JP6385883B2 - Module and module manufacturing method - Google Patents

Description

  The present invention relates to a module in which an acoustic wave chip is built in a multilayer wiring board and a method for manufacturing the module.

  2. Description of the Related Art Elastic wave devices using elastic waves are used in filters and duplexers used in mobile communication devices such as mobile phones. Further, along with miniaturization of mobile communication devices, miniaturization of modules on which acoustic wave devices are mounted is required. In order to reduce the size of the module, it is known to incorporate an elastic wave device in a multilayer wiring board (for example, Patent Documents 1 to 3). A module in which a semiconductor element is incorporated in an electrically insulating base material is also known (for example, Patent Document 4).

JP 2014-11570 A JP 2014-90340 A JP 2014-154941 A JP-A-2005-39227

  The functional part that excites the elastic wave is exposed to the air gap and hermetically sealed so that the vibration is not hindered. For example, an acoustic wave device is known in which a functional unit is exposed to a gap by flip chip mounting an acoustic wave chip on a mounting substrate, and the acoustic wave chip is sealed with a sealing portion provided on the mounting substrate. . However, when a module is formed by incorporating such an acoustic wave device in a multilayer wiring board, the module becomes large.

  The present invention has been made in view of the above problems, and an object thereof is to provide a module that can be miniaturized and a method for manufacturing the module.

The present invention relates to a multilayer wiring board in which a plurality of insulating layers and a plurality of wiring layers are laminated, and an acoustic wave chip provided in the multilayer wiring board and provided with a functional unit that excites an acoustic wave on the main surface of the substrate. And the elastic wave chip surrounds the functional part and is provided on the main surface of the substrate and a direction parallel to the main surface of the substrate. And the metal layer having the same material and the same film thickness as the wiring layer sandwiched between the plurality of insulating layers at the same position in the stacking direction in the stacking direction. Is exposed to a gap and sealed, and is built in the multilayer wiring board. According to the present invention, the module can be reduced in size.

  In the above configuration, a via wiring that penetrates at least one of the plurality of insulating layers is provided, and the metal layer includes a first metal portion that covers the main surface of the substrate and a second metal that extends from the first metal portion. And the via wiring is connected to the second metal portion of the metal layer.

  The said structure WHEREIN: The said via | veer wiring can be set as the structure which is not connected to the said 1st metal part of the said metal layer.

The said structure WHEREIN: The said metal frame and the said metal layer can be set as the structure joined directly .

  In the above configuration, the main surface of the multilayer wiring substrate is provided on the main surface opposite to the metal layer with respect to the substrate, and is electrically connected to the functional unit via an electrode penetrating the substrate. It can be set as the structure provided with the made electronic component.

  The present invention provides a step of preparing an elastic wave chip provided with a functional part for exciting an elastic wave on a main surface of a substrate and a metal frame surrounding the functional part, a first insulating layer having a metal layer and an opening, The gap of the elastic wave chip is formed in the metal layer exposed at the opening of the laminate to which the functional part of the elastic wave chip is exposed, and the functional part is sealed. A step of joining a metal frame, and a multi-layer wiring that incorporates the acoustic wave chip by laminating a plurality of insulating layers and a plurality of wiring layers with the first insulating layer interposed therebetween after joining the metal frame And a step of forming a substrate. According to the present invention, the module can be reduced in size.

  In the above configuration, the step of bonding the metal frame to the metal layer is performed by bonding a metal foil to the entire lower surface of the first insulating layer having the opening, and on the metal foil exposed at the opening. The step of mounting the elastic wave chip so that the frame and the metal foil face each other, and after mounting the elastic wave chip, the metal foil is etched to be larger than the opening of the first insulating layer. The method may include a step of forming a metal layer, and a step of bonding the metal frame to the metal layer after the metal foil is etched to form the metal layer.

  In the above configuration, the method includes a step of forming a through hole penetrating at least one of the plurality of insulating layers and the first insulating layer, and a step of forming a via wiring by embedding a metal in the through hole. In the step of forming the through hole, the second metal portion of the metal layer includes a first metal portion covering the opening of the first insulating layer and a second metal portion extending from the first metal portion. The exposed through hole may be formed, and the through hole from which the first metal portion is exposed may not be formed.

