Substrate, and communication device

Abstract

To provide a substrate that can prevent the influence on the gain of an antenna, and a communication device.SOLUTION: A clearance area 26 isolated from a through hole conductor 10 and a conductor pattern 22 is arranged around the through hole conductor 10. The clearance area has a surface exposure part 29 that is not covered by a resin composition and exposes its surface. In this case, when an antenna module 3 is mounted on the through hole conductor with solder 33, the influence on the gain of an antenna can be prevented.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a substrate and a communication device. [Background technology]

[0002] Conventionally, there has been known a board that transmits a high-frequency signal using a through-hole with a pseudo-coaxial structure to reduce transmission loss of the high-frequency signal. For example, in Patent Document 1, a pseudo-coaxial structure through-hole is formed to transmit a high-frequency signal from a first surface to a second surface of a component mounting board. This pseudo-coaxial structure through-hole is composed of a high-frequency signal through-hole and a ground through-hole provided alongside it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 145015 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described board, a clearance area is sometimes provided around the through-hole conductor to separate the through-hole conductor from the conductor pattern at ground potential. When an antenna module is mounted on such a board, it is necessary to suppress the effect of the clearance area structure on the antenna gain.

[0005] Therefore, an object of the present disclosure is to provide a substrate and a communication device that can suppress the effect on antenna gain. [Means for solving the problem]

[0006] A substrate according to one aspect of the present disclosure comprises a dielectric layer, a through-hole conductor penetrating the dielectric layer in the thickness direction, a conductor pattern provided on the surface of one side of the dielectric layer in the thickness direction and connected to a reference potential, a resin layer laminated on the conductor pattern and containing a resin composition, and a clearance region disposed around the through-hole conductor on one side of the dielectric layer in the thickness direction and separating the through-hole conductor and the conductor pattern, wherein the dielectric layer has a surface exposed portion that is exposed on the surface in the clearance region.

[0007] A substrate according to one aspect of the present disclosure comprises a dielectric layer, a through-hole conductor penetrating the dielectric layer in the thickness direction of the dielectric layer, a conductor pattern provided on the surface of one side of the dielectric layer in the thickness direction and connected to a reference potential, a first resin layer laminated on the conductor pattern and containing a resin composition, a clearance region disposed around the through-hole conductor on one side of the dielectric layer in the thickness direction and separating the through-hole conductor and the conductor pattern, and a second resin layer laminated on the surface of the dielectric layer in the clearance region and containing a resin composition, the thickness of the second resin layer being smaller than the thickness of the conductor pattern.

[0008] A communication device according to one aspect of the present disclosure includes the above-described substrate, the substrate having a cavity formed by surrounding the through-hole conductor with a ground pillar, and a substrate integrated waveguide coupled to the cavity.

[0009] A communication device according to one aspect of the present disclosure includes the above-described substrate and an antenna module mounted on one end of the substrate's through-hole conductor in the thickness direction, the antenna module having a signal through-hole conductor connected to the through-hole conductor, a reference potential conductor pattern surrounding the signal through-hole conductor and connected to a reference potential, and an antenna clearance area separating the signal through-hole conductor and the reference potential conductor pattern, the antenna clearance area having a smaller area than the clearance area of ​​the substrate, and the reference potential conductor pattern and a portion of the antenna clearance area being covered by a resin composition. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to provide a substrate and a communication device that can suppress the effect on antenna gain. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic perspective view illustrating a substrate and a communication device according to an embodiment of the present disclosure. [Figure 2] FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a plan view showing the structure around the clearance region. [Figure 5] FIG. 10 is a cross-sectional view of the periphery of a clearance region of a substrate according to a modified example. [Figure 6] FIG. 10 is a cross-sectional view of the periphery of a clearance region of a substrate according to a modified example. [Figure 7] FIG. 6(b) is a plan view of the structure shown in FIG. [Figure 8] 10 is a graph showing the results of a simulation. [Figure 9] FIG. 1 is a diagram illustrating a simulation model. [Figure 10] FIG. 10 is a cross-sectional view showing a model serving as a comparative example. [Figure 11] 10A and 10B are diagrams illustrating the relationship between the protrusion amount of the protruding portion and the characteristics. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0013] FIG. 1 is a schematic perspective view showing a substrate 1 and a communication device 100 according to an embodiment of the present disclosure. As shown in FIG. 1, the communication device 100 includes a substrate 1, a high-frequency integrated circuit 2, and an antenna module 3. The substrate 1 has one surface 1a and the other surface 1b in the thickness direction. The substrate 1 includes a coaxial conversion structure 4 for mounting the antenna module 3, and a transmission line 6 that connects the antenna module 3 and the high-frequency integrated circuit 2. Note that FIG. 1 shows a state in which the antenna module 3 is disassembled from the substrate 1.

