High frequency module and communication device

Abstract

A high-frequency module (1A) includes: a module substrate (80); an electronic component disposed on a main surface (80a); a resin member (81) covering at least a portion of the main surface (80a) and at least a portion of a side surface of the electronic component; and a metal shielding layer (85) formed on a surface of the resin member (81) and set to a ground potential, wherein the electronic component has: a top surface in contact with the metal shielding layer (85); a bottom surface facing the main surface (80a); a circuit portion formed at a position closer to the bottom surface than to the top surface; and a metal layer formed between the metal shielding layer (85) and the circuit portion, the metal layer being a barrier metal.

Description

Technical Field

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

[0002] Patent document 1 discloses a high-frequency module comprising a substrate, a sheet coil and a surface acoustic wave filter (electronic component) mounted on the substrate, a resin layer covering the sheet coil and the surface acoustic wave filter, and a metal film formed on the surface of the resin layer.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2014 / 013831 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the high-frequency module disclosed in Patent Document 1, the top surface of the surface acoustic wave filter is in contact with a metal film.

[0008] However, in the high-frequency module disclosed in Patent Document 1, since the metal film is in contact with the electronic component (surface acoustic wave filter), metal sometimes diffuses from the metal film into the circuit section (IDT electrode) of the electronic component (surface acoustic wave filter). When this diffused metal mixes into the circuit section of the electronic component as an impurity, the characteristics of the electronic component deteriorate.

[0009] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a high-frequency module and communication device that suppresses the degradation of the characteristics of electronic components caused by metal diffusion.

[0010] Solution for solving the problem

[0011] One aspect of the present invention relates to a high-frequency module comprising: a module substrate; an electronic component disposed on a main surface of the module substrate; a resin member covering at least a portion of the main surface and at least a portion of the side surface of the electronic component; and a first metal layer formed on the surface of the resin member and set to ground potential, wherein the electronic component has: a first surface in contact with the first metal layer; a second surface facing the main surface; a circuit portion formed closer to the second surface than to the first surface; and a second metal layer formed between the first metal layer and the circuit portion, the second metal layer being a barrier metal.

[0012] Additionally, one aspect of the present invention relates to a high-frequency module comprising: a module substrate; an electronic component disposed on a main surface of the module substrate; a resin component covering at least a portion of the main surface and at least a portion of the side surface of the electronic component; and a first metal layer formed on the surface of the resin component and set to ground potential, wherein the electronic component has: a first surface in contact with the first metal layer; a second surface facing the main surface; a circuit portion formed at a location closer to the second surface than to the first surface; and a second metal layer formed between the first metal layer and the circuit portion, wherein the first metal layer is copper, a copper-containing alloy, or a copper-containing laminate, and the second metal layer is titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of these.

[0013] The effects of the invention

[0014] According to the present invention, a high-frequency module and a communication device are provided that suppress the degradation of the characteristics of electronic components caused by metal diffusion. Attached Figure Description

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

[0016] Figure 2 This is a schematic diagram of the planar structure of the high-frequency module involved in the embodiment.

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

[0018] Figure 4 This is a cross-sectional structural diagram of the semiconductor IC involved in the embodiment.

[0019] Figure 5 This is a cross-sectional structural diagram of the second substrate involved in the embodiment.

[0020] Figure 6 This is a cross-sectional structural diagram showing a first example of the transmitting filter involved in the embodiment.

[0021] Figure 7 This is a cross-sectional structural diagram showing a second example of the transmitting filter involved in the embodiment. Detailed Implementation

[0022] The embodiments of the present invention will now be described in detail. Furthermore, the embodiments described below are general or specific examples. The numerical values, shapes, materials, structural elements, arrangements of structural elements, and connection methods shown in the embodiments below are examples and are not intended to limit the present invention. Structural elements in the following embodiments not described in the independent claims will be described as arbitrary structural elements. Additionally, the sizes or size ratios of the structural elements shown in the drawings are not necessarily strict. In the figures, substantially identical structures are labeled with the same reference numerals, and sometimes repeated descriptions are omitted or simplified.

[0023] In addition, the following terms, such as parallel and perpendicular, which indicate the relationship between elements, rectangular shape, which indicates the shape of elements, and numerical range, also include substantially equivalent ranges, such as a difference of a few percent, rather than just indicating a strict meaning.

[0024] Furthermore, the phrase "A is disposed on the first main surface of the substrate" below not only indicates that A is directly mounted on the first main surface, but also that A is disposed in the space on the first main surface side, which is separated from the substrate by the space on the first main surface side and the space on the second main surface side. That is to say, it includes the following situation: A is mounted on the first main surface through other circuit elements, electrodes, etc.

[0025] Furthermore, in the circuit structure disclosed herein, "connection" includes not only direct connection using connection terminals and / or wiring conductors, but also electrical connection via other circuit components. Additionally, "connected between A and B" indicates a connection between A and B, and between both A and B.

[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. The z-axis is perpendicular to the main surface of the module substrate; the positive z-axis direction represents the upward direction, and the negative z-axis direction represents the downward direction.

[0027] Furthermore, in the module structure disclosed herein, "top view" means observing an object by projecting it orthographically onto the xy plane from the positive z-axis side. "Component disposed on the main surface of the substrate" includes not only the case where the component is disposed on the main surface of the substrate in contact with it, but also the following cases: the component is disposed above the main surface without contacting it; and a portion of the component is disposed embedded in the substrate from the main surface side.

[0028] Furthermore, regarding A, B, and C mounted on the substrate, "when viewing the substrate (or the main surface of the substrate) from above, C is arranged between A and B" means that when viewing the substrate from above, at least one of the multiple line segments connecting any point in A to any point in B passes through the area of ​​C. Additionally, "viewing the substrate from above" means that the substrate and the circuit elements mounted on the substrate are projected onto a plane parallel to the main surface of the substrate for observation.

[0029] Additionally, below, "transmission path" refers to a transmission line consisting of wiring for transmitting high-frequency transmission signals, electrodes directly connected to the wiring, and terminals directly connected to the wiring or electrodes. Similarly, "reception path" refers to a transmission line consisting of wiring for transmitting high-frequency reception signals, electrodes directly connected to the wiring, and terminals directly connected to the wiring or electrodes.

[0030] (Implementation Method)

[0031] [1. Circuit structure of high-frequency module 1 and communication device 5]

[0032] Figure 1 This is a circuit diagram of the high-frequency module 1 and the communication device 5 according to the embodiment. As shown in the figure, the communication device 5 includes a high-frequency module 1, an antenna 2, an RF signal processing circuit (RFIC) 3, and a baseband signal processing circuit (BBIC) 4.

[0033] RFIC 3 is an RF signal processing circuit that processes the high-frequency signals transmitted and received using antenna 2. Specifically, RFIC 3 processes the received signal input through the receiving path of high-frequency module 1 using down-conversion and the like, and outputs the resulting received signal to BBIC 4. Additionally, RFIC 3 processes the transmitted signal input from BBIC 4 using up-conversion and the like, and outputs the resulting transmitted signal to the transmitting path of high-frequency module 1.

[0034] BBIC 4 is a circuit that uses an intermediate frequency band with a lower frequency than the high-frequency signal transmitted in high-frequency module 1 for signal processing. The signal processed by BBIC 4 can be used, for example, as an image signal to display an image, or as an audio signal to make a call using a speaker.

[0035] In addition, RFIC 3 also functions as a control unit to control the connection of switches 52, 53, and 54 of the high-frequency module 1 based on the communication frequency band used. Specifically, RFIC 3 switches the connection of switches 52 to 54 of the high-frequency module 1 using control signals (not shown). Specifically, RFIC 3 outputs digital control signals for controlling switches 52 to 54 to PA control circuit 11. PA control circuit 11 outputs digital control signals to switches 52 to 54 according to the digital control signals input from RFIC 3, thereby controlling the connection and disconnection of switches 52 to 54.

