JPH0621741A - Direct bonding method of quartz and quartz device - Google Patents

Abstract

PURPOSE:To provide the direct bonding method of quartz and quartz device by which a structure with a stable resonance frequency against temperature is easily constituted. CONSTITUTION:Quartz chips 101, 102 are directly bonded to be integrated to form an adhered quartz chip 104. Exciting electrodes 103 are placed across from each other via the adhered quartz chip 104. The relation between the respective crystal axes of the quartz chips 101, 102 and the thickness are set so that the resonance frequency versus temperature characteristics for each other are cancelled. Through the constitution, the resonance frequency of the adhered crystal chip 104 is made stable in temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal piece and a method for directly bonding the crystal piece without inclusions such as an adhesive, and a crystal device that can be used in mobile communication equipment such as a mobile phone.

[0002]

2. Description of the Related Art In recent years, with the spread of mobile communication devices such as mobile phones, the demand for crystal devices used as a reference frequency source and filters for these devices has increased.

An example of a conventional crystal device will be described below with reference to the drawings.

FIG. 32 is a side view of an essential part showing each example of the configuration of a conventional crystal oscillator. In FIG. 32, 401 and 403 are crystal pieces, and 402 and 404 are excitation electrodes. The crystal pieces 401 and 403 are processed into a disk or lens shape by a mechanical and chemical processing method.

Crystal pieces 401, 403 made of such a piezoelectric material
When an electric field is applied to the excitation electrodes 402 and 404 that are installed opposite to each other via, the quartz pieces 401 and 403 are distorted and can resonate at a frequency determined by the elastic constant and the shape dimension of the quartz. Conventionally, the crystal unit used in the mobile communication device is A
It is called a T-cut crystal oscillator (cutout angle is around 54.75 °), and it is a oscillator that utilizes thickness shear vibration. Here, the cutting angle is an angle formed by the normal line of the plate surface and the Z axis of the quartz crystal. In contrast to this AT cut, the one with a cutting angle around 135.00 ° is called a BT cut crystal unit. The resonance frequency-temperature characteristic of the AT-cut crystal unit is determined by the cutting angle, and a cubic curve is shown in FIG. 33 to show the resonance frequency-temperature characteristic of the conventional AT-cut crystal piece.
Amount of frequency deviation in the temperature range of up to 50 ° C (horizontal axis)
On the (vertical axis), frequency stability of ± 1.0 ppm is obtained. (For example, 'Piezoelectricity'; Walter Guyton Caddy, Dover Publishing Company ('Piezoelectricit
y '； edited by Walter GuytonCADY, Dover Publ., Inc.
), Or'On the adiabatic elastic constant of quartz and its temperature characteristics'; H. Ariga, Tokyo Institute of Technology, Gakuho, December 31, 1931, p. 88). Further, as a method of increasing frequency stability, a method of growing or mounting a substance having a different linear expansion coefficient on a quartz substrate (JP-A-55-138914) or (JP-A-55-158718, JP-A-56-61899). Is proposed.

Further, as shown in FIG. 32 (a), the quartz piece 401 may be formed in a shape (convex processing) in which the central portion is thicker than the peripheral portion like an optical lens (convex processing), or as shown in FIG. 32 (b). As shown in the drawing, elastic vibrations are confined in the central portion to increase the Q value in a configuration in which the central portion of the excitation electrode is thickened. (For example, JP-A-2-260910).

In addition to the convex processing, there is bevel processing in which the corners of one or both sides of the crystal piece are dropped.

As a method of extracting a plurality of vibrations from one crystal unit, a method of partially thinning a crystal piece by a chemical polishing method, a method of simultaneously using a fundamental mode and a higher order mode, and the like can be considered. .

Next, a conventional crystal oscillator, an analog temperature-compensated crystal oscillator, and a digital temperature-compensated crystal oscillator will be described with reference to the drawings.

The crystal oscillator is an oscillator whose frequency is stabilized by using a crystal oscillator having a Q of about 100,000 as a resonance element. Therefore, the output frequency-temperature characteristic of the crystal oscillator depends on the resonance frequency-temperature characteristic of the crystal unit, and when the conventional AT-cut crystal unit is used, as shown in FIG. Frequency stability of ± 1.0ppm can be obtained in the temperature range. However, a crystal oscillator used in a mobile phone is required to have a frequency stability of ± 1.0 ppm at -30 ° C to 80 ° C, and a temperature compensation circuit is required to satisfy the requirement. A crystal oscillator provided with a temperature compensating circuit is called a temperature compensating crystal oscillator and can be roughly classified into an analog system and a digital system.

34 and 35 show typical circuit configurations of a conventional analog temperature-compensated crystal oscillator and digital temperature-compensated crystal oscillator, respectively.

In FIG. 34, 411 is an oscillation circuit, 412 is an output terminal, 413 is a crystal oscillator, and 414 is a temperature compensation circuit. The temperature compensating circuit 414 is configured by using a temperature sensitive element such as a thermistor, a capacitive element such as a capacitor or a varactor diode, and a resistor. The reactance changes depending on the temperature, and the temperature of the reactance (resonance frequency) of the crystal unit 413 is changed. It compensates for changes caused by and stabilizes the output frequency.

In FIG. 35, 421 is a temperature sensor, 422 is an A / D converter, 423 is a storage device, 424 is a variable reactance circuit, 425 is an oscillation circuit, and 426 is a crystal oscillator. 427 is a digitally controlled crystal oscillator including the variable reactance circuit 424, the oscillation circuit 425 and the crystal oscillator 426. The output signal of the temperature sensor 421 is stored in the storage device 423 as A
Data in which the digital signal converted by the / D converter 422 and the control signal of the variable reactance circuit 424 are associated with each other is stored in advance. As a result, the reactance of the variable reactance circuit 424 changes according to the temperature change,
The resonance frequency-temperature characteristic of the crystal unit 426 is compensated to stabilize the oscillation output frequency.

Further, in order to suppress the temperature difference due to the difference in the installation location of the temperature sensor 421 and the crystal oscillator 426 and the difference in the thermal time constant, one crystal piece is used to generate the fundamental wave and the higher order overtone or the secondary vibration. A method of taking out is considered (for example, JP-A-2-170607 and JP-A-2-174407).

Next, an example of a conventional crystal filter will be described with reference to the drawings.

FIG. 36 shows the structure of a conventional crystal filter, (a) is a perspective view and (b) is a sectional view taken along the line aa 'in (a). In FIG. 36, 431 is a crystal piece, 432, 43
Reference numerals 3 and 434 denote electrodes, which are installed opposite to each other via a crystal piece 431. Further, the crystal in the portion where the electrodes 432, 433 and 434 face each other is thinner than the peripheral portion.

The operation of the crystal filter configured as described above will be described below.

The electrode 434 is normally grounded, and the remaining two electrodes 432 and 433 serve as electrodes for inputting and outputting electric signals. For example, when an electric signal is input to the electrode 432, the crystal piece 431 resonates at a frequency determined by its thickness and elastic constant. This resonance is mechanically transmitted in the quartz piece 431, which results in the electrode 433 and
An electric field is generated between the electrodes 434 and 434, and an electric signal can be taken out from the electrode 433. That is, the bandpass filter has a resonance frequency determined by the thickness of the crystal piece 431 and the elastic constant. Further, in this structure, the central portion is thinned by the chemical polishing method in order to increase the resonance frequency. (For example, the 39th Annual Frequency Control Symposium Bulletin, 481-4
Page 85, Fabrication of VHF band monolithic crystal filter by ion milling method (Proc. 39th Ann. Frequency Cont
orolSymposium, pp.481-485'VHF MONOLITHIC CRYSTAL
FILTERS FABRICATED BYCHEMICAL MILLING '))

[0019]

However, as described above, the three-dimensional processing is difficult and the processing time is long only by processing the crystal piece only by the mechanical and chemical polishing methods. Had a point.

Further, there is a limit to improving the stability of the crystal unit only by the cutting angle, and in the method of growing or mounting different substances on the crystal substrate, these substances cause elastic vibration of the crystal. There is a problem that it becomes a blocking resistor and deteriorates the Q of the crystal unit.

Further, as a method of increasing Q, the method of convex working a quartz piece has a problem that the precision of the resonance frequency is lowered, while the method of vapor-depositing electrode films of different sizes is time-consuming. It had a problem such as being damaged.

Further, in the method of extracting two vibrations by using the fundamental mode and the higher order mode of one crystal piece, it is not possible to set the resonance frequency and the temperature characteristic of each separately.

Further, since the resonance frequency of the crystal unit has a temperature characteristic, the reference oscillator using the crystal unit requires a temperature compensating device such as a temperature compensating circuit or a constant temperature bath. The former is a method of changing the impedance of the temperature compensation circuit so as to cancel the resonance frequency-temperature characteristic of the crystal oscillator by using the thermistor or the like for the oscillation frequency, and the latter is the crystal oscillator and the oscillation circuit in a thermostatic chamber. Is a method of keeping these at a constant temperature and keeping the oscillation frequency constant.

First, according to the former method, there is a problem that a special temperature characteristic control circuit is required, the number of circuit components is large, and adjustment work is required, resulting in an increase in cost. On the other hand, in the latter method, the volume occupied by the constant temperature bath is large and the current consumption is large.

Since the resonance frequency of the crystal unit is determined by the thickness of the crystal piece, one crystal unit has one
If only one resonance frequency can be obtained and multiple resonance frequencies are required, it is necessary to prepare crystal oscillators corresponding to the number, resulting in downsizing of equipment that requires multiple frequencies. It was difficult to reduce the price.

Also in the case of a crystal oscillator, like the above-mentioned crystal oscillator, a temperature compensating device such as a temperature compensating circuit or a constant temperature bath is incorporated in the crystal oscillator. First, according to the former method, a special temperature characteristic is obtained. There is a problem that a control circuit is required, the number of circuit components is large, and adjustment work is required, resulting in an increase in cost. On the other hand, in the latter method,
There is a problem that the volume occupied by the constant temperature bath is large and the current consumption is further increased.