[0014] The radio frequency integrated circuit 2 (RFIC) is an integrated circuit that processes radio frequency signals and is mounted on the other surface 1b of the substrate 1. The radio frequency integrated circuit 2 is electrically connected to the antenna module 3 via a transmission line 6 of the substrate 1. The radio frequency integrated circuit 2, for example, performs reception processing of a radio frequency signal output from the antenna module 3 and outputs a reception signal having a lower frequency than the radio frequency signal from an output terminal (not shown). The radio frequency integrated circuit 2, for example, performs transmission processing of a transmission signal input from an input terminal (not shown) and outputs a radio frequency signal having a higher frequency than the transmission signal to the antenna module 3.

[0015] The antenna module 3 is a substrate on which an antenna 7 is formed on or inside the substrate 1. The antenna module 3 is mounted on one surface 1a of the substrate 1 at the position of the coaxial conversion structure 4. The antenna module 3 is formed using a material with a small dielectric loss tangent (small high-frequency signal loss) and good high-frequency signal transmission characteristics. Examples of such materials include fluororesin, liquid crystal polymer (LCP), polyphenylene ether (PPE) resin, and low-temperature co-fired ceramics.

[0016] The antenna 7 may be, for example, a patch antenna array in which a plurality of radiating elements 8 are arranged two-dimensionally. In addition to a patch antenna array, a linear antenna, a microstrip antenna, or other antennas may be used as the antenna 7. The antenna 7 is not particularly limited as long as it has a structure that can be formed on the surface or inside the antenna module 3. A more detailed structure of the antenna module 3 will be described later.

[0017] Next, the detailed structure of the substrate 1 will be described with reference to FIG. 2. In the following description, the X-axis and Y-axis directions are defined relative to the plane of the substrate 1, and the Z-axis direction is defined in the thickness direction of the substrate 1. The X-axis direction is parallel to the surface 1a of the substrate 1, with one side defined as the positive side. The Y-axis direction is parallel to the surface 1a of the substrate 1 and perpendicular to the X-axis direction, with one side defined as the positive side. The Z-axis direction is perpendicular to the X-axis and Y-axis directions, with the surface 1a side defined as the positive side. The coaxial conversion structure 4 of the substrate 1 has a through-hole conductor 10 penetrating the substrate 1 in the Z-axis direction. The coaxial conversion structure 4 converts the SIW structure of the substrate integrated waveguide 13 of the transmission line 6 into a coaxial structure. The substrate 1 includes a cavity 12 and the substrate integrated waveguide 13 as the transmission line 6. The cavity 12 of the coaxial conversion structure 4 is formed by surrounding the through-hole conductor 10 with multiple ground pillars 16. The plurality of ground pillars 16 constituting the cavity 12 are arranged on the positive and negative sides of the through-hole conductor 10 in the X-axis direction and on the positive side in the Y-axis direction. In this specification, the term "cavity 12" does not refer to a space where no objects exist, but rather to a region where no conductor pattern exists but a dielectric layer exists. The substrate integrated waveguide 13 is a waveguide having a SIW (Substrate Integrated Waveguide) structure. The substrate integrated waveguide 13 is connected to the cavity 12. The substrate integrated waveguide 13 is formed by a conductor pattern connected to a reference potential provided on the surface 1a of the substrate 1, a conductor pattern connected to a reference potential provided on the surface 1b of the substrate 1, and a plurality of ground pillars 17 that penetrate a dielectric layer provided in an inner layer of the substrate 1 in the Z-axis direction and are connected to the conductor pattern on the surface 1a and the conductor pattern on the surface 1b. This structure allows electromagnetic waves to propagate through the inner layer of the substrate 1. The substrate integrated waveguide 13 extends from the through-hole conductor 10 toward the negative side in the Y-axis direction. The substrate integrated waveguide 13 has rows of ground pillars 17 on both sides in the X-axis direction. In one row, multiple ground pillars 17 are lined up at a predetermined pitch in the Y-axis direction.The ground pillar 16 penetrates a dielectric layer provided in an inner layer of the substrate 1 in the Z-axis direction and is connected to a conductor pattern on the front surface 1a side that is connected to a reference potential (ground). Note that, although an SIW structure is exemplified as an example of the transmission line 6 in this embodiment, a stripline, a microstripline, or the like may also be used as the transmission line 6.

[0018] Next, the structure of the substrate 1 near the coaxial conversion structure 4 will be described with reference to Figures 3 and 4. Figure 3 is a cross-sectional view taken along line III-III in Figure 1 when the antenna module 3 is mounted on the substrate 1. Figure 4 is a plan view of the coaxial conversion structure 4. As shown in Figure 3, the substrate 1 includes a dielectric layer 21, a through-hole conductor 10, a conductor pattern 22, a conductor pattern 23, a resin layer 24, and a clearance region 26.

