Elastic wave device chip, elastic wave device, and module including the elastic wave device chip or the elastic wave device

Abstract

An elastic wave device chip includes a chip substrate; a plurality of series resonators formed on a first main surface of the chip substrate; a plurality of parallel resonators formed on the first main surface of the chip substrate; an input pad formed on the first main surface of the chip substrate; an output pad formed on the first main surface of the chip substrate; a ground pad formed on the first main surface of the chip substrate; a wiring pattern formed on the first main surface of the chip substrate and electrically connected to the series resonators, the parallel resonators, the input pad, the output pad, and the ground pad; and a broadband attenuation circuit formed on a second main surface of the chip substrate opposite the first main surface and electrically connected to the wiring pattern at a position where two adjacent series resonators on a front half side from one side of the input pad are electrically connected by a first through-hole wiring that penetrates the chip substrate. Thus, an elastic wave device chip or the like that improves filter characteristics and achieves miniaturization can be provided.

Description

Technical Field

[0001] This disclosure relates to an elastic wave device chip, an elastic wave device, and a module comprising the elastic wave device chip or the elastic wave device. Background Technology

[0002] Patent document 1 (International Publication No. 2017 / 170071) discloses an elastic wave filter, according to which the characteristics of the filter are improved. Summary of the Invention

[0003] [The problem the invention aims to solve]

[0004] However, the elastic wave filter described in Patent Document 1 requires an attenuation circuit. Therefore, it is difficult to miniaturize the device in which the elastic wave filter is installed.

[0005] To address the aforementioned problems, this disclosure aims to provide an elastic wave device chip, an elastic wave device, and a module comprising the elastic wave device chip or the elastic wave device that can improve filter characteristics and achieve miniaturization.

[0006] [Methods used to solve problems]

[0007] The elastic wave device chip disclosed herein includes:

[0008] Chip substrate;

[0009] Several series resonators are formed on the first main surface of the chip substrate;

[0010] Several parallel resonators are formed on the first main surface of the chip substrate;

[0011] Input pads are formed on the first main surface of the chip substrate;

[0012] Output pads are formed on the first main surface of the chip substrate;

[0013] A grounding pad is formed on the first main surface of the chip substrate;

[0014] Wiring patterns are formed on the first main surface of the chip substrate and electrically connected to the series resonator, the parallel resonator, the input pad, the output pad, and the ground pad;

[0015] A first through-hole wiring extends through the chip substrate; and

[0016] A broadband attenuation circuit is formed on a second main surface of the chip substrate opposite to the first main surface. One end of the circuit is electrically connected to the wiring pattern via the first via wiring at the position where two adjacent series resonators are electrically connected on the first half side counting from one side of the input pad.

[0017] In one embodiment of this disclosure, the broadband attenuation circuit is electrically connected to the wiring pattern via the first via wiring at the location where the first series resonator and the second series resonator are electrically connected, counting from one side of the input pad.

[0018] In one embodiment of this disclosure, the series resonator and the parallel resonator are used as a transmitting filter.

[0019] In one embodiment of this disclosure, a second through-hole wiring is further included, through the chip substrate, and the other end of the broadband attenuation circuit is electrically connected to the grounding pad via the second through-hole wiring.

[0020] In one embodiment of this disclosure, the broadband attenuation circuit, when the series resonator and the parallel resonator are used as elastic wave filters, achieves band resonance between the second and third harmonics of the fundamental wave corresponding to the frequency of the elastic wave filter.

[0021] In one embodiment of this disclosure, the broadband attenuation circuit resonates in the frequency band between 3 GHz and 7 GHz.

[0022] In one embodiment of this disclosure, the broadband attenuation circuit includes an inductor and a capacitor.

[0023] In one embodiment of this disclosure, the inductor has an inductance value of 0.5nH to 4.0nHz, and the capacitor has a capacitance value of 0.2pF to 2.0pF.

[0024] In one embodiment of this disclosure, the chip substrate includes a piezoelectric substrate and a support substrate made of sapphire, silicon, alumina, spinel, crystal, or glass and bonded to the piezoelectric substrate.

[0025] In one embodiment of this disclosure, the series resonator and the parallel resonator are each an elastic surface wave resonator, and the series resonator and the parallel resonator together are used as a bandpass filter or a duplexer.

[0026] In one embodiment of this disclosure, the series resonator and the parallel resonator are each divided into acoustic thin-film resonators, and the series resonator and the parallel resonator are used as a whole as a bandpass filter or a duplexer.

[0027] The elastic wave device disclosed herein includes the elastic wave device chip and a wiring substrate electrically connected to the elastic wave device chip.

[0028] The module disclosed herein includes the elastic wave device chip or the elastic wave device.

[0029] In one embodiment of this disclosure, the module further includes integrated circuitry electrically connected to the input pads.

[0030] In one embodiment of this disclosure, the integrated circuit includes a series inductor having an inductance value of 0.5nH to 10nH and a parallel inductor having an inductance value of 5nH to 50nH.

[0031] [The effects of the invention]

[0032] The beneficial effects of the present invention are as follows: According to this disclosure, an elastic wave device chip, an elastic wave device, and a module including the elastic wave device chip or the elastic wave device can be provided to improve filter characteristics and achieve miniaturization. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view of the elastic wave device with the elastic wave device chip installed in the first embodiment.

[0034] Figure 2 This is a circuit diagram of the elastic wave device with the elastic wave device chip installed in the first embodiment.

[0035] Figure 3 This is a plan view of the first main surface of the elastic wave device chip described in the first embodiment.

[0036] Figure 4 This is a perspective view of the second main surface from the first main surface side of the elastic wave device chip in the first embodiment.

