JP7373305B2 - Acoustic wave device and its manufacturing method - Google Patents

Description

The present invention relates to an acoustic wave device and a method for manufacturing the same, and for example, to an acoustic wave device having a piezoelectric substrate bonded to a support substrate and a method for manufacturing the same.

A method for manufacturing an acoustic wave device includes mounting a second substrate on a first substrate in which a piezoelectric substrate having an acoustic wave element on the upper surface is bonded to a support substrate, and forming a sealing portion to surround the second substrate. This is known (for example, Patent Document 1).

Japanese Patent Application Publication No. 2017-169139

When the sealing portion is cut using a dicing blade and the first substrate is cut using a laser beam, the acoustic wave device becomes larger.

The present invention has been made in view of the above problems, and an object of the present invention is to miniaturize the device.

The present invention includes irradiating the support substrate with a laser beam on both sides of a center line in the width direction of a cutting region extending in the plane direction of a first substrate to which a piezoelectric substrate and a support substrate are directly or indirectly joined. , forming a groove and/or a modified region in the supporting substrate; and placing a plurality of second substrates between the cutting region on the opposite side of the piezoelectric substrate to the piezoelectric substrate with a gap in between. a step of mounting the plurality of second substrates so as to face each other and joining the first substrate in the cutting region to a region surrounding the plurality of second substrates and including the cutting region; irradiating the laser beam by forming a sealing part that seals the acoustic wave element in the gap, and forming another groove in which both sides in the width direction of the cutting area are the sides of the sealing part . cutting the sealing portion such that the distance in the width direction of the cutting region between the position of the groove and the side surface of the sealing portion is ⅕ or less of the width in the width direction of the cutting region of the other groove; and, after the step of forming the groove and/or the modified region and the step of cutting the sealing portion, cutting the first substrate on both sides of the center line of the cutting region. This is a method for manufacturing a device.

In the above configuration, the step of forming the groove and/or the modified region includes irradiating a laser beam onto a surface of the first substrate on the second substrate side before the step of forming the sealing part. The method may include a step of forming the groove and/ or the modified region.

In the above configuration, the step of forming the groove and/or the modified region includes irradiating the surface of the first substrate opposite to the second substrate with a laser beam to form the groove and/ or the modified region. The configuration may include a step of forming.

In the above configuration, the step of forming the groove and/or the modified region includes irradiating a laser beam onto the surface of the first substrate on the second substrate side before the step of forming the sealing part. After the step of forming the groove or the modified region and the step of forming the sealing part, the surface of the first substrate opposite to the second substrate is irradiated with a laser beam, thereby forming the groove. Alternatively, the method may include a step of forming the modified region.

In the above configuration, the step of forming the groove and/or the modified region may include a step of forming the groove in the support substrate.

In the above configuration, the step of forming the groove and/or the modified region may include a step of forming the modified region on the support substrate.

In the above configuration, the step of cutting the sealing portion may include a step of cutting the sealing portion using a dicing blade.

In the above configuration, the support substrate may be a sapphire substrate, a spinel substrate, or a quartz substrate, and the sealing portion may be made of solder or resin.

According to the present invention, it is possible to downsize the device.

FIG. 1 is a cross-sectional view of an acoustic wave device according to Example 1. 2(a) is a plan view of the acoustic wave element 12 in Example 1, and FIG. 2(b) is a sectional view of the acoustic wave element 22. FIG. 3 is a plan view showing a method for manufacturing an acoustic wave device according to Example 1. FIGS. 4(a) to 4(c) are cross-sectional views (part 1) showing the method for manufacturing the acoustic wave device according to the first embodiment. 5(a) and 5(b) are cross-sectional views (part 2) showing the method for manufacturing the acoustic wave device according to the first embodiment. 6(a) and 6(b) are side views of the acoustic wave device according to the first embodiment. FIGS. 7A to 7C are cross-sectional views showing a method for manufacturing an acoustic wave device according to Comparative Example 1. FIG. 8 is a cross-sectional view of an acoustic wave device according to Comparative Example 1. FIGS. 9A and 9B are cross-sectional views showing a method for manufacturing an acoustic wave device according to Modification 1 of Example 1. FIG. 10(a) to 10(c) are cross-sectional views showing a method of manufacturing an acoustic wave device according to a second modification of the first embodiment. 11(a) and 11(b) are side views of an acoustic wave device according to a second modification of the first embodiment. 12(a) and 12(b) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a third modification of the first embodiment. 13(a) to 13(c) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a fourth modification of the first embodiment. 14(a) and 14(b) are side views of an acoustic wave device according to a fourth modification of the first embodiment. 15(a) and 15(b) are cross-sectional views showing a method of manufacturing an acoustic wave device according to a fifth modification of the first embodiment. 16(a) and 16(b) are cross-sectional views showing a method of manufacturing an acoustic wave device according to a sixth modification of the first embodiment. 17(a) and 17(b) are side views of an acoustic wave device according to a sixth modification of the first embodiment. 18(a) and 18(b) are cross-sectional views showing a method for manufacturing an acoustic wave device according to Modification Example 7 of Example 1. FIG. 19(a) is a circuit diagram of a filter according to a second embodiment, and FIG. 19(b) is a circuit diagram of a duplexer according to a first modification of the second embodiment.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of an acoustic wave device according to Example 1. As shown in FIG. 1, the substrate 10 includes a support substrate 10a and a piezoelectric substrate 10b. The support substrate 10a is, for example, a sapphire substrate, an alumina substrate, a spinel substrate, a quartz substrate, a crystal substrate, or a silicon substrate. The piezoelectric substrate 10b is, for example, a lithium tantalate substrate or a lithium niobate substrate. The piezoelectric substrate 10b is bonded to the upper surface of the support substrate 10a. The linear expansion coefficient of the support substrate 10a is smaller than that of the piezoelectric substrate 10b. An insulator layer such as silicon oxide or aluminum nitride may be provided between the piezoelectric substrate 10b and the support substrate 10a. In this way, the piezoelectric substrate 10b is directly or indirectly joined to the support substrate 10a.