[0036] In addition, RFIC 3 also functions as a control unit to control the gain of the power amplifier 21 in the high-frequency module 1, the power supply voltage Vcc supplied to the power amplifier 21, and the bias voltage Vbias. Specifically, RFIC 3 outputs digital control signals to the control signal terminal 110 of the high-frequency module 1. The PA control circuit 11 outputs control signals, power supply voltage Vcc, or bias voltage Vbias to the power amplifier 21 based on the digital control signals input via the control signal terminal 110, thereby adjusting the gain of the power amplifier 21. Alternatively, the control signal terminal receiving the digital control signals for controlling the gain of the power amplifier 21 from RFIC 3 may be different from the control signal terminal receiving the digital control signals for controlling the power supply voltage Vcc and bias voltage Vbias supplied to the power amplifier 21 from RFIC 3. Furthermore, the control unit may also be located outside RFIC 3, for example, it may be located in BBIC 4.

[0037] Antenna 2 is connected to the antenna connection terminal 100 of the high-frequency module 1, radiating high-frequency signals output from the high-frequency module 1. In addition, it receives high-frequency signals from the outside and outputs them to the high-frequency module 1.

[0038] Furthermore, in the communication device 5 according to this embodiment, antenna 2 and BBIC 4 are not essential structural elements.

[0039] Next, the detailed structure of high-frequency module 1 will be described.

[0040] like Figure 1 As shown, the high-frequency module 1 includes an antenna connection terminal 100, a power amplifier 21, a PA control circuit 11, a low-noise amplifier 31, duplexers 61 and 62, matching circuits 42, 43, 44 and 45, switches 52, 53 and 54, a diplexer 73, a control signal terminal 110, a transmit input terminal 120, and a receive output terminal 130.

[0041] Antenna connection terminal 100 is an example of an input / output terminal and is a common antenna terminal connected to antenna 2.

[0042] The power amplifier 21 is an amplifier circuit that amplifies high-frequency signals from the first and second communication frequency bands input from the transmit input terminal 120. The power amplifier 21 is included in the second substrate 20. At least a portion of the second substrate 20 is made of, for example, GaAs. The power amplifier 21 includes, for example, a heterojunction bipolar transistor (HBT).

[0043] The low-noise amplifier 31 is an amplifier circuit that amplifies the high-frequency signals of the first and second communication frequency bands with low noise and outputs them to the receiving output terminal 130.

[0044] The PA control circuit 11 is an example of a control circuit that adjusts the gain of the power amplifier 21 based on a digital control signal input via the control signal terminal 110. The PA control circuit 11 is included in the first substrate 10, and is made of, for example, CMOS (Complementary Metal Oxide Semiconductor). Specifically, the PA control circuit 11 is formed using an SOI (Silicon On Insulator) process. This allows for the inexpensive manufacture of the PA control circuit 11. Furthermore, at least a portion of the first substrate 10 is made of, for example, Si.

[0045] The duplexer 61 consists of a transmitting filter 61T and a receiving filter 61R. The duplexer 62 consists of a transmitting filter 62T and a receiving filter 62R.

[0046] Transmit filter 61T is connected to the output terminal of power amplifier 21 via switch 52 and matching circuit 42, allowing the transmission signal of the first communication band to pass through. Transmit filter 61T is configured in the transmission path that connects transmit input terminal 120 to antenna connection terminal 100. Additionally, transmit filter 62T is connected to the output terminal of power amplifier 21 via switch 52 and matching circuit 42, allowing the transmission signal of the second communication band to pass through. Transmit filter 62T is connected in the transmission path that connects transmit input terminal 120 to antenna connection terminal 100.

[0047] A receiving filter 61R is connected to the receiving path that connects the receiving output terminal 130 to the antenna connection terminal 100, allowing the received signal of the first communication frequency band to pass through. Additionally, a receiving filter 62R is connected to the receiving path that connects the receiving output terminal 130 to the antenna connection terminal 100, allowing the received signal of the second communication frequency band to pass through.

[0048] Furthermore, each of the duplexers 61 and 62 can also be a filter that transmits in time-division duplex (TDD) mode. In this case, at least one of the preceding and following stages of the aforementioned filter is configured with a switch for switching between transmission and reception.

[0049] Switch 52 has a common terminal and two select terminals. The common terminal of switch 52 is connected to the output terminal of power amplifier 21 via matching circuit 42. One select terminal of switch 52 is connected to transmit filter 61T, and the other select terminal of switch 52 is connected to transmit filter 62T. In this connection structure, switch 52 switches the connection between power amplifier 21 and transmit filter 61T, and between power amplifier 21 and transmit filter 62T. Switch 52 is, for example, constructed from an SPDT (Single Pole Double Throw) type switching circuit.

[0050] Switch 53 has a common terminal and two select terminals. The common terminal of switch 53 is connected to the input terminal of low-noise amplifier 31 via matching circuit 43. One select terminal of switch 53 is connected to receiving filter 61R, and the other select terminal of switch 53 is connected to receiving filter 62R. In this connection structure, switch 53 switches between the connection and disconnection of low-noise amplifier 31 and receiving filter 61R, and between the connection and disconnection of low-noise amplifier 31 and receiving filter 62R. Switch 53 is, for example, constructed from an SPDT-type switching circuit.

[0051] Switch 54 is an example of an antenna switch, which is connected to antenna connection terminal 100 via dual-signaler 73 to switch (1) the connection and non-connection of antenna connection terminal 100 to duplexer 61, and (2) the connection and non-connection of antenna connection terminal 100 to duplexer 62.

[0052] Matching circuit 42 is connected between power amplifier 21 and transmitting filters 61T and 62T to achieve impedance matching between power amplifier 21 and transmitting filter 61T and between power amplifier 21 and transmitting filter 62T.

[0053] Matching circuit 43 is connected between low noise amplifier 31 and receiving filters 61R and 62R to achieve impedance matching between low noise amplifier 31 and receiving filter 61R and between low noise amplifier 31 and receiving filter 62R.

[0054] Matching circuit 44 is configured in the path connecting switch 54 and duplexer 61 to achieve impedance matching between antenna 2 and switch 54 and duplexer 61. Matching circuit 45 is configured in the path connecting switch 54 and duplexer 62 to achieve impedance matching between antenna 2 and switch 54 and duplexer 62.

[0055] The dual-signaler 73 is an example of a multiplexer, composed of filters 73L and 73H. Filter 73L is a filter whose passband is the frequency range of a first frequency band group that includes both the first and second communication frequency bands, while filter 73H is a filter whose passband is the frequency range of another frequency band group whose frequency differs from that of the first frequency band group. One terminal of filter 73L and one terminal of filter 73H are connected together to antenna connection terminal 100. Filters 73L and 73H are, for example, LC filters composed of at least one of a chip inductor and a capacitor.

[0056] Furthermore, in the high-frequency module 1 involved in this embodiment, as long as it has Figure 1 At least one of the power amplifier 21, the transmitting filter 61T and 62T shown in the circuit components is sufficient.

[0057] Furthermore, the low-noise amplifier 31 and switches 52-54 can also be formed within a single integrated circuit (IC). This IC can be, for example, a CMOS chip. Specifically, it is formed using an SOI process. This allows for the inexpensive manufacture of the IC. Alternatively, the IC can also be made of at least one of GaAs, SiGe, and GaN. This enables the output of high-frequency signals with high-quality amplification and noise reduction performance.