  In the above configuration, before forming the multilayer wiring board, a step of filling a space between the substrate, the metal frame, and the first insulating layer in the opening of the first insulating layer with a second insulating layer It can be set as the structure provided.

  According to the present invention, the module can be miniaturized.

FIG. 1 is a cross-sectional view illustrating the module according to the first embodiment. FIG. 2 is a plan view showing the acoustic wave chip. 3 is a cross-sectional view taken along a line AA in FIG. FIG. 4A to FIG. 4D are cross-sectional views (part 1) showing the module manufacturing method according to the first embodiment. FIG. 5A to FIG. 5D are cross-sectional views (part 2) illustrating the method for manufacturing the module according to the first embodiment. FIG. 6 is a cross-sectional view (part 3) illustrating the method for manufacturing the module according to the first embodiment. FIG. 7A to FIG. 7C are cross-sectional views (part 4) illustrating the method for manufacturing the module according to the first embodiment. FIG. 8A and FIG. 8B are cross-sectional views (part 5) illustrating the method for manufacturing the module according to the first embodiment. FIG. 9A to FIG. 9C are plan views showing the module manufacturing method according to the first embodiment. FIG. 10 is a cross-sectional view showing a module according to Comparative Example 1. FIG. 11 is a cross-sectional view illustrating the module according to the second embodiment. 12 is a cross-sectional view taken along the line AA in FIG. FIG. 13A to FIG. 13C are cross-sectional views illustrating the module manufacturing method according to the second embodiment. FIG. 14 is a cross-sectional view showing a piezoelectric thin film resonator.

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

  FIG. 1 is a cross-sectional view illustrating a module 100 according to the first embodiment. As illustrated in FIG. 1, the module 100 according to the first embodiment includes a multilayer wiring board 10, an acoustic wave chip 40 built in the multilayer wiring board 10 (that is, disposed in the multilayer wiring board 10), and the multilayer wiring board 10. And an electronic component 60 mounted on the upper surface.

  The multilayer wiring board 10 is formed by laminating a plurality of insulating layers 12, 14, 16, 18, 20 and a plurality of wiring layers 22, 24, 26, 28, 30, 32. The plurality of wiring layers are electrically connected to each other by via wiring 34 that is a wiring penetrating the insulating layer. The insulating layers 12 to 20 are made of, for example, an epoxy resin, a polyimide resin, or a thermoplastic liquid crystal polymer sheet. The wiring layers 22 to 32 are made of a metal such as copper, for example.

  The acoustic wave chip 40 is, for example, a surface acoustic wave chip. FIG. 2 is a plan view showing the acoustic wave chip 40. As shown in FIG. 2, the acoustic wave chip 40 has an IDT (Interdigital Transducer) 44 and a reflector 46 formed on the main surface of the piezoelectric substrate 42. Hereinafter, the main surface of the piezoelectric substrate 42 on which the IDT 44 is formed is referred to as an upper surface, and the main surface opposite to the upper surface is referred to as a lower surface. The piezoelectric substrate 42 is, for example, a lithium tantalate substrate or a lithium niobate substrate. The IDT 44 is a functional unit that excites an elastic wave in or on the surface of the piezoelectric substrate 42. The reflector 46 reflects elastic waves. The IDT 44 and the reflector 46 form an acoustic wave element 48 such as a resonator. The IDT 44 and the reflector 46 are made of metal such as aluminum, copper, or aluminum to which copper is added, for example. In the acoustic wave chip 40, a plurality of acoustic wave elements 48 are combined to form a filter and a duplexer.

  A wiring 50 and an electrode 52 are formed on the upper surface of the piezoelectric substrate 42. The wiring 50 electrically connects the acoustic wave elements 48 and / or the acoustic wave element 48 and the electrode 52. The electrode 52 is a via electrode provided through the piezoelectric substrate 42 (see FIG. 1). The wiring 50 is a metal film in which, for example, a titanium film and a gold film are stacked. The electrode 52 is a metal film such as a copper film, for example. The plurality of acoustic wave elements 48 formed on the upper surface of the piezoelectric substrate 42 are connected in series via the wiring 50 between the input electrode IN and the output electrode OUT.

