Power amplifier module

Abstract

In conventional power amplifier modules, thermal vias are embedded in a printed circuit board in order to ensure heat dissipation, but adequate heat dissipation may not be obtained due to design rules, the thickness, and the like of the printed circuit board. There is also a power amplifier having a structure in which an electrically connected surface and an exhaust heat surface are vertically separated. However, these structures require respectively different patterns and need to be developed individually. A power amplifier module of the present disclosure can be used in both top-surface and bottom-surface heat exhaust structures by providing an input terminal and an output terminal on both the top surface and the bottom surface.

Description

Power Amplifier Module

[0001] The present disclosure relates to a power amplifier module that amplifies high-frequency power, and in particular, can be used in both forms of upper surface heat dissipation and lower surface heat dissipation.

[0002] FIG. 9 shows an example of a conventional power amplifier module 900. A semiconductor chip 1 in which transistors are integrated on a surface pattern 50 on a multilayer resin substrate 10 is die-bonded. The surface pattern 50 is connected and electrically conducted to a lower surface grounding terminal 34 provided on the back surface of the resin substrate 10 by a through hole 12 penetrating the resin substrate 10. The back surface of the semiconductor chip 1 serves as a grounding terminal, and the lower surface grounding terminal 34 operates as the grounding terminal of the semiconductor chip 1. Further, since the heat generated during the operation of the semiconductor chip 1 is transmitted to the lower surface grounding terminal 34 through the through hole 12, the lower surface grounding terminal 34 also operates as a heat dissipation terminal and a thermal pad of the power amplifier module 900. Such a structure is disclosed in, for example, Patent Document 1.

[0003] The power amplifier module is mounted on a substrate of a higher-level transceiver, and a power supply circuit, a reception circuit, etc. are connected and used. FIG. 10 shows an example of a cross-sectional view when mounting a conventional power amplifier module 900 on a printed board 60 of, for example, a higher-level transceiver. The power amplifier module 900 is solder-mounted on the printed board 60 as a surface-mounted component.

[0004] The input terminal 32, output terminal 32a, and lower surface grounding terminal 34 of the power amplifier module 900 are respectively joined to terminals 62, terminal 62a, and terminal 64 provided on the printed board 60 of a higher-level wireless device system. The terminal 64 of the printed board 60 joined to the lower surface grounding terminal 34 is thermally coupled to the back surface electrode 66 of the printed board 60 through a thermal via 65 penetrating the printed board 60. The back surface electrode 66 is joined or contacted to a heat sink 70, and the heat generated by the semiconductor chip 1 is dissipated from the heat sink 70. In this configuration, the surface for electrically connecting the power amplifier module 900 and the heat dissipation surface are arranged on the same lower surface.

[0005] Generally, power amplifier modules generate high temperatures, making heat dissipation crucial. Therefore, thermal vias for heat dissipation are embedded in the printed circuit board 60 in the areas that come into contact with the heat dissipation terminals (thermal pads) of the power amplifier module 900, transferring heat to the heat sink 70. To achieve high heat dissipation, it is effective to increase the density of thermal vias and reduce the thermal resistance of the printed circuit board 60. However, this is limited by the design rules of the printed circuit board 60, and in some cases, sufficient heat dissipation cannot be obtained. Also, when the printed circuit board 60 is multilayered to increase the integration of circuits, and the thickness of the printed circuit board 60 increases, the thermal resistance of the printed circuit board 60 also increases, and insufficient heat dissipation may not be achieved.

[0006] On the other hand, a power amplifier having a structure in which the electrically connected surface and the heat dissipation surface are separated vertically has also been disclosed. Figure 11 shows an example of a conventional power amplifier module 910 having a separated structure in which the electrically connected surface and the heat dissipation surface are separated vertically. The back surface of the semiconductor chip 1 is a grounding terminal and is connected to a grounding terminal 24 provided on the surface of the mold 4 covering the resin substrate 10 opposite to the resin substrate 10, via a through-hole that penetrates the mold 4. The input side of the semiconductor chip 1 is connected to an input terminal 22 provided on the surface of the mold 4 covering the resin substrate 10 opposite to the resin substrate 10. The output side of the semiconductor chip 1 is connected to an output terminal 22a provided on the surface of the mold 4 covering the resin substrate 10 opposite to the resin substrate 10. In other words, the electrically connected surface is on the mold 4 side, and the heat dissipation surface is on the resin substrate 10 side, similar to the power amplifier module 900. Such a structure is disclosed, for example, in Patent Document 2.

