MEMS acoustic element

Abstract

A MEMS acoustic element (101) is provided with: a first substrate (51) having a first through-hole (51e); a second substrate (52) that covers the first through-hole (51e) and is disposed so as to at least partially overlap the first substrate (51); a vibration layer (10) that is disposed on the opposite side of the first substrate (51) from the second substrate (52) so as to overlap the first substrate (51), and that is disposed so as to straddle the first through-hole (51e); a resin layer (6) disposed so as to overlap a portion of the vibration layer (10) that overlaps the first substrate (51); a first pad electrode (41); and a second pad electrode (42). The first pad electrode (41) and the second pad electrode (42) are disposed on a surface of the resin layer (6) on the side away from the vibration layer (10). The vibrating layer (10) includes: a piezoelectric layer (4); an upper electrode layer (5), which is a first electrode layer, disposed so as to overlap a surface of the piezoelectric layer (4) on the side away from the first substrate (51); and a lower electrode layer (3), which is a second electrode layer, disposed so as to overlap the surface of the piezoelectric layer (4) on the side close to the first substrate (51). A first pad electrode (41) is electrically connected to the first electrode layer. A second pad electrode (42) is electrically connected to the second electrode layer.

Description

Technical Field

[0001] The present invention relates to a MEMS acoustic element. Background Art

[0002] Japanese Patent Application Laid-Open No. 2020-159836 (Patent Document 1) discloses a sensor module including a substrate, a sensor chip and a controller IC mounted on the substrate, and a cover covering the sensor chip and the controller IC.

[0003] Japanese Patent Gazette No. 2010-21225 (Patent Document 2) discloses a silicon microphone as an electronic component. The silicon microphone includes a substrate, a MEMS chip, and an electronic circuit chip. The MEMS chip and the electronic circuit chip are connected by wires. The MEMS chip and the electronic circuit chip are sealed by a primary molded resin. Silicone resin as a buffer material is applied around the vibration plate on the upper surface of the MEMS chip. By providing the buffer material here, it is possible to avoid the protrusion of the transfer mold directly contacting the vibration plate of the MEMS chip. Thereby, it is possible to prevent the MEMS structure from being damaged during the manufacturing process. A sound collecting portion is formed in the secondary molded resin in a manner opposite to the opening of the primary molded resin. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-159836 Patent Document 2: Japanese Patent Application Publication No. 2010-21225 Summary of the invention Problems to be solved by the invention

[0005] In the structure disclosed in Patent Document 1, the cover needs to be designed to be much larger than the sensor chip in consideration of the position accuracy during the mounting operation of the cover, and the size of the entire sensor module becomes quite large. In addition, if the cover is formed of metal, the cover must actually be made using a mold, which increases the manufacturing cost.

[0006] In the structure disclosed in Patent Document 2, space is required for the wires connecting the MEMS chip and the electronic circuit chip. Therefore, the size of the silicon microphone has to be increased. In addition, during resin molding, the MEMS chip receives a pressing force from the mold, so the MEMS chip needs to be formed into a solid structure. In order to form the MEMS chip into a solid structure, the MEMS chip is enlarged, the manufacturing cost is increased, and the degree of freedom of design is reduced.

[0007] In the structure disclosed in Patent Document 2, an electrode is disposed on the bottom surface of the substrate, and the opening of the sound collecting portion is formed on the side of the substrate opposite to the electrode. Therefore, positioning of the silicon microphone relative to the housing becomes a problem.

[0008] Therefore, an object of the present invention is to provide a MEMS acoustic element which is advantageous in miniaturization, does not require an expensive metal cover, and is easy to align during mounting. Technical means to solve problems

[0009] In order to achieve the above-mentioned purpose, the MEMS acoustic element based on the present invention comprises: a first substrate having a first through hole; a second substrate blocking the first through hole and configured in a manner that at least a portion overlaps the first substrate; a vibration layer configured in a manner that overlaps the first substrate on the side of the first substrate opposite to the second substrate and is configured to cross the first through hole; a resin layer configured in a manner that overlaps the portion of the vibration layer that overlaps the first substrate; a first pad electrode; and a second pad electrode. The first pad electrode and the second pad electrode are configured on the surface of the resin layer away from the vibration layer. The vibration layer includes: a piezoelectric layer; a first electrode layer configured in a manner that overlaps the surface of the piezoelectric layer away from the first substrate; and a second electrode layer configured in a manner that overlaps the surface of the piezoelectric layer on the side close to the first substrate. The first pad electrode is electrically connected to the first electrode layer. The second pad electrode is electrically connected to the second electrode layer. Effects of the Invention

