JP2003332873A - Piezoelectric resonator, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and thin piezoelectric resonator having a high air-tightness and available at a low cost, in which a piezoelectric resonator element is provided in a housing having a structure which permits adjustment of a frequency after sealing the housing. <P>SOLUTION: The piezoelectric resonator incorporates the piezoelectric resonator element 31 in the housing 41. The piezoelectric resonator is the surface- mount piezoelectric resonator, in which the piezoelectric resonator element is provided in the housing, having a structure which permits frequency adjustment through an opening provided in a base 1 or a lid 3 forming the housing. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator having a piezoelectric vibrator piece built in a package and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, devices such as HDDs (hard disk drives), mobile computers, and small information devices such as IC cards, and mobile communication devices such as mobile phones, car phones, and paging systems are small and thin. As a result, the piezoelectric devices such as piezoelectric vibrators used for them are required to be small and thin.

At the same time, there is a demand for a surface mount type piezoelectric vibrator which can be mounted on both sides of a circuit board of a device.

Therefore, an example of a conventional piezoelectric vibrator is shown in FIG. 23 in which a tuning fork type crystal vibrator piece is used as the piezoelectric vibrator piece.
Description will be given using the low-middle frequency crystal oscillator shown in the structural diagrams of (a) and (b). The low-medium frequency crystal oscillator is a crystal oscillator having a typical frequency of 32.768 KHz and a frequency of several KHz to several hundred KHz used for IC cards, pagers and the like.

In the structure of the conventional crystal unit shown in FIGS. 23A and 23B, a crystal unit 20 is formed from a crystal substrate in a tuning fork shape, and a driving metal electrode is formed on the surface thereof.
1 is a base 202 formed of a ceramic laminated substrate
Mounted to the pedestal portion with a conductive adhesive or the like, and sealed in a vacuum atmosphere by a lid 203 formed of a transparent glass material. After sealing, trimming is performed through the glass lid 203 by a laser or the like to adjust the frequency.

[0006]

By the way, in the above-mentioned piezoelectric vibrator, the package is composed of a three-layer ceramic base and a glass lid, and is vacuum-sealed. here,
The lid is made of a transparent, high-quality glass material such as borosilicate glass so that the frequency can be adjusted after sealing.

However, this glass lid requires a high material cost and a high cost for cutting the glass substrate into a rectangular lid with high accuracy, which makes the price of the piezoelectric vibrator expensive. In addition, the fine dust and the like generated from the glass lid affects the characteristics of the crystal unit. Furthermore, since the base is composed of three layers of ceramic substrates, the airtightness between the laminated layers becomes a problem, which causes deterioration of the characteristics of the vibrator that requires maintaining a high vacuum.

An object of the present invention is to solve the above problems of the prior art, and an object thereof is to provide a piezoelectric vibrator having a high vacuum and a high airtightness at a low cost. .

[0009]

The invention according to claim 1 is
In a piezoelectric vibrator in which the piezoelectric vibrator piece is incorporated in a package, the piezoelectric vibrator piece is frequency-adjusted by a frequency adjusting means from an opening provided in the package.

According to a second aspect of the present invention, in a piezoelectric vibrator in which a piezoelectric vibrator piece is incorporated in a package, the piezoelectric vibrator piece is a tuning fork type piezoelectric vibrator piece having two vibrating arms. A part of at least one vibrating arm of the vibrating piece is frequency-adjusted by the frequency adjusting means.

According to a third aspect of the present invention, in the structure of the first aspect, the piezoelectric vibrating piece is a tuning fork type quartz vibrating piece.

According to a fourth aspect of the present invention, in the structure of the first or second aspect, the frequency adjusting means is a trimming processing means using a laser beam or an electron beam.

According to a fifth aspect of the present invention, in the structure of the first or second aspect, the piezoelectric vibrator piece is mounted on an electrode portion of a base made of a single layer and sealed with a lid made of a single layer. Is characterized by.

The invention according to claim 6 is the invention according to claims 2 to 5.
In any one of the above configurations, the opening provided in the package has a size that does not exceed the outer shape of the tuning fork type piezoelectric vibrating arm housed inside, and the two vibrating arms included in the tuning fork type piezoelectric vibrating arm. Is formed so as to expose at least a partial region of each of the two. According to a seventh aspect of the present invention, a step of mounting the piezoelectric vibrator piece on a base, a step of positioning and sealing the base and the lid (lid), and an opening provided in the base or the lid are used, The method is characterized by including a step of adjusting the frequency of a part of the piezoelectric vibrator piece with a laser beam or an electron beam, and a step of vacuum-sealing the opening in a vacuum atmosphere.

According to an eighth aspect of the present invention, in the structure of the seventh aspect, the airtight region in which the piezoelectric vibrator is built in and sealed with a vacuum is formed of a single layer of the base and the lid. .

According to a ninth aspect of the present invention, there is provided a step of mounting the piezoelectric vibrator piece on a base, a step of positioning and sealing the base and the lid, and an opening provided in the base or the lid. , A step of adjusting a frequency of a part of the piezoelectric vibrator piece with a laser beam or an electron beam, a step of setting a sealing material in the opening, and a vacuum sealing by heating the sealing material in a vacuum atmosphere And a process.

According to a tenth aspect of the present invention, in the structure of the ninth aspect, the method includes a step of heating the periphery of the opening in a vacuum atmosphere and vacuum-sealing after setting the sealing material. .

According to an eleventh aspect of the present invention, in the configuration of the ninth aspect, in the heating step of the sealing material, the package including the piezoelectric vibrator piece is housed in a vacuum chamber, and laser light is emitted from the outside of the vacuum chamber. Alternatively, the sealing material is irradiated with a high-temperature light beam to be heated and melted.

