JP2013135264A - Elastic wave device, electronic component, and manufacturing method of elastic wave device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic wave device having an excitation electrode that is insusceptible to electromagnetic waves from the exterior.SOLUTION: An elastic wave device includes: an element substrate 3; an excitation electrode 5 positioned on an upper surface 3a of the element substrate 3; multiple electrode pads 7 positioned on the upper surface 3a of the element substrate 3 and electrically connected with the excitation electrode 5; multiple support members 2, which are positioned on the element substrate so as to enclose the excitation electrode 5 all together and be spaced apart from each other, are connected with the electrode pads 7, and are formed by a conductive material; a lid 4 which is overlapped with the multiple support members 2 so as to cover the excitation electrode 5, has through holes 4h exposing parts of the support members 2, and is made of an insulation material; and a sealing member 10 closing a gap between the adjacent support members 2 and made of an insulation material.

Description

The present invention relates to a surface acoustic wave (SAW) device or a piezoelectric thin film resonator (F).
The present invention relates to an elastic wave device such as a BAR (Film Bulk Acoustic Resonator), an electronic component using the elastic wave device, and a method of manufacturing the elastic wave device.

A so-called wafer level package (WLP: Wafer Level Package) type acoustic wave device for the purpose of downsizing is known. This WLP type acoustic wave device has a piezoelectric substrate, an excitation electrode provided on the piezoelectric substrate, and a cover for sealing the excitation electrode (see, for example, Patent Document 1).

  The cover includes a frame body disposed on the upper surface of the piezoelectric substrate so as to surround the excitation electrode and a lid body that closes the opening of the frame body. The frame and the lid are made of resin.

JP 2008-227748 A

  In the above-described conventional WLP type acoustic wave device, since the cover is composed of a frame body and a lid body made of resin, the excitation electrode is easily affected by electromagnetic waves from the outside and has electrical characteristics such as filter characteristics. Tends to deteriorate.

  When the electrical characteristics of the acoustic wave device are degraded, the electrical characteristics of the electronic component on which the acoustic wave device is mounted are also degraded.

  Therefore, it is desired to provide an elastic wave device in which the excitation electrode is hardly affected by external electromagnetic waves.

  An elastic wave device as one embodiment of the present invention includes an element substrate, an excitation electrode located on the upper surface of the element substrate, and an electrical connection to the excitation electrode located on the upper surface of the element substrate. A plurality of electrode pads, and a plurality of support members made of a conductive material, which are connected to the electrode pads so as to surround the excitation electrode as a whole and have a gap therebetween on the element substrate; Covering the plurality of support members so as to cover the excitation electrode, a cover made of an insulating material having a through hole exposing a part of the support member, and a gap between the adjacent support members And a sealing member made of an insulating material.

  An electronic component according to an aspect of the present invention includes a mounting substrate having a plurality of mounting pads on an upper surface, and the acoustic wave device is in a state where the upper surfaces face each other on the upper surface of the mounting substrate. It is mounted by bonding the support member exposed from the through hole of the lid with a conductive bonding material, and is covered with an exterior resin.

According to one aspect of the present invention, there is provided a method of manufacturing an acoustic wave device comprising: forming an excitation electrode on an upper surface of an element substrate and a plurality of electrode pads electrically connected to the excitation electrode; Forming a plurality of support members made of a conductive material, which are disposed in a state of being spaced apart from each other while surrounding the excitation electrode and connected to the electrode pad; and a plurality of the plurality of support members so as to cover the excitation electrode A step of forming a cover having a through-hole exposing a part of the support member by exposing and developing the film after a film made of a photosensitive insulating material is stacked on the support member; Forming a sealing member made of an insulating material so as to close a gap between the supporting members.

  The acoustic wave device having the above-described configuration is such that the excitation electrode is not easily affected by electromagnetic waves from the outside by forming a portion corresponding to the frame that has been formed from a resin, using a conductive material. Electrical characteristics are improved.

