Multilayer substrate and electronic device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- MURATA MFG CO LTD
- Filing Date
- 2025-11-18
- Publication Date
- 2026-06-11
Smart Images
Figure JP2025040257_11062026_PF_FP_ABST
Abstract
Description
Multilayer Substrate and Electronic Device 【0001】 The present invention generally relates to a multilayer substrate and an electronic device, and more particularly to a multilayer substrate provided with signal lines and an electronic device provided with the multilayer substrate. 【0002】 Patent Document 1 discloses an electronic device. The electronic device disclosed in Patent Document 1 includes a first substrate (mounting substrate) and a second substrate (multilayer substrate). The second substrate includes signal lines disposed between a plurality of insulating substrates. Further, the second substrate includes input / output pads and a plurality of auxiliary pads (external electrodes) on a first surface (main surface). 【0003】 International Publication No. 2016 / 88693 【0004】 In the multilayer substrate disclosed in Patent Document 1, the multilayer substrate may warp. In such a case, when the multilayer substrate is mounted on the mounting substrate, the mountability to the mounting substrate may deteriorate, such as a connection failure occurring between the terminals of the multilayer substrate and the terminals of the mounting substrate. 【0005】 An object of the present invention is to provide a multilayer substrate and an electronic device capable of improving the mountability to a mounting substrate. 【0006】 A multilayer substrate according to an aspect of the present invention includes a laminated substrate, signal lines, and a plurality of external connection electrodes. The laminated substrate has a first main surface and a second main surface. The signal lines are disposed in the laminated substrate. The plurality of external connection electrodes are disposed on the first main surface of the laminated substrate. The laminated substrate is long along a first direction orthogonal to the thickness direction of the laminated substrate. The plurality of external connection electrodes are provided in each of a plurality of first regions of the multilayer substrate that are spaced apart from each other. The laminated substrate is provided with hollow portions in each of a plurality of second regions of the multilayer substrate that are spaced apart from each other. The plurality of first regions and the plurality of second regions are alternately arranged in the first direction. 【0007】An electronic device according to one aspect of the present invention comprises a mounting substrate and a multilayer substrate. The multilayer substrate is disposed on the main surface of the mounting substrate. The multilayer substrate includes a laminated substrate, a signal line, and a plurality of external connection electrodes. The laminated substrate has a first main surface. The signal line is disposed within the laminated substrate. The plurality of external connection electrodes are disposed on the first main surface of the laminated substrate. The laminated substrate is elongated along a first direction perpendicular to the thickness direction of the laminated substrate. The plurality of external connection electrodes are provided in each of a plurality of first regions of the multilayer substrate that are spaced apart from each other. The plurality of external connection electrodes are connected to the mounting substrate by solder. The laminated substrate has hollow portions in one or more second regions of the multilayer substrate that are spaced apart from each other. The plurality of first regions and the one or more second regions are arranged alternately in the first direction. 【0008】 According to one aspect of the present invention, a multilayer substrate and electronic device make it possible to improve the mountability of the multilayer substrate onto a mounting substrate. 【0009】Figure 1 is a partially broken plan view showing a multilayer substrate according to Embodiment 1. Figure 2 is a cross-sectional view of the same multilayer substrate, corresponding to the cross-section along line X1-X1 in Figure 1. Figure 3 is a cross-sectional view of the main part of an electronic device equipped with the same multilayer substrate. Figure 4 is a cross-sectional view of the main part of a multilayer substrate according to Embodiment 2. Figure 5 is a cross-sectional view of the main part of a multilayer substrate according to a modified example of Embodiment 2. Figure 6 is a partially broken plan view showing a multilayer substrate according to Embodiment 3. Figure 7 is a partially broken plan view of a multilayer substrate according to Modification 1 of Embodiment 3. Figure 8 is a cross-sectional