JP5220538B2 - Method for manufacturing piezoelectric vibrator - Google Patents

Description

The present invention relates to a method for manufacturing piezoelectric vibration used in electronic equipment.

Conventionally, electronic boards on which electronic components are mounted are used in electronic devices. A conductive pattern made of a metal film is formed on the electronic substrate, and an electronic component is mounted on the electronic substrate by bonding a chip component such as a capacitor to the conductive pattern with solder or the like.
In addition to the chip component, the electronic component includes an electronic component such as a piezoelectric vibrator or a piezoelectric oscillator having a structure in which various elements are mounted on a container having a recess and the recess is sealed.

Here, the piezoelectric vibration element mounting member and the lid member used for the piezoelectric vibrator will be described.
For example, the piezoelectric vibration element mounting member is formed in a flat plate shape, and a metal film is provided on a surface to be joined to a lid member described later. In addition, a mounting pad for mounting the piezoelectric vibration element is provided inside the metal film. In addition, an external terminal for mounting on a wiring board such as a mother board is provided on the main surface opposite to the main surface on which the metal film is provided. This external terminal is connected to the mounting pad via an internal wiring pattern. Such a piezoelectric vibration element mounting member is provided with a metal film, a mounting pad, and an external terminal in the state of a plurality of wafers.
In addition, the lid member is provided with a recess having a size capable of sealing the piezoelectric vibration element inside, and a metal film made of a sealing material is provided on a surface to be joined to the piezoelectric vibration element mounting member. It has been. Such a lid member is provided with a metal film in the state of a wafer in which a plurality are connected.

Here, the piezoelectric vibrator is manufactured through the following steps.
First, the piezoelectric vibration element is mounted on a mounting pad provided on the piezoelectric vibration element mounting member via a conductive adhesive, and in this state, the lid member is placed in the recess of the lid member so that the piezoelectric vibration element enters the recess. Overlay the mounting member.
In a state where the piezoelectric vibration element mounting member and the lid member overlap, for example, heating is performed at 300 ° C. to 350 ° C., and the piezoelectric vibration element mounting member and the lid member are joined to each other so that a plurality of piezoelectric vibrators are formed on one wafer. Keep it in the provided state.
Thereafter, the piezoelectric vibrator is cut into individual piezoelectric vibrators and separated into individual pieces (see, for example, Patent Document 1).

In addition, a piezoelectric vibrator having a similar structure in which a piezoelectric vibration element mounting member in a wafer state and a lid member are joined without using a bonding metal film has been proposed (for example, Patent Documents). 2).
The piezoelectric vibration element mounting member and the lid member are joined by direct joining. The temperature at which this bonding is performed is set to 200 ° C to 500 ° C.
In this way, bonding is performed in the state of a wafer, and the piezoelectric vibrators are cut into pieces and cut into individual piezoelectric vibrators.

JP 2006-279872 A JP 2006-339896 A

However, the joining of the piezoelectric vibration element mounting member and the lid member requires heating. Thereby, stress may remain in the piezoelectric vibration element mounting member and the lid member due to thermal expansion due to heating and subsequent shrinkage due to cooling. Due to this stress, there is a possibility that the joint portion is peeled off.
Further, in order to be bonded, the width of the bonding surface needs to be provided as wide as, for example, about 0.15 mm, but the bonding width has become narrower than before due to downsizing of electronic components. Therefore, there is a possibility that complete sealing cannot be performed.

Therefore, an object of the present invention is to provide a method for manufacturing a piezoelectric vibrator that solves the above-described problems, is completely sealed, and prevents residual stress.

