WO2021006157A1 - Elastic wave device - Google Patents

Elastic wave device Download PDF

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Publication number
WO2021006157A1
WO2021006157A1 PCT/JP2020/025872 JP2020025872W WO2021006157A1 WO 2021006157 A1 WO2021006157 A1 WO 2021006157A1 JP 2020025872 W JP2020025872 W JP 2020025872W WO 2021006157 A1 WO2021006157 A1 WO 2021006157A1
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WO
WIPO (PCT)
Prior art keywords
support member
cover member
piezoelectric substrate
elastic wave
wave device
Prior art date
Application number
PCT/JP2020/025872
Other languages
French (fr)
Japanese (ja)
Inventor
井上　和則
慎太郎 大塚
幸一郎 川崎
正宏 福島
雅和 新
中西　秀文
巌雄 藤田
福田　大輔
豊貴 中倉
Original Assignee
株式会社村田製作所
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Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2021006157A1 publication Critical patent/WO2021006157A1/en

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/25—Constructional features of resonators using surface acoustic waves

Definitions

  • the present invention relates to an elastic wave device.
  • Patent Document 1 discloses an example of an elastic wave device.
  • This elastic wave device has an excitation electrode provided on the element substrate.
  • a frame portion is provided on the element substrate so as to surround the excitation electrode.
  • a lid is provided on the frame so as to close the frame.
  • the lid When manufacturing or using an elastic wave device, the lid may expand or contract depending on the ambient temperature. When the lid is contracted, stress is applied between the lid and the frame. As a result, the lid portion may be peeled off from the frame portion.
  • An object of the present invention is to provide an elastic wave device capable of suppressing peeling of a cover member from a support member.
  • the elastic wave device has a piezoelectric substrate, an excitation electrode provided on the piezoelectric substrate, and an opening, and is provided on the piezoelectric substrate so as to surround the excitation electrode.
  • a cover member provided on the support member so as to cover the opening of the support member, and having a central portion and a joint portion joined to the support member. The cover member is located between the central portion and the joint portion, and is located on the piezoelectric substrate rather than the distance between the central portion and the piezoelectric substrate and the distance between the joint portion and the piezoelectric substrate. Has a piezo with a short distance.
  • FIG. 1 is a schematic front sectional view of an elastic wave device according to a first embodiment of the present invention.
  • FIG. 2 is a schematic plan view showing an electrode structure on a piezoelectric substrate according to the first embodiment of the present invention.
  • FIG. 3 is a schematic plan view showing the electrode structure of the IDT electrode according to the first embodiment of the present invention.
  • FIG. 4 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member according to the first embodiment of the present invention.
  • FIG. 5 is a schematic plan view showing a cover member according to the first embodiment of the present invention.
  • FIG. 6 is a schematic plan view showing an electrode structure on a cover member according to the first embodiment of the present invention.
  • FIG. 7 is a schematic plan view of the elastic wave device according to the first embodiment of the present invention.
  • FIG. 8 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the comparative example.
  • FIG. 9 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the first embodiment of the present invention.
  • FIG. 10 is a schematic front sectional view of an elastic wave device according to a first modification of the first embodiment of the present invention.
  • FIG. 11 is a schematic front sectional view of an elastic wave device according to a second modification of the first embodiment of the present invention.
  • FIG. 12 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member according to the second embodiment of the present invention.
  • FIG. 13 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the first modification of the second embodiment of the present invention.
  • FIG. 14 is a schematic front sectional view showing a part of a support member in a second modification of the second embodiment of the present invention.
  • FIG. 15 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member according to the third embodiment of the present invention.
  • FIG. 16 is a schematic front sectional view of an elastic wave device according to a fourth embodiment of the present invention.
  • FIG. 1 is a schematic front sectional view of an elastic wave device according to a first embodiment of the present invention.
  • the elastic wave device 1 has a piezoelectric substrate 2.
  • the piezoelectric substrate 2 has a main surface 2a.
  • the piezoelectric substrate 2 is a piezoelectric substrate composed of only a piezoelectric layer.
  • the material of the piezoelectric layer for example, lithium tantalate, lithium niobate, zinc oxide, aluminum nitride, quartz, PZT or the like can be used.
  • the piezoelectric substrate 2 may be a laminated substrate having a layer other than the piezoelectric layer.
  • the piezoelectric substrate 2 of this embodiment has a rectangular shape in a plan view.
  • the shape of the piezoelectric substrate 2 is not limited to the above.
  • the plan view means a direction viewed from above as shown in FIG.
  • FIG. 2 is a schematic plan view showing the electrode structure on the piezoelectric substrate in the first embodiment.
  • the IDT electrode and the reflector which will be described later, are shown by a schematic diagram in which two diagonal lines are added to a rectangle.
  • FIG. 1 is a view of a portion corresponding to a cross section along the line II in FIG. 2 as viewed from a direction parallel to one side of the piezoelectric substrate 2.
  • FIG. 3 is a schematic plan view showing the electrode structure of the IDT electrode in the first embodiment.
  • the wiring electrode and the like connected to the IDT electrode are omitted.
  • the IDT electrode 3 has a first bus bar 16 and a second bus bar 17 facing each other, and a plurality of first electrode fingers 18 and a plurality of second electrode fingers 19. One end of each of the plurality of first electrode fingers 18 is connected to the first bus bar 16. One end of each of the plurality of second electrode fingers 19 is connected to the second bus bar 17. The plurality of first electrode fingers 18 and the plurality of second electrode fingers 19 are interleaved with each other. The plurality of first electrode fingers 18 and the plurality of second electrode fingers 19 of the IDT electrode 3 extend in the depth direction of FIG.
  • the IDT electrode 3, the reflector 14, and the reflector 15 may be made of a laminated metal film in which a plurality of metal layers are laminated, or may be made of a single-layer metal film.
  • the surface acoustic wave device 1 of the present embodiment is a SAW (Surface Acoustic Wave) element.
  • the elastic wave device according to the present invention may be a BAW (Bulk Acoustic Wave) element.
  • the elastic wave device according to the present invention may be a ladder type filter or a multiplexer having a plurality of elastic wave resonators utilizing SAW or BAW.
  • a frame-shaped support member 4 having an opening 4i is provided on the main surface 2a of the piezoelectric substrate 2.
  • the support member 4 is provided so as to surround the IDT electrode 3 by the opening 4i.
  • the support member 4 has a first end face 4a and a second end face 4b facing each other.
  • the first end face 4a is an end face located on the piezoelectric substrate 2 side.
  • the support member 4 has an outer surface 4c and an inner surface 4d.
  • the outer side surface 4c and the inner side surface 4d are surfaces that connect the first end surface 4a and the second end surface 4b.
  • the support member 4 is made of a photosensitive resin.
  • the material of the support member 4 is not limited to the above.
  • the distance between the outer surface 4c and the inner surface 4d in the direction parallel to the main surface 2a of the piezoelectric substrate 2 is defined as the width of the support member 4.
  • the inner side surface 4d of the support member 4 is inclined so that the width of the support member 4 becomes narrower toward the second end surface 4b.
  • the inner side surface 4d has a portion having a different inclination angle.
  • the inner side surface 4d has a first inclined portion 4g located on the first end surface 4a side and a second inclined portion 4h located on the second end surface 4b side.
  • the inclination angle of the first inclined portion 4g is larger than the inclination angle of the second inclined portion 4h.
  • the outer surface 4c of the support member 4 is also inclined so that the width of the support member 4 becomes narrower toward the second end surface 4b, and the first inclined portion 4e located on the first end surface 4a side and the first inclined portion 4e It has a second inclined portion 4f located on the side of the second end surface 4b. Also on the outer side surface 4c, the inclination angle of the first inclined portion 4e is larger than the inclination angle of the second inclined portion 4f, as in the case of the inner side surface 4d.
  • the configuration of the inner surface 4d and the outer surface 4c is not limited to the above.
  • the inclination angles of the inner surface 4d and the outer surface 4c may be constant from the first end surface 4a to the second end surface 4b.
  • first inclined portion 4g and the second inclined portion 4h are inclined linearly in the cross-sectional view shown in FIG. 1, but may be inclined in a curved shape.
  • the inner side surface 4d and the outer side surface 4c may extend perpendicular to the main surface 2a of the piezoelectric substrate 2.
  • a cover member 5 is provided on the second end surface 4b of the support member 4 so as to cover the opening 4i.
  • the cover member 5 reaches the second inclined portion 4h of the inner side surface 4d of the support member 4.
  • the cover member 5 has a joint portion 5c that is joined to the support member 4. More specifically, in the present embodiment, the joint portion 5c is a portion joined to the second end surface 4b and the second inclined portion 4h of the support member 4. In the present embodiment, the joint portion 5c is located on the outer peripheral portion of the cover member 5.
  • the second end surface 4b of the support member 4 has a portion that is not joined to the cover member 5.
  • the cover member 5 may cover the opening 4i and may be joined to at least a part of the second end surface 4b.
  • the cover member 5 may or may not be joined to at least a part of the inner side surface 4d of the support member 4.
  • the cover member 5 has a central portion 5a.
  • the cover member 5 is made of a photosensitive resin.
  • the material of the cover member 5 is not limited to the above.
  • FIG. 4 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the first embodiment.
  • parts other than the piezoelectric substrate, the support member, and the cover member are omitted.
  • parts other than the piezoelectric substrate, the support member, and the cover member may be omitted.
  • the height distance between the central portion 5a of the cover member 5 and the piezoelectric substrate 2 is Z1, and the height distance between the lower end of the joint portion 5c and the piezoelectric substrate 2 is Z2.
  • the distance Z2 is the distance between the lower end of the portion of the joint portion 5c that reaches the second inclined portion 4h of the support member 4 and the piezoelectric substrate 2.
  • the cover member 5 has a hanging portion 5b.
  • the hanging portion 5b is located between the central portion 5a and the joint portion 5c.
  • the distance between the hanging portion 5b and the piezoelectric substrate 2 is shorter than the distance Z1 and the distance Z2.
  • FIG. 5 is a schematic plan view showing the cover member according to the first embodiment.
  • the joint portion 5c is continuously provided along the circumferential direction when the central portion 5a of the cover member 5 is used as an axis.
  • a drooping portion 5b is provided at all portions in the circumferential direction between the joint portion 5c and the central portion 5a.
  • the drooping portion 5b is located in both of them.
  • the distance between the cover member 5 and the piezoelectric substrate 2 is the distance Z2 between the portion of the joint portion 5c that reaches the second inclined portion 4h and the hanging portion 5b. And has a portion longer than the distance Z3.
  • the distance between the cover member 5 and the piezoelectric substrate 2 becomes shorter toward the hanging portion 5b side from the portion.
  • the distance between the cover member 5 and the piezoelectric substrate 2 becomes longer from the hanging portion 5b toward the central portion 5a.
  • the distance Z1 is the longest among the distances between each part of the cover member 5 and the piezoelectric substrate 2. Not limited to this, for example, Z1 ⁇ Z2 may be used.
  • the cover member 5 may be formed by, for example, using a molding die or the like so as to have a portion to be a joint portion 5c, a hanging portion 5b, and a central portion 5a. In this way, after the cover member 5 is separately formed, the cover member 5 may be joined to the support member 4. At this time, for example, the cover member 5 and the support member 4 may be joined with an adhesive.
  • the method of forming the cover member 5 and the method of joining the cover member 5 and the support member 4 are not limited to the above.
  • a first wiring electrode 6A electrically connected to the IDT electrode 3 is provided on the main surface 2a of the piezoelectric substrate 2.
