JP2001094388A - Saw device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-mountable, small and precise SAW device and its manufacturing method. SOLUTION: An SAW device has an interdigital transducer 23 formed on a piezoelectric substrate 21, a surface acoustic wave element 20 having leading electrodes 22 electrically connected to the electrode 23, a cap 30 which is connected onto the forming surface of the electrode 23 on the piezoelectric substrate 21 and has notch parts 31 formed at sites equivalent to the electrode 22, an adhesive member 40 formed on the side of the outer peripheral surfaces of the substrate 21 and the cap 30 in order to connect the element 20 and the cap 30, having opening parts 41 at a site equivalent to the parts 31, conductive embedded parts 42 formed so as to fill the parts 41 in order to seal the element 20 and for conducting the electrodes 50 and the electrodes 22, and the electrode parts 50 formed on the surface of the cap 30 and conducted with the electrodes 22 through the members 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a SAW device and a method for manufacturing the same, and more particularly to a SAW device capable of surface mounting and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional SAW (Surface).
FIG. 8 is a configuration diagram illustrating an example of an Acoustic Wave (surface acoustic wave) device. The SAW device 1 will be described with reference to FIG.

The SAW device 1 shown in FIG. 7 has a surface acoustic wave element (hereinafter, referred to as a “SAW chip”) 2, a cap 3, an external electrode 4, an extraction electrode 5, a sealing member 6, and the like. The SAW chip 2 is a SAW resonator, a SAW filter, or the like, in which interdigital electrodes and the like are formed on the surface of a piezoelectric substrate made of, for example, a quartz plate. The cap 3 seals the surface acoustic wave element 2 with a sealing member 6, and has an external electrode portion 4 formed from one surface 3a to the other surface 3b. SAW chip 2 for external electrode 4
Of the SAW chip 2
Are electrically connected to the outside via the external electrode unit 4.

[0004]

Here, in the SAW device 1 having a so-called bare chip structure shown in FIG. 7, the sealing member 6 is formed by using a sealing adhesive, a resin, a low melting point glass or the like. . However, when a sealing adhesive or a resin is used, heating in a vacuum causes
Gases harmful to the reliability of the AW chip 2 are generated, and moisture, carbon dioxide gas, and the like are generated during the curing reaction of the adhesive. Further, when the low-melting glass is heated in a vacuum and melted, moisture and the like are generated from inside the low-melting glass. These gases and moisture are also generated inside the sealing member 6, and the gas generated due to the pressure difference from the outside is discharged to the outside.
Since the characteristics of the device 1, particularly the frequency aging characteristics, deteriorate, there is a problem that it is difficult to perform vacuum sealing. Further, when a sealing adhesive is used as the sealing member 6, there is a problem that the characteristics of the SAW device 1 are deteriorated by the influence of the gas generated from the sealing adhesive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a SAW device capable of solving the above problems and improving the characteristics of the SAW device, and a method of manufacturing the same.

[0006]

According to a first aspect of the present invention, there is provided a surface acoustic wave device having an interdigital transducer formed on a piezoelectric substrate, an extraction electrode electrically connected to the interdigital transducer, and A cap which is joined to a surface of the piezoelectric substrate on which the interdigital electrodes are formed and has a cutout formed in a portion corresponding to the lead-out electrode; and a piezoelectric substrate for joining the surface acoustic wave element and the cap. And an adhesive member formed on the outer peripheral surface side of the cap and having an opening at a position corresponding to at least one of the notches, and an adhesive member formed on the surface of the cap and electrically connected to the extraction electrode. The external electrode portion is formed so as to fill the opening in order to seal the surface acoustic wave element, and the external electrode portion and the extraction electrode are electrically connected. Wherein the conductive buried SAW device having a member for connecting to.

According to the first aspect of the present invention, the adhesive member is not applied to at least one cutout portion of the cap, but forms an opening. That is, an opening is formed between the piezoelectric substrate and the cap in the notch. By filling the opening with a conductive burying member, the lead electrode and the external electrode are electrically connected and the surface acoustic wave element is sealed. in this way,
By performing sealing using the conductive embedding member, when sealing the surface acoustic wave element, it is not necessary to use a sealing adhesive, resin, low-melting glass, or the like.