In order to solve the above-described problems, the present invention provides a method for manufacturing a piezoelectric vibrator, which is made of alumina ceramic or glass ceramic, and includes a main portion of a first wafer provided with a plurality of piezoelectric vibration element mounting members. Polishing the surface until the average surface roughness Ra becomes 1 nm or less, and after the surface roughness of the first wafer becomes 1 nm or less, the first surface roughness Ra Forming a through hole in the wafer; filling the through hole by sputtering, electrolytic plating, or electroless plating; and forming a mounting pad and an external terminal on the first wafer; and conductive bonding A step of mounting the piezoelectric vibration element on the mounting pad using an agent; and a plurality of the piezoelectric elements in the first wafer, which are made of alumina ceramic or glass ceramic Polishing the main surface of the second wafer provided with a portion to be a plurality of lid members at a position corresponding to the moving element mounting member until the average surface roughness Ra becomes 1 nm or less, the surface roughness, Forming a recess for each lid member portion of the second wafer after the average surface roughness Ra of the second wafer is 1 nm or less, and mounting the piezoelectric vibration element on the first wafer Surface activation of the main surface as a bonding surface of the member with argon plasma or oxygen plasma, and surface activation of the main surface as a bonding surface of the lid member of the second wafer with argon plasma or oxygen plasma And superimposing the first wafer and the second wafer so that the corresponding piezoelectric vibration element is inserted into each of the recesses provided in the second wafer, and bringing the temperature to room temperature in a vacuum atmosphere. Predetermined A step of directly bonding by applying force, and cutting the bonded first wafer and the second wafer along the contour of the piezoelectric vibration element mounting member or / and the contour of the lid member, A piezoelectric vibrator is formed .

The present invention also relates to a method of manufacturing a piezoelectric vibrator, wherein the main surface of the first wafer, which is made of alumina ceramic or glass ceramic and provided with a portion to be a plurality of piezoelectric vibration element mounting members, is an average surface. Polishing until the roughness Ra becomes 1 nm or less and the surface roughness where the average surface roughness Ra of the first wafer becomes 1 nm or less, and then the piezoelectric vibration element of the first wafer Forming a recess for each mounting member, forming a through hole in the bottom surface of the recess, and filling the through hole by sputtering, electrolytic plating, or electroless plating; Forming a mounting pad and further forming an external terminal on the first wafer; mounting a piezoelectric vibration element on the mounting pad using a conductive adhesive; and an alumina ceramic The main surface of the second wafer, which is made of a ceramic or glass ceramic, and has a plurality of lid member portions provided at positions corresponding to the plurality of piezoelectric vibration element mounting members in the first wafer, has an average surface roughness. A step of polishing until the surface roughness Ra becomes 1 nm or less, a step of surface activating the main surface of the first wafer as a bonding surface of the piezoelectric vibration element mounting member with argon plasma or oxygen plasma, A step of activating the main surface, which is a bonding surface of the lid member of the second wafer, with argon plasma or oxygen plasma, and mounting the piezoelectric vibration element corresponding to the first wafer and the second wafer. Aligning the positions of the portion and the lid member portion, applying a predetermined pressure at normal temperature in a vacuum atmosphere, and directly bonding, and bonding the first wafer and the second wafer Ha, the piezoelectric vibrating element mounting member contour, or / and by cutting along said contour of the lid member, and forming a plurality of piezoelectric vibrators.

Further, according to the present invention, the bonding surface of the portion to be the piezoelectric vibration element mounting member in the first wafer and the bonding surface of the portion to be the lid member in the second wafer A metal film for bonding may be provided after the average surface roughness Ra is set to be 1 nm or less .

According to such a method of manufacturing a piezoelectric vibrator, since the average surface roughness Ra of the bonding surface is 1 nm or less, direct bonding can be performed at normal temperature, and the sealing state is maintained even if the bonding surface width is smaller than the conventional one. Can be maintained.
Moreover, since the two concave portions are provided in the piezoelectric vibration element mounting member, it can be used as a space for the piezoelectric vibration element, and in addition, other electronic components can be mounted.
In addition, since the bonding metal film is provided on the bonding surface, the bonding strength between the piezoelectric vibration element mounting member and the lid member can be improved.

  Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate. Note that each component is exaggerated for easy understanding of the state.

