CN114598293A - Surface acoustic wave device and method for manufacturing the same - Google Patents
Surface acoustic wave device and method for manufacturing the same Download PDFInfo
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- CN114598293A CN114598293A CN202110870226.7A CN202110870226A CN114598293A CN 114598293 A CN114598293 A CN 114598293A CN 202110870226 A CN202110870226 A CN 202110870226A CN 114598293 A CN114598293 A CN 114598293A
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- 229910052782 aluminium Inorganic materials 0.000 claims description 12
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- 229910001069 Ti alloy Inorganic materials 0.000 claims description 4
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 claims description 4
- 229910052594 sapphire Inorganic materials 0.000 claims description 4
- 239000010980 sapphire Substances 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 239000010703 silicon Substances 0.000 claims description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
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- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 2
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- 230000004075 alteration Effects 0.000 description 2
- 229910052787 antimony Inorganic materials 0.000 description 2
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 2
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Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02543—Characteristics of substrate, e.g. cutting angles
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02614—Treatment of substrates, e.g. curved, spherical, cylindrical substrates ensuring closed round-about circuits for the acoustical waves
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02637—Details concerning reflective or coupling arrays
- H03H9/02653—Grooves or arrays buried in the substrate
- H03H9/02661—Grooves or arrays buried in the substrate being located inside the interdigital transducers
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
A surface acoustic wave element comprising: a piezoelectric substrate; and a metal pattern formed on the piezoelectric substrate and having an IDT. The IDT has a pair of comb-shaped electrodes with a plurality of electrode fingers interposed therebetween, and the metal pattern includes a1 st metal and a 2 nd metal, the 2 nd metal being covered with the 1 st metal. Thus, a highly reliable surface acoustic wave device is provided, which can sufficiently suppress the occurrence of small bumps and ensure sufficient power resistance.
Description
Technical Field
The present invention relates to a Surface Acoustic Wave (SAW) device and a method for manufacturing the same.
Background
The functions of a typical smart phone and the like in a mobile communication terminal are developed to high functionality year by year. Therefore, the number of electronic components used tends to increase.
As described in many specifications, the basic structure of a surface acoustic wave element is an IDT (Interdigital Transducer) for exciting a surface acoustic wave is formed on a piezoelectric substrate such as lithium tantalate or lithium niobate, and a resonator is thus formed. The IDT can be formed by forming a conductive film of aluminum (a1) or the like and then performing an etching process using a photoresist (photoresist) as a mask. Sometimes the structure is suitably formed with a plurality of resonators, and a DMS (Double Mode SAW) design or a ladder design is adopted to obtain the desired characteristics of the band pass filter.
Further, the surface acoustic wave device is sometimes required to have high electric resistance. When the IDT is formed of aluminum, which has been conventionally used, migration occurs under the influence of displacement of the IDT due to power application. As a result, the IDT is broken, and thus there is a problem of low power resistance.
For example, patent document 1 (international publication No. 2009/150786) describes that in order to provide a surface acoustic wave element in which a size of the surface acoustic wave element is reduced, a withstand voltage is improved, and a protrusion such as a small bump (hillock) is not easily generated, an IDT may be formed using an aluminum-copper alloy film to which a predetermined amount of copper is added.
Disclosure of Invention
[ problems to be solved by the invention ]
The main problems to be solved by the present invention will be described. If pure aluminum is used as the metal material of the pattern wiring or the IDT of the surface acoustic wave element, there is a problem that the pattern wiring or the IDT generates a small bump and the power resistance is weak. Small bumps are generated in the pattern wiring or IDT due to a load of film stress caused by a thermal history in a process or the like or a high voltage is applied. The small bumps degrade the power durability of the IDT.
Therefore, patent document 1 discloses the following technique: conventionally, copper has been added to suppress the generation of small bumps and improve the power resistance.
However, it is difficult to satisfy sufficient withstand voltage for recent demands for miniaturization and higher frequency of surface acoustic wave devices due to an increase in resistance and an influence of an anti-oxidation measure on transmission characteristics. In addition, the generation of small protrusions cannot be sufficiently suppressed.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly reliable surface acoustic wave element which sufficiently suppresses the generation of small bumps and ensures sufficient power resistance.