(A) is a top view of the SAW device concerning the embodiment of the present invention, and (b) is a top view in the state where the cover etc. of the SAW device of Drawing 1 (a) were removed. (A) is sectional drawing in the AA 'line of Fig.1 (a), (b) is sectional drawing in Fig.1 (a) BB' line, (c) is Fig.1 (a). It is sectional drawing in CC 'line. It is a perspective view of a SAW device in the state where a support member is arranged on the upper surface of an element substrate. (A) is a perspective view of a SAW device in a state where a sealing member is not provided, and (b) is a perspective view of the SAW device in a state where a sealing member is provided. It is sectional drawing of the electronic component which concerns on embodiment of this invention. (A) to (c) are cross-sectional views illustrating a method for manufacturing the SAW device shown in FIG. (A) to (c) is a cross-sectional view for explaining a method of manufacturing the SAW device shown in FIG. 1, and shows a continuation of FIG. 6 (c). (A) to (c) are cross-sectional views for explaining a method of manufacturing the SAW device shown in FIG. 1, and show a continuation of FIG. 7 (c).

  Hereinafter, a SAW device according to an embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily match the actual ones.

(Configuration of SAW device)
FIG. 1A is a plan view of a SAW device 1 according to an embodiment of the present invention, and FIG. 1B is a plan view of a state in which the cover 4 and the like of the SAW device 1 in FIG. FIG. 6 is a plan view of the element substrate 3. 2A is a cross-sectional view taken along the line AA ′ in FIG. 1A, FIG. 2B is a cross-sectional view taken along the line BB ′ in FIG. 1, and FIG. It is sectional drawing in CC 'line.

  The SAW device 1 includes an element substrate 3, an excitation electrode 5 provided on the upper surface 3a of the element substrate 3, an electrode pad 7 connected to the excitation electrode 5, an electrode pad 7, and the excitation electrode 5 as a whole. Between the adjacent support members 2 and the plurality of support members 2 arranged on the upper surface 3a of the element substrate 3 so as to cover the excitation electrodes 5, The sealing member 10 that closes the gap and the partition member 16 formed on the upper surface of the lid body 4 are main constituent members. In FIG. 1 (a), in order to make the positions of the constituent members easier to understand, the partition member 16 is given the same type of oblique lines as the oblique lines attached in the sectional view of FIG. 2, and the position of the support member 2 is indicated by a dotted line. ing.

Signals are input to the SAW device 1 through any of the plurality of through conductors 9 functioning as terminals. The input signal is filtered by the excitation electrode 5 or the like. Then, the SAW device 1 outputs the filtered signal through any of the plurality of through conductors 9. That is, the SAW device 1 functions as a filter that allows only a signal having a specific frequency to pass therethrough.

  The element substrate 3 is constituted by a piezoelectric substrate. Specifically, the element substrate 3 is composed of a single crystal substrate having piezoelectricity such as a lithium tantalate single crystal or a lithium niobate single crystal. The element substrate 3 is formed in a rectangular parallelepiped shape, for example, and has an upper surface 3a and a lower surface 3b that are rectangular and parallel to each other and are flat. The size of the element substrate 3 may be set as appropriate. For example, the thickness (Z direction) is 0.2 mm to 0.5 mm, and the length of one side (X direction or Y direction) is 0.5 mm. ~ 3mm.

As shown in FIG. 1B, the excitation electrode 5 is disposed on the upper surface 3 a of the element substrate 3. The excitation electrode 5 is a so-called IDT (Interdigital Transducer) and has a pair of comb-like electrodes. Each comb-like electrode has a bus bar extending in the SAW propagation direction on the element substrate 3 and a plurality of electrode fingers extending from the bus bar in a direction perpendicular to the propagation direction of the surface acoustic wave. The two comb-like electrodes are provided so that their electrode fingers mesh with each other.

  Since FIG. 1 and the like are schematic diagrams, a pair of comb-like electrodes having several electrode fingers is shown, but in practice, a plurality of pairs of combs having a larger number of electrode fingers are shown. Toothed electrodes may be provided. Further, a ladder-type SAW filter in which a plurality of excitation electrodes 5 are connected by a system such as series connection or parallel connection may be configured, or a plurality of excitation electrodes 5 are arranged in the propagation direction of a surface acoustic wave. A mode SAW resonator filter may be configured.