According to a twelfth aspect of the present invention, in the configuration of the tenth aspect, in the heating step of the sealing material, the package including the piezoelectric vibrator piece is housed in a vacuum chamber, and the sealing material and the opening are provided. It is characterized in that a heating jig is brought into contact with the periphery of the portion to heat and melt it.

The invention according to claim 13 is the invention according to claim 9 or 1.
The constitution of No. 0 is characterized by including a step of heating the lid or the base in a vacuum atmosphere when the sealing material is heated and vacuum-sealed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A piezoelectric vibrator according to an embodiment of the present invention will be described with reference to the drawings, taking a 32.768 KHz crystal vibrator for a watch, which uses a tuning fork type crystal vibrator piece as a piezoelectric vibrator piece as an example. It will be described with reference to FIG.

(First Embodiment) FIG. 1A is a plan view of a piezoelectric vibrator 11 according to this embodiment, and FIG. 1B is a front view of the piezoelectric vibrator 11.

As shown in these figures, a base 1 having two layers of ceramic substrates 1a and 1b laminated thereon has electrode portions 2a and 2b which are metallized with a metal and whose surfaces are plated with Ni and Au at intervals d. Has been formed. On the electrode portions 2a and 2b of the base 1, electrode portions 4a and 4b of, for example, a tuning fork type crystal resonator piece 3 as a piezoelectric resonator piece having a driving metal electrode formed on its surface are aligned and mounted. Then, they are electrically connected and fixed by the conductive adhesive 5. After that, a metal lid (lid) 6 is aligned with the base 1 and the sealant 7 is used to melt the sealant 7 by means of a beam irradiation means as a heating means, for example, a laser device or an electron beam device. The first sealing process is performed. As a result, the crystal unit 3 is attached to the base 1 and the lid 6
It is enclosed in a package 41 consisting of.

As shown in FIG. 1B, an opening 8 is formed on the bottom surface of the base 1 so as to communicate the inside and the outside of the package described later.

In FIG. 2, with the back surface of the base 1 facing upward,
The following processing steps are shown. As shown in FIG. 2, by using a circular opening 8 provided in the base 1, by means for focusing a high temperature light beam or the like as frequency adjusting means, for example, a laser device or an electron beam device 13,
The frequency adjustment is performed by trimming a part of the metal electrode portion of the tuning fork type crystal unit 3.

Finally, in a vacuum atmosphere, the opening 8
A small piece 9 made of metal or the like for sealing as shown in FIG. 1 (b) is mounted on the sheet, and the sealing agent 10 is used to seal the same with a laser device or an electron beam device as in the first sealing. Stopper 10
Is melted and a second vacuum sealing process is performed.

As described above, the crystal resonator 11 of the small and thin surface mount package is completed.

As described above, the vacuum region S containing the tuning-fork type crystal unit 3 is composed of the single layer portion 12 of the base 1 (upper substrate 1b) and the metal-made drawn lid 6. The airtightness is extremely high. That is, since the vacuum region S is partitioned only by the single layer portion 12 of the base 1 and the metal-made drawn lid 6,
In this vacuum region S, for example, there are no joints of a plurality of ceramic substrates forming the base, and it is easy to maintain the airtightness accordingly.

Here, FIG. 3 is a structural view of the back surface side of the crystal unit 11 according to the embodiment of the present invention, in which laser processing or electron beam performed as frequency adjustment of the tuning fork type crystal unit 3 is performed. The relationship between the trimmed portion by processing and the opening 8 is shown.

Here, the crystal oscillator piece 3 is formed by a photolithography process in a state in which a plurality of crystal oscillator pieces are arranged from one crystal substrate so as to have the same outer shape.
Furthermore, Cr + Au, etc. (for example,
A metal film of Au film is formed on the Cr film by sputtering) as an electrode. A metal film such as Au or Ag is formed thinner and more accurately on a part of this metal film, and the frequency is lowered by a certain amount due to the weighting effect.

After that, the crystal unit 3 is cut off from the crystal substrate, mounted on the base 1 shown in FIG. 1, and sealed with the lid 6. As described above, the resonance frequency of the crystal resonator piece 3 changes due to the thermal history due to the processing process of mounting and sealing, the generation of stress due to the thermal history, the outgas generated from the sealing agent, and the like. Therefore, it is necessary to adjust the frequency after sealing, and the frequency must be adjusted accurately.

Therefore, as shown in FIG. 3, the frequency adjusting portion 3c of at least one of the two vibrating arms 3a and 3b divided into two forks of the crystal resonator piece 3 is laser-processed from the opening 8. Alternatively, the opening 8 is formed on the back side of the base 1 so that the electron beam processing can be performed. In other words, the opening 8 is formed by adjusting a part of one of the two vibrating arms 3a and 3b of the tuning fork type crystal resonator piece 3 to the frequency adjusting portions 3d and 3b.
It is positioned so as to be exposed as e. And
A laser beam or an electron beam is radiated through the opening 8 to melt the metal film such as Au or Ag of the frequency adjusting unit 3c of the vibrating arm 21 to reduce the weight of the frequency adjusting unit 3c and increase the frequency to achieve the desired frequency. (For example, 32.7
Adjust the frequency so that it becomes 68 KHz).

Furthermore, a small piece 9 made of metal or the like is provided in the opening 8.
Is mounted, and the sealant 10 is melted by a laser device or an electron beam device to perform vacuum sealing.

As described above, since only the opening 8 having a size capable of processing only the frequency adjusting portion 3c of at least one vibrating arm 3a is sealed, the influence of the sealing on the frequency is very small.

(Second Embodiment) FIG. 4 shows a piezoelectric vibrator 42 according to another embodiment of the present invention, and the same components as those of the piezoelectric vibrator 42 according to the first embodiment are designated by the same reference numerals. , And redundant description is omitted. The piezoelectric vibrator 42 differs from the first embodiment in that a ceramic lid 31 is used instead of the metal lid 6 shown in FIG. Therefore, the piezoelectric vibrator 42 according to the second embodiment can also achieve the same effects as the first embodiment.