[0058] In this case, when the electronic component is in contact with the metal film, metal sometimes diffuses from the metal film into the circuit section of the electronic component. When this diffused metal mixes into the circuit section of the electronic component as an impurity, there is a possibility that the structure of the circuit section changes and the characteristics of the electronic component deteriorate.

[0059] To address this, the structure of the high-frequency module 1 for suppressing metal diffusion into the circuit section of electronic components will be described below.

[0060] [2. Circuit element configuration structure of the high-frequency module 1A involved in the embodiment]

[0061] Figure 2 This is a schematic planar structural diagram of the high-frequency module 1A involved in the embodiment. Additionally, Figure 3 This is a schematic cross-sectional view of the high-frequency module 1A involved in the embodiment; specifically, it is... Figure 2 A cross-sectional view at line III-III. Furthermore, Figure 2(a) shows a configuration diagram of the circuit components when viewed from the positive z-axis direction, considering the main surfaces 80a and 80b of the module substrate 80 facing each other. On the other hand, Figure 2 Figure (b) shows a diagram of the configuration of the perspective circuit components when viewed from the positive z-axis direction of the main surface 80b. Additionally, in Figure 2 In order to make the configuration relationship of each circuit component easy to understand, each circuit component is marked with a label indicating its function, but the actual high-frequency module 1A does not have this label.

[0062] The high-frequency module 1A involved in the embodiment specifically illustrates the configuration structure of each circuit element constituting the high-frequency module 1 involved in the embodiment.

[0063] like Figure 2 and Figure 3 As shown, the high-frequency module 1A involved in this embodiment, in addition to having Figure 1 In addition to the circuit structure shown, it also includes a module substrate 80, resin components 81 and 82, external connection terminals 150, a metal shielding layer 85, and a semiconductor IC 70.

[0064] In addition, semiconductor IC 70 includes Figure 1 The power amplifier 21 and PA control circuit 11 are shown in the figure.

[0065] The module substrate 80 has two opposing main surfaces, 80a (first main surface) and 80b (second main surface), and is a substrate for mounting electronic components constituting the high-frequency module 1A. The module substrate 80 may be, for example, a low-temperature co-fired ceramic (LTCC) substrate with a multi-dielectric layer stacked 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.

[0066] Alternatively, it could be, such as Figure 2 As shown in (b), an antenna connection terminal 100, a control signal terminal 110, a transmit input terminal 120, and a receive output terminal 130 are formed on the main surface 80b.

[0067] Resin component 81 is disposed on main surface 80a, covering a portion of the electronic components constituting high-frequency module 1A and main surface 80a. Resin component 82 is disposed on main surface 80b, covering a portion of the electronic components constituting high-frequency module 1A and main surface 80b. Resin components 81 and 82 have the function of ensuring the reliability of the electronic components constituting high-frequency module 1A, such as mechanical strength and moisture resistance. Furthermore, resin component 82 is not a necessary structural element for the high-frequency module 1 according to this embodiment.

[0068] The metal shielding layer 85, an example of the first metal layer, is formed on the surface of the resin component 81 and is set to ground potential. The metal shielding layer 85 is, for example, a thin metal film formed by sputtering, and is copper, a copper-containing alloy, or a copper-containing laminate.

[0069] like Figure 2 and Figure 3 As shown, in the high-frequency module 1A of this embodiment, the semiconductor IC 70, duplexers 61 and 62, and matching circuits 42-45 are disposed on the main surface 80a. On the other hand, the low-noise amplifier 31 and switches 52-54 are disposed on the main surface 80b.

[0070] Furthermore, in the high-frequency module 1A involved in this embodiment, one of the semiconductor IC 70 and the transmitting filter 61T must be configured on the main surface 80a, while other circuit components can be configured on either the main surface 80a or 80b, or can be built into the module substrate 80.

[0071] In addition, although Figure 2 and Figure 3 The dual signaler 73 is not shown in the figure, but the dual signaler 73 can be surface-mounted on either of the main surfaces 80a and 80b, or it can be built into the module substrate 80.

[0072] In addition, although Figure 2 Not shown in the image, but Figure 1 The wiring connecting the various electronic components shown is formed inside the module substrate 80, on the main surfaces 80a and 80b. In addition, the above wiring can be a bonding line whose two ends are connected to any of the main surfaces 80a, 80b and the electronic components constituting the high-frequency module 1A, or it can be a terminal, electrode or wiring formed on the surface of the electronic components constituting the high-frequency module 1A.

[0073] Furthermore, in the high-frequency module 1A of this embodiment, a plurality of external connection terminals 150 are arranged on the main surface 80b. The high-frequency module 1A exchanges electrical signals with an external substrate disposed on the negative z-axis side of the high-frequency module 1A via the plurality of external connection terminals 150. In addition, several of the plurality of external connection terminals 150 are set to the ground potential of the external substrate. On the main surface 80b facing the external substrate, which is difficult to reduce the height of duplexers, chip inductors, and capacitors (matching circuits), instead of duplexers, chip inductors, and capacitors (matching circuits), which are easy to reduce the height of the module, a low-noise amplifier 31 and switches 52-54 are arranged, thus enabling the overall height of the high-frequency module 1A to be reduced.

[0074] In addition, the external connection terminal 150 can be, for example, Figure 2 and Figure 3 Alternatively, the external connection terminal 150 can be a columnar electrode that penetrates the resin member 82 along the z-axis, as shown. In this case, the resin member 82 on the main surface 80b may not be present.

[0075] In addition, in the high-frequency module 1A involved in this embodiment, the low-noise amplifier 31 and the semiconductor IC 70 with power amplifier 21 are disposed on different main surfaces of the module substrate 80.

[0076] Accordingly, a module substrate 80 is arranged between the power amplifier 21 and the low-noise amplifier 31, thereby improving the isolation between transmission and reception.

[0077] Furthermore, the low-noise amplifier 31 and switches 52-54 can also be included in the semiconductor IC 75 on the main surface 80b. Accordingly, the high-frequency module 1A can be miniaturized.

[0078] [2.1 Stack-up structure of the power amplifier module (semiconductor IC 70)]

[0079] Semiconductor IC 70 is an example of an electronic component; more specifically, it is a power amplifier module. For example... Figure 3 As shown, the top surface (main surface 10b: first surface) of the semiconductor IC 70 is in contact with the metal shielding layer 85.

[0080] The semiconductor IC 70 includes a first substrate 10, a second substrate 20, and a barrier metal layer 78.

[0081] At least a portion of the first substrate 10 is made of a first semiconductor material. Examples of the first semiconductor material include elemental semiconductors, particularly silicon (Si). In this embodiment, at least a portion of the first substrate 10 is made of Si. Furthermore, 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), or multi-component mixed-crystal materials formed from multiple of these materials, can be used as the first semiconductor material; the material is not limited to these.

[0082] In this embodiment, the PA control circuit 11 is formed on the first substrate 10. Alternatively, the PA control circuit 11 may not be formed on the first substrate 10, or it may be disposed on the main surface 80a or 80b of the module substrate 80.

[0083] At least a portion of the second substrate 20 is made of a second semiconductor material different from the first semiconductor material, and a power amplifier 21 is formed on the second substrate 20. Examples of the second semiconductor material include compound semiconductors, particularly gallium arsenide (GaAs). In this embodiment, at least a portion of the second substrate 20 is made of GaAs. Furthermore, 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), or multi-component mixed-crystal materials formed from multiple of these materials, can be used as the second semiconductor material; the second semiconductor material is not limited to these.

