JP7417448B2 - Antenna board and antenna module - Google Patents

Description

The present disclosure relates to an antenna substrate and an antenna module.

2. Description of the Related Art Conventionally, a microstrip antenna or a patch antenna, in which a radiation conductor and a ground conductor are arranged with a dielectric substrate sandwiched between them, has been known as a small planar antenna used in various wireless devices. As an antenna substrate used in such an antenna, one in which a cavity is provided in a dielectric between a radiation conductor and a ground conductor is known (see, for example, Patent Document 1). The cavity improves the antenna characteristics by lowering the dielectric constant between the radiation conductor and the ground conductor.

Japanese Patent Application Publication No. 2012-151467

However, even if the dielectric constant between the radiation conductor and the ground conductor is lowered by providing a cavity in the dielectric, the antenna characteristics may deteriorate or vary. This is because if a cavity is provided in the dielectric between the radiating conductor and the ground conductor, which have a relatively large area, on the antenna board, the dielectric with the radiating conductor or the ground conductor located across the cavity will This is because the space between the radiating conductor and the grounding conductor becomes inconsistent due to the deformation of the conductor. In the prior art, a temporary cavity body is placed in a portion of the laminate that will become a cavity before firing, and a weight is placed on the laminate in order to suppress deformation that causes the cavity to expand. However, since the hollow temporary structure has already been fired and does not undergo firing shrinkage, deformation may occur due to the difference in shrinkage between it and the laminate. Further, the hollow temporary structure is pulled out after firing, and the hollow portion is open on the side surface of the antenna substrate, which tends to reduce the strength of the antenna substrate. That is, in the conventional antenna substrate having a cavity, the antenna characteristics vary, there is a possibility that the antenna characteristics cannot be improved as designed, and the strength is low.

The antenna substrate of the present disclosure includes a first dielectric substrate having a first surface and a second surface opposite to the first surface, and having a radiation conductor on at least one of the first surface and the second surface. , has a third surface opposite to the second surface and a fourth surface opposite to the third surface, and has a ground conductor on the third surface that overlaps with the radiation conductor when seen in plan view; a second dielectric substrate having a power supply conductor on a fourth surface or inside thereof; and a fifth surface and a second dielectric substrate located between the first dielectric substrate and the second dielectric substrate, and opposite to the fifth surface. and a frame-shaped third dielectric substrate having a through hole that extends from the fifth surface to the sixth surface and overlaps the radiation conductor and the ground conductor in plan view. and at least one of the third dielectric substrate and the first dielectric substrate and the third dielectric substrate and the second dielectric substrate are bonded with a bonding material, and the third dielectric substrate and the second dielectric substrate are bonded with a bonding material . The dielectric substrate has a step in the through hole, and at least one of the first dielectric substrate and the second dielectric substrate is bonded to the step with the bonding material .

In the antenna module of the present disclosure, the semiconductor element is mounted on the mounting part of the antenna substrate, which has the semiconductor element mounting part on the fourth surface of the second dielectric substrate.

According to the antenna substrate of one aspect of the present disclosure, since it has the above structure, deformation during manufacturing is suppressed, the antenna characteristics are improved, and the antenna substrate has high strength.

According to the antenna module of the present disclosure, compared to an antenna module in which a semiconductor element and an antenna board are mounted on an external circuit board, the antenna module is smaller, has less loss, and is more efficient in transmitting and receiving high-frequency signals. At the same time, it is possible to obtain an antenna module with high strength.

FIG. 2 is a perspective view showing an example of an antenna substrate, in which (a) is a perspective view from the first dielectric substrate side, and (b) is a perspective view from the second dielectric substrate side. FIG. 2 is an exploded perspective view of the antenna board shown in FIG. 1. FIG. (a) is a top view of the antenna substrate shown in FIG. 1, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 4, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 6, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 8, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 10, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 12, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 14, (b) is a cross-sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 16, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 18, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. FIG. 7 is an exploded perspective view showing another example of the antenna board. (a) is a top view of the antenna substrate shown in FIG. 20, (b) is a sectional view taken along line BB in (a), and (c) is a bottom view. (a) is a perspective view showing an example of an antenna substrate and an antenna module, (b) is a sectional view taken along line BB in (a), and (c) is a perspective view from the bottom.

The antenna board will be explained with reference to the attached drawings. Note that the distinction between upper and lower in the following description is for convenience, and does not limit the upper and lower positions when the antenna board is actually used. FIG. 1 is a perspective view showing an example of an antenna board, FIG. 1(a) is a perspective view from the first dielectric substrate side (top surface), and FIG. 1(b) is a perspective view from the second dielectric substrate side. It is a diagram. FIG. 2 is an exploded perspective view of the antenna board shown in FIG. 1. 3(a) is a top view of the antenna board shown in FIG. 1, FIG. 3(b) is a sectional view taken along line BB in FIG. 3(a), and FIG. 3(c) is a bottom view. . 4, FIG. 6, FIG. 8, FIG. 10, and FIG. 12 are exploded perspective views showing other examples of the antenna board. (a) in FIGS. 5, 7, 9, 11, and 13 is a top view of the antenna board shown in FIGS. 4, 6, 8, 10, and 12, respectively, and (b) is a top view of the antenna board shown in FIGS. It is a sectional view taken along the line BB of a), and (c) is a bottom view.

The antenna substrate 100 includes a first dielectric substrate 10, a second dielectric substrate 20, and a third dielectric substrate 30 located between the first dielectric substrate 10 and the second dielectric substrate 20. We are prepared. The first dielectric substrate 10 has a first surface 11 and a second surface 12 opposite to the first surface 11, and has a radiation conductor 13 on at least one of the first surface 11 and the second surface 12. There is. The second dielectric substrate 20 has a third surface 21 opposite to the second surface 12 and a fourth surface 22 opposite to the third surface 21, and overlaps the radiation conductor 13 in the third surface 21 when viewed from above. It has a ground conductor 23, and has a power supply conductor 24 on the fourth surface 22 or inside. The third dielectric substrate has a fifth surface 31 and a sixth surface 32 opposite to the fifth surface 31, and penetrates from the fifth surface 31 to the sixth surface 32 and is connected to the radiation conductor 13 and ground when seen in plan view. It has a through hole 33 that overlaps with the conductor 23. At least one of the third dielectric substrate 30 and the first dielectric substrate 10 and the third dielectric substrate 30 and the second dielectric substrate 20 are bonded with a bonding material 40.

