JP3981920B2 - Piezoelectric device, method for manufacturing the same, clock device, and package for piezoelectric device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piezoelectric device, and more particularly to a piezoelectric device having a plurality of piezoelectric vibration elements in one package, a manufacturing method thereof, a clock device, and a package for a piezoelectric device.
[0002]
[Prior art]
In Patent Document 1, for the purpose of reducing the number of parts of various electronic components and man-hours, a tuning fork crystal unit, an AT-cut crystal unit, an IC, and a capacitor are vacuum-sealed in one package. A piezoelectric device has been proposed.
[Patent Document 1]
JP 2000-349181 A
[0003]
[Problems to be solved by the invention]
As described above, the piezoelectric device described in Patent Document 1 (hereinafter referred to as a conventional piezoelectric device) has the same tuning fork type crystal vibrating piece whose frequency temperature characteristic shows a quadratic curve and the same IC as a heat source. It is stored in the cavity. For this reason, in the conventional piezoelectric device, the IC generates heat with use, and the vibration frequency of the tuning-fork type crystal vibrating piece fluctuates due to the heat. Therefore, the piezoelectric device cannot be a highly accurate piezoelectric device. In the conventional piezoelectric device, the tuning fork type crystal vibrating piece is fixed in the package and the frequency is adjusted. Then, the AT cut crystal vibrating piece is fixed and the frequency is adjusted, and then the package is vacuum-sealed. ing. Therefore, in the conventional piezoelectric device, the operating environment of the tuning-fork type crystal vibrating piece differs between when it is manufactured and when it is completed. For this reason, in the conventional piezoelectric device, the oscillation frequency of the tuning-fork type quartz vibrating piece may be shifted from that during frequency adjustment, and the manufacturing yield may be deteriorated.
[0004]
On the other hand, the piezoelectric oscillator for digital cameras, which is currently popular, is 24.54545 MHz corresponding to NTSC (National Television System Committee), which is a television broadcasting system in the United States and Japan, and PAL, which is a television broadcasting system in Western Europe. What outputs the clock signal for 24.375 MHz television images corresponding to (Phase Alternating Line) is used. Conventionally, when an oscillator corresponding to each of these two types of clock signals is manufactured, an oscillator corresponding to each frequency is mounted by replacing the piezoelectric vibrator having a different oscillation frequency and mounting the same circuit configuration of the oscillator. Is manufacturing. For this reason, the management of components is troublesome, and a clock device that can selectively output the above-described two types of clock signals by one piezoelectric vibrator is desired.
[0005]
The present invention has been made to solve the above-described drawbacks of the prior art, and an object thereof is to prevent the influence of heat generated by an integrated circuit on a piezoelectric vibration element whose frequency-temperature characteristic shows a quadratic curve.
Another object of the present invention is to enable the frequency adjustment of the piezoelectric vibration element to be performed with high accuracy.
Another object of the present invention is to obtain clock signals having a plurality of frequencies from the oscillation frequency of one piezoelectric vibration element.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a piezoelectric device according to the present invention includes a package in which a plurality of cavities partitioned from each other are formed, and a frequency temperature characteristic stored in a first cavity among the plurality of cavities. Comprising a first piezoelectric vibration element and an integrated circuit that form a cubic curve, and a second piezoelectric vibration element that has a frequency-temperature characteristic housed in a second cavity among the plurality of cavities that forms a quadratic curve. It is said.
[0007]
In the present invention configured as described above, the second piezoelectric vibration element in which the frequency temperature characteristic in which the oscillation frequency is likely to change due to a temperature change shows a quadratic curve is partitioned from the first cavity that houses the integrated circuit. Stored in the cavity. Therefore, the second piezoelectric vibration element is not affected by the heat generated by the integrated circuit, and can be a highly reliable and highly accurate piezoelectric device.
