JP2007235672A - Surface acoustic wave element and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface acoustic wave element in which an interdigital electrode or a surface acoustic wave propagation area is surely protected, and a manufacturing method therefor. <P>SOLUTION: The surface acoustic wave element includes the interdigital electrode and the surface acoustic wave propagation area 12 each formed on a piezoelectric substrate 10 wherein a space is formed for housing the interdigital electrode and the surface acoustic wave propagation area 12, and a lid body covering the interdigital electrode and the surface acoustic wave propagation area 12 is provided on the piezoelectric substrate 10, the lid body comprising, for example, a double structure composed of a bridge-like first lid body 14 forming the space for housing the interdigital electrode and the surface acoustic wave propagation area 12 and spread over the interdigital electrode and the surface acoustic wave propagation area 12, a sealing film 16 sealing the first lid body 14, and a second lid body 118 covering the first lid body 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface acoustic wave element used for a surface acoustic wave device such as a filter mounted on a mobile communication device, for example, and a manufacturing method thereof.

  In general, a surface acoustic wave device represented by a surface acoustic wave filter mounted on a mobile communication device such as a mobile phone uses a surface acoustic wave that propagates on the surface of a piezoelectric substrate. The comb electrode and the surface acoustic wave propagation region are protected so that moisture and dust do not adhere to the region and the comb electrode that excites the surface acoustic wave.

  In the following Patent Document 1, a surface acoustic wave element is mounted face-down on a mounting board with metal bumps, and the entire surface acoustic wave element mounted in this manner is covered with a resin film. A surface acoustic wave device in which a film is brought into close contact is described. In this surface acoustic wave device, the space between the mounting substrate and the surface acoustic wave element (that is, the space where the comb-shaped electrode and the surface acoustic wave propagation region exist) is sealed with a resin film, so that the comb-shaped The electrode and the surface acoustic wave propagation region are protected.

  In the following Patent Document 2, a surface acoustic wave element having a functional portion (a surface portion on which a surface acoustic wave propagates such as a comb-shaped electrode portion) having at least one comb-shaped electrode portion on a piezoelectric substrate is provided around the functional portion. A protective member (such as a sidewall surrounding the periphery of the functional part) is formed, a protective film is bonded to the piezoelectric substrate so as to cover the functional part and the protective member, and the surface acoustic wave element is then combined with the comb. A surface acoustic wave device is described in which a surface having a mold electrode portion is opposed to and bonded to a mounting substrate via a bump. In this surface acoustic wave device, the functional part (corresponding to the comb electrode or the surface acoustic wave propagation region) is sealed by adhering a protective film to the piezoelectric substrate so as to cover the functional part and the protective member. The comb-shaped electrode and the surface acoustic wave propagation region are protected.

JP 2005-184309 A Japanese Patent Laid-Open No. 2004-153212

  In each of the above conventional techniques, the mounting substrate and the surface acoustic wave element are combined (mounted), and the comb electrode and the surface acoustic wave propagation region are reliably protected (packaging). Yes. In the surface acoustic wave device described in Patent Document 1, the entire surface acoustic wave element mounted face-down on the mounting substrate is covered with a resin film, and the mounting surface of the mounting substrate and the resin film are brought into close contact with each other. The space between the surface acoustic wave element (that is, the space where the comb electrode and the surface acoustic wave propagation region exist) is sealed with a resin film to protect the comb electrode and the surface acoustic wave propagation region. .

  Further, in the surface acoustic wave device described in Patent Document 2, a functional film (comb-shaped electrode or surface acoustic wave propagation region) and a protective member are covered so that a protective film is adhered to the piezoelectric substrate to seal the functional part. By stopping, the functional portion (comb electrode or surface acoustic wave propagation region) is protected. At this time, simply covering the protective member (such as the side wall surrounding the functional part) with a protective film will cause the protective film to bend, and depending on the orientation of the surface acoustic wave element, the bent protective film will function. There is a possibility that a situation such as touching a part may occur. Therefore, in the surface acoustic wave device described in Patent Document 2, the surface acoustic wave element is bumped with the mounting substrate positioned below the surface acoustic wave element facing the surface having the comb-shaped electrode portion. Thus, the problem caused by the bending of the protective film is eliminated, and the functional part (comb electrode or surface acoustic wave propagation region) is protected by the protective film.