view of a multilayer substrate according to Embodiment 4. Figure 9 is a partially broken plan view showing a multilayer substrate according to Embodiment 5. Figure 10 is a partially broken plan view showing a multilayer substrate according to Embodiment 6. Figure 11 is a partially broken plan view showing a multilayer substrate according to Embodiment 7. Figure 12 is a partially broken plan view showing a multilayer substrate according to Embodiment 8. Figure 13 is a partially broken plan view showing a multilayer substrate according to Embodiment 9. Figure 14 is a plan view showing a multilayer substrate according to Embodiment 10, with a portion broken off. Figure 15 is a plan view of a multilayer substrate according to Embodiment 11. Figure 16 is a plan view of a multilayer substrate according to Embodiment 12. Figure 17 is a cross-sectional view of the same multilayer substrate, corresponding to the X2-X2 cross-sectional view in Figure 16. 【0010】 Embodiments 1 to 12, etc., will be described below with reference to the drawings. The drawings referenced in Embodiments 1 to 12, etc., are schematic diagrams, and the size and thickness of the components shown in the drawings do not necessarily reflect the actual dimensions, nor do the ratios of size and thickness between components necessarily reflect the actual dimensional ratios. Furthermore, each drawing defines and represents a Cartesian coordinate system having three mutually orthogonal axes: the X, Y, and Z axes. The X, Y, and Z axes are all virtual axes, and the arrows indicating "X," "Y," and "Z" in the drawings are merely for illustrative purposes and do not represent actual objects. 【0011】 (Embodiment 1) The multilayer substrate 100 and electronic device 500 according to Embodiment 1 will be described with reference to Figures 1 to 3. 【0012】(1) Multilayer substrate Embodiment 1 The multilayer substrate 100 according to Embodiment 1 comprises a laminated substrate 1, a plurality of signal lines 2 (three in Figure 1), a first ground electrode 31, and a second ground electrode 32, as shown in Figures 1 and 2. The multilayer substrate 100 according to Embodiment 1 further comprises a plurality of signal electrodes 20, a plurality of external connection electrodes 4, a plurality of first connection conductors 71, and a plurality of second connection conductors (not shown in Figure 2), as shown in Figure 2. The multilayer substrate 100 according to Embodiment 1 further comprises a first resist layer 51 and a second resist layer 52. 【0013】 The multilayer substrate 100 is placed on the mounting substrate 530 of the electronic device 500, for example, as shown in Figure 3. The multilayer substrate 100 is placed on the main surface 531 of the mounting substrate 530, for example. Multiple external connection electrodes 4 (see Figure 4) of the multilayer substrate 100 are connected to multiple electrodes 532 of the mounting substrate 530. The electronic device 500 is, for example, a mobile phone (e.g., a smartphone), but is not limited to a mobile phone; it may also be, for example, a notebook personal computer, a wearable device (e.g., a smartwatch), etc. 【0014】 Hereinafter, each component of the multilayer substrate 100 according to this embodiment will be described with reference to the drawings. 【0015】 (1.1) Laminated Substrate In this embodiment, as shown in Figure 1, the laminated substrate 1 is elongated along the Y-axis direction perpendicular to the thickness direction D1 (see Figure 2) of the laminated substrate 1, and the direction along the X-axis direction is the width direction. The direction along the Y-axis direction corresponds to the first direction. The laminated substrate 1 may have a shape other than elongated. 【0016】 As shown in Figure 2, the laminated substrate 1 has a plurality of (two in the illustrated example) insulating layers 11 and 12, and the plurality of insulating layers 11 and 12 are stacked. The thickness direction D1 of the laminated substrate 1 is the stacking direction of the plurality of insulating layers 11 and 12. 【0017】 Each of the multiple insulating layers 11, 12 may contain, for example, a thermoplastic resin. The thermoplastic resin is, for example, a thermoplastic liquid crystal polymer. Alternatively, each of the multiple insulating layers 11, 12 may also contain, for example, polyimide. 【0018】The thickness of each of the multiple insulating layers 11 and 12 is, for example, 10 μm or more and 120 μm or less. 【0019】 The insulating layer 11 has a main surface 111 and a main surface 112. The main surface 111 of the insulating layer 11 is the main surface in contact with the signal line 2. The main surface 112 of the insulating layer 11 is the main surface in contact with the first ground electrode 31 in the thickness direction D1 of the laminated substrate 1. The insulating layer 11 has a plurality of through holes 113. 