[0008]
The first piezoelectric vibration element may be composed of an AT-cut vibration piece of piezoelectric crystal such as quartz, and the second piezoelectric vibration element may be composed of a tuning fork type vibration piece. An AT-cut vibrating element made of an AT-cut vibrating piece has very good frequency temperature characteristics in a normal operating temperature range, and a stable oscillation frequency can be obtained even when the integrated circuit generates heat. In addition, since the piezoelectric vibration element composed of a tuning-fork type piezoelectric vibrating piece has low power consumption for oscillation, it can reduce power consumption for maintaining a minimum function in the standby mode (sleep mode) of the electronic device. Can do.
[0009]
The second cavity containing the tuning fork type piezoelectric vibration element is preferably vacuum-sealed. In the tuning fork type piezoelectric vibration element, the vibration arm performs flexural vibration as is well known. For this reason, by vacuum-sealing the second cavity, the vibration resistance of the tuning fork type piezoelectric vibration element can be reduced, the power consumption can be reduced, and stable vibration characteristics can be obtained over a long period of time.
[0010]
The integrated circuit can be configured to include a frequency synthesis circuit that generates a video clock signal and a transmission clock output circuit that outputs a data transmission clock signal based on the oscillation frequency of the first piezoelectric vibration element. . Thereby, when mounted on a digital camera or a DVD device, these devices can be made to correspond to an AV device such as a television and a data processing device such as a personal computer. The frequency synthesis circuit is configured to be capable of generating a plurality of video clock signals, and the integrated circuit has a select terminal for inputting a selection signal that can arbitrarily select one of the plurality of video clock signals to the frequency synthesis circuit. If comprised in this way, the piezoelectric device for NTSC and the piezoelectric device for PAL can be manufactured, for example, without replacing | exchanging a piezoelectric vibration element, and manufacturing efficiency can be improved. Further, it is desirable that the oscillation circuit corresponding to each of the first piezoelectric vibration element and the second piezoelectric vibration element provided in the integrated circuit is spaced apart by arranging a frequency synthesis circuit or the like therebetween. Thereby, both can be prevented from affecting each other, and a stable oscillation frequency can be obtained.
[0011]
The manufacturing method for obtaining the piezoelectric device includes a step of mounting an integrated circuit in a first cavity of a package body having a plurality of cavities partitioned from each other, and a frequency temperature characteristic in the first cavity. Mounting the first piezoelectric vibration element having a cubic curve, adjusting the oscillation frequency of the first piezoelectric vibration element, and the second piezoelectric element provided in the package body and partitioned from the first cavity A step of mounting a second piezoelectric vibration element having a quadratic frequency temperature characteristic in the cavity, and covering the first cavity and the second cavity, and at least a portion corresponding to the second cavity is transparent. A step of bonding a lid having optical properties to the package body, a step of sealing a sealing hole communicating the second cavity and the outside, and the lid It is characterized by having a laser beam is irradiated to the second piezoelectric vibrating element, and adjusting the frequency of the second piezoelectric vibrating elements.
[0012]
A clock device according to the present invention includes the piezoelectric device according to any one of claims 4 to 6. Thereby, a clock device having the above-described effects can be obtained.
Furthermore, the piezoelectric device package according to the present invention includes a first cavity that houses the first piezoelectric vibration element and the integrated circuit whose frequency temperature characteristics form a cubic curve, and the frequency temperature characteristics that are partitioned by the first cavity. And a second cavity that houses a second piezoelectric vibration element having a quadratic curve.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of a piezoelectric device, a manufacturing method thereof, a clock device, and a package for a piezoelectric device according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of the piezoelectric device according to the embodiment of the present invention with the package lid removed. In FIG. 1, the piezoelectric device 10 has a package body 12. As will be described in detail later, the package body 12 is a so-called ceramic package formed by laminating a plurality of ceramic sheets (four layers in the embodiment). The package body 12 is provided with a first cavity 16 and a second cavity 18 that are partitioned from each other by a partitioning portion 14. The package main body 12 is provided with a low melting point glass 20 on the upper end surface, and a lid member (package lid) (not shown) is joined via the low melting point glass 20 to seal the cavities 16 and 18. It is like that.