  • the support member 4 is provided so as to cover a part of the first wiring electrode 6A.
  • a plurality of openings 12 are provided so as to penetrate the support member 4 and the cover member 5.
  • a via electrode 7 is provided in each opening 12.
  • FIG. 6 is a schematic plan view showing the electrode structure on the cover member in the first embodiment.
  • FIG. 7 is a schematic plan view of the elastic wave device according to the first embodiment. In FIG. 6, the cover member and the like are omitted.
  • a second wiring electrode 6B is provided on the cover member 5 so as to be connected to one end of the via electrode 7.
  • the other end of the via electrode 7 is connected to the first wiring electrode 6A.
  • a sealing resin layer 13 is provided on the main surface 2a of the piezoelectric substrate 2 so as to cover the support member 4, the cover member 5, and the second wiring electrode 6B.
  • the underbump metal layer 8 is provided so as to penetrate the sealing resin layer 13 and connect one end to the second wiring electrode 6B.
  • the bump 9 is provided so as to be joined to the other end of the under bump metal layer 8.
  • the bump 9 is made of, for example, solder.
  • the IDT electrode 3 is arranged in a hollow space surrounded by a piezoelectric substrate 2, a support member 4, and a cover member 5.
  • the IDT electrode 3 is electrically connected to the outside via a first wiring electrode 6A, a via electrode 7, a second wiring electrode 6B, an under bump metal layer 8 and a bump 9.
  • the elastic wave device 1 has a WLP (Wafer Level Package) structure.
  • the feature of this embodiment is that the cover member 5 has a hanging portion 5b located between the central portion 5a and the joint portion 5c. As a result, the cover member 5 is difficult to peel off from the support member 4. This will be described below by comparing the present embodiment with a comparative example.
  • FIG. 8 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the comparative example.
  • the comparative example is different from the first embodiment in that the cover member 105 does not have the hanging portion 5b.
  • the distance between the cover member 105 and the piezoelectric substrate 2 increases from the joint portion 5c toward the central portion 5a.
  • a stress A is applied between the cover member 105 and the support member 4 as shown in FIG.
  • the component A1 of the force in the direction perpendicular to the main surface 2a of the piezoelectric substrate 2 in the stress A is a component in the direction of peeling the cover member 105 from the support member 4. Therefore, the cover member 105 may be peeled off from the support member 4.
  • FIG. 9 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the first embodiment.
  • the cover member 5 has a hanging portion 5b located between the central portion 5a and the joint portion 5c.
  • a stress B is applied between the cover member 5 and the support member 4, as shown in FIG.
  • the component B1 of the force in the direction perpendicular to the main surface 2a of the piezoelectric substrate 2 in the stress B is a component in the direction in which the cover member 5 is brought into close contact with the support member 4. Therefore, the cover member 5 is difficult to peel off from the support member 4.
  • the cover member when the cover member is made of a photosensitive resin, the cover member shrinks significantly when the cover member is cured. Therefore, in the comparative example shown in FIG. 8, the stress applied in the direction of peeling the cover member 105 and the support member 4 becomes particularly large.
  • the component B1 of the force in the stress B applied between the cover member 5 and the support member 4 is the component in the direction in which the cover member 5 is brought into close contact with the support member 4. can do. Therefore, this embodiment is particularly suitable when the cover member 5 is made of a photosensitive resin.
  • the distance between the hanging portion 5b and the piezoelectric substrate 2 may be the shortest.
  • the distance between the cover member 5 and the piezoelectric substrate 2 becomes longer from the hanging portion 5b toward the central portion 5a. Thereby, the stress applied to the cover member 5 can be relaxed.
  • a force for pressing the cover member 5 toward the IDT electrode 3 is applied from the outside, it is difficult for the cover member 5 to come into contact with the IDT electrode 3. Therefore, the elastic wave device 1 is not easily damaged.
  • the hanging portion 5b is preferably provided at a position closer to the joint portion 5c than the central portion 5a.
  • the cover member 5 does not have to reach the inner side surface 4d of the support member 4.
  • the cover member 25B is provided on the second end surface 4b of the support member 4, and the cover member 25B is the inner surface of the support member 4. It has not reached 4d.
  • the cover member 5 is joined to the second end surface 4b and the inner side surface 4d of the support member 4.
  • the bonding force between the cover member 5 and the support member 4 can be increased, and the cover member 5 is more difficult to peel off from the support member 4.
  • the cover member 5 and the second inclined portion 4h can be suitably joined. it can.
  • FIG. 12 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the second embodiment.
  • the support member 34 has a narrow portion 34X located between the first end surface 4a and the second end surface 4b, and the cover member 5 does not reach the inner surface 34d of the support member 34.
  • the elastic wave device of the present embodiment has the same configuration as the elastic wave device 1 of the first embodiment.
  • first inclined portion 4e and the first inclined portion 4g of the outer surface 34c and the inner surface 34d are formed from the first end surface 4a side to the second end surface 4b as in the first embodiment.
  • the support member 34 is inclined so as to become narrower toward the side.
  • the second inclined portion 34f and the second inclined portion 34h are inclined so that the width of the support member 34 becomes narrower from the second end surface 4b side toward the first end surface 4a side.
  • the narrow portion 34X is composed of the first inclined portion 4e and the second inclined portion 34f of the outer side surface 34c, and the first inclined portion 4g and the second inclined portion 34h of the inner side surface 34d.
  • the configuration of the narrow width portion 34X is not limited to the above, and the width of the narrow width portion 34X may be narrower than that of other portions. However, the narrow portion 34X does not have to be the narrowest portion of the support member 34.
  • the elastic wave device of this embodiment has a cover member 25B similar to that of the second modification of the first embodiment. Therefore, as in the first embodiment and the second modification thereof, the cover member 25B is difficult to peel off from the support member 34.
  • the support member 34 has a narrow portion 34X.
  • the stress can be concentrated on the narrow portion 34X, and the stress applied between the support member 34 and the piezoelectric substrate 2 can be relaxed. Therefore, as described above, in addition to the cover member 25B being difficult to peel off from the support member 34, the support member 34 is hard to peel off from the piezoelectric substrate 2.
  • the position of the narrowest portion of the support member 34 is preferably closer to the first end face 4a than to the second end face 4b. As a result, the stress can be further concentrated on the narrow portion 34X, and the stress applied between the support member 34 and the piezoelectric substrate 2 can be further relaxed. Therefore, the support member 34 is more difficult to peel off from the piezoelectric substrate 2.
  • the narrow portion 34X of the support member 34 is composed of a first inclined portion and a second inclined portion on both the outer surface 34c and the inner surface 34d.
  • the configuration of the narrow portion 34X is not limited to the above.
  • a first modification and a second modification of the second embodiment in which only the configuration of the narrow portion is different from the second embodiment, will be shown.
  • the cover member 25B is difficult to peel off from the support member, and the support member is hard to peel off from the piezoelectric substrate 2, as in the second embodiment.
  • the narrow portion 44X is configured by providing the first inclined portion 4g and the second inclined portion 34h of the support member 44A only on the inner side surface 34d. There is.
  • the inner side surface 44d has a first step portion 44g and a second step portion 44h.
  • the first step portion 44g is located on the first end surface 4a side.
  • the second step portion 44h is located on the second end surface 4b side. Between the first step portion 44g and the second step portion 44h, the first step portion 44g and the second step portion 44h are provided so that the width of the support member 44B becomes narrower.
  • the outer surface 44c has a first step portion 44e and a second step portion 44f.
  • the first step portion 44e is located on the first end surface 4a side.
  • the second step portion 44f is located on the second end surface 4b side.
  • the narrow portion 44Y is formed by providing each of the above-mentioned step portions. More specifically, each of the above-mentioned step portions is configured as a single step. In addition, each step portion may have a step-like shape having a plurality of steps. One of the outer side surface 44c and the inner side surface 44d may have a first step portion and a second step portion.
  • FIG. 15 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the third embodiment.
  • the inner side surface 54d of the support member 54 is inclined so that the width of the support member 54 becomes narrower toward the second end surface 4b, and the third inclination reaches the second end surface 4b. It differs from the second embodiment in that it has a portion 54k. A point in which the outer surface 54c of the support member 54 is inclined so that the width of the support member 54 becomes narrower toward the second end surface 4b, and has a third inclined portion 54j that reaches the second end surface 4b. Also, it is different from the second embodiment. Further, it is different from the second embodiment in that the cover member 5 reaches the third inclined portion 54k of the inner side surface 54d. Except for the above points, the elastic wave device of the present embodiment has the same configuration as the elastic wave device of the second embodiment.
  • the cover member 5 and the third inclined portion 54k can be suitably joined.
  • the joint area between the cover member 5 and the support member 54 can be increased, and the joint force between the cover member 5 and the support member 54 can be increased.
  • the elastic wave device of the present embodiment has the same cover member 5 as that of the first embodiment. Therefore, the cover member 5 is difficult to peel off from the support member 54.
  • the support member 54 since the support member 54 has a narrow portion 34X, the support member 54 is difficult to peel off from the piezoelectric substrate 2 as in the second embodiment.
  • the first end face 4a has a first inner peripheral edge 54l
  • the second end face 4b has a second inner peripheral edge 54m.
  • the alternate long and short dash line C in FIG. 15 indicates the position of the first inner peripheral edge 54l
  • the alternate long and short dash line D indicates the position of the second inner peripheral edge 54m.
  • the first inner peripheral edge 54l is located outside the second inner peripheral edge 54m when viewed from the central portion of the cover member 5. Thereby, the area of the piezoelectric substrate 2 in the hollow space surrounded by the piezoelectric substrate 2, the support member 34, and the cover member 5 can be increased. Therefore, the size of the elastic wave device can be reduced.
  • the first inner peripheral edge 54l and the second inner peripheral edge 54m may overlap, or the first inner peripheral edge 54l may be located inside the second inner peripheral edge 54m. Good.
  • FIG. 16 is a schematic front sectional view of the elastic wave device according to the fourth embodiment.
  • the elastic wave device 61 of this embodiment is a BAW element.
  • the piezoelectric substrate 62 is a laminated substrate having a support substrate 63 and a piezoelectric layer 64.
  • the support substrate 63 has a recess 63a and a support portion 63b surrounding the recess 63a in a plan view.
  • the piezoelectric layer 64 is provided on the support portion 63b of the support substrate 63.
  • the piezoelectric layer 64 has a first main surface 64a and a second main surface 64b facing each other.
  • the second main surface 64b is located on the support substrate 63 side.
  • a first flat plate electrode 65A is provided on the first main surface 64a of the piezoelectric layer 64
  • a second flat plate electrode 65B is provided on the second main surface 64b. More specifically, the first flat plate electrode 65A and the second flat plate electrode 65B are provided in the portion of the piezoelectric layer 64 that overlaps the recess 63a of the support substrate 63 in a plan view.
  • the first flat plate electrode 65A and the second flat plate electrode 65B face each other.
  • the excitation electrodes in this embodiment are a first flat plate electrode 65A and a second flat plate electrode 65B.
  • a first wiring electrode 66A electrically connected to the first flat plate electrode 65A is provided on the first main surface 64a of the piezoelectric layer 64.
  • a first wiring electrode 66B electrically connected to the second flat plate electrode 65B is provided on the second main surface 64b.
  • the same support as in the first embodiment is provided so as to surround the first flat plate electrode 65A and to cover a part of the first wiring electrode 66A.
  • the member 4 is provided.
  • a cover member 5 similar to that of the first embodiment is provided on the second end surface 4b of the support member 4.