[0084] like Figure 3 As shown, the second substrate 20 is disposed between the module substrate 80 and the first substrate 10, is bonded to the first substrate 10 via the barrier metal layer 78, and is connected to the main surface 80a via the electrode 23.

[0085] The power amplifier 21 formed on the second substrate 20 includes an amplifying transistor, which corresponds to a circuit portion formed on a portion of the semiconductor IC 70 closer to the bottom surface than to the top surface.

[0086] The barrier metal layer 78 is an example of a second metal layer, such as... Figure 3 As shown, it is formed between the first substrate 10 and the second substrate 20. The barrier metal layer 78 is, for example, titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of them.

[0087] In the high-frequency module 1A, the metal shielding layer 85 is in contact with the semiconductor IC 70. Therefore, metal (e.g., Cu atoms) sometimes diffuses from the metal shielding layer 85 into the power amplifier 21 formed on the second substrate 20. When this diffused metal is mixed into the power amplifier 21 as an impurity, there is a possibility that the construction of the power amplifier 21 changes and the amplification characteristics deteriorate.

[0088] To address this, according to the aforementioned structure of the high-frequency module 1A, a barrier metal layer 78 is disposed between the metal shielding layer 85 and the power amplifier 21. This allows for a lower degree of metal diffusion from the barrier metal layer 78 to the power amplifier 21 compared to the degree of metal diffusion from the metal shielding layer 85 to the power amplifier 21. In other words, compared to a semiconductor IC without the barrier metal layer 78, metal diffusion from the metal shielding layer 85 to the power amplifier 21 can be suppressed. Therefore, grounding enhancement of the power amplifier 21 can be achieved while suppressing the degradation of the amplification characteristics of the power amplifier 21.

[0089] Furthermore, a low degree of metal diffusion from A to B can mean, for example, a small amount of the metal material constituting A diffuses into B, or a low rate of diffusion of the metal material constituting A into B. Specifically, it is defined as a small diffusion coefficient of the metal material constituting A diffuses into B.

[0090] In this embodiment, the power amplifier 21 is formed on the second substrate 20. Therefore, the diffusion coefficient of the metal material constituting the barrier metal layer 78 (e.g., one of Ti, Ta, Co, and W) diffuses into the second substrate 20 (second semiconductor material: e.g., GaAs) is less than the diffusion coefficient of the metal material constituting the metal shielding layer 85 (e.g., Cu) diffuses into the second substrate 20 (second semiconductor material: e.g., GaAs).

[0091] In other words, the barrier metal layer 78 is defined as a metal layer in which the diffusion coefficient of the metal material constituting the barrier metal layer 78 diffuses into the circuit section less than the diffusion coefficient of the metal material constituting the metal shielding layer 85 diffuses into the circuit section. The barrier metal layer 78 is, for example, titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of them.

[0092] Furthermore, the blocking metal layer 78 only needs to be formed between the metal shielding layer 85 and the power amplifier 21. This allows for enhanced grounding of the power amplifier 21 while suppressing the degradation of its amplification characteristics.

[0093] The semiconductor IC 70 (power amplifier module) will now be described in detail. As described above, the semiconductor IC 70 includes a first substrate 10, a second substrate 20, and a barrier metal layer 78.

[0094] Figure 4This is a cross-sectional structural diagram of the semiconductor IC 70 involved in the embodiment. Additionally, Figure 5 This is a cross-sectional structural diagram of the second substrate 20 involved in the embodiment.

[0095] like Figure 4 As shown, the first substrate 10 and the second substrate 20 are stacked along the z-axis direction (the direction perpendicular to the main surface 80a).

[0096] The first substrate 10 includes, for example, a Si substrate 12, an insulating layer 13, a Si layer 14, a wiring layer 15, and a SiN layer 17, which are stacked in this order starting from the main surface 80a side.

[0097] The Si substrate 12 is, for example, made of silicon single crystal.

[0098] Si layer 14 is, for example, a layer formed of silicon, which is a layer on which circuit elements constituting PA control circuit 11 are formed.

[0099] Wiring layer 15, for example, is a layer formed inside a silicon oxide layer with through-hole wiring 16 for transmitting control signals from PA control circuit 11 to second substrate 20 and module substrate 80.

[0100] The SiN layer 17 is, for example, a protective layer formed of silicon nitride, which is used to ensure the reliability of the first substrate 10, such as its moisture resistance.

[0101] The first substrate 10 is connected to the main surface 80a via an electrode 24 (second electrode) extending from the first substrate 10 toward the main surface 80a. The electrode 24 is, for example, composed of a pillar conductor 24a and a bump electrode 24b. One end of the pillar conductor 24a is bonded to an electrode 18 formed on the SiN layer 17, and the other end is bonded to the bump electrode 24b. The bump electrode 24b is connected to the electrode formed on the main surface 80a.

[0102] Accordingly, the electronic components formed on the first substrate 10 can directly exchange high-frequency signals and digital signals with the module substrate 80, thereby reducing signal transmission loss.

[0103] Furthermore, the first substrate 10 only needs to include the Si substrate 12, and the other layers may not be necessary. In addition, switches 52 to 54 may also be included in the first substrate 10.

[0104] Furthermore, a resin member 71 is disposed on the main surface 10a of the first substrate 10. Additionally, the resin member 71 covers the second substrate 20.

[0105] Furthermore, as described above, the first substrate 10 has a Si substrate 12, a Si layer 14, and a SiN layer 17. That is, the semiconductor IC 70 has a silicon layer disposed between the circuit section and the top surface (main surface 10b: first surface).

[0106] The metal diffuses extensively from the metal shielding layer 85 to the silicon layer (high diffusion coefficient), thus, without the formation of a blocking metal layer 78, metal can easily diffuse from the metal shielding layer 85 through the first substrate 10 to the second substrate 20. In contrast, in the semiconductor IC 70 of this embodiment, a blocking metal layer 78 is formed between the metal shielding layer 85 and the circuit section. Therefore, even if metal from the metal shielding layer 85 diffuses to the first substrate 10, metal diffusion to the second substrate 20 can be suppressed.

[0107] In other words, the barrier metal layer 78 is defined as a metal layer in which the diffusion coefficient of the metal material constituting the barrier metal layer 78 diffuses into the circuit section is less than the diffusion coefficient of the metal material constituting the metal shielding layer 85 diffuses into the circuit section.

[0108] like Figure 5 As shown, the second substrate 20 includes, for example, a GaAs substrate layer 20n and an epitaxial layer 20d.

[0109] GaAs substrate layer 20n is, for example, a single-crystal substrate formed of gallium arsenide.

[0110] The epitaxial layer 20d is, for example, a GaAs layer epitaxially grown on a GaAs substrate layer 20n.

[0111] Power amplifier 21 is formed, for example, on epitaxial layer 20d.

[0112] The GaAs substrate layer 20n is bonded to the SiN layer 17 of the first substrate 10 via a barrier metal layer 78. That is, the second substrate 20 is bonded to the first substrate 10 via the barrier metal layer 78.

[0113] The power amplifier 21 includes an amplifying transistor having a collector layer 21C, a base layer 21B, and an emitter layer 21E. The collector layer 21C, the base layer 21B, and the emitter layer 21E are stacked on the epitaxial layer 20d in this order. That is, in the amplifying transistor, the collector layer 21C, the base layer 21B, and the emitter layer 21E are stacked in this order starting from the first substrate 10 side.

[0114] Furthermore, the second substrate 20 is connected to the main surface 80a via an electrode 23 (first electrode) extending from the second substrate 20 toward the main surface 80a. The electrode 23 is, for example, composed of a columnar conductor 23a and a bump electrode 23b. One end of the columnar conductor 23a is joined to the electrode 22 formed on the main surface of the second substrate 20, and the other end is joined to the bump electrode 23b. The bump electrode 23b is connected to the electrode formed on the main surface 80a.