[0014]
The first cavity 16 is formed larger than the second cavity 18. The first cavity 16 accommodates an AT-cut vibration element 22 that is a first piezoelectric vibration element whose frequency-temperature characteristic forms a cubic curve, and an integrated circuit (IC) 24. In the case of the embodiment, the AT-cut vibration element 22 is formed from an AT-cut vibration piece made of quartz that is a piezoelectric crystal. The second cavity 18 accommodates a tuning fork type vibration element (second piezoelectric vibration element) 26 whose frequency-temperature characteristic shows a quadratic curve. In the case of the embodiment, the tuning fork type vibration element 26 is composed of a quartz tuning fork type vibration piece.
[0015]
In the embodiment, the AT cut vibration element 22 has a longitudinal direction corresponding to the longitudinal direction of the package body 12. On the other hand, the tuning fork type vibration element 26 is arranged so that the longitudinal direction is the width direction of the package body 12. However, the arrangement state of the piezoelectric vibration element is not limited to this, and the AT cut vibration element 22 and the tuning fork type vibration element 26 may be arranged side by side so that the longitudinal directions thereof coincide.
[0016]
As shown in FIG. 2, the package main body 12 has two intermediate sheets 30 and 32 laminated on a base sheet 28, and an upper end sheet 34 laminated thereon. These sheets 28, 30, 32, and 34 are all made of ceramic. The intermediate sheets 30 and 32 are provided with cutout portions 36 and 38 that form the first cavity 16. These cut-out portions 36 and 38 form an arrangement space 37 of the integrated circuit 24. The upper end sheet 34 is formed with a first cutout portion 40 that forms a part of the first cavity 16. The first cutout portion 40 is formed larger than the cutout portions 36 and 38 of the intermediate sheets 30 and 32, and serves as an arrangement space 41 for the AT cut vibration element 22. That is, the AT-cut vibration element 22 is joined to the upper surface 42 of the intermediate sheet 32 exposed by the first cutout portion 40 of the upper end sheet 34 in a cantilever shape with the conductive adhesive 44. The depth of the arrangement space 37 formed by the intermediate sheets 30 and 32 is larger than the thickness of the integrated circuit 24, and the integrated circuit 24 contacts the AT-cut vibration element 22 arranged in the cutout portion 40 of the upper end sheet 34. I'm not going to do that.
[0017]
The upper end sheet 34 has a second cut-out portion 46 that forms the second cavity 18 above the intermediate sheet 32. And the upper end sheet | seat 34 is formed with the partition part 14 which partitions these in the boundary part of the 1st cut-out part 40 and the 2nd cut-out part 46. As shown in FIG. Accordingly, the first cavity 16 and the second cavity 18 are isolated from each other when the lid is joined onto the package body 12.
[0018]
Sealing holes 48 and 50 are formed in the base sheet 28 and the intermediate sheet 30 at positions corresponding to the central portion of the second cavity 18. Further, the intermediate sheet 32 is provided with through holes 52 concentric with the sealing holes 48 and 50, and the second cavity 18 and the sealing hole 50 are communicated with each other. For this reason, the second cavity 18 communicates with the outside through the through hole 52 and the sealing holes 50 and 48 even if the upper part is sealed by the lid. The sealing holes 48 and 50 are for vacuum-sealing the second cavity 18 and are filled with a sealing material (not shown) such as a gold-tin alloy in a vacuum, as will be described later. The through hole 52 has a smaller diameter than the sealing holes 48 and 50 so that the sealing material filled in the sealing holes 48 and 50 does not flow into the second cavity 18.
[0019]
As shown in FIG. 1, the tuning fork type vibration element 26 disposed in the second cavity 18 includes a base portion 54 and a pair of vibrating arms 56. As shown in FIG. 2, each vibrating arm 56 has grooves 58 formed on the upper and lower surfaces of the base side, and has a substantially H-shaped cross section. The tuning fork type vibration element 26 is formed with excitation electrodes (not shown) on the inner and outer surfaces of the vibrating arms 56 and the side surfaces of the grooves 58, thereby improving the excitation efficiency and reducing the size. . The second cavity 18 is provided with a recess 60 on the tip end side of the vibrating arm 56 of the tuning fork type vibration element 26. The recess 60 is for preventing the tip of the vibrating arm 56 from colliding with the bottom surface of the second cavity 18 when the electronic device incorporating the piezoelectric device 10 is removed, as shown in FIG. As described above, the intermediate sheet 32 is formed by a cut-out portion. The intermediate sheet 32 has a mount portion on the upper surface opposite to the concave portion 60 in the second cavity 18, and the base portion 54 of the tuning fork type vibration element 26 is joined to the mount portion by the conductive adhesive 62. It is.
