JP7540913B2 - Wireless communication module - Google Patents

Description

The present invention relates to a wireless communication module.

Some wireless communication modules have an antenna board and a radio frequency integrated circuit (RFIC: Radio Frequency Integrated Circuits) mounted on both sides of a mounting board and electrically connected to each other via a through hole in the mounting board. In this wireless communication module, the antenna board and the radio frequency integrated circuit are electrically connected to the through hole via metal terminals provided on both ends of the through hole. High frequency signals such as millimeter waves are transmitted to the through hole and metal terminals that connect the antenna board and the radio frequency integrated circuit. Patent Document 1 discloses a board (multilayer printed wiring board) in which the through hole has a coaxial structure in order to minimize the transmission loss of the high frequency signal transmitted to the through hole.

JP 2002-305377 A

However, even if the substrate of Patent Document 1 is used as a mounting substrate for a wireless communication module, there is a problem in that the reflection of the high-frequency signal increases due to the impedance mismatch at the metal terminals connected to both ends of the through-hole of the coaxial structure (coaxial through-hole), resulting in increased transmission loss of the high-frequency signal at the metal terminals.

The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a wireless communication module that can suppress transmission loss of high-frequency signals in metal terminals that connect through holes in a mounting board to an antenna board or a high-frequency integrated circuit.

A wireless communication module according to one embodiment of the present invention comprises a mounting board having a signal through hole through which a high-frequency signal is transmitted from a first surface to a second surface opposite the first surface, an antenna board mounted on the first surface side, a high-frequency integrated circuit mounted on the second surface side, a first signal metal terminal connecting a first end of the signal through hole located on the first surface side to the antenna board, a second signal metal terminal connecting a second end of the signal through hole located on the second surface side to the high-frequency integrated circuit, a plurality of first ground metal terminals between the first surface and the antenna board, the first ground metal terminals being at ground potential and provided at different circumferential positions around the first signal metal terminal in a plan view seen from a thickness direction of the mounting board, and a plurality of second ground metal terminals being at ground potential and provided at different circumferential positions around the second signal metal terminal in a plan view. the first signal metal terminal and the second signal metal terminal overlap in a thickness direction of the mounting board, and the first ground metal terminals and the second ground metal terminals overlap, respectively; the mounting board has two signal through holes, the first signal metal terminal is provided at each of first ends of the two signal through holes, and a portion of the first ground metal terminal arranged in a region between the two first signal metal terminals serves as both the first ground metal terminals arranged around one of the two first signal metal terminals and the first ground metal terminals arranged around the other of the first signal metal terminals; the second signal metal terminals are provided at each of second ends of the two signal through holes, and a portion of the second ground metal terminal arranged in a region between the two second signal metal terminals serves as both the second ground metal terminals arranged around one of the two second signal metal terminals and the second ground metal terminals arranged around the other of the two second signal metal terminals.
A wireless communication module according to another aspect of the present invention comprises a mounting board having a signal through hole through which a high-frequency signal is transmitted, penetrating from a first surface to a second surface which is the surface opposite to the first surface, an antenna board mounted on the first surface side, a high-frequency integrated circuit mounted on the second surface side, a first signal metal terminal connecting a first end of the signal through hole located on the first surface side to the antenna board, a second signal metal terminal connecting a second end of the signal through hole located on the second surface side to the high-frequency integrated circuit, a plurality of first ground metal terminals between the first surface and the antenna board, the first ground metal terminals being provided at different circumferential positions around the first signal metal terminal in a plan view seen from a thickness direction of the mounting board and at ground potential, and a plurality of second ground metal terminals being provided at different circumferential positions around the second signal metal terminal in a plan view between the second surface and the high-frequency integrated circuit and at ground potential. In the thickness direction of the mounting substrate, the first signal metal terminal and the second signal metal terminal overlap, and the first ground metal terminals and the second ground metal terminals overlap, respectively, and the first ground metal terminal is connected to only one of the first surface and the antenna substrate facing the first surface.
A wireless communication module according to another aspect of the present invention comprises a mounting board having a signal through hole through which a high-frequency signal is transmitted, penetrating from a first surface to a second surface which is the surface opposite to the first surface, an antenna board mounted on the first surface side, a high-frequency integrated circuit mounted on the second surface side, a first signal metal terminal connecting a first end of the signal through hole located on the first surface side to the antenna board, a second signal metal terminal connecting a second end of the signal through hole located on the second surface side to the high-frequency integrated circuit, a plurality of first ground metal terminals between the first surface and the antenna board, the first ground metal terminals being provided at different circumferential positions around the first signal metal terminal in a plan view seen from a thickness direction of the mounting board and at ground potential, and a plurality of second ground metal terminals being provided at different circumferential positions around the second signal metal terminal in a plan view between the second surface and the high-frequency integrated circuit and at ground potential. In the thickness direction of the mounting substrate, the first signal metal terminal and the second signal metal terminal overlap, and the first ground metal terminals and the second ground metal terminals overlap, respectively, and the second ground metal terminal is connected to only one of the second surface and the high-frequency integrated circuit facing the second surface.

