Patent Application
20250038773
A structure may include a transmission filter (fifth filter) which is provided at a main surface of a mounting board, and another transmission filter (sixth filter) which is stacked on the above transmission filter.
According to an aspect of the present disclosure, a radio frequency module includes a mounting board, a first acoustic wave filter, a second acoustic wave filter, a first resin layer, and a first shield electrode. The mounting board has a first main surface and includes a first ground electrode. The first acoustic wave filter is disposed at the first main surface of the mounting board. The second acoustic wave filter is disposed on the first acoustic wave filter. The first resin layer covers at least a part of the first acoustic wave filter and the second acoustic wave filter. The first shield electrode covers at least a part of the first resin layer. Both the first acoustic wave filter and the second acoustic wave filter are filters that support at least transmission. A first transmission signal passing through the first acoustic wave filter and a second transmission signal passing through the second acoustic wave filter are capable of simultaneous communication. A second main surface of the second acoustic wave filter on an opposite side from a first acoustic wave filter side is in contact with the first shield electrode. The first acoustic wave filter includes a first functional electrode. The first ground electrode of the mounting board is connected to the first functional electrode of the first acoustic wave filter.
The present disclosure generally relates to a radio frequency module and a communication device, and more particularly relates to a radio frequency module including a plurality of filters and a communication device including the radio frequency module.
According to an aspect of the present disclosure, a communication device includes the radio frequency module and a signal processing circuit. The signal processing circuit is connected to the radio frequency module.
With the radio frequency module and the communication device according to the aspects of the present disclosure, it is possible to improve heat dissipation properties of two transmission filters in a case of transmitting two transmission signals capable of simultaneous communication.
However, in the structure described in the Background, in a case where the simultaneous communication is performed by transmission signals passing through the two transmission filters, it is necessary to improve heat dissipation properties of the two transmission filters.
the present disclosure provides a radio frequency module and a communication device capable of improving heat dissipation properties of two transmission filters in a case of transmitting two transmission signals capable of simultaneous communication.
Hereinafter, radio frequency modules and communication devices according to exemplary embodiments 1 to 5 will be described with reference to the drawings. The drawings referred to in exemplary embodiments 1 to 5 as follows are all schematic drawings, and the ratios of the respective sizes and thicknesses of the constituent elements in the drawings do not necessarily reflect the actual dimensional ratios.
First, a configuration of a radio frequency module 1 according to exemplary embodiment 1 will be described with reference to the drawings.
A radio frequency module 1 is used, for example, in a communication device 10 as shown in
The radio frequency module 1 is, for example, a module capable of supporting carrier aggregation and dual connectivity. Carrier aggregation and dual connectivity refer to a technology used for communication that uses radio waves in a plurality of frequency bands at the same time.
The communication device 10 performs communication in a plurality of communication bands. More specifically, the communication device 10 transmits a transmission signal in each of a plurality of communication bands and receives a reception signal in each of the plurality of communication bands. Specifically, the radio frequency module 1 receives a reception signal in a first communication band and a reception signal in a second communication band. In addition, the radio frequency module 1 transmits a transmission signal in the first communication band and a transmission signal in the second communication band.
The transmission signal and the reception signal in the first communication band are, for example, frequency division duplex (FDD) signals. In addition, the transmission signal and the reception signal in the second communication band are FDD signals. FDD is a communication technology that allocates different frequency regions to transmission and reception in radio communication and performs transmission and reception.
The first communication band is, for example, Band 1 of the 3GPP LTE standard. In addition, the second communication band is, for example, Band 3 of the 3GPP LTE standard. The power classes of Band 1 and Band 3 are being examined. The signal of the power class 2 has a signal strength higher than the signal of the power class 3. That is, the signal strength of the transmission signal in the second communication band is higher than the communication strength of the transmission signal in the first communication band.
Next, a circuit configuration of the radio frequency module 1 according to exemplary embodiment 1 will be described with reference to
As shown in
As shown in
The common terminal 110 is connected to the antenna terminal 181. The selection terminal 111 is connected to the matching circuit 171. In addition, the selection terminal 112 is connected to the matching circuit 172.
The first switch 11 switches the connection between the common terminal 110, and the plurality of selection terminals 111 and 112. The first switch 11 is controlled by, for example, a signal processing circuit 2. The first switch 11 electrically connects the common terminal 110 to any one of the plurality of selection terminals 111 and 112 in accordance with a control signal from an RF signal processing circuit 21 of the signal processing circuit 2.
The first transmission filter 121 and the second transmission filter 131 are filters that cause signals in frequency bands different from each other to pass therethrough. More specifically, the first transmission filter 121 is a filter that causes a transmission signal in the first communication band to pass through the first transmission filter 121. The second transmission filter 131 is a filter that causes a transmission signal of the second communication band to pass through the second transmission filter 131.
As will be described later, each of the first transmission filter 121 and the second transmission filter 131 is an acoustic wave filter having one or more acoustic wave resonators. In the present exemplary embodiment, the first transmission filter 121 is a first acoustic wave filter. In addition, in the present exemplary embodiment, the second transmission filter 131 is a second acoustic wave filter. As will be described later, the first transmission filter 121 and the second transmission filter 131 are included in a first electronic component 51 that is a single electronic component.
The first reception filter 122 and the second reception filter 132 are filters that cause signals in frequency bands different from each other to pass therethrough. More specifically, the first reception filter 122 is a filter that causes a reception signal in the first communication band to pass through the first reception filter 122. The second reception filter 132 is a filter that causes a reception signal in the second communication band to pass through the second reception filter 132.
As will be described later, each of the first reception filter 122 and the second reception filter 132 is an acoustic wave filter having one or more acoustic wave resonators. The first reception filter 122 and the second reception filter 132 are included in a single electronic component as will be described later.
The power amplifier 141 is an amplifier that amplifies a transmission signal. More specifically, the power amplifier 141 amplifies a transmission signal in the first communication band. The power amplifier 141 is provided between the first transmission filter 121 and the first input terminal 182. The power amplifier 141 includes an input terminal and an output terminal. The input terminal of the power amplifier 141 is connected to an external circuit (for example, the signal processing circuit 2) with the first input terminal 182 interposed therebetween. The output terminal of the power amplifier 141 is connected to the matching circuit 173. The power amplifier 141 is controlled by, for example, a controller.
The power amplifier 142 is an amplifier that amplifies a transmission signal. More specifically, the power amplifier 142 amplifies a transmission signal in the second communication band. The power amplifier 142 is provided between the second transmission filter 131 and the second input terminal 183. The power amplifier 142 includes an input terminal and an output terminal. The input terminal of the power amplifier 142 is connected to the external circuit (for example, the signal processing circuit 2) with the second input terminal 183 interposed therebetween. The output terminal of the power amplifier 142 is connected to the matching circuit 174. The power amplifier 142 is controlled by, for example, a controller.
The low-noise amplifier 151 is an amplifier that amplifies a reception signal with a low noise. More specifically, the low-noise amplifier 151 amplifies a reception signal in the first communication band. The low-noise amplifier 151 is provided between the first reception filter 122 and the output terminal 184. The low-noise amplifier 151 includes an input terminal and an output terminal. The input terminal of the low-noise amplifier 151 is connected to the matching circuit 175. The output terminal of the low-noise amplifier 151 is connected to an external circuit (for example, the signal processing circuit 2) with the selection terminal 161 of the second switch 16 interposed therebetween.