[0037] Figure 5 This is the first example of an elastic wave element in the first embodiment that has the elastic wave device chip installed.

[0038] Figure 6 This is a second example of an elastic wave element in the first embodiment that has the elastic wave device chip installed.

[0039] Figure 7 The Smith charts showing the impedance characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example are shown.

[0040] Figure 8 The Smith charts show the impedance characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0041] Figure 9 The Smith charts show the impedance characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0042] Figure 10This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0043] Figure 11 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0044] Figure 12 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0045] Figure 13 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0046] Figure 14 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0047] Figure 15 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0048] Figure 16 This is a schematic diagram of the simulation results of the isolation characteristics between the elastic wave device with the elastic wave device chip installed in the first embodiment and the comparative example.

[0049] Figure 17 This is a cross-sectional view of a variation of the elastic wave device with the elastic wave device chip installed in the first embodiment.

[0050] Figure 18 This is a cross-sectional view of a module in the second embodiment that includes an elastic wave device on which the elastic wave device chip is installed.

[0051] Figure 19 This is a circuit diagram of a module in the second embodiment that includes an elastic wave device having the elastic wave device chip installed. Detailed Implementation

[0052] The specific embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the same or equivalent parts in the drawings are designated by the same reference numerals. Repeated descriptions of the same or equivalent parts will be appropriately simplified or omitted.

[0053] (First Embodiment)

[0054] Figure 1 This is a cross-sectional view of the elastic wave device 1 with the elastic wave device chip installed in the first embodiment.

[0055] like Figure 1 As shown, the elastic wave device 1 includes a wiring substrate 3, a plurality of bumps 15, at least one elastic wave device chip 5, and a sealing part 17.

[0056] For example, the wiring substrate 3 is a multilayer substrate made of multiple layers of resin. For example, the wiring substrate 3 is a low-temperature co-fired ceramic (LTCC) multilayer substrate formed of multiple dielectric layers.

[0057] The bump 15 is electrically connected to the wiring substrate 3. For example, the bump 15 is a gold bump. For example, the height of the bump 15 is 10 μm to 50 μm.

[0058] For example, the elastic wave device chip 5 is electrically connected to the wiring substrate 3, which has a chip substrate 20, a wiring pattern 21, a plurality of elastic wave elements 22, and a broadband attenuation circuit 23.

[0059] For example, the chip substrate 20 is made of lithium tantalate or lithium niobate.

[0060] The wiring pattern 21 is formed on the first main surface of the chip substrate 20. Figure 1 (The lower surface). For example, the wiring pattern 21 can be formed of suitable metals or alloys such as silver, aluminum, copper, titanium, palladium, etc. For example, the wiring pattern 21 is a multilayer metal structure composed of multiple stacked metal layers. For example, the thickness of the wiring pattern 21 is 1500 nm to 4500 nm. The wiring pattern 21 is electrically connected to the bump 15.

[0061] The elastic wave element 22 is formed on the first main surface of the chip substrate 20. The elastic wave element 22 is electrically connected to the wiring pattern 21. For example, the elastic wave element 22 allows electrical signals of a desired frequency band to pass through. For example, the elastic wave element 22 functions as a trapezoidal elastic wave filter composed of multiple series resonators and multiple parallel resonators.

[0062] The broadband attenuation circuit 23 is formed on the second main surface of the chip substrate 20 opposite to the first main surface. Figure 1 (the upper surface). For example, the broadband attenuation circuit 23 is electrically connected to the wiring pattern 21 via a first through-hole wiring 31a and a second through-hole wiring 31b through the chip substrate 20.

[0063] The sealing portion 17 covers the elastic wave device chip 5. The sealing portion 17, together with the wiring substrate 3, seals the elastic wave device chip 5 within it. For example, the sealing portion 17 is formed of an insulator such as synthetic resin. For example, the sealing portion 17 is formed of metal. For example, the sealing portion 17 is formed of a resin layer and a metal layer.

[0064] When the sealing portion 17 is formed of a synthetic resin, the synthetic resin may be epoxy resin or polyimide, etc. Preferably, the sealing portion 17 uses epoxy resin and is formed by a low-temperature curing process.

[0065] Next, by means of Figure 2 An example illustrates the elastic wave device 1.

[0066] Figure 2 This is a circuit diagram of the elastic wave device 1 in the first embodiment, which is equipped with the elastic wave device chip.

[0067] exist Figure 2 In this embodiment, the elastic wave device 1 functions as a quadplexer. Specifically, the elastic wave device 1 has four elastic wave device chips 5, which are respectively a first receiving chip 5a, a first transmitting chip 5b, a second receiving chip 5c, and a second transmitting chip 5d.

[0068] For example, the first receiving chip 5a is a receiving chip corresponding to frequency band 1. For example, the first transmitting chip 5b is a transmitting chip corresponding to frequency band 1. For example, the second receiving chip 5c is a receiving chip corresponding to frequency band 3. For example, the second transmitting chip 5d is a transmitting chip corresponding to frequency band 3.

[0069] The first receiving chip 5a includes the wiring pattern 21, the first receiving antenna pad Ant-R1, the first receiving output pad Rx-R1, and a plurality of first receiving ground pads GND-R1.