【0020】 The insulating layer 12 has a main surface 121 and a main surface 122. The main surface 121 of the insulating layer 12 is the main surface that is in contact with the insulating layer 11 in the thickness direction D1 of the laminated substrate 1. The main surface 122 of the insulating layer 12 is the main surface that is in contact with the second ground electrode 32 and the plurality of signal electrodes 20 in the thickness direction D1 of the laminated substrate 1. The insulating layer 12 has a plurality of through holes 123. 【0021】 The laminated substrate 1 has a first main surface 14 and a second main surface 15. The first main surface 14 of the laminated substrate 1 includes the main surface 112 of the insulating layer 11. The second main surface 15 of the laminated substrate 1 includes the main surface 122 of the insulating layer 12. 【0022】 The multilayer substrate 100 has different structures between two types of regions that are alternately arranged along the Y-axis. The two types of regions include a first region AR1 and a second region AR2. The multilayer substrate 100 includes multiple (three in Figure 1) first regions AR1 and one or more (two in Figure 1) second regions AR2. It is preferable that the multilayer substrate 100 includes multiple second regions AR2. The multiple first regions AR1 are spaced apart from each other. If the multilayer substrate 100 includes multiple second regions AR2, the multiple second regions AR2 are spaced apart from each other. The multiple regions AR1 and the multiple regions AR2 are alternately arranged along the Y-axis (first direction). 【0023】The laminated substrate 1 is provided with a plurality of (six in Figure 1) hollow portions 6. The plurality of hollow portions 6 are provided in each of the plurality of regions AR2 of the multilayer substrate 100. Each of the plurality of second regions AR2 is provided with one or more (three in Figure 1) hollow portions 6. In one second region AR2, the one or more (three in Figure 1) hollow portions 6 are arranged in a direction that intersects both the thickness direction D1 of the laminated substrate 1 and the extension direction of the signal line 2. In this embodiment, in one second region AR2, the three hollow portions 6 are arranged along the X axis. 【0024】 In this embodiment, as shown in Figure 2, each of the multiple hollow portions 6 includes one through-hole 113 from among the multiple through-holes 113 provided in the insulating layer 11 and one through-hole 123 from among the multiple through-holes 123 provided in the insulating layer 12. At least one of the multiple hollow portions 6 may include either one through-hole 113 or one through-hole 123. The insulating layer 11 may also have a plurality of recesses formed on its main surface 111 instead of, or separately from, the multiple through-holes 113. One or more of the multiple hollow portions 6 include one of the multiple recesses instead of one through-hole 113. The insulating layer 12 may also have a plurality of recesses formed on its main surface 121 instead of, or separately from, the multiple through-holes 123. One or more of the multiple hollow portions 6 include one of the multiple recesses instead of one through-hole 123. 【0025】(1.2) As shown in Figures 1 and 2, the signal line 2 is arranged within the laminated substrate 1. More specifically, as shown in Figure 2, the signal line 2 is formed on the main surface 111 of the insulating layer 11. The signal line 2 is, for example, a signal line on which a high-frequency signal is transmitted. The frequency of the high-frequency signal is, for example, 1 GHz or higher, but is not limited to 1 GHz or higher and may be less than 1 GHz. The multilayer substrate 100 of this embodiment is designed so that the impedance of the signal line 2 is 50 Ω. In this embodiment, the laminated substrate 1, the signal line 2, the first ground electrode 31 and the second ground electrode 32 constitute a strip line. In this embodiment, the multilayer substrate 100 includes a plurality of signal lines 2, and the plurality of signal lines 2 constitute a triplate line. 【0026】 The signal line 2 is conductive. The material of the signal line 2 includes, for example, copper. The thickness of the signal line 2 is, for example, 3 μm or more and 40 μm or less. The signal line 2 is formed in a predetermined pattern. The signal line 2 is formed, for example, by patterning a first copper foil that is attached to a resin sheet which will be the basis of the insulating layer 11. 