Further, in the analog temperature-compensated crystal oscillator using a thermistor or the like, separate compensating circuits for high temperature and low temperature are required, so that the number of circuit components is large, the adjustment work becomes complicated, and the cost becomes high. Had.

On the other hand, in the digital temperature compensation crystal oscillator,
Since a temperature sensor and a crystal oscillator for oscillation are separately provided, proper temperature compensation cannot be performed unless the temperature difference caused by the difference in thermal time constant between them and the difference in installation location is suppressed. There are problems such as the need for a large capacity memory and the high adjustment cost.

Further, in order to suppress the temperature difference between the temperature sensor and the crystal oscillator, the method of extracting the fundamental wave and the higher-order overtone or the secondary vibration with one crystal oscillator is a method of extracting the fundamental wave and the higher-order wave over a wide temperature range. It is essential to independently, selectively, and stably excite each overtone or sub-vibration. For that purpose, it is necessary to determine the design of the crystal unit and the bias and feedback capacitance of the oscillation circuit very strictly. In some cases, it is necessary to perform temperature compensation on the bias and the feedback capacitance of the oscillation circuit, which has a problem that the circuit scale is large and very complicated and difficult to make.

Further, the crystal filter has a problem that the stability of the frequency-temperature characteristic is low, and that it is difficult to miniaturize because of the planar structure.

In view of the above problems, the present invention is a method of directly joining a crystal piece and a crystal piece without an adhesive or the like, a crystal resonator having a resonance frequency-temperature characteristic superior to that of the conventional one, and a structure for increasing Q. Crystal oscillator that can be easily configured, a crystal oscillator that can extract multiple vibrations with arbitrary resonance frequency and temperature characteristics by itself, a crystal oscillator with excellent oscillation frequency-temperature characteristics, small number of parts, small size, high precision It is an object of the present invention to provide a low-cost analog temperature-compensated crystal oscillator and digital temperature-compensated crystal oscillator capable of temperature compensation, a crystal filter having stable frequency-temperature characteristics, and a small crystal filter.

[0032]

In order to solve the above-mentioned problems, the method for directly joining crystals of the present invention is such that the surfaces are mirror-polished and washed with a detergent, followed by washing with isopropyl alcohol and sulfuric acid and hydrogen peroxide solution. Cleaning with a mixture of
Alternatively, cleaning with isopropyl alcohol and drying, or cleaning with isopropyl alcohol and cleaning with hydrogen fluoride water or ammonium fluoride water, followed by heat drying, the surface is smooth and flat and terminated with hydroxyl groups. After contacting the crystal pieces treated so as to be in a state without inclusions, and by adhering with the adhesive force acting between the hydroxyl groups on the surface, the quartz crystal to obtain a stronger adhesive force It is characterized in that the heat treatment is performed within a temperature range in which no phase transition occurs.

Further, the crystal unit of the present invention includes a bonded crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. Then, the excitation electrodes are arranged opposite to each other.

The crystal oscillator, the analog temperature-compensated crystal oscillator and the digital temperature-compensated crystal oscillator of the present invention are:
A crystal resonator having a structure in which excitation electrodes are installed to face each other through a bonded crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. Is provided as a resonance element.

Further, in the digital temperature-compensated crystal oscillator of the present invention, at least two crystal pieces having a desired cut-out angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle, and Quartz vibration in which first and second vibrating sections are integrated by constructing laminated crystal pieces having two different thicknesses, and setting two sets of excitation electrodes facing each other through the desired thickness of the laminated crystal pieces. It has a child.

Further, the crystal filter of the present invention has a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. , At least 2
A structure in which a pair of opposing electrodes is formed, or at least one crystal piece having electrodes formed on both surfaces and at least one crystal piece having electrodes formed on one surface thereof are superposed so that the crystal pieces and the electrodes alternate, and, The crystal pieces are directly connected to each other at a portion where the electrodes do not intervene.

[0037]

According to the present invention, by the above method, an initial bonding state is obtained through hydrogen bonding between hydroxyl groups bonded to a flat and smooth quartz surface, and heat treatment of this causes the elimination reaction of hydroxyl groups to occur. , Crystal pieces can be directly joined without interposing foreign matter.

Further, according to the above configuration, (1) since the directly bonded quartz pieces vibrate as a unit,
Since the resonance frequency-temperature characteristics of the respective crystal pieces cancel each other out, a temperature stable crystal oscillator and crystal filter can be realized.

(2) By direct bonding, a three-dimensional structure in which the thickness of the vibrating portion and the thickness of the supporting portion are different can be realized easily and in a short time, and a high Q crystal oscillator can be realized.

(3) Since the directly bonded quartz pieces vibrate together, a quartz resonator capable of extracting a plurality of vibrations having an arbitrary resonance frequency and temperature characteristic can be realized.

(4) Since a temperature stable crystal oscillator can be used, a crystal oscillator having excellent frequency-temperature characteristics can be realized.

(5) Since a temperature stable crystal oscillator can be used, the temperature compensation circuit can be simplified, the number of bits can be reduced, and the current can be reduced. A temperature-compensated crystal oscillator can be realized.

(6) Since the temperature sensor and the crystal oscillator for oscillation can be integrally configured, a compact and highly accurate digital temperature-compensated crystal oscillator can be realized.

(7) Resonance can be three-dimensionally coupled by direct bonding, and a small crystal filter can be realized.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention (an invention according to claim 1) will be described below with reference to the drawings.

FIG. 1 shows a flow chart of a method for directly bonding quartz according to the first embodiment of the present invention. The direct crystal bonding procedure is (1) mirror polishing, (2) cleaning,
These are (3) drying, (4) contact, and (5) heat treatment.

A detailed description will be given below with reference to the flowchart of FIG.

First, the mirror-polishing step (1) is carried out to make the surfaces of the plurality of crystal pieces smooth and flat with irregularities on the order of several hundred angstroms.

Furthermore, in the cleaning step (2), a mirror polishing step
In order to remove dirt and abrasive particles attached in (1), perform wet scrubbing with a detergent and isopropyl alcohol, and then with a mixture of sulfuric acid and hydrogen peroxide solution. . In this state, the crystal surface is in a state in which hydroxyl groups are bonded to the dangling bonds of the crystal surface atoms, and these hydroxyl groups are hydrogen-bonded to surrounding water molecules.

Next, in the drying step (3), in order to remove water molecules that are hydrogen-bonded to the surface of the crystal piece, the crystal piece is heated and dried in an environment where foreign matters such as dust do not adhere. For example, 300 ℃
Hold for 1 hour. The surface of the crystal piece on which the procedure up to this point has been completed is terminated with a hydroxyl group that is dangling-bonded to the surface atoms of the crystal piece.

Next, in the contacting step (4), when the crystal pieces having the above-mentioned surface state are brought into contact with each other, the hydroxyl groups bonded to the surface of one of the crystal pieces and the crystal piece facing the hydroxyl group are contacted at the contact surface. The hydroxyl groups bonded to the surface are hydrogen-bonded to each other, and by this hydrogen bond, an initial weak bonding state between the crystal pieces can be obtained without inclusions such as an adhesive.

Further, in the heat treatment step (5), for the purpose of improving the mechanical and electrical characteristics, the crystal pieces initially bonded to each other are heat-treated within a temperature range in which the crystal crystals do not undergo phase transition. For example, it may be performed at 500 ° C. under atmospheric pressure. Due to the heat treatment, the hydroxyl groups that contributed to the initial bonding of the crystal pieces are dehydrated and condensed, some are released to the outside through the bonding interface of the crystal pieces, and some are diffused into the crystal, for example. The pieces are firmly joined directly.

It should be noted that removing the water molecules by introducing a drying step before contacting the quartz pieces prevents the water molecules from undergoing a desorption reaction and gasification in the subsequent heat treatment step, which is better. This is because such a direct bonded state can be obtained and the yield of the direct bonded quartz is improved.

As described above, according to the first embodiment,
The crystal pieces can be mechanically and firmly bonded directly to each other. Furthermore, when elastic vibration is electrically excited to the directly bonded crystal piece, the elastic vibration continuously propagates at the direct bonding interface, and the directly bonded crystal piece integrally performs elastic vibration. For example, the resonance frequency in the case of directly bonding two crystal pieces whose resonance frequency in the thickness shear vibration mode is represented by (Equation 1) can be represented by (Equation 2), and the same crystal piece can be directly joined. For example, 1 with a total thickness of two crystal pieces
It will have the same resonance frequency as one piece of crystal.

[0055]

[Equation 1]

However, t _n : thickness of the crystal piece n C _n : elastic constant of the crystal piece n ρ: density of the crystal n: 1, 2

[0057]

[Equation 2]

However, m is the number of the directly bonded crystal piece, and since the direct bonding interface does not hinder the elastic vibration, the Q of the directly bonded crystal piece does not deteriorate.

A second embodiment of the present invention (an invention according to claim 2) will be described below with reference to the drawings.

FIG. 2 shows a flow chart of a direct bonding method for quartz in the second embodiment of the present invention. Direct crystal bonding means are (1) mirror polishing, (2) cleaning,
These are (3) drying, (4) contact, and (5) heat treatment.

The basic procedure (steps (1) to (5)) and effects of the second embodiment of the present invention are similar to those of the first embodiment of the present invention, but the first embodiment of the present invention is the same. In the second embodiment, in the washing step (2), by using the drying using isopropyl alcohol as the preliminary drying before the heating and drying step (3), foreign matters such as dust adhering to the crystal surface after washing can be reduced. can do.

A third embodiment of the present invention (an invention according to claim 3) will be described below with reference to the drawings.

