Acoustic wave device and module having the acoustic wave device

Abstract

To provide an acoustic wave device which can be suppressed in deterioration of characteristic of a first reception filter and characteristic of a second transmission filter.SOLUTION: An acoustic wave device comprises: a package substrate; an antenna pad formed on the package substrate; a plurality of transmission pads; a plurality of reception pads; a plurality of ground pads; a first transmission filter that is connected to one of the antenna pad and each transmission pad; a first reception filter that is connected to one of the antenna pad and each reception pad; a second transmission filter that is connected to the other one of the antenna pad and each transmission pad; and a second reception filter that is connected to the other one of the antenna pad and each reception pad. The second transmission filter includes: a first chip connected to the antenna pad; and a second chip that is connected to one of the plurality of transmission pads.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an acoustic wave device and a module including the acoustic wave device. [Background technology]

[0002] Patent Document 1 discloses an acoustic wave device, which is a quadplexer, including a first transmit filter, a first receive filter, a second transmit filter, and a second receive filter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-054986 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the acoustic wave device described in Patent Document 1, if the piezoelectric layer of the second transmit filter is relatively thin, the characteristics of the second transmit filter are degraded, whereas if the piezoelectric layer of the second transmit filter is relatively thick, the characteristics of the first receive filter are degraded.

[0005] The present disclosure has been made to solve the above-mentioned problems. An object of the present disclosure is to provide an acoustic wave device capable of suppressing deterioration of the characteristics of a first reception filter and a second transmission filter, and a module including the acoustic wave device. [Means for solving the problem]

[0006] The acoustic wave device according to the present disclosure comprises: A package substrate; an antenna pad, a plurality of transmitting pads, a plurality of receiving pads, and a plurality of ground pads formed on the package substrate; a first transmitting filter mounted on the package substrate and connected to the antenna pad and one of the transmitting pads; a first receiving filter mounted on the package substrate and connected to the antenna pad and one of the receiving pads; a second transmission filter mounted on the package substrate and connected to the antenna pad and another of the transmission pads; a second receiving filter mounted on the package substrate and connected to the antenna pad and another of the receiving pads; Equipped with the second transmit filter includes a first chip connected to the antenna pad; a second chip connected to one of the plurality of transmit pads; Includes:

[0007] The first chip and the second chip each include a piezoelectric layer formed on a support substrate; In one aspect of the present disclosure, the thickness value of the piezoelectric layer of the second chip is greater than the thickness value of the piezoelectric layer of the first chip.

[0008] According to one aspect of the present disclosure, a transmission band of the second transmission filter is lower than a transmission band of the first transmission filter.

[0009] In one embodiment of the present disclosure, the thickness value of the piezoelectric layer of the second chip is greater than the thickness value of the piezoelectric layer of a chip constituting the second receive filter.

[0010] In one embodiment of the present disclosure, the average value of the thickness of the piezoelectric layer of the first chip and the thickness of the piezoelectric layer of the second chip is greater than the value of the thickness of the piezoelectric layer of a chip constituting the second receive filter.

[0011] In one aspect of the present disclosure, the piezoelectric layer is formed of lithium tantalate or lithium niobate.

[0012] In one aspect of the present disclosure, the support substrate is made of sapphire, silicon, alumina, spinel, quartz, or glass.

[0013] One embodiment of the present disclosure is that the antenna pad is formed in a central region of the package substrate, overlaps with a portion of the first transmitting filter, a portion of the first receiving filter, a portion of the second receiving filter, and a portion of the first chip in a top view, and does not overlap with the second chip in a top view.

[0014] the second transmit filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, In one aspect of the present disclosure, the resonators connected to the terminal of the first chip on the second chip side are a series resonator and a parallel resonator.

[0015] the second transmit filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, In one aspect of the present disclosure, the resonator connected to the terminal of the second chip on the first chip side is a series resonator.

[0016] A module including the acoustic wave device is one aspect of the present disclosure. Effect of the Invention