[0010] According to the present invention, it is possible to realize a MEMS acoustic element which is advantageous in miniaturization, does not require an expensive metal cover, and is easy to align during mounting. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a top view of the MEMS acoustic element in the first embodiment of the present invention. Figure 2 It is a schematic cross-sectional view of a MEMS acoustic element in the first embodiment of the present invention. Figure 3 This is an explanatory diagram of a first step of the method for manufacturing the MEMS acoustic element in the first embodiment of the present invention. Figure 4 It is an explanatory diagram of the second step of the method for manufacturing the MEMS acoustic element in the first embodiment of the present invention. Figure 5 It is an explanatory diagram of the third step of the method for manufacturing the MEMS acoustic element in the first embodiment of the present invention. Figure 6This is an explanatory diagram of a state where solder bumps are provided after the third step of the method for manufacturing the MEMS acoustic element in the first embodiment of the present invention. Figure 7 It is an explanatory diagram of the fourth step of the method for manufacturing the MEMS acoustic element in the first embodiment of the present invention. Figure 8 It is an explanatory diagram of the fifth step of the method for manufacturing the MEMS acoustic element in the first embodiment of the present invention. Fig. 9 It is an explanatory diagram of a first step of a method for manufacturing a modified example of the MEMS acoustic element in the first embodiment of the present invention. Fig.10 It is an explanatory diagram of the second step of the manufacturing method of the modification example of the MEMS acoustic element in the first embodiment of the present invention. Fig.11 It is an explanatory diagram of the third step of the manufacturing method of the modification example of the MEMS acoustic element in the first embodiment of the present invention. Fig.12 It is an explanatory diagram of a fourth step of the manufacturing method of the modified example of the MEMS acoustic element in the first embodiment of the present invention. Fig.13 It is an explanatory diagram of the fifth step of the manufacturing method of the modified example of the MEMS acoustic element in the first embodiment of the present invention. Fig.14 This is a schematic cross-sectional view of a MEMS acoustic element in a second embodiment of the present invention. Fig.15 This is an explanatory diagram of a first step of the method for manufacturing a MEMS acoustic element in the second embodiment of the present invention. Fig.16 It is an explanatory diagram of the second step of the method for manufacturing the MEMS acoustic element in the second embodiment of the present invention. Fig.17 It is a schematic cross-sectional view of a MEMS acoustic element in a third embodiment of the present invention. Fig.18 It is a schematic cross-sectional view of a MEMS acoustic element in a fourth embodiment of the present invention. Fig.19 It is an explanatory diagram of the first step of the method for manufacturing the MEMS acoustic element in the fourth embodiment of the present invention. Fig. 20 It is an explanatory diagram of the second step of the method for manufacturing the MEMS acoustic element in the fourth embodiment of the present invention. Fig.21 It is an explanatory diagram of the third step of the method for manufacturing the MEMS acoustic element in the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0012] The dimensional ratios shown in the drawings do not necessarily represent reality faithfully, and for the sake of convenience of explanation, the dimensional ratios may be exaggerated. In the following description, when the concept of up or down is mentioned, it does not necessarily mean absolute up or down, but sometimes means relative up or down in the illustrated posture.

[0013] (Implementation Method 1) Reference Figure 1-2 , the MEMS acoustic element in the first embodiment of the present invention is described. A top view of the MEMS acoustic element 101 in this embodiment is shown in FIG. Figure 1 . Figure 1 In the example, the acoustic hole 7 is relatively large and is located in the center. Figure 1 In FIG. 1 , the acoustic hole 7 is in the shape of a square. A schematic cross-sectional view of the MEMS acoustic element 101 is shown in FIG. Figure 2 . Figure 2 In the figure, for the sake of convenience, parts that would not originally appear in the same cross section are also shown in one cross-sectional view.