(Third Embodiment) FIG. 5 shows a piezoelectric vibrator 43 according to still another embodiment of the present invention. The same reference numerals are given to the same structures as those of the piezoelectric vibrator 43 according to the second embodiment. , And redundant description is omitted. This piezoelectric vibrator 43 is different from that of the second embodiment in that the opening 32 is formed in the lid 31 shown in FIG. Therefore, the piezoelectric vibrator 43 according to the third embodiment can also achieve the same effects as those of the first and second embodiments.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention. FIG. 6 is a view corresponding to FIG. 3 of the piezoelectric vibrator 44, and shows a state viewed from the bottom surface of the base 1.

In FIG. 6, the same components as those in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted. An opening 45 is provided in the base 1. The opening 45 is positioned so that a part of each of the two vibrating arms 3a and 3b of the tuning fork type crystal resonator piece 3 housed inside the package is exposed as the frequency adjusting portions 3d and 3e. Has been done. The size (inner diameter) of the opening 45 does not exceed the outer shape of the tuning fork type crystal unit 3.

Then, through this opening 45, a laser beam or an electron beam as a frequency adjusting means melts a metal film such as Au or Ag of the frequency adjusting sections 3d and 3e of the vibrating arms 3a and 3b to adjust the frequency. The target frequency (for example, 3
The frequency is adjusted so that it becomes 2.768 KHz). Therefore, in the fourth embodiment, when adjusting the frequency, it is possible to reduce the weight of both the vibrating arms 3a and 3b in a well-balanced manner. And this piezoelectric vibrator 4
4 is the same as that of the first embodiment in the operational effects other than the above.

In each of the above-mentioned embodiments, the sealants 7, 1
For 0, the component is Au-Sn system, Pb-Sn
A metallic material such as a silver-based or Ag-based adhesive, an organic adhesive, or the like may be used. The form of the sealants 7 and 10 may be clad or preformed.

According to the above construction, the first sealing step, the frequency adjusting step and the second sealing step can be commonly processed by the laser device or the electron beam device.
Integrated processing can be performed with the same device.

The ceramic base 1 and the lid 6 to be processed may be in the form of a single piece or a plate in which a plurality of pieces are arranged.

As described above, by using inexpensive components as compared with high quality glass such as ceramics and metals,
A small and thin crystal resonator having a width of 5 mm, a width of 2 mm and a thickness of 0.8 mm can be obtained at low cost.

Next, a fifth embodiment of the piezoelectric vibrator according to the present invention will be described in which a tuning fork type crystal vibrator piece is used as the piezoelectric vibrator piece.
A 32.768 KHz crystal oscillator for a timepiece will be described as an example with reference to the drawings.

(Fifth Embodiment) FIG. 7A is a plan view of a piezoelectric vibrator 51 according to this embodiment, and FIG. 7B is a front view of the piezoelectric vibrator 51.

As shown in these figures, a base 1 on which two layers of ceramic substrates 1a and 1b are laminated is metallized with a metal such as W (tungsten) and Ni and Au are formed on the surface.
Plated electrode portions 52a and 52b are formed. Electrode parts 54a and 54b of a tuning fork type crystal resonator piece 53 having a driving metal electrode formed on the surface are aligned and mounted on the electrode parts 52a and 52b, and electrically mounted with a conductive adhesive 55. The connection is fixed. After that, the metal (lid) lid 56 is aligned with the base 65, and the sealing agent 57 is melted by a laser device or an electron beam device using the sealing agent 57 to perform the first sealing process. As a result, the crystal oscillator piece 53 is enclosed in the package 61 including the base 65 and the lid 56.

As shown in FIG. 7B, an opening 58 is formed on the bottom surface of the base 65 so that the inside of the package, which will be described later, communicates with the outside.

Further, as shown in FIG. 8, a tuning fork type quartz vibration is made by a laser device or an electron beam device 63 as a frequency adjusting means by using a circular, oval or elliptical opening 58 provided in a base 65. Child piece 53
The frequency is adjusted by trimming a part of the metal electrode portion of the.

Finally, a high melting point P such as Au--Sn solder or 9: 1 solder is used as a sealing material in the opening 58.
For example, a spherical sealing material 59 formed of a b-Sn solder-based material is mounted, and the sealing material 59 is melted in a vacuum atmosphere by a batch-type vacuum sealing device, a laser device, an electron beam device, or the like. A second vacuum sealing process is performed. The second sealing process will be described later in more detail.

As described above, the crystal resonator 51 of the small and thin surface mount package is completed.

As described above, the vacuum region in which the tuning-fork type crystal oscillator piece 53 is built is composed of the single layer portion 52 of the base 65 and the metal-drawn lid 56, and its airtightness is extremely high. It will be very expensive. That is, the vacuum region S
Is separated only from the single-layer portion 52 of the base 1 and the metal-made drawn lid 56, so that, for example, in the vacuum region S, there is no seam of a plurality of ceramic substrates forming the base, and the like. Easy to maintain air tightness.

Here, the encapsulating material 59 is a metal alloy, and in addition to the above, Sn solder-based material, silver (Ag), copper (C).
It may be composed of the alloy of u) or a metal brazing material. The shape of the sealing material 59 will be described later.

FIG. 9 is a structural diagram of the back side of the crystal unit 51 of this embodiment, showing the relationship between the opening 58 and the trimming part of the tuning fork type crystal unit piece 53 by laser processing or electron beam processing. Shows.

