JP2005244500A - Piezoelectric device, manufacturing method thereof, package for piezoelectric device, mobile phone device using piezoelectric device, and electronic apparatus using piezoelectric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device and a package capable of avoiding the possibility of causing a short circuit by mounting and also exhibiting stable performance without causing a capacitance change on the package bottom side, and a mobile phone and an electronic device using the piezoelectric device. To provide.
SOLUTION: First to third holes 61, 62, 63 are formed in the first to third substrates 55, 56, 57 constituting the bottom of the package 37, respectively. A through hole 60 in which the three holes communicate with each other communicates the space inside the package housing the piezoelectric vibrating piece with the outside, and the through hole has at least a hole diameter of the second hole. By making the hole diameter of the third hole smaller, a downward stepped portion is provided, and the metal covering portion 64 is formed only on the downward stepped portion and the inner periphery of the second hole.
[Selection] Figure 2

Description

  The present invention relates to a piezoelectric device and a package in which a piezoelectric vibrating piece is accommodated in a package, a mobile phone and an electronic apparatus using the piezoelectric device.

Piezoelectric vibrators in small information devices such as HDDs (hard disk drives), mobile computers, and IC cards, mobile communication devices such as mobile phones, car phones, and paging systems, and measuring devices such as gyro sensors Piezoelectric devices such as piezoelectric oscillators are widely used.
A conventional piezoelectric device is configured, for example, as shown in a schematic sectional view of FIG. 8 (see Patent Document 1).

  In the figure, the piezoelectric device 1 shows an example in which a piezoelectric oscillator is configured. The piezoelectric device 1 includes a piezoelectric package 5 that contains a piezoelectric vibrating piece 5 and is hermetically sealed with a lid 6. A vibrator 2 and a second package 4 disposed below the first package 3 and containing an oscillation circuit element (IC) 7 are provided inside. The second package 4 is made of resin. 8 is resin-sealed.

The first package 3 is provided with a through hole 9 at the bottom, so that degassing in the first package 3 can be performed in a step before joining the second package 4.
FIG. 9 shows an enlarged cross section of the through-hole 9 for degassing.
The through hole 9 is formed at the bottom of the first package 3, and this bottom is formed by laminating and fixing the first substrate 18 and the second substrate 19. And the through-hole 9 has the 1st hole 11 and the 2nd hole 12 which were formed in the laminated | stacked 1st board | substrate 18 and the 2nd board | substrate 19, respectively, By communicating with the two holes 12, the inside and the outside of the first package 3 in FIG. 8 are communicated with each other.

Here, the inner diameter of the first hole 11 is formed larger than the inner diameter of the second hole 12, whereby a downward stepped portion is provided in the middle of the through hole 9. And the metallized part is formed in the inner periphery of the 1st hole 11, and the said downward step part, and the molten metal sealing material 14 which consists of Au-Ge etc. is filled.
That is, after the piezoelectric vibrating reed 5 is joined in the first package 3 of FIG. 8, it is heated and the gas component generated from the adhesive or the like is discharged from the through-hole 9 to the outside. The hole 14 is hermetically sealed by filling the material 14 into the through hole 9.

JP 2003-229720 A

However, as shown in FIG. 8, when the first package 3 is joined to the second package 4 to form a piezoelectric oscillator, the piezoelectric vibrator 2 is to be mounted on a mounting board or the like as it is. The problem as shown in FIG. 9 arises.
That is, in FIG. 9, solder 16 is applied to lands (not shown) on the mounting substrate 17, and the mounting terminals 15 provided on the bottom surface of the first package are disposed thereon, and a reflow process is performed. Implement by.

In this case, if the solder 16 flows more than necessary, it may approach the through hole 9 and touch the metal sealing material 14. As a result, the metal sealing material 14 may be interposed between the molten solder from other mounting terminals (not shown) and a short circuit may occur.
Furthermore, when the molten solder 16 conducted to the metal sealing material 14 and the mounting terminal 15 contacts, the conductor area on the bottom surface side increases, and the electrical capacitance value (capacitor) may change. If such a capacitance change occurs in the mounted state, there is a risk of malfunction.
Piezoelectric devices have been greatly reduced in size in recent years, especially in surface-mount type piezoelectric devices, due to further downsizing of the package, if the mounting terminal and the through hole are closer than the current product, such a short circuit will occur. There is a risk that the risk of happening will become reality.