[0007] Figure 12 shows an example of a cross-sectional view when a conventional power amplifier module 910 is mounted on the printed circuit board 60 and heat sink 70 of a higher-level transceiver. The input terminal 22, output terminal 22a, and ground terminal 24 of the power amplifier module 910 are connected to terminals 62, 62a, and 64, respectively, provided on the printed circuit board 60 of the higher-level wireless device system. The lower ground terminal 34 is thermally coupled to the heat sink 70 via TIM 71.

[0008] In the power amplifier module 910, the separation of the electrically connected surface and the heat dissipation surface allows for heat dissipation without using thermal vias on the printed circuit board 60, thus achieving high heat dissipation performance. This structure is sometimes called a top-side cooling structure (TSC) because, when the electrically connected surface is facing downwards, the heat dissipation surface is facing upwards. In contrast to the top-side cooling structure, the module structure shown in Figure 9, where both the electrically connected surface and the heat dissipation surface are facing downwards, is sometimes called a bottom-side cooling structure (BSC).

[0009] U.S. Patent Application No. 17 / 516360 (U.S. Patent Application Publication No. 2023 / 0133034) JP 2022-104789

[0010] Because power amplifier modules with top-side heat dissipation structures and power amplifier modules with bottom-side heat dissipation structures have different patterns for their back and front electrodes, power amplifier module vendors had to develop these modules separately.

[0011] This disclosure is made in view of the above-mentioned problems, and the purpose of this disclosure is to provide a power amplifier module that can be used for both top-side and bottom-side heat dissipation, thereby reducing the development and manufacturing costs of the power amplifier module.

[0012] The power amplifier module according to this disclosure is a power amplifier module for amplifying high frequencies and comprises a semiconductor chip on which an active element for amplifying high frequencies is formed, a substrate, and a mold that covers at least the surface of the substrate and whose surface opposite to the substrate forms an upper surface facing the lower surface of the power amplifier module. The substrate has a back surface that constitutes the lower surface of the power amplifier module and a front surface facing the back surface, a heat dissipation terminal is provided on the back surface, and a heat dissipation structure is formed in which the semiconductor chip is bonded and coupled to the heat dissipation terminal, an input matching circuit and an output matching circuit are formed to impedance match the semiconductor chip to the outside, and a control circuit for controlling the current of the semiconductor chip and a power supply circuit for supplying power to the semiconductor chip are formed. The upper surface of the power amplifier module is provided with a first input terminal that is conductive to the input matching circuit, a first output terminal that is conductive to the output matching circuit, a first control terminal that is conductive to the control circuit, and a first power supply terminal that is conductive to the power supply circuit. The underside of the power amplifier module is provided with a second input terminal connected to an input matching circuit, a second output terminal connected to an output matching circuit, a second control terminal connected to a control circuit, and a second power supply terminal connected to a power supply circuit.

[0013] This disclosure provides a power amplifier module that can be used for both top-side and bottom-side heat dissipation. Furthermore, it enables a reduction in the development and manufacturing costs of the power amplifier module.

