JP7401200B2 - Electronic device manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing an electronic device , and more particularly, to a method of manufacturing an electronic device in which a functional element is sealed using a frame.

Electronic devices are known in which a frame is provided to surround a functional element such as an acoustic wave element provided on a substrate, and a lid such as the substrate is provided on the frame to seal the functional element in a void. (For example, Patent Documents 1 to 3).

Japanese Patent Application Publication No. 2016-152612 Japanese Patent Application Publication No. 2014-143640 Japanese Patent Application Publication No. 2013-115664

Patent Document 1 does not describe a method for cutting the substrate and the lid. In Patent Document 2, a plurality of cut lids are respectively joined to a plurality of frames. In Patent Document 3, a lid formed on a support is joined onto a frame. However, the methods of Patent Documents 2 and 3 complicate the manufacturing process.

The present invention was made in view of the above problems, and an object of the present invention is to simplify the manufacturing method.

The present invention includes a step of forming, on a support substrate provided with a plurality of functional elements, a plurality of frames that respectively surround the plurality of functional elements and are separated from each other via a first gap, and a step of forming a plurality of frames that surround the plurality of functional elements and are separated from each other via a first gap; a step of bonding the lid onto the plurality of frame bodies, and a step of bonding the lid so that the supporting substrate and the lid are sealed at a position overlapping the first gap between the frame bodies. The step of dividing the supporting substrate and the lid includes forming an opening that passes through the lid by irradiating the lid with a laser beam from a side opposite to the supporting substrate. a step of forming a groove or a modified region in the supporting substrate by irradiating the supporting substrate with a laser beam through the opening, and a step of dividing the supporting substrate in the groove or the modified region. A method of manufacturing an electronic device includes the following steps .

The present invention includes a step of forming, on a support substrate provided with a plurality of functional elements, a plurality of frames that respectively surround the plurality of functional elements and are separated from each other via a first gap; a step of bonding a lid onto the plurality of frames so as to be sealed in the gap; and after a step of bonding the lid, the support substrate and the support substrate at a position overlapping the first gap between the frame bodies; dividing the lid, and the step of dividing the support substrate and the lid includes forming an opening that passes through the lid by irradiating the lid with a laser beam from a side opposite to the support substrate. a step of forming a groove or a modified region in the supporting substrate by irradiating the supporting substrate with a laser beam from a side opposite to the lid; and dividing the supporting substrate in the groove or the modified region. A method of manufacturing an electronic device includes steps.

In the above configuration, the step of dividing the support substrate and the lid includes dividing the support substrate and the lid so that the side surface of the frame body on the first gap side is located closer to the second gap than the side surface of the lid and the side surface of the support substrate. The structure may include a step of dividing the support substrate and the lid.

In the above configuration, the plurality of functional elements may be a plurality of piezoelectric elements provided on a piezoelectric substrate directly or indirectly joined to the support substrate.

In the above structure, the support substrate may be a sapphire substrate, a spinel substrate, a quartz substrate, or a crystal substrate.

In the above structure, the lid may be a metal lid.

According to the present invention, the manufacturing method can be simplified.

1(a) and 1(b) are a cross-sectional view and a plan view of an acoustic wave device according to Example 1. FIG. FIG. 2(a) is a plan view of the acoustic wave element in Example 1, and FIG. 2(b) is a sectional view of another example of the acoustic wave element. 3(a) to 3(d) are cross-sectional views (part 1) showing the method for manufacturing the acoustic wave device according to the first embodiment. FIGS. 4(a) to 4(c) are cross-sectional views (part 2) showing the method for manufacturing the acoustic wave device according to the first embodiment. FIGS. 5(a) to 5(c) are cross-sectional views (part 3) showing the method for manufacturing the acoustic wave device according to the first embodiment. FIG. 6 is a plan view showing a method for manufacturing an acoustic wave device according to Example 1. 7(a) to 7(e) are cross-sectional views (part 1) showing the method of forming the frame body in Example 1. FIG. FIGS. 8(a) to 8(d) are cross-sectional views (part 2) showing the method for forming the frame body in Example 1. FIG. FIG. 9 is a side view of the acoustic wave device according to Example 1. 10(a) to 10(c) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a first modification of the first embodiment. FIG. 11 is a cross-sectional view showing a method for manufacturing an acoustic wave device according to a second modification of the first embodiment. 12(a) to 12(c) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a third modification of the first embodiment. 13(a) and 13(b) are side views of acoustic wave devices according to Modifications 1 to 3 of Example 1. FIG. FIG. 14 is a cross-sectional view of an acoustic wave device according to a fourth modification of the first embodiment. 15(a) is a circuit diagram of a filter according to a second embodiment, and FIG. 15(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, taking an acoustic wave device as an example of an electronic device.