In the wireless communication module described above, the first signal metal terminal is surrounded by a plurality of first ground metal terminals between the mounting board and the antenna board. Similarly, the second signal metal terminal is surrounded by a plurality of second ground metal terminals between the mounting board and the high-frequency integrated circuit. Furthermore, in the thickness direction of the mounting board, the first signal metal terminal and the second signal metal terminal overlap, and the plurality of first ground metal terminals and the plurality of second ground metal terminals overlap, respectively. This allows impedance matching at the first and second signal metal terminals, and reduces reflection of high-frequency signals at the first and second signal metal terminals. Therefore, transmission loss of high-frequency signals at the first and second signal metal terminals can be suppressed.

In the wireless communication module, the first signal metal terminal and the first ground metal terminal may be arranged to form an impedance-matched pseudo-coaxial structure, and the second signal metal terminal and the second ground metal terminal may be arranged to form an impedance-matched pseudo-coaxial structure.

In the wireless communication module, the mounting board may have a plurality of ground through holes that are at ground potential and penetrate from the first surface to the second surface, and the plurality of ground through holes may be provided at different circumferential positions around the signal through hole in the plan view.

In the wireless communication module, the signal through-hole and the ground through-hole may be arranged to form an impedance-matched pseudo-coaxial structure.

The present invention makes it possible to suppress transmission loss of high-frequency signals in the first and second signal metal terminals that connect the signal through-hole of the mounting board to the antenna board or high-frequency integrated circuit.

1 is a side cross-sectional view showing a configuration of a main part of a wireless communication module according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 11 is a cross-sectional plan view showing a wireless communication module according to a modified example. FIG. 2 is a plan view for explaining a region between signal through holes. FIG. 11 is a side cross-sectional view showing a wireless communication module according to another embodiment of the present invention. FIG. 11 is a cross-sectional plan view showing a wireless communication module according to another embodiment of the present invention. FIG. 11 is a side cross-sectional view showing a wireless communication module according to another embodiment of the present invention.

The wireless communication module according to the embodiment of the present invention will be described in detail below with reference to the drawings. Note that the drawings used in the following description may show characteristic parts in an enlarged scale for the sake of convenience in order to make the characteristics easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality. Furthermore, the present invention is not limited to the following embodiment.

<Main components of the antenna module>
Fig. 1 is a side cross-sectional view showing a main configuration of a wireless communication module according to an embodiment of the present invention. As shown in Fig. 1, the wireless communication module 1 includes a mounting substrate 10, an antenna substrate 20, and an RFIC 30 (radio frequency integrated circuit). The wireless communication module 1 transmits and receives high frequency signals such as millimeter waves having a frequency of about 50 to 70 GHz. The wireless communication module 1 may only transmit high frequency signals or may only receive high frequency signals.

<Mounting board>
The mounting substrate 10 is a substrate on which components such as the antenna substrate 20 and the RFIC 30 are mounted. The mounting substrate 10 may be formed of a material having a dielectric tangent larger than that of the antenna substrate 20. Examples of such materials include inexpensive materials (e.g., epoxy, polyimide, etc.) that have been conventionally and generally used as materials for rigid substrates and flexible substrates.

The mounting board 10 has a signal through hole 11 and a ground through hole 12. The signal through hole 11 and the ground through hole 12 each penetrate from the first surface 10a of the mounting board 10 to the second surface 10b, which is the surface opposite the first surface 10a.

The signal through hole 11 is a through hole for transmitting a high-frequency signal. Note that in FIG. 1, in order to simplify the illustration, only one signal through hole 11 is shown, but multiple signal through holes 11 may be provided on the mounting board 10.

The ground through holes 12 are through holes at ground potential, and multiple ground through holes 12 are provided for the same signal through hole 11 (see FIG. 2). The multiple ground through holes 12 are provided at different positions in the circumferential direction centered on the signal through hole 11 in a plan view seen from the thickness direction of the mounting board 10 as shown in FIG. 2. The multiple ground through holes 12 may be arranged at equal intervals in the circumferential direction centered on the signal through hole 11, for example. In this embodiment, the number of ground through holes 12 corresponding to the same signal through hole 11 is four. These four ground through holes 12 are positioned at 90 degrees apart in the circumferential direction centered on the signal through hole 11.