【0027】 As shown in Figure 1, in a plan view from the thickness direction D1 of the laminated substrate 1, the signal line 2 is straight. The length of the signal line 2 in the direction along the Y axis is longer than the length in the direction along the X axis. In this embodiment, the signal line 2 has a line width in the X axis direction. In the Y axis direction, the length of the signal line 2 is shorter than the length of the laminated substrate 1. In a plan view from the thickness direction D1 of the laminated substrate 1, the signal line 2 may have a shape other than straight; for example, it may be curved or bent. 【0028】As shown in Figure 1, in a plan view from the thickness direction D1 of the laminated substrate 1, a portion of each signal line 2 overlaps with one or more (two in Figure 1) of the multiple hollow portions 6 of the laminated substrate 1. In this embodiment, a portion of the signal line 2 is exposed to the hollow portion 6. More specifically, in each of the second region AR2, the main surfaces 24 and 25 of the signal line 2 are exposed within the laminated substrate 1 by the hollow portion 6. In each of the second region AR2, the main surfaces 24 and 25 of each of the multiple signal lines 2 (see Figure 2) are in contact with the gas in the hollow portion 6. 【0029】 (1.3) External connection electrodes As shown in Figure 2, a plurality of external connection electrodes 4 are arranged on the second main surface 15 of the laminated substrate 1. 【0030】 The multiple external connection electrodes 4 include two or more (two in Figure 2) first connection electrodes 4a and two or more (four in Figure 2) second connection electrodes 4b. The two first connection electrodes 4a are connected one-to-one with multiple (two in Figure 2) signal electrodes 20. The two or more second connection electrodes 4b are connected to the second ground electrode 32. Note that the four second connection electrodes 4b are not necessarily located on the X1-X1 cross section, so in Figure 2, the second connection electrodes 4b are not hatched to show the cross section. The multiple external connection electrodes 4 are arranged in each of the multiple first regions AR1. On the other hand, the multiple external connection electrodes 4 are not arranged in any of the multiple second regions AR2. 【0031】 (1.4) First ground electrode The first ground electrode 31 is positioned on the first main surface 14 of the laminated substrate 1, as shown in Figure 2. The first ground electrode 31 is in contact with the first main surface 14 of the laminated substrate 1. In the thickness direction D1 of the laminated substrate 1, the first ground electrode 31 faces the signal line 2 and the second ground electrode 32. 【0032】The first ground electrode 31 is conductive. The material of the first ground electrode 31 includes, for example, copper. The thickness of the first ground electrode 31 is, for example, 3 μm or more and 40 μm or less. The first ground electrode 31 is formed in a predetermined pattern. In a plan view from the thickness direction D1 of the laminated substrate 1, the first ground electrode 31 has a long shape, for example, with a length in the direction along the Y axis being longer than a length in the direction along the X axis. The first ground electrode 31 is arranged on the main surface 112 of the insulating layer 11 so as to cover most of the main surface 112 of the insulating layer 11. The first ground electrode 31 is formed, for example, by patterning a second copper foil that is attached to the resin sheet that forms the basis of the insulating layer 11. 【0033】 (1.5) Second ground electrode The second ground electrode 32 is located on the second main surface 15 of the laminated substrate 1, as shown in Figure 2. The second ground electrode 32 is in contact with the second main surface 15 of the laminated substrate 1. In the thickness direction D1 of the laminated substrate 1, the second ground electrode 32 faces the signal line 2 and the first ground electrode 31. 【0034】 The second ground electrode 32 is conductive. The material of the second ground electrode 32 includes, for example, copper. The thickness of the second ground electrode 32 is, for example, 3 μm or more and 40 μm or less. The second ground electrode 32 is formed in a predetermined pattern. In a plan view from the thickness direction D1 of the laminated substrate 1, the second ground electrode 32 has a long shape, for example, with a length in the direction along the Y axis being longer than a length in the direction along the X axis. The second ground electrode 32 is positioned on the main surface 122 of the insulating layer 12 so as to cover most of the main surface 122 of the insulating layer 12. The second ground electrode 32 is formed, for example, by patterning copper foil that is attached to the resin sheet that forms the basis of the insulating layer 12. 