[0014] This is a circuit block diagram of the power amplifier module 100 according to Embodiment 1. This is a cross-sectional view showing the power amplifier module 100. This is a cross-sectional view when the power amplifier module 100 is mounted as a bottom heat dissipation structure. This is a cross-sectional view when the power amplifier module 100 is mounted as a top heat dissipation structure. This is a cross-sectional view showing a modified example of the heat dissipation structure of the power amplifier module 100. This is a cross-sectional view showing a modified example of the power amplifier module 100 according to Embodiment 1. This is a top view showing the interior of the power amplifier module 200 according to Embodiment 2. This is a top view showing the interior of the power amplifier module 210 according to a modified example of Embodiment 2. This is a cross-sectional view showing a conventional power amplifier module 900. This is a cross-sectional view when the power amplifier module 900 is mounted as a bottom heat dissipation structure. This is a cross-sectional view showing a conventional power amplifier module 910. This is a cross-sectional view when the power amplifier module 910 is mounted as a top heat dissipation structure.

[0015] Embodiment 1. A power amplifier according to an embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding components are denoted by the same reference numerals, and repetition of the description may be omitted.

[0016] Figure 1 is a circuit block diagram of a power amplifier module 100 according to Embodiment 1 of the present invention. The power amplifier module 100 comprises a semiconductor chip 1 and an input matching circuit 16, an output matching circuit 17, a control circuit 18, and a power supply circuit 19, all of which are connected to the semiconductor chip 1. Input terminals 22 and 32 are connected to the input matching circuit 16. Output terminals 22a and 32a are connected to the output matching circuit 17. Control terminals 23 and 33 are connected to the control circuit 18. Power supply terminals 25 and 35 are connected to the power supply circuit 19.

[0017] Figure 2 is a cross-sectional view showing a power amplifier module 100 according to Embodiment 1 of the present invention. The power amplifier module 100 has a resin substrate 10. In Embodiment 1, the resin substrate 10 is a two-layer substrate consisting of an upper layer 10a and a lower layer 10b. An intermediate wiring layer is provided between the upper layer 10a and the lower layer 10b. The resin substrate 10 may be a further multilayer substrate. The back surface of the resin substrate 10 constitutes the lower surface 105 of the power amplifier module 100.

[0018] An input matching circuit 16, an output matching circuit 17, a control circuit 18 (not shown), and a power supply circuit 19 (not shown) are formed on the resin substrate 10. The surface 13 of the resin substrate 10, including the input matching circuit 16, the output matching circuit 17, the control circuit 18, the power supply circuit 19, and the semiconductor chip 1, is covered by the mold 4. In other words, the upper side of the power amplifier module 100 is covered by the mold 4. The surface of the mold 4 on the opposite side of the resin substrate 10 constitutes the upper surface 103 of the power amplifier module 100.

[0019] A semiconductor chip 1, in which transistors are integrated, is die-bonded to a surface pattern 50 on a resin substrate 10 using metal solder, conductive resin, etc. Through-holes 12 that penetrate the resin substrate 10 connect the surface pattern 50 to a lower grounding terminal 34 provided on the back surface of the resin substrate 10, creating electrical contact. The back surface of the semiconductor chip 1 is a grounding terminal, and the lower grounding terminal 34 functions as the grounding terminal of the power amplifier module 100. Heat generated during the operation of the semiconductor chip 1 is transferred to the lower grounding terminal 34 via the through-holes 12, so the lower grounding terminal 34 also functions as a heat dissipation terminal and thermal pad of the power amplifier module 100.

[0020] In Embodiment 1, the semiconductor chip 1 is a semiconductor die on which a HEMT (High Electron Mobility Transistor) made primarily of GaN (Gallium Nitride) is formed as an active element. The semiconductor chip 1 may also be made primarily of other materials, such as gallium arsenide or silicon, and the active element may be a MOSFET. In Embodiment 1, the power amplifier module 100 forms a single-stage amplifier, but it may also be a multi-stage amplifier or configured as a Doherty amplifier. It may also be configured using multiple semiconductor chips, or a configuration in which a passive element is formed on the semiconductor chip 1.