  • a via electrode 67A is provided so as to penetrate the support member 4 and the cover member 5.
  • One end of the via electrode 67A is connected to the first wiring electrode 66A.
  • a second wiring electrode 6B is provided on the cover member 5 so as to be joined to the other end of the via electrode 67A.
  • the via electrode 67B is provided so as to penetrate the piezoelectric layer 64, the support member 4, and the cover member 5.
  • One end of the via electrode 67B is connected to the first wiring electrode 66B.
  • a second wiring electrode 6B different from the above is provided on the cover member 5 so as to be connected to the other end of the via electrode 67B.
  • a sealing resin layer 13 is provided on the first main surface 64a of the piezoelectric layer 64 so as to cover the support member 4, the cover member 5, and each of the second wiring electrodes 6B.
  • the underbump metal layer 8 is provided so as to penetrate the sealing resin layer 13 and connect one end to each of the second wiring electrodes 6B.
  • the bump 9 is provided so as to be joined to the other end of the under bump metal layer 8.
  • the elastic wave device 61 of the present embodiment has the same cover member 5 as that of the first embodiment, when the cover member 5 contracts, the stress applied between the cover member 5 and the support member 4 is supported. It has a force component in the direction in which the cover member 5 is brought into close contact with the member 4. Therefore, the cover member 5 is difficult to peel off from the support member 4.
  • Elastic wave device 2 Piezoelectric substrate 2a ... Main surface 3 ... IDT electrode 4 ... Support members 4a, 4b ... First and second end surfaces 4c ... Outer surface 4d ... Inner surface 4e, 4f ... First and second Inclined portions 4g, 4h ... First and second inclined portions 4i ... Opening 5 ... Cover member 5a ... Central portion 5b ... Drooping portion 5c ... Joint portions 6A, 6B ... First and second wiring electrodes 7 ... Vias Electrode 8 ... Under bump metal layer 9 ... Bump 12 ... Opening 13 ... Sealing resin layers 14, 15 ... Reflector 16 ... First bus bar 17 ... Second bus bar 18 ... First electrode finger 19 ...
  • Support portion 64 Piezoelectric layer 64a, 64b ... First and second main surfaces 65A, 65B ... 1st and 2nd flat plate electrodes 66A, 66B ... 1st wiring electrode 67A, 67B ... Via electrode 105 ... Cover member A, B ... Stress A1, B1 ... Force component

Abstract

Provided is an elastic wave device that can suppress peeling of a cover member from a support member.　The elastic wave device 1 comprises: a piezoelectric substrate 2; an IDT electrode 3 (excitation electrode) that is provided on the piezoelectric substrate 2; a support member that has an opening part 4i and is provided on the piezoelectric substrate 2 to surround the IDT electrode 3; and a cover member 5 that is provided on the support member 4 to cover the opening part 4i of the support member 4 and has a central part 5a and a joint part 5c joined to the support member 4. The cover member 5 has a drooping part 5b which is located between the central part 5a and the joint part 5c and in which the distance between the drooping part 5b and the piezoelectric substrate 2 is shorter than the distance between the central part 5a and the piezoelectric substrate 2 and the distance between the joint part 5c and the piezoelectric substrate 2.

Description

弾性波装置Elastic wave device
　本発明は、弾性波装置に関する。 The present invention relates to an elastic wave device.
　従来、弾性波装置は携帯電話機のフィルタなどに広く用いられている。下記の特許文献１には、弾性波装置の一例が開示されている。この弾性波装置は、素子基板上に設けられた励振電極を有する。励振電極を囲むように、素子基板上に枠部が設けられている。枠部を塞ぐように、枠部上に蓋部が設けられている。 Conventionally, elastic wave devices have been widely used as filters for mobile phones. The following Patent Document 1 discloses an example of an elastic wave device. This elastic wave device has an excitation electrode provided on the element substrate. A frame portion is provided on the element substrate so as to surround the excitation electrode. A lid is provided on the frame so as to close the frame.
特開２０１４－００７７２７号公報Japanese Unexamined Patent Publication No. 2014-007727
　弾性波装置の製造時や使用時においては、周囲温度によって、蓋部が膨張または収縮する場合がある。蓋部が収縮したときには、蓋部と枠部との間に応力が加わる。これにより、枠部から蓋部が剥離するおそれがある。 When manufacturing or using an elastic wave device, the lid may expand or contract depending on the ambient temperature. When the lid is contracted, stress is applied between the lid and the frame. As a result, the lid portion may be peeled off from the frame portion.
　本発明の目的は、支持部材からのカバー部材の剥離を抑制することができる、弾性波装置を提供することにある。 An object of the present invention is to provide an elastic wave device capable of suppressing peeling of a cover member from a support member.
　本発明に係る弾性波装置は、圧電性基板と、前記圧電性基板上に設けられている励振電極と、開口部を有し、前記励振電極を囲むように前記圧電性基板上に設けられている支持部材と、前記支持部材の前記開口部を覆うように前記支持部材上に設けられており、中央部と、前記支持部材に接合されている接合部とを有するカバー部材とを備え、前記カバー部材が、前記中央部と前記接合部との間に位置し、かつ前記中央部と前記圧電性基板との距離及び前記接合部と前記圧電性基板との距離よりも、前記圧電性基板との距離が短い下垂部を有する。 The elastic wave device according to the present invention has a piezoelectric substrate, an excitation electrode provided on the piezoelectric substrate, and an opening, and is provided on the piezoelectric substrate so as to surround the excitation electrode. A cover member provided on the support member so as to cover the opening of the support member, and having a central portion and a joint portion joined to the support member. The cover member is located between the central portion and the joint portion, and is located on the piezoelectric substrate rather than the distance between the central portion and the piezoelectric substrate and the distance between the joint portion and the piezoelectric substrate. Has a piezo with a short distance.
　本発明に係る弾性波装置によれば、支持部材からのカバー部材の剥離を抑制することができる。 According to the elastic wave device according to the present invention, peeling of the cover member from the support member can be suppressed.
図１は、本発明の第１の実施形態に係る弾性波装置の模式的正面断面図である。FIG. 1 is a schematic front sectional view of an elastic wave device according to a first embodiment of the present invention. 図２は、本発明の第１の実施形態における圧電性基板上の電極構造を示す略図的平面図である。FIG. 2 is a schematic plan view showing an electrode structure on a piezoelectric substrate according to the first embodiment of the present invention. 図３は、本発明の第１の実施形態におけるＩＤＴ電極の電極構造を示す模式的平面図である。FIG. 3 is a schematic plan view showing the electrode structure of the IDT electrode according to the first embodiment of the present invention. 図４は、本発明の第１の実施形態における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。FIG. 4 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member according to the first embodiment of the present invention. 図５は、本発明の第１の実施形態におけるカバー部材を示す略図的平面図である。FIG. 5 is a schematic plan view showing a cover member according to the first embodiment of the present invention. 図６は、本発明の第１の実施形態におけるカバー部材上の電極構造を示す略図的平面図である。FIG. 6 is a schematic plan view showing an electrode structure on a cover member according to the first embodiment of the present invention. 図７は、本発明の第１の実施形態に係る弾性波装置の略図的平面図である。FIG. 7 is a schematic plan view of the elastic wave device according to the first embodiment of the present invention. 図８は、比較例において、カバー部材と支持部材との間に加わる応力を説明するための模式的正面断面図である。FIG. 8 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the comparative example. 図９は、本発明の第１の実施形態において、カバー部材と支持部材との間に加わる応力を説明するための模式的正面断面図である。FIG. 9 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the first embodiment of the present invention. 図１０は、本発明の第１の実施形態の第１の変形例に係る弾性波装置の模式的正面断面図である。FIG. 10 is a schematic front sectional view of an elastic wave device according to a first modification of the first embodiment of the present invention. 図１１は、本発明の第１の実施形態の第２の変形例に係る弾性波装置の模式的正面断面図である。FIG. 11 is a schematic front sectional view of an elastic wave device according to a second modification of the first embodiment of the present invention. 図１２は、本発明の第２の実施形態における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。FIG. 12 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member according to the second embodiment of the present invention. 図１３は、本発明の第２の実施形態の第１の変形例における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。FIG. 13 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the first modification of the second embodiment of the present invention. 図１４は、本発明の第２の実施形態の第２の変形例における支持部材の一部を示す模式的正面断面図である。FIG. 14 is a schematic front sectional view showing a part of a support member in a second modification of the second embodiment of the present invention. 図１５は、本発明の第３の実施形態における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。FIG. 15 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member according to the third embodiment of the present invention. 図１６は、本発明の第４の実施形態に係る弾性波装置の模式的正面断面図である。FIG. 16 is a schematic front sectional view of an elastic wave device according to a fourth embodiment of the present invention.
　以下、図面を参照しつつ、本発明の具体的な実施形態を説明することにより、本発明を明らかにする。 Hereinafter, the present invention will be clarified by explaining a specific embodiment of the present invention with reference to the drawings.
　なお、本明細書に記載の各実施形態は、例示的なものであり、異なる実施形態間において、構成の部分的な置換または組み合わせが可能であることを指摘しておく。 It should be noted that each of the embodiments described herein is exemplary and that partial replacement or combination of configurations is possible between different embodiments.
　図１は、本発明の第１の実施形態に係る弾性波装置の模式的正面断面図である。 FIG. 1 is a schematic front sectional view of an elastic wave device according to a first embodiment of the present invention.
　弾性波装置１は圧電性基板２を有する。圧電性基板２は主面２ａを有する。本実施形態では、圧電性基板２は圧電体層のみからなる圧電基板である。圧電体層の材料としては、例えば、タンタル酸リチウム、ニオブ酸リチウム、酸化亜鉛、窒化アルミニウム、水晶、またはＰＺＴなどを用いることができる。なお、圧電性基板２は、圧電体層以外の層を有する積層基板であってもよい。 The elastic wave device 1 has a piezoelectric substrate 2. The piezoelectric substrate 2 has a main surface 2a. In the present embodiment, the piezoelectric substrate 2 is a piezoelectric substrate composed of only a piezoelectric layer. As the material of the piezoelectric layer, for example, lithium tantalate, lithium niobate, zinc oxide, aluminum nitride, quartz, PZT or the like can be used. The piezoelectric substrate 2 may be a laminated substrate having a layer other than the piezoelectric layer.
　本実施形態の圧電性基板２は、平面視において、矩形の形状を有する。なお、圧電性基板２の形状は上記に限定されない。本明細書において平面視とは、図１などの上方から見る方向をいう。 The piezoelectric substrate 2 of this embodiment has a rectangular shape in a plan view. The shape of the piezoelectric substrate 2 is not limited to the above. In the present specification, the plan view means a direction viewed from above as shown in FIG.
　図２は、第１の実施形態における圧電性基板上の電極構造を示す略図的平面図である。図２においては、後述するＩＤＴ電極や反射器を、矩形に２本の対角線を加えた略図により示す。 FIG. 2 is a schematic plan view showing the electrode structure on the piezoelectric substrate in the first embodiment. In FIG. 2, the IDT electrode and the reflector, which will be described later, are shown by a schematic diagram in which two diagonal lines are added to a rectangle.
