High-frequency modules and communication devices

Abstract

The high-frequency module (1) comprises: a first substrate (71) made of a first semiconductor material; a second substrate (72) made of a second semiconductor material with a lower thermal conductivity than the first semiconductor material, wherein a power amplifier circuit (11) is formed on the second substrate (72); a third substrate (73) wherein a transmit filter circuit (61T and / or 62T) is formed on the third substrate (73); and a module substrate (90) having a main surface (90a) on which the first substrate (71), the second substrate (72) and the third substrate (73) are disposed, wherein the first substrate (71) is bonded to the main surface (90a) via an electrode (717), and in a cross-sectional view, the second substrate (72) is disposed between the module substrate (90) and the first substrate (71) and is bonded to the main surface (90a) via an electrode (724), and in a top view, at least a portion of the first substrate (71) overlaps with at least a portion of the second substrate (72) and at least a portion of the third substrate (73).

Description

Technical Field

[0001] This invention relates to a high-frequency module and a communication device. Background Technology

[0002] In mobile communication devices such as portable phones, especially with the advancement of multi-band technology, the configuration structure of circuit elements constituting the high-frequency front-end circuit has become more complex.

[0003] Patent document 1 discloses a high-frequency module comprising a mounting substrate, a duplexer (filter circuit) disposed on the mounting substrate, and a semiconductor integrated circuit (IC) including an amplifier stacked on the duplexer. Miniaturization of the high-frequency module is achieved by stacking the semiconductor IC on the duplexer.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2020 / 179541 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, in the aforementioned prior art, the semiconductor IC is made of gallium arsenide (GaAs), which has relatively low thermal conductivity. Therefore, the heat generated by the amplifier within the semiconductor IC is difficult to dissipate. As a result, the temperature of the semiconductor IC rises, and heat flows from the semiconductor IC into the duplexer, thereby degrading the characteristics of the duplexer.

[0009] Therefore, the present invention provides a high-frequency module and communication device that can suppress the degradation of filter circuit characteristics caused by heat and achieve miniaturization.

[0010] Solution for solving the problem

[0011] One aspect of the present invention relates to a high-frequency module comprising: a first substrate, at least a portion of which is made of a first semiconductor material; a second substrate, at least a portion of which is made of a second semiconductor material having a lower thermal conductivity than the first semiconductor material, wherein an amplification circuit is formed on the second substrate; a third substrate, at least a portion of which is made of a piezoelectric material, wherein a filter circuit is formed on the third substrate; and a module substrate having a main surface on which the first substrate, the second substrate, and the third substrate are disposed, wherein the first substrate is bonded to the main surface via a first electrode, and in a cross-sectional view, the second substrate is disposed between the module substrate and the first substrate and is bonded to the main surface via a second electrode, and in a top view, at least a portion of the first substrate overlaps with at least a portion of the second substrate and at least a portion of the third substrate.

[0012] One aspect of the present invention relates to a high-frequency module comprising: a first substrate, at least a portion of which is made of silicon or gallium nitride, and a first electrical circuit is formed thereon on the first substrate; a second substrate, at least a portion of which is made of gallium arsenide or silicon germanium, and an amplifier circuit is formed thereon on the second substrate; a third substrate, at least a portion of which is made of a piezoelectric material, and a filter circuit is formed thereon on the third substrate; and a module substrate having a main surface on which the first substrate, the second substrate, and the third substrate are disposed, wherein the first substrate is bonded to the main surface via a first electrode, and in a cross-sectional view, the second substrate is disposed between the module substrate and the first substrate and is bonded to the main surface via a second electrode, and in a top view, at least a portion of the first substrate overlaps with at least a portion of the second substrate and at least a portion of the third substrate.

[0013] The effects of the invention

[0014] According to one aspect of the present invention, the high-frequency module is capable of suppressing the degradation of filter characteristics caused by heat and achieving miniaturization. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the high-frequency module and communication device involved in Implementation Method 1.

[0016] Figure 2 This is a top view of the high-frequency module involved in Implementation Method 1.

[0017] Figure 3 This is a cross-sectional view of the high-frequency module involved in Implementation Method 1.

[0018] Figure 4 This is a partial cross-sectional view of the high-frequency module involved in Implementation Method 1.

[0019] Figure 5 This is a partial cross-sectional view of the high-frequency module involved in Implementation Method 1.

[0020] Figure 6 This is a partial cross-sectional view of the high-frequency module involved in Implementation Method 2.

[0021] Figure 7 This is a partial cross-sectional view of the high-frequency module involved in Implementation Method 3.

[0022] Figure 8 This is a partial cross-sectional view of the high-frequency module involved in Implementation Method 4.

[0023] Figure 9 This is a partial cross-sectional view of the high-frequency module involved in Implementation Method 5. Detailed Implementation

[0024] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, the embodiments described below are general or specific examples. The numerical values, shapes, materials, constituent elements, arrangements of constituent elements, and connection methods shown in the following embodiments are examples and are not intended to limit the present invention.

[0025] Furthermore, the figures are schematic diagrams that have been appropriately emphasized, omitted, or proportionally adjusted for the purpose of illustrating the invention, and are not necessarily strictly illustrative, sometimes differing from the actual shapes, positional relationships, and proportions. In the figures, substantially identical structures are labeled with the same reference numerals, and sometimes repeated descriptions are omitted or simplified.

[0026] In the figures below, the x-axis and y-axis are mutually orthogonal axes on a plane parallel to the main surface of the module substrate. Specifically, in the top view where the module substrate has a rectangular shape, the x-axis is parallel to the first side of the module substrate, and the y-axis is parallel to the second side of the module substrate, which is orthogonal to the first side. Additionally, the z-axis is perpendicular to the main surface of the module substrate, with its positive direction representing the upward direction and its negative direction representing the downward direction.

[0027] In the circuit structure of this invention, "connection" refers not only to direct connection via connection terminals and / or wiring conductors, but also to electrical connection via other circuit elements. Furthermore, "connected between A and B" means connected to both A and B.

[0028] In the component configuration of this invention, "top view" refers to observing an object by projecting it orthographically onto the xy-plane from the positive z-axis. "In the top view, A and B overlap" means that the area of ​​A projected onto the xy-plane overlaps with the area of ​​B projected onto the xy-plane. "Cross-sectional view" refers to observing an object cut off at a section perpendicular to the xy-plane. "In the cross-sectional view, A is positioned between B and C" means that within a section perpendicular to the xy-plane, at least one of a plurality of line segments connecting any point in region B to any point in region C passes through region A. Furthermore, terms indicating relationships between elements, such as "parallel" and "perpendicular," terms indicating the shape of elements, such as "rectangle," and numerical ranges do not merely indicate strictness but also include substantially equivalent ranges, such as approximately a few percent of an error.

[0029] Furthermore, "component disposed on substrate" means, in addition to the case where the component is disposed on the substrate in contact with the substrate, it also includes the case where the component is disposed above the substrate without contacting the substrate (e.g., the component is stacked on top of other components disposed on the substrate), and the case where part or all of the component is disposed in a manner embedded within the substrate. Additionally, "component disposed on the main surface of substrate" means, in addition to the case where the component is disposed on the main surface of the substrate in contact with the main surface, it also includes the case where the component is disposed above the main surface without contacting the main surface, and the case where part of the component is disposed in a manner embedded within the substrate from the main surface side.

[0030] In the material structure of this invention, "object A is composed of material B" means that the principal component of A is B. Here, the principal component refers to the component with the largest weight ratio among the multiple components contained in the object.

[0031] (Implementation Method 1)

[0032] [1.1 Circuit structure of high-frequency module 1 and communication device 5]

[0033] Reference Figure 1 The circuit structure of the high-frequency module 1 and the communication device 5 equipped with the high-frequency module 1 in this embodiment will be explained. Figure 1 This is a circuit diagram of the high-frequency module 1 and the communication device 5 involved in Implementation Method 1.