(First embodiment)
FIG. 1A is a conceptual diagram illustrating an example of a state in which external terminals and mounting pads are provided on a wafer. FIG. 1B is a conceptual diagram illustrating an example of a state in which a piezoelectric vibration element is mounted. Is a conceptual diagram showing a state before the lid member is joined, and (d) is a conceptual diagram showing a state in which the lid member is joined. FIG. 2 is a conceptual diagram showing an example of the piezoelectric vibrator according to the first embodiment of the present invention.
The piezoelectric vibrator 101 according to the first embodiment of the present invention includes a piezoelectric vibration element mounting member 10A, a piezoelectric vibration element 20, and a lid member 30A.

As shown in FIG. 1B, the piezoelectric vibration element 20 is provided with excitation electrodes 22 on both main surfaces of a crystal piece 21 having a rectangular shape in plan view, which is a piezoelectric piece, for example. A lead pattern 23 extending from the excited electrode 22 to the end side of the crystal piece 21 is formed (see FIG. 1).
The piezoelectric vibration element 20 is bonded to the lead pattern 23 connected to the excitation electrode 22 and the mounting pad P provided on the piezoelectric vibration element mounting member 10A by the conductive adhesive D.
Thereby, the piezoelectric vibration element 20 is mounted on the piezoelectric vibration element mounting member 10A.

The piezoelectric vibration element mounting member 10A is made of a sintered alumina ceramic or a baked glass ceramic and has a surface roughness with an average surface roughness Ra of 1 nm or less. The piezoelectric vibration element mounting member 10A has a surface roughness with an average surface roughness Ra of 1 nm or less even on a joint surface with a lid member 30A described later.
When the average surface roughness Ra of the bonding surface is 1 nm or less, direct bonding at room temperature is facilitated. However, when the average surface roughness Ra of the bonding surface is larger than 1 nm, direct bonding at room temperature becomes difficult and bonding is performed while heating, so that the piezoelectric vibration element mounting member 10A may be distorted.

Further, the bonding surface is provided on the main surface on which the mounting pad P (see FIG. 1A) is provided along the outer peripheral edge of the piezoelectric vibration element mounting member 10A, and the width is, for example, 20 μm. It has become.
This bonding surface is activated by argon plasma or oxygen plasma before being overlapped with a lid member 30A described later.
Further, as shown in FIG. 1A, the piezoelectric vibration element mounting member 10A is provided with a mounting pad P for mounting the piezoelectric vibration element 20 on the inner side of the bonding surface, and the mounting pad P is provided. An external terminal G is provided on the main surface opposite to the main surface.
The mounting pad P and the external terminal G are connected through a through hole provided in advance.

The lid member 30 </ b> A is made of a fired alumina ceramic or a fired glass ceramic and has a surface roughness with an average surface roughness Ra of 1 nm or less. The lid member 30A has a surface roughness with an average surface roughness Ra of 1 nm or less even on the joint surface with the piezoelectric vibration element mounting member 10A.
This bonding surface is activated by argon plasma or oxygen plasma before being overlapped with the piezoelectric vibration element mounting member 10A.
When the average surface roughness Ra of the bonding surface is 1 nm or less, direct bonding at room temperature is facilitated. However, when the average surface roughness Ra of the bonding surface is larger than 1 nm, direct bonding at room temperature becomes difficult and bonding is performed while heating, so that the lid member 30A may be distorted.
Moreover, as shown in FIG.1 (c), the recessed part 31 is formed in the cover member 30A. The recess 31 is formed to have a size that covers the piezoelectric vibration element 20 mounted on the piezoelectric vibration element mounting member 10A.
The joining surface is between the outer peripheral edge of the lid member 30A and the recess 31 and has a width of, for example, 20 μm.