An acoustic wave element 12, wiring 14, and an annular metal layer 32 are provided on the upper surface of the substrate 10. The annular metal layer 32 is embedded in the piezoelectric substrate 10b and is provided so as to surround the acoustic wave element 12 and the wiring 14 in plan view. An annular metal layer 34 is provided on the annular metal layer 32 . Terminals 18 are provided on the lower surface of the substrate 10. The terminal 18 is a foot pad for connecting the acoustic wave elements 12 and 22 to the outside. A via wiring 16 is provided that penetrates the substrate 10. The via wiring 16 electrically connects the terminal 18 and the wiring 14. The wiring 14, the via wiring 16, the terminal 18, and the annular metal layer 32 are, for example, metal layers such as a copper layer, an aluminum layer, a platinum layer, or a gold layer. The annular metal layer 34 is, for example, a nickel layer.

A substrate 20 is mounted on the substrate 10. The substrate 20 is, for example, a sapphire substrate, an alumina substrate, a spinel substrate, a quartz substrate, a crystal substrate, or a silicon substrate. An acoustic wave element 22 and wiring 24 are provided on the lower surface of the substrate 20. The wiring 24 is, for example, a metal layer such as a copper layer, an aluminum layer, a platinum layer, or a gold layer. The board 20 is flip-chip mounted (face-down mounted) on the board 10 via bumps 28. Bumps 28 are, for example, gold bumps, solder bumps, or copper bumps. Bump 28 connects to wirings 14 and 24.

A sealing section 30 is provided on the substrate 10 so as to surround the substrate 20. The sealing portion 30 is, for example, a metal layer such as solder (tin-silver, tin, or tin-silver-copper) or an insulating layer such as resin. The sealing part 30 is joined to the annular metal layer 34. A flat lid 36 is provided on the upper surface of the substrate 20 and the upper surface of the sealing section 30. The lid 36 is, for example, a metal plate such as a Kovar plate or an insulating plate. A protective film 38 is provided to cover the lid 36 and the sealing part 30. The protective film 38 is a metal film such as a nickel film or an insulating film.

The acoustic wave element 12 faces the substrate 20 with a gap 26 in between. The acoustic wave element 22 faces the piezoelectric substrate 10b with a gap 26 in between. Acoustic wave elements 12 and 22 are sealed by sealing part 30, substrate 10, substrate 20, and lid 36. Bump 28 is surrounded by void 26. The terminal 18 is electrically connected to the acoustic wave element 12 via the via wiring 16 and the wiring 14, and further electrically connected to the acoustic wave element 22 via the bump 28 and the wiring 24.

The thickness of the support substrate 10a is, for example, 50 μm to 300 μm. The thickness of the piezoelectric substrate 10b is, for example, 0.5 μm to 30 μm, which is, for example, less than the wavelength of an elastic wave. The thickness of the bump 28 is, for example, 10 μm to 20 μm. The thickness of the substrate 20 is, for example, 50 μm to 200 μm.