According to the antenna substrate 100 having such a configuration, a hollow portion surrounded by the first dielectric substrate 10, the second dielectric substrate 20, and the third dielectric substrate 30 is provided between the radiation conductor 13 and the ground conductor 23. (a hollow part). Since the dielectric constant between the radiation conductor 13 and the ground conductor 23 is small, the antenna substrate 100 has improved antenna characteristics. In addition, the first dielectric substrate 10, the second dielectric substrate 20, and the third dielectric substrate 30 are not easily deformed during manufacturing, such as a flat plate, a flat plate with a through hole, or a flat plate with a recess, as described later. It is something. Therefore, in the antenna substrate 100 in which these are bonded together using the bonding material 40, the distance between the radiation conductor 13 and the ground conductor 23 is constant, so that variations in antenna characteristics are small. Furthermore, since the cavity is hollow with no openings on the sides, the antenna substrate 100 has higher strength and is more reliable than those having cavities that open on the sides. Furthermore, for example, by preparing first dielectric substrates 10 having radiation conductors 13 of different sizes, the antenna substrate 100 can have antenna characteristics that can be easily changed.

The examples shown in FIGS. 1 to 3 and the examples shown in FIGS. 4 and 5 each have a first dielectric substrate 10 having a radiation conductor 13 on the first surface 11 and a grounding conductor 23 on the third surface 21. , a second dielectric substrate 20 having a power supply conductor 24 on a fourth surface 22, and a third dielectric substrate 30 having a through hole 33. Further, in these examples, the second dielectric substrate 20 and the third dielectric substrate 30 are integrated into one dielectric substrate having a recessed portion on the upper surface. The third dielectric substrate 30 and the first dielectric substrate 10 are bonded together using a bonding material 40.

The structures of the antennas are different between the examples shown in FIGS. 1 to 3 and the examples shown in FIGS. 4 and 5. These have different forms of power feeding from the power feeding conductor 24 to the radiation conductor 13.

In the example shown in FIGS. 1 to 3, the power supply conductor 24 is a so-called microstrip line conductor, which extends from the outer edge of the fourth surface 22 (lower surface) of the second dielectric substrate 20 toward the center, and has a tip end. is located at the center of the fourth surface 22 (lower surface) of the second dielectric substrate 20. The ground conductor 23 has an opening 23a (slot) at a position overlapping one end of the power supply conductor 24. The opening 23a has a long shape in a direction perpendicular to the power supply conductor 24 when seen in plan view, and has a rectangular shape, for example. When a high frequency current (high frequency signal) flows into the power supply conductor 24 from an external circuit (not shown) connected to the other end of the power supply conductor 24, a magnetic field is generated around it, and this magnetic field passes through this opening 23a. , power is supplied from the power supply conductor 24 to the radiation conductor 13 by coupling the power supply conductor 24 and the radiation conductor 13. The length of the opening 23a (slot) and the length of the power supply conductor 24 can be set depending on the frequency of use. When the antenna is in operation, the ground conductor 23 is also connected to an external circuit (not shown) and has a ground potential. Although omitted in the examples shown in FIGS. 1 to 5 and in the examples described later, a conductor for connecting the ground conductor 23 to an external circuit can be provided.

In the example shown in FIGS. 4 and 5, the tip of the power supply conductor 24 and the radiation conductor 13 are electrically connected through a conductor, and power is supplied from the power supply conductor 24 to the radiation conductor 13. Electrical connection between the power supply conductor 24 and the radiation conductor 13 is achieved through a second through conductor 25 which is connected to one end of the power supply conductor 24 and is provided through the second dielectric substrate 20, and a third dielectric substrate. 30 , the conductive bonding material 40 , and the first through conductor 15 provided through the first dielectric substrate 10 and connected to the radiation conductor 13 . ing. It can also be said that the power supply conductor 24, the second penetration conductor 25, the third penetration conductor 36, the conductive bonding material 40, and the first penetration conductor 15 constitute a substantial power supply conductor. In this example, the first through conductor 15 is connected not to the center of the radiation conductor 13 but between the center and the outer edge. The position of the connection point (feeding point) of the first penetrating conductor 15 in the radiation conductor 13 (and the length of the feeding conductor 24) can be set depending on the frequency used. By optimizing the connection point (feeding point), the antenna substrate 100 has reduced loss. In order to connect the power supply conductor 24 and the radiation conductor 13 with the through conductor, a dielectric must be provided between the power supply conductor 24 and the radiation conductor 13. Therefore, the third dielectric substrate 30 in the example shown in FIGS. 4 and 5 has a protrusion 34 extending inward compared to the third dielectric substrate 30 in the example shown in FIGS. 1 to 3, A third through conductor 36 is provided in this protrusion 34 .

In the example shown in FIGS. 4 and 5, the lower surface (second surface 12) of the first dielectric substrate 10 and the upper surface (the upper surface of the third dielectric substrate 30) A bonding metal film 41 is provided on the fifth surface 31). The bonding metal film 41 has a frame shape for mechanically bonding the first dielectric substrate 10 and the third dielectric substrate 30, and a bonding layer between the first through conductor 15 and the third through conductor 36. A pad-like thing for electrical connection is provided. The pad-shaped bonding metal film 41 is provided inside the frame-shaped bonding metal film 41, and is provided on the upper surface of the protrusion 34 in the third dielectric substrate 30. Furthermore, a connection land (no reference numeral) is provided between the third through conductor 36 and the second through conductor 25 to prevent connection failures due to positional deviation. On the other hand, the ground conductor 23 is provided with an opening in order to provide a clearance between the ground conductor 23 and the connection land to prevent short circuit between them. The shape of this opening when viewed in plan is, for example, circular.

Note that when an opening 23a (slot) is provided in the grounding conductor 23 as in the example shown in FIGS. can radiate. If you want to increase the directivity of radio waves, it is possible to connect the feeding conductor 24 and the radiation conductor 13 with a through conductor 4a or the like so that the radio waves are radiated only in one direction outward from the radiation conductor 13. can. In this case, similarly to the examples shown in FIGS. 4 and 5, the third dielectric substrate 30 is provided with the protrusion 34, and the first to third dielectric substrates 10, 20, 30 are provided with the first to third dielectric substrates 10, 20, 30. Penetrating conductors 15, 25, and 36 may be provided.