[0070] In the first receiving chip 5a, the elastic wave element 22 includes a plurality of series resonators S1-R1, S2-R1, S3-R1, S4-R1 and a plurality of parallel resonators P1-R1, P2-R1, P3-R1, P4-R1. The series resonators S1-R1, S2-R1, S3-R1, S4-R1 and the parallel resonators P1-R1, P2-R1, P3-R1, P4-R1 are electrically connected to the wiring pattern 21. In the wiring pattern 21 between the first receiving output pad Rx-R1 and the first receiving antenna pad Ant-R1, the series resonators S1-R1, S2-R1, S3-R1, S4-R1 are arranged relative to the first receiving output pad Rx-R1 from near to far in the aforementioned order. In the wiring pattern 21 between the first receiving antenna pad Ant-R1 and the first receiving output pad Rx-R1, the parallel resonators P1-R1, P2-R1, P3-R1, and P4-R1 are arranged relative to the first receiving output pad Rx-R1 from near to far in the aforementioned order. The series resonators S1-R1, S2-R1, S3-R1, and S4-R1, along with the parallel resonators P1-R1, P2-R1, P3-R1, and P4-R1, function as a first receiving filter.

[0071] The first receiving antenna pad Ant-R1 serves as the input pad of the first receiving filter. The first receiving output pad Rx-R1 serves as the output pad of the first receiving filter. The first receiving ground pad GND-R1 serves as the ground pad of the first receiving filter.

[0072] Once an electrical signal is input to the first receiving antenna pad Ant-R1, only the electrical signal corresponding to the receiving frequency band of frequency band 1 will pass completely through the series resonators S1-R1, S2-R1, S3-R1, S4-R1 and the parallel resonators P1-R1, P2-R1, P3-R1, P4-R1. Therefore, the electrical signal corresponding to the receiving frequency band of frequency band 1 will be output from the first receiving output pad Rx-R1.

[0073] The first transmitting chip 5b includes the wiring pattern 21, the first transmitting input pads Tx-T1, the first transmitting antenna pad Ant-T1, and a plurality of first transmitting ground pads GND-T1.

[0074] In the first transmitting chip 5b, the elastic wave element 22 includes a plurality of series resonators S1-T1, S2-T1, S3-T1, S4-T1, S5-T1 and a plurality of parallel resonators P1-T1, P2-T1, P3-T1, P4-T1. The series resonators S1-T1, S2-T1, S3-T1, S4-T1, S5-T1 and the parallel resonators P1-T1, P2-T1, P3-T1, P4-T1 are electrically connected to the wiring pattern 21. In the wiring pattern 21 between the first transmitting input pad Tx-T1 and the first transmitting antenna pad Ant-T1, the series resonators S1-T1, S2-T1, S3-T1, S4-T1, S5-T1 are arranged relative to the first transmitting input pad Tx-T1 from near to far in the aforementioned order. In the wiring pattern 21 between the first transmitting input pad Tx-T1 and the first transmitting antenna pad Ant-T1, the parallel resonators P1-T1, P2-T1, P3-T1, and P4-T1 are arranged relative to the first transmitting input pad Tx-T1 from near to far in the aforementioned order. The series resonators S1-T1, S2-T1, S3-T1, S4-T1, and S5-T1, along with the parallel resonators P1-T1, P2-T1, P3-T1, and P4-T1, function as a first transmitting filter.

[0075] The first transmit pads Tx-T1 are used as the input pads of the first transmit filter. The first transmit pads Ant-T1 are used as the output pads of the first transmit filter. The first transmit pads GND-T1 are used as the ground pads of the first transmit filter.

[0076] Once an electrical signal is input to the first transmitting input pad Tx-T1, only the electrical signal corresponding to the transmitting frequency band of frequency band 1 will pass completely through the series resonators S1-T1, S2-T1, S3-T1, S4-T1, S5-T1 and the parallel resonators P1-T1, P2-T1, P3-T1, P4-T1. Therefore, the electrical signal corresponding to the transmitting frequency band of frequency band 1 will be output from the first transmitting antenna pad Ant-T1.

[0077] The second receiving chip 5c includes the wiring pattern 21, the second receiving antenna pad Ant-R2, the second receiving output pad Rx-R2, and a plurality of second receiving ground pads GND-R2.

[0078] In the second receiving chip 5c, the elastic wave element 22 includes a plurality of series resonators S1-R2, S2-R2, S3-R2, S4-R2 and a plurality of parallel resonators P1-R2, P2-R2, P3-R2, P4-R2. The series resonators S1-R2, S2-R2, S3-R2, S4-R2 and the parallel resonators P1-R2, P2-R2, P3-R2, P4-R2 are electrically connected to the wiring pattern 21. In the wiring pattern 21 between the second receiving output pad Rx-R2 and the second receiving antenna pad Ant-R2, the series resonators S1-R2, S2-R2, S3-R2, S4-R2 are arranged relative to the second receiving output pad Rx-R2 from near to far in the aforementioned order. In the wiring pattern 21 between the second receiving output pad Rx-R2 and the second receiving antenna pad Ant-R2, the parallel resonators P1-R2, P2-R2, P3-R2, and P4-R2 are arranged relative to the second receiving output pad Rx-R2 from near to far in the aforementioned order. The series resonators S1-R2, S2-R2, S3-R2, and S4-R2, along with the parallel resonators P1-R2, P2-R2, P3-R2, and P4-R2, function as a second receiving filter.

[0079] The second receiving antenna pad Ant-R2 serves as the input pad of the second receiving filter. The second receiving output pad Rx-R2 serves as the output pad of the second receiving filter. The second receiving ground pad GND-R2 serves as the ground pad of the second receiving filter.

[0080] Once an electrical signal is input to the second receiving antenna pad Ant-R2, only the electrical signal corresponding to the receiving frequency band of frequency band 3 will pass completely through the series resonators S1-R2, S2-R2, S3-R2, S4-R2 and the parallel resonators P1-R2, P2-R2, P3-R2, P4-R2. Therefore, the electrical signal corresponding to the receiving frequency band of frequency band 3 will be output from the second receiving output pad Rx-R2.