2(a) is a plan view of the acoustic wave element 12 in Example 1, and FIG. 2(b) is a sectional view of the acoustic wave element 22. As shown in FIG. 2(a), the acoustic wave element 12 is a surface acoustic wave resonator. An IDT (Interdigital Transducer) 40 and a reflector 42 are formed on the piezoelectric substrate 10b of the substrate 10. The IDT 40 has a pair of comb-shaped electrodes 40a facing each other. The comb-shaped electrode 40a has a plurality of electrode fingers 40b and a bus bar 40c connecting the plurality of electrode fingers 40b. Reflectors 42 are provided on both sides of the IDT 40. The IDT 40 excites surface acoustic waves in the piezoelectric substrate 10b. The wavelength of the elastic wave is approximately equal to the pitch of the electrode fingers 40b of one of the pair of comb-shaped electrodes 40a. That is, the wavelength of the elastic wave is approximately equal to twice the pitch of the electrode fingers 40b of the pair of comb-shaped electrodes 40a. The IDT 40 and the reflector 42 are formed of, for example, an aluminum film or a copper film. A protective film or a temperature compensation film may be provided on the piezoelectric substrate 10b so as to cover the IDT 40 and the reflector 42.

As shown in FIG. 2(b), the acoustic wave element 22 is a piezoelectric thin film resonator. A piezoelectric film 46 is provided on the substrate 20. A lower electrode 44 and an upper electrode 48 are provided so as to sandwich the piezoelectric film 46 therebetween. A gap 45 is formed between the lower electrode 44 and the substrate 20. A region where the lower electrode 44 and the upper electrode 48 face each other with at least a portion of the piezoelectric film 46 in between is a resonance region 47 . In the resonance region 47, the lower electrode 44 and the upper electrode 48 excite elastic waves in the thickness longitudinal vibration mode within the piezoelectric film 46. The substrate 20 is, for example, a sapphire substrate, a spinel substrate, an alumina substrate, a glass substrate, a crystal substrate, or a silicon substrate. The lower electrode 44 and the upper electrode 48 are, for example, metal films such as ruthenium films. The piezoelectric film 46 is, for example, an aluminum nitride film. Instead of the void 45, an acoustic reflection film that reflects elastic waves may be provided.

Acoustic wave elements 12 and 22 include electrodes that excite elastic waves. For this reason, the elastic wave elements 12 and 22 are covered with a void 26 so as not to limit the elastic waves.

[Production method of Example 1]
FIG. 3 is a plan view showing a method for manufacturing an acoustic wave device according to Example 1. FIGS. 4(a) to 5(b) are cross-sectional views showing a method for manufacturing an acoustic wave device according to Example 1. FIG. As shown in FIG. 3, cutting areas 68 are provided on the wafer 66 in a grid pattern. The cutting area 68 is an area where the sealing part 30 is removed when the wafer 66 is cut. The width of the cutting region 68 is, for example, 50 μm to 200 μm.

As shown in FIG. 4(a), an acoustic wave element 12 and wiring 14 are provided on a substrate 10. A via wiring 16 is provided that penetrates the substrate 10. An annular metal layer 32 is provided in the area where the piezoelectric substrate 10b has been removed. An annular metal layer 34 is provided on the annular metal layer 32 . Terminals 18 are provided below the substrate 10. For example, resist is formed as a protective film 55 under the substrate 10 . The protective film 55 protects the lower surface of the substrate 10. A tape 56 such as a resin tape is attached to the lower surface of the protective film 55. Tape 56 reinforces substrate 10.

By irradiating the substrate 10 with laser light 54 from above, grooves 60 are formed in the upper portions of the annular metal layer 32, the piezoelectric substrate 10b, and the support substrate 10a. Part of the piezoelectric substrate 10b and the support substrate 10a are sublimated by the laser ablation, and a groove 60 is formed. As shown in FIG. 3, the grooves 60 are formed at both ends of the cutting region 68 so as to extend in the direction in which the cutting region 68 extends. The depth of the groove 60 in the support substrate 10a is, for example, 10 μm to 40 μm. The laser beam 54 is, for example, the third harmonic of an Nd:YAG laser, and the wavelength of the laser beam 54 is, for example, 355 nm, for example, from 100 nm to 600 nm. Laser light 54 may be visible light, ultraviolet light, or infrared light.

As shown in FIG. 4(b), the substrate 20 is flip-chip mounted on the substrate 10. As shown in FIG. 3, the substrate 20 is mounted so as to be surrounded by the cutting area 68. A sealing part 30 is formed to surround the substrate 20. The sealing portion 30 is made of solder, for example, and is bonded to the upper surface of the annular metal layer 34 . A lid 36 is provided on the upper surface of the substrate 20 and the sealing part 30.

As shown in FIG. 4C, the lid 36, the sealing part 30, and the piezoelectric substrate 10b in the cutting area 68 are cut using the dicing blade 58. As a result, a groove 64 is formed in the cutting region 68. The side surface of the groove 64 substantially coincides with the position of the groove 60. The support substrate 10a is exposed at the bottom of the groove 64.

As shown in FIG. 5(a), a tape 57 such as a resin tape is attached to the upper surface of the lid 36. Tape 57 reinforces substrate 10. After peeling off the tape 56, a groove 62 is formed in the lower part of the support substrate 10a by irradiating the substrate 10 with laser light 54 from below. Grooves 62 are formed at both ends of cutting region 68. The depth of the groove 62 at the bottom of the support substrate 10a is, for example, 10 μm to 40 μm.