1(a) and 1(b) are a cross-sectional view and a plan view of an acoustic wave device according to Example 1. FIG. FIG. 1(b) mainly shows the support substrate 10, the piezoelectric substrate 11, the frame 20, and the lid 26.

As shown in FIGS. 1(a) and 1(b), a piezoelectric substrate 11 is bonded onto a support substrate 10. As shown in FIG. The support substrate 10 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 11 is, for example, a lithium tantalate substrate or a lithium niobate substrate. The linear expansion coefficient of the support substrate 10 is smaller than that of the piezoelectric substrate 11. Thereby, the frequency temperature coefficient of the acoustic wave device can be reduced. An insulating layer such as silicon oxide or aluminum nitride may be provided between the piezoelectric substrate 11 and the support substrate 10. In this way, the piezoelectric substrate 11 is directly or indirectly joined to the support substrate 10.

An acoustic wave element 12 and wiring 14 are provided on the upper surface of the piezoelectric substrate 11. No piezoelectric substrate 11 is provided in the peripheral area of the support substrate 10 . A frame 20 is provided on the support substrate 10 so as to surround the piezoelectric substrate 11. The frame 20 includes an annular metal layer 22, an annular bonding layer 24, and a protective layer 21. The annular metal layer 22 contacts the top surface of the support substrate 10 . The annular bonding layer 24 is provided on the annular metal layer 22 . The protective layer 21 is provided on the side surfaces of the annular metal layer 22 and the annular bonding layer 24 to protect the annular metal layer 22 and the annular bonding layer 24 . The protective layer 21 may not be provided.

Terminals 18 are provided on the lower surface of the support substrate 10. The terminal 18 is a foot pad for connecting the acoustic wave element 12 to the outside. Via wiring 16 is provided that penetrates piezoelectric substrate 11 and support substrate 10 . The via wiring 16 electrically connects the terminal 18 and the wiring 14. Via wiring 16a passing through the support substrate 10 is provided. Via wiring 16a electrically connects terminal 18 and frame 20.

A lid 26 is joined onto the frame 20. The acoustic wave element 12 is sealed in the gap 28 by the lid 26 and the frame 20. The lid 26 includes a bonding layer 26a and a main body 26b. The bonding layer 26a is bonded to the annular bonding layer 24. The main body 26b is thicker than the bonding layer 26a and made of a harder material than the bonding layer 26a to prevent the lid 26 from being crushed.

The wiring 14, the via wiring 16, the terminal 18, and the annular metal layer 22 are, for example, metal layers such as a copper layer, an aluminum layer, a platinum layer, a nickel layer, or a gold layer. The annular bonding layer 24 is, for example, a brazing metal layer such as gold-tin, tin-silver, tin, or tin-silver-copper. The bonding layer 26a is a metal layer bonded to the annular bonding layer 24, and is, for example, a gold layer. The main body 26b is a metal layer with a small coefficient of linear expansion, such as a Kovar layer. The protective layer 21 is, for example, a metal layer such as a nickel layer. The frame 20 may be made of an insulator such as resin. The lid 26 may be an insulating substrate such as a sapphire substrate, an alumina substrate, a spinel substrate, a quartz substrate, a crystal substrate, or a silicon substrate. When the frame 20 and the lid 26 are made of metal, the frame 20 and the lid 26 can be used as a shield by supplying a ground potential to the via wiring 16a.

The support substrate 10 is, for example, a sapphire substrate, and its thickness T1 is from 50 μm to 300 μm. The piezoelectric substrate 11 is, for example, a 42° rotated Y-cut, X-propagating lithium tantalate substrate, and its thickness is, for example, from 0.5 μm to 30 μm, which is, for example, less than the wavelength of an elastic wave. The thickness T2 of the frame body 20 is, for example, 10 μm to 30 μm. The annular metal layer 22 is, for example, a copper layer with a thickness of 15 μm to 20 μm and a nickel layer with a thickness of 2.5 μm from the support substrate 10 side. The annular bonding layer 24 is, for example, a gold-tin layer with a thickness of 3.5 μm. The main body 26b of the lid 26 is, for example, a Kovar plate with a thickness of 30 μm to 100 μm. The via wirings 16 and 16a are made of copper and have a diameter of 30 μm to 100 μm, for example. The terminal 18 is, for example, a copper layer with a thickness of 2 μm, a nickel layer with a thickness of 5 μm, and a gold layer with a thickness of 0.3 μm from the support substrate 10 side. The protective layer 21 is, for example, a nickel layer with a thickness of 1 μm to 2 μm.

