High-frequency module

Abstract

A high-frequency module (1) comprises a mounting substrate (90) having mutually opposing main surfaces (90a and 90b) and including a plurality of layers, amplifiers (10 and 20) disposed in the mounting substrate (90), and a transformer (30) including a primary coil (31) and a secondary coil (32) formed in the mounting substrate (90), wherein: the amplifier (10) includes a ground terminal (104); the mounting substrate (90) includes a via conductor (91) that extends in a direction perpendicular to the main surface (90a), overlaps the amplifier (10) in a plan view of the main surface (90a), and is connected to a ground terminal (104); one end (311) of the primary coil (31) is connected to a signal output terminal (102) of the amplifier (10); the secondary coil (32) is connected to the amplifier (20); and the other end (312) of the primary coil (31) is connected to the ground terminal (104) or the via conductor (91) in the layer of the mounting substrate (90) in which the primary coil (31) is formed.

Description

High-frequency module

[0001] The present invention relates to a high-frequency module.

[0002] Patent Document 1 discloses a high-frequency module including a front-stage amplifying element and a rear-stage amplifying element, a transformer connected between the front-stage amplifying element and the rear-stage amplifying element and having a primary coil and a secondary coil, and a mounting board on which the front-stage amplifying element, the rear-stage amplifying element, and the transformer are mounted.

[0003] Japanese Patent Application Laid-Open No. 2021-145290

[0004] In the high-frequency module disclosed in Patent Document 1, for example, if the ground path connecting the ground terminal of the transformer and the ground terminal of the pre-stage amplifying element or the post-stage amplifying element becomes long, the transmission loss of the transformer increases due to an unnecessary magnetic field generated by a current loop in the ground path.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a low-loss high-frequency module in which the transmission loss in the transformer is reduced.

[0006] In order to achieve the above object, a high-frequency module according to one aspect of the present invention includes a mounting board having first and second main surfaces facing each other and including a plurality of layers, a first amplifier and a second amplifier arranged on the mounting board, and a transformer including a primary coil and a secondary coil formed on the mounting board, wherein the first amplifier includes a first ground terminal, the mounting board includes a first via conductor that extends in a direction perpendicular to the first main surface, overlaps with the first amplifier when the first main surface is viewed in a plane, and is connected to the first ground terminal, one end of the primary coil is connected to a first output terminal of the first amplifier, one end of the secondary coil is connected to a first input terminal of the second amplifier, and the other end of the secondary coil is connected to the first ground terminal or the first via conductor in the layer of the mounting board on which the primary coil is formed.

[0007] According to the present invention, it is possible to provide a low-loss high-frequency module in which the transmission loss in the transformer is reduced.

[0008] FIG. 1 is a circuit configuration diagram of a radio frequency module according to an embodiment. FIG. 2A is a perspective view of the radio frequency module according to the embodiment. FIG. 2B is a plan view of the radio frequency module according to the embodiment. FIG. 2C is a cross-sectional view of the radio frequency module according to the embodiment. FIG. 3A is a plan view of a radio frequency module according to a comparative example. FIG. 3B is a cross-sectional view of the radio frequency module according to the comparative example. FIG. 4A is a perspective view of a radio frequency module according to a first modification of the embodiment. FIG. 4B is a plan view of the radio frequency module according to the first modification of the embodiment. FIG. 4C is a cross-sectional view of the radio frequency module according to the first modification of the embodiment. FIG. 5A is a plan view of a radio frequency module according to a second modification of the embodiment. FIG. 5B is a plan view of a radio frequency module according to a third modification of the embodiment. FIG. 5C is a plan view of a radio frequency module according to a fourth modification of the embodiment. FIG. 5D is a plan view of a radio frequency module according to a fifth modification of the embodiment. FIG. 6A is a perspective view of a radio frequency module according to a sixth modification of the embodiment. FIG. 6B is a plan view of a radio frequency module according to the sixth modification of the embodiment. FIG. 6C is a cross-sectional view of the radio frequency module according to the sixth modification of the embodiment.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangements and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention.

[0010] It should be noted that the drawings are schematic diagrams in which emphasis, omission, or adjustment of proportions has been appropriately made to illustrate the present invention, and are not necessarily strictly illustrated, and may differ from the actual shapes, positional relationships, and proportions. In the drawings, the same reference numerals are used to denote substantially the same components, and redundant explanations may be omitted or simplified.

[0011] In the following figures, the x-axis and y-axis are axes that are orthogonal to each other on a plane parallel to the main surface of the mounting substrate. Specifically, when the mounting substrate has a rectangular shape in a plan view, the x-axis is parallel to a first side of the mounting substrate, and the y-axis is parallel to a second side that is orthogonal to the first side of the mounting substrate. The z-axis is an axis perpendicular to the main surface of the mounting substrate, with its positive direction indicating the upward direction and its negative direction indicating the downward direction.

[0012] In the component placement of the present disclosure, "a component is placed on a substrate" includes a component being placed on the main surface of the substrate and a component being placed within the substrate. "A component is placed on the main surface of the substrate" includes a component being placed in contact with the main surface of the substrate, as well as a component being placed above the main surface without contacting the main surface (for example, a component being stacked on another component placed in contact with the main surface). "A component is placed on the main surface of the substrate" may also include a component being placed in a recess formed in the main surface. "A component is placed within the substrate" includes a component being encapsulated within a module substrate, as well as a component being entirely placed between both main surfaces of the substrate but partially not covered by the substrate, and a component being only partially placed within the substrate.

[0013] In the component placement of the present invention, "planar view of the main surface" means viewing an object by orthogonally projecting it onto the xy plane from the positive side of the z axis. "A overlaps with B in planar view" means that at least a portion of the area of ​​A orthogonally projected onto the xy plane overlaps with at least a portion of the area of ​​B orthogonally projected onto the xy plane. "A is placed between B and C" means that at least one of multiple line segments connecting any point in B with any point in C passes through A. "A is joined to B" means that A is physically connected to B.

[0014] In the circuit configuration of the present disclosure, "connected" includes not only direct connection by connection terminals and / or wiring conductors, but also electrical connection via other circuit elements. "Connected between A and B" means connected to both A and B between A and B.