The signal through-hole 11 and the ground through-hole 12 are arranged to form an impedance-matched pseudo-coaxial structure. Here, the impedance-matched pseudo-coaxial structure refers to a structure in which, when considering a coaxial structure with the signal through-hole 11 as the central conductor, the ground through-hole 12 is arranged on or near a virtual circle on which the ground conductor surrounding the central conductor should be arranged. The positional deviation of the ground through-hole 12 from the virtual circle is permissible if the impedance error is within a range of about ±10 [Ω], for example.

The signal through-hole 11 and the ground through-hole 12 are preferably formed by any of a conductor pin, a conductor wire, metal plating, a conductive paste, etc., but are not limited to these. Examples of conductors used for the signal through-hole 11 and the ground through-hole 12 include metals such as copper, silver, gold, alloys, and carbon. The shapes of the signal through-hole 11 and the ground through-hole 12 are not particularly limited, but include pin-shaped, linear, layered, particle-shaped, scale-shaped, fibrous, nanotube, etc. As shown in FIG. 1, electrode pads 11P, 12P are formed on both ends of the signal through-hole 11 and the ground through-hole 12. In other words, the signal through-hole 11 and the ground through-hole 12 have a so-called pad-on-via structure.

A ground pattern 13 is formed on the mounting board 10. The ground pattern 13 is an inner layer pattern of the mounting board 10, and is formed in a plate or film shape that spreads in a direction along the first surface 10a and the second surface 10b of the mounting board 10. The ground pattern 13 is electrically connected to the ground through hole 12 and reinforces the ground through hole 12. The ground pattern 13 has an opening 13a that penetrates in its thickness direction, and the signal through hole 11 is located inside the opening 13a. This electrically insulates the ground pattern 13 and the signal through hole 11. The above-mentioned ground pattern 13 may be formed in multiple layers on the mounting board 10.

The thickness of the mounting substrate 10 is preferably, for example, about 1.6 mm or less. However, in order to form fine through-holes in the mounting substrate 10, it is advantageous for the mounting substrate 10 to be as thin as possible. For example, when forming fine through-holes with a diameter of about 0.1 mm, it is preferable for the mounting substrate 10 to be about 0.8 mm or less in thickness.

<Antenna board>
The antenna substrate 20 is a substrate having an antenna (not shown) formed on its first surface 20a or inside. Any material may be used for the antenna substrate 20, but it is more preferable that the material has a small dielectric tangent (small loss of high-frequency signals) and good transmission characteristics for high-frequency signals. Examples of such materials include fluororesin, liquid crystal polymer (LCP), polyphenylene ether (PPE) resin, and low-temperature fired ceramics.

The antenna of the antenna substrate 20 may be, for example, an array antenna in which multiple radiating elements (not shown) are arranged two-dimensionally on the first surface 20a of the antenna substrate 20. The antenna may also be any antenna, such as a linear antenna, a planar antenna, a microstrip antenna, or a patch antenna. The antenna is not particularly limited as long as it has a structure that can be formed on or inside the first surface 20a of the antenna substrate 20.

The antenna substrate 20 is mounted on the first surface 10a side of the mounting substrate 10. In this state, the second surface 20b of the antenna substrate 20 faces the first surface 10a of the mounting substrate 10. A first signal metal terminal 25 and a first ground metal terminal 26 are provided between the first surface 10a of the mounting substrate 10 and the antenna substrate 20. The first signal metal terminal 25 and the first ground metal terminal 26 can be made of a metal such as solder (such as SnAgCu solder), gold, silver, or copper.

The first signal metal terminal 25 electrically connects a first end of the signal through hole 11 located on the first surface 10a side of the mounting substrate 10 to the antenna substrate 20. The first signal metal terminal 25 is joined to the first end (electrode pad 11P) of the signal through hole 11, and is disposed at a position overlapping with the signal through hole 11 in the thickness direction of the mounting substrate 10. This makes it possible to reduce the transmission distance of the high frequency signal from the signal through hole 11 to the antenna substrate 20 and suppress the transmission loss of the high frequency signal, compared to a case where the first signal metal terminal 25 is disposed at a position not overlapping with the signal through hole 11.
In FIG. 1, for simplicity of illustration, only one first signal metal terminal 25 is shown, but a plurality of first signal metal terminals 25 may be provided on the first surface 10a of the mounting substrate 10.

The first ground metal terminal 26 is a metal terminal at ground potential, and multiple first ground metal terminals 26 are provided for the same first signal metal terminal 25 (see FIG. 2). The multiple first ground metal terminals 26 are provided at different positions in the circumferential direction centered on the first signal metal terminal 25 in a plan view seen from the thickness direction of the mounting substrate 10 as shown in FIG. 2. The multiple first ground metal terminals 26 may be arranged at equal intervals in the circumferential direction centered on the first signal metal terminal 25, for example. In this embodiment, the number of first ground metal terminals 26 corresponding to the same first signal metal terminal 25 is four. These four first ground metal terminals 26 are positioned at 90 degrees offset from each other in the circumferential direction centered on the first signal metal terminal 25.