  A metal frame 54 is formed on the upper surface of the piezoelectric substrate 42. The metal frame 54 is formed on the outer periphery of the piezoelectric substrate 42 so as to collectively surround the plurality of acoustic wave elements 48, the wiring 50, and the electrodes 52. The metal frame 54 is a columnar metal layer such as gold. Further, the metal frame 54 is electrically connected to the reflector 46 via the wiring 50.

  As shown in FIG. 1, the metal frame 54 of the acoustic wave chip 40 built in the multilayer wiring board 10 is bonded to the metal layer 36 formed in the multilayer wiring board 10. As a result, a gap 38 in which the IDT 44 is exposed is formed between the piezoelectric substrate 42 and the metal layer 36. The IDT 44 is hermetically sealed by the metal frame 54 and the metal layer 36. The metal layer 36 is electrically connected to the wiring layer 32 via the via wiring 34. The metal layer 36 is formed of a metal such as copper, for example.

  3 is a cross-sectional view taken along a line AA in FIG. In FIG. 3, the metal layer 36 is shown through the insulating layer 16, and the via wiring 34 is not shown. As shown in FIG. 3, the metal layer 36 has a larger shape than the piezoelectric substrate 42 in a direction parallel to the upper and lower surfaces of the piezoelectric substrate 42.

  As shown in FIG. 1, the electronic component 60 mounted on the upper surface of the multilayer wiring board 10 includes, for example, a chip component such as a resistance element, an inductor, or a capacitor, and a power amplifier, an antenna switch, or a high frequency IC (Integrated Circuit). It is comprised from active elements, such as. The wiring layer 22 formed on the upper surface of the multilayer wiring board 10 functions as a terminal for mounting the electronic component 60 as described above. The electronic component 60 is fixed to the wiring layer 22 by solder 62, for example. The electronic component 60 is electrically connected to the acoustic wave chip 40 (that is, the acoustic wave element 48) via the via wiring 34 or the like. The electronic component 60 is sealed with a mold resin 64.

  The wiring layer 32 formed on the lower surface of the multilayer wiring board 10 functions as a terminal for external connection in the module. In other words, the module 100 according to the first embodiment is electrically connected to terminals and the like on the motherboard of the electronic device through the wiring layer 32 formed on the lower surface of the multilayer wiring board 10.

  Next, a method for manufacturing the module according to the first embodiment will be described. FIG. 4A to FIG. 8B are cross-sectional views illustrating the module manufacturing method according to the first embodiment. FIG. 9A to FIG. 9C are plan views showing the module manufacturing method according to the first embodiment.

  As shown in FIG. 4A, a laminate 70 in which a metal foil 72 is bonded to the entire lower surface of the insulating layer 16 is prepared. The laminated body 70 is formed, for example, by bonding the insulating layer 16 and the metal foil 72 with an adhesive, or by applying and solidifying the liquid insulating layer 16 on the metal foil 72. It may be formed by any method. The thickness of the insulating layer 16 is, for example, about 100 μm to 200 μm, and the thickness of the metal foil 72 is, for example, about 5 μm to 20 μm.

  As shown in FIGS. 4B and 9A, the insulating layer 16 in the region where the acoustic wave chip 40 is mounted is removed to form an opening 74 where the metal foil 72 is exposed. The insulating layer 16 can be removed by, for example, wet etching or dry etching.

  As shown in FIGS. 4C and 9B, the metal foil in the opening 74 of the insulating layer 16 is prepared so that the elastic wave chip 40 prepared in advance is opposed to the metal foil 72. The metal frame 54 and the metal foil 72 are thermocompression bonded. The acoustic wave chip 40 can be formed using a known means. For example, the IDT 44 and the reflector 46 of the acoustic wave chip 40 can be formed using a vapor deposition method and a lift-off method, and the electrode 52 and the metal frame 54 can be formed using an electrolytic plating method. In addition, after mounting the acoustic wave chip 40 on the metal foil 72, the lower surface of the piezoelectric substrate 42 is flush with the upper surface of the insulating layer 16, or the metal foil 72 side of the upper surface of the insulating layer 16. It is preferable that it is located in.