The width D1 of the frame body 20 is, for example, 20 μm to 30 μm. The side surface 30 of the support substrate 10 is located on the outside of the side surface 31 of the frame body 20, and the side surface 32 of the lid 26 is located on the outside of the side surface 31 of the frame body 20. The distance D2 between the side surfaces 30 and 31 is, for example, 5 μm to 10 μm, and the distance D3 between the side surfaces 32 and 31 is, for example, 4 μm to 9 μm. The size of the support substrate 10 is, for example, 1.2 mm x 1 mm. The distance between the lower surface of the support substrate 10 and the upper surface of the lid 26 is, for example, 0.15 mm.

FIG. 2(a) is a plan view of the acoustic wave element in Example 1, and FIG. 2(b) is a sectional view of another example of the acoustic wave element. 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 11. 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 11. 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, a copper film, or a molybdenum film. A protective film or a temperature compensation film may be provided on the piezoelectric substrate 11 so as to cover the IDT 40 and the reflector 42.

As shown in FIG. 2(b), the acoustic wave element 12 may be a piezoelectric thin film resonator. The piezoelectric substrate 11 is not provided, and the acoustic wave element 12 is provided on the upper surface of the support substrate 10. A piezoelectric film 46 is provided on the support substrate 10. 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 support substrate 10. 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 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.

[Production method of Example 1]
FIGS. 3(a) to 5(c) are cross-sectional views showing the method for manufacturing the acoustic wave device according to the first embodiment. FIG. 6 is a plan view showing a method for manufacturing an acoustic wave device according to Example 1.

As shown in FIG. 3A, the lower surface of the piezoelectric substrate 11 is bonded to the upper surface of the support substrate 10 at room temperature using, for example, a surface activation method. The support substrate 10 and the piezoelectric substrate 11 may be directly bonded via an amorphous layer or the like of several nanometers, or may be bonded indirectly via an insulating layer. The upper surface of the piezoelectric substrate 11 is polished using, for example, a CMP (Chemical Mechanical Polishing) method. This allows the piezoelectric substrate 11 to have a desired thickness.

As shown in FIG. 3(b), the piezoelectric substrate 11 is removed, for example, by etching to form openings 15b and 15c. For example, a laser beam is irradiated onto the upper surface of the support substrate 10 within the openings 15b and 15c to form a via 15d. A through hole 15a is formed by the opening 15b and the via 15d. The area between the piezoelectric substrates 11 where the piezoelectric substrate 11 is removed is the area 74 .

As shown in FIG. 3C, a metal layer such as copper is formed in the through hole 15a and via 15d using, for example, a plating method. The upper surface of the metal layer is planarized using, for example, a CMP method so that the surfaces of the support substrate 10 and the piezoelectric substrate 11 are exposed. As a result, via wirings 16 and 16a are formed.

As shown in FIG. 3(d), an acoustic wave element 12 is formed on a piezoelectric substrate 11. Wiring 14 is formed on piezoelectric substrate 11 and via wiring 16.

As shown in FIG. 4A, an annular metal layer 22 and an annular bonding layer 24 are formed on the support substrate 10 in a region 74 surrounding the piezoelectric substrate 11. As shown in FIG. Illustration of the protective layer 21 is omitted.

As shown in FIG. 6, a plurality of piezoelectric substrates 11 on which acoustic wave elements (not shown) are formed are provided in a matrix on the support substrate 10. The region 74 where the piezoelectric substrate 11 is not provided is provided in a grid pattern. The plurality of frames 20 are provided within the region 74 so as to surround the plurality of piezoelectric substrates 11, respectively. The plurality of frames 20 are separated from each other via a region 76. A cutting line 78 for cutting the support substrate 10 and the lid 26 is shown near the center of the region 76.

As shown in FIG. 4(b), the lid 26 is bonded onto the annular bonding layer 24 of the frame 20. As shown in FIG. Thereby, the acoustic wave element 12 is sealed in the gap 28 by the lid 26 and the frame 20. The region 76 between the frames 20 becomes a gap 29.

As shown in FIG. 4C, the lower surface of the support substrate 10 is polished using, for example, a CMP method. Thereby, the support substrate 10 is made to have a desired thickness. Via wiring 16 and 16a are exposed on the lower surface of support substrate 10. Terminals 18 connected to via wirings 16 and 16a are formed on the lower surface of support substrate 10.