In this embodiment, each first ground metal terminal 26 is electrically connected to both the mounting substrate 10 and the antenna substrate 20. That is, the first ground metal terminal 26 electrically connects the mounting substrate 10 and the antenna substrate 20. Also, each first ground metal terminal 26 is electrically connected to a first end of the ground through hole 12 located on the first surface 10a side of the mounting substrate 10. Specifically, the first ground metal terminal 26 is joined to the first end (electrode pad 12P) of the ground through hole 12 and is positioned so as to overlap the ground through hole 12 in the thickness direction of the mounting substrate 10.

The first signal metal terminal 25 and the first ground metal terminal 26 are arranged to form an impedance-matched pseudo-coaxial structure, similar to the signal through-hole 11 and ground through-hole 12 described above.

When the antenna substrate 20 is mounted on the first surface 10a of the mounting substrate 10 as shown in FIG. 1, it is preferable that the first signal metal terminal 25 is not covered with resin or the like, and the first ground metal terminal 26 is covered with resin. By not covering the first signal metal terminal 25 with resin or the like, it is possible to reduce the transmission loss of high frequency signals. By covering the first ground metal terminal 26 with resin, it is possible to reinforce the connection portion between the antenna substrate 20 and the mounting substrate 10.

It is desirable that no other components are mounted (implemented) on the antenna board 20. This allows the area and thickness of the antenna board 20 to be minimized, and also ensures the reliability of the antenna board 20. However, if necessary, other components may be mounted on the antenna board 20.

<RFIC>
The RFIC 30 is an integrated circuit that processes high-frequency signals, and is mounted on the second surface 10b side of the mounting substrate 10. The IC package applied to the RFIC 30 may be, for example, a BGA (Ball Grid Alley), a CSP (Chip Size Package), a FOWLP (Fan Out Wafer Level Package), or the like. The RFIC 30 is electrically connected to the antenna substrate 20 via a second signal metal terminal 35, a signal through hole 11 of the mounting substrate 10, and a first signal metal terminal 25, which will be described later. The RFIC 30, for example, performs reception processing of a high-frequency signal output from the antenna substrate 20, and outputs a reception signal having a lower frequency than the high-frequency signal from an output terminal (not shown). In addition, the RFIC 30, for example, performs transmission processing of a transmission signal input from an input terminal (not shown), and outputs a high-frequency signal having a higher frequency than the transmission signal to the antenna substrate 20.

A second signal metal terminal 35 and a second ground metal terminal 36 are provided between the mounting substrate 10 and the RFIC 30. The second signal metal terminal 35 and the second ground metal terminal 36 may be made of a metal such as solder (e.g., SnAgCu solder), gold, silver, or copper.

The second signal metal terminal 35 electrically connects the second end of the signal through hole 11 located on the second surface 10b side of the mounting substrate 10 to the RFIC 30. The second signal metal terminal 35 is joined to the second end (electrode pad 11P) of the signal through hole 11, and is arranged at a position overlapping the signal through hole 11 in the thickness direction of the mounting substrate 10. This makes it possible to reduce the transmission distance of the high frequency signal from the signal through hole 11 to the RFIC 30 and suppress the transmission loss of the high frequency signal, compared to a case where the second signal metal terminal 35 is arranged at a position not overlapping the signal through hole 11.
In FIG. 1, for the sake of simplicity, only one second signal metal terminal 35 is shown, but a plurality of second signal metal terminals 35 may be provided on the second surface 10b of the mounting substrate 10.

The second ground metal terminals 36 are metal terminals at ground potential, and multiple second ground metal terminals 36 are provided for the same second signal metal terminal 35 (see FIG. 2). The multiple second ground metal terminals 36 are provided at different circumferential positions around the second signal metal terminal 35 in a plan view, similar to the multiple first ground metal terminals 26. The multiple second ground metal terminals 36 may be arranged at equal intervals in the circumferential direction around the second signal metal terminal 35. In this embodiment, the number of second ground metal terminals 36 corresponding to the same second signal metal terminal 35 is four. These four second ground metal terminals 36 are positioned at 90 degrees apart in the circumferential direction around the second signal metal terminal 35.