  The electrode pad 7 is formed on the upper surface 3a. The planar shape of the electrode pad 7 may be set as appropriate. For example, the planar shape is circular. The number and arrangement position of the electrode pads 7 are appropriately set according to the configuration of the filter constituted by the excitation electrodes 5. In the SAW device 1, the case where six electrode pads 7 are arranged along the outer periphery of the upper surface 3a is illustrated. Of the six electrode pads 7, the electrode pad 7 disposed at the center on the upper side of the drawing is a signal input pad. For example, an unbalanced signal is input from the electrode pad 7 to the excitation electrode 5. Further, the two electrode pads 7 arranged at both ends on the lower side of the drawing are signal output pads. For example, a balanced signal from the excitation electrode 5 is output from these two electrode pads 7. The remaining three electrode pads 7 are, for example, reference potential pads.

  Excitation electrode 5 and electrode pad 7 are connected to each other by wiring 15. The wiring 15 is formed on the upper surface 3 a of the element substrate 3 and connects the bus bar of the excitation electrode 5 and the electrode pad 7. In addition, the wiring 15 may be three-dimensionally crossed with not only a portion formed on the upper surface 3a but also two wirings 15 through which different signals flow with an insulator interposed therebetween.

  The excitation electrode 5, the electrode pad 7, and the wiring 15 are made of the same conductive material, for example. The conductive material is, for example, an Al alloy such as Al or an Al—Cu alloy. Moreover, the excitation electrode 5, the electrode pad 7, and the wiring 15 are formed with the same thickness, for example, and these thicknesses are 100-500 nm, for example. Further, when the wirings 15 are three-dimensionally crossed, the wiring 15 on the upper surface 3a side is formed of, for example, an Al—Cu alloy, and the wirings 15 disposed thereon via an insulator are, for example, Cr / Ni / Au in order from the bottom. Alternatively, it is formed by wiring having a multilayer structure made of Cr / Al.

On the upper surface of the electrode pad 7, there is provided a connection reinforcing layer 6 whose main purpose is to reinforce the connection between the electrode pad 7 and the support member 2 disposed thereon. The connection reinforcing layer 6 includes, for example, a nickel layer superimposed on the electrode pad 7 and a gold layer superimposed on the nickel layer.

  As shown in FIG. 2, a protective film 8 that covers the excitation electrode 5 is formed on the upper surface 3 a of the element substrate 3. The protective film 8 is formed over substantially the entire upper surface 3a of the element substrate 3, but an opening is provided on the electrode pad 7, and the electrode pad 7 and the connection reinforcing layer 6 are exposed from the opening. Yes. The opening of the protective film 8 for exposing the connection reinforcing layer 6 may have the same shape and area as the connection reinforcing layer 6 or may be larger than the connection reinforcing layer 6. Further, the opening of the protective film 8 may be smaller than the connection reinforcing layer 6, and in this case, the portion around the opening of the protective film 8 covers the outer peripheral portion of the connection reinforcing layer 6.

The protective film 8 contributes to the oxidation prevention of the excitation electrode 5 by covering the excitation electrode 5. The protective film 8 is made of, for example, silicon oxide such as SiO ₂ , aluminum oxide, zinc oxide, titanium oxide, silicon nitride, or silicon. The thickness of the protective film 8 is, for example, about 1/10 (10 to 30 nm) of the thickness of the excitation electrode 5 or 200 nm to 1500 nm, which is thicker than the excitation electrode 5.

  The support member 2 is disposed on the electrode pad 7 or the connection reinforcing layer 6 exposed from the protective film 8. The support member 2 is made of a conductive material such as a conductive polymer material, a conductive resin material containing metal particles, or a metal material.

  FIG. 3 is a perspective view showing a state in which the support member 2 is disposed on the upper surface 3 a of the element substrate 3. A total of six support members 2 are provided on the electrode pads 7 one by one. These six support members 2 are shaped and arranged so as to surround the excitation electrode 5 as a whole.

  Accordingly, the excitation electrode 5 is surrounded by the support member 2 made of a conductive material. As a result, the excitation electrode 5 is not easily affected by electromagnetic waves from the outside, and the electrical characteristics of the SAW device 1 are improved.