[0081] The second transmitting chip 5d includes the wiring pattern 21, the second transmitting input pads Tx-T2, the second transmitting antenna pad Ant-T2, and a plurality of second transmitting ground pads GND-T2.

[0082] In the second transmitting chip 5d, the elastic wave element 22 includes a plurality of series resonators S1-T2, S2-T2, S3-T2, S4-T2, S5-T2 and a plurality of parallel resonators P1-T2, P2-T2, P3-T2, P4-T2. The series resonators S1-T2, S2-T2, S3-T2, S4-T2, S5-T2 and the parallel resonators P1-T2, P2-T2, P3-T2, P4-T2 are electrically connected to the wiring pattern 21. In the wiring pattern 21 between the second transmitting input pad Tx-T2 and the second transmitting antenna pad Ant-T2, the series resonators S1-T2, S2-T2, S3-T2, S4-T2, S5-T2 are arranged relative to the second transmitting input pad Tx-T2 from near to far in the aforementioned order. In the wiring pattern 21 between the second transmitting input pad Tx-T2 and the second transmitting antenna pad Ant-T2, the parallel resonators P1-T2, P2-T2, P3-T2, and P4-T2 are arranged relative to the second transmitting input pad Tx-T2 in the aforementioned order from near to far. The series resonators S1-T2, S2-T2, S3-T2, S4-T2, and S5-T2, along with the parallel resonators P1-T2, P2-T2, P3-T2, and P4-T2, function as a second transmitting filter.

[0083] The second transmit uses input pads Tx-T2 as the input pads of the second transmit filter. The second transmit uses antenna pad Ant-T2 as the output pad of the second transmit filter. The second transmit uses ground pad GND-T2 as the ground pad of the second transmit filter.

[0084] Once an electrical signal is input to the second transmitting input pad Tx-T2, only the electrical signal corresponding to the transmitting frequency band of frequency band 3 will pass completely through the series resonators S1-T2, S2-T2, S3-T2, S4-T2, S5-T2 and the parallel resonators P1-T2, P2-T2, P3-T2, P4-T2. Therefore, the electrical signal corresponding to the transmitting frequency band of frequency band 3 will be output from the second transmitting antenna pad Ant-T2.

[0085] For example, the broadband attenuation circuit 23 is disposed on the circuit of the second transmitting chip 5d. The broadband attenuation circuit 23 corresponds to the band resonance between the second and third harmonics of the fundamental frequency of the second transmitting filter. For example, the broadband attenuation circuit 23 resonates in the band between 3 GHz and 7 GHz. For example, the broadband attenuation circuit 23 includes an inductor 23a and a capacitor 23b.

[0086] For example, the inductor 23a has an inductance value of 0.5nH to 4.0nH. Preferably, the inductor 23a has an inductance value of 1.9nH. For example, the capacitor 23b has a capacitance value of 0.2pF to 2.0pF. Preferably, the capacitor 23b has a capacitance value of 0.52pF.

[0087] One end of the inductor 23a is electrically connected to the wiring pattern 21 at the position where two adjacent series resonators are electrically connected, counting from one side of the second transmitting input pad Tx-T2. Specifically, one end of the inductor 23a is electrically connected to the wiring pattern 21 at the position where the first series resonator S1-T2 and the second series resonator S2-T2 are electrically connected, counting from one side of the second transmitting input pad Tx-T2.

[0088] One end of the capacitor element 23b is electrically connected to the other end of the inductor element 23a. The other end of the capacitor element 23b is electrically connected to the second transmitting grounding pad GND-T2.

[0089] Next, by means of Figure 3 and Figure 4 The configuration of the broadband attenuation circuit 23 is described.

[0090] Figure 3 This is a plan view of the first main surface of the second transmitting chip 5d in the first embodiment. Figure 4 This is a perspective view of the second main surface from the first main surface side of the second transmitting chip 5d in the first embodiment.

[0091] exist Figure 3 Three second transmitting grounding pads GND-T2 are formed on the upper, central and lower parts of the chip substrate 20, respectively, on the left outer edge of the chip substrate 20.

[0092] exist Figure 3 On the right outer edge of the chip substrate 20, the second transmitting antenna pad Ant-T2 is formed on the upper part of the chip substrate 20. The second transmitting ground pad GND-T2 is formed in the center of the chip substrate 20. The second transmitting input pad Tx-T2 is formed on the lower part of the chip substrate 20.

[0093] For example, the first via wiring 31a passes through the chip substrate 20 near the second transmitting input pads Tx-T2. One end of the first via wiring 31a is electrically connected to the wiring pattern 21 at the position where the first series resonator S1-T2 and the second series resonator S2-T2 are electrically connected, counting from one side of the second transmitting input pads Tx-T2.

[0094] For example, the second via wiring 31b passes through the chip substrate 20 near the second transmitting ground pad GND-T2 located in the center left side. One end of the second via wiring 31b is electrically connected to the second transmitting ground pad GND-T2 located in the center left side.

[0095] like Figure 4 As shown, the inductor element 23a has a serpentine portion 41a. The serpentine portion 41a is formed on the underside of the chip substrate 20 and extends back and forth between one side and the other side of the chip substrate 20. The inductor element 23a is formed with a metal pattern to obtain the desired inductance value. One end of the inductor element 23a is electrically connected to the other end of the first through-hole wiring 31a.

