Multilayer substrate

Abstract

The multilayer substrate of the utility model is provided with the following components: a laminated body which is provided with a plurality of laminated flexible resin layers and is internally provided with a space; a first inner layer resin disposed in the space of the laminate; and a plurality of conductors including a signal conductor and disposed in the first inner layer resin, at least a portion of the first inner layer resin being separated from the laminated body in the space, the plurality of conductors including a plurality of inner layer ground conductors, the signal conductor being disposed between the plurality of inner layer ground conductors, and the signal conductor being disposed between the plurality of inner layer ground conductors. The laminated body has a first main surface and a second main surface facing each other in a lamination direction of the laminated body, and the multilayer substrate is further provided with a plurality of conductive shields disposed on the first main surface and the second main surface, the plurality of conductive shields being disposed at positions overlapping the signal conductor when viewed in the lamination direction. The first inner layer resin floats from the laminate in a cross-section in a direction perpendicular to the extending direction of the signal conductor.

Description

Technical Field

[0001] The utility model relates to a multi-layer substrate with a plurality of conductors. Background Art

[0002] As a conventional invention involving a multilayer substrate, for example, a high-speed transmission laminate substrate is known, as described in Patent Document 1. This high-speed transmission laminate substrate is a high-speed transmission substrate using a flexible substrate comprising copper foil and a resin insulating base material, and has a structure with high-speed transmission signal wiring and an air layer surrounding the wiring.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-118361 Utility Model Content

[0006] Problems to be solved by utility models

[0007] Furthermore, in the multilayer substrate described in Patent Document 1, when the multilayer substrate is bent, there is a possibility that the gap between the signal wiring and the copper foil may vary.

[0008] Therefore, an object of the present invention is to provide a multilayer substrate capable of suppressing fluctuations in gaps between a plurality of conductors.

[0009] Technical solutions to solve problems

[0010] One embodiment of the present invention relates to a multilayer substrate comprising:

[0011] A laminate having a plurality of laminated flexible resin layers and a space provided therein;

[0012] A first inner layer resin is disposed in the space of the laminate; and

[0013] A plurality of conductors, including a signal conductor, are disposed in the first inner layer of resin,

[0014] At least a portion of the first inner layer resin is separated from the laminate within the space.

[0015] The plurality of conductors include a plurality of inner ground conductors,

[0016] The signal conductor is arranged between the plurality of inner ground conductors.

[0017] The stacked body has a first main surface and a second main surface facing each other in a stacking direction of the stacked body,

[0018] The multilayer substrate further includes a plurality of conductive shielding members arranged on the first main surface and the second main surface.

[0019] The plurality of conductive shields are arranged at positions overlapping the signal conductors when viewed in the stacking direction.

[0020] The first inner layer resin floats from the laminate in a cross section taken in a direction perpendicular to the extending direction of the signal conductor.

[0021] Utility model effect

[0022] According to the multilayer substrate of the present invention, it is possible to suppress variations in the gaps between the plurality of conductors. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a perspective view of the appearance of the multilayer substrate according to the first embodiment.

[0024] Figure 2 It is an exploded plan view of the multilayer substrate according to the first embodiment.

[0025] Figure 3 It is a transverse cross-sectional view of the multilayer substrate according to the first embodiment after deformation.

[0026] Figure 4 yes Figure 1 AA cross-sectional view.

[0027] Figure 5 yes Figure 1 BB cross-sectional view.

[0028] Figure 6 It is a longitudinal sectional view of the multilayer substrate according to the first modification.

[0029] Figure 7 It is a longitudinal sectional view of a multilayer substrate according to a second modification.

[0030] Figure 8 This is a partially enlarged view of a multilayer substrate according to the second embodiment.

[0031] Figure 9 It is a longitudinal sectional view of a multilayer substrate according to a third embodiment.

[0032] Figure 10 It is a longitudinal sectional view of a multilayer substrate according to a fourth embodiment.

[0033] Figure 1 1A is a longitudinal sectional view of a multilayer substrate according to a fifth embodiment.

[0034] Figure 1 1B is a partially enlarged view showing an example of a plurality of first through holes provided in the laminate.

[0035] Figure 1 1C is a partially enlarged cross-sectional view showing an example of a porous material.

[0036] Figure 1 1D is a partially enlarged cross-sectional view showing another example of the porous material.

[0037] Figure 12A It is a longitudinal sectional view of a multilayer substrate according to the sixth embodiment.

[0038] Figure 12B This is a partially enlarged view showing an example of a plurality of second through holes provided in the second inner layer resin.

[0039] Figure 13A It is a longitudinal sectional view of a multilayer substrate according to the seventh embodiment.

[0040] Figure 13B This is a partially enlarged view showing an example of a plurality of third through holes provided in the flexible resin layer.

[0041] Figure 14A It is a longitudinal sectional view of a multilayer substrate according to the eighth embodiment.

[0042] Figure 14B This is a partially enlarged view showing an example of a plurality of first protrusions provided on the first inner layer resin.

[0043] Figure 15A It is a longitudinal sectional view of a multilayer substrate according to the ninth embodiment.

[0044] Figure 15B This is a partially enlarged view showing an example of a plurality of second protrusions provided on the second inner layer resin.

[0045] Figure 16 It is a longitudinal sectional view of a multilayer substrate according to a tenth embodiment.

[0046] Figure 17 It is an exploded plan view of the multilayer substrate according to the tenth embodiment.

[0047] Figure 18 It is a transverse cross-sectional view of a multilayer substrate according to the tenth embodiment after deformation.

[0048] Figure 19 It is a longitudinal sectional view of a multilayer substrate according to the eleventh embodiment.

[0049] Figure 20 It is a longitudinal sectional view of a multilayer substrate according to the twelfth embodiment.

[0050] Figure 21 It is a longitudinal sectional view of a multilayer substrate according to the thirteenth embodiment.

[0051] Figure 22 It is a longitudinal sectional view of a multilayer substrate according to the fourteenth embodiment.

[0052] Description of Reference Numerals

[0053] 10: laminate;

[0054] 1 1 a, 1 1 b: protective film;

[0055] 25: 1st inner layer resin;

[0056] 26, 26A, 26B: second inner layer resin;

[0057] 27: first protrusion;

[0058] 28: second protrusion;

[0059] 29: 3rd protrusion;

[0060] 30, 30A, 30B: multiple conductors;

[0061] 31: signal conductor;

[0062] 32: Inner grounding conductor;

[0063] 34: conductive shielding member;

[0064] 36: 1st grounding conductor;

[0065] 38: Second grounding conductor;

[0066] 40: Space;

[0067] 41: Part 1;

[0068] 42: Part 2;

[0069] 43: Part 3;

[0070] 44: Part 4;

[0071] 50: interlayer connection conductor;

[0072] 52: lead conductor;

[0073] 53: second through hole;

[0074] 54: 3rd through hole;

[0075] 60: 1st through hole;

[0076] 70-84: flexible resin layer;

[0077] 100~115: multi-layer substrate;

[0078] S: substrate extension direction;

[0079] T: thickness direction. DETAILED DESCRIPTION

[0080] Hereinafter, the structure of the multi-layer substrate 100 according to the embodiment of the present invention will be described with reference to the drawings. Figure 1 1 is a perspective view of the appearance of the multi-layer substrate 100 . Figure 2 This is a plan view of each layer of the multilayer substrate 100 as viewed from the thickness direction. Figure 3 It is a transverse cross-sectional view of the multi-layer substrate 100 according to the first embodiment after deformation. Figure 4 is an AA cross-sectional view of the multi-layer substrate 100, Figure 5 BB is a cross-sectional view of the multi-layer substrate 100 .

[0081] In this specification, directions are defined as follows. First, the X-axis direction corresponds to the substrate extension direction S of the multilayer substrate 100, the Y-axis direction corresponds to the width direction W of the multilayer substrate 100, and the Z-axis direction corresponds to the thickness direction T of the multilayer substrate 100. The substrate extension direction S is the direction in which the multilayer substrate 100 extends when viewed in the thickness direction T. The width direction W is a direction orthogonal to the direction in which the multilayer substrate 100 extends when viewed in the thickness direction T. The thickness direction T is the stacking direction in which at least one flexible resin layer 70 is stacked. The thickness direction T, the width direction W, and the substrate extension direction S are orthogonal to each other. In addition, the thickness direction T, the width direction W, and the substrate extension direction S in this specification may not be consistent with the thickness direction, the width direction, and the signal transmission direction of the multilayer substrate 100 when actually used.

[0082] The following describes the definitions of terms used in this specification. First, the positional relationship of components used in this specification is defined. In this specification, the phrase "A and B are electrically connected" means that electrical conduction is possible between A and B. Therefore, A and B may be in contact, or A and B may not be in contact. For example, when C having conductivity is arranged between A and B, A and B are electrically connected via C even if A and B are not in contact. On the other hand, in this specification, the phrase "A and B are in contact" means that A and B are connected in a contacting state.

[0083] In addition, in this specification, terms such as "first" and "second" are used for illustrative purposes only and should not be understood as indicating or implying the relative importance or order of technical features. Features specified as "first" or "second" expressly or implicitly include one or more of the features.

[0084] Reference Figure 1The structure of multilayer substrate 100 is described below. Multilayer substrate 100 is used to transmit high-frequency signals. For example, in electronic devices such as smartphones, multilayer substrate 100 is used to electrically connect two circuits. Multilayer substrate 100 is flexible and can be bent appropriately.

[0085] like Figure 1 As shown in FIG. 1 , the multilayer substrate 100 of the first embodiment has a shape extending in the substrate extending direction S. As shown in FIG.

[0086] Next, specific components of the multi-layer substrate 100 will be described.

[0087] like Figure 1-Figure 5 As shown, the multilayer substrate 100 includes a laminate 10 , a first inner layer resin 25 , a plurality of conductors 30 , and a conductive shield 34 .

