Acoustic wave device and manufacturing method of the acoustic wave device

Abstract

To provide an acoustic wave device in which a short circuit failure is suppressed.SOLUTION: An acoustic wave device 1 comprises: a piezoelectric substrate 10 which includes main surfaces 10a and 10b; a mounting substrate 20 which includes main surfaces 20a and 20b and in which the main surface 20a is arranged so as to be faced to the main surface 10a; a function electrode 11 which is arranged on the main surface 10a, and performs electromechanical conversion with the piezoelectric substrate 10; a plurality of flat electrodes 12 which are arranged on the main surface 10a, and are connected to the function electrode 11; a plurality of flat electrodes 21 which are arranged on the main surface 20a; a flat electrode 13 which is arranged on the main surface 10a so as to be contacted to an end side of the piezoelectric substrate 10, and is not contacted to the function electrode 11 and each flat electrode 12; and a plurality of bump electrodes 14 which are bonded to the main surfaces 10a and 20a. A maximum distance D13max of two end parts of the flat electrode 13 is smaller than a minimum distance D1min of a distance of one of the plurality of flat electrodes 12 and one of the plurality of flat electrodes 21 that become a different potential each other.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to an acoustic wave device and a method for manufacturing an acoustic wave device. [Background technology]

[0002] Patent Document 1 discloses the structure of an acoustic wave device having a WLP (Wafer Level Package) structure. The acoustic wave device is fabricated by dicing an aggregate substrate on which functional electrodes and wiring electrodes are formed into a plurality of chips, and bonding the chips face-down to a mounting substrate. Measurement electrodes for inspecting characteristics of the aggregate substrate are formed on the dicing lines, and the measurement electrodes are separated from the functional electrodes and wiring electrodes by dicing and are made non-potential. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 100505 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the acoustic wave device described in Patent Document 1, the measurement electrodes are rendered potentialless after dicing. However, if the measurement electrodes peel off or become separated due to the dicing process, they may come into contact across multiple electrodes that are at different potentials, potentially causing a short circuit.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide an acoustic wave device in which short-circuit defects are suppressed, and a method for manufacturing such an acoustic wave device. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, an elastic wave device according to one embodiment of the present invention comprises a first substrate having piezoelectricity and including a first main surface and a second main surface, a second substrate including a third main surface and a fourth main surface and arranged so that the third main surface faces the first main surface, a functional electrode arranged on the first main surface and performing electromechanical conversion with the first substrate, a plurality of first planar electrodes arranged on the first main surface and connected to the functional electrode, a plurality of second planar electrodes arranged on the third main surface, a third planar electrode arranged on the first main surface in contact with an edge of the first substrate and not connected to the functional electrode and the first planar electrode, and a plurality of bump electrodes joined to the first and third main surfaces, wherein the maximum distance between two ends of the third planar electrode is smaller than the smallest distance between one of the plurality of first planar electrodes and one of the plurality of second planar electrodes which are at different potentials from each other.

[0007] Furthermore, an elastic wave device according to one embodiment of the present invention comprises a first substrate having piezoelectricity and including a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface and arranged so that the third main surface faces the first main surface; a functional electrode arranged on the first main surface and performing electromechanical transduction with the first substrate; a plurality of first planar electrodes arranged on the first main surface and connected to the functional electrode; a plurality of second planar electrodes arranged on the third main surface; a third planar electrode arranged on the first main surface in contact with an edge of the first substrate and not connected to the functional electrode and the first planar electrode; and a plurality of bump electrodes joined to the first and third main surfaces, wherein the maximum distance between two ends of the third planar electrode is smaller than the minimum distance between two bump electrodes of the plurality of bump electrodes that have different potentials.

[0008] Furthermore, a method for manufacturing an acoustic wave device according to one aspect of the present invention includes the steps of: forming, on a first main surface of a piezoelectric wafer having piezoelectricity and including a first main surface and a second main surface, a functional electrode that performs electromechanical conversion with the piezoelectric wafer, a plurality of first planar electrodes connected to the functional electrode, a stylus electrode disposed on a dicing line having a predetermined cutting width, and a plurality of bump electrodes to fabricate an aggregate substrate; bringing a measurement stylus into contact with the stylus electrode to inspect the transmission characteristics of an IDT electrode composed of the functional electrode and the plurality of first planar electrodes; and measuring the transmission characteristics of the IDT electrode. and after inspecting the acoustic wave chips, dicing the collective substrate along a dicing line to separate the collective substrate into a plurality of acoustic wave chips. In the process of producing the collective substrate, the stylus electrode is connected to the functional electrode and has a slit portion where no conductive material is formed at both ends perpendicular to the dicing line, and when the collective substrate is viewed in a planar view, a portion of the slit portion overlaps the dicing line. Effect of the Invention

[0009] According to the present invention, it is possible to suppress short-circuit defects in an elastic wave device. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 2 is a plan view of an acoustic wave chip according to an embodiment. [Figure 1B] FIG. 2 is a plan view of a mounting board according to the embodiment. [Figure 1C] 1 is a cross-sectional view of an elastic wave device according to an embodiment. [Figure 2A] 1A and 1B are a plan view and a cross-sectional view illustrating a first example of an elastic wave resonator included in an elastic wave device according to an embodiment of the present invention. [Figure 2B] 10 is a cross-sectional view illustrating a schematic diagram of a second example of an elastic wave resonator included in an elastic wave device according to an embodiment. FIG. [Figure 2C] 11 is a cross-sectional view illustrating a schematic diagram of a third example of an elastic wave resonator included in an elastic wave device according to an embodiment. FIG. [Diagram 3] 5 is a flowchart showing a method for manufacturing an elastic wave device according to an embodiment. [Figure 4] FIG. 2 is a plan view of the aggregate substrate according to the embodiment. [Diagram 5] 1A to 1C are diagrams illustrating configurations of planar electrodes near a dicing line of an aggregate substrate and planar electrodes near an edge of an acoustic wave chip according to an embodiment. [Figure 6] FIG. 11 is a plan view of an aggregate substrate according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangements and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. Among the components in the following embodiments, components that are not described in the independent claims are described as optional components. Also, the size or size ratio of the components shown in the drawings is not necessarily strict.

[0012] In addition, each figure is a schematic diagram in which emphasis, omission, or adjustment of the ratio is appropriately performed in order to illustrate the present invention, and is not necessarily a strict illustration, and may differ from the actual shape, positional relationship, and ratio. In each figure, the same reference numerals are given to substantially the same configurations, and duplicated explanations may be omitted or simplified.

[0013] In the circuit configuration of the present disclosure, "connected" includes not only direct connection by electrodes and / or wiring conductors, but also electrical connection via matching elements such as inductors and capacitors, and switch circuits. "Connected between A and B" means connected to both A and B between A and B.

[0014] In addition, terms indicating the relationship between elements, such as "parallel" and "perpendicular," terms indicating the shape of an element, such as "rectangle," and numerical ranges do not only indicate the strict meaning, but also include a substantially equivalent range, for example, an error of about a few percent.

[0015] (Embodiment) [1 Structure of Elastic Wave Device 1] Fig. 1A is a plan view of an acoustic wave chip 3 according to an embodiment. Fig. 1B is a plan view of a mounting substrate 20 according to an embodiment. Fig. 1C is a cross-sectional view of an acoustic wave device 1 according to an embodiment. Fig. 1A is a see-through view of a main surface 10a of a piezoelectric substrate 10 from the positive side of the z axis, Fig. 1B is a see-through view of a main surface 20a of a mounting substrate 20 from the positive side of the z axis, and Fig. 1C is a cross-sectional view taken along line IC-IC in Figs. 1A and 1B.

[0016] As shown in FIG. 1C, the acoustic wave device 1 includes an acoustic wave chip 3, a mounting substrate 20, and a resin member 30.

