Elastic wave device and method for manufacturing elastic wave device

Abstract

Provided are an elastic wave device in which short-circuit defects are suppressed, and a method for manufacturing the same. An elastic wave device is provided with: a piezoelectric substrate including a first main surface and a second main surface; a mounting substrate including a third main surface and a fourth main surface, the third main surface being disposed so as to face the first main surface; a functional electrode that is disposed on the first main surface and that performs electromechanical transformation with the piezoelectric 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 main surface; a third planar electrode that is disposed on the first main surface, is in contact with an end edge of the piezoelectric substrate, and is not connected to the functional electrode and the first planar electrode; and a plurality of bump electrodes joined to the first main surface and the third main surface, the maximum distance between both end portions of the third planar electrode being smaller than the minimum distance among the distances between one of the plurality of first planar electrodes and one of the plurality of second planar electrodes having different potentials.

Description

Technical Field

[0001] The present invention relates to an elastic wave device and a method for manufacturing the elastic wave device. Background Art

[0002] Patent document 1 discloses the structure of an elastic wave device having a WLP (Wafer Level Package) structure. The elastic wave device is manufactured by singulating a collective substrate on which functional electrodes and wiring electrodes are formed into a plurality of chips by dicing, and bonding the chips face-down to a mounting substrate. In the collective substrate, measurement electrodes for performing characteristic inspection in the state of the collective substrate are formed at the dicing lines, and the measurement electrodes are divided into functional electrodes and wiring electrodes by dicing, and are made potential-free.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2021 / 100505

[0006] However, in the elastic wave device described in Patent Document 1, although the measuring electrodes are rendered potential-free after cutting, if the measuring electrodes are peeled or separated by cutting, they may come into contact across a plurality of electrodes having different potentials, possibly causing a short circuit. Summary of the invention

[0007] Problem that the invention aims to solve

[0008] Therefore, an object of the present invention is to provide an elastic wave device and a method for manufacturing the elastic wave device in which short-circuit failure is suppressed.

[0009] Technical solutions to solve problems

[0010] In order to achieve the above-mentioned purpose, an elastic wave device involved in 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, configured so that the third main surface faces the first main surface; a functional electrode configured on the first main surface and performing electromechanical transformation with the first substrate; a plurality of first plane electrodes configured on the first main surface and connected to the functional electrode; a plurality of second plane electrodes configured on the third main surface; a third plane electrode configured on the first main surface and configured to be in contact with the end edge of the first substrate and not connected to the functional electrode and the first plane electrode; and a plurality of bump electrodes bonded to the first main surface and the third main surface, the maximum distance between the two ends of the third plane electrode being less than the minimum distance between one of the plurality of first plane electrodes and one of the plurality of second plane electrodes having different potentials from each other.

[0011] In addition, an elastic wave device involved in 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 configured so that the third main surface faces the first main surface; a functional electrode, which is arranged on the first main surface and performs electromechanical transformation with the first substrate; a plurality of first plane electrodes, which are arranged on the first main surface and connected to the functional electrodes; a plurality of second plane electrodes, which are arranged on the third main surface; a third plane electrode, which is arranged on the first main surface and configured to be in contact with the end edge of the first substrate and is not connected to the functional electrode and the first plane electrode; and a plurality of bump electrodes, which are bonded to the first main surface and the third main surface, and the maximum distance between the two ends of the third plane electrode is less than the minimum distance between two bump electrodes of different potentials among the plurality of bump electrodes.

[0012] In addition, a method for manufacturing an elastic wave device according to one embodiment of the present invention includes: a step of forming a functional electrode for performing electromechanical conversion with a piezoelectric wafer, a plurality of first plane electrodes connected to the functional electrode, a probe electrode arranged on a cutting line having a given cutting width, and a plurality of bump electrodes on a first main surface of a piezoelectric wafer having piezoelectricity and including a first main surface and a second main surface, thereby manufacturing an integrated substrate; and a step of bringing a measuring probe into contact with the probe electrode to inspect the through-pass characteristics of an IDT electrode composed of the functional electrode and the plurality of first plane electrodes. ; a process of cutting the collective substrate along a cutting line after inspecting the through characteristics of the IDT electrode, thereby singulating the collective substrate into a plurality of elastic wave chips; and a process of joining a plurality of bump electrodes of each of the singulated plurality of elastic wave chips to a third main surface of the mounting substrate on which a plurality of second plane electrodes are formed, wherein in the process of manufacturing the collective substrate, the contact pin electrode is connected to the functional electrode, and both ends in a direction perpendicular to the cutting line have slit portions where no conductive material is formed, and a portion of the slit portion overlaps with the cutting line when the collective substrate is viewed from above.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to suppress short-circuit failure of an elastic wave device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A It is a top view of the elastic wave chip according to the embodiment.

[0016] Figure 1B It is a top view of the mounting substrate according to the embodiment.

[0017] Figure 1C is a cross-sectional view of an elastic wave device according to an embodiment.

[0018] Figure 2A1 and 2 are a plan view and a cross-sectional view schematically showing a first example of an elastic wave resonator constituting the elastic wave device according to the embodiment.

[0019] Figure 2B FIG. 1 is a cross-sectional view schematically showing a second example of the elastic wave resonator constituting the elastic wave device according to the embodiment.

[0020] Figure 2C FIG. 1 is a cross-sectional view schematically showing a third example of the elastic wave resonator constituting the elastic wave device according to the embodiment.

[0021] Figure 3 1 is a flowchart showing a method for manufacturing an elastic wave device according to an embodiment.

[0022] Figure 4 It is a top view of the collective substrate according to the embodiment.

[0023] Figure 5 The diagram shows the structure of a planar electrode near a cutting line of an aggregate substrate and a planar electrode near an edge of an elastic wave chip according to an embodiment.

[0024] Figure 6 It is a top view of an aggregate substrate according to a comparative example.

[0025] Description of Reference Numerals

[0026] 1: Elastic wave device;

[0027] 2. 200: Collection substrate;

[0028] 3.203: elastic wave chip;

[0029] 10: Piezoelectric substrate;

[0030] 10a, 10b, 20a, 20b: main surface;

[0031] 11: functional electrode;

[0032] 12, 13, 21, 22, 43, 45: planar electrodes;

[0033] 14: Bump electrode;

[0034] 20: Install the substrate;

[0035] 30: resin component;

[0036] 40: Piezoelectric chip;

[0037] 44: Lead-out wiring;

[0038] 51: high acoustic velocity support substrate;

[0039] 52: Low sound velocity membrane;

[0040] 53: piezoelectric film;

[0041] 54: IDT electrode;

[0042] 55, 58: protective layer;

[0043] 57: Piezoelectric single crystal substrate;

[0044] 60: elastic wave resonator;

[0045] 60a, 60b: comb-shaped electrodes;

[0046] 61a, 61b: electrode fingers;

[0047] 62a, 62b: bus bar electrodes;

[0048] 65: Support base plate;

[0049] 66: lower electrode;

[0050] 67: piezoelectric layer;

[0051] 68: upper electrode;

[0052] 70: slit portion;

[0053] 71: electrode main body;

[0054] 101, 102, 103, 104: end edges. DETAILED DESCRIPTION

[0055] Hereinafter, the embodiments of the present disclosure will be described in detail using the accompanying drawings. In addition, the embodiments described below all show general or specific examples. The numerical values, shapes, materials, components, configurations of components, and connection methods shown in the following embodiments are examples, and their purpose is not to limit the present invention. Among the components in the following embodiments, the components that are not recorded in the independent claims are described as arbitrary components. In addition, the sizes or size ratios of the components shown in the drawings may not be strict.

[0056] In addition, each figure is a schematic diagram that appropriately emphasizes, omits, or adjusts the ratio in order to illustrate the present invention, and is not necessarily strictly illustrated, and sometimes differs from the actual shape, positional relationship, and ratio. In each figure, the same reference numerals are marked for substantially the same structure, and repeated descriptions are sometimes omitted or simplified.