[0088] <Laminate>

[0089] The laminate 10 has a plate shape having a first main surface 10a and a second main surface 10b separated in the thickness direction T. Specifically, the first main surface 10a and the second main surface 10b are opposed to each other. In this specification, the first main surface 10a may also be referred to as the upper main surface, and the second main surface 10b may also be referred to as the lower main surface.

[0090] like Figure 4 as well as Figure 5 As shown, a space 40 is provided inside the stacked body 10 .

[0091] The laminate 10 includes a plurality of laminated flexible resin layers 70, 71, 72, 73, and 74. The flexible resin layers 70, 71, 72, 73, and 74 are laminated along the thickness direction T. Specifically, the flexible resin layers 70, 71, 72, 73, and 74 are laminated in sequence from the first principal surface 10a toward the second principal surface 10b. The flexible resin layers 70, 71, 72, 73, and 74 have plate shapes of substantially the same size. In this embodiment, the outer surface of the flexible resin layer 70 in the thickness direction T forms the first principal surface 10a, and the outer surface of the flexible resin layer 74 forms the second principal surface 10b.

[0092] The space 40 can be provided, for example, by removing a portion of the flexible resin layers 71, 72, and 73. In this embodiment, holes forming the space 40 are provided in the flexible resin layers 71, 72, and 73. When viewed in the thickness direction T, the flexible resin layers 71, 72, and 73 are provided with, for example, rectangular holes. The flexible resin layers 70 and 74 are not provided with holes and have a continuous shape. In the laminate 10, the multiple holes provided in the flexible resin layers 71, 72, and 73 are connected in the thickness direction T. The flexible resin layers 71, 72, and 73 are sandwiched between the flexible resin layers 70 and 74 in the thickness direction T. The flexible resin layer 70 blocks the openings of the holes in the flexible resin layer 71, and the flexible resin layer 74 blocks the openings of the holes in the flexible resin layer 73. Thus, a space 40 formed by the multiple connected holes is formed inside the laminate 10. The space 40 is formed into a rectangular shape when viewed in the thickness direction T. Air exists in the space 40 .

[0093] Flexible resin layers 70, 71, 72, 73, and 74 are, for example, flexible dielectric sheets. In this embodiment, the material of flexible resin layers 70, 71, 72, 73, and 74 is a thermoplastic resin. Examples of thermoplastic resins include liquid crystal polymers and PTFE (polytetrafluoroethylene). Alternatively, the material of flexible resin layers 70, 71, 72, 73, and 74 may be a thermosetting resin. An example of a thermosetting resin is polyimide.

[0094] The laminate 10 has an inner surface defining the space 40. More specifically, the laminate 10 includes a first inner wall 10A facing the first main surface 10a, a second inner wall 10B facing the second main surface 10b, and an inner side wall 10S connecting these.

[0095] The first inner wall 10A is defined by the flexible resin layer 70. Specifically, the first inner wall 10A is the inner surface of the flexible resin layer 70 connected to the flexible resin layer 71. The first inner wall 10A is formed on the side opposite to the first main surface 10a formed on the flexible resin layer 70.

[0096] The second inner wall 10B is defined by the flexible resin layer 74. Specifically, the second inner wall 10B is the inner surface of the flexible resin layer 74 on the side connected to the flexible resin layer 73. The second inner wall 10B is formed on the side opposite to the second main surface 10b formed on the flexible resin layer 74.

[0097] Inner wall 10S is defined by flexible resin layers 71, 72, and 73. Specifically, inner wall 10S is formed by multiple inner wall surfaces that define the holes formed in flexible resin layers 71, 72, and 73. In this embodiment, space 40 is defined by multiple inner walls, but it may also be defined by a single inner wall. For example, a spherical inner wall may be used.

[0098] <First Inner Layer Resin>

[0099] The first inner layer resin 25 is disposed in the space 40 of the laminate 10. The first inner layer resin 25 has a sheet shape extending in the substrate extension direction S of the multilayer substrate 100. The first inner layer resin 25 has a third main surface 25a and a fourth main surface 25b separated in the thickness direction T.

[0100] The first inner layer resin 25 is formed of a flexible resin. Therefore, it can be bent by applying a force from the outside. For example, when a force is applied from the outside of the laminate 10, as shown in FIG. Figure 3 As shown, the first inner layer resin 25 is deformed and curved within the space 40 .

[0101] The first inner layer resin 25 extends in the direction in which the signal conductors 31 extend and is connected to the laminate 10 in the extension direction. In other words, the first inner layer resin 25 is connected to the laminate 10 in the substrate extension direction S of the multilayer substrate 100. Specifically, both ends of the first inner layer resin 25 in the substrate extension direction S of the multilayer substrate 100 are connected to the inner sidewalls 10S of the laminate 10.

[0102] The first inner layer resin 25 is separated from the laminate 10 within the space 40. Specifically, in a cross-section taken in a direction perpendicular to the direction in which the signal conductor 31 extends (the Z direction), the first inner layer resin 25 within the space 40 is separated from the first inner wall 10A, the second inner wall 10B, and the inner sidewall 10S of the laminate 10 and floats from the laminate 10. That is, in a cross-section taken in a direction perpendicular to the direction in which the signal conductor 31 extends (the Z direction), a hollow portion 40a is formed within the laminate 10, annularly surrounding the first inner layer resin 25. For example, the hollow portion 40a is filled with air.

[0103] Furthermore, within the space 40, a portion of the first inner layer resin 25 may be in contact with the laminate 10. For example, even when the multilayer substrate 100 is bent, a portion of the first inner layer resin 25 may be in contact with the laminate 10. In other words, it is sufficient that at least a portion of the first inner layer resin 25 is separated from the laminate 10 within the space 40.

[0104] In this embodiment, the first inner layer resin 25 is formed integrally with the flexible resin layer 72. Therefore, the first inner layer resin 25 is formed of the same resin as the flexible resin layer 72. In other words, the first inner layer resin 25 is formed of a portion of the laminate 10.

[0105] In addition, the first inner layer resin 25 may be formed of a member different from the flexible resin layer 72 , or may be formed of a material different from that of the flexible resin layer 72 .

[0106] <Multiple Conductors>

[0107] like Figure 2 As shown, the plurality of conductors 30 are provided on a portion of the laminate 10 and a conductor pattern of the first inner layer resin 25, and extend along the substrate extending direction S. Figure 4 As shown, the plurality of conductors 30 are provided on the third main surface 25 a of the first inner layer resin 25 .

[0108] Alternatively, the plurality of conductors 30 may be provided on at least one of the third principal surface 25 a or the fourth principal surface 25 b of the first inner layer resin 25 .

[0109] The plurality of conductors 30 includes a signal conductor 31 and a plurality of inner-layer ground conductors 32. The plurality of conductors 30 is, for example, a conductor layer formed by patterning a metal foil bonded to the flexible resin layer 70. The metal foil is, for example, copper foil. Alternatively, the plurality of conductors may be formed by plating.

[0110] The signal conductor 31 is a conductor for transmitting a signal. In this embodiment, the signal conductor 31 transmits a high-frequency signal. The signal conductor 31 is arranged with a gap between two inner-layer ground conductors 32.

[0111] like Figure 2 as well as Figure 5 As shown, both ends of the signal conductor 31 in the substrate extending direction S are arranged on the flexible resin layer 72 that defines the laminate 10. Specifically, both ends of the signal conductor 31 in the substrate extending direction S are arranged on the portion of the flexible resin layer 72 where the flexible resin layer 71 is laminated. Both ends of the signal conductor 31 in the substrate extending direction S are connected to the interlayer connection conductor 50a provided in the flexible resin layers 70 and 71.

[0112] The interlayer connection conductor 50a is a conductor arranged in a through-hole provided in the thickness direction of the flexible resin layers 70 and 71. The interlayer connection conductor 50a is connected to a lead conductor 52a provided on the first main surface 10a of the flexible resin layer 70.

[0113] The lead conductor 52 a is arranged in the opening 46 a provided in the conductive shield 34 and the protective film 11 a arranged on the first main surface 10 a of the laminate 10 .

[0114] The plurality of inner ground conductors 32 are conductors connected to the ground potential. Figure 2As shown, the plurality of inner-layer ground conductors 32 are arranged at intervals, sandwiching the signal conductors 31 therebetween. Similar to the signal conductors 31, the ends of the plurality of inner-layer ground conductors 32 in the substrate extension direction S are arranged on the flexible resin layer 72 that defines the laminate 10. Specifically, the ends of the plurality of inner-layer ground conductors 32 in the substrate extension direction S are arranged on the portion of the flexible resin layer 72 where the flexible resin layer 71 is laminated. The ends of the plurality of inner-layer ground conductors 32 in the substrate extension direction S are connected to the interlayer connection conductors 50b provided on the flexible resin layer 71.

[0115] The interlayer connection conductor 50 b is a conductor arranged in a through-hole provided in the thickness direction of the flexible resin layers 70 and 71 . The interlayer connection conductor 50 b is connected to the lead conductor 52 b provided in the flexible resin layer 70 .

[0116] The lead conductor 52 b is arranged in the opening 46 b provided in the conductive shield 34 and the protective film 11 a arranged on the first main surface 10 a of the laminate 10 .

[0117] <Conductive Shield>

[0118] like Figure 4 As shown, the conductive shield 34 is provided on the first main surface 10a and the second main surface 10b of the laminate 10. Specifically, the conductive shield 34 is a film-like conductor pattern provided on the flexible resin layers 70 and 74, covering the main surfaces of the flexible resin layers 70 and 74 in the thickness direction. The conductive shield 34 is a conductor layer formed by patterning a metal foil bonded to the flexible resin layers 70 and 74. The metal foil is, for example, copper foil.

