High frequency module and communication device

Abstract

To reduce the height of a high frequency module.SOLUTION: A high frequency module 1 includes a mounting substrate 2 and a power amplifier 3. The mounting substrate 2 has a first main surface 21 and a second main surface 22. The first main surface 21 and the second main surface 22 face each other. The power amplifier 3 is disposed on the first main surface 21 of the mounting substrate 2, and has an RF bump 35 and a ground bump 34. The ground bump 34 is taller than the RF bump 35. The mounting substrate 2 has a first recess 51. The first recess 51 is formed on the first main surface 21 of the mounting substrate 2. The ground bump 34 is disposed in the first recess 51 of the mounting substrate 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention generally relates to a high-frequency module and a communication device, and more particularly to a high-frequency module including a power amplifier and a communication device including the high-frequency module. [Background technology]

[0002] Patent Document 1 describes a passive on-package including a substrate having a recessed portion. In the passive on-package described in Patent Document 1, bumps are arranged in the recessed portion of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-515295 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the conventional passive on package described in Patent Document 1, it is difficult to reduce the height of a high-frequency module in which electronic components such as passive on package are arranged on a mounting board.

[0005] The present invention has been made in view of the above-mentioned points, and has an object to provide a high-frequency module and a communication device that can be made low-profile. [Means for solving the problem]

[0006] A high-frequency module according to one aspect of the present invention includes a mounting substrate and a power amplifier. The mounting substrate has a first main surface and a second main surface. The first main surface and the second main surface face each other. The power amplifier is disposed on the first main surface of the mounting substrate and has an RF bump and a ground bump. The ground bump is taller than the RF bump. The mounting substrate has a first recess. The first recess is formed on the first main surface of the mounting substrate. The ground bump is disposed in the first recess of the mounting substrate.

[0007] A communication device according to an aspect of the present invention includes the radio frequency module and a signal processing circuit, the signal processing circuit being connected to the radio frequency module. Effect of the Invention

[0008] According to the high-frequency module and the communication device according to the above aspects of the present invention, the high-frequency module can be made low-profile. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of the high-frequency module according to the first embodiment. [Diagram 2] FIG. 2 is a bottom view of the power amplifier of the high-frequency module. [Diagram 3] FIG. 3 is a plan view of a mounting board of the high-frequency module. [Figure 4] FIG. 4 is a block diagram of the communication device according to the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of the high-frequency module according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the high-frequency module according to the third embodiment. [Figure 7] FIG. 7 is a plan view of a main part of a mounting board of a high-frequency module according to the fourth embodiment. [Figure 8]Fig. 8A is a cross-sectional view of a main part of a mounting board of a high-frequency module according to embodiment 5. Fig. 8B is a cross-sectional view of a main part of a mounting board of a high-frequency module according to modification 1 of embodiment 5. Fig. 8C is a cross-sectional view of a main part of a mounting board of a high-frequency module according to modification 2 of embodiment 5. [Figure 9] FIG. 9 is a plan view of a main part of a mounting board of a high-frequency module according to the sixth embodiment. [Figure 10] FIG. 10 is a cross-sectional view of the high-frequency module according to the seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a high-frequency module 1 and a communication device 8 according to embodiments 1 to 7 will be described with reference to the drawings. Figs. 1 to 3 and 5 to 10 referred to in the following embodiments are schematic diagrams, and the ratios of sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0011] (Embodiment 1) (1) High-frequency module The configuration of a high-frequency module 1 according to the first embodiment will be described with reference to the drawings.

[0012] As shown in Fig. 1, the high-frequency module 1 according to the first embodiment includes a mounting substrate 2, a power amplifier 3, and a resin layer 41. The mounting substrate 2 has a first main surface 21 and a second main surface 22. The first main surface 21 and the second main surface 22 face each other. The power amplifier 3 is disposed on the first main surface 21 of the mounting substrate 2. The power amplifier 3 has a plurality of RF bumps 35 and a ground bump 34. The ground bump 34 is taller than the plurality of RF bumps 35. The mounting substrate 2 has a first recess 51. The first recess 51 is formed on the first main surface 21 of the mounting substrate 2. The ground bump 34 is disposed in the first recess 51 of the mounting substrate 2.

[0013] According to the high-frequency module 1 of the first embodiment, the height of the high-frequency module 1 can be reduced.

[0014] (2) Components of the RF module Hereinafter, each component of the high-frequency module 1 according to the first embodiment will be described with reference to the drawings.

[0015] As shown in FIG. 1, the high-frequency module 1 according to the first embodiment includes a mounting substrate 2, a power amplifier 3, a resin layer 41, and a plurality of external connection terminals (not shown).

[0016] (2.1) Mounting board 1, the mounting board 2 has a first main surface 21 and a second main surface 22. The first main surface 21 and the second main surface 22 face each other. More specifically, the first main surface 21 and the second main surface 22 face each other in a thickness direction D1 of the mounting board 2. The mounting board 2 is a board for arranging a plurality of electronic components, and is, for example, a rectangular plate. The first main surface 21 and the second main surface 22 are, for example, rectangular. The second main surface 22 faces an external board (not shown) when the high-frequency module 1 is provided on the external board.

[0017] The mounting substrate 2 has a plurality of dielectric layers 23 and a plurality of conductive layers. The mounting substrate 2 is, for example, a multi-layer substrate having a plurality of dielectric layers 23 and a plurality of conductive layers. The plurality of dielectric layers 23 and the plurality of conductive layers are stacked in a thickness direction D1 of the mounting substrate 2.

[0018] Each of the plurality of conductive layers includes one or more conductor portions in a plane perpendicular to the thickness direction D1 of the mounting substrate 2. The plurality of conductive layers are formed in a predetermined pattern determined for each layer. The material of each conductive layer is, for example, copper.

[0019] The multiple conductive layers include a ground layer 64. The ground layer 64 is a layer set to a ground potential (reference potential) and is provided inside the mounting board 2. When the high-frequency module 1 is placed on an external board (e.g., a motherboard), the ground layer 64 is connected to the ground of the external board through a via conductor or the like of the mounting board 2 and is maintained at the ground potential (reference potential).

[0020] The mounting substrate 2 is, for example, a low temperature co-fired ceramics (LTCC) substrate. Note that the mounting substrate 2 is not limited to an LTCC substrate, and may be, for example, a printed wiring board, a high temperature co-fired ceramics (HTCC) substrate, or a resin multilayer substrate.

[0021] (2.2) Power Amplifier 1, the power amplifier 3 is disposed on the first main surface 21 of the mounting board 2. More specifically, the power amplifier 3 is mounted on the first main surface 21 of the mounting board 2. The power amplifier 3 amplifies and outputs a transmission signal from a signal processing circuit 82 (see FIG. 4).

[0022] 1 to 3, the power amplifier 3 has a main body 31, multiple electrodes 32, 33, a ground bump 34, and multiple RF bumps 35. The power amplifier 3 is disposed on the first main surface 21 of the mounting substrate 2 with the multiple electrodes 32, 33 being connected to a first electrode 61 and multiple second electrodes 62 provided on the first main surface 21 of the mounting substrate 2 via the ground bump 34 and the multiple RF bumps 35.

[0023] The main body 31 has a functional part. The main body 31 is disposed on the mounting board 2 such that one main surface 311 of the main body 31 faces the mounting board 2 in the thickness direction D1 of the mounting board 2. More specifically, the one main surface 311 of the main body 31 faces the first main surface 21 of the mounting board 2 in a state in which the power amplifier 3 is disposed on the mounting board 2.

[0024] The electrode 32 is formed on one main surface 311 of the main body 31. The one main surface 311 of the main body 31 faces the mounting board 2 in the thickness direction D1 of the mounting board 2. The electrode 32 is formed, for example, in an elongated shape. In the example of Fig. 2, the electrode 32 is formed in an elongated shape along the second direction D22.

[0025] The multiple electrodes 33 are formed on one main surface 311 of the main body portion 31. The multiple electrodes 33 are provided, for example, around the electrode 32 on the one main surface 311 of the main body portion 31. For example, the multiple electrodes 33 are provided on both sides of the electrode 32 in the first direction D21.

[0026] The electrode 32 is a ground electrode. In order to stabilize the ground potential, it is preferable to make the ground electrode large. For this reason, as shown in Fig. 2 and Fig. 3, in a plan view from a normal direction of one main surface 311 on which the electrode 32 and the multiple electrodes 33 are arranged, the area of ​​the electrode 32 is larger than the area of ​​each of the electrodes 33. In other words, the area of ​​the electrode 32 for ground is larger than the area of ​​the electrode 33 for the RF signal.

[0027] 1, the ground bump 34 is a bump for connecting the ground electrode 32 to the ground layer 64 of the mounting substrate 2. The ground bump 34 is disposed on the electrode 32. The ground bump 34 is formed, for example, in an elongated shape. The ground bump 34 is formed, for example, from solder.