[0017] As shown in FIG. 1A, the acoustic wave chip 3 includes a piezoelectric substrate 10, a functional electrode 11, a plurality of planar electrodes 12, a plurality of planar electrodes 13, and a plurality of bump electrodes 14.

[0018] The piezoelectric substrate 10 is an example of a first substrate, has piezoelectricity, and includes a main surface 10a (first main surface) and a main surface 10b (second main surface).

[0019] The functional electrode 11 is disposed on the main surface 10a, and performs electromechanical transduction with the piezoelectric substrate 10.

[0020] Each of the plurality of planar electrodes 12 is an example of a first planar electrode, and is disposed on the main surface 10 a and connected to the functional electrode 11 .

[0021] 1A, each of the multiple planar electrodes 13 is an example of a third planar electrode, and is disposed on the main surface 10a in contact with an edge 101, 102, 103 or 104 of the main surface 10a, and is not connected to the functional electrode 11 and the planar electrode 12. The planar electrodes 13 are part of a stylus electrode for measuring the transmission characteristics of the acoustic wave chip 3 in the state of the collective substrate 2 before the acoustic wave chip 3 is divided into individual pieces.

[0022] The detailed structures of the piezoelectric substrate 10, the functional electrode 11, and the planar electrode 12 will be described later with reference to Figures 2A and 2B. The detailed structure of the planar electrode 13 will be described later with reference to Figure 5.

[0023] Each of the plurality of bump electrodes 14 is connected to the principal surface 10a and the principal surface 20a, as shown in Fig. 1C. Each of the plurality of bump electrodes 14 may be directly bonded to the principal surface 10a and the principal surface 20a, or may be bonded to the principal surface 10a via a planar electrode 12 and connected to the principal surface 20a via a planar electrode 21. The bump electrodes 14 are ball-shaped electrodes made of a highly conductive metal, and examples of such electrodes include solder bumps made of Sn / Ag / Cu and bumps mainly composed of Au.

[0024] The mounting substrate 20 is an example of the second substrate, and includes a main surface 20a (third main surface) and a main surface 20b (fourth main surface) as shown in FIG. 1C, and is disposed so that the main surface 20a faces the main surface 10a. The mounting substrate 20 and the acoustic wave chip 3 are face-down bonded via a plurality of bump electrodes 14 so that the main surface 20a of the mounting substrate 20 faces the main surface 10a of the piezoelectric substrate 10. As the mounting substrate 20, for example, a low temperature co-fired ceramics (LTCC) substrate having a laminated structure of a plurality of dielectric layers, a high temperature co-fired ceramics (HTCC) substrate, a component-embedded substrate, a substrate having a redistribution layer (RDL), a printed circuit board, or the like is used.

[0025] The mounting substrate 20 has a plurality of planar electrodes 21 and a plurality of planar electrodes 22, as shown in FIGS. 1B and 1C.

[0026] Each of the multiple planar electrodes 21 is an example of a second planar electrode, and is disposed on the main surface 20a. Each of the multiple planar electrodes 22 is disposed on the main surface 20b. The planar electrodes 21 and 22 are connected to each other by via conductors formed inside the mounting substrate 20.

[0027] 1C, the resin member 30 is disposed in contact with the main surface 20a so as to cover the acoustic wave chip 3, and has a function of ensuring reliability such as mechanical strength and moisture resistance of the acoustic wave chip 3. Note that the resin member 30 is not disposed in an area where the functional electrodes 11 are formed.

[0028] Here, the maximum distance D13 between the two ends of the planar electrode 13 max (See FIG. 5B) is the minimum distance D1 between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 that are at different potentials. min (See Figure 1C).

[0029] The maximum distance D13 between the two ends of the flat electrode 13 max is defined as the maximum distance between any two ends of one planar electrode 13 when the planar electrode 13 is viewed from above.

[0030] According to the above-mentioned configuration, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D1 min , it is possible to prevent the peeled or freed planar electrode 13 from coming into contact with the planar electrodes 12 and 21 across each other and shorting out the functional electrode 11. As a result, it is possible to provide an elastic wave device 1 in which short-circuit defects are suppressed.

[0031] Also, the maximum distance D13 between the two ends of the planar electrode 13 max(see FIG. 5B) is the minimum distance Db min (See FIG. 1C).

[0032] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance Db min Since the distance between the bump electrodes 14 is smaller than the distance between the bump electrodes 14, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two bump electrodes 14 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short circuit defects are suppressed.

[0033] Also, the maximum distance D13 between the two ends of the planar electrode 13 max (See FIG. 5B) is the minimum distance D3 between two planar electrodes 21 that are at different potentials among the multiple planar electrodes 21. min It is desirable that the thickness of the casing be smaller than that shown in FIG. 1C.

[0034] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D3 min , it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 21 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0035] Also, the maximum distance D13 between the two ends of the planar electrode 13 max (See FIG. 5B) is the minimum distance D2 between two planar electrodes 12 that are at different potentials among the multiple planar electrodes 12. min It is desirable that the thickness of the casing be smaller than that shown in FIG. 1C.

[0036] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D2 min, it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 12 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0037] [2. Configuration of the piezoelectric substrate 10, the functional electrode 11 and the planar electrode 12] 2A is a plan view and a cross-sectional view that typically show a first example of an acoustic wave resonator that constitutes the acoustic wave device 1 according to an embodiment. The figure illustrates a basic structure of an acoustic wave resonator 60 that constitutes the acoustic wave chip 3. Note that the acoustic wave resonator 60 shown in FIG. 2A is intended to illustrate a typical structure of an acoustic wave resonator that constitutes the acoustic wave chip 3, and the number and length of electrode fingers that constitute the electrodes are not limited thereto.

[0038] The acoustic wave resonator 60 is composed of a piezoelectric substrate 10 and comb-shaped electrodes 60a and 60b.

[0039] As shown in FIG. 2A(a), a pair of comb electrodes 60a and 60b facing each other are formed on the piezoelectric substrate 10. The comb electrode 60a is composed of a plurality of electrode fingers 61a (first electrode fingers) parallel to each other and a busbar electrode 62a (first busbar electrode) connecting one ends of the plurality of electrode fingers 61a. The comb electrode 60b is composed of a plurality of electrode fingers 61b (second electrode fingers) parallel to each other and a busbar electrode 62b (second busbar electrode) connecting one ends of the plurality of electrode fingers 61b. The plurality of electrode fingers 61a and 61b are formed along a direction perpendicular to the elastic wave propagation direction (X-axis direction). The busbar electrode 62a and the busbar electrode 62b are arranged facing each other with the electrode fingers 61a and 61b in between. The comb electrodes 60a and 60b form an IDT (InterDigital Transducer) electrode 54.

[0040] Here, the functional electrode 11 shown in Figures 1A and 1C includes a plurality of electrode fingers 61a and a plurality of electrode fingers 61b, and the planar electrode 12 shown in Figures 1A and 1C includes busbar electrodes 62a and 62b.

[0041] The acoustic wave resonator 60 constituting the acoustic wave chip 3 may have reflectors on both ends of the IDT electrode 54 in the acoustic wave propagation direction (X-axis direction).

[0042] As shown in FIG. 2B, the IDT electrode 54 has a laminated structure of an adhesive layer 540 and a main electrode layer 542, for example.

[0043] The adhesion layer 540 is a layer for improving adhesion between the piezoelectric substrate 10 and the main electrode layer 542, and is made of, for example, Ti. The main electrode layer 542 is made of, for example, Al containing 1% Cu. The protective layer 55 is formed so as to cover the comb-shaped electrodes 60a and 60b. The protective layer 55 is a layer intended to protect the main electrode layer 542 from the external environment, adjust the frequency-temperature characteristics, and increase moisture resistance, and is, for example, a dielectric film whose main component is silicon dioxide.