The low-noise amplifier 152 is an amplifier that amplifies a reception signal with a low noise. More specifically, the low-noise amplifier 152 amplifies a reception signal in the second communication band. The low-noise amplifier 152 is provided between the second reception filter 132 and the output terminal 184. The low-noise amplifier 152 includes an input terminal and an output terminal. The input terminal of the low-noise amplifier 152 is connected to the matching circuit 176. The output terminal of the low-noise amplifier 152 is connected to an external circuit (for example, the signal processing circuit 2) with the selection terminal 162 of the second switch 16 interposed therebetween.
As shown in
The common terminal 160 is connected to the output terminal 184. The selection terminal 161 is connected to the low-noise amplifier 151. In addition, the selection terminal 162 is connected to the low-noise amplifier 152.
The second switch 16 switches the connection between the common terminal 160, and the plurality of selection terminals 161 and 162. The second switch 16 is controlled by, for example, the signal processing circuit 2. The second switch 16 electrically connects the common terminal 160 to any one of the plurality of selection terminals 161 and 162 in accordance with a control signal from the RF signal processing circuit 21 of the signal processing circuit 2.
The plurality of matching circuits 171 to 176 are circuits for performing impedance matching of a circuit connected with each of the matching circuits 171 to 176 interposed therebetween. The matching circuit 171 is provided between the first switch 11, and the first transmission filter 121 and the first reception filter 122. The matching circuit 172 is provided between the first switch 11, and the second transmission filter 131 and the second reception filter 132. The matching circuit 173 is provided between the first transmission filter 121 and the power amplifier 141. The matching circuit 174 is provided between the second transmission filter 131 and the power amplifier 142. The matching circuit 175 is provided between the first reception filter 122 and the low-noise amplifier 151. The matching circuit 176 is provided between the second reception filter 132 and the low-noise amplifier 152.
Each of the matching circuits 171 to 176 has a configuration including, for example, one or more inductors or one or more capacitors.
The plurality of external connection terminals 18 are terminals for electrical connection to an external circuit (for example, the signal processing circuit 2). The plurality of external connection terminals 18 include the antenna terminal 181, the first input terminal 182, the second input terminal 183, the output terminal 184, a plurality of control terminals, and a plurality of ground terminals.
The antenna terminal 181 is connected to an antenna 3. In the radio frequency module 1, the antenna terminal 181 is connected to the common terminal 110 of the first switch 11.
The first input terminal 182 is a terminal for inputting a transmission signal from the external circuit (for example, the signal processing circuit 2) to the radio frequency module 1. More specifically, the first input terminal 182 receives an input of a transmission signal in the first communication band. In the radio frequency module 1, the first input terminal 182 is connected to the input terminal of the power amplifier 141.
The second input terminal 183 is a terminal for inputting a transmission signal from the external circuit (for example, the signal processing circuit 2) to the radio frequency module 1. More specifically, the second input terminal 183 receives an input of a transmission signal in the second communication band. In the radio frequency module 1, the second input terminal 183 is connected to the input terminal of the power amplifier 142.
The output terminal 184 is a terminal for outputting a reception signal from the radio frequency module 1 to the external circuit (for example, the signal processing circuit 2). More specifically, the output terminal 184 outputs a reception signal in the first communication band or a reception signal in the second communication band. In the radio frequency module 1, the output terminal 184 is connected to the common terminal 160 of the second switch 16.
The plurality of ground terminals are terminals that are electrically connected to a ground electrode of an external board included in the communication device 10, and to which a ground potential is applied. In the radio frequency module 1, the plurality of ground terminals are connected to a ground electrode 43 (see
Next, a structure of the radio frequency module 1 according to exemplary embodiment 1 will be described with reference to
As shown in
The radio frequency module 1 is electrically connected to an external board. The external board is, for example, a mother board of the communication device 10 (see
As shown in
The mounting board 4 is a multilayer substrate in which a plurality of dielectric layers are laminated. The mounting board 4 has a plurality of conductive layers and a plurality of via conductors (including through-electrodes). The plurality of conductive layers include the ground electrode 43 having a ground potential. In the present exemplary embodiment, the ground electrode 43 is a first ground electrode. The plurality of via conductors are used for electrical connection between the elements (including the first electronic component 51, the second electronic component 52, the third electronic component 53, the fourth electronic component 54, the fifth electronic component 55, and the sixth electronic component 56 described above) mounted on both the main surface 41 and the main surface 42 and the conductive layers of the mounting board 4.
As illustrated in
Each of the two acoustic wave filters included in the first electronic component 51 is, for example, an acoustic wave filter including a plurality of series arm resonators and a plurality of parallel arm resonators. For example, the acoustic wave filter is a surface acoustic wave (SAW) filter using a surface acoustic wave. Further, each of the two acoustic wave filters included in the first electronic component 51 may include at least one of an inductor and a capacitor connected in series to any of the plurality of series arm resonators. In addition, each of the two acoustic wave filters included in the first electronic component 51 may include an inductor or a capacitor connected in series to any of the plurality of parallel arm resonators.
In addition, in a plan view from the thickness direction D1 of the mounting board 4, the first electronic component 51 including the first transmission filter 121 and the second transmission filter 131 overlap the ground electrode 43 of the mounting board 4. Here, the phrase that the first electronic component 51 overlaps the ground electrode 43 of the mounting board 4 in a plan view from the thickness direction D1 of the mounting board 4 means that, in a plan view from the thickness direction D1 of the mounting board 4, there is a region including at least a part of the first electronic component 51 and at least a part of the ground electrode 43.
As shown in
As shown in
As shown in
As shown in
As shown in
The first resin layer 681 (see
The second resin layer 682 (see
The first shield electrode 69 (see
The mounting board 4 shown in
Further, the mounting board 4 is not limited to the LTCC substrate, and may be, for example, a wiring structural body. The wiring structural body is, for example, a multilayer structural body. The multilayer structural body includes at least one insulating layer and at least one conductive layer. The insulating layer is formed in a predetermined pattern. In a case where a plurality of insulating layers are provided, the plurality of insulating layers are formed in a predetermined pattern determined for each layer. The conductive layer is formed in a predetermined pattern different from the predetermined pattern of the insulating layer. In a case where a plurality of conductive layers are provided, the plurality of conductive layers are formed in a predetermined pattern determined for each layer. The conductive layer may include one or a plurality of rewiring portions. In the wiring structural body, a first surface of two surfaces facing each other in a thickness direction of the multilayer structural body is the main surface 41 of the mounting board 4, and a second surface is the main surface 42 of the mounting board 4. The wiring structural body may be, for example, an interposer. The interposer may be an interposer using a silicon substrate or may be a substrate constituted by multiple layers.