[0028] The multiple RF bumps 35 are conductive members for connecting the multiple electrodes 33 for RF signals to a conductive layer of the mounting substrate 2. The multiple RF bumps 35 are formed on the multiple electrodes 33. The multiple RF bumps 35 are formed of, for example, solder.

[0029] The power amplifier 3 is, for example, an IC chip including a substrate and an amplifying function unit. The substrate has a first surface and a second surface facing each other. The substrate is, for example, a gallium arsenide substrate. The amplifying function unit includes at least one transistor formed on the first surface of the substrate. The amplifying function unit is a function unit having a function of amplifying a transmission signal of a predetermined frequency band. The transistor is, for example, an HBT (Heterojunction Bipolar Transistor). In the power amplifier 3, a power supply voltage from a power supply circuit (not shown) is applied between the collector and the emitter of the HBT. The power amplifier 3 may include, for example, a DC cut capacitor in addition to the amplifying function unit. The power amplifier 3 is, for example, flip-chip mounted on the first main surface 21 of the mounting substrate 2 so that the first surface of the substrate faces the first main surface 21 of the mounting substrate 2. In a plan view from the thickness direction D1 of the mounting substrate 2, the outer periphery of the power amplifier 3 is a quadrangle.

[0030] (2.3) Layout of the mounting board and power amplifier 1, the mounting substrate 2 has a first recess 51 and a plurality of second recesses 52. The first recess 51 is formed on the first main surface 21 of the mounting substrate 2. The first recess 51 has a bottom surface 511 and a side surface 512. The plurality of second recesses 52 are formed on the first main surface 21 of the mounting substrate 2. Each of the plurality of second recesses 52 has a bottom surface 521 and a side surface 522.

[0031] The mounting substrate 2 has a first electrode 61 and a plurality of second electrodes 62. The first electrode 61 is disposed in the first recess 51. More specifically, the first electrode 61 is disposed on a bottom surface 511 of the first recess 51. The plurality of second electrodes 62 are disposed in the plurality of second recesses 52. More specifically, the plurality of second electrodes 62 are disposed on bottom surfaces 521 of the plurality of second recesses 52.

[0032] The ground bump 34 of the power amplifier 3 is disposed in a first recess 51 of the mounting substrate 2. More specifically, the ground bump 34 is disposed in the first recess 51 such that at least a portion of the ground bump 34 is accommodated in the first recess 51.

[0033] By arranging the ground bump 34 of the power amplifier 3 in the first recess 51 of the mounting substrate 2, the height of the power amplifier 3 from the surface of the first main surface 21 of the mounting substrate 2 on which the first recess 51 and the second recess 52 are not formed can be reduced, thereby making it possible to reduce the height of the high-frequency module 1.

[0034] The multiple RF bumps 35 of the power amplifier 3 are disposed in multiple second recesses 52 of the mounting substrate 2. More specifically, for each of the multiple RF bumps 35, the RF bump 35 is disposed in the second recess 52 such that at least a portion of the RF bump 35 is accommodated in the second recess 52.

[0035] By arranging the multiple RF bumps 35 of the power amplifier 3 in the multiple second recesses 52 of the mounting substrate 2, the height of the power amplifier 3 from the surface of the first main surface 21 of the mounting substrate 2 on which the first recesses 51 and the second recesses 52 are not formed can be further reduced, thereby making it possible to reduce the height of the high-frequency module 1.

[0036] As described above, in a plan view from the normal direction of one main surface 311 on which the ground bump 34 and the multiple RF bumps 35 are arranged, the area of ​​the electrode 32 for ground is larger than the area of ​​the electrode 33 for RF signals. Since the ground bump 34 covers the electrode 32 with a larger area, the area of ​​the ground bump 34 is larger than the area of ​​each RF bump 35. Therefore, as shown in FIG. 1 , in the normal direction of the one main surface 311 of the power amplifier 3, i.e., in the thickness direction D1 of the mounting substrate 2, the height of the ground bump 34 is larger than the height of each of the multiple RF bumps 35.

[0037] The first recess 51 of the mounting substrate 2 is deeper than each of the multiple second recesses 52 in the thickness direction D1 of the mounting substrate 2. This allows the ground bump 34, which is larger than each RF bump 35, to be disposed in the first recess 51, which is deeper than each second recess 52.

[0038] The mounting board 2 further has a plurality of via conductors 66. The plurality of via conductors 66 are, for example, columnar conductive members, and are provided inside the mounting board 2. The plurality of via conductors 66 are used for electrically connecting electronic components arranged on the first main surface 21 of the mounting board 2 to a conductive layer of the mounting board 2. The plurality of via conductors 66 are also used for electrically connecting the conductive layer of the mounting board 2 to an external connection terminal (not shown).

[0039] 1 is connected to the first recess 51 in which the ground bump 34 is disposed. The via conductor 66 is used for electrically connecting the power amplifier 3 disposed on the first main surface 21 of the mounting board 2 to the ground layer 64 of the mounting board 2.

[0040] By connecting the via conductor 66 to the first recess 51 in which the ground bump 34 is arranged, the length of the via conductor 66 can be made shorter than when the first recess 51 is not formed, and therefore, for example, the distance from the ground bump 34 to the ground layer 64 can be made shorter.

[0041] The power amplifier 3 has a main body 31 including a functional section. The main body 31 of the power amplifier 3 is located outside the mounting substrate 2.

[0042] This allows the strength of mounting board 2 to be increased, as compared to a case in which a recess for accommodating main body 31 of power amplifier 3 is formed in mounting board 2.

[0043] (2.4) Resin layer 1, the resin layer 41 is disposed on the first main surface 21 of the mounting board 2. The resin layer 41 contacts the first main surface 21 of the mounting board 2 and covers at least a part of the power amplifier 3. This makes it possible to protect the mounting board 2 and the power amplifier 3.

[0044] The resin layer 41 includes a resin and a filler (not shown). The resin is, for example, an epoxy resin. In the high-frequency module 1, the distance L1 between the main body 31 of the power amplifier 3 and the mounting substrate 2 is larger than the diameter of the filler included in the resin layer 41. This allows the resin layer 41 to penetrate up to the periphery of the bumps (ground bumps 34, RF bumps 35) of the power amplifier 3, making it possible to prevent solder splash when the high-frequency module 1 is mounted on a motherboard. As a result, the connection reliability of the power amplifier 3 can be improved.

[0045] (2.5) External connection terminal The multiple external connection terminals (not shown) are arranged, for example, on the second main surface 22 of the mounting board 2. The multiple external connection terminals are terminals for electrically connecting the mounting board 2 to an external board (not shown). The multiple external connection terminals are arranged on the second main surface 22 of the mounting board 2 at intervals from each other.

[0046] Each of the external connection terminals is a flat conductive member, and is made of, for example, a metal (for example, copper, a copper alloy, etc.).

[0047] Each external connection terminal is connected to an external connection electrode of an external substrate. In this specification, "A (e.g., an external connection terminal) is connected to B (e.g., an external connection electrode of an external substrate)" does not only mean that A and B are in contact with each other, but also means that A and B are electrically connected via a conductor electrode, a conductor terminal, wiring, or other circuit components. The multiple external connection terminals are connected to the external connection electrodes of the external substrate via, for example, a connection member (e.g., a solder bump) formed of a conductor.

[0048] The multiple external connection terminals include an antenna terminal, a signal input terminal, a signal output terminal, a control terminal, and a ground terminal. The antenna terminal is a terminal to which an antenna 81 (see FIG. 4) is connected. The signal input terminal is a terminal for inputting a transmission signal (high frequency signal) from a signal processing circuit 82 (see FIG. 4) to the high frequency module 1. The signal output terminal is a terminal for outputting a reception signal (high frequency signal) from the high frequency module 1 to the signal processing circuit 82. The control terminal is a terminal for inputting a control signal from the signal processing circuit 82 to a controller (not shown).

[0049] (3) Communications equipment 4, the communication device 8 includes a high-frequency module 1, an antenna 81, and a signal processing circuit 82. The communication device 8 is, for example, a mobile terminal (for example, a smartphone). Note that the communication device 8 is not limited to a mobile terminal, and may be, for example, a wearable terminal (for example, a smart watch).

[0050] The high frequency module 1 is configured to amplify a transmission signal (high frequency signal) from the signal processing circuit 82 and output the amplified signal to the antenna 81. The high frequency module 1 is also configured to amplify a reception signal (high frequency signal) received by the antenna 81 and output the amplified signal to the signal processing circuit 82. The high frequency module 1 is controlled by the signal processing circuit 82, for example.

[0051] The high frequency module 1 is a module that can support, for example, the 4G (fourth generation mobile communication) standard and the 5G (fifth generation mobile communication) standard. The 4G standard is, for example, the 3GPP (registered trademark, Third Generation Partnership Project) LTE (registered trademark, Long Term Evolution) standard. The 5G standard is, for example, the 5G NR (New Radio). The high frequency module 1 is a module that can support carrier aggregation and dual connectivity.