[0115] Accordingly, the power amplifier 21 of the second substrate 20 can directly exchange signals with the module substrate 80, thereby reducing signal transmission loss.

[0116] In addition, the power amplifier 21 of the second substrate 20 can also receive digital control signals and DC signals from the PA control circuit 11 of the first substrate 10 via the through-hole wiring 16.

[0117] like Figure 4 and Figure 5 As shown, the top surface (main surface 10b: first surface) of the semiconductor IC 70 is in contact with the metal shielding layer 85, and the bottom surface (surface of the resin component 71: second surface) of the semiconductor IC 70 faces the main surface 80a.

[0118] Furthermore, the top surface of semiconductor IC 70 refers to the main surface of semiconductor IC 70 that is farther from the main surface 80a (positive z-axis direction side) among the mutually facing surfaces, and the bottom surface of semiconductor IC 70 refers to the main surface of semiconductor IC 70 that is closer to the main surface 80a (negative z-axis direction side) among the mutually facing surfaces.

[0119] Alternatively, the thermal conductivity of the first semiconductor material constituting the first substrate 10 may be higher than that of the second semiconductor material constituting the second substrate 20.

[0120] Accordingly, the heat dissipation from the second substrate 20 to the first substrate 10 is improved.

[0121] Alternatively, it could be, such as Figure 4 As shown, the second substrate 20 is thinner than the first substrate 10. In other words, the thickness of the second substrate 20 in the thickness direction (z-axis direction) is smaller than the thickness of the first substrate 10 in the thickness direction (z-axis direction).

[0122] Accordingly, the second substrate 20 with low thermal conductivity is relatively thin, while the first substrate 10 with high thermal conductivity is relatively thick, thus promoting heat conduction from the second substrate 20 to the first substrate 10 and improving heat dissipation.

[0123] [2.2 Stacked Structure of Transmit Filter 61T]

[0124] Figure 6This is a cross-sectional structural diagram showing a first example of the transmitting filter 61T involved in the embodiment.

[0125] The transmitting filter 61T is an example of an electronic component; more specifically, it is a surface acoustic wave filter. For example... Figure 6 As shown, the top surface (support substrate 63: first surface) of the transmitting filter 61T is in contact with the metal shielding layer 85. In addition, the bottom surface (piezoelectric layer 93: second surface) of the transmitting filter 61T faces the main surface 80a and is connected to the main surface 80a via bump electrodes 25 formed on the surface of the piezoelectric layer 93.

[0126] Furthermore, the top surface of the transmitting filter 61T refers to the main surface of the transmitting filter 61T that is farther from the main surface 80a (positive z-axis direction side) among the mutually facing surfaces, and the bottom surface of the transmitting filter 61T refers to the main surface of the transmitting filter 61T that is closer to the main surface 80a (negative z-axis direction side) among the mutually facing surfaces.

[0127] The transmitting filter 61T comprises a piezoelectric layer 93, a support substrate 63, a blocking metal layer 68, a high-velocity layer 91, a low-velocity layer 92, and an IDT electrode 94, which are stacked in the order of support substrate 63, blocking metal layer 68, high-velocity layer 91, low-velocity layer 92, piezoelectric layer 93, and IDT electrode 94.

[0128] The piezoelectric layer 93 is formed, for example, from a LiTaO3 piezoelectric single crystal or a piezoelectric ceramic.

[0129] The support substrate 63 is a substrate that supports the high-velocity layer 91, the low-velocity layer 92, the piezoelectric layer 93, and the IDT electrode 94, and is made of silicon, for example.

[0130] The high-velocity layer 91 is a layer in which the velocity of sound of bulk waves propagating in the high-velocity layer 91 is higher than the velocity of sound of elastic waves such as surface waves and interface waves propagating in the piezoelectric layer. The high-velocity layer 91 functions in such a way that it confines surface acoustic waves to the portion where the piezoelectric layer 93 and the low-velocity layer 92 are stacked, preventing them from leaking from the high-velocity layer 91 to the lower part.

[0131] The low-velocity layer 92 is a layer in which the velocity of sound of volume waves propagating in the low-velocity layer 92 is lower than the velocity of sound of volume waves propagating in the piezoelectric layer 93, and the low-velocity layer 92 is disposed between the piezoelectric layer 93 and the high-velocity layer 91. This structure, along with the property that elastic waves inherently concentrate energy in a low-velocity medium, is used to suppress the leakage of surface acoustic wave energy to the IDT electrode 94.

[0132] Furthermore, the support substrate 63 and the hypersonic layer 91 can also be made of the same material, in which case the hypersonic support substrate can also be used.

[0133] In the above structure, when a high-frequency signal is input between a pair of comb-shaped electrodes constituting the IDT electrode 94, a potential difference is generated between the pair of comb-shaped electrodes. As a result, the piezoelectric layer 93 deforms, thereby generating a surface acoustic wave. Here, the wavelength of the IDT electrode 94 (twice the distance between the electrodes) is made approximately the same as the wavelength of the passband of the transmit filter 61T, so that only high-frequency signals with the desired frequency components pass through the transmit filter 61T.

[0134] Furthermore, based on the aforementioned stacked structure of the transmitting filter 61T, compared to the conventional structure using a single-layer piezoelectric substrate, the Q value at both the resonant and anti-resonant frequencies can be significantly improved. That is, a high-Q elastic wave resonator can be constructed, and therefore this elastic wave resonator can be used to construct a filter with low insertion loss.

[0135] Furthermore, surface acoustic waves (SAWs) refer to the propagation of elastic waves on the surface of the piezoelectric layer 93 or at the interface of multiple materials. SAWs are various elastic waves configured using IDT electrodes 94. Examples of SAWs include surface waves, Love waves, leaky waves, Rayleigh waves, interface waves, leaky SAWs, pseudo-SAWs, and plate waves.

[0136] IDT electrode 94, piezoelectric layer 93 and low-velocity layer 92 are formed on the bottom side of the top and bottom surfaces of the transmitting filter 61T, which corresponds to the circuit part for propagating surface acoustic waves.

[0137] The barrier metal layer 68 is an example of a second metal layer, such as... Figure 6 As shown, it is formed between the support substrate 63 and the high-velocity acoustic layer 91. The barrier metal layer 68 is, for example, titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of them.

[0138] The barrier metal layer 68 is defined as a metal layer in which the diffusion coefficient of the metal material constituting the barrier metal layer 68 diffuses into the circuit section less than the diffusion coefficient of the metal material constituting the metal shielding layer 85 diffuses into the circuit section.

[0139] In the high-frequency module 1A, the metal shielding layer 85 is in contact with the transmitting filter 61T, so sometimes metal (e.g., Cu atoms) diffuses from the metal shielding layer 85 into the circuit section. In particular, in the transmitting filter that allows high-power transmitting signals to pass through, the temperature rises, promoting metal diffusion. When this diffused metal mixes into the circuit section as an impurity, there is a possibility that the construction of the transmitting filter 61T changes, resulting in a deterioration of its transmission characteristics.

[0140] To address this, according to the aforementioned structure of the high-frequency module 1A, a blocking metal layer 68 is disposed between the metal shielding layer 85 and the circuit section. This reduces the degree of metal diffusion from the blocking metal layer 68 to the circuit section compared to the degree of metal diffusion from the metal shielding layer 85 to the circuit section. In other words, compared to a transmit filter without the blocking metal layer 68, the diffusion of metal from the metal shielding layer 85 to the circuit section can be suppressed. Therefore, while enhancing the grounding of the transmit filter 61T, the degradation of the transmit filter 61T's pass-through characteristics can be suppressed.