[0119] The conductive shield 34 includes a first ground conductor 36 and a second ground conductor 38. The first ground conductor 36 is disposed on the first main surface 10a of the laminate 10. The second ground conductor 38 is disposed on the second main surface 10b of the laminate 10.

[0120] The first ground conductor 36 and the second ground conductor 38 are conductors connected to the ground potential. The first ground conductor 36 and the second ground conductor 38 have a function of suppressing the influence of noise from the outside on the signal conductor 31, for example.

[0121] Protective films 11a and 11b are arranged on the surface of the conductive shield 34 .

[0122] The protective film 11a is, for example, a protective layer for protecting the first ground conductor 36 disposed on the first principal surface 10a of the laminate 10. The protective film 11b is, for example, a protective layer for protecting the second ground conductor 38 disposed on the second principal surface 10b of the laminate 10. The protective films 11a and 11b respectively cover substantially the entire first principal surface 10a and second principal surface 10b of the laminate 10. In this embodiment, the protective films 11a and 11b are, for example, resin barrier layers applied to the laminate 10. Alternatively, the protective films 11a and 11b may be cover layers adhered to the laminate 10.

[0123] like Figure 1 As shown in FIG. 1 , a plurality of openings 46a and 46b are provided in the protective film 11a. The openings 46a and 46b are openings provided for connecting the plurality of conductors 30 to the outside. Figure 1 Although omitted in the figure, lead conductors 52a and 52b electrically connected to the plurality of conductors 30 are arranged in the plurality of openings 46a and 46b.

[0124] Here, use Figure 4 as well as Figure 5 The positional relationship between the first inner layer resin 25 and the space 40 will be described.

[0125] When viewed in the thickness direction T, the first inner layer resin 25 overlaps the space 40. In the multilayer substrate 100, the space 40 is provided at a position sandwiching the first inner layer resin 25 in the thickness direction T and in the width direction W. The first inner layer resin 25 is separated from the inner surface of the laminate 10 in the thickness direction and in the width direction W. Specifically, the first inner layer resin 25 is separated from the first inner wall 10A and the second inner wall 10B in the thickness direction T. Furthermore, the first inner layer resin 25 is separated from the inner side wall 10S in the width direction W, but is connected to the inner side wall 10S in the substrate extension direction S.

[0126] In addition, if Figure 4 As shown, when viewed in the thickness direction T, the plurality of conductors 30 are arranged to face the first ground conductor 36 and the second ground conductor 38 .

[0127] According to such an arrangement of the multi-layer substrate 100 , it is possible to suppress fluctuations in the gaps between the conductors 30 caused by deformation of the multi-layer substrate 100 .

[0128] For example, when the multi-layer substrate 100 is bent in the thickness direction T, as shown in FIG. Figure 3As shown, the outer portion of the laminate 10 is bent and deformed. At this time, if the plurality of conductors 30 are not disposed in the first inner layer resin 25 and only the conductor pattern is disposed in the space 40, the plurality of conductors 30 may deform to varying degrees. In this case, it is believed that the gaps between the plurality of conductors 30 vary, degrading signal characteristics.

[0129] The multilayer substrate 100 according to this embodiment includes a laminate 10, a first inner layer resin 25, and a plurality of conductors 30. The laminate 10 includes a plurality of stacked flexible resin layers 70 to 74 and a space 40 provided therein. The first inner layer resin 25 is disposed in the space 40 of the laminate 10. The plurality of conductors 30, including signal conductors, are disposed in the first inner layer resin 25. With this structure, the plurality of conductors 30 deform along with the deformation of the first inner layer resin 25, making it easier for the plurality of conductors 30 to deform in the same manner. This makes it less likely that differences in deformation will occur among the plurality of conductors 30. As a result, even if the multilayer substrate 100 deforms, variations in the gaps between the plurality of conductors 30 can be suppressed.

[0130] Furthermore, in this embodiment, the signal conductor 31 is used for high-frequency signals and transmits them. This can be expected to suppress changes in the gap with the inner-layer ground conductor 32, thereby minimizing degradation in signal characteristics. Furthermore, signals other than high-frequency signals, such as low-frequency signals, can also be transmitted through the signal conductor 31.

[0131] In this embodiment, interlayer connection conductors 50a, 50b and lead conductors 52a, 52b are provided in the flexible resin layers 70, 71 on one side and the other side of the laminate 10 in the substrate extending direction S. In this configuration, the lead conductors 52a, 52b are arranged in the openings 46a, 46b provided in the conductive shield 34 and the protective film 11a provided on the first main surface 10a of the laminate 10. However, the interlayer connection conductors 50a, 50b and lead conductors 52a, 52b may be provided in the flexible resin layers 73, 74 on at least one of the one side or the other side of the laminate 10 in the substrate extending direction S. In this configuration, the openings 46a, 46b may also be provided in the conductive shield 34 and the protective film 11a provided on the second main surface 10b of the laminate 10. The lead conductors 52 a and 52 b may be arranged in the openings 46 a and 46 b provided in the conductive shield 34 and the protective film 11 a arranged on the second main surface 10 b of the laminate 10 .

[0132] (First Modification)

[0133] Hereinafter, a multilayer substrate according to a first modification of the first embodiment will be described with reference to the accompanying drawings. In the first modification of the first embodiment, descriptions of the contents overlapping with those of the first embodiment will be omitted as appropriate. This also applies to subsequent modifications and embodiments.

[0134] Figure 6 It is a longitudinal sectional view of a multilayer substrate 101 according to a first modification.

[0135] The multilayer substrate 101 according to the first modification example differs from the multilayer substrate 100 according to the first embodiment in that the multilayer substrate 101 does not include the first ground conductor 36 and the second ground conductor 38 .

[0136] The multilayer substrate 101 has a structure in which protective films 11a and 11b are laminated on a laminate 10 in the thickness direction T. Specifically, the protective film 11a is laminated on the first main surface 10a of the laminate 10, and the protective film 11b is laminated on the second main surface 10b.

[0137] In the above-described structure, as in the multilayer substrate 100 according to the first embodiment, variations in the gaps between the plurality of conductors 30 can be suppressed.

[0138] (Second Modification)

[0139] Hereinafter, a multilayer substrate according to a second modification of the first embodiment will be described with reference to the drawings.

[0140] Figure 7 It is a longitudinal sectional view of a multilayer substrate 102 according to a second modification.

[0141] The multilayer substrate 102 according to the second modification example differs from the multilayer substrate 100 according to the first embodiment in the structure of the plurality of conductors 30 .

[0142] like Figure 7 As shown, the plurality of conductors 30 includes a signal conductor 31 and an inner ground conductor 32 .

[0143] In the above-described structure, as in the multilayer substrate 100 according to the first embodiment, variations in the gaps between the plurality of conductors 30 can be suppressed.

[0144] The structure of the plurality of conductors 30 is not limited to the structures of the first embodiment and the second modification. The plurality of conductors 30 may be any structure as long as the gaps between the conductors affect the characteristics.

[0145] For example, the plurality of conductors 30 may include two signal conductors 31, and the two signal conductors 31 may constitute a differential line. Furthermore, two inner-layer ground conductors 32 may be arranged between the differential line.

[0146] (Second embodiment)

[0147] Hereinafter, a multi-layer substrate according to a second embodiment will be described with reference to the drawings.

[0148] Figure 8 This is a partially enlarged view of a multilayer substrate 103 according to the second embodiment. Figure 8 A partially enlarged view of the first inner layer resin 25 in which the plurality of conductors 30 are provided is shown.

[0149] The multilayer substrate 103 according to the second embodiment differs from the multilayer substrate 100 according to the first embodiment in the width of the signal conductor 31 and the width of the inner-layer ground conductor 32 .

[0150] The signal conductor 31 includes a first portion 41 and a second portion 42. When viewed in the thickness direction T, the width of the first portion 41 is greater than the width of the second portion 42.

[0151] In the multi-layer substrate 103 , two second portions 42 are connected to both ends of the first portion 41 . That is, the first portion 41 is sandwiched between the two second portions 42 .

[0152] The first portion 41 is located in the space 40 of the stacked body 10. Specifically, when viewed in the thickness direction T of the stacked body 10, the first portion 41 is located in a first region R1 where the space 40 is formed in the stacked body 10. When viewed in the thickness direction T, the first region R1 is a region defined by the inner sidewall 10S of the stacked body 10.

[0153] The second portion 42 is not located within the space 40 within the laminate 10. When viewed in the thickness direction T of the laminate 10, the second portion 42 is located within the second region R2 of the laminate 10, where the space 40 is not formed. Specifically, when viewed in the thickness direction T, the second region R2 is located outside the first region R1 and is the region where the flexible resin layer 72 is disposed. When viewed in the thickness direction T, the second region R2 is located outside the first region R1 in the substrate extension direction S. Therefore, when viewed in the thickness direction T, the second portion 42 extends from the interior of the laminate 10 into the space 40 and is connected to the first portion 41.

[0154] For example, the width of the first portion 41 is 1.1 times or greater and 3.0 times or less than the width of the second portion 42. Furthermore, the width of the first portion 41 may refer to the maximum dimension in the width direction W when viewed from the thickness direction T. Furthermore, the width of the second portion 42 may refer to the minimum dimension in the width direction W when viewed from the thickness direction T.

[0155] This structure facilitates impedance matching of the signal conductor 31. By making the width of the signal conductor 31 wider than the second portion 42 in the first portion 41 located in the space 40 containing air having a low dielectric constant, impedance variation is less likely to occur.

[0156] In the multilayer substrate 103, the inner-layer ground conductor 32 includes a third portion 43 and a fourth portion 44 having a width greater than that of the third portion 43. In the multilayer substrate 103, two fourth portions 44 are connected to both ends of the third portion 43. That is, the third portion 43 is sandwiched between the two fourth portions 44.