[ means for solving problems ]
In order to solve the above problem, the present invention is a surface acoustic wave device including:
a piezoelectric substrate; and
a metal pattern formed on the piezoelectric substrate and having an IDT having a pair of comb-shaped electrodes of a plurality of electrode fingers that are inserted into each other;
wherein the metal pattern comprises a1 st metal and a 2 nd metal,
the 2 nd metal is covered by the 1 st metal.
In one aspect of the surface acoustic wave device of the present invention, the 1 st metal has a characteristic of having a smaller linear expansion coefficient than the 2 nd metal.
In one aspect of the surface acoustic wave device according to the present invention, the 1 st metal is titanium or a titanium alloy.
In one aspect of the surface acoustic wave device of the present invention, the 2 nd metal is aluminum, copper, or an alloy containing any of the foregoing.
In one aspect of the surface acoustic wave device according to the present invention, the piezoelectric substrate is a substrate containing lithium tantalate or lithium niobate.
In one aspect of the surface acoustic wave device according to the present invention, the piezoelectric substrate is bonded to a substrate made of sapphire, silicon, alumina, spinel, crystal, or glass on a main surface opposite to a surface on which the metal pattern is formed.
In one aspect of the surface acoustic wave device according to the present invention, the metal pattern has a bump pad (bump pad) and a pattern wiring electrically connecting the IDT and the bump pad.
Another aspect of the present invention is a method for manufacturing a surface acoustic wave device, including:
step (a): forming a metal pattern having a recessed shape of an IDT having a pair of comb-like electrodes of a plurality of electrode fingers interposed with each other on a piezoelectric substrate with a1 st metal;
a step (b): filling a 2 nd metal in the concave part shape formed by the 1 st metal; and
step (c): forming the 1 st metal on the 2 nd metal.
In one aspect of the method for manufacturing a surface acoustic wave device according to the present invention, the step (a) includes the steps of:
forming a sacrificial layer on the piezoelectric substrate; and
and patterning the sacrificial layer to partially expose the piezoelectric substrate.
In one aspect of the method for manufacturing a surface acoustic wave device of the present invention, in the step (a), the bottom portion and the side wall portion of the recess shape are formed together with the 1 st metal.
In one aspect of the method for manufacturing a surface acoustic wave device according to the present invention, the method further includes, after the step (b), a step of polishing the 2 nd metal until the sacrificial layer is exposed.
[ Effect of the invention ]
According to the present invention, it is possible to provide a highly reliable surface acoustic wave device which sufficiently suppresses the generation of small bumps and ensures sufficient power resistance.
Drawings
Fig. 1 is a sectional view of a surface acoustic wave device according to the present embodiment.
Fig. 2 is a plan view for explaining the structure of a resonator including an IDT.
Fig. 3 is a plan view schematically showing a state on a piezoelectric substrate including pattern wiring.
Fig. 4(a) to 4(c) are diagrams for explaining a method of manufacturing a surface acoustic wave device according to the present invention.
Fig. 5(a) to 5(b) are cross-sectional views of an IDT to which the present invention is applied and an IDT as a comparative example.
Fig. 6 is a diagram showing the stress generated in the IDT to which the present invention is applied.
Fig. 7 is a diagram showing stresses generated in an IDT of a comparative example.
Detailed Description
Hereinafter, the present invention will be explained by describing specific embodiments thereof with reference to the accompanying drawings.
(examples)
Fig. 1 is a sectional view of a surface acoustic wave element 1 of the present embodiment. As shown in fig. 1, the surface acoustic wave element 1 of the present embodiment includes a piezoelectric substrate 3.
In the present embodiment, the piezoelectric substrate 3 includes lithium tantalate single crystal. The thickness of the piezoelectric substrate 3 may be 20 μm, for example.
The piezoelectric substrate 3 may be formed using another piezoelectric single crystal, for example, a piezoelectric single crystal such as lithium niobate or quartz, or a piezoelectric ceramic.