【0035】 (1.6) Signal electrodes The plurality of signal electrodes 20 are arranged on the second main surface 15 of the laminated substrate 1, as shown in Figure 2. The plurality of signal electrodes 20 are in contact with the second main surface 15 of the laminated substrate 1. In the thickness direction D1 of the laminated substrate 1, the plurality of signal electrodes 20 face the signal line 2 and the first ground electrode 31. 【0036】The multiple signal electrodes 20 are conductive. The material of the multiple signal electrodes 20 includes, for example, copper. The thickness of each of the multiple signal electrodes 20 is, for example, 3 μm to 40 μm. The multiple signal electrodes 20 are formed in a predetermined pattern. In a plan view from the thickness direction D1 of the laminated substrate 1, for example, each of the multiple signal electrodes 20 overlaps with one of the multiple signal lines 2. The multiple signal electrodes 20 are formed in the same process as the second ground electrode 32, for example, by patterning the copper foil described above which is attached to a resin sheet that forms the basis of the insulating layer 12. 【0037】 (1.7) Multiple connecting conductors As shown in Figure 2, the multiple first connecting conductors 71 penetrate the insulating layer 12 and are connected to two or more first connecting electrodes 4a. In the first region AR1, the multiple first connecting conductors 71 connect the multiple signal electrodes 20 and the multiple signal lines 2. The multiple first connecting conductors 71 are conductive. The material of each of the multiple first connecting conductors 71 includes, for example, copper, copper-tin alloy, and resin. 【0038】 Multiple second connecting conductors (not shown) penetrate the insulating layers 11 and 12 and are connected to two or more second connecting electrodes 4b. In the first region AR1, the multiple second connecting conductors connect the first ground electrode 31 and the second ground electrode 32. The multiple second connecting conductors are conductive. The material of each of the multiple second connecting conductors includes, for example, copper, copper-tin alloy, and resin. 【0039】 (1.8) First resist layer As shown in Figure 2, the first resist layer 51 covers the insulating layer 11 and the first ground electrode 31. 【0040】 The first resist layer 51 includes, for example, a polyimide film and an adhesive layer. The material of the adhesive layer includes, for example, an acrylic resin, a silicone resin, an epoxy resin, or a urethane resin. The first resist layer 51 is not limited to a configuration including a polyimide film and an adhesive layer; for example, it may be a resist layer without an adhesive layer. The resist layer is formed using, for example, printing technology, spin coating technology, and photolithography technology. 【0041】(1.9) Second resist layer As shown in Figure 2, the second resist layer 52 covers the insulating layer 12 and the second ground electrode 32. The second resist layer 52 has a plurality of openings 520 through which a plurality of external connection electrodes 4 pass. 【0042】 The second resist layer 52 includes, for example, a polyimide film and an adhesive layer. The material of the adhesive layer includes, for example, an acrylic resin, a silicone resin, an epoxy resin, or a urethane resin. The second resist layer 52 is not limited to a configuration including a polyimide film and an adhesive layer; for example, it may be a resist layer without an adhesive layer. The resist layer is formed using, for example, printing technology, spin coating technology, and photolithography technology. 【0043】 (2) Hollow parts As shown in Figures 1 and 2, two or more (three in Figures 1 and 2) hollow parts 6 are provided in each of a plurality of second regions AR2 that are spaced apart from each other. The three second regions AR2 located in one second region AR2 are aligned in the X direction. Each of the plurality of hollow parts 6 includes the internal space of the through hole 113 of the insulating layer 11 and the internal space of the through hole 123 of the insulating layer 12. 【0044】(3) Electronic device As shown in FIG. 3 of the electronic device, the electronic device 500 includes a multilayer substrate 100 and a mounting substrate 530. The multilayer substrate 100 is disposed on the main surface 531 of the mounting substrate 530. The multilayer substrate 100 is mounted on the main surface 531 of the mounting substrate 530, for example, without passing through a connector or the like. Each of the plurality of external connection electrodes 4 (see FIG. 4) of the multilayer substrate 100 is connected to one of the plurality of electrodes 532 of the mounting substrate 530 by solder 533. Note that the electronic device 500 further includes a housing (not shown) that houses the multilayer substrate 100 and the mounting substrate 