[0034] [1.1.1 Circuit structure of communication device 5]

[0035] like Figure 1As shown, the communication device 5 involved in this embodiment includes a high-frequency module 1, an antenna 2, an RFIC (Radio Frequency Integrated Circuit) 3, and a BBIC (Baseband Integrated Circuit) 4.

[0036] High-frequency module 1 transmits high-frequency signals between antenna 2 and RFIC 3. The internal structure of high-frequency module 1 will be described later.

[0037] Antenna 2 is connected to the antenna connection terminal 100 of high-frequency module 1, and after receiving high-frequency signals from the outside, it outputs the high-frequency signals to high-frequency module 1.

[0038] RFIC 3 is an example of a signal processing circuit that processes high-frequency signals. Specifically, RFIC 3 processes the high-frequency received signal input via the receiving path of high-frequency module 1 through down-conversion or similar methods, and outputs the resulting received signal to BBIC 4. Furthermore, RFIC 3 has a control unit that controls the switching circuits and amplification circuits of high-frequency module 1. Moreover, some or all of the functions of the control unit in RFIC 3 can be configured externally, for example, in BBIC 4 or high-frequency module 1.

[0039] BBIC 4 is a baseband signal processing circuit that uses an intermediate frequency band with a frequency lower than that of the high-frequency signal transmitted by high-frequency module 1 for signal processing. Signals processed by BBIC 4 include, for example, image signals used for displaying images and / or sound signals used for communication via a speaker.

[0040] Furthermore, in the communication device 5 according to this embodiment, the antenna 2 and BBIC 4 are not essential components.

[0041] [1.1.2 Circuit Structure of High-Frequency Module 1]

[0042] Next, the circuit structure of high-frequency module 1 will be described. For example... Figure 1 As shown, the high-frequency module 1 includes a power amplifier circuit 11, a low-noise amplifier circuit 21, impedance matching circuits (MN) 41 to 44, a switching circuit 51 to 55, duplexers 61 and 62, a control circuit 80, an antenna connection terminal 100, high-frequency input terminals 111 and 112, high-frequency output terminals 121 and 122, and a control terminal 130.

[0043] Antenna connection terminal 100 is connected to antenna 2 externally to high frequency module 1.

[0044] Each of the high-frequency input terminals 111 and 112 is an input terminal for receiving high-frequency transmission signals from outside the high-frequency module 1. In this embodiment, the high-frequency input terminals 111 and 112 are connected to the RFIC 3 outside the high-frequency module 1.

[0045] Each of the high-frequency output terminals 121 and 122 is used to provide high-frequency received signals to the outside of the high-frequency module 1. In this embodiment, the high-frequency output terminals 121 and 122 are connected to the RFIC 3 outside the high-frequency module 1.

[0046] Control terminal 130 is a terminal used for transmitting control signals. That is, control terminal 130 is a terminal for receiving control signals from outside the high-frequency module 1 and / or for supplying control signals to outside the high-frequency module 1. Control signals refer to signals related to the control of the electronic components included in the high-frequency module 1. Specifically, control signals are, for example, digital signals used to control the power amplifier circuit 11.

[0047] Power amplifier circuit 11 is an example of an amplifier circuit capable of amplifying transmitted signals in frequency bands A and B. The input terminals of power amplifier circuit 11 are connected to high-frequency input terminals 111 and 112 via switching circuit 52. The output terminals of power amplifier circuit 11 are connected to transmitting filter circuits 61T and 62T via impedance matching circuit 41 and switching circuit 51. The structure of power amplifier circuit 11 is not particularly limited; for example, it can be a multi-stage amplifier circuit or a differential amplifier circuit.

[0048] The low-noise amplifier circuit 21 amplifies the received signals in frequency bands A and B. The input terminals of the low-noise amplifier circuit 21 are connected to the receiving filter circuits 61R and 62R via the impedance matching circuit 42 and the switching circuit 54. The output terminals of the low-noise amplifier circuit 21 are connected to the high-frequency output terminals 121 and 122 via the switching circuit 55.

[0049] Impedance matching circuit 41 is connected to the output of power amplifier circuit 11 and is connected to the input of transmitting filter circuits 61T and 62T via switching circuit 51. Impedance matching circuit 41 achieves impedance matching between the output impedance of power amplifier circuit 11 and the input impedance of switching circuit 51.

[0050] Impedance matching circuit 42 is connected to the input of low-noise amplifier circuit 21 and is connected to the output of receiving filter circuits 61R and 62R via switching circuit 54. Impedance matching circuit 42 achieves impedance matching between the output impedance of switching circuit 54 and the input impedance of low-noise amplifier circuit 21.

[0051] Impedance matching circuit 43 is connected to the output of transmitting filter circuit 61T and the input of receiving filter circuit 61R, and is connected to antenna connection terminal 100 via switching circuit 53. Impedance matching circuit 43 enables impedance matching between switching circuit 53 and duplexer 61.

[0052] Impedance matching circuit 44 is connected to the output of transmitting filter circuit 62T and the input of receiving filter circuit 62R, and is connected to antenna connection terminal 100 via switching circuit 53. Impedance matching circuit 44 enables impedance matching between switching circuit 53 and duplexer 62.

[0053] Switching circuit 51, an example of a first switching circuit, is connected between the output of power amplifier circuit 11 and the inputs of transmitting filter circuits 61T and 62T. Switching circuit 51 has terminals 511 to 513. Terminal 511 is connected to the output of power amplifier circuit 11 via impedance matching circuit 41. Terminal 512 is connected to the input of transmitting filter circuit 61T. Terminal 513 is connected to the input of transmitting filter circuit 62T.

[0054] In this connection structure, the switching circuit 51 can, for example, connect terminal 511 to one of terminals 512 and 513 based on a control signal from RFIC 3. That is, the switching circuit 51 can switch the connection of the output of the power amplifier circuit 11 between the transmit filter circuit 61T and the transmit filter circuit 62T. The switching circuit 51 is constructed, for example, using an SPDT (Single-Pole Double-Throw) type switch, sometimes referred to as a band selection switch.

[0055] Switching circuit 52 is an example of a second switching circuit, connected between high-frequency input terminals 111 and 112 and the input terminal of power amplifier circuit 11. Switching circuit 52 has terminals 521 to 523. Terminal 521 is connected to the input terminal of power amplifier circuit 11. Terminals 522 and 523 are connected to high-frequency input terminals 111 and 112, respectively.

[0056] In this connection structure, the switching circuit 52 can, for example, connect terminal 521 to one of terminals 522 and 523 based on a control signal from RFIC 3. That is, the switching circuit 52 can switch the connection of the input terminal of the power amplifier circuit 11 between the high-frequency input terminal 111 and the high-frequency input terminal 112. The switching circuit 52 is constructed using, for example, an SPDT-type switch, and is sometimes referred to as an input switch.

[0057] Switching circuit 53, an example of a third switching circuit, is connected between antenna connection terminal 100 and duplexers 61 and 62. Switching circuit 53 has terminals 531 to 533. Terminal 531 is connected to antenna connection terminal 100. Terminal 532 is connected to the output of transmit filter circuit 61T and the input of receive filter circuit 61R via impedance matching circuit 43. Terminal 533 is connected to the output of transmit filter circuit 62T and the input of receive filter circuit 62R via impedance matching circuit 44.

[0058] In this connection structure, the switching circuit 53 can, for example, connect terminal 531 to one or both of terminals 532 and 533 based on a control signal from RFIC 3. That is, the switching circuit 53 can switch the connection and disconnection between antenna connection terminal 100 and duplexer 61, and can switch the connection and disconnection between antenna connection terminal 100 and duplexer 62. The switching circuit 53 is configured using a multi-connection type switch, and is sometimes referred to as an antenna switch.

[0059] Switching circuit 54 is connected between the input terminal of low-noise amplifier circuit 21 and the output terminals of receiving filter circuits 61R and 62R. Switching circuit 54 has terminals 541 to 543. Terminal 541 is connected to the input terminal of low-noise amplifier circuit 21 via impedance matching circuit 42. Terminal 542 is connected to the output terminal of receiving filter circuit 61R. Terminal 543 is connected to the output terminal of receiving filter circuit 62R.