[0015] In addition, in this disclosure, a "path" means a transmission line composed of a wiring through which a high-frequency signal propagates, an electrode directly connected to the wiring, and a terminal directly connected to the wiring or the electrode.

[0016] In this disclosure, the terms "terminal," "input end," and "output end" refer to the point where a conductor within an element terminates. Note that a terminal is interpreted as any point on the conductor between elements or the entire conductor, not just a single point, provided that the impedance of the conductor between elements is sufficiently low.

[0017] Furthermore, terms indicating the relationship between elements, such as "parallel" and "perpendicular," terms indicating the shape of elements, such as "rectangle," and numerical ranges do not only represent strict meanings, but also include substantially equivalent ranges, for example, including an error of a few percent.

[0018] In addition, in this disclosure, a transformer is defined as follows: A transformer is composed of an input coil and an output coil. The output coil is defined as a wiring conductor provided along the input coil and arranged in a section where a first distance from the input coil is equal to or less than a predetermined value.

[0019] 1 is a circuit diagram of a radio frequency module 1 according to an embodiment. As shown in the figure, the radio frequency module 1 includes amplifiers 10 and 20, transformers 30 and 40, a matching circuit 57, and a signal output terminal 110.

[0020] The amplifier 10 is an example of a first amplifier and is arranged in a stage preceding the transformer 30. The amplifier 10 includes an amplifying transistor 11, matching circuits 51 and 52, a signal input terminal 101, a signal output terminal 102 (first output terminal), a power supply terminal 103, and a ground terminal 104 (first ground terminal).

[0021] The amplifier transistor 11 is an example of a first amplifier transistor, and is, for example, a field effect transistor (FET) using a Si-based CMOS (Complementary Metal Oxide Semiconductor) and SOI (Silicon On Insulator) structure, with its gate connected to a signal input terminal 101 via a matching circuit 51, its drain connected to a power supply terminal 103, and its source connected to a signal output terminal 102 via a matching circuit 52, and its source connected to a ground terminal 104. At least one of an inductor and a capacitor may be connected between the drain of the amplifier transistor 11 and the power supply terminal 103 and / or between the source of the amplifier transistor 11 and the ground terminal 104.

[0022] The amplifier 10 amplifies an unbalanced signal input from a signal input terminal 101 and outputs the unbalanced signal from a signal output terminal 102 .

[0023] The amplifier 20 is an example of a second amplifier and is arranged after the transformer 30. The amplifier 20 includes amplifying transistors 21 and 22, matching circuits 53, 54, 55, and 56, signal input terminals 201 (first input terminal) and 202 (second input terminal), signal output terminals 203 and 204, and ground terminals 207 and 208.

[0024] The amplifier transistors 21 and 22 are examples of the second amplifier transistor and the third amplifier transistor, respectively, and are, for example, GaAs-based heterojunction bipolar transistors (HBTs). The base of the amplifier transistor 21 is connected to a signal input terminal 201 via a matching circuit 53, the collector is connected to a signal output terminal 203 via a matching circuit 55, and the emitter is connected to a ground terminal 208. The base of the amplifier transistor 22 is connected to a signal input terminal 202 via a matching circuit 54, the collector is connected to a signal output terminal 204 via a matching circuit 56, and the emitter is connected to a ground terminal 207. At least one of an inductor and a capacitor may be connected between the emitter of the amplifier transistor 21 and the ground terminal 208. At least one of an inductor and a capacitor may be connected between the emitter of the amplifier transistor 22 and the ground terminal 207.

[0025] The amplifier 20 amplifies the balanced signals input from the signal input terminals 201 and 202 and outputs the balanced signals from the signal output terminals 203 and 204 .

[0026] The transformer 30 includes a primary coil 31 and a secondary coil 32. The primary coil 31 is connected to the output end of the amplifier 10, and the secondary coil 32 is connected to the input end of the amplifier 20. More specifically, one end 311 of the primary coil 31 is connected to the signal output terminal 102 of the amplifier 10, and the other end 312 of the primary coil 31 is connected to ground. One end 321 of the secondary coil 32 is connected to the signal input terminal 201 of the amplifier 20, and the other end 322 of the secondary coil 32 is connected to the signal input terminal 202 of the amplifier 20.

[0027] The transformer 30 converts an unbalanced signal input from one end 311 of the primary coil 31 into a balanced signal and outputs it from one end 321 and the other end 322 of the secondary coil 32 .

[0028] The transformer 40 includes a primary coil 41 and a secondary coil 42. One end 411 of the primary coil 41 is connected to the signal output terminal 203 of the amplifier 20, and the other end 412 of the primary coil 41 is connected to the signal output terminal 204 of the amplifier 20. One end 421 of the secondary coil 42 is connected to the signal output terminal 110 via the matching circuit 57, and the other end 422 of the secondary coil 42 is connected to ground.

[0029] The transformer 40 converts a balanced signal input from one end 411 and the other end 412 of the primary coil 41 into an unbalanced signal and outputs it from one end 421 of the secondary coil 42 .

[0030] According to the above configuration, the high-frequency module 1 can be configured as a hybrid amplifier circuit in which the amplifier 10 arranged in the front stage is composed of Si-based transistors and the amplifier 20 arranged in the rear stage is composed of GaAs-based transistors.

[0031] The amplifier 10 does not have to be configured with Si-based transistors, and the amplifier 20 does not have to be configured with GaAs-based transistors. The amplifier 20 may be a differential amplifier, a balanced amplifier, or a Doherty amplifier, or may be an unbalanced signal input / unbalanced signal output amplifier having only one amplifying transistor.

[0032] [2 Component Arrangement of High-Frequency Module 1] Fig. 2A is a perspective view of the high-frequency module 1 according to the embodiment. Fig. 2B is a plan view of the high-frequency module 1 according to the embodiment. Fig. 2C is a cross-sectional view of the high-frequency module 1 according to the embodiment. Fig. 2B shows the arrangement of circuit components when the main surface 90a of the mounting substrate 90 is seen through from the positive z-axis direction. Fig. 2C is a cross-sectional view taken along line IIC-IIC in Figs. 2A and 2B.