According to a second aspect of the present invention, in the configuration of the first aspect, the notch is formed in at least one corner of the cap, and the lead electrode is formed in a corner of the piezoelectric substrate. SAW devices.

According to the configuration of the second aspect, when the SAW device thermally expands, stress concentrates on a corner portion of the joint surface between the piezoelectric substrate and the cap. Also, stress is concentrated on the corners, which are connection portions, due to deformation of the substrate. Therefore, by providing the notch in the corner, concentration of stress on the corner is prevented.

[0010] The invention of claim 3 is claim 1 or claim 2.
In any one of the above structures, the external electrode section is characterized by a SAW device formed of a conductive thin film.

The invention according to claim 4 is the invention according to claim 1 or claim 2.
In any one of the above configurations, the external electrode portion is characterized in that a SAW device is formed by filling the cutout portion with a conductive member and applying a conductive member to the surface of the cap.

According to the third and fourth aspects, the external electrode portion is formed by filling a conductive thin film or a conductive member from the extraction electrode to the cap surface. The SAW device is surface-mounted on the substrate by the external electrode portions.

[0013] The invention of claim 5 is the invention of claims 1 to 4.
In any one of the above structures, the SAW device is characterized in that the adhesive member has a thickness such that the cap does not contact the surface of the surface acoustic wave element.

According to the fifth aspect of the present invention, when the surface acoustic wave element is sealed by the cap, the thickness is such that the cap does not contact the IDT formed on the surface of the piezoelectric substrate. This prevents a change in SAW device characteristics due to the cap coming into contact with the surface of the piezoelectric substrate.

The invention of claim 6 is the first to fifth aspects of the present invention.
In any one of the above configurations, the piezoelectric substrate has a bonding electrode portion formed at a bonding site with the bonding member.
W device.

According to the sixth aspect of the present invention, the bonding electrode portion is formed at the bonding portion of the piezoelectric substrate with the bonding member, and the bonding electrode portion improves the bonding strength between the piezoelectric substrate and the bonding member. Become.

According to a seventh aspect of the present invention, in the configuration of the sixth aspect, the bonding electrode portion is characterized in that it is an electrically grounded SAW device.

According to the seventh aspect of the present invention, since the bonding electrode portion is electrically grounded, it is possible to prevent a signal leakage path from being formed between the external electrodes which are signal input / output terminals, and The effect of external noise is suppressed.

The invention of claim 8 is the first to seventh aspects of the present invention.
In any of the above structures, the cap is characterized by a SAW device having substantially the same linear expansion coefficient as the piezoelectric substrate.

According to a ninth aspect of the present invention, in the configuration of the eighth aspect, the cap is formed of a SAW device made of the same material as the piezoelectric substrate.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the piezoelectric substrate is a SAW device made of quartz.

According to the constitutions of claims 8 to 10,
The piezoelectric substrate and the cap are formed from a material having substantially the same linear expansion coefficient. Therefore, when the SAW device thermally expands, distortion due to thermal expansion hardly occurs.

According to an eleventh aspect of the present invention, in the first to tenth aspects, the adhesive member is a SAW device made of low melting point glass.

According to a twelfth aspect of the present invention, in any one of the first to eleventh aspects, the surface acoustic wave element is a SAW device that is a surface acoustic wave resonator.

According to a thirteenth aspect of the present invention, in any one of the first to eleventh aspects, the surface acoustic wave element is a surface acoustic wave filter. Features a SAW device.

According to a fourteenth aspect of the present invention, in any one of the first to eleventh aspects, the surface acoustic wave element is a SAW device that is a surface acoustic wave convolver.