Here, the crystal unit 53 of the present embodiment is
It is formed by photolithography in a state where a large number of crystals are arranged on a quartz substrate, and a metal film of Cr + Au or the like (for example, an Au film is sputtered on a Cr film) is formed as an electrode. A metal film such as Au or Ag is formed thinner and more accurately on a part of this metal film, and the frequency is lowered by a certain amount due to the weighting effect.

After that, the crystal oscillator piece 53 is broken from the crystal substrate, mounted on the base 65 shown in FIG. 7, and sealed with the lid 56. In this way, the resonance frequency of the crystal resonator piece 53 changes due to the thermal history due to the processing process of mounting and sealing, the generation of stress due to it, the effect of outgas from the conductive adhesive 55 and the sealing agent 57, and the like. Resulting in. Therefore, it is necessary to adjust the frequency after sealing, and the frequency must be adjusted accurately.

As shown in FIG. 9, the frequency adjusting portion 53c of at least one vibrating arm 53a of the crystal unit 53 is
The opening 58 is formed on the back side of the base 65 so that laser processing or electron beam processing can be performed through the opening 58. A laser beam or an electron beam passes through the opening 58, and Au of the frequency adjusting unit 53c of the vibrating arm 53a.
Alternatively, by melting a metal film such as Ag, the frequency adjusting unit 53
The target frequency (3
2.768 KHz) to adjust the frequency.

Then, a sealing material 59 is mounted on the opening 58, and the sealing material 59 is melted by a vacuum sealing device, a laser device, or an electron beam device to perform vacuum sealing.

Thus, at least one vibrating arm 53a
Since only the opening 58 having a size capable of processing only the frequency adjusting portion 53c is sealed, the influence of the sealing on the frequency is very small.

Next, the process of the above-mentioned second sealing process in which the sealing material 59 as the sealing material is mounted in the opening 58 and the vacuum sealing is performed will be described in detail.

FIG. 10A is a view showing only the opening 58 of the piezoelectric vibrator 51 when viewed from the back surface of the base 65, and FIG. 10B is a side view of the piezoelectric vibrator 51. FIG.

As shown in FIGS. 10 (a) and 10 (b), the base 65 is formed with an opening 58 consisting of a hole 73 having a diameter of 0.3 mm and a step portion 74 having a diameter of 0.6 mm. That is,
A through hole 73 is formed in the first substrate 1a forming the base 65, and another through hole 76 smaller than this through hole 73 is formed in the second substrate 1b. A stepped portion 74 is formed between them.

The base 65 is provided on the surface of the step portion 74.
Similar to the electrode portions 52a and 52b formed in the above, a metal coating portion 74a which is a metallized portion having high thermal conductivity, which is metallized with W (tungsten) and plated with Ni and Au on the surface is formed. As a result, the metallized metal (metal-coated portion 74a) is transferred to the package 61.
Since it is arranged in the vicinity of the opening 58 provided in the above, by heating this as described later, the heat at the time of sealing can be efficiently conducted to the sealing portion, and a very high vacuum is obtained. Degree can be achieved.

Around the opening 58, there is provided a metal embedding portion 75 which is a metallized portion formed by embedding W (tungsten) or the like having a plurality of diameters of, for example, φ0.2 mm to 0.25 mm. The metal embedding portion 75 and the metal coating portion 74a of the step portion 74 are electrically connected. As a result, as will be described later, by heating the metal-embedded portion 75 buried around the opening 58, it becomes possible to directly heat the opening 58 formed by the minute holes. Therefore, highly reliable vacuum sealing can be performed instantaneously. Further, since heat is not directly conducted to a portion other than the sealing portion, the piezoelectric vibrator piece 53
The influence of heat on the mount part of the above is eliminated, and it is possible to obtain a highly accurate piezoelectric vibrator without frequency deviation after sealing.

Next, the piezoelectric vibrator 51 whose frequency is adjusted as shown in FIG. 10 (b) is set in a batch type vacuum sealing device or the like (not shown in FIG. 10 (b)) and opened. Part 58
Then, a metal member as the sealing material 59 is set.

Here, FIG. 11 is an enlarged sectional view showing the sealing material 59.

In the figure, this sealing material 59 is, for example,
Au-Sn solder type or high melting point Pb- such as 9: 1 solder
For example, diameter φ0.35 formed of Sn solder-based material
It is a spherical metal alloy of about mm. Further, as the sealing material 59, for example, a metal alloy having a melting point of 250 ° C. to 500 ° C. can be easily used. In addition to the above, Sn solder-based material,
It may be composed of an alloy of silver (Ag) or copper (Cu), or a metal brazing material.

By constructing the sealing material 59 in this way,
The sealing can be performed at a low temperature, and the highly reliable vacuum sealing can be instantaneously performed. Φ0.3-0.4
Since it is a spherical (ball-shaped) metal alloy having a very small size of about mm, the sealing member can be easily processed and can be manufactured at low cost.

The hole 58 of the opening 58 preferably has a circular shape, an elliptical shape, an oval shape, or the like. Then, for example, in the case of an elliptical shape or an oval shape, a plurality of sealing materials 59 may be applied at the same time.

Here, as shown in FIG. 11, when a spherical sealing agent 59 is used, assuming that the diameter of the sealing material 59 is L1 and the diameter of the through hole 76 is L2, L1 is preferably L2.
It is set to 1.1 to 1.3 times. If L1 is smaller than this range, the sealing material 59 may fall into the package 61. If L1 is larger than this range,
It largely protrudes from the opening 58. In addition, the heat capacity of the encapsulant 59 may become a problem, and the heating work may not be performed properly, and the material cost becomes correspondingly large.