The main surface 41 and the main surface 42 of the mounting board 4 are separated in the thickness direction D1 of the mounting board 4, and intersect with the thickness direction D1 of the mounting board 4. The main surface 41 of the mounting board 4 is, for example, perpendicular to the thickness direction D1 of the mounting board 4, and may include, for example, a side surface or the like of a conductor portion as a surface that is not perpendicular to the thickness direction D1 of the mounting board 4. In addition, the main surface 42 of the mounting board 4 is, for example, perpendicular to the thickness direction D1 of the mounting board 4, and may include, for example, a side surface or the like of a conductor portion as a surface that is not perpendicular to the thickness direction D1 of the mounting board 4. In addition, fine irregularities, recesses, or protrusions may be formed in the main surface 41 and the main surface 42 of the mounting board 4.
A detailed structure of the first electronic component 51 shown in
The first electronic component 51 includes the first transmission filter 121 and the second transmission filter 131 as two acoustic wave filters. As shown in
As shown in
The materials of the first piezoelectric layer 63A and the second piezoelectric layer 63B are, for example, lithium niobate or lithium tantalate. The materials of the first low acoustic velocity film 62A and the second low acoustic velocity film 62B are, for example, silicon oxide. In the first low acoustic velocity film 62A, the acoustic velocity of a bulk wave propagating in the first low acoustic velocity film 62A is lower than the acoustic velocity of a bulk wave propagating in the first piezoelectric layer 63A. In addition, in the second low acoustic velocity film 62B, the acoustic velocity of a bulk wave propagating in the second low acoustic velocity film 62B is lower than the acoustic velocity of a bulk wave propagating in the second piezoelectric layer 63B. The materials of the first low acoustic velocity film 62A and the second low acoustic velocity film 62B are not limited to silicon oxide, and may be, for example, silicon oxide, glass, silicon oxynitride, tantalum oxide, a compound obtained by adding fluorine, carbon, or boron to silicon oxide, or a material containing the above-described materials as a main component.
Each of the first substrate 61A and the second substrate 61B is, for example, a silicon substrate. That is, the materials of the first substrate 61A and the second substrate 61B of the first electronic component 51 are silicon. In the first substrate 61A, the acoustic velocity of a bulk wave propagating in the first substrate 61A is higher than the acoustic velocity of a bulk wave propagating in the first piezoelectric layer 63A. Here, the bulk wave propagating in the first substrate 61A is a bulk wave having the lowest acoustic velocity among a plurality of bulk waves propagating in the first substrate 61A. In the present exemplary embodiment, a high acoustic velocity member is constituted by the first substrate 61A and the first low acoustic velocity film 62A provided on the first substrate 61A. In addition, in the present exemplary embodiment, the first substrate 61A is a first support substrate formed of a silicon substrate. Similarly, in the second substrate 61B, the acoustic velocity of a bulk wave propagating in the second substrate 61B is higher than the acoustic velocity of a bulk wave propagating in the second piezoelectric layer 63B. Here, the bulk wave propagating in the second substrate 61B is a bulk wave having the lowest acoustic velocity among a plurality of bulk waves propagating in the second substrate 61B. In addition, in the present exemplary embodiment, the second substrate 61B is a second support substrate formed of a silicon substrate. In addition, the materials of the first substrate 61A and the second substrate 61B are not limited to silicon, and may be, for example, materials containing, as a main component, any one of aluminum nitride, aluminum oxide, silicon carbide, silicon nitride, sapphire, lithium tantalate, lithium niobate, quartz, alumina, zirconia, cordierite, mullite, steatite, forsterite, magnesia, and diamond.
The main surface 611A of the first substrate 61A and the main surface 611B of the second substrate 61B face each other in the first direction D1. That is, the second transmission filter 131 is disposed on the first transmission filter 121. In addition, as shown in
In addition, as shown in
A relationship between the first resin layer 681 and the second resin layer 682, and the first electronic component 51 will be described below in detail.
The first resin layer 681 covers at least a part of the first transmission filter 121 and the second transmission filter 131 in the first electronic component 51. Here, the first resin layer 681 covers the outer peripheral surface of each of the first substrate 61A, the first low acoustic velocity film 62A, the first piezoelectric layer 63A, the conductor 661, the frame 662, the second piezoelectric layer 63B, the second low acoustic velocity film 62B, and the second substrate 61B.
The second resin layer 682 is located between the first substrate 61A and the mounting board 4 in the first electronic component 51. More specifically, the second resin layer 682 is disposed between the main surface 612A of the first substrate 61A and the main surface 41 of the mounting board 4. Here, the second resin layer 682 may be located on the ground electrode 43 of the mounting board 4.
The first resin layer 681 and the second resin layer 682 contains a resin (for example, an epoxy resin). The first resin layer 681 and the second resin layer 682 may contain a filler in addition to the resin.
A relationship between the first shield electrode 69 and the first electronic component 51 will be described below in detail.
The first shield electrode 69 covers at least a part of the first resin layer 681. Here, the first shield electrode 69 is in contact with the main surface 133 of the second transmission filter 131 in the first electronic component 51.
The first shield electrode 69 has a multilayer structure in which a plurality of metal layers are laminated, but is not limited to the multilayer structure, and may be one metal layer. One metal layer includes one type or a plurality of types of metal.
As shown in
The antenna 3 is connected to the antenna terminal 181 of the radio frequency module 1. The antenna 3 has a transmission function of emitting a transmission signal output from the radio frequency module 1 as radio waves, and a reception function of receiving a reception signal from an outside as radio waves and outputting the reception signal to the radio frequency module 1.
The signal processing circuit 2 includes the RF signal processing circuit 21 and a baseband signal processing circuit 22. The signal processing circuit 2 processes a signal passing through the radio frequency module 1. More specifically, the signal processing circuit 2 processes the transmission signal and the reception signal.
For example, the RF signal processing circuit 21 is a radio frequency integrated circuit (RFIC). The RF signal processing circuit 21 performs signal processing on a radio frequency signal.
The RF signal processing circuit 21 performs signal processing such as up-conversion on a radio frequency signal output from the baseband signal processing circuit 22, and outputs the radio frequency signal subjected to the signal processing to the radio frequency module 1. Specifically, the RF signal processing circuit 21 performs signal processing such as up-conversion on the transmission signal output from the baseband signal processing circuit 22, and outputs the transmission signal subjected to the signal processing to the first input terminal 182 or the second input terminal 183 of the radio frequency module 1.
The RF signal processing circuit 21 performs signal processing such as down-conversion on a radio frequency signal output from the radio frequency module 1, and outputs the radio frequency signal subjected to the signal processing to the baseband signal processing circuit 22. Specifically, the RF signal processing circuit 21 performs signal processing on the reception signal output from the output terminal 184 of the radio frequency module 1, and outputs the reception signal subjected to the signal processing to the baseband signal processing circuit 22.
For example, the baseband signal processing circuit 22 is a baseband integrated circuit (BBIC). The baseband signal processing circuit 22 performs predetermined signal processing on the transmission signal from the outside of the signal processing circuit 2. The reception signal processed by the baseband signal processing circuit 22 is used, for example, as an image signal for an image display or as an audio signal for a call.