[0157] The third portion 43 is located in the space 40 in the laminate 10. Similar to the first portion 41, the third portion 43 is located in the first region R1 when viewed in the thickness direction T of the laminate 10.

[0158] The fourth portion 44 is not located in the space 40 within the laminate 10. Similar to the second portion 42, the fourth portion 44 is located in the second region R2 when viewed in the thickness direction T of the laminate 10. Therefore, when viewed in the thickness direction T, the fourth portion 44 extends from the interior of the laminate 10 into the space 40 and is connected to the third portion 43.

[0159] This structure makes it easier to maintain a constant gap between the signal conductor 31 and the inner ground conductor 32 when viewed in the thickness direction T. This reduces the chance of differences in gaps between the conductors 30 , making it easier to achieve impedance matching for the signal conductor 31 .

[0160] Furthermore, by adjusting the width of the inner-layer ground conductor 32 in accordance with the width of the signal conductor 31, it is possible to reduce the space for arranging the plurality of conductors 30. This allows the multi-layer substrate 103 to be miniaturized.

[0161] Furthermore, the width of the fourth portion 44 of the inner-layer ground conductor 32 may be greater than the width of the second portion 42 of the signal conductor 31 when viewed in the thickness direction T. The width of the second portion 42 and the width of the fourth portion 44 refer to the dimensions in the width direction W when viewed in the thickness direction T.

[0162] In addition, in this embodiment, an example in which the widths of the inner-layer ground conductor 32 are different has been described, but the present invention is not limited thereto and the width of the inner-layer ground conductor 32 may be fixed.

[0163] (Third embodiment)

[0164] Hereinafter, a multi-layer substrate according to a third embodiment will be described with reference to the drawings.

[0165] Figure 9 It is a longitudinal sectional view of a multilayer substrate 104 according to the third embodiment.

[0166] The multilayer substrate 104 according to the third embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and the position of the first inner layer resin 25 .

[0167] like Figure 9 As shown in FIG, the laminate 10 further includes a flexible resin layer 75. The flexible resin layer 75 is disposed between the flexible resin layers 73 and 74. The flexible resin layer 75 has the same shape as that of the flexible resin layer 73, for example.

[0168] The first inner layer resin 25 is offset relative to the multilayer substrate 104 in the thickness direction T of the multilayer substrate 104. The first inner layer resin 25 is arranged closer to the flexible resin layer 70 than to the flexible resin layer 74. Specifically, the first inner layer resin 25 is arranged closer to the first principal surface 10a of the laminate 10 than to the second principal surface 10b in the thickness direction T. In other words, in the thickness direction T, the distance between the first inner wall 10A of the laminate 10 and the third principal surface 25a of the first inner layer resin 25 is smaller than the distance between the second inner wall 10B of the laminate 10 and the fourth principal surface 25b of the first inner layer resin 25.

[0169] The bending stress of the first inner layer resin 25 depends on the distance from the bending neutral line. When the first inner layer resin 25 is bent, compressive stress is generated on the inner peripheral side of the bent portion, and tensile stress is generated on the outer peripheral side of the bent portion. The compressive stress and tensile stress decrease as they move toward the inner center in the thickness direction of the first inner layer resin 25, and there is a position where the compressive stress and tensile stress become zero. This position is called the bending neutral line. When the distance from the bending neutral line is zero, the bending stress becomes zero, and the greater the distance, the greater the bending stress. Since the first inner layer resin 25 is separated from the laminate 10 in the space 40, the bending stress can be reduced even if it is in a position far away from the bending neutral line.

[0170] Therefore, also in the structure of the multilayer substrate 104 , fluctuations in the gaps between the plurality of conductors 30 can be effectively suppressed.

[0171] In addition, in this embodiment, an example is described in which the first inner layer resin 25 is unevenly distributed in the thickness direction T by adding a flexible resin layer 75 to the laminate 10, but the present invention is not limited to this. For example, the first inner layer resin 25 may be unevenly distributed in the thickness direction T by increasing the thickness of the flexible resin layer 73. Alternatively, the first inner layer resin 25 may be unevenly distributed in the thickness direction T by adding one or more flexible resin layers 75.

[0172] In this embodiment, the flexible resin layer 75 has the same shape as the flexible resin layer 73 , but the present invention is not limited thereto. For example, the flexible resin layer 75 may have a different shape and thickness from the flexible resin layer 73 .

[0173] Furthermore, in this embodiment, an example is described in which the first inner layer resin 25 is disposed closer to the flexible resin layer 70 than to the flexible resin layer 74 in the thickness direction T. However, the present invention is not limited thereto. For example, the first inner layer resin 25 may be disposed closer to the flexible resin layer 74 than to the flexible resin layer 70 in the thickness direction T.

[0174] (Fourth embodiment)

[0175] Hereinafter, a multi-layer substrate according to a fourth embodiment will be described with reference to the drawings.

[0176] Figure 10 It is a longitudinal sectional view of a multilayer substrate 105 according to the fourth embodiment.

[0177] The multilayer substrate 105 according to the fourth embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and in that a plurality of second inner layer resins 26 are further provided.

[0178] like Figure 10 As shown, laminate 10 further includes flexible resin layers 77, 78, 79, and 80. Flexible resin layers 77 and 78 are disposed between flexible resin layers 71 and 72. Flexible resin layers 79 and 80 are disposed between flexible resin layers 72 and 73. Flexible resin layers 77 and 80 have, for example, the same shape as flexible resin layer 72. Flexible resin layers 78 and 79 have, for example, the same shape as flexible resin layer 71.

[0179] The multilayer substrate 105 also includes a plurality of second inner layer resins 26. The plurality of second inner layer resins 26 have, for example, the same shape as the first inner layer resin 25. The plurality of second inner layer resins 26 are arranged in the space 40 of the laminate 10. Specifically, the plurality of second inner layer resins 26 are arranged in the space 40 of the laminate 10 at intervals in the thickness direction T of the laminate 10. The first inner layer resin 25 is arranged between the plurality of second inner layer resins 26 in the thickness direction T. More specifically, the plurality of second inner layer resins 26 are arranged between the third principal surface 25a of the first inner layer resin 25 and the first inner wall 10A of the laminate 10, and between the fourth principal surface 25b of the first inner layer resin 25 and the second inner wall 10B of the laminate 10.

[0180] In this embodiment, the plurality of second inner resin layers 26 are formed integrally with the flexible resin layers 77 and 80. Therefore, the plurality of second inner resin layers 26 are formed from the same resin as the flexible resin layers 77 and 80. In other words, the plurality of second inner resin layers 26 are formed from a portion of the laminate 10.

[0181] Furthermore, the plurality of second inner layer resins 26 are connected to the laminate 10 in the substrate extending direction S of the multilayer substrate 100. Specifically, the plurality of second inner layer resins 26 are separated from the first inner wall 10A and the second inner wall 10B in the thickness direction T. The plurality of second inner layer resins 26 are separated from the inner sidewall 10S in the width direction W, while being connected to the inner sidewall 10S in the substrate extending direction S.

[0182] With this configuration, since the multilayer substrate 105 includes the plurality of second inner layer resins 26, the first inner layer resin 25 and the plurality of conductors 30 are prevented from approaching the first ground conductor 36 and the second ground conductor 38. For example, when the multilayer substrate 105 is deformed, the first inner layer resin 25 and the second inner layer resin 26 come into contact, thereby preventing the distance between the plurality of conductors 30 and the first ground conductor 36 and the second ground conductor 38 from decreasing. Consequently, fluctuations in the impedance of the plurality of conductors 30 can be suppressed.

[0183] In addition, in this embodiment, an example is described in which the multilayer substrate 105 includes a plurality of second inner layer resins 26, but the present invention is not limited thereto. The multilayer substrate 105 may include one or more second inner layer resins 26. For example, even when the multilayer substrate 105 includes one second inner layer resin 26, a space 40 may be provided that becomes the peak fold side relative to the first inner layer resin 25 when the multilayer substrate 105 is bent.

[0184] (Fifth embodiment)

[0185] Hereinafter, a multi-layer substrate according to a fifth embodiment will be described with reference to the drawings.

[0186] Figure 11A It is a longitudinal sectional view of a multilayer substrate 106 according to the fifth embodiment. Figure 11B This is a partially enlarged view showing an example of the plurality of first through holes 60 provided in the laminated body 10 .

[0187] The multilayer substrate 106 according to the fifth embodiment differs from the multilayer substrate 105 according to the fourth embodiment in the structures of the flexible resin layers 70A to 78A, the first inner layer resin 25A, and the second inner layer resin 26A.

[0188] like Figure 11A as well as Figure 11BAs shown, in the multilayer substrate 106 , a plurality of first through holes 60 are provided throughout the laminate 10 , the first inner layer resin 25A, and the second inner layer resin 26A.

[0189] The laminated body 10 includes flexible resin layers 70A to 74A and flexible resin layers 77A to 80A.

[0190] The flexible resin layers 70A to 74A and the flexible resin layers 77A to 80A respectively have the same shapes as the flexible resin layers 70 to 74 and the flexible resin layers 77 to 80 , for example, except that a plurality of first through holes 60 are provided.

[0191] like Figure 11B As shown, the plurality of first through holes 60 are regularly arranged. Specifically, the plurality of first through holes 60 have substantially the same shape and size and are arranged at equal intervals. For example, the plurality of first through holes 60 are arranged in a matrix when viewed from the thickness direction T.

[0192] The plurality of first through-holes 60 have, for example, a circular shape when viewed in the thickness direction T. The plurality of first through-holes 60 have, for example, an opening width of 81 μm or greater and 500 μm or less. In this specification, "opening width" refers to the maximum dimension of the first through-holes 60. In this embodiment, the opening width refers to the maximum diameter of the first through-holes 60 when viewed in the thickness direction T. The spacing between the plurality of first through-holes 60 is, for example, 73 μm or greater and 730 μm or less.