Therefore, the metal coating portion 74a has the step portion 7a.
The molten metal of the melted sealing material 59 on the surface of FIG.
It is preferable to determine the area of the coating so that it does not protrude from the surface A and the surface B of 1. When the molten metal comes out from the surface A, it becomes difficult to mount the piezoelectric vibrator 51 on a substrate or the like. Further, if it comes out of the surface of B, it may come into contact with the piezoelectric vibrator piece 53 in the package 61 to cause a short circuit. For this reason, as shown in the drawing, the metal-coated portion 74a is the next portion to the periphery (the surface C) of the through hole 76 of the opening 58. That is, in FIG. 11, the metal coating portion 74a formed around the opening 58 is formed.
Has an extension portion 76a extending not only around the through hole 76 but also on the inner peripheral edge portion. Thereby, as will be described later, when the sealing material 59 is heated and melted, the melted metal adheres to the extension portion 76a, and the sealing effect can be improved. In this case, the extension portion 76a has the through hole 7
It is preferable to keep the inner peripheral edge portion of 6 so as not to reach the opposite side of the hole. By doing so, the sealing material 59
This is because the molten metal may reach the inside of the package 61 in the melting step. Therefore, the extension portion 76a is 1/3 to 1/1 of the depth of the through hole 76.
It is preferably set to 2.

Further, as shown in FIG. 12, the metal coating portion 74a is provided with a thick film coating portion 74b whose coating thickness is particularly thicker than the surrounding area in the peripheral region near the through hole 76. It is preferable. Thereby, when the sealing material 59 is heated and melted, the wettability with the molten metal is particularly improved, and the sealing effect is improved.

In this way, the sealing material 59 applied to the opening 58 is further arranged around the opening 58 in FIG.
The metal-embedded portion 75 shown in FIG. 0 is heated by a tip portion such as a heater, and the step portion 74 is heated by the heat conduction, and the sealing material 59 is further heated and melted. Then, the sealing material 59 is melted in the metallization of the step portion 74, and at the same time, the hole 76 is sealed and the second vacuum sealing process is completed.

The vacuum sealing means for performing the second vacuum sealing will be described in detail with reference to FIG.

In FIG. 13, the vacuum sealing means 100 is
The heating jig 80 includes a heat source 101, a heat conductor 81, and a contact jig 82. The heat conductor 81 is the heat source 101.
Is a heat conductor connected to the heat conductor 81.
Abutting jig 82 (first heating means) so that heat is transferred
Is attached.

The heat conductor 81 and the contact jig 82 constitute a heating jig 80. Preferably, a plurality of the contact jigs 82 may be attached to the heat conducting portion 81 with a predetermined space. Further, the heat conducting portion 81 may itself be configured by an electric heater (carbon heater) or the like as a heat source, or may be connected to the heat source 101. The heating jig 80 is driven by a driving means such as a triaxial robot in a horizontal XY direction and a vertical Z direction (not shown).

As shown in FIG. 13, the contact jig 82 has the opening 5
8, the first pin 83 disposed in the vicinity of the center so as to contact the sealing material 59 and the first pin 83 so as to contact the upper surface of the metal coating portion 74a. The second pins 84, 84 provided around the

As a result, the heating jig 80 and the package 6
1 are both placed in a vacuum atmosphere, the heating jig 80 is positioned with respect to the opening 58, and at least the contact jig 82.
As shown in the drawing, the first pin 83 is brought into contact with the sealing material 59, and the second pin 84 is attached to the metal-coated portion 7 by lowering the portion.
4a is contacted at the same time. At this time, the metal embedding portion 75 not shown in FIG. 13 may be brought into contact with the second pin 84.

Next, heat is transferred from the heat source 101 such as an electric heater to the heat conducting section 81, and this heat is transferred to the sealing material 59 and the metal coating section 74a via the contact jig 82.
Further, when the embedded metal portion 75 is provided as described above, heat is also transmitted to the embedded metal portion 75.

As a result, with respect to the sealing material 59, the first
Not only from the pin 83, but also from the metal coating portion 74a and the embedded metal portion 75, heat is transferred at the same time, and is heated and melted extremely efficiently. Then, as shown in FIG. 20, the molten metal closes the through hole 76 of the opening 58,
The second sealing process is performed in a vacuum atmosphere.

FIG. 20 shows a sectional view of the opening 58 after sealing. In this drawing, the diameter of the sealing material 59 is adjusted so that the sealing material 59 does not protrude from the back surface of the package 61. Is set.

Here, regarding the profile of the vacuuming of the vacuum sealing device and the profile of the heating temperature of the heater as the heat source, the inside of the package of the piezoelectric vibrator 11 before the sealing material 59 is completely melted. It is set to reach a sufficiently high degree of vacuum.

FIG. 14 shows another example for performing the second vacuum sealing.

As shown, the vacuum sealing means 110 comprises a vacuum chamber 91 and a heating means 93.

A package 61 is provided in the vacuum chamber 91.
Is housed. In this state, the vacuum chamber 91 has a high vacuum.

A part of the partition wall or cover 92 of the vacuum chamber 91 shown in FIG. 14 is transparent. Then, on the cover 92 side, the opening 58 of the package 61 is formed.
Are arranged and housed so as to face each other.

On the other hand, the heating means 93 is arranged outside the vacuum chamber 91. Heating means 93
Is driven by a driving means such as a three-axis robot in a horizontal XY direction and a vertical Z direction (not shown). The heating means 93 includes, for example, a drive source 94 and a beam irradiation means 95 connected to the drive source 94. The beam irradiating means 95 irradiates the cover 92 of the vacuum chamber 91 with a high temperature light beam such as a laser beam of a large capacity laser.

As a result, the heating means 93 is moved,
As shown in FIG. 14, alignment is performed with respect to the vacuum chamber 91, the driving means 94 is driven, and, for example, a laser light beam is emitted from the beam emitting means 95. The light beam passes through the transparent cover 92 and is applied to the sealing material 59, which heats and melts the sealing material 59.