A metal pattern is formed on one main surface of the piezoelectric substrate 3 of the surface acoustic wave element 1 of the present embodiment. The metal pattern has an IDT5, which is a pair of comb-shaped electrodes having a plurality of electrode fingers that are interposed between each other 5.
Fig. 2 is a plan view for explaining the structure of the resonator including the IDT 5.
As shown in fig. 2, IDT5 and reflectors 5a are formed on the piezoelectric substrate 3. The IDT5 has a pair of comb-shaped electrodes 5b facing each other. The comb-shaped electrode 5b includes a plurality of electrode fingers 5c and a bus bar 5d connecting the plurality of electrode fingers 5 c. Reflectors 5a are provided on both sides of the IDT 5.
As shown in fig. 1, IDT5 includes 1 st metal 51 and 2 nd metal 52. The 2 nd metal 52 is covered by the 1 st metal 51. In this embodiment, IDT5 uses titanium (Ti) as the 1 st metal and aluminum (a1) as the 2 nd metal. IDT5 is a thin film with a thickness of, for example, 150nm to 400 nm.
The linear expansion coefficient of titanium (Ti) is about 8.5X 10-6and/K. The linear expansion coefficient of aluminum (A1) is about 23.9X 10-6and/K. Therefore, titanium (Ti) has a smaller linear expansion coefficient than aluminum (a 1).
The 1 st metal 51 may include, for example, a suitable metal (including semimetal) such as silver, copper, tungsten, molybdenum, chromium, zirconium, iridium, antimony, or an alloy thereof, in addition to a titanium alloy or an iron-nickel alloy (including invar), and may be formed of an alloy thereof.
The 2 nd metal 52 may be formed of, for example, an alloy of an appropriate metal such as silver, copper, iron, and nickel, or an alloy thereof, in addition to an aluminum alloy.
A pattern wiring 7 included in a metal pattern is formed on one main surface of the piezoelectric substrate 3 of the surface acoustic wave element 1 of the present embodiment. Fig. 3 is a plan view schematically showing the condition on the piezoelectric substrate 3 including the pattern wiring 7.
As shown in fig. 3, the pattern wiring 7 included in the metal pattern, the IDT5, and the reflector 5a are formed on the piezoelectric substrate 3.
The pattern wiring 7, IDT5, and reflectors 5a formed on the piezoelectric substrate 3 may be appropriately designed in a DMS design, a trapezoidal design, or the like to obtain desired characteristics of the bandpass filter.
As shown In fig. 3, the pattern wiring 7 includes an input pad In, an output pad Out, and a ground pad GND. In addition, the pattern wiring 7 is electrically connected to the IDT 5.
As shown in fig. 1, in the present embodiment, the pattern wiring 7 includes a1 st metal 71 and a 2 nd metal 72. The 2 nd metal 72 is covered with the 1 st metal 71. In the present embodiment, the pattern wiring 7 uses titanium (Ti) as the 1 st metal and aluminum (a1) as the 2 nd metal. The pattern wiring 7 is a thin film having a thickness of, for example, 150nm to 400 nm.
The 1 st metal 71 may include, for example, a suitable metal (including semimetal) such as silver, copper, tungsten, molybdenum, chromium, zirconium, iridium, antimony, or an alloy thereof, in addition to a titanium alloy or an iron-nickel alloy (including invar), and may be formed of an alloy thereof.
The 2 nd metal 72 may be formed of, for example, an alloy of an appropriate metal such as silver, copper, iron, and nickel, or an alloy thereof, in addition to an aluminum alloy.
As shown In fig. 1, bumps 9 are bonded to the input pad In, the output pad Out, and the ground pad GND included In the pattern wiring 7 of the surface acoustic wave element 1 of the present embodiment.
In the present embodiment, the bump 9 includes gold (Au). The height of the bump 9 is, for example, 20 μm to 50 μm.