[0017] According to the present disclosure, it is possible to suppress deterioration of the characteristics of the first receiving filter and the second transmitting filter. [Brief description of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of an acoustic wave device according to a first embodiment. [Diagram 2] 3 is a diagram illustrating an example of an acoustic wave element of the acoustic wave device according to the first embodiment. [Diagram 3] 3 is a plan view of a plurality of chip substrates of the acoustic wave device according to the first embodiment and a plurality of comparative chip substrates viewed from above. FIG. [Figure 4] 2 is a plan view of a package substrate of the acoustic wave device according to the first embodiment. FIG. [Diagram 5] 2 is a circuit diagram corresponding to a chip substrate of the acoustic wave device according to the first embodiment. FIG. [Figure 6] 5 is a diagram illustrating the attenuation of a first transmission filter, a first reception filter, a second transmission filter, and a second reception filter of the acoustic wave device according to the first embodiment and a first comparative example. FIG. [Figure 7] 6 is a diagram illustrating the insertion loss of a second transmission filter of the acoustic wave device according to the first embodiment and a first comparative example. FIG. [Figure 8] 5 is a diagram illustrating the attenuation of a second transmission filter in a pass band of a first reception filter of the acoustic wave device according to the first embodiment and a first comparative example. FIG. [Figure 9] 10 is a diagram illustrating a voltage standing wave ratio (VSWR) of a second transmission filter of the acoustic wave device according to the first embodiment and a first comparative example. FIG. [Figure 10] 5 is a diagram illustrating the insertion loss of a first receive filter of the acoustic wave device according to the first embodiment and a first comparative example. FIG. [Figure 11] 11 is a diagram illustrating cross isolation between a second transmit filter and a first receive filter in a pass band of the first receive filter of the acoustic wave device according to the first embodiment and a first comparative example. FIG. [Figure 12] 10 is a diagram illustrating the attenuation of a first transmission filter, a first reception filter, a second transmission filter, and a second reception filter of the acoustic wave device in the first embodiment and a second comparative example. FIG. [Figure 13] 11 is a diagram illustrating the insertion loss of a second transmission filter of the acoustic wave device according to the first embodiment and a second comparative example. FIG. [Figure 14] 11 is a diagram illustrating the attenuation of a second transmission filter in a pass band of a first reception filter of the acoustic wave device according to the first embodiment and a second comparative example. FIG. [Figure 15] 13 is a diagram illustrating a voltage standing wave ratio (VSWR) of a second transmission filter of the acoustic wave device according to the first embodiment and a second comparative example. FIG. [Figure 16]11 is a diagram illustrating the insertion loss of a first receiving filter of the acoustic wave device according to the first embodiment and a second comparative example. FIG. [Figure 17] 13 is a diagram illustrating cross isolation between a second transmit filter and a first receive filter in the pass band of the first receive filter of the acoustic wave device in the first embodiment and a second comparative example. FIG. [Figure 18] 11 is a cross-sectional view of a module to which an acoustic wave device according to a second embodiment is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The embodiments will be described with reference to the accompanying drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals. Duplicate descriptions of the parts will be appropriately simplified or omitted.

[0020] Embodiment 1 FIG. 1 is a cross-sectional view of an acoustic wave device according to a first embodiment.

[0021] As shown in FIG. 1, an acoustic wave device 1 includes a package substrate 2, a plurality of chip substrates 3, a plurality of bumps 4, and a sealing portion 5.

[0022] For example, the package substrate 2 is a multi-layer substrate containing resin. For example, the package substrate 2 is a low temperature co-fired ceramics (LTCC) multi-layer substrate made of a plurality of dielectric layers. For example, the package substrate 2 is a high temperature co-fired ceramics (HTCC) multi-layer substrate made of a plurality of dielectric layers. For example, the package substrate 2 has a built-in passive element (not shown) such as a capacitor or an inductor.

[0023] 1, the upper surface of the package substrate 2 is a component mounting surface. A plurality of conductive pads 2A are formed on the upper surface of the package substrate 2. For example, the plurality of conductive pads 2A are made of copper.

[0024] The lower surface of the package substrate 2 is a surface to be attached to a motherboard etc. A plurality of conductive pads 2B are formed on the lower surface of the package substrate 2. For example, the plurality of conductive pads 2B are made of copper.

[0025] The multiple internal conductors 2C are built into the package substrate 2. For example, the multiple internal conductors 2C are made of copper. Each of the internal conductors 2C electrically connects the corresponding conductive pads 2A and 2B.

[0026] The multiple chip substrates 3 are mounted on the package substrate 2. The multiple chip substrates 3 face the package substrate 2. For example, each of the multiple chip substrates 3 includes at least a piezoelectric layer 3A. For example, the piezoelectric layer 3A is made of a piezoelectric single crystal such as lithium tantalate, lithium niobate, or quartz. For example, the piezoelectric layer 3A is made of piezoelectric ceramics.

[0027] Each of the multiple chip substrates 3 may include a support substrate 3B. For example, the support substrate 3B is made of sapphire, silicon, alumina, spinel, quartz, or glass. For example, the support substrate 3B is bonded to the piezoelectric layer 3A via an adhesive layer (not shown).

[0028] For example, a bandpass filter is formed on the main surface (the lower surface in FIG. 1) of each of the plurality of chip substrates 3. For example, a receiving filter or a transmitting filter is formed.

[0029] The receive filter is configured to pass electrical signals in a desired frequency band, and the transmit filter is configured to pass electrical signals in a desired frequency band.

[0030] For example, each of the multiple chip substrates 3 includes a wiring pattern 6 and multiple acoustic wave elements 7. For example, the wiring pattern 6 and the multiple acoustic wave elements 7 are formed of a metal or an alloy such as silver, aluminum, copper, titanium, or palladium. For example, the wiring pattern 6 and the multiple acoustic wave elements 7 are formed by stacking multiple metal layers. For example, the thickness of the wiring pattern 6 and the multiple acoustic wave elements 7 is 150 nm to 400 nm.

[0031] For example, a plurality of acoustic wave elements 7 receive a high frequency electric field via wiring pattern 6 to excite surface acoustic waves, and convert the surface acoustic waves into a high frequency electric field by a piezoelectric effect, thereby obtaining desired filter characteristics.