The antenna substrate 100 of the example shown in FIGS. 6 and 7 has the same antenna structure as the antenna substrate 100 of the example shown in FIGS. 1 to 3, and the ground conductor 23 has an opening 23a. In the antenna substrate 100 of this example, the first dielectric substrate 10 and the third dielectric substrate 30 are integrated into one dielectric substrate having a recessed portion on the lower surface. The third dielectric substrate 30 and the second dielectric substrate 20 are bonded together using a bonding material 40. Further, the radiation conductor 13 is provided on the second surface 12 (lower surface) of the first dielectric substrate 10. Therefore, the first dielectric substrate 10 is not present between the radiation conductor 13 and the ground conductor 23, and the radiation conductor 13 and the ground conductor 23 face the hollow portion. In this case, the dielectric constant between the radiation conductor 13 and the ground conductor 23 can be made smaller. Therefore, the antenna substrate 100 can have excellent high frequency signal transmission characteristics. Further, since the radiation conductor 13 is covered with the first dielectric substrate 10, the radiation conductor 13 is less likely to be corroded by the atmosphere of the environment in which the antenna substrate 100 is used.

When the radiation conductor 13 is provided on the outer surface of the first dielectric substrate 10 as in the examples shown in FIGS. 1 to 5, there is no dielectric material or the like on the surface from which radio waves are radiated, so that the radio waves can be emitted further. can. The radiation conductor 13 can be arranged depending on the characteristics required of the antenna substrate 100.

Further, in the antenna substrate 100 shown in FIGS. 6 and 7, the feeding conductor 24 is inside the second dielectric substrate 20. Therefore, the feeding conductor 24 is less likely to be corroded by the atmosphere of the environment in which the antenna board 100 is used.

In the example antenna substrate 100 shown in FIGS. 8 and 9, the first dielectric substrate 10 and the second dielectric substrate 20 are flat plates, and the third dielectric substrate 30 is a frame-shaped flat plate having a through hole 33. The second surface 12 (lower surface) of the first dielectric substrate 10, the fifth surface 31 (upper surface) of the third dielectric substrate 30, and the third surface 21 (upper surface) of the second dielectric substrate 20 and the third The sixth surface 32 (lower surface) of the dielectric substrate 30 is bonded with a bonding material 40, respectively. Furthermore, although the structure of the antenna in this example is such that the ground conductor 23 has an opening 23a, one radiator is provided on both the first surface 11 and the second surface 12 of the first dielectric substrate 10, respectively. A conductor 13 is provided. The radiation conductor 13 on the first surface 11 and the radiation conductor 13 on the second surface 12 overlap with each other with the first dielectric substrate 10 in between when viewed from above. Further, in the antenna substrate 100 of this example as well, since the feeding conductor 24 is located inside the second dielectric substrate 20, the feeding conductor 24 is not easily corroded. Further, a power supply conductor 24 is provided inside the second dielectric substrate 20, and a ground conductor 23 is provided on the third surface 21 and the fourth surface 22 with the second dielectric substrate 20 interposed therebetween. That is, while the feed conductor 24 in the examples shown in FIGS. 1 to 7 is a microstrip line conductor, it is a strip line conductor. By connecting the ground conductor 23 on the third surface 21 and the ground conductor 23 on the fourth surface 22 with a through conductor that penetrates the second dielectric substrate 20, the potential difference between the two ground conductors 23 can be eliminated. At this time, the through conductors can be arranged along both sides of the feed conductor 24 (strip line).

In the example antenna substrate 100 shown in FIGS. 10 and 11, the second dielectric substrate 20 and the third dielectric substrate 30 are integrated into one dielectric substrate having a recessed portion on the upper surface. . The third dielectric substrate 30 and the first dielectric substrate 10 are bonded together using a bonding material 40. In this example, the through hole 33 of the third dielectric substrate 30 has a smaller opening on the sixth surface 32 (lower surface) than the opening on the fifth surface 31 (upper surface), and there is a step between the upper surface and the lower surface in the through hole 33. It has a section 35. The first dielectric substrate 10 has a size smaller than the third dielectric substrate 30 in a plan view, and is approximately the same size as the opening on the fifth surface 31 of the through hole 33 of the third dielectric substrate 30. The first dielectric substrate 10 enters the through hole 33 of the third dielectric substrate 30, and the second surface 12 (bottom surface) and the step surface (top surface) of the step portion 35 of the third dielectric substrate 30 are bonded together. It is joined at 40. The structure of the antenna in this example is also such that the ground conductor 23 has an opening 23a, but one radiation conductor is provided on both the first surface 11 and the second surface 12 of the first dielectric substrate 10, respectively. 13 are provided.

In the antenna substrate 100 of the example shown in FIGS. 12 and 13, the first dielectric substrate 10 and the second dielectric substrate 20 are flat plates, and the third dielectric substrate 30 is made of the first dielectric substrate 10 and the second dielectric substrate. It has a frame shape that is thicker than the substrate 20. In the third dielectric substrate 30 in this example, an intermediate portion in the thickness direction on the inner surface of the through hole 33 protrudes to form a stepped portion 35 . The opening in the middle part surrounded by the square frame-shaped step 35 is smaller than the opening on the fifth surface 31 (top surface) and the opening on the sixth surface 32 (bottom surface) of the through hole 33, and The bottom surface is a stepped surface. Further, in the third dielectric substrate 30 of this example, the portion above the step portion 35 has a square frame shape, and the portion below the step portion 35 has a C-shape in which a part of the square frame is cut out. It has become. The first dielectric substrate 10 is inserted into the opening on the upper surface of the third dielectric substrate 30, and the second surface 12 (lower surface) and the stepped surface (upper surface) of the stepped portion 35 of the third dielectric substrate 30 are bonded to each other. It is joined at 40. Further, the second dielectric substrate 20 enters into the opening on the lower surface of the third dielectric substrate 30, and the third surface 21 (upper surface) and the stepped surface (lower surface) of the stepped portion 35 of the third dielectric substrate 30 are connected to each other. They are joined with a joining material 40. Further, a portion of the side surface of the second dielectric substrate 20 protrudes, and this protruding portion enters a notch portion on the lower surface of the third dielectric substrate 30. The structure of the antenna in this example is also such that the ground conductor 23 has an opening 23a, and one radiation conductor 13 is provided on both the first surface 11 and the second surface 12 of the first dielectric substrate 10, respectively. is provided.