[0021] The surface pattern 51, surface pattern 52, and chip component 42 constitute part of the input matching circuit 16. The surface pattern 51 is electrically connected to the input side of the semiconductor chip 1 via wire 3. The input terminal 32 provided on the back surface of the resin substrate 10 is electrically connected to the surface pattern 52 via through-hole 36 and internal conductor pattern layer 38. The input terminal 22 provided on the upper surface of the mold 4 is electrically connected to the surface pattern 52 via conductor 26 that penetrates the mold 4. In other words, the input side of the semiconductor chip 1 is connected via the input matching circuit 16 formed on the resin substrate 10 to the input terminal 32 provided on the back surface of the resin substrate 10, i.e., the lower surface 105 of the power amplifier module 100, and to the input terminal 22 provided on the upper surface of the mold 4, i.e., the upper surface 103 of the power amplifier module 100, via the input matching circuit 16 formed on the resin substrate 10.

[0022] The input matching circuit 16 is an impedance matching circuit that matches the impedance seen from the input terminal 32 to the outside (usually 50Ω) with the impedance on the input side of the semiconductor chip 1. The input matching circuit 16 is also an impedance matching circuit that matches the impedance seen from the input terminal 22 to the outside (usually 50Ω) with the impedance on the input side of the semiconductor chip 1.

[0023] The surface patterns 53 and 54, and the chip component 44 constitute part of the output matching circuit 17. The surface pattern 53 is electrically connected to the output side of the semiconductor chip 1 via the wire 3a. The output terminal 32a provided on the back surface of the resin substrate 10 is electrically connected to the surface pattern 54 via the through-hole 37 and the internal conductor pattern layer 39. The output terminal 22a provided on the upper surface of the mold 4 is electrically connected to the surface pattern 54 via the conductor 27 that penetrates the mold 4. In other words, the output side of the semiconductor chip 1 is connected via the output matching circuit 17 formed on the resin substrate 10 to the output terminal 32a provided on the back surface of the resin substrate 10, i.e., the lower surface 105 of the power amplifier module 100, and to the output terminal 22a provided on the upper surface of the mold 4, i.e., the upper surface 103 of the power amplifier module 100, via the output matching circuit 17 formed on the resin substrate 10.

[0024] The output matching circuit 17 is an impedance matching circuit that matches the impedance seen from the output terminal 32a to the outside (usually 50Ω) with the impedance on the output side of the semiconductor chip 1. The output matching circuit 17 is also an impedance matching circuit that matches the impedance seen from the output terminal 22a to the outside (usually 50Ω) with the impedance on the output side of the semiconductor chip 1.

[0025] High-frequency signals input from an external source to input terminal 22 or input terminal 32 are input to semiconductor chip 1 via input matching circuit 16. The high-frequency signals amplified by semiconductor chip 1 are output to the outside from output terminal 22a or output terminal 32a via output matching circuit 17.

[0026] The resin substrate 10 has a control circuit 18 (not shown) for controlling the current of the semiconductor chip 1 and a power supply circuit 19 (not shown) for supplying power to the semiconductor chip 1. The control circuit 18 is electrically connected to the input side of the semiconductor chip 1. The control circuit 18 is also electrically connected to a control terminal 33 (not shown) provided on the back surface of the resin substrate 10 and a control terminal 23 (not shown) provided on the upper surface of the mold 4. The power supply circuit 19 is electrically connected to the output side of the semiconductor chip 1. The power supply circuit 19 is also electrically connected to a power supply terminal 35 (not shown) provided on the back surface of the resin substrate 10 and a power supply terminal 25 (not shown) provided on the upper surface of the mold 4.

[0027] The control circuit 18 is a circuit for applying a negative bias to the gate in order to set the idle current of the GaN-HEMT formed on the semiconductor chip 1. The control circuit 18 applies a bias voltage applied externally to the control terminal 23 or control terminal 33 to the gate of the semiconductor chip 1. The control circuit 18 may be configured as a passive circuit composed of surface patterns, chip components, etc., or it may be a control IC that generates the bias voltage applied to the semiconductor chip 1 according to a digital signal applied externally to the control terminal 23 or control terminal 33 or the ambient temperature, or a combination of these. At the frequency in which the power amplifier module 100 performs amplification operation, it is desirable that the impedance of the control circuit 18 is set so that it appears open to the gate of the semiconductor chip 1.