[0019] The dielectric layer 21 is a flat layer made of a dielectric material. The material of the dielectric layer 21 is not particularly limited, but may be made of a material having a dielectric loss tangent greater than that of the antenna module 3. Examples of such materials include inexpensive materials that have been commonly used for rigid or flexible substrates (e.g., resin materials such as epoxy and polyimide). Other materials that may be used for the dielectric layer 21 include fluororesin, bismaleimide resin, glass, and low-temperature fired ceramics. The thickness of the dielectric layer 21 is not particularly limited, but may be set to, for example, 50 μm to 1000 μm.

[0020] The through-hole conductor 10 is a conductor that penetrates the dielectric layer 21 in the Z-axis direction in the coaxial conversion structure 4. When a center line CL1 extending in the Z-axis direction is set for the coaxial conversion structure 4, the through-hole conductor 10 has a cylindrical shape centered on the center line CL1. The through-hole conductor 10 has an expanded diameter portion 27 on a surface 21a on one side (the positive side in the Z-axis direction) of the dielectric layer 21. This expanded diameter portion 27 functions as a pad on which the antenna module 3 can be mounted via solder 22. The material of the through-hole conductor 10 is not particularly limited, and Cu, Ag, Au, Cr, Ti, etc. may be used. Similar materials may also be used for other conductors.

[0021] The conductor pattern 22 is provided on the surface 21a on the positive side (one side) of the dielectric layer 21 in the Z-axis direction, and is a pattern connected to a reference potential (ground potential). The conductor pattern 22 is formed to extend along the XY plane so as to cover the surface 21a except for the clearance region 26. The thickness of the conductor pattern 22 is not particularly limited, but may be set to, for example, 5 μm to 50 μm.

[0022] The conductor pattern 23 is a pattern provided on the surface 21b on the negative side (other side) of the dielectric layer 21 in the Z-axis direction. The conductor pattern 23 is formed to extend along the XY plane so as to cover the surface 21b. The thickness of the conductor pattern 23 is not particularly limited, but may be set to, for example, 5 μm to 50 μm. The end of the through-hole conductor 10 on the negative side in the Z-axis direction is connected to the conductor pattern 23. The conductor pattern 23 is also a pattern connected to the reference potential (ground potential). The layer structure of the substrate 1 is not limited to that shown in the figure, and the substrate may be a multilayer substrate in which a dielectric layer or other conductor patterns are further laminated below the conductor pattern 23.

[0023] The resin layer 24 is a layer containing a resin composition and is laminated on the conductor pattern 22 at the reference potential (ground potential). The resin layer 24 corresponds to the "first resin layer" in the claims. The resin layer 24 is formed to extend along the XY plane so as to cover the surface of the conductor pattern 22 on the positive side in the Z-axis direction. The thickness of the resin layer 24 is not particularly limited, but may be set to, for example, 5 μm to 50 μm. The resin composition is not particularly limited as long as it is an insulating material, but epoxy resin, alkaline-soluble resin, etc. may be used. Note that similar materials may also be used for the resin composition used in other parts. The resin layer 24 is a member called a solder resist, and when mounting the antenna module 3 in the through-hole conductor 10, it plays a role (insulation) in preventing solder from adhering to areas other than the enlarged diameter portion 27 (pad) of the through-hole conductor 10.

[0024] Clearance region 26 is disposed around through-hole conductor 10 and separates through-hole conductor 10 from conductor pattern 22 at a reference potential (ground potential). In clearance region 26, outer peripheral surface 27a of enlarged diameter portion 27 of through-hole conductor 10 is formed in a circular shape centered on center line CL1 when viewed from the Z-axis direction (see FIG. 4). Conductive pattern 22 has hole 28 at a position corresponding to clearance region 26, surrounding through-hole conductor 10 when viewed from the Z-axis direction. Hole 28 is formed in a circular shape centered on center line CL1. Inner peripheral surface 28a of hole 28 of such conductor pattern 22 is disposed at a position spaced radially outward from outer peripheral surface 27a of enlarged diameter portion 27.

[0025] With this configuration, the surface 21a of the dielectric layer 21 is not covered with a conductor between the outer peripheral surface 27a of the through-hole conductor 10 and the hole 28 of the conductive pattern 22. Furthermore, in this embodiment, no resin composition is provided on the surface 21a of the dielectric layer 21 in the clearance region 26, and the entire surface 21a is exposed. Therefore, the dielectric layer 21 has an exposed surface portion 29 that is exposed to the surface in the clearance region 26. In this case, when viewed from the Z-axis direction, the exposed surface portion 29 is disposed so as to contact the inner edge (outer peripheral surface 27a) of the clearance region 26. Furthermore, when viewed from the Z-axis direction, the exposed surface portion 29 is disposed so as to contact the outer edge (inner peripheral surface 28a of the hole 28) of the clearance region 26. As a result, the exposed surface portion 29 occupies the entire clearance region 26. When viewed from the Z-axis direction, the exposed surface portion 29 has an annular shape centered on the center line CL1 (see FIG. 4).