According to a fifteenth aspect of the present invention, in order to form a surface acoustic wave device having an interdigital transducer and an extraction electrode electrically connected to the interdigital transducer on a piezoelectric substrate, and to expose the extraction electrode. An adhesive member is applied so as to have an opening in at least one of the notch portions on the outer peripheral surface side of the cap in which the notch portion is formed, and the surface acoustic wave element and the cap are bonded by the adhesive member. Bonding, forming an external electrode portion on the surface of the cap, electrically connecting the external electrode portion and the lead electrode, and filling the opening with a conductive material to seal the surface acoustic wave element. SAW for filling components
A method for manufacturing a device is characterized.

According to the configuration of claim 15, the opening is formed in at least one notch of the cap without applying the adhesive member. Therefore, when the surface acoustic wave element and the cap are joined, an opening is formed between the surface acoustic wave element and the cap in the cutout portion. The sealing of the surface acoustic wave element is performed by filling an opening provided in the cutout portion with a conductive burying member. In this way, by sealing the surface acoustic wave element using the conductive buried member, it is not necessary to use a sealing adhesive, a resin, a low-melting glass, or the like.

According to a sixteenth aspect of the present invention, in the configuration according to the fifteenth aspect, the filling of the conductive buried member into the opening is performed by disposing the conductive buried member in the notch and melting it in a substantially vacuum state. SA performed by
It is characterized by a method of manufacturing a W device.

According to the configuration of claim 16, when the conductive buried member is filled into the opening, the filling is performed by melting the conductive buried member in a substantially vacuum state. Thereby, S
Sealing is performed in a state where the inside of the AW device is almost in a vacuum state.

According to a seventeenth aspect of the present invention, in any one of the fifteenth and sixteenth aspects, the external electrode portion is
A method for manufacturing a SAW device formed by forming a conductive thin film on the surfaces of the extraction electrode and the cap is characterized.

In the invention according to claim 18, in the structure according to any one of claims 15 to 16, the external electrode portion is formed by screen-printing a conductive member on the surface of the extraction electrode and the cap. The method is characterized by a method for manufacturing a SAW device.

According to the seventeenth and eighteenth aspects, the external electrode portion is formed by screen-printing a conductive thin film or a conductive member on the extraction electrode and the cap surface. The SAW device is surface-mounted on the substrate by the external electrode portions.

According to a nineteenth aspect of the present invention, in any one of the fifteenth to eighteenth aspects, the external electrode portion is
A method of manufacturing a SAW device formed after etching the surface of the extraction electrode is characterized.

According to the nineteenth aspect, an oxide film may be formed on the surface of the extraction electrode immediately after the extraction electrode is formed. At this time, by forming the external electrode portion after etching the surface of the extraction electrode, the oxide film on the surface is removed, and the electrical connection between the extraction electrode and the external electrode portion is improved.

According to a twentieth aspect of the present invention, in any one of the fifteenth to nineteenth aspects, the piezoelectric substrate includes:
A method of manufacturing a SAW device in which a bonding electrode portion is formed at a portion where the bonding member is bonded.

According to the twentieth aspect, a bonding electrode portion is formed on the piezoelectric substrate, and the bonding electrode portion has an adhesive member bonded to the piezoelectric substrate for sealing the surface acoustic wave element with a cap. In this case, the bonding strength between the bonding member and the piezoelectric substrate is improved.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view showing an example of the usage of the SAW device of the present invention. The SAW device 10 will be described with reference to FIG. SAW of FIG.
The device 10 is surface-mounted and electrically connected to a substrate 100 such as a printed wiring board by a conductive adhesive 101 such as solder.

FIGS. 2 and 3 are a sectional view and a schematic perspective view showing a preferred embodiment of the SAW device of the present invention. The SAW device 10 will be described with reference to FIGS.

The SAW device 10 shown in FIGS.
It is composed of an AW chip 20, a cap 30, an adhesive member 40, an external electrode section 50, and the like. SAW chip 2 in FIG.
Numeral 0 denotes, for example, a SAW resonator, a SAW filter, a SAW concorver, or the like.
digital Transducer) ") 2
3. It has a reflector 24 and the like.