[0033] As shown in FIGS. 2A to 2C, the high-frequency module 1 further includes a mounting substrate 90 in addition to the circuit configuration shown in FIG.

[0034] The mounting substrate 90 has opposing main surfaces 90a (first main surface) and 90b (second main surface) and includes multiple layers. Examples of the mounting substrate 90 include a low temperature co-fired ceramics (LTCC) substrate having a laminated structure of multiple dielectric layers, a high temperature co-fired ceramics (HTCC) substrate, a component-embedded substrate, a substrate having a redistribution layer (RDL), a printed circuit board, and the like.

[0035] The amplifier 10 is included in the semiconductor IC 61 and is disposed on the main surface 90a. The amplifier 20 is included in the semiconductor IC 62 and is disposed on the main surface 90a.

[0036] The semiconductor IC 61 is made of, for example, a Si-based CMOS and is formed by an SOI process. This allows the semiconductor IC 61 to be manufactured inexpensively. On the other hand, the semiconductor IC 62 is made of, for example, GaAs. This allows it to have high-quality amplification performance. The semiconductor IC 61 has opposing main surfaces 61a (fourth main surface) and 61b (third main surface). The semiconductor IC 62 has opposing main surfaces 62a (sixth main surface) and 62b (fifth main surface).

[0037] The primary coil 31 and secondary coil 32 that constitute the transformer 30 are formed on a mounting substrate 90. The primary coil 31 is formed, for example, on a second layer of the mounting substrate 90, and the secondary coil 32 is formed, for example, on a third layer of the mounting substrate 90. When the main surface 90a is viewed in plan, the secondary coil 32 is disposed along the primary coil 31.

[0038] 2C , in the present embodiment, the transformer 30 is disposed between the semiconductor IC 61 and the semiconductor IC 62 in the plan view. This allows the wiring connecting the amplifier 10 and the primary coil 31 and the wiring connecting the amplifier 20 and the secondary coil 32 to be shortened, thereby reducing the transmission loss of the high-frequency module 1.

[0039] Each of the primary coil 31 and the secondary coil 32 does not have to be arranged on only a single layer of the mounting substrate 90, but may be arranged across multiple layers. Furthermore, each of the primary coil 31 and the secondary coil 32 does not have to be a circular planar coil (with a portion interrupted) in the above-mentioned planar view as shown in Figures 2A and 2B, but may be a meandering, spiral, or linear coil.

[0040] Although not shown in FIGS. 2A to 2C, the matching circuits 51 to 57 and the transformer 40 that configure the high-frequency module 1 may be disposed either on the main surface of the mounting substrate 90 or inside the mounting substrate 90.

[0041] As shown in FIG. 2C, the ground terminal 104 (first ground terminal) is disposed on the outer surface (main surface 61 b ​​) of the semiconductor IC 61 .

[0042] As shown in Figures 2A and 2C, the mounting substrate 90 includes a via conductor 91 and a ground plane electrode 100. The via conductor 91 is an example of a first via conductor, extends perpendicular to the main surface 90a, overlaps with the amplifier 10 when the main surface 90a is viewed in plan, and is connected to a ground terminal 104. The ground plane electrode 100 is an example of a first ground plane electrode, and is disposed on the main surface 90b. The ground plane electrode 100 is a reference ground for the high-frequency module 1. When the high-frequency module 1 is mounted on a motherboard, the ground plane electrode 100 is directly connected to, for example, a ground electrode (or ground terminal) of the motherboard. As shown in Figure 2C, one end of the via conductor 91 is joined to the ground terminal 104, and the other end of the via conductor 91 is joined to the ground plane electrode 100.

[0043] 2B and 2C , the other end 312 of the primary coil 31 is connected to a via conductor 91 through a wiring 92 formed on the layer of the mounting substrate 90 on which the primary coil 31 is formed. In other words, the other end 312 of the primary coil 31 is connected to the via conductor 91 without going through the ground plane electrode 100.

[0044] According to the above arrangement, it is possible to provide a low-loss high-frequency module 1 in which the transmission loss in the transformer 30 is reduced.

[0045] Here, to explain that the transmission loss of the transformer 30 of the high-frequency module 1 can be reduced, a high-frequency module 500 according to a comparative example will be exemplified.

[0046] Fig. 3A is a plan view of a high-frequency module 500 according to a comparative example. Fig. 3B is a cross-sectional view of the high-frequency module 500 according to the comparative example. Fig. 3A shows the layout of circuit components when the main surface 90a of the mounting substrate 90 is seen through from the positive z-axis direction. Fig. 3B is a cross-sectional view taken along line IIIB-IIIB in Fig. 3A.

[0047] The high-frequency module 500 according to the comparative example includes amplifiers 10 and 20, transformers 530 and 40, a matching circuit 57, and a signal output terminal 110. The high-frequency module 500 according to the comparative example differs from the high-frequency module 1 according to the embodiment in that a transformer 530 is provided instead of the transformer 30, and in the connection configuration between the transformer 530 and the amplifier 10. Therefore, the following description of the high-frequency module 500 according to the comparative example will omit a description of the same configuration as the high-frequency module 1 according to the embodiment, and will focus on the different configuration.

[0048] The transformer 530 includes a primary coil 531 and a secondary coil 532. The primary coil 531 is connected to the output end side of the amplifier 10, and the secondary coil 532 is connected to the input end side of the amplifier 20. More specifically, one end of the primary coil 531 is connected to the signal output terminal 102 of the amplifier 10, and the other end of the primary coil 531 is connected to the ground. One end of the secondary coil 532 is connected to the signal input terminal 201 of the amplifier 20, and the other end of the secondary coil 532 is connected to the signal input terminal 202 of the amplifier 20.

[0049] 3A and 3B , the primary coil 531 and the secondary coil 532 are formed on the mounting substrate 90. The primary coil 531 is formed, for example, on the second layer of the mounting substrate 90, and the secondary coil 532 is formed, for example, on the third layer of the mounting substrate 90. When the main surface 90a is viewed from above, the secondary coil 532 is disposed along the primary coil 531.