[0193] The flexible resin layers 70A to 74A, the flexible resin layers 77A to 80A, the first inner layer resin 25A, and the second inner layer resin 26A are each formed of a mesh member, for example.

[0194] The plurality of first through holes 60 are provided using, for example, a laser.

[0195] The plurality of first through holes 60 are not holes for interlayer connection conductors such as via conductors. Therefore, air exists in the first through holes 60.

[0196] With such a configuration, it is possible to improve the flexibility of the multilayer substrate 106 and suppress variations in the gaps between the conductors of the plurality of conductors 30 .

[0197] More specifically, by providing a plurality of first through holes 60 throughout the laminate 10, the first inner layer resin 25A, and the second inner layer resin 26A, the amount of resin in the multilayer substrate 106 is reduced, thereby making the multilayer substrate 106 easier to bend and improving its usability.

[0198] In addition, in this embodiment, an example is described in which a plurality of first through-holes 60 are provided throughout the laminate 10, the first inner layer resin 25A, and the second inner layer resin 26A, but the present invention is not limited thereto. Alternatively, a plurality of first through-holes 60 may be provided in at least a portion of the laminate 10, the first inner layer resin 25A, or the second inner layer resin 26A.

[0199] For example, the plurality of first through-holes 60 may be provided in a portion of the flexible resin layers 70A and 74A of the laminated body 10 , and the plurality of first through-holes 60 may not be provided in other portions.

[0200] For example, a plurality of first through-holes 60 may be provided in a portion of the first inner layer resin 25A or the second inner layer resin 26A. A plurality of first through-holes 60 may also be provided in the first inner layer resin 25A or the second inner layer resin 26A at a position overlapping with the signal conductor 31 as viewed in the thickness direction T of the laminate 10. This reduces the dielectric constant and dielectric loss tangent around the signal conductor 31, thereby improving electrical characteristics.

[0201] The shape of the plurality of first through holes 60 is not limited, and may be, for example, a triangular pyramid. The shape when viewed in the thickness direction T is also not limited, and may be, for example, an ellipse.

[0202] Furthermore, the plurality of first through-holes 60 is not limited to being provided throughout the flexible resin layers 70A to 74A, the flexible resin layers 77A to 80A, the first inner layer resin 25A, and the second inner layer resin 26A. Furthermore, the plurality of first through-holes 60 is not limited to being provided individually in the flexible resin layers 70A to 74A, the flexible resin layers 77A to 80A, the first inner layer resin 25A, and the second inner layer resin 26A.

[0203] Furthermore, the plurality of first through holes 60 may be arranged irregularly. For example, the plurality of first through holes 60 may be randomly arranged. Furthermore, the plurality of first through holes 60 may have different sizes or shapes.

[0204] In addition, in the multi-layer substrate 106 , the second inner layer resin 26A is not an essential structure.

[0205] (Variation)

[0206] Below, use Figure 11C A multilayer substrate according to a modified example of the fifth embodiment will be described.

[0207] Figure 1 1C is a partially enlarged cross-sectional view showing an example of a porous material.

[0208] The multilayer substrate according to the modification of the fifth embodiment differs from the multilayer substrate 106 according to the fifth embodiment in that the laminate 10 , the first inner layer resin 25A, and the second inner layer resin 26A are made of porous materials.

[0209] like Figure 11C As shown, the porous material is a raw material having a porous structure. The porous structure is a structure in which a plurality of bubbles P are dispersed throughout the porous region A. The porous region A refers to the region in which the bubbles P are provided within the body 12 of the porous material. The porous region A is provided throughout the laminate 10, the first inner layer resin 25A, and the second inner layer resin 26A.

[0210] The porous region A contains a plurality of closed cells. The closed cells P are entirely surrounded by the material of the main body 12, preventing the gas within the cells P from leaking outside the main body 12. Furthermore, adjacent closed cells P are not connected to each other. The porosity of the porous region A is, for example, 30% to 80%. The porosity is the ratio of the volume of the cells P to the total volume of the main body 12.

[0211] Even in such a structure, the same effects as those of the multi-layer substrate 106 according to the fifth embodiment can be achieved.

[0212] Furthermore, although the laminate 10, the first inner layer resin 25A, and the second inner layer resin 26A are entirely composed of a porous material, the present invention is not limited thereto. For example, at least a portion of the laminate 10, the first inner layer resin 25A, or the second inner layer resin 26A may be composed of a porous material. Furthermore, the porous region A may be provided in at least a portion of the laminate 10, the first inner layer resin 25A, or the second inner layer resin 26A.

[0213] Furthermore, in the modification of the fifth embodiment, an example in which the porous material includes a plurality of closed cells has been described, but the present invention is not limited thereto.

[0214] Figure 1 ID is a partially enlarged cross-sectional view showing another example of a porous material. Figure 1 As shown in FIG1D , a plurality of cells Q may be provided in a continuous manner in the porous material. Furthermore, the plurality of cells Q may have different shapes and / or sizes.

[0215] (Sixth embodiment)

[0216] Hereinafter, a multi-layer substrate according to a sixth embodiment will be described with reference to the drawings.

[0217] Figure 12AIt is a longitudinal sectional view of a multilayer substrate 107 according to the sixth embodiment. Figure 12B This is a partially enlarged view showing an example of a plurality of second through holes 53 provided in the second inner layer resin 26B.

[0218] The multi-layer substrate 107 according to the sixth embodiment is different from the multi-layer substrate 105 according to the fourth embodiment in the structure of the second inner layer resin 26B.

[0219] like Figure 12A as well as Figure 12B As shown, in the multi-layer substrate 107, a plurality of second through holes 53 are provided in the second inner layer resin 26B. In the present embodiment, a plurality of second through holes 53 are provided in each of the two second inner layer resins 26B.

[0220] like Figure 12B As shown, the plurality of second through holes 53 are provided at positions overlapping the signal conductor 31 as viewed in the thickness direction T. As viewed in the thickness direction T, the plurality of second through holes 53 are provided along the direction in which the signal conductor 31 extends, that is, the substrate extending direction S.

[0221] When viewed in the thickness direction T, the plurality of second through-holes 53 have, for example, a circular shape. In the multilayer substrate 107, the length of the second through-holes 53 in the width direction W is longer than the length of the signal conductor 31 in the width direction W. The second through-holes 53 have, for example, an opening width that is not less than 1 / 6 and not more than 1 / 3 of the length of the laminate 10 in the width direction W. Here, "opening width" refers to the maximum dimension of the second through-holes 53 in the width direction W of the laminate 10. In this embodiment, the opening width refers to the maximum diameter of the second through-holes 53.

[0222] Similar to the space 40 , air exists in the plurality of second through holes 53 provided in the second inner layer resin 26B.

[0223] With this configuration, by providing a plurality of second through-holes 53 in the second inner layer resin 26B, the portion of the second inner layer resin 26B that overlaps the signal conductor 31 as viewed in the thickness direction T can be reduced. Air, which has a lower dielectric constant than the second inner layer resin 26B, exists within the plurality of second through-holes 53. Consequently, the signal characteristics of the signal conductor 31 can be improved.

[0224] Furthermore, the length of the second through hole 53 in the width direction W is longer than the length of the signal conductor 31 in the width direction W. With this configuration, the signal characteristics of the signal conductor 31 can be further improved.

[0225] In addition, in this embodiment, the multilayer substrate 107 is described as including two second inner layer resins 26B, but the present invention is not limited thereto. For example, the multilayer substrate 107 may include one or more second inner layer resins 26B.

[0226] Furthermore, in this embodiment, the second inner layer resin 26B is provided with a plurality of second through-holes 53, but the present invention is not limited thereto. For example, the second inner layer resin 26B may be provided with one or more second through-holes 53. For example, the second inner layer resin 26B may be provided with a single rectangular second through-hole 53.

[0227] In addition, in this embodiment, the example in which the plurality of second through holes 53 are provided in both the two second inner layer resins 26B is described, but the present invention is not limited thereto. For example, the plurality of second through holes 53 may be provided in at least one of the two second inner layer resins 26B.

[0228] The shape of the second through hole 53 is not limited, and may be, for example, a triangular pyramid. The shape of the second through hole 53 when viewed in the thickness direction T is also not limited, and may be, for example, an ellipse, a rectangle, or a polygon.

[0229] (Seventh embodiment)

[0230] Hereinafter, a multi-layer substrate according to a seventh embodiment will be described with reference to the drawings.

[0231] Figure 13A It is a longitudinal sectional view of a multilayer substrate 108 according to the seventh embodiment. Figure 13B This is a partially enlarged view showing an example of the plurality of third through holes 54 provided in the flexible resin layer 70 .

[0232] The multilayer substrate 108 according to the seventh embodiment differs from the multilayer substrate 107 according to the sixth embodiment in the structure of the laminate 10 .

[0233] like Figure 13A as well as Figure 13B As shown, a plurality of third through holes 54 are further provided in the flexible resin layers 70 and 74 .

[0234] like Figure 13B As shown, the plurality of third through holes 54 are provided at positions overlapping the signal conductor 31 as viewed in the thickness direction T. Furthermore, as viewed in the thickness direction T, the plurality of third through holes 54 are provided along the direction in which the signal conductor 31 extends, that is, the substrate extending direction S.

[0235] When viewed in the thickness direction T, the plurality of third through-holes 54 have, for example, a circular shape. In the multilayer substrate 108, the length of the through-holes 54 in the width direction W is longer than the length of the signal conductor 31 in the width direction W. The third through-holes 54 have, for example, an opening width that is not less than 1 / 6 and not more than 1 / 3 of the length of the laminate 10 in the width direction W. Here, "opening width" refers to the maximum dimension of the third through-holes 54 in the width direction W of the laminate 10. In this embodiment, the opening width refers to the maximum diameter of the third through-holes 54.

