JP2006211182A - Surface acoustic wave device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and highly reliable surface acoustic wave device capable of preventing the corrosion of IDT electrodes and a comb-shape electrode by the use of an ink jet method, and to provide its manufacturing method. <P>SOLUTION: Resists 19a, 19b as liquid materials are discharged and formed by the use of the ink jet method in an area including a part of connection lands 7a, 7b, and a part of the main surface 3 of a piezo-electric body 2, in a first process S10. A second process for forming hardened films by performing drying to coat the resists 19a, 19b as the liquid materials which are formed by discharge in an S10, and performing a hardening step is defined as an S11. It is preferable that the hardened resists 19a, 19b resist boiling water and the electrolytic solution of a sulfuric acid, a chromic acid, a phosphoric acid, and an alkaline solution, etc., in anodising which is performed in the IDT electrodes 5 in an S12 as a third process. A fourth process for removing the hardened resists 19a, 19b as the hardened films of the connection lands 7a, 7b is defined as an S13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surface acoustic wave device used for, for example, communication equipment and a method for manufacturing the same.

  Using microfabrication technology such as IC, it is possible to form fine electrodes on the surface of the piezoelectric body, and it is possible to electrically drive or detect a surface acoustic wave (SAW). By utilizing this, it has become possible to stably obtain a high frequency of about 100 MHz to a giga Hz band. The SAW device using the surface acoustic wave is used as a high frequency filter (SAW filter) or a surface acoustic wave resonator (SAW resonator) for forming an oscillation circuit.

  In order to provide a surface acoustic wave device in which an IDT electrode is not adversely affected by a developer and a manufacturing method thereof, a first aluminum oxide film is formed on the surface of an aluminum film of a piezoelectric substrate on which an aluminum film is formed. Then, an IDT electrode and a connection electrode are formed by a photolithography method to obtain a surface acoustic wave element, a resist film is formed on the entire upper surface of the piezoelectric substrate so as to cover the IDT electrode and the connection electrode, and a resist film on the surface of the connection electrode is left. The resist film on the surface of the IDT electrode is removed with a developing solution, and the surface of the IDT electrode is further oxidized by anodic oxidation to form a second aluminum oxide film. The resist film is removed, the surface acoustic wave element is accommodated in the package, the connection electrode and the external lead terminal are electrically connected by a wire, and the package Manufacturing method for sealing the opening in the lid has been disclosed (see Patent Document 1).

  For the purpose of providing a method of manufacturing a SAW device having stable element characteristics, a step of forming a comb-shaped electrode having a predetermined shape on a substrate, a step of forming an insulating film on the comb-shaped electrode and the substrate, A step of forming a first resist having a predetermined shape, a step of etching the insulating film using the first resist as a mask, a step of forming a pad electrode layer on the entire surface of the substrate including the first resist, and a pad electrode A manufacturing method is disclosed that includes a step of forming a second resist having a predetermined shape on a layer and a step of etching the pad electrode layer using the second resist as a mask (see Patent Document 2).

JP 2000-278067 A JP 2001-168667 A

  However, in any method, the IDT electrode, the comb-shaped electrode, the connection electrode, and the pad electrode layer are manufactured by a photolithography method. Thereafter, anodization is performed to stabilize the surface of the electrode. When the anodizing treatment is performed, the connection electrode and the pad electrode layer are electrically connected to an external electric circuit. Therefore, it is necessary to ensure the electrical connection without performing the anodizing treatment.

  Conventionally, a resist film is applied again on the entire surface in order to protect the connection electrode and the pad electrode layer, and the resist film is left on the connection electrode and the pad electrode layer by photolithography. At this time, the IDT electrode and the comb-shaped electrode are corroded by being immersed in a resist film developer in a state where the anodizing treatment is not performed. For this reason, the performance which detects the surface acoustic wave of an IDT electrode and a comb-shaped electrode has generate | occur | produced.

  Accordingly, an object of the present invention is to provide an inexpensive and highly reliable surface acoustic wave device and a method for manufacturing the same by preventing the corrosion of the IDT electrode and the comb-shaped electrode described above by using the ink jet method. It is.

  In order to solve the above-described problems, in the present invention, a liquid material covers a region including a part of a connection land portion of a pair of cross finger electrodes formed on the surface of a piezoelectric body and a part of the piezoelectric body. At least a first step, a second step of curing the liquid material to form a cured film, and a third step of anodizing by electrolysis in an electrolytic solution using the crossed finger electrode as an anode. This is the gist.

  According to this, in the first step of covering the region including a part of the connection land part of the pair of cross finger electrodes formed on the surface of the piezoelectric body and the part of the piezoelectric body with the liquid material, the connection is performed. A region including a part of the land part and a part of the piezoelectric body adjacent to the land part is covered with a liquid material. Further, the liquid material is cured to form a cured film in a second step of curing the liquid material to form a cured film. Further, the connection in which the cured film formed in the first step and the second step is covered by a third step of performing anodization by electrolysis in an electrolytic solution using the crossed finger electrode as an anode. Since a part of the land part is not subjected to the anodizing process in the third step, the part of the connection land part covered by the cured film can maintain conductivity.

  The present invention is a method for manufacturing a surface acoustic wave device, comprising a fourth step of removing the cured film of the connection land portion in addition to the first step to the third step. The gist.

  According to this, by providing the fourth step of removing the cured film of the connection land portion, the conductivity of the connection land portion can be ensured when the cured film is insulative.