[0014] The MEMS acoustic element 101 includes: a first substrate 51 having a first through hole 51e; a second substrate 52 blocking the first through hole 51e and arranged to overlap at least a portion of the first substrate 51; a vibration layer 10 arranged to overlap the first substrate 51 on the side of the first substrate 51 opposite to the second substrate 52 and arranged to straddle the first through hole 51e; a resin layer 6 arranged to overlap the portion of the vibration layer 10 overlapping the first substrate 51; a first pad electrode 41; and a second pad electrode 42. The resin layer 6 is formed of, for example, a polyimide resin.

[0015] The first pad electrode 41 and the second pad electrode 42 are arranged on the surface of the resin layer 6 away from the vibration layer 10. The vibration layer 10 includes: a piezoelectric layer 4; an upper electrode layer 5 as a first electrode layer, which is arranged to overlap the surface of the piezoelectric layer 4 on the side away from the first substrate 51; and a lower electrode layer 3 as a second electrode layer, which is arranged to overlap the surface of the piezoelectric layer 4 on the side close to the first substrate 51.

[0016] The first pad electrode 41 is electrically connected to the upper electrode layer 5 as the first electrode layer. The second pad electrode 42 is electrically connected to the lower electrode layer 3 as the second electrode layer. At least a portion of the piezoelectric layer 4 is sandwiched between the upper electrode layer 5 and the lower electrode layer 3. In fact, most of the piezoelectric layer 4 is sandwiched between the upper electrode layer 5 and the lower electrode layer 3.

[0017] Figure 1In the embodiment, a portion of the vibration layer 10 is exposed through the acoustic hole 7. The vibration layer 10 is provided with gaps 14 in a certain pattern. Figure 1 As shown, in the central portion of the vibration layer 10 , the gap 14 may include a meandering portion. Figure 1 The shape of the slit 14 shown is only an example. Figure 2 In the figure, the gap 14 is greatly simplified for the sake of convenience of explanation. This also applies to the following cross-sectional views.

[0018] More preferably, the MEMS acoustic element 101 includes a ring metal layer 40 disposed on a surface of the resin layer 6 on the side away from the vibration layer 10 so as to surround a projection area of ​​the first through hole 51 e .

[0019] In this embodiment, since there is no need to use a cover, wire, etc., the MEMS acoustic element can be miniaturized. In particular, since no expensive metal cover is used, it can be manufactured cheaply. As described above, according to this embodiment, a MEMS acoustic element can be realized, which is conducive to miniaturization, does not require an expensive metal cover, and is easy to align during installation.

[0020] In this embodiment, it is further preferred that the MEMS acoustic element 101 has a ring metal layer 40 disposed on the surface of the resin layer 6 on the side away from the vibration layer 10 so as to surround the projection area of ​​the first through hole 51e, so that it can be mounted using the ring metal layer 40. Here, although the MEMS acoustic element is shown to have a configuration with the ring metal layer 40, this is only an example, and the MEMS acoustic element may also be configured without the ring metal layer 40.

[0021] (Manufacturing method) Reference Figure 3 to Figure 8 , a method for manufacturing the MEMS acoustic element 101 in this embodiment is described.

[0022] Here, in order to obtain a plurality of MEMS acoustic elements at a time, each step of the manufacturing method is performed using a collective substrate having a size corresponding to the plurality of MEMS acoustic elements instead of a size corresponding to one MEMS acoustic element.

[0023] like Figure 3 As shown, in a configuration in which an oxide film 2 is formed on the upper surface of a first substrate 51, and a silicon layer as a lower electrode layer 3 is further formed on the upper surface of the oxide film 2, a piezoelectric layer 4, a metal layer as an upper electrode layer 5, and conductive layers 31 and 32 are formed, and a resin layer 6 is further formed in a manner covering the entire upper surface thereof. The resin layer 6 is formed of, for example, photosensitive polyimide.

[0024] like Figure 4As shown, the resin layer 6 is patterned. As a result, at least a portion of each of the conductive layers 31 and 32 is exposed, and the acoustic holes 7 are opened.