[0028] The power supply circuit 19 is a circuit for supplying power to the drain of the GaN-HEMT formed on the semiconductor chip 1. The power supply circuit 19 supplies power applied from an external source to the power supply terminal 25 or power supply terminal 35 to the drain of the semiconductor chip 1. The power supply circuit 19 may be configured as a passive circuit composed of surface patterns, chip components, etc., or it may be a circuit that uses active elements such as regulator elements in combination. At the frequency in which the power amplifier module 100 performs amplification operation, it is desirable that the impedance of the power supply circuit 19 be set so that it appears open to the drain of the semiconductor chip 1.

[0029] A grounding terminal 24 is provided on the upper surface of the mold 4. The grounding terminal 24 is electrically connected to the surface pattern 50 via a conductor 28 that penetrates the mold 4. The grounding terminal 24, like the lower contact grounding terminal 34, functions as the grounding terminal of the power amplifier module 100.

[0030] As described above, the power amplifier module 100 according to Embodiment 1 has electrode terminals with the same function on both the upper surface 103 and the lower surface 105, so it can be used as both an upper and lower heat dissipation structure in a higher-level wireless device. Therefore, development costs can be reduced. Figure 3 shows an example of a cross-sectional view when the power amplifier module 100 is mounted as a lower heat dissipation structure. Figure 4 shows an example of a cross-sectional view when the power amplifier module 100 is mounted as an upper heat dissipation structure.

[0031] As shown in Figure 3, when implemented as a bottom heat dissipation structure, the input terminal 32, output terminal 32a, and bottom contact terminal 34 of the power amplifier module 100 are connected to terminals 62, 62a, and 64, respectively, provided on the printed circuit board 60 of the higher-level wireless device system. Although not shown, the control terminal 33 and power supply terminal 35 are also connected to terminals provided on the printed circuit board 60. Metal solder, conductive resin, etc., can be used for the connections. The terminal 64 of the printed circuit board 60, which is connected to the bottom contact terminal 34, is thermally coupled to the back electrode 66 of the printed circuit board 60 via a thermal via 65 that penetrates the printed circuit board 60. The back electrode 66 is connected to or in contact with the heat sink 70, and the heat generated by the semiconductor chip 1 is dissipated from the heat sink 70.

[0032] As shown in Figure 4, when implemented as a top-surface heat dissipation structure, the input terminal 22, output terminal 22a, and grounding terminal 24 of the power amplifier module 100 are connected to terminals 62, 62a, and 64, respectively, provided on the printed circuit board 60 of the higher-level wireless device system. Although not shown, the control terminal 23 and power supply terminal 25 are also connected to terminals provided on the printed circuit board 60. Metal solder, conductive resin, etc., can be used for the connections.

[0033] The lower contact terminal 34 is thermally bonded to the heat sink 70 via an insulating TIM 71. TIM (Thermal Interface Material) is a thermally conductive material inserted between components to efficiently dissipate unwanted heat generated inside electronic equipment. Examples include high-heat-dissipating grease, and sheets with improved thermal conductivity achieved by filling resins such as silicone or epoxy with high thermal conductivity fillers. TIM is generally an insulator. Generally, the heat sink 70 is made of a conductive metal, but by using an insulating TIM, the input terminal 22, output terminal 22a, grounding terminal 24, control terminal 23, and power supply terminal 25 will not short-circuit.