[0236] In this embodiment, the third through holes 54 are provided at positions overlapping with the through holes 53 provided in the second inner layer resin 26B as viewed in the thickness direction T. Specifically, the third through holes 54 have the same shape, size, and arrangement as the through holes 53 .

[0237] Air exists in the plurality of through holes 54 , similar to the space 40 .

[0238] According to this structure, by providing a plurality of third through-holes 54 in the flexible resin layers 70 and 74, the portion of the flexible resin layers 70 and 74 that overlaps the signal conductor 31 when viewed in the thickness direction T can be reduced. Air having a lower dielectric constant than that of the flexible resin layers 70 and 74 exists within the plurality of third through-holes 54. Therefore, in the multilayer substrate 108, the signal characteristics of the signal conductor 31 can be improved.

[0239] Furthermore, the plurality of third through holes 54 are provided at positions overlapping with the plurality of through holes 53 provided in the second inner layer resin 26B when viewed in the thickness direction T. With such a structure, the signal characteristics of the signal conductor 31 can be further improved.

[0240] Furthermore, the length of the through hole 54 in the width direction W is longer than the length of the signal conductor 31 in the width direction W. Thus, the dielectric constant around the signal conductor 31 is reduced, and the signal characteristics of the signal conductor 31 can be improved.

[0241] In this embodiment, the example in which the flexible resin layers 70 and 74 are provided with a plurality of through-holes 54 is described, but the present invention is not limited thereto. For example, a plurality of third through-holes 54 may be provided in at least one of the flexible resin layers 70 and 74 .

[0242] Furthermore, one or more third through-holes 54 may be provided in the flexible resin layer 70 or 74. For example, one rectangular third through-hole 54 may be provided in the flexible resin layer 70 or 74.

[0243] Furthermore, the plurality of third through holes 54 may have a shape, size, and arrangement different from those of the plurality of through holes 53 .

[0244] The shape of the through hole 54 is not limited, and may be, for example, a triangular pyramid. The shape of the third through hole 54 when viewed in the thickness direction T is also not limited, and may be, for example, an ellipse, a rectangle, or a polygon.

[0245] (Eighth embodiment)

[0246] Hereinafter, a multi-layer substrate according to an eighth embodiment will be described with reference to the drawings.

[0247] Figure 14A It is a longitudinal sectional view of a multilayer substrate 109 according to the eighth embodiment. Figure 14B This is a partially enlarged view showing an example of the plurality of first protrusions 27 provided in the first inner layer resin 25 .

[0248] The multilayer substrate 109 according to the eighth embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and in that a plurality of first protrusions 27 are further provided.

[0249] like Figure 14A As shown, the laminate 10 further includes flexible resin layers 78 and 79. Flexible resin layer 78 is disposed between flexible resin layers 71 and 72, and flexible resin layer 79 is disposed between flexible resin layers 72 and 73. Flexible resin layers 78 and 79 have the same shape as flexible resin layer 73, for example.

[0250] In addition, if Figure 14A as well as Figure 14B As shown, the multilayer substrate 109 further includes first protrusions 27. Specifically, the first inner layer resin 25 includes a plurality of first protrusions 27 that protrude in the thickness direction T of the laminate 10. More specifically, the plurality of first protrusions 27 are provided on both the third principal surface 25a and the fourth principal surface 25b of the first inner layer resin 25 in the thickness direction T. The plurality of first protrusions 27 are formed to have substantially the same shape and size.

[0251] In the multilayer substrate 109, the plurality of first protrusions 27 each have a rectangular parallelepiped shape. On the third principal surface 25a of the first inner layer resin 25, the plurality of first protrusions 27 are arranged outside the plurality of conductors 30 as viewed in the thickness direction T. Specifically, as viewed in the thickness direction T, the plurality of first protrusions 27 are arranged on both sides of the plurality of conductors 30 in the width direction W in which the plurality of conductors 30 are arranged. On the third principal surface 25a of the first inner layer resin 25, the height of the plurality of first protrusions 27 in the thickness direction T is greater than the thickness of the plurality of conductors 30 in the thickness direction T. Furthermore, the height of the plurality of first protrusions 27 in the thickness direction T is smaller than the distance in the thickness direction T between the first inner wall 10A of the laminate 10 and the third principal surface 25a of the first inner layer resin 25.

[0252] The plurality of first protrusions 27 provided on the fourth principal surface 25b of the first inner layer resin 25 are provided at positions overlapping with the plurality of first protrusions 27 provided on the third principal surface 25a as viewed in the thickness direction T. Furthermore, on the fourth principal surface 25b of the first inner layer resin 25, the height of the plurality of first protrusions 27 in the thickness direction T is smaller than the distance in the thickness direction T between the second inner wall 10B of the laminate 10 and the fourth principal surface 25b of the first inner layer resin 25.

[0253] like Figure 14B As shown, in the multilayer substrate 109, the plurality of first protrusions 27 are located outside the two inner-layer ground conductors 32. Specifically, when viewed in the thickness direction T, the plurality of first protrusions 27 are arranged between the end of the first inner layer resin 25 in the width direction W and the inner-layer ground conductors 32. The plurality of first protrusions 27 are arranged at intervals along the substrate extension direction S. For example, the plurality of first protrusions 27 are arranged at equal intervals along the substrate extension direction S.

[0254] With this configuration, the multilayer substrate 109 includes the plurality of first protrusions 27 , thereby preventing the first inner layer resin 25 and the plurality of conductors 30 from approaching the first ground conductor 36 and the second ground conductor 38 . This prevents fluctuations in the impedance of the signal conductor 31 .

[0255] In addition, in this embodiment, an example in which a plurality of first protrusions 27 are provided on the first inner layer resin 25 is described, but the present invention is not limited thereto. Alternatively, one or more first protrusions 27 may be provided on the first inner layer resin 25. For example, one or more first protrusions 27 may be provided on the third principal surface 25a or the fourth principal surface 25b of the first inner layer resin 25.

[0256] Alternatively, the plurality of first protrusions 27 may be provided on both the third principal surface 25a and the fourth principal surface 25b of the first inner layer resin 25 in the thickness direction T. For example, the plurality of first protrusions 27 may be provided on at least one of the third principal surface 25a or the fourth principal surface 25b of the first inner layer resin 25. For example, the plurality of first protrusions 27 may be provided on at least one of the third principal surface 25a and the fourth principal surface 25b of the first inner layer resin 25. For example, the plurality of first protrusions 27 may be provided on at least the surface that becomes the peak fold side when the multilayer substrate 109 is bent.

[0257] The shape of the first protrusion 27 is not limited, and may be, for example, a cylindrical shape or a triangular pyramid shape. The cross-sectional shape of the first protrusion 27 is also not limited.

[0258] Furthermore, the first protrusion 27 may be arranged outside the plurality of conductors 30. For example, the first protrusion 27 may be arranged between the plurality of conductors 30. In this case, the width of the first protrusion 27 provided on the third main surface 25a of the first inner layer resin 25 in the width direction W is smaller than the spacing between the plurality of conductors 30. Furthermore, the distance between the first protrusion 27 and the signal conductor 31 in the width direction W may be shorter than the distance between the inner layer ground conductor 32 and the signal conductor 31. By placing the first protrusion 27 closer to the signal conductor 31 than to the inner layer ground conductor 32, impedance fluctuations can be further suppressed.

[0259] In addition, in this embodiment, the example in which the plurality of first protrusions 27 are arranged at equal intervals along the substrate extending direction S has been described, but the present invention is not limited thereto. For example, a single first protrusion 27 may be arranged continuously along the substrate extending direction S.

[0260] In addition, in this embodiment, the example in which the plurality of first protrusions 27 are formed in substantially the same shape and the same size is described, but the present invention is not limited thereto. For example, the plurality of first protrusions 27 may be formed in different shapes or sizes.

[0261] (Ninth embodiment)

[0262] Hereinafter, a multi-layer substrate according to a ninth embodiment will be described with reference to the drawings.

[0263] Figure 15A It is a longitudinal sectional view of a multilayer substrate 110 according to the ninth embodiment. Figure 15B This is a partially enlarged view showing an example of the plurality of second protrusions 28 provided on the second inner layer resin 26 .

[0264] The multilayer substrate 110 according to the ninth embodiment differs from the multilayer substrate 105 according to the fourth embodiment in the structure of the laminate 10 and in that a plurality of second protrusions 28 are further provided.

[0265] like Figure 15A As shown, the laminate 10 further includes flexible resin layers 81 and 82. Flexible resin layer 81 is disposed between flexible resin layers 71 and 77. Flexible resin layer 82 is disposed between flexible resin layers 80 and 73. Flexible resin layers 81 and 82 have, for example, the same shape as flexible resin layer 73.

[0266] In addition, if Figure 15A as well as Figure 15B As shown, the multilayer substrate 110 further includes a plurality of second protrusions 28. Specifically, the second inner layer resin 26 includes a plurality of second protrusions 28 protruding in the thickness direction T of the laminate 10. The plurality of second protrusions 28 are formed in substantially the same shape and size.

[0267] In the multilayer substrate 110, the plurality of second protrusions 28 are arranged at positions that do not overlap with the signal conductor 31 when viewed in the thickness direction T. The plurality of second protrusions 28 are located between the inner-layer ground conductor 32 and the conductive shield 34. In the present embodiment, the plurality of second protrusions 28 are arranged at positions that overlap with the inner-layer ground conductor 32 when viewed in the thickness direction T.

[0268] The plurality of second protrusions 28 are arranged at intervals along the substrate extending direction S. For example, when viewed in the thickness direction T, the plurality of second protrusions 28 are arranged at equal intervals along the substrate extending direction S.