  Further, the support member 2 functions as a wiring for inputting / outputting an electric signal to / from the excitation electrode 5 or a wiring for a reference potential by being connected to the electrode pad 7. Therefore, the support members 2 through which different types of electrical signals flow, or the support members 2 through which the electrical signals flow and the reference potential support members 2 need to be insulated. In the SAW device 1, the adjacent support members 2 are insulated by arranging the adjacent support members 2 with a predetermined gap therebetween. The interval between the adjacent support members 2 is, for example, 50 μm to 250 μm. Moreover, the thickness of the supporting member 2 is several micrometers-30 micrometers, for example.

  As shown in FIG. 4A, the support member 2 is covered with a lid 4 so as to cover the excitation electrode 5. The lid 4 is composed of a layer having a substantially constant thickness, and the thickness is, for example, several μm to 30 μm. The planar shape of the lid 4 is, for example, a generally rectangular shape. The size of the lid 4 in plan view is substantially the same as the size of the six support members 2 viewed together, and the side surface of the lid 4 and the side surface of each support member 2 are located in the same plane. ing.

  The lid 4 is made of, for example, a photosensitive resin material having insulating properties. The photosensitive resin is, for example, a urethane acrylate-based, polyester acrylate-based, or epoxy acrylate-based resin that is cured by radical polymerization of an acryl group or a methacryl group. In addition, a polyimide resin or the like can also be used.

As shown in FIG. 2A, a through hole 4h that penetrates the lid 4 in the thickness direction is formed in the lid 4. Six through holes 4 h are formed on each support member 2 in the lid 4. That is, the bottom surface of the through hole 4h is the upper surface of the support member 2 exposed from the through hole 4h. SAW device 1
Then, a through conductor 9 is provided so as to fill the through hole 4.

  The upper end of the through conductor 9 is exposed on the upper surface of the lid 4. The through conductor 9 has a cylindrical shape, for example, but the shape is not limited to this, and may be a quadrangular prism shape. Further, as the shape of the through conductor 9, the side surface may be inclined so that the diameter becomes narrower toward the upper end side of the through conductor 9, or conversely, the diameter becomes narrower toward the lower end side of the through conductor 9. The side surface may be inclined.

  Since the through hole 4 is formed on the support member 2, the through conductor 9 formed so as to fill the through hole 4 is connected to the support member 2 therebelow. Accordingly, the through conductor 9 is electrically connected to the excitation electrode 5. The through conductor 9 functions as a terminal when the SAW device 1 is mounted on another substrate. That is, it is connected to a mounting pad of another substrate via a bonding material such as solder.

  The through conductor 9 is made of a material mainly composed of metal. In the SAW device 1, the through conductor 9 is formed by copper plating. In the SAW device 1, after forming a plating base layer on the inner surface of the through hole 4h by sputtering or the like, plating is grown by electrolytic plating. The plating base layer is made of, for example, titanium or copper.

  In addition to the through hole 4h, the lid 4 is formed with a recess 4c as shown in FIGS. 2 (a) and 2 (b). The recess 4c is provided with a reinforcing layer 17 that fills the recess 4c. The reinforcing layer 17 is for reinforcing the strength of the lid body 4. For example, after the SAW device 1 is mounted on an external mounting substrate or the like, the entire SAW device 1 may be resin-molded. Depending on the resin molding method, a large pressure is applied to the SAW device 1 at that time. Even in such a case, the lid 4 can be prevented from being deformed by providing the reinforcing layer 17. As a result, the shape of the sealing space 6 can be prevented from being greatly distorted, so that the reliability of the SAW device 1 can be improved.

  The reinforcing layer 17 is formed of a material having a higher Young's modulus than the material constituting the lid body 4. For example, the Young's modulus of the lid 4 is 0.5 to 1.0 GPa, whereas the Young's modulus of the reinforcing layer 17 is 100 to 250 GPa. Specifically, the reinforcing layer 17 is made of a material whose main component is a metal such as copper.

  Since the reinforcing layer 17 is embedded in the concave portion 4 c formed on the upper surface of the lid body 4, compared with the case where the reinforcing layer 17 is formed on the upper surface of the lid body 4 without providing the concave portion 4 c, the SAW device 1 has a low profile. Can be used for conversion.