FIG. 3 shows a flow chart of a method for directly joining crystals according to the third embodiment of the present invention. Direct crystal bonding means are (1) mirror polishing, (2) cleaning,
These are (3) drying, (4) contact, and (5) heat treatment.

The basic procedure and effects of the third embodiment of the present invention are the same as those of the first embodiment of the present invention, but in the third embodiment of the present invention, the cleaning step is performed.
In (2), by cleaning with hydrogen fluoride water or ammonium fluoride water, the crystal surface can be chemically polished, and a cleaner surface can be obtained.

The first, second and third aspects of the present invention
In each of the examples, a step of holding for a long time in a dry atmosphere may be used instead of the heat drying.

Hereinafter, fourth and fifth embodiments of the present invention will be described.
(Invention of Claim 4) will be described with reference to the drawings.

FIG. 4 shows a crystal resonator according to a fourth embodiment of the present invention. (A) is a side view, (b) is a plan view of (a) from above, and (c) is a laminated view. It is an example figure of the resonance frequency-temperature characteristic of the crystal piece. 4 (a) and (b),
101 and 102 are crystal pieces, 103 is an excitation electrode, and 104 is a laminated crystal piece. P is the normal to the plate surfaces of both the crystal pieces 101 and 102, X ₁ , Y ₁ and Z ₁ are the crystal axes of the crystal piece 101, and X ₂ , Y ₂ and Z ₂ are the crystal axes of the crystal piece 102. ,
θ is the angle formed by P and Z ₁ , and φ is the angle formed by P and Z ₂ .

The crystal pieces 101 and 102 are directly joined and integrated by the direct joining method according to the first to third embodiments so that X ₁ and X ₂ coincide with each other to form a bonded crystal piece 104. In addition, the excitation electrode 103 is a laminated crystal piece 104.
Are installed opposite to each other.

The operation of the crystal resonator having the above structure will be described below.

The crystal pieces 101 and 102 apply an electric field to the excitation electrode 103.
When (electric field in P direction) is applied, thickness slip strain occurs,
Resonance frequencies f ₁ and f ₂ are represented by (Equation 1) using respective thicknesses and elastic constants.

Further, since the quartz pieces 101 and 102 are directly joined, elastic vibration is continuous at the joining surface, and at this time, the resonance frequency f of the laminated quartz piece 104 is expressed by (Equation 2). Therefore, the temperature characteristic of the bonded crystal piece 104 is determined by the resonance frequency-temperature characteristic (that is, the cutting angles θ and φ) of the crystal pieces 101 and 102 and the thickness ratio. For example, if the thickness ratio of the crystal piece 101 and the crystal piece 102 is 5: 1 and θ and φ are 55.01 ° (AT cut) and 145.00 ° (BT cut), respectively, as shown in FIG. 4 (c). In the temperature range of 10 to 80 ° C. (horizontal axis), the frequency deviation amount (vertical axis) has a frequency stability of ± 1.0 ppm.

As described above, according to this embodiment, the excitation electrode is formed through the bonded crystal piece in which two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so as to have a desired crystal axis relationship. , The resonance frequency-temperature characteristics of the crystal pieces cancel each other out, and as shown in FIG. 4 (c), it is possible to realize a crystal resonator with a stable resonance frequency over a wide temperature range. .

The fifth embodiment of the present invention will be described below with reference to the drawings.

5A and 5B show a crystal resonator according to a fifth embodiment of the present invention. FIG. 5A is a side view and FIG. 5B is a plan view of FIG. In FIG. 5, 111, 112 and
Reference numeral 113 is a crystal piece, 114 is an excitation electrode, and 115 is a bonded crystal piece. P is a normal to the plate surfaces of all the crystal pieces 111, 112 and 113. Further, X ₁ , Y ₁ and Z ₁ are crystal pieces 111
X ₂ , Y ₂ and Z ₂ are the crystal axes of the quartz piece 112,
₃ , Y ₃ and Z ₃ are crystal axes of the crystal piece 113, and θ, φ and ξ are angles formed by P and Z ₁ , P and Z ₂ and P and Z ₃ , respectively. The crystal pieces 111, 112 and 113 are directly joined and integrated so that X ₁ , X ₂ and X ₃ coincide with each other,
It is a laminated crystal piece 115. Also, the excitation electrode 114
Are installed opposite to each other with a laminated crystal piece 115 interposed therebetween.

The resonance frequency-temperature characteristic of the crystal unit constructed as described above is similar to that of the fourth embodiment.
Depending on the thickness ratio of 1, 112 and 113 and the respective cutting angles θ, φ and ξ, it can be made as desired. Further, compared with the fourth embodiment, when three crystal pieces are directly joined to form a bonded crystal piece, a bonded crystal resonator having a resonance frequency-temperature characteristic with higher stability can be realized. .

The sixth to tenth embodiments of the present invention will be described below.
(Invention of Claim 5) will be described with reference to the drawings.

6A and 6B show a crystal resonator according to a sixth embodiment of the present invention. FIG. 6A is a side view, and FIG. 6B is a plan view of FIG. In FIG. 6, 121 and 122 are crystal pieces, 123 is an excitation electrode, and 124 is a bonded crystal piece. Each of the crystal pieces 121 and 122 has a thick central portion on one side, and is processed (convex processing) toward the end portions. The crystal pieces 121 and 122 have a crystal axis relationship and a thickness ratio as shown in the fourth embodiment (FIG. 4), and are directly bonded and integrated on the side not subjected to the convex processing to form a bonded crystal piece 124. There is. In addition, the excitation electrodes 123 are installed opposite to each other with the bonded crystal piece 124 interposed therebetween.

With the above-described structure, the resonance frequency can be stably maintained over a wide temperature range, and at the same time, the central portion of the bonded crystal piece 124 is thick and goes toward the end portion, as in the fourth embodiment. Since the thickness becomes thinner as a result, the effect of confining elastic vibration in the central portion can be obtained, and a high Q crystal resonator can be realized.

In the present embodiment, the same results can be obtained by using the quartz pieces 121 and 122 which have been subjected to a double-sided convex processing or a processing (beveling) in which one end or both end portions have corners dropped. .

In each of the above-mentioned fourth, fifth and sixth embodiments of the present invention, the cutting angle, thickness, number and the crystal axes of the crystal pieces to be directly bonded to each other to form the bonded crystal piece are set. The relationship is not limited in any way, and the laminated crystal piece can be set so as to have a desired resonance frequency-temperature characteristic.

Also in the vibration modes other than the thickness shear vibration, the desired temperature characteristics can be realized by using the laminated crystal piece as shown in the fourth and fifth embodiments of the present invention.

The seventh to tenth embodiments of the present invention will be described below with reference to the drawings.

FIGS. 7 to 10 show crystal oscillators according to the seventh to tenth embodiments of the present invention, respectively.
In each figure, (a) is a side view and (b) is a plan view of (a) as seen from above.

In the seventh embodiment of FIG. 7, 131 and 1
32 is a crystal piece, 133 is an excitation electrode, 134 and 135 are supporting portions, 1
36 is a vibrating part, and 137 is a laminated crystal piece. The crystal pieces 131 and 132 are directly bonded and integrated in the vibrating portion 136 to form a bonded crystal piece 137. Further, the excitation electrodes 133 are installed opposite to each other via the vibrating section 136.

In the eighth embodiment of FIG. 8, 141 is a crystal piece, 142 is a crystal piece larger than the crystal piece 141, 143 is an excitation electrode, 144 and 145 are support portions, 146 is a vibrating portion, and 147 is It is a laminated crystal piece. The crystal pieces 141 and 142 are directly bonded and integrated so that the centers of the crystal pieces 141 and 142 are substantially coincident with each other to form a bonded crystal piece 147. Also, the excitation electrode 143
Are installed opposite to each other via the vibrating section 146.

In the ninth embodiment of FIG. 9, 151, 152 and 153 are crystal pieces, 154 are excitation electrodes, 155 and 156 are support parts, 157 is a vibrating part, and 158 is a bonded crystal piece. The crystal pieces 152 and 153 are smaller than the crystal piece 151, and are directly bonded and integrated into a bonded crystal piece 158 in the order of bonding shown in FIG. Further, the excitation electrodes 154 are installed opposite to each other via the vibrating section 157.

In the tenth embodiment of FIG. 10, 161, 162 and 163 are crystal pieces, 164 are excitation electrodes, 165 and 166 are support parts, 167 is a vibrating part, and 168 is a bonded crystal piece. The crystal pieces 161, 162, and 163 are directly bonded and integrated into a bonded crystal piece 168 in the bonding order shown in FIG. Further, the excitation electrodes 164 are installed so as to face each other via the vibrating section 167.

In each of the seventh to tenth embodiments configured as described above, when an electric field is applied to the excitation electrode, the vibrating portion causes thickness slip strain, and as shown in (Equation 1) and (Equation 2), In addition, the resonance frequency of the vibrating part is determined by the thickness and elastic constant of each crystal piece. The elastic vibration generated in the vibrating part tries to be transmitted to the end of the bonded crystal piece through the supporting part, but since the thickness of the supporting part is thinner than that of the vibrating part, the elastic vibration is sharp in the supporting part. Decay.

As described above, according to each of the seventh to tenth embodiments, at least two crystal pieces are directly joined to form a thick bonded crystal piece in the central portion, and the thick portion in the central portion is Since the excitation electrode is installed via the elastic electrode, elastic vibration can be confined, and a high-Q crystal oscillator can be easily realized.

The eleventh embodiment of the present invention (the invention according to claim 6) will be described below with reference to the drawings.

