Elastic wave device and module comprising same

Abstract

The invention discloses an elastic wave device and a module comprising the elastic wave device. The elastic wave device includes: a package substrate; an antenna pad, a plurality of transmission pads, a plurality of reception pads, and a plurality of ground pads, which are formed on the package substrate; a first transmission filter mounted on the package substrate and connected to the one transmission pad and the antenna pad; a first reception filter mounted on the package substrate and connected to the one reception pad and the antenna pad; a second transmission filter mounted on the package substrate and connected to the other transmission pad and the antenna pad; a second reception filter mounted on the package substrate and connected to the other reception pad and the antenna pad; wherein the second transmission filter includes a first chip connected to the antenna pad and a second chip connected to one of the transmission pads. The elastic wave device can prevent deterioration of characteristics of the first reception filter and the second transmission filter.

Description

Technical Field

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

[0002] Patent document 1 discloses an elastic wave device. The elastic wave device is a quadplexer. The device includes a first transmission filter, a first reception filter, a second transmission filter, and a second reception filter. However, in the elastic wave device disclosed in patent document 1, if the piezoelectric layer of the second transmission filter is thinner, the characteristics of the second transmission filter will deteriorate. On the other hand, if the piezoelectric layer of the second transmission filter is thicker, the characteristics of the first reception filter will deteriorate.

[0003] Prior art document: Japanese Patent Publication No. 2022-054986. Summary of the invention

[0004] An object of the present disclosure is to provide an elastic wave device capable of preventing degradation of characteristics of a first reception filter and a second transmission filter, and a module including the elastic wave device.

[0005] According to the present disclosure, an elastic wave device includes: a packaging substrate; an antenna pad, multiple transmitting pads, multiple receiving pads and multiple grounding pads formed on the packaging substrate; a first transmitting filter mounted on the packaging substrate and connected to one transmitting pad and the antenna pad; a first receiving filter mounted on the packaging substrate and connected to one receiving pad and the antenna pad; a second transmitting filter mounted on the packaging substrate and connected to another transmitting pad and the antenna pad; a second receiving filter mounted on the packaging substrate and connected to another receiving pad and the antenna pad; wherein the second transmitting filter includes a first chip connected to the antenna pad and a second chip connected to one of the multiple transmitting pads.

[0006] In some embodiments, the first chip and the second chip include a supporting substrate and a piezoelectric layer formed on the supporting substrate, and the thickness of the piezoelectric layer of the second chip is greater than the thickness of the piezoelectric layer of the first chip.

[0007] In some embodiments, a thickness value of a piezoelectric layer of the second chip is greater than a thickness value of a piezoelectric layer of a chip constituting the second receive filter.

[0008] In some embodiments, an 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 a value of the thickness of the piezoelectric layer of a chip constituting the second receive filter.

[0009] In some embodiments, the piezoelectric layer is formed of lithium niobate or lithium tantalate.

[0010] In some embodiments, the support substrate is composed of sapphire, silicon, alumina, spinel, quartz or glass.

[0011] In some embodiments, a transmission bandwidth of the second transmit filter is lower than a transmission bandwidth of the first transmit filter.

[0012] In some embodiments, the antenna pad is formed in the central area of ​​the packaging substrate, overlapping with a portion of the first transmit filter, a portion of the first receive filter, a portion of the second receive filter, and a portion of the first chip in a top view, but not overlapping with the second chip in a top view.

[0013] In some embodiments, the second transmit filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, and in the first chip, the resonators connected to the second chip side terminals are series resonators and parallel resonators.

[0014] In some embodiments, the second transmit filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, and in the second chip, the resonator connected to the first chip-side terminal is a series resonator.

[0015] The present disclosure also provides a module, comprising the elastic wave device of the present disclosure.

[0016] According to the present disclosure, it is possible to prevent the deterioration of the characteristics of the first receive filter and the second transmit filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0018] Figure 1 is a cross-sectional view of the elastic wave device in Example 1.

[0019] Figure 2 This is a diagram showing an example of the elastic wave element in Example 1.

[0020] Figure 3 1 and 2 are top views of a plurality of chip substrates of the elastic wave device in Example 1 and a plurality of chip substrates of a comparative example.

[0021] Figure 4 It is a plan view of a package substrate of the elastic wave device in Example 1.

[0022] Figure 5FIG. 4 is a circuit diagram of a chip substrate corresponding to the elastic wave device in Example 1. FIG.

[0023] Figure 6 A graph showing the attenuation amounts of the first transmit filter, the first receive filter, the second transmit filter, and the second receive filter in Embodiment 1 and the first comparative example.