[0052] In the communication device 8, the high-frequency module 1 can be electrically connected to an external board (not shown). The external board corresponds to, for example, a motherboard of a mobile terminal, a communication device, or the like. Note that the high-frequency module 1 being electrically connectable to an external board includes not only the case where the high-frequency module 1 is directly mounted on the external board, but also the case where the high-frequency module 1 is indirectly mounted on the external board. Moreover, the case where the high-frequency module 1 is indirectly mounted on the external board includes the case where the high-frequency module 1 is mounted on another high-frequency module mounted on the external board, etc.

[0053] (3.1) Antenna The antenna 81 is connected to an antenna terminal (not shown) of the high-frequency module 1. The antenna 81 has a transmitting function of emitting a transmission signal output from the high-frequency module 1 as radio waves and a receiving function of receiving a reception signal from the outside as radio waves and outputting the reception signal to the high-frequency module 1.

[0054] (3.2) Signal processing circuit The signal processing circuit 82 is connected to the high-frequency module 1. The signal processing circuit 82 processes high-frequency signals passing through the high-frequency module 1. More specifically, the signal processing circuit 82 is configured to process a reception signal received from the high-frequency module 1. The signal processing circuit 82 is also configured to process a transmission signal to be output to the high-frequency module 1.

[0055] The signal processing circuit 82 includes a baseband signal processing circuit 83 and an RF signal processing circuit 84.

[0056] The baseband signal processing circuit 83 is, for example, a BBIC (Baseband Integrated Circuit).

[0057] The baseband signal processing circuit 83 performs predetermined signal processing on a signal from outside the signal processing circuit 82. More specifically, the baseband signal processing circuit 83 generates a transmission signal from a baseband signal (e.g., an audio signal and an image signal) from outside the signal processing circuit 82, and outputs the generated transmission signal to the RF signal processing circuit 84.

[0058] The baseband signal processing circuit 83 performs a predetermined signal processing on the signal from the RF signal processing circuit 84. More specifically, the baseband signal processing circuit 83 outputs to the outside the received signal received from the RF signal processing circuit 84. The received signal processed by the baseband signal processing circuit 83 is used, for example, as an image signal for image display, or as an audio signal for telephone conversation.

[0059] The RF signal processing circuit 84 is, for example, an RFIC (Radio Frequency Integrated Circuit), and performs signal processing on high frequency signals (transmission signals and reception signals).

[0060] The RF signal processing circuit 84 performs signal processing on the transmission signal output from the baseband signal processing circuit 83, and outputs the processed transmission signal to the high-frequency module 1. Specifically, the RF signal processing circuit 84 performs signal processing such as up-conversion on the transmission signal output from the baseband signal processing circuit 83, and outputs the processed transmission signal to a transmission path of the high-frequency module 1.

[0061] The RF signal processing circuit 84 performs signal processing on the received signal output from the high frequency module 1, and outputs the processed received signal to the baseband signal processing circuit 83. Specifically, the RF signal processing circuit 84 performs signal processing such as down-conversion on the received signal output from the reception path of the high frequency module 1, and outputs the processed received signal to the baseband signal processing circuit 83.

[0062] (4) Effects In the high-frequency module 1 according to the first embodiment, the ground bumps 34 of the power amplifier 3 are disposed in the first recesses 51 of the mounting substrate 2. This makes it possible to reduce the height of the power amplifier 3 from the surface of the first main surface 21 of the mounting substrate 2 on which the first recesses 51 and the second recesses 52 are not formed, thereby enabling the high-frequency module 1 to be made low-profile.

[0063] In the high-frequency module 1 according to the first embodiment, a first recess 51 is formed in the mounting substrate 2. This makes it possible to shorten the distance between the power amplifier 3 and the wiring conductor or wiring element built into the mounting substrate 2, compared to a case in which the first recess 51 is not formed.

[0064] In the high-frequency module 1 according to the first embodiment, the ground bumps 34 are disposed in the first recesses 51 of the mounting substrate 2, and the RF bumps 35 are disposed in the second recesses 52 of the mounting substrate 2. This makes it possible to further reduce the height of the power amplifier 3 from the surface of the first main surface 21 of the mounting substrate 2 on which the first recesses 51 and the second recesses 52 are not formed, thereby making it possible to further reduce the height of the high-frequency module 1.

[0065] In the high-frequency module 1 according to the first embodiment, the second recess 52 is formed in the mounting substrate 2. This makes it possible to shorten the distance between the power amplifier 3 and the wiring conductor or wiring element built into the mounting substrate 2, compared to a case in which the second recess 52 is not formed.

[0066] In the high-frequency module 1 according to the first embodiment, the via conductor 66 is provided in the first recess 51 in which the ground bump 34 is disposed. This allows the length of the via conductor 66 to be shorter than when the first recess 51 is not formed, and therefore, for example, the distance from the ground bump 34 to the ground layer 64 of the mounting board 2 can be shortened.

[0067] In the high-frequency module 1 according to the first embodiment, a resin layer 41 is provided in contact with the first main surface 21 of the mounting board 2 and covering at least a part of the power amplifier 3. This makes it possible to protect the mounting board 2 and the power amplifier 3.

[0068] In the high-frequency module 1 according to the first embodiment, the distance L1 between the main body 31 of the power amplifier 3 and the mounting substrate 2 is larger than the diameter of the filler contained in the resin layer 41. This allows the resin layer 41 to penetrate up to the periphery of the bumps of the power amplifier 3, making it possible to prevent solder splash when the high-frequency module 1 is mounted on a motherboard. As a result, the connection reliability of the power amplifier 3 can be improved.

[0069] In the high-frequency module 1 according to the first embodiment, the main body 31 of the power amplifier 3 is located outside the mounting board 2. This makes it possible to increase the strength of the mounting board 2 compared to a case in which a recess for accommodating the main body 31 of the power amplifier 3 is formed in the mounting board 2.

[0070] According to the high-frequency module 1 of the first embodiment, even when power amplifiers 3 of different sizes are arranged on the mounting board 2, the high-frequency module 1 can be made low-profile simply by processing the mounting board 2. In other words, the high-frequency module 1 can be made low-profile simply by performing processing to form the first recess 51 and the second recess 52 of the mounting board 2.

[0071] In the high-frequency module 1 according to the first embodiment, the ground bumps 34 are disposed in the first recesses 51, and at least a portion of the solder of the ground bumps 34 fills the first recesses 51. This makes it possible to increase the sum of the thickness of the mounting substrate 2 and the thickness of the ground bumps 34 compared to a case in which the ground bumps 34 are not disposed in the first recesses 51, thereby increasing the strength of the mounting substrate 2.

[0072] In the high-frequency module 1 according to the first embodiment, the RF bump 35 is disposed in the second recess 52, and at least a portion of the solder of the RF bump 35 fills the second recess 52. This makes it possible to increase the sum of the thickness of the mounting substrate 2 and the thickness of the RF bump 35 compared to a case in which the RF bump 35 is not disposed in the second recess 52, thereby increasing the strength of the mounting substrate 2.

[0073] In the high-frequency module 1 according to the first embodiment, a first recess 51 and a second recess 52 are formed in the mounting substrate 2, and a ground bump 34 and an RF bump 35 protruding from one main surface 311 of a main body 31 are provided in the power amplifier 3. This makes it possible to reduce non-leveling of the first main surface 21 of the mounting substrate 2 on which the power amplifier 3 is arranged.

[0074] In the high-frequency module 1 of embodiment 1, the presence of the first recess 51 and the second recess 52 in the mounting substrate 2 makes it possible to limit the amount of self-alignment movement that occurs when the solder of the ground bump 34 and the multiple RF bumps 35 melts to within the first recess 51 and the second recess 52, thereby improving the mountability of the power amplifier 3 on the mounting substrate 2.

[0075] In the high-frequency module 1 according to the first embodiment, the first recess 51 and the second recess 52 are formed in the mounting board 2. As a result, the thickness of the mounting board 2 can be increased while maintaining the height of the high-frequency module 1, compared to a case in which the first recess 51 and the second recess 52 are not formed, and therefore the strength of the mounting board 2 can be increased.

[0076] In the communication device 8 according to the first embodiment, in the high-frequency module 1, the ground bumps 34 of the power amplifier 3 are disposed in the first recess 51 of the mounting substrate 2. This allows the high-frequency module 1 to have a low height.

[0077] (5) Variations A modification of the first embodiment will now be described.

[0078] (5.1) Variation 1 The high-frequency module 1 according to the first modification of the first embodiment includes a mounting substrate 2, a power amplifier 3, a resin layer 41, a plurality of external connection terminals (not shown), and a shield layer (not shown).

[0079] The shielding layer covers at least a portion of the resin layer 41 and the mounting substrate 2. More specifically, the shielding layer covers one main surface and an outer peripheral surface of the resin layer 41, and the outer peripheral surface of the mounting substrate 2. The one main surface of the resin layer 41 is a main surface of the resin layer 41 on the side opposite to the mounting substrate 2 side.

[0080] The shield layer is electrically conductive. More specifically, the shield layer has a multi-layer structure in which a plurality of metal layers are stacked. The metal layers include one or more types of metal. Note that the shield layer is not limited to the multi-layer structure, and may be a single metal layer.