In addition, the RF signal processing circuit 21 also has a function as a control unit that controls each of the first switch 11 and the second switch 16 included in the radio frequency module 1 based on the transmission and reception of the radio frequency signals (transmission signal and reception signal). Specifically, the RF signal processing circuit 21 switches the connection of each of the first switch 11 and the second switch 16 of the radio frequency module 1 by a control signal. The control unit may be provided outside the RF signal processing circuit 21, and may be provided in the radio frequency module 1 or the baseband signal processing circuit 22, for example.
The first shield electrode 69 and the second shield electrode 65 will be described in detail with reference to the drawings.
As shown in
In addition, in the radio frequency module 1 according to exemplary embodiment 1, the first IDT electrode 641A and the ground electrode 43 of the mounting board 4 are electrically connected to each other. Thus, heat generated in the first IDT electrode 641A is dissipated to the ground electrode 43 of the mounting board 4 through electrical connection. In addition, in the radio frequency module 1 according to exemplary embodiment 1, the ground electrode of the first transmission filter 121 and the ground electrode of the second transmission filter 131 are connected to the ground electrode 43 of the mounting board 4 with the conductor 661, the frame 662, the via conductor 671, and the bump 672 interposed therebetween. Thus, the heat generated in the first IDT electrode 641A is likely to be dissipated to the ground electrode 43 of the mounting board 4 that is electrically connected. Further, in the radio frequency module 1 according to exemplary embodiment 1, there is the second resin layer 682 between the first transmission filter 121 and the ground electrode 43 of the mounting board 4. In addition, in the radio frequency module 1 according to exemplary embodiment 1, in a plan view from the thickness direction D1 of the mounting board 4, the first transmission filter 121 and the ground electrode 43 of the mounting board 4 overlap each other. Thus, the heat generated in the first IDT electrode 641A is likely to be dissipated to the ground electrode 43 of the mounting board 4 that is electrically connected. As a result, it is possible to reduce the influence of the heat generated in the first transmission filter 121 on the second transmission filter 131.
In addition, as shown in
In the radio frequency module 1 according to exemplary embodiment 1, the first resin layer 681 covers at least a part of the first transmission filter 121 and the second transmission filter 131, and the first shield electrode 69 covers at least a part of the first resin layer 681. Thus, it is possible to dissipate the heat generated in the first transmission filter 121 and the second transmission filter 131 through the first shield electrode 69.
In addition, in the radio frequency module 1 according to exemplary embodiment 1, the first shield electrode 69 is in contact with the main surface 133 of the second transmission filter 131 on an opposite side from the first transmission filter 121 side. Thus, the heat generated in the acoustic wave resonator of the second transmission filter 131 is dissipated from the first shield electrode 69. Thus, the heat dissipation properties of the second transmission filter 131 are improved, and it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121.
In addition, in the radio frequency module 1 according to exemplary embodiment 1, the conductor 661 located between the second substrate 61B and the first substrate 61A and the via conductor 671 that penetrates the first substrate 61A in the first direction D1 are connected to the ground electrode 43 of the mounting board 4. Thus, the conductor 661 and the via conductor 671 function as a heat conduction path from the first IDT electrode 641A to the ground electrode 43. Thus, it is possible to reduce the conduction of the heat generated in the first transmission filter 121 to the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 1, the maximum output power of the power class of the signal passing through the second transmission filter 131 is higher than the maximum output power of the power class of the signal passing through the first transmission filter 121. Thus, the heat generation by the second transmission filter 131 is greater than the heat generation by the first transmission filter 121. As described above, in the radio frequency module 1 according to exemplary embodiment 1, since the heat generation of the second transmission filter 131 is dissipated from the first shield electrode 69, the heat dissipation properties of the second transmission filter 131 are higher than the heat dissipation properties of the first transmission filter 121. Thus, it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121 and the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 1, the second shield electrode 65 is located in the hollow space SP0 and covers at least one of the first IDT electrode 641A that is the first functional electrode, and the second IDT electrode 641B that is the second functional electrode. Thus, it is possible to hinder the transfer of heat between the first transmission filter 121 and the second transmission filter 131. Further, it is possible to improve isolation between the first transmission filter 121 and the second transmission filter 131.
A radio frequency module 1 according to exemplary embodiment 2 will be described. Regarding the radio frequency module 1 according to exemplary embodiment 2, the similar configuration to the radio frequency module 1 according to exemplary embodiment 1 is denoted by the same reference numerals, and the description thereof will be omitted.
The radio frequency module 1 according to exemplary embodiment 2 includes a first electronic component 51a instead of the first electronic component 51. As shown in
The detailed structure of the first electronic component 51a will be described. As shown in
In addition, as shown in
In the radio frequency module 1 according to exemplary embodiment 2, a first resin layer 681 covers at least a part of the first transmission filter 121 and the second transmission filter 131, and a first shield electrode 69 covers at least a part of the first resin layer 681. Thus, it is possible to dissipate the heat generated in the first transmission filter 121 and the second transmission filter 131 through the first shield electrode 69.
In addition, in the radio frequency module 1 according to exemplary embodiment 2, the first shield electrode 69 is in contact with a main surface 133 of the second transmission filter 131. Thus, heat generated in the BAW resonator of the second transmission filter 131 is dissipated from the first shield electrode 69. Thus, the heat dissipation properties of the second transmission filter 131 are improved, and it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121.
In addition, in the radio frequency module 1 according to exemplary embodiment 2, a conductor 661 located between the second substrate 61B and the first substrate 61A and a via conductor 671 that penetrates the first substrate 61A in the first direction D1 are connected to a ground electrode 43 of a mounting board 4. Thus, the conductor 661 and the via conductor 671 function as a heat conduction path from the first upper electrode 643A to the ground electrode 43. Thus, it is possible to reduce the conduction of the heat generated in the first transmission filter 121 to the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 2, the maximum output power of the power class of a signal passing through the second transmission filter 131 is higher than the maximum output power of the power class of a signal passing through the first transmission filter 121. Thus, the heat generation by the second transmission filter 131 is greater than the heat generation by the first transmission filter 121. As described above, in the radio frequency module 1 according to exemplary embodiment 2, since the heat generation of the second transmission filter 131 is dissipated from the first shield electrode 69, the heat dissipation properties of the second transmission filter 131 are higher than the heat dissipation properties of the first transmission filter 121. Thus, it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121 and the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 2, the second shield electrode 65 covers one of the first upper electrode 643A and the second upper electrode 643B. Thus, in the radio frequency module 1 according to exemplary embodiment 2, it is possible to hinder the transfer of heat between the first transmission filter 121 and the second transmission filter 131. Further, it is possible to improve isolation between the first transmission filter 121 and the second transmission filter 131.
A radio frequency module 1 according to exemplary embodiment 3 will be described. Regarding the radio frequency module 1 according to exemplary embodiment 3, the similar configuration to the radio frequency module 1 according to exemplary embodiment 1 is denoted by the same reference numerals, and the description thereof will be omitted.