[0024] Figure 7 A graph showing the insertion loss of the second transmission filter in Embodiment 1 and the first comparative example.

[0025] Figure 8 A graph showing the attenuation amount of the second transmit filter within the passband of the first receive filter in Example 1 and the first comparative example.

[0026] Fig. 9 A graph showing the voltage standing wave ratio (VSWR) of the second transmission filter in Example 1 and the first comparative example.

[0027] Fig.10 A graph showing the insertion loss of the first reception filter in Embodiment 1 and the first comparative example.

[0028] Fig.11 A graph showing the cross isolation between the second transmit filter and the first receive filter within the passband of the first receive filter in Example 1 and the first comparative example.

[0029] Fig.12 A graph showing the attenuation amounts of the first transmit filter, the first receive filter, the second transmit filter, and the second receive filter in Example 1 and the second comparative example.

[0030] Fig.13 A graph showing the insertion loss of the second transmission filter in Example 1 and the second comparative example.

[0031] Fig.14 A graph showing the attenuation amount of the second transmit filter within the passband of the first receive filter in Example 1 and the second comparative example.

[0032] Fig.15 A graph showing the voltage standing wave ratio (VSWR) of the second transmission filter in Example 1 and the second comparative example.

[0033] Fig.16 A graph showing the insertion loss of the first reception filter in Example 1 and the second comparative example.

[0034] Fig.17 A graph showing the cross isolation between the second transmit filter and the first receive filter within the passband of the first receive filter in Example 1 and the second comparative example.

[0035] Fig.18A cross-sectional view of a module to which an elastic wave device is applied in Example 2 is shown.

[0036]

Explanation of symbols

[0037] The embodiments will be described below with reference to the accompanying drawings. In the drawings, the same or corresponding parts are marked with the same reference numerals, and the repeated description of these parts will be appropriately simplified or omitted.

[0038] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with general skills in the technical field to which this application belongs. The words "one", "a", "the", "these" and the like in this application do not indicate a quantitative limitation, and they may be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" may mean: A exists alone, A and B exist at the same time, and B exists alone. Generally, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0039] The following is based on Figures 1 to 18 , typical embodiments of the present invention are described.

[0040] Example 1 Figure 1 is a cross-sectional view of the elastic wave device in Example 1.

[0041] like Figure 1 As shown, elastic wave device 1 includes a package substrate 2 , a plurality of chip substrates 3 , a plurality of bumps 4 , and a sealing portion 5 .

[0042] Specifically, the package substrate 2 may be a multi-layer substrate containing resin. For example, the package substrate 2 may be a low temperature co-fired ceramic (LTCC) multi-layer substrate composed of multiple dielectric layers, or may be a high temperature co-fired ceramic (HTCC) multi-layer substrate composed of multiple dielectric layers. In some embodiments, the package substrate 2 may also have built-in passive components (not shown in the figure) such as capacitors or inductors (not shown).

[0043] exist Figure 1 In the embodiment, the top surface of the package substrate 2 is a component mounting surface. A plurality of conductive pads 2A are formed on the top surface of the package substrate 2. For example, the plurality of conductive pads 2A are made of copper.

[0044] The bottom surface of the package substrate 2 is a mounting surface mounted on a mother board or the like. A plurality of conductive pads 2B are formed on the bottom surface of the package substrate 2. The plurality of conductive pads 2B are made of copper, for example.

[0045] A plurality of internal conductors 2C are built into the package substrate 2. For example, the plurality of internal conductors 2C are made of copper. Each internal conductor 2C electrically connects a corresponding pair of conductive pads 2A and conductive pads 2B.

[0046] A plurality of chip substrates 3 are mounted on the package substrate 2. The plurality of chip substrates 3 face the package substrate 2. For example, each chip substrate 3 includes at least one piezoelectric layer 3A. For example, the piezoelectric layer 3A is made of a piezoelectric single crystal such as lithium niobate, lithium tantalate or quartz, or can be made of a piezoelectric ceramic material.

[0047] Each of the plurality of chip substrates 3 may further 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 unillustrated bonding layer.

[0048] For example, on each main surface ( Figure 1 A bandpass filter is formed on the surface (the lower surface in the figure). For example, a receiving filter or a transmitting filter is formed.

[0049] The receiving filter is designed to allow the electrical signal of the required frequency band to pass through. The transmitting filter is designed to allow the electrical signal of the required frequency band to pass through.