[0057] In the circuit structure of the present disclosure, the term "connection" includes not only direct connection via electrodes and / or wiring conductors, but also electrical connection via matching elements such as inductors and capacitors and switch circuits. The term "connection between A and B" means connection between A and B and both A and B.

[0058] Furthermore, terms such as “parallel” and “perpendicular” indicating the relationship between elements, terms such as “rectangular” indicating the shape of an element, and numerical ranges do not have strict meanings but include substantially equivalent ranges, for example, errors of several %.

[0059] (Implementation Method)

[0060] [1. Structure of elastic wave device 1]

[0061] Figure 1A It is a plan view of the elastic wave chip 3 according to the embodiment. Figure 1B It is a top view of the mounting substrate 20 according to the embodiment. Figure 1C It is a cross-sectional view of the elastic wave device 1 according to the embodiment. Figure 1A This is a view showing the principal surface 10 a side of the piezoelectric substrate 10 as viewed from the positive z-axis side. Figure 1B This is a view showing the main surface 20a side of the mounting substrate 20 as viewed from the positive side of the z-axis. Figure 1C yes Figure 1A as well as Figure 1B Cross-sectional view at line IC-IC.

[0062] like Figure 1C As shown, the elastic wave device 1 includes an elastic wave chip 3 , a mounting substrate 20 , and a resin member 30 .

[0063] like Figure 1A As shown, the elastic 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 .

[0064] The piezoelectric substrate 10 is an example of a first substrate, has piezoelectricity, and includes a principal surface 10 a (first principal surface) and a principal surface 10 b (second principal surface).

[0065] The functional electrode 11 is disposed on the main surface 10 a and performs electromechanical conversion with the piezoelectric substrate 10 .

[0066] Each of the plurality of planar electrodes 12 is an example of a first planar electrode, is disposed on the principal surface 10 a , and is connected to the functional electrode 11 .

[0067] Each of the plurality of planar electrodes 13 is an example of a third planar electrode. Figure 1AAs shown, the planar electrode 13 is disposed on the main surface 10a and is disposed in contact with the 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 electrode 13 is a part of a probe electrode for measuring the through-pass characteristic of the elastic wave chip 3 in the state of the collective substrate 2 before the elastic wave chip 3 is singulated.

[0068] In addition, the detailed structures of the piezoelectric substrate 10, the functional electrode 11, and the planar electrode 12 are described using Figure 2A 2B will be described later. In addition, regarding the detailed structure of the planar electrode 13, use Figure 5 This will be described later.

[0069] like Figure 1C As shown, the plurality of bump electrodes 14 are connected to the main surface 10a and the main surface 20a, respectively. In addition, the plurality of bump electrodes 14 can be directly bonded to the main surface 10a and the main surface 20a, or can be bonded to the main surface 10a via the plane electrode 12 and connected to the main surface 20a via the plane electrode 21. The bump electrode 14 is a spherical electrode made of a highly conductive metal, for example, a solder bump made of Sn / Ag / Cu and a bump with Au as the main component can be cited.

[0070] The mounting substrate 20 is an example of a second substrate. Figure 1C As shown, the main surface 20a (third main surface) and the main surface 20b (fourth main surface) are arranged so that the main surface 20a faces the main surface 10a. The mounting substrate 20 and the elastic 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 and the main surface 10a of the piezoelectric substrate 10 face each other. As the mounting substrate 20, for example, a low temperature co-fired ceramic (LTCC) substrate having a stacked structure of a plurality of dielectric layers, a high temperature co-fired ceramic (HTCC) substrate, a component-embedded substrate, a substrate having a redistribution layer (RDL), or a printed substrate can be used.

[0071] like Figure 1B as well as Figure 1C As shown, the mounting substrate 20 has a plurality of planar electrodes 21 and a plurality of planar electrodes 22 .

[0072] The plurality of planar electrodes 21 are each an example of a second planar electrode and are arranged on the principal surface 20 a. The plurality of planar electrodes 22 are each arranged on the principal surface 20 b. The planar electrodes 21 and 22 are connected by via conductors formed inside the mounting substrate 20 .

[0073] like Figure 1C As shown, the resin member 30 is disposed in contact with the main surface 20a and covers the elastic wave chip 3, and has a function of ensuring reliability such as mechanical strength and moisture resistance of the elastic wave chip 3. The resin member 30 is not disposed in a region where the functional electrode 11 is formed.

[0074] Here, the maximum distance D13 between the two ends of the planar electrode 13 is max (Refer to Figure 5 (b)) is smaller than the minimum distance D1 between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 having different potentials from each other. min (Refer to Figure 1C ).

[0075] In addition, the maximum distance D13 between the two ends of the planar electrode 13 is max , is defined as the maximum distance between any two ends within a planar electrode 13 when looking down at the planar electrode 13.

[0076] According to the above structure, 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 is max Less than the minimum distance D1 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from making contact across the planar electrode 12 and the planar electrode 21 and causing a short circuit in the functional electrode 11. Therefore, it is possible to provide the elastic wave device 1 in which a short circuit failure is prevented.

[0077] In addition, the maximum distance D13 between the two ends of the planar electrode 13 max (Refer to Figure 5 (b)) may be smaller than the minimum distance Db between two bump electrodes 14 having different potentials among the plurality of bump electrodes 14. min (Refer to Figure 1C ).

[0078] Therefore, 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 is max Less than the minimum distance Db min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two bump electrodes 14 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is prevented.

[0079] In addition, the maximum distance D13 between the two ends of the planar electrode 13 max (Refer to Figure 5(b)) is preferably smaller than the minimum distance D3 between two planar electrodes 21 of different potentials among the plurality of planar electrodes 21. min (Refer to Figure 1C ).

[0080] Therefore, 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 is max Less than the minimum distance D3 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 21 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0081] In addition, the maximum distance D13 between the two ends of the planar electrode 13 max (Refer to Figure 5 (b)) is preferably less than the minimum distance D2 between two planar electrodes 12 of different potentials among the plurality of planar electrodes 12. min (Refer to Figure 1C ).

[0082] Therefore, 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 is max Less than the minimum distance D2 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 12 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0083] [2. Structure of the piezoelectric substrate 10, the functional electrode 11, and the planar electrode 12]

[0084] Figure 2A 1 is a plan view and a cross-sectional view schematically showing a first example of an elastic wave resonator constituting the elastic wave device 1 according to the embodiment. In the same figure, a basic structure of an elastic wave resonator 60 constituting the elastic wave chip 3 is illustrated. Figure 2A The elastic wave resonator 60 shown is for explaining a typical structure of the elastic wave resonator constituting the elastic wave chip 3 , and the number and length of the electrode fingers constituting the electrodes are not limited thereto.

[0085] The elastic wave resonator 60 is composed of the piezoelectric substrate 10 and comb-shaped electrodes 60 a and 60 b .

[0086] like Figure 2AAs shown in (a), a pair of comb-shaped electrodes 60a and 60b facing each other are formed on the piezoelectric substrate 10. The comb-shaped electrode 60a is composed of a plurality of electrode fingers 61a (first electrode fingers) parallel to each other and a bus bar electrode 62a (first bus bar electrode) connecting one ends of the plurality of electrode fingers 61a to each other. In addition, the comb-shaped electrode 60b is composed of a plurality of electrode fingers 61b (second electrode fingers) parallel to each other and a bus bar electrode 62b (second bus bar electrode) connecting one ends of the plurality of electrode fingers 61b to each other. The plurality of electrode fingers 61a and 61b are formed along a direction orthogonal to the direction of propagation of the elastic wave (X-axis direction). The bus bar electrode 62a and the bus bar electrode 62b are arranged opposite to each other with the electrode fingers 61a and 61b sandwiched therebetween. The comb-shaped electrodes 60a and 60b constitute an IDT (Inter Digital Transducer) electrode 54.