The piezoelectric substrate 21 is made of, for example, a quartz plate, and a lead electrode 22, an IDT 23, a reflector 24, etc. made of, for example, aluminum are formed on the surface thereof by a thin film forming technique. The extraction electrode 22 is electrically connected to the IDT 23, and is connected to the IDT 2.
3 for transmitting and receiving electric signals. The extraction electrode 22 is provided, for example, at a corner of the piezoelectric substrate 21.

When an electric signal is supplied from the extraction electrode 22, the IDT 23 generates a surface acoustic wave (SA) by a piezoelectric effect.
W), and has a function of converting the excited surface acoustic wave into an electric signal and outputting the electric signal. Reflector 2
Reference numerals 4 and 24 are formed so as to sandwich the IDT 23.
It has a function of confining the surface acoustic waves output from the DT 23 in the reflectors 24, 24.

On the functional surface of the piezoelectric substrate 21 on which the IDT 23 and the like are formed, the cap 30 is
Are joined. The cap 30 has substantially the same linear expansion coefficient as the piezoelectric substrate 21, for example, and is preferably made of the same material as the piezoelectric substrate 21, for example, a quartz plate. Thereby, the SAW chip 2
0 and the cap 30 are deformed by thermal expansion, the linear expansion coefficients of the piezoelectric substrate 21 and the cap 30 are the same.
The piezoelectric substrate 21 is hardly distorted and the SA
Changes in the characteristics of the W chip 20 can be minimized.

A cut-out portion 31 is formed at the portion of the cap 30 where the extraction electrode 22 is formed, that is, at the corner of the cap 30 in FIG. Here, the extraction electrode 22 and the notch 31 are formed at the corners for the following reason. When the piezoelectric substrate 21 and the cap 30 thermally expand, stress concentrates on the corners of the joint surface between the piezoelectric substrate 21 and the cap 30. Therefore, by providing the extraction electrode 22 and the notch 31 at the corners of the piezoelectric substrate 21 and the cap 30, stress concentration can be prevented, and the bonding strength between the SAW chip 20 and the cap 30 can be improved.

Further, since the piezoelectric material is generally a brittle material, the corners of the cap 30 made of the piezoelectric material are easily chipped or cracked even without thermal expansion. Therefore, by preliminarily notching a portion where a problem easily occurs, stress concentration, chipping and cracking can be prevented. When the SAW device 10 is a SAW filter, the notch 31
Is provided at a corner (corner), the distance between the input terminal and the output terminal increases, so that a direct wave can be prevented. Furthermore, when the cutout portions 31 are formed at the corners (corners) of the cap 30, the cutout portions 31 of the four caps 30 are formed at the same time in the wafer state, so that the processing efficiency is improved.

An external electrode portion 50 is formed on the surface 30a of the cap 30, and the external electrode portion 50 is electrically connected to the extraction electrode 22 by a conductive burying member 42 described later. Specifically, the external electrode unit 50 is formed by forming a thin film or screen printing on the extraction electrode 22, the side surface 31 a of the notch 31, and the surface 30 a of the cap 30.

The external electrode portion 50 is connected to an electrode (not shown) of the substrate 100 by a conductive adhesive member 101 as shown in FIGS.
00 is electrically connected. That is, S
The AW device and the substrate 100 need not be electrically connected to the substrate by wire bonding, and can be surface-mounted using the external electrode unit 50.

FIG. 4 is a view showing a state of the adhesive member 40 in the SAW device 10. The adhesive member 40 will be described with reference to FIG.

The bonding member 40 shown in FIG. 4A is for bonding the piezoelectric substrate 21 and the cap 30 as described above, and is made of, for example, low melting point glass. Also,
Adhesive member 4 after bonding piezoelectric substrate 21 and cap 30
The thickness D of 0 is such that the functional surface of the SAW chip 20 does not contact the cap 30 as shown in FIG. Thereby, it is possible to prevent a change in the characteristics of the SAW chip 20 due to the cap 30 coming into contact with the functional surface of the SAW chip 20. Then, the adhesive member 40 is provided on the outer peripheral surface side of the piezoelectric substrate 21 and the cap 30 except for the cutout portion 31. That is, as shown in FIG. 4B, an opening 41 is formed in at least one of the notches 31, and the piezoelectric substrate 21 and the cap 30 are not joined by the adhesive member 40.