[0050] For example, each of the plurality of chip substrates 3 includes a wiring pattern 6 and a plurality of elastic wave elements 7. For example, the wiring pattern 6 and the plurality of elastic wave elements 7 are made of a metal or alloy such as silver, aluminum, copper, titanium or palladium, or are formed by stacking multiple layers of metal. For example, the thickness of the wiring pattern 6 and the plurality of elastic wave elements 7 is between 150 nm and 400 nm.

[0051] For example, the plurality of elastic wave elements 7 receive a high-frequency electric field through the wiring pattern 6 to excite surface acoustic waves, and convert the surface acoustic waves into a high-frequency electric field by the piezoelectric effect, thereby obtaining desired filtering characteristics.

[0052] Each of the plurality of bumps 4 may be made of gold, conductive paste, solder, etc. For example, the height of the bump 4 is between 20 μm and 50 μm. Each bump 4 electrically connects the conductive pad 2A and the wiring pattern 6 at a corresponding position.

[0053] The sealing part 5 seals the plurality of chip substrates 3 together with the packaging substrate 2 while leaving a space 8 between the packaging substrate 2 and the plurality of chip substrates 3. For example, the sealing part 5 may be made of an insulating material such as a synthetic resin, such as epoxy resin, polyimide, or the like.

[0054] Next, combine Figure 2 An example of elastic wave element 7 will be described.

[0055] Figure 2 This is a diagram showing an example of an elastic wave element of the elastic wave device in the first embodiment.

[0056] exist Figure 2 In the embodiment, the elastic wave element 7 is a surface acoustic wave (SAW) resonator. Figure 2 As shown, a pair of IDT electrodes 7A and a pair of reflectors 7B are formed on the main surface of the chip substrate 3. The IDT electrodes 7A and the reflectors 7B are configured to be able to excite surface acoustic waves.

[0057] For example, the pair of IDT electrodes 7A and the pair of reflectors 7B are made of an alloy of aluminum and copper, or of a suitable metal such as titanium, palladium or silver or an alloy thereof, or of stacked metal thin films.

[0058] The IDT electrode 7A includes a plurality of electrode fingers 7C and a bus bar 7D. The plurality of electrode fingers 7C are arranged in the longitudinal direction. The bus bar 7D connects the plurality of opposing electrode fingers 7C.

[0059] One of the pair of reflectors 7B is close to one side of the pair of IDT electrodes 7A. One of the other pair of reflectors 7B is close 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 connected to the wiring pattern 6 ( Figure 2 ) is formed and patterned by the same process.

[0060] Next, combine Figure 3 The plurality of chip substrates 3 will be described.

[0061] Figure 3 The figure shows a plan view of a plurality of chip substrates of the elastic wave device in Embodiment 1 and a plurality of comparative chip substrates as viewed from above. In reality, the components formed on the chip substrate 3 are located inside the drawing. Figure 3 In the figure, each component is represented by a solid line for convenience of explanation.

[0062] Figure 3 Part A of FIG. 1 shows a plurality of chip substrates 3 of the elastic wave device 1 in Example 1. FIG.

[0063] The plurality of chip substrates 3 work as a quadplexer as a whole. Figure 3 The chip substrate 3 at the lower right corner of the A portion works as the first transmission filter B1Tx. For example, the first transmission filter B1Tx is a transmission filter for Band 1. Figure 3 The chip substrate 3 at the upper left corner of the A portion operates as a first reception filter B1Rx. For example, the first reception filter B1Rx is a reception filter for Band 1.

[0064] Figure 3 The chip substrate 3 in the upper middle and upper right corner of the A part works as the second transmit filter B3Tx. For example, the second transmit filter B3Tx is a transmit filter for Band 3. The chip substrate 3 in the upper middle is called the first chip C1, and the chip substrate 3 in the upper right corner is called the second chip C2. Figure 3 The chip substrate 3 at the lower left corner of the A portion operates as a second reception filter B3Rx. For example, the second reception filter B3Rx is a reception filter for Band 3.

[0065] In a specific implementation, the thickness of the piezoelectric layer of the first transmit filter B1Tx is 1.5 μm. The thickness of the piezoelectric layer 3A of the first receive filter B1Rx is 1.5 μm. The thickness of the piezoelectric layer 3A of the second receive filter B3Rx is 1.2 μm. The thickness of the piezoelectric layer 3A of the first chip C1 is 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.

[0066] The thickness value of the piezoelectric layer 3A of the second chip C2 is greater than the thickness value 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 value of the piezoelectric layer 3A of the chip substrate 3 constituting the second receive filter B3Rx.

[0067] Wiring patterns 6 and a plurality of elastic wave elements 7 are formed on each main surface of a plurality of chip substrates 3 .