　圧電性基板２の主面２ａ上には複数の励振電極が設けられている。より具体的には、励振電極は、本実施形態ではＩＤＴ電極３である。なお、励振電極は、少なくとも１つ設けられていればよい。図１は、図２中のＩ－Ｉ線に沿う断面に相当する部分を、圧電性基板２の一辺に平行な方向から見た図である。 A plurality of excitation electrodes are provided on the main surface 2a of the piezoelectric substrate 2. More specifically, the excitation electrode is the IDT electrode 3 in this embodiment. It is sufficient that at least one excitation electrode is provided. FIG. 1 is a view of a portion corresponding to a cross section along the line II in FIG. 2 as viewed from a direction parallel to one side of the piezoelectric substrate 2.
　図３は、第１の実施形態におけるＩＤＴ電極の電極構造を示す模式的平面図である。なお、図３においては、ＩＤＴ電極に接続されている配線電極などを省略している。 FIG. 3 is a schematic plan view showing the electrode structure of the IDT electrode in the first embodiment. In FIG. 3, the wiring electrode and the like connected to the IDT electrode are omitted.
　ＩＤＴ電極３は、対向し合う第１のバスバー１６及び第２のバスバー１７と、複数の第１の電極指１８及び複数の第２の電極指１９とを有する。複数の第１の電極指１８のそれぞれの一端は、第１のバスバー１６に接続されている。複数の第２の電極指１９のそれぞれの一端は、第２のバスバー１７に接続されている。複数の第１の電極指１８と複数の第２の電極指１９とは互いに間挿し合っている。ＩＤＴ電極３の複数の第１の電極指１８及び複数の第２の電極指１９は、図１の奥行方向に延びる。 The IDT electrode 3 has a first bus bar 16 and a second bus bar 17 facing each other, and a plurality of first electrode fingers 18 and a plurality of second electrode fingers 19. One end of each of the plurality of first electrode fingers 18 is connected to the first bus bar 16. One end of each of the plurality of second electrode fingers 19 is connected to the second bus bar 17. The plurality of first electrode fingers 18 and the plurality of second electrode fingers 19 are interleaved with each other. The plurality of first electrode fingers 18 and the plurality of second electrode fingers 19 of the IDT electrode 3 extend in the depth direction of FIG.
　ＩＤＴ電極３に信号電力を印加することにより、弾性表面波が励振される。圧電性基板２上における、ＩＤＴ電極３の弾性波伝搬方向両側には、一対の反射器１４及び反射器１５が設けられている。ＩＤＴ電極３、反射器１４及び反射器１５は、複数の金属層が積層された積層金属膜からなっていてもよく、単層の金属膜からなっていてもよい。 Surface acoustic waves are excited by applying signal power to the IDT electrode 3. A pair of reflectors 14 and reflectors 15 are provided on both sides of the IDT electrode 3 in the elastic wave propagation direction on the piezoelectric substrate 2. The IDT electrode 3, the reflector 14, and the reflector 15 may be made of a laminated metal film in which a plurality of metal layers are laminated, or may be made of a single-layer metal film.
　このように、本実施形態の弾性波装置１はＳＡＷ（Ｓｕｒｆａｃｅ　Ａｃｏｕｓｔｉｃ　Ｗａｖｅ）素子である。もっとも、本発明に係る弾性波装置は、ＢＡＷ（Ｂｕｌｋ　Ａｃｏｕｓｔｉｃ　Ｗａｖｅ）素子であってもよい。あるいは、本発明に係る弾性波装置は、ＳＡＷまたはＢＡＷを利用する複数の弾性波共振子を有するラダー型フィルタやマルチプレクサなどであってもよい。 As described above, the surface acoustic wave device 1 of the present embodiment is a SAW (Surface Acoustic Wave) element. However, the elastic wave device according to the present invention may be a BAW (Bulk Acoustic Wave) element. Alternatively, the elastic wave device according to the present invention may be a ladder type filter or a multiplexer having a plurality of elastic wave resonators utilizing SAW or BAW.
　図１に戻り、圧電性基板２の主面２ａ上には、開口部４ｉを有する枠状の支持部材４が設けられている。支持部材４は、開口部４ｉによりＩＤＴ電極３を囲むように設けられている。支持部材４は、対向し合う第１の端面４ａ及び第２の端面４ｂを有する。第１の端面４ａが圧電性基板２側に位置する端面である。支持部材４は外側面４ｃ及び内側面４ｄを有する。外側面４ｃ及び内側面４ｄは、第１の端面４ａと第２の端面４ｂとを接続する面である。本実施形態では、支持部材４は感光性樹脂からなる。なお、支持部材４の材料は上記に限定されない。 Returning to FIG. 1, a frame-shaped support member 4 having an opening 4i is provided on the main surface 2a of the piezoelectric substrate 2. The support member 4 is provided so as to surround the IDT electrode 3 by the opening 4i. The support member 4 has a first end face 4a and a second end face 4b facing each other. The first end face 4a is an end face located on the piezoelectric substrate 2 side. The support member 4 has an outer surface 4c and an inner surface 4d. The outer side surface 4c and the inner side surface 4d are surfaces that connect the first end surface 4a and the second end surface 4b. In the present embodiment, the support member 4 is made of a photosensitive resin. The material of the support member 4 is not limited to the above.
　ここで、図１に示す断面視において、圧電性基板２の主面２ａに対して平行な方向における、外側面４ｃと内側面４ｄとの距離を、支持部材４の幅とする。本実施形態では、支持部材４の内側面４ｄは、第２の端面４ｂに向かうほど、支持部材４の幅が細くなるように傾斜している。圧電性基板２の主面２ａに垂直な方向に対して傾斜している角度を傾斜角度としたときに、内側面４ｄは、傾斜角度が異なる部分を有する。より具体的には、内側面４ｄは、第１の端面４ａ側に位置する第１の傾斜部４ｇと、第２の端面４ｂ側に位置する第２の傾斜部４ｈとを有する。第１の傾斜部４ｇの傾斜角度は、第２の傾斜部４ｈの傾斜角度よりも大きい。 Here, in the cross-sectional view shown in FIG. 1, the distance between the outer surface 4c and the inner surface 4d in the direction parallel to the main surface 2a of the piezoelectric substrate 2 is defined as the width of the support member 4. In the present embodiment, the inner side surface 4d of the support member 4 is inclined so that the width of the support member 4 becomes narrower toward the second end surface 4b. When the angle of inclination with respect to the direction perpendicular to the main surface 2a of the piezoelectric substrate 2 is taken as the inclination angle, the inner side surface 4d has a portion having a different inclination angle. More specifically, the inner side surface 4d has a first inclined portion 4g located on the first end surface 4a side and a second inclined portion 4h located on the second end surface 4b side. The inclination angle of the first inclined portion 4g is larger than the inclination angle of the second inclined portion 4h.
　支持部材４の外側面４ｃも、第２の端面４ｂに向かうほど、支持部材４の幅が細くなるように傾斜しており、第１の端面４ａ側に位置する第１の傾斜部４ｅと、第２の端面４ｂ側に位置する第２の傾斜部４ｆとを有する。外側面４ｃにおいても、内側面４ｄと同様に、第１の傾斜部４ｅの傾斜角度は、第２の傾斜部４ｆの傾斜角度よりも大きい。なお、内側面４ｄ及び外側面４ｃの構成は上記に限定されない。例えば、内側面４ｄ及び外側面４ｃの傾斜角度は、第１の端面４ａから第２の端面４ｂにかけて一定であってもよい。本実施形態においては、第１の傾斜部４ｇ及び第２の傾斜部４ｈは、図１に示す断面視において直線状に傾斜しているが、曲線状に傾斜していてもよい。あるいは、内側面４ｄ及び外側面４ｃは、圧電性基板２の主面２ａに垂直に延びていてもよい。 The outer surface 4c of the support member 4 is also inclined so that the width of the support member 4 becomes narrower toward the second end surface 4b, and the first inclined portion 4e located on the first end surface 4a side and the first inclined portion 4e It has a second inclined portion 4f located on the side of the second end surface 4b. Also on the outer side surface 4c, the inclination angle of the first inclined portion 4e is larger than the inclination angle of the second inclined portion 4f, as in the case of the inner side surface 4d. The configuration of the inner surface 4d and the outer surface 4c is not limited to the above. For example, the inclination angles of the inner surface 4d and the outer surface 4c may be constant from the first end surface 4a to the second end surface 4b. In the present embodiment, the first inclined portion 4g and the second inclined portion 4h are inclined linearly in the cross-sectional view shown in FIG. 1, but may be inclined in a curved shape. Alternatively, the inner side surface 4d and the outer side surface 4c may extend perpendicular to the main surface 2a of the piezoelectric substrate 2.
　支持部材４の第２の端面４ｂ上には、開口部４ｉを覆うように、カバー部材５が設けられている。カバー部材５は、支持部材４の内側面４ｄの第２の傾斜部４ｈに至っている。カバー部材５は、支持部材４に接合されている接合部５ｃを有する。より具体的には、本実施形態においては、接合部５ｃは、支持部材４の第２の端面４ｂ及び第２の傾斜部４ｈに接合されている部分である。本実施形態では、接合部５ｃはカバー部材５の外周部に位置する。 A cover member 5 is provided on the second end surface 4b of the support member 4 so as to cover the opening 4i. The cover member 5 reaches the second inclined portion 4h of the inner side surface 4d of the support member 4. The cover member 5 has a joint portion 5c that is joined to the support member 4. More specifically, in the present embodiment, the joint portion 5c is a portion joined to the second end surface 4b and the second inclined portion 4h of the support member 4. In the present embodiment, the joint portion 5c is located on the outer peripheral portion of the cover member 5.
　支持部材４の第２の端面４ｂは、カバー部材５に接合されていない部分を有する。このように、カバー部材５は、開口部４ｉを覆っていればよく、第２の端面４ｂの少なくとも一部に接合されていればよい。カバー部材５は、支持部材４の内側面４ｄの少なくとも一部に接合されていてもよく、あるいは、内側面４ｄに接合されていなくともよい。 The second end surface 4b of the support member 4 has a portion that is not joined to the cover member 5. As described above, the cover member 5 may cover the opening 4i and may be joined to at least a part of the second end surface 4b. The cover member 5 may or may not be joined to at least a part of the inner side surface 4d of the support member 4.
　カバー部材５は中央部５ａを有する。本実施形態では、カバー部材５は感光性樹脂からなる。なお、カバー部材５の材料は上記に限定されない。 The cover member 5 has a central portion 5a. In the present embodiment, the cover member 5 is made of a photosensitive resin. The material of the cover member 5 is not limited to the above.
　図４は、第１の実施形態における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。図４においては、圧電性基板、支持部材及びカバー部材以外を省略している。図４以外の模式的正面断面図においても、圧電性基板、支持部材及びカバー部材以外を省略することがある。 FIG. 4 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the first embodiment. In FIG. 4, parts other than the piezoelectric substrate, the support member, and the cover member are omitted. Also in the schematic front sectional view other than FIG. 4, parts other than the piezoelectric substrate, the support member, and the cover member may be omitted.