[0081] The shield layer is provided, for example, for the purpose of electromagnetic shielding between the inside and outside of the high-frequency module 1. The shield layer is in contact with at least a part of the ground layer of the mounting board 2. This allows the potential of the shield layer to be the same as the potential of the ground layer.

[0082] The shielding layer covers at least a portion of the main surface of the power amplifier 3. The shielding layer may be connected to the main surface of the power amplifier 3 by, for example, contacting the main surface.

[0083] (5.2) Variation 2 In the high-frequency module 1 according to the second modification of the first embodiment, the distance L1 between the main body 31 of the power amplifier 3 and the mounting substrate 2 (see FIG. 1) is smaller than the diameter of the filler contained in the resin layer 41.

[0084] According to the high-frequency module 1 according to the second modification of the first embodiment, the height of the high-frequency module 1 can be further reduced.

[0085] (5.3) Variation 3 In the high-frequency module 1 according to the third modification of the first embodiment, the resin layer 41 does not include a filler. The resin layer 41 does not include a filler and includes only a resin, for example.

[0086] The high-frequency modules 1 according to the above-described modifications also provide the same effects as those of the high-frequency module 1 according to the first preferred embodiment.

[0087] (Embodiment 2) 5, the high-frequency module 1 according to the second embodiment differs from the high-frequency module 1 according to the first embodiment (see FIG. 1) in that the first recess 51 and the multiple second recesses 52 of the mounting substrate 2 are continuous with each other. Note that, in the high-frequency module 1 according to the second embodiment, the same components as those in the high-frequency module 1 according to the first embodiment are denoted by the same reference numerals and will not be described.

[0088] (1) Composition In the mounting board 2 of the second embodiment, as shown in FIG. 5, a first recess 51 and a plurality of second recesses 52 are continuous with each other.

[0089] In a state in which the first recess 51 and the multiple second recesses 52 are continuous with each other, the depth of the first recess 51 is deeper than the depth of each of the second recesses 52. In other words, a step is formed near the boundary between the first recess 51 and each of the second recesses 52.

[0090] Regarding the mounting board 2 of the second embodiment, the description of the configuration and functions similar to those of the mounting board 2 of the first embodiment (see FIG. 1) will be omitted.

[0091] (2) Effects In the high-frequency module 1 according to the second embodiment, the first recess 51 and the multiple second recesses 52 are continuous with each other in the mounting substrate 2. This eliminates the need to form walls between the first recess 51 and each of the second recesses 52, and therefore makes it possible to easily form the first recess 51 and the multiple second recesses 52.

[0092] In the high-frequency module 1 according to the second embodiment, the first recess 51 and the multiple second recesses 52 are continuous with each other in the mounting substrate 2. This makes it possible to form the first recess 51 and each second recess 52 even when the distance between two adjacent electrodes 32, 33 in a planar direction (e.g., the first direction D21 and the second direction D22) of one main surface 311 of the power amplifier 3 is short, that is, even when the distance between the ground bump 34 and the RF bump 35 is short.

[0093] (3) Modifications A modification of the second embodiment will now be described.

[0094] The high-frequency module 1 according to the modification of the second embodiment further includes a shield layer (not shown), similar to the high-frequency module 1 according to the first modification of the first embodiment.

[0095] The high-frequency module 1 according to the above-described modified example also provides the same effects as those of the high-frequency module 1 according to the second preferred embodiment.

[0096] (Embodiment 3) 6, the high-frequency module 1 according to the third embodiment differs from the high-frequency module 1 according to the first embodiment (see FIG. 1) in that there are no second recesses 52 (see FIG. 1) in the mounting substrate 2. Note that, in the high-frequency module 1 according to the third embodiment, components similar to those in the high-frequency module 1 according to the first embodiment are denoted by the same reference numerals and will not be described.

[0097] (1) Composition As shown in FIG. 6, the mounting board 2 of the third embodiment does not have the multiple second recesses 52 (see FIG. 1).

[0098] The second electrodes 62 of the third embodiment are disposed on the first main surface 21 of the mounting substrate 2 in a portion where no recess is formed.

[0099] The multiple RF bumps 35 are disposed on the multiple second electrodes 62. That is, the multiple RF bumps 35 are disposed on a portion of the first main surface 21 of the mounting substrate 2 where no recess is formed.

[0100] Regarding the mounting board 2 of the third embodiment, the description of the configuration and functions similar to those of the mounting board 2 of the first embodiment (see FIG. 1) will be omitted.

[0101] (2) Effects The high-frequency module 1 according to the third embodiment does not have a plurality of second recesses 52. This makes it possible to simplify the process of forming recesses in the mounting substrate 2.

[0102] (3) Modifications A modification of the third embodiment will now be described.

[0103] Like the high-frequency module 1 according to the modification of the first embodiment, the high-frequency module 1 according to the modification of the third embodiment further includes a shield layer (not shown).

[0104] The high-frequency module 1 according to the above-described modified example also provides the same effects as those of the high-frequency module 1 according to the third preferred embodiment.

[0105] (Embodiment 4) 7, the high-frequency module 1 according to the fourth embodiment differs from the high-frequency module 1 according to the first embodiment (see FIG. 1) in that the side surface 512 of the first recess 51 and the side surface 522 of the second recess 52 of the mounting substrate 2 are curved surfaces. Note that, in the high-frequency module 1 according to the fourth embodiment, the same components as those in the high-frequency module 1 according to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0106] (1) Composition In the mounting board 2 of the fourth embodiment, the side surface 512 of the first recess 51 is a curved surface when viewed in a thickness direction D1 of the mounting board 2 in a plan view.

[0107] In the mounting board 2 of the fourth embodiment, the side surface 522 of the second recess 52 is a curved surface when viewed from a thickness direction D1 of the mounting board 2 in a plan view, as shown in FIG.

[0108] Regarding the mounting board 2 of the fourth embodiment, the description of the configuration and functions similar to those of the mounting board 2 of the first embodiment (see FIG. 1) will be omitted.

[0109] (2) Effects In the radio-frequency module 1 according to the fourth embodiment, the side surface 512 of the first recess 51 is curved in plan view in the thickness direction D1 of the mounting substrate 2. This allows the shape of the first recess 51 to be closer to the shape of the ground bump 34, so that when the power amplifier 3 is disposed on the mounting substrate 2, the amount of self-alignment of the solder can be kept within the range of the first recess 51. As a result, the mountability of the power amplifier 3 on the mounting substrate 2 can be improved. In other words, the mounting variation of the power amplifier 3 can be reduced.

[0110] In the radio-frequency module 1 according to the fourth embodiment, the side surface 522 of the second recess 52 is a curved surface when viewed from a plane in the thickness direction D1 of the mounting substrate 2. This allows the shape of the second recess 52 to be close to the shape of the RF bump 35, so that when the power amplifier 3 is disposed on the mounting substrate 2, the amount of self-alignment of the solder can be kept within the range of the second recess 52. As a result, the mountability of the power amplifier 3 on the mounting substrate 2 can be improved. In other words, the mounting variation of the power amplifier 3 can be reduced.

[0111] (3) Modifications A modification of the fourth embodiment will now be described.

[0112] (3.1) Variation 1 In the high-frequency module 1 according to the first modification of the fourth embodiment, among the side surface 512 of the first recess 51 and the side surfaces 522 of the plurality of second recesses 52 of the mounting substrate 2, only the side surface 512 of the first recess 51 is a curved surface.

[0113] In the high-frequency module 1 according to the first modification of the fourth embodiment, the mountability of the power amplifier 3 on the mounting board 2 can also be improved.

[0114] (3.2) Variation 2 In the high-frequency module 1 according to the second modification of the fourth embodiment, among the side surface 512 of the first recess 51 and the side surfaces 522 of the second recesses 52 of the mounting substrate 2, only the side surfaces 522 of the second recesses 52 are curved. Note that the side surfaces 522 of some, not all, of the second recesses 52 may be curved.

[0115] In the high-frequency module 1 according to the second modification of the fourth embodiment, the mountability of the power amplifier 3 on the mounting board 2 can also be improved.

[0116] In short, it is only necessary that at least one of the side surfaces 512, 522 of the first recess 51 and the multiple second recesses 52 of the mounting substrate 2 is a curved surface when viewed in a plan view from the thickness direction D1 of the mounting substrate 2.

[0117] The high-frequency modules 1 according to the above-described modifications also provide the same effects as those of the high-frequency module 1 according to the fourth preferred embodiment.

[0118] (Embodiment 5) 8A, the radio frequency module 1 according to the fifth embodiment differs from the radio frequency module 1 according to the first embodiment (see FIG. 1) in that a side electrode 63 is formed on a side surface 512 of the first recess 51 and on side surfaces 522 of the second recesses 52. Note that, in the radio frequency module 1 according to the fifth embodiment, components similar to those in the radio frequency module 1 according to the first embodiment are denoted by the same reference numerals and will not be described.