11A and 11B show a crystal resonator according to an eleventh embodiment of the present invention. FIG. 11A is a side view and FIG. 11B is a plan view of FIG. In FIG. 11, 171 is a crystal piece having a hole 171a in the center, 172 is a crystal piece, 173 is an excitation electrode, and 174 is a bonded crystal piece. Crystal pieces 171 and 17
The two are directly joined and integrated to form a laminated crystal piece 174. In addition, the excitation electrode 173 is the crystal piece 171 in the central portion.
And 172 are not attached to each other, and are opposed to each other via the crystal piece 172 in the vibrating portion 177. Also, crystal pieces 171 and 172
The supporting portions 175 and 176 are formed in the region where they are directly joined.

In the eleventh embodiment constructed as described above, when an electric field is applied to the excitation electrode 173, the crystal blank 172 causes thickness shear strain, and as shown in (Equation 1) and (Equation 2), The resonance frequency of the vibrating part is determined by the thickness and elastic constant.
The elastic vibration generated in the vibrating portion 177 tries to be transmitted to the end portion of the laminated crystal piece 174, but the supporting portion 1 is larger than the vibrating portion 177.
Since the thickness of 75 and 176 is large, that is, the central portion is made of a laminated crystal piece having a smaller thickness than the peripheral portion, elastic vibration can be trapped in the vibrating portion 177.

As described above, according to the 11th embodiment,
Since at least two crystal pieces are directly bonded to each other to form a thin crystal piece in the central portion and the excitation electrode is installed through the thin portion in the central portion, elastic vibration can be confined and high. A Q crystal unit can be easily realized.

The seventh, eighth, ninth and ninth aspects of the present invention are as follows.
In each of the 10th and 11th embodiments, there is no limitation on the number and thickness of the crystal pieces to be directly bonded, and the same effect can be obtained if the thickness of the vibrating portion is thicker or thinner than the thickness of the supporting portion. Obtainable.

In each of the seventh, eighth, tenth and eleventh embodiments of the present invention, for example, the fourth and fourth embodiments of the present invention are used.
Resonance frequency-temperature characteristics are stable if the crystal pieces having the cutting angles and the thicknesses as shown in the fifth and sixth embodiments are directly joined in the crystal axis relationship to form the vibrating section.
In addition, a crystal oscillator with high Q can be realized.

The seventh, eighth, ninth and ninth aspects of the present invention are also
There is no limitation on the shapes of the vibrating portion and the supporting portion in each of the 10th and 11th embodiments, and the shape of the crystal piece is not limited to the disc shape shown in the embodiment of the present invention, and any shape such as a square plate shape Shapes can be used.

In each of the fourth, fifth, sixth, seventh, eighth, ninth, tenth and eleventh embodiments of the present invention,
The crystal piece may be a crystal piece having a double-sided or single-sided convex or beveled surface as shown in the sixth embodiment of the present invention (FIG. 6), or a convex piece (the central portion of the crystal piece is It is also possible to combine a crystal piece that has been processed thicker than the peripheral portion) or beveled (processing in which one or both sides of the crystal piece has been cut) with a flat crystal piece.

The twelfth, thirteenth and fourteenth embodiments of the present invention (the invention according to claim 7) will be described below with reference to the drawings.

FIGS. 12, 13 and 14 are side views showing the structure of the crystal unit in the twelfth, thirteenth and fourteenth embodiments of the present invention, respectively.

In the twelfth embodiment of FIG. 12, 181 and 1
82 is a quartz piece of different thickness, 183 is a direct joint, 184 and
Reference numeral 185 is an excitation electrode, and 186 is a laminated crystal piece.
The crystal pieces 181 and 182 are directly bonded to each other to become one,
A laminated crystal piece 186 is formed. The bonded crystal piece 186 has a direct bonding portion 183 having a thickness obtained by combining the crystal pieces 181 and 182 and a portion having the thickness of only the crystal piece 181 (the portion of the excitation electrode 185 on the left side in the drawing). The excitation electrodes 184 are installed opposite to each other via the direct bonding portion 183, and the excitation electrodes 185 are installed opposite to each other via the crystal piece 181.

In the thirteenth embodiment shown in FIG. 13, 19
1,192 and 193 are crystal pieces of different thickness, 194
Is a direct joint portion, 195 and 196 are excitation electrodes, and 197 is a bonded quartz piece. The crystal pieces 191, 192, and 193 are directly bonded to each other to become one body, and the crystal piece 197 is attached.
Is formed. The bonded crystal piece 197 is a crystal piece 191,
192 and 193 combined thickness direct joint 194 and quartz piece 1
Thickness of only 91 (Excitation electrode 195 on the left side in the figure)
have. The excitation electrodes 196 are installed opposite to each other via the direct bonding portion 194, and the excitation electrodes 195 are installed opposite to each other via the crystal piece 191.

In each of the twelfth and thirteenth embodiments configured as described above, when an electric field is applied to the excitation electrode, a thickness slip strain occurs, and the crystal piece between the excitation electrodes 185 and 195 is (Equation 1). It vibrates at the resonance frequency represented by. Further, the direct joint portion vibrates at the resonance frequency represented by (Equation 2) as described in the fourth embodiment (FIG. 4).

As described above, according to the twelfth and thirteenth embodiments, two or three crystal pieces are directly joined to form bonded crystal pieces 186 and 197 having two thicknesses, respectively. Since two sets of excitation electrodes are installed opposite to each other through the thickness of, the crystal resonator having any two resonance frequencies can be easily realized.

FIG. 14 is a side view showing the structure of the crystal unit in the fourteenth embodiment of the present invention. In FIG. 14, 201
And 202 are crystal pieces of different thickness, 203 is a direct joint, 20
4, 205 and 206 are excitation electrodes, and 207 is a laminated crystal piece. The crystal pieces 201 and 202 are directly bonded to each other and integrated to form a bonded crystal piece 207. The bonded crystal piece 207 includes a direct joint portion 203 having a thickness obtained by combining the crystal pieces 201 and 202, and a portion having a thickness of only the crystal pieces 201 and 202 (the left and right excitation electrodes 205 and 206 in the figure).
have. The excitation electrodes 204 are installed opposite to each other via the direct joint portion 203, and the excitation electrodes 205 and 206 are installed opposite to each other via the crystal pieces 201 and 202, respectively.

As described above, according to this embodiment, the 12th
And, similarly to each of the thirteenth embodiments, it is possible to realize a crystal resonator having arbitrary three resonance frequencies.

In addition, the number shown in FIG. 12, FIG. 13 and FIG.
In the twelfth, thirteenth and fourteenth embodiments, crystal pieces 181, 1
91 and 201, 202 are laminated crystal pieces 186, 197 and
It may be composed of directly bonded crystal pieces similar to 207, and a crystal resonator having any of three resonance frequencies can be realized as described above.

The fifteenth, sixteenth and seventeenth embodiments of the present invention (the invention according to claim 8) will be described below with reference to the drawings.

FIGS. 15, 16 and 17 are side views showing the structure of the crystal unit in each of the 15th, 16th and 17th embodiments of the present invention.

In the fifteenth embodiment of FIG. 15, 211, 212 and 213 are crystal pieces having different thicknesses, 211 and 213, respectively.
Have the same thickness. 216 and 217 are excitation electrodes, 21
Reference numerals 4 and 215 are direct joints, and 218 is a bonded crystal piece.
The crystal piece 211 is directly bonded and integrated with the crystal pieces 212 and 213 to form a bonded crystal piece 218. The bonded crystal piece 218 has a direct joint portion 214 having a combined thickness of the crystal pieces 211 and 212 and a direct joint portion 215 having a combined thickness of the crystal pieces 211 and 213, and further between the direct joint portions 214 and 215. It has a portion having the thickness of only the crystal piece 211 (the central portion in the drawing). The excitation electrodes 216 are installed opposite to each other via the direct bonding portion 214, and the excitation electrodes 217 are installed opposite to each other via the direct bonding portion 215.

In the sixteenth embodiment of FIG. 16, 221, 222,
223 and 224 are crystal pieces having different thicknesses. 227 and 2
Reference numeral 28 is an excitation electrode, 225 and 226 are direct bonding portions, and 229 is a bonded crystal piece. The crystal piece 221 and the crystal pieces 222, 223, and 224 are directly joined and integrated to form a bonded crystal piece 2
Forming 29. The bonded crystal piece 229 is the crystal piece 22.
1, 222 and 223 have a direct joint portion 225 with a total thickness, and crystal pieces 221 and 224 have a direct joint portion 226 with a total thickness. Has a part. The excitation electrodes 227 are installed opposite to each other via the direct bonding portion 225, and the excitation electrodes 228 are installed opposite to each other via the direct bonding portion 226.

As described above, according to the fifteenth and sixteenth embodiments, similarly to the twelfth and thirteenth embodiments (FIGS. 12 and 13), crystals having arbitrary two resonance frequencies are provided. Since a vibrator can be obtained and a region thinner than both direct joints can be provided between the two direct joints, elastic vibrations generated in each of the two direct joints can be confined inside. Therefore, the isolation between both elastic vibrations can be increased.

FIG. 17 is a side view showing the structure of the crystal unit in the seventeenth embodiment of the present invention. In FIG. 17, 23
1,232 and 233 are crystal pieces of different thickness, 234,235,236
Is a direct bonding portion, 237 and 238 are excitation electrodes, and 239 is a bonded crystal piece. Crystal piece 231, crystal piece 232 and
233 are directly bonded to each other to form an integrated crystal piece 239. The bonded crystal piece 239 includes a direct joint portion 234 having a total thickness of the crystal pieces 231 and 232, a direct joint portion 235 having a total thickness of the crystal pieces 231 and 233, and a direct joint having a total thickness of the crystal pieces 231, 232 and 233. It has a portion 236. The excitation electrodes 237 are installed opposite to each other via the direct bonding portion 234, and the excitation electrodes 238 are installed opposite to each other via the direct bonding portion 235.