[0050] 3A and 3B , the other end of the primary coil 531 is connected to a via conductor 93 through a connection point 533 on the layer of the mounting substrate 90 on which the primary coil 531 is formed. One end of the via conductor 93 is joined to the connection point 533, and the other end of the via conductor 93 is connected to the ground plane electrode 100 arranged on the main surface 90 b. In other words, the other end of the primary coil 531 is connected to the via conductor 91 through the via conductor 93 and the ground plane electrode 100.

[0051] According to the above-described configuration of the high-frequency module 500 of the comparative example, the ground terminal 104 of the amplifier 10 and the other end of the primary coil 531 of the transformer 530 are independently connected to the plane ground electrode 100. This results in a long ground path connecting the other end of the primary coil 531 of the transformer 530, the via conductor 93, the plane ground electrode 100, the via conductor 91, and the ground terminal 104. Due to the influence of this long ground path and the large current generated in the amplifier 10, an unnecessary magnetic field is generated by a large current loop IG flowing through the ground path, and the transmission efficiency of the transformer 530 is reduced.

[0052] In contrast, in the high-frequency module 1 according to this embodiment, as shown in FIG. 2C , the other end 312 of the primary coil 31 of the transformer 30 is connected to the via conductor 91 through the wiring 92 formed on the layer on which the primary coil 31 is disposed. In other words, the ground terminal 104 of the amplifier 10 and the other end 312 of the primary coil 31 are connected without the ground plane electrode 100. Furthermore, because the via conductor 91 is disposed so as to overlap the amplifier 10 in the planar view, the wiring 92 can be shortened. This shortens the ground path connecting the other end 312 of the primary coil 31, the wiring 92, the via conductor 91, and the ground terminal 104. This suppresses unnecessary magnetic fields generated by current loops flowing through the ground path, thereby preventing a decrease in the transmission efficiency of the transformer 30. Therefore, a low-loss high-frequency module 1 can be provided, in which the transmission loss in the transformer 30 is reduced.

[0053] In the high-frequency module 1 according to this embodiment, when the primary coil 31 is formed on the outermost layer (e.g., the main surface 90a) of the mounting substrate 90, the other end 312 of the primary coil 31 may be directly connected to the ground terminal 104 via wiring formed on the outermost layer of the mounting substrate 90 on which the primary coil 31 is formed. In other words, the other end 312 of the primary coil 31 may be connected to the ground terminal 104 without going through the ground plane electrode 100 and the via conductor 91. This shortens the ground path, thereby further suppressing unnecessary magnetic fields generated by current loops flowing through the ground path.

[0054] In addition, in the high-frequency module 1 according to this embodiment, it is desirable that the distance between the layer of the mounting substrate 90 on which the primary coil 31 is formed and the main surface 90a is smaller than the distance between that layer and the main surface 90b.

[0055] This allows the via conductor 91 portion of the ground path formed by the other end 312 of the primary coil 31, the wiring 92, the via conductor 91, and the ground terminal 104 to be shorter, thereby further suppressing unnecessary magnetic fields generated by the current loop flowing in the ground path.

[0056] [3 Component Arrangement of High-Frequency Module 1A According to Modification 1] Fig. 4A is a perspective view of a high-frequency module 1A according to Modification 1 of the embodiment. Fig. 4B is a plan view of the high-frequency module 1A according to Modification 1 of the embodiment. Fig. 4C is a cross-sectional view of the high-frequency module 1A according to Modification 1 of the embodiment. Fig. 4B shows the arrangement of circuit components when the main surface 90a of the mounting board 90 is seen through from the positive z-axis direction. Fig. 4C is a cross-sectional view taken along line IVC-IVC in Figs. 4A and 4B.

[0057] The high-frequency module 1A according to this modification is different from the high-frequency module 1 according to the embodiment in the arrangement and configuration of the transformer 30. Therefore, in the following, the high-frequency module 1A according to this modification will be described mainly with reference to the different configurations, and a description of the same configurations as those of the high-frequency module 1 according to the embodiment will be omitted.

[0058] The primary coil 31 and secondary coil 32 that constitute the transformer 30 are formed on a mounting substrate 90. The primary coil 31 is formed, for example, on a second layer of the mounting substrate 90, and the secondary coil 32 is formed, for example, on a third layer of the mounting substrate 90. When the main surface 90a is viewed in plan, the secondary coil 32 is disposed along the primary coil 31.

[0059] 4A to 4C, in this modification, the transformer 30 at least partially overlaps the semiconductor IC 61 in the plan view. This allows the wiring connecting the amplifier 10 and the primary coil 31 to be further shortened, thereby reducing the transmission loss of the high-frequency module 1A.

[0060] Furthermore, the other end 312 of the primary coil 31 is connected to the via conductor 94 in the layer of the mounting substrate 90 on which the primary coil 31 is formed. In other words, the other end 312 of the primary coil 31 is connected to the via conductor 94 without going through the ground plane electrode 100. Note that in the high-frequency module 1A according to this modification, the transformer 30 and the semiconductor IC 61 overlap each other, so that the wiring connecting the other end 312 of the primary coil 31 and the via conductor 94 (corresponding to the wiring 92 in the embodiment) can be shortened.

[0061] This shortens the ground path, thereby further suppressing the unwanted magnetic field generated by the current loop flowing through the ground path, thereby further suppressing the decrease in the transmission efficiency of the transformer 30 and providing a low-loss high-frequency module 1A with reduced transmission loss in the transformer 30.

[0062] [4 Component Arrangement of Radio-Frequency Modules 1B to 1E According to Modifications 2 to 5] Fig. 5A is a plan view of a radio-frequency module 1B according to Modification 2 of the embodiment. Fig. 5B is a plan view of a radio-frequency module 1C according to Modification 3 of the embodiment. Fig. 5C is a plan view of a radio-frequency module 1D according to Modification 4 of the embodiment. Fig. 5D is a plan view of a radio-frequency module 1E according to Modification 5 of the embodiment. Note that Figs. 5A to 5D show the arrangement of circuit components when the main surface 90a of the mounting board 90 is seen through from the positive z-axis direction.

[0063] The radio frequency modules 1B to 1E according to the modified examples differ from the radio frequency module 1 according to the embodiment in the terminal arrangement configuration of the semiconductor ICs 61 and 62. Therefore, in the following, for the radio frequency modules 1B to 1E according to the modified examples, a description of the same configuration as the radio frequency module 1 according to the embodiment will be omitted, and the description will focus on the different terminal arrangement configuration.