The piezoelectric vibration element mounting member 10A on which the piezoelectric vibration element 20 is mounted and the lid member 30A are directly bonded by applying a predetermined pressure in a vacuum atmosphere at room temperature in a state where the bonding surfaces are overlapped. Here, normal temperature is set to a range of 20 ± 15 ° C., for example.
As a result, the piezoelectric vibration element mounting member 10A and the lid member 30A are directly joined to form the piezoelectric vibrator 101.

  As described above, since the piezoelectric vibrator 101 according to the first embodiment of the present invention is configured, a structure capable of easily performing direct bonding can be obtained. In addition, since the average surface roughness Ra of the bonding surface is 1 nm, direct bonding can be performed at room temperature, and the sealed state can be maintained even if the width of the bonding surface is smaller than the conventional one.

Next, a method for manufacturing the piezoelectric vibrator 101 according to the first embodiment of the present invention will be described. As shown in FIG. 1A, the plurality of piezoelectric vibration element mounting members 10A are provided on a single wafer. That is, this wafer is provided with a portion to be a plurality of piezoelectric vibration element mounting members 10A.
The wafer is polished until the average surface roughness Ra is 1 nm or less. The average surface roughness Ra may be 1 nm or less. Moreover, the average surface roughness Ra of the main surface to be the bonding surface may be 1 nm or less, but the average surface roughness Ra of both surfaces may be 1 nm or less.

When the average surface roughness Ra of the wafer is 1 nm or less, a through hole is formed using a predetermined laser, sand blasting, etching or the like.
Next, after the through hole is filled with any one of sputtering, electrolytic plating, and electroless plating, the mounting pad P and the external terminal G are formed.
As shown in FIG. 1B, in this state, the piezoelectric vibration element 20 is mounted on the mounting pad P using the conductive adhesive D.
After the conductive adhesive D is cured, a part of the excitation electrode 22 of the piezoelectric vibration element 20 is removed or added to adjust the frequency.

At the same time or after these steps, the wafer provided with the plurality of lid members 30A is polished.
The wafer is also polished until the average surface roughness Ra becomes 1 nm or less, as in the wafer provided with the plurality of piezoelectric vibration element mounting members 10A. The average surface roughness Ra may be 1 nm or less. Moreover, the average surface roughness Ra of the main surface to be the bonding surface may be 1 nm or less, but the average surface roughness Ra of both surfaces may be 1 nm or less.
The main surface serving as the bonding surface is the main surface on the side where the recess 31 is provided.
When the average surface roughness Ra of the wafer is 1 nm or less, the recess 31 is formed using sand blasting, etching, or the like.

As shown in FIGS. 1C and 1D, the piezoelectric vibration element 20 is mounted.
Thereafter, the surface of the bonding surface of the piezoelectric vibration element mounting member 10A is activated with argon plasma or oxygen plasma before being overlapped with the lid member 30A.
Further, the surface of the joining surface of the lid member 30A is activated by argon plasma or oxygen plasma before being overlapped with the piezoelectric vibration element mounting member 10A.
In this state, the wafer provided with the plurality of piezoelectric vibration element mounting members 10A and the wafer provided with the recesses 31 and provided with the plurality of lid members 30A are overlapped.
At this time, the piezoelectric vibration element 20 is superposed so as to enter the recess 31 provided in the wafer provided with the plurality of lid members 30A.
In this state, in a vacuum atmosphere in which the degree of vacuum is 5 × 10 ⁻⁵ Pa or less, a predetermined pressure is applied at normal temperature to bond the wafers directly.

  After the joining, the piezoelectric vibrator 101 is cut along the outline of the piezoelectric vibration element mounting member 10A and / or the outline of the lid member 30A to form a plurality of piezoelectric vibrators 101 (see FIG. 2).

  Therefore, since a heating step for bonding is not required, direct bonding can be easily performed, and distortion of the piezoelectric vibration element mounting member 10A and the lid member 30A can be eliminated.