The radio frequency module 1 according to exemplary embodiment 3 includes a first electronic component 51b instead of the first electronic component 51. As shown in
A detailed structure of the first electronic component 51b will be described. As shown in
As shown in
The main surface 611A of the first substrate 61A and a main surface 41 of a mounting board 4 face each other in the first direction D1. In addition, as shown in
In addition, the main surface 611B of the second substrate 61B and the main surface 612A of the first substrate 61A face each other in the first direction D1. In addition, as shown in
A first resin layer 681 covers at least a part of the first transmission filter 121 and the second transmission filter 131 in the first electronic component 51b. Here, the first resin layer 681 covers the outer peripheral surface of each of the conductors 673, the bumps 674, and the second substrate 61B.
A first shield electrode 69 covers at least a part of the first resin layer 681. Here, the first shield electrode 69 is in contact with the main surface 133 of the second transmission filter 131 on an opposite side from the first transmission filter 121 in the first electronic component 51b.
In the radio frequency module 1 according to exemplary embodiment 3, the first substrate 61A is located between the first IDT electrode 641A that is the first functional electrode, and the second IDT electrode 641B that is the second functional electrode. Thus, the first substrate 61A functions as a shield between the first IDT electrode 641A and the second IDT electrode 641B. Therefore, it is possible to hinder the transfer of heat between the first transmission filter 121 and the second transmission filter 131. Further, it is possible to improve isolation between the first transmission filter 121 and the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 3, the first resin layer 681 covers the outer peripheral surface of each of the conductors 673, the bumps 674, and the second substrate 61B, and the first shield electrode 69 covers at least a part of the first resin layer 681. Thus, it is possible to dissipate the heat generated in the second transmission filter 131 through the first shield electrode 69.
In addition, in the radio frequency module 1 according to exemplary embodiment 3, the first shield electrode 69 is in contact with the main surface 133 of the second transmission filter 131 on the opposite side from the first transmission filter 121 side. Thus, the heat generated in an acoustic wave resonator of the second transmission filter 131 is dissipated from the first shield electrode 69. Thus, the heat dissipation properties of the second transmission filter 131 are improved, and it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121.
In addition, in the radio frequency module 1 according to exemplary embodiment 3, the first IDT electrode 641A faces the ground electrode 43 of the mounting board 4. Thus, the heat conduction from the first IDT electrode 641A to the ground electrode 43 is facilitated. Thus, it is possible to reduce the conduction of the heat generated in the first transmission filter 121 to the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 3, the maximum output power of the power class of a signal passing through the second transmission filter 131 is higher than the maximum output power of the power class of a signal passing through the first transmission filter 121. Thus, the heat generation by the second transmission filter 131 is greater than the heat generation by the first transmission filter 121. As described above, in the radio frequency module 1 according to exemplary embodiment 3, since the heat generation of the second transmission filter 131 is dissipated from the first shield electrode 69, the heat dissipation properties of the second transmission filter 131 are higher than the heat dissipation properties of the first transmission filter 121. Thus, it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121 and the second transmission filter 131.
A radio frequency module 1 according to exemplary embodiment 4 will be described. Regarding the radio frequency module 1 according to exemplary embodiment 4, the similar configuration to the radio frequency module 1 according to exemplary embodiment 1 is denoted by the same reference numerals, and the description thereof will be omitted.
The radio frequency module 1 according to exemplary embodiment 4 includes a first electronic component 51c instead of the first electronic component 51. As shown in
The detailed structure of the first electronic component 51c will be described. The first electronic component 51c includes the first transmission filter 121 and the second transmission filter 131 as two acoustic wave filters. The first transmission filter 121 includes a first substrate 61A, a first low acoustic velocity film 62A, a first piezoelectric layer 63A, and a first circuit portion 642A. The second transmission filter 131 includes a second substrate 61B, a second low acoustic velocity film 62B, a second piezoelectric layer 63B, and a second circuit portion 642B. In addition, in the second transmission filter 131, the main surface 133 on an opposite side from the first transmission filter 121 side is a main surface 612B of the second substrate 61B.
The first electronic component 51c further includes a first resin layer 681. The first resin layer 681 covers the outer peripheral surface of each of the first substrate 61A, the first low acoustic velocity film 62A, the first piezoelectric layer 63A, a conductor 661, a frame 662, the second piezoelectric layer 63B, the second low acoustic velocity film 62B, and the second substrate 61B. The first resin layer 681 further covers the main surface 612B of the second substrate 61B. That is, the first resin layer 681 covers the main surface 133 of the second transmission filter 131 on an opposite side from the first transmission filter 121 side.
The first electronic component 51c further includes a first shield electrode 69. A first shield electrode 69 covers at least a part of the first resin layer 681. Here, the first shield electrode 69 indirectly covers the main surface 133 of the second transmission filter 131. That is, a part of the first resin layer 681 is located between the first shield electrode 69 and the main surface 133 of the second transmission filter 131.
In the radio frequency module 1 according to exemplary embodiment 4, the first resin layer 681 covers at least a part of the first transmission filter 121 and the second transmission filter 131, and the first shield electrode 69 covers at least a part of the first resin layer 681. Thus, it is possible to dissipate the heat generated in the first transmission filter 121 and the second transmission filter 131 through the first shield electrode 69.
In addition, in the radio frequency module 1 according to exemplary embodiment 4, the first shield electrode 69 indirectly covers the main surface 133 of the second transmission filter 131 on the opposite side from the first transmission filter 121 side. Thus, the heat generated in an acoustic wave resonator of the second transmission filter 131 is dissipated from the first shield electrode 69. Thus, the heat dissipation properties of the second transmission filter 131 are improved, and it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121.
In addition, in the radio frequency module 1 according to exemplary embodiment 4, a conductor 661 located between the second substrate 61B and the first substrate 61A and a via conductor 671 that penetrates the first substrate 61A in the first direction D1 are connected to a ground electrode 43 of a mounting board 4. Thus, the conductor 661 and the via conductor 671 function as a heat conduction path from the first IDT electrode 641A to the ground electrode 43. Thus, it is possible to reduce the conduction of the heat generated in the first transmission filter 121 to the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 4, the maximum output power of the power class of a signal passing through the second transmission filter 131 is higher than the maximum output power of the power class of a signal passing through the first transmission filter 121. Thus, the heat generation by the second transmission filter 131 is greater than the heat generation by the first transmission filter 121. As described above, in the radio frequency module 1 according to exemplary embodiment 4, since the heat generation of the second transmission filter 131 is dissipated from the first shield electrode 69, the heat dissipation properties of the second transmission filter 131 are higher than the heat dissipation properties of the first transmission filter 121. Thus, it is possible to reduce the influence of the heat generated in the second transmission filter 131 on the first transmission filter 121 and the second transmission filter 131.
In addition, in the radio frequency module 1 according to exemplary embodiment 4, the second shield electrode 65 is located in the hollow space SP0 and covers at least one of the first IDT electrode 641A that is the first functional electrode, and the second IDT electrode 641B that is the second functional electrode. Thus, it is possible to hinder the transfer of heat between the first transmission filter 121 and the second transmission filter 131. Further, it is possible to improve isolation between the first transmission filter 121 and the second transmission filter 131.
A radio frequency module 1a according to exemplary embodiment 5 will be described. Regarding the radio frequency module 1a according to exemplary embodiment 5, the similar configuration to the radio frequency module 1 according to exemplary embodiment 1 is denoted by the same reference numerals, and the description thereof will be omitted.