[0026] The end 10a of the through-hole conductor 10 on the positive side (one side) in the Z-axis direction has a conductor central portion 30, a covering portion 31, and a first conductor exposed portion 32. The conductor central portion 30 is a region including the center line CL1 and its periphery, where the end 10a of the through-hole conductor 10 is exposed from the resin composition. In the conductor central portion 30 before the antenna module 3 is mounted, the end 10a of the through-hole conductor 10 is exposed (see FIG. 4). After the antenna module 3 is mounted, the antenna module 3 is joined to the conductor central portion 30 via solder 33 (see FIG. 3). The covering portion 31 is a portion covered with the resin composition that surrounds the conductor central portion 30. The covering portion 31 has an annular shape centered on the center line CL1 when viewed in the Z-axis direction (see FIG. 4). The thickness of the covering portion 31 may be equivalent to that of the resin layer 24 (first resin layer).

[0027] The first conductor exposed portion 32 is a surface-exposed portion of the through-hole conductor 10 located at the boundary between the coating 31 and the clearance region 26. The inner end of the clearance region 26 is the outer peripheral surface 27a of the expanded diameter portion 27. The first conductor exposed portion 32 corresponds to the edge portion near the outer peripheral surface 27a. Specifically, the outer peripheral surface 31a of the coating 31 is located radially inward of the outer peripheral surface 27a of the expanded diameter portion 27. Therefore, the portion of the end 10a of the through-hole conductor 10 that is outer than the coating 31 is exposed from the resin composition. This portion constitutes the first conductor exposed portion 32. The first conductor exposed portion 32 has an annular shape centered on the center line CL1 when viewed from the Z-axis direction (see FIG. 4).

[0028] The conductor pattern 22 has a second conductor exposed portion 36 where the surface of the conductor pattern 22 is exposed at an edge located at the boundary with the clearance region 26. The outer peripheral end of the clearance region 26 is the inner circumferential surface 28a of the hole 28 of the conductor pattern 22. The second conductor exposed portion 36 corresponds to the edge near the inner circumferential surface 28a of the hole 28. Specifically, the inner circumferential surface 24a of the resin layer 24 is disposed radially outer than the inner circumferential surface 28a of the hole 28. Therefore, the portion of the surface of the conductor pattern 22 that is inner than the resin layer 24 is exposed from the resin composition. This portion constitutes the second conductor exposed portion 36. The second conductor exposed portion 36 has an annular shape centered on a center line CL1 when viewed from the Z-axis direction (see FIG. 4).

[0029] Next, with reference to FIG. 4, the dimensional relationship between each part of the coaxial conversion structure 4 will be described. The diameter of the clearance region 26, i.e., the diameter of the inner circumferential surface 28a of the hole 28, may be set to 100 μm to 1000 μm. This dimension is set to 663 μm in the simulation of FIG. 8 described later. The diameter of the through-hole conductor 10, i.e., the diameter of the outer circumferential surface 27a of the expanded diameter portion 27, may be set to 50 μm to 500 μm. This dimension is set to 300 μm in the simulation of FIG. 8 described later. The radial width of the covering portion 31 may be set to 5 μm to 100 μm. This dimension is set to 50 μm in the simulation of FIG. 8 described later. The diameter of the conductor central portion 30 may be set to 50 μm to 500 μm. This dimension is set to 150 μm in the simulation of FIG. 8 described later. The diameter of the ground pillar 16 adjacent to the coaxial conversion structure 4 may be set to the same dimension as the conductor central portion 30. The radial width of the first conductor exposed portion 32 and the second conductor exposed portion 36 may be set to 5 μm to 100 μm. In the simulation of FIG. 8 described later, this dimension is set to 25 μm.

[0030] Next, with reference to FIG. 3 , the configuration of the antenna module 3 will be described in detail. The antenna module 3 includes a dielectric layer 40, a signal through-hole conductor 41, a reference potential conductor pattern 42, and an antenna clearance region 43. The dielectric layer 40 is a flat member that constitutes the main body of the antenna module 3. The signal through-hole conductor 41 is a conductor connected to the through-hole conductor 10 via solder 33. The signal through-hole conductor 41 is disposed on the surface 40a on the negative side in the Z-axis direction of the dielectric layer 40. The signal through-hole conductor 41 is disposed coaxially with the through-hole conductor 10, centered on a center line CL1. The reference potential conductor pattern 42 is a conductor pattern that surrounds the signal through-hole conductor 41 and is connected to a reference potential. The reference potential conductor pattern 42 is disposed on the surface 40a of the dielectric layer 40. The antenna clearance region 43 is a region that separates the signal through-hole conductor 41 and the reference potential conductor pattern 42. The inner peripheral surface 42a of the reference potential conductor pattern 42 is disposed radially outwardly from the outer peripheral surface 41a of the signal through-hole conductor 41. An antenna clearance region 43 is formed between the inner peripheral surface 42a of the reference potential conductor pattern 42 and the outer peripheral surface 41a of the signal through-hole conductor 41. When viewed from the Z-axis direction, the antenna clearance region 43 has an annular shape centered on a center line CL1. Note that, since the antenna module 3 of this embodiment is a patch antenna, it may also include a ground conductor facing the radiating element. Furthermore, since this embodiment illustrates an array antenna, a high-frequency signal input to the signal through-hole conductor is supplied to each radiating element via a wiring layer (not shown).