Like the antenna substrate 100 shown in FIGS. 8 to 13, the first dielectric substrate 10 has a radiation conductor 13 on both the first surface 11 and the second surface 12, and the radiation conductor 13 on the first surface 11 The antenna substrate 100 may have the radiation conductor 13 on the second surface 12 overlapping with the first dielectric substrate 10 in between. Since the two radiation conductors 13 are arranged so as to overlap with the first dielectric substrate 10 in between, a complex resonance occurs between the two radiation conductors 13, so that it is possible to transmit and receive signals in a wide frequency band. A possible broadband antenna substrate 100 can be provided.

As described above, in the antenna substrate 100 of the example shown in FIGS. 1 to 5 and FIGS. 10 and 11, the second dielectric substrate 20 and the third dielectric substrate 30 are integrated, and the first dielectric substrate 10 is integrated. They are joined with a joining material 40. In the example antenna substrate 100 shown in FIGS. 6 and 7, the first dielectric substrate 10 and the third dielectric substrate 30 are integrated, and the second dielectric substrate 20 is bonded with a bonding material 40. In the antenna substrate 100 of the example shown in FIGS. 8 and 9 and FIGS. 12 and 13, the first dielectric substrate 10, the second dielectric substrate 20, and the third dielectric substrate 30 are each separate bodies, and the first dielectric substrate The body substrate 10 and the third dielectric substrate 30 and the third dielectric substrate 30 and the second dielectric substrate 20 are bonded with a bonding material 40 .

The antenna characteristics can be changed by changing the size of the radiation conductor 13, the dielectric constant between the radiation conductor 13 and the ground conductor 23, and the like. If the first dielectric substrate 10, second dielectric substrate 20, and third dielectric substrate 30 are separate bodies, a wide variety of antenna substrates 100 with different antenna characteristics can be created by preparing a plurality of types of each and combining them. It can be made. On the other hand, since the number of joints using the bonding material 40 increases, there is a possibility that variations in characteristics will occur due to variations in the thickness of the bonding material 40, and manufacturing costs tend to increase. Therefore, if the first dielectric substrate 10 and the third dielectric substrate 30, or the second dielectric substrate 20 and the third dielectric substrate 30 are manufactured integrally, there will be only one joint. Characteristic variations and manufacturing costs are suppressed. Further, the antenna characteristics can be greatly changed depending on the size, arrangement, and number of the radiation conductors 13. If a plurality of types of antennas are prepared for changing antenna characteristics, manufacturing costs can be reduced by using a flat plate. For this reason, the second dielectric substrate 20 and the third dielectric substrate 30 are integrated, and the second surface 12 of the first dielectric substrate 10 and the third dielectric substrate 30 are bonded with the bonding material 40. The antenna substrate 100 can be bonded with

During the manufacturing process of the antenna board 100, the positional relationship in the planar direction between the radiation conductor 13, the ground conductor 23 (the opening 23a thereof), and the feeding conductor 24 is changed due to the positional deviation in the planar direction of the three dielectric substrates 10, 20, and 30. There is a possibility that the antenna characteristics will vary due to variations in the antenna characteristics. In order to reduce misalignment between the three dielectric substrates 10, 20, and 30, they may have irregularities that allow them to be easily positioned relative to each other.

As described above, the third dielectric substrate 30 in the antenna substrate 100 of the example shown in FIGS.
enters the opening in the upper surface of the third dielectric substrate 30 and is located above the step portion 35 . In other words, the third dielectric substrate 30 has a frame-shaped convex portion on the outer periphery of the upper surface, and the first dielectric substrate 10 is positioned inside the convex portion. Furthermore, in the antenna substrate 100 shown in FIGS. 12 and 13, the intermediate portion in the thickness direction of the inner surface of the through hole 33 of the third dielectric substrate 30 protrudes to form a stepped portion 35. The first dielectric substrate 10 enters into the opening on the upper surface of the third dielectric substrate 30 and is located above the stepped portion 35, and the second dielectric substrate 20 enters into the opening on the lower surface of the third dielectric substrate 30. It is located below the stepped portion 35.

In this way, the third dielectric substrate 30 has the step 35 on the inner surface of the through hole 33, and at least one of the first dielectric substrate 10 and the second dielectric substrate 20 is bonded to the step with the bonding material 40. The antenna substrate 100 may be joined to the antenna substrate 35. With such a configuration, the first dielectric substrate 10 and the second dielectric substrate 20 can be easily positioned, and misalignment is less likely to occur during the manufacturing process. Then, variations in the positional relationship between the radiation conductor 13 of the first dielectric substrate 10, the ground conductor 23 (opening 23a) of the second dielectric substrate 20, and the feed conductor 24 are reduced, so variations in antenna characteristics are reduced. The resulting antenna board 100 is obtained.

Here, FIG. 14 is an exploded perspective view showing another example of the antenna board. 15(a) is a top view of the antenna board shown in FIG. 14, FIG. 15(b) is a sectional view taken along line BB in FIG. 15(a), and FIG. 15(c) is a bottom view. . FIG. 16 is an exploded perspective view showing another example of the antenna board. 17(a) is a top view of the antenna board shown in FIG. 16, FIG. 17(b) is a sectional view taken along line BB in FIG. 17(a), and FIG. 17(c) is a bottom view. . FIG. 18 is an exploded perspective view showing another example of the antenna board. 19(a) is a top view of the antenna board shown in FIG. 18, FIG. 19(b) is a sectional view taken along line BB in FIG. 19(a), and FIG. 19(c) is a bottom view. . FIG. 20 is an exploded perspective view showing another example of the antenna board. 21(a) is a top view of the antenna board shown in FIG. 20, FIG. 21(b) is a sectional view taken along the line BB in FIG. 21(a), and FIG. 21(c) is a bottom view. . FIG. 22(a) is a perspective view showing an example of an antenna board and an antenna module, FIG. 22(b) is a cross-sectional view taken along line BB in FIG. 22(a), and FIG. 22(c) is a perspective view from the bottom. FIG.

The explanation so far has been about an example in which the antenna substrate 100 has one radiation conductor 13, in other words, an explanation about the antenna substrate 100 which has one antenna element. Substrate 100 may have multiple antenna elements.

That is, the antenna substrate 100 can have a plurality of radiation conductors 13 in the plane direction of the first surface 11 and the second surface 12 of the first dielectric substrate 10. Unlike the examples shown in FIGS. 8 to 13 in which the first dielectric substrate 10 has the radiation conductor 13 on both the first surface 11 and the second surface 12, the first surface of the first dielectric substrate 10 A plurality of radiation conductors 13 are provided on at least one of the first surface 11 and the second surface 12 in the plane direction of the first surface 11 and the second surface 12. It can also be referred to as a so-called array antenna substrate in which a plurality of antenna elements are arranged in a plane direction. Since such an antenna board 100 has a plurality of antenna elements, it is possible to increase the communication distance. Further, it can be a so-called phased array antenna in which directivity can be controlled by controlling the amplitude and phase of each of a plurality of antenna elements.