[0034] As described above, the power amplifier module 100 according to Embodiment 1 has a semiconductor chip 1 on which an active element for amplifying high frequencies is formed. The resin substrate 10 has a back surface which constitutes the bottom surface 105 of the power amplifier module 100, and a bottom contact terminal 34 which acts as a heat dissipation terminal for the power amplifier module 100 is provided on its back surface. An input matching circuit 16 and an output matching circuit 17 are formed on the resin substrate 10 to impedance match the semiconductor chip 1 with the outside, and a control circuit 18 which controls the current of the semiconductor chip 1 and a power supply circuit 19 which supplies power to the semiconductor chip are also formed. The surface pattern 50, through holes 12 and bottom contact terminal 34 form a heat dissipation structure, and the semiconductor chip 1 is bonded to the surface pattern 50, which is the exposed part on the surface side. The surface 13 of the resin substrate 10, including the input matching circuit 16, output matching circuit 17, control circuit 18, power supply circuit 19 and semiconductor chip 1, is covered by the mold 4. In other words, the top side of the power amplifier module 100 is covered by the mold 4. The surface of mold 4 constitutes the upper surface 103 of the power amplifier module 100. The upper surface 103 of the power amplifier module is provided with an input terminal 22, which is a first input terminal connected to the input matching circuit 16; an output terminal 22a, which is a first output terminal connected to the output matching circuit 17; a control terminal 23, which is a first control terminal connected to the control circuit 18; and a power supply terminal 25, which is a first power supply terminal connected to the power supply circuit 19. The lower surface 105 of the power amplifier module is provided with an input terminal 32, which is a second input terminal connected to the input matching circuit 16; an output terminal 32a, which is a second output terminal connected to the output matching circuit 17; a control terminal 33, which is a second control terminal connected to the control circuit 18; and a power supply terminal 35, which is a second power supply terminal connected to the power supply circuit 19.

[0035] As described above, the power amplifier module 100 according to Embodiment 1 has terminals for connecting to the outside on both the top and bottom surfaces. Therefore, when used in a wireless device, it can be used as either a top-side heat dissipation structure or a bottom-side heat dissipation structure. Furthermore, the development cost of the power amplifier module itself can be reduced. When used as a top-side heat dissipation structure, the insulator TIM is sandwiched between the heat sinks, so there is no short circuit between the terminals on the top side.

[0036] In Embodiment 1, the surface pattern 50, through-holes 12, and lower contact terminals 34 form a heat dissipation structure, and the semiconductor chip 1 is bonded to the surface pattern 50, which is the exposed part on the surface side. However, as shown in Figure 5(A), a so-called copper inlay substrate with a metal body 14 embedded through the resin substrate 10 may also be used as the heat dissipation structure. Alternatively, as shown in Figure 5(B), a cavity 15 is provided through the resin substrate 10, and the semiconductor chip 1 is die-bonded to the lower contact terminals 34 exposed from the cavity 15 when viewed from above. In this case, the lower contact terminals 34 should be made of a relatively thick metal body.

[0037] Modified form of Embodiment 1. Note that, as shown in Figure 6 of the power amplifier module 101, the size of the grounding terminal 24 on the top surface and the bottom grounding terminal 34 on the bottom surface may be made the same. As shown in Figure 3, when the power amplifier module 100 is used for bottom heat dissipation, the top surface is open, and a separate shield was required to suppress unwanted waves. In contrast, as in the power amplifier module 101, by making the size of the grounding terminal 24 on the top surface and the bottom grounding terminal 34 on the bottom surface the same size and wide, the top and bottom surfaces of the power amplifier module are shielded by metal layers, thus suppressing unwanted waves.

[0038] Embodiment 2. Figure 7 is a top view showing the inside of the power amplifier module 200 according to Embodiment 2. Here, the resin substrate 11 is shown from above, through the mold 4. In Embodiment 2, the resin substrate 11 is used instead of the resin substrate 10 in Embodiment 1. Chip component 48 constitutes part of the input matching circuit 16. Chip component 49 constitutes part of the output matching circuit 17.

[0039] The surface pattern 52 on the resin substrate 10 is divided into surface pattern 52a and surface pattern 52b on the resin substrate 11. The end of surface pattern 52a is an internal terminal 56a, and the end of surface pattern 52b is an internal terminal 56b. Internal terminals 56a and 56b are a pair of internal terminals arranged adjacent to each other while spaced apart. Surface pattern 52b is electrically connected to an input terminal 32 provided on the back surface of the resin substrate 11 via a through-hole 36 and an internal conductor pattern layer 38. The surface pattern 54 on the resin substrate 10 is divided into surface pattern 54a and surface pattern 54b on the resin substrate 11. The end of surface pattern 54a is an internal terminal 57a, and the end of surface pattern 52b is an internal terminal 57b. Internal terminals 57a and 57b are a pair of internal terminals arranged adjacent to each other while spaced apart. The surface pattern 54b is electrically connected to the output terminal 32a provided on the back surface of the resin substrate 11 via the through-hole 37 and the internal conductor pattern layer 39.