[0096] like Figure 4 As shown, the capacitor element 23b has a pair of comb-shaped portions 41b. The comb-shaped portions 41b are opposite to each other. The comb-shaped portions 41b are formed with a metal pattern to obtain the desired capacitance value. The other end of the capacitor element 23b is electrically connected to the other end of the second through-hole wiring 31b.

[0097] Next, by means of Figure 5 This describes a first example of the elastic wave element 22.

[0098] Figure 5 This is the first example of an elastic wave element 22 in the first embodiment that is equipped with the elastic wave device chip 5.

[0099] Figure 5 The example illustrates the case where the elastic wave element 22 is an elastic surface wave resonator. For example... Figure 5 As shown, an IDT (Interdigital Transducer) 22a and a pair of reflectors 22b are formed on the first main surface of the chip substrate 20. One of the reflectors 22b is adjacent to one side of the IDT 22a. The other reflector 22b is adjacent to the other side of the IDT 22a. The IDT 22a and the reflectors 22b are arranged in a manner that can excite elastic surface waves.

[0100] For example, the IDT 22a and the reflector 22b are formed of an alloy of aluminum and copper. Alternatively, the IDT 22a and the reflector 22b are formed of a suitable metal such as titanium, palladium, or silver, or an alloy thereof. For example, the IDT 22a and the reflector 22b can also be a multilayer metal structure composed of multiple stacked metal layers. For example, the thickness of the IDT 22a and the reflector 22b is 150 nm to 400 nm.

[0101] The IDT 22a has a pair of comb-shaped electrodes 22c. The comb-shaped electrodes 22c are opposite to each other. Each comb-shaped electrode 22c has a plurality of electrode fingers 22d and a bus bar 22e. The electrode fingers 22d extend longitudinally. The bus bar 22e connects the electrode fingers 22d.

[0102] Next, by means of Figure 6 This describes a second example of the elastic wave element 22.

[0103] Figure 6 This is a second example of an elastic wave element 22 in the first embodiment that is equipped with the elastic wave device chip 5.

[0104] Figure 6 The example illustrates the case where the elastic wave element 22 is an acoustic thin-film resonator. Figure 6 In the chip substrate 60, it is a semiconductor substrate such as silicon, or an insulating substrate such as sapphire, alumina, spinel or glass.

[0105] The chip substrate 60 is provided with a piezoelectric film 62. The material of the piezoelectric film 62 is, for example, aluminum nitride.

[0106] The lower electrode 64 and the upper electrode 66 sandwich the piezoelectric film 62 therein. The lower electrode 64 and the upper electrode 66 are made of metals such as ruthenium.

[0107] A gap 68 is formed between the lower electrode 64 and the chip substrate 60.

[0108] The lower electrode 64 and the upper electrode 66 excite elastic waves in the piezoelectric film 62 in a thickness longitudinal vibration mode.

[0109] Next, by means of Figures 7 to 9 Explain the impedance characteristics of the second receiving chip 5c and the second transmitting chip 5d.

[0110] Figures 7 to 9 The Smith charts showing the impedance characteristics of the elastic wave device 1 with the elastic wave device chip 5 installed in the first embodiment and the comparative example are shown.

[0111] Specifically, Figure 7 The Smith chart showing the impedance characteristics was observed from one side of the elastic wave device in the first embodiment, which is equipped with the elastic wave device chip 5, and the second receiving antenna pad Ant-R2 and the second transmitting antenna pad Ant-T2 in the comparative example. Figure 8 The Smith chart showing the impedance characteristics was observed from one side of the elastic wave device with the elastic wave device chip 5 installed in the first embodiment and the second receiving output pad Rx-R2 of the comparative example. Figure 9The Smith charts showing the impedance characteristics were observed from one side of the elastic wave device with the elastic wave device chip 5 installed in the first embodiment and the second transmitting antenna pad Ant-T2 in the comparative example.

[0112] exist Figures 7 to 9 In the diagram, dashed line A shows the impedance characteristics of a comparative example without the broadband attenuation circuit 23. Solid line B shows the impedance characteristics of the elastic wave device 1 of the first embodiment.

[0113] like Figures 7 to 9 The dotted line A and the solid line B are not significantly different.

[0114] By means of Figures 10 to 12 Explain the frequency characteristics of the second receiving chip 5c.

[0115] Figures 10 to 12 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device 1 with the elastic wave device chip 5 installed in the first embodiment and the comparative example.

[0116] Specifically, Figure 10 This is a schematic diagram of the insertion loss of the second receiving chip 5c in the first embodiment and the insertion loss of the second receiving chip 5c in the comparative example. The insertion loss is represented by the attenuation (dB). Figure 11 This is a schematic diagram of the attenuation of the second receiving chip 5c in the first embodiment and the attenuation of the second receiving chip 5c in the comparative example. Figure 12 This is a schematic diagram showing the attenuation of the second receiving chip 5c in the first embodiment and the attenuation of the second receiving chip 5c in the comparative example, with the frequency range extended to the third harmonic.

[0117] exist Figures 10 to 12 In the diagram, dashed line C shows the frequency characteristics of the second receiving chip 5c in the comparative example without the broadband attenuation circuit 23. Solid line D shows the frequency characteristics of the second receiving chip 5c of the elastic wave device 1 in the first embodiment.

[0118] like Figures 10 to 12 As shown, the dashed line C and the solid line D are not significantly different.

[0119] Next, by means of Figures 13 to 15 Explain the frequency characteristics of the second transmitting chip 5d. Figures 13 to 15 This is a schematic diagram of the simulation results of the frequency characteristics of the elastic wave device 1 with the elastic wave device chip 5 installed in the first embodiment and the comparative example.