The antenna board 100 of the example shown in FIGS. 14 and 15 has the radiation conductor 13 of the example antenna board shown in FIGS. 8 and 9 on the first surface 11 and the second surface 12 of the first dielectric substrate 10, respectively. , is an example in which four 2×2 arrays are arranged in the plane direction. In accordance with the arrangement of the radiation conductor 13, four openings (slots) 23a of the ground conductor 23 are also arranged. Four power supply conductors 24 on the second surface 22 of the second dielectric substrate 20 are also arranged to correspond to the four slots 23a. The four power supply conductors 24 are connected to each other by a transmission conductor 26, and an end of the transmission conductor 26 is located on the outer periphery of the fourth surface 22. An end portion of the transmission conductor 26 located on the outer periphery is connected to an external circuit, and a high frequency current (high frequency signal) is supplied from the external circuit to each power supply conductor 24 via the transmission conductor 26. The length from the end of the transmission conductor 26 to each of the four power supply conductors 24 is the same. Therefore, the signal transmission loss due to the transmission conductor 26 is approximately the same, and variations in the characteristics of the four antenna elements can be suppressed. In this example, the first dielectric substrate 10 and the third dielectric substrate 30 and the third dielectric substrate 30 and the second dielectric substrate 20 are bonded using a bonding material 40.

The antenna substrate 100 of the example shown in FIGS. 16 and 17 differs greatly from the example shown in FIGS. 14 and 15 in that the third dielectric substrate 30 has four through holes 33. The third dielectric substrate 30 has four through holes 33 that overlap the four radiation conductors 13, respectively. Similarly, the first dielectric substrate 10 and the third dielectric substrate 30 and the third dielectric substrate 30 and the second dielectric substrate 20 are bonded using a bonding material 40.

Since the size of the array antenna in the planar direction is large, if the third dielectric substrate 30 has only one through hole 33, the through hole 33 will also be large. If the dimensions of the through hole 33 become larger than the dimensions of the third dielectric substrate 30, the strength of the third dielectric substrate 30 may decrease. Furthermore, if the size of the through hole 33 is larger than that of the first dielectric substrate 10 located above the through hole 33, the size of the first dielectric substrate 10 may vary depending on the thickness and material of the first dielectric substrate 10. The central portion is likely to be deformed, such as being depressed, or it is likely to be significantly deformed when the first dielectric substrate 10 comes into contact with an external object. These may change the antenna characteristics or break the first dielectric substrate 10.

When there are a plurality of through holes 33 that overlap the radiation conductor 13 of the third dielectric substrate 30, the size of the through hole 33 can be made smaller than when there is only one through hole 33. Therefore, the strength of the third dielectric substrate 30 does not decrease significantly, and the possibility of deformation or cracking of the first dielectric substrate 10 is reduced.

In the example antenna substrate 100 shown in FIGS. 16 and 17, the third dielectric substrate 30 has four through holes 33 that overlap with the four radiation conductors 13, respectively. In other words, one through hole 33 overlaps one radiation conductor 13. On the other hand, in the antenna substrate 100 shown in FIG. 22, the third dielectric substrate 30 has four through holes 33, but one through hole 33 overlaps with four radiation conductors 13. There is. In this way, the number of radiation conductors 13 overlapping each of the plurality of through holes 33 may be one or more. Depending on the size of the antenna substrate 100 and the materials and thicknesses of the first to third dielectric substrates 10, 20, and 30, the number and arrangement of the through holes 33 can be set so as to obtain sufficient strength.

Further, the antenna substrate 100 in the example shown in FIGS. 16 and 17 has not only the radiation conductor 13 provided on each of the first surface 11 and the second surface 12 but also four ground conductors 23. Each of the four ground conductors 23 is located at a position overlapping the radiation conductor 13 on the first surface 11 and the radiation conductor 13 on the second surface 12 when viewed from above. In contrast, the antenna substrate 100 shown in FIGS. 14 and 15 has one ground conductor to which four ground conductors 23 are connected. Since the ground conductors 23 are connected to the same ground potential, there may be a plurality of through holes 33 corresponding to each other on a one-to-one basis, or there may be one. Further, the number of ground conductors 23 may be one for a plurality of through holes 33, for example, two ground conductors may overlap two for four through holes 33.

The feeding conductor 24 in the antenna board 100 in the example shown in FIGS. 16 and 17 is different from the feeding conductor 24 in the example shown in FIGS. 14 and 15 in that the four feeding conductors 24 are connected to each other by a transmission conductor 26. Similarly, four feed conductors 24 are located inside the second dielectric substrate 20 and are connected to transmission conductors 26 . The transmission conductor 26 includes a film-like internal conductor layer that connects the four power supply conductors 24 to each other inside the second dielectric substrate 20 , and a film-like connection pad on the fourth surface 22 of the second dielectric substrate 20 . , a through conductor that penetrates a part of the second dielectric substrate 20 and connects the internal conductor layer and the connection pad. The connection pad is a part that is connected to an external circuit. It is also possible to provide conductors that lead out each of the four ground conductors 23 or all of the four ground conductors 23 to the fourth surface 22.

The antenna substrate 100 of the example shown in FIGS. 18 and 19 has a different shape of the through hole 33 from the example shown in FIGS. 16 and 17. In this example, the through-hole 33 has four openings on the sixth surface 32 and only one opening on the fifth surface 31 whose size overlaps with these four openings. The step portion 35 is provided in the through hole 33 in the example shown in FIGS. 16 and 17, and the width of the step portion 35 is widened so that adjacent step portions 35 are connected. The radiation conductors 13 on the first surface 11 and the second surface 12 of the antenna substrate 100 in the example shown in FIGS. It can also be said that the shape is such that the portion (sixth surface 32 side) is divided into four parts. In the antenna substrate 100 of this example, the second dielectric substrate 20 and the third dielectric substrate 30 are integrated into one dielectric substrate. The first dielectric substrate 10 and the third dielectric substrate 30 are bonded together using a bonding material 40 . The first dielectric substrate 10 has a size smaller than the third dielectric substrate 30 in a plan view, and is approximately the same size as the opening on the fifth surface 31 of the through hole 33 of the third dielectric substrate 30. The first dielectric substrate 10 enters the through hole 33 of the third dielectric substrate 30, and the second surface 12 (lower surface) of the first dielectric substrate 10 and the step part 35 of the third dielectric substrate 30 are connected to each other. The cross-shaped step surface (upper surface) is joined with a joining material 40.