[0040] Internal terminals 56a, 56b, 57a, and 57b are provided so that bonding wires can be joined or chip components can be mounted. In Embodiment 2, internal terminals 56a and 56b are wired together by wire 74 and are electrically connected. Internal terminals 57a and 57b are wired together by wire 75 and are electrically connected. Similarly, although not shown, the wiring that connects the control circuit 18 and the second control terminal, control terminal 33, is provided with a pair of internal terminals that are spaced apart but adjacent to each other and are electrically connected by wire. The wiring that connects the power supply circuit 19 and the second power supply terminal, power supply terminal 35, is provided with a pair of internal terminals that are spaced apart but adjacent to each other and are electrically connected by wire. The other parts are the same as those of the power amplifier module 100.

[0041] The power amplifier module 200 according to Embodiment 2, like the power amplifier module 100 according to Embodiment 1, has terminals for connecting to the outside on both the top and bottom surfaces. Therefore, when used in a wireless device, it can be used as either a top-side heat dissipation structure or a bottom-side heat dissipation structure. However, when the power amplifier module 100 is used as a top-side heat dissipation structure, as explained in Embodiment 1, if the top surface 103 of the power amplifier module 100 is thermally coupled to the heat sink 70 via an insulating TIM 71, the input terminal 22, output terminal 22a, grounding terminal 24, control terminal 23, and power supply terminal 25 will not short-circuit even if the heat sink 70 is conductive. However, conductive TIMs are also available on the market, and short-circuiting becomes a problem when using them.

[0042] In the power amplifier module 200 according to Embodiment 2, by eliminating the wiring using the wires 74, 75, the wire that conducts the control circuit 18 and the control terminal 33, and the wire that conducts the power supply circuit 19 and the control terminal 33 during its manufacture, even when using a conductive TIM or directly contacting a conductive heat sink with the upper surface 103, there is no short circuit between the terminals. By simply eliminating the predetermined wiring in the manufacturing process in this way, the power amplifier module 200 can prevent a short circuit between the terminals without changing other designs. Also, the development cost of the power amplifier module itself can be suppressed.

[0043] Modification example of Embodiment 2. In Embodiment 2, the paired internal terminals are conducted by wiring, but they may be conducted by chip components instead of wires. FIG. 8 is a top view showing the inside of a power amplifier module 210 according to a modification example of Embodiment 2. Here, the resin substrate 11 is shown from above through the mold 4. In the modification example of Embodiment 2, the internal terminal 56a and the internal terminal 56b are conducted by a chip component 40 instead of the wire 74. The internal terminal 57a and the internal terminal 57b are conducted by a chip component 46 instead of the wire 75.

[0044] Similarly, although not shown, the wiring that conducts the control circuit 18 and the control terminal 33 which is the second control terminal is provided with paired internal terminals arranged adjacent to each other while being separated, and they are conducted by chip components. And the wiring that conducts the power supply circuit 19 and the power supply terminal 35 which is the second power supply terminal is provided with paired internal terminals arranged adjacent to each other while being separated, and they are conducted by chip components. Other parts are the same as those of the power amplifier module 200. Note that conduction by wiring and conduction by chip components may be mixed.

[0045] This disclosure is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are described in detail to make the disclosure easier to understand, and are not necessarily limited to those having all the configurations described. In addition, it is possible to add, delete, or replace some of the configurations in the embodiments with other configurations. The power amplifier module according to the embodiment of the present invention is suitable for a small base station for a fifth-generation mobile communication system that uses the 3.7 GHz band of the sub-6 GHz band (Sub6) and introduces Massive MIMO.