  The present invention has been made to solve the above problems, and avoids the possibility of short circuiting due to mounting, and at the same time, without causing a change in capacitance on the bottom side of the package, and a piezoelectric device that can exhibit stable performance It is an object of the present invention to provide a cellular phone and an electronic device using a package and a piezoelectric device.

  According to the first aspect of the present invention, there is provided a piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package and the package is hermetically sealed by a lid. On the other hand, a bottom portion is formed by stacking at least three first to third insulating substrates, and a mounting terminal is exposed on the bottom surface, and the first portion constituting the bottom portion of the package is formed. 1st hole, 2nd hole, and 3rd hole are each formed in thru | or 3rd board | substrate, and the said piezoelectric vibrating piece is accommodated by the through-hole by which these 1st thru | or 3rd hole was connected. The space inside the package is communicated with the outside, and the through hole has a stepped portion facing downward by making the hole diameter of the third hole smaller than at least the hole diameter of the second hole. Comprising the bottom And Kinodan unit, characterized in that the formation of the metallization only on the inner periphery of the second hole, a piezoelectric device.

According to the configuration of the first invention, the bottom of the package of the piezoelectric device of the present invention is formed by laminating at least three layers of substrates. And the metal coating | coated part is formed in the inner periphery of the 2nd hole which is the hole provided in the 2nd board | substrate which is the 2nd board | substrate from the bottom face side, and the said downward step part, The bottom face side No metal coating is formed on the inner surface of the first hole which is the hole of the substrate. For this reason, when the molten metal sealing material is filled in the through hole, the metal sealing material does not adhere to the inner surface of the first hole which is the hole of the substrate on the bottom surface side. Therefore, when the package is mounted on the mounting substrate, there is no possibility that the molten solder will come into contact with the metal sealing material by reflow, and a short circuit between the mounting terminals does not occur. Similarly, the metal sealing material is integrated with the reflow solder on the bottom surface side of the package, so that the capacitance does not change.
Thus, according to the present invention, it is possible to provide a piezoelectric device that avoids the possibility of short-circuiting due to mounting and can exhibit stable performance without causing a change in capacitance on the package bottom side.

According to a second invention, in the configuration of the first invention, the hole diameter of the first hole is larger than the hole diameter of the second hole.
According to the configuration of the second invention, the distance between the metal sealing material and the solder attached to the mounting terminal is increased by increasing the diameter of the first hole, which is a hole provided in the substrate on the bottom surface side of the package. Is also secured in the horizontal direction. For this reason, a short circuit and a capacity | capacitance change can be prevented more reliably.

A third invention is characterized in that, in the configuration of any one of the first and second inventions, at least the second hole is filled with a metal sealing material, and the first hole is filled with a potting agent. To do.
According to the structure of 3rd invention, since a metal sealing material is covered with a potting agent, it is insulated reliably with respect to the mounting substrate side.

  According to a fourth aspect of the present invention, there is provided a package for accommodating a piezoelectric vibrating piece in a space formed therein, wherein at least the first to third at least from the outside toward the inside. A bottom portion is formed by laminating three insulating substrates, and mounting terminals are exposed on the bottom surface. The first to third substrates constituting the bottom portion have a first hole. A second hole and a third hole are formed, and the internal space and the outside are communicated with each other by a through hole in which the first to third holes communicate with each other. The hole is provided with a downward stepped portion by making the hole diameter of the third hole smaller than the hole diameter of the second hole, and the downward stepped portion and the inner periphery of the second hole Achieved by the package, which only formed the metal coating on the

  According to the configuration of the fourth invention, by the same principle as described for the configuration of the first invention, the possibility of short circuit due to mounting is avoided, and the capacitance on the bottom side of the package is not changed, and the stability is stable. It is possible to provide a package that can exhibit the improved performance.

1 and 2 show an embodiment of a piezoelectric device according to the present invention. FIG. 1 is a schematic plan view thereof, and FIG. 2 is a schematic sectional view taken along line AA of FIG.
In these drawings, the piezoelectric device 30 shows an example in which a piezoelectric vibrator is configured, and the piezoelectric device 30 houses a piezoelectric vibrating piece 32 in a package 37.
The package 37 is formed, for example, by laminating a plurality of substrates formed by molding an aluminum oxide ceramic green sheet as an insulating material, and then sintering.