Furthermore, the feed conductor 24 in the antenna board 100 in the example shown in FIGS. 18 and 19 has the same shape and arrangement as the feed conductor 24 in the example shown in FIGS. 16 and 17, and has a similar transmission conductor 26. The same is true. In the example shown in FIGS. 18 and 19, there is also a ground conductor 23 on the fourth surface 22 of the second dielectric substrate 20, and the feed conductor 24 is a strip line conductor as in the example shown in FIGS. 8 and 9. ing. The ground conductor 23 on the fourth surface 22 has an opening that provides a clearance between the ground conductor 23 and the connection pad of the transmission conductor 26 so as not to short-circuit with the connection pad. Also in this example, the ground conductor 23 on the third surface 21 and the ground conductor 23 on the fourth surface 22 are connected by a through conductor that penetrates the second dielectric substrate 20 to eliminate the potential difference between the two ground conductors 23. I can do it. At this time, the through conductors can be arranged along both sides of the inner conductor layers of the feed conductor 24 and the transmission conductor 26.

The antenna substrate 100 of the example shown in FIGS. 20 and 21 differs from the example shown in FIGS. 18 and 19 in the shapes of the first dielectric substrate 10 and the through hole 33. The third dielectric substrate 30 has four through holes 33. Further, it has four first dielectric substrates 10 that close each of the four through holes 33. One through hole 33 overlaps one radiation conductor 13 on the first surface 11 and one radiation conductor 13 on the second surface 12. Further, each of the four through holes 33 has a stepped portion 35. The first dielectric substrate 10 has a size smaller than the third dielectric substrate 30 in a plan view, and is approximately the same size as the opening on the fifth surface 31 of the through hole 33 of the third dielectric substrate 30. The four first dielectric substrates 10 are inserted into each of the four through holes 33 of the third dielectric substrate 30, one by one, and the second surface 12 (lower surface) of the first dielectric substrate 10 and the through holes 33 The stepped surface (upper surface) of the stepped portion 35 is bonded with a bonding material 40 . In the antenna substrate 100 of this example, the second dielectric substrate 20 and the third dielectric substrate 30 are integrated into one dielectric substrate having four recesses.

In the antenna substrate 100 shown in FIGS. 16 and 17, the plurality of through holes 33 are closed with one first dielectric substrate 10. In contrast, the antenna substrate 100 in the example shown in FIGS. 20 and 21 includes a plurality of first dielectric substrates 10 that close each of the plurality of through holes 33. With such a configuration, the first dielectric substrate 10 can be made smaller, so that warping and the like of the first dielectric substrate 10 is reduced. Furthermore, one first dielectric substrate 10 having a radiation conductor 13 is mounted for each ground conductor 23. Therefore, the positional accuracy of the radiation conductor 13 and the ground conductor is increased, and the antenna characteristics are highly accurate and have small variations.

Furthermore, in the antenna substrate 100 shown in FIGS. 20 and 21, the four feed conductors 24 are located inside the second dielectric substrate 20, and the ground conductor 23 is located on the fourth surface 22 of the second dielectric substrate 20. They are the same in that they are equipped as strip line conductors. However, the difference is that the four power supply conductors 24 are not connected to each other by one transmission conductor 26. A transmission conductor 26 is connected to each power supply conductor 24 and drawn out to the fourth surface 22 of the second dielectric substrate 20 at different positions. The transmission conductor 26 is a through conductor that penetrates a film-like connection pad on the fourth surface 22 of the second dielectric substrate 20 and a part of the second dielectric substrate 20 and connects the power supply conductor 24 and the connection pad. It is made up of. The ground conductor 23 on the fourth surface 22 has an opening that provides a clearance between the ground conductor 23 and the connection pad of the transmission conductor 26 so as not to short-circuit with the connection pad. With such a configuration, the high frequency currents (high frequency signals) supplied from the external circuit to each power supply conductor 24 can be made different from each other. Thereby, a phased array antenna capable of beam forming can be obtained.

The antenna substrate 100 shown in FIG. 22 is an example in which a total of 16 antenna elements (4×4) are arranged. The third dielectric substrate 30 in this example has four through holes 33 each having a stepped portion 35 . The third dielectric substrate 30 and the second dielectric substrate 20 are integrated into one dielectric substrate having four recesses. The antenna substrate 100 has four first dielectric substrates 10, and each of the four through holes 33 is closed with one first dielectric substrate 10. The second surface 11 of the first dielectric substrate 10 and the stepped portion 35 are bonded with a bonding material 40 . One first dielectric substrate 10 has four radiation conductors 13 on each of the first surface 11 and the second surface 12. The second dielectric substrate 20 has one ground conductor 23 on the third surface 21 that overlaps all the radiation conductors 13 in plan view. The ground conductor 23 has a total of 16 openings (slots) 23a, one at a position overlapping each radiation conductor 13. Each through hole 33 overlaps with the four radiation conductors 13 on the first surface 11 and the second surface 12 in plan view, and overlaps with a region of the ground conductor 23 on the third surface 21 including the four slots 23a. Further, inside the second dielectric substrate 20, there is a ground conductor 23 at a position sandwiching the power supply conductor 24 between a total of 16 power supply conductors 24 and the ground conductor 23 on the third surface 21. is a strip line conductor. Each feed conductor 24 is connected to a transmission conductor 26. The transmission conductor 26 includes a film-like internal conductor layer extending in the direction of the third surface 21 and the fourth surface 22 inside the second dielectric substrate 20 , and a film on the fourth surface 22 of the second dielectric substrate 20 . It is composed of a shaped connection pad and a through conductor that penetrates a part of the second dielectric substrate 20 and connects the power supply conductor 24 and the internal conductor layer, or connects the internal conductor layer and the connection pad. . The transmission conductor 26 may include one that is not connected to the power supply conductor 24. For example, one end is connected to the ground conductor 23 and the other end is a connection pad.

