JP5144166B2 - Piezoelectric oscillator - Google Patents

Description

  The present invention relates to a piezoelectric oscillator used in an electronic device or the like.

FIG. 6 is an exploded perspective view showing one embodiment of a conventional piezoelectric oscillator. As shown in FIG. 6, the conventional piezoelectric oscillator 200 mainly includes a package 201 having a recessed space 205, a piezoelectric vibration element 202, an integrated circuit element 203, and a lid 204.
The package 201 is formed of a substantially rectangular parallelepiped made of a ceramic material or the like, and has a recessed space 205 opened on one main surface. The mounting portion 206 is located in the recessed space 205 at a position higher than the bottom surface of the recessed space 205. Is formed.
The piezoelectric vibration element 202 is mounted on a piezoelectric vibration element mounting pad 207 formed in the mounting portion 206.
The integrated circuit element 203 is mounted on an integrated circuit element mounting pad 208 formed on the bottom surface in the recess space of the package 201.
The lid 204 is placed on the concave space 205 of the package 201 and is fixed to the top of the side wall of the package 201 to hermetically seal the interior of the concave space 205.
In such a piezoelectric oscillator 200, the power supply voltage terminal, the ground terminal, the output terminal, and the inhibit terminal, which are the external connection electrode terminals 209, are formed one by one at the four corners of the other main surface of the package 201, respectively. A known structure is known (see, for example, Patent Document 1).

Further, two groove portions extending vertically are formed on the side surface of the package 201, and a monitor electrode terminal 210 is provided at a central portion in each groove portion. The monitor electrode terminal is electrically connected to the piezoelectric vibration element.
When measuring the characteristics of the piezoelectric vibration element 202, a pair of contact probes are juxtaposed from one direction and brought into contact with the monitor electrode terminal 210, whereby characteristics such as a CI (crystal impedance) value and a frequency of the piezoelectric vibration element 201 are measured. Is measured (see, for example, Patent Document 2).
FIG. 7 is a block diagram showing a circuit configuration of a conventional piezoelectric oscillator. The piezoelectric oscillator shown in FIG. 7 includes a piezoelectric vibration element Xtal, the integrated circuit element, an oscillation circuit section X, an amplification circuit section Y, a memory section M for storing temperature compensation control data, and temperature compensation. And a temperature compensation signal control circuit unit T for performing temperature compensation based on the control data.
XM1 which is one end of the piezoelectric vibration element Xtal and XM2 which is the other end of the piezoelectric vibration element Xtal are used as monitor electrode terminals.

FIG. 8 is a block diagram showing a circuit configuration of a conventional piezoelectric oscillator. The piezoelectric oscillator shown in FIG. 8 is provided with a power supply voltage terminal 302, a frequency control terminal 303, a ground terminal 304, an output terminal 305, a write terminal 306, and an adjustment terminal 307 in a package constituting the piezoelectric oscillator. In addition, a piezoelectric vibration element 301 is mounted in the package 308.
Further, an integrated circuit element is mounted in the package 308.
The integrated circuit element 313 is provided with an electronic circuit that is electrically connected to each of the terminals and that performs control processing on a signal from the piezoelectric vibration element 301. As an electronic circuit, an oscillation circuit 309 having a temperature compensation circuit, controlling a signal from the piezoelectric vibration element 301 and outputting the signal to the output terminal 305, supplied with a power supply voltage from a power supply voltage terminal 302, and a writing terminal The storage unit 310 stores the temperature compensation data input from 306 and is supplied with the power supply voltage from the power supply voltage terminal 302, the first switching units 311a and 311b, and the second switching units 312a and 312b. ing. Here, the first switching means 311 a and 311 b switch disconnection and connection between the piezoelectric vibration element 301 and the oscillation circuit 309 according to the selection signal input from the adjustment terminal 307. Further, the second switching means 312 a connects the power supply voltage terminal 302 to either the oscillation circuit 309 and the storage means 310 or the piezoelectric vibration element 301 according to the selection signal input from the adjustment terminal 307. Switch to.
In the circuit having such a configuration, when the piezoelectric oscillator 300 functions as an oscillator, the first switching means 311a and 311b are connected to the piezoelectric vibration element 301 and the oscillation circuit 309 by a selection signal input from the adjustment terminal 307. The second switching means 312b is switched to the side where the frequency control terminal 303 and the oscillation circuit 309 are connected.
When measuring the frequency characteristics of the piezoelectric vibration element mounted on the piezoelectric oscillator 300, the first switching means 311 a and 311 b are connected to the piezoelectric vibration element 301, the oscillation circuit 309, and the selection signal input from the adjustment terminal 307. The second switching means 312a is switched to the side connecting the power supply voltage terminal 302 and the piezoelectric vibration element 301, and the second switching means 312b is connected between the frequency control terminal 303 and the piezoelectric vibration element 301. Switch to the side.
By the disconnection and connection by each switching means, the piezoelectric vibration element 301 is connected to the power supply voltage terminal 302 and the frequency control terminal 303 in a state of being completely disconnected from the oscillation circuit 309 and the storage means 310. The terminal 302 and the frequency control terminal 303 can be used as monitoring electrode terminals of the piezoelectric vibration element 301 (see, for example, Patent Document 3).

JP 2006-42096 A JP 2003-163542 A JP 2006-25336 A

However, in the conventional piezoelectric oscillator 200, when the size of the piezoelectric oscillator 200 is reduced, it becomes impossible to secure an area for forming the monitor electrode terminal 210 on the surface of the piezoelectric oscillator, and it becomes difficult to provide the monitor electrode terminal 210 on the piezoelectric oscillator 200. Even when the monitor electrode terminal 210 is provided, the interval between the two groove portions formed on one side surface is narrowed, and the formation area of the monitor electrode terminal 210 formed in the groove portion is also reduced. As a result, there is a problem in that the probes that are in contact with the groove portions come into contact with each other, or the monitor electrode terminal 210 cannot be contacted correctly.
In addition, in order to prevent contact failure, the contact probe is brought into contact with the monitor electrode terminal 210 in the groove many times, so that the tip of the contact probe comes into contact with a portion other than the monitor electrode terminal in the groove. There has been a problem that the package 201 is cracked or chipped.
Further, when the monitor electrode terminal 210 is formed on the side surface of the package 201, there is a problem that the frequency of the piezoelectric vibration element 202 fluctuates when a foreign material such as a fill material adheres.