Then, for example, solder,
Conductive embedded member 42 made of a conductive material such as gold tin alloy
Are embedded, for example, by melting in a substantially vacuum state. By melting in a substantially vacuum state, the SAW device 10 is sealed in a substantially vacuum state.
The characteristics of the W device 10 can be improved. In addition, since it is not necessary to use a sealing adhesive or a resin which has been conventionally used for sealing, it is possible to prevent deterioration of characteristics of the SAW device 10 due to a gas generated from the sealing adhesive or the like. Can be. Since the conductive buried member 42 also has a function of electrically connecting the extraction electrode 22 and the external electrode 50, the opening 41 is formed in the notch 31.

Next, FIG. 5 is a process chart showing a preferred embodiment of the method for manufacturing a SAW device according to the present invention.
A method for manufacturing a SAW device will be described with reference to FIG.

First, in FIG. 5A, a piezoelectric substrate 21 made of, for example, a quartz plate is prepared, and in FIG.
3. The reflector 24 and the like are formed by a thin film forming technique.

On the other hand, in FIG. 5C, a cap 30 made of, for example, the same material as the piezoelectric substrate 21 is prepared, and in FIG.
1 is formed. Then, in FIG. 5 (E), the adhesive member 40 is applied so that the opening 41 is formed on the outer peripheral surface side of the cap 30 at a position corresponding to the notch 31. At this time, the thickness of the adhesive member 40 is set to a thickness D ′ (> D) so that the thickness of the cap 30 becomes D after curing.
Applied to

Thereafter, in FIG. 5F, the cap 30 is joined to the SAW chip 20. At this time, the extraction electrode 22 is exposed by the notch 31. Then, in FIG. 5G, the external electrode portion 50 is formed from the top of the cap 30 by forming a conductive thin film by sputtering, or by applying a conductive member by screen printing. At this time, an opening 41 is formed between the piezoelectric substrate 21 and the cap 22 in the notch 31.

Thereafter, as shown in FIG. 5 (H), a granular conductive burying member 42 having a diameter larger than the opening 41 is arranged in the notch 31 and is heated in a substantially vacuum state. Then, the conductive buried member 42 is melted and filled in the opening 41, so that the extraction electrode 22 and the external electrode unit 50 are conducted. At the same time, since the heat treatment is performed in a substantially vacuum state, the inside of the SAW device 10 is sealed in a substantially vacuum state. Thus, the vacuum-sealed SAW device 10 is completed.

Further, before forming the external electrode portion 50 on the extraction electrode 22, the surface of the extraction electrode 22 is etched in a vacuum, and then the external electrode portion 50 is formed in a vacuum by sputtering, vacuum deposition, or the like. You may do so. This is because when the aluminum forming the extraction electrode 22 comes into contact with air, the surface of the extraction electrode 22 is oxidized and an alumina (Al ₂ O ₃ ) film is formed. Accordingly, by removing the alumina film formed on the surface of the extraction electrode 22 and forming the external electrode portion 50 in a state where the alumina film is not formed on the extraction electrode 22, the conductivity between the extraction electrode 22 and the external electrode portion 50 is improved. Can be improved.

As described above, by forming the opening 41 in the adhesive member 40 and embedding the opening 41 in the vacuum with the conductive burying member 42, the SAW device 10 can be sealed in a vacuum. And SAW device 1
0 can be improved. That is, the sealing is performed by melting the conductive buried member 42 in a vacuum, instead of using a sealing adhesive as in the related art, so that the vacuum sealing of the SAW device 10 is realized. be able to. Further, the characteristics of the SAW device 10 are not deteriorated by the influence of the gas generated from the sealing adhesive, and the aging characteristics can be improved. Furthermore, vacuum sealing can be performed with a device having a simple configuration, and manufacturing costs can be reduced.

Further, in the method of manufacturing the SAW device 10 shown in FIG. 5, processing in a wafer state is possible, so that a plurality of SAW devices 10 can be manufactured at the same time. That is, FIGS. 5 (A) to 5
After the processing up to (H) is performed, each SAW device 10
By cutting each time, a plurality of SAW devices 10 can be manufactured at the same time.