  The gist of the present invention is a method for manufacturing a surface acoustic wave device, wherein the connection land portion from which the cured film has been removed in the fourth step and the support are electrically connected.

  According to this, the connection land portion from which the cured film has been removed by the fourth step and the support are electrically connected to each other, so that an electrical circuit external to the surface acoustic wave device is electrically connected. Can be connected and can function as a surface acoustic wave device.

  The gist of the present invention is a method for manufacturing a surface acoustic wave device, wherein the cured film has conductivity.

  According to this, since the cured film has conductivity, it is not necessary to remove the cured film, and a part of the connection land portion can be protected from the anodic oxidation treatment of the third step. .

  The gist of the present invention is a method for manufacturing a surface acoustic wave device, wherein the cured film and the support are electrically connected.

  According to this, since the cured film and the support are electrically connected, they can be electrically connected to an external electric circuit of the surface acoustic wave device and function as a surface acoustic wave device. be able to.

  The present invention is a method for manufacturing a surface acoustic wave device, comprising a fifth step of disposing a plurality of the piezoelectric bodies on a piezoelectric wafer and cutting the piezoelectric wafer into the respective piezoelectric bodies. And

  According to this, a plurality of the piezoelectric bodies are arranged on the piezoelectric wafer, and the fifth step of cutting the piezoelectric wafer into the respective piezoelectric bodies is provided, thereby improving the working efficiency in each step. At the same time, the quality of each piezoelectric body can be made uniform.

  The present invention is a method for manufacturing a surface acoustic wave device, wherein the region including each of the connection land portions of each of the plurality of piezoelectric bodies arranged on the piezoelectric wafer and a part of the piezoelectric body is provided. The gist is to cover with a liquid material.

  According to this, work efficiency is improved by covering the region including each of the connection land portions of each of the plurality of piezoelectric bodies arranged on the piezoelectric wafer and a part of the piezoelectric body with the liquid material. The quality of each piezoelectric body can be made uniform while improving.

  The gist of the present invention is a method for manufacturing a surface acoustic wave device, wherein the liquid material is ejected and formed by an ink jet method.

  According to this, the liquid material is ejected and formed by an ink jet method, so that a part of the connection land part and a part of the piezoelectric body are used without using a developer for a photoresist by a photolithography method. Therefore, it is possible to prevent the pair of cross finger electrodes formed on the surface of the piezoelectric body from being corroded by the developer for the photoresist.

  The gist of the present invention is a surface acoustic wave device manufactured by the method for manufacturing a surface acoustic wave device.

  According to this, the surface acoustic wave device is manufactured by the method for manufacturing the surface acoustic wave device, thereby preventing corrosion of a pair of the interdigital electrodes formed on the surface of the piezoelectric body, and an inexpensive and highly reliable elastic surface. A wave device can be provided.

  Embodiments of the method for manufacturing a surface acoustic wave device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a SAW resonator element 1 of this embodiment.
The SAW resonance piece 1 is configured as a piezoelectric body 2 obtained by cutting a piezoelectric body such as quartz, LiTaO, LiNbO, PZT, or ZnO thin film into a rectangle. The piezoelectric body 2 of the present embodiment is cut into a flat rectangular shape, and an IDT (Inter Digital Transducer) electrode 5 is constituted by a set of electrodes 4a, 4b, a reflector 6a and a reflector 6b on its main surface 3. Has been.

  The grid-like reflector 6 a and reflector 6 b are formed on both sides of the IDT electrode 5 in the longitudinal direction. The pair of electrodes 4a and 4b forming the IDT electrode 5 is guided to the end 2a of the piezoelectric body 2 through the outside of one reflector 6a, that is, the edge side of the piezoelectric body 2, and has a slightly wide area. The connection land portion 7a and the connection land portion 7b are formed. The electrode 4a and the electrode 4b, the reflector 6a and the reflector 6b, the connection land portion 7a and the connection land portion 7b are usually made of a conductive material, for example, gold, aluminum, aluminum copper alloy, and the like. Aluminum-based materials are most often used in terms of cost. The set of cross finger electrodes includes an IDT electrode 5 (a set of electrodes 4a and 4b), a reflector 6a, and a reflector 6b.

FIG. 2 is a process flowchart of the SAW resonator element 1 of this embodiment.
The piezoelectric body 2 cleans the piezoelectric body 2 in step (hereinafter referred to as S) 1. In S2, aluminum is vapor-deposited substantially uniformly on the main surface 3 (see FIG. 1) of the piezoelectric body 2 while ensuring the cleanliness of the surface in S1.

  In S3, a photoresist is applied substantially uniformly on the aluminum deposited in S2. In this case, heat treatment may be performed to improve the adhesion between aluminum and the photoresist. In S4, the photomask is brought into close contact with the photoresist applied in S3, and the mask exposure is performed by irradiating parallel light having a wavelength that the photoresist is exposed to.

  In S5, unnecessary portions of the photoresist exposed by the parallel light irradiated in S4 are removed. In S6, the aluminum layer deposited in S2 exposed in the portion where the photoresist has been removed in S5 is removed by etching.

  In S <b> 7, desired IDT electrode patterning is completed on the main surface 3 of the piezoelectric body 2.

  In S8, the whole surface is cleaned in a state where a desired IDT electrode is patterned on the main surface 3 of the piezoelectric body 2 in S7 to ensure cleanliness. In S9, the piezoelectric body 2 is dried in an environment where cleanliness is ensured.