  Further, in the conventional piezoelectric oscillator 300, since a power supply voltage terminal 302 and a frequency control terminal 303 are used as measurement terminals of the piezoelectric vibration element 202, a new electrode terminal called an adjustment terminal 307 must be provided in the package. The number of terminals increases, and there has been a problem that each electrode terminal cannot be provided unless the area is reduced in a package that is reduced in size.

  Therefore, the present invention has been made in view of the above problems, and even if the piezoelectric oscillator equipped with the piezoelectric vibration element is miniaturized, the piezoelectric vibration element can be easily measured without increasing the number of electrode terminals provided in the piezoelectric oscillator. It is an object of the present invention to provide a piezoelectric oscillator that can be performed in a simple manner.

The piezoelectric oscillator of the present invention includes a piezoelectric vibration element, an integrated circuit element, a power supply voltage terminal that is an external connection electrode terminal, an output terminal, a ground terminal, and an inhibit terminal, and accommodates the piezoelectric vibration element and the integrated circuit element. A piezoelectric oscillator including a package and a lid for hermetically sealing the package, wherein the integrated circuit element includes a first inverter that outputs an oscillation signal based on a resonance frequency of the piezoelectric vibration element A circuit unit, an amplifier circuit unit including a second inverter for amplifying an oscillation signal, a reference voltage generation circuit unit for generating a reference voltage, a reference voltage input from the reference voltage generation circuit unit, and an input from a power supply voltage terminal A switching circuit unit having a comparator that outputs an output signal when the power supply voltage is larger than the reference voltage or when the power supply voltage and the reference voltage have the same value, A first switch disposed between a connection between one end of the vibration element and the input side of the first inverter of the oscillation circuit unit, and operating with an output signal from the comparator, the other end of the piezoelectric vibration element, and the oscillation circuit unit A second switch arranged between the connection to the output side of the first inverter and operated by an output signal from the comparator; the other end of the piezoelectric vibration element; and the output side of the second inverter of the amplifier circuit section and the output A third switch that is arranged between the connection to the terminal and switches the connection between the other end of the piezoelectric vibration element or the output side of the second inverter of the amplification circuit unit and the output terminal by an output signal from the comparator; The piezoelectric vibration element is arranged between the one end of the piezoelectric vibration element, the second switch of the amplifier circuit section and the fifth terminal connected between the power supply voltage terminal and the inhibit terminal, and the piezoelectric vibration is generated by the output signal from the comparator. One end of the element or An input terminal of a signal for operating the fifth switch and is characterized by comprising a fourth switch for switching the connection between the inhibit terminal.

  The piezoelectric oscillator according to the present invention includes a piezoelectric vibration element, an integrated circuit element, a power supply voltage terminal that is an electrode terminal for external connection, an output terminal, a ground terminal, and a frequency control terminal. A piezoelectric oscillator including a package to be accommodated and a lid for hermetically sealing the package, wherein the integrated circuit element includes a first inverter that outputs an oscillation signal based on a resonance frequency of the piezoelectric vibration element. Including an oscillation circuit unit, an amplification circuit unit including a second inverter for amplifying an oscillation signal, a memory unit for storing temperature compensation data, and a temperature compensation signal generation circuit unit for performing temperature compensation based on the temperature compensation data The reference voltage generation circuit unit that generates the reference voltage, the reference voltage input from the reference voltage generation circuit unit, and the power supply voltage input from the power supply voltage terminal are compared. A switching circuit unit having a comparator that outputs an output signal when the value greater than the pressure or the power supply voltage and the reference voltage have the same value, one end of the piezoelectric vibration element, and the input side of the first inverter of the oscillation circuit unit Between the first switch operated by the output signal from the comparator and the other end of the piezoelectric vibration element and the output side of the first inverter of the oscillation circuit unit. The second switch that operates in accordance with the output signal from, the other end of the piezoelectric vibration element, and the output side of the second inverter of the amplifier circuit unit and the output terminal are connected, and by the output signal from the comparator, Frequency control of the third switch for switching the connection between the other end of the piezoelectric vibration element or the output side of the second inverter of the amplification circuit section and the output terminal, one end of the piezoelectric vibration element, the second inverter of the amplification circuit section Between connection to terminal And a fourth switch for switching the connection between the one end of the piezoelectric vibration element or the input side of the second inverter of the amplifier circuit unit and the frequency control terminal according to the output signal from the comparator. To do.

According to the piezoelectric oscillator of the present invention, the comparator of the switching circuit unit is connected to the power supply voltage terminal, so that the power supply voltage applied to the power supply voltage terminal is connected to the comparator. When a value larger than the reference voltage from the reference voltage or the power supply voltage and the reference voltage become the same value, an output signal is output from the comparator, and the first switch, the second switch, the third switch, the fourth switch Is switched.
The piezoelectric vibration element is disconnected from the oscillation circuit unit by the first switch and the second switch, and the piezoelectric vibration element is connected to the output terminal and the inhibit terminal by the third switch and the fourth switch. Thus, the output terminal and the inhibit terminal can be used as the monitoring electrode terminal of the piezoelectric vibration element, and the frequency characteristic of the piezoelectric vibration element can be measured by bringing the probe into contact with the output terminal and the inhibit terminal.
Therefore, it is not necessary to form the monitor electrode terminal on the side surface of the package, and it can also be used as the external connection electrode terminal. As a result, since the probe is applied to the external connection electrode terminal at a distant position, the probes do not come into contact with each other, and the measurement can be performed stably.
Also, in order to prevent contact failure by using the external connection electrode terminal formed on the other main surface of the package without forming the monitor electrode terminal in the narrow groove as in the prior art, what Since the probe does not need to be contacted again, the tip of the contact probe does not contact any part other than the electrode terminal for external connection, so that it is possible to prevent the package from cracking or chipping.
Further, since it is not necessary to form the monitor electrode terminal on the side surface of the package, it is possible to prevent fluctuations in the frequency of the piezoelectric vibration element caused by foreign matters such as fills adhering to the monitor electrode terminal.