[0087] Here, Figure 1A as well as Figure 1C The functional electrode 11 shown includes a plurality of electrode fingers 61a and a plurality of electrode fingers 61b. Figure 1A as well as Figure 1C The planar electrode 12 shown includes bus bar electrodes 62a and 62b.

[0088] The elastic wave resonator 60 constituting the elastic wave chip 3 may include reflectors at both ends of the IDT electrode 54 in the elastic wave propagation direction (X-axis direction).

[0089] like Figure 2A As shown in (b) of FIG. 5 , the IDT electrode 54 has a stacked structure of, for example, an adhesion layer 540 and a main electrode layer 542 .

[0090] The adhesion layer 540 is a layer for improving the adhesion between the piezoelectric substrate 10 and the main electrode layer 542, and as a material, for example, Ti can be used. As a material of the main electrode layer 542, for example, Al containing 1% Cu can be used. The protective layer 55 is formed to cover the comb-shaped electrodes 60a and 60b. The protective layer 55 is a layer for the purpose of protecting the main electrode layer 542 from the external environment, adjusting the frequency-temperature characteristics, and improving moisture resistance, and is, for example, a dielectric film with silicon dioxide as the main component.

[0091] In addition, 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 may not be the above-mentioned stacked structure. The IDT electrode 54 may be composed of a metal or alloy such as Ti, Al, Cu, Pt, Au, Ag, Pd, etc., or may be composed of a plurality of stacked bodies composed of the above-mentioned metals or alloys. In addition, the protective layer 55 may not be formed.

[0092] Next, the stacked structure of the piezoelectric substrate 10 will be described.

[0093] like Figure 2A As shown in (c), the piezoelectric substrate 10 includes a high-acoustic-velocity supporting substrate 51, a low-acoustic-velocity film 52, and a piezoelectric film 53, and has a structure in which the high-acoustic-velocity supporting substrate 51, the low-acoustic-velocity film 52, and the piezoelectric film 53 are stacked in this order.

[0094] The piezoelectric film 53 includes, for example, a θ°Y-cut X-propagation LiTaO3 piezoelectric single crystal or a piezoelectric ceramic (a lithium tantalate single crystal or ceramic cut at a plane whose normal line is an axis rotated from the Y axis by θ° with the X axis as the center axis, and a single crystal or ceramic in which a surface acoustic wave propagates in the X-axis direction). In addition, the material of the piezoelectric single crystal used for the piezoelectric film 53 and the cutting angle θ can be appropriately selected according to the specifications required for each filter.

[0095] 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. Furthermore, the high-acoustic-velocity support substrate 51 is a substrate in which the acoustic velocity of the body wave in the high-acoustic-velocity support substrate 51 becomes higher than the elastic waves such as the surface wave and the boundary wave propagating in the piezoelectric film 53, and functions to confine the surface acoustic wave in the portion where the piezoelectric film 53 and the low-acoustic-velocity film 52 are stacked so as not to leak from the high-acoustic-velocity support substrate 51 to the lower side. As the material of the high-acoustic-velocity support substrate 51, for example, piezoelectrics such as aluminum nitride, lithium tantalate, lithium niobate, and quartz, alumina, sapphire, magnesium oxide, silicon nitride, silicon carbide, zirconium oxide, ceramics such as cordierite, mullite, steatite, forsterite, spinel, and sialon, dielectrics such as aluminum oxide, silicon oxynitride, DLC (diamond-like carbon), and diamond, or semiconductors such as silicon, or materials containing the above materials as main components can be used. 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.

[0096] The low-acoustic-velocity film 52 is a film that makes the acoustic velocity of the body wave in the low-acoustic-velocity film 52 lower than that of the body wave propagating in the piezoelectric film 53, and is disposed between the piezoelectric film 53 and the high-acoustic-velocity support substrate 51. Due to this structure and the property that the energy of the elastic wave is essentially concentrated in the medium with a low acoustic velocity, it is possible to suppress the leakage of the surface acoustic wave energy to the outside of the IDT electrode. As the material of the low-acoustic-velocity film 52, for example, dielectrics such as glass, silicon oxide, silicon oxynitride, lithium oxide, tantalum oxide, or compounds in which fluorine, carbon, or boron is added to silicon oxide, or materials containing the above materials as main components can be used.

[0097] In addition, the stacked structure of the piezoelectric substrate 10 can significantly improve the Q value at the resonant frequency and the anti-resonant frequency compared to the conventional structure using a single piezoelectric substrate. That is, an elastic wave resonator with a high Q value can be formed, and thus a filter with a small insertion loss can be formed using the elastic wave resonator.

[0098] In addition, the high-acoustic-velocity support substrate 51 may have a structure in which a support substrate and a high-acoustic-velocity film are stacked so that the acoustic velocity of the propagating body wave becomes higher than that of elastic waves such as surface waves and boundary waves propagating in the piezoelectric film 53. In this case, as a material of the high-acoustic-velocity film, the same material as that of the high-acoustic-velocity support substrate 51 can be used. In addition, as a material of the support substrate, for example, piezoelectrics such as aluminum nitride, lithium tantalate, lithium niobate, and quartz, alumina, sapphire, magnesium oxide, silicon nitride, silicon carbide, zirconium oxide, ceramics such as cordierite, mullite, steatite, and forsterite, dielectrics such as diamond and glass, semiconductors such as silicon and gallium nitride, or resins, or materials containing the above materials as main components can be used.

[0099] In this specification, the term "main component of a material" refers to a component that accounts for more than 50% by weight of the material. The main component may be present in any state of single crystal, polycrystalline, or amorphous, or in a state of a mixture of these.

[0100] Figure 2B 2 is a cross-sectional view schematically showing a second example of an elastic wave resonator constituting the elastic wave device 1 according to the embodiment. Figure 2A In the elastic wave resonator 60 shown in the figure, an example is shown in which the IDT electrode 54 is formed on the piezoelectric substrate 10 having the piezoelectric film 53, but it is also possible to Figure 2B As shown, the substrate on which the IDT electrode 54 is formed is a piezoelectric single crystal substrate 57 composed of a single piezoelectric layer.

[0101] The piezoelectric single crystal substrate 57 is made of, for example, a piezoelectric single crystal of LiNbO 3 . The elastic wave resonator according to this example is made of a piezoelectric single crystal substrate 57 of LiNbO 3 , an IDT electrode 54 , and a protective layer 58 formed on the piezoelectric single crystal substrate 57 and the IDT electrode 54 .

[0102] The piezoelectric film 53 and the piezoelectric single crystal substrate 57 may be appropriately changed in terms of the stacking structure, material, cutting angle, and thickness according to the transmission characteristics required of the elastic wave filter device. Even an elastic wave resonator using a LiTaO3 piezoelectric substrate having a cutting angle other than the above-mentioned cutting angle can achieve the same effect as the elastic wave resonator 60 using the piezoelectric film 53.

[0103] In addition, the piezoelectric substrate forming the IDT electrode 54 may also have a structure in which a supporting substrate, an energy confinement layer, and a piezoelectric film are stacked in sequence. The IDT electrode 54 is formed on the piezoelectric film. Regarding the piezoelectric film, for example, a LiTaO3 piezoelectric single crystal or a piezoelectric ceramic can be used. The supporting substrate is a substrate that supports the piezoelectric film, the energy confinement layer, and the IDT electrode 54.

[0104] The energy confinement layer is composed of one layer or a plurality of layers, in which the speed of the body acoustic wave propagating in at least one layer is greater than the speed of the elastic wave propagating near the piezoelectric film. For example, the energy confinement layer may also be a stacked structure of a low acoustic velocity layer and a high acoustic velocity layer. The low acoustic velocity layer is a film in which the sound velocity of the body wave in the low acoustic velocity layer becomes low speed compared to the sound velocity of the elastic wave propagating in the piezoelectric film. The high acoustic velocity layer is a film in which the sound velocity of the body wave in the high acoustic velocity layer becomes high speed compared to the sound velocity of the elastic wave propagating in the piezoelectric film. In addition, the supporting substrate may also be set as a high acoustic velocity layer.