In this embodiment, each second ground metal terminal 36 is electrically connected to both the mounting substrate 10 and the RFIC 30. That is, the second ground metal terminal 36 electrically connects the mounting substrate 10 and the RFIC 30. Also, each second ground metal terminal 36 is electrically connected to the second end of the ground through hole 12 located on the second surface 10b side of the mounting substrate 10. Specifically, the second ground metal terminal 36 is joined to the second end (electrode pad 12P) of the ground through hole 12 and is positioned so as to overlap the ground through hole 12 in the thickness direction of the mounting substrate 10.

The second signal metal terminal 35 and the second ground metal terminal 36 are arranged to form an impedance-matched pseudo-coaxial structure, similar to the signal through-hole 11 and ground through-hole 12 described above.

When the RFIC 30 is mounted on the second surface 10b of the mounting substrate 10, it is desirable that the second signal metal terminal 35 is not covered with resin or the like. For example, it is desirable that the space between the RFIC 30 and the second surface 10b of the mounting substrate 10 is not sealed with resin such as underfill. By not covering the second signal metal terminal 35 with resin or the like, it is possible to reduce the transmission loss of high frequency signals. Note that the portion between the RFIC 30 and the second surface 10b of the mounting substrate 10, excluding the second signal metal terminal 35, may be sealed with resin such as underfill.

In the wireless communication module 1, as shown in FIGS. 1 and 2, the first signal metal terminal 25 and the second signal metal terminal 35 overlap in the thickness direction of the mounting substrate 10. Furthermore, the four first ground metal terminals 26 and the four second ground metal terminals 36 overlap in the thickness direction of the mounting substrate 10. The first signal metal terminal 25 and the second signal metal terminal 35 may overlap completely or only partially. Similarly, the first ground metal terminal 26 and the second ground metal terminal 36 may overlap completely or only partially.

As described above, in the wireless communication module 1 of this embodiment, the first signal metal terminal 25 is surrounded by a plurality of first ground metal terminals 26 between the mounting substrate 10 and the antenna substrate 20. Similarly, the second signal metal terminal 35 is surrounded by a plurality of second ground metal terminals 36 between the mounting substrate 10 and the RFIC 30. Furthermore, in the thickness direction of the mounting substrate 10, the first signal metal terminal 25 and the second signal metal terminal 35 overlap, and the plurality of first ground metal terminals 26 and the plurality of second ground metal terminals 36 overlap. This allows impedance matching at the first and second signal metal terminals 25, 35 to be achieved, and the reflection of high-frequency signals at the first and second signal metal terminals 25, 35 can be reduced. Therefore, the transmission loss of high-frequency signals at the first and second signal metal terminals 25, 35 can be suppressed.

In addition, since the first signal metal terminal 25 is surrounded by a plurality of first ground metal terminals 26, it is possible to suppress the high-frequency signal passing through the first signal metal terminal 25 from being affected by external disturbances. Similarly, since the second signal metal terminal 35 is surrounded by a plurality of second ground metal terminals 36, it is possible to suppress the high-frequency signal passing through the second signal metal terminal 35 from being affected by external disturbances.

Furthermore, because the first signal metal terminal 25 is surrounded by a plurality of first ground metal terminals 26, even if there are a plurality of first signal metal terminals 25 on the first surface 10a of the mounting board 10, it is possible to suppress the transition of high-frequency signals between adjacent first signal metal terminals 25. Similarly, because the second signal metal terminal 35 is surrounded by a plurality of second ground metal terminals 36, it is possible to suppress the transition of high-frequency signals between adjacent second signal metal terminals 35, even if there are a plurality of second signal metal terminals 35 on the second surface 10b of the mounting board 10.

Furthermore, in the wireless communication module 1 of the present embodiment, the signal through hole 11 of the mounting board 10 is surrounded by a plurality of ground through holes 12. This makes it possible to achieve impedance matching of the signal through hole 11 and reduce the reflection of the high-frequency signal at the signal through hole 11. This makes it possible to suppress the transmission loss of the high-frequency signal at the signal through hole 11.
Furthermore, since the signal through hole 11 of the mounting board 10 is surrounded by multiple ground through holes 12, it is possible to shorten the lead time and reduce costs of the wireless communication module 1 (particularly the mounting board 10) compared to the case where a through hole with a completely coaxial structure is formed as in Patent Document 1.

In addition, in the wireless communication module 1 of this embodiment, the first signal metal terminal 25 and the first ground metal terminal 26 are arranged to form an impedance-matched pseudo-coaxial structure. Furthermore, the second signal metal terminal 35 and the second ground metal terminal 36 are arranged to form an impedance-matched pseudo-coaxial structure. Furthermore, the signal through hole 11 and the ground through hole 12 of the mounting board 10 are arranged to form an impedance-matched pseudo-coaxial structure. This further reduces the reflection of the high-frequency signal due to impedance mismatch, and further suppresses the transmission loss of the high-frequency signal in the signal through hole 11 and the first and second signal metal terminals 25, 35.