[0031] The antenna clearance region 43 has a smaller area than the clearance region 26 of the substrate 1. The diameter of the outer peripheral surface 41a of the signal through-hole conductor 41 may be set to 10 μm to 100 μm. The diameter of the inner peripheral surface 42a of the reference potential conductor pattern 42 may be set to 20 μm to 200 μm. The reference potential conductor pattern 42 and a portion of the antenna clearance region 43 are covered with a resin layer 44 of a resin composition. The resin layer 44 covers the reference potential conductor pattern 42. The inner peripheral surface 44a of the resin layer 44 is positioned more inward than the inner peripheral surface 42a and is spaced radially outward from the outer peripheral surface 41a of the signal through-hole conductor 41. As a result, the resin composition of the resin layer 44 covers a portion of the surface 40a in the antenna clearance region 43. The resin layer 44 is a material known as solder resist, and when mounting the antenna module 3 in the through-hole conductor 10, it serves to prevent solder from adhering to any area other than the enlarged diameter portion 27 (pad) of the through-hole conductor 10 (insulation).

[0032] The structure near the clearance region 26 is not limited to that shown in Fig. 3. For example, as shown in Fig. 5(a), a structure without the first conductor exposed portion 32 and the second conductor exposed portion 36 may be employed. In this case, the outer peripheral surface 31a of the covering portion 31 is located at the same position as the outer peripheral surface 27a of the through-hole conductor 10. The inner peripheral surface 24a of the resin layer 24 is located at the same position as the inner peripheral surface 28a of the hole 28 of the conductor pattern 22.

[0033] Furthermore, as shown in FIG. 5( b), a second resin layer 51 containing a resin composition may be disposed in the clearance region 26 and stacked on the surface 21 a of the dielectric layer 21. The thickness of the second resin layer 51 is smaller than the thickness of the conductive pattern 22. Furthermore, the thickness of the second resin layer 51 is smaller than the thickness of the resin layer 24. However, the thickness of the second resin layer 51 may be equal to or greater than the thickness of the resin layer 24. In FIG. 5( b), the second resin layer 51 is disposed over the entire clearance region 26. Alternatively, as shown in FIG. 5( c), the dielectric layer 21 may have an exposed surface portion 29 exposed from the second resin layer 51 in the clearance region 26. In the example of FIG. 5( c), the exposed surface portion 29 is disposed in a portion of the inner circumferential side of the clearance region 26. However, the position of the exposed surface portion 29 is not limited, and may be in a portion of the outer circumferential side of the clearance region 26 or in a portion of the radial center side.

[0034] Furthermore, a structure such as that shown in FIG. 6 may be employed. In FIG. 6(a), protruding portion 52 of the resin composition of covering portion 31 covers outer peripheral surface 27a of through-hole conductor 10, extending to surface 21a. Furthermore, protruding portion 53 of the resin composition of resin layer 24 covers inner peripheral surface 28a of conductor pattern 22, extending to surface 21a. In this case, as shown in FIG. 7, when viewed from the Z-axis direction, part of the inner and outer peripheral sides of clearance region 26 are covered with the resin composition. As shown in FIG. 6(b), protruding portion 52 of the resin composition of covering portion 31 covers outer peripheral surface 27a of through-hole conductor 10, and exposed surface portion 29 may be disposed so as to contact the outer edge of clearance region 26. Also, as shown in Figure 6(c), the protruding portion 53 of the resin composition of the resin layer 24 covers the inner surface 28a of the conductive pattern 22, and the surface exposed portion 29 may be arranged so as to contact the inner edge of the clearance region 26.

[0035] Next, the relationship between the thickness of the second resin layer 51 provided in the clearance region 26 and the antenna characteristics will be described with reference to FIG. 8. As shown in FIG. 9, a simulation model was constructed in which the antenna module 3 was mounted on the substrate 1, and the gain of the antenna module 3 in the front direction was measured. The resin layer on the substrate 1 side had εr = 4.6, tan δ = 0.027, and the resin layer on the antenna module 3 side had εr = 3.3, tan δ = 0.01. The "exposed conductor" model in FIG. 8 was a model that had exposed conductor portions 32 and 36, and the entire clearance region 26 was the exposed surface portion 29, as shown in FIGS. 3 and 4. The dimensions around the clearance region 26 were the same as those described with reference to FIG. 4. The thicknesses of the resin layer 24 and the covering portion 31 were 10 μm. The model with thickness dimensions shown in FIG. 8 was a model that did not have exposed conductor portions 32 and 36 but had the second resin layer 51, as shown in FIG. 5(b). The dimensions of each model are the thickness dimensions of the second resin layer 51. "0 μm" is the model shown in FIG. 5(a). "25 μm" is a model in which the thickness of the second resin layer 51 is the same as the thickness of the conductive pattern 22. "44 μm" is a comparative model in which the upper surface of the second resin layer 51 is the same as the upper surfaces of the resin layer 24 and the covering portion 31, as shown in FIG. 10.