As shown in FIG. 5(b), a tape 56 such as a resin tape is attached to the lower surface of the protective film 55. Press the break blade 59 from below the tape 56. As a result, a crack 65 is formed in the support substrate 10a, starting from the grooves 60 and 62 and penetrating the support substrate 10a. As a result, the support substrate 10a is cut. By expanding the tapes 56 and 57, the substrate 10 is separated into pieces. Thereafter, tapes 56 and 57 are peeled off. A protective film 38 is formed on the surfaces of the annular metal layers 32 and 34, the sealing portion 30, and the lid 36 using, for example, a plating method. Through the above steps, the acoustic wave device of Example 1 is manufactured.

6(a) and 6(b) are side views of the acoustic wave device according to the first embodiment. FIG. 6(b) is a side view through the protective film 38. As shown in FIGS. 6(a) and 6(b), laser marks 61 and 63 are provided on the side surface of the support substrate 10a. The laser mark 61 is provided on the upper part of the support substrate 10a, and the laser mark 63 is provided on the lower part of the support substrate 10a. The heights H1 and H2 of the laser marks 61 and 63 are, for example, 10 μm to 40 μm, and an example of an average value is about 13 μm.

4(a) and FIG. 5(a), when the laser beam 54 is pulsed light and both ends of the cutting area 68 of the wafer 66 in FIG. 3 are scanned at a constant speed, a The laser marks 61 and 63 have a triangular wave shape. The period D2 of the triangular wave is determined by the pulse period of the pulsed light and the scanning speed of the laser beam 54, and is, for example, 1 μm to 50 μm. The laser marks 61 and 63 are the side surfaces of the grooves 60 and 62 formed by sublimation of the support substrate 10a, and the surfaces are polycrystalline or amorphous. The side surfaces of the lid 36 and the sealing portion 30 are side surfaces 70 cut by a blade dicing method. The side surface of the supporting substrate 10a other than the laser marks 61 and 63 is a broken side surface 72.

[Comparative example 1]
FIGS. 7A to 7C are cross-sectional views showing a method for manufacturing an acoustic wave device according to Comparative Example 1. As shown in FIG. 7(a), in FIG. 4(a) of Example 1, before irradiating the laser beam 54, the substrate 20 is mounted on the substrate 10, and the sealing part 30 and the lid 36 are formed. . The lid 36, the sealing part 30, and the piezoelectric substrate 10b in the cutting area 68 are cut using the dicing blade 58.

As shown in FIG. 7B, the groove 60 is formed in the upper part of the support substrate 10a by irradiating the bottom surface of the groove 64 with the laser beam 54. As shown in FIG. 7(c), the support substrate 10a is separated into pieces by pressing the break blade 59 in the same way as in FIG. 5(b). Hereinafter, the steps in and after FIG. 5(b) of Example 1 are performed.

FIG. 8 is a cross-sectional view of an acoustic wave device according to Comparative Example 1. The support substrate 10a supports the piezoelectric substrate 10b and is therefore harder than the piezoelectric substrate 10b and the sealing portion 30. Therefore, if the supporting substrate 10a is blade-diced at the same time as the sealing part 30, cracks or the like will occur in the supporting substrate 10a. Moreover, the sealing part 30 is soft like metal or resin. Therefore, it is difficult to break the sealing portion 30 using the break blade 59. Therefore, in Comparative Example 1, after cutting the sealing portion 30 using a blade dicing method, the supporting substrate 10a is irradiated with the laser beam 54 and cut using the break blade 59. However, as shown in FIG. 7A, the width of the groove 64 formed by the dicing blade 58 is as large as the width of the dicing blade 58. On the other hand, the width of the groove 60 formed by the laser beam 54 is small.

Therefore, as shown in FIG. 8, the side surface of the support substrate 10a is located outside the side surface of the sealing portion 30 by a distance D1. The distance D1 is approximately 1/2 the width of the groove 64 in FIG. 7(a), and approximately 1/2 the width of the dicing blade 58. For example, D1 is 40 μm. In Comparative Example 1, the width of the acoustic wave device is increased by 2×D1. This increases the size of the elastic wave device. Further, if the sizes of the acoustic wave devices are the same, the area on the piezoelectric substrate 10b in which the acoustic wave element 12 and the wiring 24 can be arranged becomes smaller.