As shown in FIG. 5(a), a tape 50 such as a resin tape is attached to the lower surface of the support substrate 10. The tape 50 is a tape for reinforcing the support substrate 10. The lid 26 is irradiated with a laser beam 60 from above so as to overlap the gap 29 in the region 76 . Irradiation with the laser beam 60 is performed while moving the position (irradiation position) on the lid 26 where the laser beam 60 is irradiated. A portion of the lid 26 is sublimated by laser ablation, and a groove 34 passing through the lid 26 is formed. Groove 34 extends along cut line 78 in FIG. The laser beam 60 is, for example, ultraviolet light, has a power of 2 W, a pulse frequency of 40 kHz, and a moving speed of the irradiation position of the laser beam 60 of 130 mm/sec. After focusing the laser beam 60 on the top surface of the lid 26 and irradiating the laser beam 60, the focusing position is set within the lid 26 below the top surface of the lid 26, and the laser beam 60 is focused while moving the irradiation position of the laser beam 60 again. irradiate. By irradiating the laser beam 60 while moving the irradiation position of the laser beam 60 multiple times, the groove 34 penetrating the lid 26 can be formed. Laser light 60 may be visible light or infrared light. The irradiation position of the laser beam 60 may be moved only once.

As shown in FIG. 5B, the support substrate 10 is irradiated with laser light 62 from above through the groove 34 of the lid 26. As shown in FIG. A portion of the support substrate 10 is sublimated by the laser ablation, and a groove 36 is formed on the upper surface of the support substrate 10. Groove 36 extends along cut line 78 in FIG. The irradiation conditions of the laser beam 62 are the same as those of the laser beam 60. The laser beam 62 is focused on the upper surface of the support substrate 10, and the laser beam 62 is irradiated while moving the irradiation position of the laser beam 62 along the cutting line 78 in FIG. Laser light 62 may be visible light or infrared light. The laser beam 62 may be irradiated by moving the irradiation position of the laser beam 62 multiple times.

As shown in FIG. 5(c), a reinforcing tape 52 such as a resin tape is attached to the upper surface (lower surface in FIG. 5(c)) of the lid 26. The break blade 64 is pressed against the tape 50 from below (from above in FIG. 5(c)). As a result, a crack 38 is formed in the support substrate 10 starting from the groove 36 and penetrating the support substrate 10 . As a result, the support substrate 10 is cut. Peel off tapes 50 and 52. Through the above steps, the acoustic wave device of Example 1 is manufactured.

7(a) to FIG. 8(d) are cross-sectional views showing a method of forming a frame in Example 1. The vicinity of the region where the frame body 20 is formed is shown in an enlarged manner. As shown in FIG. 7A, the wiring 14 is formed within the opening 15b formed in the piezoelectric substrate 11. As shown in FIG. The via wiring 16 may penetrate the support substrate 10 and the piezoelectric substrate 11 as shown in FIG. 3(d), or may penetrate only the support substrate 10 as shown in FIG. 7(a).

As shown in FIG. 7(b), a protective layer 56 is formed to cover the piezoelectric substrate 11. The protective layer 56 is not formed in the region 75 within the region 76 where the frame body 20 is to be formed. The protective layer 56 is, for example, a photoresist, and is formed by coating, exposing, developing, and post-baking.

As shown in FIG. 7(c), a seed layer 22a is formed on the protective layer 56 and the support substrate 10. The seed layer 22a is, for example, a titanium layer and a copper layer from the support substrate 10 side, and is formed using a sputtering method.

As shown in FIG. 7D, a mask layer 57 is formed on the seed layer 22a above the protective layer 56 except for the region 75. The mask layer 57 is made of, for example, a photoresist, and is formed by coating, exposing, and developing.

As shown in FIG. 7E, using the mask layer 57 as a mask, the metal layers 22b and 22c and the annular bonding layer 24 are formed on the seed layer 22a in the region 75 using, for example, electrolytic plating. The metal layers 22b and 22c are, for example, a copper layer and a nickel layer, and the annular bonding layer 24 is, for example, a gold-tin layer.

As shown in FIG. 8(a), the mask layer 57 is removed. Using the annular bonding layer 24 as a mask, the seed layer 22a is removed using, for example, a dry etching method. Thereby, an annular metal layer 22 including a seed layer 22a, metal layers 22b and 22c is formed.

As shown in FIG. 8(b), a protective layer 21 is formed on the side and top surfaces of the frame 20. The protective layer 21 is, for example, a nickel layer, and is formed using an electroless plating method. As a result, the frame 20 including the protective layer 21, the annular metal layer 22, and the annular bonding layer 24 is formed.

As shown in FIG. 8(c), the protective layer 21 on the upper surface of the frame body 20 is removed using, for example, a milling method. As a result, a frame 20 is formed, which includes the annular metal layer 22, the annular bonding layer 24, and the protective layer 21 formed on the side surfaces thereof.