[0060] In this connection structure, the switching circuit 54 can, for example, connect terminal 541 to one of terminals 542 and 543 based on a control signal from RFIC 3. That is, the switching circuit 54 can switch the connection of the input terminal of the low-noise amplifier circuit 21 between the receiving filter circuit 61R and the receiving filter circuit 62R. The switching circuit 54 is configured, for example, using an SPDT type switch.

[0061] Switching circuit 55 is connected between high-frequency output terminals 121 and 122 and the output terminal of low-noise amplifier circuit 21. Switching circuit 55 has terminals 551 to 553. Terminal 551 is connected to the output terminal of low-noise amplifier circuit 21. Terminals 552 and 553 are connected to high-frequency output terminals 121 and 122, respectively.

[0062] In this connection structure, the switching circuit 55 can, for example, connect terminal 551 to one of terminals 552 and 553 based on a control signal from RFIC 3. That is, the switching circuit 55 can switch the connection of the output terminal of the low-noise amplifier circuit 21 between the high-frequency output terminal 121 and the high-frequency output terminal 122. The switching circuit 55 is constructed using, for example, an SPDT-type switch, and is sometimes referred to as an output switch.

[0063] The duplexer 61 enables high-frequency signals in frequency band A to pass through. The duplexer 61 transmits and receives signals in frequency band A using frequency division duplex (FDD) mode. The duplexer 61 includes a transmit filter circuit 61T and a receive filter circuit 61R.

[0064] The transmit filter circuit 61T (A-Tx) has a passband that includes the uplink operating frequency band of frequency band A. Therefore, the transmit filter circuit 61T allows transmit signals of frequency band A to pass through. The transmit filter circuit 61T is connected between the power amplifier circuit 11 and the antenna connection terminal 100. Specifically, the input terminal of the transmit filter circuit 61T is connected to the output terminal of the power amplifier circuit 11 via the switching circuit 51 and the impedance matching circuit 41. On the other hand, the output terminal of the transmit filter circuit 61T is connected to the antenna connection terminal 100 via the impedance matching circuit 43 and the switching circuit 53.

[0065] The receiver filter circuit 61R (A-Rx) has a passband that includes the downlink operating frequency band of frequency band A. Therefore, the receiver filter circuit 61R allows received signals of frequency band A to pass through. The receiver filter circuit 61R is connected between the antenna connection terminal 100 and the low-noise amplifier circuit 21. Specifically, the input terminal of the receiver filter circuit 61R is connected to the antenna connection terminal 100 via the impedance matching circuit 43 and the switching circuit 53. On the other hand, the output terminal of the receiver filter circuit 61R is connected to the low-noise amplifier circuit 21 via the switching circuit 54 and the impedance matching circuit 42.

[0066] The duplexer 62 enables high-frequency signals in band B to pass through. The duplexer 62 transmits and receives band B signals in FDD mode. The duplexer 62 includes a transmit filter circuit 62T and a receive filter circuit 62R.

[0067] The transmit filter circuit 62T (B-Tx) has a passband that includes the uplink operating frequency band of frequency band B. Therefore, the transmit filter circuit 62T allows transmit signals of frequency band B to pass through. The transmit filter circuit 62T is connected between the power amplifier circuit 11 and the antenna connection terminal 100. Specifically, the input terminal of the transmit filter circuit 62T is connected to the output terminal of the power amplifier circuit 11 via the switch circuit 51 and the impedance matching circuit 41. On the other hand, the output terminal of the transmit filter circuit 62T is connected to the antenna connection terminal 100 via the impedance matching circuit 44 and the switch circuit 53.

[0068] The receiver filter circuit 62R (B-Rx) has a passband that includes the downlink operating frequency band of band B. Therefore, the receiver filter circuit 62R allows the received signal of band B to pass through. The receiver filter circuit 62R is connected between the antenna connection terminal 100 and the low-noise amplifier circuit 21. Specifically, the input terminal of the receiver filter circuit 62R is connected to the antenna connection terminal 100 via the impedance matching circuit 44 and the switching circuit 53. On the other hand, the output terminal of the receiver filter circuit 62R is connected to the low-noise amplifier circuit 21 via the switching circuit 54 and the impedance matching circuit 42.

[0069] The control circuit 80 is a power amplifier controller used to control the power amplifier circuit 11. After receiving the control signal from RFIC3 via the control terminal 130, the control circuit 80 outputs the control signal to the power amplifier circuit 11.

[0070] also, Figure 1 One or more of the circuits shown may not be included in the high-frequency module 1. For example, the high-frequency module 1 may only have the circuitry for transmitting, but not the circuitry for receiving. That is, the high-frequency module 1 may also omit the low-noise amplifier circuit 21, the impedance matching circuit 42, the switching circuits 54 and 55, and the receiving filter circuits 61R and 62R. Conversely, the high-frequency module 1 may only have the circuitry for receiving, but not the circuitry for transmitting.

[0071] [1.2 Component Configuration of High-Frequency Module 1]

[0072] Next, refer to Figure 2 and Figure 3 Here is a specific example of the component configuration of the high-frequency module 1 as described above.

[0073] Figure 2 This is a top view of the high-frequency module 1 involved in Embodiment 1. Figure 3 This is a cross-sectional view of the high-frequency module 1 involved in Implementation Method 1. Figure 3 The cross-section of the high-frequency module 1 in the middle is Figure 2 The cross section at line iii-iii.

[0074] In addition to having the following components, high-frequency module 1 Figure 1 In addition to the components shown in the circuit, it also includes a module substrate 90, a resin component 91, a shielding electrode layer 92, and multiple external connection terminals 150. Furthermore, in Figure 2 The resin component 91 and the shielding electrode layer 92 are omitted from the illustration. Furthermore, in... Figure 2 and Figure 3 The diagram omits the wiring that connects the various components disposed on the module substrate 90, excluding the side wiring 736.

[0075] The module substrate 90 has main surfaces 90a and 90b facing each other. In this embodiment, the module substrate 90 has a rectangular shape in top view, but the shape of the module substrate 90 is not limited to this. As the module substrate 90, for example, a low temperature co-fired ceramic (LTCC) substrate with a multilayer dielectric structure, a high temperature co-fired ceramic (HTCC) substrate, a component-embedded substrate, a substrate with a redistribution layer (RDL), or a printed circuit board can be used, but it is not limited to these substrates.

[0076] Integrated circuits 20 and 70, impedance matching circuits 41 to 44, switching circuit 53, and receiving filter circuits 61R and 62R are arranged on the main surface 90a. The main surface 90a and the components on the main surface 90a are covered by resin component 91.

[0077] Integrated circuit 20 includes a low-noise amplifier circuit 21 and switching circuits 54 and 55. Integrated circuit 20 can be constructed using, for example, CMOS (Complementary Metal Oxide Semiconductor), specifically, it can also be manufactured using SOI (Silicon on Insulator) technology. This allows for the inexpensive manufacture of integrated circuit 20. Furthermore, integrated circuit 20 can also be constructed from at least one of gallium arsenide, silicon germanium (SiGe), and gallium nitride (GaN). This enables the realization of high-quality low-noise amplifier circuit 21 and switching circuits 54 and 55.

[0078] The integrated circuit 70 includes a first substrate 71, a second substrate 72, and a third substrate 73. The second substrate 72, the first substrate 71, and the third substrate 73 are sequentially stacked on the main surface 90a of the module substrate 90. The third substrate 73 is connected to the first substrate 71 via side wiring 736 formed on the sides of the third substrate 73 and the first substrate 71. Figure 4 and Figure 5 The details of integrated circuit 70 will be described later.

[0079] Furthermore, the wiring connecting the third substrate 73 and the first substrate 71 is not limited to the side wiring 736. For example, the third substrate 73 and the first substrate 71 may be connected via a bonding wire. Alternatively, the third substrate 73 and the first substrate 71 may be connected via a through-hole conductor penetrating the third substrate 73.