  In S10, a resist as a liquid material is discharged and formed on two connection land portions 7a and 7b (see FIG. 1) by an ink jet method (details will be described later).

  In S11, the resist of the connection land portions 7a and 7b ejected and formed by the ink jet method in S10 is cured to form a cured film.

  S12 is a third step in which an anodizing process is performed on the IDT electrode 5 excluding the connection land portions 7a and 7b on which the resist is discharged and formed in S11. This anodizing treatment, also called anodizing treatment, is a relatively thick oxide film that has a unique shape on the surface when aluminum is used as an anode in an electrolyte such as sulfuric acid, odorous acid, chromic acid, phosphoric acid, or alkaline solution. Is generated. The produced oxide film is a high-hardness film, and when it is further boiled in boiling water, the hole in the film is subjected to a sealing treatment to form a chemically inert film. Therefore, even if impurities or the like adhere to the film, it is less affected and the SAW resonator element is stable. Moreover, the oxide film produced | generated by the anodizing process becomes electrically insulating.

  Even if the anodic oxidation process in S12 is performed, the aluminum in the two connection land portions 7a and 7b on which the resist is discharged and formed in S10 and S11 does not come into contact with the above-described electrolytic solution, so that it does not become an oxide film. This is because the electrical connection between the SAW resonator element 1 (see FIG. 1) and an external electric circuit is made by two connection land portions 7a and 7b via a support (described later). .

  S13 is a fourth step of removing the resist as the cured film of the two connection land portions 7a and 7b. The removal liquid for removing the resist is in contact with the IDT electrode, but is hardly affected by the anodic oxidation process already performed in S12.

  In S14, the SAW resonator element 1 is cleaned and the surface is cleaned and dried. In this way, in S15, the SAW resonance piece 1 (see FIG. 1) is completed.

FIG. 3A is a plan view of the surface acoustic wave device 20 in which the SAW resonator element 1 of the present embodiment is mounted on the support 10, and FIG. 3B is a cross-sectional view of the surface acoustic wave device 20. .
A concave groove 12 is provided in the lower support 11 to prevent resonance between the surface acoustic wave of the SAW resonance piece 1 and the lower support 11. Further, two output terminals 13 a and 13 b as a support are fixed to the lower support 11. The output terminals 13a and 13b may be any metal having electrical conductivity, and preferably, gold plating or nickel plating is applied to improve solderability.

  The SAW resonance piece 1 is fixed to the lower support 11 with an adhesive or the like. For ease of explanation in FIG. 5A, the upper support 14 is removed. On the main surface 3 of the piezoelectric body 2, electrodes 4 a and 4 b and reflectors 6 a and 6 b constituting an IDT electrode 5 are disposed as a pair of cross finger electrodes. Each of the electrodes 4a and 4b extends to one end of the piezoelectric body 2, and each tip portion is slightly widened for electrical connection. This connection part is called connection land part 7a, 7b.

  The connecting lines 15a and 15b are connected between one end of each of the output terminals 13a and 13b fixed to the lower support 11 and the connection land portions 7a and 7b of the SAW resonance piece 1 fixed to the lower support 11. Is moored. The respective ends of the connecting wires 15a and 15b are fixed and electrically connected with solder or a conductive adhesive or the like. Further, the upper support 14 is fixed to the lower support 11 while maintaining airtightness. The connection lines 15a and 15b may be any metal having conductivity. Further, the connecting wires 15a and 15b may be wire-bonded.

  One end of each of the output terminals 13 a and 13 b is electrically connected to the conductive pattern 17 disposed on the circuit board 16 by solder 18. In this embodiment, the output terminals 13a and 13b penetrate the circuit board 16 and are electrically connected to the conductive pattern 17. However, the output terminals 13a and 13b are disposed below the lower support 11, and the circuit board is provided. The 16 conductive patterns 17 may be electrically connected while facing each other.

  Further, the SAW resonance piece 1 is fixed to the lower support 11 in a both-sided state, but may be fixed in a cantilevered state. Further, an inert gas such as nitrogen gas may be sealed in the space formed by the lower support 11 and the upper support 14.

FIG. 4 is a perspective view of the SAW resonance piece 1 for explaining S10 to S13 in the process flowchart of the SAW resonance piece 1 of FIG.
Between S1 to S9 in the process flowchart of the SAW resonator element 1 in FIG. 2, a set of crossed finger electrodes is formed on the main surface 3 of the piezoelectric body 2 by a set of electrodes 4a, 4b, reflectors 6a, and reflectors 6b. The IDT electrode 5 is configured. In S10 as the first step, resists 19a and 19b as liquid materials are discharged and formed in an area including a part of the connection land portions 7a and 7b and a part of the main surface 3 of the piezoelectric body 2 by an ink jet method. Is done. Here, the material of the resists 19a and 19b may be an organic or inorganic material. The solvent liquid as the liquid material may be oily or aqueous.

  S11 is a second step of forming a cured film by drying and curing the resists 19a and 19b, which are liquid materials discharged and formed in S10, in order to form a film. Curing is performed by heating, ultraviolet irradiation, infrared irradiation or the like, and the resists 19a and 19b as liquid materials become the cured resists 19a and 19b. The cured resists 19a and 19b are applied to an electrolytic solution such as sulfuric acid, odorous acid, chromic acid, phosphoric acid, and alkaline solution, which is applied to the IDT electrode 5 in S12 as a third step, and boiling water. Anything that can withstand.