  As shown in FIG. 4D, the insulating layer 16 a is formed by embedding a resin around the acoustic wave chip 40 in the opening 74 of the insulating layer 16. That is, the insulating layer 16 a is formed by being embedded between the piezoelectric substrate 42 and the metal frame 54 in the opening 74 of the insulating layer 16 and the insulating layer 16. In the drawings other than FIG. 4D and FIG. 5A, the insulating layer 16a is also shown as the insulating layer 16.

  As shown in FIGS. 5A and 9C, the metal foil 72 is etched to form the metal layer 36 that is slightly larger than the opening 74 of the insulating layer 16 (that is, the outer contour of the insulating layer 16a). At the same time, the wiring layer 28 is formed in a region where the via wiring 34 is formed. Thereby, the laminated body 70 becomes a laminated body in which the metal layer 36 and the insulating layer 16 are joined. The reason for etching the metal foil 72 is that the signal wiring cannot be extended from the upper surface to the lower surface of the multilayer wiring board 10 unless the metal foil 72 is etched. On the other hand, when the metal layer 36 formed by etching the metal foil 72 becomes smaller than the opening 74 of the insulating layer 16, the metal layer 36 may be separated from the insulating layer 16. The shape is slightly larger than the opening 74. Therefore, it is preferable that the size of the metal layer 36 is a size that can maintain a bonding state with the insulating layer 16. In FIG. 9C, the metal layer 36 is shown through the insulating layer 16.

  As shown in FIG. 5B, the acoustic wave chip 40 and the metal layer 36 are heated and pressurized from above and below using a support 76. Thereby, the metal frame 54 and the metal layer 36 are joined, and the IDT 44 is exposed to the gap 38 and hermetically sealed.

  As shown in FIG. 5C, a through-hole 78 that penetrates the insulating layer 16 and exposes the upper surface of the wiring layer 28 is formed. The through hole 78 can be formed, for example, by irradiating the insulating layer 16 with laser light.

  As shown in FIG. 5D, the via wiring 34 is formed by embedding a metal (for example, copper) in the through hole 78. The via wiring 34 can be formed, for example, by first forming a seed metal using an electroless plating method, and then using an electroplating method using the seed metal as a power supply line. A plating layer is also formed on the upper surface of the insulating layer 16. By forming a resist film or the like that covers the metal layer 36 and the wiring layer 28 on the lower surface of the insulating layer 16, it is possible to suppress the formation of a plating layer on the lower surface of the insulating layer 16. Thereafter, the wiring layer 26 is patterned by performing an etching process on the plating layer formed on the upper surface of the insulating layer 16 using, for example, a resist layer (not shown) as a mask.

  As shown in FIG. 6, the prepreg insulating layer 14 and the wiring layer 24 are sequentially arranged on the upper surface side of the insulating layer 16, and the prepreg insulating layer 18 and the wiring layer 30 are sequentially arranged on the lower surface side of the insulating layer 16. . Thereafter, the insulating layers 14 and 18 and the wiring layers 24 and 30 are heated, and the insulating layers 14 and 18 and the wiring layers 24 and 30 are pressed toward the insulating layer 16 using the support 80. As a result, the insulating layers 14 and 18 and the wiring layers 24 and 30 are pressure-bonded to the insulating layer 16 as shown in FIG.

  Next, as shown in FIG. 7B, openings are formed in the wiring layers 24 and 30 by performing an etching process on the wiring layers 24 and 30 using, for example, a resist layer (not shown) as a mask. By irradiating the insulating layers 14 and 18 exposed through the openings with, for example, laser light, through holes 82 penetrating the insulating layers 14 and 18 are formed. As a result, the wiring layers 26 and 28 are exposed.

  As shown in FIG. 7C, a metal (for example, copper) is embedded in the through hole 82 to form the via wiring 34. The via wiring 34 can be formed, for example, by first forming a seed metal using an electroless plating method, and then using an electroplating method using the seed metal as a power supply line. Further, since plating layers are also formed on the upper surface of the insulating layer 14 and the lower surface of the insulating layer 18, the wiring layers 24 and 30 are formed again on the entire upper surface of the insulating layer 14 and the entire lower surface of the insulating layer 18.