As shown in fig. 1, the surface acoustic wave element 1 of the present embodiment includes a wiring substrate 11. The wiring substrate 11 is an insulating substrate, for example, a Ceramic substrate or a resin substrate such as an HTCC (High Temperature Co-Fired Ceramic) or an LTCC (Low Temperature Co-Fired Ceramic).
The wiring board 11 has a plurality of land pads (land pads) 11a on one main surface and a plurality of external connection terminals 11b on the other main surface. The piezoelectric substrate 3 is flip-chip mounted on the wiring substrate 11 via bumps 9. The piezoelectric substrate 3 is electrically connected to the external connection terminals 11b via the bumps 9 and the pad pads 11 a.
As shown in fig. 1, the surface acoustic wave element 1 of the present embodiment has a sealing portion 13 for sealing a space between the piezoelectric substrate 3 and the wiring substrate 11 so as to be a hermetically sealed hollow space. The sealing portion 13 is provided on the wiring substrate 11 so as to surround the piezoelectric substrate 3.
The sealing portion 13 may be formed of an insulator such as a synthetic resin, or may be formed of a metal. As the metal, solder (brazing material) such as tin-silver solder or gold-tin solder can be used.
Examples of the synthetic resin include, but are not limited to, epoxy resin, polyimide, and the like. It is preferable to use an epoxy resin, and to form the sealing portion 13 using a low-temperature hardening process.
As shown in fig. 1, the piezoelectric substrate 3 of the surface acoustic wave element 1 of the present embodiment is bonded to the support substrate 15 on the main surface opposite to the surface on which the metal pattern is formed. In the present embodiment, the support substrate 15 is a substrate including sapphire. The support substrate 15 may be formed using, for example, silicon, polycrystalline alumina, polycrystalline spinel, crystal, or glass.
Next, a method for manufacturing the surface acoustic wave element 1 according to another aspect of the present invention will be described.
(production method 1)
Fig. 4(a) to 4(c) are views for explaining a method of manufacturing a surface acoustic wave device according to the present invention. Fig. 4(a) to 4(c) show cross sections in the traveling direction of the elastic surface wave.
Fig. 4(a) to 4(c) are views showing a method for manufacturing the surface acoustic wave element 1 according to the present embodiment.
Hereinafter, a method for manufacturing the surface acoustic wave element 1 of the present embodiment will be described with reference to fig. 4(a) to 4 (c). A sapphire substrate activated by FAB (Fast Atomic Beam) or the like is bonded to the piezoelectric substrate 3, but not shown.
As shown in fig. 4(a), a patterned sacrificial layer S is formed on the piezoelectric substrate 3, and the piezoelectric substrate 3 is partially exposed. Next, a1 st metal M1 film is formed on the piezoelectric substrate 3 and on the sacrifice layer S.
The sacrificial layer S may be silicon, for example. The sacrificial layer S is patterned by, for example, etching a region where a metal pattern is formed by photolithography.
The 1 st metal M1 may be titanium (Ti), for example. The 1 st metal M1 is deposited by sputtering, for example, to form a film. The 1 st metal M1 is continuously formed on the piezoelectric substrate 3 and on the upper surface and the side surfaces of the sacrifice layer S. That is, the 1 st metal M1 forms both the bottom and the side wall portions in the shape of the recessed portion. The 1 st metal M1 can be set to a thickness of 20 μ M to 30 μ M, for example.
As shown in fig. 4(b), the 2 nd metal M2 was filled in the concave shape portion of the 1 st metal M1. Then, the 2 nd metal M2 and the 1 st metal M1 are polished until the sacrificial layer S is exposed. The Polishing may be performed by, for example, a CMP (Chemical Mechanical Polishing) method.
For the 2 nd metal M2, aluminum (Al) may be used, for example. The 2 nd metal M2 is filled in the recess-shaped portion of the 1 st metal M1 by, for example, a plating method.
Here, the 2 nd metal M2 was filled in the recessed portion of the 1 st metal M1, the 2 nd metal M2 was also formed on the 1 st metal M1 formed on the upper surface of the sacrificial layer S, and the 1 st metal M1 and the 2 nd metal M2 were polished until the upper surface of the sacrificial layer S was exposed.