  As described above, conventionally, as a surface acoustic wave device in a state where the mounting substrate and the surface acoustic wave element are combined (mounted), reliable protection of the comb-shaped electrode and the propagation area of the surface acoustic wave (packaging) ) Is realized. Here, if reliable protection (packaging) of the comb-shaped electrode and the propagation region of the surface acoustic wave can be realized only on the surface acoustic wave element side, it becomes possible to supply the bare chip of the surface acoustic wave element to the mounting substrate. Since the advantageous effects such as simplification of the mounting process can be obtained, the comb-shaped electrode and the surface acoustic wave propagation region can be reliably protected (packaging) only on the surface acoustic wave element side. It is very preferable.

  Accordingly, an object of the present invention is to provide a surface acoustic wave element in which a comb-shaped electrode and a surface acoustic wave propagation region are reliably protected (packaged) and a method for manufacturing the same.

  In order to achieve the above object, a surface acoustic wave element according to the present invention includes a piezoelectric substrate, a comb-shaped electrode formed on the piezoelectric substrate, and a surface acoustic wave propagation region that propagates from the comb-shaped electrode to the surface of the piezoelectric substrate and the vicinity of the surface. And forming a space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region on the piezoelectric substrate, and covering the comb-shaped electrode and the surface acoustic wave propagation region on the piezoelectric substrate. This lid is characterized in that the comb electrode and the surface acoustic wave propagation region are sealed.

  Here, in the surface acoustic wave element having the above-described configuration, the lid forms a space in which the comb electrode and the surface acoustic wave propagation region are accommodated, and bridges over the comb electrode and the surface acoustic wave propagation region. It is good to have a configuration including a lid-shaped lid portion and a sealing film that seals the opening of the bridge-shaped lid body portion. Alternatively, a bridge-shaped first lid body that forms a space in which the comb-shaped electrode and the surface acoustic wave propagation region are accommodated and covers the comb-shaped electrode and the surface acoustic wave propagation region, and the first lid It is good to set it as the structure containing the sealing film which seals the opening part of a body part, and the 2nd cover body part which covers the 1st cover body part sealed with the sealing film.

  In the surface acoustic wave device having the above-described configuration, it is preferable that an inclined surface is processed in the opening of the bridge-shaped lid.

  In the surface acoustic wave device having the above-described structure, an electrode pad disposed outside the lid body and an electrode pattern connecting the electrode pad and the comb-shaped electrode are formed on the piezoelectric substrate, and further on the electrode pad It is preferable that bumps are formed on the.

  The surface acoustic wave element manufacturing method of the present invention includes a plurality of surface acoustic wave elements each having a comb-shaped electrode and a surface acoustic wave propagation region propagating from the comb-shaped electrode to the surface of the piezoelectric substrate and the vicinity of the surface. Each surface acoustic wave element has a bridge-shaped lid that forms a space in which a comb electrode and a surface acoustic wave propagation region are accommodated, and covers the comb electrode and the surface acoustic wave propagation region. Forming a sealing body for sealing each of the surface acoustic wave elements, and forming a sealing film for sealing the opening of the bridge-shaped lid body formed on each surface acoustic wave element. And a sealing step of individually sealing the space in which the propagation area of the surface acoustic wave is accommodated. Alternatively, after the sealing step, a step of individually forming a second lid portion covering the bridge-like lid portion (first lid portion) in each surface acoustic wave element for each surface acoustic wave element It is characterized by having.