  As shown in FIG. 8A, the wiring layers 24 and 30 are patterned into a desired shape by etching the wiring layers 24 and 30 using, for example, a resist layer (not shown) as a mask.

  Next, as shown in FIG. 8B, the same or equivalent processing as the processing described with reference to FIGS. 6 to 7C is repeated to form the multilayer wiring board 10 in which the acoustic wave chip 40 is built. Thereafter, the electronic component 60 is mounted on the wiring layer 22 on the upper surface of the multilayer wiring board 10 by supplying solder 62 and reflowing, and then the electronic component 60 is sealed with a mold resin 64, as shown in FIG. A module 100 is formed.

  Here, in describing the effect of the module 100 of the first embodiment, the module 500 of the first comparative example will be described first. FIG. 10 is a cross-sectional view illustrating a module 500 according to the first comparative example. As shown in FIG. 10, the module 500 of Comparative Example 1 has the acoustic wave device 400 built in the multilayer wiring board 300. In the acoustic wave device 400, an acoustic wave chip 406 having an IDT 404 or the like formed on the main surface of the piezoelectric substrate 402 is flip-chip mounted on the mounting substrate 410 using bumps 408. The acoustic wave chip 406 is sealed by a sealing portion 416 formed of a solder 412 and a lid 414 formed on the mounting substrate 410. A metal film 418 such as nickel is formed on the surface of the sealing portion 416.

  In the module 500 of Comparative Example 1, the acoustic wave device 400 built in the multilayer wiring board 300 includes a sealing portion 416 in which the acoustic wave chip 406 is flip-chip mounted on the mounting substrate 410 and formed on the mounting substrate 410. It has a sealed structure. For this reason, the elastic wave device 400 has a relatively large shape. Therefore, the module 500 in which such an acoustic wave device 400 is built in the multilayer wiring board 300 has a relatively large shape.

  On the other hand, in the module 100 according to the first embodiment, as shown in FIG. 1, the acoustic wave chip 40 includes a metal frame 54 provided on the upper surface of the piezoelectric substrate 42 so as to surround the IDT 44 and a metal layer provided on the multilayer wiring substrate 10. As a result, the IDT 44 is exposed and sealed in the gap 38 and is built in the multilayer wiring board 10. Thereby, the module 100 can be reduced in size (for example, low-profile). Moreover, the module 100 of Example 1 is formed including the following processes. That is, the void 38 where the IDT 44 is exposed is formed in the metal layer 36 exposed at the opening 74 of the laminate 70 in which the metal layer 36 and the insulating layer 16 having the opening 74 are laminated, and the IDT 44 is sealed. Then, the metal frame 54 of the acoustic wave chip 40 is joined (FIG. 5B). Thereafter, a plurality of insulating layers 12, 14, 18, 20 and a plurality of wiring layers 22, 24, 30, 32 are stacked with the insulating layer 16 interposed therebetween to form the multilayer wiring substrate 10 containing the acoustic wave chip 40. (FIG. 8B). With such a manufacturing method, as shown in FIGS. 1 and 3, the metal layer 36 has a larger shape than the piezoelectric substrate 42 in a direction parallel to the upper surface of the piezoelectric substrate 42.

  Moreover, according to Example 1, joining the metal frame 54 to the metal layer 36 is performed including the following processes. That is, the metal foil 72 is bonded to the entire lower surface of the insulating layer 16 having the opening 74, and the elastic wave chip 40 is placed on the metal foil 72 exposed through the opening 74 so that the metal frame 54 and the metal foil 72 face each other. It is mounted (FIG. 4C). Thereafter, the metal foil 72 is etched to form a metal layer 36 larger than the opening 74 of the insulating layer 16 (FIG. 5A). Thereafter, the metal frame 54 is joined to the metal layer 36 (FIG. 5B). Accordingly, since the acoustic wave chip 40 is mounted on the metal foil 72 bonded to the entire lower surface of the insulating layer 16, it is possible to suppress the metal foil 72 from being peeled off from the insulating layer 16 due to an impact at that time.