  S13 is a fourth step of removing the cured resists 19a and 19b as the cured films of the connection land portions 7a and 7b. There are two methods for removal, namely, a chemical dissolution method and a mechanical scraping method. Any method that does not damage the IDT electrode 5 may be used.

FIG. 5 is a partial cross-sectional view of the SAW resonance piece 1 for explaining a state in which the liquid material 21 is discharged and formed as the first step.
As a first step, the liquid material 21 is discharged from an ink jet head (not shown) of a droplet discharge device (not shown), and a part of the connection land portions 7a and 7b and a part of the piezoelectric body 2 are separated. Resist 19a, 19b is formed in the including region. Here, when the liquid material 21 is discharged and formed only on the connection land portions 7a and 7b, the electrolytic solution and boiling water such as sulfuric acid, odorous acid, chromic acid, phosphoric acid and alkaline solution for anodizing treatment are: Since it is in direct contact with the aluminum around the connection land portions 7a and 7b, it is corroded and the quality of the connection land portions 7a and 7b is deteriorated.

  Therefore, in this embodiment, the liquid material 21 is discharged to a region including a part of the piezoelectric body 2 so that the peripheral portions of the connection land portions 7a and 7b are covered with the resists 19a and 19b. And no direct contact with boiling water. By this method, corrosion around the connection land portions 7a and 7b can be prevented.

  Further, it is desirable that the over amount 22 in which the resists 19a and 19b include a part of the piezoelectric body 2 from the peripheral portion 7c of the connection land portion is equal to or greater than the thickness of the connection land portions 7a and 7b. The thickness of the connection land portions 7a and 7b is 200 nm or more.

The effects of this example will be described below.
(1) Covering the region including the connection land portions 7a and 7b and a part of the piezoelectric body 2 with a liquid material prevents corrosion of the connection land portions 7a and 7b due to anodization, and is inexpensive and highly reliable. A surface acoustic wave device and a manufacturing method thereof can be provided.

Hereinafter, other embodiments embodying the method of manufacturing the surface acoustic wave device of the present invention will be described with reference to the drawings. This embodiment will describe matters different from the above embodiment.
FIG. 6 is a partial cross-sectional view of the SAW resonator element 1 for explaining a first step in which the conductive liquid material 111 as the liquid material is discharged to form the conductive layers 110a and 110b.
As a first step, a conductive liquid material 111 is discharged from an ink jet head (not shown) of a droplet discharge device (not shown), and a part of connection land portions 7a and 7b and a part of piezoelectric body 2 are discharged. Conductive layers 110a and 110b are formed in a region including

  Here, in this embodiment, the “conductive liquid material 111” refers to a material having a viscosity that can be discharged from a nozzle (not shown) of an inkjet head. In this case, it does not matter whether the material is aqueous or oily. It is sufficient if it has fluidity (viscosity) that can be discharged from the nozzle, and even if a solid substance is mixed, it may be a fluid as a whole.

  The viscosity of the conductive liquid material 111 is preferably 1 mPa · s or more and 50 mPa · s or less. When the viscosity is less than 1 mPa · s, the peripheral portion of the nozzle is easily contaminated by the outflow of the conductive liquid material 111 when droplets of the conductive liquid material 111 are ejected. On the other hand, when the viscosity is higher than 50 mPa · s, the clogging frequency in the nozzle is increased, and therefore, it is difficult to smoothly discharge droplets.

  Here, the material of the conductive liquid material 111 will be described. The conductive liquid material 111 to be the conductive layers 110a and 110b contains at least one of conductive fine particles and an organometallic compound, and is connected to a part of the connection land portions 7a and 7b by a droplet discharge device (not shown). The conductive layers 110a and 110b are formed in a predetermined shape and in a predetermined position in a region including a part of the piezoelectric body 2. Examples of the conductive liquid material 111 containing at least one of conductive fine particles and organometallic compounds include dispersions in which conductive fine particles are dispersed in a dispersion medium, liquid organometallic compounds, solutions of organometallic compounds, or the like. Is used.

  The conductive fine particles used here are, for example, metal fine particles containing at least one of gold, silver, copper, aluminum, palladium, manganese, indium, tin, antimony and nickel, and oxides thereof. In addition, fine particles of conductive polymer or superconductor are used.

  In order to improve the dispersibility, these conductive fine particles can be used by coating the surface with an organic solvent such as xylene or toluene, citric acid or the like. The particle diameter of the conductive fine particles is preferably 1 nm or more and 0.1 μm or less. If it is larger than 0.1 μm, there is a risk of clogging in the discharge nozzle of the droplet discharge head described later. On the other hand, if the thickness is smaller than 1 nm, the volume ratio of the coating material to the conductive fine particles becomes large, and the ratio of organic substances in the obtained film becomes excessive. In the case of using a coating material coated with conductive fine particles, an ink that does not exhibit conductivity in the form of a liquid but exhibits conductivity when dried or sintered can be used.

  As a coating agent for conductive fine particles, amine, alcohol, thiol and the like are known. More specifically, as a conductive fine particle coating agent, amine compounds such as 2-methylaminoethanol, diethanolamine, diethylmethylamine, 2-dimethylaminoethanol, methyldiethanolamine, alkylamines, ethylenediamine, alkylalcohols, ethylene Glycol, propylene glycol, alkylthiols, and ethanedithiol can be used.