FIG. 6 is a schematic perspective view showing another embodiment of the SAW device of the present invention. Referring to FIG.
The device 60 will be described. In the SAW device 60 shown in FIG. 6, parts having the same configuration as the SAW device 10 shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

The SAW device 60 shown in FIG.
The difference from the device 10 is that a bonding electrode portion 61 is formed on the piezoelectric substrate 21. The bonding electrode unit 61
For example, the extraction electrode 22, the IDT 23 and the reflector 24
It is made of the same material as aluminum, and is formed at a portion to be joined to the adhesive member 40 applied to the cap 30. Here, for example, the bonding strength of the bonding member 40 made of low-melting glass to aluminum is higher than the bonding strength to quartz. Therefore, by providing the bonding electrode portion 61 at a position where the piezoelectric substrate 21 and the bonding member 40 are bonded, the bonding strength between the piezoelectric substrate 21 and the cap 40 can be improved. Further, preferably, the bonding electrode portion 61 has an area of 90 to be bonded to the adhesive member 40.
(%) Or more.

Further, it is preferable that a ground extraction electrode (not shown) is electrically connected to the bonding electrode portion 61, and that the bonding electrode portion 61 is electrically grounded. As a result, since the bonding electrode portion 61 does not become electrically floating, it is possible to prevent a signal leakage path from being formed between the external electrodes, which are signal input / output terminals, and to reduce the isolation of the SAW device. Can be enhanced. In addition, the presence of the bonding electrode portion 61 grounded on the outer peripheral surface side of the IDT 23 can suppress the influence of external noise on the SAW device 10.

The present invention is not limited to the above embodiment,
Various changes can be made without departing from the scope of the claims.

For example, FIG. 3 shows a SAW chip 20 in which only one IDT 23 is formed on a piezoelectric substrate 21 as an example of the SAW chip 20.
A SAW chip in which two or more DTs 23 are formed may be used.

In the SAW chip 20 shown in FIG.
Although only two extraction electrodes 22 are formed on the piezoelectric substrate 21, when two or more IDTs 23 are formed on the piezoelectric substrate 21, the extraction electrodes 22 are provided by the number of IDT 23 electrodes. At this time, the cap 30
Is also formed at a portion corresponding to the extraction electrode 22. In FIG. 3, the extraction electrode 22 and the notch 31 are formed at the corners.
The extraction electrode 22 and the cut-out portion 31
May be formed.

Further, the conductive filling member 42 is filled in the opening 41 by melting in a substantially vacuum state. However, the conductive filling member 42 is filled in the opening 41 in a substantially vacuum state by a thin film forming technique such as sputtering or vapor deposition. The member 42 may be filled. At this time, the opening 41 can be filled with the conductive filling member 42 in the same step as the step of forming the external electrode section 50.

In the step of forming the external electrode portion 50 in FIG. 5G, the external electrode portion 50 may be formed into a thin film by sputtering, vacuum deposition, or the like, and then may be formed into a thick film by plating.

[0068]

According to the present invention, an opening is formed between the piezoelectric substrate and the cap without providing an adhesive member at the cutout portion of the cap, and a conductive buried member is formed in the opening. Thereby, the SAW device can be sealed in a vacuum, and the characteristics of the SAW device can be improved.

Further, by melting the conductive buried member in a vacuum and welding the extraction electrode and the external electrode portion, the extraction electrode and the external electrode portion can be electrically connected and vacuum sealed, thereby improving aging characteristics. Manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a preferred use form of a SAW device of the present invention.

FIG. 2 is a sectional view showing a preferred embodiment of the SAW device of the present invention.

FIG. 3 is a schematic perspective view showing a preferred embodiment of the SAW device of the present invention.

FIG. 4 is a diagram showing a portion around a notch in the SAW device of the present invention.

FIG. 5 is a process chart showing a preferred embodiment of a method for manufacturing a SAW device of the present invention.