[0044] The materials constituting the adhesion layer 540, the main electrode layer 542, and the protective layer 55 are not limited to the above-mentioned materials. Furthermore, the IDT electrode 54 does not have to have the above-mentioned laminated structure. The IDT electrode 54 may be made of a metal or alloy such as Ti, Al, Cu, Pt, Au, Ag, or Pd, or may be made of a laminate of multiple layers made of the above-mentioned metals or alloys. Furthermore, the protective layer 55 does not have to be formed.

[0045] Next, the layered structure of the piezoelectric substrate 10 will be described.

[0046] As shown in (c) of Figure 2A, the piezoelectric substrate 10 includes a high acoustic speed support substrate 51, a low acoustic speed film 52, and a piezoelectric film 53, and has a structure in which the high acoustic speed support substrate 51, the low acoustic speed film 52, and the piezoelectric film 53 are laminated in this order.

[0047] The piezoelectric film 53 is made of, for example, θ°Y-cut X-propagation LiTaO3 piezoelectric single crystal or piezoelectric ceramics (lithium tantalate single crystal or ceramics cut on a plane whose normal is an axis rotated θ° from the Y axis around the X axis, and whose surface acoustic wave propagates in the X axis direction). Note that the material and cut angle θ of the piezoelectric single crystal used as the piezoelectric film 53 are appropriately selected depending on the required specifications of each filter.

[0048] The high acoustic velocity support substrate 51 is a substrate that supports the low acoustic velocity film 52, the piezoelectric film 53, and the IDT electrode 54. The high acoustic velocity support substrate 51 is a substrate in which the acoustic velocity of the bulk waves in the high acoustic velocity support substrate 51 is faster than that of the surface waves and boundary waves propagating through the piezoelectric film 53, and functions to confine the surface acoustic waves to the portion where the piezoelectric film 53 and the low acoustic velocity film 52 are laminated, and to prevent the surface acoustic waves from leaking below the high acoustic velocity support substrate 51. Examples of materials that can be used for the high acoustic velocity support substrate 51 include piezoelectric materials such as aluminum nitride, lithium tantalate, lithium niobate, and quartz, ceramics such as alumina, sapphire, magnesia, silicon nitride, silicon carbide, zirconia, cordierite, mullite, steatite, forsterite, spinel, and sialon, dielectric materials such as aluminum oxide, silicon oxynitride, DLC (diamond-like carbon), and diamond, semiconductors such as silicon, and materials mainly composed of the above materials. The spinel includes an aluminum compound containing oxygen and one or more elements selected from Mg, Fe, Zn, Mn, etc. Examples of the spinel include MgAl2O4, FeAl2O4, ZnAl2O4, and MnAl2O4.

[0049] The low acoustic velocity film 52 is a film in which the acoustic velocity of the bulk waves in the low acoustic velocity film 52 is slower than that of the bulk waves propagating through the piezoelectric film 53, and is disposed between the piezoelectric film 53 and the high acoustic velocity support substrate 51. This structure and the property of the acoustic wave concentrating energy in a medium with an essentially low acoustic velocity suppress leakage of the surface acoustic wave energy outside the IDT electrode. The low acoustic velocity film 52 can be made of a dielectric material such as glass, silicon oxide, silicon oxynitride, lithium oxide, tantalum oxide, or a compound in which fluorine, carbon, or boron is added to silicon oxide, or a material mainly composed of the above materials.

[0050] The above-described laminated structure of piezoelectric substrate 10 makes it possible to significantly increase the Q value at the resonant frequency and anti-resonant frequency, compared to a conventional structure using a single-layer piezoelectric substrate. In other words, an elastic wave resonator with a high Q value can be configured, and therefore a filter with low insertion loss can be configured using the elastic wave resonator.

[0051] The high acoustic velocity support substrate 51 may have a structure in which a support substrate and a high acoustic velocity film in which the acoustic velocity of the propagating bulk wave is faster than that of the elastic wave such as the surface wave and boundary wave propagating through the piezoelectric film 53 are laminated. In this case, the material of the high acoustic velocity film can be the same as the material of the high acoustic velocity support substrate 51. The material of the support substrate can be, for example, a piezoelectric material such as aluminum nitride, lithium tantalate, lithium niobate, or quartz; a ceramic material such as alumina, sapphire, magnesia, silicon nitride, silicon carbide, zirconia, cordierite, mullite, steatite, or forsterite; a dielectric material such as diamond or glass; a semiconductor material such as silicon or gallium nitride; or a resin; or a material mainly composed of the above-mentioned material.

[0052] In this specification, the term "major component of a material" refers to a component that accounts for more than 50% by weight of the material. The major component may be in any of the following states: single crystal, polycrystalline, or amorphous, or a mixture of these.

[0053] Fig. 2B is a cross-sectional view illustrating a schematic diagram of a second example of an elastic wave resonator constituting elastic wave device 1 according to an embodiment. In elastic wave resonator 60 illustrated in Fig. 2A, IDT electrode 54 is formed on piezoelectric substrate 10 having piezoelectric film 53. However, the substrate on which IDT electrode 54 is formed may be piezoelectric single crystal substrate 57 consisting of a single piezoelectric layer, as illustrated in Fig. 2B.

[0054] The piezoelectric single crystal substrate 57 is made of, for example, a piezoelectric single crystal of LiNbO3. The elastic wave resonator according to this example is made of the piezoelectric single crystal substrate 57 made of LiNbO3, an IDT electrode 54, and a protective layer 58 formed on the piezoelectric single crystal substrate 57 and the IDT electrode 54.

[0055] The laminated structure, material, cut angle, and thickness of the piezoelectric film 53 and the piezoelectric single crystal substrate 57 may be changed as appropriate depending on the required pass characteristics of the acoustic wave filter device, etc. An acoustic wave resonator using a LiTaO3 piezoelectric substrate having a cut angle other than the above-mentioned cut angle can also achieve the same effect as the acoustic wave resonator 60 using the piezoelectric film 53 described above.

[0056] The piezoelectric substrate on which the IDT electrode 54 is formed may have a structure in which a support substrate, an energy trapping layer, and a piezoelectric film are laminated in this order. The IDT electrode 54 is formed on the piezoelectric film. For example, a LiTaO3 piezoelectric single crystal or a piezoelectric ceramic is used for the piezoelectric film. The support substrate is a substrate that supports the piezoelectric film, the energy trapping layer, and the IDT electrode 54.

[0057] The energy trapping layer is composed of one or more layers, and the speed of the bulk acoustic wave propagating through at least one of the layers is greater than the speed of the acoustic wave propagating near the piezoelectric film. For example, the energy trapping layer may have a laminated structure of a low acoustic velocity layer and a high acoustic velocity layer. The low acoustic velocity layer is a film in which the acoustic velocity of the bulk wave in the low acoustic velocity layer is slower than the acoustic velocity of the acoustic wave propagating through the piezoelectric film. The high acoustic velocity layer is a film in which the acoustic velocity of the bulk wave in the high acoustic velocity layer is faster than the acoustic velocity of the acoustic wave propagating through the piezoelectric film. The support substrate may be the high acoustic velocity layer.

[0058] The energy trapping layer may be an acoustic impedance layer having a configuration in which low acoustic impedance layers having a relatively low acoustic impedance and high acoustic impedance layers having a relatively high acoustic impedance are alternately laminated.

[0059] The maximum distance D13 between the two ends of the flat electrode 13 max (see FIG. 5B) is the minimum distance D4 between adjacent electrode fingers 61a and 61b. min It is preferable that the thickness is smaller than (see FIG. 2A (b)).