[0046] 1 Semiconductor chip, 4 Mold, 10, 11 Resin substrate, 12 Through-hole, 13 Surface, 16 Input matching circuit, 17 Output matching circuit, 18 Control circuit, 19 Power supply circuit, 22, 32 Input terminals, 22a, 32a Output terminals, 23, 33 Control terminals, 24 Grounding terminal, 25, 35 Power supply terminals, 26, 27, 28 Conductor, 34 Bottom grounding terminal, 48, 49 Chip component, 50 Surface pattern, 56a, 56b, 57a, 57b Internal terminal, 60 Printed circuit board, 65 Thermal via, 66 Back electrode, 70 Heat sink, 74, 75 Wire, 100, 101, 200, 201 Power amplifier module, 103 Top surface, 105 Bottom surface

Claims

1. A power amplifier module for amplifying high frequencies, comprising: a semiconductor chip on which an active element for amplifying high frequencies is formed; a substrate having a back surface constituting the lower surface of the power amplifier module and a front surface facing the back surface, with a heat dissipation terminal provided on the back surface, the semiconductor chip being bonded to and coupled to the heat dissipation terminal, an input matching circuit and an output matching circuit for impedance matching between the semiconductor chip and the outside, and a control circuit for controlling the current of the semiconductor chip and a power supply circuit for supplying power to the semiconductor chip; and a mold covering at least the front surface of the substrate, the front surface opposite to the substrate forming an upper surface facing the lower surface of the power amplifier module, wherein the upper surface of the power amplifier module is provided with a first input terminal connected to the input matching circuit, a first output terminal connected to the output matching circuit, a first control terminal connected to the control circuit, and a first power supply terminal connected to the power supply circuit. A power amplifier module characterized in that the lower surface of the power amplifier module is provided with a second input terminal connected to the input matching circuit, a second output terminal connected to the output matching circuit, a second control terminal connected to the control circuit, and a second power supply terminal connected to the power supply circuit.

2. The power amplifier module according to claim 1, characterized in that each of the paths connecting the second input terminal and the input matching circuit, the path connecting the second output terminal and the output matching circuit, the path connecting the second power supply terminal and the power supply circuit, and the path connecting the second control terminal and the control circuit are provided with a pair of internal terminals that are adjacent to each other but spaced apart on the path.

3. The power amplifier module according to claim 2, characterized in that the pair of internal terminals are wired together to provide electrical conductivity.

4. The power amplifier module according to claim 2, characterized in that the pair of internal terminals are electrically connected by mounted chip components.

5. A power amplifier module for amplifying high frequencies, comprising: a semiconductor chip on which an active element for amplifying high frequencies is formed; a substrate having a back surface constituting the lower surface of the power amplifier module and a surface facing the back surface, with a heat dissipation terminal provided on the back surface, the semiconductor chip being bonded and coupled to the heat dissipation terminal, having an input matching circuit and an output matching circuit formed for impedance matching between the semiconductor chip and the outside, and having a control circuit for controlling the current of the semiconductor chip and a power supply circuit formed for supplying power to the semiconductor chip; and a mold covering at least the surface of the substrate, the surface opposite to the substrate forming an upper surface facing the lower surface of the power amplifier module, wherein the upper surface of the power amplifier module is provided with a first input terminal connected to the input matching circuit, a first output terminal connected to the output matching circuit, a first control terminal connected to the control circuit, and a first power supply terminal connected to the power supply circuit. The power amplifier module is characterized in that a second input terminal, a second output terminal, a second power supply terminal, and a second control terminal are provided on the lower surface of the power amplifier module, and a connection path for connecting the second input terminal to the input matching circuit, a connection path for connecting the second output terminal to the output matching circuit, a connection path for connecting the second power supply terminal to the power supply circuit, and a connection path for connecting the second control terminal to the control circuit are provided, and each of the connection paths has adjacent yet spaced-apart internal terminals that can be electrically connected by wiring or mounting chip components.

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