[0105] Alternatively, the energy confinement layer may be an acoustic impedance layer having a structure in which low acoustic impedance layers having relatively low acoustic impedance and high acoustic impedance layers having relatively high acoustic impedance are alternately stacked.

[0106] In addition, the maximum distance D13 between the two ends of the planar electrode 13 max (Refer to Figure 5 (b)) is preferably smaller than the minimum distance D4 between the adjacent electrode fingers 61a and 61b. min (Refer to Figure 2A (b)).

[0107] Therefore, 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 is max Less than the minimum distance D4 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact across two adjacent electrode fingers. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0108] also, Figure 2C 2 is a cross-sectional view schematically showing a third example of the elastic wave resonator constituting the elastic wave device 1 according to the embodiment. Figure 2C , a bulk acoustic wave resonator is shown as an elastic wave resonator of the elastic wave device 1. As shown in the figure, the bulk acoustic wave resonator has, for example, a support substrate 65, a lower electrode 66, a piezoelectric layer 67, and an upper electrode 68, and has a structure in which the support substrate 65, the lower electrode 66, the piezoelectric layer 67, and the upper electrode 68 are stacked in this order.

[0109] The support substrate 65 is a substrate, such as a silicon substrate, for supporting the lower electrode 66, the piezoelectric layer 67, and the upper electrode 68. The support substrate 65 has a cavity in a region in contact with the lower electrode 66. This allows the piezoelectric layer 67 to vibrate freely.

[0110] 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. As a material of the lower electrode 66 and the upper electrode 68, Al containing 1% Cu can be used, for example.

[0111] The piezoelectric layer 67 is formed between the lower electrode 66 and the upper electrode 68. The piezoelectric layer 67 mainly contains at least one of ZnO (zinc oxide), AlN (aluminum nitride), PZT (lead zirconate titanate), KN (potassium niobate), LN (lithium niobate), LT (lithium tantalate), quartz, and LiBO (lithium borate).

[0112] The bulk acoustic wave resonator having the above-mentioned stacked structure excites bulk acoustic waves in the piezoelectric layer 67 and causes resonance by applying electric energy between the lower electrode 66 and the upper electrode 68. The bulk acoustic waves generated by the 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 using bulk acoustic waves.

[0113] Here, Figure 1A as well as Figure 1C The functional electrode 11 shown includes a lower electrode 66 and an upper electrode 68. In addition, Figure 1A as well as Figure 1C The planar electrode 12 shown includes a wiring electrode connected to the lower electrode 66 and a wiring electrode connected to the upper electrode 68. Figure 1A as well as Figure 1C The piezoelectric substrate 10 shown includes a supporting substrate 65. In addition, the piezoelectric substrate 10 may not have piezoelectricity.

[0114] [3. Method for Manufacturing Elastic Wave Device 1]

[0115] Next, a method for manufacturing the elastic wave device 1 according to the present embodiment will be described. Figure 3 1 is a flowchart showing a method for manufacturing the elastic wave device 1 according to the embodiment.

[0116] 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 the first principal surface of a piezoelectric chip 40 including a first principal surface and a second principal surface, thereby manufacturing an aggregate substrate 2 (S10).

[0117] Figure 4 2 is a top view of the collective substrate 2 according to the embodiment. In the same figure, the electrode layout of a part of the collective substrate 2 produced in the above-mentioned electrode forming step is shown. The collective substrate 2 has a piezoelectric chip 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.

[0118] The piezoelectric wafer 40 is a wafer having piezoelectricity, and is a collection of the piezoelectric substrates 10 before the piezoelectric substrates 10 are singulated. On the first main surface of the piezoelectric wafer 40, the functional electrodes 11, the planar electrodes 12, and the bump electrodes 14 constituting the elastic wave chip 3 are arranged in a matrix. In addition, the planar electrodes 13 of the elastic wave chip 3 after singulation correspond to the planar electrodes 43 in the collective substrate 2.

[0119] like Figure 2A As shown in (c), the piezoelectric wafer 40 has a structure in which a high-acoustic-velocity support substrate, a low-acoustic-velocity film, and a piezoelectric film are stacked in this order. Figure 2B As shown, the piezoelectric wafer 40 may be formed of a piezoelectric single crystal substrate. In addition, the piezoelectric wafer 40 may have a structure in which a supporting substrate, an energy confinement layer, and a piezoelectric film are stacked in this order.

[0120] The flat electrode 43 is an example of a stylus electrode and is arranged on a surface having a given cutting width W. D The cutting line.

[0121] Figure 5 FIG. 4 is a diagram showing the structure of the planar electrode 43 near the cutting line of the collective substrate 2 and the planar electrode 13 near the edge of the elastic wave chip 3 according to the embodiment. Figure 5 In (a), the layout of the planar electrode 43 before cutting (in step S10) is shown. Figure 5 (b) shows the layout of the planar electrode 13 after cutting (which the elastic wave chip 3 has after being singulated). Figure 5 (a) is to Figure 4 A magnified view of region IV.

[0122] like Figure 5 As shown in (a), in the collective substrate 2, the planar electrode 43 has an electrode main body 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 a direction perpendicular to the cutting line (y-axis direction), and is formed at both ends of the planar electrode 43 in the direction perpendicular to the cutting line (y-axis direction).

[0123] In the process of manufacturing the collective substrate 2 , the planar electrode 43 is formed so that the width of the slit portion 70 in the direction along the cutting line (x-axis direction) is smaller than the contact diameter of the tip of the measuring stylus (probe).

[0124] Thus, the front end of the measuring contact needle (probe) can cross over and make contact with the multiple electrode main body parts 71 of the planar electrode 43, so in the process of inspecting the through characteristics of the IDT electrode of the collective substrate 2, the front end of the measuring contact needle (probe) and the planar electrode 43 can be reliably electrically connected.

[0125] In addition, the planar electrode 43 is connected to the planar electrode 12 and the functional electrode 11 via the lead wiring 44. Figure 5 As shown in (a), the lead wiring 44 is connected to the plurality of electrode main body portions 71, formed on the cutting line, and formed at a given cutting width W of the cutting line. D In other words, the lead wiring 44 is formed on the cutting line, and the width W of the lead wiring 44 is L Smaller than cutting width W D .

[0126] Thus, when the collective substrate 2 is cut along the cutting line and singulated into a plurality of elastic wave chips 3, the planar electrode 43 is not connected to the functional electrode 11 and the planar electrode 12 and is rendered potential-free. Therefore, even if a portion of the planar electrode 43 (the planar electrode 13) after cutting is peeled off and contacts the functional electrode 11 and the planar electrode 12, it is possible to prevent the elastic wave chip 3 from becoming short-circuited.

[0127] In addition, when the first main surface of the collective substrate 2 is viewed from above, a portion of the slit portion 70 and the cutting width W of the cutting line are aligned. D overlapping.

[0128] Therefore, if Figure 5 As shown in (b), when the collective substrate 2 is cut and singulated into a plurality of elastic wave chips 3, the plurality of electrode main bodies 71 constituting one planar electrode 43 are each separated and are not connected to any electrode. In addition, in the elastic wave device 1 that has been manufactured, even if a portion of the plurality of electrode main bodies 71 (planar electrode 13) remaining in the elastic wave chip 3 is peeled off or separated from the elastic wave chip 3, since the portion of the plurality of electrode main bodies 71 (planar electrode 13) is each an electrode obtained by subdividing the planar electrode 43, it is possible to prevent the functional electrode 11 from being short-circuited due to contact across the planar electrode 12 and the planar electrode 21. Therefore, it is possible to provide an elastic wave device 1 in which a short-circuit failure is prevented.