As shown in FIG. 8(d), the protective layer 56 is removed. As a result, the frame 20 surrounding the piezoelectric substrate 11 is formed in the region 76, as shown in FIGS. 4(a) and 6.

FIG. 9 is a side view of the acoustic wave device according to Example 1. As shown in FIG. 9, the lower part 30a of the side surface 30 of the support substrate 10 is a broken side surface. Laser marks 35 are provided on the upper part 30b of the side surface 30 of the support substrate 10. The height H1 of the laser mark 35 is, for example, 10 μm to 30 μm. In FIG. 5B, when the laser beam 62 is pulsed and irradiated while moving the irradiation position of the laser beam 62 at a constant speed, the laser mark 35 formed on the side surface 30 of the support substrate 10 has a triangular wave shape. The period D4 of the triangular wave is determined by the pulse period of the pulsed light and the moving speed of the irradiation position of the laser beam 62, and is, for example, 1 μm to 50 μm. The laser mark 35 is a part of the groove 36 formed by sublimation of the support substrate 10, and the surface is polycrystalline or amorphous. The side surface of the frame 20 is a protective layer 21 . The entire side surface 32 of the lid 26 has laser marks 33. The laser mark 33 is a part of the groove 34 formed by sublimation of the lid 26, and the surface is polycrystalline or amorphous.

[Modification 1 of Example 1]
10(a) to 10(c) are cross-sectional views showing a method for manufacturing an acoustic wave device according to a first modification of the first embodiment. As shown in FIG. 10(a), after FIG. 4(c) of Example 1, a tape 54 such as a resin tape is attached to the upper surface (lower surface in FIG. 10(a)) of the lid 26. By irradiating the lower surface of the support substrate 10 with laser light 62, the grooves 36 are formed on the lower surface of the support substrate 10. The method of forming the grooves 36 is the same as that of the first embodiment shown in FIG. 5(b).

As shown in FIG. 10(b), the tape 54 is peeled off and the tape 50 is attached to the lower surface of the support substrate 10. A laser beam 60 is irradiated from above the lid 26 to form a groove 34 passing through the lid 26. The method of forming the grooves 34 is the same as that of the first embodiment shown in FIG. 5(a).

As shown in FIG. 10(c), a tape 52 is attached to the upper surface (lower surface in FIG. 10(c)) of the lid 26. The break blade 64 is pressed against the tape 50 from below (from above in FIG. 10(c)). As a result, a crack 38 is formed in the support substrate 10 starting from the groove 36 and penetrating the support substrate 10 . As a result, the support substrate 10 is cut. Peel off tapes 50 and 52. As described above, the elastic wave device of Modification 1 of Example 1 is manufactured.

[Modification 2 of Example 1]
FIG. 11 is a cross-sectional view showing a method for manufacturing an acoustic wave device according to a second modification of the first embodiment. As shown in FIG. 11, a modified region 36a is formed in the support substrate 10 by irradiating the lower surface of the support substrate 10 with laser light 60 in FIG. 10A of the first modification of the first embodiment. The modified region 36a is formed by focusing the laser beam 62 on a desired position on the support substrate 10. In the modified region 36a, the supporting substrate 10 is melted and then solidified to become an amorphous or polycrystalline region. When the laser beam 62 is pulsed and the laser beam 62 is irradiated while moving the irradiation position of the laser beam 62 at a constant speed, the modified regions 36a are arranged at substantially the same height in the plane direction. One or more modified regions 36a are formed in the thickness direction of the support substrate 10. Thereafter, the same steps as in Modified Example 1 of Example 1 are performed.

[Modification 3 of Example 1]
12(a) to 12(c) 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 groove 34 is formed on the upper surface of the lid 26, similar to FIG. 5(a) of the first embodiment.

As shown in FIG. 12(b), a tape 54 is attached to the upper surface of the lid 26 (the lower surface of the lid 26 in FIG. 12(b)). Peel off the tape 50. The grooves 36 are formed by irradiating the lower surface (upper surface in FIG. 12(b)) of the support substrate 10 with a laser beam 62.

As shown in FIG. 12(c), a tape 50 is attached to the lower surface of the support substrate 10. A break blade 64 is pressed against the tape 54 from above. As a result, a crack 38 is formed in the support substrate 10 starting from the groove 36 and penetrating the support substrate 10 . As a result, the support substrate 10 is cut. Peel off tapes 50 and 54. As described above, the acoustic wave device of Modification 3 of Example 1 is manufactured.

13(a) and 13(b) are side views of acoustic wave devices according to Modifications 1 to 3 of Example 1. FIG. FIG. 13(a) is a side view when the groove 36 is formed using the laser beam 62, and FIG. 13(b) is a side view when the modified region 36a is formed using the laser beam 62.