[0080] Each impedance matching circuit in impedance matching circuits 41-44 includes an inductor. Furthermore, each impedance matching circuit in impedance matching circuits 41-44 may include a capacitor instead of an inductor, or it may include both an inductor and a capacitor. Figure 2 In the impedance matching circuits 41-44, the inductors are constructed using surface mount devices (SMDs). Alternatively, some or all of the inductors in the impedance matching circuits 41-44 may also be constructed using integrated passive devices (IPDs).

[0081] The switching circuit 53 is, for example, composed of multiple MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) connected in series. The number of MOSFETs connected in series can be determined according to the required voltage withstand capability and is not particularly limited.

[0082] The receiver filter circuits of receiver filter circuits 61R and 62R can be constructed using any of the following: surface acoustic wave (SAW) filter, bulk acoustic wave (BAW) filter, LC resonant filter, and dielectric filter, and are not limited to these filters.

[0083] The resin component 91 covers the main surface 90a and the components on the main surface 90a. The resin component 91 has the function of ensuring the reliability of the components on the main surface 90a, such as mechanical strength and moisture resistance. Alternatively, the resin component 91 may not be present.

[0084] The shielding electrode layer 92 is formed, for example, by sputtering a thin metal film, covering the upper and side surfaces of the resin component 91 and the side surfaces of the module substrate 90. The shielding electrode layer 92 is set to ground potential to suppress the intrusion of external noise into the components constituting the high-frequency module 1.

[0085] Multiple external connection terminals 150 are configured on the main surface 90b. These multiple external connection terminals 150 include, in addition to... Figure 1 In addition to the antenna connection terminal 100, high-frequency input terminals 111 and 112, high-frequency output terminals 121 and 122, and control terminal 130 shown, a ground terminal is also included. Each of the plurality of external connection terminals 150 is coupled to input / output terminals and / or ground terminals disposed on the motherboard in the negative z-axis direction of the high-frequency module 1. As the plurality of external connection terminals 150, for example, bump electrodes can be used, but are not limited thereto.

[0086] also, Figure 2 and Figure 3 The component configuration shown is an example and is not limited thereto. For example, some or all of the multiple components may be configured on the main surface 90b of the module substrate 90. In this case, the main surface 90b and the components on the main surface 90b may also be covered by a resin component.

[0087] [1.3 Structure of Integrated Circuit 70]

[0088] Next, refer to Figure 4 and Figure 5 This will illustrate the structure of integrated circuit 70. Figure 4 and Figure 5 This is a partial cross-sectional view of the high-frequency module 1 according to Embodiment 1. Specifically, Figure 4 and Figure 5 This is an enlarged cross-sectional view of the integrated circuit 70 disposed on the main surface 90a of the module substrate 90. Furthermore, in Figure 4 The diagrams of wiring and electrodes on or within the module substrate 90 are omitted.

[0089] like Figure 4 As shown, the integrated circuit 70 includes a first substrate 71, a second substrate 72, and a third substrate 73. In a top view, at least a portion of the first substrate 71 overlaps with at least a portion of the second substrate 72 and at least a portion of the third substrate 73.

[0090] [1.3.1 Structure of the first substrate 71]

[0091] Here, the first substrate 71 is described. At least a portion of the first substrate 71 is made of a first semiconductor material. Here, silicon (Si) is used as the first semiconductor material. However, the first semiconductor material is not limited to silicon. For example, materials comprising any one of gallium arsenide, aluminum arsenide (AlAs), indium arsenide (InAs), indium phosphide (InP), gallium phosphide (GaP), indium antimonide (InSb), gallium nitride, indium nitride (InN), aluminum nitride (AlN), silicon, germanium (Ge), silicon carbide (SiC), and gallium (III) oxide (Ga2O3) as the main component, or materials comprising a multi-component mixed crystal material composed of multiple of these materials as the main component, can be used, but are not limited to these materials.

[0092] A control circuit 80 and switching circuits 51 and 52 are formed on the first substrate 71 as a first electrical circuit. However, the first electrical circuit formed on the first substrate 71 is not limited to the control circuit 80 and the switching circuits 51 and 52. For example, only one or both of the control circuit 80 and the switching circuits 51 and 52 may be formed on the first substrate 71 as the first electrical circuit. Alternatively, a control circuit (not shown) for controlling the switching circuits 51 and / or 52 may be formed on the first substrate 71 as the first electrical circuit. Furthermore, at least one of the impedance matching circuits 41 to 44 may be formed on the first substrate 71 as the first electrical circuit.

[0093] like Figure 4 As shown, the first substrate 71 includes a silicon substrate 711, a silicon dioxide (SiO2) layer 712, a silicon layer 713, a silicon dioxide layer 714, and a silicon nitride (SiN) layer 715. The silicon dioxide layer 712, silicon layer 713, silicon dioxide layer 714, and silicon nitride layer 715 are sequentially stacked on the silicon substrate 711 in this order.

[0094] The silicon substrate 711 is made of, for example, monocrystalline silicon and is used as a support substrate.

[0095] A silicon dioxide layer 712 is disposed on a silicon substrate 711 and serves as an insulating layer.

[0096] A silicon layer 713 is disposed on a silicon dioxide layer 712 and serves as a device layer. Multiple circuit elements 7130 constituting the control circuit 80 and the switching circuits 51 and 52 are formed on the silicon layer 713.

[0097] A silicon dioxide layer 714 is disposed on a silicon layer 713 and serves as a wiring layer. Wiring is formed on the silicon dioxide layer 714 for connecting the control circuit 80 and switching circuits 51 and 52 formed on the silicon layer 713 to electrodes 716 formed on the surface of the silicon nitride layer 715. This wiring includes multiple wiring layers (not shown) and via conductors 7140 connecting the multiple wiring layers. The multiple wiring layers and via conductors 7140 are made, for example, of copper or aluminum.

[0098] A silicon nitride layer 715 is disposed on a silicon dioxide layer 714 and serves as a passivation layer. An electrode 716 is formed on a portion of the surface of the silicon nitride layer 715 as a redistribution layer. Furthermore, a second substrate 72 is bonded to another portion of the surface of the silicon nitride layer 715.

[0099] Electrode 716 is bonded to an electrode (not shown) disposed on module substrate 90 via electrode 717. The surface of electrode 716 is coated with an insulating resin layer 718.

[0100] Electrode 717 is an example of a first electrode, which protrudes from the first substrate 71 toward the main surface 90a of the module substrate 90, and the front end of electrode 717 is engaged with the main surface 90a. Electrode 717 has a columnar conductor 717a and a bump electrode 717b. Bump electrode 717b is engaged with an electrode (not shown) disposed on the main surface 90a of the module substrate 90.

[0101] Furthermore, the first substrate 71 is not limited to Figure 4 The structure can be varied. For example, the first substrate 71 may not include one or more of the multiple layers on the silicon substrate 711.

[0102] [1.3.2 Structure of the second substrate 72]

[0103] Next, the second substrate 72 will be described. At least a portion of the second substrate 72 is composed of a second semiconductor material with a lower thermal conductivity than the first semiconductor material. Gallium arsenide is used as the second semiconductor material. However, the second semiconductor material is not limited to gallium arsenide. For example, materials comprising any one of gallium arsenide, aluminum arsenide, indium arsenide, indium phosphide, gallium phosphide, indium antimonide, gallium nitride, indium nitride, aluminum nitride, silicon germanium, silicon carbide, gallium (III) oxide, and gallium bismuth (GaBi) as the main component, or materials comprising a multi-component mixed crystal material composed of multiple of these materials as the main component, can be used, but the material is not limited to these materials.

[0104] A power amplifier circuit 11 is formed on the second substrate 72. Specifically, a plurality of circuit elements 721, electrodes (not shown) for applying voltage to the plurality of circuit elements 721, or electrodes (not shown) for supplying current are formed on the second substrate 72. The plurality of circuit elements 721 are, for example, heterojunction bipolar transistors (HBTs) formed by multiple unit transistors connected in parallel, and the plurality of circuit elements 721 constitute the power amplifier circuit 11. Alternatively, a low-noise amplifier circuit 21 may be formed on the second substrate 72 instead of the power amplifier circuit 11. That is, it is sufficient to form an amplifier circuit on the second substrate 72.