(Second embodiment)
Next, a piezoelectric vibrator according to a second embodiment of the present invention will be described.
As shown in FIG. 3, the piezoelectric vibrator 102 according to the second embodiment of the present invention is the first in that the concave portion 11B is formed in the piezoelectric vibration element mounting member 10B and the lid member 30B is formed in a flat plate shape. Different from one embodiment.
The piezoelectric vibrator 102 according to the second embodiment of the present invention is mainly configured by a piezoelectric vibration element mounting member 10B having a recess 11B, a piezoelectric vibration element 20, and a flat lid member 30B.

The piezoelectric vibration element mounting member 10B is provided with a recess 11B on one main surface, and a mounting pad P for mounting the piezoelectric vibration element 20 is provided inside the recess 11B. The other main surface is provided with an external terminal G for connection to a wiring board such as a mother board. The external terminal G is connected to the mounting pad P through a through hole provided in the piezoelectric vibration element mounting member 10B.
The main surface on the side where the concave portion 11B of the piezoelectric vibration element mounting member 10B is provided has an average surface roughness Ra of 1 nm or less. The surface roughness Ra of both main surfaces of the piezoelectric vibration element mounting member 10B may be 1 nm or less.

  The lid member 30B has a flat plate shape, and the planar shape is the same as the planar shape at the outer peripheral edge of the piezoelectric vibration element mounting member 10B. The average surface roughness Ra of the main surface of the lid member 30B on the side to be joined to the piezoelectric vibration element mounting member 10B is 1 nm or less. The average surface roughness Ra of both main surfaces of the lid member 30B may be 1 nm or less.

  The piezoelectric vibration element 102 configured as described above has a flat plate-like shape that is formed by mounting the piezoelectric vibration element 20 on a mounting pad P provided in each of the recesses 11B on a wafer provided with the recesses 11B. The wafers are stacked after surface activation, and directly bonded in a vacuum atmosphere by applying a predetermined pressure at room temperature. Thereafter, cutting is performed along the contour of the piezoelectric vibration element mounting member 10 </ b> B and / or the contour of the lid member 30 </ b> B to form a plurality of piezoelectric vibrators 102.

  Thus, even if the piezoelectric vibrator 102 according to the second embodiment of the present invention is configured, the same effects as those of the first embodiment can be obtained.

(Third embodiment)
Next, a piezoelectric vibrator according to a third embodiment of the present invention will be described.
As shown in FIG. 4, in the piezoelectric vibrator 103 according to the third embodiment of the present invention, a second concave portion 11CB is further provided in the first concave portion 11CA provided in the piezoelectric vibration element mounting member 10C. It differs from the second embodiment in that it has a structure.

The piezoelectric vibration element mounting member 10C has a structure in which two concave portions 11CA and 11CB are provided. The recesses 11CA and 11CB may be formed before or after polishing the average surface roughness Ra of the piezoelectric vibration element mounting member 10C to 1 nm or less.
When the recesses 11CA and 11CB are formed before polishing, before manufacturing the wafer, for example, the recesses 11CA and 11CB are formed by laminating alumina ceramic or glass ceramic to form the recesses 11CA and 11CB. It is good also as a wafer which has 11CA and 11CB.

In the piezoelectric vibration element mounting member 10C, a mounting pad P is provided in the recess 11CA, and the piezoelectric vibration element 20 is mounted on the mounting pad P so as to be positioned in the recess 11CA.
Thus, since the piezoelectric vibrator 103 according to the third embodiment of the present invention is configured, a structure capable of easily performing direct bonding can be obtained. In addition, since the average surface roughness Ra of the bonding surface is 1 nm, direct bonding can be performed at room temperature, and the sealed state can be maintained even if the width of the bonding surface is smaller than the conventional one.
In addition, since the piezoelectric vibration element 20 is mounted in the recess 11CA, the recess 11CB becomes a vacant space, so that the piezoelectric vibration element mounting member 10C can be contacted even when the free end portion of the piezoelectric vibration element 20 is lowered. There is no. Thereby, the factor that the frequency of the piezoelectric vibration element 20 changes can be removed.