[0036] As shown in FIG. 8, the thickness of the second resin layer 51 significantly affected the gain in the 280-290 GHz range. As the thickness decreased from 44 μm to 25 μm, the characteristics decreased. However, after 25 μm, the characteristics improved as the thickness decreased. This demonstrates that by setting the thickness to 25 μm or less, it is possible to adjust the characteristics appropriately according to requirements. In particular, good characteristics were obtained by setting the thickness of the second resin layer 51 to 10 μm or less, which is the thickness of the resin layer 24 and the coating portion 31. Furthermore, the characteristics were further improved by employing the exposed conductor portions 32 and 36 as shown in FIG. 4.

[0037] FIG. 11 is a graph showing the relationship between the thickness and characteristics of the protruding portions 52, 53 as shown in FIGS. 6(b) and (c). Here, a model with the structure shown in FIGS. 6(b) and (c) but with different protruding amounts was created, and a simulation was performed using the same method as in FIG. 8. The horizontal axis shows the protruding amount of each protruding portion 52, 53 into the clearance region 26. As shown in FIG. 11, it can be seen that the protruding portion 53 on the outer periphery has a greater impact. Therefore, it can be seen that the antenna characteristics can be improved by suppressing the protrusion of the resin composition on the outer periphery.

[0038] Next, the functions and effects of the substrate 1 and communication device 100 according to this embodiment will be described.

[0039] A substrate 1 according to one aspect of the present disclosure comprises a dielectric layer 21, a through-hole conductor 10 penetrating the dielectric layer 21 in the Z-axis direction (thickness direction), a conductor pattern 22 provided on a surface 21a on one side of the dielectric layer 21 in the Z-axis direction and connected to a reference potential, a resin layer 24 laminated on the conductor pattern 22 and containing a resin composition, and a clearance region 26 arranged around the through-hole conductor 10 on one side of the dielectric layer 21 in the Z-axis direction and isolating the through-hole conductor 10 and the conductor pattern 22, and the dielectric layer 21 has a surface exposed portion 29 exposed on the surface in the clearance region 26.

[0040] A clearance region 26 is disposed around the through-hole conductor 10, isolating the through-hole conductor 10 from the conductor pattern 22. This clearance region has an exposed surface portion 29 that is not covered with the resin composition and is exposed to the surface. In this case, when the antenna module 3 is mounted on the through-hole conductor via solder 33, the effect on the antenna gain can be suppressed.

[0041] When viewed from the Z-axis direction, the exposed surface portion 29 may be disposed so as to contact at least one of the inner edge and the outer edge of the clearance region 26. In other words, at least one of the inner edge and the outer edge of the clearance region 26 may be configured not to be covered with the resin composition. In this case, the effect on the antenna gain can be further suppressed.

[0042] When viewed from the Z-axis direction, the exposed surface portion 29 may be disposed so as to be in contact with the outer edge of the clearance region 26. The effect of providing the resin composition on the outer edge side of the clearance region 26 is greater than that on the inner edge side (see FIG. 11). Therefore, by disposing the exposed surface portion 29 on the outer edge side, the effect on the antenna gain can be further suppressed.

[0043] The exposed surface portion 29 may occupy the entire clearance region 26. In this case, by preventing a large area of ​​the clearance region 26 from being covered with the resin composition, the effect on the antenna gain can be further suppressed.

[0044] One end 10a of through-hole conductor 10 in the Z-axis direction may have conductor central portion 30, covering portion 31 that is covered with a resin composition and surrounds conductor central portion 30, and first conductor exposed portion 32 that is a part of through-hole conductor 10 that is exposed on the surface and located at the boundary between covering portion 31 and clearance region 26. In this case, it is possible to prevent the resin composition from being applied to clearance region 26 from the covering portion 31 side due to manufacturing variations when applying the resin composition.

[0045] The conductor pattern 22 may have a second conductor exposed portion 36 where the conductor pattern 22 is exposed on the surface at an edge located at the boundary with the clearance region 26. In this case, it is possible to prevent the resin composition from being applied to the clearance region 26 from the resin layer 24 side due to manufacturing variations when applying the resin composition.

[0046] A substrate 1 according to one aspect of the present disclosure comprises a dielectric layer 21, a through-hole conductor 10 penetrating the dielectric layer 21 in the Z-axis direction of the dielectric layer 21, a conductor pattern 22 provided on a surface 21a of one side of the dielectric layer 21 in the Z-axis direction and connected to a reference potential, a resin layer 24 (first resin layer) laminated on the conductor pattern 22 and containing a resin composition, a clearance region 26 arranged around the through-hole conductor 10 on one side of the dielectric layer 21 in the thickness direction and isolating the through-hole conductor 10 and the conductor pattern 22, and a second resin layer 51 laminated on the surface of the dielectric layer 21 in the clearance region 26 and containing a resin composition, the thickness of the second resin layer 51 being smaller than the thickness of the conductor pattern 22.