[0105] like Figure 5 As shown, the second substrate 72 includes a semiconductor layer 72a, an epitaxial layer 72b formed on the surface of the semiconductor layer 72a, and a plurality of circuit elements 721. The semiconductor layer 72a is made of a second semiconductor material and is bonded to the silicon nitride layer 715 of the first substrate 71. The semiconductor layer 72a is, for example, a GaAs layer. The circuit element 721 has a collector layer 721C, a base layer 721B, and an emitter layer 721E. The collector layer 721C, the base layer 721B, and the emitter layer 721E are stacked sequentially on the epitaxial layer 72b in this order. That is, in the circuit element 721, the collector layer 721C, the base layer 721B, and the emitter layer 721E are stacked sequentially from the first substrate 71 side in this order.

[0106] As an example, the collector layer 721C is made of n-type gallium arsenide, the base layer 721B is made of p-type gallium arsenide, and the emitter layer 721E is made of n-type indium gallium phosphide (InGaP). The emitter layer 721E is bonded to the electrode 723 via an electrode 722 formed on the surface of the second substrate 72. The electrode 723 is bonded to the main surface 90a of the module substrate 90 via an electrode 724.

[0107] Electrode 724 is an example of a second electrode, which protrudes from the second substrate 72 toward the main surface 90a of the module substrate 90, and the front end of electrode 724 is engaged with the main surface 90a. Electrode 724 has a columnar conductor 724a and a bump electrode 724b. The bump electrode 724b is engaged with an electrode (not shown) disposed on the main surface 90a of the module substrate 90.

[0108] Furthermore, the second substrate 72 is not limited to Figure 4 and Figure 5 Structure

[0109] [1.3.3 Structure of the third substrate 73]

[0110] Next, the third substrate 73 will be described. At least a portion of the third substrate 73 is made of a piezoelectric material. Transmitting filter circuits 61T and 62T are formed on the third substrate 73. Furthermore, the filter circuits formed on the third substrate 73 are not limited to transmitting filter circuits 61T and 62T. Only one of the transmitting filter circuits 61T and 62T may be formed on the third substrate 73, or receiving filter circuits 61R and / or 62R may be formed.

[0111] In this embodiment, each of the transmit filter circuits 61T and 62T is constructed using SAW filters. For example... Figure 4 As shown, the third substrate 73 includes a piezoelectric layer 731, a low-velocity layer 732, a high-velocity layer 733, an IDT (Interdigital Transducer) electrode 734, and a capping layer 735.

[0112] The piezoelectric layer 731 is made of a piezoelectric material, and an IDT electrode 734 is formed on its surface. For example, lithium tantalate (LiTaO3) or lithium niobate (LiNbO3) can be used as the piezoelectric material, but it is not limited to these.

[0113] In the cross-sectional view, the low-velocity layer 732 is disposed between the piezoelectric layer 731 and the high-velocity layer 733. The sound speed of the bulk wave propagating in the low-velocity layer 732 is lower than that of the bulk wave propagating in the piezoelectric layer 731. The material of the low-velocity layer 732 can be, for example, glass, silicon oxide, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon, or boron to silicon oxide, but is not limited to these materials.

[0114] The high-velocity acoustic layer 733 is supported by the silicon substrate 711 of the first substrate 71. The sound speed of the bulk wave propagating in the high-velocity acoustic layer 733 is higher than the sound speed of the elastic wave propagating in the piezoelectric layer 731. As the material of the high-velocity acoustic layer 733, for example, aluminum nitride (AlN), aluminum oxide (Al2O3), silicon carbide (SiC), silicon oxynitride (SiON), silicon, diamond-like carbon (DLC), or diamond can be used, but it is not limited to these.

[0115] The high-velocity layer 733, the low-velocity layer 732, and the piezoelectric layer 731 are stacked sequentially on the silicon substrate 711 in this order.

[0116] The capping layer 735 forms a space on the surface of the piezoelectric layer 731 on which the IDT electrode 734 is formed.

[0117] Furthermore, the structure of the third substrate 73 is not limited to Figure 4The structure is as follows. For example, the third substrate 73 may also exclude one or both of the low-velocity layer 732 and the high-velocity layer 733. Alternatively, the third substrate 73 may include a silicon dioxide film on the piezoelectric layer 731.

[0118] Furthermore, here, silicon and gallium arsenide are used as the combination of the first and second semiconductor materials, but the combination of the first and second semiconductor materials is not limited to this. Any combination can be used as long as the first semiconductor material is different from the second semiconductor material and has a higher thermal conductivity than the second semiconductor material. Conversely, any combination can be used as long as the second semiconductor material is different from the first semiconductor material and has a lower thermal conductivity than the first semiconductor material. The thermal conductivity of silicon is 156 (W / m·K), and the thermal conductivity of gallium arsenide is 46 (W / m·K), therefore, the combination of silicon and gallium arsenide can be used as the combination of the first and second semiconductor materials.

[0119] [1.4 Effects, etc.]

[0120] As described above, the high-frequency module 1 according to this embodiment includes: a first substrate 71, at least a portion of which is made of a first semiconductor material; a second substrate 72, at least a portion of which is made of a second semiconductor material with a lower thermal conductivity than the first semiconductor material, and a power amplifier circuit 11 is formed on the second substrate 72; a third substrate 73, at least a portion of which is made of a piezoelectric material, and a transmit filter circuit 61T and / or 62T is formed on the third substrate 73; and a module substrate 90 having a main surface 90a on which the first substrate 71, the second substrate 72 and the third substrate 73 are disposed, wherein the first substrate 71 is bonded to the main surface 90a via an electrode 717, in a cross-sectional view, the second substrate 72 is disposed between the module substrate 90 and the first substrate 71 and is bonded to the main surface 90a via an electrode 724, and in a top view, at least a portion of the first substrate 71 overlaps with at least a portion of the second substrate 72 and at least a portion of the third substrate 73.

[0121] Accordingly, in the top view, the second substrate 72 on which the power amplifier circuit 11 is formed and the third substrate 73 on which the transmit filter circuits 61T and / or 62T are formed overlap with the first substrate 71, thus contributing to the miniaturization of the high-frequency module 1. Furthermore, the heat generated by the power amplifier circuit 11 formed on the second substrate 72 can be effectively dissipated to the outside via the first substrate 71, which is made of a first semiconductor material having a higher thermal conductivity than the second semiconductor material constituting the second substrate 72, and the electrodes 717. Moreover, the thermal-induced performance degradation of the transmit filter circuits 61T and / or 62T formed on the third substrate 73 can be suppressed.

[0122] Alternatively, for example, in the high-frequency module 1 according to this embodiment, a first electrical circuit may be formed on the first substrate 71.

[0123] This can help to further miniaturize the high-frequency module 1.

[0124] Alternatively, for example, in the high-frequency module 1 of this embodiment, the second substrate 72, the first substrate 71, and the third substrate 73 may be stacked sequentially from the module substrate 90 side in this order.

[0125] Accordingly, the second substrate 72, the first substrate 71 and the third substrate 73 are stacked in this order, thereby improving the heat dissipation efficiency of the power amplifier circuit 11 and reducing the component mounting area.

[0126] Alternatively, for example, in the high-frequency module 1 of this embodiment, the third substrate 73 is connected to the first substrate 71 via a side wiring 736 formed on the side of the third substrate 73.

[0127] Accordingly, the electrical connection between the third substrate 73 and the first substrate 71 can be achieved using the side wiring 736.

[0128] Alternatively, for example, in the high-frequency module 1 of this embodiment, the transmitting filter circuits 61T and / or 62T may include SAW filters.

[0129] Accordingly, a SAW filter can be formed on the third substrate 73.