According to the first embodiment, as shown in FIGS. 4(a) and 5(a), the support substrate is cut on both sides of the center line 67 in the width direction of the cutting region 68 extending in the plane direction of the substrate 10 (first substrate). Grooves 60 and 62 are formed in the supporting substrate 10a by irradiating the laser beam 54 onto the supporting substrate 10a. As shown in FIGS. 3 and 4(b), a plurality of substrates 20 (second substrates) are placed between the cutting region 68 on the top surface of the piezoelectric substrate 10b (the surface opposite to the supporting substrate 10a), and be installed so that they are facing each other. A sealing part 30 that surrounds the plurality of substrates 20 and is joined to the substrate 10 in the cutting area 68 in a region including the cutting area 68, and seals the piezoelectric substrate 10b and the acoustic wave elements 12 and 22 provided on the substrate 20 in the gap 26. form. As shown in FIG. 4C, the sealing portion 30 is cut by forming a groove 64 whose side surfaces are both sides of the cutting region 68 in the width direction. As shown in FIG. 5B, after forming the grooves 60 and 62 and cutting the sealing portion 30, the substrate 10 is cut on both sides of the center line of the cutting region 68.

In FIGS. 4A and 5A, the acoustic wave device can be made smaller than Comparative Example 1 by irradiating the laser beam 54 on both sides of the center line 67 in the width direction of the cutting region 68. Furthermore, the area in which the acoustic wave element 12 is arranged can be increased. By irradiating the laser beam 54 at or near both sides of the cutting region 68 in the width direction, as shown in FIG. Approximately matches. The distance between the position where the laser beam 54 is irradiated and both sides of the cutting region 68 in the width direction is preferably 1/5 or less of the width of the groove 64, and more preferably 1/10 or less.

In the manufactured acoustic wave device, as shown in FIGS. 6(a) and 6(b), the supporting substrate 10a has laser marks 61 and 63.

As shown in FIG. 4C, the sealing portion 30 may be cut using an etching method or a sandblasting method, but it is preferable to use a dicing blade 58. Thereby, the sealing part 30 can be easily cut.

The support substrate 10a is a sapphire substrate, a spinel substrate, or a quartz substrate, and the sealing portion 30 is made of solder or resin. The sapphire substrate is a substrate whose main component is single crystal Al ₂ O ₃ . A spinel substrate is a substrate whose main component is single crystal or polycrystalline MgAl ₂ O ₄ . The quartz substrate is a substrate whose main component is amorphous SiO ₂ . In this case, since the supporting substrate 10a is hard, the supporting substrate 10a is irradiated with laser light 54 and then cut. Since the sealing part 30 is soft, it is difficult to cut it. Therefore, if the groove 64 is formed in the sealing part 30, the acoustic wave device becomes larger as in Comparative Example 1. Therefore, it is preferable to irradiate both sides of the center line of the cutting region 68 with the laser light 54 as in the first embodiment. The piezoelectric substrate 10b is a lithium tantalate substrate or a lithium niobate substrate. At this time, since the piezoelectric substrate 10b is not as hard as the support substrate 10a, the groove 64 can be formed to cut the piezoelectric substrate 10b.

[Modification 1 of Example 1]
FIGS. 9A and 9B are cross-sectional views showing a method for manufacturing an acoustic wave device according to Modification 1 of Example 1. FIG. As shown in FIG. 9(a), the tape 56 is peeled off after FIG. 4(b) of Example 1. A tape 57 is pasted on the lid 36. Laser light 54 is irradiated from below the substrate 10 to form grooves 62. As shown in FIG. 9(b), a tape 56 is attached to the lower surface of the protective film 55. Peel off the tape 57. The lid 36, the sealing part 30, and the piezoelectric substrate 10b are removed by cutting with a dicing blade 58 to form a groove 64. Thereafter, the steps in and after FIG. 5(b) of Example 1 are performed. The other steps are the same as in Example 1, and their explanation will be omitted.

[Modification 2 of Example 1]
10(a) to 10(c) are cross-sectional views showing a method of manufacturing an acoustic wave device according to a second modification of the first embodiment. As shown in FIG. 10(a), a tape 56 is attached to the lower surface of the support substrate 10a without providing the protective film 55. Thereafter, grooves 60 are formed in the same manner as in FIG. 4(a) of Example 1. Similarly to FIG. 4(b), the substrate 20 is mounted on the substrate 10, and the sealing portion 30 and the lid 36 are formed. As shown in FIG. 10(b), grooves 64 are formed using the dicing blade 58 in the same manner as in FIG. 4(c) of Example 1.

As shown in FIG. 10(c), a tape 57 is pasted on the lid 36. Peel off the tape 56. Laser light 54 is irradiated from below the substrate 10 to form a modified region 62a in the support substrate 10a. The modified region 62a is formed by focusing the laser beam 54 on a desired position on the support substrate 10a. In order to focus on the support substrate 10a, it is preferable not to provide the protective film 55. In the modified region 62a, the supporting substrate 10a is melted and then solidified to become an amorphous or polycrystalline region. Thereafter, the steps from FIG. 5(b) onwards are performed. The other steps are the same as in Example 1, and their explanation will be omitted.