[0064] In each of the high-frequency modules 1B to 1E, the semiconductor IC 61 has main surfaces 61a (fourth main surface) and 61b (third main surface) that face each other. The semiconductor IC 62 has main surfaces 62a (sixth main surface) and 62b (fifth main surface) that face each other. The main surface 61b of the semiconductor IC 61 faces the main surface 90a of the mounting substrate 90. The main surface 62b of the semiconductor IC 62 also faces the main surface 90a of the mounting substrate 90. The semiconductor IC 61 includes a ground terminal 104 arranged on the main surface 61b, a signal input terminal 101 arranged on the main surface 61b, and a signal output terminal 102 (first signal terminal) arranged on the main surface 61b.

[0065] The semiconductor IC 62 includes signal input terminals 201 (second signal terminal) and 202 (third signal terminal) arranged on the main surface 62b, and signal output terminals 203 and 204 arranged on the main surface 62b.

[0066] Here, as shown in Figures 5A to 5D, when the main surface 90a is viewed in a plane, the virtual line L1 (first virtual line) connecting the signal output terminal 102 and the ground terminal 104 and the virtual line L2 (second virtual line) connecting the signal input terminals 201 and 202 are parallel, and the distance d1 (first distance) between the signal output terminal 102 and the signal input terminal 201 and the distance d2 (second distance) between the ground terminal 104 and the signal input terminal 202 are equal.

[0067] In Modification 2, as shown in Fig. 5A, the lines connecting the signal output terminal 102, the ground terminal 104, and the signal input terminals 202 and 201 are rectangular. In Modification 3, as shown in Fig. 5B, the lines connecting the signal output terminal 102, the ground terminal 104, and the signal input terminals 202 and 201 are parallelograms. In Modification 4, as shown in Fig. 5C, the lines connecting the signal output terminal 102, the ground terminal 104, and the signal input terminals 202 and 201 are trapezoids. In Modification 5, as shown in Fig. 5D, the lines connecting the signal output terminal 102, the ground terminal 104, and the signal input terminals 202 and 201 are trapezoids.

[0068] This allows the lead-out wiring from one end 321 of the secondary coil 32 to the signal input terminal 201 to be the same length as the lead-out wiring from the other end 322 of the secondary coil 32 to the signal input terminal 202, and also allows the distance between one end 311 of the primary coil 31 and one end 321 of the secondary coil 32 to be equal to the distance between the other end 312 of the primary coil 31 and the other end 322 of the secondary coil 32. This suppresses imbalance in the two balanced signals output from the secondary coil 32, and improves the transmission efficiency of the transformer 30.

[0069] [5. Component Arrangement of Radio-Frequency Module 1F According to Modification 6] Fig. 6A is a perspective view of a radio-frequency module 1F according to Modification 6 of the embodiment. Fig. 6B is a plan view of the radio-frequency module 1F according to Modification 6 of the embodiment. Fig. 6C is a cross-sectional view of the radio-frequency module 1F according to Modification 6 of the embodiment. Fig. 6B shows the arrangement of circuit components when the main surface 90a of the mounting board 90 is seen through from the positive z-axis direction. Fig. 6C is a cross-sectional view taken along line VIC-VIC in Figs. 6A and 6B.

[0070] The radio frequency module 1F according to this modification differs from the radio frequency module 1 according to the embodiment in that the amplifiers 10 and 20 are arranged separately on both main surfaces of the mounting substrate 90. Therefore, in the following, a description of the same configuration as the radio frequency module 1 according to the embodiment will be omitted, and the description will focus on the different configuration.

[0071] Amplifier 10 is included in semiconductor IC 61 and is disposed on main surface 90b. Amplifier 20 is included in semiconductor IC 62 and is disposed on main surface 90a. In this way, semiconductor ICs 61 and 62 constituting high-frequency module 1F are disposed separately on both main surfaces of mounting substrate 90, which allows for miniaturization of high-frequency module 1F.

[0072] The primary coil 31 and secondary coil 32 that constitute the transformer 30 are formed on a mounting substrate 90. The primary coil 31 is formed, for example, on a second layer of the mounting substrate 90, and the secondary coil 32 is formed, for example, on a third layer of the mounting substrate 90. When the main surface 90a is viewed in plan, the secondary coil 32 is disposed along the primary coil 31.

[0073] 6A to 6C, in this modification, the transformer 30 at least partially overlaps the semiconductor IC 61 in the plan view. This allows the high-frequency module 1F to be miniaturized and the wiring connecting the amplifier 10 and the primary coil 31 to be shortened, thereby reducing the transmission loss of the high-frequency module 1F.

[0074] In the radio-frequency module 1F according to this modification, in the above-described plan view, the transformer 30 may be disposed between the semiconductor IC 61 and the semiconductor IC 62 without overlapping with the semiconductor IC 61. This allows the wiring connecting the amplifier 10 and the primary coil 31 and the wiring connecting the amplifier 20 and the secondary coil 32 to be shortened, thereby reducing the transmission loss of the radio-frequency module 1F.

[0075] As shown in FIG. 6C, the ground terminal 104 is disposed on the outer surface (main surface 61 b ​​) of the semiconductor IC 61 .

[0076] As shown in FIGS. 6A and 6C , the mounting substrate 90 includes a via conductor 95 and a ground plane electrode 100. The via conductor 95 is an example of a first via conductor, extends perpendicular to the main surface 90a, overlaps with the amplifier 10 when the main surface 90a is viewed in plan, and is connected to a ground terminal 104. The ground plane electrode 100 is an example of a first ground plane electrode, and is disposed on the main surface 90b. The ground plane electrode 100 serves as a reference ground for the high-frequency module 1F. When the high-frequency module 1F is mounted on a motherboard, the ground plane electrode 100 is directly connected to, for example, a ground electrode (or ground terminal) of the motherboard. As shown in FIG. 6C , one end of the via conductor 95 is bonded to the ground terminal 104 and the ground plane electrode 100, and the other end of the via conductor 95 is bonded to the other end 312 of the primary coil 31. Note that if the via conductor 95 extends to the main surface 90a, the other end of the via conductor 95 may be bonded to a second ground plane electrode disposed on the main surface 90a.