[0025] like Figure 5 As shown, a ring metal layer 40, a first pad electrode 41, and a second pad electrode 42 are formed. These can be formed by forming a metal film by plating or the like so as to cover the entire upper surface of the resin layer 6 or the like, and then patterning the metal film.

[0026] like Figure 6 As shown in FIG. 1 , a conductive connection member 11 may be disposed on the ring metal layer 40, the first pad electrode 41, and the second pad electrode 42. The conductive connection member 11 is, for example, a solder bump. The solder bump as the conductive connection member 11 may be formed by disposing solder at a desired position by printing and then reflowing the solder. Figure 6 The following description is based on the premise that the conductive connecting member 11 is shown.

[0027] like Figure 7 As shown, deep reactive ion etching (DRIE) is performed on the first substrate 51 and the oxide film 2 from the back side. Thus, the cavity 1 is formed. If only the first substrate 51 is focused on, it can be said that the first through hole 51e is formed in the first substrate 51.

[0028] like Figure 8 As shown, a silicon wafer as the second substrate 52 is bonded to the lower side of the first substrate 51. This bonding is performed by resin bonding. That is, the second substrate 52 is bonded to the first substrate 51 via the resin film 12. The opening of the cavity 1 is closed by the second substrate 52.

[0029] So far, each process has been carried out in the state of the assembled substrate, but here, the second substrate 52 side is cut with a blade to separate the individual MEMS acoustic elements. Figure 1 and Figure 2 A MEMS acoustic element 101 is shown.

[0030] (Manufacturing method of modified example) Reference Figures 9 to 13 , a method for manufacturing a modified example of the MEMS acoustic element in this embodiment is described.

[0031] and Figure 4 Similarly, when the first resin layer 61 is patterned, as shown in Fig. 9 The resin sheet 60 is attached. The entire upper surface is covered with the resin sheet 60. The resin sheet 60 can be attached by pressing with a roller.

[0032] like Fig.10 As shown, the resin sheet 60 is patterned to form a second resin layer 62. The second resin layer 62 is only arranged in a desired area. The area where the second resin layer 62 exists is not necessarily the area where the first resin layer 61 exists. The second resin layer 62 is formed to be exposed and overhanging from the first resin layer 61 in a part of the area. Here, the first resin layer 61 and the second resin layer 62 together form the resin layer 6.

[0033] like Fig.11 As shown, the first pad electrode 41 and the second pad electrode 42 are formed. These can be formed by forming a metal film by plating or the like so as to cover the entire upper surface of the second resin layer 62 or the like, and then patterning the metal film.

[0034] like Fig.12 As shown, the cavity 1 is formed by performing DRIE on the first substrate 51 and the oxide film 2 from the back. Figure 7 The same as described.

[0035] like Fig.13 As shown, a silicon wafer as the second substrate 52 is bonded to the bottom of the first substrate 51. Figure 8 The same as described.

[0036] In this modification, the resin layer 6 has a double-layer structure of a first resin layer 61 and a second resin layer 62, and the second resin layer 62 has a suspended structure in a manner that narrows the opening of the acoustic hole 7. With such a structure, foreign matter is difficult to enter from the acoustic hole 7. Therefore, the vibration layer 10 can be protected from the invasion of foreign matter. In addition, the second resin layer 62 has a suspended structure, which can also protect the vibration layer 10 from impact.

[0037] (Implementation Method 2) Reference Fig.14 , a MEMS acoustic element according to a second embodiment of the present invention is described. A schematic cross-sectional view of a MEMS acoustic element 201 according to this embodiment is shown in Fig.14 .exist Fig.14 In, also with Figure 2 Likewise, for ease of explanation, parts that would not originally appear in the same cross section are also shown simultaneously in one cross-sectional view.

[0038] The MEMS acoustic element 201 includes a relay substrate 50 and a MEMS acoustic element 102. The MEMS acoustic element 102 is similar to the MEMS acoustic element 101, but differs from the MEMS acoustic element 101 in that the MEMS acoustic element 102 is configured without the ring metal layer 40. In the MEMS acoustic element 102, mounting on the relay substrate 50 is performed by the first pad electrode 41 and the second pad electrode 42.