[0060] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D4 min Since the distance between the electrode fingers is smaller than the distance between the electrode fingers, peeled or separated planar electrode 13 can be prevented from coming into contact with two adjacent electrode fingers. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0061] 2C is a cross-sectional view that typically illustrates a third example of an elastic wave resonator that constitutes elastic wave device 1 according to an embodiment. In FIG. 2C, a bulk elastic wave resonator is illustrated as the elastic wave resonator of elastic wave device 1. As illustrated in the figure, the bulk elastic wave resonator has, for example, a support substrate 65, a lower electrode 66, a piezoelectric layer 67, and an upper electrode 68, in which support substrate 65, lower electrode 66, piezoelectric layer 67, and upper electrode 68 are laminated in this order.

[0062] The support substrate 65 is a substrate for supporting the lower electrode 66, the piezoelectric layer 67, and the upper electrode 68, and is, for example, a silicon substrate. The support substrate 65 has a cavity in an area in contact with the lower electrode 66. This allows the piezoelectric layer 67 to vibrate freely.

[0063] The lower electrode 66 is formed on one surface of the support substrate 65. The upper electrode 68 is formed on one surface of the support substrate 65. The lower electrode 66 and the upper electrode 68 are made of a material such as Al containing 1% Cu.

[0064] The piezoelectric layer 67 is formed between the lower electrode 66 and the upper electrode 68. The piezoelectric layer 67 is mainly composed of at least one of ZnO (zinc oxide), AlN (aluminum nitride), PZT (lead zirconate titanate), KN (potassium niobate), LN (lithium niobate), LT (lithium tantalate), quartz crystal, and LiBO (lithium borate).

[0065] A bulk acoustic wave resonator having the above-described laminated structure generates resonance by inducing bulk acoustic waves in the piezoelectric layer 67 by applying electrical energy between the lower electrode 66 and the upper electrode 68. The bulk acoustic waves generated by this bulk acoustic wave resonator propagate between the lower electrode 66 and the upper electrode 68 in a direction perpendicular to the film surface of the piezoelectric layer 67. In other words, the bulk acoustic wave resonator is a resonator that utilizes bulk acoustic waves.

[0066] Here, the functional electrode 11 shown in Figures 1A and 1C includes a lower electrode 66 and an upper electrode 68. Also, the planar electrode 12 shown in Figures 1A and 1C includes a wiring electrode connected to the lower electrode 66 and a wiring electrode connected to the upper electrode 68. Also, the piezoelectric substrate 10 shown in Figures 1A and 1C includes a support substrate 65. Also, the piezoelectric substrate 10 does not have to have piezoelectricity.

[0067] [3. Manufacturing method of acoustic wave device 1] Next, a method for manufacturing elastic wave device 1 according to a preferred embodiment of the present invention will be described below. Fig. 3 is a flowchart showing a method for manufacturing elastic wave device 1 according to a preferred embodiment of the present invention.

[0068] First, a functional electrode 11, a plurality of planar electrodes 12 (first planar electrodes) connected to the functional electrode 11, a planar electrode 43, and a plurality of bump electrodes 14 are formed on a first main surface of a piezoelectric wafer 40, which includes a first main surface and a second main surface, to prepare an aggregate substrate 2 (S10).

[0069] 4 is a plan view of the aggregate substrate 2 according to the embodiment. The figure shows a partial electrode layout of the aggregate substrate 2 produced in the electrode formation process. The aggregate substrate 2 has a piezoelectric wafer 40, a plurality of functional electrodes 11, a plurality of planar electrodes 12, a plurality of planar electrodes 43, and a plurality of bump electrodes 14.

[0070] The piezoelectric wafer 40 is a wafer having piezoelectricity, and is an assembly of piezoelectric substrates 10 before the piezoelectric substrates 10 are singulated. On a first main surface of the piezoelectric wafer 40, the functional electrodes 11, the planar electrodes 12, and the bump electrodes 14 constituting the acoustic wave chip 3 are arranged in a matrix. In addition, the planar electrodes 13 of the acoustic wave chips 3 after singulation correspond to the planar electrodes 43 in the assembly substrate 2.

[0071] As shown in (c) of Fig. 2A, the piezoelectric wafer 40 has a structure in which, for example, a high acoustic velocity support substrate, a low acoustic velocity film, and a piezoelectric film are laminated in this order. Alternatively, the piezoelectric wafer 40 may be composed of a piezoelectric single crystal substrate as shown in Fig. 2B. Alternatively, the piezoelectric wafer 40 may have a structure in which a support substrate, an energy trapping layer, and a piezoelectric film are laminated in this order.

[0072] The flat electrode 43 is an example of a stylus electrode, and is used for the cutting W of dicing. D The electrodes are arranged on a dicing line having a groove.

[0073] 5 is a diagram showing the configuration of a planar electrode 43 near a dicing line of an aggregate substrate 2 and a planar electrode 13 near an edge of an acoustic wave chip 3 according to an embodiment. Specifically, FIG. 5(a) shows a layout of the planar electrodes 43 before dicing (in step S10). FIG. 5(b) shows a layout of the planar electrodes 13 after dicing (included in the acoustic wave chip 3 after being singulated). FIG. 5(a) is an enlarged view of region IV in FIG. 4.

[0074] 5(a), in the collective substrate 2, the planar electrode 43 has an electrode main body portion 71 and a slit portion 70. The slit portion 70 is formed between two electrode main bodies 71 adjacent to each other in the x-axis direction. The slit portion 70 is a region where no conductive material is formed, and is formed between the electrode main bodies 71 along the direction perpendicular to the dicing line (the y-axis direction), and is formed at both ends of the planar electrode 43 in the direction perpendicular to the dicing line (the y-axis direction).

[0075] In the process of producing collective substrate 2, flat electrode 43 is formed so that the width of slit portion 70 in the direction along the dicing line (x-axis direction) is smaller than the contact diameter of the tip of a measurement stylus (prober).

[0076] This allows the tip of the measurement stylus (prober) to make contact across multiple electrode main body portions 71 of the planar electrode 43, making it possible to reliably electrically connect the tip of the measurement stylus (prober) to the planar electrode 43 in the process of inspecting the transmission characteristics of the IDT electrodes of the aggregate substrate 2.

[0077] The planar electrode 43 is connected to the planar electrode 12 and the functional electrode 11 via the lead-out wiring 44. As shown in FIG. 5A, the lead-out wiring 44 is connected to a plurality of electrode main bodies 71 and is formed on the dicing line. D In other words, the lead wiring 44 is formed on the dicing line, and the lead wiring 44 has a width W L is the cutting width W D Less than.

[0078] According to this, when the collective substrate 2 is diced along the dicing lines and separated into a plurality of acoustic wave chips 3, the planar electrode 43 is not connected to the functional electrode 11 and the planar electrode 12 and is made potentialless. Therefore, even if a part of the planar electrode 43 (the planar electrode 13) after dicing peels off and comes into contact with the functional electrode 11 and the planar electrode 12, it is possible to prevent the acoustic wave chip 3 from becoming defective by short circuit.

[0079] In addition, when the first main surface of the collective substrate 2 is viewed in plan, a part of the slit portion 70 is diced to have a width W D It overlaps with.

[0080] 5(b), when the assembly substrate 2 is diced into a plurality of acoustic wave chips 3, each of the plurality of electrode main bodies 71 constituting one planar electrode 43 is in a separated state and is not connected to any of the electrodes. Even if some of the plurality of electrode main bodies 71 remaining on the acoustic wave chip 3 (planar electrodes 13) are peeled off or separated from the acoustic wave chip 3 in the manufactured acoustic wave device 1, each of the portions of the plurality of electrode main bodies 71 (planar electrodes 13) is an electrode obtained by dividing the planar electrode 43, and therefore can be prevented from contacting the planar electrodes 12 and 21 across and causing a short circuit in the functional electrode 11. This makes it possible to provide an acoustic wave device 1 in which short circuit defects are suppressed.