In addition, according to the piezoelectric oscillator of the present invention, the comparator of the switching circuit unit is connected to the power supply voltage terminal, so that the power supply voltage applied to the power supply voltage terminal is connected to the comparator. When the reference voltage from the circuit unit is larger than the reference voltage or the power supply voltage and the reference voltage are the same value, a signal is output from the comparator, and the first switch, the second switch, the third switch, The switch is switched. Accordingly, the piezoelectric vibration element is disconnected from the oscillation circuit unit by the first switch and the second switch, and the piezoelectric vibration element is connected to the output terminal and the frequency control terminal by the third switch and the fourth switch. . Accordingly, the output terminal and the frequency control terminal can be used as the monitoring electrode terminal of the piezoelectric vibration element, and the frequency characteristic of the piezoelectric vibration element can be measured by bringing the probe into contact with the output terminal and the frequency control terminal. it can.
Therefore, the switch can be switched without providing a new electrode terminal such as an adjustment terminal unlike the conventional piezoelectric oscillator.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
For the sake of clarity, a part of the structure unnecessary for the description is not shown. Further, the illustrated dimensions are partially exaggerated.

(First embodiment)
FIG. 1 is an exploded perspective view showing a piezoelectric oscillator according to an embodiment of the present invention.
As shown in FIG. 1, a piezoelectric oscillator 100 according to an embodiment of the present invention includes a piezoelectric vibration element 20, an integrated circuit element 30, a power supply voltage terminal that is an external connection electrode terminal, an output terminal, a ground terminal, and an inhibit terminal. And the package 10 for accommodating the piezoelectric vibration element and the integrated circuit element, and the lid 50 for hermetically sealing the package 10.

For example, a quartz base plate is used as the piezoelectric vibration element 20. Excitation electrodes 21 are formed on both the front and back main surfaces of the quartz base plate, and an alternating voltage from the outside passes through the excitation electrode 21. When applied to a quartz base plate, excitation occurs in a predetermined vibration mode and frequency.
The quartz base plate is a substantially flat plate shape that is cut from an artificial crystalline lens at a predetermined cut angle and is subjected to external processing, and has a planar shape of, for example, a quadrangle.
Such a piezoelectric vibration element 20 includes an excitation electrode 21 attached to both main surfaces of the piezoelectric vibration element 20 and a piezoelectric vibration element mounting pad 15 formed on the opening side surface of the mounting portion 16 in the recessed space 11. It is mounted on the mounting portion 16 of the recessed space 11 by being electrically and mechanically connected via the conductive adhesive 40. The mounting portion 16 is formed to be higher than the bottom surface of the recessed space 11. In addition, the piezoelectric vibration element mounting pad 15 is electrically connected to the integrated circuit element 30 via the wiring conductor and via hole conductor inside the package 10 and the integrated circuit element connection electrode pad 14 formed on the bottom surface in the recessed space. Connected.

  The conductive adhesive 40 contains a conductive filler in a silicone resin, and examples of the conductive powder include aluminum (Al), molybdenum (Mo), tungsten (W), platinum (Pt), One containing palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or any combination thereof is used.

  The integrated circuit element 30 is provided with an electronic circuit including an oscillation circuit for generating an oscillation output from the piezoelectric vibration element 20 on the circuit forming surface, and an output signal generated by the oscillation circuit is an external connection electrode terminal. 13 is output to the outside of the piezoelectric oscillator via an output terminal, and is used as a reference signal such as a clock signal, for example. The integrated circuit element 30 is mounted on the integrated circuit element mounting pad 14 formed in the recessed space 11 of the package 10.

  The package 10 is formed, for example, by laminating a plurality of insulating layers made of a ceramic material such as alumina ceramics or glass-ceramic, and a rectangular shape opening in the central region is formed on one main surface of the package 10. A recessed space 11 is formed. An annular sealing conductor pattern 12 is formed on the entire periphery of the opening side top surface of the side wall portion of the package 10 that surrounds the recessed space 11. In the recessed space 11, a mounting portion 16 provided at a higher position due to a step from the bottom surface of the recessed space 11, a piezoelectric vibration element mounting pad 15 formed on the mounting portion 16, and a bottom surface of the recessed space 11 An integrated circuit element mounting pad 12 is provided. Further, a power supply voltage terminal, a ground terminal, an output terminal, and an inhibit terminal which are external connection electrode terminals 13 are formed on the other main surface of the package 10.

The integrated circuit element mounting pad 14 is formed on the inner bottom surface of the recess space 11 of the package 10.
The integrated circuit element mounting pad 14 is electrically connected to the connection pad formed in the integrated circuit element 30 electrically and mechanically, and is externally connected via a wiring conductor or via hole conductor formed in the package 10. Of the connection electrode terminals 13, the output terminal, the inhibit terminal, and the power supply voltage terminal are electrically connected.

The external connection electrode terminal 13 is composed of a power supply voltage terminal, a ground terminal, an output terminal, and an inhibit terminal. These external connection electrode terminals 13 mount the piezoelectric oscillator 100 on an external electric circuit such as a mother board. At this time, it is electrically connected to the circuit wiring of the external electric circuit by soldering or the like.
In addition, the sealing conductor pattern 12 formed on the top surface of the side wall portion of the package 10 has, for example, a nickel (Ni) layer and gold (Au) on the surface of a base layer made of tungsten (W), molybdenum (Mo), or the like. The layers are formed in a thickness of 10 μm to 25 μm by sequentially depositing the layers so as to surround the package 10 in an annular shape, and the sealing conductor pattern 12 has a lid 50 described later on the lid 50. It is for bonding to the top surface of the side wall portion of the package 10 through the formed sealing member 51, and a Ni layer and a surface of a base layer made of W or Mo are formed on the sealing conductor pattern 12. The structure in which the Au layer is sequentially deposited improves the wettability of the sealing member 51 with respect to the sealing conductor pattern 12, and improves the hermetic reliability and productivity of the piezoelectric oscillator 100. Improve.