  The thickness of the reinforcing layer 17 (depth of the recess 4c) is, for example, 1 μm to 50 μm. The reinforcing layer 17 is formed in a rectangular shape over a relatively wide range of the lid body 4. As can be seen from the positional relationship between the support member 2 indicated by the dotted line in FIG. 1A and the inner peripheral surface of the recess 4c, the recess 4c is formed so that the inner peripheral surface of the recess 4c overlaps all the support members 2. Has been. Therefore, the reinforcing layer 17 filling the concave portion 4c is formed so that the outer peripheral edge thereof overlaps all the supporting members 2. By forming the reinforcing layer 17 in this manner, the reinforcing layer 17 is supported by the support member 2 and the lid body 4 is more difficult to deform.

  As shown in FIG. 1A, a partition member 16 is formed on the entire top surface of the lid 4. The partition member 16 is made of an insulating material. As the insulating material, for example, a photosensitive resin can be used.

The partition member 16 made of such an insulating material is formed in the region between the through hole 4h and the recess 4c, thereby preventing the through conductor 9 functioning as a terminal and the reinforcing layer 17 from being short-circuited. be able to.

  The partition member 16 may be formed at least in the region between the through hole 4h and the recess 4c on the upper surface of the lid body 4, but may be formed over the entire upper surface of the lid body 4 like the SAW device 1. For example, the partition member 16 can be prevented from being peeled off from the upper surface of the lid body 4, and the occurrence of a short circuit between adjacent through conductors can be suppressed. The thickness of the partition member 16 is, for example, 5 μm to 20 μm.

  By providing the support member 2 and the lid body 4, as shown in FIGS. 2A and 2B, the surface of the support member 2 facing the excitation electrode 5 and the bottom surface of the lid body 4. In addition, a vibration space 21 that is a space surrounded by the upper surface 3a of the element substrate 3 is formed. Since the excitation electrode 5 is disposed in the vibration space 21, it is possible to prevent the SAW vibration excited by the excitation electrode 5 from being hindered by other members. The planar shape of the vibration space 21 may be set as appropriate, but the SAW device 1 has a substantially rectangular shape.

  Further, when external moisture or the like enters the vibration space 21, it causes corrosion of the excitation electrode 5. Therefore, the vibration space 21 needs to be sealed as tightly as possible. In the SAW device 1, since there is a gap between the adjacent support members 2, the vibration space 21 is directly connected to the outside air through the gap as it is, and the airtightness of the vibration space 21 is not maintained. Therefore, in the SAW device 1, a sealing member 10 that closes the gap between the support members 2 is provided. By closing the gap between the adjacent support members 2 with the sealing member 10, the vibration space 21 is blocked from the outside, and the airtightness of the vibration space 21 can be maintained for a long time.

  The sealing member 10 is made of an insulating material. As the insulating material, for example, a photosensitive resin material can be used. In the SAW device 1, the sealing member 10 is made of the same material as that of the partition member 16, and is integrally formed by the same manufacturing process. A thickness t (FIG. 2A) in the horizontal direction of the sealing member 10 is, for example, 20 μm to 100 μm.

  FIG. 4A shows a perspective view of the SAW device 1 in a state where the sealing member 10 is not provided, and FIG. 4B shows a perspective view of the SAW device 1 in a state where the sealing member 10 is provided. In FIG. 4, in order to make the sealing member 10 and the like easier to understand, the sealing member 10, the penetrating conductor 9, the partition member 16, and the reinforcing layer 17 are the same as those attached to those members in the cross-sectional view of FIG. 2. The type is shaded.

  The sealing member 10 may have any shape as long as it closes the gap between the adjacent support members 2, but as shown in FIG. 4B, in the SAW device 1, the support member 2 and the lid 4 The gap between the adjacent support members 2 is closed by covering the entire side surface. That is, the sealing member 10 in the SAW device 1 is formed in a continuous frame shape along the side surfaces of the support member 2 and the lid body 4. By making the sealing member 10 into such a shape, it becomes difficult for the sealing member 10 to be peeled off from the side surfaces of the support member 2 and the lid body 4, and the airtightness of the vibration space 21 can be maintained for a longer period.

  In addition to the shape shown in FIG. 4B, the shape of the sealing member 10 may be partially provided only in the gap portion between the adjacent support members 2, for example. Moreover, you may make it a part of sealing member 10 enter in a clearance gap.