[0081] Next, a measurement probe is brought into contact with the planar electrode 43 to inspect the transmission characteristics of the IDT electrode formed of the functional electrode 11 and the plurality of planar electrodes 12 (S20).

[0082] According to this, the transmission characteristics of the IDT electrodes are measured for the acoustic wave chip 3 alone before the acoustic wave chip 3 is face-down bonded to the mounting substrate 20, so that a pass / fail determination can be made at the chip level, thereby improving the yield of the finished acoustic wave device 1 and improving manufacturing efficiency.

[0083] It should be noted that the plurality of bump electrodes 14 do not have to be formed in the step of fabricating aggregate substrate 2, and may be formed after the step (S20) of inspecting the transmission characteristics of the IDT electrodes.

[0084] Next, the aggregate substrate 2 is diced along dicing lines to separate the aggregate substrate 2 into a plurality of acoustic wave chips 3 (S30).

[0085] As shown in FIG. 5B, after dicing, the aggregate substrate 2 is divided into a plurality of acoustic wave chips 3. At this time, the dicing width W D As a result, the planar electrode 43 is divided into a plurality of planar electrodes 13.

[0086] Next, each of the plurality of individual acoustic wave chips 3 is bonded (face down) via the plurality of bump electrodes 14 to the main surface 20a of the mounting substrate 20 on which the plurality of planar electrodes 21 are formed (S40).

[0087] Note that the resin member 30 may be disposed in contact with the main surface 20a and to cover the acoustic wave chip 3 in step S40 or after step S40.

[0088] Here, after step S40, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 max is the minimum distance D1 between one of the planar electrodes 12 and one of the planar electrodes 21 that are at different potentials in the acoustic wave device 1. min Less than.

[0089] According to this, even if the planar electrode 13 is peeled off or separated from the acoustic wave chip 3, the maximum distance D13 of the planar electrode 13 max is the minimum distance D1 min , it is possible to prevent peeled or freed planar electrode 13 from coming into contact with planar electrode 12 and planar electrode 21 across each other and shorting out functional electrode 11. It is therefore possible to provide an acoustic wave device 1 in which short-circuit defects are suppressed.

[0090] The mounting substrate 20 used in step S40 may be a mounting substrate 20 that has been singulated to correspond to one acoustic wave chip 3, or may be an assembly of mounting substrates 20 before being singulated into a plurality of mounting substrates 20. When an assembly of mounting substrates 20 is used, the assembly and the plurality of acoustic wave chips 3 may be bonded to each other via the plurality of bump electrodes 14, a resin member may be disposed, and then the assembly in which the assembly and the plurality of acoustic wave chips 3 are bonded to each other may be diced to form individual acoustic wave devices.

[0091] After step S40, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 formed on the end of the acoustic wave chip 3 after dicing is max is the minimum distance Db between two bump electrodes 14 that have different potentials. min It may be smaller than.

[0092] According to this, even if the planar electrode 13 is peeled off or separated from the acoustic wave chip 3, the maximum distance D13 of the planar electrode 13 max is the minimum distance Db min , it is possible to prevent peeled or detached planar electrode 13 from coming into contact across two bump electrodes 14 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0093] In addition, after step S40, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 formed at the end of the acoustic wave chip 3 after dicing is max is the minimum distance D3 between two planar electrodes 21 that are at different potentials among the multiple planar electrodes 21. min It may be smaller than.

[0094] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D3 min, it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 21 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0095] In addition, after step S40, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 formed at the end of the acoustic wave chip 3 after dicing is max is the minimum distance D2 between two planar electrodes 12 that are at different potentials among the multiple planar electrodes 12. min It may be smaller than.

[0096] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D2 min , it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 12 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0097] In step S10, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 formed at the end of the acoustic wave chip 3 after dicing is max is the minimum distance D4 between the adjacent electrode fingers 61a and 61b. min It may be smaller than.

[0098] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D4 min Since the distance between the electrode fingers is smaller than the distance between the electrode fingers, peeled or separated planar electrode 13 can be prevented from coming into contact with two adjacent electrode fingers. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0099] [4. Configuration of Acoustic Wave Device According to Comparative Example] Here, the configuration of a (conventional) elastic wave device according to a comparative example will be described. The elastic wave device according to the comparative example is different from elastic wave device 1 according to the present embodiment in the configuration of planar electrode 45 formed on a dicing line in the process of forming an IDT electrode. In the following, the elastic wave device according to the comparative example and its manufacturing method will be described focusing on the differences from elastic wave device 1 according to the present embodiment, while omitting the description of the similarities between the elastic wave device according to the comparative example and its manufacturing method.

[0100] A manufacturing method for an acoustic wave device according to the comparative example includes the steps of: (1) producing an aggregate substrate 200 by forming, on a main surface of a piezoelectric wafer, a functional electrode, a plurality of first planar electrodes connected to the functional electrode, a planar electrode 45 arranged on a dicing line having a predetermined cutting width, and a plurality of bump electrodes; (2) bringing a measurement stylus into contact with the planar electrode 45 to inspect the transmission characteristics of an IDT electrode composed of the functional electrode and the plurality of first planar electrodes; (3) after inspecting the transmission characteristics of the IDT electrode, dicing the aggregate substrate 200 along the dicing line to separate into a plurality of acoustic wave chips 203; and (4) face-down bonding the plurality of bump electrodes of each of the plurality of individual acoustic wave chips 203 to a third main surface of the mounting substrate on which the plurality of second planar electrodes are formed.

[0101] 6 is a plan view of an aggregate substrate 200 according to a comparative example. The figure shows a partial electrode layout of the aggregate substrate 200 produced in a process of producing the aggregate substrate 200. The aggregate substrate 200 has a piezoelectric wafer 40, a plurality of functional electrodes 11, a plurality of planar electrodes 12, and a plurality of planar electrodes 45.

[0102] The flat electrode 45 is an example of a stylus electrode, and has a cutting width W D 6, in the collective substrate 200, the planar electrodes 45 are rectangular in plan view of the collective substrate 200, and the width in the direction perpendicular to the dicing line (y-axis direction) is equal to the dicing cutting width W D Greater than.

[0103] After the collective substrate 200 is diced, the collective substrate 200 is divided into a plurality of acoustic wave chips 203. At this time, a cutting width W D As a result, a part of the planar electrode 45 remains on the edge of the individual acoustic wave chip 203.

[0104] Here, the size of the part of the planar electrode 45 remaining in the individualized acoustic wave chip 203 is not specified, and therefore the maximum distance between the two ends of the remaining planar electrode 45 is the minimum distance D1 between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 that are at different potentials in the acoustic wave device according to the comparative example. min It may be more than that.

[0105] According to this, when a part of the remaining planar electrode 45 is separated from the acoustic wave chip 203, the maximum distance of the part of the remaining planar electrode 45 is the minimum distance D1 min As a result, a part of the free planar electrode 45 may come into contact with the planar electrode 12 and the planar electrode 21, possibly shorting out the functional electrode 11. Therefore, the acoustic wave device in accordance with the comparative example cannot prevent the occurrence of short-circuit defects.

[0106] In contrast, according to the acoustic wave device 1 and the manufacturing method thereof according to the present embodiment, even if the planar electrodes 13 remaining on the individualized acoustic wave chips 3 are peeled off or separated from the acoustic wave chips 3, the maximum distance D13 of the planar electrodes 13 is max is the minimum distance D1 min , it is possible to prevent peeled or freed planar electrode 13 from coming into contact with planar electrode 12 and planar electrode 21 across each other and shorting out functional electrode 11. It is therefore possible to provide an acoustic wave device 1 in which short-circuit defects are suppressed.