[0077] 6A to 6C, the other end 312 of the primary coil 31 is connected to the via conductor 95 in the layer of the mounting substrate 90 on which the primary coil 31 is formed. In other words, the other end 312 of the primary coil 31 is connected to the via conductor 95 without going through the ground plane electrode 100.

[0078] This shortens the ground path connecting the other end 312 of the primary coil 31, the via conductor 95, and the ground terminal 104. This reduces unnecessary magnetic fields generated by current loops flowing through the ground path, and prevents a decrease in the transmission efficiency of the transformer 30. This makes it possible to provide a low-loss high-frequency module 1F in which the transmission loss in the transformer 30 is reduced.

[0079] In the high-frequency module 1F according to this modification, when the primary coil 31 is formed on the outermost layer (e.g., the main surface 90b) of the mounting substrate 90, the other end 312 of the primary coil 31 may be directly connected to the ground terminal 104 on the outermost layer of the mounting substrate 90 on which the primary coil 31 is formed. This shortens the ground path, thereby further suppressing unnecessary magnetic fields generated by current loops flowing through the ground path.

[0080] [6. Effects, etc.] As described above, the high-frequency module 1 according to the present embodiment includes a mounting substrate 90 having principal surfaces 90 a and 90 b facing each other and including a plurality of layers, amplifiers 10 and 20 arranged on the mounting substrate 90, and a transformer 30 including a primary coil 31 and a secondary coil 32 formed on the mounting substrate 90, wherein the amplifier 10 includes a ground terminal 104, the mounting substrate 90 extends in a direction perpendicular to the principal surface 90 a, overlaps with the amplifier 10 when the principal surface 90 a is viewed in plan, and includes a via conductor 91 connected to the ground terminal 104, one end 311 of the primary coil 31 is connected to the signal output terminal 102 of the amplifier 10, one end 321 of the secondary coil 32 is connected to the signal input terminal 201 of the amplifier 20, the other end 322 of the secondary coil 32 is connected to the signal input terminal 202 of the amplifier 20, and the other end 312 of the primary coil 31 is connected to the ground terminal 104 or the via conductor 91 in the layer of the mounting substrate 90 on which the primary coil 31 is formed.

[0081] This allows the ground terminal 104 of the amplifier 10 and the other end 312 of the primary coil 31 to be connected without the plane ground electrode 100. Furthermore, because the via conductor 91 is arranged to overlap the amplifier 10 in the planar view, the wiring 92 connecting the other end 312 of the primary coil 31 and the via conductor 91 can be shortened. This shortens the ground path connecting the other end 312 of the primary coil 31, the wiring 92, the via conductor 91, and the ground terminal 104. This suppresses unnecessary magnetic fields generated by current loops flowing through the ground path, thereby preventing a decrease in the transmission efficiency of the transformer 30. This allows a low-loss high-frequency module 1 to be provided, with reduced transmission loss in the transformer 30.

[0082] Furthermore, for example, in the high-frequency module 1 , the amplifier 10 is included in the semiconductor IC 61 , the amplifier 20 is included in the semiconductor IC 62 , and the ground terminal 104 is disposed on the outer surface of the semiconductor IC 61 .

[0083] According to this, the amplifiers 10 and 20 are integrated on an IC chip, so that the high frequency module 1 can be made smaller.

[0084] Furthermore, for example, in the high frequency module 1, the semiconductor IC 61 is arranged on the main surface 90a, the semiconductor IC 62 is arranged on the main surface 90a, and the transformer 30 is arranged between the semiconductor IC 61 and the semiconductor IC 62 in the plan view.

[0085] This allows the wiring connecting the amplifier 10 and the primary coil 31 and the wiring connecting the amplifier 20 and the secondary coil 32 to be shortened, thereby reducing the transmission loss of the high-frequency module 1.

[0086] Furthermore, for example, in the high-frequency module 1A according to the first modification, the semiconductor IC 61 is arranged on the main surface 90a, the semiconductor IC 62 is arranged on the main surface 90a, and the transformer 30 at least partially overlaps with the semiconductor IC 61 in the plan view.

[0087] This allows the wiring connecting the amplifier 10 and the primary coil 31 to be further shortened, thereby reducing the transmission loss of the high-frequency module 1A.

[0088] For example, in the high-frequency module 1 (1A), the mounting substrate 90 includes a ground plane electrode 100 arranged on the main surface 90b, one end of the via conductor 91 (94) is joined to the ground terminal 104, the other end of the via conductor 91 (94) is joined to the ground plane electrode 100, and the other end 312 of the primary coil 31 is connected to the ground terminal 104 or the via conductor 91 (94) without going through the ground plane electrode 100.

[0089] Furthermore, for example, in the high-frequency module 1 (1A), the distance between the layer of the mounting substrate 90 on which the primary coil 31 is formed and the main surface 90a is smaller than the distance between the layer and the main surface 90b.

[0090] This allows the via conductor 91 portion of the ground path formed by the other end 312 of the primary coil 31, the wiring 92, the via conductor 91, and the ground terminal 104 to be shorter, thereby further suppressing unnecessary magnetic fields generated by the current loop flowing in the ground path.

[0091] Furthermore, for example, in a high-frequency module 1F according to the sixth modification, the semiconductor IC 61 is arranged on the main surface 90b, and the semiconductor IC 62 is arranged on the main surface 90a.

[0092] According to this, the semiconductor ICs 61 and 62 are arranged separately on both main surfaces of the mounting substrate 90, so that the high frequency module 1F can be made smaller.

[0093] Furthermore, for example, in the high-frequency module 1F, the transformer 30 at least partially overlaps with the semiconductor IC 61 in the plan view.

[0094] This allows the high frequency module 1F to be miniaturized, and also allows the wiring connecting the amplifier 10 and the primary coil 31 to be shortened, thereby reducing the transmission loss of the high frequency module 1F.