[0120] Specifically, Figure 13This is a schematic diagram showing the insertion loss of the second transmitting chip 5d in the first embodiment and the insertion loss of the second transmitting chip 5d in the comparative example. Figure 14 This is a schematic diagram of the attenuation of the second transmitting chip 5d in the first embodiment and the attenuation of the second transmitting chip 5d in the comparative example. Figure 15 This is a schematic diagram showing the attenuation of the second transmitting chip 5d in the first embodiment and the attenuation of the second transmitting chip 5d in the comparative example, with the frequency range extended to the third harmonic.

[0121] exist Figures 13 to 15 In the diagram, dashed line E shows the frequency characteristics of the second transmitting chip 5d in the comparative example without the broadband attenuation circuit 23. Solid line F shows the frequency characteristics of the second transmitting chip 5d of the elastic wave device 1 in the first embodiment.

[0122] like Figure 13 As shown, the attenuation of the dashed line E and the solid line F reaches almost the same frequency at which they reach 5.0 dB. As shown in region W1, in the region with an attenuation of 3.0 dB, the width of the solid line F is approximately 1.2 MHz wider than the width of the dashed line E. Therefore, the transition width of the solid line F is improved by approximately 1.2 MHz compared to the transition width of the dashed line E.

[0123] like Figure 14 As shown, in regions W2 and W3, the attenuation of the solid line F is improved by approximately 5.0 dB compared to the attenuation of the dashed line E.

[0124] like Figure 15 As shown, in the second harmonic region W4, the attenuation of the solid line F is improved by approximately 4.0 dB compared to the attenuation of the dashed line E. In the third harmonic region W5, the attenuation of the solid line F is improved by approximately 7.0 dB compared to the attenuation of the dashed line E.

[0125] Next, by means of Figure 16 Explain the isolation characteristics between the second receiving chip 5c and the second transmitting chip 5d.

[0126] Figure 16 This is a schematic diagram of the simulation results of the isolation characteristics of the elastic wave device 1 with the elastic wave device chip 5 installed in the first embodiment and the comparative example.

[0127] exist Figure 16 In the diagram, the dashed line G shows the isolation characteristics of the comparative example without the broadband attenuation circuit 23. The solid line H shows the isolation characteristics of the elastic wave device 1 of the first embodiment.

[0128] like Figure 16As shown, in the receiving frequency band region W6 of the second receiving filter, the solid line H is improved by about 5.0 dB compared to the dashed line G.

[0129] According to the first embodiment, the broadband attenuation circuit 23 is electrically connected to the wiring pattern 21 via the first via wiring 31a at the position where two adjacent series resonators are electrically connected, counting from one side of the second transmitting input pad Tx-T2. Specifically, among the n (n is an integer greater than or equal to 3) series resonators, any two adjacent series resonators from the 1st to the mth (m is an integer greater than 1 and less than n / 2+1) counting from the second transmitting input pad Tx-T2 side are electrically connected to the wiring pattern 21 via the first via wiring 31a. Therefore, the filter characteristics of the second transmitting chip 5d can be improved, and the miniaturization of the second transmitting chip 5d can be achieved.

[0130] For example, the broadband attenuation circuit 23 is electrically connected to the wiring pattern 21 at the location where the first series resonator S1-T2 and the second series resonator S2-T2 are electrically connected, counting from one side of the second transmitting input pad Tx-T2. Therefore, the filter characteristics of the second transmitting chip 5d can be reliably improved.

[0131] Furthermore, the broadband attenuation circuit 23 is disposed on the second transmitting chip 5d. Therefore, the heat dissipation of the second transmitting chip 5d, which serves as the second transmitting filter, can be improved. Therefore, the voltage withstand capability of the second transmitting chip 5d can be improved.

[0132] Furthermore, the broadband attenuation circuit 23 is electrically connected to the second transmitting ground pad GND-T2 via the second via wiring 31b. Therefore, the filter characteristics of the second transmitting chip 5d can be reliably improved.

[0133] Furthermore, the broadband attenuation circuit 23 corresponds to the band resonance between the second and third harmonics of the fundamental frequency of the second transmitting filter. Therefore, it can reliably improve the filter characteristics of the second transmitting chip 5d.

[0134] Furthermore, the broadband attenuation circuit 23 resonates across the frequency band between 3 GHz and 7 GHz. Therefore, it can reliably improve the filter characteristics of the second transmitting chip 5d.

[0135] Furthermore, the broadband attenuation circuit 23 includes the inductor 23a and the capacitor 23b. With this simple construction, the filter characteristics of the second transmitting chip 5d can be improved.

[0136] Furthermore, the inductor 23a has an inductance value of 0.5nH to 4.0nH. The capacitor 23b has a capacitance value of 0.2pF to 2.0pF. Therefore, the filter characteristics of the second transmitting chip 5d can be reliably improved.

[0137] Alternatively, the broadband attenuation circuit 23 can be provided in one of the elastic wave device chips 5—the first receiving chip 5a, the first transmitting chip 5b, and the second receiving chip 5c. In this case, the filter characteristics of the elastic wave device chip 5 can be improved, and the miniaturization of the elastic wave device chip 5 can be achieved.

[0138] Furthermore, as a duplexer, one of the elastic wave device chips 5 can also function as the first receiving filter and the first transmitting filter. As a duplexer, one of the elastic wave device chips 5 can also function as the second receiving filter and the second transmitting filter. As a quadplexer, one of the elastic wave device chips 5 can also function as the first receiving filter, the first transmitting filter, the second receiving filter, and the second transmitting filter.

[0139] Furthermore, all of the series resonators and the parallel resonators can also be used as bandpass filters.