[0047] A clearance region 26 is arranged around the through-hole conductor 10 to separate the through-hole conductor 10 from the conductor pattern 22. A second resin layer 51 containing a resin composition is arranged in this clearance region 26 and is laminated on the surface 21a of the dielectric layer 21. The thickness of this second resin layer 51 is smaller than the thickness of the conductor pattern 22. By reducing the thickness of the second resin layer 51 in this way, when the antenna module 3 is mounted on the through-hole conductor via solder 33, the effect on the antenna gain can be reduced.

[0048] The thickness of the second resin layer 51 may be smaller than the thickness of the resin layer 24 (first resin layer). In this case, by further reducing the thickness of the second resin layer 51, the effect on the antenna gain can be further suppressed.

[0049] The dielectric layer 21 may have an exposed surface portion 29 that is exposed from the second resin layer 51 in the clearance region 26. In this case, the exposed surface portion 29 can further suppress the influence on the gain of the antenna.

[0050] A communication device 100 according to one aspect of the present disclosure includes the above-described substrate 1, which has a cavity 12 formed by surrounding a through-hole conductor 10 with a ground pillar 16, and a substrate integrated waveguide 13 coupled to the cavity 12.

[0051] In this case, it is possible to obtain a communication device 100 in which the SIW structure of the substrate integrated waveguide 13 can be converted into a coaxial structure while suppressing the effect on the antenna gain.

[0052] A communication device 100 according to one aspect of the present disclosure includes the above-described substrate 1 and an antenna module 3 mounted on one end 10a of a through-hole conductor 10 of the substrate 1 in the Z-axis direction, the antenna module 3 having a signal through-hole conductor 41 connected to the through-hole conductor 10, a reference potential conductor pattern 42 surrounding the signal through-hole conductor 41 and connected to a reference potential, and an antenna clearance area 43 isolating the signal through-hole conductor 41 and the reference potential conductor pattern 42, the antenna clearance area 43 having an area smaller than the clearance area 26 of the substrate 1, and a portion of the reference potential conductor pattern 42 and the antenna clearance area 43 being covered by a resin composition.

[0053] In this case, by making the area of ​​the antenna clearance region 43 smaller than the area of ​​the clearance region 26 of the substrate 1, it is possible to achieve insulation between the signal through-hole conductor of the antenna module and the reference potential conductor pattern while suppressing the impact on the antenna gain.

[0054] The present disclosure is not limited to the above-described embodiments.

[0055] For example, the configurations of the substrate 1 and the communication device are not limited to the above-described embodiments and may be modified as appropriate without departing from the spirit of the invention. For example, other layers or conductors may be added to the above-described embodiments. Furthermore, the shape, arrangement, and number of conductors are not limited to the above-described embodiments and may be modified as appropriate.

[0056] [Form 1] a dielectric layer; a through-hole conductor penetrating the dielectric layer in a thickness direction; a conductor pattern provided on one surface of the dielectric layer in the thickness direction and connected to a reference potential; a resin layer laminated on the conductor pattern and containing a resin composition; a clearance region disposed around the through-hole conductor on one side of the dielectric layer in the thickness direction, the clearance region isolating the through-hole conductor from the conductor pattern; The substrate, wherein the dielectric layer has a surface exposed portion that is exposed at the clearance region. [Form 2] The substrate according to embodiment 1, wherein the exposed surface portion is disposed so as to contact at least one of an inner edge and an outer edge of the clearance region when viewed from the thickness direction. [Form 3] The substrate according to embodiment 2, wherein the exposed surface portion is disposed so as to contact the outer edge of the clearance region when viewed in the thickness direction. [Form 4] 4. The substrate according to any one of aspects 1 to 3, wherein the exposed surface portion occupies the entire clearance region. [Form 5] One end of the through-hole conductor in the thickness direction is a central portion of the conductor; a covering portion that surrounds the central portion of the conductor and is covered with a resin composition; 5. The board according to any one of embodiments 1 to 4, further comprising: a first conductor exposed portion at a boundary between the covering portion and the clearance region, the first conductor exposed at a surface of a part of the through-hole conductor. [Form 6] 6. The substrate according to any one of embodiments 1 to 5, wherein the conductor pattern has a second conductor exposed portion where the conductor pattern is exposed on the surface at an edge portion located on the boundary with the clearance region. [Form 7] a dielectric layer; a through-hole conductor penetrating the dielectric layer in a thickness direction of the dielectric layer; a conductor pattern provided on one surface of the dielectric layer in the thickness direction and connected to a reference potential; a first resin layer laminated on the conductor pattern and containing a resin composition; a clearance region disposed around the through-hole conductor on one side of the dielectric layer in the thickness direction, the clearance region separating the through-hole conductor from the conductor pattern; a second resin layer including a resin composition, the second resin layer being laminated on the surface of the dielectric layer in the clearance region; A substrate, wherein the thickness of the second resin layer is smaller than the thickness of the conductive pattern. [Form 8] The substrate according to embodiment 7, wherein the thickness of the second resin layer is smaller than the thickness of the first resin layer. [Form 9] The substrate according to embodiment 7 or 8, wherein the dielectric layer has a surface exposed portion that is exposed from the second resin layer in the clearance region. [Form 10] A substrate according to any one of aspects 1 to 9, the substrate includes a cavity formed by surrounding the through-hole conductor with a ground pillar; a substrate integrated waveguide coupled to the cavity. [Form 11] A substrate according to any one of aspects 1 to 9; an antenna module mounted on one end of the through-hole conductor of the substrate in the thickness direction, The antenna module includes: a signal through-hole conductor connected to the through-hole conductor; a reference potential conductor pattern that surrounds the signal through-hole conductor and is connected to a reference potential; an antenna clearance area separating the signal through-hole conductor and the reference potential conductor pattern; the antenna clearance area is smaller in area than the clearance area of ​​the substrate; A communication device, wherein the reference potential conductor pattern and a portion of the antenna clearance area are covered with a resin composition. [Explanation of symbols]