[0095] For example, in the high-frequency module 1F, the mounting substrate 90 includes a ground plane electrode 100 arranged on the main surface 90b, one end of the via conductor 95 is joined to the ground plane electrode 100 and the ground terminal 104, and the other end of the via conductor 95 is joined to a second ground plane electrode arranged on the main surface 90a or the other end 312 of the primary coil 31.

[0096] This shortens the ground path connecting the other end 312 of the primary coil 31, the via conductor 95, and the ground terminal 104. This reduces unnecessary magnetic fields generated by current loops flowing through the ground path, and prevents a decrease in the transmission efficiency of the transformer 30. This makes it possible to provide a low-loss high-frequency module 1F in which the transmission loss in the transformer 30 is reduced.

[0097] Furthermore, for example, in high-frequency modules 1B to 1E according to modifications 2 to 5, semiconductor IC 61 has principal surfaces 61a and 61b facing each other, semiconductor IC 62 has principal surfaces 62a and 62b facing each other, semiconductor IC 61 includes ground terminal 104 arranged on principal surface 61b and signal output terminal 102 arranged on principal surface 61b and connected to one end 311 of primary coil 31, semiconductor IC 62 includes signal input terminal 201 arranged on principal surface 62b and connected to one end 321 of secondary coil 32, and signal input terminal 202 arranged on principal surface 62b and connected to the other end 322 of secondary coil 32, and in the above-mentioned plan view, imaginary line L1 connecting signal output terminal 102 and ground terminal 104 and imaginary line L2 connecting signal input terminals 201 and 202 are parallel, and distance d1 between signal output terminal 102 and signal input terminal 201 is equal to distance d2 between ground terminal 104 and signal input terminal 202.

[0098] This allows the lead-out wiring from one end 321 of the secondary coil 32 to the signal input terminal 201 to be the same length as the lead-out wiring from the other end 322 of the secondary coil 32 to the signal input terminal 202, and also allows the distance between one end 311 of the primary coil 31 and one end 321 of the secondary coil 32 to be equal to the distance between the other end 312 of the primary coil 31 and the other end 322 of the secondary coil 32. This suppresses imbalance in the two balanced signals output from the secondary coil 32, and improves the transmission efficiency of the transformer 30.

[0099] For example, in the high-frequency module 1, the amplifier 10 includes an amplifying transistor 11, the amplifier 20 includes amplifying transistors 21 and 22, the amplifying transistor 11 is a Si-based field-effect transistor, and each of the amplifying transistors 21 and 22 is a GaAs-based bipolar transistor, the drain of the amplifying transistor 11 is connected to a signal output terminal 102, the source of the amplifying transistor 11 is connected to a ground terminal 104, the base of the amplifying transistor 21 is connected to a signal input terminal 201, and the base of the amplifying transistor 22 is connected to a signal input terminal 202.

[0100] This allows the high-frequency module 1 to be a hybrid amplifier circuit in which the amplifier 10 arranged in the front stage is made up of Si-based transistors and the amplifier 20 arranged in the rear stage is made up of GaAs-based transistors.

[0101] (Other Embodiments, etc.) While the high-frequency module according to the present invention has been described above with reference to embodiments and modifications thereof, the present invention is not limited to the above embodiments and modifications. The present invention also includes other embodiments realized by combining any of the components in the above embodiments and modifications, as well as modifications obtained by applying various modifications to the above embodiments and modifications that would occur to those skilled in the art without departing from the spirit of the present invention.

[0102] For example, in the high-frequency modules according to the above-described embodiments and modifications, other circuit elements and wiring may be inserted between the paths connecting the circuit elements and signal paths disclosed in the drawings.

[0103] The features of the high frequency module described based on the above embodiment and modifications will be described below.

[0104] <1> A high-frequency module comprising: a mounting board having first and second main surfaces opposing each other and including a plurality of layers; a first amplifier and a second amplifier arranged on the mounting board; and a transformer including a primary coil and a secondary coil formed on the mounting board, wherein the first amplifier includes a first ground terminal, the mounting board extends in a direction perpendicular to the first main surface, overlaps with the first amplifier when the first main surface is viewed in a plane, and includes a first via conductor connected to the first ground terminal, one end of the primary coil is connected to a first output terminal of the first amplifier, one end of the secondary coil is connected to a first input terminal of the second amplifier, and the other end of the secondary coil is connected to the first ground terminal or the first via conductor in the layer of the mounting board on which the primary coil is formed.

[0105] <2> The radio frequency module according to <1>, wherein the first amplifier is included in a first semiconductor IC, the second amplifier is included in a second semiconductor IC, and the first ground terminal is disposed on an outer surface of the first semiconductor IC.

[0106] <3> The high-frequency module according to <2>, wherein the first semiconductor IC is disposed on the first main surface, the second semiconductor IC is disposed on the first main surface, and the transformer is disposed between the first semiconductor IC and the second semiconductor IC in the planar view.

[0107] <4> The high-frequency module according to <2>, wherein the first semiconductor IC is disposed on the first main surface, the second semiconductor IC is disposed on the first main surface, and the transformer at least partially overlaps with the first semiconductor IC in the plan view.

[0108] <5> The high-frequency module according to <3> or <4>, wherein the mounting substrate includes a first ground plane electrode arranged on the second main surface, one end of the first via conductor is joined to the first ground terminal, the other end of the first via conductor is joined to the first ground plane electrode, and the other end of the primary coil is connected to the first ground terminal or the first via conductor without going through the first ground plane electrode.

[0109] <6> The high-frequency module according to <5>, wherein a distance between a layer of the mounting substrate on which the primary coil is formed and the first main surface is smaller than a distance between the layer and the second main surface.

[0110] <7> The high-frequency module according to <2>, wherein the first semiconductor IC is disposed on the second main surface, and the second semiconductor IC is disposed on the first main surface.

[0111] <8> The high-frequency module according to <7>, wherein the transformer at least partially overlaps with the first semiconductor IC in the plan view.

[0112] <9> The high-frequency module according to <7> or <8>, wherein the mounting substrate includes a first ground plane electrode arranged on the second main surface, one end of the first via conductor is joined to the first ground plane electrode and the first ground terminal, and the other end of the first via conductor is joined to a second ground plane electrode arranged on the first main surface or the other end of the primary coil.