530. (4) Effect The multilayer substrate 100 according to Embodiment 1 includes a laminated substrate 1, a plurality of signal lines 2, and a plurality of external connection electrodes 4. The laminated substrate 1 has a first main surface 14 and a second main surface 15. The signal lines 2 are disposed within the laminated substrate 1. The plurality of external connection electrodes 4 are disposed on the second main surface 15 of the laminated substrate 1. The plurality of external connection electrodes 4 are provided in two or more first regions AR1 of the multilayer substrate 100 that are spaced apart from each other. The laminated substrate 1 is elongated along the Y-axis direction orthogonal to the thickness direction D1 of the laminated substrate 1. In the laminated substrate 1, a hollow portion 6 is provided in each of the plurality of second regions AR2 of the multilayer substrate 100 that are spaced apart from each other. The plurality of first regions AR1 and the plurality of second regions AR2 are alternately arranged in the Y-axis direction orthogonal to the thickness direction D1 of the laminated substrate 1. 【0045】 According to the above configuration, it is possible to improve the mounting property of the multilayer substrate 100 to the mounting substrate 530. In the multilayer substrate 100 according to Embodiment 1, since the second region AR2 is more easily deformed than the first region AR1, it is possible to make the multilayer substrate 100 follow the main surface 531 of the mounting substrate 530. Thereby, it is possible to improve the mounting property of the multilayer substrate 100 to the mounting substrate 530. 【0046】 Further, in the multilayer substrate 100 according to Embodiment 1, in a plan view from the thickness direction D1 of the laminated substrate 1, the hollow portion 6 overlaps a part of the signal lines 2. 【0047】According to the above configuration, it is possible to further improve the mountability of the multilayer substrate 100 to the mounting substrate 530. In the multilayer substrate 100 according to Embodiment 1, in a plan view from the thickness direction D1 of the laminated substrate 1, the ratio of the area of the hollow portion 6 to the area of the second region AR2 is easily improved. Therefore, in the multilayer substrate 100, the second region AR2 is more likely to deform than the first region AR1. 【0048】 In the multilayer substrate 100 according to Embodiment 1, a part of the signal line 2 is exposed in the hollow portion 6. 【0049】 According to the above configuration, it is possible to further improve the mountability of the multilayer substrate 100 to the mounting substrate 530. In the multilayer substrate 100 according to Embodiment 1, it is easy to expand the width of the hollow portion 6 in the thickness direction D1 of the laminated substrate 1. Therefore, in the multilayer substrate 100, the second region AR2 is more likely to deform than the first region AR1. 【0050】 In the multilayer substrate 100 according to Embodiment 1, none of the plurality of external connection electrodes 4 are provided in any of the plurality of second regions AR2. 【0051】 According to the above configuration, it is possible to further improve the mountability of the multilayer substrate 100 to the mounting substrate 530. More specifically, in the multilayer substrate 100 according to Embodiment 1, since none of the plurality of external connection electrodes 4 are arranged in the second region AR2, the flexibility of the second region AR2 is further improved. 【0052】 In the multilayer substrate 100 according to Embodiment 1, the laminated substrate 1 includes insulating layers 11 and 12 containing a thermoplastic liquid crystal polymer as a material. 【0053】 According to the above configuration, it is possible to enhance the flexibility of the multilayer substrate 100. 【0054】Furthermore, the electronic device 500 according to Embodiment 1 comprises a mounting substrate 530 and a multilayer substrate 100. The multilayer substrate 100 is arranged on the main surface 531 of the mounting substrate 530. The multilayer substrate 100 includes a laminated substrate 1, a signal line 2, and a plurality of external connection electrodes 4. The laminated substrate 1 has a second main surface 15. The signal line 2 is arranged within the laminated substrate 1. The plurality of external connection electrodes 4 are arranged on the second main surface 15 of the laminated substrate 1. The laminated substrate 1 is elongated along the Y-axis direction perpendicular to the thickness direction D1 of the laminated substrate 1. The plurality of external connection electrodes 4 are provided in each of a plurality of first regions AR1 of the multilayer substrate 100 that are spaced apart from each other. The plurality of external connection electrodes 4 are connected to the mounting substrate 530 by solder 533. The laminated substrate 1 has hollow portions 6 in one or more second regions AR2 of the multilayer substrate 100 that are spaced apart from each other. Multiple first regions AR1 and one or more second regions AR2 are arranged alternately in the Y-axis direction (first direction). 