[0057] 1...substrate, 3...antenna module, 10...through-hole conductor, 12...cavity, 16...ground pillar, 21...dielectric layer, 22...conductor pattern, 24...resin layer (first resin layer), 26...clearance area, 30...conductor center portion, 31...coating portion, 32...first conductor exposed portion, 36...second conductor exposed portion, 41...signal through-hole conductor, 42...reference potential conductor pattern, 43...antenna clearance area, 51...second resin layer, 100...communication device.

Claims

1. a dielectric layer; a through-hole conductor penetrating the dielectric layer in a thickness direction; a conductor pattern provided on one surface of the dielectric layer in the thickness direction and connected to a reference potential; a resin layer laminated on the conductor pattern and containing a resin composition; a clearance region disposed around the through-hole conductor on one side of the dielectric layer in the thickness direction, the clearance region isolating the through-hole conductor from the conductor pattern; The substrate, wherein the dielectric layer has a surface exposed portion that is exposed at the clearance region.

2. The substrate according to claim 1 , wherein the exposed surface portion is disposed so as to contact at least one of an inner edge and an outer edge of the clearance region when viewed in the thickness direction.

3. The substrate according to claim 2 , wherein the exposed surface portion is disposed so as to contact the outer edge of the clearance region when viewed in the thickness direction.

4. The substrate of claim 1 , wherein the exposed surface portion occupies the entire clearance region.

5. One end of the through-hole conductor in the thickness direction is a central portion of the conductor; a covering portion that surrounds the central portion of the conductor and is covered with a resin composition; The board according to claim 1 , further comprising: a first conductor exposed portion in which a part of the through-hole conductor located at the boundary between the covering portion and the clearance region is exposed on the surface.

6. The substrate according to claim 1 , wherein the conductor pattern has a second conductor exposed portion at an edge located at a boundary with the clearance region, where the conductor pattern is exposed on the surface.

7. a dielectric layer; a through-hole conductor penetrating the dielectric layer in a thickness direction of the dielectric layer; a conductor pattern provided on one surface of the dielectric layer in the thickness direction and connected to a reference potential; a first resin layer laminated on the conductor pattern and containing a resin composition; a clearance region disposed around the through-hole conductor on one side of the dielectric layer in the thickness direction, the clearance region separating the through-hole conductor from the conductor pattern; a second resin layer including a resin composition, the second resin layer being laminated on the surface of the dielectric layer in the clearance region; A substrate, wherein the thickness of the second resin layer is smaller than the thickness of the conductive pattern.

8. The substrate according to claim 7 , wherein the thickness of the second resin layer is smaller than the thickness of the first resin layer.

9. The substrate according to claim 7 , wherein the dielectric layer has a surface exposed portion that is exposed from the second resin layer in the clearance region.

10. A substrate according to any one of claims 1 to 9, the substrate includes a cavity formed by surrounding the through-hole conductor with a ground pillar; a substrate integrated waveguide coupled to the cavity.

11. A substrate according to any one of claims 1 to 9; an antenna module mounted on one end of the through-hole conductor of the substrate in the thickness direction, The antenna module includes: a signal through-hole conductor connected to the through-hole conductor; a reference potential conductor pattern that surrounds the signal through-hole conductor and is connected to a reference potential; an antenna clearance area separating the signal through-hole conductor and the reference potential conductor pattern; the antenna clearance area is smaller in area than the clearance area of ​​the substrate; A communication device, wherein the reference potential conductor pattern and a portion of the antenna clearance area are covered with a resin composition.

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