As shown in FIG. 13(a), laser marks 35 are formed on the lower part 30a of the side surface 30 of the support substrate 10. The upper part 30b of the side surface 30 is a broken side surface. The laser marks 35 are formed by grooves 36 as in the first embodiment. The side surface 31 of the frame body 20 and the side surface 32 of the lid 26 are the same as those in FIG. 9 of the first embodiment, and their explanation will be omitted.

As shown in FIG. 13(b), a laser mark 35a consisting of a modified region 36a is formed in the lower part 30a of the side surface 30 of the support substrate 10. The width D5 of the modified region 36a is, for example, 1 μm to 10 μm. The period D6 of the modified region 36a is, for example, from 2 μm to 50 μm. The side surface 31 of the frame body 20 and the side surface 32 of the lid 26 are the same as those in FIG. 9 of the first embodiment, and their explanation will be omitted.

[Modification 4 of Example 1]
FIG. 14 is a cross-sectional view of an acoustic wave device according to a fourth modification of the first embodiment. As shown in FIG. 14, the piezoelectric substrate 11 is not provided on the support substrate 10. A wiring 14 is provided on the upper surface of the support substrate 10 to connect the acoustic wave element 12, which is the piezoelectric thin film resonator described in FIG. 2(b), and the via wiring 16. The other configurations are the same as those of the first embodiment and its modified examples 1 to 3, and the explanation thereof will be omitted. As in the fourth modification of the first embodiment, the piezoelectric substrate 11 may not be provided.

In the method of joining cut lids on a plurality of frames as in Patent Document 2, the plurality of lids are aligned with the frames and then joined, which complicates the manufacturing method. As in Patent Document 3, a method of forming a lid on a support and then bonding the lid onto a frame includes a step of forming the lid on a support substrate, a step of aligning the lid with the frame, and a step of bonding the lid to the support. The manufacturing method becomes complicated because it involves a process of peeling it off.

According to the first embodiment and its modification, a plurality of acoustic wave elements 12 (functional elements) are formed on the support substrate 10, as shown in FIG. 3(d). As shown in FIGS. 4A and 6, a plurality of frames 20 are formed on the support substrate 10, each surrounding a plurality of acoustic wave elements 12 and separated from each other via a gap 29 (first gap). As shown in FIG. 4(b), the lids 26 are bonded onto the plurality of frames 20 so that the plurality of acoustic wave elements 12 are sealed in the gaps 28 (second gaps). After the step of joining the lid 26, the support substrate 10 and the lid 26 are divided at positions overlapping the gaps 29 between the plurality of frames 20, as shown in FIGS. 5(a) to 5(c).

Since the lid 26 is cut after being joined to the plurality of frames 20, there is no need to align and join the plurality of lids as in Patent Document 2, and the number of manufacturing steps can be reduced. Further, unlike Patent Document 3, there is no need to perform the steps of forming a plurality of lids on a support, aligning the lid with a frame, and peeling off the support from the lid, and the number of manufacturing steps can be reduced.

Furthermore, since there is a gap 29 between the support substrate 10 and the lid 26 between the frame bodies 20, it is essentially necessary to cut only the support substrate 10 and the lid 26. Therefore, the width of the cutting area can be reduced. This allows the elastic wave device to be miniaturized.

If the gaps 29 are not formed between the frames 20 and are filled with the same material as the frames, a blade dicing method is used to cut the thick structure. In this case, the width of the cutting area is approximately the same as the width of the dicing blade. The width of the dicing blade is about 100 μm, which increases the size of the acoustic wave device. Further, when the support substrate 10 and the lid 26 are cut using a dicing blade, chipping or cracking occurs if the support substrate 10 and the lid 26 are hard like sapphire. Further, when the lid 26 and the frame 20 are made of metal, burrs and the like are formed.

In the first embodiment and its modified examples, since there is a gap 29 between the support substrate 10 and the lid 26 between the frame body 20, the support substrate 10 and the lid 26 can be cut separately. Therefore, in the step of cutting the support substrate 10 and the lid 26, the support substrate 10 can be divided using the laser beam 60, and the lid 26 can be divided using the laser beam 62. This allows the elastic wave device to be miniaturized. Moreover, even if the supporting substrate 10 and the lid 26 are hard, chipping or cracking can be suppressed. Furthermore, even if the lid 26 and the frame 20 are made of metal, burrs and the like can be suppressed.

As in Example 1, as shown in FIG. 5A, a groove 34 (opening) passing through the lid 26 is formed by irradiating the lid 26 with laser light 60 from the side opposite to the support substrate 10. As shown in FIG. 5(b), a groove 36 is formed in the support substrate 10 via the groove 34. As shown in FIG. 5(c), the support substrate 10 is divided at the grooves 36. Thereby, the number of tape changes can be minimized, and the manufacturing process can be simplified.