【0055】 According to the above configuration, it is possible to improve the mountability of the multilayer substrate 100 onto the mounting substrate 530. More specifically, in the multilayer substrate 100 according to Embodiment 1, the second region AR2 is more easily deformed than the first region AR1, so it is possible to make the multilayer substrate 100 conform to the shape of the main surface 531 of the mounting substrate 530. 【0056】 (Embodiment 2) The multilayer substrate 100 according to Embodiment 2 will be described with reference to Figure 4. With respect to the multilayer substrate 100 according to Embodiment 2, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0057】 (1) The multilayer substrate 100 according to the second embodiment differs from the multilayer substrate 100 according to the first embodiment in that each of the multiple signal lines 2 is not exposed to any of the multiple hollow portions 6. 【0058】In this embodiment, as shown in Figure 4, a portion of the multiple (only one shown in Figure 1) hollow portions 6 is a single hollow portion 114. More specifically, multiple hollow portions 114 are provided in the insulating layer 11. In a plan view from the thickness direction D1 of the laminated substrate 1, the multiple hollow portions 114 overlap with the signal line 2. The insulating layer 12 does not have through holes 123 (see Figure 2). The signal line 2 is in contact with both the main surface 111 of the insulating layer 11 and the main surface 121 of the insulating layer 12, even in the second region AR2. 【0059】 (2) The multilayer substrate 100 according to Embodiment 2 also provides the same effects as the multilayer substrate 100 according to Embodiment 1. 【0060】 (Modified Version) A modified version of the multilayer substrate 100 according to Embodiment 2 will be described with reference to Figure 5. With respect to the multilayer substrate 100 according to the modified version of Embodiment 2, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0061】 (1) The multilayer substrate 100 according to a modified example of the configuration embodiment 2 differs from the multilayer substrate 100 according to embodiment 1 in that the signal line 2 does not penetrate the hollow portion 6. 【0062】 In this modified example, as shown in Figure 5, a portion of the multiple (one shown in Figure 5) hollow portions 6 is a single hollow portion 124. More specifically, multiple hollow portions 124 are provided in the insulating layer 12. In a plan view from the thickness direction D1 of the laminated substrate 1, the multiple hollow portions 124 overlap with the signal line 2. The insulating layer 11 does not have through holes 113 (see Figure 2) or hollow portions 114 (see Figure 4). The signal line 2 is in contact with both the main surface 111 of the insulating layer 11 and the main surface 121 of the insulating layer 12 in the second region AR2. 【0063】 (2) Effects The multilayer substrate 100 according to the modified embodiment 2 also produces the same effects as the multilayer substrate 100 according to embodiment 2. 【0064】(Embodiment 3) The multilayer substrate 100a according to Embodiment 3 will be described with reference to Figure 6. With respect to the multilayer substrate 100a according to Embodiment 3, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0065】 The multilayer substrate 100a according to Embodiment 3 differs from the multilayer substrate 100 according to Embodiment 1 in that the hollow portion 6a has a long shape with the longitudinal direction along the X-axis and the width direction along the Y-axis, and in a plan view from the thickness direction D1 of the laminated substrate 1 (see Figure 1), one hollow portion 6a overlaps with multiple (three in Figure 6) signal lines 2. 【0066】 In this embodiment, as shown in Figure 6, the multilayer substrate 100a is provided with hollow portions 6a in place of the hollow portion 6 in Embodiment 1. Multiple hollow portions 6a (only one is shown in Figure 6) are provided in each of the multiple second regions AR2 of the multilayer substrate 100a. In a plan view from the thickness direction D1 of the laminated substrate 1, the outer edges of the multiple hollow portions 6a have an elongated shape with the longitudinal direction along the X-axis direction and the width direction along the Y-axis direction. In a plan view from the thickness direction D1 of the laminated substrate 1, the multiple hollow portions 6a overlap with the signal line 2. 