[0119] (1) Composition 8A, the mounting board 2 of embodiment 5 further has a side electrode 63. The side electrode 63 is formed on a side surface 512 of the first recess 51. The side electrode 63 is also formed on a side surface 522 of the second recess 52. Note that, with regard to the mounting board 2 of embodiment 5, a description of the same configuration and functions as the mounting board 2 of embodiment 1 (see FIG. 1) will be omitted.

[0120] (2) Effects In the radio-frequency module 1 according to the fifth embodiment, a first electrode 61 is formed on a bottom surface 511 of the first recess 51, and a side electrode 63 is formed on a side surface 512 of the first recess 51. This makes it possible to increase the contact area between the ground bump 34 of the power amplifier 3 and the electrodes (first electrode 61, side electrode 63) in the first recess 51, thereby increasing the bonding strength between the ground bump 34 and the electrodes in the first recess 51. As a result, the mountability of the power amplifier 3 on the mounting board 2 can be improved.

[0121] In the high-frequency module 1 according to the fifth embodiment, a side electrode 63 is formed on the side surface 512 of the first recess 51. This allows wiring to extend from the side surface 512 of the first recess 51, thereby increasing the degree of freedom in wiring.

[0122] In the radio-frequency module 1 according to the fifth embodiment, a second electrode 62 is formed on a bottom surface 521 of the second recess 52, and a side electrode 63 is formed on a side surface 522 of the second recess 52. This makes it possible to increase the contact area between the RF bump 35 of the power amplifier 3 and the electrodes (second electrode 62, side electrode 63) in the second recess 52, thereby increasing the bonding strength between the RF bump 35 of the power amplifier 3 and the electrodes in the second recess 52. As a result, the mountability of the power amplifier 3 on the mounting board 2 can be improved.

[0123] In the high-frequency module 1 according to the fifth embodiment, the side electrode 63 is formed on the side surface 522 of the second recess 52. This allows wiring to extend from the side surface 522 of the second recess 52, thereby increasing the degree of freedom in wiring.

[0124] (3) Modifications A modification of the fifth embodiment will now be described.

[0125] (3.1) Variation 1 8B, the mounting board 2 has a wiring pattern conductor 65. The wiring pattern conductor 65 is provided on the first main surface 21 of the mounting board 2 so as to be continuous with the side electrode 63.

[0126] In the high-frequency module 1 according to the first modification of the fifth embodiment, a side electrode 63 is formed on at least one of the side surfaces 512, 522 of the first recess 51 and the second recess 52. This allows wiring to extend from the side surfaces 512, 522 of the recesses (the first recess 51 and the second recess 52), thereby increasing the degree of freedom in wiring.

[0127] (3.2) Variation 2 In the high-frequency module 1 according to the second modification of the fifth embodiment, the mounting board 2 has a via conductor 66 and a plurality of wiring pattern conductors 671 and 672, as shown in FIG. 8C.

[0128] The via conductor 66 connects the first electrode 61 and the wiring pattern conductor 671. The wiring pattern conductor 672 is connected to the side electrode 63. The wiring pattern conductor 672 extends from the side electrode 63 in a direction perpendicular to the thickness direction D1 of the mounting substrate 2. The via conductor 66 may be a conductor that connects the second electrode 62 and the wiring pattern conductor 671.

[0129] In the high-frequency module 1 according to the second modification of the fifth embodiment, a side electrode 63 is formed on at least one of the side surfaces 512, 522 of the first recess 51 and the second recess 52. This allows wiring to extend from the side surfaces 512, 522 of the recesses (the first recess 51 and the second recess 52), thereby increasing the degree of freedom in wiring.

[0130] (3.3) Variation 3 In the high-frequency module 1 according to the third modification of the fifth embodiment, the side electrode 63 is formed only on the side surfaces 512 of the first recesses 51, among the side surfaces 512 of the first recesses 51 and the side surfaces 522 of the second recesses 52 of the mounting substrate 2. Note that the side electrode 63 may be formed on the side surfaces 512 of some of the first recesses 51, rather than on all of the first recesses 51.

[0131] The high-frequency module 1 according to the third modification of the fifth embodiment also allows for greater freedom in wiring.

[0132] (3.4) Variation 4 In the high-frequency module 1 according to the fourth modification of the fifth embodiment, the side electrode 63 is formed only on the side surfaces 522 of the second recesses 52 out of the side surfaces 512 of the first recesses 51 and the side surfaces 522 of the second recesses 52 of the mounting substrate 2. Note that the side electrode 63 may be formed on the side surfaces 522 of some of the second recesses 52 rather than on all of the second recesses 52.

[0133] The high-frequency module 1 according to the fourth modification of the fifth embodiment also allows for greater freedom in wiring.

[0134] In short, it is sufficient that the mounting substrate 2 has the side electrode 63 formed on at least one of the side surfaces 512, 522 of the first recess 51 and the second recess 52.

[0135] The high-frequency modules 1 according to the above-described modifications also provide the same effects as those of the high-frequency module 1 according to the fifth preferred embodiment.

[0136] (Embodiment 6) 9, the high-frequency module 1 according to the sixth embodiment differs from the high-frequency module 1 according to the first embodiment (see FIG. 1) in that a wiring pattern conductor 68 is formed in a first recess 51 and a plurality of second recesses 52 of a mounting substrate 2. Note that, in the high-frequency module 1 according to the sixth embodiment, components similar to those in the high-frequency module 1 according to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0137] (1) Composition The mounting board 2 of the sixth embodiment has a plurality of wiring pattern conductors 68 as shown in Fig. 9. The wiring pattern conductors 68 are formed in the first recess 51. More specifically, the wiring pattern conductors 68 are formed on the bottom surface 511 of the first recess 51. Also, as shown in Fig. 9, the wiring pattern conductors 68 are formed in each of the second recesses 52. More specifically, the wiring pattern conductors 68 are formed on the bottom surface 521 of each of the second recesses 52. Note that, with regard to the mounting board 2 of the sixth embodiment, a description of the same configuration and functions as those of the mounting board 2 of the first embodiment (see Fig. 1) will be omitted.

[0138] (2) Effects In the high-frequency module 1 according to the sixth embodiment, the wiring pattern conductor 68 is formed in at least one of the first recess 51 and the plurality of second recesses 52. This increases the degree of freedom in wiring.

[0139] (3) Modifications A modification of the sixth embodiment will now be described.

[0140] (3.1) Variation 1 In the high-frequency module 1 according to the first modification of the sixth embodiment, among the plurality of first recesses 51 and the plurality of second recesses 52 of the mounting substrate 2, the wiring pattern conductors 68 are formed only in the plurality of first recesses 51. Note that the wiring pattern conductors 68 may be formed in some of the plurality of first recesses 51 rather than in all of the plurality of first recesses 51.

[0141] The high-frequency module 1 according to the first modification of the sixth embodiment also allows for greater freedom in wiring.

[0142] (3.2) Variation 2 In the high-frequency module 1 according to the second modification of the sixth embodiment, among the plurality of first recesses 51 and the plurality of second recesses 52 of the mounting substrate 2, the wiring pattern conductors 68 are formed only in the plurality of second recesses 52. Note that the wiring pattern conductors 68 may be formed in some of the plurality of second recesses 52 rather than in all of the plurality of second recesses 52.

[0143] The high-frequency module 1 according to the second modification of the sixth embodiment also allows for greater freedom in wiring.

[0144] In short, it is sufficient that the mounting board 2 has the wiring pattern conductors 68 in at least one of the first recess 51 and the second recess 52.

[0145] (3.3) Variation 3 In the high-frequency module 1 according to the third modification of the sixth embodiment, the number of wiring pattern conductors 68 provided in the first recess 51 is not limited to two and may be one, or three or more. The number of wiring pattern conductors 68 provided in the plurality of second recesses 52 is not limited to two and may be one, or three or more.

[0146] The high-frequency module 1 according to the above-described modified example also provides the same effects as those of the high-frequency module 1 according to the sixth preferred embodiment.

[0147] (Embodiment 7) The high-frequency module 1 according to the seventh embodiment differs from the high-frequency module 1 according to the first embodiment (see FIG. 1) in that it has a double-sided mounting structure, as shown in FIG. 10. Note that, in the high-frequency module 1 according to the seventh embodiment, components similar to those in the high-frequency module 1 according to the first embodiment are denoted by the same reference numerals and descriptions thereof will be omitted.

[0148] (1) Composition As shown in FIG. 10, the high-frequency module 1 according to the seventh embodiment includes a mounting substrate 2, a power amplifier 3, an electronic component 7, a plurality of resin layers 41 and 42, and a plurality of external connection terminals (not shown).

[0149] (1.1) Mounting board 10, the mounting board 2 of the seventh embodiment has a first main surface 21 and a second main surface 22. The mounting board 2 is a double-sided mounting board in which electronic components are mounted on each of the first main surface 21 and the second main surface 22.