On the lower surface 3b of the element substrate 3, a back surface portion 11 is provided as shown in FIG. The back surface portion 11 includes, for example, a back electrode that covers substantially the entire lower surface 3b of the element substrate 3 and an insulating protective layer that covers the back electrode. Charges may be charged on the surface of the element substrate 3 due to temperature changes, etc., but the charged charges can be discharged by providing the back electrode, and the breakdown of the excitation electrode 5 due to static electricity is suppressed. can do. Further, the protective layer suppresses damage to the element substrate 3.

  FIG. 5 is a cross-sectional view showing a part of the electronic component 51 on which the SAW device 1 is mounted. Note that the cross-sectional view of the SAW device 1 in FIG. 5 corresponds to a cross section taken along line A-A ′ in FIG. 1.

  The electronic component 51 includes a mounting substrate 53, a SAW device 1 mounted on the mounting substrate 53, and an exterior resin 59 that covers the SAW device 1.

  The SAW device 1 is mounted on the mounting substrate 53 by bonding a mounting pad 55 provided on the upper surface 53 a of the mounting substrate 53 and the through conductor 9 of the SAW device 1 via a conductive bonding material 57. Yes.

  In addition to this, the electronic component 51 includes an active component such as an IC mounted on the mounting substrate 53 and sealed together with the SAW device 1 by the exterior resin 59 and a passive component such as a capacitor to constitute a module.

  The mounting board 53 is configured by, for example, a printed wiring board. The printed wiring board may be a rigid board or a flexible board. The printed wiring board may be a single-layer board, a two-layer board, or a multilayer board having two or more layers. Moreover, the base material, insulating material, and conductive material of the printed wiring board may be selected from appropriate materials.

  The bonding material 57 is in contact with both the through conductor 9 of the SAW device 1 and the mounting pad 55 of the mounting substrate 53. The bonding material 57 is formed of a metal that is melted by heating and bonded to the through conductor 9. The bonding material 57 is made of, for example, solder. The solder may be a solder using lead such as Pb—Sn alloy solder, or lead-free solder such as Au—Sn alloy solder, Au—Ge alloy solder, Sn—Ag alloy solder, Sn—Cu alloy solder, etc. It may be.

  The exterior resin 59 includes, for example, an epoxy resin, a curing material, and a filler as main components. The exterior resin 59 not only covers the SAW device 1 from the side of the back surface 11 and from the side, but is also filled between the SAW device 1 and the mounting substrate 53. Specifically, the exterior resin 59 is filled between the upper surface of the lid 4 and the upper surface 53 a of the mounting substrate 53 and around the bonding material 57.

(Method for manufacturing SAW device)
FIG. 6A to FIG. 8C are cross-sectional views (corresponding to the line AA ′ in FIG. 1) for explaining the method for manufacturing the SAW device 1. The manufacturing process proceeds in order from FIG. 6 (a) to FIG. 8 (c).

  The steps of FIG. 6A to FIG. 8B corresponding to the method for manufacturing the SAW device 1 are realized in a so-called wafer process. That is, a thin film formation, a photolithography method, or the like is performed on the mother substrate that becomes the element substrate 3 by being divided, and then a plurality of SAW devices 1 are formed in parallel by dicing. . However, in FIG. 6A to FIG. 8C, only a portion corresponding to one SAW device 1 is illustrated. In addition, although the shape of the conductive layer and the insulating layer changes with the progress of the process, a common code may be used before and after the change.

As shown in FIG. 6A, first, the excitation electrode 5 is formed on the upper surface 3 a of the element substrate 3. Specifically, first, sputtering, vapor deposition, or CVD (Chemical Vapor Deposition)
A metal layer is formed on the upper surface 3a by a thin film forming method such as a method. Next, for the metal layer,
Patterning is performed by a photolithography method using a reduction projection exposure machine (stepper) and an RIE (Reactive Ion Etching) apparatus. The excitation electrode 5 is formed by patterning the metal layer. The wiring 15 and the electrode pad 7 are formed simultaneously with the excitation electrode 5. Note that a back surface portion 11 is formed on the lower surface 3 b of the element substrate 3.

  When the excitation electrode 5 and the like are formed, a protective film 8 is formed as shown in FIG. Specifically, first, a thin film to be the protective film 8 is formed by an appropriate thin film forming method. The thin film forming method is, for example, a sputtering method or CVD. Next, a part of the thin film is removed by RIE or the like so that the electrode pad 7 and the connection reinforcing layer 6 are exposed. Thereby, the protective film 8 is formed.