  Examples of the organometallic compound include compounds and complexes containing, for example, gold, silver, copper, palladium, etc., which deposit metal by thermal decomposition. Specifically, chlorotriethylphosphine gold (I), chlorotrimethylphosphine gold (I), chlorotriphenylphosphine gold (I), silver (I) 2,4-pentanedionate complex, trimethylphosphine (hexafluoroacetylacetonate ) Silver (I) complex, copper (I) hexafluoropentanediotocyclooctadiene complex, and the like.

  As the liquid dispersion medium or solvent containing at least one of the conductive fine particles and the organometallic compound, those having a vapor pressure at room temperature of 0.001 mmHg or more and 200 mmHg or less (about 0.133 Pa or more and 26600 Pa or less) are preferable. . This is because if the vapor pressure is higher than 200 mmHg, the dispersion medium or solvent will be rapidly evaporated after ejection, making it difficult to form a good film.

  The vapor pressure of the dispersion medium or solvent is more preferably 0.001 mmHg to 50 mmHg (about 0.133 Pa to 6650 Pa). This is because if the vapor pressure is higher than 50 mmHg, nozzle clogging due to drying tends to occur when droplets are ejected by the droplet ejection method, and stable ejection becomes difficult. On the other hand, in the case of a dispersion medium or solvent whose vapor pressure at room temperature is lower than 0.001 mmHg, drying becomes slow and the dispersion medium or solvent tends to remain in the film, and after heat and / or light treatment in the post-process It becomes difficult to obtain a good conductive film.

  The dispersion medium is not particularly limited as long as it can disperse the conductive fine particles and does not cause aggregation. For example, in addition to water, alcohols such as methanol, ethanol, propanol, butanol, n-heptane, n-octane, decane, dodecane, tetradecane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydro Hydrocarbon compounds such as naphthalene and cyclohexylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane, bis (2- Methoxyethyl) ether, ether compounds such as p-dioxane, propylene carbonate, γ- Butyrolactone, N- methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, can be exemplified polar compounds such as cyclohexanone. Of these, water, alcohols, hydrocarbon compounds, and ether compounds are preferable and more preferable dispersion media in terms of fine particle dispersibility, dispersion stability, and ease of application to the droplet discharge method. Examples thereof include water and hydrocarbon compounds.

  The dispersoid concentration when the conductive fine particles are dispersed in a dispersion medium is preferably 1% by mass or more and 80% by mass or less, and can be adjusted according to the desired film thickness of the conductive film. If it exceeds 80% by mass, aggregation tends to occur and it becomes difficult to obtain a uniform film. For the same reason, the solute concentration in the organometallic compound solution is preferably in the same range as the dispersoid concentration.

  The surface tension of the dispersion of conductive fine particles is preferably in the range of 0.02 N / m to 0.07 N / m. When ink is ejected by the droplet ejection method, if the surface tension is less than 0.02 N / m, the wettability of the ink with respect to the nozzle surface increases, and thus flight bending tends to occur, and if the surface tension exceeds 0.07 N / m. Since the shape of the meniscus at the nozzle tip is not stable, it becomes difficult to control the discharge amount and the discharge timing. In order to adjust the surface tension, a small amount of a surface tension modifier such as a fluorine-based, silicone-based, or non-ionic-based material may be added to the dispersion within a range that does not significantly decrease the contact angle with the substrate. The nonionic surface tension modifier improves the wettability of the ink to the substrate, improves the leveling property of the film, and helps prevent the occurrence of fine irregularities on the film. The surface tension modifier may contain an organic compound such as alcohol, ether, ester, or ketone, if necessary.

  As such a conductive liquid material 111, specifically, a dispersion medium of silver fine particle dispersion (trade name “Perfect Silver”, manufactured by Vacuum Metallurgical Co., Ltd.) in which silver fine particles having a diameter of about 10 nm are dispersed in an organic solvent is tetradecane. This can be used as an example, and diluted to have a concentration of 60 wt%, a viscosity of 8 mPa · s, and a surface tension of 0.022 N / m.

  In addition, the discharged conductive liquid material 111 is subjected to a film formation process such as heat and / or light processing to obtain a desired conductive layer 110. The heat and / or light treatment is a treatment for activating and reacting a substance constituting the conductive layer 110 by heating, ultraviolet irradiation, infrared irradiation, or visible light irradiation to obtain the performance as the conductive layer 110. Say. Hereinafter, this process is referred to as a film forming process.

  The discharge range of the conductive liquid material 111 in this embodiment is between the vicinity of the comb-shaped electrode of the IDT electrode 5 that electrically drives or detects the surface acoustic wave and the connection land portions 7a and 7b. By forming in this way, it is possible to avoid an increase in the electrical resistance value between the IDT electrode 5 and the connection land portions 7a and 7b due to the anodizing treatment. Of course, the discharge range may be only in the vicinity of the connection land portions 7a and 7b.

  Further, in this embodiment, the conductive liquid material 111 is discharged to a region including a part of the surface of the piezoelectric body 2 between the vicinity of the comb electrode of the IDT electrode 5 and the connection land portions 7a and 7b. Thereby, the anodic oxidation process from the cross-sectional direction (thickness direction) of the electrode between the vicinity of the comb electrode of the IDT electrode 5 and the connection land portions 7a and 7b can be prevented.

FIG. 7 is a process flowchart of the SAW resonator element 1 of this embodiment.
About S101-S109, since it is the same as that of S1-S9 of the said Example 1, description is abbreviate | omitted. In S110, as a first step, the conductive liquid material 111 is transferred from the two connection land portions 7a and 7b to the IDT electrode 5 by an inkjet method from an inkjet head (not shown) of a droplet discharge device (not shown). It discharges to the area | region containing the part to the vicinity of the comb-shaped electrode and a part of piezoelectric body 2 (refer FIG. 6).