As described above, according to the seventeenth embodiment, as in the twelfth and thirteenth embodiments (FIGS. 12 and 13), a crystal oscillator having two arbitrary resonance frequencies is provided. Further, it is possible to provide a direct joint 236 between the direct joints 234 and 235, which is thicker than both the direct joints,
The elastic vibration generated in each of the direct joint portions 234 and 235 can be confined inside, and the isolation between both elastic vibrations can be increased.

The twelfth, thirteenth, fourteenth, and twelfth aspects of the present invention are
In each of the fifteenth, sixteenth and seventeenth embodiments, there is no limitation on the number of crystal pieces, the cutting angle, the thickness, and the crystal axis relationship at the time of direct bonding.
As shown in the fifth and sixth embodiments, each crystal piece or laminated crystal piece has a desired resonance frequency-
It can be freely set to have temperature characteristics.

There is no limitation on the number of sets of excitation electrodes,
It can be set to obtain any number of desired frequencies.

The shape of the crystal piece and the shape of the excitation electrode are not limited in any way, and can be arbitrarily set such as a circle or a square. Further, as the crystal piece, the convex crystal piece as shown in the sixth embodiment can be used.

In each of the fourth to seventeenth embodiments of the present invention, there is no limitation on the number of excitation electrodes, the pattern shape, the composition and the thickness.

The eighteenth embodiment of the present invention (the invention according to claim 9) will be described below with reference to the drawings.

FIG. 18 is a circuit diagram of a crystal oscillator according to the 18th embodiment of the present invention. In FIG. 18, reference numeral 241 is a crystal oscillator as described in each of the fourth to eleventh embodiments (FIGS. 4 to 11) of the present invention, and at least two crystal oscillators having a desired cutting angle and a desired thickness are provided. The crystal unit is a crystal unit with a stable resonance frequency over a wide temperature range, with the excitation electrodes facing each other through the bonded crystal unit that is directly bonded so that the crystal axes intersect at a desired angle. . Further, 242 is an oscillation circuit and 243 is an output terminal.

In the crystal oscillator configured as described above,
In the vicinity of the resonance frequency of the crystal unit 241, the oscillation circuit 2
The oscillation conditions of 42 and the crystal oscillator 241 are satisfied, and the oscillation signal is output from the output terminal 243. Here, the output frequency-temperature characteristic is almost determined by the resonance frequency-temperature characteristic of the crystal unit 241.

As described above, according to this embodiment, the fourth
Since the stable crystal oscillator is used as the resonance element for the temperature as shown in each of the eleventh embodiments, it is possible to realize the stable crystal oscillator of the output frequency over a wide temperature range.

The nineteenth embodiment of the present invention (the invention of claim 10) will be described below with reference to the drawings.

FIG. 19 is a circuit diagram of an analog temperature compensated crystal oscillator according to the 19th embodiment of the present invention. In FIG. 19, reference numeral 251 denotes a crystal resonator as described in each of the fourth to eleventh embodiments (FIGS. 4 to 11) of the present invention, and at least two crystal oscillators having a desired cutting angle and a desired thickness. The crystal unit is a crystal unit with a stable resonance frequency over a wide temperature range, with the excitation electrodes facing each other through the bonded crystal unit that is directly bonded so that the crystal axes intersect at a desired angle. . Further, 252 is a temperature compensating circuit, 253 is an oscillating circuit, 254 is an output terminal, and the temperature compensating circuit 252 is a circuit composed of a temperature sensitive element, a resistor, a capacitive element, and the like, the reactance of which changes with temperature.

In the analog temperature-compensated crystal oscillator configured as described above, the output frequency-temperature characteristic is stabilized by compensating the temperature-dependent change in the reactance (resonance frequency) of the crystal resonator 251 with the temperature compensation circuit 252. ing. By the way, the resonance frequency-temperature characteristic of the crystal unit 251 is shown in FIG.
As shown in (c), a frequency stability of ± 1.0ppm can be obtained in the temperature range from 10 ℃ to 80 ℃, so when configuring a temperature-compensated crystal oscillator for mobile communication devices such as mobile phones, Compensation is required in the temperature range of -30 ℃ to 10 ℃. Therefore, conventionally, the temperature compensating circuit which has been separately required for the high temperature and the low temperature is only the temperature compensating circuit for the low temperature, and the circuit scale of the temperature compensating circuit 252 can be halved.

As described above, according to the present embodiment, by using the crystal oscillator whose resonance frequency is stable over a wide temperature range as shown in each of the fourth to eleventh embodiments of the present invention, Since the scale of the compensation circuit can be halved and the manufacturing process and the adjustment process can be simplified, a compact and low-cost analog temperature-compensated crystal oscillator can be realized.

In the nineteenth embodiment of the present invention, a thermistor or a diode can be used as the temperature sensitive element, and a capacitor or a variable capacitance diode can be used as the capacitive element.

Hereinafter, twentieth to twenty-second embodiments of the present invention will be described with reference to the drawings.

20 to 22 are block diagrams showing the configurations of the digital temperature-compensated crystal oscillators in the twentieth to twenty-second embodiments of the present invention.

The twentieth embodiment of FIG. 20 (the invention according to claim 11)
In the left block, 266 is a temperature sensor and 265 is A
A / D converter, 264 is a storage device, 263 is a variable reactance circuit for digital signal control, and 262 is an oscillation circuit. Also, 2
Reference numeral 61 is a crystal oscillator as described in each of the fourth to eleventh embodiments of the present invention, in which at least two crystal pieces having a desired cutting angle and a desired thickness have their respective crystal axes desired. This is a crystal resonator having a stable resonance frequency over a wide temperature range, with excitation electrodes facing each other through laminated crystal pieces that are directly bonded so as to intersect at an angle.

Reference numeral 267 is a digitally controlled crystal oscillator including a crystal resonator 261, a variable reactance circuit 263, and an oscillation circuit 262.

Hereinafter, the twenty-first and twenty-second embodiments (claim 1
(Invention 2) will be described with reference to the drawings.

In the twenty-first embodiment of FIG. 21, 273 is a temperature sensor, 274 is an A / D converter, 275 is a memory device, 276 is a programmable frequency divider, 272 is a crystal oscillator, and 271 is the first embodiment of the present invention. As shown in each of the fourth to eleventh embodiments, a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle, By virtue of the structure in which the excitation electrodes are installed opposite to each other, the crystal oscillator is a crystal resonator having a stable resonance frequency over a wide temperature range, and is a resonance element of the crystal oscillator 272.

In the twenty-second embodiment of FIG. 22, 282 and 2
83 is a crystal oscillator, 284 is a frequency counter, 285 is a storage device, 286 is a programmable frequency divider, 281 is a desired cutting angle and a desired cutting angle as shown in each of the fourth to eleventh embodiments of the present invention. At least two crystal pieces having a thickness are directly joined so that their crystal axes intersect at a desired angle, and the excitation electrodes are arranged to face each other through a laminated crystal piece, so that the resonance frequency is stable over a wide temperature range. It is a crystal oscillator and a resonance element of the crystal oscillator 282. Further, the crystal oscillator 283 is a crystal oscillator used as a temperature sensor, and is configured by using a crystal oscillator having a resonance frequency-temperature characteristic in which temperature detection is easy.

In the digital temperature-compensated crystal oscillator configured as described above, the A / Ds are stored in the storage devices 264, 275 and 285.
Data in which the output signal of the converter 265 or 274 or the frequency counter 284 is associated with the control signal of the variable reactance circuit 263 or the programmable frequency divider 276 or 286 is stored in advance. As a result, the reactance of the variable reactance circuit or the frequency division ratio of the programmable frequency divider changes according to the temperature change, and the resonance frequency-temperature characteristic of the crystal unit is compensated to stabilize the oscillation output frequency.

By the way, the characteristics of the crystal resonators 261, 271 and 281 of FIGS. 20, 21 and 22 are ± 1.0 ppm in the temperature range from 10 ° C. to 80 ° C. as shown in FIG. 4 (c). Since frequency stability can be obtained, when configuring a temperature-compensated crystal oscillator for mobile communication devices such as mobile phones, temperature compensation is required in the temperature range of -30 ° C to 10 ° C.
The temperature range is greatly reduced to about 2/5 of the conventional range.

As described above, according to the twentieth to twenty-second embodiments of the present invention, a crystal having a resonance frequency stable over a wide temperature range as shown in the fourth to eleventh embodiments of the present invention. Since the oscillator is used, the temperature range to be compensated is greatly reduced, the capacity of the memory device and the number of bits of the A / D converter can be reduced, and the manufacturing and adjustment processes can be simplified, so A low temperature and low cost digital temperature compensated crystal oscillator can be realized. Further, the temperature sensor is also only required to be able to detect the temperature at a low temperature, and the degree of freedom of elements and circuits is increased.

In each of the twentieth and twenty-first embodiments of the present invention, as the temperature sensor, an element or circuit which uses a thermistor, a diode or the like and whose potential difference or current value changes with temperature can be used. A crystal oscillator can be used as the temperature sensor, and when the crystal oscillator is used, a frequency counter can be used as the A / D converter.

In the twentieth embodiment of the present invention, as the variable reactance circuit, for example, a D / A converter and a variable capacitance diode are used, and the output voltage of the D / A converter is applied to the variable capacitance diode. And a method of directly changing the capacitance value by switching with a digital signal can be used.

In the twenty-second embodiment of the present invention, the crystal oscillators used in the crystal oscillator 281 and the crystal oscillator 283 are, for example, the twelfth, thirteenth, fifteenth, sixteenth, It can be integrally configured by the configuration shown in each of the seventeenth embodiments.

The eighteenth, nineteenth, twentieth and twenty-first aspects of the present invention
In the twenty-first and twenty-second embodiments, the crystal oscillators 241, 251, 261, 271 and 281 shown in FIGS. 18 to 22 do not necessarily have the resonance frequency-temperature characteristics shown in FIG. 4 (c). It is not necessary to use a child, and it is possible to arbitrarily set the number of crystal pieces to be directly bonded, their respective cutting angles, thicknesses, and crystal axis relationships so that stable resonance frequency-temperature characteristics can be obtained in a desired temperature range. it can.