[0068] For example, the wiring pattern 6 is made of metal or alloy such as silver, aluminum, copper, titanium, palladium, etc., or is formed by stacking multiple layers of metal. For example, the thickness of the wiring pattern 6 is between 150nm and 400nm.

[0069] exist Figure 3 On the chip substrate 3 at the lower right corner of the A portion, the wiring pattern 6 includes four grounding bump pads GND, a transmission bump pad Tx1, and an antenna bump pad ANT. These bump pads are connected to the bump 4 ( Figure 3 The electrically connected parts are not shown.

[0070] exist Figure 3 On the chip substrate 3 at the upper left corner of the A portion, the wiring pattern 6 includes four grounding bump pads GND, a receiving bump pad Rx1, and an antenna bump pad ANT. These bump pads are connected to the bump 4 ( Figure 3 The electrically connected parts are not shown.

[0071] In the first chip C1, the wiring pattern 6 includes two grounding bump pads GND, an antenna bump pad ANT, and a connection bump pad P1. These bump pads are connected to the bump 4 ( Figure 3 The electrically connected parts are not shown.

[0072] In the second chip C2, the wiring pattern 6 includes two grounding bump pads GND, a transmission bump pad Tx3, and a connection bump pad P2. These bump pads are connected to the bump 4 ( Figure 3 The electrically connected parts are not shown.

[0073] exist Figure 3 In the chip substrate 3 at the lower left corner of A, 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 connected to the bump 4 ( Figure 3 The electrically connected parts are not shown.

[0074] In each chip substrate 3 , a plurality of elastic wave elements 7 include a plurality of series resonators and a plurality of parallel resonators. A plurality of elastic wave elements 7 are electrically connected via wiring patterns 6 .

[0075] In the first transmission filter B1Tx, a high-frequency electrical signal is input to the transmission bump pad Tx1, and the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. In this process, 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.

[0076] In the first reception filter B1Rx, a high frequency electrical signal is input to the antenna bump pad ANT, and the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. In this process, only the electrical signal of the desired frequency band reaches the reception bump pad Rx1. As a result, only the electrical signal of the desired frequency band is output from the reception bump pad Rx1.

[0077] In the second chip C2, a high-frequency electric signal is input to the transmission bump pad Tx3, and the electric signal passes through a plurality of series resonators and a plurality of parallel resonators, and then reaches the connection bump pad P2, and then reaches the connection bump pad P1 through the package substrate 2.

[0078] After that, in the first chip C1, the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. In this process, 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.

[0079] In the second receiving filter B3Rx, a high-frequency electrical signal is input to the antenna bump pad ANT, and the electrical signal passes through a plurality of series resonators and a plurality of parallel resonators. In this process, only the electrical signal of the desired frequency band reaches the receiving bump pad Rx3. As a result, only the electrical signal of the desired frequency band is output from the receiving bump pad Rx3.

[0080] Figure 3 Part B shows a plurality of chip substrates of the first comparative example. The plurality of chip substrates are almost identical to the plurality of chip substrates 3 of the elastic wave device 1 in Example 1. Specifically, the chip substrate in the lower right corner works as a first transmitting filter B1Tx. The chip substrate in the upper left corner works as a first receiving filter B1Rx. The chip substrate in the upper right corner works as a second transmitting filter B3Tx. The chip substrate in the lower left corner works as a second receiving filter B3Rx. However, the second transmitting filter B3Tx is composed of a single chip substrate.

[0081] Next, combine Figure 4 The package substrate 2 will be described.

[0082] Figure 4 This is a plan view of the packaging substrate in Example 1.

[0083] like Figure 4 As shown, the packaging substrate 2 includes Figure 1 The conductive pads 2A include an antenna pad AP, a plurality of transmission pads TP, a plurality of reception pads RP, a plurality of ground pads GP and a connection pad CP.

[0084] The antenna pad AP is formed in the central area of ​​the package substrate 2. Figure 4 Although not shown, 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 packaging substrate 2, the antenna pad AP overlaps with a portion of the first transmit filter B1Tx, a portion of the first receive filter B1Rx, a portion of the second receive filter B3Rx, and a portion of the first chip C1 in a top view.

[0085] Specifically, the antenna pad AP overlaps with the antenna bump pad ANT of the first transmit filter B1Tx, the antenna bump pad ANT of the first receive filter B1Rx, the antenna bump pad ANT of the second receive filter B3Rx, and the antenna bump pad ANT of the first chip C1 in a plan view.

[0086] In contrast, even if the second chip C2 is mounted on the package substrate 2 , the antenna pad AP does not overlap with the second chip C2 in a plan view.

