1 can be applied to, for example, an H-type oscillator as shown in FIG. 16 in addition to an oscillator with a single seal structure as shown in FIG. In the oscillator 1 shown in FIG. 16, the package 4 is provided with two recesses on the opposing surfaces, and the cover 5 covers one recess to form the accommodation chamber 7 a, and the sealing member 8 forms the other recess. It becomes the accommodation chamber 7b by covering. The accommodating chamber 7a accommodates the vibrator 3, and the accommodating chamber 7b accommodates the integrated circuit (IC) 2. Wiring (not shown) for electrically connecting the XO terminal and the XI terminal of the integrated circuit (IC) 2 and the two terminals of the vibrator 3 is provided inside the package 4 or on the surface of the recess. . In addition, wiring (not shown) for electrically connecting each terminal of the integrated circuit (IC) 2 and each corresponding external terminal 6 is provided inside the package 4 or on the surface of the recess. Even in the oscillator 1 having such a structure, before the package 4 is sealed with the lid 5, the excitation electrode 3a provided on the surface of the vibrator 3 is irradiated with laser light, and the excitation electrode 3a is cut to reduce the frequency. Can be adjusted.

2. Electronic Device FIG. 17 is a functional block diagram showing an example of the configuration of the electronic device of the present embodiment. Moreover, FIG. 18 is a figure which shows an example of the external appearance of the smart phone which is an example of the electronic device of this embodiment.

  The electronic device 300 according to the present embodiment includes an oscillator 310, a CPU (Central Processing Unit) 320, an operation unit 330, a ROM (Read Only Memory) 340, a RAM (Random Access Memory) 350, a communication unit 360, and a display unit 370. It is configured. Note that the electronic device of the present embodiment may be configured such that some of the components (each unit) in FIG. 17 are omitted or changed, or other components are added.

  The oscillator 310 includes an integrated circuit (IC) 312 and a vibrator 313. The integrated circuit (IC) 312 oscillates the vibrator 313 to generate an oscillation signal. This oscillation signal is output from the OUT terminal of the oscillator 310 to the CPU 320.

  The CPU 320 performs various calculation processes and control processes using the oscillation signal input from the oscillator 310 as a clock signal in accordance with a program stored in the ROM 340 or the like. Specifically, the CPU 320 performs various processes according to operation signals from the operation unit 330, processes for controlling the communication unit 360 to perform data communication with an external device, and displays various types of information on the display unit 370. The process of transmitting the display signal is performed.

  The operation unit 330 is an input device including operation keys, button switches, and the like, and outputs an operation signal corresponding to an operation by the user to the CPU 320.

  The ROM 340 stores programs, data, and the like for the CPU 320 to perform various calculation processes and control processes.

  The RAM 350 is used as a work area of the CPU 320, and temporarily stores programs and data read from the ROM 340, data input from the operation unit 330, calculation results executed by the CPU 320 according to various programs, and the like.

  The communication unit 360 performs various controls for establishing data communication between the CPU 320 and an external device.

  The display unit 370 is a display device configured by an LCD (Liquid Crystal Display) or the like, and displays various types of information based on a display signal input from the CPU 320. The display unit 370 may be provided with a touch panel that functions as the operation unit 330.

  By applying, for example, the oscillator 1 manufactured using the manufacturing method of the present embodiment described above as the oscillator 310, a highly reliable electronic device can be realized.

  Various electronic devices can be considered as such an electronic device 300, for example, a personal computer (for example, a mobile personal computer, a laptop personal computer, a tablet personal computer), a mobile terminal such as a smartphone or a mobile phone, Digital cameras, inkjet discharge devices (for example, inkjet printers), storage area network devices such as routers and switches, local area network devices, mobile terminal base station devices, televisions, video cameras, video recorders, car navigation devices, real time Clock devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game machines, game controllers, word processors, word processors Station, video phone, security TV monitor, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measurements Examples of such devices include instruments, instruments (for example, vehicles, aircraft, and ship instruments), flight simulators, head mounted displays, motion traces, motion tracking, motion controllers, and PDR (pedestrian orientation measurement).