[0032] Each of the bumps 4 is made of gold, a conductive adhesive, solder, etc. For example, the height of the bumps 4 is 20 μm to 50 μm. Each of the bumps 4 electrically connects the conductive pad 2A and the wiring pattern 6 at a corresponding position.

[0033] The sealing portion 5 hermetically seals the multiple chip substrates 3 together with the package substrate 2 while leaving a space 8 between the package substrate 2 and the multiple chip substrates 3. For example, the sealing portion 5 is made of an insulating material such as a synthetic resin. The synthetic resin is an epoxy resin, a polyimide, or the like.

[0034] Next, an example of acoustic wave element 7 will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of an acoustic wave element of the acoustic wave device according to the first embodiment. In FIG.

[0035] 2, acoustic wave element 7 is a SAW (Surface Acoustic Wave) resonator. As shown in FIG 2, a pair of IDT electrodes 7A and a pair of reflectors 7B are formed on a main surface of chip substrate 3. The pair of IDT electrodes 7A and the pair of reflectors 7B are provided so as to be able to excite surface acoustic waves.

[0036] For example, the pair of IDT electrodes 7A and the pair of reflectors 7B are made of an alloy of aluminum and copper. For example, the pair of IDT electrodes 7A and the pair of reflectors 7B are made of an appropriate metal such as titanium, palladium, or silver, or an alloy thereof. For example, the pair of IDT electrodes 7A and the pair of reflectors 7B are made of a laminated metal film in which multiple metal layers are laminated.

[0037] The IDT electrode 7A includes a plurality of electrode fingers 7C and a bus bar 7D. The electrode fingers 7C are arranged with their longitudinal directions aligned. The bus bar 7D connects the electrode fingers 7C so that they face each other.

[0038] One of the pair of reflectors 7B is adjacent to one side of the pair of IDT electrodes 7A. The other of the pair of reflectors 7B is adjacent to the other side of the pair of IDT electrodes 7A. For example, the pair of IDT electrodes 7A and the pair of reflectors 7B are formed and patterned in the same process as the wiring pattern 6 (not shown in FIG. 2).

[0039] Next, the multiple chip substrates 3 will be described with reference to FIG. 3 is a plan view of a plurality of chip substrates of the acoustic wave device according to the first embodiment and a plurality of comparative chip substrates as viewed from above. In reality, each component formed on the chip substrate 3 is disposed on the back side of the page. In FIG. 3, each component is shown by a solid line for convenience.

[0040] FIG. 3A shows a plurality of chip substrates 3 of the acoustic wave device 1 according to the first embodiment.

[0041] The multiple chip substrates 3 function as a quadplexer as a whole. The chip substrate 3 at the bottom right of A in FIG. 3 functions as a first transmit filter B1Tx. For example, the first transmit filter B1Tx is a band 1 transmit filter. The chip substrate 3 at the top left of A in FIG. 3 functions as a first receive filter B1Rx. For example, the first receive filter B1Rx is a band 1 receive filter.

[0042] The chip substrate 3 at the top center and top right of A in FIG. 3 functions as a second transmit filter B3Tx. For example, the second transmit filter B3Tx is a band 3 transmit filter. The chip substrate 3 at the top center is the first chip C1. The chip substrate 3 at the top right is the second chip C2. The chip substrate 3 at the bottom left of A in FIG. 3 functions as a second receive filter B3Rx. For example, the second receive filter B3Rx is a band 3 receive filter.

[0043] The piezoelectric layer of the first transmit filter B1Tx has a thickness of 1.5 μm. The piezoelectric layer 3A of the first receive filter B1Rx has a thickness of 1.5 μm. The piezoelectric layer 3A of the second receive filter B3Rx has a thickness of 1.2 μm. The piezoelectric layer 3A of the first chip C1 has a thickness of 1.1 μm. The thickness of the piezoelectric layer 3A of the second chip C2 is greater than the thickness of the piezoelectric layer 3A of the first chip C1.

[0044] The thickness of the piezoelectric layer 3A of the second chip C2 is greater than the thickness of the piezoelectric layer 3A of the chip substrate 3 constituting the second receive filter B3Rx. Specifically, the thickness of the piezoelectric layer 3A of the second chip C2 is 1.5 μm. In this case, the average value of the thickness of the piezoelectric layer 3A of the first chip C1 and the thickness of the piezoelectric layer 3A of the second chip C2 is greater than the thickness of the piezoelectric layer 3A of the chip substrate 3 constituting the second receive filter B3Rx.

[0045] On the main surface of each of the plurality of chip substrates 3, a wiring pattern 6 and a plurality of acoustic wave elements 7 are formed.

[0046] For example, the wiring pattern 6 is formed of a metal or an alloy such as silver, aluminum, copper, titanium, or palladium. For example, the wiring pattern 6 is formed by stacking a plurality of metal layers. For example, the thickness of the wiring pattern 6 is 150 nm to 400 nm.