[0087] Although not shown in the figure, when the first transmitting filter B1Tx, the first receiving filter B1Rx, the second receiving filter B3Rx, the first chip C1 and the second chip C2 are installed on the packaging substrate 2, the antenna pad AP, multiple transmitting pads TP, multiple receiving pads RP, multiple grounding pads GP and the connection pad CP will be connected to the bump pads at corresponding positions in the first transmitting filter B1Tx, the first receiving filter B1Rx, the second receiving filter B3Rx, the first chip C1 and the second chip C2.

[0088] In the package substrate 2, the large-area metal pattern except for the antenna pad AP, multiple transmission pads TP, multiple reception pads RP, multiple ground pads GP, and connection pads CP is a ground portion. The ground portion is connected to multiple ground bump pads GND in the first reception filter B1Rx, the second reception filter B3Rx, the first chip C1, and the second chip C2.

[0089] For example, in the lower right area of ​​the packaging substrate 2, the ground pad GP is connected to the ground bump pad GND of the first transmitting filter B1Tx, the transmitting pad TP is connected to the transmitting bump pad Tx1 of the first transmitting filter B1Tx, and the antenna pad AP is connected to the antenna bump pad ANT of the first transmitting filter B1Tx.

[0090] For example, in the upper left area 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.

[0091] For example, in the lower left area of ​​the packaging substrate 2, the ground pad GP is connected to the ground bump pad GND of the second receiving filter B3Rx, the antenna pad AP is connected to the antenna bump pad ANT of the second receiving filter B3Rx, and the receiving pad RP is connected to the receiving bump pad Rx3 of the second receiving filter B3Rx.

[0092] For example, in the upper right area 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.

[0093] Next, combine Figure 5 The circuit configuration of the chip substrate 3 will be described.

[0094] Figure 5 This is a circuit diagram corresponding to the chip substrate of the elastic wave device in Example 1.

[0095] like Figure 5 As shown, 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.

[0096] In the first chip C1 , the resonators connected to the second chip C2 side terminal are the series resonator S and the parallel resonator P. In the second chip C2 , the resonator connected to the first chip C1 side terminal is the series resonator S.

[0097] Next, use Figures 6 to 11To illustrate the characteristic simulation results of elastic wave device 1 and the first comparative example. In elastic wave device 1, piezoelectric layer 3A is made of lithium tantalate. Support substrate 3B is made of sapphire. The first comparative example is an elastic wave device in which a second transmission filter is formed by a 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.

[0098] Figure 6 Graph showing attenuation values ​​of the elastic wave device in Example 1 and the first transmission filter, the first reception filter, the second transmission filter, and the second reception filter of the first comparative example.

[0099] Figure 7 This is a graph showing the insertion loss of the elastic wave device in Example 1 and the second transmission filter in the first comparative example.

[0100] Figure 8 Graph showing attenuation values ​​of the second transmission filter within the passband of the first reception filter of the elastic wave device in Example 1 and the first comparative example.

[0101] Fig. 9 Graph showing the voltage standing wave ratio (VSWR) of the elastic wave device in Example 1 and the second transmission filter in the first comparative example. Fig. 9 The upper part is the voltage standing wave ratio (VSWR) on the antenna bump pad ANT side. Fig. 9 The lower part is the voltage standing wave ratio (VSWR) on the transmission bump pad Tx3 side.

[0102] Fig.10 Graph showing the insertion loss of the elastic wave device in Example 1 and the first receiving filter in the first comparative example.

[0103] Fig.11 1 is a graph showing the cross isolation between the second transmission filter and the first reception filter within the pass band of the elastic wave device in Example 1 and the first reception filter in the first comparative example.

[0104] exist Figures 6 to 11 In FIG. 1 , the solid line shows the characteristics of the elastic wave device 1 in Example 1. The dotted line shows the characteristics of the first comparative example.

[0105] The elastic wave device in Example 1 is compared with the first comparative example in that the characteristics of the first transmission filter B1Tx, the second transmission filter B3Tx, and the second reception filter B3Rx are almost the same.

[0106] For example, Figure 6As shown, in the transmission bandwidth of Band 1 (1920 MHz to 1980 MHz), the transmission bandwidth of Band 3 (1710 MHz to 1785 MHz), and the reception bandwidth of Band 3 (1805 MHz to 1880 MHz), the attenuation values ​​of the elastic wave device 1 in Example 1 and the first comparative example are almost the same.

[0107] For example, Figure 7 As shown, regarding the insertion loss of the second transmission filter B3Tx, the characteristics of the elastic wave device 1 in the first embodiment and the first comparative example are almost the same.