In this way, the sealing material 59 is heated and melted, and the molten metal closes the through hole 76 of the opening 58 as shown in FIG. Processing is performed.

Therefore, the sealing material 59 is the metal coating 7
It is also possible to melt only by heating the sealing material 59 without heating the 4a and the metal-embedded portion 75.

FIG. 15 shows a vacuum sealing means 120 for performing the above-mentioned second vacuum sealing.

With respect to the vacuum sealing means 120, the same reference numerals as those in the vacuum sealing means 100 described with reference to FIG. 13 have the same structure, and the overlapping description will be omitted and the different points will be mainly described. . The vacuum sealing means 120 is different from the vacuum sealing means 100 of FIG. 13 in that the second heating means 121, the heat source 101, and the second heating means 121 arranged so as to contact the lid 56 of the package 61, for example. The difference is that it includes a heating control means 102 connected to 121.
The second heating means 121 may itself be composed of a heater block such as a carbon heater as a heat source. In that case, the heat source 101 and the heat conducting portion 81 in FIG. 15 are the same.

By using such a vacuum sealing means 120, the package 61 can be heated to a temperature below the melting point of the sealing material 59 to perform the second vacuum sealing.

Specifically, as shown in FIGS. 16 and 17, heating is performed to perform vacuum sealing. First, unlike the state shown in FIG. 15, the contact jig 82 is held above the sealing material 59 and each contact pin 8 of the contact jig 82 is held.
3, 84 are not in contact with the sealing material 59.
Then, the heating control means 102 uses the second heating means 121.
To heat the package 61. This heat is transmitted to the sealing material 59 which is in contact with the package 61, and the sealing material 59 is heated up to, for example, about 200 degrees Celsius as shown in FIG. In this case, the temperature of the sealing material 59 may be measured and supplied to the heating control means 102, or the heating control means may hold preliminarily tested data and seal it from the heating time and the heating rate. The temperature of the stopper 59 may be known. And the above package 6
The heating time of 1 is preferably about 5 minutes to 10 minutes prior to the heating and melting of the sealing material 91 described later. According to this time setting, harmful outgas generated from the sealant 57 and the adhesive 55 of the lid 56 can be evacuated. Note that FIG. 18 shows a vacuum drawing profile at this time.

On the other hand, the heating control means 102 is the heat source 101.
To heat the heat conducting portion (heater) 81, and this heat is transmitted to the contact jig 82,
The temperature of the (first heating means) is raised until the temperature reaches, for example, about 320 degrees Celsius (see FIG. 16).

Then, as described above, when the sealing material 59 is, for example, about 200 degrees Celsius and the contact jig 82 is, for example, 320 degrees Celsius, the driving means (not shown) is driven to contact. The jig 82 is lowered to the state shown in FIG.

That is, the first pin 83 of the contact jig 82.
Comes into contact with the vicinity of the center of the sealing member 59, and the second pin 8
4 and 84 abut on the metal coating portion 74a and / or the embedded metal portion to rapidly raise the temperature of the sealing material 59 as shown by the symbol A in FIG. Bring to a temperature above the melting point. The shorter the time required to raise the temperature, the better, preferably 10 seconds or less, more preferably 3 seconds.
The best result was obtained when the time was 1.5 seconds or less and 1.5 seconds or less.

Particularly, regarding the temperature rise of the sealing material 59, the portion indicated by the symbol A in FIG.
The enlarged view is shown in FIG. According to this figure, the temperature change is steep at the rising portion A1 of the temperature, and the temperature change is slightly gradual at the falling portion A2.

In this case, in order to make the temperature of the package 61 lower than the melting point of the encapsulating material 59, for example, when Au—Sn solder alloy is used as the encapsulating material, the temperature of the encapsulating material 59 is as described above. The temperature is raised to about 200 degrees Celsius. However, depending on the material of the sealing material 59, a higher temperature may be used when the melting point is higher, and a lower temperature may be used when the melting point is lower. However,
If the temperature of the package 61 is 240 degrees Celsius or higher, the sealing agent 57, the adhesive 55, etc. of the lid 56 may be melted and harmful gas may be generated, which is not preferable.

Thus, the vacuum sealing means 1 shown in FIG.
When the package 61 is preheated to a temperature equal to or lower than the melting point of the encapsulating material 59 by 20 and melted with the encapsulating material 59,
9 melts to the periphery of the opening 58 and becomes easy to flow. This enables stable vacuum sealing of the package 61.

Further, as shown in FIG. 17, the package 61
Is heated to a temperature not higher than the melting point of the sealing material 59 in advance, and then the sealing material 5
By rapidly heating 9 above its melting point, the sealing material 59
Can be instantly heated and melted to realize a high degree of vacuum in the package 61. If the heating time of the sealing material 59 is longer than that described above, for example, if it takes 1 minute or more, the sealing agent 57 of the lid 56, the adhesive agent 55 and the like may be melted to generate harmful gas, which is not preferable. . Therefore, the shorter the heating time, the better. Considering the time required for melting the sealing material 59,
It has been confirmed by the present inventors that the above range is achieved.

FIG. 19 shows a vacuum sealing means 130 as still another means for performing the above-mentioned second vacuum sealing.

Regarding this vacuum sealing means 130, FIG.
The parts denoted by the same reference numerals as those of the vacuum sealing means 110 described in 1) have the same configuration, and the overlapping description will be omitted, and the different points will be mainly described. The vacuum sealing means 130 is different from the vacuum sealing means 110 of FIG. 14 in that the second heating means 121, which is arranged so as to contact the lid 56 of the package 61, the driving source 94 and the second heating means 121. Means 121
The difference is that the heating control means 102 is connected to.

Therefore, according to the vacuum sealing means 130, in addition to the effect of the vacuum sealing means 110 described in FIG. 14, the sealing material 59 is easily melted and flows around the opening 58, As a result, the function and effect of enabling stable vacuum sealing of the package 61 is exhibited.