  The lid 50 is manufactured by adopting a conventionally known metal processing method and molding a metal such as 42 alloy into a predetermined shape, and a nickel (Ni) layer is formed on the upper surface of the lid 50. A gold tin (Au—Sn) layer, which is the sealing member 51, is formed at a location corresponding to the sealing conductor pattern 12 on the upper surface of the nickel (Ni) layer. The thickness of the gold tin (Au—Sn) layer is 10 μm to 40 μm. For example, the component ratio is 80% gold and 20% tin. Moreover, such a sealing member 51 can relieve unevenness of the sealing conductor pattern 12 and prevent a decrease in hermeticity. Further, if the sealing member 51 is too thin, the function is not sufficiently exhibited.

FIG. 2 is a block diagram showing a state in which the piezoelectric oscillator functions as the first embodiment of the present invention.
FIG. 3 is a block diagram showing a state in which the frequency characteristic of the piezoelectric vibration element of the piezoelectric oscillator according to the first embodiment of the present invention is measured.
In the first embodiment, the piezoelectric vibration element 20 and the integrated circuit element 30 include an oscillation circuit unit X, an amplification circuit unit Y, a first switch SW1, a second switch SW2, and a third switch. A switch circuit including a switch SW3, a fourth switch SW4, a comparator COMP1 connected to the first switch SW1, the second switch SW2, the third switch SW3, and the fourth switch SW4. A unit Z and a reference voltage generation circuit unit for applying the reference voltage Vref to the comparator COMP1 are provided.
The integrated circuit element 30 includes an oscillation circuit unit X, an amplification circuit unit Y, a first switch SW1, a second switch SW2, a third switch SW3, a fourth switch SW4, and a switching circuit. An electronic circuit in which the unit Z and the reference voltage generation circuit unit are integrated is included.

As shown in FIGS. 2 and 3, a constant voltage is applied to the oscillation circuit unit X and the amplification circuit unit Y by the power supply voltage applied to the power supply voltage terminal Vdd.
2 and 3, the power supply voltage terminal Vdd is connected to the first inverter INV1 and the second inverter INV2 in the oscillation circuit unit X and the amplifier circuit unit Y.

As shown in FIGS. 2 and 3, the oscillation circuit unit X includes a first inverter INV1, a resistor R3, and capacitors C1 and C2.
The resistor R3 is connected in parallel between the input and output of the first inverter INV1.
XT1, which is one end of the piezoelectric vibration element 20, is connected to the input side of the first inverter INV1, one end of the resistor R3, and one end of the capacitor C1 serving as a load capacitance. The other end of the capacitor C1 is connected to the ground terminal GND.
XT2, which is the other end of the piezoelectric vibration element 20, is connected to the output side of the first inverter INV1, the other end of the resistor R3, and one end of a capacitor C2 serving as a load capacitance. The other end of the capacitor C2 is connected to the ground terminal GND.

As shown in FIGS. 2 and 3, the amplifier circuit unit Y is configured by a second inverter INV2.
The input side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output side of the first inverter INV1 of the oscillation circuit unit X.
The output side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output terminal OUT.
The second inverter INV2 and the power supply voltage terminal Vdd of the amplifier circuit unit Y are connected via a fifth switch SW5.
The inhibit terminal INH and the fifth switch SW5 are connected, and when the constant voltage is applied to the inhibit terminal INH, the fifth switch SW5 is connected to the second inverter INV2 of the amplifier circuit unit Y and the power supply voltage terminal Vdd. Is connected to the second inverter INV2 of the amplifier circuit unit Y and the power supply voltage terminal Vdd, and the constant voltage from the power supply voltage terminal Vdd is changed to the second inverter INV2 of the amplifier circuit unit Y. Therefore, the output of the oscillation signal from the output terminal OUT is stopped.
That is, by applying a predetermined voltage to the inhibit terminal INH, the output as the piezoelectric oscillator can be stopped while oscillating the piezoelectric vibration element 20, so that when the output of the piezoelectric oscillator is required, the predetermined voltage to the inhibit terminal INH is determined. When the voltage application is stopped, the fifth switch SW5 is connected and can be immediately output as a piezoelectric oscillator. Therefore, the rise time of the piezoelectric oscillator can be shortened.

  As shown in FIGS. 2 and 3, the reference voltage generation circuit unit R is connected to the negative input side of the comparator COMP1 of the switching circuit unit Z, and applies the set reference voltage Vref to the comparator COMP1.

As shown in FIGS. 2 and 3, the switching circuit section Z is configured by resistors R1 and R2 and a comparator COMP1.
One end of the resistor R1 is connected to the power supply voltage terminal Vdd, and the other end of the resistor R1 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the ground terminal GND.
The positive input side of the comparator COMP1 is connected to the other end of the resistor R1 and one end of the resistor R2. The negative input side of the comparator COMP1 is connected to a reference voltage generating circuit unit for applying the reference voltage Vref.
The output side of the comparator COMP1 is connected to the first switch SW1, the second switch SW2, the third switch SW3, and the fourth switch SW4.

As shown in FIGS. 2 and 3, the first switch SW <b> 1 is arranged between the connection between XT <b> 1 that is one end of the piezoelectric vibration element 20 and the input side of the first inverter INV <b> 1 of the oscillation circuit unit X. Yes.
The second switch SW2 is disposed between the connection of XT2, which is the other end of the piezoelectric vibration element 20, and the output side of the first inverter INV1 of the oscillation circuit unit X.
The third switch SW3 is disposed between the connection between XT2, which is the other end of the piezoelectric vibration element 20, and the output side of the second inverter INV2 of the amplification circuit unit Y and the output terminal OUT. Is provided with a function of switching the connection between XT2, the other inverter INV2, and the output terminal OUT.
The fourth switch SW4 includes XT1 which is one end of the piezoelectric vibration element 20, the fifth switch SW5 and the inhibit terminal INH connected between the second inverter INV2 of the amplifier circuit unit Y and the power supply voltage terminal Vdd. Between the input terminal of the signal for operating XT1 and the fifth switch SW5, which is one end of the crystal resonator element, and the inhibit terminal INH.