　カバー部材５における中央部５ａと、圧電性基板２との高さ方向の距離をＺ１とし、接合部５ｃの下端と、圧電性基板２との高さ方向の距離をＺ２とする。なお、本実施形態では、距離Ｚ２は、接合部５ｃにおける支持部材４の第２の傾斜部４ｈに至っている部分の下端と圧電性基板２との距離である。ここで、カバー部材５は下垂部５ｂを有する。下垂部５ｂは、中央部５ａと接合部５ｃとの間に位置する。下垂部５ｂと圧電性基板２との距離は、距離Ｚ１及び距離Ｚ２よりも短い。下垂部５ｂと圧電性基板２との高さ方向の距離をＺ３としたとき、Ｚ３＜Ｚ１であり、かつＺ３＜Ｚ２である。 The height distance between the central portion 5a of the cover member 5 and the piezoelectric substrate 2 is Z1, and the height distance between the lower end of the joint portion 5c and the piezoelectric substrate 2 is Z2. In the present embodiment, the distance Z2 is the distance between the lower end of the portion of the joint portion 5c that reaches the second inclined portion 4h of the support member 4 and the piezoelectric substrate 2. Here, the cover member 5 has a hanging portion 5b. The hanging portion 5b is located between the central portion 5a and the joint portion 5c. The distance between the hanging portion 5b and the piezoelectric substrate 2 is shorter than the distance Z1 and the distance Z2. When the distance between the hanging portion 5b and the piezoelectric substrate 2 in the height direction is Z3, Z3 <Z1 and Z3 <Z2.
　図５は、第１の実施形態におけるカバー部材を示す略図的平面図である。 FIG. 5 is a schematic plan view showing the cover member according to the first embodiment.
　平面視において、カバー部材５の中央部５ａを軸としたときの周回方向に沿って、接合部５ｃが連続的に設けられている。接合部５ｃと中央部５ａとの間の周回方向における全ての部分において、下垂部５ｂが設けられている。圧電性基板２の主面２ａに垂直な方向に沿う断面においては、カバー部材５の一方端側の接合部５ｃと中央部５ａとの間及び他方端側の接合部５ｃと中央部５ａとの間の両方に、下垂部５ｂが位置する。 In a plan view, the joint portion 5c is continuously provided along the circumferential direction when the central portion 5a of the cover member 5 is used as an axis. A drooping portion 5b is provided at all portions in the circumferential direction between the joint portion 5c and the central portion 5a. In the cross section along the direction perpendicular to the main surface 2a of the piezoelectric substrate 2, between the joint portion 5c on one end side and the central portion 5a of the cover member 5 and between the joint portion 5c and the central portion 5a on the other end side. The drooping portion 5b is located in both of them.
　図４に示すように、カバー部材５は、接合部５ｃにおける第２の傾斜部４ｈに至っている部分と下垂部５ｂとの間において、カバー部材５と圧電性基板２との距離が、距離Ｚ２及び距離Ｚ３よりも長い部分を有する。該部分から下垂部５ｂ側に向かうほど、カバー部材５と圧電性基板２との距離は短くなっている。他方、カバー部材５と圧電性基板２との距離は、下垂部５ｂから中央部５ａ側に向かうほど長くなっている。本実施形態では、カバー部材５の各部分と圧電性基板２との距離のうち、距離Ｚ１が最も長い。なお、これに限られず、例えば、Ｚ１＜Ｚ２であってもよい。 As shown in FIG. 4, in the cover member 5, the distance between the cover member 5 and the piezoelectric substrate 2 is the distance Z2 between the portion of the joint portion 5c that reaches the second inclined portion 4h and the hanging portion 5b. And has a portion longer than the distance Z3. The distance between the cover member 5 and the piezoelectric substrate 2 becomes shorter toward the hanging portion 5b side from the portion. On the other hand, the distance between the cover member 5 and the piezoelectric substrate 2 becomes longer from the hanging portion 5b toward the central portion 5a. In the present embodiment, the distance Z1 is the longest among the distances between each part of the cover member 5 and the piezoelectric substrate 2. Not limited to this, for example, Z1 <Z2 may be used.
　カバー部材５は、例えば、成形型などを用いて、接合部５ｃとなる部分、下垂部５ｂ及び中央部５ａを有するように成形することにより形成してもよい。このように、カバー部材５を別途形成した後、カバー部材５を支持部材４に接合してもよい。このとき、例えば、接着剤によりカバー部材５と支持部材４とを接合してもよい。なお、カバー部材５の形成の方法やカバー部材５と支持部材４との接合の方法は上記に限定されない。 The cover member 5 may be formed by, for example, using a molding die or the like so as to have a portion to be a joint portion 5c, a hanging portion 5b, and a central portion 5a. In this way, after the cover member 5 is separately formed, the cover member 5 may be joined to the support member 4. At this time, for example, the cover member 5 and the support member 4 may be joined with an adhesive. The method of forming the cover member 5 and the method of joining the cover member 5 and the support member 4 are not limited to the above.
　図１に戻り、圧電性基板２の主面２ａ上には、ＩＤＴ電極３に電気的に接続されている第１の配線電極６Ａが設けられている。支持部材４は、第１の配線電極６Ａの一部を覆うように設けられている。支持部材４及びカバー部材５を貫通するように、複数の開口部１２が設けられている。各開口部１２内にビア電極７が設けられている。 Returning to FIG. 1, a first wiring electrode 6A electrically connected to the IDT electrode 3 is provided on the main surface 2a of the piezoelectric substrate 2. The support member 4 is provided so as to cover a part of the first wiring electrode 6A. A plurality of openings 12 are provided so as to penetrate the support member 4 and the cover member 5. A via electrode 7 is provided in each opening 12.
　図６は、第１の実施形態におけるカバー部材上の電極構造を示す略図的平面図である。図７は、第１の実施形態に係る弾性波装置の略図的平面図である。なお、図６においては、カバー部材などを省略している。 FIG. 6 is a schematic plan view showing the electrode structure on the cover member in the first embodiment. FIG. 7 is a schematic plan view of the elastic wave device according to the first embodiment. In FIG. 6, the cover member and the like are omitted.
　図１及び図６に示すように、カバー部材５上に、ビア電極７の一端に接続されるように、第２の配線電極６Ｂが設けられている。なお、ビア電極７の他端は第１の配線電極６Ａに接続されている。図１及び図７に示すように、圧電性基板２の主面２ａ上には、支持部材４、カバー部材５及び第２の配線電極６Ｂを覆うように、封止樹脂層１３が設けられている。封止樹脂層１３を貫通し、一端が第２の配線電極６Ｂに接続されるように、アンダーバンプメタル層８が設けられている。アンダーバンプメタル層８の他端に接合されるように、バンプ９が設けられている。バンプ９は、例えば、半田からなる。 As shown in FIGS. 1 and 6, a second wiring electrode 6B is provided on the cover member 5 so as to be connected to one end of the via electrode 7. The other end of the via electrode 7 is connected to the first wiring electrode 6A. As shown in FIGS. 1 and 7, a sealing resin layer 13 is provided on the main surface 2a of the piezoelectric substrate 2 so as to cover the support member 4, the cover member 5, and the second wiring electrode 6B. There is. The underbump metal layer 8 is provided so as to penetrate the sealing resin layer 13 and connect one end to the second wiring electrode 6B. The bump 9 is provided so as to be joined to the other end of the under bump metal layer 8. The bump 9 is made of, for example, solder.
　図１に示すように、上記ＩＤＴ電極３は、圧電性基板２、支持部材４及びカバー部材５により囲まれた中空空間内に配置されている。ＩＤＴ電極３は、第１の配線電極６Ａ、ビア電極７、第２の配線電極６Ｂ、アンダーバンプメタル層８及びバンプ９を介して外部に電気的に接続される。このように、弾性波装置１はＷＬＰ（Ｗａｆｅｒ　Ｌｅｖｅｌ　Ｐａｃｋａｇｅ）構造である。 As shown in FIG. 1, the IDT electrode 3 is arranged in a hollow space surrounded by a piezoelectric substrate 2, a support member 4, and a cover member 5. The IDT electrode 3 is electrically connected to the outside via a first wiring electrode 6A, a via electrode 7, a second wiring electrode 6B, an under bump metal layer 8 and a bump 9. As described above, the elastic wave device 1 has a WLP (Wafer Level Package) structure.
　本実施形態の特徴は、カバー部材５が、中央部５ａと接合部５ｃの間に位置する下垂部５ｂを有することにある。それによって、カバー部材５が支持部材４から剥離し難い。これを、本実施形態と比較例とを比較することにより、以下において説明する。 The feature of this embodiment is that the cover member 5 has a hanging portion 5b located between the central portion 5a and the joint portion 5c. As a result, the cover member 5 is difficult to peel off from the support member 4. This will be described below by comparing the present embodiment with a comparative example.
　図８は、比較例において、カバー部材と支持部材との間に加わる応力を説明するための模式的正面断面図である。 FIG. 8 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the comparative example.
　比較例は、カバー部材１０５が下垂部５ｂを有しない点において、第１の実施形態と異なる。カバー部材１０５と圧電性基板２との距離は、接合部５ｃから中央部５ａ側に向かうほど長くなっている。例えば、カバー部材１０５が温度変化などにより収縮した場合、カバー部材１０５と支持部材４との間において、図８に示すように応力Ａが加わる。応力Ａにおける、圧電性基板２の主面２ａに垂直な方向の力の成分Ａ１は、支持部材４からカバー部材１０５を剥離する方向の成分となっている。そのため、支持部材４からカバー部材１０５が剥離するおそれがある。 The comparative example is different from the first embodiment in that the cover member 105 does not have the hanging portion 5b. The distance between the cover member 105 and the piezoelectric substrate 2 increases from the joint portion 5c toward the central portion 5a. For example, when the cover member 105 contracts due to a temperature change or the like, a stress A is applied between the cover member 105 and the support member 4 as shown in FIG. The component A1 of the force in the direction perpendicular to the main surface 2a of the piezoelectric substrate 2 in the stress A is a component in the direction of peeling the cover member 105 from the support member 4. Therefore, the cover member 105 may be peeled off from the support member 4.
　図９は、第１の実施形態において、カバー部材と支持部材との間に加わる応力を説明するための模式的正面断面図である。 FIG. 9 is a schematic front sectional view for explaining the stress applied between the cover member and the support member in the first embodiment.
　本実施形態においては、カバー部材５は、中央部５ａと接合部５ｃとの間に位置する下垂部５ｂを有する。これにより、カバー部材５が収縮した場合においては、カバー部材５と支持部材４との間において、図９に示すように、応力Ｂが加わる。応力Ｂにおける、圧電性基板２の主面２ａに垂直な方向の力の成分Ｂ１は、支持部材４にカバー部材５を密着させる方向の成分となっている。従って、支持部材４からカバー部材５が剥離し難い。 In the present embodiment, the cover member 5 has a hanging portion 5b located between the central portion 5a and the joint portion 5c. As a result, when the cover member 5 contracts, a stress B is applied between the cover member 5 and the support member 4, as shown in FIG. The component B1 of the force in the direction perpendicular to the main surface 2a of the piezoelectric substrate 2 in the stress B is a component in the direction in which the cover member 5 is brought into close contact with the support member 4. Therefore, the cover member 5 is difficult to peel off from the support member 4.
　例えば、カバー部材が感光性樹脂からなる場合には、カバー部材を硬化させるに際し、カバー部材が大きく収縮する。そのため、図８に示す比較例においては、カバー部材１０５と支持部材４を剥離する方向に加わる応力が特に大きくなる。これに対して、図９に示す本実施形態においては、カバー部材５と支持部材４との間に加わる応力Ｂにおける力の成分Ｂ１を、支持部材４にカバー部材５を密着させる方向の成分とすることができる。よって、本実施形態はカバー部材５が感光性樹脂からなる場合に特に好適である。 For example, when the cover member is made of a photosensitive resin, the cover member shrinks significantly when the cover member is cured. Therefore, in the comparative example shown in FIG. 8, the stress applied in the direction of peeling the cover member 105 and the support member 4 becomes particularly large. On the other hand, in the present embodiment shown in FIG. 9, the component B1 of the force in the stress B applied between the cover member 5 and the support member 4 is the component in the direction in which the cover member 5 is brought into close contact with the support member 4. can do. Therefore, this embodiment is particularly suitable when the cover member 5 is made of a photosensitive resin.