[0039] The MEMS acoustic element 201 includes a relay substrate 50 having a second through hole 50e corresponding to the first through hole 51e. The second through hole 50e is connected to the acoustic hole 7 of the MEMS acoustic element 102. The first pad electrode 41 and the second pad electrode 42 are connected to the relay substrate 50 via the conductive connection member 11. The outer peripheral side surface of the resin layer 6, the outer peripheral side surface of the first substrate 51, the outer peripheral side surface of the second substrate 52, and the surface of the second substrate 52 away from the first substrate 51 are covered with a first coating resin 71.

[0040] A plurality of pad electrodes 18 are provided on the lower surface of the relay substrate 50. The upper surface of the relay substrate is covered with an insulating film 19. A plurality of connecting conductors 17 are arranged inside the relay substrate 50. The connecting conductors 17 connect the pad electrodes 18 to the upper surface of the relay substrate 50. Some openings are provided in the insulating film 19. Parts of the connecting conductors 17 are exposed in the openings of the insulating film 19. The first pad electrode 41 and the second pad electrode 42 of the MEMS acoustic element 102 are connected via the conductive connecting member 11, respectively.

[0041] In this embodiment, the same effects as those in the first embodiment can be obtained. In this embodiment, the MEMS acoustic element 102 is also protected by being covered by the first coating resin 71 and the relay substrate 50, so the resistance to physical impact during assembly and use is improved. The MEMS acoustic element 201 can be mounted on other objects using the pad electrode 18.

[0042] (Manufacturing method) Reference Figure 15-16 , a method for manufacturing the MEMS acoustic element 201 in this embodiment is described.

[0043] First, the MEMS acoustic element 102 and the relay substrate 50 are prepared. At this point in time, the relay substrate 50 is treated as a collective substrate having a size equivalent to that of a plurality of products. An insulating film 19 is formed on the upper surface of the relay substrate 50. Fig.15 As shown, the MEMS acoustic element 102 is flip-chip mounted on the upper surface of the relay substrate 50 with the acoustic hole 7 facing the relay substrate 50. The first pad electrode 41 and the second pad electrode 42 of the MEMS acoustic element 102 are connected to the relay substrate 50 via the conductive connection member 11. The conductive connection member 11 is, for example, a solder bump.

[0044] Then, if Fig.16As shown, the space around the MEMS acoustic element 102 on the upper surface side of the relay substrate 50 is covered with the first coating resin 71. By appropriately adjusting the viscosity of the first coating resin 71 and the height of the conductive connection member 11, the degree of intrusion of the first coating resin 71 into the gap between the MEMS acoustic element 102 and the relay substrate 50 can be controlled. The upper surface of the first coating resin 71 is ground to reduce the thickness to the desired level. The first coating resin 71 is cut by a blade to separate the sizes of individual products. In this way, Fig.14 A MEMS acoustic element 201 is shown.

[0045] (Implementation Method 3) Reference Fig.17 , the MEMS acoustic element in the third embodiment of the present invention is described. A schematic cross-sectional view of the MEMS acoustic element 202 in this embodiment is shown in Fig.17 .

[0046] The MEMS acoustic element 202 includes a relay substrate 50, a MEMS acoustic element 102, and a circuit chip component 15. The circuit chip component 15 is an IC. In the MEMS acoustic element 202, the circuit chip component 15 is mounted on the surface of the first substrate 51 side of the relay substrate 50, and the circuit chip component 15 is covered with a first coating resin 71. That is, the MEMS acoustic element 102 and the circuit chip component 15 are in a state of being sealed by the first coating resin 71. Between the circuit chip component 15 and the relay substrate 50, connecting members such as solder bumps are arranged, and the bottom filler 16 is filled in a manner to seal these connecting members. The periphery of the bottom filler 16 is further sealed by the first coating resin 71.

[0047] A pad electrode 20 is arranged on the lower surface of the relay substrate 50. A connecting conductor 21 is arranged in a manner that penetrates the relay substrate 50. The connecting conductor 21 connects the pad electrode 20 to an electrode 23 provided on the upper surface of the relay substrate 50. The electrode 23 is exposed from the insulating film 19. A plurality of electrodes are provided on the lower surface of the circuit chip component 15. One terminal provided on the lower surface of the circuit chip component 15 is connected to the electrode 23 via a solder bump or the like. Another terminal provided on the lower surface of the circuit chip component 15 is electrically connected to the first pad electrode 41 and the second pad electrode 42 of the MEMS acoustic element 102 via a wiring 22. The wiring 22 is arranged on the upper surface of the relay substrate 50, but is covered by the insulating film 19 except for the portion required for connection.