  That is, in this embodiment, the package 37 includes, in order from the outside (the lower side in FIG. 2), the first substrate 55, the second substrate 56, the third substrate 57, and the first substrate obtained by molding the green sheet. 4 is an insulator formed by stacking four substrates 58 and then firing them. The total length L1 shown in FIG. 2 of the package 37 is extremely small, for example, about 3 mm. As shown in FIG. 2, the package 37 forms a space of the internal space S by removing the material inside the fourth substrate 58. This internal space S is a housing space for housing the piezoelectric vibrating piece 32.

In the inner space S of the package 37, in the vicinity of the left end portion, the third substrate 57 as an insulating base that is exposed to the inner space S and forms the inner bottom portion is, for example, nickel-plated and gold-plated on tungsten metallization. The electrode parts 31, 31 formed in (1) are provided.
The electrode portions 31 and 31 are connected to the mounting terminals 41 and 42 shown in FIG. 2, respectively, and supply a driving voltage applied from the outside to the piezoelectric vibrating piece 32. Specifically, the mounting terminals 41 and 42 are each formed in, for example, a rectangle at the four corners of the bottom surface of the package 37. The mounting terminals 41 and 42 and the electrode portions 31 and 31 are conductive through holes formed by metallizing the outside of the package 37 or by using tungsten metallization or the like before firing the first substrate 55 and the second substrate 56. It can be formed by connecting through holes 31a or the like. In FIG. 2, the horizontal lengths L2 and L2 of the mounting terminals 41 and 42 are about 0.8 mm.
A conductive adhesive 43 is applied on each electrode portion 31, and the base portion 51 of the piezoelectric vibrating piece 32 is joined. As this conductive adhesive 43, for example, a binder component using a synthetic resin or the like is mixed with conductive particles such as silver particles, and can perform mechanical joining and electrical connection at the same time. .
Furthermore, a recess 59 is formed by removing a part of the inside of the third substrate 57. The recess 59 is provided in a region located below the vicinity of the tip of each vibrating arm of the piezoelectric vibrating piece 32. As a result, when the piezoelectric vibrating piece 32 is lowered and joined at the tip end of the vibrating arm, or when there is an impact from the outside of the package 37 in that state, the vibrating arm moves in the direction of arrow D. Even in the case of swinging, the inner bottom surface of the package 37 is touched so as not to be damaged.

  The piezoelectric vibrating piece 32 is formed of, for example, quartz, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to quartz. In the case of this embodiment, as shown in FIG. 1, the piezoelectric vibrating reed 32 is divided into two forks toward the right in the figure with the base 51 fixed to the package 37 side and the base 51 as the base end. A so-called tuning fork type piezoelectric vibrating piece having a pair of vibrating arms 33 and 34 extending in parallel and having a shape like a tuning fork as a whole is used.

  Here, long grooves 36 and 35 extending in the length direction are preferably formed on the main surfaces of the vibrating arms 33 and 34, and excitation electrodes (not shown) are formed in the long grooves. The long grooves are formed on the front and back surfaces, which are the main surfaces of the vibrating arm 33 and the vibrating arm 34, respectively. Excitation electrodes (not shown) are formed in the long grooves 36 and 35, respectively, and are formed in the long grooves of the vibrating arms. The excitation electrodes are a pair of electrodes separated from each other. As a result, by applying a driving voltage to the excitation electrode, the electric field efficiency inside each vibrating arm can be increased during driving.

  In addition, as described above, lead electrodes 38 a and 39 a are formed as electrode portions for connection with the electrode portions 31 and 31 of the package 37 near both ends in the width direction of the end portion of the base portion 51 of the piezoelectric vibrating piece 32. ing. Each extraction electrode 38 a and 39 a is provided on the front and back of the base 51 of the piezoelectric vibrating piece 32 so as to go around the outer edge of the base 51. These lead electrodes 38a and 39a are connected to the above-described excitation electrodes, and can be formed, for example, by sequentially plating chromium (Cr) and gold (Au) on the quartz surface. Further, a metal film for frequency adjustment may be formed at the same time as the electrode is formed by using the same metal as the electrode metal in at least the front end regions of the vibrating arms 33 and 34.