In the radio frequency module 1a according to exemplary embodiment 5, a transmission signal and a reception signal in the first communication band are time division duplex (TDD) signals. In addition, a transmission signal and a reception signal in the second communication band are TDD signals. The TDD is a radio communication technology in which the same frequency band is allocated to transmission and reception in radio communication, and transmission and reception are switched by the hour. In addition, communication in the first communication band and communication in the second communication band are asynchronous communication. The communication in the first communication band and the communication in the second communication band may be synchronous communication in which a transmission period of the first communication band and a reception period of the second communication band overlap each other in time.
The first communication band is, for example, Band 39 of the 3GPP LTE standard. In addition, the second communication band is, for example, Band 41 of the 3GPP LTE standard. A transmission signal of Band 39 is a signal of the power class 3, and a transmission signal of Band 41 is a signal of the power class 2. The maximum output power of the signal of the power class 2 is larger than the maximum output power of the signal of the power class 3. That is, the maximum output power of the transmission signal in the second communication band is larger than the maximum output power of the transmission signal in the first communication band. The maximum output power is measured by a method defined by, for example, 3GPP.
As shown in
The first filter 12 and the second filter 13 are filters that cause signals in frequency bands different from each other to pass therethrough. More specifically, the first filter 12 is a filter that causes a transmission signal and a reception signal in the first communication band to pass through the first filter 12. The second filter 13 is a filter that causes a transmission signal and a reception signal in the second communication band to pass through the second filter 13.
Each of the first filter 12 and the second filter 13 is an acoustic wave filter having one or more acoustic wave resonators, similar to the first transmission filter 121 and the second transmission filter 131. That is, in the present exemplary embodiment, the first filter 12 is a first acoustic wave filter. In addition, in the present exemplary embodiment, the second filter 13 is a second acoustic wave filter. The first filter 12 and the second filter 13 are included in a single first electronic component 51, similar to the first transmission filter 121 and the second transmission filter 131.
The third switch 19 is a switch for switching a path connected to the third switch 19 from among a power amplifier 141 and a low-noise amplifier 151. That is, the third switch 19 is a switch for switching a path to be connected to the first filter 12. The third switch 19 has a common terminal 190 and a plurality of (two in the shown example) selection terminals 191 and 192.
The common terminal 190 is connected to the first filter 12. The selection terminal 191 is connected to the power amplifier 141. In addition, the selection terminal 192 is connected to the low-noise amplifier 151.
The third switch 19 switches the connection between the common terminal 190 and the plurality of selection terminals 191 and 192. The third switch 19 is controlled by, for example, a signal processing circuit 2. The third switch 19 electrically connects the common terminal 190 to any one of the plurality of selection terminals 191 and 192 in accordance with a control signal from the RF signal processing circuit 21 of the signal processing circuit 2.
A fourth switch 23 is a switch for switching a path connected to the fourth switch 23 from among a power amplifier 142 and a low-noise amplifier 152. That is, the fourth switch 23 is a switch for switching a path connected to the fourth switch 23. The fourth switch 23 has a common terminal 230 and a plurality of (two in the shown example) selection terminals 231 and 232.
The common terminal 230 is connected to the second filter 13. The selection terminal 231 is connected to the power amplifier 142. In addition, the selection terminal 232 is connected to the low-noise amplifier 152.
The fourth switch 23 switches the connection between the common terminal 230 and the plurality of selection terminals 231 and 232. The fourth switch 23 is controlled by, for example, the signal processing circuit 2. The fourth switch 23 electrically connects the common terminal 230 to any one of the plurality of selection terminals 231 and 232 in accordance with a control signal from the RF signal processing circuit 21 of the signal processing circuit 2.
The plurality of external connection terminals 18 are terminals for electrical connection to an external circuit (for example, the signal processing circuit 2). The plurality of external connection terminals 18 include an antenna terminal 181, a first input terminal 182, a second input terminal 183, a first output terminal 185, a second output terminal 186, a plurality of control terminals, and a plurality of ground terminals.
The first output terminal 185 is a terminal for outputting a reception signal from the radio frequency module 1 to an external circuit (for example, the signal processing circuit 2). More specifically, the first output terminal 185 outputs a reception signal in the first communication band. In the radio frequency module 1, the first output terminal 185 is connected to the low-noise amplifier 151.
The second output terminal 186 is a terminal for outputting a reception signal from the radio frequency module 1 to the external circuit (for example, the signal processing circuit 2). More specifically, the second output terminal 186 outputs a reception signal in the second communication band. In the radio frequency module 1, the second output terminal 186 is connected to the low-noise amplifier 152.
The radio frequency module 1a includes a first electronic component 51. The first electronic component 51 includes the first filter 12 instead of the first transmission filter 121. In addition, the first electronic component 51 includes the second filter 13 instead of the second transmission filter 131. That is, in the present exemplary embodiment, the first filter 12 is a first acoustic wave filter. In addition, in the present exemplary embodiment, the second filter 13 is a second acoustic wave filter.
The radio frequency module 1a includes a sixth electronic component 56. The sixth electronic component 56 is an IC including the third switch 19 and the fourth switch 23. In addition, in a plan view from the thickness direction D1 of the mounting board 4, the first electronic component 51 and the sixth electronic component overlap each other.
In the radio frequency module 1a according to exemplary embodiment 5, the first resin layer 681 covers at least a part of the first filter 12 and the second filter 13, and the first shield electrode 69 covers at least a part of the first resin layer 681. Thus, it is possible to dissipate the heat generated in the first filter 12 and the second filter 13 through the first shield electrode 69.
In addition, in the radio frequency module 1a according to exemplary embodiment 5, the first shield electrode 69 is in contact with the main surface 133 of the second filter 13 on an opposite side from the first filter 12 side. Thus, the heat generated in an acoustic wave resonator of the second filter 13 is dissipated from the first shield electrode 69. Thus, the heat dissipation properties of the second filter 13 are improved, and it is possible to reduce the influence of the heat generated in the second filter 13 on the first filter 12.
In addition, in the radio frequency module 1a according to exemplary embodiment 5, a conductor 661 located between the second substrate 61B and the first substrate 61A and a via conductor 671 that penetrates the first substrate 61A in the first direction D1 are connected to a ground electrode 43 of a mounting board 4. Thus, the conductor 661 and the via conductor 671 function as a heat conduction path from the first IDT electrode 641A to the ground electrode 43. Thus, it is possible to reduce the conduction of the heat generated in the first filter 12 to the second filter 13.
In addition, in the radio frequency module 1a according to exemplary embodiment 5, the maximum output power of the power class of the transmission signal passing through the second filter 13 is higher than the maximum output power of the power class of the transmission signal passing through the first filter 12. Thus, the heat generation by the second filter 13 is larger than the heat generation by the first filter 12. As described above, since the heat generation of the second filter 13 is dissipated from the first shield electrode 69, the heat dissipation properties of the second filter 13 are higher than the heat dissipation properties of the first filter 12. Thus, it is possible to reduce the influence of the heat generated in the second filter 13 on the first filter 12 and the second filter 13.