　カバー部材５における各部分と圧電性基板２との距離のうち、下垂部５ｂと圧電性基板２との距離が最も短ければよい。例えば、図１０に示す第１の実施形態の第１の変形例においては、下垂部５ｂから中央部５ａまでの部分において、カバー部材２５Ａと圧電性基板２との距離が一定であり、Ｚ１＝Ｚ３である。 Of the distances between each part of the cover member 5 and the piezoelectric substrate 2, the distance between the hanging portion 5b and the piezoelectric substrate 2 may be the shortest. For example, in the first modification of the first embodiment shown in FIG. 10, the distance between the cover member 25A and the piezoelectric substrate 2 is constant in the portion from the hanging portion 5b to the central portion 5a, and Z1 = It is Z3.
　もっとも、図１に示す第１の実施形態のように、カバー部材５と圧電性基板２との距離は、下垂部５ｂから中央部５ａ側に向かうほど長くなっていることが好ましい。それによって、カバー部材５に加わる応力を緩和することができる。加えて、外部からカバー部材５をＩＤＴ電極３側に押圧する力が加わった場合において、カバー部材５がＩＤＴ電極３に接触し難い。よって、弾性波装置１が破損し難い。 However, as in the first embodiment shown in FIG. 1, it is preferable that the distance between the cover member 5 and the piezoelectric substrate 2 becomes longer from the hanging portion 5b toward the central portion 5a. Thereby, the stress applied to the cover member 5 can be relaxed. In addition, when a force for pressing the cover member 5 toward the IDT electrode 3 is applied from the outside, it is difficult for the cover member 5 to come into contact with the IDT electrode 3. Therefore, the elastic wave device 1 is not easily damaged.
　カバー部材５において、下垂部５ｂは中央部５ａよりも接合部５ｃに近い位置に設けられていることが好ましい。それによって、カバー部材５と支持部材４の間に加わる応力における、圧電性基板２の主面２ａに垂直な方向の力の成分を効果的に大きくすることができる。より具体的には、該応力における支持部材４にカバー部材５を密着させる方向の力の成分を効果的に大きくすることができる。よって、支持部材４からカバー部材５を効果的に剥離し難くすることができる。 In the cover member 5, the hanging portion 5b is preferably provided at a position closer to the joint portion 5c than the central portion 5a. Thereby, the component of the force in the direction perpendicular to the main surface 2a of the piezoelectric substrate 2 in the stress applied between the cover member 5 and the support member 4 can be effectively increased. More specifically, the component of the force in the direction in which the cover member 5 is brought into close contact with the support member 4 under the stress can be effectively increased. Therefore, it is possible to make it difficult to effectively peel off the cover member 5 from the support member 4.
　カバー部材５は、支持部材４の内側面４ｄに至っていなくともよい。例えば、図１１に示す第１の実施形態における第２の変形例においては、カバー部材２５Ｂは支持部材４の第２の端面４ｂ上に設けられており、カバー部材２５Ｂは支持部材４の内側面４ｄに至っていない。もっとも、図１に示す第１の実施形態のように、カバー部材５は、支持部材４の第２の端面４ｂ及び内側面４ｄに接合されていることが好ましい。それによって、カバー部材５と支持部材４との接合力を高めることができ、支持部材４からカバー部材５がより一層剥離し難い。なお、本実施形態においては、内側面４ｄの第２の傾斜部４ｈにおける面がカバー部材５側に位置しているため、カバー部材５と第２の傾斜部４ｈとを好適に接合させることができる。 The cover member 5 does not have to reach the inner side surface 4d of the support member 4. For example, in the second modification of the first embodiment shown in FIG. 11, the cover member 25B is provided on the second end surface 4b of the support member 4, and the cover member 25B is the inner surface of the support member 4. It has not reached 4d. However, as in the first embodiment shown in FIG. 1, it is preferable that the cover member 5 is joined to the second end surface 4b and the inner side surface 4d of the support member 4. As a result, the bonding force between the cover member 5 and the support member 4 can be increased, and the cover member 5 is more difficult to peel off from the support member 4. In the present embodiment, since the surface of the inner side surface 4d on the second inclined portion 4h is located on the cover member 5 side, the cover member 5 and the second inclined portion 4h can be suitably joined. it can.
　図１２は、第２の実施形態における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。 FIG. 12 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the second embodiment.
　本実施形態は、支持部材３４が第１の端面４ａと第２の端面４ｂとの間に位置する細幅部３４Ｘを有する点及びカバー部材５が支持部材３４の内側面３４ｄに至っていない点において、第１の実施形態と異なる。上記の点以外においては、本実施形態の弾性波装置は第１の実施形態の弾性波装置１と同様の構成を有する。 In the present embodiment, the support member 34 has a narrow portion 34X located between the first end surface 4a and the second end surface 4b, and the cover member 5 does not reach the inner surface 34d of the support member 34. , Different from the first embodiment. Except for the above points, the elastic wave device of the present embodiment has the same configuration as the elastic wave device 1 of the first embodiment.
　より具体的には、外側面３４ｃ及び内側面３４ｄの第１の傾斜部４ｅ及び第１の傾斜部４ｇは、第１の実施形態と同様に、第１の端面４ａ側から第２の端面４ｂ側に向かうほど、支持部材３４の幅が細くなるように傾斜している。他方、第２の傾斜部３４ｆ及び第２の傾斜部３４ｈは、第２の端面４ｂ側から第１の端面４ａ側に向かうほど、支持部材３４の幅が細くなるように傾斜している。外側面３４ｃの第１の傾斜部４ｅ及び第２の傾斜部３４ｆ、並びに内側面３４ｄの第１の傾斜部４ｇ及び第２の傾斜部３４ｈにより、細幅部３４Ｘが構成されている。なお、細幅部３４Ｘの構成は上記に限定されず、細幅部３４Ｘの幅が他の部分よりも細ければよい。もっとも、細幅部３４Ｘは、支持部材３４において最も幅が細い部分ではなくともよい。 More specifically, the first inclined portion 4e and the first inclined portion 4g of the outer surface 34c and the inner surface 34d are formed from the first end surface 4a side to the second end surface 4b as in the first embodiment. The support member 34 is inclined so as to become narrower toward the side. On the other hand, the second inclined portion 34f and the second inclined portion 34h are inclined so that the width of the support member 34 becomes narrower from the second end surface 4b side toward the first end surface 4a side. The narrow portion 34X is composed of the first inclined portion 4e and the second inclined portion 34f of the outer side surface 34c, and the first inclined portion 4g and the second inclined portion 34h of the inner side surface 34d. The configuration of the narrow width portion 34X is not limited to the above, and the width of the narrow width portion 34X may be narrower than that of other portions. However, the narrow portion 34X does not have to be the narrowest portion of the support member 34.
　本実施形態の弾性波装置は、第１の実施形態の第２の変形例と同様のカバー部材２５Ｂを有する。よって、第１の実施形態及びその第２の変形例と同様に、支持部材３４からカバー部材２５Ｂが剥離し難い。 The elastic wave device of this embodiment has a cover member 25B similar to that of the second modification of the first embodiment. Therefore, as in the first embodiment and the second modification thereof, the cover member 25B is difficult to peel off from the support member 34.
　なお、カバー部材２５Ｂが温度変化などにより収縮した場合においては、支持部材３４と圧電性基板２との間にも応力が加わる。本実施形態においては、支持部材３４が細幅部３４Ｘを有する。それによって、応力を細幅部３４Ｘに集中させることができ、支持部材３４と圧電性基板２との間に加わる応力を緩和することができる。従って、上記のように、カバー部材２５Ｂが支持部材３４から剥離し難いことに加えて、支持部材３４が圧電性基板２から剥離し難い。 When the cover member 25B contracts due to a temperature change or the like, stress is also applied between the support member 34 and the piezoelectric substrate 2. In the present embodiment, the support member 34 has a narrow portion 34X. As a result, the stress can be concentrated on the narrow portion 34X, and the stress applied between the support member 34 and the piezoelectric substrate 2 can be relaxed. Therefore, as described above, in addition to the cover member 25B being difficult to peel off from the support member 34, the support member 34 is hard to peel off from the piezoelectric substrate 2.
　支持部材３４における最も幅が細い部分の位置は、第２の端面４ｂよりも第１の端面４ａに近いことが好ましい。それによって、応力を細幅部３４Ｘにより一層集中させることができ、支持部材３４と圧電性基板２との間に加わる応力をより一層緩和することができる。従って、支持部材３４が圧電性基板２からより一層剥離し難い。 The position of the narrowest portion of the support member 34 is preferably closer to the first end face 4a than to the second end face 4b. As a result, the stress can be further concentrated on the narrow portion 34X, and the stress applied between the support member 34 and the piezoelectric substrate 2 can be further relaxed. Therefore, the support member 34 is more difficult to peel off from the piezoelectric substrate 2.
　本実施形態においては、支持部材３４の細幅部３４Ｘは、外側面３４ｃ及び内側面３４ｄの両方における第１の傾斜部及び第２の傾斜部により構成されている。なお、細幅部３４Ｘの構成は上記に限定されない。以下において、細幅部の構成のみが第２の実施形態と異なる、第２の実施形態の第１の変形例及び第２の変形例を示す。第１の変形例及び第２の変形例においても、第２の実施形態と同様に、カバー部材２５Ｂが支持部材から剥離し難く、かつ支持部材が圧電性基板２から剥離し難い。 In the present embodiment, the narrow portion 34X of the support member 34 is composed of a first inclined portion and a second inclined portion on both the outer surface 34c and the inner surface 34d. The configuration of the narrow portion 34X is not limited to the above. In the following, a first modification and a second modification of the second embodiment, in which only the configuration of the narrow portion is different from the second embodiment, will be shown. In the first modification and the second modification, the cover member 25B is difficult to peel off from the support member, and the support member is hard to peel off from the piezoelectric substrate 2, as in the second embodiment.
　図１３に示す第１の変形例においては、支持部材４４Ａの第１の傾斜部４ｇ及び第２の傾斜部３４ｈが内側面３４ｄにのみ設けられていることにより、細幅部４４Ｘが構成されている。 In the first modification shown in FIG. 13, the narrow portion 44X is configured by providing the first inclined portion 4g and the second inclined portion 34h of the support member 44A only on the inner side surface 34d. There is.