  Further, according to the first embodiment, as shown in FIG. 1, the electronic component 60 is provided on the upper surface of the multilayer wiring substrate 10 (that is, the main surface opposite to the metal layer 36 with respect to the piezoelectric substrate 42). Yes. The electronic component 60 is electrically connected to the IDT 44 via an electrode 52 that penetrates the piezoelectric substrate 42. Thereby, the wiring (via wiring and wiring layer) connecting the IDT 44 and the electronic component 60 can be shortened, and the characteristics can be improved.

  Further, according to the first embodiment, as shown in FIG. 4D, the insulating layer 16 a is embedded between the piezoelectric substrate 42 and the metal frame 54 and the insulating layer 16 in the opening 74 of the insulating layer 16. . Thereby, it can suppress that an extra cavity is formed in the multilayer wiring board 10, and can improve the intensity | strength of a module.

  Further, according to the first embodiment, the metal layer 36 is connected to the wiring layer 32 through the via wiring 34. Since the wiring layer 32 functions as a terminal for external connection, the metal layer 36 can be connected to the ground potential. Thereby, IDT44 etc. can be shielded from an external electromagnetic field. Further, the heat generated in the elastic wave chip 40 can be released through the metal layer 36.

  In Example 1, the metal foil 72 of the laminate 70 in which the metal foil 72 and the insulating layer 16 having the opening 74 are joined is etched to form the metal layer 36, and then exposed through the opening 74. The elastic wave chip 40 may be mounted on the metal layer 36.

  FIG. 11 is a cross-sectional view illustrating the module 200 according to the second embodiment. 12 is a cross-sectional view taken along the line AA in FIG. In FIG. 12, the metal layer 36 is shown through the insulating layer 16, and the via wiring 34 is not shown.

  In the module 200 of the second embodiment, as shown in FIGS. 11 and 12, the metal layer 36 includes a first metal part 36a covering the upper surface of the piezoelectric substrate 42 and a second metal part drawn from the first metal part 36a. 36b. The first metal part 36a and the second metal part 36b are formed on the same surface with the same material and the same film thickness. The first metal portion 36a is not limited to a rectangular shape, but preferably has a shape similar to that of the piezoelectric substrate 42. A via wiring 34 is connected to the second metal portion 36 b of the metal layer 36. On the other hand, the via wiring 34 is not connected to the first metal portion 36 a of the metal layer 36. The metal layer 36 is electrically connected to the wiring layers 22 and 32 of the multilayer wiring board 10 through the via wiring 34 connected to the second metal portion 36b. Other configurations are the same as or equivalent to those of the first embodiment, and thus description thereof is omitted.

  FIG. 13A to FIG. 13C are cross-sectional views illustrating a method for manufacturing the module 200 according to the second embodiment. In the manufacturing method of the module 200 according to the second embodiment, first, the same or equivalent process as the process described in the first embodiment with reference to FIGS. Thereafter, as shown in FIG. 13A, the metal foil 72 is etched, and the first metal portion 36a having a shape slightly larger than the opening 74 of the insulating layer 16 (that is, the outer contour of the insulating layer 16a); A metal layer 36 having a second metal portion 36b extending from the first metal portion 36a is formed. Simultaneously with the formation of the metal layer 36, the wiring layer 28 is formed in the region where the via wiring 34 is to be formed. Thereafter, the same or equivalent process as that described in FIG. 5B of the first embodiment is performed to join the metal frame 54 to the metal layer 36.

  Next, as shown in FIG. 13B, a through hole 78 that penetrates the insulating layer 16 and exposes the upper surface of the second metal portion 36 b of the metal layer 36, and a through hole 78 that exposes the upper surface of the wiring layer 28. And form. The through hole 78 can be formed, for example, by irradiating the insulating layer 16 with laser light.

  As shown in FIG. 13C, a metal (for example, copper) is embedded in the through hole 78 to form the via wiring 34, and the patterned wiring layer 26 is formed on the upper surface of the insulating layer 16. The via wiring 34 and the wiring layer 26 can be formed by the same or equivalent process as the process described in FIG.