In addition, in the radio frequency module 1a according to exemplary embodiment 5, the second shield electrode 65 is located in the hollow space SP0 and covers at least one of the first IDT electrode 641A that is the first functional electrode, and the second IDT electrode 641B that is the second functional electrode. Thus, it is possible to hinder the transfer of heat between the first transmission filter 121 and the second transmission filter 131. Further, it is possible to improve the isolation between the first filter 12 and the second filter 13.
In addition, in the radio frequency module 1a according to exemplary embodiment 5, in a plan view from the thickness direction D1 of the mounting board 4, the first electronic component 51 including the first filter 12 and the second filter 13 overlaps the sixth electronic component including the third switch 19 and the fourth switch 23. Thus, the wiring between the first filter 12 and the third switch 19 is shortened. Similarly, the wiring between the second filter 13 and the fourth switch 23 is shortened. Thus, it is possible to improve the signal quality of a signal passing through the first filter 12 and a signal passing through the second filter 13. That is, in the radio frequency module 1a, the noise resistance of the first filter 12 and the second filter 13 is improved.
Modification Examples of exemplary embodiments 1 to 5 will be described below.
Each of the first transmission filter 121, the second transmission filter 131, the first reception filter 122, the second reception filter 132, the first filter 12, and the second filter 13 according to exemplary embodiments 1 and 3 to 5 is not limited to a ladder filter, and may be, for example, a longitudinally coupled resonator type acoustic wave filter.
In addition, each of the first transmission filter 121, the second transmission filter 131, the first reception filter 122, the second reception filter 132, the first filter 12, and the second filter 13 according to exemplary embodiments 1 and 3 to 5 is a surface acoustic wave filter. In addition, each of the first transmission filter 121, the second transmission filter 131, the first reception filter 122, and the second reception filter 132 according to exemplary embodiment 2 is a bulk acoustic wave filter. The acoustic wave filters are not limited to these. For example, the first transmission filter 121 may be a surface acoustic wave filter, and the second transmission filter 131 may be a bulk acoustic wave filter. In addition, the acoustic wave filter may be, for example, an acoustic wave filter using a boundary acoustic wave, a plate wave, or the like.
The first transmission filter 121 and the second transmission filter 131 according to exemplary embodiments 1 to 4 are transmission filters that cause a transmission signal to pass therethrough. However, the present disclosure is not limited to this. For example, at least one of the first transmission filter 121 and the second transmission filter 131 may be a transmission/reception filter that causes a transmission signal and a reception signal to pass therethrough.
In the radio frequency module 1 according to exemplary embodiments 1, 2, 4, and 5, it is assumed that the second shield electrode 65 covers the second IDT electrode 641B or the second upper electrode 643B. However, the present disclosure is not limited to this. For example, the second shield electrode 65 may be configured to cover the first IDT electrode 641A or the first upper electrode 643A.
In the radio frequency module 1 according to exemplary embodiments 1 to 4, the first communication band is Band 1 of the 3GPP LTE standard, and the second communication band is Band 3 of the 3GPP LTE standard. In addition, in the radio frequency module 1 according to exemplary embodiment 5, the first communication band is Band 39 of the 3GPP LTE standard, and the second communication band is Band 41 of the 3GPP LTE standard. However, a combination of the first communication band and the second communication band is not limited to this. The combination of the first communication band and the second communication band is freely made as long as the simultaneous communication is possible. In this case, in a case where the maximum output power of the power class of the signal in the second communication band is larger than the maximum output power of the power class of the signal in the first communication band, the heat generated in the second transmission filter 131 or the second filter 13 is dissipated from the first shield electrode 69 as described above, so that the heat dissipation properties of the radio frequency module 1 are improved.
The maximum output power of the power class of the signal in the first communication band may be larger than the maximum output power of the power class of the signal in the second communication band. For example, the first communication band is Band 41 of the 3GPP LTE standard, and the second communication band is Band 39 of the 3GPP LTE standard. In this case, the heat generated in the first transmission filter 121 or the first filter 12 is dissipated from the mounting board 4, so that the heat dissipation properties of the radio frequency module 1 are improved.
In the radio frequency module 1 according to exemplary embodiments 1 to 4, the first reception filter 122 and the second reception filter 132 are included in the first electronic components 51, 51a, 51b, and 51c, but the present disclosure is not limited to this. For example, each of the first reception filter 122 and the second reception filter 132 may be configured to be included in an electronic component including a single acoustic wave filter.
The radio frequency module 1 according to exemplary embodiments 1 to 5 includes the antenna terminal 181, and the antenna 3 of the communication device 10 is connected to the antenna terminal 181 of the radio frequency module 1. However, the present disclosure is not limited to this. For example, the radio frequency module 1 may include a plurality of antenna terminals, and the communication device 10 may include antennas connected to the plurality of respective antenna terminals. In this case, the radio frequency module 1 includes an antenna switch that selects which transmission path, reception path, or transmission and reception path each of the plurality of antenna terminals is to be connected. The antenna switch may be integrated with the first switch 11 according to exemplary embodiments 1 to 4.
In the present specification, “an element is disposed at a first main surface of a board” includes not only a case where the element is directly mounted on the first main surface of the board but also a case where the element is disposed in a space on the first main surface side between the space on the first main surface side and a space on the second main surface side separated by the board. That is, “the element is disposed at the first main surface of the board” includes a case where the element is mounted on the first main surface of the board with another circuit element, an electrode, or the like interposed therebetween. The element is, for example, the first electronic component 51, but is not limited to the first electronic component 51. The board is, for example, the mounting board 4. In a case where the board is the mounting board 4, the first main surface is the main surface 41, and the second main surface is the main surface 42.
The following aspects are disclosed in the present specification.
A radio frequency module (1; 1a) according to a first aspect includes a mounting board (4), a first acoustic wave filter (121; 12), a second acoustic wave filter (131; 13), a first resin layer (681), and a first shield electrode (69). The mounting board (4) has a first main surface (41) and includes a first ground electrode (43). The first acoustic wave filter (121; 12) is disposed at the first main surface (41) of the mounting board (4). The second acoustic wave filter (131; 13) is disposed on the first acoustic wave filter (121; 12). The first resin layer (681) covers at least a part of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13). The first shield electrode (69) covers at least a part of the first resin layer (681). Both the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) are filters that support at least transmission. A first transmission signal passing through the first acoustic wave filter (121; 12) and a second transmission signal passing through the second acoustic wave filter (131; 13) are capable of simultaneous communication. A second main surface (133) of the second acoustic wave filter (131; 13) on an opposite side from a first acoustic wave filter (121; 12) side is in contact with the first shield electrode (69). The first acoustic wave filter (121; 12) includes a first functional electrode (641A; 643A). The first ground electrode (43) of the mounting board (4) is connected to the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12).
With the radio frequency module (1; 1a) according to the above aspect, there is a heat dissipation path in which heat generated in the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12) is dissipated to a mounting board (4) side through the first ground electrode (43) of the mounting board (4). In addition, there is a heat dissipation path in which heat generated in the second acoustic wave filter (131; 13) is dissipated to a first shield electrode (69) side through the first shield electrode (69). Thus, it is possible to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) in the radio frequency module (1; 1a).