　図１４に示す第２の変形例の支持部材４４Ｂにおいては、内側面４４ｄが第１の段差部４４ｇと、第２の段差部４４ｈとを有する。第１の段差部４４ｇは第１の端面４ａ側に位置する。第２の段差部４４ｈは第２の端面４ｂ側に位置する。第１の段差部４４ｇ及び第２の段差部４４ｈの間において、支持部材４４Ｂの幅が細くなるように、第１の段差部４４ｇ及び第２の段差部４４ｈが設けられている。同様に、外側面４４ｃは第１の段差部４４ｅと、第２の段差部４４ｆとを有する。第１の段差部４４ｅは第１の端面４ａ側に位置する。第２の段差部４４ｆは第２の端面４ｂ側に位置する。第１の段差部４４ｅ及び第２の段差部４４ｆの間において、支持部材４４Ｂの幅が細くなるように、第１の段差部４４ｅ及び第２の段差部４４ｆが設けられている。上記各段差部が設けられていることにより細幅部４４Ｙが構成されている。より具体的には、上記各段差部は一段の段差として構成されている。なお、各段差部は複数の段差を有する階段状の形状を有していてもよい。外側面４４ｃ及び内側面４４ｄのうち一方が第１の段差部及び第２の段差部を有していてもよい。 In the support member 44B of the second modified example shown in FIG. 14, the inner side surface 44d has a first step portion 44g and a second step portion 44h. The first step portion 44g is located on the first end surface 4a side. The second step portion 44h is located on the second end surface 4b side. Between the first step portion 44g and the second step portion 44h, the first step portion 44g and the second step portion 44h are provided so that the width of the support member 44B becomes narrower. Similarly, the outer surface 44c has a first step portion 44e and a second step portion 44f. The first step portion 44e is located on the first end surface 4a side. The second step portion 44f is located on the second end surface 4b side. Between the first step portion 44e and the second step portion 44f, the first step portion 44e and the second step portion 44f are provided so that the width of the support member 44B becomes narrower. The narrow portion 44Y is formed by providing each of the above-mentioned step portions. More specifically, each of the above-mentioned step portions is configured as a single step. In addition, each step portion may have a step-like shape having a plurality of steps. One of the outer side surface 44c and the inner side surface 44d may have a first step portion and a second step portion.
　図１５は、第３の実施形態における圧電性基板、支持部材及びカバー部材の一部を示す模式的正面断面図である。 FIG. 15 is a schematic front sectional view showing a part of the piezoelectric substrate, the support member, and the cover member in the third embodiment.
　本実施形態は、支持部材５４の内側面５４ｄが、第２の端面４ｂに向かうほど、支持部材５４の幅が細くなるように傾斜しており、第２の端面４ｂに至っている第３の傾斜部５４ｋを有する点において、第２の実施形態と異なる。支持部材５４の外側面５４ｃが、第２の端面４ｂに向かうほど、支持部材５４の幅が細くなるように傾斜しており、第２の端面４ｂに至っている第３の傾斜部５４ｊを有する点においても、第２の実施形態と異なる。さらに、内側面５４ｄの第３の傾斜部５４ｋにカバー部材５が至っている点においても第２の実施形態と異なる。上記の点以外においては、本実施形態の弾性波装置は第２の実施形態の弾性波装置と同様の構成を有する。 In the present embodiment, the inner side surface 54d of the support member 54 is inclined so that the width of the support member 54 becomes narrower toward the second end surface 4b, and the third inclination reaches the second end surface 4b. It differs from the second embodiment in that it has a portion 54k. A point in which the outer surface 54c of the support member 54 is inclined so that the width of the support member 54 becomes narrower toward the second end surface 4b, and has a third inclined portion 54j that reaches the second end surface 4b. Also, it is different from the second embodiment. Further, it is different from the second embodiment in that the cover member 5 reaches the third inclined portion 54k of the inner side surface 54d. Except for the above points, the elastic wave device of the present embodiment has the same configuration as the elastic wave device of the second embodiment.
　第３の傾斜部５４ｋにおける面が、カバー部材５側に位置しているため、カバー部材５と第３の傾斜部５４ｋとを好適に接合させることができる。これにより、第１の実施形態と同様に、カバー部材５と支持部材５４との接合面積を大きくすることができ、カバー部材５と支持部材５４との接合力を高めることができる。さらに、本実施形態の弾性波装置は、第１の実施形態と同様のカバー部材５を有する。よって、支持部材５４からカバー部材５が剥離し難い。 Since the surface of the third inclined portion 54k is located on the cover member 5 side, the cover member 5 and the third inclined portion 54k can be suitably joined. As a result, as in the first embodiment, the joint area between the cover member 5 and the support member 54 can be increased, and the joint force between the cover member 5 and the support member 54 can be increased. Further, the elastic wave device of the present embodiment has the same cover member 5 as that of the first embodiment. Therefore, the cover member 5 is difficult to peel off from the support member 54.
　加えて、支持部材５４は細幅部３４Ｘを有するため、第２の実施形態と同様に、圧電性基板２から支持部材５４が剥離し難い。 In addition, since the support member 54 has a narrow portion 34X, the support member 54 is difficult to peel off from the piezoelectric substrate 2 as in the second embodiment.
　図１５に示すように、第１の端面４ａは第１の内周縁５４ｌを有し、第２の端面４ｂは第２の内周縁５４ｍを有する。図１５中の一点鎖線Ｃは第１の内周縁５４ｌの位置を示し、一点鎖線Ｄは第２の内周縁５４ｍの位置を示す。平面視において、カバー部材５の中央部から見て、第１の内周縁５４ｌが第２の内周縁５４ｍの外側に位置する。それによって、圧電性基板２、支持部材３４及びカバー部材５により囲まれた中空空間内における、圧電性基板２の面積を大きくすることができる。従って、弾性波装置の小型化を進めることができる。なお、平面視において、第１の内周縁５４ｌと第２の内周縁５４ｍとは重なっていてもよく、あるいは、第１の内周縁５４ｌが第２の内周縁５４ｍの内側に位置していてもよい。 As shown in FIG. 15, the first end face 4a has a first inner peripheral edge 54l, and the second end face 4b has a second inner peripheral edge 54m. The alternate long and short dash line C in FIG. 15 indicates the position of the first inner peripheral edge 54l, and the alternate long and short dash line D indicates the position of the second inner peripheral edge 54m. In a plan view, the first inner peripheral edge 54l is located outside the second inner peripheral edge 54m when viewed from the central portion of the cover member 5. Thereby, the area of the piezoelectric substrate 2 in the hollow space surrounded by the piezoelectric substrate 2, the support member 34, and the cover member 5 can be increased. Therefore, the size of the elastic wave device can be reduced. In a plan view, the first inner peripheral edge 54l and the second inner peripheral edge 54m may overlap, or the first inner peripheral edge 54l may be located inside the second inner peripheral edge 54m. Good.
　図１６は第４の実施形態に係る弾性波装置の模式的正面断面図である。 FIG. 16 is a schematic front sectional view of the elastic wave device according to the fourth embodiment.
　本実施形態の弾性波装置６１はＢＡＷ素子である。圧電性基板６２は、支持基板６３と、圧電体層６４とを有する積層基板である。支持基板６３は、凹部６３ａと、平面視において凹部６３ａを囲んでいる支持部６３ｂとを有する。圧電体層６４は、支持基板６３の支持部６３ｂ上に設けられている。 The elastic wave device 61 of this embodiment is a BAW element. The piezoelectric substrate 62 is a laminated substrate having a support substrate 63 and a piezoelectric layer 64. The support substrate 63 has a recess 63a and a support portion 63b surrounding the recess 63a in a plan view. The piezoelectric layer 64 is provided on the support portion 63b of the support substrate 63.
　圧電体層６４は、対向し合う第１の主面６４ａ及び第２の主面６４ｂを有する。第２の主面６４ｂが支持基板６３側に位置する。圧電体層６４の第１の主面６４ａ上には第１の平板電極６５Ａが設けられており、第２の主面６４ｂ上には第２の平板電極６５Ｂが設けられている。より具体的には、圧電体層６４における、平面視において支持基板６３の凹部６３ａと重なっている部分に、第１の平板電極６５Ａ及び第２の平板電極６５Ｂが設けられている。第１の平板電極６５Ａと第２の平板電極６５Ｂとは対向し合っている。本実施形態における励振電極は、第１の平板電極６５Ａ及び第２の平板電極６５Ｂである。 The piezoelectric layer 64 has a first main surface 64a and a second main surface 64b facing each other. The second main surface 64b is located on the support substrate 63 side. A first flat plate electrode 65A is provided on the first main surface 64a of the piezoelectric layer 64, and a second flat plate electrode 65B is provided on the second main surface 64b. More specifically, the first flat plate electrode 65A and the second flat plate electrode 65B are provided in the portion of the piezoelectric layer 64 that overlaps the recess 63a of the support substrate 63 in a plan view. The first flat plate electrode 65A and the second flat plate electrode 65B face each other. The excitation electrodes in this embodiment are a first flat plate electrode 65A and a second flat plate electrode 65B.
　圧電体層６４の第１の主面６４ａ上には、第１の平板電極６５Ａに電気的に接続されている第１の配線電極６６Ａが設けられている。第２の主面６４ｂ上には、第２の平板電極６５Ｂに電気的に接続されている第１の配線電極６６Ｂが設けられている。 On the first main surface 64a of the piezoelectric layer 64, a first wiring electrode 66A electrically connected to the first flat plate electrode 65A is provided. On the second main surface 64b, a first wiring electrode 66B electrically connected to the second flat plate electrode 65B is provided.
　圧電体層６４の第１の主面６４ａ上には、第１の平板電極６５Ａを囲むように、かつ第１の配線電極６６Ａの一部を覆うように、第１の実施形態と同様の支持部材４が設けられている。支持部材４の第２の端面４ｂ上には、第１の実施形態と同様のカバー部材５が設けられている。支持部材４及びカバー部材５を貫通するように、ビア電極６７Ａが設けられている。ビア電極６７Ａの一端は第１の配線電極６６Ａに接続されている。カバー部材５上に、ビア電極６７Ａの他端に接合されるように、第２の配線電極６Ｂが設けられている。他方、圧電体層６４、支持部材４及びカバー部材５を貫通するように、ビア電極６７Ｂが設けられている。ビア電極６７Ｂの一端は第１の配線電極６６Ｂに接続されている。カバー部材５上に、ビア電極６７Ｂの他端に接続されるように、上記とは別の第２の配線電極６Ｂが設けられている。 On the first main surface 64a of the piezoelectric layer 64, the same support as in the first embodiment is provided so as to surround the first flat plate electrode 65A and to cover a part of the first wiring electrode 66A. The member 4 is provided. A cover member 5 similar to that of the first embodiment is provided on the second end surface 4b of the support member 4. A via electrode 67A is provided so as to penetrate the support member 4 and the cover member 5. One end of the via electrode 67A is connected to the first wiring electrode 66A. A second wiring electrode 6B is provided on the cover member 5 so as to be joined to the other end of the via electrode 67A. On the other hand, the via electrode 67B is provided so as to penetrate the piezoelectric layer 64, the support member 4, and the cover member 5. One end of the via electrode 67B is connected to the first wiring electrode 66B. A second wiring electrode 6B different from the above is provided on the cover member 5 so as to be connected to the other end of the via electrode 67B.
　圧電体層６４の第１の主面６４ａ上には、支持部材４、カバー部材５及び各第２の配線電極６Ｂを覆うように、封止樹脂層１３が設けられている。封止樹脂層１３を貫通し、一端が各第２の配線電極６Ｂに接続されるように、アンダーバンプメタル層８がそれぞれ設けられている。アンダーバンプメタル層８の他端に接合されるように、バンプ９が設けられている。 A sealing resin layer 13 is provided on the first main surface 64a of the piezoelectric layer 64 so as to cover the support member 4, the cover member 5, and each of the second wiring electrodes 6B. The underbump metal layer 8 is provided so as to penetrate the sealing resin layer 13 and connect one end to each of the second wiring electrodes 6B. The bump 9 is provided so as to be joined to the other end of the under bump metal layer 8.
　本実施形態の弾性波装置６１は、第１の実施形態と同様のカバー部材５を有するため、カバー部材５が収縮した場合において、カバー部材５と支持部材４との間に加わる応力は、支持部材４にカバー部材５を密着させる方向の力の成分を有する。従って、支持部材４からカバー部材５が剥離し難い。 Since the elastic wave device 61 of the present embodiment has the same cover member 5 as that of the first embodiment, when the cover member 5 contracts, the stress applied between the cover member 5 and the support member 4 is supported. It has a force component in the direction in which the cover member 5 is brought into close contact with the member 4. Therefore, the cover member 5 is difficult to peel off from the support member 4.