The 2 nd metal M2 filled in the recess-shaped portion of the 1 st metal M1 can be set to a thickness of, for example, 300 to 400 μ M.
As shown in fig. 4(c), a1 st metal M1 is formed on the 2 nd metal M2. The 1 st metal M1 is deposited by sputtering, for example, to form a film. The 1 st metal M1 can be set to a thickness of 20 μ M to 30 μ M, for example.
Next, as shown in fig. 4(c), in order to remove the 1 st metal M1 formed on the region other than the 2 nd metal M2, a photoresist PR is patterned on the metal pattern.
Next, the 1 st metal M1 formed in the region other than the recess-shaped portion of the 1 st metal M1 and the 2 nd metal M2 was removed by etching. Next, by removing the photoresist PR, a metal pattern in which the 2 nd metal M2 is covered with the 1 st metal M1 may be formed.
In addition, the following method can also be used using the procedure described in fig. 4 (c): the photoresist is patterned on the region except the metal pattern, and then the 1 st metal M1 is formed on the recess-shaped portion of the 1 st metal M1 and the 2 nd metal M2. In this case, the metal pattern in which the 1 st metal M2 is covered with the 1 st metal M1 can be formed in the same step as described with reference to fig. 4(c) by removing the photoresist after forming the 1 st metal M1 on the recess-shaped portion of the 1 st metal M1 and the 2 nd metal M2 and peeling off the excess 1 st metal M1.
Then, a gold bump is bonded to the pad of the pattern wiring using a bonding device.
Then, the piezoelectric substrate 3 is singulated and flip-chip mounted on the array of wiring substrates 11. The surface acoustic wave element 1 is obtained by filling a sealing material, curing the sealing material, and then singulating the element.
Next, the effects of the present invention will be described.
Fig. 5 is a sectional view of an IDT to which the present invention is applied and an IDT as a comparative example. Fig. 5(a) is a cross-sectional view of an IDT to which the present invention is applied. Fig. 5(b) is a cross-sectional view of an IDT of a comparative example for comparing effects with the present invention. The width of the IDT to which the present invention is applied and the width of the IDT of the comparative example are both 500 nm.
Further, the IDT to which the present invention is applied and the IDT of the comparative example are formed on the piezoelectric substrate 3. In both the IDT to which the present invention is applied and the IDT of the comparative example, a titanium (Ti) film having a thickness of 25nm was formed in the upper and lower portions and aluminum (a1) having a thickness of 350nm was formed in the central portion in the cross section in the traveling direction of the elastic surface wave.
As shown in fig. 5(a), the IDT structure to which the present invention is applied is formed with titanium (Ti) films having a thickness of 25nm on both side wall portions, and aluminum (a1) in the central portion is completely covered with the titanium (Ti) films.
Fig. 6 is a diagram showing the stress generated in the IDT to which the present invention is applied, which is described with reference to fig. 5 (a).
Fig. 7 is a diagram showing stresses generated in the IDT of the comparative example described with reference to fig. 5 (b).
The IDT to which the present invention was applied and the IDT of the comparative example were subjected to the same power application, and the stress was measured. As a result, as shown in fig. 6 and 7, the maximum stress is generated at the end portion of the lower portion of the IDT in both structures.
As shown in FIG. 6, the maximum stress generated in the IDT to which the present invention is applied is 1.1x 109〔N/m2And (c) a temperature sensor. On the other hand, as shown in fig. 7, the maximum stress generated in the IDT of the comparative example was 1.32 × 109〔N/m2And (c) a temperature sensor. That is, the IDT to which the present invention is applied can suppress stress more significantly than the IDT of the comparative example.
Under the influence of stress applied to the IDT, voids or small bumps, migration, which cause the IDT to crack, may occur. That is, by suppressing the stress applied to the IDT, the electric resistance of the surface acoustic wave element can be improved.
According to the structure of the present invention described above, it is possible to provide a highly reliable surface acoustic wave element in which generation of small bumps is sufficiently suppressed and sufficient power resistance is ensured.