The antenna substrate 100 in the example shown in FIGS. 14 to 21 includes four antenna elements, and the antenna substrate 100 in the example shown in FIG. 22 is an array antenna substrate including 16 antenna elements. The number of radiation conductors 13 arranged in the plane direction of the first surface 11 and the second surface 12 is not limited to these, and an array antenna substrate having even more radiation conductors 13 can be formed. Since the antenna substrate 100 becomes larger when it has more radiation conductors 13, it is important to ensure strength by providing the third dielectric substrate 30 with a structure having a plurality of through holes 33. Further, the structure having a plurality of first dielectric substrates 10 has a remarkable effect of reducing the accuracy and variation in antenna characteristics.

In the antenna substrate 100 shown in FIGS. 14 to 21, each antenna element is oriented in the same direction (the length direction of the feeding conductor 24), but antenna elements may be oriented in different directions.
Further, although the description is given as having the radiation conductor 13 and transmitting radio waves, it may be one that transmits and receives radio waves. In the case of an array antenna, the plurality of antenna elements may include a transmitting antenna element and a receiving antenna element.

The antenna substrate 100 as described above can be used for an antenna module, and in that case, the antenna substrate 100 will have a semiconductor element 200 mounted thereon. For example, as in the example shown in FIG. 22, the antenna substrate 100 may have a mounting portion 27 for the semiconductor element 200 on the fourth surface 22 of the second dielectric substrate 20. Then, the semiconductor element 200 is mounted on the mounting portion 27 of such an antenna substrate 100 to form an antenna module 300. In FIG. 22(c), the mounting portion 27 is an area located at the center of the fourth surface 22 and surrounded by a two-dot chain line. In the example antenna substrate 100 shown in FIG. 22, the mounting portion 27 on the fourth surface 22 of the second dielectric substrate 20 has a connection pad for the transmission conductor 26 connected to the power supply conductor 24. The semiconductor element 200 is mounted on the mounting part 27, and the electrodes (not shown) of the semiconductor element 200 and the connection pads 26a of the mounting part 27 are electrically connected to form an antenna module 300. The semiconductor element 200 includes circuits for signal processing, amplification, transmission/reception switching, phase switching, frequency switching, etc., and the signals transmitted and received by the antenna board 100 are controlled by this circuit.

Compared to the case where the semiconductor element 200 and the antenna board are mounted on an external circuit board to form a communication module, the wiring length between the semiconductor element 200 and the antenna element (the feeding conductor 24 thereof) is shorter, so the loss is smaller. High frequency signal transmission and reception become efficient. Further, since the antenna substrate 100 and the semiconductor element 200 are arranged in an overlapping manner, the antenna module 300 becomes small.

The mounting portion 27 in the example antenna substrate 100 shown in FIG. 22 is located at the center of the flat fourth surface 22 of the second dielectric substrate 20. A recess may be provided on the fourth surface 22 of the second dielectric substrate 20, and a mounting portion 27 may be provided on the bottom surface of the recess. In this way, the semiconductor element 200 can be prevented from protruding from the antenna substrate 100 (the fourth surface 22 of the second dielectric substrate 20), so the semiconductor element 200 can be easily protected, and the connection pad 26a It is easy to connect to an external circuit board. Alternatively, the semiconductor element 200 can be sealed by filling the recess with a sealing resin. Further, there are connection pads 26a around the mounting portion 27, but these are connection pads 26a of the transmission conductor 26 that are not connected to the power supply conductor 24 described above. Although shown schematically in FIG. 22(b), the length from the connection pad 26a of the transmission conductor 26 to each power supply conductor 24 can be made the same as described above.

The first dielectric substrate 10, the second dielectric substrate 20, and the third dielectric substrate 30 are the basic structural parts of the antenna substrate 100, and are used to ensure the mechanical strength of the antenna substrate 100, the radiation conductor 13, It has functions such as ensuring insulation between the ground conductor 23 and the power supply conductor 24. The first dielectric substrate 10 and the second dielectric substrate 20 have, for example, a rectangular shape such as a square when viewed from above (in plan view), and are flat. The third dielectric substrate 30 has a similar outer shape, such as a square, and has at least one through hole 33 . These dimensions include, for example, the length of one side of the rectangle is 2 mm to 60 mm, and the thickness is 0.3 mm to 3 mm. The through hole 33 has a rectangular shape such as a square in a plan view, and has an inner dimension of, for example, 1 mm to 54 mm. A rectangular shape such as a square includes not only a strict square but also a square with rounded corners.

The first dielectric substrate 10, the second dielectric substrate 20, and the third dielectric substrate 30 (hereinafter collectively referred to as dielectric substrates) may be made of, for example, an aluminum oxide sintered body, a glass ceramic sintered body, or a mullite-based sintered body. It is formed of a dielectric material made of a ceramic material such as a sintered body or an aluminum nitride sintered body.

For example, if the dielectric substrate is made of a glass ceramic sintered body, it can be manufactured as follows. First, a raw material powder mainly composed of powders such as silicon oxide and boron oxide as glass components and aluminum oxide as a filler component is kneaded with an organic solvent and a binder to form a slurry. A ceramic green sheet (hereinafter also referred to as a green sheet) is formed into a sheet shape using a molding method such as a lip coater method to serve as a dielectric substrate. One dielectric substrate may be fabricated using one green sheet, or one dielectric substrate may be fabricated by laminating a plurality of green sheets. The through hole 33 of the third dielectric substrate 30 can be easily formed by providing a through hole in a ceramic green sheet using a mold or the like. When producing one dielectric substrate by laminating a plurality of green sheets, a laminate is produced by laminating a plurality of green sheets. The laminate can be produced by stacking green sheets and pressing them. Thereafter, a dielectric substrate can be manufactured by firing this green sheet or laminate at a temperature of about 900 to 1000°C. When the first dielectric substrate 10 and the third dielectric substrate 30 are integrated, a laminate of a green sheet for the first dielectric substrate 10 and a green sheet for the third dielectric substrate 30 is used. All you have to do is prepare it and then fire it. When the second dielectric substrate 20 and the third dielectric substrate 30 are integrated, a laminate of a green sheet for the second dielectric substrate 20 and a green sheet for the third dielectric substrate 30 is used. All you have to do is prepare it and then fire it. When the third dielectric substrate 30 has a stepped portion 35 in the through hole 33, a laminate may be produced by laminating green sheets having different sizes of through holes.

A radiation conductor 13 is provided on at least one of the first surface 11 and second surface 12 of the first dielectric substrate 10, a ground conductor 23 is provided on the third surface 21 of the second dielectric substrate 20, and a ground conductor 23 is provided on the fourth surface 22 or inside. A power supply conductor 24 is provided. Moreover, when using solder as the bonding material 40, a bonding metal film 41 is provided.