[0129] Next, a measurement probe is brought into contact with the planar electrode 43 to inspect the transmission characteristics of the IDT electrode composed of the functional electrode 11 and the plurality of planar electrodes 12 ( S20 ).

[0130] Thus, before the elastic wave chip 3 is face-down bonded to the mounting substrate 20 , the transmission characteristics of the IDT electrode of the elastic wave chip 3 alone are measured, and the quality of the chip can be determined at the chip level. This can improve the yield of the finished elastic wave device 1 and the manufacturing efficiency.

[0131] In addition, the plurality of bump electrodes 14 may not be formed in the step of manufacturing the collective substrate 2 , but may be formed after the step ( S20 ) of inspecting the through-pass characteristics of the IDT electrode.

[0132] Next, the collective substrate 2 is cut on a cutting line, thereby individualizing the collective substrate 2 into a plurality of elastic wave chips 3 ( S30 ).

[0133] like Figure 5 As shown in (b), after cutting, the collective substrate 2 is separated into a plurality of elastic wave chips 3. At this time, the cutting width W of the cutting line at the boundary between adjacent elastic wave chips 3 is D Thus, the planar electrode 43 is divided into a plurality of planar electrodes 13 .

[0134] Next, the plurality of individual elastic wave chips 3 are bonded (face down) to the principal surface 20 a of the mounting substrate 20 on which the plurality of planar electrodes 21 are formed, respectively, via the plurality of bump electrodes 14 ( S40 ).

[0135] In addition, during or after step S40 , the resin member 30 may be disposed so as to be in contact with the main surface 20 a and cover the elastic wave chip 3 .

[0136] Here, after step S40, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max is smaller than the minimum distance D1 among the distances between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 that have different potentials from each other in the elastic wave device 1. min .

[0137] Therefore, even if the planar electrode 13 is peeled off or separated from the elastic wave chip 3, the maximum distance D13 of the planar electrode 13 max Less than the minimum distance D1 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from making contact across the planar electrode 12 and the planar electrode 21 and causing a short circuit in the functional electrode 11. Therefore, it is possible to provide the elastic wave device 1 in which a short circuit failure is prevented.

[0138] The mounting substrate 20 used in step S40 may be a mounting substrate 20 singulated corresponding to one elastic wave chip 3, or may be a collection of mounting substrates 20 before a plurality of mounting substrates 20 are singulated. When a collection of mounting substrates 20 is used, after the collection and the plurality of elastic wave chips 3 are bonded via a plurality of bump electrodes 14 and a resin member is arranged, the collection formed by bonding the collection and the plurality of elastic wave chips 3 may be cut to form individual elastic wave devices.

[0139] Alternatively, 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 elastic wave chip 3 after cutting may be max is smaller than the minimum distance Db between two bump electrodes having different potentials among the plurality of bump electrodes 14. min .

[0140] Therefore, even if the planar electrode 13 is peeled off or separated from the elastic wave chip 3, the maximum distance D13 of the planar electrode 13 max Less than the minimum distance Db min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two bump electrodes 14 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0141] Alternatively, 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 elastic wave chip 3 after cutting may be max is smaller than the minimum distance D3 between two planar electrodes 21 having different potentials among the plurality of planar electrodes 21. min .

[0142] Therefore, 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 is max Less than the minimum distance D3 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 21 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0143] Alternatively, 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 elastic wave chip 3 after cutting may be max is smaller than the minimum distance D2 between two planar electrodes 12 having different potentials among the plurality of planar electrodes 12 min .

[0144] Therefore, 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 is max Less than the minimum distance D2 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 12 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0145] Alternatively, 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 elastic wave chip 3 after cutting may be max The minimum distance D4 between the adjacent electrode fingers 61a and 61b is smaller than min .

[0146] Therefore, 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 is max Less than the minimum distance D4 min Therefore, it is possible to prevent the peeled or separated planar electrode 13 from coming into contact across two adjacent electrode fingers. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0147] [4. Structure of elastic wave device according to comparative example]

[0148] Here, the structure of the (conventional) elastic wave device according to the comparative example is described in advance. The elastic wave device according to the comparative example is different from the elastic wave device 1 according to the present embodiment in that the structure of the planar electrode 45 formed on the cutting line in the process of forming the IDT electrode is different. Hereinafter, with respect to the elastic wave device according to the comparative example and the manufacturing method thereof, the description of the same points as the elastic wave device 1 according to the present embodiment and the manufacturing method thereof is omitted, and the description is mainly focused on the differences.

[0149] The manufacturing method of the elastic wave device involved in the comparative example includes: (1) forming a functional electrode, a plurality of first plane electrodes connected to the functional electrode, a plane electrode 45 arranged on a cutting line with a given cutting width, and a plurality of bump electrodes on the main surface of a piezoelectric chip, thereby preparing an aggregate substrate 200; (2) bringing a measuring probe into contact with the plane electrode 45 to inspect the through-characteristics of an IDT electrode composed of the functional electrode and the plurality of first plane electrodes; (3) after inspecting the through-characteristics of the IDT electrode, cutting on the cutting line to singulate the aggregate substrate 200 into a plurality of elastic wave chips 203; and (4) bonding the plurality of bump electrodes of each of the singulated plurality of elastic wave chips 203 face-down to the third main surface of the mounting substrate on which a plurality of second plane electrodes are formed.

[0150] Figure 6 2 is a top view of an aggregate substrate 200 according to a comparative example. The same figure shows an electrode layout of a portion of an aggregate substrate 200 produced in the 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.

[0151] The planar electrode 45 is an example of a stylus electrode and is disposed on a surface having a given cutting width W. D on the cutting line. Figure 6 As shown, in the assembly substrate 200, the planar electrode 45 is rectangular when viewed from above the assembly substrate 200, and the width in the direction perpendicular to the cutting line (y-axis direction) is greater than the given cutting width W. D .

[0152] After the collective substrate 200 is cut, the collective substrate 200 is separated into a plurality of elastic wave chips 203. At this time, the cutting width W is 100 mm at the boundary between adjacent elastic wave chips 203. D As a result, a portion of the planar electrode 45 remains on the edge of the individualized elastic wave chip 203 .

[0153] Here, since the size of the portion of the planar electrode 45 remaining in the singulated elastic wave chip 203 is not specified, the maximum distance between the two ends of the remaining planar electrode 45 may be the minimum distance D1 among the distances between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 having different potentials from each other in the elastic wave device according to the comparative example. min above.

[0154] Therefore, when a portion of the remaining planar electrode 45 is separated from the elastic wave chip 203 , the maximum distance of the portion of the remaining planar electrode 45 may become the minimum distance D1.min As described above, a portion of the detached planar electrode 45 may cross the planar electrode 12 and the planar electrode 21 to make contact and short-circuit the functional electrode 11. Therefore, in the elastic wave device according to the comparative example, the occurrence of a short-circuit failure cannot be suppressed.

[0155] In contrast, according to the elastic wave device 1 and the method for manufacturing the same according to the present embodiment, even when the planar electrode 13 remaining in the individualized elastic wave chip 3 is peeled off or separated from the elastic wave chip 3, the maximum distance D13 of the planar electrode 13 is not max Less than the minimum distance D1 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from making contact across the planar electrode 12 and the planar electrode 21 and causing a short circuit in the functional electrode 11. Therefore, it is possible to provide the elastic wave device 1 in which a short circuit failure is prevented.

[0156] [5. Effects, etc.]