FIG. 6 is a schematic perspective view showing another embodiment of the SAW device of the present invention.

FIG. 7 is a configuration diagram showing an example of a conventional SAW device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10, 60 SAW device 20 SAW chip 21 Piezoelectric substrate 22 Leader electrode 23 IDT (interdigital electrode) 30 Cap 30a Cap surface 31 Notch 40 Adhesive member 41 Opening 42 Conductive embedding member 50 External electrode part 61 Joint electrode part

Claims (20)

[Claims] 1. An interdigital transducer formed on a piezoelectric substrate, a surface acoustic wave element having an extraction electrode electrically connected to the interdigital transducer, and a surface of the piezoelectric substrate on which the interdigital transducer is formed. And a cap having a notch formed in a portion corresponding to the extraction electrode; and a piezoelectric substrate and an outer peripheral surface of the cap for joining the surface acoustic wave element and the cap. An adhesive member having an opening at a position corresponding to at least one of the cutout portions; an external electrode portion formed on a surface of the cap and electrically connected to the extraction electrode; A conductive embedding formed to fill the opening for sealing the element and electrically connecting the external electrode and the lead electrode. SAW device; and a member. 2. The SAW device according to claim 1, wherein the notch is formed at a corner of the cap, and the lead electrode is formed at a corner of the piezoelectric substrate. 3. The SAW device according to claim 1, wherein said external electrode portion is formed of a conductive thin film. 4. The external electrode portion according to claim 1, wherein the cutout portion is filled with a conductive member, and the outer electrode portion is formed by applying a conductive member to a surface of the cap. SAW device. 5. The SAW device according to claim 1, wherein the adhesive member has a thickness such that the cap does not contact the surface of the surface acoustic wave element. 6. The SAW device according to claim 1, wherein a bonding electrode portion is formed on the piezoelectric substrate at a bonding portion with the bonding member. 7. The SAW device according to claim 6, wherein the bonding electrode portion is electrically grounded. 8. The SAW device according to claim 1, wherein the cap has substantially the same linear expansion coefficient as the piezoelectric substrate. 9. The SAW device according to claim 8, wherein the cap is formed from the same material as the piezoelectric substrate. 10. The SAW device according to claim 1, wherein the piezoelectric substrate is made of quartz. 11. The SAW device according to claim 1, wherein said adhesive member is made of low-melting glass. 12. The SAW device according to claim 1, wherein the surface acoustic wave element is a surface acoustic wave resonator. 13. The SAW device according to claim 1, wherein the surface acoustic wave element is a surface acoustic wave filter. 14. The SAW device according to claim 1, wherein the surface acoustic wave element is a surface acoustic wave convolver. 15. A surface acoustic wave element having an interdigital transducer and an extraction electrode electrically connected to the interdigital transducer on a piezoelectric substrate, and a cutout for exposing the extraction electrode is provided. On the outer peripheral surface side of the formed cap, an adhesive member is applied so as to have an opening in at least one of the notches, and the surface acoustic wave element and the cap are joined by the adhesive member. Forming an external electrode portion on the surface of the cap, electrically connecting the external electrode portion to the lead electrode, and filling the opening with a conductive burying member to seal the surface acoustic wave element. S characterized by
Manufacturing method of AW device. 16. The SAW device according to claim 15, wherein the filling of the conductive buried member into the opening is performed by disposing the conductive buried member in the cutout portion and melting it in a substantially vacuum state. Manufacturing method. 17. The SAW according to claim 15, wherein the external electrode portion is formed by forming a conductive thin film on surfaces of the extraction electrode and the cap.
Device manufacturing method. 18. The method for manufacturing a SAW device according to claim 15, wherein the external electrode portion is formed by screen-printing a conductive member on a surface of the extraction electrode and the cap. 19. The method for manufacturing a SAW device according to claim 15, wherein the external electrode portion is formed after etching a surface of the extraction electrode. 20. The method for manufacturing a SAW device according to claim 15, wherein a bonding electrode portion is formed on the piezoelectric substrate at a portion where the bonding member is bonded.