[0130] Alternatively, for example, in the high-frequency module 1 of this embodiment, the third substrate 73 may have: a piezoelectric layer 731, which is made of a piezoelectric material and has an IDT electrode 734 formed thereon; a low-velocity layer 732, in which the velocity of a bulk wave propagating is lower than that of a bulk wave propagating in the piezoelectric layer 731; and a high-velocity layer 733, in which the velocity of a bulk wave propagating is higher than that of an elastic wave propagating in the piezoelectric layer 731, wherein the high-velocity layer 733, the low-velocity layer 732, and the piezoelectric layer 731 are sequentially stacked on the first substrate 71 in this order.

[0131] Accordingly, the first substrate 71 can be used as the support substrate for the SAW filter, which can help reduce the material used for the support substrate and miniaturize the high-frequency module 1.

[0132] Alternatively, for example, in the high-frequency module 1 of this embodiment, the first electrical circuit may include at least one of the following: a control circuit 80 that controls the power amplifier circuit 11; a switching circuit 51 connected between the output terminal of the power amplifier circuit 11 and the transmitting filter circuits 61T and / or 62T; and a switching circuit 52 connected between the input terminal of the power amplifier circuit 11 and the high-frequency input terminals 111 and 112 for receiving high-frequency signals from the outside.

[0133] Accordingly, at least one of the control circuit 80 and the switching circuits 51 and 52 is formed at the first substrate 71, which overlaps with the second substrate 72, in a top view. When the control circuit 80 is formed at the first substrate 71, the wiring length between the power amplifier circuit 11 formed on the second substrate 72 and the control circuit 80 can be shortened, reducing the impact of digital noise caused by the control signal. Furthermore, when the switching circuit 51 or 52 is formed at the first substrate 71, the wiring length between the switching circuit 51 or 52 and the power amplifier circuit 11 can be shortened, reducing wiring losses and mismatch losses caused by parasitic capacitance of the wiring.

[0134] Alternatively, for example, in the high-frequency module 1 involved in this embodiment, the first semiconductor material may be silicon.

[0135] Accordingly, silicon can be used as a first semiconductor material, thus enabling the manufacture of a first substrate 71 with relatively high thermal conductivity at a relatively low cost.

[0136] Alternatively, for example, in the high-frequency module 1 involved in this embodiment, the second semiconductor material may be gallium arsenide.

[0137] Therefore, gallium arsenide can be used as a second semiconductor material, thus enabling the manufacture of a relatively high-performance power amplifier circuit 11.

[0138] Alternatively, for example, in the high-frequency module 1 of this embodiment, the power amplifier circuit 11 includes a circuit element 721 having a collector layer 721C, a base layer 721B, and an emitter layer 721E, with the collector layer 721C, the base layer 721B, and the emitter layer 721E stacked sequentially from the first substrate 71 side in this order.

[0139] Accordingly, the wiring connecting the collector layer 721C, base layer 721B, and emitter layer 721E can be simplified in the manufacturing process. Furthermore, in a top view, the area of ​​the collector layer 721C is larger than the areas of the base layer 721B and emitter layer 721E. Therefore, by bonding the collector layer 721C to the first substrate 71, the bonding area can be increased compared to bonding the base layer 721B or emitter layer 721E to the first substrate 71. As a result, the bonding between the first substrate 71 and the second substrate 72 can be strengthened, thereby suppressing the peeling of the second substrate 72 from the first substrate 71.

[0140] The high-frequency module 1 according to this embodiment includes: a first substrate 71, at least a portion of which is made of silicon or gallium nitride; a second substrate 72, at least a portion of which is made of gallium arsenide or silicon germanium, and a power amplifier circuit 11 is formed on the second substrate 72; a third substrate 73, at least a portion of which is made of piezoelectric material, and a transmit filter circuit 61T and / or 62T is formed on the third substrate 73; and a module substrate 90 having a main surface 90a on which the first substrate 71, the second substrate 72 and the third substrate 73 are disposed, wherein the first substrate 71 is bonded to the main surface 90a via an electrode 717, and in a cross-sectional view, the second substrate 72 is disposed between the module substrate 90 and the first substrate 71 and is bonded to the main surface 90a via an electrode 724, and in a top view, at least a portion of the first substrate 71 overlaps with at least a portion of the second substrate 72 and at least a portion of the third substrate 73.

[0141] Accordingly, in the top view, the second substrate 72, on which the power amplifier circuit 11 is formed, and the third substrate 73, on which the transmit filter circuits 61T and / or 62T are formed, overlap with the first substrate 71, thus contributing to the miniaturization of the high-frequency module 1. Furthermore, the heat generated by the power amplifier circuit 11 formed on the second substrate 72 can be effectively dissipated to the outside via the first substrate 71, which is made of silicon or gallium nitride and has a higher thermal conductivity than gallium arsenide or silicon germanium constituting the second substrate 72, and the electrodes 717. Moreover, the thermal-induced performance degradation of the transmit filter circuits 61T and / or 62T formed on the third substrate 73 can be suppressed.

[0142] The communication device 5 according to this embodiment includes: an RFIC 3 that processes high-frequency signals; and a high-frequency module 1 that transmits high-frequency signals between the RFIC 3 and the antenna 2.

[0143] Therefore, the same effect as the high-frequency module 1 described above can be achieved in the communication device 5.

[0144] (Implementation Method 2)

[0145] Next, Embodiment 2 will be described. The main difference between this embodiment and Embodiment 1 is the structure of the integrated circuit comprising a first substrate, a second substrate, and a third substrate. The high-frequency module involved in this embodiment will now be described, focusing on the differences from Embodiment 1.

[0146] The communication device 5 and high-frequency module 1 in this embodiment are the same as in embodiment 1, except that they use integrated circuit 70A instead of integrated circuit 70. Therefore, the description of the communication device 5 and high-frequency module 1 is omitted, and will refer to... Figure 6 This will illustrate the structure of the integrated circuit 70A.

[0147] [2.1 Structure of Integrated Circuit 70A]

[0148] Figure 6 This is a partial cross-sectional view of the high-frequency module 1 involved in Embodiment 2. Specifically, Figure 6 This is a cross-sectional view of the 70A integrated circuit.

[0149] Integrated circuit 70A includes a first substrate 71, a second substrate 72, and a third substrate 73A. Similar to Embodiment 1, at least a portion of the third substrate 73A is made of a piezoelectric material. Transmitter filter circuits 61T and 62T are formed on the third substrate 73A. In this embodiment, each transmit filter circuit of transmit filter circuits 61T and 62T is constructed using an SMR (Solid Mounted Resonator) type BAW filter. Figure 6 As shown, the third substrate 73A includes an acoustic multilayer film 731A, a lower electrode 732A, a piezoelectric layer 733A, and an upper electrode 734A.

[0150] The acoustic multilayer film 731A functions as a mirror layer for reflecting elastic waves and is supported by the first substrate 71. The acoustic multilayer film 731A includes multiple low acoustic impedance films 7311A and multiple high acoustic impedance films 7312A, each of the high acoustic impedance films 7312A having a higher acoustic impedance than the multiple low acoustic impedance films 7311A. The multiple low acoustic impedance films 7311A and the multiple high acoustic impedance films 7312A are alternately stacked on the silicon substrate 711 of the first substrate 71.

[0151] Materials for the low acoustic impedance film 7311A, such as silicon oxide or aluminum, can be used. Materials for the high acoustic impedance film 7312A, such as tungsten, platinum, molybdenum, or gold, can be used.

[0152] The piezoelectric layer 733A, made of a piezoelectric material, is disposed between the lower electrode 732A and the upper electrode 734A. That is, the lower electrode 732A, the piezoelectric layer 733A, and the upper electrode 734A are sequentially stacked on the acoustic multilayer film 731A in this order. For example, aluminum nitride (AlN) can be used as the piezoelectric material.

[0153] Furthermore, the structure of the third substrate 73A is not limited to Figure 6 The structure is as follows. For example, an FBAR (Film Bulk Acoustic Resonator) type BAW filter can also be formed on the third substrate 73A.

[0154] [2.2 Effects, etc.]

[0155] As described above, in the high-frequency module 1 of this embodiment, the transmitting filter circuits 61T and / or 62T include BAW filters.

[0156] Accordingly, a BAW filter can be formed on the third substrate 73A.