[0150] (1.2) Electronic Components 10, the electronic component 7 is disposed on the second main surface 22 of the mounting board 2. The electronic component 7 is, for example, an IC (Integrated Circuit) component. Note that a part of the electronic component 7 may be disposed on the second main surface 22 of the mounting board 2, and the remainder of the electronic component 7 may be incorporated within the mounting board 2. In short, the electronic component 7 is located on the second main surface 22 side of the first main surface 21 on the mounting board 2, and has at least a portion mounted on the second main surface 22.

[0151] The electronic component 7 has a main body 71, a plurality of electrodes 72, and a plurality of bumps 73. The electronic component 7 is disposed on the second main surface 22 of the mounting substrate 2 by connecting the plurality of electrodes 72 to a plurality of third electrodes 69 provided on the second main surface 22 of the mounting substrate 2 via the plurality of bumps 73.

[0152] The main body portion 71 has a functional portion. The main body portion 71 is disposed on the mounting board 2 such that one main surface 711 of the main body portion 71 faces the mounting board 2 in the thickness direction D1 of the mounting board 2. More specifically, the one main surface 711 of the main body portion 71 faces the second main surface 22 of the mounting board 2 in a state in which the electronic component 7 is disposed on the mounting board 2.

[0153] The multiple electrodes 72 are formed on one main surface 711 of the main body portion 71. The multiple electrodes 72 are provided, for example, on the one main surface 711 of the main body portion 71 and spaced apart from each other.

[0154] The bumps 73 are for connecting the electrodes 72 to a conductive layer of the mounting substrate 2. The bumps 73 are arranged on the electrodes 72. Each bump 73 is formed, for example, in a circular shape. Each bump 73 is formed, for example, of solder.

[0155] When the electronic component 7 is an IC component, the electronic component 7 includes, for example, a low-noise amplifier and a switch. When viewed from a thickness direction D1 of the mounting board 2, the outer periphery of the electronic component 7 is rectangular.

[0156] The low-noise amplifier has an input terminal and an output terminal. The low-noise amplifier amplifies a received signal input to the input terminal and outputs the amplified signal from the output terminal. The input terminal of the low-noise amplifier is connected to the common terminal of the switch via an input matching circuit. The output terminal of the low-noise amplifier is connected to a signal output terminal. Therefore, the output terminal of the low-noise amplifier is connected to the signal processing circuit 82 via the signal output terminal.

[0157] The switch has a common terminal and a plurality of selection terminals. The switch is controlled by a controller (not shown). The switch switches the connection state between the common terminal and the plurality of selection terminals in accordance with a control signal from the controller.

[0158] Examples of the switches included in the IC component include a first switch, a second switch, and a third switch.

[0159] The first switch is an antenna switch connected to an antenna terminal (not shown). The common terminal is connected to the antenna terminal. An antenna (not shown) is connected to the antenna terminal. The selection terminal is connected to, for example, a transmission filter (not shown) or a reception filter (not shown). The first switch is a switch capable of connecting at least one of a plurality of selection terminals to the common terminal. The first switch is, for example, a switch capable of one-to-one and one-to-many connection.

[0160] The second switch is, for example, a band select switch for switching signal paths for a plurality of transmission signals having different communication bands. The second switch has a common terminal and a plurality of selection terminals. The common terminal is connected to the power amplifier 3. The selection terminal is connected to the transmission filter. The second switch is a switch capable of connecting at least one of the plurality of selection terminals to the common terminal. The second switch is, for example, a switch capable of one-to-one and one-to-many connection.

[0161] The third switch has a common terminal and a plurality of selection terminals. The common terminal is connected to the low noise amplifier via an input matching circuit. The selection terminal is connected to the receiving filter. The third switch is a switch capable of connecting at least one of the plurality of selection terminals to the common terminal. The third switch is, for example, a switch capable of one-to-one and one-to-many connection.

[0162] (1.3) Layout of the mounting board, power amplifier, and electronic components 10, the mounting substrate 2 has a first recess 51, a plurality of second recesses 52, and a plurality of third recesses 53. The plurality of third recesses 53 are formed on the second main surface 22 of the mounting substrate 2. Each of the plurality of third recesses 53 has a bottom surface 531 and a side surface 532. Similar to the first recess 51 and the plurality of second recesses 52 of the first embodiment (see FIG. 1), the first recess 51 and the plurality of second recesses 52 are formed on the first main surface 21 of the mounting substrate 2.

[0163] The mounting substrate 2 has a first electrode 61, a plurality of second electrodes 62, and a plurality of third electrodes 69. The plurality of third electrodes 69 are arranged on bottom surfaces 531 of the plurality of third recesses 53. Similar to the first electrode 61 and the plurality of second electrodes 62 (see FIG. 1) of the first embodiment, the first electrode 61 is arranged on the bottom surface 511 of the first recess 51, and the plurality of second electrodes 62 are arranged on bottom surfaces 521 of the plurality of second recesses 52.

[0164] The multiple bumps 73 of the electronic component 7 are disposed in the multiple third recesses 53 of the mounting substrate 2. More specifically, for each of the multiple bumps 73, the bumps 73 are disposed in the third recesses 53 such that at least a portion of the bumps 73 is accommodated in the third recesses 53.

[0165] By arranging the multiple bumps 73 of the electronic component 7 in the multiple third recesses 53 of the mounting substrate 2, the height of the electronic component 7 from the surface of the second main surface 22 of the mounting substrate 2 on which the multiple third recesses 53 are not formed can be reduced, thereby making it possible to reduce the height of the high-frequency module 1.

[0166] In the mounting board 2 of the seventh embodiment, at least one of the multiple third recesses 53 overlaps with the second recess 52 in plan view from the thickness direction D1 of the mounting board 2. In the example of Fig. 10, the central third recess 53 of the three third recesses 53 overlaps with the left second recess 52 of the two second recesses 52 in plan view from the thickness direction D1 of the mounting board 2.

[0167] In the mounting board 2 of the seventh embodiment, at least one of the multiple third recesses 53 overlaps with the first recess 51 in plan view from the thickness direction D1 of the mounting board 2. In the example of Fig. 10, the rightmost third recess 53 of the three third recesses 53 overlaps with the first recess 51 in plan view from the thickness direction D1 of the mounting board 2.

[0168] (1.4) Resin layer 10, the resin layer 41 is disposed on the first main surface 21 of the mounting board 2. The resin layer 41 contacts the first main surface 21 of the mounting board 2 and covers at least a part of the power amplifier 3. This makes it possible to protect the mounting board 2 and the power amplifier 3.

[0169] The resin layer 41 includes a resin and a filler (not shown). The resin is, for example, an epoxy resin. In the high-frequency module 1, the distance L1 between the main body 31 of the power amplifier 3 and the mounting substrate 2 is larger than the diameter of the filler included in the resin layer 41. This allows the resin layer 41 to penetrate up to the periphery of the bumps (ground bumps 34, RF bumps 35) of the power amplifier 3, making it possible to prevent solder splash when the high-frequency module 1 is mounted on a motherboard. As a result, the connection reliability of the power amplifier 3 can be improved.

[0170] 10, the resin layer 42 is disposed on the second main surface 22 of the mounting board 2. The resin layer 42 covers at least a portion of each of the multiple electronic components (including the electronic component 7) disposed on the second main surface 22 of the mounting board 2. More specifically, the resin layer 42 covers the outer peripheral surface of each electronic component and the main surface of each electronic component on the side opposite to the mounting board 2 side. The resin layer 42 contains a resin. The resin is, for example, an epoxy resin. The resin layer 42 may contain a filler in addition to the resin. The material of the resin layer 42 may be the same as the material of the resin layer 41, or may be a different material.

[0171] 10, the resin layer 42 is disposed on the second main surface 22 of the mounting board 2. The resin layer 42 contacts the second main surface 22 of the mounting board 2 and covers at least a part of the electronic component 7. This makes it possible to protect the mounting board 2 and the electronic component 7.

[0172] The resin layer 42 includes a resin and a filler (not shown). The resin is, for example, an epoxy resin. In the high-frequency module 1, the distance L2 between the main body 71 of the electronic component 7 and the mounting substrate 2 is greater than the diameter of the filler included in the resin layer 42. This allows the resin layer 42 to penetrate up to the periphery of the bumps 73 of the electronic component 7, making it possible to prevent solder splash when the high-frequency module 1 is mounted on a motherboard. As a result, the connection reliability of the electronic component 7 can be improved.

[0173] (1.5) External connection terminal The multiple external connection terminals (not shown) are disposed, for example, on the second main surface 22 of the mounting substrate 2. The multiple external connection terminals are arranged on the second main surface 22 of the mounting substrate 2 at intervals from one another.

[0174] Each of the plurality of external connection terminals is a columnar (e.g., cylindrical) conductive member. The material of the plurality of external connection terminals is, for example, a metal (e.g., copper, copper alloy, etc.). The tip of each of the plurality of external connection terminals may include, for example, a gold plating layer.

[0175] (2) Effects In the high-frequency module 1 according to the seventh embodiment, the electronic components 7 are disposed on the second main surface 22 of the mounting board 2. This can increase the mounting efficiency of the high-frequency module 1.