[0020]
The package main body 12 has a wiring pattern formed between the sheets constituting the package main body 12. On the upper surface of the intermediate sheet 32, as shown in FIG. 4, a pair of AT electrode patterns 64 and a pair of tuning fork electrode patterns 66 are formed in a portion exposed in the first cavity 16. is there. The AT electrode pattern 64 and the tuning fork electrode pattern 66 are provided substantially symmetrically on both sides of the arrangement space 37 of the integrated circuit 24. Further, the AT electrode pattern 64 is electrically connected to the electrode pattern (not shown) of the AT cut vibration element 22 through the AT wiring pattern 68 formed on the upper surface of the intermediate sheet 32 and the conductive adhesive 44. It is. Similarly, the tuning fork electrode pattern 66 is electrically connected to the tuning fork type vibration element 26 electrode pattern via the tuning fork wiring pattern 70 formed on the upper surface of the intermediate sheet 32 and the conductive adhesive 62.
[0021]
The integrated circuit 24 arranged in the first cavity 16 is fixed to the upper surface of the base sheet 28 which is the bottom of the arrangement space 37 with the active surface facing up. The integrated circuit 24 includes an oscillation circuit 72 for the AT cut vibration element 22 and an oscillation circuit 74 for the tuning fork type vibration element 26. In the case of the embodiment, these oscillation circuits 72 and 74 are provided apart from each other in the width direction in the integrated circuit 24 so that they do not affect each other. The oscillation circuits 72 and 74 are electrically connected to excitation pads 78 and 80 provided on the surface of the integrated circuit 24. The excitation pad 78 and the AT electrode pattern 64, and the excitation pad 80 and the tuning fork electrode pattern 66 are connected by a wire 82.
[0022]
In the case of the embodiment, the oscillation frequency of the AT cut vibration element 22 is 48.0 MHz, and the oscillation frequency of the tuning fork type vibration element 26 is 32.768 kHz for a watch. As shown in FIG. 5, the integrated circuit 24 has an amplifier 84 that amplifies the 32.768 kHz clock signal output from the oscillation circuit 74, and the output side of the amplifier 84 is connected to the output terminal (pad) OUT1. It is. Further, the integrated circuit 24 includes a frequency synthesizer (frequency synthesis circuit) 86 including a PLL circuit, and a frequency divider circuit 88, which are connected in parallel to the output side of the oscillation circuit 72. In the case of the embodiment, the frequency synthesizer 86 has three types of TV video clock signals (video clock signal) from 28.0 MHz, 24.54545 MHz, and 24.375 MHz from the 48.0 MHz frequency that is the source oscillation output from the oscillation circuit 72. ) Can be generated. The frequency synthesizer 86 is connected to select terminals S0 and S1, and one of 27.0 MHz, 24.54545 MHz, and 24.375 MHz is selected depending on how the selection signal is input to the select terminals S0 and S1. A video clock signal can be selected and output. The clock signal output from the frequency synthesizer 86 is output to the output terminal OUT2 via the amplifier 90.
[0023]
On the other hand, the output terminal OUT3 of the integrated circuit 24 outputs a clock signal for USB (Universal Serial Bus), which is a serial interface for data transmission, and is connected to the output side of the frequency divider circuit 88 through an amplifier 92. It is. The frequency divider circuit 88 functions as a transmission clock output circuit, and can divide the frequency of 48.0 MHz, which is the source oscillation output from the oscillation circuit 72, into 1/1, 1/2, and 1/4. It has become. The frequency dividing circuit 88 outputs a clock signal for data transmission of 48.0 MHz, 24.0 MHz, or 12.0 MHz by being preset.