[0047] In the chip substrate 3 at the lower right of A in Fig. 3, the wiring pattern 6 includes four ground bump pads GND, a transmission bump pad Tx1, and an antenna bump pad ANT. These bump pads are electrically connected to the bumps 4 (not shown in Fig. 3).

[0048] In the chip substrate 3 at the upper left of A in Fig. 3, the wiring pattern 6 includes four ground bump pads GND, a receiving bump pad Rx1, and an antenna bump pad ANT. These bump pads are electrically connected to the bumps 4 (not shown in Fig. 3).

[0049] In the first chip C1, the wiring pattern 6 includes two ground bump pads GND, an antenna bump pad ANT, and a connection bump pad P1. These bump pads are electrically connected to the bumps 4 (not shown in FIG. 3).

[0050] In the second chip C2, the wiring pattern 6 includes two ground bump pads GND, a transmission bump pad Tx3, and a connection bump pad P2. These bump pads are electrically connected to the bumps 4 (not shown in FIG. 3).

[0051] In the chip substrate 3 at the lower left of A in Fig. 3, the wiring pattern 6 includes four ground bump pads GND, an antenna bump pad ANT, and a receiving bump pad Rx3. These bump pads are electrically connected to the bumps 4 (not shown in Fig. 3).

[0052] In each of the chip substrates 3, the acoustic wave elements 7 include a plurality of series resonators and a plurality of parallel resonators. The acoustic wave elements 7 are electrically connected to each other via the wiring pattern 6.

[0053] In the first transmission filter B1Tx, when a high-frequency electrical signal is input to the transmission bump pad Tx1, the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. At this time, only the electrical signal in the desired frequency band reaches the antenna bump pad ANT. As a result, only the electrical signal in the desired frequency band is output from the antenna bump pad ANT.

[0054] In the first receiving filter B1Rx, when a high-frequency electrical signal is input to the antenna bump pad ANT, the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. At this time, only the electrical signal in the desired frequency band reaches the receiving bump pad Rx1. As a result, only the electrical signal in the desired frequency band is output from the receiving bump pad Rx1.

[0055] In the second chip C2, when a high-frequency electrical signal is input to the transmitting bump pad Tx3, the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. Then, the electrical signal reaches the connecting bump pad P2. Then, the electrical signal reaches the connecting bump pad P1 through the package substrate 2.

[0056] Then, in the first chip C1, the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. At this time, only the electrical signal of the desired frequency band reaches the antenna bump pad ANT. As a result, only the electrical signal of the desired frequency band is output from the antenna bump pad ANT.

[0057] In the second receiving filter B3Rx, when a high-frequency electrical signal is input to the antenna bump pad ANT, the electrical signal passes through multiple series resonators and multiple parallel resonators. At this time, only the electrical signal in the desired frequency band reaches the receiving bump pad Rx3. As a result, only the electrical signal in the desired frequency band is output from the receiving bump pad Rx3.

[0058] FIG. 3B shows a comparative multiple chip substrate.

[0059] The multiple chip substrates are substantially similar to the multiple chip substrates 3 of the acoustic wave device 1 in the first embodiment. Specifically, the lower right chip substrate functions as a first transmit filter B1Tx. The upper left chip substrate functions as a first receive filter B1Rx. The upper right chip substrate functions as a second transmit filter B3Tx. The lower left chip substrate functions as a second receive filter B3Rx. However, the second transmit filter B3Tx is formed of a single chip substrate.

[0060] Next, the package substrate 2 will be described with reference to FIG. FIG. 4 is a plan view of a package substrate of the acoustic wave device according to the first embodiment.

[0061] 4, the package substrate 2 includes, as the conductive pad 2A in FIG. 1, an antenna pad AP, a plurality of transmitting pads TP, a plurality of receiving pads RP, a plurality of ground pads GP and a connection pad CP.

[0062] The antenna pad AP is formed in the central region of the package substrate 2. Although not shown in Fig. 4, when the first transmit filter B1Tx, the first receive filter B1Rx, the second receive filter B3Rx, and the first chip C1 are mounted on the package substrate 2, the antenna pad AP overlaps with a part of the first transmit filter B1Tx, a part of the first receive filter B1Rx, a part of the second receive filter B3Rx, and a part of the first chip C1 in a top view.

[0063] Specifically, the antenna pad AP overlaps with the antenna bump pad ANT of the first transmitting filter B1Tx, the antenna bump pad ANT of the first receiving filter B1Rx, the antenna bump pad ANT of the second receiving filter B3Rx, and the antenna bump pad ANT of the first chip C1 in a top view.

[0064] In contrast, even when the second chip C2 is mounted on the package substrate 2, the antenna pad AP does not overlap the second chip C2 in top view.

[0065] Although not shown, when the first transmit filter B1Tx, the first receive filter B1Rx, the second receive filter B3Rx, the first chip C1, and the second chip C2 are mounted on the package substrate 2, the antenna pad AP, the multiple transmit pads TP, the multiple receive pads RP, the multiple ground pads GP, and the connection pad CP are connected to bump pads at corresponding positions among the first transmit filter B1Tx, the first receive filter B1Rx, the second receive filter B3Rx, the first chip C1, and the second chip C2.