  Here, in the method of manufacturing the surface acoustic wave element having the above-described configuration, the step of forming the bridge-shaped lid body portion covers the comb-shaped electrode and the surface acoustic wave propagation region in each surface acoustic wave element. A step of individually forming a sacrificial layer for each surface acoustic wave element, a step of applying and curing a resin so as to straddle each sacrificial layer, and a step of removing each sacrificial layer by sacrificial layer etching. Each of the sacrificial layers is removed to form a space in which the comb-shaped electrode and the surface acoustic wave propagation region are accommodated, and a bridge-shaped lid that covers the comb-shaped electrode and the surface acoustic wave propagation region. It is preferable to form each surface acoustic wave element individually. In the method of manufacturing the surface acoustic wave device having the above-described structure, a photosensitive resin is used as the resin for forming the bridge-shaped lid, and the sacrificial layer can withstand the curing temperature of the photosensitive resin. It is preferable that the sacrificial layer be removed by performing a sacrificial layer etching using an organic solvent using a resist having heat resistance that can be obtained and removed by an organic solvent.

  In the method of manufacturing the surface acoustic wave device having the above-described configuration, after the step of forming the bridge-shaped lid, a step of forming an inclined surface at the opening of the bridge-shaped lid is performed and then the sealing step is performed. It is good to do so.

  According to the surface acoustic wave element of the present invention, reliable protection (packaging) of the comb-shaped electrode and the propagation area of the surface acoustic wave can be realized only on the surface acoustic wave element side. Therefore, it becomes possible to supply the bare chip of the surface acoustic wave element, and it is possible to obtain an advantageous effect that the mounting process on the mounting substrate is simplified or the surface acoustic wave element is easily handled. Become.

  The surface acoustic wave element according to the embodiment of the present invention has a configuration in which the comb-shaped electrode on the piezoelectric substrate 10 and the surface acoustic wave propagation region 12 are sealed with a lid. Regardless of the relationship, the comb-shaped electrode and the surface acoustic wave propagation region 12 are reliably protected (packaged) on the surface acoustic wave element side. For example, as shown in FIG. 5, an opening of the bridge-shaped lid portion 14 straddling the comb-shaped electrode and the surface acoustic wave propagation region 12 in a state where a space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region 12 is formed. By forming a sealing film 16 (for example, a metal film or a passivation film) for sealing the opening in the vicinity of the opening, the space in which the comb electrode and the surface acoustic wave propagation region 12 are accommodated is sealed. The sealed bridge-shaped lid 14 reliably protects the comb-shaped electrode and the surface acoustic wave propagation region 12 in the surface acoustic wave element. Alternatively, as shown in FIG. 6, in a state where a space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region 12 is formed, a bridge-shaped lid portion (first step) straddling the comb-shaped electrode and the surface acoustic wave propagation region 12 is formed. A comb-shaped electrode and a surface acoustic wave propagation region are formed by forming a sealing film 16 (for example, a metal film, a passivation film, etc.) for sealing the opening in the vicinity of the opening of the (one lid) 14. The first lid portion 14 and the second lid body whose opening is sealed with the sealing film 16 are sealed by sealing the space in which 12 is accommodated and further covering the space with the second lid body portion 18 from the outside. A lid having a double structure with the portion 18 is formed, and the comb-shaped electrode and the surface acoustic wave propagation region 12 are reliably protected in the surface acoustic wave element by the double structure.

  The surface acoustic wave element according to this embodiment is manufactured as follows. First, as shown in FIG. 1, a plurality of surface acoustic wave elements are formed on the piezoelectric substrate 10. Each surface acoustic wave element is formed with a comb-shaped electrode and a surface acoustic wave propagation region 12, and an electrode pattern 20 and an electrode pad 30 drawn from the comb-shaped electrode. In FIG. 1, for convenience of explanation, two sets of surface acoustic wave elements formed on the piezoelectric substrate 10 are shown as an example. In this embodiment, for each of the surface acoustic wave elements formed on the piezoelectric substrate 10, a lid for sealing each comb-shaped electrode and the surface acoustic wave propagation region 12 is produced.

  In the lid manufacturing process, first, the sacrificial layer 40 is formed on the comb-shaped electrode on the piezoelectric substrate 10 and the surface acoustic wave propagation region 12 (see FIG. 2). The sacrificial layer 40 is formed by applying a sacrificial layer to the entire piezoelectric substrate 10 and then applying a known photolithography technique to remove the extra sacrificial layer, and comb electrodes in each surface acoustic wave element. The sacrificial layer 40 may be formed as shown in FIG. 2 so as to cover the surface acoustic wave propagation region 12. Here, the height H1 of the formed sacrificial layer 40 is about 1 to 10 μm.