[0024]
In the piezoelectric device 10 according to the embodiment thus configured, the AT-cut vibration element 22 is housed in the first cavity 16 together with the integrated circuit 24, and the tuning-fork vibration element 26 is housed in the second cavity 18. A highly accurate piezoelectric device can be obtained. In other words, the AT-cut vibration element 22 made of quartz shows a cubic curve in the frequency temperature characteristic, and a very stable oscillation frequency can be obtained in the normal operating temperature range. Therefore, even if the integrated circuit 24 generates heat, the AT-cut vibration element 22 outputs a clock signal having a highly accurate frequency with a small fluctuation amount of the oscillation frequency.
[0025]
On the other hand, the tuning fork type vibration element 26 shows a quadratic curve in frequency temperature characteristics, and the frequency fluctuation amount in the normal operating temperature range is larger than that of the AT cut vibration element 22. However, in the piezoelectric device 10 according to the embodiment, the tuning fork type vibration element 26 is accommodated in the second cavity 18 that is partitioned from the first cavity 16 by the partition portion 14, and the second cavity 18 is vacuum-sealed. I have to. For this reason, the tuning fork type vibration element 26 is not affected by the heat generated by the integrated circuit 24 and vibrates at a stable oscillation frequency. Therefore, the piezoelectric device 10 can be a highly accurate device with high reliability and stable frequency of each output clock signal.
[0026]
Further, the piezoelectric device 10 of the embodiment is provided with a frequency synthesizer 86 in the integrated circuit 24 so that a plurality of video clock signals having different frequencies can be output. Therefore, when manufacturing clock devices with different video clock signals, it is not necessary to replace and mount piezoelectric vibration elements (AT-cut vibration elements) with different oscillation frequencies, simplifying the management of parts and the manufacturing process. be able to. That is, when the piezoelectric device 10 is assembled in a clock device mounted on a digital camera (not shown) or the like, the select signal output from the control unit of the clock device is input to the select terminals S0 and S1 of the integrated circuit 24, thereby 27.0 MHz. Any video clock signal of 24.54545 MHz or 24.375 MHz can be output arbitrarily.
[0027]
FIG. 6 is a flowchart showing an outline of the manufacturing process of the piezoelectric device 10 described above. First, as shown in step 100 of FIG. 6, the base sheet 28, the intermediate sheets 30 and 32, and the upper end sheet 34 that are ceramic sheets are stacked and sintered to form the package body 12. Each ceramic sheet is preliminarily formed with a wiring pattern, a cutout portion, a sealing hole, and the like. In addition, a layer of low-melting glass 20 is provided on the upper end surface of the package body 12 in order to join the lid.
[0028]
Next, an adhesive is applied to the bottom surface of the first cavity 16 formed in the package body 12, and the integrated circuit (IC) 24 is adhered and mounted in the first cavity 16 as shown in Step 101. Die attach. Thereafter, wire bonding for electrically connecting the pads of the integrated circuit 24 and the wiring pattern of the package body 12 by a gold wire or the like is performed (step 102). Further, the AT cut vibrating element 22 is mounted (mounted) in the first cavity 16 using a conductive adhesive (step 103). Then, the package body 12 on which the AT cut vibration element 22 is mounted is carried into a vacuum container, and the frequency of the AT cut vibration element 22 is adjusted (step 104). That is, the electrode film formed thick on the surface of the AT-cut vibration element 22 is etched with plasma of an etching gas, and the oscillation frequency is adjusted by thinning the electrode film.
[0029]
Next, as shown in step 105, after cleaning the package body 12 on which the AT cut vibration element 22 is mounted, the tuning fork type vibration element 26 is mounted (mounted) in the second cavity 18 using a conductive adhesive. (Step 106). Thereafter, a glass lid is placed on the package body 12, the low melting point glass 20 is melted, the lid is joined to the package body 12, and the upper surface of the package body 12 is sealed (step 107). The sealing with the lid may be performed in a nitrogen atmosphere or in a vacuum. Moreover, the lid | cover should just be formed with the translucent material which permeate | transmits a laser beam at least the part corresponding to the 2nd cavity 18. FIG.