[0066] In the package substrate 2, the metal pattern having a large area other than the antenna pad AP, the multiple transmitting pads TP, the multiple receiving pads RP, the multiple ground pads GP, and the connection pads CP is a ground section. The ground section is connected to many of the ground bump pads GND of the first receiving filter B1Rx, the second receiving filter B3Rx, the first chip C1, and the second chip C2.

[0067] For example, in the lower right region of the package substrate 2, the ground pad GP is connected to the ground bump pad GND of the first transmit filter B1Tx, the transmit pad TP is connected to the transmit bump pad Tx1 of the first transmit filter B1Tx, and the antenna pad AP is connected to the antenna bump pad ANT of the first transmit filter B1Tx.

[0068] For example, in the upper left region of the package substrate 2, the ground pad GP is connected to the ground bump pad GND of the first reception filter B1Rx, the antenna pad AP is connected to the antenna bump pad ANT of the first reception filter B1Rx, and the reception pad RP is connected to the reception bump pad Rx1 of the first reception filter B1Rx.

[0069] For example, in the lower left region of the package substrate 2, the ground pad GP is connected to the ground bump pad GND of the second receive filter B3Rx. The antenna pad AP is connected to the antenna bump pad ANT of the second receive filter B3Rx. The receive pad RP is connected to the receive bump pad Rx3 of the second receive filter B3Rx.

[0070] For example, in the upper right region of the package substrate 2, the ground pad GP is connected to the ground bump pad GND of the first chip C1 or the second chip C2. The connection pad CP is connected to the connection bump pad P1 of the first chip C1 and the connection bump pad P2 of the second chip C2. The transmission pad TP is connected to the transmission bump pad Tx3 of the second chip C2. The antenna pad AP is connected to the antenna bump pad ANT of the first chip C1.

[0071] Next, the circuit configuration of the chip substrate 3 will be described with reference to FIG. FIG. 5 is a circuit diagram corresponding to the chip substrate of the acoustic wave device according to the first embodiment.

[0072] As shown in FIG. 5, the first transmit filter B1Tx, the first receive filter B1Rx, the second transmit filter B3Tx, and the second receive filter B3Rx are ladder filters including a plurality of series resonators S and a plurality of parallel resonators P.

[0073] In the first chip C1, the resonators connected to the terminal on the second chip C2 side are a series resonator S and a parallel resonator P. In the second chip C2, the resonator connected to the terminal on the first chip C1 side is the series resonator S.

[0074] Next, the results of simulating the characteristics of the acoustic wave device 1 and the first comparative example will be described with reference to Figs. 6 to 11. In the acoustic wave device 1, the piezoelectric layer 3A is lithium tantalate. The support substrate 3B is sapphire. The first comparative example is an acoustic wave device in which the second transmission filter is configured with a single chip substrate. In the first comparative example, the piezoelectric layer is lithium tantalate with a thickness of 1.5 µm. The support substrate is sapphire.

[0075] FIG. 6 illustrates the attenuation of a first transmit filter, a first receive filter, a second transmit filter, and a second receive filter in the acoustic wave device according to the first embodiment and a first comparative example.

[0076] FIG. 7 illustrates the insertion loss of the second transmission filter in the acoustic wave device according to the first embodiment and the second transmission filter in the first comparative example.

[0077] FIG. 8 illustrates the attenuation of the second transmission filter in the passband of the first reception filter of the acoustic wave device according to the first embodiment and the first comparative example.

[0078] Fig. 9 is a diagram showing the voltage standing wave ratio (VSWR) of the second transmit filter of the acoustic wave device according to the first embodiment and the first comparative example. The upper side of Fig. 9 shows the voltage standing wave ratio (VSWR) on the antenna bump pad ANT side. The lower side of Fig. 9 shows the voltage standing wave ratio (VSWR) on the transmit bump pad Tx3 side.

[0079] FIG. 10 illustrates the insertion loss of the first receiving filter of the acoustic wave device according to the first embodiment and the first comparative example.

[0080] FIG. 11 illustrates cross isolation between the second transmit filter and the first receive filter in the pass band of the first receive filter of the acoustic wave device according to the first embodiment and the first comparative example.

[0081] 6 to 11, the solid lines indicate the characteristics of the acoustic wave device 1 according to the first embodiment, and the dashed lines indicate the characteristics of the first comparative example.

[0082] In the acoustic wave device according to the first embodiment and the first comparative example, the first transmit filter B1Tx, the second transmit filter B3Tx, and the second receive filter B3Rx have substantially the same characteristics.

[0083] For example, as shown in FIG. 6, in the transmission band of band 1 (1920 MHz to 1980 MHz), the transmission band of band 3 (1710 MHz to 1785 MHz), and the reception band of band 3 (1805 MHz to 1880 MHz), the attenuation of the acoustic wave device 1 in embodiment 1 and the first comparative example are approximately the same.