[0176] In the high-frequency module 1 according to the seventh embodiment, the bumps 73 of the electronic component 7 are disposed in the third recesses 53 of the mounting substrate 2. As a result, recesses (the first recess 51, the second recess 52, the third recess 53) are formed on both the first main surface 21 side and the second main surface 22 side of the mounting substrate 2, and the bumps (the ground bumps 34, the RF bumps 35, the bumps 73 of the electronic component 7) are disposed in the recesses, thereby making it possible to further reduce the height of the high-frequency module 1.

[0177] In the high-frequency module 1 according to the seventh embodiment, the first recess 51, the second recess 52, and the third recess 53 are formed in the mounting substrate 2. This allows the distance between the RF bump 35 of the power amplifier 3 and the bump 73 of the electronic component 7 to be shorter than in the case where the first recess 51, the second recess 52, and the third recess 53 are not formed, and therefore the wiring length can be shortened. As a result, the wiring loss can be reduced.

[0178] In the high-frequency module 1 according to the seventh embodiment, the third recess 53 overlaps with the second recess 52 in the thickness direction D1 of the mounting substrate 2. This makes it possible to further shorten the distance between the RF bumps 35 of the power amplifier 3 and the bumps 73 of the electronic components 7. This makes it possible to further reduce the wiring loss.

[0179] In the high-frequency module 1 according to the seventh embodiment, the first recess 51, the second recess 52, and the third recess 53 are formed in the mounting board 2. As a result, the thickness of the mounting board 2 can be increased while maintaining the height of the high-frequency module 1, compared to a case in which the first recess 51, the second recess 52, and the third recess 53 are not formed in the mounting board 2, and therefore the strength of the mounting board 2 can be increased.

[0180] (3) Modifications A modification of the seventh embodiment will now be described.

[0181] (3.1) Variation 1 The high-frequency module 1 according to the first modification of the seventh embodiment includes a mounting substrate 2, a power amplifier 3, an electronic component 7, a plurality of resin layers 41, 42, a plurality of external connection terminals (not shown), and a shielding layer (not shown).

[0182] The shielding layer covers at least a portion of the resin layers 41 and 42 and the mounting board 2. More specifically, the shielding layer covers one main surface and outer peripheral surface of the resin layer 41, the outer peripheral surface of the mounting board 2, and the outer peripheral surface of the resin layer 42. One main surface of the resin layer 41 is the main surface of the resin layer 41 on the side opposite to the mounting board 2 side. Note that with regard to the shielding layer in Variation 1 of Embodiment 7, a description of the same configuration and function as the shielding layer in Variation 1 of Embodiment 1 will be omitted.

[0183] (3.2) Variation 2 In the high-frequency module 1 according to the second modification of the seventh embodiment, the electronic component 7 is not an IC component including a low-noise amplifier and a switch, but is a component other than an IC component. The electronic component 7 may be, for example, only a low-noise amplifier or only a switch.

[0184] The high-frequency modules 1 according to the above-described modifications also provide the same effects as those of the high-frequency module 1 according to the seventh preferred embodiment.

[0185] The above-described embodiment and modifications are merely a part of the various embodiments and modifications of the present invention. Furthermore, the embodiment and modifications can be modified in various ways depending on the design, etc., as long as the object of the present invention can be achieved.

[0186] (Aspect) The present specification discloses the following aspects.

[0187] A high-frequency module (1) according to a first aspect includes a mounting board (2) and a power amplifier (3). The mounting board (2) has a first main surface (21) and a second main surface (22). The first main surface (21) and the second main surface (22) face each other. The power amplifier (3) is disposed on the first main surface (21) of the mounting board (2) and has an RF bump (35) and a ground bump (34). The ground bump (34) is taller than the RF bump (35). The mounting board (2) has a first recess (51). The first recess (51) is formed on the first main surface (21) of the mounting board (2). The ground bump (34) is disposed in the first recess (51) of the mounting board (2).

[0188] According to the high-frequency module (1) of the first aspect, the high-frequency module (1) can be made low-profile.

[0189] According to the high-frequency module (1) of the first aspect, the distance between the power amplifier (3) and the wiring conductor or wiring element built into the mounting board (2) can be made shorter than in a case where the first recess (51) is not formed.

[0190] In the high-frequency module (1) according to the second aspect, in the first aspect, the mounting board (2) further has a second recess (52). The second recess (52) is formed in the first main surface (21) of the mounting board (2). The RF bumps (35) of the power amplifier (3) are disposed in the second recess (52) of the mounting board (2).

[0191] According to the high-frequency module (1) of the second aspect, the height of the power amplifier (3) from the surface of the first main surface (21) of the mounting board (2) on which the first recess (51) and the second recess (52) are not formed can be reduced, thereby making it possible to reduce the height of the high-frequency module (1).

[0192] According to the high-frequency module (1) of the second aspect, the distance between the power amplifier (3) and the wiring conductor or wiring element built into the mounting board (2) can be made shorter than in the case where the second recess (52) is not formed.

[0193] In the high-frequency module (1) according to the third aspect, in the second aspect, the first recess (51) and the second recess (52) are continuous with each other.

[0194] According to the high-frequency module (1) of the third aspect, since there is no need to form a wall between the first recess (51) and the second recess (52), the first recess (51) and the second recess (52) can be easily formed.

[0195] According to the high-frequency module (1) of the third aspect, even when the distance between two adjacent electrodes (32, 33) of the power amplifier (3) is short, that is, even when the distance between the ground bump (34) and the RF bump (35) is short, the first recess (51) and the second recess (52) can be formed.

[0196] In the high-frequency module (1) according to the fourth aspect, in the second aspect, the side surface (522) of the second recess (52) of the mounting board (2) is curved in a plan view in the thickness direction (D1) of the mounting board (2).

[0197] According to the high-frequency module (1) of the fourth aspect, the shape of the second recess (52) can be made close to the shape of the RF bump (35), so that when the power amplifier (3) is arranged on the mounting board (2), the amount of self-alignment of the solder can be suppressed within the range of the second recess (52). As a result, the mountability of the power amplifier (3) on the mounting board (2) can be improved. In other words, the mounting variation of the power amplifier (3) can be reduced.

[0198] In the high-frequency module (1) according to the fifth aspect, in the second aspect, the mounting board (2) has a wiring pattern conductor (68). The wiring pattern conductor (68) is formed in at least one of the first recess (51) and the second recess (52).

[0199] According to the high-frequency module (1) of the fifth aspect, the degree of freedom in wiring can be increased.

[0200] In the high-frequency module (1) according to the sixth aspect, in the second aspect, the mounting board (2) has a side electrode (63). The side electrode (63) is formed on a side surface (522) of the second recess (52).

[0201] According to the high-frequency module (1) of the sixth aspect, the contact area between the RF bumps (35) of the power amplifier (3) and the electrodes in the second recesses (52) can be increased, thereby increasing the bonding strength between the RF bumps (35) of the power amplifier (3) and the electrodes in the second recesses (52). As a result, the mountability of the power amplifier (3) on the mounting board (2) can be improved.

[0202] According to the high-frequency module (1) of the sixth aspect, the wiring can be extended from the side surface (522) of the second recess (52), thereby increasing the degree of freedom in wiring.

[0203] In the high-frequency module (1) according to the seventh aspect, in the first aspect, the RF bumps (35) of the power amplifier (3) are arranged on a portion of the first main surface (21) of the mounting substrate (2) where no recess is formed.

[0204] According to the high-frequency module (1) of the seventh aspect, the process of forming the recess in the mounting board (2) can be simplified.

[0205] In the high-frequency module (1) according to an eighth aspect, in any one of the first to seventh aspects, the mounting board (2) has a via conductor (66). The via conductor (66) is connected to the first recess (51) in which the ground bump (34) is disposed.

[0206] According to the high-frequency module (1) of the eighth aspect, the length of the via conductor (66) can be made shorter than when the first recess (51) is not formed, and therefore, for example, the distance between the ground bump (34) and the ground layer (64) of the mounting board (2) can be made shorter.

[0207] In the high-frequency module (1) according to the ninth aspect, in any one of the first to eighth aspects, the side surface (512) of the first recess (51) of the mounting board (2) is curved in a plan view in the thickness direction (D1) of the mounting board (2).

[0208] According to the high-frequency module (1) of the ninth aspect, the shape of the first recess (51) can be made close to the shape of the ground bump (34), so that when the power amplifier (3) is arranged on the mounting board (2), the amount of self-alignment of the solder can be suppressed within the range of the first recess (51). As a result, the mountability of the power amplifier (3) on the mounting board (2) can be improved. In other words, the mounting variation of the power amplifier (3) can be reduced.

[0209] In a high-frequency module (1) according to a tenth aspect, in any one of the first to ninth aspects, the mounting board (2) has a side electrode (63). The side electrode (63) is formed on a side surface (512) of the first recess (51).