[0030]
Next, as shown in step 108, the second cavity 18 of the package body 12 is vacuum-sealed. That is, the package body 12 is carried into a vacuum container, and in the vacuum, the sealing holes 48 and 50 provided in the base sheet 28 and the intermediate sheet 30 are filled with a molten sealing material such as a gold-tin alloy and sealed. The sealing material is cooled to close the sealing holes 48 and 50. Thereafter, the frequency of the tuning fork type vibration element 26 is adjusted (step 109). This frequency adjustment is performed by irradiating the tuning fork type vibration element 26 with laser light through a glass lid and evaporating a weight such as gold (not shown) provided at the tip of the vibrating arm 56 with the laser light. Thus, in the embodiment, since the frequency adjustment of the tuning fork type vibration element 26 is performed after the second cavity 18 is vacuum-sealed, the fluctuation of the oscillation frequency of the tuning fork type vibration element 26 after the frequency adjustment is performed. The frequency control with high accuracy is possible. Further, since the weight is evaporated in the vacuum-sealed second cavity 18, it is possible to prevent the metal constituting the weight from being scattered around.
[0031]
Thereafter, as shown in step 110, the electrical characteristics of the piezoelectric device 10 are inspected. In this electrical property inspection process, a product satisfying a predetermined standard is selected as a finished product, and a product out of the standard is selected and removed as a defective product.
[0032]
FIG. 7 shows another embodiment of the integrated circuit. The integrated circuit 24a of this embodiment has two frequency synthesizers 86 and 86a. These frequency synthesizers 86 and 86 a are connected in parallel to the output side of the oscillation circuit 72 of the AT cut vibration element 22 together with the frequency dividing circuit 88. These frequency synthesizers 86 and 86a have the same specifications, and both are based on the 48.0 MHz signal output from the oscillation circuit 72, and the video clock signals of 27.0 MHz, 244.5545 MHz, and 24.375 MHz. Can be generated and output.
[0033]
The frequency synthesizer 86 is connected to select terminals S0 and S1, and outputs one of the three types of video clock signals to the output terminal OUT2 via the amplifier 90 in response to a selection signal input to the select terminals S0 and S1. The frequency synthesizer 86a is connected to select terminals S2 and S3. Depending on the state of the selection signal input to these select terminals, one of the video clock signals of 27.0 MHz, 244.5545 MHz, and 24.375 MHz is selected. Is output. The video clock signal output from the frequency synthesizer 86a is output to the output terminal OUT3 via the amplifier 90a. The frequency dividing circuit 88 divides the 48.0 MHz signal output from the oscillation circuit 72 and outputs a data transmission clock signal for USB to the output terminal OUT4 via the amplifier 92. Other configurations are the same as those of the integrated circuit 24 described above. In FIG. 7, a 24.54545 MHz video clock signal is output to the output terminal OUT2, a 24.375 MHz video clock signal is output to the output terminal OUT3, and a 48.0 MHz clock signal is output to the output terminal OUT4. The case is shown.
[0034]
In addition, the said embodiment shows the one aspect | mode of this invention, and is not limited to this. For example, in the above embodiment, the case where two frequency synthesizers are provided has been described, but it is also possible to provide three or more frequency synthesizers. In this case, each frequency synthesizer may generate different clock signals, or each frequency synthesizer may be configured to generate three or more clock signals. In the embodiment, the case where the first piezoelectric vibration element is the AT-cut vibration element 22 has been described. However, the first piezoelectric vibration element may be a surface acoustic wave (SAW) vibration element. Furthermore, in the above-described embodiment, the case where two cavities are provided in the package body has been described, but it is also possible to provide three or more cavities.
[0035]
As described above, according to the present invention, the frequency temperature characteristic in which the oscillation frequency is likely to change due to a temperature change shows a quadratic curve for a package in which a plurality of cavities partitioned from each other are formed. A configuration in which the piezoelectric vibration element is housed in a second cavity partitioned from the first cavity housing the integrated circuit is employed. Therefore, the second piezoelectric vibration element is not affected by the heat generated by the integrated circuit, and can be a highly reliable and highly accurate piezoelectric device.