[0107] [5 Effects, etc.] As described above, the elastic wave device 1 according to the present embodiment includes a piezoelectric substrate 10 having piezoelectricity and including principal surfaces 10a and 10b, a mounting substrate 20 including principal surfaces 20a and 20b and arranged such that principal surface 20a faces principal surface 10a, a functional electrode 11 arranged on principal surface 10a and performing electromechanical transduction with the piezoelectric substrate 10, a plurality of planar electrodes 12 arranged on principal surface 10a and connected to the functional electrode 11, a plurality of planar electrodes 21 arranged on principal surface 20a, a planar electrode 13 arranged on principal surface 10a in contact with an edge of the piezoelectric substrate 10 and not connected to the functional electrode 11 and the planar electrode 12, and a plurality of bump electrodes 14 joined to principal surfaces 10a and 20a. max is the minimum distance D1 between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 that are at different potentials from each other. min Less than.

[0108] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D1 min , it is possible to prevent the peeled or freed planar electrode 13 from coming into contact with the planar electrodes 12 and 21 across each other and shorting out the functional electrode 11. As a result, it is possible to provide an elastic wave device 1 in which short-circuit defects are suppressed.

[0109] Moreover, the elastic wave device 1 according to the present embodiment includes a piezoelectric substrate 10 having piezoelectricity and including principal surfaces 10a and 10b, a mounting substrate 20 including principal surfaces 20a and 20b and arranged such that principal surface 20a faces principal surface 10a, a functional electrode 11 arranged on principal surface 10a and performing electromechanical transduction with the piezoelectric substrate 10, a plurality of planar electrodes 12 arranged on principal surface 10a and connected to the functional electrode 11, a plurality of planar electrodes 21 arranged on principal surface 20a, a planar electrode 13 arranged on principal surface 10a in contact with an edge of the piezoelectric substrate 10 and not connected to the functional electrode 11 and the planar electrode 12, and a plurality of bump electrodes 14 joined to principal surfaces 10a and 20a. maxis the minimum distance Db between two bump electrodes 14 that have different potentials among the multiple bump electrodes 14. min Less than.

[0110] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance Db min Since the distance between the bump electrodes 14 is smaller than the distance between the bump electrodes 14, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two bump electrodes 14 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short circuit defects are suppressed.

[0111] For example, in the acoustic wave device 1, the maximum distance D13 between the two ends of the planar electrode 13 max is the minimum distance D3 between two planar electrodes 21 that are at different potentials among the multiple planar electrodes 21. min Less than.

[0112] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D3 min , it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 21 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0113] For example, in the acoustic wave device 1, the maximum distance D13 between the two ends of the planar electrode 13 max is the minimum distance D2 between two planar electrodes 12 that are at different potentials among the multiple planar electrodes 12. min Less than.

[0114] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D2 min, it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 12 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0115] For example, the elastic wave device 1 has an IDT electrode 54 arranged on the principal surface 10a, the IDT electrode 54 having a plurality of electrode fingers 61a and 61b arranged parallel to each other, a busbar electrode 62a configured to connect one ends of the plurality of electrode fingers 61a to each other, and a busbar electrode 62b configured to connect one ends of the plurality of electrode fingers 61b to each other and arranged opposite the busbar electrode 62a with the plurality of electrode fingers 61a and 61b in between. Here, the functional electrode 11 includes the plurality of electrode fingers 61a and 61b, and the plurality of planar electrodes 12 include the plurality of busbar electrodes 62a and 62b.

[0116] This prevents peeled or separated planar electrode 13 from coming into contact with bus bar electrode 62a or 62b and planar electrode 21 across each other, thereby preventing a short circuit of functional electrode 11. It is therefore possible to provide an elastic wave device 1 in which short circuit defects are prevented.

[0117] For example, in the acoustic wave device 1, the maximum distance D13 between the two ends of the planar electrode 13 max is the minimum distance D4 between the adjacent electrode fingers 61a and 61b. min Less than.

[0118] The method for manufacturing elastic wave device 1 according to the present embodiment includes forming, on principal surface 10a of piezoelectric wafer 40, which has piezoelectric properties and includes principal surfaces 10a and 10b, functional electrode 11 that performs electromechanical conversion with piezoelectric wafer 40, a plurality of planar electrodes 12 connected to functional electrode 11, and a predetermined cutting width W Dthe planar electrode 43 and a plurality of bump electrodes 14 arranged on a dicing line having a dicing line (S10) to fabricate the aggregate substrate 2; a step (S20) of inspecting the transmission characteristics of an IDT electrode 54 composed of a functional electrode 11 and a plurality of planar electrodes 12 by contacting a measurement stylus with the planar electrode 43; a step (S30) of dicing the aggregate substrate 2 along the dicing line to separate the aggregate substrate 2 into a plurality of acoustic wave chips 3 after inspecting the transmission characteristics of the IDT electrode 54; and a step (S40) of joining the plurality of bump electrodes 14 of each of the plurality of individual acoustic wave chips 3 to a main surface 20a of the mounting substrate 20 on which a plurality of planar electrodes 21 are formed. In the step of fabricating the aggregate substrate 2, the planar electrode 43 is connected to the functional electrode 11 and has a slit portion 70 in which no conductive material is formed at both ends in a direction perpendicular to the dicing line, and when the aggregate substrate 2 is viewed in a planar view, a portion of the slit portion 70 overlaps the dicing line.

[0119] According to this, when the assembly substrate 2 is diced into a plurality of acoustic wave chips 3, each of the portions of the plurality of electrode main bodies 71 constituting one planar electrode 43 is in a separated state and is not connected to any electrode. Furthermore, even if a portion of the plurality of electrode main bodies 71 remaining on the acoustic wave chip 3 in the manufactured acoustic wave device 1 is peeled off or separated from the acoustic wave chip 3, each of the portions of the plurality of electrode main bodies 71 is an electrode obtained by dividing the planar electrode 43, and therefore can be prevented from contacting the planar electrode 12 and the planar electrode 21 across the planar electrode 12 and causing a short circuit in the functional electrode 11. Thus, it is possible to provide an acoustic wave device 1 in which short circuit defects are suppressed.

[0120] For example, in the manufacturing method of the acoustic wave device 1, in the step of manufacturing the assembly substrate 2, the planar electrodes 43 are connected to the functional electrodes 11 via the lead wiring 44 formed on the dicing line, and the lead wiring 44 is formed within the cutting width W of the dicing line. D is formed within the range.

[0121] According to this, when the collective substrate 2 is diced along the dicing lines and divided into a plurality of acoustic wave chips 3, the planar electrode 43 is not connected to the functional electrode 11 and the planar electrode 12 and is made potentialless. Therefore, even if the planar electrode 13, which is a part of the planar electrode 43 after dicing, peels off and comes into contact across the functional electrode 11 and / or the planar electrode 12, it is possible to prevent the acoustic wave chip 3 from becoming defective by short circuit.

[0122] Furthermore, for example, in the process of producing collective substrate 2 in the method of manufacturing acoustic wave device 1, planar electrode 43 is formed so that the width of slit portion 70 in the direction along the dicing line is smaller than the contact diameter of the tip of a measurement stylus.

[0123] According to this, the tip of the measurement stylus contacts across multiple electrode main bodies 71 of the planar electrode 43, making it possible to reliably electrically connect the tip of the measurement stylus to the planar electrode 43 in the process of inspecting the transmission characteristics of the IDT electrode 54 of the aggregate substrate 2.

[0124] For example, in the manufacturing method of the acoustic wave device 1, in the step of dividing the acoustic wave device 1 into a plurality of acoustic wave chips 3, the planar electrode 43 is divided into a plurality of planar electrodes 13 by dicing. After the step of bonding each of the plurality of acoustic wave chips 3 to the mounting substrate 20, the maximum distance D13 between two ends of each of the plurality of planar electrodes 13 is max is the minimum distance D1 between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 that are at different potentials from each other. min Less than.