[0157] As described above, the elastic wave device 1 according to the present embodiment comprises: 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 so that the principal surface 20a faces the principal surface 10a; a functional electrode 11 arranged on the principal surface 10a and performing electromechanical transformation with the piezoelectric substrate 10; a plurality of planar electrodes 12 arranged on the principal surface 10a and connected to the functional electrode 11; a plurality of planar electrodes 21 arranged on the principal surface 20a; a planar electrode 13 arranged on the principal surface 10a and arranged to be in contact with the 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 bonded to the principal surfaces 10a and 20a, with the maximum distance D13 between the two ends of the planar electrode 13 being max is smaller than the minimum distance D1 among the distances between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 having different potentials from each other. min .

[0158] Therefore, 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 is max Less than the minimum distance D1 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from making contact across the planar electrode 12 and the planar electrode 21 and causing a short circuit in the functional electrode 11. Therefore, it is possible to provide the elastic wave device 1 in which a short circuit failure is prevented.

[0159] In addition, 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 so that the principal surface 20a faces the principal surface 10a; a functional electrode 11 arranged on the principal surface 10a and performing electromechanical conversion with the piezoelectric substrate 10; a plurality of planar electrodes 12 arranged on the principal surface 10a and connected to the functional electrode 11; a plurality of planar electrodes 21 arranged on the principal surface 20a; a planar electrode 13 arranged on the principal surface 10a and arranged to be in contact with the 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 bonded to the principal surfaces 10a and 20a, with the maximum distance D13 between the two ends of the planar electrode 13 being max is smaller than the minimum distance Db between two bump electrodes 14 having different potentials among the plurality of bump electrodes 14 min .

[0160] Therefore, 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 is max Less than the minimum distance Db min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two bump electrodes 14 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is prevented.

[0161] For another example, in the elastic wave device 1 , the maximum distance D13 between the two ends of the planar electrode 13 is max is smaller than the minimum distance D3 between two planar electrodes 21 having different potentials among the plurality of planar electrodes 21. min .

[0162] Therefore, 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 is max Less than the minimum distance D3 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 21 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0163] For another example, in the elastic wave device 1 , the maximum distance D13 between the two ends of the planar electrode 13 is max is smaller than the minimum distance D2 between two planar electrodes 12 having different potentials among the plurality of planar electrodes 12 min .

[0164] Therefore, 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 ismax Less than the minimum distance D2 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 12 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0165] For another example, the elastic wave device 1 includes an IDT electrode 54 disposed on the main surface 10a, and the IDT electrode 54 includes: a plurality of electrode fingers 61a and 61b disposed in parallel with each other; a bus bar electrode 62a configured to connect one ends of the plurality of electrode fingers 61a to each other; and a bus bar electrode 62b configured to connect one ends of the plurality of electrode fingers 61b to each other, and disposed opposite to the bus bar electrode 62a with the plurality of electrode fingers 61a and 61b interposed therebetween. Here, the functional electrode 11 includes the plurality of electrode fingers 61a and 61b, and the plurality of planar electrodes 12 includes the bus bar electrodes 62a and 62b.

[0166] This can prevent the peeled or detached planar electrode 13 from coming into contact with the planar electrode 21 across the bus bar electrode 62a or 62b and short-circuiting the functional electrode 11. Therefore, the elastic wave device 1 can be provided in which a short-circuit failure is prevented.

[0167] For another example, in the elastic wave device 1 , the maximum distance D13 between the two ends of the planar electrode 13 is max The minimum distance D4 between the adjacent electrode fingers 61a and 61b is smaller than min .

[0168] The method for manufacturing the elastic wave device 1 according to the present embodiment includes forming, on the principal surface 10a of the piezoelectric wafer 40 having piezoelectricity and including the principal surfaces 10a and 10b, a functional electrode 11 for performing electromechanical conversion with the piezoelectric wafer 40, a plurality of planar electrodes 12 connected to the functional electrode 11, and a plurality of planar electrodes 12 arranged on a surface having a predetermined cutting width W. DA process (S10) of manufacturing an aggregate substrate 2 by connecting a planar electrode 43 and a plurality of bump electrodes 14 along a cutting line; a process (S20) of bringing a measuring probe into contact with the planar electrode 43 to inspect the through-characteristics of an IDT electrode 54 composed of a functional electrode 11 and a plurality of planar electrodes 12; a process (S30) of cutting the aggregate substrate 2 along the cutting line after inspecting the through-characteristics of the IDT electrode 54 to singulate the aggregate substrate 2 into a plurality of elastic wave chips 3; and a process (S40) of joining the plurality of bump electrodes 14 respectively possessed by the singulated plurality of elastic wave chips 3 to the main surface 20a of the mounting substrate 20 on which a plurality of planar electrodes 21 are formed, wherein in the process of manufacturing 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 cutting line, and a portion of the slit portion 70 overlaps with the cutting line when the aggregate substrate 2 is viewed from above.

[0169] Thus, when the collective substrate 2 is cut and singulated into a plurality of elastic wave chips 3, a portion of each of the plurality of electrode main bodies 71 constituting one planar electrode 43 is separated and not connected to any electrode. In addition, in the elastic wave device 1 that has been manufactured, even if a portion of the plurality of electrode main bodies 71 remaining in the elastic wave chip 3 is peeled off or separated from the elastic wave chip 3, since a portion of each of the plurality of electrode main bodies 71 is an electrode obtained by subdividing the planar electrode 43, it is possible to prevent the functional electrode 11 from being short-circuited due to contact across the planar electrode 12 and the planar electrode 21. Therefore, it is possible to provide an elastic wave device 1 in which a short-circuit failure is prevented.

[0170] For another example, in the method for manufacturing the elastic wave device 1, in the step of manufacturing the collective substrate 2, the planar electrode 43 is connected to the functional electrode 11 via the lead wiring 44 formed on the cutting line, and the lead wiring 44 is formed on the cutting width W of the cutting line. D within the range.

[0171] Thus, when the collective substrate 2 is cut along the cutting line and singulated into a plurality of elastic wave chips 3, the planar electrode 43 is not connected to the functional electrode 11 and the planar electrode 12 and is rendered potential-free. Therefore, even if a part of the planar electrode 43 after cutting, i.e., the planar electrode 13, is peeled off and contacts the functional electrode 11 and / or the planar electrode 12, it is possible to prevent the elastic wave chip 3 from becoming short-circuited.

[0172] For another example, in the method of manufacturing elastic wave device 1 , in the step of manufacturing collective substrate 2 , planar electrode 43 is formed so that the width of slit portion 70 along the cutting line is smaller than the contact diameter of the tip of the measuring stylus.

[0173] Thus, the tip of the measuring probe crosses over the plurality of electrode main bodies 71 of the planar electrode 43 and makes contact therewith. Therefore, in the step of inspecting the through-pass characteristic of the IDT electrode 54 of the collective substrate 2 , the tip of the measuring probe and the planar electrode 43 can be reliably electrically connected.

[0174] For another example, in the method for manufacturing the elastic wave device 1, in the process of singulating into a plurality of elastic wave chips 3, the planar electrode 43 is divided into the plurality of planar electrodes 13 by cutting, and after the process of bonding the plurality of elastic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max is smaller than the minimum distance D1 among the distances between one of the plurality of planar electrodes 12 and one of the plurality of planar electrodes 21 having different potentials from each other. min .

[0175] Therefore, even if the planar electrode 13 is peeled off or separated from the elastic wave chip 3, the maximum distance D13 of the planar electrode 13 max Less than the minimum distance D1 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from making contact across the planar electrode 12 and the planar electrode 21 and causing a short circuit in the functional electrode 11. Therefore, it is possible to provide the elastic wave device 1 in which a short circuit failure is prevented.

[0176] For another example, in the method for manufacturing the elastic wave device 1, after the step of bonding each of the plurality of elastic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max is smaller than the minimum distance Db between two bump electrodes 14 having different potentials among the plurality of bump electrodes 14 min .