  When the protective film 8 is formed, the support member 2 is formed as shown in FIG. The support member 2 is made of a conductive polymer material that can be patterned by, for example, photolithography. Specifically, by forming a layer (conductive layer) made of a conductive polymer material or the like on the element substrate 3 by a method such as coating, a photomask is placed on the conductive layer, and exposure and development are performed. A plurality of support members 2 as shown in FIG. 3 are obtained.

  Note that in the case where the conductive layer is made of a conductive resin material or the like to which the photolithography method is not applied, a resist layer patterned into a predetermined shape is first formed on the conductive layer. Thereafter, a portion of the conductive layer exposed from the resist layer is removed by a method such as wet etching, and the support member 2 can be formed by removing the resist layer.

  Next, the lid 4 is formed. Specifically, first, as shown in FIG. 7A, a film-like first resist layer 25 to be the lid 4 is placed on the support member 2, and the first resist layer 25 is Irradiate light L 1 such as ultraviolet rays through one photomask 30. The first resist layer 25 is made of, for example, a negative photoresist. The first photomask 30 is configured by forming a first light shielding portion 29 on a first transparent substrate 28. The first light shielding portion 29 is formed at a position corresponding to a portion where the first resist layer 25 is to be removed when the first photomask 30 is set on the element substrate 3. That is, in the method for manufacturing the SAW device 1, the first light shielding portion 29 is formed at a position corresponding to the through hole 4h and the dicing line.

  Thereafter, development processing is performed as shown in FIG. 7B, and the portion of the first resist layer 25 irradiated with the light L1 is left, and the portion not irradiated with the light L1 is removed. Thereby, the lid body 4 having the through hole 4h is completed. Further, the opening of the support member 2 is closed by the lid 4, so that the vibration space 21 is simultaneously formed. However, in this state, since the gap between the adjacent support members 2 is not closed, the vibration space 21 is not sealed.

  Next, the sealing member 10 and the partition member 16 are formed. Specifically, first, as shown in FIG. 7C, a second resist layer 26 to be the sealing member 10 and the partition member 16 is applied over the entire upper surface side of the element substrate 3, and the second resist layer 26 is applied to the second resist layer 26. On the other hand, light L2 such as ultraviolet rays is irradiated through the second photomask 33. The second resist layer 26 is made of, for example, a negative photoresist. The second photomask 33 is configured by forming the second light shielding part 32 on the second transparent substrate 31. The second light shielding portion 32 is formed at a position corresponding to a portion where the second resist layer 26 is to be removed when the second photomask 33 is set on the element substrate 3. That is, in the method for manufacturing the SAW device 1, the second light shielding portion 32 is formed at a position corresponding to the through hole 4h, the concave portion 4c, and the dicing line.

Thereafter, development processing is performed as shown in FIG. 8A, and the portion of the second resist layer 26 that has been irradiated with the light L2 is left and the portion that has not been irradiated with the light L2 is removed. Heat cure at temperature. Thereby, the sealing member 10 and the partition member 1 as shown in FIG.
6 is obtained. That is, in the method for manufacturing the SAW device 1, the sealing member 10 and the partition member 16 are integrally formed at the same time.

  Next, as shown in FIG. 8B, a recess 4c is formed on the upper surface of the lid 4 by an etching method such as dry etching.

  Thereafter, the through conductor 9 filling the through hole 4h and the reinforcing layer 17 filling the recess 4c are formed. The through conductor 9 and the reinforcing layer 17 are formed by, for example, a plating method. When the through conductor 9 and the reinforcing layer 17 are formed by electrolytic plating among plating methods, a plating base layer is formed in advance on the inner surface of the through-hole 4h and the inner surface of the recess 4c by a sputtering method or the like. The plating is grown from the starting point.

  When the through conductor penetrates the lid and the frame as in the conventional WLP type SAW device, the through hole for forming the through conductor is deepened by the amount of the frame, but such a deep penetration Voids are easily formed when plating is grown in the holes. On the other hand, according to the manufacturing method of the SAW device 1, the depth of the through hole 4h is only the thickness of the lid 4 and is relatively shallow. Therefore, even if plating is grown on the through-hole 4h, voids are hardly formed, and connection reliability when the SAW device 1 is mounted on another substrate can be improved.