The twenty-third to twenty-sixth embodiments of the present invention will be described below.
The invention of claim 13 will be described with reference to the drawings.

23 to 26 are block diagrams showing the configurations of the digital temperature-compensated crystal oscillators in the twenty-third to twenty-sixth embodiments of the present invention, respectively.

In the twenty-third embodiment of FIG. 23, reference numeral 291 is a single unit as shown in the twelfth embodiment of the present invention (FIG. 12), and can take out two vibrations having arbitrary resonance frequencies and temperature characteristics. It is a crystal unit. Reference numerals 292 and 293 denote two first and second vibrating portions formed on the crystal unit 291. Reference numeral 294 is a first oscillation circuit, 295 is a variable reactance circuit for digital signal control, and 296 is a digitally controlled crystal oscillator including the first vibrating section 292, the first oscillation circuit 294 and the variable reactance circuit 295. 297 is a storage device, 298 is A
It is a / D converter. Further, 299 is a second oscillating circuit, and 300 is a temperature sensor composed of the second vibrating section 293 and the second oscillating circuit 299. Here, the crystal resonator 291 is provided so that the second vibrating section 293 has a resonance frequency-temperature characteristic that allows easy temperature detection, and the first vibrating section 292 has a stable resonance frequency-temperature characteristic. The two crystal pieces that are configured are directly bonded with the cutting angle, thickness, and crystal axis relationship set.

In the twenty-fourth embodiment of FIG. 24, reference numeral 301 denotes two vibrations having arbitrary resonance frequency and temperature characteristics as shown in the twelfth embodiment of the present invention (FIG. 12). It is a crystal oscillator that can be taken out. 302 and 303 are crystal units 301
The two first and second vibrating portions formed on the upper side. 304
Is a digitally controlled crystal oscillator including the first vibrating section 302, the first oscillating circuit 294 and the variable reactance circuit 295, and 305 is the second vibrating section 303 and the second oscillating circuit.
It is a temperature sensor consisting of 299. Here, the second vibrating section 3
The crystal resonator 301 is configured so that 03 has a resonance frequency-temperature characteristic that enables easy temperature detection, and the first vibrating section 302 has a stable resonance frequency-temperature characteristic.
The cut-out angles, thicknesses, and crystal axis relationships of the crystal pieces are set and directly joined.

In the twenty-fifth embodiment of FIG. 25, 311 is a single unit as shown in the thirteenth embodiment (FIG. 13) of the present invention and can extract two vibrations having arbitrary resonance frequencies and temperature characteristics. It is a crystal unit. Reference numerals 312 and 313 denote two first and second vibrating portions formed on the crystal oscillator 311. 314 is a digitally controlled crystal oscillator including a first vibrating section 312, a first oscillating circuit 294 and a variable reactance circuit 295, and 315 is a temperature sensor including a second vibrating section 313 and a second oscillating circuit 299. . Here, the second vibrating unit 313 has a resonance frequency-temperature characteristic such that the temperature can be easily detected,
In addition, the three crystal pieces forming the crystal unit 311 are set with the cut-out angle, the thickness, and the crystal axis relationship so that the first vibrating unit 312 has a stable resonance frequency-temperature characteristic.
It is directly joined.

In the twenty-sixth embodiment of FIG. 26, 321 is a single unit as shown in the fifteenth embodiment (FIG. 15) of the present invention and can extract two vibrations having arbitrary resonance frequencies and temperature characteristics. It is a crystal unit. Reference numerals 322 and 323 denote two first and second vibrating portions formed on the crystal oscillator 321. 324 is a digitally controlled crystal oscillator including a first vibrating section 322, a first oscillating circuit 294 and a variable reactance circuit 295, and 325 is a temperature sensor including a second vibrating section 323 and a second oscillating circuit 299. . Here, the second vibrating section 323 has a resonance frequency-temperature characteristic such that the temperature can be easily detected,
In addition, the three crystal pieces forming the crystal unit 321 have the cut-out angle, the thickness, and the crystal axis relationship set so that the first vibrating unit 322 has a stable resonance frequency-temperature characteristic.
It is directly joined.

In the digital temperature-compensated crystal oscillator configured as described above, the storage device stores data in which the digital signal obtained by converting the output signal of the temperature sensor by the A / D converter and the control signal of the variable reactance circuit are associated with each other. Remember in advance. As a result, the reactance of the variable reactance circuit changes according to the temperature change, and the output frequency of the digitally controlled crystal oscillator can be stabilized. Further, since the vibrating section for the temperature sensor and the digitally controlled crystal oscillator are integrally formed, there is almost no temperature difference between them, and the temperature information of the vibrating section for the digitally controlled oscillator can be obtained accurately. it can.

As described above, according to each of the twenty-third to twenty-sixth embodiments of the present invention, as shown in each of the twelfth, thirteenth and fifteenth embodiments of the present invention, a single resonance frequency can be set independently. By using a crystal oscillator that can extract two vibrations with temperature characteristics, the vibration parts for the temperature sensor and the digitally controlled crystal oscillator can be integrally formed, and each vibration part has the optimum temperature characteristics according to the purpose. Since it can be set separately, it is possible to realize a digital temperature-compensated crystal oscillator that is small in size, inexpensive, and capable of highly accurate temperature compensation even with a low bit number.

In the twenty-fifth embodiment, the vibrator 311 of the first vibrating section 312 is formed by laminating the three crystal pieces (191, 192, 193) shown in the thirteenth embodiment (FIG. 13). The crystal piece 197 of the digital temperature compensation crystal oscillator according to the third embodiment, which has a more stable resonance frequency-temperature characteristic than the twenty-third and twenty-fourth embodiments. Can be obtained.

Further, in the twenty-sixth embodiment, since an area thinner than the thickness of either of the two vibrating sections is provided between the two first and second vibrating sections 322 and 323, both vibrating sections are generated. Isolation between elastic vibrations can be increased. In the twenty-sixth embodiment of the present invention, the thickness between the two first and second vibrating portions is configured to be thinner than the thickness of either of the two vibrating portions, but it is not necessarily required to be thin. As in the crystal unit described in the seventeenth embodiment (FIG. 17) of the present invention, the thickness of the direct joint portion 236 between the two vibrating portions 234 and 235 is made thicker than the thickness of both vibrating portions 234 and 235. Even in this case, the same effect can be obtained.

The twenty-seventh embodiment of the present invention (the invention according to claim 14) will be described below with reference to the drawings.

FIG. 27 is a block diagram showing the structure of the digital temperature-compensated crystal oscillator according to the 27th embodiment of the present invention. Figure 27
In the figure, reference numeral 331 is a crystal oscillator capable of extracting three vibrations having arbitrary resonance frequencies and temperature characteristics by itself as shown in the fourteenth embodiment (FIG. 14) of the present invention. 332, 333 and
Reference numeral 334 denotes three first, second and third vibrating portions formed on the crystal oscillator 331. 335 is the first vibrating section 332 and the first
Is a digitally controlled crystal oscillator including an oscillation circuit 294 and a variable reactance circuit 295, and 336 is a second vibrating unit 333.
And 337 is a second temperature sensor including a third vibrating section 334 and a third oscillating circuit 338. Here, the second and third vibrating sections 333 and 334 have a resonance frequency-temperature characteristic that allows easy temperature detection, and the first vibrating section 332 has a stable resonance frequency-temperature characteristic. The two crystal pieces constituting the crystal unit 331 are directly bonded to each other with the cut-out angle, thickness and crystal axis relationship set.

As described above, according to the twenty-seventh embodiment of the present invention, in addition to the effects of the twenty-third to twenty-sixth embodiments of the present invention, in addition to the effects of the first and second temperature sensors 336 and 337, Since both are used to detect the temperature, the temperature can be detected more accurately.

In the twenty-seventh embodiment of the present invention, four or more sets of excitation electrodes may be provided, and the same effect can be obtained even when four or more sets of excitation electrodes are formed.

In each of the twenty-third to twenty-seventh embodiments of the present invention, there is no limitation on the cutting angle, the thickness, the shape and the number of the crystal pieces, and the vibrating section can be freely set so as to have desired characteristics. be able to. Further, the relationship between the crystal axes at the time of bonding can be freely set so that desired characteristics can be obtained. A frequency counter or the like can be used as the A / D converter. further,
As the variable reactance circuit, for example, a D / A converter and a variable capacitance diode are used to apply the output voltage of the D / A converter to the variable capacitance diode, or the capacitance value is directly changed by switching with a digital signal. A method or the like can be used.

28th and 29th Embodiments of the Present Invention
(Invention of Claim 15) will be described with reference to the drawings.

FIG. 28 shows the structure of a crystal filter according to the 28th embodiment of the present invention. (A) is a plan view and (b) is a side view. In FIG. 28, 341 and 342 are crystal pieces, 344, 345,
346 and 347 are electrodes. The crystal pieces 341 and 342 have a desired cutting angle and a desired thickness so that the frequency-temperature characteristics cancel each other out, and the crystal pieces 341 and 342 are directly bonded so that their crystal axes intersect at a desired angle, and the crystal pieces 343 are bonded together. Has become. Electrodes 344 and 345 and 3
46 and 347 are installed opposite to each other with a laminated crystal piece 343 interposed therebetween.

The operation of the crystal filter configured as described above will be described below.