In FIG. 5B of the first embodiment, the modified region 36a may be formed in the support substrate 10 as in the second modification of the first embodiment.

In the first embodiment, if the lid 26 is thick and the groove 34 is narrow, there is a possibility that the laser beam 62 reaching the support substrate 10 in FIG. 5(b) becomes weak. Therefore, as in Modifications 1 to 3 of Embodiment 1, as shown in FIGS. 10(b) and 12(a), the lid 26 is irradiated with the laser beam 60 from the side opposite to the supporting substrate 10. A groove 34 (opening) passing through 26 is formed. As shown in FIGS. 10(a), 11, and 12(b), grooves 36 or modified regions 36a are formed in the supporting substrate 10 by irradiating the supporting substrate 10 with a laser beam 62 from the side opposite to the lid 26. do. As shown in FIGS. 10(c) and 12(c), the support substrate 10 is divided at the grooves 36 or modified regions 36a. Thereby, the groove 36 or the modified region 36a can be formed in the support substrate 10 regardless of the thickness of the lid 26 and the width of the groove 34.

As in Modifications 1 and 2 of Example 1, the grooves 34 may be formed after forming the grooves 36 or modified regions 36a, or as in Modification 3 of Example 1, the grooves 34 may be formed. Grooves 36 or modified regions 36a may be formed later.

In a first modification of the first embodiment, the tape 54 in FIG. 10(a) is replaced with the tape 50 in FIG. 10(b) with the groove 36 formed in the support substrate 10. This may cause the support substrate 10 to break. In the second modification of the first embodiment, since the modified region 36a is formed instead of the groove 36, it is possible to suppress the support substrate 10 from cracking when the tapes 54 and 50 are replaced. In the third modification of the first embodiment, since the tape 54 is not replaced after the grooves 36 are formed, cracking of the support substrate 10 during tape replacement can be suppressed.

In the second modification of the first embodiment, the load on the break blade 64 increases because the support substrate 10 is cut starting from the modified region 36a as a stealth dicing method. In the third modification of the first embodiment, since a load is applied to the break blade 64 from the lid 26 side, the lid 26 may be damaged. In the first modification of the first embodiment, although the tape is replaced many times, it is possible to suppress an increase in the load on the break blade 64 and damage to the lid 26.

The support substrate 10 is a sapphire substrate, a spinel substrate, a quartz substrate, or a crystal substrate. 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 . The quartz substrate is a substrate whose main component is single crystal SiO ₂ . In this case, since the support substrate 10 is hard, chipping or cracking occurs when the support substrate 10 is cut using the blade dicing method. In Example 1 and its modifications, the grooves 36 or modified regions 36a are formed in the support substrate 10 using the laser beam 62, and the support substrate 10 is cut by cutting. Thereby, chipping or cracking of the support substrate 10 can be suppressed.

The lid 26 is a metal lid. Thereby, the lid 26 can be cut by the laser beam 60. Therefore, as in the first embodiment, the support substrate 10 can be irradiated with the laser light 62 through the groove 34. When the lid 26 is an insulator such as a sapphire substrate, a spinel substrate, a quartz substrate, or a crystal substrate, a laser beam is irradiated onto the lid 26 to form a groove or a modified region on the upper surface of the lid 26, and a blade is used to close the lid 26. 26 may be cut.

As functional elements, a plurality of acoustic wave elements 12 (piezoelectric elements) are formed on a piezoelectric substrate 11 directly or indirectly joined to a support substrate 10. By making the linear expansion coefficient of the support substrate 10 smaller than that of the piezoelectric substrate 11, the frequency temperature coefficient of the acoustic wave element can be reduced. When the piezoelectric substrate 11 is a lithium tantalate substrate or a lithium niobate substrate, the piezoelectric substrate 11 is fragile. Therefore, it is preferable to remove the support substrate 10 in the area where the frame 20 is to be formed and form the frame 20 so as to be in contact with the support substrate 10.

The acoustic wave devices formed according to Example 1 and its modifications have laser marks 35 or 35a on the side surface 30 of the support substrate 10, as shown in FIGS. 9, 13(a) and 13(b). A side surface 31 of the frame 20 (a second side surface opposite to the first side surface on which the acoustic wave element 12 is provided) is located inside the side surface 30 of the support substrate 10 (on the acoustic wave element 12 side). A side surface 32 of the lid 26 has laser marks 33 and is located outside the side surface 31 of the frame 20 (on the opposite side from the acoustic wave element 12).