[0125] According to this, even if the planar electrode 13 is peeled off or separated from the acoustic wave chip 3, the maximum distance D13 of the planar electrode 13 max is the minimum distance D1 min , it is possible to prevent peeled or freed planar electrode 13 from coming into contact with planar electrode 12 and planar electrode 21 across each other and shorting out functional electrode 11. It is therefore possible to provide an acoustic wave device 1 in which short-circuit defects are suppressed.

[0126] For example, in the method for manufacturing the acoustic wave device 1, after the step of bonding each of the acoustic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the planar electrodes 13 is max is the minimum distance Db between two bump electrodes 14 that have different potentials among the multiple bump electrodes 14. min Less than.

[0127] According to this, even if the planar electrode 13 is peeled off or separated from the acoustic wave chip 3, the maximum distance D13 of the planar electrode 13 max is the minimum distance Db min , it is possible to prevent peeled or detached planar electrode 13 from coming into contact across two bump electrodes 14 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0128] For example, in the method for manufacturing the acoustic wave device 1, after the step of bonding each of the acoustic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the planar electrodes 13 is max is the minimum distance D3 between two planar electrodes 21 that are at different potentials among the multiple planar electrodes 21. min Less than.

[0129] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D3 min , it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 21 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0130] For example, in the method for manufacturing the acoustic wave device 1, after the step of bonding each of the acoustic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the planar electrodes 13 is max is the minimum distance D2 between two planar electrodes 12 that are at different potentials among the multiple planar electrodes 12. min Less than.

[0131] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D2 min , it is possible to prevent peeled or separated planar electrode 13 from coming into contact across two planar electrodes 12 at different potentials. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0132] For example, in the method for manufacturing the acoustic wave device 1, after the step of dividing the assembly substrate 2 into a plurality of acoustic wave chips 3, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max is the minimum distance D4 between the adjacent electrode fingers 61a and 61b. min Less than.

[0133] According to this, even if the planar electrode 13 is peeled off or separated from the piezoelectric substrate 10, the maximum distance D13 of the planar electrode 13 max is the minimum distance D4 min Since the distance between the electrode fingers is smaller than the distance between the electrode fingers, peeled or separated planar electrode 13 can be prevented from coming into contact with two adjacent electrode fingers. This makes it possible to provide an acoustic wave device 1 in which short-circuit defects are further suppressed.

[0134] (Other embodiments) Although the elastic wave device and the manufacturing method thereof according to the present invention have been described with reference to the embodiments, the present invention is not limited to the above-described embodiments. The present invention also includes modifications that can be made by those skilled in the art without departing from the spirit of the present invention, and various devices incorporating the elastic wave device according to the present invention.

[0135] Furthermore, for example, in the elastic wave devices according to the above embodiments, matching elements such as inductors and capacitors, and switch circuits may be connected between the respective components.

[0136] The features of the acoustic wave device and the manufacturing method thereof described based on the above embodiment will be described below.

[0137] <1> A first substrate having piezoelectricity and including a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface, the second substrate being disposed such that the third main surface faces the first main surface; a functional electrode disposed on the first main surface and performing electromechanical transduction with the first substrate; a plurality of first planar electrodes disposed on the first main surface and connected to the functional electrodes; a plurality of second planar electrodes disposed on the third major surface; a third planar electrode disposed on the first main surface in contact with an edge of the first substrate, the third planar electrode being not connected to the functional electrode and the first planar electrode; a plurality of bump electrodes bonded to the first main surface and the third main surface; An elastic wave device, wherein the maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between one of the plurality of first planar electrodes and one of the plurality of second planar electrodes that are at different potentials.

[0138] <2> A first substrate having piezoelectricity and including a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface, the second substrate being disposed such that the third main surface faces the first main surface; a functional electrode disposed on the first main surface and performing electromechanical transduction with the first substrate; a plurality of first planar electrodes disposed on the first main surface and connected to the functional electrodes; a plurality of second planar electrodes disposed on the third major surface; a third planar electrode disposed on the first main surface in contact with an edge of the first substrate, the third planar electrode being not connected to the functional electrode and the first planar electrode; a plurality of bump electrodes bonded to the first main surface and the third main surface; An acoustic wave device, wherein a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes.

[0139] <3> a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes; <1> The acoustic wave device according to claim 1 .

[0140] <4> a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes; <1> ~ <3> 2. The acoustic wave device according to claim 1 ,

[0141] <5> a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes; <1> ~ <4> 2. The acoustic wave device according to claim 1 ,

[0142] <6> The acoustic wave device includes: an IDT electrode disposed on the first main surface; The IDT electrode is a plurality of first electrode fingers and a plurality of second electrode fingers arranged parallel to each other; a first bus bar electrode configured to connect one ends of the first electrode fingers to each other; a second bus bar electrode configured to connect one ends of the second electrode fingers to each other and disposed opposite the first bus bar electrode with the first electrode fingers and the second electrode fingers interposed therebetween, the functional electrode includes the plurality of first electrode fingers and the plurality of second electrode fingers, the plurality of first planar electrodes include the first bus bar electrode and the second bus bar electrode; <1> ~ <5> 2. The acoustic wave device according to claim 1 ,

[0143] <7> a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between one of the first electrode fingers and one of the second electrode fingers adjacent to each other; <6> The acoustic wave device according to claim 1 .

[0144] <8> a step of forming, on a first main surface of a piezoelectric wafer having piezoelectricity and including a first main surface and a second main surface, a functional electrode for electromechanical conversion with the piezoelectric wafer, a plurality of first planar electrodes connected to the functional electrode, a stylus electrode disposed on a dicing line having a predetermined cutting width, and a plurality of bump electrodes, thereby fabricating an aggregate substrate; a step of contacting a measurement stylus with the stylus electrode to inspect a transmission characteristic of an IDT electrode constituted by the functional electrode and the plurality of first planar electrodes; a step of inspecting a transmission characteristic of the IDT electrode, and then dicing the aggregate substrate along the dicing lines to separate the aggregate substrate into a plurality of acoustic wave chips; and bonding the bump electrodes of each of the individual acoustic wave chips to a third main surface of a mounting substrate on which a plurality of second planar electrodes are formed, In the step of producing the aggregate substrate, the stylus electrode is connected to the functional electrode and has slits at both ends in a direction perpendicular to the dicing line where no conductive material is formed; A method for manufacturing an acoustic wave device, wherein, when the collective substrate is viewed in a plan view, a portion of the slit portion overlaps the dicing line.

[0145] <9> In the step of producing the aggregate substrate, the stylus electrode is connected to the functional electrode via a lead wiring formed on the dicing line, the lead-out wiring is formed within the range of the predetermined cutting width of the dicing line; <8> A method for manufacturing the acoustic wave device according to claim 1 .

[0146] <10> In the step of producing the aggregate substrate, forming the stylus electrode so that the width of the slit portion in the direction along the dicing line is smaller than a contact diameter of the tip of the measurement stylus; <8> or <9> A method for manufacturing the acoustic wave device according to claim 1 .

[0147] <11> In the step of singulating into a plurality of acoustic wave chips, The stylus electrode is divided into a plurality of third planar electrodes by dicing, After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between one of the plurality of first planar electrodes and one of the plurality of second planar electrodes that are at different potentials; <8> ~ <10> 2. A method for manufacturing the acoustic wave device according to claim 1 .

[0148] <12> In the step of singulating into a plurality of acoustic wave chips, The stylus electrode is divided into a plurality of third planar electrodes by dicing, After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes; <8> ~ <10> 2. A method for manufacturing the acoustic wave device according to claim 1 .

[0149] <13> After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes; <11> or <12> A method for manufacturing the acoustic wave device according to claim 1 .