Either one of the electrodes 344 and 345 and 346 and 347 is normally grounded. For example, electrode 345
When 347 and 347 are grounded, the electrode 344 is an input terminal, and the electrode 346 is an output terminal, when an electric signal is input to the electrode 344, the laminated crystal piece 343 resonates at a frequency determined by its thickness and elastic constant. This resonance is mechanically transmitted in the laminated crystal piece 343, and as a result, an electric field is generated between the electrodes 346 and 347, and an electric signal can be taken out from the electrode 346. That is,
The bandpass filter has a resonance frequency determined by the thickness and elastic constant of the laminated crystal piece 343. Further, since the laminated crystal piece 343 is formed by laminating the crystal pieces 341 and 342 whose frequency-temperature characteristics cancel each other out, the resonance frequency is stable with respect to temperature.

As described above, according to the twenty-eighth embodiment, two crystal pieces having a desired cutting angle and a desired thickness are set so that the frequency-temperature characteristics cancel each other out. Since the electrodes are opposed to each other through the bonded crystal pieces that are directly bonded so that the crystal axes intersect at a desired angle, it is possible to realize a crystal filter with stable frequency temperature characteristics.

The twenty-ninth embodiment of the present invention will be described below with reference to the drawings.

FIG. 29 shows the structure of a crystal filter according to a twenty-ninth embodiment of the present invention. (A) is a plan view and (b) is a side view.

In FIG. 29, reference numeral 348 is an electrode. The operation of the twenty-ninth embodiment is the same as that of the twenty-eighth embodiment (FIG. 28), but the structure and assembly are simplified by integrating the electrodes to be grounded into one electrode 348.

The thirtieth embodiment of the present invention (the invention according to claim 16) will be described below with reference to the drawings.

30A and 30B show the structure of a crystal filter according to a thirtieth embodiment of the present invention. FIG. 30A is a plan view and FIG. 30B is a side view.

In FIG. 30, 349 and 350 are crystal pieces, and 351, 352 and 353 are electrodes. Electrodes 352 and 35 on both sides
A crystal piece 350 formed by facing 3 and a crystal piece 349 having an electrode 351 formed on one surface are connected to the electrodes 351 and 352 via the crystal piece 349.
Are directly joined to each other so as not to face each other via the electrode 352.

The operation of the crystal filter configured as described above will be described below.

Normally, electrode 352 is grounded and electrodes 351 and 353 are
Are the electrodes that input and output electrical signals. For example, electrode 351
When an electric signal is input to the crystal element 350, the crystal element 350 resonates at a frequency determined by its size and elastic constant. Since the crystal pieces 349 and 350 are directly bonded, this resonance is mechanically transmitted to the crystal piece 349, an electric field is generated between the electrodes 351 and 352, and an electric signal is output from the electrode 353.

As described above, according to the thirtieth embodiment, the resonance can be three-dimensionally coupled by sandwiching the electrodes and directly joining the two crystal resonators, thereby realizing a small crystal filter. can do.

The 31st embodiment of the present invention (the invention of claim 17) will be described below with reference to the drawings.

FIG. 31 shows the structure of a crystal filter according to a 31st embodiment of the present invention. (A) is a plan view and (b) is a side view.

In FIG. 31, 355, 356, 357 and 358 are crystal pieces. The crystal pieces 355 and 356 and 357 and 358 have a desired cutting angle and a desired thickness so that their frequency characteristics cancel each other out, and are directly bonded so that their crystal axes intersect at a desired angle. It is made of laminated crystal pieces 359 and 360. The operation of this embodiment is similar to that of the thirtieth embodiment (FIG. 30), but the bonded crystal pieces 359 and 360 are used instead of the crystal pieces 349 and 350 in FIG. Example
Similar to (FIG. 28), stable frequency-temperature characteristics can be obtained.

In each of the twenty-eighth to thirty-first embodiments, the crystal pieces and the electrodes have a rectangular shape, but any shape such as a circular shape may be used. Further, there is no limitation on the number of crystal pieces, the cutting angle, the thickness, and the crystal axis relationship when directly joining. Further, there is no limitation on the number of electrodes, the pattern shape, the composition and the thickness.

[0174]

As described above, according to the present invention, the surface is mirror-polished and washed with a detergent, followed by washing with isopropyl alcohol and washing with a mixed solution of sulfuric acid and hydrogen peroxide, and then heat drying. Then, the crystal pieces treated so that the surface is smooth and flat and terminated with a hydroxyl group are brought into contact with each other without any interposition, and are bonded by the adhesive force acting between the hydroxyl groups on the surface. After that, by performing heat treatment within a temperature range where the crystal does not undergo phase transition so that stronger adhesion can be obtained, it becomes possible to directly bond the crystal, improve the three-dimensional processability, and increase the resonance frequency-temperature. It is possible to realize a crystal unit with improved characteristics.

Further, the excitation electrodes are arranged opposite to each other via the laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. As a result, it is possible to realize a crystal resonator having a stable resonance frequency in a wide temperature range.

Further, at least two pieces of crystal having a desired cutting angle and a desired thickness are directly joined so that their crystal axes intersect at a desired angle, and the thickness of the central portion is different from that of the peripheral portion. Compose a laminated crystal piece,
A crystal oscillator having a high Q value can be realized by disposing the excitation electrodes so as to face each other via the central portion of the laminated crystal piece.

Further, at least two crystal pieces having a desired cut-out angle and a desired thickness are directly joined so that the crystal axis relationships of the crystal pieces intersect at a desired angle to obtain a laminated crystal piece having at least two different thicknesses. And by arranging at least two sets of excitation electrodes so as to face each other through the desired thickness of the laminated crystal piece, a single crystal resonator having a plurality of vibrations having arbitrary resonance frequencies and temperature characteristics can be obtained. realizable.

Further, the excitation electrodes are installed opposite to each other via the laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. By using the crystal oscillator having the configuration as a resonance element, a crystal oscillator having a stable output frequency over a wide temperature range and an analog or digital temperature-compensated crystal oscillator of small size, low current consumption, high accuracy and low cost can be realized.

Further, at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect each other at a desired angle to form a bonded crystal piece having at least two different thicknesses. Configure and
Crystal vibrations for a temperature sensor and a digitally controlled crystal oscillator are obtained by installing two sets of excitation electrodes so as to face each other with the desired thickness of the laminated crystal piece facing each other and integrating the first and second vibrating portions. It becomes possible to integrate the child, and it is possible to realize a highly accurate digital temperature-compensated crystal oscillator by suppressing the temperature difference between the temperature sensor and the crystal oscillator for the digitally controlled crystal oscillator.

Further, at least two sets of counter electrodes are provided through the bonded crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. A crystal filter having a stable frequency-temperature characteristic can be realized by adopting the configuration in which

In addition, at least two or more crystal pieces and one more electrode than the number of the crystal pieces are alternately superposed,
Moreover, a small crystal filter can be realized by adopting a configuration in which the respective crystal pieces facing each other via the respective electrodes are directly bonded at a portion not interposing the electrodes.

[Brief description of drawings]

FIG. 1 is a diagram showing a flowchart of a direct bonding method for a quartz crystal piece according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a flowchart of a direct bonding method for a crystal element in a second embodiment of the present invention.

FIG. 3 is a diagram showing a flowchart of a method for directly joining crystal pieces in a third embodiment of the present invention.

FIG. 4 is a side view (a) and a plan view (b) of a crystal unit according to a fourth embodiment of the present invention, and a resonance frequency of a laminated crystal piece-
It is a figure (c) which shows an example of a temperature characteristic.

FIG. 5 is a side view (a) and a plan view (b) of a crystal unit according to a fifth embodiment of the present invention.

FIG. 6 is a side view (a) and a plan view (b) of a crystal unit according to a sixth embodiment of the present invention.

FIG. 7 is a side view (a) and a plan view (b) of a crystal unit according to a seventh embodiment of the present invention.

FIG. 8 is a side view (a) and a plan view (b) of a crystal unit according to an eighth embodiment of the present invention.

FIG. 9 is a side view (a) and a plan view (b) of a crystal unit according to a ninth embodiment of the present invention.

FIG. 10 is a side view (a) and a plan view (b) of a crystal unit according to a tenth embodiment of the present invention.

FIG. 11 is a side view (a) and a plan view (b) of a crystal unit according to an eleventh embodiment of the present invention.

FIG. 12 is a side view showing a structure of a crystal resonator according to a twelfth embodiment of the present invention.

FIG. 13 is a side view showing the structure of a crystal resonator according to a thirteenth embodiment of the present invention.

FIG. 14 is a side view showing the structure of a crystal resonator according to a fourteenth embodiment of the present invention.

FIG. 15 is a side view showing a structure of a crystal resonator according to a fifteenth embodiment of the present invention.

FIG. 16 is a side view showing the structure of a crystal resonator according to a sixteenth embodiment of the present invention.

FIG. 17 is a side view showing the structure of a crystal resonator according to a seventeenth embodiment of the present invention.

FIG. 18 is a circuit diagram of a crystal oscillator according to an eighteenth embodiment of the present invention.

FIG. 19 is a circuit diagram of an analog temperature compensation crystal oscillator according to a nineteenth embodiment of the present invention.

FIG. 20 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a twentieth embodiment of the present invention.

FIG. 21 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a twenty-first embodiment of the present invention.

FIG. 22 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a 22nd embodiment of the present invention.

FIG. 23 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a 23rd embodiment of the present invention.

FIG. 24 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a twenty-fourth embodiment of the present invention.

FIG. 25 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a twenty-fifth embodiment of the present invention.

FIG. 26 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a twenty-sixth embodiment of the present invention.

FIG. 27 is a block diagram showing the structure of a digital temperature-compensated crystal oscillator according to a twenty-seventh embodiment of the present invention.

FIG. 28 is a plan view (a) and a side view (b) showing a structure of a crystal filter according to a twenty-eighth embodiment of the present invention.

FIG. 29 is a plan view (a) and a side view (b) showing a structure of a crystal filter according to a twenty-ninth embodiment of the present invention.

FIG. 30 is a plan view (a) and a side view (b) showing a structure of a crystal filter according to a thirtieth embodiment of the present invention.