[0084] For example, as shown in FIG. 7, the acoustic wave device 1 according to the first embodiment and the first comparative example have substantially the same characteristics regarding the insertion loss of the second transmitting filter B3Tx.

[0085] For example, as shown in FIG. 8, with respect to the attenuation of the second transmission filter B3Tx in the passband of the first reception filter B1Rx, the acoustic wave device 1 according to the first embodiment has better characteristics than the acoustic wave device 1 according to the first comparative example.

[0086] For example, as shown in FIG. 9, the acoustic wave device 1 according to the first embodiment and the first comparative example have substantially the same characteristics regarding the voltage standing wave ratio (VSWR) of the second transmitting filter B3Tx.

[0087] Regarding the first receive filter B1Rx, the characteristics of the acoustic wave device 1 according to the first embodiment are better than those of the first comparative example. For example, as shown in Fig. 6, in the receive band of Band 1 (2110 MHz to 2170 MHz), the characteristics of the acoustic wave device 1 according to the first embodiment are better than those of the first comparative example.

[0088] For example, as shown in FIG. 10, the acoustic wave device 1 according to the first embodiment has better characteristics in terms of the insertion loss of the first receive filter B1Rx than the characteristics of the first comparative example.

[0089] For example, as shown in FIG. 11, the acoustic wave device 1 according to the first embodiment has better cross-isolation characteristics between the second transmit filter B3Tx and the first receive filter B1Rx than the first comparative example.

[0090] Next, the results of a simulation of the characteristics of the acoustic wave device 1 and a second comparative example will be described with reference to FIGS.

[0091] In the acoustic wave device 1, the piezoelectric layer 3A is made of lithium tantalate. The support substrate 3B is made of sapphire. The second comparative example is an acoustic wave device in which the second transmission filter is configured with a single chip substrate. In the second comparative example, the piezoelectric layer is made of lithium tantalate with a thickness of 1.1 μm. The support substrate is made of sapphire.

[0092] FIG. 12 illustrates the attenuation of a first transmit filter, a first receive filter, a second transmit filter, and a second receive filter in the acoustic wave device according to the first embodiment and a second comparative example.

[0093] FIG. 13 illustrates the insertion loss of the second transmission filter in the acoustic wave device according to the first embodiment and the second comparative example.

[0094] FIG. 14 illustrates the attenuation of the second transmission filter in the pass band of the first reception filter of the acoustic wave device according to the first embodiment and the second comparative example.

[0095] Fig. 15 is a diagram showing the voltage standing wave ratio (VSWR) of the second transmit filter of the acoustic wave device according to the first embodiment and the second comparative example. The upper side of Fig. 15 shows the voltage standing wave ratio (VSWR) on the antenna bump pad ANT side. The lower side of Fig. 15 shows the voltage standing wave ratio (VSWR) on the transmit bump pad Tx3 side.

[0096] FIG. 16 illustrates the insertion loss of the first receive filter in the acoustic wave device according to the first embodiment and the second comparative example.

[0097] 17 is a diagram illustrating cross isolation between the second transmit filter and the first receive filter in the pass band of the first receive filter of the acoustic wave device according to the first embodiment and a second comparative example. The solid line indicates the characteristics of the acoustic wave device 1 according to the first embodiment. The dashed line indicates the characteristics of the second comparative example.

[0098] In the acoustic wave device 1 according to the first embodiment and the second comparative example, the characteristics of the first transmit filter B1Tx, the first receive filter B1Rx, and the second receive filter B3Rx are substantially the same. For example, as shown in Fig. 12, in the transmit band of band 1, the receive band of band 1, and the receive band of band 3, the characteristics of the acoustic wave device 1 according to the first embodiment and the second comparative example are substantially the same.

[0099] For example, as shown in FIG. 16, the acoustic wave device 1 according to the first embodiment and the second comparative example have substantially the same characteristics regarding the insertion loss of the first receive filter B1Rx.

[0100] For example, as shown in FIG. 17, with respect to cross-isolation between the second transmit filter B3Tx and the first receive filter B1Rx in the passband of the first receive filter B1Rx, the characteristics of the acoustic wave device 1 in the first embodiment and the second comparative example are superior to those of the second comparative example.

[0101] With respect to the second transmission filter B3Tx, the characteristics of the acoustic wave device 1 according to the first embodiment are better than those of the second comparative example. For example, although it cannot be determined in FIG. 12, in the transmission band of Band 3, the characteristics of the acoustic wave device 1 according to the first embodiment are better than those of the second comparative example.

[0102] 13, for example, the characteristics of the acoustic wave device 1 according to the first embodiment with respect to the insertion loss of the second transmitting filter B3Tx are better than those of the second comparative example. Also, with respect to steepness, the characteristics of the acoustic wave device 1 according to the first embodiment are better than those of the second comparative example.

[0103] For example, as shown in FIG. 14, the acoustic wave device 1 according to the first embodiment has better characteristics in terms of the attenuation of the second transmission filter B3Tx in the pass band of the first reception filter B1Rx than the characteristics of the second comparative example.