[0269] In the multilayer substrate 110, the plurality of second protrusions 28 each have a rectangular parallelepiped shape. In the second inner layer resin 26 disposed between the first inner layer resin 25 and the flexible resin layer 70, the height of the plurality of second protrusions 28 in the thickness direction T is shorter than the distance between the first inner wall 10A of the laminate 10 and the second inner layer resin 26. Furthermore, in the second inner layer resin 26 disposed between the first inner layer resin 25 and the flexible resin layer 74, the height of the plurality of second protrusions 28 in the thickness direction T is shorter than the distance between the second inner wall 10B of the laminate 10 and the second inner layer resin 26.

[0270] With this configuration, the multilayer substrate 110 includes the plurality of second protrusions 28 , which prevents the first inner layer resin 25 and the plurality of conductors 30 from approaching the first ground conductor 36 and the second ground conductor 38 . This prevents fluctuations in the impedance of the signal conductor 31 .

[0271] Furthermore, the plurality of second protrusions 28 are arranged at positions that do not overlap with the signal conductor 31 when viewed in the thickness direction T. With this structure, the dielectric constant and dielectric loss tangent around the signal conductor 31 are reduced, thereby improving electrical characteristics.

[0272] Furthermore, in this embodiment, the example in which a plurality of second protrusions 28 are provided on each of the two second inner layer resins 26 is described, but the present invention is not limited thereto. For example, a plurality of second protrusions 28 may be provided on at least one second inner layer resin 26. For example, a plurality of second protrusions 28 may be provided on the surface of the second inner layer resin 26 that becomes the peak fold side when the multilayer substrate 110 is bent.

[0273] The shape of the second protrusion 28 is not limited, and may be, for example, cylindrical or triangular pyramidal. The cross-sectional shape of the second protrusion 28 is also not limited.

[0274] Furthermore, in this embodiment, the plurality of second protrusions 28 are described as being provided at positions overlapping the inner-layer ground conductor 32 as viewed in the thickness direction T. However, the present invention is not limited thereto. For example, the plurality of second protrusions 28 may be provided at positions not overlapping the inner-layer ground conductor 32 as viewed in the thickness direction T.

[0275] In addition, in this embodiment, the example in which a plurality of second protrusions 28 are provided on the second inner layer resin 26 is described, but the present invention is not limited thereto. The second inner layer resin 26 may be provided with one or more second protrusions 28 .

[0276] In addition, in this embodiment, the example in which the plurality of second protrusions 28 are formed in substantially the same shape and the same size is described, but the present invention is not limited thereto. For example, the plurality of second protrusions 28 may be formed in different shapes or sizes.

[0277] (10th embodiment)

[0278] Hereinafter, a multi-layer substrate according to a tenth embodiment will be described with reference to the drawings.

[0279] Figure 16 It is a longitudinal sectional view of a multi-layer substrate 111 according to the tenth embodiment. Figure 17 It is an exploded plan view of a multi-layer substrate 111 according to the tenth embodiment. Figure 18 It is a transverse cross-sectional view of a deformed multilayer substrate 111 according to the tenth embodiment.

[0280] The multilayer substrate 111 according to the tenth embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and in that a plurality of third protrusions 29 are further provided.

[0281] like Figure 16 as well as Figure 17 As shown, the laminate 10 further includes flexible resin layers 83 and 84 .

[0282] The flexible resin layer 83 is disposed between the flexible resin layers 70 and 71. The flexible resin layer 84 is disposed between the flexible resin layers 73 and 74. The flexible resin layers 83 and 84 have the same shape as that of the flexible resin layer 73, for example.

[0283] The multilayer substrate 111 also includes a plurality of third protrusions 29. Specifically, the multilayer substrate 111 includes a plurality of third protrusions 29 that protrude in the thickness direction T of the laminate 10. The plurality of third protrusions 29 are provided on the inner surface of the laminate 10. Specifically, the plurality of third protrusions 29 are provided on the first inner wall 10A and the second inner wall 10B of the laminate 10. The plurality of third protrusions 29 provided on the first inner wall 10A of the laminate 10 protrude in the thickness direction T from the first inner wall 10A toward the third main surface 25a of the first inner layer resin 25. The plurality of third protrusions 29 provided on the second inner wall 10B of the laminate 10 protrude from the second inner wall 10B toward the fourth main surface 25b of the first inner layer resin 25.

[0284] In the multilayer substrate 111, the plurality of third protrusions 29 are arranged at positions that do not overlap with the signal conductor 31 when viewed in the thickness direction T. The plurality of third protrusions 29 are located between the inner-layer ground conductor 32 and the conductive shield 34. In this embodiment, the plurality of third protrusions 29 are arranged at positions that overlap with the inner-layer ground conductor 32 when viewed in the thickness direction T.

[0285] The plurality of third protrusions 29 are arranged at intervals along the substrate extending direction S. For example, the plurality of third protrusions 29 are arranged at equal intervals along the substrate extending direction S. The plurality of third protrusions 29 are formed in substantially the same shape and the same size.

[0286] In the multilayer substrate 111, the plurality of third protrusions 29 each have a rectangular parallelepiped shape. The height of the plurality of third protrusions 29 in the thickness direction T is smaller than the distance between the inner surface of the laminate 10 and the first inner layer resin 25 in the thickness direction T. Specifically, the height of the plurality of third protrusions 29 provided on the first inner wall 10A of the laminate 10 is smaller than the distance between the first inner wall 10A and the third main surface 25a of the first inner layer resin 25. Furthermore, the height of the plurality of third protrusions 29 provided on the second inner wall 10B of the laminate 10 is smaller than the distance between the second inner wall 10B and the fourth main surface 25b of the first inner layer resin 25.

[0287] like Figure 18 As shown, when the multilayer substrate 111 is bent in the thickness direction T, the outer portion of the laminate 10 bends and deforms. As the laminate 10 deforms, the first inner layer resin 25 and the plurality of conductors 30 also deform. At this time, the plurality of third protrusions 29 protruding from the inner surface of the laminate 10 prevent the first inner layer resin 25 and the plurality of conductors 30 from approaching the first ground conductor 36 and the second ground conductor 38. For example, when the first inner layer resin 25 deforms, the first inner layer resin 25 contacts the plurality of third protrusions 29, thereby maintaining a separation from the first ground conductor 36 and the second ground conductor 38.

[0288] With this configuration, the multilayer substrate 111 includes the plurality of third protrusions 29 , which prevents the first inner layer resin 25 and the plurality of conductors 30 from approaching the first ground conductor 36 and the second ground conductor 38 . This prevents fluctuations in the impedance of the signal conductor 31 .

[0289] Furthermore, the plurality of third protrusions 29 are arranged at positions that do not overlap with the signal conductor 31 when viewed in the thickness direction T. With this structure, the dielectric constant and dielectric loss tangent around the signal conductor 31 are reduced, thereby improving electrical characteristics.

[0290] In addition, in this embodiment, an example in which a plurality of third protrusions 29 are provided on the inner surface of the stacked body 10 is described, but the present invention is not limited thereto. For example, one or more third protrusions 29 may be provided on the inner surface of the stacked body 10 .

[0291] Furthermore, while this embodiment describes an example in which multiple third protrusions 29 are provided on both the first inner wall 10A and the second inner wall 10B of the laminate 10, the present invention is not limited thereto. For example, multiple third protrusions 29 may be provided on at least one of the first inner wall 10A or the second inner wall 10B. For example, they may be provided on the inner surface of the laminate 10 that forms the peak fold when the multilayer substrate 111 is bent.

[0292] The shape of the third protrusion 29 is not limited, and may be, for example, cylindrical or triangular pyramidal. The cross-sectional shape of the third protrusion 29 is also not limited.

[0293] Furthermore, the third protrusion 29 may be arranged at a position that does not overlap with the inner-layer ground conductor 32 when viewed in the thickness direction T.

[0294] In addition, in this embodiment, the example in which the plurality of third protrusions 29 are formed in substantially the same shape and the same size is described, but the present invention is not limited thereto. For example, the plurality of third protrusions 29 may be formed in different shapes or sizes.

[0295] (11th embodiment)

[0296] Hereinafter, a multi-layer substrate according to an eleventh embodiment will be described with reference to the drawings.

[0297] Figure 19 It is a longitudinal sectional view of a multi-layer substrate 112 according to the eleventh embodiment.

[0298] The multilayer substrate 112 according to the eleventh embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and in that the plurality of conductors 30 are provided on the third principal surface 25 a and the fourth principal surface 25 b of the first inner layer resin 25 .

[0299] like Figure 19 As shown, in the multi-layer substrate 112 , the laminate 10 includes flexible resin layers 71 to 76 . The flexible resin layers 71 to 73 and 75 to 76 are arranged between the flexible resin layers 70 and 74 .

[0300] In the multilayer substrate 112, a plurality of conductors 30 are provided on the third principal surface 25a and the fourth principal surface 25b of the first inner layer resin 25. In this embodiment, a signal conductor 31 is provided on the third principal surface 25a, and an inner layer ground conductor 32 is provided on the fourth principal surface 25b.

[0301] In this manner, the plurality of conductors 30 may not be provided on the same surface of the first inner layer resin 25 .

[0302] Even in such a structure, the same effects as those of the multilayer substrate 100 according to the first embodiment can be achieved.

[0303] In this embodiment, the signal conductor 31 is provided on the third principal surface 35a of the first inner layer resin 25, and the inner layer ground conductor 32 is provided on the fourth principal surface 25b. However, the present invention is not limited thereto. For example, the signal conductor 31 may be provided on the fourth principal surface 25b, and the inner layer ground conductor 32 may be provided on the third principal surface 25a.

[0304] (12th embodiment)

[0305] Hereinafter, a multi-layer substrate according to a twelfth embodiment will be described with reference to the drawings.

[0306] Figure 20 It is a longitudinal sectional view of a multi-layer substrate 113 according to the twelfth embodiment.

[0307] The multilayer substrate 113 according to the twelfth embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and in that the plurality of conductors 30 are embedded in the first inner layer resin 25 .