  In S111, film formation processing such as heat and / or light processing is performed to obtain desired conductive layers 110a and 110b (see FIG. 6). The heat and / or light treatment means that the materials constituting the conductive layers 110a and 110b are activated and reacted by heating, ultraviolet irradiation, infrared irradiation, or visible light irradiation, and the performance as the conductive layers 110a and 110b is improved. It is a process to obtain.

  S112 is a third step in which an anodizing process is performed on the IDT electrode excluding the region where the conductive liquid material 111 is discharged and formed in S111. This anodizing treatment, also called anodizing treatment, is a relatively thick oxide film that has a unique shape on the surface when aluminum is used as an anode in an electrolyte such as sulfuric acid, odorous acid, chromic acid, phosphoric acid, or alkaline solution. Is generated. The produced oxide film is a high-hardness film, and when it is further boiled in boiling water, the hole in the film is subjected to a sealing treatment to form a chemically inert film. Therefore, even if impurities or the like adhere to the film, it is less affected and the SAW resonator element is stable. Moreover, the oxide film produced | generated by the anodizing process becomes electrically insulating.

  Even if the anodic oxidation process in S112 is performed, the two conductive land portions 7a and 7b formed by discharging the conductive liquid material 111 and covered by the conductive layer 110 in S110 and S111 and the comb electrode of the IDT electrode 5 are formed. Aluminum in the vicinity does not form an oxide film because it does not come into contact with the aforementioned electrolyte. This is because the electrical connection between the SAW resonator element 1 (see FIG. 1) and an external electric circuit through the support is made by the two connection land portions 7a and 7b, and the IDT electrode 5 The electrical resistance value between the comb-shaped electrode and the external electric circuit can be reduced.

  In S113, the SAW resonator element 1 is cleaned and the surface is cleaned and dried. In this way, in S114, the SAW resonance piece 1 (see FIG. 6) is completed.

The effects of this example will be described below.
(2) In the above-described embodiment, the fourth step of removing the cured film of the connection land portions 7a and 7b is necessary. However, in this embodiment, the conductive layer 110 includes a part of the connection land portions 7a and 7b. Therefore, the fourth step is not necessary. For this reason, an inexpensive surface acoustic wave device can be provided.

  (3) By providing the conductive layers 110a and 110b between the connection land portions 7a and 7b and the IDT electrode 5, the electrical resistance value can be kept low, so that a highly reliable surface acoustic wave device is provided. be able to.

Hereinafter, other embodiments embodying the method of manufacturing the surface acoustic wave device of the present invention will be described with reference to the drawings. This embodiment will describe matters different from the above embodiment.
FIG. 8A is a plan view showing the piezoelectric wafer 120, and FIG. 8B is a perspective view showing the SAW resonance piece 1 completed by cutting from the piezoelectric wafer 120. FIG. 9 is a plan view of the piezoelectric wafer 120 showing details of FIG. FIG. 10 is a process flowchart of the piezoelectric wafer 120 and the SAW resonator element 1 of FIGS. 8 and 9.

  On the main surface 3 of the piezoelectric wafer 120 in FIG. 8A, a plurality of SAW resonance pieces 1 manufactured along S201 to S212 in the flowchart shown in FIG. In S201, the piezoelectric wafer 120 is cleaned and the surface is cleaned. In S <b> 202, aluminum or the like is vapor deposited substantially uniformly on the main surface 3 of the piezoelectric wafer 120. In S203, a photoresist is applied substantially uniformly on the aluminum deposited in S202 by spin coating or dipping coating.

  In S204, chromium or the like is vapor-deposited on a transparent mask substrate (not shown) such as glass, and patterned so that a desired IDT electrode 5 is obtained. The surface of the mask substrate on which chromium or the like is vapor-deposited and the surface on which aluminum or the like is vapor-deposited in S202 are brought into close contact with each other, irradiated with parallel rays from above the mask substrate, and the photoresist applied in S203 is exposed to mask. Exposure.

  In S205, the photoresist exposed in S204 is developed, and the photoresist is left so that aluminum or the like remains on the main surface 3 of the piezoelectric wafer 120 in a desired pattern.

  In step S206, the aluminum or the like where the photoresist does not remain is removed by etching. In S207, patterning of the plurality of IDT electrodes 5 as the SAW resonance piece 1 is completed on the main surface 3 of the piezoelectric wafer 120.

  In S208, the piezoelectric wafer is cleaned to ensure cleanliness, and in S209, the piezoelectric wafer is dried.

  This patterning method will be described in detail. In FIG. 8A, six IDT electrodes 5 as SAW resonator elements 1 are arranged at a constant pitch in the array L1. In array L2, ten IDT electrodes 5 as SAW resonator elements 1 are arranged at the same pitch as array L1. The array L1 and the array L2 are arranged so that the IDT electrodes 5 face each other.

  That is, a plurality of connection land portions 7a and 7b in the array L1 and a plurality of connection land portions 7a and 7b in the array L2 are arranged to face each other. By doing so, in S210 shown in FIG. 10, the region including the connection land portion 7a of the array L1 and the connection land portion 7b of the array L2, and the connection land portion 7b of the array L1 and the connection land portion 7a of the array L2 are arranged. And a region including at least one of the adjacent connection land portions 7a or 7b of the array L1 and the array land 2b, the conductive liquid material 111 is a nozzle of a droplet discharge device (not shown). The conductive liquid material 111 discharged from (not shown) and discharged in S211 is subjected to a film forming process to form the conductive layer 110.