[0157] Alternatively, for example, in the high-frequency module 1 of this embodiment, the third substrate 73A may have: an acoustic multilayer film 731A, which is formed by alternating layers of a plurality of low acoustic impedance films 7311A and a plurality of high acoustic impedance films 7312A, wherein the plurality of high acoustic impedance films 7312A have an acoustic impedance that is higher than that of the plurality of low acoustic impedance films 7311A; a lower electrode 732A; a piezoelectric layer 733A, which is made of a piezoelectric material; and an upper electrode 734A, wherein the acoustic multilayer film 731A, the lower electrode 732A, the piezoelectric layer 733A and the upper electrode 734A are sequentially stacked on the first substrate 71 in this order.

[0158] Accordingly, the first substrate 71 can be used as the support substrate for the BAW filter, which can help reduce the material used for the support substrate and miniaturize the high-frequency module 1.

[0159] (Implementation Method 3)

[0160] Next, Embodiment 3 will be described. The main difference between this embodiment and Embodiment 1 is the structure of the integrated circuit comprising a first substrate, a second substrate, and a third substrate. The high-frequency module involved in this embodiment will now be described, focusing on the differences from Embodiment 1.

[0161] The communication device 5 and high-frequency module 1 in this embodiment are the same as in embodiment 1, except that they have integrated circuit 70B instead of integrated circuit 70. Therefore, the description of the communication device 5 and high-frequency module 1 is omitted, and will refer to... Figure 7This will illustrate the structure of the integrated circuit 70B.

[0162] [3.1 Structure of Integrated Circuit 70B]

[0163] Figure 7 This is a partial cross-sectional view of the high-frequency module 1 involved in Embodiment 3. Specifically, Figure 7 This is a cross-sectional view of integrated circuit 70B. Furthermore, in Figure 7 The diagram of the wiring connecting the substrates within the integrated circuit 70B is omitted.

[0164] In addition to the first substrate 71, the second substrate 72, and the third substrate 73, the integrated circuit 70B also includes a fourth substrate 74. At least a portion of the fourth substrate 74 is made of a third semiconductor material. Here, silicon, the same semiconductor material as the first semiconductor material, is used as the third semiconductor material. A switching circuit 53 is formed on the fourth substrate 74 as a second electrical circuit. However, the second electrical circuit is not limited to the switching circuit 53.

[0165] [3.2 Effects, etc.]

[0166] As described above, the high-frequency module 1 of this embodiment includes a fourth substrate 74, at least a portion of which is made of a third semiconductor material. A second electrical circuit is formed on the fourth substrate 74. The second substrate 72, the first substrate 71, the third substrate 73 and the fourth substrate 74 are stacked sequentially from the module substrate 90 side in this order.

[0167] Accordingly, in addition to the first substrate 71, the second substrate 72 and the third substrate 73, a fourth substrate 74 is also laminated, which can further reduce the component mounting area.

[0168] Alternatively, for example, in the high-frequency module 1 of this embodiment, the second electrical circuit may include a switching circuit 53 connected between the transmitting filter circuit 61T and / or 62T and the antenna connection terminal 100.

[0169] Accordingly, a switching circuit 53 connected to the transmitting filter circuits 61T and / or 62T is formed on a fourth substrate 74 stacked on the third substrate 73. This shortens the wiring length between the switching circuit 53 and the transmitting filter circuits 61T and / or 62T, thereby reducing wiring losses and mismatch losses caused by parasitic capacitance in the wiring.

[0170] (Implementation Method 4)

[0171] Next, Embodiment 4 will be described. The main difference between this embodiment and Embodiment 1 is the structure of the integrated circuit comprising a first substrate, a second substrate, and a third substrate. The high-frequency module involved in this embodiment will now be described, focusing on the differences from Embodiment 1.

[0172] The communication device 5 and high-frequency module 1 in this embodiment are the same as in Embodiment 1, except that they use integrated circuit 70C instead of integrated circuit 70. Therefore, the description of the communication device 5 and high-frequency module 1 is omitted, and will refer to... Figure 8 This will illustrate the structure of the integrated circuit 70C.

[0173] [4.1 Structure of Integrated Circuit 70C]

[0174] Figure 8 This is a partial cross-sectional view of the high-frequency module 1 involved in Embodiment 4. Specifically, Figure 8 This is a cross-sectional view of the 70C integrated circuit. Furthermore, in Figure 8 The diagram of the wiring connecting the substrates within the integrated circuit 70C is omitted.

[0175] In addition to the first substrate 71, the second substrate 72 and the third substrate 73, the integrated circuit 70C also includes an insulating layer 75.

[0176] In the cross-sectional view, the insulating layer 75 is disposed between the first substrate 71 and the third substrate 73. That is, in the integrated circuit 70C, the second substrate 72, the first substrate 71, the insulating layer 75, and the third substrate 73 are stacked sequentially from the module substrate 90 side in this order.

[0177] The insulating layer 75 is made of a material with a lower thermal conductivity than the first semiconductor material. For example, silicon dioxide, silicon nitride, tantalum pentoxide (Ta2O5), polyimide, or epoxy resin can be used as the insulating layer 75, but it is not limited to these.

[0178] [4.2 Effects, etc.]

[0179] As described above, the high-frequency module 1 according to this embodiment includes an insulating layer 75. In a cross-sectional view, the insulating layer 75 is disposed between the first substrate 71 and the third substrate 73. The insulating layer 75 is made of a material with a lower thermal conductivity than the first semiconductor material.

[0180] Accordingly, the heat transmitted from the first substrate 71 to the third substrate 73 can be reduced using the insulating layer 75. Therefore, the performance degradation of the transmitting filter circuits 61T and / or 62T formed on the third substrate 73 due to temperature rise can be suppressed.

[0181] (Implementation Method 5)

[0182] Next, Embodiment 5 will be described. The main difference between this embodiment and Embodiment 1 is the structure of the integrated circuit comprising a first substrate, a second substrate, and a third substrate. The high-frequency module involved in this embodiment will now be described, focusing on the differences from Embodiment 1.

[0183] The communication device 5 and high-frequency module 1 in this embodiment are the same as in embodiment 1, except that they use integrated circuit 70D instead of integrated circuit 70. Therefore, the description of the communication device 5 and high-frequency module 1 is omitted, and will refer to... Figure 9 This will illustrate the structure of the integrated circuit 70D.

[0184] [5.1 Structure of Integrated Circuit 70D]

[0185] Figure 9 This is a partial cross-sectional view of the high-frequency module 1 according to embodiment 5. Specifically, Figure 9 This is a cross-sectional view of the 70D integrated circuit. Furthermore, in... Figure 9 The diagram of the wiring connecting the substrates within the integrated circuit 70D is omitted.

[0186] Integrated circuit 70D includes a first substrate 71, a second substrate 72, and a third substrate 73. In a cross-sectional view, in integrated circuit 70D, in addition to the second substrate 72 being disposed between the module substrate 90 and the first substrate 71, the third substrate 73 is also disposed between the module substrate 90 and the first substrate 71. That is, in a top view, a portion of the first substrate 71 overlaps with at least a portion of the second substrate 72, and another portion of the first substrate 71 overlaps with at least a portion of the third substrate 73. Furthermore, in a top view, the second substrate 72 does not overlap with the third substrate 73.

[0187] [5.2 Effects, etc.]

[0188] As described above, in the high-frequency module 1 of this embodiment, in a cross-sectional view, the third substrate 73 is disposed between the module substrate 90 and the first substrate 71; in a top view, a portion of the first substrate 71 overlaps with at least a portion of the second substrate 72; in a top view, another portion of the first substrate 71 overlaps with at least a portion of the third substrate 73; and in a top view, the second substrate 72 does not overlap with the third substrate 73.

[0189] Accordingly, in the top view, the second substrate 72 does not overlap with the third substrate 73, thus reducing the heat transmitted from the second substrate 72 to the third substrate 73. Consequently, the performance degradation of the transmitting filter circuits 61T and / or 62T formed on the third substrate 73 due to temperature rise can be suppressed.