[0141] Furthermore, the blocking metal layer 68 only needs to be formed between the metal shielding layer 85 and the circuit section. Therefore, it is possible to enhance the grounding of the transmitting filter 61T while suppressing the degradation of its transmission characteristics.

[0142] In addition, the transmitting filter 61T can be a surface acoustic wave filter or a bulk acoustic wave filter.

[0143] Figure 7 This is a cross-sectional structural diagram showing a second example of the transmitting filter 61T involved in the embodiment.

[0144] The transmitting filter 61T is an example of an electronic component; more specifically, it is an SMR (Solidly Mounted Resonator) type bulk acoustic wave filter. For example... Figure 7 As shown, the top surface (support substrate 63: first surface) of the transmitting filter 61T is in contact with the metal shielding layer 85. In addition, the bottom surface (upper electrode 66 and lower electrode 67: second surface) of the transmitting filter 61T faces the main surface 80a and is connected to the main surface 80a via bump electrodes 25 formed on the surfaces of the upper electrode 66 and the lower electrode 67.

[0145] The transmitting filter 61T involved in this example includes a support substrate 63, a barrier metal layer 68, a low acoustic impedance film 65, a high acoustic impedance film 64, an upper electrode 66 (third electrode), a lower electrode 67 (fourth electrode), and a piezoelectric layer 72. The low acoustic impedance film 65 and the high acoustic impedance film 64 are alternately stacked to form an acoustic multilayer film. In the transmitting filter 61T, the layers are stacked in the following order: support substrate 63, barrier metal layer 68, acoustic multilayer film, upper electrode 66, piezoelectric layer 72, and lower electrode 67.

[0146] The support substrate 63 is a substrate that supports the acoustic multilayer film, the upper electrode 66, the piezoelectric layer 72 and the lower electrode 67, and is made of silicon, for example.

[0147] With the above structure, the SMR type bulk acoustic resonator uses Bragg reflection based on the acoustic multilayer film disposed between the support substrate 63 and the upper electrode 66 to confine the bulk acoustic waves to the area below the acoustic multilayer film (upper electrode 66, piezoelectric layer 72 and lower electrode 67).

[0148] In the above structure, when a high-frequency signal is input between the upper electrode 66 and the lower electrode 67, a potential difference is generated between the two electrodes. This causes the piezoelectric layer 72 to deform, thereby generating a bulk acoustic wave in the stacked direction of the upper electrode 66, the piezoelectric layer 72, and the lower electrode 67. Here, the thickness of the piezoelectric layer 72 is aligned with the wavelength of the passband of the transmitting filter 61T, thus allowing only high-frequency signals with the desired frequency components to pass through the transmitting filter 61T.

[0149] The upper electrode 66, the piezoelectric layer 72, and the lower electrode 67 are formed on the bottom side of the top and bottom surfaces of the transmitting filter 61T, which corresponds to the circuit part of the propagating sound wave.

[0150] The barrier metal layer 68 is an example of a second metal layer, such as... Figure 7 As shown, it is formed between the support substrate 63 and the acoustic multilayer film. The barrier metal layer 68 is, for example, titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of them.

[0151] The barrier metal layer 68 is defined as a metal layer in which the diffusion coefficient of the metal material constituting the barrier metal layer 68 diffuses into the circuit section less than the diffusion coefficient of the metal material constituting the metal shielding layer 85 diffuses into the circuit section.

[0152] According to the structure of the high-frequency module 1A described in this example, a blocking metal layer 68 is disposed between the metal shielding layer 85 and the circuit section. This allows for a lower degree of metal diffusion from the blocking metal layer 68 to the circuit section compared to the degree of metal diffusion from the metal shielding layer 85 to the circuit section. In other words, compared to a transmit filter without the blocking metal layer 68, the diffusion of metal from the metal shielding layer 85 to the circuit section can be suppressed. Therefore, it is possible to enhance the grounding of the transmit filter 61T while suppressing the degradation of the transmit filter 61T's pass-through characteristics.

[0153] Furthermore, the blocking metal layer 68 only needs to be formed between the metal shielding layer 85 and the circuit section. Therefore, it is possible to enhance the grounding of the transmitting filter 61T while suppressing the degradation of its transmission characteristics.

[0154] In addition, such as Figure 3 As shown, in addition to the transmitting filter 61T, a blocking metal layer 69 may also be formed in the receiving filter 61R. Accordingly, it is possible to enhance the grounding of the receiving filter 61R while suppressing the degradation of the transmission characteristics of the receiving filter 61R.

[0155] Furthermore, in the high-frequency module 1A involved in this embodiment, it is sufficient that at least one of the semiconductor IC 70 and the transmitting filter 61T has the blocking metal layer 68 or 78 shown above.

[0156] [3. Effects, etc.]

[0157] The high-frequency module 1A according to this embodiment includes: a module substrate 80; an electronic component disposed on a main surface 80a; a resin component 81 covering at least a portion of the main surface 80a and at least a portion of the side surface of the electronic component; and a metal shielding layer 85 formed on the surface of the resin component 81 and set to ground potential. The electronic component has: a top surface in contact with the metal shielding layer 85; a bottom surface facing the main surface 80a; a circuit portion formed closer to the bottom surface than to the top surface; and a metal layer formed between the metal shielding layer 85 and the circuit portion, the metal layer being a barrier metal.

[0158] Accordingly, a barrier metal is disposed between the metal shielding layer 85 and the circuit section, thereby reducing the degree of metal diffusion from the barrier metal to the circuit section compared to the degree of metal diffusion from the metal shielding layer 85 to the circuit section. In other words, compared to the case where no barrier metal is disposed, the diffusion of metal from the metal shielding layer 85 to the circuit section can be suppressed. Therefore, it is possible to enhance the grounding of electronic components while suppressing the degradation of electronic component characteristics caused by metal diffusion.

[0159] Furthermore, the high-frequency module 1A involved in this embodiment includes: a module substrate 80; electronic components disposed on a main surface 80a; a resin member 81 covering at least a portion of the main surface 80a and at least a portion of the side surface of the electronic components; and a metal shielding layer 85 formed on the surface of the resin member 81 and set to ground potential. The electronic components have: a top surface in contact with the metal shielding layer 85; a bottom surface facing the main surface 80a; a circuit portion formed closer to the bottom surface than to the top surface; and a metal layer formed between the metal shielding layer 85 and the circuit portion. The metal shielding layer 85 is copper, an alloy containing copper, or a laminate containing copper, and the metal layer is titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of them.

[0160] Alternatively, in the high-frequency module 1A, the electronic component may also have a silicon layer disposed between the circuit section and the top surface.

[0161] The metal diffuses to the silicon layer from the metal shielding layer 85 to a high degree (large diffusion coefficient). Therefore, without the formation of a blocking metal, the metal can easily diffuse from the metal shielding layer 85 through the silicon layer to the circuit section. In contrast, the high-frequency module 1A forms a blocking metal between the metal shielding layer 85 and the circuit section. Therefore, even if the metal in the metal shielding layer 85 diffuses to the silicon layer, the diffusion of metal to the circuit section can be suppressed.

[0162] Alternatively, in the high-frequency module 1A, the diffusion coefficient of the metal material constituting the metal layer diffusing into the circuit section may be less than the diffusion coefficient of the metal material constituting the metal shielding layer 85 diffusing into the circuit section.