  Next, for example, using a resin, the resin is applied with a dispenser or the like so as to straddle the sacrificial layer 40, and the resin is cured (see FIG. 3). This cured resin becomes the bridge-shaped lid portion 14 later. Also in this resin application and curing process, after applying the resin to the entire piezoelectric substrate 10, by applying a known photolithography technique such as exposure, baking, development, resist removal, etc., the excess resin is removed, As shown in FIG. 3, the resin bodies may be cured after the resin bodies are individually straddled over the sacrificial layers 40. Here, the height H2 of the formed resin body (that is, the height H2 of the bridge-shaped lid body portion 14) is about 5 to 100 μm.

  And after the resin body which straddles each sacrificial layer 40 is formed in this way, sacrificial layer etching is performed. As a result, only the sacrificial layer 40 is removed, so that a space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region 12 is formed and straddled so as to cover the comb-shaped electrode and the surface acoustic wave propagation region 12. A resin body, that is, a bridge-shaped lid portion 14 is formed on the piezoelectric substrate 10 (see FIG. 4). Since the lid portion 14 has a bridge-like structure, the etching solution used for removing the sacrificial layer 40 can easily escape from the inside of the lid portion 14 to perform the etching process satisfactorily and efficiently. .

  In the present embodiment, a photosensitive resin (for example, a chemically amplified resist or a permanent resist) is used as the resin for forming the bridge-shaped lid portion 14, and a chemically amplified resist or a permanent resist is used for the sacrificial layer 40. A resist having heat resistance that can withstand the curing temperature of the permanent resist and removable by an organic solvent is used. In particular, the reason why the resist that can be removed by the organic solvent is used as the sacrificial layer 40 is as follows. In an acoustic wave device, it is common to use an electrode made of aluminum. However, if the etching solution is made acidic or alkaline, it reacts with the aluminum electrode during the sacrificial layer etching. The frequency characteristics of this will change. Therefore, in order to avoid a reaction between the etchant and the electrode, it is preferable to use a resist that can be removed by an organic solvent for the sacrificial layer 40 and perform the etching using the organic solvent.

  Further, a chemically amplified resist or permanent resist having a high curing temperature (for example, 150 ° C.) is used as a material for the bridge-shaped lid body portion 14. The use of a removable resist as the sacrificial layer 40 has the following advantages. Since a normal resist needs to be used at 95 ° C. or lower, when such a resist is used as the sacrificial layer 40, a temperature of 95 ° C. or higher is applied when the bridge-shaped lid portion 14 is formed. The resin cannot be cured, and if a higher temperature is applied, the resist will adhere to the electrode fingers of the comb electrode, and the resist removal residue will remain after the sacrificial layer removal treatment. There is a concern that However, a chemically amplified resist or permanent resist having a high curing temperature (for example, 150 ° C.) is used as a material for the bridge-shaped lid portion 14 and has heat resistance that can withstand this high curing temperature, and depending on the organic solvent. If a removable resist is used as the sacrificial layer 40, exposure, baking and development are performed after the sacrificial layer 40 is formed, followed by curing by hard baking at 150 ° C., and the bridge-shaped lid portion 14 straddling the sacrificial layer 40. Even when the sacrificial layer is formed, the sacrificial layer 40 has heat resistance that can withstand a high curing temperature, and thus the problem that occurs in the case of a normal resist is solved. Therefore, according to the material used in the present embodiment, the sacrificial layer 40 can be reliably removed, and the bridge-shaped lid portion 14 can be reliably cured. A space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region 12 (that is, a space having a height H1 of about 1 to 10 μm) is formed and straddles the comb-shaped electrode and the surface acoustic wave propagation region 12. The bridge-shaped lid portion 14 can be satisfactorily formed on the piezoelectric substrate 10.