[0104] For example, as shown in FIG. 15, the voltage standing wave ratio (VSWR) of the second transmitting filter B3Tx of the acoustic wave device 1 according to the first embodiment is better than that of the second comparative example.

[0105] As described above, with respect to the first transmit filter B1Tx, the first receive filter B1Rx, the second transmit filter B3Tx, and the second receive filter B3Rx, the acoustic wave device 1 according to the first embodiment has better characteristics in terms of the insertion loss and cross isolation of the first receive filter B1Rx than the first comparative example.The acoustic wave device 1 according to the first embodiment has better characteristics in terms of the insertion loss and voltage standing wave ratio (VSWR) of the second transmit filter B3Tx than the second comparative example.

[0106] The acoustic wave device 1 according to the first embodiment exhibited overall better characteristics than the first and second comparative examples.

[0107] This result is obtained by making the thickness of the piezoelectric layer 3A of the first chip C1 relatively thin, as in the second comparative example, and making the thickness of the piezoelectric layer 3A of the second chip C2 relatively thick, as in the first comparative example.

[0108] That is, by making the thickness of the piezoelectric layer 3A of the first chip C1 relatively thin, deterioration of the characteristics of the first reception filter B1Rx is suppressed, and in particular, the influence of spurious noise of the second transmission filter B3Tx on the first reception filter B1Rx is suppressed.

[0109] As a result, the deterioration of the insertion loss of the first reception filter B1Rx is suppressed. By making the thickness of the piezoelectric layer 3A of the second chip C2 relatively large, the deterioration of the characteristics of the second transmission filter B3Tx is suppressed.

[0110] When the thickness of the piezoelectric layer is smaller than one wavelength, energy can be trapped by utilizing the difference in sound speed between the piezoelectric layer and the supporting substrate, which has a faster sound speed than the piezoelectric layer. However, bulk waves are reflected between the piezoelectric layer and the supporting substrate, resulting in high-frequency spurious responses.

[0111] When the piezoelectric layer is made thinner, the frequency of such high frequency spurious noise shifts to a higher frequency, whereas when the piezoelectric layer is made thicker, the frequency of such high frequency spurious noise shifts to a lower frequency.

[0112] By using such a mechanism, it is possible to set the thickness of the piezoelectric layer that is most effective in suppressing the deterioration of the insertion loss of the first receiving filter B1Rx and suppressing the deterioration of the characteristics of the second transmitting filter B3Tx, while taking into account the range of the energy trapping effect of the second transmitting filter B3Tx.

[0113] According to the first embodiment described above, the second transmit filter B3Tx is composed of the first chip C1 and the second chip C2. This makes it possible to suppress deterioration of the characteristics of the first receive filter B1Rx and the second transmit filter B3Tx.

[0114] Furthermore, the thickness of the piezoelectric layer 3A of the second chip C2 is greater than the thickness of the piezoelectric layer 3A of the first chip C1, which makes it possible to more reliably suppress deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx.

[0115] Furthermore, the thickness of the piezoelectric layer 3A of the second chip C2 is greater than the thickness of the piezoelectric layer 3A of the chip substrate 3 constituting the second reception filter B3Rx. This makes it possible to more reliably suppress deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx.

[0116] Furthermore, the average value of the thickness of the piezoelectric layer 3A of the first chip C1 and the thickness of the piezoelectric layer 3A of the second chip C2 is greater than the thickness of the piezoelectric layer 3A of the chip substrate 3 constituting the second reception filter B3Rx. This makes it possible to more reliably suppress deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx.

[0117] Furthermore, the piezoelectric layer 3A is made of lithium tantalate or lithium niobate. Therefore, in an acoustic wave device 1 including a piezoelectric layer 3A made of lithium tantalate or lithium niobate, deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx can be suppressed.

[0118] Furthermore, the support substrate 3B is made of sapphire, silicon, alumina, spinel, quartz, or glass. Therefore, in the acoustic wave device 1 including the support substrate 3B made of sapphire, silicon, alumina, spinel, quartz, or glass, it is possible to suppress deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx.

[0119] Moreover, the antenna pad AP is formed in the central region of the package substrate 2. The antenna pad AP overlaps with a part of the first transmit filter B1Tx, a part of the first receive filter B1Rx, a part of the second receive filter B3Rx, and a part of the first chip C1 in top view. The antenna pad AP does not overlap with the second chip C2 in top view. This makes it possible to more reliably suppress deterioration of the characteristics of the first receive filter B1Rx and the second transmit filter B3Tx.

[0120] Moreover, the resonators connected to the terminal of the first chip C1 on the side of the second chip C2 are a series resonator S and a parallel resonator P. This makes it possible to more reliably suppress deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx.

[0121] Moreover, the resonator connected to the terminal of the second chip C2 on the first chip C1 side is a series resonator S. This makes it possible to more reliably suppress deterioration in the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx.

[0122] Embodiment 2 18 is a cross-sectional view of a module to which the acoustic wave device according to the embodiment 2 is applied. Note that the same reference numerals are used to designate the same or corresponding parts as those in the embodiment 1. Description of these parts will be omitted.