[0163] Alternatively, in the high-frequency module 1A, the aforementioned electronic component may be a power amplifier module, comprising: a first substrate 10, at least a portion of which is made of a first semiconductor material; a second substrate 20, at least a portion of which is made of a second semiconductor material different from the first semiconductor material, wherein a power amplifier 21 is formed on the second substrate 20; and the aforementioned metal layer, wherein the second substrate 20 is disposed between the main surface 80a and the first substrate 10, is bonded to the first substrate 10 via the aforementioned metal layer, and is connected to the main surface 80a via an electrode 23, and the aforementioned circuitry includes an amplifying transistor included in the power amplifier 21.

[0164] Accordingly, a barrier metal layer 78 is disposed between the metal shielding layer 85 and the power amplifier 21, thereby reducing the degree of metal diffusion from the barrier metal layer 78 to the power amplifier 21 compared to the degree of metal diffusion from the metal shielding layer 85 to the power amplifier 21. Therefore, it is possible to suppress the degradation of the amplification characteristics of the power amplifier 21 while simultaneously achieving grounding enhancement of the power amplifier 21.

[0165] Alternatively, in the high-frequency module 1A, the first substrate 10 may be connected to the main surface 80a via the electrode 24.

[0166] Accordingly, the electronic components formed on the first substrate 10 can directly exchange high-frequency signals and control signals with the module substrate 80, thereby reducing signal transmission loss.

[0167] Alternatively, in the high-frequency module 1A, the thermal conductivity of the first semiconductor material may be higher than that of the second semiconductor material.

[0168] Accordingly, the heat dissipation from the second substrate 20 to the first substrate 10 is improved.

[0169] Alternatively, in the high-frequency module 1A, the amplifying transistor may be composed of a collector layer, a base layer, and an emitter layer, which are stacked in the order of collector layer, base layer, and emitter layer starting from the first substrate 10 side.

[0170] Alternatively, in the high-frequency module 1A, the first substrate 10 may include a PA control circuit 11.

[0171] Therefore, the digital control signal wiring used to control the power amplifier 21 is short.

[0172] Alternatively, in the high-frequency module 1A, the aforementioned electronic component may be a surface acoustic wave filter. The aforementioned electronic component includes a piezoelectric layer 93, a support substrate 63, a blocking metal layer 68, a high-velocity layer 91, a low-velocity layer 92, and an IDT electrode 94, which are stacked in the order of support substrate 63, blocking metal layer 68, high-velocity layer 91, low-velocity layer 92, piezoelectric layer 93, and IDT electrode 94.

[0173] Accordingly, a barrier metal layer 68 is disposed between the metal shielding layer 85 and the circuit section (low-velocity sound layer 92, piezoelectric layer 93, and IDT electrode 94). This ensures that the degree of metal diffusion from the barrier metal layer 68 to the circuit section is lower than the degree of metal diffusion from the metal shielding layer 85 to the circuit section. Therefore, it is possible to achieve grounding enhancement of the surface acoustic wave filter while suppressing the degradation of the pass-through characteristics of the surface acoustic wave filter.

[0174] Alternatively, in the high-frequency module 1A, the aforementioned electronic component may be a bulk acoustic wave filter, which includes: a support substrate 63; a blocking metal layer 68; an acoustic multilayer film having a structure in which low acoustic impedance film 65 and high acoustic impedance film 64 are alternately stacked; an upper electrode 66 and a lower electrode 67; and a piezoelectric layer 72, wherein the layers are stacked in the following order: support substrate 63, blocking metal layer 68, acoustic multilayer film, upper electrode 66, piezoelectric layer 72, and lower electrode 67.

[0175] Accordingly, a barrier metal layer 68 is disposed between the metal shielding layer 85 and the circuit section (upper electrode 66, piezoelectric layer 72, and lower electrode 67). This allows the degree of metal diffusion from the barrier metal layer 68 to the circuit section to be lower than the degree of metal diffusion from the metal shielding layer 85 to the circuit section. Therefore, it is possible to achieve grounding enhancement of the bulk acoustic wave filter while suppressing the degradation of the bulk acoustic wave filter's transmission characteristics.

[0176] Alternatively, the high-frequency module 1A may also include a power amplifier 21 for amplifying the transmitted signal, and the aforementioned electronic component is a transmitting filter 61T connected to the output terminal of the power amplifier 21.

[0177] In a transmission filter that allows high-power signals to pass through, the temperature rises, promoting metal diffusion. When this diffused metal is mixed into the circuit section as an impurity, the transmission filter's structure changes, leading to a deterioration in its transmission characteristics.

[0178] To address this, according to the aforementioned structure of the transmitting filter 61T, a blocking metal layer 68 is disposed between the metal shielding layer 85 and the circuit section. This allows for a lower degree of metal diffusion from the blocking metal layer 68 to the circuit section compared to the degree of metal diffusion from the metal shielding layer 85 to the circuit section. Therefore, it is possible to enhance the grounding of the transmitting filter 61T while suppressing the degradation of its throughput characteristics.

[0179] In addition, the communication device 5 includes an RFIC 3 for processing high-frequency signals transmitted and received using the antenna 2, and a high-frequency module 1 for transmitting high-frequency signals between the antenna 2 and the RFIC 3.

[0180] Accordingly, a communication device 5 can be provided that suppresses the degradation of the characteristics of electronic components caused by metal diffusion.

[0181] (Other implementation methods, etc.)

[0182] The above description, which outlines embodiments of the high-frequency module and communication device according to the present invention, provides examples and examples. However, the high-frequency module and communication device of the present invention are not limited to the above embodiments and examples. Other embodiments implemented by combining any structural elements in the above embodiments and examples, variations of the above embodiments and examples that can be conceived by those skilled in the art without departing from the spirit of the present invention, and various devices incorporating the above high-frequency module and communication device are also included in the present invention.

[0183] For example, in the high-frequency module 1A described in the above embodiment, the circuit components constituting the high-frequency module 1A are distributed on the main surfaces 80a and 80b of the module substrate 80, but they may also be disposed only on the main surface 80a. That is, the circuit components constituting the high-frequency module 1A may be mounted on one side of the module substrate or on both sides.

[0184] For example, in the high-frequency modules and communication devices involved in the above embodiments and examples, other circuit elements and wiring may be inserted between the paths that connect the circuit elements and signal paths disclosed in the drawings.

[0185] Industrial availability

[0186] This invention, as a high-frequency module configured in the front end that supports multiple frequency bands, can be widely used in communication devices such as portable telephones.

[0187] Explanation of reference numerals in the attached figures

[0188] 1, 1A: High-frequency module; 2: Antenna; 3: RF signal processing circuit (RFIC); 4: Baseband signal processing circuit (BBIC); 5: Communication device; 10: First substrate; 10a, 10b, 80a, 80b: Main surfaces; 11: PA control circuit; 12: Si substrate; 13: Insulating layer; 14: Si layer; 15: Wiring layer; 16: Through-hole wiring; 17: SiN layer; 18, 22, 23, 24: Electrodes; 20: Second substrate; 20d: Epitaxial layer; 20n: GaAs substrate layer; 21: Power amplifier; 21B: Base layer; 21C: Collector layer; 21E: Emitter layer; 23a, 24a: Columnar conductors; 23b, 24b, 25: Bump electrodes; 31: Low-noise amplifier; 42, 43, 44, 4 5: Matching circuit; 52, 53, 54: Switches; 61, 62: Duplexers; 61R, 62R: Receive filters; 61T, 62T: Transmit filters; 63: Support substrate; 64: High acoustic impedance film; 65: Low acoustic impedance film; 66: Upper electrode; 67: Lower electrode; 68, 69, 78: Barrier metal layer; 70, 75: Semiconductor IC; 71, 81, 82: Resin components; 72, 93: Piezoelectric layer; 73: Dual signaler; 73H, 73L: Filters; 80: Module substrate; 85: Metal shielding layer; 91: High velocity layer; 92: Low velocity layer; 94: IDT electrode; 100: Antenna connection terminal; 110: Control signal terminal; 120: Transmit input terminal; 130: Receive output terminal; 150: External connection terminal.