[0190] (Other implementation methods)

[0191] The high-frequency module and communication device of the present invention have been described above based on the embodiments, but the high-frequency module and communication device of the present invention are not limited to the above embodiments. Other embodiments implemented by combining any of the constituent elements in the above embodiments, variations obtained by implementing the above embodiments with various modifications that can be conceived by those skilled in the art without departing from the spirit of the present invention, and various devices that incorporate the above high-frequency module and communication device are also included in the present invention.

[0192] For example, Embodiment 2 can be combined with Embodiments 3 to 5. Specifically, in Embodiments 3 to 5, a third substrate 73A with a BAW filter can be used instead of the third substrate 73 with a SAW filter. Furthermore, the variations described in Embodiment 1 can also be applied to Embodiments 2 to 5.

[0193] Industrial availability

[0194] This invention, as a high-frequency module configured in the front end, can be widely used in communication devices such as portable telephones.

[0195] Explanation of reference numerals in the attached figures

[0196] 1: High-frequency module; 2: Antenna; 3: RFIC; 4: BBIC; 5: Communication device; 11: Power amplifier circuit; 20, 70, 70A, 70B, 70C, 70D: Integrated circuits; 21: Low-noise amplifier circuit; 41, 42, 43, 44: Impedance matching circuits; 51, 52, 53, 54, 55: Switching circuits; 61, 62: Duplexers; 61R, 62R: Receiver filter circuits; 61T, 62T: Transmitter filter circuits; 71: First substrate; 72: Second substrate; 72a: Semiconductor layer; 72b: Epitaxial layer; 73, 73A: Third substrate; 74: Fourth substrate; 75: Insulating layer; 80: Control circuit; 90: Module substrate; 90a, 90b: Main surface; 91: Resin component; 92: Shielding electrode layer; 100: Antenna connection terminal; 111, 112: High-frequency input terminal; 121 122: High-frequency output terminal; 130: Control terminal; 150: External connection terminal; 711: Silicon substrate; 712, 714: Silicon dioxide layer; 713: Silicon layer; 715: Silicon nitride layer; 716, 717, 722, 723, 724: Electrodes; 717a, 724a: Columnar conductors; 717b, 724b: Bump electrodes; 718: Resin layer; 721, 7130: Circuit elements; 721 B: Base layer; 721C: Collector layer; 721E: Emitter layer; 731, 733A: Piezoelectric layer; 731A: Acoustic multilayer film; 732: Low acoustic velocity layer; 732A: Lower electrode; 733: High acoustic velocity layer; 734: IDT electrode; 734A: Upper electrode; 735: Capping layer; 736: Side wiring; 7140: Through-hole conductor; 7311A: Low acoustic impedance film; 7312A: High acoustic impedance film.

Claims

1. A high-frequency module, comprising: A first substrate, wherein at least a portion of the first substrate is composed of a first semiconductor material; The second substrate, at least a portion of which is made of a second semiconductor material with a lower thermal conductivity than the first semiconductor material, has an amplification circuit formed thereon. A third substrate, at least a portion of which is made of a piezoelectric material, on which a filter circuit is formed; as well as The module substrate has a main surface on which the first substrate, the second substrate, and the third substrate are disposed. The first substrate is bonded to the main surface via a first electrode. In a cross-sectional view, the second substrate is disposed between the module substrate and the first substrate, and is bonded to the main surface via a second electrode. In a top view, at least a portion of the first substrate overlaps with at least a portion of the second substrate and at least a portion of the third substrate.

2. The high-frequency module according to claim 1, wherein, A first electrical circuit is formed on the first substrate.

3. The high-frequency module according to claim 1 or 2, wherein, The second substrate, the first substrate, and the third substrate are stacked sequentially from the module substrate side in this order.

4. The high-frequency module according to claim 2, wherein, The third substrate is connected to the first substrate via side wiring formed on the side of the third substrate.

5. The high-frequency module according to claim 3, wherein, The high-frequency module includes a fourth substrate, at least a portion of which is made of a third semiconductor material, and a second electrical circuit is formed on the fourth substrate. The second substrate, the first substrate, the third substrate, and the fourth substrate are stacked sequentially from the module substrate side in this order.

6. The high-frequency module according to claim 3, wherein, The high-frequency module has an insulating layer, which, in a cross-sectional view, is disposed between the first substrate and the third substrate. The insulating layer is made of a material with a lower thermal conductivity than the first semiconductor material.

7. The high-frequency module according to claim 1 or 2, wherein, In the cross-sectional view, the third substrate is disposed between the module substrate and the first substrate. In a top view, a portion of the first substrate overlaps with at least a portion of the second substrate. In the top view, another portion of the first substrate overlaps with at least a portion of the third substrate. In the top view, the second substrate does not overlap with the third substrate.

8. The high-frequency module according to claim 1 or 2, wherein, The amplifier circuit is a power amplifier circuit.

9. The high-frequency module according to claim 1 or 2, wherein, The filter circuit includes a SAW filter, i.e., a surface acoustic wave filter.

10. The high-frequency module according to claim 9, wherein, The third substrate has: A piezoelectric layer, which is composed of the piezoelectric material, has IDT electrodes, i.e., interdigitated transducer electrodes; A low-velocity layer in which the velocity of sound of volume waves propagating is lower than that of sound waves propagating in the piezoelectric layer. as well as A high-velocity layer in which the velocity of sound for volume waves propagating is higher than the velocity of sound for elastic waves propagating in the piezoelectric layer. The high-velocity layer, the low-velocity layer, and the piezoelectric layer are stacked sequentially on the first substrate in this order.

11. The high-frequency module according to claim 1 or 2, wherein, The filter circuit includes a BAW filter, i.e., a bulk acoustic wave filter.

12. The high-frequency module according to claim 11, wherein, The third substrate has: The acoustic multilayer film is composed of multiple low acoustic impedance films and multiple high acoustic impedance films stacked alternately, wherein each of the multiple high acoustic impedance films has an acoustic impedance that is higher than that of the multiple low acoustic impedance films. Lower electrode; A piezoelectric layer, which is composed of the piezoelectric material; and Upper electrode, The acoustic multilayer film, the lower electrode, the piezoelectric layer, and the upper electrode are stacked sequentially on the first substrate in this order.

13. The high-frequency module according to claim 2, wherein, The first electrical circuit includes at least one of the following: a control circuit for controlling the amplifier circuit, a first switching circuit connected between the output terminal of the amplifier circuit and the filter circuit, and a second switching circuit connected between the input terminal of the amplifier circuit and an input terminal for receiving high-frequency signals from the outside.

14. The high-frequency module according to claim 5, wherein, The second electrical circuit includes a third switching circuit connected between the filter circuit and the antenna connection terminal.

15. The high-frequency module according to claim 1 or 2, wherein, The first semiconductor material is silicon.

16. The high-frequency module according to claim 1 or 2, wherein, The second semiconductor material is gallium arsenide.

17. The high-frequency module according to claim 1 or 2, wherein, The amplifier circuit includes circuit elements having a collector layer, a base layer, and an emitter layer. The current collector layer, the base layer, and the emitter layer are stacked sequentially from the first substrate side in this order.

18. A high-frequency module, comprising: A first substrate, at least a portion of which is made of silicon or gallium nitride, and a first electrical circuit is formed thereon; The second substrate, at least a portion of which is composed of gallium arsenide or silicon germanium, has an amplifier circuit formed thereon. A third substrate, at least a portion of which is made of a piezoelectric material, on which a filter circuit is formed; as well as The module substrate has a main surface on which the first substrate, the second substrate, and the third substrate are disposed. The first substrate is bonded to the main surface via a first electrode. In a cross-sectional view, the second substrate is disposed between the module substrate and the first substrate, and is bonded to the main surface via a second electrode. In a top view, at least a portion of the first substrate overlaps with at least a portion of the second substrate and at least a portion of the third substrate.

19. A communication device comprising: Signal processing circuitry that processes high-frequency signals; and The high-frequency module according to any one of claims 1 to 18 transmits the high-frequency signal between the signal processing circuit and the antenna.

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