[0308] like Figure 20 As shown, in the multilayer substrate 113, the laminate 10 includes flexible resin layers 71 to 74. The flexible resin layer 72 includes two flexible resin layers 72B and 72C. The flexible resin layer 72B is laminated on the flexible resin layer 72C.

[0309] The flexible resin layers 72B and 72C form the first inner layer resin 25. That is, the first inner layer resin 25 is formed by a part of the flexible resin layers 72B and 72C.

[0310] The first inner layer resin 25 includes an inner layer resin 25B and an inner layer resin 25C. The inner layer resin 25B is laminated on the inner layer resin 25C. In this embodiment, the inner layer resin 25B is formed by a portion of the flexible resin layer 72B. The inner layer resin 25C is formed by a portion of the flexible resin layer 72C.

[0311] A plurality of conductors 30 are embedded in the first inner layer resin 25. Specifically, the plurality of conductors 30 are covered with the inner layer resin 25B and the inner layer resin 25C.

[0312] In this manner, the plurality of conductors 30 may be buried in the first inner layer resin 25 and not exposed from the first inner layer resin 25 .

[0313] Even in such a structure, the same effects as those of the multilayer substrate 100 according to the first embodiment can be achieved.

[0314] Furthermore, since the plurality of conductors 30 can be protected by the first inner layer resin 25 , the quality of the multi-layer substrate 113 can be improved.

[0315] (Thirteenth embodiment)

[0316] Hereinafter, a multi-layer substrate according to a thirteenth embodiment will be described with reference to the drawings.

[0317] Figure 21 It is a longitudinal sectional view of a multilayer substrate 114 according to the thirteenth embodiment.

[0318] The multilayer substrate 114 according to the thirteenth embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and the arrangement in which the first principal surface 10 a of the laminate 10 is in contact with the wall surface of the housing 90 .

[0319] like Figure 21 As shown, in the multi-layer substrate 114 , the laminate 10 includes flexible resin layers 71 to 76 .

[0320] In the multi-layer substrate 114 , no ground conductor is provided on the first main surface 10 a of the laminate 10 , but the wall surface of the housing 90 is arranged.

[0321] The housing 90 is formed of metal, for example. The housing 90 is, for example, an outer shell of a battery pack. Alternatively, the housing 90 may be a shielding member.

[0322] Thus, in the multilayer substrate 114, the housing 90 may be disposed on the first main surface 10a of the laminate 10 without providing a ground conductor. Even in such a configuration, the same effects as those of the multilayer substrate 100 of the first embodiment can be achieved.

[0323] (14th embodiment)

[0324] Hereinafter, a multi-layer substrate according to a fourteenth embodiment will be described with reference to the drawings.

[0325] Figure 22 It is a longitudinal sectional view of a multilayer substrate 115 according to the fourteenth embodiment.

[0326] The multilayer substrate 115 according to the fourteenth embodiment differs from the multilayer substrate 100 according to the first embodiment in the structure of the laminate 10 and the provision of two inner resin layers 25D and 25E provided with a plurality of conductors 30 .

[0327] like Figure 22 As shown, in multilayer substrate 115, laminate 10 includes flexible resin layers 71 to 74. Flexible resin layer 72 includes three flexible resin layers 72D, 72E, and 72F. Flexible resin layer 72F is laminated on flexible resin layer 72E, and flexible resin layer 72D is laminated on flexible resin layer 72F. In other words, flexible resin layer 72F is provided between flexible resin layers 72D and 72E.

[0328] The first inner resin layer 25 includes two inner resin layers 25D and 25E. The two inner resin layers 25D and 25E are arranged with space between them in the stacking direction (Z direction) of the stacked body 10. In this embodiment, the inner resin layer 25D is formed from a portion of the flexible resin layer 72D. The inner resin layer 25E is formed from a portion of the flexible resin layer 72E.

[0329] The inner layer resin 25D has a sheet shape extending in the substrate extension direction S of the multilayer substrate 115. A plurality of conductors 30A are provided on the surface of the inner layer resin 25D. The plurality of conductors 30A include signal conductors 31 and inner layer ground conductors 32, forming a coplanar line.

[0330] The inner layer resin 25E has a sheet shape extending in the substrate extension direction S of the multilayer substrate 115. A plurality of conductors 30B are provided on the surface of the inner layer resin 25E. The plurality of conductors 30B include a signal conductor 31 and an inner layer ground conductor 32, forming a coplanar line.

[0331] Thus, in the multilayer substrate 115, the first inner layer resin 25 includes two inner layer resins 25D and 25E spaced apart in the stacking direction (Z direction) of the laminate 10. Multiple conductors 30A and 30B are provided in the two inner layer resins 25D and 25E, respectively. That is, in the first inner layer resin 25, the two coplanar lines provided in the two inner layer resins 25D and 25E run parallel to the stacking direction (Z direction). This structure also achieves the same effects as the multilayer substrate 100 of the first embodiment.

[0332] Furthermore, although the first inner layer resin 25 is described as including two inner layer resins 25D and 25E provided with a plurality of conductors 30A and 30B, the present invention is not limited thereto. For example, the first inner layer resin 25 may include two or more inner layer resins, each of which may include a plurality of conductors 30.

[0333] (other)

[0334] As described above, the above embodiments and modifications are described as examples of the technology disclosed in this application. However, the technology disclosed in this application is not limited thereto and can also be applied to embodiments in which appropriate changes, substitutions, additions, omissions, etc. are made. Therefore, other embodiments are exemplified below.

[0335] The conductive shield 34 may be provided by a conductive paste or a conductive seal. This structure can improve the shielding performance.

[0336] For example, when the laminate 10 is provided with the through holes 53 and 54, a conductive sealant may be used as the conductive shield 34. The conductive sealant can block the through holes 53 and 54 and improve the shielding property.

[0337] Furthermore, when the multi-layer substrate is bent, a conductive shield 34 such as a conductive paste or a conductive sealant may be provided after the bending. By using this manufacturing method, cracks in the conductive shield 34 can be suppressed.

Claims

1. A multi-layer substrate, characterized in that: have: A laminate having a plurality of laminated flexible resin layers and a space provided therein; A first inner layer resin is disposed in the space of the laminate; and A plurality of conductors, including a signal conductor, are disposed in the first inner layer of resin, At least a portion of the first inner layer resin is separated from the laminate within the space. The plurality of conductors include a plurality of inner ground conductors, The signal conductor is arranged between the plurality of inner ground conductors. The stacked body has a first main surface and a second main surface facing each other in a stacking direction of the stacked body, The multilayer substrate further includes a plurality of conductive shielding members arranged on the first main surface and the second main surface. The plurality of conductive shields are arranged at positions overlapping the signal conductors when viewed in the stacking direction. The first inner layer resin floats from the laminate in a cross section taken in a direction perpendicular to the extending direction of the signal conductor.

2. The multi-layer substrate according to claim 1, wherein A plurality of first through holes are provided in at least a portion of the laminate or the first inner layer resin.

3. The multi-layer substrate according to claim 2, wherein: The plurality of first through holes are provided in the first inner layer resin at positions overlapping with the signal conductors when viewed in the stacking direction of the stacked body.

4. The multi-layer substrate according to any one of claims 1 to 3, wherein: The first inner layer resin has a first protrusion protruding in the stacking direction of the stacked body.

5. The multi-layer substrate according to claim 4, wherein The first protrusion is arranged outside the plurality of conductors in the direction in which the plurality of conductors are arranged.

6. The multi-layer substrate according to any one of claims 1 to 3, wherein: The multilayer substrate further includes a plurality of second inner layer resins, the plurality of second inner layer resins being arranged at intervals in the stacking direction of the stack in the space of the stack. The first inner layer resin is arranged between the plurality of second inner layer resins.

7. The multi-layer substrate according to claim 6, wherein: At least one of the plurality of second inner layer resins has a second protrusion protruding in the stacking direction.

8. The multi-layer substrate according to claim 7, wherein: The second protrusion is arranged at a position not overlapping with the signal conductor when viewed in the stacking direction of the stacked body.

9. The multi-layer substrate according to any one of claims 1 to 3, characterized in that The stacked body includes an inner surface defining the space, and a third protrusion protruding from the inner surface in a stacking direction of the stacked body.

10. The multi-layer substrate according to claim 9, wherein The third protrusion is arranged at a position not overlapping with the signal conductor when viewed in the stacking direction of the stacked body.

11. The multi-layer substrate according to claim 1, wherein The conductive shield includes at least one of a metal foil, a conductive paste, or a conductive seal.

12. The multi-layer substrate according to claim 1 or 11, characterized in that: The conductive shield is connected to ground potential, The multilayer substrate further includes a plurality of second inner layer resins, the plurality of second inner layer resins being arranged in the space of the laminate at intervals in the stacking direction and overlapping with the inner layer ground conductor when viewed in the stacking direction. The first inner layer resin is arranged between the plurality of second inner layer resins in the stacking direction.

13. The multi-layer substrate according to claim 12, wherein: At least one of the plurality of second inner layer resins has a second through hole provided at a position overlapping with the signal conductor when viewed in the stacking direction.

14. The multi-layer substrate according to claim 12, wherein: The laminate is provided with a third through hole at a position overlapping with the signal conductor when viewed in the lamination direction.

15. The multi-layer substrate according to any one of claims 1 to 3, characterized in that The first inner layer resin extends in the extending direction of the signal conductor, The first inner layer resin is connected to the laminate in the extending direction.

16. The multi-layer substrate according to any one of claims 1 to 3, characterized in that The signal conductor includes: a first portion located in the space when viewed from the stacking direction of the stack; and a second portion extending from the inside of the stack and connected to the first portion. When viewed in the stacking direction of the stacked body, the width of the first portion is greater than the width of the second portion.

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