[0177] Therefore, even if the planar electrode 13 is peeled off or separated from the elastic wave chip 3, the maximum distance D13 of the planar electrode 13 max Less than the minimum distance Db min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two bump electrodes 14 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0178] For another example, in the method for manufacturing the elastic wave device 1, after the step of bonding each of the plurality of elastic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max is smaller than the minimum distance D3 between two planar electrodes 21 having different potentials among the plurality of planar electrodes 21. min .

[0179] Therefore, 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 is max Less than the minimum distance D3 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 21 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0180] For another example, in the method for manufacturing the elastic wave device 1, after the step of bonding each of the plurality of elastic wave chips 3 to the mounting substrate 20, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max is smaller than the minimum distance D2 between two planar electrodes 12 having different potentials among the plurality of planar electrodes 12 min .

[0181] Therefore, 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 is max Less than the minimum distance D2 min Therefore, it is possible to prevent the peeled or detached planar electrode 13 from coming into contact with two planar electrodes 12 having different potentials. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0182] For another example, in the method for manufacturing the elastic wave device 1, after the step of singulating the collective substrate 2 into the plurality of elastic wave chips 3, the maximum distance D13 between the two ends of each of the plurality of planar electrodes 13 is max The minimum distance D4 between the adjacent electrode fingers 61a and 61b is smaller than min .

[0183] Therefore, 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 is max Less than the minimum distance D4 min Therefore, it is possible to prevent the peeled or separated planar electrode 13 from coming into contact across two adjacent electrode fingers. Therefore, it is possible to provide an elastic wave device 1 in which a short circuit failure is further prevented.

[0184] (Other embodiments)

[0185] The elastic wave device and its manufacturing method according to the present invention are described by enumerating the embodiments above, but the present invention is not limited to the above embodiments. Modifications obtained by implementing various modifications conceived by those skilled in the art to the above embodiments within the scope of the main purpose of the present invention and various devices incorporating the elastic wave device according to the present invention are also included in the present invention.

[0186] Furthermore, for example, in the elastic wave devices according to the above-described embodiments, matching elements such as inductors and capacitors, switching circuits, and the like may be connected between the components.

[0187] Features of the elastic wave device and the method for manufacturing the same described based on the above-mentioned embodiments are described below.

[0188] <1>

[0189] An elastic wave device comprising:

[0190] The first substrate has piezoelectricity and includes a first main surface and a second main surface;

[0191] a second substrate including a third main surface and a fourth main surface, wherein the third main surface is arranged to face the first main surface;

[0192] A functional electrode is arranged on the first main surface and performs electromechanical conversion with the first substrate;

[0193] A plurality of first planar electrodes are arranged on the first main surface and connected to the functional electrodes;

[0194] A plurality of second planar electrodes are arranged on the third main surface;

[0195] a third planar electrode disposed on the first main surface and arranged to be in contact with an edge of the first substrate and not connected to the functional electrode and the first planar electrode; and

[0196] A plurality of bump electrodes are bonded to the first main surface and the third main surface,

[0197] 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 having different potentials from each other.

[0198] <2>

[0199] An elastic wave device comprising:

[0200] The first substrate has piezoelectricity and includes a first main surface and a second main surface;

[0201] a second substrate including a third main surface and a fourth main surface, wherein the third main surface is arranged to face the first main surface;

[0202] A functional electrode is arranged on the first main surface and performs electromechanical conversion with the first substrate;

[0203] A plurality of first planar electrodes are arranged on the first main surface and connected to the functional electrodes;

[0204] A plurality of second planar electrodes are arranged on the third main surface;

[0205] a third planar electrode disposed on the first main surface and arranged to be in contact with an edge of the first substrate and not connected to the functional electrode and the first planar electrode; and

[0206] A plurality of bump electrodes are bonded to the first main surface and the third main surface,

[0207] The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes.

[0208] <3>

[0209] according to <1> The elastic wave device, wherein:

[0210] The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes.

[0211] <4>

[0212] according to <1> ~ <3> The elastic wave device according to any one of claims , wherein:

[0213] The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes.

[0214] <5>

[0215] according to <1> ~ <4> The elastic wave device according to any one of claims , wherein:

[0216] The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes.

[0217] <6>

[0218] according to <1> ~ <5> The elastic wave device according to any one of claims , wherein:

[0219] The elastic wave device comprises: an IDT electrode disposed on the first main surface;

[0220] The IDT electrode has:

[0221] a plurality of first electrode fingers and a plurality of second electrode fingers arranged in parallel with each other;

[0222] a first bus bar electrode configured to connect one ends of the plurality of first electrode fingers to each other; and

[0223] a second bus bar electrode configured to connect one ends of the plurality of second electrode fingers to each other and arranged to face the first bus bar electrode with the plurality of first electrode fingers and the plurality of second electrode fingers interposed therebetween;

[0224] The functional electrode includes the plurality of first electrode fingers and the plurality of second electrode fingers.

[0225] The plurality of first planar electrodes include the first bus bar electrodes and the second bus bar electrodes.

[0226] <7>

[0227] according to <6> The elastic wave device, wherein:

[0228] The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between adjacent one of the plurality of first electrode fingers and one of the plurality of second electrode fingers.

[0229] <8>

[0230] A method for manufacturing an elastic wave device, comprising:

[0231] A step of forming, on the first main surface of a piezoelectric chip having piezoelectricity and including a first main surface and a second main surface, a functional electrode for performing electromechanical conversion with the piezoelectric chip, a plurality of first plane electrodes connected to the functional electrode, a stylus electrode arranged on a cutting line having a given cutting width, and a plurality of bump electrodes, thereby manufacturing an aggregate substrate;

[0232] a step of bringing a measurement probe into contact with the probe electrode to inspect the through-pass characteristic of an IDT electrode composed of the functional electrode and the plurality of first planar electrodes;

[0233] After inspecting the through-pass characteristics of the IDT electrodes, the collective substrate is cut along the cutting lines to separate the collective substrate into a plurality of elastic wave chips; and

[0234] a step of bonding the plurality of bump electrodes of each of the plurality of individual elastic wave chips to the third main surface of the mounting substrate on which the plurality of second planar electrodes are formed,

[0235] In the process of manufacturing the collective substrate,

[0236] The stylus electrode is connected to the functional electrode and has slit portions where no conductive material is formed at both ends in a direction perpendicular to the cutting line.

[0237] When the assembly substrate is viewed in plan, a portion of the slit portion overlaps the cutting line.

[0238] <9>

[0239] according to <8> The method for manufacturing an elastic wave device, wherein:

[0240] In the process of manufacturing the collective substrate,

[0241] The stylus electrode is connected to the functional electrode via a lead-out wiring formed on the cutting line.

[0242] The lead wiring is formed within the range of the given cutting width of the cutting line.

[0243] <10>

[0244] according to <8> or <9> The method for manufacturing an elastic wave device, wherein:

[0245] In the process of manufacturing the collective substrate,

[0246] The stylus electrode is formed so that the width of the slit portion in the direction along the cutting line is smaller than the contact diameter of the tip of the measuring stylus.

[0247] <11>

[0248] according to <8> ~ <10> The method for manufacturing an elastic wave device according to any one of claims , wherein:

[0249] In the step of singulating the plurality of elastic wave chips,

[0250] The stylus electrode is divided into a plurality of third plane electrodes by cutting.

[0251] After the step of bonding each of the plurality of elastic wave chips to the mounting substrate,

[0252] The maximum distance between both ends of each of the plurality of third planar electrodes is smaller than the minimum distance between one of the plurality of first planar electrodes and one of the plurality of second planar electrodes having different potentials from each other.

[0253] <12>

[0254] according to <8> ~ <10> The method for manufacturing an elastic wave device according to any one of claims , wherein:

[0255] In the step of singulating the plurality of elastic wave chips,

[0256] The stylus electrode is divided into a plurality of third plane electrodes by cutting.

[0257] After the step of bonding each of the plurality of elastic wave chips to the mounting substrate,

[0258] The maximum distance between the two ends of each of the plurality of third planar electrodes is smaller than the minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes.