[0108] For example, Figure 8 As shown, regarding the attenuation value of the second transmission filter B3Tx within the passband of the first reception filter B1Rx, the elastic wave device 1 in the first embodiment is better than that in the first comparative example.

[0109] For example, Fig. 9 As shown, regarding the voltage standing wave ratio (VSWR) of the second transmission filter B3Tx, the characteristics of the elastic wave device 1 in Example 1 and the first comparative example are almost the same.

[0110] Regarding the first receiving filter B1Rx, the characteristics of the elastic wave device 1 in the first embodiment are better than those of the first comparative example. Figure 6 As shown, in the reception bandwidth of Band 1 (2110 MHz to 2170 MHz), the characteristics of the elastic wave device 1 in Example 1 are better than those of the first comparative example.

[0111] For example, Fig.10 As shown, regarding the insertion loss of the first receive filter B1Rx, the characteristics of the elastic wave device 1 in Example 1 are better than those of the first comparative example.

[0112] For example, Fig.11 As shown, regarding the cross isolation between the second transmit filter B3Tx and the first receive filter B1Rx, the characteristics of the elastic wave device 1 in Example 1 are better than those of the first comparative example.

[0113] Next, use Figures 12 to 17 To explain the characteristics simulation results of elastic wave device 1 and the second comparative example.

[0114] In the elastic wave device 1, the piezoelectric layer 3A is made of lithium tantalate. The supporting substrate 3B is made of sapphire. The second comparative example is an elastic wave device in which the second transmission filter is formed by a chip substrate. In the second comparative example, the piezoelectric layer is lithium tantalate with a thickness of 1.1 μm. The supporting substrate is sapphire.

[0115] Fig.12: is a graph showing attenuation values ​​of the elastic wave device in Example 1 and the first transmission filter, the first reception filter, the second transmission filter, and the second reception filter of the second comparative example.

[0116] Fig.13 Graphs showing the insertion losses of the elastic wave device in Example 1 and the second transmission filter in the second comparative example.

[0117] Fig.14 1 is a graph showing the attenuation value of the second transmission filter within the pass band of the first reception filter of the elastic wave device in Example 1 and the second comparative example.

[0118] Fig.15 1 is a graph showing the voltage standing wave ratio (VSWR) of the elastic wave device in Example 1 and the second transmission filter in the second comparative example. Fig.15 The upper part is the voltage standing wave ratio (VSWR) on the antenna bump pad ANT side. Fig.15 The lower part is the voltage standing wave ratio (VSWR) on the transmission bump pad Tx3 side.

[0119] Fig.16 Graphs showing the insertion loss of the elastic wave device in Example 1 and the first reception filter in the second comparative example.

[0120] Fig.17 1 is a graph showing the cross isolation between the second transmission filter and the first reception filter within the passband of the elastic wave device in Example 1 and the first reception filter in the second comparative example. The solid line shows the characteristics of the elastic wave device 1 in Example 1. The dotted line shows the characteristics of the second comparative example.

[0121] Compared with the second comparative example, the elastic wave device 1 in the first embodiment has almost the same characteristics as the first transmission filter B1Tx, the first reception filter B1Rx, and the second reception filter B3Rx. Fig.12 As shown, in the transmission bandwidth of Band 1, the reception bandwidth of Band 1, and the reception bandwidth of Band 3, the characteristics of the elastic wave device 1 in Example 1 and the second comparative example are almost the same.

[0122] For example, Fig.16 As shown, regarding the insertion loss of the first receive filter B1Rx, the characteristics of the elastic wave device 1 in the first embodiment and the second comparative example are almost the same.

[0123] For example, Fig.17 As shown, regarding the cross isolation between the second transmit filter B3Tx and the first receive filter B1Rx within the passband of the first receive filter B1Rx, the elastic wave device 1 in Example 1 has better cross isolation characteristics than the elastic wave device in the second comparative example.

[0124] Regarding the second transmission filter B3Tx, the characteristics of the elastic wave device 1 in the first embodiment are better than those of the second comparative example. Fig.12 , but in the transmission bandwidth of Band 3, the characteristics of the elastic wave device 1 in Example 1 are better than those of the second comparative example.

[0125] For example, Fig.13 As shown, the characteristics of elastic wave device 1 in Example 1 are superior to those of the second comparative example in terms of insertion loss of second transmission filter B3Tx. Also, the characteristics of elastic wave device 1 in Example 1 are superior to those of the second comparative example in terms of steepness.