As shown in FIG. 2, the piezoelectric vibration element 20 is connected in parallel to the first inverter INV1 of the oscillation circuit section X in a state where the first switch SW1 and the second switch SW2 are connected. The third switch SW3 is switched so that the output side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output terminal Out.
The fourth switch SW4 is switched so that the second inverter INV2 of the amplifier circuit unit Y and the inhibit terminal INH are connected.
Further, as shown in FIG. 3, the reference voltage Vref input from the reference voltage generation circuit R is compared with the power supply voltage input from the power supply voltage terminal Vdd, and the power supply voltage is larger than the reference voltage Vref, or When the power supply voltage has the same value as the reference voltage Vref, the comparators COMP1 output signals S1, S2, S3, and S4, and the first switch SW1 and the second switch SW2 are disconnected, The third switch SW3 is switched so that the output terminal OUT is connected to XT2 which is the other end of the piezoelectric vibration element 20, and the fourth switch SW4 is connected to XT1 which is one end of the piezoelectric vibration element 20 and the inhibit terminal INH. The piezoelectric vibrating element 20 is completely disconnected from the oscillation circuit unit X, the amplification circuit unit Y, and the switching circuit unit Z. Since both ends of the separated piezoelectric vibration element 20 are connected to the output terminal OUT and the inhibit terminal INH, respectively, the frequency characteristics of the piezoelectric vibration element 20 from the external connection electrode terminal serving as the output terminal OUT and the inhibit terminal INH are obtained. Can be measured.

When the signal S1 is input to the first switch SW1, the first switch SW1 is disconnected from XT1 that is one end of the piezoelectric vibration element 20 and the input side of the first inverter INV1 of the oscillation circuit unit X.
When the signal S2 is input to the second switch SW2, the second switch SW2 is disconnected from the output side of the first inverter INV1 of the oscillation circuit section X and XT2 which is the other end of the piezoelectric vibration element 20. .
When the signal S3 is input to the third switch SW3, the third switch SW3 is connected to the output terminal OUT and XT2 which is the other end of the piezoelectric vibration element.
When the signal S4 is input to the fourth switch SW4, the fourth switch SW4 is connected to the inhibit terminal INH and XT1 which is one end of the piezoelectric vibration element.

For example, when the resistance values of the resistor R1 and the resistor R2 are the same, and the reference voltage Vref applied to the negative input side of the comparator COMP1 is set to 2.0 (V), the power supply applied to the power supply voltage terminal Vdd When the voltage is 3.0 (V), since 1.5 (V) is input to the positive input side of the comparator, the signals S1, S2, S3, and S4 from the comparator are not output and oscillation occurs. The circuit unit X and the amplifier circuit unit Y operate, and a signal is output from the output terminal OUT.
When the power supply voltage applied to the power supply voltage terminal Vdd is 4.0 (V), 2.0 (V) is input to the positive input side of the comparator 40, so that the signal S1, S2, S3, and S4 are output, and the piezoelectric vibration element 20 is connected to the output terminal OUT and the inhibit terminal INH.

The signals S1 to S4 are different signals. The signal S1 is input to the first switch SW1. Thereby, XT1 which becomes one end of the piezoelectric vibration element 20 from the state where the first switch SW1 is connected to XT1 which is one end of the piezoelectric vibration element 20 and the input side of the first inverter INV1 of the oscillation circuit section X, and the oscillation circuit section The input side of the X first inverter INV1 is disconnected.
The signal S2 is input to the second switch SW2. As a result, the second switch SW2 oscillates with XT2, which is the other end of the piezoelectric vibration element 20, from the state where the second switch SW2 is connected to the other end of the piezoelectric vibration element 20, and the output side of the first inverter INV1 of the oscillation circuit unit X The output side of the first inverter INV1 of the circuit unit X is disconnected.
The signal S3 is input to the third switch SW3. As a result, the third switch SW3 is connected to the output terminal OUT and XT2, which is the other end of the piezoelectric vibration element 20, from the state where the output side of the second inverter INV2 of the amplifier circuit Y is connected to the output terminal OUT. It becomes a state. The signal S4 is input to the fourth switch SW4. As a result, the fourth switch SW4 changes from the state where the fifth switch SW5 and the inhibit terminal INH are connected to the state where the XT1 which is one end of the piezoelectric vibration element 20 and the inhibit terminal INH are connected.

Thus, by the piezoelectric oscillator according to the first embodiment of the present invention, the comparator of the switching circuit unit Z is connected to the power supply voltage terminal Vdd, so that the power supply voltage applied to the power supply voltage terminal Vdd is compared. When the reference voltage Vref from the reference voltage generation circuit R connected to the comparator COMP1 is larger than the reference voltage Vref, or the power supply voltage and the reference voltage Vref have the same value, the output signals S1, S2, S3, S4 is output, and the first switch SW1, the second switch SW2, the third switch SW3, and the fourth switch SW4 are switched.
The piezoelectric vibration element 20 is disconnected from the oscillation circuit unit X by the first switch SW1 and the second switch SW2, and the piezoelectric vibration element 20 is output from the output terminal OUT and the inhibit terminal by the third switch SW3 and the fourth switch SW4. Connected to INH. As a result, the output terminal OUT and the inhibit terminal INH can be used as monitoring electrode terminals of the piezoelectric vibration element, and a probe is brought into contact with the output terminal OUT and the inhibit terminal INH to measure the frequency characteristics of the piezoelectric vibration element. Can do.
Therefore, it is not necessary to form the monitor electrode terminal on the side surface of the package, and it can also be used as the external connection electrode terminal.
As a result, since the probe is applied to the external connection electrode terminal at a distant position, the probes do not come into contact with each other, and the measurement can be performed stably.
Also, in order to prevent contact failure by using the external connection electrode terminal formed on the other main surface of the package without forming the monitor electrode terminal in the narrow groove as in the prior art, what Since the probe does not need to be contacted again, the tip of the contact probe does not contact any part other than the electrode terminal for external connection, so that it is possible to prevent the package from cracking or chipping.
Further, since it is not necessary to form the monitor electrode terminal on the side surface of the package, it is possible to prevent fluctuations in the frequency of the piezoelectric vibration element caused by foreign matters such as fills adhering to the monitor electrode terminal.
Therefore, the switch can be switched without providing a new electrode terminal such as an adjustment terminal unlike the conventional piezoelectric oscillator.