In addition, in the wireless communication module 1 of this embodiment, the first ground metal terminal 26 connects the mounting substrate 10 and the antenna substrate 20. This makes it possible to more effectively prevent high-frequency signals from transitioning between the first signal metal terminals 25 and to prevent the high-frequency signals passing through the first signal metal terminals 25 from being affected by external disturbances. Similarly, the second ground metal terminal 36 connects the mounting substrate 10 and the RFIC 30 makes it possible to more effectively prevent high-frequency signals from transitioning between the second signal metal terminals 35 and to prevent the high-frequency signals passing through the second signal metal terminals 35 from being affected by external disturbances.

<Modification>
Next, a wireless communication module according to a modified example will be described with reference to Figures 3 and 4. The plan cross-sectional view shown in Figure 3 corresponds to the cross-sectional view taken along line II-II in Figure 1. In Figure 3, the same components as those shown in Figure 2 are denoted by the same reference numerals.
3, in the wireless communication module of the modified example, the mounting board 10 has two signal through holes 11, and a first signal metal terminal 25 is provided at each first end (the first surface 10a side of the mounting board 10) of the two adjacent signal through holes 11. A first ground metal terminal 26A arranged in a region between the two first signal metal terminals 25 serves as one of the four first ground metal terminals 26 arranged around one of the two first signal metal terminals 25 and as one of the four first ground metal terminals 26 arranged around the other first signal metal terminal 25. The number of first ground metal terminals 26A serving as the first ground metal terminal 26 arranged around one first signal metal terminal 25 and the first ground metal terminal 26 arranged around the other first signal metal terminal 25 is not limited to one and may be multiple.

The region between one first signal metal terminal 25 and the other first signal metal terminal 25 is, for example, region R1 shown by a line segment in FIG. 4. This region R1 is a region partitioned by two parallel straight lines L11 and L12 that are perpendicular to the straight line L1 connecting the centers of the two first signal metal terminals 25 and circumscribe the two circles CR. Here, the two circles CR are circles with the two first signal metal terminals 25 at their centers, respectively, and the diameters of these two circles CR are equal to each other. In FIG. 4, the first ground metal terminal 26 arranged in the region between the two first signal metal terminals 25 is located at the part of region R1 that intersects with the straight line L1, but this is not limited to this. In addition, the four first ground metal terminals 26 surrounding each first signal metal terminal 25 are arranged so that their centers are located on the circle CR, but this is not limited to this.

As shown in FIG. 3, similar to the first signal metal terminal 25 and the first ground metal terminal 26 described above, the second ground metal terminal 36A arranged in the area between the two second signal metal terminals 35 serves both as the four second ground metal terminals 36 arranged around one of the two second signal metal terminals 35 and as the four second ground metal terminals 36 arranged around the other second signal metal terminal 35.

In the configuration illustrated in Figures 3 and 4, the two first signal metal terminals 25 can be brought closer to each other than when a first ground metal terminal 26 for surrounding one first signal metal terminal 25 and a first ground metal terminal 26 for surrounding the other first signal metal terminal 25 are separately arranged in the region between the two first signal metal terminals 25. Similarly, the two second signal metal terminals 35 can be brought closer to each other. This makes it possible to arrange the multiple first and second signal metal terminals 25, 35 at a higher density.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be freely modified within the scope of the present invention.

In the wireless communication module of the present invention, the first and second ground metal terminals 26, 36 may not be joined to both ends of the ground through hole 12 of the mounting substrate 10, as shown in, for example, Figures 5 and 6. The first and second ground metal terminals 26, 36 may be positioned with a radial offset (left and right direction in Figure 5) with respect to the ground through hole 12, centered on the signal through hole 11 and the first and second signal metal terminals 25, 35, as shown in, for example, Figure 5. The first and second ground metal terminals 26, 36 may be positioned with a circumferential offset with respect to the ground through hole 12, centered on the signal through hole 11 and the first and second signal metal terminals 25, 35, as shown in, for example, Figure 6. When the first and second ground metal terminals 26, 36 are positioned with a offset with respect to the ground through hole 12 of the mounting substrate 10, the first and second ground metal terminals 26, 36 may or may not be directly connected to the ground through hole 12 by wiring. However, it is preferable that the first and second ground metal terminals 26, 36 are connected as closely as possible to the ground through hole 12.