A radio frequency module (1; 1a) according to a second aspect in the first aspect further includes conductors (661 and 662). The conductors (661 and 662) connect the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) to each other. The first acoustic wave filter (121; 12) further includes a first support member (61A), a second ground electrode, and a via conductor (671). The first support member (61A) includes two main surfaces (611A and 612A) facing each other. The second ground electrode is connected to the conductors (661 and 662). The via conductor (671) penetrates the first support member (61A) and connects the two main surfaces (611A and 612A) of the first support member (61A) to each other. The second acoustic wave filter (131; 13) further includes a third ground electrode connected to the conductors (661 and 662). The conductors (661 and 662) and the via conductor (671) are connected to the first ground electrodes (43) of the mounting board (4).
With the radio frequency module (1; 1a) according to the above aspect, the thermal conductivity of a heat dissipation path in which heat generated in the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12) is dissipated to the mounting board (4) side through the first ground electrode (43) of the mounting board (4) is improved. Thus, it is possible to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) in the radio frequency module (1; 1a).
In a radio frequency module (1; 1a) according to a third aspect, in the first or second aspect, in a plan view from a thickness direction (D1) of the mounting board (4), the first ground electrode (43) of the mounting board (4) and the first functional electrode (641A; 643A) overlap each other.
With the radio frequency module (1; 1a) according to the above aspect, thermal conductivity from the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12) to the first ground electrode (43) of the mounting board (4) is improved. Thus, it is possible to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) in the radio frequency module (1; 1a).
A radio frequency module (1; 1a) according to a fourth aspect in any one of the first to third aspects further includes a second resin layer (682). The second resin layer (682) is located between the first acoustic wave filter (121; 12) and the first ground electrode (43) of the mounting board (4).
With the radio frequency module (1; 1a) according to the above aspect, the thermal conductivity of a heat dissipation path from the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12) to the first ground electrode (43) of the mounting board (4) through the second resin layer (682) is improved. Thus, it is possible to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) in the radio frequency module (1; 1a).
A radio frequency module (1; 1a) according to a fifth aspect in any one of the first to fourth aspects further includes a second shield electrode (65). The second shield electrode (65) is connected to the first ground electrode (43) of the mounting board (4). The first acoustic wave filter (121; 12) further includes a first support member (61A). The first support member (61A) includes two main surfaces (611A and 612A) facing each other. The second acoustic wave filter (131; 13) further includes a second support member (61B) and a second functional electrode (641B; 643B). The second support member (61B) includes two main surfaces (611B and 612B) facing each other. The first functional electrode (641A; 643A) is provided at the main surface (611A) of the first support member (61A) on a second acoustic wave filter (131; 13) side. The second functional electrode (641B; 643B) is provided at the main surface (611B) of the second support member (61B) on a first acoustic wave filter (121; 12) side. The first functional electrode (641A; 643A) and the second functional electrode (641B; 643B) are located in a hollow space (SP0) and face each other in the thickness direction (D1) of the mounting board (4). The hollow space (SP0) is formed between the first support member (61A) and the second support member (61B) in the thickness direction (D1) of the mounting board (4). The second shield electrode (65) is located in the hollow space (SP0) and covers at least one of the first functional electrode (641A; 643A) or the second functional electrode (641B; 643B).
With the radio frequency module (1; 1a) according to the above aspect, the second shield electrode (65) reduces the heat dissipation from the first acoustic wave filter (121; 12) to the second acoustic wave filter (131; 13) and the heat dissipation from the second acoustic wave filter (131; 13) to the first acoustic wave filter (121; 12). Thus, it is possible to reduce the transfer of heat dissipation between the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) and to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13).
In a radio frequency module (1; 1a) according to a sixth aspect, in any one of the first or third aspects, the first acoustic wave filter (121; 12) further includes a first support member (61A). The first support member (61A) includes two main surfaces (611A and 612A) facing each other. The second acoustic wave filter (131; 13) further includes a second support member (61B) and a second functional electrode (641B; 643B). The second support member (61B) includes two main surfaces (611B and 612B) facing each other. The first functional electrode (641A; 643A) is provided at the main surface (611A) of the first support member (61A) on an opposite side from the second acoustic wave filter (131; 13). The second functional electrode (641B; 643B) is provided at the main surface (611B) of the second support member (61B) on the first acoustic wave filter (121 or 12) side.
With the radio frequency module (1; 1a) according to the above aspect, there is a heat dissipation path in which heat generated in the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12) is dissipated to the mounting board (4) side. In addition, there is a heat dissipation path in which the heat generated in the second acoustic wave filter (131; 13) is dissipated to the first shield electrode (69) side. Thus, it is possible to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) in the radio frequency module (1; 1a).
In a radio frequency module (1; 1a) according to a seventh aspect, in any one of the first to sixth aspects, the first acoustic wave filter (121; 12) is a filter for a signal of a first power class. The second acoustic wave filter (131; 13) is a filter for a signal of a second power class. The second power class has a maximum output power higher than the first power class.
With the radio frequency module (1; 1a) according to the aspect, the heat dissipation of the second acoustic wave filter (131; 13) is larger than the heat dissipation of the first acoustic wave filter (121; 12). Thus, since the heat dissipation to the first shield electrode (69) side is larger than the heat dissipation to the mounting board (4) side, it is possible to suppress an increase in the temperature of the radio frequency module (1; 1a).
In a radio frequency module (1; 1a) according to an eighth aspect in any one of the first to seventh aspects, the first acoustic wave filter (121; 12) is a filter that causes a transmission signal of Band 39 of a 3GPP LTE standard to pass, and the second acoustic wave filter (131; 13) is a filter that causes a transmission signal of Band 41 of the 3GPP LTE standard to pass.
With the radio frequency module (1; 1a) according to the aspect, it is possible to perform simultaneous communication using Band 39 and Band 41 of the 3GPP LTE standard.
A communication device (10) according to a ninth aspect includes the radio frequency module (1; 1a) according to any one of the first to eighth aspects, and a signal processing circuit (2). The signal processing circuit (2) is connected to the radio frequency module (1; 1a).
With the communication device (10) according to the aspect, there is a heat dissipation path in which the heat generated in the first functional electrode (641A; 643A) of the first acoustic wave filter (121; 12) is dissipated to the mounting board (4) side through the first ground electrode (43) of the mounting board (4). In addition, there is a heat dissipation path in which heat generated in the second acoustic wave filter (131; 13) is dissipated to a first shield electrode (69) side through the first shield electrode (69). Thus, it is possible to improve the heat dissipation properties of the first acoustic wave filter (121; 12) and the second acoustic wave filter (131; 13) in the radio frequency module (1; 1a).
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-065868 | Apr 2022 | JP | national |
The present application is a continuation application of PCT International Application No. PCT/JP2023/014387 filed on Apr. 7, 2023, designating the United States of America, which is based on and claims priority to Japanese patent application JP 2022-065868, filed Apr. 12, 2022. The entire disclosures of the above-identified applications, including the specifications, the drawings, and the claims are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/014387 | Apr 2023 | WO |
| Child | 18910105 | US |