(Second Embodiment)
The difference is that the inhibit terminal INH of the external connection electrode terminal provided in the package 10 is the frequency control terminal Vcont. Further, the integrated circuit element is different in that a memory portion and a temperature compensation signal control circuit portion are provided.
FIG. 4 is a block diagram showing a state of functioning as a piezoelectric oscillator according to the second embodiment of the present invention, and FIG. 5 shows a piezoelectric vibration element of the piezoelectric oscillator according to the second embodiment of the present invention. It is a block diagram which shows the state which measures a frequency characteristic.
In the second embodiment, an oscillation circuit unit X, an amplification circuit unit Y, a memory unit M for storing temperature compensation control data, and a temperature compensation control data in the piezoelectric vibration element 20 and the integrated circuit element. Based on the temperature compensation signal control circuit unit T for performing temperature compensation, the first switch SW1, the second switch SW2, the third switch SW3, the fourth switch SW4, and the first switch SW1, A switching circuit unit Z including a comparator COMP1 connected to the second switch SW2, the third switch SW3, and the fourth switch SW4, and a reference voltage for applying a reference voltage Vref to the comparator COMP1 And a generation circuit unit R.

As shown in FIGS. 4 and 5, a constant voltage is applied to the oscillation circuit unit X and the amplification circuit unit Y by the power supply voltage applied to the power supply voltage terminal Vdd.
As shown in FIGS. 4 and 5, in the oscillation circuit unit X and the amplification circuit unit Y, the power supply voltage terminal Vdd is connected to the first inverter INV1 and the second inverter INV2.

As shown in FIGS. 4 and 5, the oscillation circuit unit X includes a first inverter INV1, a resistor R3, and variable capacitance diodes Cv1 and Cv2.
The second inverter INV2 of the oscillation circuit section X and the power supply voltage terminal Vdd are connected. The resistor R3 is connected in parallel between the input and output of the second inverter INV2.
XT1, which is one end of the piezoelectric vibration element 20, is connected to the input side of the first inverter INV1, one end of the resistor R3, and the cathode of the variable capacitance diode Cv1 serving as a load capacitance. The anode of the variable capacitance diode Cv1 is connected to the ground terminal GND.
XT2, which is the other end of the piezoelectric vibration element 20, is connected to the output side of the first inverter INV1, the other end of the resistor R3, and the cathode of the variable capacitance diode Cv2 serving as a load capacitance. The anode of the variable capacitance diode Cv2 is connected to the ground terminal GND.
The frequency control terminal Vcont and the cathodes of the variable capacitance diodes Cv1 and Cv2 are connected. The load capacity is adjusted by applying a constant voltage to the frequency control terminal Vcont. Thus, by adjusting the load capacity, the oscillation characteristic of the piezoelectric vibration element 20 (Xtal) is compensated to the reference frequency.
That is, in the wide temperature range region, the voltage supplied to the variable capacitance diodes Cv1 and Cv2 is controlled, and the inherent temperature frequency characteristic of the piezoelectric vibration element 20 can be flattened over a wide temperature range.

As shown in FIGS. 4 and 5, the amplifier circuit unit Y is configured by a second inverter INV2.
The input side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output side of the first inverter INV1 of the oscillation circuit unit X.
The output side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output terminal OUT.
The second inverter INV2 of the amplifier circuit unit Y and the power supply voltage terminal Vdd are connected.

As shown in FIGS. 4 and 5, the memory M for storing the temperature compensation control data is composed of PROM and EEPROM.
Temperature compensation control for parameters that are the basis of a cubic function represented by the following equation 1 as a temperature compensation function, for example, a third-order component adjustment value α, a first-order component adjustment value β, and a zero-order component adjustment value γ Data is input from the write / read terminals INPUT / OUTPUT and stored in the memory unit M.
f = α (T−T ₀ ) ³ + β (T−T ₀ ) + γ (Expression 1)
Note that f indicates a frequency, α indicates a constant of a third-order component, β indicates a constant of a first-order component, γ indicates a constant of a zero-order component, and T and T ₀ indicate temperatures.

The temperature compensation signal control circuit unit T includes a cubic function generation circuit, a quintic function generation circuit, and the like. For example, in the case of a cubic function generating circuit, the temperature compensation control data input to the memory unit M is read, and a voltage derived from the temperature compensation control data with a cubic function is generated for each temperature. . The external ambient temperature at this time is obtained from a temperature sensor (not shown) in the integrated circuit element.
The temperature compensation signal control circuit unit T is connected to the cathodes of the variable capacitance diodes Cv1 and Cv2, and the voltage from the temperature compensation signal control circuit unit T is applied thereto.
As described above, by applying the voltage from the temperature compensation signal control circuit T to the variable capacitance diodes Cv1 and Cv2, the frequency temperature characteristic of the piezoelectric vibration element 20 is corrected to flatten the frequency temperature characteristic.

  As shown in FIGS. 4 and 5, the reference voltage generation circuit unit R is connected to the negative input side of the comparator COMP1 of the switching circuit unit Z and applies the reference voltage Vref set to the comparator COMP1.

As shown in FIGS. 4 and 5, the switching circuit unit Z includes resistors R1 and R2 and a comparator COMP1.
One end of the resistor R1 is connected to the power supply voltage terminal Vdd, and the other end of the resistor R1 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the ground terminal GND.
The positive input side of the comparator COMP1 is connected to the other end of the resistor R1 and one end of the resistor R2. The negative input side of the comparator COMP1 is connected to a reference voltage generation circuit unit R for applying the reference voltage Vref.
The output side of the comparator COMP1 is connected to the first switch SW1, the second switch SW2, the third switch SW3, and the fourth switch SW4.