[Brief description of the drawings]
FIG. 1 is a perspective view of a piezoelectric device according to an embodiment with a lid removed.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3 is a cross-sectional view taken along line BB in FIG.
FIG. 4 is a diagram showing a part of a wiring pattern according to the embodiment.
FIG. 5 is a block diagram of an integrated circuit according to the embodiment.
FIG. 6 is a flowchart of a method for manufacturing a piezoelectric device according to an embodiment.
FIG. 7 is a block diagram illustrating another embodiment of an integrated circuit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ...... Piezoelectric device, 12 ...... Package body, 14 ...... Partition part, 16 ...... 1st cavity, 18 ...... 2nd cavity, 22 ...... 1st piezoelectric vibration element (AT) (Cut vibration element), 24, 24a ......... integrated circuit, 26 ......... second piezoelectric vibration element (tuning fork type vibration element), 48, 50 ......... sealing hole, 52 ......... through hole, 72, 74 ... Oscillator circuit 86, 86a... Frequency synthesis circuit (frequency synthesizer) 88... Transmission clock output circuit (frequency divider circuit) S0 to S3.

Claims (9)

A package formed with a plurality of cavities partitioned from each other;
Of the plurality of cavities, a first piezoelectric vibration element and an integrated circuit in which a frequency temperature characteristic housed in the first cavity forms a cubic curve,
Of the plurality of cavities, a second piezoelectric vibration element in which a frequency temperature characteristic accommodated in a second cavity forms a quadratic curve;
A piezoelectric device characterized by comprising: The piezoelectric device according to claim 1.
The first piezoelectric vibration element comprises an AT-cut vibration piece of piezoelectric crystal,
The second piezoelectric vibration element is composed of a tuning fork type vibration piece.
A piezoelectric device characterized by that. The piezoelectric device according to claim 2, wherein
The piezoelectric device is characterized in that the second cavity is vacuum-sealed. The piezoelectric device according to any one of claims 1 to 3,
The integrated circuit includes a frequency synthesis circuit that generates a video clock signal based on an oscillation frequency of the first piezoelectric vibration element, and a transmission clock output circuit that outputs a data transmission clock signal. Piezoelectric device. The piezoelectric device according to claim 4, wherein
The frequency synthesis circuit is capable of generating a plurality of video clock signals,
The integrated circuit has a select terminal for inputting a selection signal capable of arbitrarily selecting one of the plurality of video clock signals to the frequency synthesis circuit.
A piezoelectric device characterized by that. The piezoelectric device according to any one of claims 1 to 5,
The integrated circuit includes an oscillation circuit corresponding to each of the first piezoelectric vibration element and the second piezoelectric vibration element, and the oscillation circuits are provided apart from each other. Mounting an integrated circuit in a first cavity of a package body having a plurality of cavities partitioned from each other;
Mounting a first piezoelectric vibration element whose frequency temperature characteristic forms a cubic curve in the first cavity;
Adjusting the oscillation frequency of the first piezoelectric vibrating element;
Mounting a second piezoelectric vibrating element having a quadratic frequency frequency characteristic in a second cavity provided in the package body and partitioned from the first cavity;
A step of covering the first cavity and the second cavity and bonding a lid having a light transmitting property at least in a portion corresponding to the second cavity to the package body;
Sealing a sealing hole communicating the second cavity with the outside;
Irradiating the second piezoelectric resonator element with laser light through the lid and adjusting the frequency of the second piezoelectric resonator element;
A method for manufacturing a piezoelectric device, comprising: A clock device comprising the piezoelectric device according to claim 4. A first cavity that houses the first piezoelectric resonator element and the integrated circuit whose frequency-temperature characteristics form a cubic curve;
A second cavity that houses the second piezoelectric vibration element that is partitioned from the first cavity and has a quadratic frequency-frequency characteristic;
A package for a piezoelectric device, comprising:

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