After the bridge-like lid portion 14 as shown in FIG. 4 is formed in this way, a film (sealing film) 16 is formed so as to seal the opening of the lid portion 14, and the bridge-like lid is formed. The accommodation space of the comb-shaped electrode and the surface acoustic wave propagation region 12 formed between the body portion 14 and the piezoelectric substrate 10 is sealed with a sealing film 16 (see FIG. 5). In this process, a known photolithography technique such as exposure, baking, development, resist removal, etc. is applied after the film 16 is formed on the entire piezoelectric substrate 10 by using, for example, a known vapor deposition method or sputtering method. Then, the excess film 16 may be removed, and the sealing film 16 may be formed on each of the first lid portions 14 as shown in FIG. Alternatively, the film 16 is formed only in the vicinity of the opening of each lid body 14 using a mask, and then, in the vicinity of the opening of each lid body 14 using a known vapor deposition method or sputtering method. The sealing film 16 may be formed. Further, as shown in FIG. 5C, the piezoelectric substrate 10 is formed by using a known vapor deposition method, sputtering method, or the like by processing and forming an inclined surface in the opening of the bridge-shaped lid portion 14. Even if the film is formed by vapor deposition from above, the opening can be easily sealed together with the formation of the film 16. As the sealing film 16, a metal film such as Ti / Al, or the like may be used passivation film such as a metal oxide film or SiN, such as SiO _2.

  As described above, in the present embodiment, in the plurality of surface acoustic wave elements formed on the piezoelectric substrate 10, the lid body having a structure in which the bridge-shaped lid body portion 14 is sealed with the sealing film 16. It is produced for each surface acoustic wave element. With such a lid, the comb-shaped electrode and the surface acoustic wave propagation region 12 are reliably protected in each surface acoustic wave element.

  Then, in the piezoelectric substrate 10 on which a plurality of surface acoustic wave elements are formed, after the above-described lid is formed on each surface acoustic wave element, by cutting out individual surface acoustic wave elements from the piezoelectric substrate 10, A surface acoustic wave element in which the comb electrode and the surface acoustic wave propagation region 12 are reliably protected by the lid is manufactured.

  Here, the lid formed on each surface acoustic wave element is not only good sealability of the comb-shaped electrode and the surface acoustic wave propagation region 12 but also external force by the resin bridge-like lid 14. It also has sufficient durability. Therefore, there is an advantage that the surface acoustic wave element after the lid is manufactured can be easily handled.

  By the way, when the deposition property of the sealing film 16 that seals the bridge-shaped lid portion 14 is poor, good sealing property cannot be expected. In addition, before the individual surface acoustic wave elements are cut out from the piezoelectric substrate 10 on which a plurality of surface acoustic wave elements are formed as described later, a bump base metal (UBM) 50 is formed on the electrode pad 30 in each surface acoustic wave element. When the bumps 60 are formed, various chemicals are used at the time of formation. Therefore, the sealing film 16 may be deteriorated by the chemicals, and a favorable sealing performance cannot be expected.

  Therefore, in each of the plurality of surface acoustic wave elements formed on the piezoelectric substrate 10, when each bridge-shaped lid (first lid) 14 is sealed with the sealing film 16 as shown in FIG. Further, a resin is applied with a dispenser or the like so as to cover the entire bridge-shaped first lid portion 14 sealed with the sealing film 16, and the resin is cured, thereby sealing with the sealing film 16. You may form the 2nd cover body part 18 which further covers the whole 1st cover body part 14 stopped (refer FIG. 6). Thus, as shown in FIG. 6, a lid having a double structure of the first lid portion 14 and the second lid portion 18 can be formed. Also in the formation process of the second lid 18, after applying a resin to the entire piezoelectric substrate 10, a known photolithography technique such as exposure, baking, development, resist removal, etc. is applied to remove excess resin. The second lid body portion 18 that is removed and further covers the entire first lid body portion 14 sealed with the sealing film 16 may be formed on each of the first lid body portions 14. .

  The resin is applied and cured so as to cover the first lid portion 14 without being sealed with the sealing film 16, and the opening of the first lid portion 14 is opened by the second lid portion 18. If it is going to block, since the height of the opening part of this 1st cover body part 14 is about 1-10 micrometers, resin will become the inside of the 1st cover body part 14 (namely, comb shape) by capillary action. However, in the present embodiment, the presence of the sealing film 16 also prevents such a situation from occurring in the space where the electrode and the surface acoustic wave propagation region 12 are accommodated. .