As shown in FIGS. 4 and 5, the first switch SW1 is disposed between the connection between XT1 which is one end of the piezoelectric vibration element 20 and the input side of the first inverter INV1 of the oscillation circuit section X. Yes. When the signal S1 is input to the first switch SW1, the first switch SW1 is disconnected from XT1 that is one end of the piezoelectric vibration element 20 and the input side of the first inverter INV1 of the oscillation circuit unit X.
The second switch SW2 is disposed between the connection of XT2, which is the other end of the piezoelectric vibration element 20, and the output side of the first inverter INV1 of the oscillation circuit unit X. When the signal S2 is input to the second switch SW2, the second switch SW2 is disconnected from the output side of the first inverter INV1 of the oscillation circuit section X and XT2 which is the other end of the piezoelectric vibration element 20. .
The third switch SW3 is disposed between the connection between XT2, which is the other end of the piezoelectric vibration element 20, and the output side of the second inverter INV2 of the amplification circuit unit Y and the output terminal OUT. 20 is provided with a function of switching the connection between XT2, which is the other end of 20, the second inverter INV2, and the output terminal OUT.
The fourth switch SW4 is arranged between XT1, which is one end of the piezoelectric vibration element 20, and the connection between the second inverter INV2 of the amplification circuit unit Y and the frequency control terminal Vcont. A function of switching connection between a certain XT1, a second inverter INV2, and a frequency control terminal Vcont is provided.
When the signal S4 is input to the fourth switch SW4, the fourth switch SW4 is connected to the frequency control terminal Vcont and XT1 which is one end of the piezoelectric vibration element.

As shown in FIG. 4, the piezoelectric vibration element 20 is connected in parallel to the first inverter INV1 of the oscillation circuit section X with the first switch SW1 and the second switch SW2 connected. The third switch SW3 is switched so that the output side of the second inverter INV2 of the amplifier circuit unit Y and the output terminal OUT are connected.
The fourth switch SW4 is connected to the second inverter INV2 of the amplifier circuit unit Y and the frequency control terminal Vcont.
Further, as shown in FIG. 5, the reference voltage Vref input from the reference voltage generation circuit R is compared with the power supply voltage input from the power supply voltage terminal Vdd, and the power supply voltage is larger than the reference voltage Vref or the power supply voltage. Is equal to the reference voltage Vref, signals S1, S2, S3, S4 are output from the comparator COMP1, and the first switch SW1 and the second switch SW2 are disconnected, and the third switch SW3 is switched so that XT2 which is the other end of the piezoelectric vibration element 20 and the output terminal OUT are connected, and the fourth switch SW4 is connected so that XT1 which is one end of the piezoelectric vibration element 20 and the frequency control terminal Vcont are connected. The piezoelectric vibration element 20 is completely separated from the oscillation circuit unit X, the amplification circuit unit Y, and the switching circuit unit Z. Since both ends of the separated piezoelectric vibration element 20 are connected to the output terminal OUT and the frequency control terminal Vcont, respectively, the external connection electrode terminal serving as the output terminal OUT and the frequency control terminal Vcont is connected to the piezoelectric vibration element 20. It becomes possible to measure frequency characteristics.

  For example, when the resistance values of the resistor R1 and the resistor R2 are the same, and the reference voltage Vref applied to the negative input side of the comparator COMP1 is set to 2.0 (V), the power supply applied to the power supply voltage terminal Vdd When the voltage is 3.0 (V), since 1.5 (V) is input to the positive input side of the comparator COMP1, the signals S1, S2, S3, and S4 from the comparator COMP1 are not output. The oscillation circuit unit X and the amplification circuit unit Y operate, and a signal is output from the output terminal OUT. When the power supply voltage applied to the power supply voltage terminal Vdd is 4.0 (V), 2.0 (V) is input to the positive input side of the comparator 40, so that the signal S1 is output from the comparator COMP1. , S2, S3, and S4 are output, and the piezoelectric vibration element 20 is connected to the output terminal OUT and the frequency control terminal Vcont.

The signals S1 to S4 are different signals. The signal S1 is input to the first switch SW1. Thereby, XT1 which becomes one end of the piezoelectric vibration element 20 from the state where the first switch SW1 is connected to XT1 which is one end of the piezoelectric vibration element 20 and the input side of the first inverter INV1 of the oscillation circuit section X, and the oscillation circuit section The state is disconnected from the input side of the X first inverter INV1.
The signal S2 is input to the second switch. Accordingly, the second switch SW2 is connected to the other side of the piezoelectric vibration element 20 from the state in which the second switch SW2 is connected to XT2 which is the other end of the piezoelectric vibration element 20 and the output side of the first inverter INV1 of the oscillation circuit unit X. The terminal XT2 and the output side of the first inverter INV1 of the oscillation circuit section X are disconnected.
The signal S3 is input to the third switch SW3. As a result, the third switch SW3 is connected to the output terminal OUT and XT2, which is the other end of the piezoelectric vibration element 20, from the state where the output side of the second inverter INV2 of the amplifier circuit unit Y and the output terminal OUT are connected. It becomes a state.
The signal S4 is input to the fourth switch SW4. As a result, the fourth switch SW4 is connected to the frequency control terminal Vcont and XT1, which is one end of the piezoelectric vibration element 20, from the state where the cathodes of the variable capacitance diodes Cv1 and Cv2 of the oscillation circuit unit X and the frequency control terminal Vcont are connected. It becomes a state.

  Thus, with the piezoelectric oscillator according to the second embodiment of the present invention, the piezoelectric vibration element 20 is disconnected from the oscillation circuit section X by the first switch SW1 and the second switch SW2, and the piezoelectric vibration element 20 is third. By connecting the output terminal OUT and the frequency control terminal Vcont by the switch SW3 and the fourth switch SW4, the probe is brought into contact with the output terminal OUT and the frequency control terminal Vcont to measure the piezoelectric vibration element 30. be able to.