[0113] <10> The high-frequency module according to any one of <2> to <9>, wherein the first semiconductor IC has a third main surface and a fourth main surface opposing each other, the second semiconductor IC has a fifth main surface and a sixth main surface opposing each other, the first semiconductor IC includes: the first ground terminal arranged on the third main surface; and a first signal terminal arranged on the third main surface and connected to one end of the primary coil, the second semiconductor IC includes: a second signal terminal arranged on the fifth main surface and connected to one end of the secondary coil, and a third signal terminal arranged on the fifth main surface and connected to the other end of the secondary coil, and a first virtual line connecting the first signal terminal and the first ground terminal and a second virtual line connecting the second signal terminal and the third signal terminal are parallel to each other in the plan view, and a first distance between the first signal terminal and the second signal terminal and a second distance between the first ground terminal and the third signal terminal are equal.

[0114] <11> The radio-frequency module according to any one of <1> to <10>, wherein the first amplifier includes a first amplifying transistor, the second amplifier includes a second amplifying transistor and a third amplifying transistor, the first amplifying transistor is a Si-based field-effect transistor, the second amplifying transistor and the third amplifying transistor are each a GaAs-based bipolar transistor, the drain of the first amplifying transistor is connected to the first output terminal, the source of the first amplifying transistor is connected to the first ground terminal, the base of the second amplifying transistor is connected to the first input terminal, and the base of the third amplifying transistor is connected to the second input terminal.

[0115] The present invention can be widely used as a high-frequency module disposed in a multi-band front end portion of communication devices such as mobile phones.

[0116] 1, 1A, 1B, 1C, 1D, 1E, 1F, 500 High frequency module 10, 20 Amplifier 11, 21, 22 Amplifying transistor 30, 40, 530 Transformer 31, 41, 531 Primary coil 32, 42, 532 Secondary coil 51, 52, 53, 54, 55, 56, 57 Matching circuit 61, 62 Semiconductor IC 61a, 61b, 62a, 62b, 90a, 90b Main surface 90 Mounting substrate 91, 93, 94, 95 Via conductor 92 Wiring 100 Ground plane electrode 101, 201, 202 Signal input terminal 102, 110, 203, 204 Signal output terminal 103 Power supply terminal 104, 207, 208 Ground terminal 311, 321, 411, 421 One end 312, 322, 412, 422 Other end 533 Connection point

Claims

1. A high-frequency module comprising: a mounting board having first and second principal surfaces opposing each other and including a plurality of layers; a first amplifier and a second amplifier arranged on the mounting board; and a transformer including a primary coil and a secondary coil formed on the mounting board, wherein the first amplifier includes a first ground terminal, the mounting board extends in a direction perpendicular to the first principal surface, overlaps with the first amplifier when the first principal surface is viewed in a plane, and includes a first via conductor connected to the first ground terminal, one end of the primary coil is connected to a first output terminal of the first amplifier, one end of the secondary coil is connected to a first input terminal of the second amplifier, and the other end of the secondary coil is connected to the first ground terminal or the first via conductor in the layer of the mounting board on which the primary coil is formed.

2. The high frequency module according to claim 1, wherein the first amplifier is included in a first semiconductor IC, the second amplifier is included in a second semiconductor IC, and the first ground terminal is disposed on an outer surface of the first semiconductor IC.

3. The high-frequency module according to claim 2, wherein the first semiconductor IC is disposed on the first main surface, the second semiconductor IC is disposed on the first main surface, and the transformer is disposed between the first semiconductor IC and the second semiconductor IC in the plan view.

4. The high-frequency module according to claim 2, wherein the first semiconductor IC is disposed on the first main surface, the second semiconductor IC is disposed on the first main surface, and the transformer at least partially overlaps with the first semiconductor IC in the plan view.

5. The high-frequency module according to claim 3 or 4, wherein the mounting board includes a first ground plane electrode arranged on the second main surface, one end of the first via conductor is joined to the first ground terminal, the other end of the first via conductor is joined to the first ground plane electrode, and the other end of the primary coil is connected to the first ground terminal or the first via conductor without going through the first ground plane electrode.

6. The high-frequency module according to claim 5, wherein the distance between the layer of the mounting board on which the primary coil is formed and the first main surface is smaller than the distance between the layer and the second main surface.

7. The high frequency module according to claim 2, wherein the first semiconductor IC is disposed on the second main surface, and the second semiconductor IC is disposed on the first main surface.

8. The high-frequency module according to claim 7, wherein the transformer at least partially overlaps with the first semiconductor IC in the plan view.

9. The high-frequency module according to claim 7 or 8, wherein the mounting board includes a first ground plane electrode arranged on the second main surface, one end of the first via conductor is joined to the first ground plane electrode and the first ground terminal, and the other end of the first via conductor is joined to a second ground plane electrode arranged on the first main surface or the other end of the primary coil.

10. The radio frequency module according to any one of claims 2 to 9, wherein the first semiconductor IC has third and fourth main surfaces opposing each other, the second semiconductor IC has fifth and sixth main surfaces opposing each other, the first semiconductor IC includes: the first ground terminal arranged on the third main surface; and a first signal terminal arranged on the third main surface and connected to one end of the primary coil, the second semiconductor IC includes: a second signal terminal arranged on the fifth main surface and connected to one end of the secondary coil, and a third signal terminal arranged on the fifth main surface and connected to the other end of the secondary coil, wherein a first imaginary line connecting the first signal terminal and the first ground terminal and a second imaginary line connecting the second signal terminal and the third signal terminal are parallel in the plan view, and a first distance between the first signal terminal and the second signal terminal and a second distance between the first ground terminal and the third signal terminal are equal.

11. The radio frequency module according to any one of claims 1 to 10, wherein the first amplifier includes a first amplifying transistor, the second amplifier includes a second amplifying transistor and a third amplifying transistor, the first amplifying transistor is a Si-based field effect transistor, the second amplifying transistor and the third amplifying transistor are each a GaAs-based bipolar transistor, the drain of the first amplifying transistor is connected to the first output terminal, the source of the first amplifying transistor is connected to the first ground terminal, the base of the second amplifying transistor is connected to the first input terminal, and the base of the third amplifying transistor is connected to the second input terminal.

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