(Fourth embodiment)
Next, a piezoelectric vibrator according to a fourth embodiment of the present invention will be described.
As shown in FIG. 5, in the piezoelectric vibrator 104 according to the fourth embodiment of the present invention, the bonding metal films 12 and 32 are provided on the bonding surfaces of the piezoelectric vibration element mounting member 10D and the lid member 30D. This is different from the first embodiment.

The piezoelectric vibration element mounting member 10D is polished until the average surface roughness Ra of the main surface on the side where the mounting pad P is provided is 1 nm or less. Thereafter, the bonding metal film 12 is formed simultaneously with or separately from the mounting pad P. Provide. The bonding metal film 12 is provided on the bonding surface provided on the piezoelectric vibration element mounting member 10A in the first embodiment.
The bonding metal film 12 is surface activated by argon plasma or oxygen plasma before being overlapped with a lid member 30D described later.
Thus, when the bonding metal film 12 is provided in a state where the average surface roughness Ra of the piezoelectric vibration element mounting member 10D is 1 nm or less, the adhesion between the piezoelectric vibration element mounting member 10D and the bonding metal film 12 is good. Further, airtight leakage from the boundary between the piezoelectric vibration element mounting member 10D and the bonding metal film 12 can be prevented.

The lid member 30D is polished until the average surface roughness Ra of the main surface on the side where the recesses 31 are provided is 1 nm or less, and then the bonding metal film 32 is provided after the recesses 31 are formed.
The bonding metal film 32 is provided on the bonding surface provided on the lid member 30A in the first embodiment. That is, the joint surface is between the outer peripheral edge of the lid member 30 </ b> D and the edge of the recess 31, and the joining metal film 32 is provided on the joint surface.
The bonding metal film 32 is surface activated by argon plasma or oxygen plasma before being superimposed on the piezoelectric vibration element mounting member 10D.
As described above, when the bonding metal film 32 is provided in a state where the average surface roughness Ra of the lid member 30D is 1 nm or less, the adhesion between the lid member 30D and the bonding metal film 32 is good, and the lid member 30D is bonded to the lid member 30D. Airtight leakage from the boundary with the metal film 32 can be prevented.

The piezoelectric vibration element 20 is mounted on the piezoelectric vibration element mounting member 10D configured as described above. After that, the surface of the bonding metal film 12 of the piezoelectric vibration element mounting member 10D is activated by argon plasma or oxygen plasma before being overlapped with a lid member 30D described later.
Further, the surface of the bonding metal film 32 of the lid member 30D is activated by argon plasma or oxygen plasma before being superimposed on the piezoelectric vibration element mounting member 10D.
In this state, the piezoelectric vibration element mounting member 10 </ b> D and the lid member 30 </ b> D are overlapped and directly bonded by applying a predetermined pressure at room temperature in a vacuum atmosphere.
Thereby, the piezoelectric vibration element mounting member 10D and the lid member 30D are joined.
Specifically, each of the piezoelectric vibration elements 20 is mounted on a wafer provided with a plurality of piezoelectric vibration element mounting members 10D, and the wafer provided with a plurality of lid members 30D is overlapped. At this time, the bonding metal film 12 is provided on the portion that becomes the piezoelectric vibration element mounting member 10D that does not enter the recess 31 of the lid member 30D, and the bonding metal is also provided on the main surface on which the recess 31 of the lid member 30D is provided. A membrane 32 is provided.

  The bonding metal films 12 and 32 are made of the same material. The mounting pad may be made of the same material.