As an example of the electronic apparatus 300 according to this embodiment, the above-described oscillator 310 is used as a reference signal source, a voltage variable oscillator (VCO), or the like, for example, a terminal base station apparatus that performs wired or wireless communication with a terminal. As a transmission device. The electronic apparatus 300 according to the present embodiment employs, for example, the oscillator 1 manufactured by using the manufacturing method according to the present embodiment described above as the oscillator 310, so that it can be used for, for example, a communication base station. The present invention can also be applied to a transmission device in which the performance is desired.

3. FIG. 19 is a diagram (top view) illustrating an example of a moving object according to the present embodiment. A moving body 400 shown in FIG. 19 includes controllers 420, 430, and 440 that perform various controls such as an oscillator 410, an engine system, a brake system, and a keyless entry system, a battery 450, and a backup battery 460. Note that the mobile body of this embodiment may have a configuration in which some of the components (each unit) in FIG. 19 are omitted or other components are added.

  The oscillator 410 includes an integrated circuit (IC) (not shown) and a vibrator, and the integrated circuit (IC) oscillates the vibrator and generates an oscillation signal. This oscillation signal is output from the external terminal of the oscillator 410 to the controllers 420, 430, and 440, and is used as, for example, a clock signal.

  The battery 450 supplies power to the oscillator 410 and the controllers 420, 430, and 440. The backup battery 460 supplies power to the oscillator 410 and the controllers 420, 430, and 440 when the output voltage of the battery 450 falls below a threshold value.

  By applying, for example, the oscillator 1 manufactured using the manufacturing method of the present embodiment described above as the oscillator 410, a highly reliable moving body can be realized.

  As such a moving body 400, various moving bodies can be considered, and examples thereof include automobiles (including electric automobiles), aircraft such as jets and helicopters, ships, rockets, and artificial satellites.

  The present invention is not limited to the present embodiment, and various modifications can be made within the scope of the gist of the present invention.

  The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 Oscillator, 2 Integrated circuit (IC), 3 Oscillator, 3a, 3b Excitation electrode, 4 Package, 5 Lid, 6 External terminal (External electrode), 7a, 7b Storage chamber, 8 Sealing member, 9 Laser light source, 10 Oscillation circuit, 20 output circuit, 30 frequency adjustment circuit, 32 AFC circuit, 40 temperature compensation circuit, 41-1 primary voltage generation circuit, 41-n n-order voltage generation circuit, 42 addition circuit, 50 temperature sensor, 60 regulator circuit , 70 Storage unit, 72 Non-volatile memory, 74 register, 80 Serial interface (I / F) circuit, 300 Electronic device, 310 Oscillator, 312 Integrated circuit (IC), 313 Vibrator, 320 CPU, 330 Operation unit, 340 ROM , 350 RAM, 360 communication unit, 370 display unit, 400 moving body, 410 oscillator, 420, 430, 440 Controller, 450 battery, 460 backup battery

Claims (7)

A method of manufacturing an oscillator including a vibrator and an integrated circuit for oscillating the vibrator, wherein the integrated circuit includes a storage unit and a temperature compensation circuit;
Mounting the integrated circuit in a container;
Mounting the vibrator on the container;
Storing the temperature compensation data for the temperature compensation circuit to bring the primary component of the frequency temperature characteristic of the oscillator close to 0 in the storage unit;
And a frequency adjustment step of adjusting the frequency by oscillating the vibrator and measuring the frequency in a state where the integrated circuit and the vibrator are electrically connected. The temperature compensation circuit includes a primary voltage generation circuit that generates a primary voltage with respect to temperature,
The method of manufacturing an oscillator according to claim 1, wherein the temperature compensation data is data for controlling the primary voltage generation circuit.   The method for manufacturing an oscillator according to claim 1, wherein the frequency adjustment step is performed at a temperature of 15 ° C. or more and 35 ° C. or less.   4. The oscillator manufacture according to claim 1, wherein the temperature compensation data is data calculated based on measurement results of frequency temperature characteristics of a plurality of vibrators of the same type as the vibrator. 5. Method.   The method for manufacturing an oscillator according to any one of claims 1 to 3, further comprising a step of measuring a frequency temperature characteristic of the oscillator and calculating the temperature compensation data based on a measurement result. In the frequency adjustment step,
The method for manufacturing an oscillator according to claim 1, wherein the frequency is adjusted by irradiating the vibrator with laser light. In the frequency adjustment step,
The method for manufacturing an oscillator according to claim 1, wherein the vibrator is an AT-cut quartz crystal vibrator.

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