The shape and arrangement of the metal-embedded portion 75 are not limited to those in the above embodiment, and the shape and arrangement thereof are not limited to those of the base 6.
It can be freely set within the range in which the strength of No. 5 is not impaired. Further, as described above, it is not always necessary to provide both the metal coating portion 74a and the metal embedding portion 75. Either one may be provided.

Further, the metallization of the opening or the electrode pattern electrically connected to the metal-embedded portion 75 may be extended to the side surface of the package 61 or the like for wiring.

(Sixth Embodiment) FIG. 21 shows a piezoelectric vibrator 95 according to a sixth embodiment of the present invention. The structure of the piezoelectric vibrator 95 common to the fifth embodiment is the same. The reference numerals are given and the duplicated description is omitted. Piezoelectric vibrator 9
5 is different from the fifth embodiment in that a ceramic lid 96 is used instead of the metal lid 56 shown in FIG. Therefore, the piezoelectric vibrator 95 according to the sixth embodiment can also achieve the same effect as that of the fifth embodiment.

(Seventh Embodiment) FIG. 22 shows a piezoelectric vibrator 97 according to a seventh embodiment of the present invention, and the same reference numerals are given to the same constituents as those of the piezoelectric vibrator 97 of the fifth embodiment. A duplicate description will be omitted. This piezoelectric vibrator 9
7 is different from the sixth embodiment in that the opening 99 is formed in the lid 96 shown in FIG. Therefore, the piezoelectric vibrator 97 according to the seventh embodiment can also achieve the same effects as those of the fifth and sixth embodiments.

The present invention is not limited to the above embodiments,
The components can be combined freely.

Further, the component of the sealing agent 57 may be a metal material such as Au—Sn system, Sn system, Pb—Sn system, Ag braze system, or an organic adhesive. Also, the sealant 57
The form may be clad or preformed.

According to the above configuration, the first sealing step, the frequency adjusting step and the second sealing step can be commonly processed in a laser device or the like. Can be done.

The ceramic base 65 and the lid 56 to be processed may be in the form of a single piece or a plate in which a plurality of pieces are arranged.

Further, an IC having an oscillation circuit or the like in the package
This structure can be applied to a crystal oscillator with a built-in chip and crystal oscillator, a real-time clock oscillator, and the like.

As described above, by using inexpensive components as compared with high quality glass such as ceramics and metals,
A small and thin crystal resonator having a width of 5 mm, a width of 2 mm and a thickness of 0.8 mm can be obtained at low cost.

[0114]

According to the invention described in claims 1, 2, 4, and 7, the piezoelectric vibrator is provided from the opening provided in the package,
By adjusting the frequency with the frequency adjusting means, the base and the lid constituting the vacuum-sealed package can be made of an inexpensive material, and the surface mount type crystal resonator can be provided at a low cost.

According to the third aspect of the invention, stable frequency adjustment can be performed by adjusting the frequency by using a part of at least one vibrating arm of the tuning fork type vibrator element.

According to the sixth aspect of the invention, when the tuning fork type piezoelectric vibrator element is used, it is possible to adjust the frequencies of the two vibrating arms in a well-balanced manner.

As described above, in these inventions, the opening for frequency adjustment can be made small, and it is possible to prevent the crystal resonator element from being affected by sealing the opening. is there. Then, by performing frequency adjustment in such a minute range, it is possible to provide a small and thin piezoelectric vibrator having more stable characteristics.

According to the fifth and eighth aspects of the invention, since the airtight region in which the piezoelectric vibrator piece is built and sealed in a vacuum is formed by the base and the lid made of a single layer, the airtightness is improved. This is extremely expensive and has an effect that a high-quality piezoelectric vibrator can be provided at low cost.

According to the invention described in claim 7, since the first sealing step, the frequency adjusting step and the second vacuum sealing step can be performed by processing with a light beam, integrated processing can be performed by the same apparatus. It has an effect that the cost can be reduced.

According to the tenth and thirteenth aspects of the invention, in the piezoelectric vibrator in which the piezoelectric vibrator is built in the package,
By arranging the metallized metal around the opening provided in the package, the heat at the time of sealing can be efficiently conducted to the sealing portion, and a very high degree of vacuum can be achieved. Have an effect. As a result, the built-in piezoelectric vibrator piece stably vibrates, and a high-quality piezoelectric vibrator is obtained.

According to the ninth, eleventh and thirteenth aspects of the present invention, the frequency adjusting step and the vacuum sealing step can be precisely performed by using the same laser beam or electron beam irradiation means.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a piezoelectric vibrator according to a first embodiment of the present invention, (a) is a schematic plan view of the piezoelectric vibrator,
FIG. 3B is a schematic side sectional view of the piezoelectric vibrator.

FIG. 2 is a schematic diagram showing a frequency adjustment process of the piezoelectric vibrator of FIG.

FIG. 3 is a schematic rear view of the piezoelectric vibrator of FIG.

FIG. 4 is a schematic front cross-sectional view showing a piezoelectric vibrator according to a second embodiment of the present invention.

FIG. 5 is a schematic front sectional view showing a piezoelectric vibrator according to a third embodiment of the present invention.

FIG. 6 is a schematic rear view showing a piezoelectric vibrator according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a structure of a piezoelectric vibrator according to a fifth embodiment of the present invention, (a) is a schematic plan view of the piezoelectric vibrator,
(B) is a schematic front sectional view of the piezoelectric vibrator.

FIG. 8 is a schematic diagram showing a frequency adjustment process of the piezoelectric vibrator of FIG.

9 is a schematic rear view of the piezoelectric vibrator shown in FIG.