It is to be understood that the present invention is not limited to the above-described embodiments, but encompasses embodiments which achieve the objects of the present invention.
Furthermore, while at least one embodiment has been described above, it is to be appreciated various alterations, modifications, or improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the scope of the invention. It is to be understood that the aspects of the method or apparatus described herein are not limited in their application to the details of construction and the arrangements of the components set forth in the above description or illustrated in the drawings. The methods and apparatus may be practiced in other embodiments or with other embodiments. The examples are given by way of illustration only and not by way of limitation. Furthermore, the descriptions and terminology used herein are for the purpose of description and not of limitation. The use of "including," "comprising," "having," "containing," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The use of the term "or any other term in the description using the term" or "may be interpreted to mean one, more than one, or all of the recited term. Front, back, left, right, top, bottom, up, down, and horizontal and vertical references are for convenience of description and do not limit the position and spatial arrangement of any of the constituent elements of the present invention. Accordingly, the foregoing description and drawings are by way of example only.
Claims (11)
1. A surface acoustic wave element comprising:
a piezoelectric substrate; and
a metal pattern formed on the piezoelectric substrate and having an IDT having a pair of comb-shaped electrodes of a plurality of electrode fingers that are inserted into each other;
wherein the metal pattern comprises a1 st metal and a 2 nd metal,
the 2 nd metal is covered with the 1 st metal.
2. A surface acoustic wave device as set forth in claim 1 wherein: the surface acoustic wave element has a characteristic that the linear expansion coefficient of the 1 st metal is smaller than that of the 2 nd metal.
3. A surface acoustic wave device as set forth in claim 1 wherein: the 1 st metal is titanium or titanium alloy.
4. A surface acoustic wave device as set forth in claim 1 wherein: the 2 nd metal is aluminum, copper, or an alloy comprising any of the foregoing.
5. A surface acoustic wave device as set forth in claim 1 wherein: the piezoelectric substrate is a substrate containing lithium tantalate or lithium niobate.
6. A surface acoustic wave device as set forth in claim 1 wherein: the piezoelectric substrate is bonded to a substrate made of sapphire, silicon, alumina, spinel, crystal, or glass on a main surface opposite to a surface on which the metal pattern is formed.
7. A surface acoustic wave device as set forth in claim 1 wherein: the metal pattern has a bump pad, and a pattern wiring electrically connecting the IDT and the bump pad.
8. A method for manufacturing a surface acoustic wave device includes:
step (a): forming a metal pattern having a recessed shape of an IDT having a pair of comb-like electrodes of a plurality of electrode fingers interposed with each other on a piezoelectric substrate with a1 st metal;
step (b): filling a 2 nd metal in the concave part shape formed by the 1 st metal; and
step (c): forming the 1 st metal on the 2 nd metal.
9. A method for manufacturing a surface acoustic wave device as defined in claim 8, wherein: the step (a) comprises the steps of:
forming a sacrificial layer on the piezoelectric substrate; and
and patterning the sacrificial layer to partially expose the piezoelectric substrate.
10. A method for manufacturing a surface acoustic wave device as defined in claim 8, wherein: in the step (a), the bottom portion and the side wall portion of the recess shape are formed together by the 1 st metal.
11. A method for manufacturing a surface acoustic wave device as defined in claim 9, wherein: after the step (b), grinding the 2 nd metal until the sacrificial layer is exposed.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020-202334 | 2020-12-05 | ||
| JP2020202334A JP2022089712A (en) | 2020-12-05 | 2020-12-05 | Surface acoustic wave device |
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| Publication Number | Publication Date |
|---|---|
| CN114598293A true CN114598293A (en) | 2022-06-07 |
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|---|---|---|---|
| CN202110870226.7A Pending CN114598293A (en) | 2020-12-05 | 2021-07-30 | Surface acoustic wave device and method for manufacturing the same |
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|---|---|
| JP (1) | JP2022089712A (en) |
| CN (1) | CN114598293A (en) |
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| JP2022089712A (en) | 2022-06-16 |
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