Therefore, the bonding metal film 12 of the piezoelectric vibration element mounting member 10D and the bonding metal film 32 of the lid member 30D are overlapped. In this state, a predetermined pressure is applied at normal temperature in a vacuum atmosphere to perform direct bonding, and the piezoelectric vibration element mounting member 10D and the lid member 30D are bonded.
Thereafter, cutting is performed at the contours of the piezoelectric vibration element mounting member 10 </ b> D and the lid member 30 </ b> D to form a plurality of piezoelectric vibrators 104.
Since the piezoelectric vibrator 104 according to the fourth embodiment is configured as described above, the bonding metal film 12 of the piezoelectric vibration element mounting member 10D and the bonding metal film 32 of the lid member 30D are bonded by direct bonding. Even at room temperature, direct bonding can be performed by applying a predetermined pressure.

  Thereby, the piezoelectric vibrator 104 according to the fourth embodiment can improve the airtightness as compared with the first embodiment.

(Fifth embodiment)
Next, a piezoelectric oscillator according to a fifth embodiment of the invention will be described.
As shown in FIG. 6, the piezoelectric oscillator 105 according to the fifth embodiment of the present invention includes at least an oscillation circuit in the piezoelectric vibrators 101 to 104 according to any one of the first to fourth embodiments. The integrated circuit element 40 is provided.

  This integrated circuit element 40 is of a flip chip type, and the temperature characteristics of, for example, a temperature sensitive element (thermistor) for detecting the ambient temperature state and the piezoelectric vibration element 20 are provided on the lower surface of a main body made of single crystal silicon or the like. Temperature compensation data to be compensated is stored, and a temperature compensation circuit for correcting the vibration characteristics of the crystal resonator element 30 according to a temperature change based on the temperature compensation data, and connected to the temperature compensation circuit to generate a predetermined oscillation output An electronic circuit such as an oscillation circuit is provided. The oscillation output generated by such an oscillation circuit is used as a reference signal such as a clock signal after being output to the outside.

The integrated circuit element 40 is mounted on the ceramic container Y and connected to the piezoelectric vibrator according to any one of the first to fourth embodiments. Hereinafter, the case where the piezoelectric vibrator 101 according to the first embodiment is used will be described.
For example, the ceramic container Y has a concave portion 41 formed on one main surface, and a connection terminal S corresponding to the position of the external terminal G provided on the piezoelectric vibrator 101 on one main surface. The other main surface is provided with an IC-side external terminal ICG for connection to a wiring board such as a mother board. In the recess 41, a plurality of IC mounting pads P2 are provided at positions corresponding to the mounting pads provided in the integrated circuit element 40. Two predetermined IC mounting pads P2 are connected to the connection terminal S. Among the remaining IC mounting pads P2, a predetermined one is connected to the IC side external terminal IG.
Here, the external terminal G provided on the piezoelectric vibrator 101 and the connection terminal S of the ceramic container Y are connected by, for example, a conductive adhesive D2.
As described above, since the piezoelectric oscillator 105 according to the fifth embodiment of the present invention is configured, airtight leakage from the portion sealing the piezoelectric vibration element 20 can be prevented, and the yield can be improved. .

  In addition, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, a structure in which a recess is formed in the lid member and a recess is formed in the piezoelectric vibration element mounting member may be used.

(A) is a conceptual diagram which shows an example of the state which provided the external terminal and the mounting pad in the wafer, (b) is a conceptual diagram which shows an example of the state which mounted the piezoelectric vibration element, (c) is a lid | cover. It is a conceptual diagram which shows the state before joining a member, (d) is a conceptual diagram which shows the state which joined the cover member. It is a conceptual diagram which shows an example of the piezoelectric vibrator which concerns on 1st embodiment of this invention. It is a conceptual diagram which shows an example of the piezoelectric vibrator which concerns on 2nd embodiment of this invention. It is a conceptual diagram which shows an example of the piezoelectric vibrator which concerns on 3rd embodiment of this invention. It is a conceptual diagram which shows an example of the piezoelectric vibrator which concerns on 4th embodiment of this invention, (a) is a conceptual diagram which shows the state before joining a cover member, (b) is joining a cover member. It is a conceptual diagram which shows the state which carried out, (c) is a conceptual diagram which shows the state separated into pieces. It is a conceptual diagram which shows an example of the piezoelectric oscillator which concerns on 5th embodiment of this invention.