  Thereafter, the module 200 of the second embodiment is formed by performing the same or equivalent process as the process described in FIGS. 6 to 8B of the first embodiment.

  According to the second embodiment, as shown in FIGS. 11 and 12, the metal layer 36 includes a first metal portion 36a covering the upper surface of the piezoelectric substrate 42, a second metal portion 36b extending from the first metal portion 36a, Have The via wiring 34 is connected to the second metal portion 36 b of the metal layer 36. Thereby, it is possible to make electrical contact with the metal layer 36 from the upper surface side and / or the lower surface side of the multilayer wiring board 10. In FIG. 11, the via wiring 34 is connected to both the upper surface and the lower surface of the second metal portion 36 b of the metal layer 36, but it may be connected to at least one of them.

  Further, according to the second embodiment, as illustrated in FIG. 11, the via wiring 34 is connected to the second metal portion 36 b of the metal layer 36, but is connected to the first metal portion 36 a of the metal layer 36. Not. The via wiring is formed by forming a through hole penetrating at least one of the plurality of insulating layers and embedding a metal in the through hole. Therefore, the via hole in which the second metal portion 36b of the metal layer 36 is exposed is formed. However, the through hole in which the first metal portion 36a is exposed is not formed. If the via wiring 34 is formed in the vicinity of the acoustic wave chip 40, the effect of forming the through hole may affect the acoustic wave chip 40, resulting in deterioration of characteristics and / or reliability. However, in Example 2, since the via wiring 34 connected to the first metal portion 36a of the metal layer 36 is not formed, the through hole is formed away from the acoustic wave chip 40, and the characteristics and / Or deterioration of reliability can be suppressed.

  For example, in Example 2, since the through-hole is formed using laser light, there is a concern about the influence of the heat of the laser, but since the through-hole is formed away from the acoustic wave chip 40, the heat of the laser Can be suppressed from affecting the acoustic wave chip 40. The through hole is not limited to being formed using laser light, and may be formed by, for example, etching. Even in this case, since the through hole is formed away from the elastic wave chip 40, it is possible to suppress the influence of etching on the elastic wave chip 40.

  Further, according to the second embodiment, as shown in FIG. 13A, the metal layer 36 having the first metal portion 36 a and the second metal portion 36 b is formed by etching the metal foil 72. For this reason, the 1st metal part 36a and the 2nd metal part 36b are formed with the same material, and have the same film thickness. Thereby, the metal layer 36 which has the 1st metal part 36a and the 2nd metal part 36b can be formed easily.

  Further, according to the second embodiment, the metal layer 36 and the electronic component 60 can be connected to the ground potential via the same via wiring 34, so that via wiring and wiring layers can be reduced.

  In the second embodiment, the via wiring 34 connected to the second metal portion 36b of the metal layer 36 penetrates at least one of the plurality of insulating layers 12, 14, 16, 18, and 20. If it is.

  In the first and second embodiments, the acoustic wave chip 40 may be a case where the piezoelectric substrate 42 is bonded onto the support substrate. In this case, the electrode 52 is formed through the piezoelectric substrate 42 and the support substrate.

  In the first and second embodiments, the acoustic wave chip 40 is not limited to an acoustic wave chip using a surface acoustic wave, and an acoustic wave chip using a bulk wave (for example, a piezoelectric thin film resonator) may be used. it can. FIG. 14 is a cross-sectional view showing a piezoelectric thin film resonator. As shown in FIG. 14, in the piezoelectric thin film resonator, a lower electrode 88, a piezoelectric film 90, and an upper electrode 92 are laminated in this order on a substrate 86 such as silicon, quartz, glass, ceramic, or gallium arsenide. For the lower electrode 88 and the upper electrode 92, a single-layer film such as chromium, ruthenium, aluminum, titanium, copper, molybdenum, tungsten, tantalum, platinum, rhodium, or iridium, or a stacked film thereof can be used. As the piezoelectric film 90, an aluminum nitride film, a zinc oxide film, a lead zirconate titanate film, a lead titanate film, or the like can be used.