When the tip of the feeding conductor 24 and the radiation conductor 13 are electrically connected by a conductor, as in the antenna substrate 100 shown in FIGS. 4 and 5, the first dielectric substrate 10 has a first through hole. The conductor 15 is provided, the second through conductor 25 is provided on the second dielectric substrate 20, and the third through conductor 36 is provided on the third dielectric substrate 30, respectively. In addition, in the antenna substrate 100 of this example, the first dielectric substrate 10 and the third dielectric substrate 30 are joined by soldering as the bonding material 40, so that the second surface 12 of the first dielectric substrate 10 and the second surface 12 of the first dielectric substrate 10 and A bonding metal film 41 is provided on the upper surface of the 3-dielectric substrate 30. Further, a connection land (no reference numeral) is provided between the second through conductor 25 and the third dielectric substrate 30. Further, in the case of the antenna substrate 100 which is an array antenna such as the examples shown in FIGS. 14 to 22, the transmission conductor 26 is provided on the fourth surface 22 of the second dielectric substrate 20 or inside.

Radiation conductor 13, ground conductor 23, power supply conductor 24, connection land, bonding metal film 41, internal conductor layer and connection pad 26a of transmission conductor 26 (hereinafter also collectively referred to as conductor layer), and first penetration The through conductors of the conductor 15, the second through conductor 25, the third through conductor 36, and the transmission conductor 26 (hereinafter, these three are also simply referred to as through conductors) are made of, for example, tungsten, molybdenum, manganese, copper, or silver. The conductor material mainly contains metals such as palladium, gold, platinum, nickel, or cobalt, or alloys containing these metals. Such a metal material can be provided on the surface and inside of the dielectric substrate, for example, as a so-called metallized conductor.

For example, when the conductor layer is a copper metallized layer, a metal paste prepared by mixing copper powder with an organic solvent and an organic binder is printed on a predetermined position of the green sheet by a method such as screen printing. It can be formed by a method in which the green sheet is fired together with the green sheet. Further, the through conductor can be formed by providing a through hole at a predetermined position of the green sheet prior to printing the metal paste described above, and filling the through hole with the same metal paste as described above.

Furthermore, a plating layer of nickel, gold, or the like may be further deposited on the exposed surface of the metallized layer, which becomes the conductor layer, by a plating method such as electrolytic plating or electroless plating.

The shape of the radiation conductor 13 in plan view is rectangular or circular, and can be square in order to provide the radiation conductor 13 as large as possible on the square first dielectric substrate 10. Further, the shape of the ground conductor 23 in a plan view can be similar to the radiation conductor 13 and slightly larger. The ground conductor 23 can be arranged so that the outer periphery of the ground conductor 23 is located outside and overlaps the outer periphery of the radiation conductor 13 when seen in plan view. By doing so, radio waves can be reliably radiated to the outer circumference of the radiation conductor 13.

The sizes of the radiation conductor 13 and the ground conductor 23 are determined depending on the antenna characteristics required for the antenna substrate 100 and the relative permittivity between the radiation conductor 13 and the ground conductor 23, that is, the ratio of the first dielectric substrate 10. It can be set as appropriate depending on the dielectric constant, thickness, and distance between the first dielectric substrate 10 and the second dielectric substrate 20. The same applies to the dimensions of the opening 23a (slot) provided in the ground conductor 23 and the power supply conductor 24.

As the bonding material 40, other than the above-mentioned solder, glass, a mixture of glass and ceramics, an adhesive mainly composed of an organic resin, etc. can be used. For example, bonding can be performed by applying a paste-like precursor of the bonding material 40 to a predetermined position and heating it. Instead of applying a paste, for example, a bonding material 40 processed into a predetermined shape, such as a solder preform, is placed at a treatment position, such as between the first dielectric substrate 10 and the third dielectric substrate 30. You can leave it there.

10... First dielectric substrate 11... First surface 12... Second surface 13... Radiation conductor 15... First through conductor 20... Second dielectric substrate 21... ...Third surface 22...Fourth surface 23...Grounding conductor 23a...Opening (slot)
24...Feeding conductor 25...Second through conductor 26...Transmission conductor 26a...Connection pad 27...Mounting section 30...Third dielectric substrate 31... Fifth surface 32...Sixth surface 33...Through hole 34...Protrusion 35...Step 36...Third through conductor 40...Joining material 41...・Metal film for bonding 100...Antenna substrate 200...Semiconductor element 300...Antenna module

Claims (8)

a first dielectric substrate having a first surface and a second surface opposite to the first surface, and having a radiation conductor on at least one of the first surface and the second surface;
It has a third surface and a fourth surface opposite to the third surface, has a ground conductor on the third surface that overlaps the radiation conductor in plan view, and has a power supply conductor on the fourth surface or inside. a second dielectric substrate having;
It is located between the first dielectric substrate and the second dielectric substrate, has a fifth surface and a sixth surface opposite to the fifth surface, and has a fifth surface and a sixth surface opposite to the fifth surface. a third dielectric substrate having a through hole that extends through the surface and overlaps the radiation conductor and the ground conductor in plan view;
At least one of the third dielectric substrate and the first dielectric substrate and the third dielectric substrate and the second dielectric substrate are bonded with a bonding material,
The third dielectric substrate has a step in the through hole, and at least one of the first dielectric substrate and the second dielectric substrate is bonded to the step with the bonding material. antenna board. The first dielectric substrate has the radiation conductor on both the first surface and the second surface, and the radiation conductor on the first surface and the radiation conductor on the second surface are connected to the first dielectric substrate. The antenna substrate according to claim 1, wherein the antenna substrates are sandwiched and overlapped. The second dielectric substrate and the third dielectric substrate are integrated, and the second surface of the first dielectric substrate and the third dielectric substrate are bonded with the bonding material. 3. The antenna substrate according to claim 1 or claim 2. The antenna board according to any one of claims 1 to 3, comprising a plurality of said radiation conductors in the plane direction of said first surface and said second surface. The antenna board according to claim 4 , wherein the third dielectric substrate has a plurality of the through holes that overlap with one or more of the radiation conductors. The antenna board according to claim 5 , comprising a plurality of said first dielectric substrates that close each of said plurality of through holes. 7. The antenna board according to claim 4 , further comprising a mounting portion for a semiconductor element on the fourth surface of the second dielectric substrate. An antenna module in which a semiconductor element is mounted on the mounting portion of the antenna substrate according to claim 7 .

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