[0140] Furthermore, when the capacitor element 23b is formed with a metal pattern, air in the gaps of the metal pattern or resin in the sealing portion 17 can generate parasitic capacitance.

[0141] Here, the relative permittivity of lithium tantalate, which forms the chip substrate 20, is 40, the relative permittivity of air is 1, and the relative permittivity of resin is 3.6. Therefore, the capacitance generated by lithium tantalate is the primary factor, while the capacitance generated by air and resin is within the tolerance range.

[0142] For example, when the total capacitance generated by air is 0.52pF, the capacitance generated by lithium tantalate is 0.5pF, and the capacitance generated by air is 0.02pF. For example, when the total capacitance generated by resin is 0.52pF, the capacitance generated by lithium tantalate is 0.47pF, and the capacitance generated by resin is 0.05pF.

[0143] Therefore, even if resin enters the gaps in the metal pattern of the capacitor element 23b, the change in parasitic capacitance is very small. Thus, by adjusting the metal pattern and taking into account the magnitude of the parasitic capacitance, the desired capacitance value can be obtained within the expected frequency range.

[0144] Furthermore, the metal pattern of the inductor element 23a can also achieve the desired inductance value within the expected frequency range using the same approach.

[0145] Furthermore, the broadband attenuation circuit 23 can be covered with resin before the wafer is diced into the elastic wave device chip 5. This allows the elastic wave device chip 5 to be diced while protecting the broadband attenuation circuit 23. Moreover, when bonding the elastic wave device chip 5 to the wiring substrate 3 using a flip-chip bonding process, ultrasonic bonding can be performed on the second main surface of the elastic wave device chip 5 where the broadband attenuation circuit 23 is formed. In this case, when performing the flip-chip bonding process using ultrasonic bonding, the resin covering the broadband attenuation circuit 23 is preferably a resin with sufficient hardness to protect the broadband attenuation circuit 23.

[0146] Next, using Figure 17 Explaining a variation of the elastic wave device 1.

[0147] Figure 17 This is a cross-sectional view of a variation of the elastic wave device 1 in the first embodiment, in which the elastic wave device chip 5 is installed.

[0148] like Figure 17 As shown, the chip substrate 20 has a piezoelectric substrate 20a and a support substrate 20b. For example, the piezoelectric substrate 20a is made of lithium tantalate or lithium niobate. For example, the support substrate 20b is made of sapphire, silicon, alumina, spinel, crystal, or glass. The support substrate 20b is bonded to the upper surface of the piezoelectric substrate 20a.

[0149] The wiring pattern 21 is formed on the lower surface of the piezoelectric substrate 20a. The elastic wave element 22 is formed on the lower surface of the piezoelectric substrate 20a. The broadband attenuation circuit 23 is formed on the upper surface of the support substrate 20b.

[0150] According to the aforementioned variation, the heat dissipation of the chip substrate 20 is improved by the piezoelectric substrate 20a and the support substrate 20b. Therefore, the voltage withstand capability of the chip substrate 20 can be improved.

[0151] (Second Embodiment)

[0152] Figure 18 This is a cross-sectional view of a module in the second embodiment that includes an elastic wave device on which the elastic wave device chip is mounted. It should be understood that the same or equivalent parts as in the first embodiment are referred to by the same reference numerals. Descriptions of these same or equivalent parts will be omitted.

[0153] exist Figure 18 In the module 100, there are wiring board 130, integrated circuit component IC, elastic wave device 1, integrated circuit 111 and sealing part 117.

[0154] The wiring substrate 130 is the same as the wiring substrate 3 in the first embodiment.

[0155] The integrated circuit component IC is mounted on the wiring substrate 130. The integrated circuit component IC includes a switching circuit and a low-noise amplifier.

[0156] The elastic wave device 1 is installed on the main surface of the wiring substrate 130.

[0157] The integrated circuit 111 is mounted on the main surface of the wiring substrate 130. The integrated circuit 111 is mounted for impedance matching. For example, the integrated circuit 111 is an integrated passive device (IPD).

[0158] The sealing part 117 seals multiple electronic components, including the elastic wave device 1.

[0159] Next, by means of Figure 19 Explain the integrated circuit 111.

[0160] Figure 19 This is a circuit diagram of a module in the second embodiment that includes an elastic wave device having the elastic wave device chip installed.

[0161] like Figure 19 As shown, the module 100 includes a first receiving end P-R1, a first transmitting end P-T1, a second receiving end P-R2, a second transmitting end P-T2, and an antenna end P-Ant.

[0162] The first receiving terminal P-R1 is electrically connected to the first receiving output pad Rx-R1. The first transmitting terminal P-T1 is electrically connected to the first transmitting input pad Tx-T1. The second receiving terminal P-R2 is electrically connected to the second receiving output pad Rx-R2. The second transmitting terminal P-T2 is electrically connected to the second transmitting input pad Tx-T2. The antenna terminal P-Ant is electrically connected to the first receiving antenna pad Ant-R1, the first transmitting antenna pad Ant-T1, the second receiving antenna pad Ant-R2, and the second transmitting antenna pad Ant-T2.

[0163] The integrated circuit 111 includes a series inductor 111a, a parallel inductor 111b, and a terminating impedance 111c.

[0164] One end of the series inductor 111a is electrically connected to the second transmitting input pad Tx-T2. The other end of the series inductor 111a is electrically connected to the second transmitting terminal P-T2. For example, the series inductor 111a has an inductance value of 0.5nH to 10nH. Preferably, the series inductor 111a has an inductance value of 5nH.

[0165] One end of the parallel inductor 111b is electrically connected to the wiring between the series inductor 111a and the second transmitting input pads Tx-T2. The other end of the parallel inductor 111b is grounded. For example, the parallel inductor 111b has an inductance value of 5nH to 50nH. Preferably, the parallel inductor 111b has an inductance value of 25nH.