In addition, this invention is not limited to the said embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
For example, in the above-described embodiment, the case where quartz is used as the piezoelectric material constituting the piezoelectric vibration element 20 has been described. However, as other piezoelectric materials, lithium niobate, lithium tantalate, or piezoelectric ceramics is used as the piezoelectric material. The piezoelectric vibration element used may be used.

  The piezoelectric oscillator 100 according to the present invention includes a piezoelectric vibration element 20 and an integrated circuit element 30 housed in a recessed space 11 of a package 10 and hermetically sealed with a lid 40, but formed on one main surface of the package. A piezoelectric oscillator in which a piezoelectric vibration element is mounted in the first recess space formed and an integrated circuit element is mounted in a second recess space formed on the other main surface of the package may be used.

1 is an exploded perspective view showing a piezoelectric oscillator according to an embodiment of the present invention. It is a block diagram which shows the state which the piezoelectric oscillator which concerns on the 1st Embodiment of this invention is functioning. It is a block diagram which shows the state which measures the frequency characteristic of the piezoelectric vibration element of the piezoelectric oscillator which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the state which the piezoelectric oscillator which concerns on the 2nd Embodiment of this invention is functioning. It is a block diagram which shows the state which measures the frequency characteristic of the piezoelectric vibration element of the piezoelectric oscillator which concerns on the 2nd Embodiment of this invention. It is a disassembled perspective view which shows the conventional piezoelectric oscillator. It is a block diagram which shows the conventional piezoelectric oscillator. It is a block diagram which shows the conventional piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Package 11 ... Recessed space 12 ... Conductive pattern for sealing 13 ... Electrode terminal for external connection 14 ... Piezoelectric vibration element mounting pad 15 ... Integrated circuit element mounting pad 20 ... Piezoelectric vibration element 21 ... excitation electrode 30 ... integrated circuit element 40 ... conductive adhesive 50 ... lid 51 ... sealing member 100 ... piezo oscillator X ... oscillation Circuit unit Y: Amplifier circuit unit Z: Switching circuit unit C1, C2: Capacitors Cv1, Cv2: Variable capacitance diodes R1, R2, R3: Resistors INV1: First inverter INV2 ... Second inverter SW1 ... First switch SW2 ... Second switch SW3 ... Third switch SW4 ... Fourth switch COMP1 ... Comparator Vdd ... Power supply Voltage Child INH · · · Inhibit terminal Vcont · · · frequency control terminal OUT · · · output terminal GND · · · ground terminal INPUT / OUTPUT · · · writing reading terminal

Claims (2)

A piezoelectric vibration element; an integrated circuit element; a package having a power supply voltage terminal, an output terminal, a ground terminal, and an inhibit terminal which are electrode terminals for external connection; and the package accommodating the piezoelectric vibration element and the integrated circuit element; A piezoelectric oscillator having a lid for hermetically sealing
The integrated circuit element includes an oscillation circuit unit including a first inverter that outputs an oscillation signal based on a resonance frequency of the piezoelectric vibration element;
An amplifier circuit unit including a second inverter for amplifying the oscillation signal;
A reference voltage generation circuit unit for generating a reference voltage;
The reference voltage input from the reference voltage generation circuit unit is compared with the power supply voltage input from the power supply voltage terminal, and output when the power supply voltage is greater than the reference voltage or the power supply voltage and the reference voltage are the same value. A switching circuit unit having a comparator for outputting a signal;
A first switch disposed between a connection between one end of the piezoelectric vibration element and an input side of the first inverter of the oscillation circuit unit, and operated by an output signal from the comparator;
A second switch disposed between the other end of the piezoelectric vibration element and the output side of the first inverter of the oscillation circuit unit, and operated by an output signal from the comparator;
The other end of the piezoelectric vibration element is arranged between the other end of the piezoelectric vibration element and the output side of the second inverter of the amplification circuit unit and the output terminal. A third switch for switching the connection between the output side of the second inverter of the circuit unit and the output terminal;
An output signal from the comparator is arranged between one end of the piezoelectric vibration element, the second switch of the amplifier circuit unit, and a fifth switch connected between the power supply voltage terminal and the inhibit terminal. A piezoelectric oscillator comprising: a fourth switch for switching connection between one end of the piezoelectric vibration element or a signal input terminal for operating the fifth switch and the inhibit terminal. A piezoelectric vibration element, an integrated circuit element, a power supply voltage terminal that is an external connection electrode terminal, an output terminal, a ground terminal, and a frequency control terminal, and a package that accommodates the piezoelectric vibration element and the integrated circuit element; A piezoelectric oscillator comprising a lid for hermetically sealing the package,
The integrated circuit element includes an oscillation circuit unit including a first inverter that outputs an oscillation signal based on a resonance frequency of the piezoelectric vibration element;
An amplifier circuit unit including a second inverter for amplifying the oscillation signal;
A memory unit for storing temperature compensation data;
Based on the temperature compensation data, a temperature compensation signal generation circuit unit for performing temperature compensation;
A reference voltage generation circuit unit for generating a reference voltage;
The reference voltage input from the reference voltage generation circuit unit is compared with the power supply voltage input from the power supply voltage terminal, and output when the power supply voltage is greater than the reference voltage or the power supply voltage and the reference voltage are the same value. A switching circuit unit having a comparator for outputting a signal;
A first switch disposed between a connection between one end of the piezoelectric vibration element and an input side of the first inverter of the oscillation circuit unit, and operated by an output signal from the comparator;
A second switch disposed between the other end of the piezoelectric vibration element and the output side of the first inverter of the oscillation circuit unit, and operated by an output signal from the comparator;
The other end of the piezoelectric vibration element is arranged between the other end of the piezoelectric vibration element and the output side of the second inverter of the amplification circuit unit and the output terminal. A third switch for switching the connection between the output side of the second inverter of the circuit unit and the output terminal;
The piezoelectric vibration element is disposed between one end of the piezoelectric vibration element and a second inverter of the amplification circuit unit and a frequency control terminal. Depending on an output signal from the comparator, one end of the piezoelectric vibration element or the first of the amplification circuit unit A piezoelectric oscillator comprising: a fourth switch for switching connection between an input side of the inverter of 2 and the frequency control terminal.

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