[0048] In this embodiment, the entire MEMS acoustic element 202 can be packaged as a single unit including the circuit chip component 15. In this embodiment, the entirety can be miniaturized.

[0049] Furthermore, the first coating resin 71 may also have conductivity. By adopting this configuration, electromagnetic shielding can be performed on the MEMS acoustic element 102. If electromagnetic shielding can be performed on the MEMS acoustic element 102, the MEMS acoustic element 201 can be used even in an environment with much electromagnetic noise.

[0050] (Implementation Method 4) Reference Fig.18 , the MEMS acoustic element in the fourth embodiment of the present invention is described. A schematic cross-sectional view of the MEMS acoustic element 203 in this embodiment is shown in Fig.18 .

[0051] The MEMS acoustic element 203 is provided with a second coating resin 72. The second coating resin 72 is arranged to cover the surface and side surface of the first coating resin 71 away from the relay substrate 50. The second coating resin 72 has conductivity. In the MEMS acoustic element 203, the first coating resin 71 does not have conductivity. The other configurations are the same as those described in the third embodiment.

[0052] In this embodiment, similarly to the third embodiment, the entire MEMS acoustic element 203 can be packaged in an integrated manner including the circuit chip component 15 .

[0053] In this embodiment, the conductive second coating resin 72 covers the first coating resin 71, so that electromagnetic shielding can be performed on the MEMS acoustic element 102. Therefore, the MEMS acoustic element 203 can be used even in an environment with much electromagnetic noise.

[0054] (Manufacturing method) Reference Figure 19 to Figure 21 , a method for manufacturing the MEMS acoustic element 203 in this embodiment is described.

[0055] Here, in order to obtain a plurality of MEMS acoustic elements at a time, each step of the manufacturing method is performed using a collective substrate having a size corresponding to the plurality of MEMS acoustic elements instead of a size corresponding to one MEMS acoustic element.

[0056] First, if Fig.19 As shown in FIG. 1 , the MEMS acoustic element 102 and the circuit chip component 15 are mounted on the upper surface of the relay substrate 50. Fig. 20 As shown, the MEMS acoustic element 102 and the circuit chip component 15 on the upper surface side of the relay substrate 50 are sealed with the first coating resin 71. Half cutting is performed by blade cutting. The groove 24 is formed by half cutting. The lower end of the groove 24 exceeds the insulating film 19 and reaches the relay substrate 50.

[0057] like Fig.21 As shown, a conductive second coating resin 72 is configured. The second coating resin 72 covers the upper surface of the first coating resin 71 and fills the groove 24. After that, it is cut by a blade to separate the size of the individual products. In this way, Fig.18 The MEMS acoustic element 203 is shown.