[0126] For example, Fig.14 As shown, regarding the attenuation value of the second transmission filter B3Tx within the passband of the first reception filter B1Rx, the characteristics of the elastic wave device 1 in the first embodiment are better than those of the second comparative example.

[0127] For example, Fig.15 As shown, regarding the voltage standing wave ratio (VSWR) of the second transmission filter B3Tx, the characteristics of the elastic wave device 1 in Example 1 are better than those of the second comparative example.

[0128] Therefore, regarding the first transmission filter B1Tx, the first reception filter B1Rx, the second transmission filter B3Tx, and the second reception filter B3Rx, the characteristics of the elastic wave device 1 in Example 1 are better than those of the first comparative example in terms of the insertion loss and cross isolation characteristics of the first reception filter B1Rx. The characteristics of the elastic wave device 1 in Example 1 are better than those of the second comparative example in terms of the insertion loss and voltage standing wave ratio (VSWR) of the second transmission filter B3Tx.

[0129] The characteristics of the elastic wave device 1 in Example 1 are better than those of the first comparative example and the second comparative example.

[0130] This result is obtained by setting the thickness of the piezoelectric layer 3A of the first chip C1 to be relatively small like the second comparative example, and setting the thickness of the piezoelectric layer 3A of the second chip C2 to be relatively large like the first comparative example.

[0131] That is, by setting the thickness of the piezoelectric layer 3A of the first chip C1 to be relatively small, the deterioration of the characteristics of the first receive filter B1Rx can be suppressed. In particular, the spurious influence of the second transmit filter B3Tx on the first receive filter B1Rx can be suppressed. Therefore, the deterioration of the insertion loss of the first receive filter B1Rx can be suppressed. By setting the thickness of the piezoelectric layer 3A of the second chip C2 to be relatively large, the deterioration of the characteristics of the second transmit filter B3Tx can be suppressed.

[0132] When the thickness of the piezoelectric layer is less than the length of one wavelength, energy can be confined by exploiting the difference in the speed of sound between the piezoelectric layer and the faster supporting substrate, but the bulk waves between the piezoelectric layer and the supporting substrate will reflect and appear as high-frequency stray signals.

[0133] This high-frequency spurious frequency will shift to the high-frequency side as the piezoelectric layer becomes thinner, and will shift to the low-frequency side as the piezoelectric layer becomes thicker.

[0134] By utilizing this mechanism, the most effective piezoelectric layer thickness can be set, thereby suppressing the degradation of the insertion loss of the first reception filter B1Rx while considering the energy confinement effect range of the second transmission filter B3Tx and suppressing the degradation of the characteristics of the second transmission filter B3Tx.

[0135] According to the above-described first embodiment, the second transmit filter B3Tx is composed of the first chip C1 and the second chip C2. Therefore, it is possible to suppress the deterioration of the characteristics of the first receive filter B1Rx and the second transmit filter B3Tx.

[0136] Furthermore, the thickness of the piezoelectric layer 3A of the second chip C2 is greater than that of the first chip C1. Therefore, the deterioration of the first reception filter B1Rx characteristics and the second transmission filter B3Tx characteristics can be more reliably suppressed.

[0137] Furthermore, the thickness of the piezoelectric layer 3A of the second chip C2 is greater than that of the chip substrate 3 constituting the second receive filter B3Rx. Therefore, the deterioration of the first receive filter B1Rx and the second transmit filter B3Tx characteristics can be more reliably suppressed.

[0138] In addition, 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. Therefore, the deterioration of the characteristics of the first reception filter B1Rx and the second transmission filter B3Tx can be more reliably suppressed.

[0139] In addition, piezoelectric layer 3A is formed of lithium tantalate or lithium niobate. Therefore, in elastic wave device 1 having piezoelectric layer 3A formed of lithium tantalate or lithium niobate, degradation of first receive filter B1Rx characteristics and second transmit filter B3Tx characteristics can be suppressed.

[0140] In addition, the support substrate 3B is made of sapphire, silicon, alumina, spinel, quartz or glass. Therefore, in the elastic wave device 1 having the support substrate 3B made of sapphire, silicon, alumina, spinel, quartz or glass, the deterioration of the first receiving filter B1Rx characteristics and the second transmitting filter B3Tx characteristics can be suppressed.

[0141] In addition, the antenna pad AP is formed in the central area of ​​the package substrate 2. The antenna pad AP overlaps a portion of the first transmit filter B1Tx, a portion of the first receive filter B1Rx, a portion of the second receive filter B3Rx, and a portion of the first chip C1 in a top view. The antenna pad AP does not overlap the second chip C2 in a top view. Therefore, the deterioration of the characteristics of the first receive filter B1Rx and the second transmit filter B3Tx can be more reliably suppressed.