  As described above, in each of the plurality of surface acoustic wave elements formed on the piezoelectric substrate 10, each elastic surface is formed by the lid having the double structure of the first lid 14 and the second lid 18. The comb electrode and the surface acoustic wave propagation region 12 in the wave element may be reliably protected.

  At this time, the lid formed on each surface acoustic wave element has a structure in which the first lid body portion 14 and the second lid body portion 18 made of resin overlap with each other. In comparison, it also has sufficient durability against external forces.

  In addition, before cutting out each surface acoustic wave element from the piezoelectric substrate 10 on which a plurality of surface acoustic wave elements are formed, a bump base metal (UBM) 50 and a bump 60 are formed on the electrode pad 30 in each surface acoustic wave element. By forming and then cutting out individual surface acoustic wave elements from the piezoelectric substrate 10, a plurality of surface acoustic wave elements having the structure shown in FIG. 7 can be produced. It is possible to supply a bare chip of a surface acoustic wave element that is reliably protected by a lid. In this case, the step of forming the bump base metal (UBM) 50 and the bump 60 may be performed for each cut out surface acoustic wave element after the surface acoustic wave element is cut out. Here, in FIG. 7, the bump base metal (UBM) 50 and the bump 60 are formed on the surface acoustic wave element in which the lid of the double structure is formed. As a matter of course, the bump base metal (UBM) 50 and the bump 60 may be formed on the surface acoustic wave element in which the lid having the structure shown in FIG. 6 is formed.

It is a figure which shows an example of a structure of the several surface acoustic wave element formed on a piezoelectric substrate. FIGS. 2A and 2B are diagrams illustrating a process of manufacturing a cover for a surface acoustic wave element according to an embodiment of the present invention. FIG. 2A is a cross-sectional view illustrating a state where a sacrificial layer is formed on a substrate, and FIG. It is a top view. FIGS. 3A and 3B are views showing a process of manufacturing a surface acoustic wave element lid according to an embodiment of the present invention, FIG. 3A is a cross-sectional view showing a state where a resin is applied on a sacrificial layer, and FIG. It is a top view. It is a figure which shows the process of producing the cover body of the surface acoustic wave element in embodiment of this invention, and is sectional drawing which shows the state which removed the sacrificial layer. It is a figure which shows the structure of the surface acoustic wave element in embodiment of this invention which sealed the bridge-shaped cover part after sacrificial layer removal with the sealing film, Fig.5 (a) was seen from the side FIG. 5B is a cross-sectional view taken along line AA, and FIG. 5C is a diagram illustrating another configuration example. It is a figure which shows the structure of the surface acoustic wave element in other embodiment, Fig.6 (a) is the figure seen from the side, FIG.6 (b) is a BB sectional drawing, FIG.6 (c) is others It is a figure which shows the example of a structure. It is a figure which shows the state which attached the bump to the surface acoustic wave element of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Piezoelectric substrate, 12 Comb-shaped electrode and surface acoustic wave propagation region, 14 Bridge-shaped lid (first lid), 16 Sealing film, 18 Second lid, 20 Electrode pattern, 30 Electrode pad, 40 sacrificial layer, 50 bump base metal, 60 bump.

Claims (11)