[0123] In FIG. 18, a module 100 includes a package substrate 101 , an integrated circuit component 102 , an acoustic wave device 1 , an inductor 103 , and a sealing portion 104 .

[0124] The package substrate 101 is the same as the package substrate 2 of the embodiment 1. The integrated circuit component 102 is mounted inside the package substrate 101.

[0125] The integrated circuit component 102 includes a switching circuit and a low-noise amplifier. The acoustic wave device 1 is mounted on a main surface of a package substrate 101. The inductor 103 is mounted on the main surface of the package substrate 101.

[0126] The inductor 103 is mounted for impedance matching. For example, the inductor 103 is an Integrated Passive Device (IPD). The sealing portion 104 seals a plurality of electronic components including the acoustic wave device 1.

[0127] According to the second embodiment described above, the module 100 includes the acoustic wave device 1. Therefore, it is possible to obtain the module 100 including the acoustic wave device 1 in which degradation of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx is suppressed.

[0128] Having described several aspects of at least one embodiment, it should be understood that various alterations, modifications, and improvements will readily occur to those skilled in the art and are intended to be part of this disclosure, and are intended to be within the scope of this disclosure.

[0129] It should be understood that the embodiments of the method and apparatus described herein are not limited in their application to the details of construction and the arrangement of components set forth in the above description or illustrated in the accompanying drawings. The method and apparatus can be implemented in other embodiments and practiced or carried out in various ways. The specific implementation examples are provided herein for purposes of illustration only and are not intended to be limiting.

[0130] The phraseology and terminology used in this disclosure are for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," "including" and variations thereof herein means the inclusion of the items listed thereafter and equivalents thereof as well as additional items.

[0131] References to "or" may be construed as meaning that any term described using "or" refers to one, more than one, and all of those described terms.

[0132] All references to front, back, left, right, top, bottom, up, down, horizontal, vertical, front and back are intended for convenience of description. Such references are not intended to limit the components of this disclosure to any one positional or spatial orientation. Accordingly, the foregoing description and drawings are by way of example only. [Explanation of symbols]

[0133] 1 Acoustic wave device, 2 Package substrate, 2A Conductive pad, 2B Conductive pad, 2C Internal conductor, 3 Chip substrate, 3A Piezoelectric layer, 3B Support substrate, 4 Bump, 5 Sealing portion, 6 Wiring pattern, 7 Acoustic wave element, 7A IDT electrode, 7B Reflector, 7C Electrode finger, 7D Bus bar 8 Space, 100 Module, 101 Package substrate, 102 Integrated circuit component, 103 Inductor, 104 Sealing portion

Claims

1. A package substrate; an antenna pad, a plurality of transmitting pads, a plurality of receiving pads, and a plurality of ground pads formed on the package substrate; a first transmission filter mounted on the package substrate and connected to the antenna pad and one of the transmission pads; a first receiving filter mounted on the package substrate and connected to the antenna pad and one of the receiving pads; a second transmission filter mounted on the package substrate and connected to the antenna pad and another of the transmission pads; a second receiving filter mounted on the package substrate and connected to the antenna pad and another of the receiving pads; Equipped with the second transmit filter includes a first chip connected to the antenna pad; a second chip connected to one of the plurality of transmitting pads; An acoustic wave device comprising:

2. The first chip and the second chip each include a piezoelectric layer formed on a support substrate; The acoustic wave device according to claim 1 , wherein a thickness value of the piezoelectric layer of the second chip is greater than a thickness value of the piezoelectric layer of the first chip.

3. The acoustic wave device according to claim 2 , wherein a transmission band of the second transmission filter is lower than a transmission band of the first transmission filter.

4. The acoustic wave device according to claim 2 , wherein a thickness value of the piezoelectric layer of the second chip is greater than a thickness value of the piezoelectric layer of a chip constituting the second receiving filter.

5. The acoustic wave device according to claim 2 , wherein an average value of a thickness of the piezoelectric layer of the first chip and a thickness of the piezoelectric layer of the second chip is greater than a thickness value of the piezoelectric layer of a chip constituting a second receiving filter.

6. The acoustic wave device according to claim 2 , wherein the piezoelectric layer is made of lithium tantalate or lithium niobate.

7. 3. The acoustic wave device according to claim 2, wherein the supporting substrate is made of sapphire, silicon, alumina, spinel, quartz, or glass.

8. 2. The acoustic wave device according to claim 1, wherein the antenna pad is formed in a central region of the package substrate, overlaps with a portion of the first transmitting filter, a portion of the first receiving filter, a portion of the second receiving filter, and a portion of the first chip in a top view, and does not overlap with the second chip in a top view.

9. the second transmit filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, The acoustic wave device according to claim 1 , wherein the resonators connected to the terminals of the first chip on the second chip side include a series resonator and a parallel resonator.

10. the second transmit filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, The acoustic wave device according to claim 1 , wherein the resonator connected to the terminal of the second chip on the side of the first chip is a series resonator.

11. A module comprising the acoustic wave device according to claim 1 or 2.

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