[0150] <14> After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes; <11> ~ <13> 2. A method for manufacturing the acoustic wave device according to claim 1 .

[0151] <15> In the step of singulating into a plurality of acoustic wave chips, each of the plurality of acoustic wave chips has an IDT electrode disposed on the first main surface, The IDT electrode is a plurality of first electrode fingers and a plurality of second electrode fingers arranged parallel to each other; a first bus bar electrode configured to connect one ends of the first electrode fingers to each other; a second bus bar electrode configured to connect one ends of the second electrode fingers to each other and disposed opposite the first bus bar electrode with the first electrode fingers and the second electrode fingers interposed therebetween, the functional electrode includes the plurality of first electrode fingers and the plurality of second electrode fingers, After the step of dividing the assembly substrate into a plurality of acoustic wave chips, a maximum distance connecting two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between one of the plurality of first electrode fingers and one of the plurality of second electrode fingers adjacent to each other; <11> ~ <14> 2. A method for manufacturing the acoustic wave device according to claim 1 . [Industrial Applicability]

[0152] INDUSTRIAL APPLICABILITY The present invention, as a small-sized acoustic wave device in which short circuit defects are suppressed, can be widely used in communication devices such as mobile phones. [Explanation of symbols]

[0153] 1. Elastic wave device 2, 200 aggregate board 3. 203 Acoustic Wave Chip 10 Piezoelectric Substrate 10a, 10b, 20a, 20b main surface 11 Functional electrodes 12, 13, 21, 22, 43, 45 Planar electrode 14 Bump electrode 20 Mounting board 30 Resin parts 40 Piezoelectric Wafer 44 Output wiring 51 High-sonic support substrate 52 Low sound velocity membrane 53 Piezoelectric Film 54 IDT electrode 55, 58 protective layer 57 Piezoelectric single crystal substrate 60 Elastic Wave Resonator 60a, 60b comb-shaped electrode 61a, 61b electrode fingers 62a, 62b Busbar electrodes 65 Support substrate 66 Lower electrode 67 Piezoelectric layer 68 Upper electrode 70 Slit section 71 Electrode body 101, 102, 103, 104 Edge

Claims

1. A first substrate having piezoelectricity and including a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface, the second substrate being disposed so that the third main surface faces the first main surface; a functional electrode disposed on the first main surface and performing electromechanical transduction with the first substrate; a plurality of first planar electrodes disposed on the first main surface and connected to the functional electrodes; a plurality of second planar electrodes disposed on the third major surface; a third planar electrode disposed on the first main surface in contact with an edge of the first substrate, the third planar electrode being not connected to the functional electrode and the first planar electrode; a plurality of bump electrodes bonded to the first main surface and the third main surface; a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between one of the first planar electrodes and one of the second planar electrodes that are at different potentials from each other; Elastic wave device.

2. A first substrate having piezoelectricity and including a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface, the second substrate being disposed so that the third main surface faces the first main surface; a functional electrode disposed on the first main surface and performing electromechanical transduction with the first substrate; a plurality of first planar electrodes disposed on the first main surface and connected to the functional electrodes; a plurality of second planar electrodes disposed on the third major surface; a third planar electrode disposed on the first main surface in contact with an edge of the first substrate, the third planar electrode being not connected to the functional electrode and the first planar electrode; a plurality of bump electrodes bonded to the first main surface and the third main surface; a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes; Elastic wave device.

3. a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes; The acoustic wave device according to claim 1 .

4. a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes; The elastic wave device according to any one of claims 1 to 3.

5. a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes; The elastic wave device according to any one of claims 1 to 3.

6. The acoustic wave device includes: an IDT electrode disposed on the first main surface; The IDT electrode is a plurality of first electrode fingers and a plurality of second electrode fingers arranged parallel to each other; a first bus bar electrode configured to connect one ends of the first electrode fingers to each other; a second bus bar electrode configured to connect one ends of the second electrode fingers to each other and disposed opposite the first bus bar electrode with the first electrode fingers and the second electrode fingers interposed therebetween, the functional electrode includes the first electrode fingers and the second electrode fingers, the plurality of first planar electrodes include the first bus bar electrode and the second bus bar electrode; The elastic wave device according to any one of claims 1 to 3.

7. a maximum distance between two ends of the third planar electrode is smaller than a minimum distance between one of the first electrode fingers and one of the second electrode fingers adjacent to each other; The acoustic wave device according to claim 6 .

8. a step of forming, on a first main surface of a piezoelectric wafer having piezoelectricity and including a first main surface and a second main surface, a functional electrode for electromechanical conversion with the piezoelectric wafer, a plurality of first planar electrodes connected to the functional electrode, a stylus electrode disposed on a dicing line having a predetermined cutting width, and a plurality of bump electrodes, thereby fabricating an aggregate substrate; a step of contacting a measurement stylus with the stylus electrode to inspect a transmission characteristic of an IDT electrode constituted by the functional electrode and the plurality of first planar electrodes; a step of inspecting a transmission characteristic of the IDT electrode, and then dicing the aggregate substrate along the dicing lines to separate the aggregate substrate into a plurality of acoustic wave chips; and bonding the bump electrodes of each of the individual acoustic wave chips to a third main surface of a mounting substrate on which a plurality of second planar electrodes are formed, In the step of producing the aggregate substrate, the stylus electrode is connected to the functional electrode and has slits at both ends in a direction perpendicular to the dicing line where no conductive material is formed; When the collective substrate is viewed in a plan view, a portion of the slit portion overlaps with the dicing line. A method for manufacturing an acoustic wave device.

9. In the step of producing the aggregate substrate, the stylus electrode is connected to the functional electrode via a lead wiring formed on the dicing line, the lead-out wiring is formed within the range of the predetermined cutting width of the dicing line; The method for manufacturing the acoustic wave device according to claim 8 .

10. In the step of producing the aggregate substrate, forming the stylus electrode so that the width of the slit portion in the direction along the dicing line is smaller than a contact diameter of the tip of the measurement stylus; The method for manufacturing the acoustic wave device according to claim 8 .

11. In the step of singulating into a plurality of acoustic wave chips, The stylus electrode is divided into a plurality of third planar electrodes by dicing, After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the third planar electrodes is smaller than a minimum distance between one of the first planar electrodes and one of the second planar electrodes that are at different potentials from each other; A method for manufacturing the elastic wave device according to any one of claims 8 to 10.

12. In the step of singulating into a plurality of acoustic wave chips, The stylus electrode is divided into a plurality of third planar electrodes by dicing, After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes; A method for manufacturing the elastic wave device according to any one of claims 8 to 10.

13. After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes; The method for manufacturing the acoustic wave device according to claim 11 .

14. After the step of bonding each of the plurality of acoustic wave chips to the mounting substrate, a maximum distance between two ends of each of the plurality of third planar electrodes is smaller than a minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes; The method for manufacturing the acoustic wave device according to claim 11 .

15. In the step of singulating into a plurality of acoustic wave chips, each of the plurality of acoustic wave chips has an IDT electrode disposed on the first main surface, The IDT electrode is a plurality of first electrode fingers and a plurality of second electrode fingers arranged parallel to each other; a first bus bar electrode configured to connect one ends of the first electrode fingers to each other; a second bus bar electrode configured to connect one ends of the second electrode fingers to each other and disposed opposite the first bus bar electrode with the first electrode fingers and the second electrode fingers interposed therebetween, the functional electrode includes the first electrode fingers and the second electrode fingers, After the step of dividing the assembly substrate into a plurality of acoustic wave chips, a maximum distance connecting two ends of each of the third planar electrodes is smaller than a minimum distance between one of the first electrode fingers and one of the second electrode fingers adjacent to each other; The method for manufacturing the acoustic wave device according to claim 11 .

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