[0142] Furthermore, the resonators connected to the second chip C2 side terminal of the first chip C1 are the series resonator S and the parallel resonator P. Therefore, the deterioration of the first reception filter B1Rx characteristics and the second transmission filter B3Tx characteristics can be more reliably suppressed.

[0143] Furthermore, the resonator connected to the first chip C1 -side terminal of the second chip C2 is the series resonator S. Therefore, it is possible to more reliably suppress the deterioration of the first reception filter B1Rx characteristics and the second transmission filter B3Tx characteristics.

[0144] Example 2 Fig.18 is a cross-sectional view of a module to which an elastic wave device is applied in Embodiment 2. It should be noted that the same reference numerals are used for the same or corresponding parts as in Embodiment 1, and description thereof will be omitted.

[0145] like Fig.18 As shown, module 100 includes a package substrate 101 , an integrated circuit component 102 , an elastic wave device 1 , an inductor 103 , and a sealing portion 104 .

[0146] The package substrate 101 is the same as the package substrate 2 in Embodiment 1. The integrated circuit component 102 is mounted inside the package substrate 101 .

[0147] Integrated circuit component 102 includes a switch circuit and a low noise amplifier. Elastic wave device 1 is mounted on a main surface of package substrate 101. Inductor 103 is mounted on a main surface of package substrate 101.

[0148] The inductor 103 is used 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 elastic wave device 1 .

[0149] According to the second embodiment described above, module 100 includes elastic wave device 1. Therefore, module 100 including elastic wave device 1 including first reception filter B1Rx and second transmission filter B3Tx with characteristics deterioration suppressed can be obtained.

[0150] Although several aspects of some embodiments have been described, it will be appreciated that various modifications, changes, and improvements will be apparent to those skilled in the art, and such modifications, changes, and improvements are intended to be part of this disclosure and are intended to be within the scope of this disclosure.

[0151] It should be noted that the embodiments of the methods and apparatus described herein are not limited to the specific configurations and arrangements described in the above description or illustrated in the accompanying drawings. The methods and apparatus may be implemented in other embodiments and may be practiced or performed in a variety of ways. The specific embodiments are given only as examples and are not intended to be limiting.

Claims

1. An elastic wave device, characterized in that: The elastic wave device comprises: Package substrate; An antenna pad, a plurality of transmission pads, a plurality of reception pads, and a plurality of ground pads formed on the packaging substrate; A first transmission filter mounted on the package substrate and connected to a transmission pad and an antenna pad; A first receiving filter mounted on the package substrate and connected to a receiving pad and an antenna pad; A second transmission filter mounted on the package substrate and connected to another transmission pad and the antenna pad; A second reception filter mounted on the package substrate and connected to another reception pad and the antenna pad; The second transmission filter includes a first chip connected to the antenna pad and a second chip connected to one of the plurality of transmission pads.

2. The elastic wave device according to claim 1, characterized in that: The first chip and the second chip include a supporting substrate and a piezoelectric layer formed on the supporting substrate, and the thickness of the piezoelectric layer of the second chip is greater than the thickness of the piezoelectric layer of the first chip.

3. The elastic wave device according to claim 2, characterized in that: The thickness of the piezoelectric layer of the second chip is greater than the thickness of the piezoelectric layer of the chip constituting the second receive filter.

4. The elastic wave device according to claim 2, characterized in that: An 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 a value of the thickness of the piezoelectric layer of the chip constituting the second receive filter.

5. The elastic wave device according to claim 2, characterized in that: The piezoelectric layer is formed of lithium niobate or lithium tantalate.

6. The elastic wave device according to claim 1, characterized in that: A transmission bandwidth of the second transmit filter is lower than a transmission bandwidth of the first transmit filter.

7. The elastic wave device according to claim 1, characterized in that: The antenna pad is formed in the central area of ​​the packaging substrate, overlapping with a portion of the first transmit filter, a portion of the first receive filter, a portion of the second receive filter, and a portion of the first chip in a top view, but not overlapping with the second chip in a top view.

8. The elastic wave device according to claim 1, characterized in that: The second transmission filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, and in the first chip, the resonators connected to the second chip side terminals are series resonators and parallel resonators.

9. The elastic wave device according to claim 1, characterized in that: The second transmission filter is a ladder filter including a plurality of series resonators and a plurality of parallel resonators, and in the second chip, the resonator connected to the first chip side terminal is a series resonator.

10. A module, characterized in that: The elastic wave device comprises any one of claims 1 to 9.

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