FIG. 31 is a plan view (a) and a side view (b) showing a structure of a crystal filter according to a thirty-first embodiment of the present invention.

FIG. 32 is a side view of the essential parts showing each example of the configuration of the conventional crystal resonator.

FIG. 33 is a diagram showing a resonance frequency-temperature characteristic of a conventional AT-cut crystal piece.

FIG. 34 is a diagram showing a typical configuration of a conventional analog-type temperature-compensated crystal oscillator.

FIG. 35 is a diagram showing a typical configuration of a conventional digital temperature-compensated crystal oscillator.

FIG. 36 is a perspective view showing the structure of a conventional crystal filter (a).
And its aa 'sectional drawing (b).

[Explanation of symbols]

101, 102, 111, 112, 113, 121, 122, 131, 132, 141,
142, 151, 152, 153, 161, 162, 163, 171, 172, 181,
182, 191, 192, 193, 201, 202, 211, 212, 213, 221,
222, 223, 224, 231, 232, 233, 341, 342, 349, 350,
355, 356, 357, 358, 401, 403, 431 ... Crystal piece, 103,
114, 123, 133, 143, 154, 164, 173, 184, 185, 195,
196, 204, 205, 206, 216, 217, 227, 228, 237, 238,
402, 404 ... Excitation electrodes, 104, 115, 124, 137, 147, 15
8,168,174,186,197,207,218,229,239,343,35
9, 360… Laminated crystal pieces, 134, 135, 144, 145, 15
5, 156, 165, 166, 175, 176 ... Supporting part, 136, 146, 15
7, 167, 177, 292, 293, 302, 303, 312, 313, 322, 32
3,332,333,334 ... Vibration part, 183,194,203,214,21
5, 225, 226, 234, 235, 236 ... Direct joint, 241, 25
1, 261, 271, 281, 291, 301, 311, 321, 331, 413, 42
6 ... Crystal oscillator, 242, 253, 262, 294, 299, 338, 41
1,425 ... Oscillation circuit, 243, 254, 412 ... Output terminal, 25
2, 414 ... Temperature compensation circuit, 263, 295, 424 ... Temperature compensation circuit, 263, 295, 424 ... Variable reactance circuit, 264,
275, 285, 297, 423 ... Storage device, 265, 274, 298, 422
... A / D converter, 266, 273, 300, 305, 315, 325, 33
6,337,421… Temperature sensor, 267,296,304,314,32
4, 335, 427 ... Digitally controlled crystal oscillator, 272, 282, 2
83 ... Crystal oscillator, 276, 286 ... Programmable frequency divider,
284 ... Frequency counter, 344, 345, 346, 347, 348,
351, 352, 353, 432, 433, 434 ... Electrode, X ... X-axis of quartz crystal, Y ... Y-axis of quartz crystal, Z ... Z of quartz crystal
Axis, P ... normal to the plate surface of the crystal piece, θ, φ, ξ ... angle formed by each crystal axis.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number Japanese Patent Application No. 4-31669 (32) Priority Date Hei 4 (1992) February 19 (33) Country of priority claim Japan (JP) (31) Priority Claim No. Japanese Patent Application No. 4-44772 (32) Priority Date No. 4 (1992) March 2 (33) Country of priority claim Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-113526 (32) Priority Hihei 4 (1992) May 6 (33) Priority claiming country Japan (JP)

Claims (17)

[Claims] 1. The surface is mirror-polished and washed with a detergent, followed by washing with isopropyl alcohol and washing with a mixed solution of sulfuric acid and hydrogen peroxide solution, and then heat drying to make the surface smooth and flat. , And the crystal pieces treated so as to be terminated with hydroxyl groups are brought into contact with each other without any intervening substance, and are bonded by the adhesive force acting between the hydroxyl groups on the surface, and a stronger adhesive force is obtained. As described above, a method for directly bonding quartz is characterized in that heat treatment is performed within a temperature range in which the quartz crystal does not undergo phase transition. 2. The surface is mirror-polished, washed with a detergent and isopropyl alcohol, then dried with a dryer using isopropyl alcohol, and then heat-dried so that the surface is smooth and flat. , And by contacting the crystal pieces treated so as to be in a state of being terminated with a hydroxyl group without any inclusions, and by adhering with the adhesive force acting between the hydroxyl groups on the surface, a stronger adhesive strength is obtained. As described above, a method for directly bonding quartz is characterized in that heat treatment is performed within a temperature range in which the quartz crystal does not undergo phase transition. 3. The surface is mirror-polished and washed with a detergent, followed by washing with isopropyl alcohol and washing with hydrogen fluoride water or ammonium fluoride water,
Next, heat drying is performed to bring the crystal pieces, which have been treated so that the surface is smooth and flat and terminated with a hydroxyl group, into contact with each other without inclusion, and act between the hydroxyl groups on the surface. A method for directly joining crystals, characterized in that after bonding with an adhesive force, heat treatment is performed within a temperature range in which the crystal does not undergo a phase transition so as to obtain a stronger adhesive force. 4. Exciting electrodes are installed opposite to each other via a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that respective crystal axes intersect at a desired angle. A crystal unit characterized by this. 5. A laminated structure in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that respective crystal axes intersect at a desired angle, and a central portion is thicker than a peripheral portion. A crystal resonator comprising a crystal piece, wherein excitation electrodes are installed opposite to each other via a thick region in a central portion of the laminated crystal piece. 6. A laminated structure in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly joined so that respective crystal axes intersect at a desired angle, and a central portion is thinner than a peripheral portion. A crystal unit comprising a crystal piece, wherein excitation electrodes are installed opposite to each other via a thin region in a central portion of the laminated crystal piece. 7. At least two or more different thicknesses obtained by directly bonding at least two crystal pieces having a desired cutting angle and a desired thickness so that respective crystal axes intersect at a desired angle. A crystal resonator comprising: a bonded crystal piece having a region, wherein at least two sets of excitation electrodes are provided so as to face each other between the regions having different thicknesses. 8. At least two sets of excitation electrodes are provided through a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. A first region having a thickness different from both the first region and the second region is provided between the first region provided opposite to each other and provided with the first excitation electrode pair and the second region provided with the second excitation electrode pair. A crystal unit provided with three regions. 9. A structure in which excitation electrodes are installed to face each other via a bonded crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. A crystal oscillator characterized by using the crystal oscillator of 1. as a resonance element. 10. A structure in which excitation electrodes are opposed to each other via a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that respective crystal axes intersect at a desired angle. An analog temperature-compensated crystal oscillator, comprising: the crystal resonator according to 1); and a temperature compensation circuit configured by using a temperature sensitive element, a resistor, and a capacitive element. 11. A structure in which excitation electrodes are opposed to each other via a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that respective crystal axes intersect at a desired angle. , A digitally controlled crystal oscillator consisting of a crystal oscillator, a variable reactance circuit for digital signal control, and an oscillation circuit, and a temperature sensor,
A for converting the output signal of the temperature sensor into a digital signal
A digital temperature-compensated crystal oscillator, comprising: an A / D converter and a storage device that stores data corresponding to a digital signal of the A / D converter and outputs the data to the variable reactance circuit. 12. A structure in which excitation electrodes are opposed to each other via a laminated crystal piece in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that respective crystal axes intersect at a desired angle. A crystal oscillator using the crystal oscillator, a temperature sensor, an A / D converter for converting an output signal of the temperature sensor into a digital signal, and data corresponding to the digital signal of the A / D converter are stored. A digital temperature compensated crystal oscillator, comprising: a storage device; and a programmable frequency divider that divides an output frequency of the crystal oscillator according to the data of the storage device. 13. At least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded to each other so that their crystal axes intersect at a desired angle to form at least 2.
Two laminated crystal pieces with two different thicknesses
A pair of excitation electrodes are installed to face each other with a desired thickness of the laminated crystal piece, the first and second vibrating sections are integrally configured, and the first vibrating section and the variable reactance circuit for digital signal control are integrated. And a digitally controlled crystal oscillator including a first oscillating circuit, a temperature sensor including the second vibrating section and a second oscillating circuit, and an A / D converter that converts an output signal of the temperature sensor into a digital signal. , A /
A digital temperature-compensated crystal oscillator, comprising: a storage device that stores data corresponding to a digital signal of a D converter and outputs the data to the variable reactance circuit. 14. At least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded to each other so that their crystal axes intersect at a desired angle, and at least two.
3 pieces of bonded crystal pieces having three different thicknesses
A pair of excitation electrodes are installed to face each other with a desired thickness of the bonded crystal piece, and the first, second, and third vibrating sections are integrally configured, and the first vibrating section and the digital signal control A digitally controlled crystal oscillator including a variable reactance circuit and a first oscillating circuit; first and second temperature sensors including the second and third oscillating portions and second and third oscillating circuits; An A / D converter that converts the output signals of the first and second temperature sensors into a digital signal, and data that corresponds to the digital signal of the A / D converter is stored, and the data is output to the variable reactance circuit. A temperature compensated crystal oscillator, comprising: 15. At least two sets of opposing electrodes via bonded crystal pieces in which at least two crystal pieces having a desired cutting angle and a desired thickness are directly bonded so that their crystal axes intersect at a desired angle. A crystal filter characterized by being formed. 16. A crystal piece having electrodes formed on both surfaces thereof and at least one crystal piece having electrodes formed on one surface thereof are stacked so that the crystal pieces and the electrodes are alternately arranged, and each crystal piece is laminated. A crystal filter, wherein the electrodes are directly bonded to each other at a portion where the electrodes are not interposed. 17. A bonded crystal piece, which is obtained by directly bonding at least two crystal pieces having a desired cut-out angle and a desired thickness so that their crystal axes intersect at a desired angle, is used as the crystal piece. The crystal filter according to claim 16.