[0166] One end of the terminating impedance 111c is electrically connected to the wiring between the other end of the series inductor 111a and the second transmitting terminal P-T2. The other end of the terminating impedance 111c is grounded. The impedance value of the terminating impedance 111c is designed to suppress the reflection of the output signal at the second transmitting terminal P-T2. For example, the terminating impedance 111c is 50Ω.

[0167] According to the second embodiment, the module 100 includes the elastic wave device 1 of the first embodiment. Therefore, the filter characteristics of the module 100 can be improved, and the miniaturization of the module 100 can be achieved.

[0168] Furthermore, the module 100 includes the integrated circuit 111. Therefore, impedance matching of the module 100 can be reliably achieved.

[0169] Furthermore, the series inductor 111a has an inductance value of 0.5nH to 10nH. The parallel inductor 111b has an inductance value of 5nH to 50nH. Therefore, impedance matching of the module 100 can be reliably achieved.

[0170] While at least one embodiment has been described above, it should be understood that various changes, modifications, or improvements will readily occur to those skilled in the art. These changes, modifications, or improvements are also part of and fall within the scope of this disclosure.

[0171] It should be understood that the embodiments of the methods or apparatus described herein are not limited to the architecture and arrangement of the constituent components described above or illustrated in the accompanying drawings. The methods and apparatus can be installed or performed in other embodiments.

[0172] The embodiments described are for illustrative purposes only and are not intended to be limiting.

[0173] The descriptions and terms used in this disclosure are for illustrative purposes only and are not intended to be limiting. The use of "including," "possessing," "having," "comprise," and variations thereof here means to include the items listed below, their equivalents, and additional items.

[0174] The word “or”, or any word used in a description, may be interpreted as one, more than one, or all of the descriptive terms.

[0175] The references to front, back, left, right, top, bottom, upper, lower, and horizontal and vertical are for ease of description and are not intended to limit the position and spatial configuration of any component in this invention. Therefore, the above description and drawings are merely exemplary.

Claims

1. An elastic wave device chip, characterized by: The elastic wave device chip includes: Chip substrate; Several series resonators are formed on the first main surface of the chip substrate; Several parallel resonators are formed on the first main surface of the chip substrate; Input pads are formed on the first main surface of the chip substrate; Output pads are formed on the first main surface of the chip substrate; A grounding pad is formed on the first main surface of the chip substrate; Wiring patterns are formed on the first main surface of the chip substrate and electrically connected to the series resonator, the parallel resonator, the input pad, the output pad, and the ground pad; The first through-hole wiring penetrates the chip substrate; and A broadband attenuation circuit is formed on a second main surface of the chip substrate opposite to the first main surface. One end of the circuit is electrically connected to the wiring pattern via the first via wiring at the position where two adjacent series resonators are electrically connected on the first half side counting from one side of the input pad.

2. The elastic wave device chip according to claim 1, characterized by: The broadband attenuation circuit is electrically connected to the wiring pattern via the first via wiring at the location where the first series resonator and the second series resonator are electrically connected, counting from one side of the input pad.

3. The elastic wave device chip according to claim 2, characterized by: The series resonator and the parallel resonator are used as transmitting filters.

4. The elastic wave device chip according to any one of claims 1 to 3, characterized by: The elastic wave device chip also includes a second through-hole wiring that penetrates the chip substrate, and the other end of the broadband attenuation circuit is electrically connected to the grounding pad through the second through-hole wiring.

5. The elastic wave device chip according to any one of Claims 1 to 3, characterized by: When the series resonator and the parallel resonator are used as elastic wave filters, the broadband attenuation circuit achieves band resonance between the second and third harmonics of the fundamental wave corresponding to the frequency of the elastic wave filter.

6. The elastic wave device chip according to any one of claims 1 to 3, characterized by: The broadband attenuation circuit resonates in the frequency band between 3 GHz and 7 GHz.

7. The elastic wave device chip according to any one of Claims 1 to 3, wherein: The broadband attenuation circuit includes inductors and capacitors.

8. The elastic wave device chip according to claim 7, characterized by: The inductor has an inductance value of 0.5nH to 4.0nH, and the capacitor has a capacitance value of 0.2pF to 2.0pF.

9. The elastic wave device chip according to any one of Claims 1 to 3, wherein: The chip substrate includes a piezoelectric substrate and a support substrate made of sapphire, silicon, alumina, spinel, crystal or glass and bonded to the piezoelectric substrate.

10. The elastic wave device chip according to any one of claims 1 to 3, characterized by: The series resonator and the parallel resonator are each elastic surface wave resonators, and the series resonator and the parallel resonator together are used as a bandpass filter or a duplexer.

11. The elastic wave device chip according to any one of claims 1 to 3, characterized by: The series resonator and the parallel resonator are each acoustic thin-film resonators, and the series resonator and the parallel resonator together are used as a bandpass filter or a duplexer.

12. An elastic wave device characterized by: The elastic wave device comprises: an elastic wave device chip according to any one of claims 1 to 11, and a wiring substrate electrically connected to the elastic wave device chip.

13. A module characterized by: The module comprises: an elastic wave device chip according to any one of claims 1 to 11, or an elastic wave device according to claim 12.

14. The module of claim 13, wherein: The module also includes integrated circuitry electrically connected to the input pads.

15. The module of claim 14, wherein: The integrated circuit includes a series inductor with an inductance value of 0.5nH to 10nH and a parallel inductor with an inductance value of 5nH to 50nH.

Images