Since the side surface 31 of the frame body 20 is located inside the side surface 30 of the support substrate 10 and the side surface 32 of the lid 26, damage to the frame body 20 can be suppressed in the cutting process. For example, damage to the protective layer 21 can be suppressed. Furthermore, even if an external force is applied to the acoustic wave device, no external pressure is applied to the frame 20, so the width D1 of the frame 20 can be reduced. This allows the elastic wave device to be miniaturized.

When at least one of the side surfaces 30, 31, and 32 is curved or inclined, the portion of the side surface 31 of the frame 20 that contacts the support substrate 10 is located inside the portion of the side surface 30 of the support substrate 10 that contacts the frame 20. Just be located. The portion of the side surface 32 of the lid 26 that is in contact with the frame may be located outside of the portion of the side surface 31 of the frame 20 that is in contact with the lid 26.

In order to irradiate the support substrate 10 with the laser beam 60 through the groove 34 as in the first embodiment, the distance D3 in FIGS. 1(a) and 1(b) is preferably shorter than D2.

In the first embodiment and its modified examples, the acoustic wave device 12 is used as an example of the functional device. However, 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). It may also be an element or the like.

Example 2 is an example of a filter and a duplexer. FIG. 15(a) is a circuit diagram of a filter according to the second embodiment. As shown in FIG. 15(a), one or more series resonators S1 to S4 are connected in series between the input terminal Tin and the output terminal Tout. One or more parallel resonators P1 to P3 are connected in parallel between the input terminal Tin and the output terminal Tout. At least one of the series resonators S1 to S4 and the parallel resonators P1 to P3 may be the acoustic wave element 12 of the first embodiment and its modifications. Further, a filter may be formed on the upper surface of the piezoelectric substrate 11 of the first embodiment and its modified examples. 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. 15(b) is a circuit diagram of a duplexer according to a first modification of the second embodiment. As shown in FIG. 15(b), a transmission filter 70 is connected between the common terminal Ant and the transmission terminal Tx. A reception filter 72 is connected between the common terminal Ant and the reception terminal Rx. The transmission filter 70 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 72 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 70 and the reception filter 72 can be the filter of the second embodiment.

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.

10 Support substrate 11 Piezoelectric substrate 12 Acoustic wave element 14 Wiring 16 Via wiring 18 Terminal 20 Frame 26 Lid 28, 29 Gap 30, 31, 32 Side surface 33, 35, 35a Laser mark 34, 36 Groove 36a Modified region 70 Transmission filter 72 Reception filter 60, 62 Laser light 64 Break blade

Claims (6)

forming, on a support substrate provided with a plurality of functional elements, a plurality of frames surrounding each of the plurality of functional elements and separated from each other via a first gap;
joining a lid onto the plurality of frames so that the plurality of functional elements are sealed in a second cavity;
After the step of joining the lid, dividing the supporting substrate and the lid at a position overlapping the first gap between the frames;
including;
The step of dividing the support substrate and the lid,
forming an opening that penetrates the lid by irradiating the lid with a laser beam from a side opposite to the support substrate;
forming a groove or a modified region in the support substrate by irradiating the support substrate with laser light through the opening;
dividing the support substrate in the groove or the modified region;
A method of manufacturing an electronic device including . forming, on a support substrate provided with a plurality of functional elements, a plurality of frames surrounding each of the plurality of functional elements and separated from each other via a first gap;
joining a lid onto the plurality of frames so that the plurality of functional elements are sealed in a second cavity;
After the step of joining the lid, dividing the support substrate and the lid at a position overlapping the first gap between the frames;
including;
The step of dividing the support substrate and the lid,
forming an opening that penetrates the lid by irradiating the lid with a laser beam from a side opposite to the support substrate;
forming a groove or a modified region in the support substrate by irradiating the support substrate with a laser beam from a side opposite to the lid;
dividing the supporting substrate in the groove or the modified region;
A method of manufacturing an electronic device including. The step of dividing the support substrate and the lid includes dividing the support substrate and the lid so that the side surface of the frame on the first gap side is located closer to the second gap than the side surface of the lid and the side surface of the support substrate. The method for manufacturing an electronic device according to claim 1 or 2, comprising the step of dividing the lid. Manufacturing the electronic device according to any one of claims 1 to 3 , wherein the plurality of functional elements are a plurality of piezoelectric elements provided on a piezoelectric substrate directly or indirectly bonded to the support substrate. Method. 5. The method for manufacturing an electronic device according to claim 1 , wherein the supporting substrate is a sapphire substrate, a spinel substrate, a quartz substrate, or a crystal substrate. 6. The method of manufacturing an electronic device according to claim 1, wherein the lid is a metal lid.

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