11(a) and 11(b) are side views of an acoustic wave device according to a second modification of the first embodiment. FIG. 11(b) is a side view through the protective film 38. As shown in FIGS. 11(a) and 11(b), laser marks 61 are provided on the upper part of the support substrate 10a, and laser marks 63a are provided on the lower part of the support substrate 10a. The laser mark 61 is the same as in the first embodiment.

When the laser beam 54 is a pulsed beam and both ends of the cutting area 68 of the wafer 66 in FIG. The marks are arranged in the plane direction. The width of the modified region 62a is, for example, 1 μm to 10 μm. The period D3 of the modified region 62a is, for example, from 2 μm to 50 μm. One or more modified regions 62a are provided in the thickness direction of the support substrate 10a. The distance D4 between the modified regions 62a in the thickness direction is, for example, 2 μm to 20 μm. The side surfaces of the lid 36 and the sealing portion 30 are side surfaces 70 cut by a blade dicing method. The side surface of the support substrate 10a other than the laser marks 61 and 63a is a broken side surface 72.

[Modification 3 of Example 1]
12(a) and 12(b) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a third modification of the first embodiment. As shown in FIG. 12(a), a tape 57 is pasted on the lid 36 after FIG. 10(a) of the second modification of the first embodiment. Peel off the tape 56 on the bottom surface of the substrate 10. Laser light 54 is irradiated from below the substrate 10 to form a modified region 62a in the support substrate 10a. As shown in FIG. 12(b), a protective film 55 is formed on the lower surface of the substrate 10. A tape 56 is attached to the lower surface of the protective film 55. Peel off the tape 57. A groove 64 is formed by cutting the lid 36, sealing portion 30, and piezoelectric substrate 10b using a dicing blade 58. Thereafter, the steps in and after FIG. 5(b) of Example 1 are performed. The other steps are the same as those in Modification 2 of Example 1, and their explanation will be omitted.

[Modification 4 of Example 1]
13(a) to 13(c) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a fourth modification of the first embodiment. As shown in FIG. 13A, the substrate 20 is mounted on the substrate 10 without forming the groove 60 on the upper surface of the support substrate 10a, and the sealing portion 30 and the lid 36 are formed. A tape 56 is applied to the lower surface of the substrate 10, and a groove 64 is formed using a dicing blade 58 in the same manner as in FIG. 4C of Example 1.

As shown in FIG. 13(b), a tape 57 is pasted on the lid 36. Peel off the tape 56 on the bottom surface of the substrate 10. A laser beam 54 is irradiated from below the substrate 10 to form a groove 62 on the lower surface of the support substrate 10a. As shown in FIG. 13C, a tape 56 is attached under the protective film 55 and a crack 65 is formed using a break blade 59 to separate the substrate 10 into pieces. The other configurations are the same as those in Example 1, and their explanation will be omitted.

14(a) and 14(b) are side views of an acoustic wave device according to a fourth modification of the first embodiment. FIG. 14(b) is a side view through the protective film 38. As shown in FIGS. 14(a) and 14(b), no laser marks are provided on the upper part of the support substrate 10a, but laser marks 63 are provided on the lower part of the support substrate 10a. The laser mark 63 is the same as in the first embodiment. The side surfaces of the lid 36, the sealing portion 30, and the annular metal layers 32 and 34 are side surfaces 70 cut by a blade dicing method. The side surface of the support substrate 10a other than the laser mark 63 is a broken side surface 72.

[Modification 5 of Example 1]
15(a) and 15(b) are cross-sectional views showing a method of manufacturing an acoustic wave device according to a fifth modification of the first embodiment. As shown in FIG. 15A, a tape 57 is pasted on the lid 36 before the tape 56 is pasted on the lower surface of the substrate 10 in FIG. 13A of the fourth modification of the first embodiment. A laser beam 54 is irradiated from below the substrate 10 to form a groove 62 on the lower surface of the support substrate 10a. As shown in FIG. 15(b), a tape 56 is applied to the lower surface of the protective film 55, and the tape 57 is peeled off. A groove 64 is formed in the lid 36, the sealing part 30, and the piezoelectric substrate 10b using the dicing blade 58. Thereafter, the steps in and after FIG. 5(b) of Example 1 are performed. The other steps are the same as those in Modified Example 4 of Example 1, and the explanation will be omitted.

[Modification 6 of Example 1]
16(a) and 16(b) are cross-sectional views showing a method of manufacturing an acoustic wave device according to a sixth modification of the first embodiment. As shown in FIG. 16(a), a tape 56 is pasted on the lower surface of the substrate 10 without providing a protective film 55. Grooves 64 are formed using the dicing blade 58 in the same manner as in FIG. 13(a) of the fourth modification of the first embodiment. As shown in FIG. 16(b), similarly to FIG. 10(c) of Modification 2 of Example 1, the substrate 10 is irradiated with laser light 54 from below to form a modified region 62a in the support substrate 10a. . Thereafter, the steps in and after FIG. 5(b) of Example 1 are performed. The other steps are the same as in Example 1, and their explanation will be omitted.