10A, 10B, 10C, 10D Piezoelectric vibration element mounting member 11B, 11CA, 11CB, 31 Recess 12, 32 Metal film for bonding 20 Piezoelectric vibration element 30A, 30B, 30D Lid member 40 Integrated circuit element

Claims (3)

A step of polishing the main surface of the first wafer made of alumina ceramic or glass ceramic and provided with a portion to be a plurality of piezoelectric vibration element mounting members until the average surface roughness Ra becomes 1 nm or less. When,
A step of forming a through hole in the first wafer after the average surface roughness Ra of the first wafer is 1 nm or less.
A step of forming a mounting pad and an external terminal on the first wafer after filling the through hole by sputtering, electrolytic plating, or electroless plating;
Mounting the piezoelectric vibration element on the mounting pad using a conductive adhesive;
The main surface of the second wafer, which is made of alumina ceramic or glass ceramic and has a plurality of lid member portions at positions corresponding to the plurality of piezoelectric vibration element mounting members in the first wafer, has an average surface roughness. Polishing until the surface roughness Ra is 1 nm or less;
Forming a recess for each lid member portion of the second wafer after the average surface roughness Ra of the second wafer is 1 nm or less.
A step of activating the principal surface of the piezoelectric wafer mounting member of the first wafer by surface activation with argon plasma or oxygen plasma;
A step of activating the main surface to be a bonding surface of the lid member of the second wafer with argon plasma or oxygen plasma;
The first wafer and the second wafer are overlapped with each other so that the corresponding piezoelectric vibration element enters each of the recesses provided in the second wafer, and predetermined in a vacuum atmosphere at room temperature. Applying pressure and joining directly;
The bonded first and second wafers are cut along the outline of the piezoelectric vibration element mounting member and / or the outline of the lid member to form a plurality of piezoelectric vibrators. A method for manufacturing a piezoelectric vibrator. A step of polishing the main surface of the first wafer made of alumina ceramic or glass ceramic and provided with a portion to be a plurality of piezoelectric vibration element mounting members until the average surface roughness Ra becomes 1 nm or less. When,
Forming a recess for each piezoelectric vibration element mounting member portion of the first wafer after the average surface roughness Ra of the first wafer is 1 nm or less.
Forming a through hole in the bottom surface of the recess;
After filling the through hole by any one of sputtering, electrolytic plating, and electroless plating, forming a mounting pad on the bottom surface of the recess, and further forming an external terminal on the first wafer;
Mounting the piezoelectric vibration element on the mounting pad using a conductive adhesive;
The main surface of the second wafer, which is made of alumina ceramic or glass ceramic and has a plurality of lid member portions at positions corresponding to the plurality of piezoelectric vibration element mounting members in the first wafer, has an average surface roughness. Polishing until the surface roughness Ra is 1 nm or less;
A step of activating the principal surface of the piezoelectric wafer mounting member of the first wafer by surface activation with argon plasma or oxygen plasma;
A step of activating the main surface to be a bonding surface of the lid member of the second wafer with argon plasma or oxygen plasma;
The first wafer and the second wafer are overlapped with the corresponding piezoelectric vibration element mounting portion and the lid member portion aligned, and directly bonded by applying a predetermined pressure at room temperature in a vacuum atmosphere. And a process of
The bonded first and second wafers are cut along the outline of the piezoelectric vibration element mounting member and / or the outline of the lid member to form a plurality of piezoelectric vibrators. A method for manufacturing a piezoelectric vibrator. An average surface roughness Ra of each of the bonding surfaces of the bonding surface of the portion to be the piezoelectric vibration element mounting member in the first wafer and the bonding surface of the portion to be the lid member in the second wafer is The method for manufacturing a piezoelectric vibrator according to claim 1 , wherein a bonding metal film is provided after the surface roughness is 1 nm or less .

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