As a result, a drive voltage is applied to the excitation electrode (not shown) from the extraction electrodes 38a and 39a, so that an electric field is appropriately formed in each of the vibrating arms 33 and 34, and the tip portions of the vibrating arms 33 and 34 are mutually connected. It is driven to approach or separate and vibrates at a predetermined frequency.
The piezoelectric vibrating piece is not limited to the tuning-fork type piezoelectric vibrating piece as shown in the figure, and various piezoelectric vibrating pieces such as an AT cut vibrating piece obtained by cutting a piezoelectric material into a rectangular shape or a convex type vibrating piece may be used. Can do.

A lid 40 is bonded to the opened upper end of the package 37 so as to be sealed.
The lid 40 can be formed of a metal such as ceramic or Kovar, but is preferably formed of a light transmissive material, for example, a plate made of glass such as borosilicate glass. As a result, as shown in FIG. 2, the laser beam LB2 is irradiated from the outside so as to pass through the lid body 40, and a part of the excitation electrode provided on the vibrating arm of the piezoelectric vibrating piece 32 or the above-described metal film By evaporating, the frequency can be adjusted after sealing the lid.

Furthermore, in the piezoelectric device 30 of this embodiment, as shown in FIG. 2, a through hole 60 is formed at the bottom of the package 37. The through hole 60 includes a first hole 61 provided in the first substrate 55, a second hole 62 provided in the second substrate 56, and a third hole 63 provided in the third substrate 57. The first hole 61, the second hole 62, and the third hole 63 are concentric and communicate with each other. The through-hole 60 communicates the outside of the package 37 and the internal space S of the package 37, and is used for degassing the package 37. Each hole is formed at the time of molding each substrate before firing. In FIG. 2, the horizontal distance L3 between the mounting terminal 42 and the through hole 60 is approximately 0.5 mm.
Further, in this embodiment, the hole diameters of the first hole 61 and the second hole 62 are equal, and these are larger than the hole diameter of the third hole 63. Thereby, a downward stepped portion 66 is formed in the middle of the through hole 60. A metal cover 64 is formed on the inner periphery of the second hole 62 and the stepped portion 66. For the metal covering portion 64, a metal material that is familiar with a metal sealing material described later, that is, is easily attached is selected. The metal cover 64 can be formed by, for example, nickel plating and gold plating (Ni—Au) on tungsten metallization.

  FIG. 3 is an enlarged cross-sectional view showing a simplified manner of sealing the through hole 60. A spherical metal sealing material 65 a is disposed using the step portion 66 of the through hole 60. This step is performed, for example, by accommodating the package in a vacuum chamber or the like, and the gas inside the package generated by heating is passed through the gap between the through hole 60 and the spherical metal sealing material 65a. To be discharged. That is, harmful gas or the like generated during the curing process of the conductive adhesive 43 or the like described with reference to FIG. 2, or the gas in which the moisture in the package is evaporated is discharged to the outside during the degassing process. Actually, this step is executed with the top and bottom reversed from FIG. 3, with the stepped portion 66 facing upward and the spherical metal sealing material 65 a disposed. For example, an alloy such as Au—Ge or Au—Sn is suitable for the spherical metal sealing material 65a. In this state, as shown by an arrow LB, laser light is irradiated to melt the metal sealing material 65a.

FIG. 4 shows a state after the spherical metal sealing material 65 a is melted in FIG. 3, and shows a state where the piezoelectric device is mounted on the mounting substrate 70. In FIG. 3, lands on the mounting substrate 70 are not shown.
The metal sealing material 65 has a high affinity with the metal cover 64, but has a low affinity with the insulating material that is the material of the first substrate 55 and the third substrate. Therefore, as shown in FIG. 4, the metal sealing material 65 is filled in the through-hole 60 so as to adhere to the place where the metal coating 64 is present, and seals this. For this reason, the metal sealing material 65 does not adhere to the first hole 61 of the first substrate 55.
On the other hand, the solder 71 applied on the land of the mounting substrate 70 is attached to the mounting terminal 42 of the piezoelectric device and flows on the mounting substrate 70 toward the through hole 60 in the reflow process. However, the metal sealing material 65 does not exist in the first hole 61 of the first substrate 55, and only the insulating member constituting the package (first substrate 55) is exposed, and the metal sealing material 65 is exposed. Is higher than the solder 71 by the thickness of the first substrate 55, the metal sealing material 65 and the solder 71 do not come into contact with each other. Furthermore, the solder 71 has a high affinity with the metal that is the material of the mounting terminal 41 and the metal covering portion 64, but the affinity with the insulating material that is the material of the first substrate 55 is low. The possibility of contact with the sealing material 65 and the metal cover 64 can be reduced.