  In S212, the anodizing process of the IDT electrode 5 is performed. In this case, since the lower electrode on which the conductive layer 110 is disposed does not come into contact with the anodizing electrolyte, the anodizing process is not performed, and the conductivity is ensured to be low.

  Further, each conductive layer 110 includes a cutting line 121 cut by a slicing machine or the like as the fifth step. For this reason, the conductive layer 110 of the adjacent SAW resonator element 1 is shared on the piezoelectric wafer 120, but the conductive layer 110a as each SAW resonator element 1 and the SAW resonator element 1 are cut by cutting the piezoelectric wafer 120 in S213. The conductive layer 110b (see FIG. 8B) is formed.

  In S214, the SAW resonance piece is cleaned and dried. In S215, the SAW resonance piece is completed.

  In this embodiment, the IDT electrodes 5 face each other between the arrays L1 to L7. However, when the number of arrays is an odd number as in this embodiment, the array L7 has a facing array. Therefore, the conductive layers 110 are shared between adjacent ones in the same arrangement.

  In this embodiment, as a first step, a part of the connection land portions 7a and 7b as a connection land portion of a pair of cross finger electrodes formed on the surface of the piezoelectric body and a main surface as a part of the piezoelectric body. 3 is covered by a conductive liquid material 111 as a liquid material.

The effects of this example will be described below.
(4) According to the present embodiment, the plurality of SAW resonance pieces 1 are not simply disposed on the main surface 3 of the piezoelectric wafer 120, but the connection land portions 7a and 7b are arranged to provide other connections. Since the conductive layer 110 can be formed into one large shape so as to face the arrangement of the land portions 7a and 7b, it is possible to increase the discharge amount of the conductive liquid material 111 discharged at a time and to manufacture in a short time. can do.

  (5) In addition, the conductive layer 110 of each SAW resonance piece 1 is disposed in a region including the cutting line 121. By cutting the piezoelectric wafer 120 along the cutting line 121, each SAW resonance piece 1. The conductive layers 110a and 110b can function.

Hereinafter, other embodiments embodying the method of manufacturing the surface acoustic wave device of the present invention will be described with reference to the drawings. This embodiment will describe matters different from the above embodiment.
FIG. 11 is a plan view showing the piezoelectric wafer 120. The difference between the present embodiment and the third embodiment is that the connection land portions 7a and 7b are arranged in the short direction. A plurality of IDT electrodes 5 are arranged on the piezoelectric wafer 120 as in arrays R1 to R8. For example, array R4 and array R5 will be described. The IDT electrode 5a in the array R4 is provided with a connection land portion 7a in the right direction with respect to the paper surface. On the other hand, the connection land portion 7a of the IDT electrode 5b in the array R5 is arranged in the left direction with respect to the paper surface. In other words, the IDT electrode 5 a and the IDT electrode 5 b are disposed at positions symmetrical with respect to the cutting line 121.

  As a result, the connection land portion 7b of the IDT electrode 5a in the array R4 and the connection land portion 7b of the IDT electrode 5b in the array R5 are in the same position, so that the conductive liquid material 111 is connected to the IDT electrode 5a in the array R4. The conductive layer 110 is formed by being discharged into one region including the portion 7b, the connection land portion 7b of the IDT electrode 5b in the array R5, and a part of the main surface 3 of the piezoelectric wafer 120 and being subjected to film formation. Thereafter, an anodic oxidation treatment is performed. The region of the conductive layer 110 includes a cutting line 121, and is cut on the cutting line 121 by a slicing machine or the like.

  The cut piezoelectric wafer 120 functions as the SAW resonance piece 1. The conductive layers 110 disposed on and cut off the connection land portions 7a and 7b of the respective SAW resonance pieces 1 function as the conductive layers 110 of the connection land portions 7a and 7b.

The effects of this example will be described below.
(6) Even when the connection land portions 7a and 7b are arranged in the short direction of the SAW resonator element 1, the conductive layer 110 can be formed into one large shape, so that the conductive liquid discharged at one time is used. The discharge amount of the material 111 can be increased and manufacturing can be performed in a short time.

  (7) In addition, the conductive layer 110 of each SAW resonance piece 1 is disposed in a region including the cutting line 121, and the piezoelectric wafer 120 is cut along the cutting line 121, whereby each SAW resonance piece 1. It can function as the conductive layer 110 of the connection land portions 7a and 7b.

Hereinafter, other embodiments embodying the present invention will be described with reference to the drawings. This embodiment will describe matters different from the above embodiment.
FIG. 12 is a process flowchart of the piezoelectric wafer 120 and the SAW resonance piece 1. In this embodiment, a resist as a liquid material is ejected and formed on the connection land portions 7a and 7b of each SAW resonance piece 1 of the piezoelectric wafer 120 by an ink jet method, and the connection land portions 7a and 7b and the connection land portions 7a, The electrode between 7b and the IDT electrode 5 is not anodized.

  S301 to S309 in the figure are the same as S201 to S209 in FIG. In S310, the resist 19 (see FIG. 9) is formed on the connection land portions 7a and 7b and the electrodes between the connection land portions 7a and 7b and the IDT electrode 5 by the ink jet method as the first step. (Not shown).