[0259] <13>

[0260] according to <11> or <12> The method for manufacturing an elastic wave device, wherein:

[0261] After the step of bonding each of the plurality of elastic wave chips to the mounting substrate,

[0262] The maximum distance between the two ends of each of the plurality of third planar electrodes is smaller than the minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes.

[0263] <14>

[0264] according to <11> ~ <13> The method for manufacturing an elastic wave device according to any one of claims , wherein:

[0265] After the step of bonding each of the plurality of elastic wave chips to the mounting substrate,

[0266] The maximum distance between the two ends of each of the plurality of third planar electrodes is smaller than the minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes.

[0267] <15>

[0268] according to <11> ~ <14> The method for manufacturing an elastic wave device according to any one of claims , wherein:

[0269] In the step of singulating the plurality of elastic wave chips, each of the plurality of elastic wave chips has an IDT electrode disposed on the first main surface.

[0270] The IDT electrode has:

[0271] a plurality of first electrode fingers and a plurality of second electrode fingers arranged in parallel with each other;

[0272] a first bus bar electrode configured to connect one ends of the plurality of first electrode fingers to each other; and

[0273] a second bus bar electrode configured to connect one ends of the plurality of second electrode fingers to each other and arranged to face the first bus bar electrode with the plurality of first electrode fingers and the plurality of second electrode fingers interposed therebetween;

[0274] The functional electrode includes the plurality of first electrode fingers and the plurality of second electrode fingers.

[0275] After the step of singulating the collective substrate into a plurality of elastic wave chips,

[0276] A maximum distance connecting both ends of each of the plurality of third planar electrodes is smaller than a minimum distance between adjacent one of the plurality of first electrode fingers and one of the plurality of second electrode fingers.

[0277] Industrial Applicability

[0278] The present invention can be widely used in communication equipment such as mobile phones as a small elastic wave device that suppresses short-circuit failures.

Claims

1. An elastic wave device comprising: The first substrate has piezoelectricity and includes a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface, wherein the third main surface is arranged to face the first main surface; A functional electrode is arranged on the first main surface and performs electromechanical conversion with the first substrate; A plurality of first planar electrodes are arranged on the first main surface and connected to the functional electrodes; A plurality of second planar electrodes are arranged on the third main surface; a third plane electrode, arranged on the first main surface and arranged to be in contact with an edge of the first substrate, and not connected to the functional electrode and the first plane electrode; as well as A plurality of bump electrodes are bonded to the first main surface and the third main surface, 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 having different potentials from each other.

2. The elastic wave device according to claim 1, wherein: The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes.

3. An elastic wave device comprising: The first substrate has piezoelectricity and includes a first main surface and a second main surface; a second substrate including a third main surface and a fourth main surface, wherein the third main surface is arranged to face the first main surface; A functional electrode is arranged on the first main surface and performs electromechanical conversion with the first substrate; A plurality of first planar electrodes are arranged on the first main surface and connected to the functional electrodes; A plurality of second planar electrodes are arranged on the third main surface; a third plane electrode, arranged on the first main surface and arranged to be in contact with an edge of the first substrate, and not connected to the functional electrode and the first plane electrode; as well as A plurality of bump electrodes are bonded to the first main surface and the third main surface, The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two bump electrodes having different potentials among the plurality of bump electrodes.

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

5. The elastic wave device according to any one of claims 1 to 4, wherein: The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes.

6. The elastic wave device according to any one of claims 1 to 5, wherein: The elastic wave device comprises: an IDT electrode disposed on the first main surface; The IDT electrode has: a plurality of first electrode fingers and a plurality of second electrode fingers arranged in parallel with each other; a first bus bar electrode configured to connect one ends of the plurality of first electrode fingers to each other; as well as a second bus bar electrode configured to connect one ends of the plurality of second electrode fingers to each other and arranged to face the first bus bar electrode with the plurality of first electrode fingers and the plurality of 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 electrodes and the second bus bar electrodes.

7. The elastic wave device according to claim 6, wherein: The maximum distance between the two ends of the third planar electrode is smaller than the minimum distance between adjacent one of the plurality of first electrode fingers and one of the plurality of second electrode fingers.

8. A method for manufacturing an elastic wave device, comprising: A step of forming, on the first main surface of a piezoelectric chip having piezoelectricity and including a first main surface and a second main surface, a functional electrode for performing electromechanical conversion with the piezoelectric chip, a plurality of first plane electrodes connected to the functional electrode, a stylus electrode arranged on a cutting line having a given cutting width, and a plurality of bump electrodes, thereby manufacturing an aggregate substrate; a step of bringing a measurement probe into contact with the probe electrode to inspect the through-pass characteristic of an IDT electrode composed of the functional electrode and the plurality of first planar electrodes; After inspecting the through-pass characteristics of the IDT electrodes, the collective substrate is cut along the cutting lines to separate the collective substrate into a plurality of elastic wave chips; as well as a step of bonding the plurality of bump electrodes of each of the plurality of individual elastic wave chips to the third main surface of the mounting substrate on which the plurality of second planar electrodes are formed, In the process of manufacturing the collective substrate, The stylus electrode is connected to the functional electrode and has slit portions where no conductive material is formed at both ends in a direction perpendicular to the cutting line. When the assembly substrate is viewed in plan, a portion of the slit portion overlaps the cutting line.

9. The method for manufacturing an elastic wave device according to claim 8, wherein: In the process of manufacturing the collective substrate, The stylus electrode is connected to the functional electrode via a lead-out wiring formed on the cutting line. The lead wiring is formed within the range of the given cutting width of the cutting line.

10. The method for manufacturing an elastic wave device according to claim 8 or 9, wherein: In the process of manufacturing the collective substrate, The stylus electrode is formed so that the width of the slit portion in the direction along the cutting line is smaller than the contact diameter of the tip of the measuring stylus.

11. The method for manufacturing an elastic wave device according to any one of claims 8 to 10, wherein: In the step of singulating the plurality of elastic wave chips, The stylus electrode is divided into a plurality of third plane electrodes by cutting. After the step of bonding each of the plurality of elastic wave chips to the mounting substrate, The maximum distance between both ends of each of the plurality of third planar electrodes is smaller than the minimum distance between one of the plurality of first planar electrodes and one of the plurality of second planar electrodes having different potentials from each other.

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

13. The method for manufacturing an elastic wave device according to claim 11 or 12, wherein: After the step of bonding each of the plurality of elastic wave chips to the mounting substrate, The maximum distance between the two ends of each of the plurality of third planar electrodes is smaller than the minimum distance between two second planar electrodes having different potentials among the plurality of second planar electrodes.

14. The method for manufacturing an elastic wave device according to any one of claims 11 to 13, wherein: After the step of bonding each of the plurality of elastic wave chips to the mounting substrate, The maximum distance between the two ends of each of the plurality of third planar electrodes is smaller than the minimum distance between two first planar electrodes having different potentials among the plurality of first planar electrodes.

15. The method for manufacturing an elastic wave device according to any one of claims 11 to 14, wherein: In the step of singulating the plurality of elastic wave chips, each of the plurality of elastic wave chips has an IDT electrode disposed on the first main surface. The IDT electrode has: a plurality of first electrode fingers and a plurality of second electrode fingers arranged in parallel with each other; a first bus bar electrode configured to connect one ends of the plurality of first electrode fingers to each other; as well as a second bus bar electrode configured to connect one ends of the plurality of second electrode fingers to each other and arranged to face the first bus bar electrode with the plurality of first electrode fingers and the plurality of 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 singulating the collective substrate into a plurality of elastic wave chips, A maximum distance connecting both ends of each of the plurality of third planar electrodes is smaller than a minimum distance between adjacent one of the plurality of first electrode fingers and one of the plurality of second electrode fingers.

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