As described above, in the piezoelectric device 30 according to the present embodiment, when the package 37 is mounted on the mounting substrate 70, there is no possibility that the solder 71 melted by reflow comes into contact with the metal sealing material 65, and the mounting terminals are short-circuited. Does not occur. Similarly, since the metal sealing material 65 is integrated with the reflow solder 71 on the bottom surface side of the package and does not cause a change in capacity, stable performance can be exhibited.
In particular, as described with reference to the dimensions L2 and L3 in FIG. 2, since the dimensions of the package 37 are extremely small, it is inevitable that the distance between the mounting terminal and the through hole is inevitable. Is an important and effective configuration for avoiding short circuits.

FIG. 5 shows a first modification of the above-described embodiment, and only the portions that are the main parts are shown. In the first modification, in the through hole 60-1 formed at the bottom of the package, the hole diameter of the first hole 61-1 provided in the first substrate 55 is the second hole provided in the second substrate 56. The difference is that the hole diameter is larger than 62.
As described above, by increasing the hole diameter of the first hole 61-1 which is the hole provided in the first substrate 55 which is the substrate on the bottom surface side of the package, it adheres to the metal sealing material 65 and the mounting terminal. The distance from the solder to be used is also ensured in the horizontal direction. For this reason, a short circuit and a capacity | capacitance change can be prevented more reliably.

FIG. 6 shows a second modification of the above-described embodiment, and only the portions that are the main parts are shown. In the second modification, the potting agent 73 is filled in the first hole 61 provided in the first substrate 55 in the through hole 60-2 formed in the bottom of the package. As the potting agent 73, a thermosetting resin which is a widely used sealing resin can be suitably used.
According to such a structure, since the metal sealing material 65 is covered with the potting agent 73, it is reliably insulated with respect to the mounting substrate side.

FIG. 7 is a diagram illustrating a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using the piezoelectric device according to the above-described embodiment of the present invention.
In the figure, a microphone 308 for receiving the voice of the sender and a speaker 309 for outputting the received content as a voice output are provided, and further, an integrated circuit or the like as a control unit connected to the modulation and demodulation unit of the transmission / reception signal. The CPU (Central Processing Unit) 301 is provided.
In addition to modulation and demodulation of transmission / reception signals, the CPU 301 includes an information input / output unit 302 including an LCD as an image display unit and operation keys for inputting information, and an information storage unit (memory) 303 including a RAM, a ROM, and the like. Control is to be performed. For this reason, the piezoelectric device 30 and other embodiments of the present invention such as the piezoelectric device 30 and modifications are attached to the CPU 301, and the output frequency thereof is determined by a predetermined frequency dividing circuit (not shown) incorporated in the CPU 301. The clock signal is adapted to the control contents. The piezoelectric device attached to the CPU 301 may be a piezoelectric vibrator or a piezoelectric oscillator.

  The CPU 301 is further connected to a temperature compensated crystal oscillator (TCXO) 305, and the temperature compensated crystal oscillator 305 is connected to the transmitter 307 and the receiver 306. Thus, even if the basic clock from the CPU 301 fluctuates when the environmental temperature changes, it is corrected by the temperature compensated crystal oscillator 305 and supplied to the transmission unit 307 and the reception unit 306.

  As described above, the piezoelectric device 30 according to the above-described embodiment can be used for an electronic apparatus such as the digital cellular phone device 300 including the control unit. In this case, the location of the through hole 60 described in FIG. 2 is reliably insulated, and the mounting terminals provided in the package 37 are not short-circuited, and the metal sealing material 65 is reflow soldered 71 on the bottom surface side of the package. Since it does not cause a change in capacity, it can exhibit stable performance.