  In S <b> 311, as a second step of curing the liquid material to form a cured film, the discharged resist 19 as the liquid material is heated and cured to form a cured film of the resist 19.

  In S312, anodization treatment as a third step is performed in the same manner as in the above embodiment. In S313, as a fourth step of removing the cured film of the connection land portion, the resist 19 formed by being cured on the connection land portions 7a and 7b and the electrode between the connection land portions 7a and 7b and the IDT electrode 5 is formed. The resist 19 is removed by chemical dissolution.

  In S314, as a fifth step of cutting the piezoelectric wafer 120 for each piezoelectric body 2, the piezoelectric wafer 120 is cut along the cutting line 121, and the plurality of SAW resonance pieces 1 are taken out. In S315, the plurality of SAW resonance pieces 1 taken out are cleaned and dried to clean the surface. In this way, the SAW resonator element 1 is completed in S316.

The effects of this example will be described below.
(8) According to the present embodiment, the plurality of SAW resonance pieces 1 are not simply disposed on the main surface 3 of the piezoelectric wafer 120, but the connection land portions 7a and 7b are arranged to provide other connections. Since the resist 19 can be formed into one large shape so as to face the arrangement of the land portions 7a and 7b, the discharge amount of the resist 19 as a liquid material discharged at a time can be increased, and the manufacturing can be performed in a short time. can do.

1 is a perspective view of a SAW resonator element 1 in Embodiment 1. FIG. 5 is a process flowchart of the SAW resonator element 1 in the first embodiment. (A) is a top view of the surface acoustic wave device 20 which mounted | wore the support body 10 with the SAW resonance piece 1 in Example 1, (b) is sectional drawing of the surface acoustic wave device 20 in Example 1. FIG. The perspective view of the SAW resonance piece 1 explaining S10-S13 of the process flowchart of the SAW resonance piece 1 in FIG. FIG. 3 is a partial cross-sectional view of the SAW resonance piece 1 for explaining a state in which the liquid material 21 is discharged and formed as the first step in the first embodiment. FIG. 6 is a partial cross-sectional view of the SAW resonator element 1 illustrating a first step in which a conductive liquid material 111 as a liquid material is discharged to form conductive layers 110a and 110b in the second embodiment. 9 is a process flowchart of the SAW resonator element 1 of the present embodiment in the second embodiment. In Example 3, (a) is a top view which shows the piezoelectric wafer 120, (b) is a perspective view which shows the SAW resonance piece 1 cut and completed from the piezoelectric wafer 120. FIG. FIG. 9 is a plan view of a piezoelectric wafer 120 showing details of FIG. 8 in Example 3. FIG. 10 is a process flowchart of the piezoelectric wafer 120 and the SAW resonance piece 1 of FIGS. 8 and 9 in Embodiment 3. FIG. FIG. 6 is a plan view showing a piezoelectric wafer 120 in Example 4. 10 is a process flowchart of the piezoelectric wafer 120 and the SAW resonator element 1 in the fifth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... SAW resonance piece, 2 ... Piezoelectric body, 2a ... End part, 3 ... Main surface, 4a, 4b ... Electrode, 5, 5a, 5b ... IDT electrode, 6a, 6b ... Reflector, 7a, 7b ... Connection land part , 7c ... peripheral part of connection land part, 10 ... support, 11 ... lower support, 12 ... groove, 13a, 13b ... output terminal, 14 ... upper support, 15a, 15b ... connection line, 16 ... circuit board, 17 ... Conductive pattern, 18 ... Solder, 19, 19a, 19b ... Resist, 20 ... Surface acoustic wave device, 21 ... Liquid material, 22 ... Over amount, 110, 110a, 110b ... Conductive layer, 111 ... Conductive liquid material, 120 ... piezoelectric wafer, 121 ... cutting line, L1-L7, R1-R8 ... array.

Claims (9)

A first step of covering, with a liquid material, a region including a part of a connection land portion of a pair of cross-finger electrodes formed on the surface of the piezoelectric body and a part of the piezoelectric body;
A second step of curing the liquid material to form a cured film;
A method of manufacturing a surface acoustic wave device, comprising at least a third step of performing anodization by electrolysis in an electrolytic solution using the crossed finger electrode as an anode.   In addition to said 1st process thru | or said 3rd process of Claim 1, It provided with the 4th process of removing the said cured film of the said connection land part, The manufacture of the surface acoustic wave device characterized by the above-mentioned Method.   The method for manufacturing a surface acoustic wave device, wherein the connection land portion from which the cured film has been removed by the fourth step according to claim 2 and the support are electrically connected.   The method for manufacturing a surface acoustic wave device, wherein the cured film according to claim 1 has conductivity.   The method for producing a surface acoustic wave device, wherein the cured film according to claim 4 and the support are electrically connected.   A plurality of the piezoelectric bodies according to any one of claims 1 to 5 are provided on a piezoelectric wafer, and a fifth step of cutting the piezoelectric wafer into the respective piezoelectric bodies is provided. A method for manufacturing a surface acoustic wave device.   An area including each of the connection land portions and a part of the piezoelectric bodies of the plurality of piezoelectric bodies arranged on the piezoelectric wafer according to claim 6 is covered with the liquid material. A method of manufacturing a surface acoustic wave device.   The method for manufacturing a surface acoustic wave device according to claim 1, wherein the liquid material according to claim 1 is formed by ejection by an ink jet method. A surface acoustic wave device manufactured by the method for manufacturing the surface acoustic wave device according to claim 1.

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