[0058] Furthermore, a plurality of the above-described embodiments may be appropriately combined and adopted. The above-described embodiments disclosed this time are illustrative in all aspects and are not restrictive. The scope of the present invention is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are encompassed. [Note 1] A MEMS acoustic element, comprising: A first substrate having a first through hole; a second substrate blocking the first through hole and arranged in such a manner that at least a portion of the second substrate overlaps the first substrate; a vibration layer, which is arranged on a side of the first substrate opposite to the second substrate in a manner overlapping the first substrate and arranged to straddle the first through hole; a resin layer arranged so as to overlap a portion of the vibration layer overlapping the first substrate; a first pad electrode; and The second pad electrode, The first pad electrode and the second pad electrode are arranged on a surface of the resin layer that is away from the vibration layer. The vibration layer comprises: Piezoelectric layer; a first electrode layer arranged to overlap a surface of the piezoelectric layer on a side away from the first substrate; and a second electrode layer arranged so as to overlap with a surface of the piezoelectric layer on a side close to the first substrate, The first pad electrode is electrically connected to the first electrode layer, The second pad electrode is electrically connected to the second electrode layer. [Note 2] The MEMS acoustic element according to Supplementary Note 1, wherein a ring metal layer is provided on a surface of the resin layer on a side away from the vibration layer so as to surround a projection area of ​​the first through hole. [Note 3] The MEMS acoustic element according to Appendix 1 or 2, wherein the relay substrate is provided, the relay substrate having a second through hole corresponding to the first through hole, the first pad electrode and the second pad electrode are connected to the relay substrate via a conductive connecting member, respectively. The outer peripheral side surface of the resin layer, the outer peripheral side surface of the first substrate, the outer peripheral side surface of the second substrate, and the surface of the second substrate on the side away from the first substrate are covered with a first coating resin. [Note 4] The MEMS acoustic element according to Supplementary Note 3, wherein a circuit chip component is mounted on a surface of the relay substrate on the first substrate side, and the circuit chip component is covered with the first coating resin. [Note 5] The MEMS acoustic element according to Appendix 3 or 4, wherein the first coating resin has conductivity. [Note 6] The MEMS acoustic element according to Appendix 3 or 4, further comprising a second coating resin which is arranged to cover a surface and a side surface of the first coating resin which are away from the relay substrate and has conductivity. Description of Reference Numerals

[0059] 1 cavity, 2 oxide film, 3 lower electrode layer (as second electrode layer), 4 piezoelectric layer, 5 upper electrode layer (as first electrode layer), 6 resin layer, 7 acoustic hole, 8 opening (of relay substrate), 10 vibration layer, 11 conductive connecting member, 12 resin film, 14 gap, 15 circuit chip component, 16 bottom filler, 17, 21 connecting conductor, 18, 20 pad electrode, 19 insulating film, 22 wiring, 23 electrode, 24 groove, 31, 32 conductive layer, 40 ring metal layer, 41 first pad electrode, 42 second pad electrode, 50 relay substrate, 50e second through hole, 51 first substrate, 51e first through hole, 52 second substrate, 60 resin sheet, 61 first resin layer, 62 second resin layer, 71 first coating resin, 72 second coating resin, 101, 102, 103, 104 MEMS acoustic element.

Claims

1. A MEMS acoustic element, comprising: A first substrate having a first through hole; a second substrate blocking the first through hole and arranged in such a manner that at least a portion of the second substrate overlaps the first substrate; a vibration layer, which is arranged on a side of the first substrate opposite to the second substrate in a manner overlapping the first substrate and arranged to straddle the first through hole; a resin layer arranged so as to overlap a portion of the vibration layer overlapping the first substrate; a first pad electrode; as well as The second pad electrode, The first pad electrode and the second pad electrode are arranged on a surface of the resin layer that is away from the vibration layer. The vibration layer comprises: Piezoelectric layer; a first electrode layer arranged to overlap a surface of the piezoelectric layer on a side away from the first substrate; and a second electrode layer arranged so as to overlap with a surface of the piezoelectric layer on a side close to the first substrate, The first pad electrode is electrically connected to the first electrode layer, The second pad electrode is electrically connected to the second electrode layer.

2. The MEMS acoustic element according to claim 1, wherein: The resin layer includes a ring metal layer on a surface on a side away from the vibration layer and arranged so as to surround a projection area of ​​the first through hole.

3. The MEMS acoustic element according to claim 1 or 2, wherein: A relay substrate is provided, the relay substrate having a second through hole corresponding to the first through hole, the first pad electrode and the second pad electrode are connected to the relay substrate via a conductive connecting member, The outer peripheral side surface of the resin layer, the outer peripheral side surface of the first substrate, the outer peripheral side surface of the second substrate, and the surface of the second substrate on the side away from the first substrate are covered with a first coating resin.

4. The MEMS acoustic element according to claim 3, wherein: A circuit chip component is mounted on the surface of the relay substrate on the first substrate side, and the circuit chip component is covered with the first coating resin.

5. The MEMS acoustic element according to claim 3 or 4, wherein: The first coating resin has electrical conductivity.

6. The MEMS acoustic element according to claim 3 or 4, wherein: A second coating resin is provided, the second coating resin being arranged so as to cover the surface and side surfaces of the first coating resin on the side away from the interconnect substrate and having conductivity.

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