Claims

1. A high-frequency module, comprising: Module baseboard; Electronic components are disposed on the main surface of the module substrate; A resin component covering at least a portion of the main surface and at least a portion of the side surface of the electronic component; and A first metal layer, formed on the surface of the resin component, is set to ground potential. in, The electronic component has: The first surface is in contact with the first metal layer; The second side faces the main side; The circuit section is formed at a location closer to the second surface than to the first surface; as well as A second metal layer is formed between the first metal layer and the circuit portion. The second metal layer is a barrier metal.

2. The high-frequency module according to claim 1, wherein, The electronic component also has a silicon layer disposed between the circuit section and the first surface.

3. The high-frequency module according to claim 1 or 2, wherein, The diffusion coefficient of the metal material constituting the second metal layer diffuses into the circuit section less than the diffusion coefficient of the metal material constituting the first metal layer diffuses into the circuit section.

4. The high-frequency module according to claim 1 or 2, wherein, The electronic component is a power amplifier module. The electronic component includes: A first substrate, wherein at least a portion of the first substrate is composed of a first semiconductor material; A second substrate, at least a portion of which is composed of a second semiconductor material different from the first semiconductor material, wherein a power amplifier is formed on the second substrate; and The second metal layer, The second substrate is disposed between the main surface and the first substrate. The second substrate is bonded to the first substrate via the second metal layer and connected to the main surface via the first electrode. The circuit section includes the amplifying transistors included in the power amplifier.

5. The high-frequency module according to claim 4, wherein, The first substrate is connected to the main surface via a second electrode.

6. The high-frequency module according to claim 4, wherein, The thermal conductivity of the first semiconductor material is higher than that of the second semiconductor material.

7. The high-frequency module according to claim 4, wherein, The amplifying transistor consists of a collector layer, a base layer, and an emitter layer. The collector layer, the base layer, and the emitter layer are stacked in the order of collector layer, base layer, and emitter layer, starting from the first substrate side.

8. The high-frequency module according to claim 4, wherein, The first substrate includes a control circuit for controlling the power amplifier.

9. The high-frequency module according to claim 1 or 2, wherein, The electronic component is a surface acoustic wave filter. The electronic component includes: piezoelectric layer; support base plate; The second metal layer; A high-velocity layer in which the velocity of sound of bulk waves propagating is higher than the velocity of sound of surface waves and interface waves propagating in the piezoelectric layer. 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 The interdigitated transducer electrode, also known as the IDT electrode, is formed in the piezoelectric layer. The layers are stacked in the following order: the support substrate, the second metal layer, the high-velocity layer, the low-velocity layer, the piezoelectric layer, and the IDT electrode.

10. The high-frequency module according to claim 1 or 2, wherein, The electronic component is a bulk acoustic wave filter. The electronic component includes: support base plate; The second metal layer; The acoustic multilayer film has a structure consisting of alternating layers of low acoustic impedance films and high acoustic impedance films; The third and fourth electrodes; as well as piezoelectric layer The components are stacked in the following order: the supporting substrate, the second metal layer, the acoustic multilayer film, the third electrode, the piezoelectric layer, and the fourth electrode.

11. The high-frequency module according to claim 9, wherein, It also has a power amplifier to amplify the transmitted signal. The electronic component is a transmitting filter connected to the output terminal of the power amplifier.

12. The high-frequency module according to claim 10, wherein, It also has a power amplifier to amplify the transmitted signal. The electronic component is a transmitting filter connected to the output terminal of the power amplifier.

13. A high-frequency module, comprising: Module baseboard; Electronic components are disposed on the main surface of the module substrate; A resin component covering at least a portion of the main surface and at least a portion of the side surface of the electronic component; and A first metal layer, formed on the surface of the resin component, is set to ground potential. in, The electronic component has: The first surface is in contact with the first metal layer; The second side faces the main side; The circuit section is formed at a location closer to the second surface than to the first surface; as well as A second metal layer is formed between the first metal layer and the circuit portion. The first metal layer is copper, a copper-containing alloy, or a copper-containing laminate. The second metal layer is titanium, tantalum, cobalt, tungsten, or an alloy containing at least one of them.

14. The high-frequency module according to claim 13, wherein, The electronic component also has a silicon layer disposed between the circuit section and the first surface.

15. The high-frequency module according to claim 13 or 14, wherein, The diffusion coefficient of the metal material constituting the second metal layer diffuses into the circuit section less than the diffusion coefficient of the metal material constituting the first metal layer diffuses into the circuit section.

16. The high-frequency module according to claim 13 or 14, wherein, The electronic component is a power amplifier module. The electronic component includes: A first substrate, wherein at least a portion of the first substrate is composed of a first semiconductor material; A second substrate, at least a portion of which is composed of a second semiconductor material different from the first semiconductor material, wherein a power amplifier is formed on the second substrate; and The second metal layer, The second substrate is disposed between the main surface and the first substrate. The second substrate is bonded to the first substrate via the second metal layer and connected to the main surface via the first electrode. The circuit section includes the amplifying transistors included in the power amplifier.

17. The high-frequency module according to claim 16, wherein, The first substrate is connected to the main surface via a second electrode.

18. The high-frequency module according to claim 16, wherein, The thermal conductivity of the first semiconductor material is higher than that of the second semiconductor material.

19. The high-frequency module according to claim 16, wherein, The amplifying transistor consists of a collector layer, a base layer, and an emitter layer. The collector layer, the base layer, and the emitter layer are stacked in the order of collector layer, base layer, and emitter layer, starting from the first substrate side.

20. The high-frequency module according to claim 16, wherein, The first substrate includes a control circuit for controlling the power amplifier.

21. The high-frequency module according to claim 13 or 14, wherein, The electronic component is a surface acoustic wave filter. The electronic component includes: piezoelectric layer; support base plate; The second metal layer; A high-velocity layer in which the velocity of sound of bulk waves propagating is higher than the velocity of sound of surface waves and interface waves propagating in the piezoelectric layer. 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 The interdigitated transducer electrode, also known as the IDT electrode, is formed in the piezoelectric layer. The layers are stacked in the following order: the support substrate, the second metal layer, the high-velocity layer, the low-velocity layer, the piezoelectric layer, and the IDT electrode.

22. The high-frequency module according to claim 13 or 14, wherein, The electronic component is a bulk acoustic wave filter. The electronic component includes: support base plate; The second metal layer; The acoustic multilayer film has a structure consisting of alternating layers of low acoustic impedance films and high acoustic impedance films; The third and fourth electrodes; as well as piezoelectric layer The components are stacked in the following order: the supporting substrate, the second metal layer, the acoustic multilayer film, the third electrode, the piezoelectric layer, and the fourth electrode.

23. The high-frequency module according to claim 21, wherein, It also has a power amplifier to amplify the transmitted signal. The electronic component is a transmitting filter connected to the output terminal of the power amplifier.

24. The high-frequency module according to claim 22, wherein, It also has a power amplifier to amplify the transmitted signal. The electronic component is a transmitting filter connected to the output terminal of the power amplifier.

25. A communication device comprising: RF signal processing circuits, also known as radio frequency signal processing circuits, process high-frequency signals transmitted and received using an antenna; and The high-frequency module according to any one of claims 1 to 24 transmits the high-frequency signal between the antenna and the RF signal processing circuit.

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