10A is a view showing the periphery of an opening on the back surface of the piezoelectric vibrator of FIG. 7, and FIG. 10B is a schematic front sectional view of the piezoelectric vibrator of FIG.

11 is a schematic enlarged view of the piezoelectric vibrator of FIG. 7 as seen from the side surface of the opening.

FIG. 12 is a schematic enlarged view of a modified example of the opening of the piezoelectric vibrator of FIG. 7 viewed from the side.

13 is an explanatory diagram showing an example of a second sealing step of the piezoelectric vibrator of FIG.

FIG. 14 is an explanatory view showing another example of the second sealing step of the piezoelectric vibrator of FIG.

FIG. 15 is an explanatory diagram showing still another example of the second sealing step of the piezoelectric vibrator of FIG. 7.

16 is a diagram showing a temperature rising state of the first heating means in the second sealing step of FIG.

FIG. 17 is a diagram showing a temperature rising state of the second heating means in the second sealing step of FIG. 15.

FIG. 18 is a diagram showing a profile of vacuum evacuation in the second sealing step of FIG. 15.

FIG. 19 is an explanatory view showing a further different example of the second sealing step of the piezoelectric vibrator of FIG. 7.

20 is a schematic front cross-sectional view showing a sealed state of the opening of the piezoelectric vibrator of FIG.

FIG. 21 is a schematic front sectional view showing a piezoelectric vibrator according to a sixth embodiment of the present invention.

FIG. 22 is a schematic front sectional view showing a piezoelectric vibrator according to a seventh embodiment of the present invention.

FIG. 23 is a structural diagram of a conventional piezoelectric vibrator, (a)
Is a plan view thereof, and (b) is a schematic side sectional view thereof.

[Explanation of symbols]

1,65 Bases 2a, 2b, 52a, 52b Electrode parts 3,53 Crystal resonator pieces 54a, 54b Electrode parts 5,55 Adhesives 6,56 Lids 7,57 Sealants 8,45,58 Openings 11,51 Piezoelectric vibrator 12,52 Single layer portion 13,63 Frequency adjusting means (laser device or electron beam device) 59 Sealing material 73 Through hole 74 Stepped portion 74a Metal coating portion (metallized portion) 76 Through hole 80 Heating jig 82 Bonding jig 91 Vacuum chamber 93 Heating means 201 Crystal oscillator piece 202 Base 203 Lid

Continued front page    (72) Inventor Hideo Tanaya             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation F term (reference) 5J108 AA02 BB02 CC06 EE03 EE07                       EE18 GG03 GG09 GG15 GG16                       GG20 KK04 KK06 MM02 NA03                       NB05

Claims (13)

[Claims] 1. A piezoelectric vibrator having a piezoelectric vibrator piece built in a package, wherein the piezoelectric vibrator piece is frequency-adjusted by a frequency adjusting means from an opening provided in the package. Child. 2. A piezoelectric vibrator having a piezoelectric vibrator piece built in a package, wherein the piezoelectric vibrator piece is a tuning fork type piezoelectric vibrator piece having two vibrating arms, and at least one of the two vibrating pieces is used. A piezoelectric vibrator, wherein a part of the vibrating arm is frequency-adjusted by a frequency adjusting means. 3. The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator piece is a tuning fork type crystal vibrator piece. 4. The piezoelectric vibrator according to claim 1, wherein the frequency adjusting means is a trimming processing means using a laser beam or an electron beam. 5. The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator piece is mounted on an electrode portion of a base made of a single layer and sealed with a lid made of a single layer. 6. The opening provided in the package,
The size is such that it does not exceed the outer shape of the tuning fork type piezoelectric vibrating arm housed inside, and is formed so as to expose at least part of each of both vibrating arms of the tuning fork type piezoelectric vibrating arm. The piezoelectric vibrator according to any one of claims 2 to 5, wherein 7. A method of mounting a piezoelectric vibrator piece on a base, a step of positioning and sealing the base and a lid (lid), and the piezoelectric vibration using an opening provided in the base or the lid. A method of manufacturing a piezoelectric vibrator, comprising: a step of frequency-adjusting a part of a child piece by a laser beam or an electron beam; and a step of vacuum-sealing the opening in a vacuum atmosphere. 8. The method of manufacturing a piezoelectric vibrator according to claim 7, wherein the hermetically sealed region in which the piezoelectric vibrator is contained and sealed in a vacuum is composed of a single layer of the base and the lid. 9. A piezoelectric vibrator piece using a step of mounting a piezoelectric vibrator piece on a base, a step of positioning and sealing the base and the lid, and using an opening provided in the base or the lid. A step of adjusting the frequency of a part of the sealing material with a laser beam or an electron beam, a step of setting a sealing material in the opening, and a step of heating the sealing material in a vacuum atmosphere and vacuum sealing. A method for manufacturing a characteristic piezoelectric vibrator. 10. The method of manufacturing a piezoelectric vibrator according to claim 9, further comprising the step of heating the periphery of the opening in a vacuum atmosphere and sealing the vacuum in a vacuum atmosphere after setting the sealing material. 11. The step of heating the encapsulant includes housing a package including the piezoelectric vibrator piece in a vacuum chamber,
10. The method for manufacturing a piezoelectric vibrator according to claim 9, wherein the sealing material is heated and melted by irradiating the sealing material with a laser beam or a high-temperature light beam from the outside of the vacuum chamber. 12. The heating step of the encapsulant, the package including the piezoelectric vibrator piece is housed in a vacuum chamber,
The method for manufacturing a piezoelectric vibrator according to claim 10, wherein a heating jig is brought into contact with the sealing material and the periphery of the opening to heat and melt the piezoelectric material. 13. The method according to claim 9, further comprising heating the lid or the base in a vacuum atmosphere when the sealing material is heated and vacuum-sealed. A method for manufacturing a piezoelectric vibrator according to item 1.