17(a) and 17(b) are side views of an acoustic wave device according to a sixth modification of the first embodiment. FIG. 17(b) is a side view through the protective film 38. As shown in FIGS. 17(a) and 17(b), no laser marks are provided on the upper part of the support substrate 10a, but laser marks 63a are provided on the lower part of the support substrate 10a. The laser mark 63a is the same as the second modification of the first embodiment. The side surfaces of the lid 36, the sealing portion 30, and the annular metal layers 32 and 34 are side surfaces 70 cut by a blade dicing method. The side surface of the support substrate 10a other than the laser mark 63a is a broken side surface 72.

[Modification 7 of Example 1]
18(a) and 18(b) are cross-sectional views showing a method for manufacturing an acoustic wave device according to Modification Example 7 of Example 1. FIG. As shown in FIG. 18(a), a tape 57 is pasted on the lid 36. Laser light 54 is irradiated from below the substrate 10 to form a modified region 62a in the support substrate 10a. As shown in FIG. 18(b), a tape 56 is applied to the lower surface of the substrate 10 and the tape 57 is peeled off. A groove 64 is formed in the lid 36, the sealing part 30, and the piezoelectric substrate 10b using the dicing blade 58. Thereafter, the steps in and after FIG. 5(b) of Example 1 are performed. The other steps are the same as those in Modified Example 6 of Example 1, and their explanation will be omitted.

Annular metal layers 32 and 34 are formed on the upper surface of the substrate 10. If it is difficult to form grooves and/or modified regions by irradiating the laser beam 54 from above the substrate 10, the laser beam 54 may be irradiated from above the substrate 10 as in Modifications 4 to 7 of the first embodiment. The grooves and/or modified regions may be formed by irradiating the substrate 10 with laser light 54 from below, without performing the step of forming the grooves and/or modified regions.

As in Modifications 2, 3, 6, and 7 of Embodiment 1, modified regions 62a may be formed in support substrate 10a instead of grooves 62. Since the grooves 62 are formed using laser ablation, a protective film 55 that is opaque to the laser beam 54 and annular metal layers 32 and 34 may be formed on the surface of the substrate 10. Formation of the modified region 62a focuses the laser beam 54 within the support substrate 10a. For this reason, it is preferable not to provide a film that is opaque to the laser beam 54 on the surface of the substrate 10. In this manner, by irradiating the support substrate 10a with the laser beam 54 on both sides of the center line 67 in the width direction of the cutting region 68, grooves and/or modified regions may be formed in the support substrate 10a.

As in Example 1 and Modifications 1 to 3 thereof, before the step of forming the sealing part 30, the groove 60 or the modified region 62a is formed by irradiating the upper surface of the substrate 10 with the laser beam 54. . Thereby, a groove or a modified region can be formed in the upper part of the support substrate 10a.

As in the first embodiment and its modifications, the grooves 62 or modified regions 62a are formed by irradiating the lower surface of the substrate 10 with the laser beam 54. Thereby, the groove 62 or the modified region 62a can be formed in the lower part of the support substrate 10a. The groove 62 or the modified region 62a may be formed after cutting the sealing portion 30 as in the first embodiment and its modifications 2, 4 and 6, or may be formed after the sealing portion 30 is cut, as in the first embodiment and modifications 2, 4 and 6 thereof, or in the modification 1, 3 and 6 of the first embodiment. As shown in steps 5 and 7, the step may be performed before cutting the sealing portion 30.

As in Example 1 and Modifications 1 to 3 thereof, before the step of forming the sealing part 30, the groove 60 is formed by irradiating the upper surface of the substrate 10 with the laser beam 54, and the sealing part 30 is formed. After the step of forming the grooves 62 or modified regions 62a, the lower surface of the substrate 10 is irradiated with laser light 54 to form grooves 62 or modified regions 62a. This facilitates live splitting of the support substrate 10a. A modified region 62a may be formed instead of the groove 60.

In the first embodiment and its modification, the acoustic wave elements 12 and 22 are provided, but it is sufficient that at least one of the acoustic wave elements 12 and 22 is provided. Although a piezoelectric thin film resonator has been described as an example of the acoustic wave element 22, the acoustic wave element 22 may also be a surface acoustic wave resonator. Although an example of the acoustic wave device 22 has been described as a functional device provided on the lower surface of the substrate 20, the functional device may be a passive device such as an inductor or a capacitor, an active device including a transistor, or a MEMS (Micro Electro Mechanical Systems) device. .