In the wireless communication module of the present invention, the first and second ground metal terminals 26, 36 may be connected only to the mounting substrate 10, as shown in FIG. 7, and may not be connected to the antenna substrate 20 or the RFIC 30. The first ground metal terminal 26 may be connected only to the antenna substrate 20, and may not be connected to the mounting substrate 10. Similarly, the second ground metal terminal 36 may be connected only to the RFIC 30, and may not be connected to the mounting substrate 10. The first and second ground metal terminals 26, 36 may be provided such that some of them connect the mounting substrate 10 and the antenna substrate 20 or the RFIC 30, and the remaining parts do not connect the mounting substrate 10 and the antenna substrate 20 or the RFIC 30.

Even with this configuration, it is possible to suppress transmission loss and transitions of the high-frequency signal, and to suppress the high-frequency signal from being affected by external disturbances, as in the above-mentioned embodiment. However, if the first and second ground metal terminals 26, 36 are connected to both the mounting board 10 and the antenna board 20 or the RFIC 30, as in the above-mentioned embodiment, it is possible to more effectively suppress transitions of the high-frequency signal and the high-frequency signal from being affected by external disturbances.

In addition, in a configuration in which the first ground metal terminal 26 is connected to only one of the mounting board 10 and the antenna board 20, a pad for joining the first ground metal terminal 26 (electrode pad 12P in the example of FIG. 7) may be provided only on one of the mounting board 10 and the antenna board 20. In this case, since there is no need to provide a pad for joining the first ground metal terminal 26 on the other of the mounting board 10 and the antenna board 20, wiring for another purpose (for example, wiring for transmitting a high-frequency signal) can be formed instead of the pad. Similarly, in a configuration in which the second ground metal terminal 36 is connected to only one of the mounting board 10 and the RFIC 30, there is no need to provide a pad for joining the second ground metal terminal 36 on the other of the mounting board 10 and the RFIC 30, and wiring for another purpose (for example, wiring for transmitting a high-frequency signal) can be formed instead of the pad. This makes it possible to arrange wiring for another purpose more densely in the mounting board 10, the antenna board 20, and the RFIC 30.

In FIG. 7, the first and second ground metal terminals 26, 36 connected only to the mounting substrate 10 are formed in a hemispherical shape. The hemispherical first and second ground metal terminals 26, 36 can be formed, for example, by printing solder paste on the electrode pad 12P of the mounting substrate 10 and melting it by reflow. The first and second ground metal terminals 26, 36 connected only to the antenna substrate 20 or the RFIC 30 can also be formed in a hemispherical shape in a similar manner.

In the wireless communication module of the present invention, the number of ground through holes 12 corresponding to the same signal through hole 11 may be two or more. If at least two ground through holes 12 are provided corresponding to the same signal through hole 11, the effect of confining the electric field of the high frequency signal can be sufficiently obtained, that is, the transmission loss of the high frequency signal can be suppressed. However, if the number of ground through holes 12 is excessively large, it becomes unsuitable for narrowing the pitch of the signal through holes 11. In addition, the cost increases, and the spacing between the ground through holes 12 becomes narrow, making it more likely that problems such as breakage will occur. For this reason, it is desirable to appropriately design the number of ground through holes 12 in consideration of multiple parameters.

In the wireless communication module of the present invention, the number of first and second ground metal terminals 26, 36 corresponding to the same first and second signal metal terminals 25, 35, respectively, may be two or more. If at least two first and second ground metal terminals 26, 36 are provided corresponding to the same first and second signal metal terminals 25, 35, the transmission loss of high frequency signals can be suppressed. Considering the influence of disturbances on the high frequency signals passing through the first and second signal metal terminals 25, 35, it is more desirable to have a large number of first and second signal metal terminals 25, 35. On the other hand, considering narrow pitch and costs, it is desirable to have as few first and second signal metal terminals 25, 35 as possible (two or more).

In the wireless communication module of the present invention, the mounting substrate 10 only needs to have at least a signal through hole 11, and does not need to have a ground through hole 12 corresponding to the signal through hole 11.

1...wireless communication module, 10...mounting board, 10a...first surface, 10b...second surface, 11...signal through hole, 12...ground through hole, 20...antenna board, 25...first signal metal terminal, 26, 26A...first ground metal terminal, 30...RFIC (radio frequency integrated circuit), 35...second signal metal terminal, 36, 36A...second ground metal terminal