  A region where the lower electrode 88 and the upper electrode 92 overlap with the piezoelectric film 90 interposed therebetween is a resonance region 94. The resonance region 94 has, for example, an elliptical shape or a polygonal shape, and is a region (functional part) where an elastic wave in the thickness longitudinal vibration mode is excited. A recess serving as a gap 96 is formed on the upper surface of the substrate 86 below the resonance region 94. The recess may be formed through the substrate 86. Further, the upper surface of the substrate 86 may have a flat shape, and a dome-shaped gap may be formed between the upper surface of the substrate 86 and the lower electrode 88. Moreover, the case where the acoustic reflection film which reflects an elastic wave instead of a space | gap is formed may be sufficient.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Multilayer wiring board 12-20 Insulating layer 16a Insulating layer 22-32 Wiring layer 34 Via wiring 36 Metal layer 36a 1st metal part 36b 2nd metal part 38, 96 Cavity 40 Elastic wave chip 42 Piezoelectric board 44 IDT
DESCRIPTION OF SYMBOLS 50 Wiring 52 Electrode 54 Metal frame 60 Electronic component 70 Laminate 72 Metal foil 74 Opening 78, 82 Through-hole 86 Substrate 88 Lower electrode 90 Piezoelectric film 92 Upper electrode 94 Resonance region

Claims (9)

A multilayer wiring board in which a plurality of insulating layers and a plurality of wiring layers are laminated;
An acoustic wave chip provided in the multilayer wiring board and provided with a functional unit for exciting an acoustic wave on a main surface of the board;
The elastic wave chip surrounds the functional part and is provided on the main surface of the substrate and on the multilayer wiring substrate, and is larger than the substrate in a direction parallel to the main surface of the substrate. The functional part is exposed to the gap by joining the metal layer having the same material and the same film thickness as the wiring layer sandwiched between the plurality of insulating layers at the same position in the stacking direction. And a module embedded in the multilayer wiring board. A via wiring penetrating at least one of the plurality of insulating layers;
The metal layer has a first metal part that covers the main surface of the substrate and a second metal part that extends from the first metal part,
The module according to claim 1, wherein the via wiring is connected to the second metal portion of the metal layer.   The module according to claim 2, wherein the via wiring is not connected to the first metal portion of the metal layer. The module according to any one of claims 1 to 3, wherein the metal frame and the metal layer are directly joined .   An electronic component that is provided on the main surface of the multilayer wiring substrate opposite to the metal layer with respect to the substrate and is electrically connected to the functional unit via an electrode that penetrates the substrate The module according to claim 1, further comprising: Preparing an elastic wave chip provided with a functional part that excites an elastic wave on a main surface of the substrate and a metal frame surrounding the functional part;
A gap exposing the functional part of the acoustic wave chip is formed in the metal layer exposed at the opening of the laminate in which the metal layer and the first insulating layer having the opening are joined, and the functional part is sealed. The step of joining the metal frame of the acoustic wave chip,
Forming a multilayer wiring board containing the acoustic wave chip by laminating a plurality of insulating layers and a plurality of wiring layers with the first insulating layer interposed therebetween after joining the metal frame. A method for manufacturing a module. The step of joining the metal frame to the metal layer includes:
A metal foil is bonded to the entire lower surface of the first insulating layer having the opening, and the elastic wave chip is mounted on the metal foil exposed through the opening so that the metal frame and the metal foil face each other. And a process of
After mounting the acoustic wave chip, etching the metal foil to form the metal layer larger than the opening of the first insulating layer;
The method of manufacturing a module according to claim 6, further comprising: joining the metal frame body to the metal layer after etching the metal foil to form the metal layer. Forming a through hole penetrating at least one of the plurality of insulating layers and the first insulating layer;
Forming a via wiring by embedding a metal in the through hole, and
The step of forming the through hole exposes the second metal part of the metal layer having a first metal part covering the opening of the first insulating layer and a second metal part extending from the first metal part. The method for manufacturing a module according to claim 6 or 7, wherein the through hole is formed, and the through hole from which the first metal portion is exposed is not formed.   Before forming the multilayer wiring board, a step of filling a space between the substrate and the metal frame and the first insulating layer in the opening of the first insulating layer with a second insulating layer is provided. A method for manufacturing a module according to any one of claims 6 to 8.

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