Example 2 is an example of a filter and a duplexer. FIG. 19(a) is a circuit diagram of a filter according to the second embodiment. As shown in FIG. 19(a), one or more series resonators S1 to S4 are connected in series between the input terminal T1 and the output terminal T2. One or more parallel resonators P1 to P4 are connected in parallel between the input terminal T1 and the output terminal T2. The filter of the second embodiment may be formed of the acoustic wave elements 12 and/or 22. The number of series resonators and parallel resonators can be set as appropriate. Although the filter has been described using a ladder filter as an example, the filter may be a multimode filter.

FIG. 19(b) is a circuit diagram of a duplexer according to a first modification of the second embodiment. As shown in FIG. 19(b), a transmission filter 50 is connected between the common terminal Ant and the transmission terminal Tx. A reception filter 52 is connected between the common terminal Ant and the reception terminal Rx. The transmission filter 50 passes a signal in the transmission band among the high frequency signals inputted from the transmission terminal Tx to the common terminal Ant as a transmission signal, and suppresses signals of other frequencies. The reception filter 52 passes a signal in the reception band among the high-frequency signals inputted from the common terminal Ant to the reception terminal Rx as a reception signal, and suppresses signals at other frequencies. At least one of the transmission filter 50 and the reception filter 52 can be the filter of the second embodiment. Alternatively, the transmission filter 50 may be formed of the elastic wave element 12 and the reception filter 52 may be formed of the elastic wave element 22.

Although a duplexer has been described as an example of a multiplexer, a triplexer or a quadplexer may also be used.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and variations can be made within the scope of the gist of the present invention as described in the claims. Changes are possible.

10a Support substrate 10b Piezoelectric substrate 12, 22 Acoustic wave element 14, 24 Wiring 16 Via wiring 18 Terminal 20 Substrate 26 Gap 28 Bump 30 Sealing portion 32, 34 Annular metal layer 36 Lid 50 Transmission filter 52 Reception filter 54 Laser light 60, 62, 64 Groove 61, 63, 63a Laser mark 62a Modified area 67 Center line 68 Cut area

Claims (8)

By irradiating the support substrate with laser light on both sides of the center line in the width direction of the cutting region extending in the plane direction of the first substrate where the piezoelectric substrate and the support substrate are directly or indirectly joined, the support substrate forming grooves and/or modified regions in the
mounting a plurality of second substrates between the cutting regions on the opposite side of the support substrate of the piezoelectric substrate so as to face the piezoelectric substrate with a gap in between;
A region surrounding the plurality of second substrates and including the cutting region is joined to the first substrate in the cutting region, and an acoustic wave element provided on at least one of the piezoelectric substrate and the second substrate is sealed in the gap. a step of forming a sealing part to seal;
By forming another groove in which both sides of the cutting area in the width direction are the side surfaces of the sealing part , the distance in the width direction of the cutting area between the position where the laser beam is irradiated and the side surface of the sealing part can be reduced. cutting the sealing portion so that the width in the width direction of the cutting region of the other groove is 1/5 or less ;
After the step of forming the groove and/or the modified region and the step of cutting the sealing portion, cutting the first substrate on both sides of the center line of the cutting region;
A method of manufacturing an acoustic wave device including: The step of forming the groove and/or the modified region is performed by irradiating the surface of the first substrate on the second substrate side with a laser beam before the step of forming the sealing portion. The method for manufacturing an acoustic wave device according to claim 1, further comprising the step of : and/ or forming the modified region. The step of forming the groove and/or the modified region is a step of forming the groove and/ or the modified region by irradiating a surface of the first substrate opposite to the second substrate with a laser beam. The method for manufacturing an acoustic wave device according to claim 1, comprising: The step of forming the groove and/or the modified region includes:
Before the step of forming the sealing portion, forming the groove or the modified region by irradiating a surface of the first substrate on the second substrate side with a laser beam;
After the step of forming the sealing portion, forming the groove or the modified region by irradiating a surface of the first substrate opposite to the second substrate with a laser beam;
The method for manufacturing an acoustic wave device according to claim 1, comprising: The method for manufacturing an acoustic wave device according to any one of claims 1 to 4, wherein the step of forming the groove and/or the modified region includes a step of forming the groove in the support substrate. The method for manufacturing an acoustic wave device according to any one of claims 1 to 4, wherein the step of forming the groove and/or the modified region includes a step of forming the modified region on the support substrate. The method for manufacturing an acoustic wave device according to any one of claims 1 to 6, wherein the step of cutting the sealing portion includes a step of cutting the sealing portion using a dicing blade. 8. The method for manufacturing an acoustic wave device according to claim 1, wherein the support substrate is a sapphire substrate, a spinel substrate, or a quartz substrate, and the sealing portion is solder or resin.

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