１…弾性波装置
２…圧電性基板
２ａ…主面
３…ＩＤＴ電極
４…支持部材
４ａ，４ｂ…第１，第２の端面
４ｃ…外側面
４ｄ…内側面
４ｅ，４ｆ…第１，第２の傾斜部
４ｇ，４ｈ…第１，第２の傾斜部
４ｉ…開口部
５…カバー部材
５ａ…中央部
５ｂ…下垂部
５ｃ…接合部
６Ａ，６Ｂ…第１，第２の配線電極
７…ビア電極
８…アンダーバンプメタル層
９…バンプ
１２…開口部
１３…封止樹脂層
１４，１５…反射器
１６…第１のバスバー
１７…第２のバスバー
１８…第１の電極指
１９…第２の電極指
２５Ａ，２５Ｂ…カバー部材
３４…支持部材
３４ｃ…外側面
３４ｄ…内側面
３４ｆ，３４ｈ…第２の傾斜部
３４Ｘ…細幅部
４４Ａ，４４Ｂ…支持部材
４４ｃ…外側面
４４ｄ…内側面
４４ｅ，４４ｆ…第１，第２の段差部
４４ｇ，４４ｈ…第１，第２の段差部
４４Ｘ，４４Ｙ…細幅部
５４…支持部材
５４ｃ…外側面
５４ｄ…内側面
５４ｊ，５４ｋ…第３の傾斜部
５４ｌ，５４ｍ…第１，第２の内周縁
６１…弾性波装置
６２…圧電性基板
６３…支持基板
６３ａ…凹部
６３ｂ…支持部
６４…圧電体層
６４ａ，６４ｂ…第１，第２の主面
６５Ａ，６５Ｂ…第１，第２の平板電極
６６Ａ，６６Ｂ…第１の配線電極
６７Ａ，６７Ｂ…ビア電極
１０５…カバー部材
Ａ，Ｂ…応力
Ａ１，Ｂ１…力の成分 1 ... Elastic wave device 2 ... Piezoelectric substrate 2a ... Main surface 3 ... IDT electrode 4 ... Support members 4a, 4b ... First and second end surfaces 4c ... Outer surface 4d ... Inner surface 4e, 4f ... First and second Inclined portions 4g, 4h ... First and second inclined portions 4i ... Opening 5 ... Cover member 5a ... Central portion 5b ... Drooping portion 5c ... Joint portions 6A, 6B ... First and second wiring electrodes 7 ... Vias Electrode 8 ... Under bump metal layer 9 ... Bump 12 ... Opening 13 ... Sealing resin layers 14, 15 ... Reflector 16 ... First bus bar 17 ... Second bus bar 18 ... First electrode finger 19 ... Second Electrode fingers 25A, 25B ... Cover member 34 ... Support member 34c ... Outer surface 34d ... Inner side surface 34f, 34h ... Second inclined portion 34X ... Narrow portion 44A, 44B ... Support member 44c ... Outer surface 44d ... Inner side surface 44e, 44f ... First and second stepped portions 44g, 44h ... First and second stepped portions 44X, 44Y ... Narrow width portion 54 ... Support member 54c ... Outer surface 54d ... Inner side surface 54j, 54k ... Third inclined portion 54l, 54m ... 1st and 2nd inner peripheral edges 61 ... Elastic wave device 62 ... Piezoelectric substrate 63 ... Support substrate 63a ... Recessed portion 63b ... Support portion 64 ... Piezoelectric layer 64a, 64b ... First and second main surfaces 65A, 65B ... 1st and 2nd flat plate electrodes 66A, 66B ... 1st wiring electrode 67A, 67B ... Via electrode 105 ... Cover member A, B ... Stress A1, B1 ... Force component

Claims (12)

  1. 　圧電性基板と、
    　前記圧電性基板上に設けられている励振電極と、
    　開口部を有し、前記励振電極を囲むように前記圧電性基板上に設けられている支持部材と、
    　前記支持部材の前記開口部を覆うように前記支持部材上に設けられており、中央部と、前記支持部材に接合されている接合部と、を有するカバー部材と、
    を備え、
    　前記カバー部材が、前記中央部と前記接合部との間に位置し、かつ前記中央部と前記圧電性基板との距離及び前記接合部と前記圧電性基板との距離よりも、前記圧電性基板との距離が短い下垂部を有する、弾性波装置。     Piezoelectric substrate and
    Excitation electrodes provided on the piezoelectric substrate and
    A support member having an opening and provided on the piezoelectric substrate so as to surround the excitation electrode,
    A cover member provided on the support member so as to cover the opening of the support member, and having a central portion and a joint portion joined to the support member.
    With
    The cover member is located between the central portion and the joint portion, and the piezoelectric substrate is more than the distance between the central portion and the piezoelectric substrate and the distance between the joint portion and the piezoelectric substrate. An elastic wave device having a drooping portion having a short distance from and.
  2. 　平面視において、前記カバー部材の前記中央部を軸としたときの周回方向に沿って、前記接合部が連続的に設けられており、前記接合部と前記中央部との間の前記周回方向における全ての部分において、前記下垂部が設けられている、請求項１に記載の弾性波装置。 In a plan view, the joint portion is continuously provided along the circumferential direction when the central portion of the cover member is taken as an axis, and the joint portion is provided in the circumferential direction between the joint portion and the central portion. The elastic wave device according to claim 1, wherein the hanging portion is provided in all portions.
  3. 　前記カバー部材において、前記下垂部が前記中央部よりも前記接合部に近い位置に設けられている、請求項１または２に記載の弾性波装置。 The elastic wave device according to claim 1 or 2, wherein in the cover member, the hanging portion is provided at a position closer to the joint portion than the central portion.
  4. 　前記支持部材が、前記圧電性基板側に位置する第１の端面と、前記カバー部材側に位置する第２の端面と、前記第１の端面及び前記第２の端面に接続されている内側面及び外側面と、を有し、
    　前記カバー部材が、前記第２の端面の少なくとも一部及び前記内側面の少なくとも一部に接合されている、請求項１～３のいずれか１項に記載の弾性波装置。     The inner surface surface of the support member connected to the first end surface located on the piezoelectric substrate side, the second end surface located on the cover member side, the first end surface, and the second end surface. And with an outer surface,
    The elastic wave device according to any one of claims 1 to 3, wherein the cover member is joined to at least a part of the second end surface and at least a part of the inner surface surface.
  5. 　前記支持部材が、前記圧電性基板側に位置する第１の端面と、前記カバー部材側に位置する第２の端面と、前記第１の端面及び前記第２の端面に接続されている内側面及び外側面と、を有し、
    　前記圧電性基板の主面と平行な方向における前記外側面と前記内側面との距離を前記支持部材の幅としたときに、前記支持部材が、前記第１の端面と前記第２の端面との間に位置する細幅部を有する、請求項１～４のいずれか１項に記載の弾性波装置。     The inner surface surface of the support member connected to the first end surface located on the piezoelectric substrate side, the second end surface located on the cover member side, the first end surface, and the second end surface. And with an outer surface,
    When the distance between the outer surface and the inner surface in the direction parallel to the main surface of the piezoelectric substrate is defined as the width of the support member, the support member is formed by the first end surface and the second end surface. The elastic wave device according to any one of claims 1 to 4, which has a narrow portion located between the two.
  6. 　前記支持部材の最も幅が細い部分の位置が、前記第２の端面よりも前記第１の端面に近い、請求項５に記載の弾性波装置。 The elastic wave device according to claim 5, wherein the position of the narrowest portion of the support member is closer to the first end face than to the second end face.
  7. 　前記外側面及び前記内側面のうち少なくとも一方が、前記第１の端面側から前記第２の端面側に向かうほど前記支持部材の幅が細くなるように傾斜している第１の傾斜部と、前記第２の端面側から前記第１の端面側に向かうほど前記支持部材の幅が細くなるように傾斜している第２の傾斜部と、を有し、前記第１の傾斜部及び前記第２の傾斜部により前記細幅部が構成されている、請求項５または６に記載の弾性波装置。 A first inclined portion in which at least one of the outer surface and the inner surface is inclined so that the width of the support member becomes narrower from the first end surface side toward the second end surface side. It has a second inclined portion that is inclined so that the width of the support member becomes narrower from the second end surface side toward the first end surface side, and the first inclined portion and the first inclined portion. The elastic wave device according to claim 5 or 6, wherein the narrow portion is formed by the inclined portion of 2.
  8. 　前記外側面及び前記内側面の両方が、前記第１の傾斜部と、前記第２の傾斜部と、を有する、請求項７に記載の弾性波装置。 The elastic wave device according to claim 7, wherein both the outer surface and the inner surface have the first inclined portion and the second inclined portion.
  9. 　前記支持部材の前記内側面が、前記第２の端面に向かうほど前記支持部材の幅が細くなるように傾斜しており、前記第２の端面に至っている第３の傾斜部を有する、請求項５～８のいずれか１項に記載の弾性波装置。 The claim that the inner side surface of the support member is inclined so that the width of the support member becomes narrower toward the second end surface, and has a third inclined portion that reaches the second end surface. The elastic wave device according to any one of 5 to 8.
  10. 　前記支持部材が、前記圧電性基板側に位置する第１の端面と、前記カバー部材側に位置する第２の端面と、を有し、前記第１の端面が第１の内周縁を含み、前記第２の端面が第２の内周縁を含み、
    　平面視において、前記第１の内周縁が前記第２の内周縁の外側に位置する、請求項１～９のいずれか１項に記載の弾性波装置。     The support member has a first end face located on the piezoelectric substrate side and a second end face located on the cover member side, and the first end face includes a first inner peripheral edge. The second end face includes a second inner peripheral edge.
    The elastic wave device according to any one of claims 1 to 9, wherein the first inner peripheral edge is located outside the second inner peripheral edge in a plan view.
  11. 　前記カバー部材が感光性樹脂からなる、請求項１～１０のいずれか１項に記載の弾性波装置。 The elastic wave device according to any one of claims 1 to 10, wherein the cover member is made of a photosensitive resin.
  12. 　前記励振電極がＩＤＴ電極である、請求項１～１１のいずれか１項に記載の弾性波装置。 The elastic wave device according to any one of claims 1 to 11, wherein the excitation electrode is an IDT electrode.
PCT/JP2020/025872 2019-07-10 2020-07-01 Elastic wave device WO2021006157A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02131344U (en) * 1989-04-06 1990-10-31
JP2006261158A (en) * 2005-03-15 2006-09-28 Mitsubishi Electric Corp Semiconductor package
JP2013074411A (en) * 2011-09-27 2013-04-22 Kyocera Corp Acoustic wave device, electronic component and acoustic wave device manufacturing method
WO2018110057A1 (en) * 2016-12-16 2018-06-21 株式会社村田製作所 Acoustic wave device, high-frequency front-end circuit, and communication device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02131344U (en) * 1989-04-06 1990-10-31
JP2006261158A (en) * 2005-03-15 2006-09-28 Mitsubishi Electric Corp Semiconductor package
JP2013074411A (en) * 2011-09-27 2013-04-22 Kyocera Corp Acoustic wave device, electronic component and acoustic wave device manufacturing method
WO2018110057A1 (en) * 2016-12-16 2018-06-21 株式会社村田製作所 Acoustic wave device, high-frequency front-end circuit, and communication device

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