The present invention is not limited to the above-described embodiment. Each configuration of the embodiment and each modified example can be appropriately combined or omitted, and can be combined with other configurations not shown.
The present invention can also be applied to a gyro device that detects an angular velocity or the like as long as it is covered with a package or a box-shaped lid and accommodates a piezoelectric vibrating piece therein. Regardless of the name of the piezoelectric oscillator, etc., it can be applied to all piezoelectric devices.

The schematic plan view which shows embodiment of the piezoelectric device of this invention. The AA line schematic sectional drawing of FIG. The figure which shows the mode of hole sealing of the piezoelectric device of FIG. The elements on larger scale of the state which mounted the piezoelectric device of FIG. The figure of the modification 1 of the piezoelectric device of FIG. The figure of the modification 2 of the piezoelectric device of FIG. 1 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using a piezoelectric device according to an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing an example of a conventional piezoelectric device. The enlarged view of the through-hole of the piezoelectric device of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 30 ... Piezoelectric device, 32 ... Piezoelectric vibrating piece, 33, 34 ... Vibrating arm, 31 ... Electrode part, 37 ... Package, 43 ... Conductive adhesive, 60 ... Through hole, 55... First substrate, 56... Second substrate, 57... Third substrate, 58.

Claims (6)

A piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package and the package is hermetically sealed with a lid,
The package is
From the outside to the inside, the bottom is formed by laminating at least three insulating substrates of the first to third, and the mounting terminals are exposed on the bottom,
A first hole, a second hole, and a third hole are respectively formed in the first to third substrates constituting the bottom of the package, and the first to third holes are communicated with each other. Through the through hole, the space inside the package accommodating the piezoelectric vibrating piece is communicated with the outside,
The through-hole is provided with a downward stepped portion by making the hole diameter of the third hole smaller than at least the hole diameter of the second hole,
A piezoelectric device, wherein a metal covering portion is formed only on an inner periphery of the downward stepped portion and the second hole.   2. The piezoelectric device according to claim 1, wherein a hole diameter of the first hole is larger than a hole diameter of the second hole.   The piezoelectric device according to claim 1, wherein at least the second hole is filled with a metal sealing material, and the first hole is filled with a potting agent. A package for accommodating a piezoelectric vibrating piece in a space formed inside,
From the outside to the inside, the bottom is formed by laminating at least three insulating substrates of the first to third, and the mounting terminals are exposed on the bottom,
A first hole, a second hole, and a third hole are formed in the first to third substrates constituting the bottom portion, and the first to third holes communicate with each other. The internal space is communicated with the outside,
The through-hole is provided with a downward stepped portion by making the hole diameter of the third hole smaller than at least the hole diameter of the second hole,
A package characterized in that a metal covering portion is formed only on an inner periphery of the downward stepped portion and the second hole. A cellular phone device using a piezoelectric device that houses a piezoelectric vibrating piece in a package and hermetically seals the package with a lid,
The package is
From the outside to the inside, the bottom is formed by laminating at least three insulating substrates of the first to third, and the mounting terminals are exposed on the bottom,
A first hole, a second hole, and a third hole are respectively formed in the first to third substrates constituting the bottom of the package, and the first to third holes are communicated with each other. Through the through hole, the space inside the package accommodating the piezoelectric vibrating piece is communicated with the outside,
The through-hole is provided with a downward stepped portion by making the hole diameter of the third hole smaller than at least the hole diameter of the second hole,
A cellular phone device characterized in that a clock signal for control is obtained by the downward stepped portion and a piezoelectric device in which a metal coating portion is formed only on the inner periphery of the second hole. An electronic device using a piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package and the package is hermetically sealed with a lid,
The package is
From the outside to the inside, the bottom is formed by laminating at least three insulating substrates of the first to third, and the mounting terminals are exposed on the bottom,
A first hole, a second hole, and a third hole are respectively formed in the first to third substrates constituting the bottom of the package, and the first to third holes are communicated with each other. Through the through hole, the space inside the package accommodating the piezoelectric vibrating piece is communicated with the outside,
The through-hole is provided with a downward stepped portion by making the hole diameter of the third hole smaller than at least the hole diameter of the second hole,
An electronic apparatus characterized in that a clock signal for control is obtained by a piezoelectric device in which a metal step is formed only on an inner periphery of the second step and the downward stepped portion.

Images