  Thereafter, the SAW device 1 is completed by polishing the upper surface of the partition member 16 by CMP or the like as necessary.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The elastic wave device is not limited to the SAW device. For example, the acoustic wave device may be a piezoelectric thin film resonator.

  In the SAW device, the through conductor 9, the connection reinforcing layer 6, the protective film 8, the back surface portion 11, the reinforcing layer 17 and the like are not essential requirements and may be omitted.

  In the above-described embodiment, the size of the lid body 4 in plan view is substantially the same as the size when the plurality of support members 2 are viewed together, and the side surface of the lid body 4 and the side surface of each support member 2 are the same. Although the SAW device located in the same plane has been described, the size of the lid 4 is not limited to this, and for example, the size of the lid 4 is slightly smaller than the size when the plurality of support members 2 are viewed together. The lid 4 may be formed. In this case, a step portion formed by the upper surface of the support member 2 is formed between the side surface of the lid 4 and the side surface of the support member 2, but if the sealing member 10 is formed so as to cover the step portion, The peeling of the sealing member 10 from the support member 2 or the lid 4 can be suppressed.

  Further, in the electronic component according to the above-described embodiment, the through conductor 9 of the SAW device 1 and the mounting pad 55 of the mounting substrate 53 are connected via the bonding material 57, but the through conductor 9 is not provided. The upper surface of the support member 2 exposed from 4h and the mounting pad 55 of the mounting substrate 53 may be connected via a bonding material 57.

DESCRIPTION OF SYMBOLS 1 ... SAW apparatus 2 ... Support member 3 ... Element board | substrate 4 ... Cover body 5 ... Excitation electrode 6 ... Connection reinforcement | strengthening layer 7 ... Electrode pad 8 ... Protective film 10 ... Sealing members

Claims (8)

An element substrate;
An excitation electrode located on the upper surface of the element substrate;
A plurality of electrode pads located on the upper surface of the element substrate and electrically connected to the excitation electrode;
A plurality of support members made of a conductive material, which are located on the element substrate as a whole so as to surround the excitation electrode and are spaced from each other and connected to the electrode pad;
A lid made of an insulating material that covers the excitation electrode and overlaps the plurality of support members, and has a through hole that exposes a part of the support member;
An elastic wave device comprising: a sealing member made of an insulating material that closes a gap between adjacent support members.   The acoustic wave device according to claim 1, further comprising a through conductor filling the through hole. The lid body has a concave portion on the upper surface side whose inner peripheral surface overlaps over all the support members when seen through a plane.
The elastic wave device according to claim 2, further comprising a reinforcing layer made of a metal material filling the concave portion.   The acoustic wave device according to claim 3, further comprising a partition member made of an insulating material, which is located at least in a region between the through hole and the concave portion on the upper surface of the lid. The elastic wave device according to claim 1;
A mounting substrate having a plurality of mounting pads on the upper surface;
The elastic wave device joins the mounting pad and the support member exposed from the through hole of the lid with a conductive bonding material in a state where the upper surfaces of the mounting substrate face each other. An electronic component that is mounted and coated with an exterior resin. The elastic wave device according to any one of claims 2 to 4,
A mounting substrate having a plurality of mounting pads on the upper surface;
The elastic wave device is mounted by bonding the mounting pad and the through conductor with a conductive bonding material in a state where the upper surfaces of the mounting substrate face each other, and is covered with an exterior resin. Electronic components. Forming an excitation electrode and a plurality of electrode pads electrically connected to the excitation electrode on an upper surface of the element substrate;
Forming a plurality of support members made of a conductive material disposed on the element substrate as a whole so as to surround the excitation electrode and connected to the electrode pad in a state having a gap;
After a film made of a photosensitive insulating material is overlaid on the plurality of support members so as to cover the excitation electrode, a through hole exposing a part of the support member is formed by exposing and developing the film. Forming a lid with
Forming a sealing member made of an insulating material so as to close a gap between the adjacent supporting members. The method for manufacturing an acoustic wave device according to claim 7, further comprising a step of forming a through conductor filling the through hole by a plating method.