Claims (10)

a mounting board having a signal through hole through which a high frequency signal is transmitted, the signal through hole penetrating from a first surface to a second surface opposite to the first surface;
An antenna substrate mounted on the first surface side;
a high frequency integrated circuit mounted on the second surface side;
a first signal metal terminal that connects a first end of the signal through hole located on the first surface side to the antenna substrate;
a second signal metal terminal that connects a second end of the signal through hole located on the second surface side to the high frequency integrated circuit;
a plurality of first ground metal terminals, which are provided at different circumferential positions around the first signal metal terminal in a plan view seen from a thickness direction of the mounting substrate between the first surface and the antenna substrate and are set to a ground potential;
a plurality of second ground metal terminals, which are provided at different circumferential positions around the second signal metal terminal in the plan view between the second surface and the high frequency integrated circuit and are set to a ground potential;
Equipped with
the first signal metal terminal and the second signal metal terminal overlap each other in a thickness direction of the mounting substrate, and the first ground metal terminals and the second ground metal terminals overlap each other in a thickness direction of the mounting substrate;
the mounting board has two of the signal through holes,
the first signal metal terminal is provided at each of the first ends of the two signal through holes;
a portion of the first ground metal terminal disposed in a region between the two first signal metal terminals serves as a plurality of the first ground metal terminals disposed around one of the two first signal metal terminals and a plurality of the first ground metal terminals disposed around the other of the two first signal metal terminals;
the second signal metal terminal is provided at each of the second ends of the two signal through holes;
A wireless communication module in which a portion of the second ground metal terminal arranged in an area between two of the second signal metal terminals serves both as a plurality of second ground metal terminals arranged around one of the two second signal metal terminals and as a plurality of second ground metal terminals arranged around the other of the two second signal metal terminals. The wireless communication module according to claim 1 , wherein the first ground metal terminal is connected to only one of the first surface and the antenna substrate facing the first surface. a mounting board having a signal through hole through which a high frequency signal is transmitted, the signal through hole penetrating from a first surface to a second surface opposite to the first surface;
An antenna substrate mounted on the first surface side;
a high frequency integrated circuit mounted on the second surface side;
a first signal metal terminal that connects a first end of the signal through hole located on the first surface side to the antenna substrate;
a second signal metal terminal that connects a second end of the signal through hole located on the second surface side to the high frequency integrated circuit;
a plurality of first ground metal terminals, which are provided at different circumferential positions around the first signal metal terminal in a plan view seen from a thickness direction of the mounting substrate between the first surface and the antenna substrate and are set to a ground potential;
a plurality of second ground metal terminals, which are provided at different circumferential positions around the second signal metal terminal in the plan view between the second surface and the high frequency integrated circuit and are set to a ground potential;
Equipped with
the first signal metal terminal and the second signal metal terminal overlap each other in a thickness direction of the mounting substrate, and the first ground metal terminals and the second ground metal terminals overlap each other in a thickness direction of the mounting substrate;
A wireless communication module in which the first ground metal terminal is connected to only one of the first surface and the antenna substrate facing the first surface . 4 . The wireless communication module according to claim 1 , wherein the second ground metal terminal is connected to only one of the second surface and the high-frequency integrated circuit facing the second surface. a mounting board having a signal through hole through which a high frequency signal is transmitted, the signal through hole penetrating from a first surface to a second surface opposite to the first surface;
An antenna substrate mounted on the first surface side;
a high frequency integrated circuit mounted on the second surface side;
a first signal metal terminal that connects a first end of the signal through hole located on the first surface side to the antenna substrate;
a second signal metal terminal that connects a second end of the signal through hole located on the second surface side to the high frequency integrated circuit;
a plurality of first ground metal terminals, which are provided at different circumferential positions around the first signal metal terminal in a plan view seen from a thickness direction of the mounting substrate between the first surface and the antenna substrate and are set to a ground potential;
a plurality of second ground metal terminals, which are provided at different circumferential positions around the second signal metal terminal in the plan view between the second surface and the high frequency integrated circuit and are set to a ground potential;
Equipped with
the first signal metal terminal and the second signal metal terminal overlap each other in a thickness direction of the mounting substrate, and the first ground metal terminals and the second ground metal terminals overlap each other in a thickness direction of the mounting substrate;
The second ground metal terminal is connected to only one of the second surface and the high-frequency integrated circuit facing the second surface . the first signal metal terminal and the first ground metal terminal are arranged to form an impedance-matched pseudo-coaxial structure;
The wireless communication module according to claim 1 , wherein the second signal metal terminal and the second ground metal terminal are arranged to form an impedance-matched pseudo-coaxial structure. the mounting board has a plurality of ground through holes that penetrate from the first surface to the second surface and are at a ground potential;
7. The wireless communication module according to claim 1, wherein the ground through holes are provided at different positions in a circumferential direction around the signal through hole in the plan view. The first ground metal terminal is connected to a first end of the ground through hole located on the first surface side,
The wireless communication module according to claim 7 , wherein the second ground metal terminal is connected to a second end of the ground through hole located on the second surface side. The wireless communication module according to claim 7 , wherein the first ground metal terminal and the second ground metal terminal are not connected to the ground through-hole. 10. The wireless communication module according to claim 7, wherein the signal through-hole and the ground through-hole are arranged to form an impedance-matched pseudo-coaxial structure.

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