In a surface acoustic wave device having a piezoelectric substrate, a comb electrode formed on the piezoelectric substrate, and a surface acoustic wave propagation region propagating from the comb electrode to the surface of the piezoelectric substrate and the vicinity of the surface,
Forming a space in which the comb electrode and the surface acoustic wave propagation region are accommodated, and having a lid on the piezoelectric substrate covering the comb electrode and the surface acoustic wave propagation region;
A surface acoustic wave element in which a comb electrode and a surface acoustic wave propagation region are sealed by the lid. The surface acoustic wave device according to claim 1,
The lid is
Forming a space in which the comb-shaped electrode and the surface acoustic wave propagation region are accommodated, and a bridge-shaped lid portion covering the comb-shaped electrode and the surface acoustic wave propagation region;
A sealing film for sealing the opening of the bridge-shaped lid body;
A surface acoustic wave device comprising: The surface acoustic wave device according to claim 1,
The lid is
A bridge-shaped first lid portion that forms a space in which the comb-shaped electrode and the surface acoustic wave propagation region are accommodated and covers the comb-shaped electrode and the surface acoustic wave propagation region;
A sealing film for sealing the opening of the first lid,
A second lid portion covering the first lid portion sealed by the sealing film;
A surface acoustic wave device comprising: The surface acoustic wave device according to claim 2 or 3,
A surface acoustic wave device characterized in that an inclined surface is processed in an opening of a bridge-shaped lid. In the surface acoustic wave device according to any one of claims 1 to 4,
An electrode pad arranged outside the lid, an electrode pattern connecting the electrode pad and the comb-shaped electrode are formed on the piezoelectric substrate, and a bump is formed on the electrode pad. A surface acoustic wave device.   A surface acoustic wave device formed by mounting the surface acoustic wave element according to claim 5 on a mounting surface of a mounting substrate via a bump. For a piezoelectric substrate on which a plurality of surface acoustic wave elements having a comb-shaped electrode and a surface acoustic wave propagation region propagating from the comb-shaped electrode to the surface of the piezoelectric substrate and the vicinity of the surface are formed,
A space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region is formed, and a bridge-shaped lid that covers the comb-shaped electrode and the surface acoustic wave propagation region is individually formed for each surface acoustic wave element. A lid part forming step,
A sealing film is formed to seal the opening of the bridge-shaped lid portion formed in each surface acoustic wave element, and a space for accommodating the comb-shaped electrode and the surface acoustic wave propagation area in each surface acoustic wave element is accommodated. A sealing process for individually sealing;
A method for producing a surface acoustic wave device, comprising: For a piezoelectric substrate on which a plurality of surface acoustic wave elements having a comb-shaped electrode and a surface acoustic wave propagation region propagating from the comb-shaped electrode to the surface of the piezoelectric substrate and the vicinity of the surface are formed,
For each surface acoustic wave element, a bridge-shaped first lid that forms a space in which the comb electrode and the surface acoustic wave propagation region are accommodated and covers the comb electrode and the surface acoustic wave propagation region. A first lid part forming step to be formed individually;
A sealing film that seals the opening of the first lid portion formed in each surface acoustic wave element is formed, and a space in which the comb-shaped electrode and the surface acoustic wave propagation region in each surface acoustic wave element are accommodated A sealing process for individually sealing;
A second lid part forming step for individually forming a second lid part covering the first lid part in each surface acoustic wave element for each surface acoustic wave element;
A method for producing a surface acoustic wave device, comprising: In the manufacturing method of the surface acoustic wave element according to claim 7 or 8,
The step of forming the bridge-shaped lid is as follows:
Forming a sacrificial layer individually for each surface acoustic wave element so as to cover the comb-shaped electrode and the surface acoustic wave propagation region in each surface acoustic wave element;
Applying and curing a resin so as to straddle over each sacrificial layer;
Removing each sacrificial layer by sacrificial layer etching;
Have
By removing each sacrificial layer, a space for accommodating the comb-shaped electrode and the surface acoustic wave propagation region is formed, and a bridge-shaped lid portion covering the comb-shaped electrode and the surface acoustic wave propagation region is provided for each elastic surface. Formed individually for each wave element,
A method of manufacturing a surface acoustic wave device. In the manufacturing method of the surface acoustic wave device according to claim 9,
For the resin for forming the bridge-shaped lid, a photosensitive resin is used,
For the sacrificial layer, a resist having heat resistance that can withstand the curing temperature of the photosensitive resin and removable by an organic solvent is used.
Removing the sacrificial layer by performing sacrificial layer etching using an organic solvent;
A method of manufacturing a surface acoustic wave device. In the manufacturing method of the surface acoustic wave element according to any one of claims 7 to 10,
After the step of forming the bridge-shaped lid portion, the sealing step is performed after the step of forming the inclined surface in the opening of the bridge-shaped lid portion.
A method of manufacturing a surface acoustic wave device.

Images