[0210] According to the high-frequency module (1) of the tenth aspect, the contact area between the ground bumps (34) of the power amplifier (3) and the electrodes in the first recesses (51) can be increased, thereby increasing the bonding strength between the ground bumps (34) and the electrodes in the first recesses (51). As a result, the mountability of the power amplifier (3) on the mounting board (2) can be improved.

[0211] According to the high-frequency module (1) of the tenth aspect, the wiring can be extended from the side surface (512) of the first recess (51), thereby increasing the degree of freedom in wiring.

[0212] The high-frequency module (1) according to an eleventh aspect is any one of the third to tenth aspects, further including an electronic component (7). The electronic component (7) is disposed on the second main surface (22) of the mounting board (2) and has bumps (73).

[0213] According to the high-frequency module (1) of the eleventh aspect, the mounting efficiency of the high-frequency module (1) can be improved.

[0214] In a high-frequency module (1) according to a twelfth aspect, in the eleventh aspect, the mounting board (2) further has a third recess (53). The third recess (53) is formed in the second main surface (22). The bumps (73) of the electronic component (7) are disposed in the third recess (53) of the mounting board (2).

[0215] According to the high-frequency module (1) of the twelfth aspect, recesses (first recess 51, second recess 52, third recess 53) are formed on both the first main surface (21) and the second main surface (22) of the mounting substrate (2), and bumps (ground bump 34, RF bump 35, bump 73 of electronic component 7) are arranged in the recesses, thereby further reducing the height of the high-frequency module (1).

[0216] According to the high-frequency module (1) of the twelfth aspect, the distance between the RF bumps (35) of the power amplifier (3) and the bumps (73) of the electronic components (7) can be made shorter than in the case where the first recess (51), the second recess (52), and the third recess (53) are not formed, and therefore the wiring length can be made shorter. As a result, the wiring loss can be reduced.

[0217] In a high-frequency module (1) according to a thirteenth aspect, in the twelfth aspect, the mounting board (2) further includes a second recess (52). The second recess (52) is formed on a first main surface (21) of the mounting board (2). The RF bumps (35) of the power amplifier (3) are disposed in the second recess (52) of the mounting board (2). The third recess (53) of the mounting board (2) overlaps with the second recess (52) of the mounting board (2) in a plan view in a thickness direction (D1) of the mounting board (2).

[0218] According to the high-frequency module (1) of the thirteenth aspect, the distance between the RF bumps (35) of the power amplifier (3) and the bumps (73) of the electronic components (7) can be further shortened, thereby further reducing the wiring loss.

[0219] The high-frequency module (1) according to a fourteenth aspect is the same as any one of the first to thirteenth aspects, and further includes a resin layer (41). The resin layer (41) is in contact with the first main surface (21) of the mounting board (2) and covers at least a part of the power amplifier (3).

[0220] According to the high-frequency module (1) of the fourteenth aspect, the mounting board (2) and the power amplifier (3) can be protected.

[0221] In the high-frequency module (1) according to the fifteenth aspect, in the fourteenth aspect, the resin layer (41) contains a filler. A distance (L1) between the power amplifier (3) and the mounting board (2) is greater than a diameter of the filler contained in the resin layer (41).

[0222] According to the high-frequency module (1) of the fifteenth aspect, the resin layer (41) penetrates into the periphery of the bumps of the power amplifier (3), so that it is possible to prevent solder splash when mounting the high-frequency module (1) on a motherboard, thereby improving the connection reliability of the power amplifier (3).

[0223] In the high-frequency module (1) according to a sixteenth aspect, in the fourteenth aspect, the resin layer (41) contains a filler. A distance (L1) between the power amplifier (3) and the mounting board (2) is smaller than a diameter of the filler contained in the resin layer (41).

[0224] According to the high-frequency module (1) of the sixteenth aspect, the height of the high-frequency module (1) can be further reduced.

[0225] The high-frequency module (1) according to a seventeenth aspect is the same as any one of the fourteenth to sixteenth aspects, and further includes a shielding layer. The shielding layer covers the resin layer (41) and at least a part of the mounting board (2). The mounting board (2) has a ground layer (64). The shielding layer is in contact with at least a part of the ground layer (64).

[0226] In the high-frequency module (1) according to the seventeenth aspect, the potential of the shield layer can be made the same as the potential of the ground layer (64).

[0227] In the high-frequency module (1) according to an eighteenth aspect, in any one of the first to seventeenth aspects, the power amplifier (3) further includes a main body (31) including a functional part. The main body (31) of the power amplifier (3) is located outside the mounting board (2).

[0228] According to the high-frequency module (1) of the eighteenth aspect, the strength of the mounting board (2) can be increased compared to a case in which a recess for accommodating the main body (31) of the power amplifier (3) is formed in the mounting board (2).

[0229] A communication device (8) according to a nineteenth aspect includes the high-frequency module (1) according to any one of the first to eighteenth aspects, and a signal processing circuit (82). The signal processing circuit (82) is connected to the high-frequency module (1).

[0230] According to the communication device (8) of the nineteenth aspect, the high-frequency module (1) can be made low-profile. [Explanation of symbols]

[0231] 1 High frequency module 2. Mounting Board 21 First main surface 22 Second main surface 23 Dielectric layer 3. Power Amplifier 31 Main body 311 First Main Surface 32,33 electrode 34 Grand Bump 35 RF Bump 41,42 Resin layer 51 First recess 511 Bottom 512 Side 52 Second recess 521 Bottom 522 Side 53 Third recess 531 Bottom 532 Side 61 1st electrode 62 2nd electrode 63 Side electrode 64 Ground Layer 65,671,672,68 Wiring pattern conductor 66 Via conductor 69 3rd electrode 7. Electronic Components 71 Main body 711 First Main Surface 72 electrode 73 Bump 8. Communications Equipment 81 Antenna 82 Signal Processing Circuit 83 Baseband signal processing circuit 84 RF signal processing circuit L1,L2 distance D1 Thickness direction D21 1st direction D22 2nd direction

Claims

1. a mounting substrate having a first main surface and a second main surface opposed to each other; a power amplifier disposed on the first main surface of the mounting substrate, the power amplifier having an RF bump and a ground bump that is higher than the RF bump; the mounting substrate has a first recess formed in the first main surface of the mounting substrate, the ground bump is disposed in the first recess of the mounting substrate; High frequency module.

2. the mounting substrate further includes a second recess formed on the first main surface of the mounting substrate, the RF bump of the power amplifier is disposed in the second recess of the mounting substrate; The high frequency module according to claim 1 .

3. The first recess and the second recess are continuous. The high frequency module according to claim 2 .

4. a side surface of the second recess of the mounting substrate is a curved surface when viewed in a thickness direction of the mounting substrate; The high frequency module according to claim 2 .

5. the mounting board has a wiring pattern conductor formed in at least one of the first recess and the second recess; The high frequency module according to claim 2 .

6. the mounting substrate has a side electrode formed on a side surface of the second recess; The high frequency module according to claim 2 .

7. the RF bumps of the power amplifier are disposed on a portion of the first main surface of the mounting substrate where no recess is formed; The high frequency module according to claim 1 .

8. the mounting board has a via conductor connected to the first recess in which the ground bump is disposed; The high frequency module according to any one of claims 1 to 7.

9. a side surface of the first recess of the mounting substrate is a curved surface when viewed in a thickness direction of the mounting substrate; The high frequency module according to any one of claims 1 to 7.

10. the mounting substrate has a side electrode formed on a side surface of the first recess; The high frequency module according to any one of claims 1 to 7.

11. an electronic component disposed on the second main surface of the mounting substrate and having a bump; The high frequency module according to any one of claims 3 to 7.

12. the mounting substrate further has a third recess formed in the second main surface, the bump of the electronic component is disposed in the third recess of the mounting substrate; The high frequency module according to claim 11.

13. the mounting substrate further includes a second recess formed on the first main surface of the mounting substrate, the RF bump of the power amplifier is disposed in the second recess of the mounting substrate, the third recess of the mounting substrate overlaps with the second recess of the mounting substrate in a plan view in a thickness direction of the mounting substrate; The high frequency module according to claim 12.

14. a resin layer in contact with the first main surface of the mounting substrate and covering at least a portion of the power amplifier; The high frequency module according to any one of claims 1 to 7.

15. The resin layer contains a filler, a distance between the power amplifier and the mounting substrate is greater than a diameter of the filler contained in the resin layer; The high frequency module according to claim 14.

16. The resin layer contains a filler, a distance between the power amplifier and the mounting substrate is smaller than a diameter of the filler contained in the resin layer; The high frequency module according to claim 14.

17. a shielding layer covering the resin layer and at least a portion of the mounting substrate; the mounting board has a ground layer; The shield layer is in contact with at least a portion of the ground layer. The high frequency module according to claim 14.

18. The power amplifier further includes a main body including a functional unit, The main body of the power amplifier is located outside the mounting substrate. The high frequency module according to any one of claims 1 to 7.

19. A high-frequency module according to any one of claims 1 to 7, A signal processing circuit connected to the high-frequency module. Communications equipment.

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