【0067】 The signal line 2 is exposed to the hollow portion 6a, similar to the signal line 2 in the multilayer substrate 100 according to Embodiment 1. Furthermore, the hollow portion 6a is provided in the insulating layer 11, similar to the multilayer substrate 100 according to Embodiment 2, and a portion of the signal line 2 does not need to be in contact with the hollow portion 6. Alternatively, the hollow portion 6a is provided in the insulating layer 12, similar to the multilayer substrate 100 according to a modified example of Embodiment 2, and a portion of the signal line 2 does not need to be in contact with the hollow portion 6a. The multilayer substrate 100a according to Embodiment 3 also provides the same effects as the multilayer substrate 100 according to Embodiment 1. 【0068】 (Modification 1) A multilayer substrate 100c according to Modification 1 of Embodiment 3 will be described with reference to Figure 7. With respect to the multilayer substrate 100c according to Modification 1 of Embodiment 3, components that are the same as those in the multilayer substrate 100a according to Embodiment 3 (see Figure 6) are denoted by the same reference numerals and their description is omitted. 【0069】(1) The multilayer substrate 100c according to Modification 1 of Embodiment 3 differs from the multilayer substrate 100a according to Embodiment 3 in that the hollow portion 6c is open to two side surfaces 13 of the outer surface of the laminated substrate 1 that are aligned in the Y-axis direction. 【0070】 In this modified example, as shown in Figure 7, the multilayer substrate 100c is provided with hollow portions 6c instead of hollow portions 6a (see Figure 6). Multiple hollow portions 6c (only one is shown in Figure 7) are arranged in each of multiple (only one is shown in Figure 7) second regions AR2 of the multilayer substrate 100b. In a plan view from the thickness direction D1 of the laminated substrate 1, the multiple hollow portions 6c have an elongated shape with the direction along the X-axis as the longitudinal direction and the direction along the Y-axis as the width direction. In a plan view from the thickness direction D1 of the laminated substrate 1, the multiple hollow portions 6c overlap with the signal line 2. The multiple hollow portions 6c open into each of the two side surfaces 13 of the outer surface of the laminated substrate 1 that extend along the Y-axis. Each of the multiple hollow portions 6c penetrates the laminated substrate 1 in the X-axis direction intersecting the extension direction of the signal line 2. Each of the multiple hollow portions 6c communicates with the outside of the multilayer substrate 100b. 【0071】 The hollow portion 6c is provided, for example, in the insulating layer 11, and the signal line 2 is not exposed to the hollow portion 6c. Alternatively, the hollow portion 6c may be provided in the insulating layer 12, and the signal line 2 is not exposed to the hollow portion 6c. When the signal line 2 is not exposed to the hollow portion 6c, the signal line 2 is not in contact with the outside air, which reduces the deterioration of the signal line 2. 【0072】 (2) Effect: In the multilayer substrate 100c according to the modified example 1 of Embodiment 3, the hollow portion 6c penetrates the laminated substrate 1 in the X-axis direction intersecting the Y-axis direction (first direction). 【0073】 According to the above configuration, it is possible to further improve the mountability of the multilayer substrate 100c onto the mounting substrate 530. More specifically, in the multilayer substrate 100c according to the modified example 1 of Embodiment 3, the flexibility of the second region AR2 is further improved. 【0074】(Embodiment 4) The multilayer substrate 100b according to Embodiment 4 will be described with reference to Figure 8. With respect to the multilayer substrate 100b according to Embodiment 4, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0075】 The multilayer substrate 100b according to Embodiment 4 differs from the multilayer substrate 100 according to Embodiment 1 in that it includes an insulating layer 18 between the main surface 112 of the insulating layer 11 and the first ground electrode 31, and an insulating layer 19 between the main surface 122 of the insulating layer 12 and the second ground electrode 32. 【0076】 In this embodiment, as shown in Figure 8, the laminated substrate 1 has a plurality of insulating layers 18, 11, 12, and 19, and the plurality of insulating layers 18, 11, 12, and 19 are stacked in this order. 【0077】 Each of the multiple insulating layers 18, 19 is made of a material such as a thermoplastic resin. The thermoplastic resin is, for example, a liquid crystal polymer. 【0078】 The insulating layer 18 has a main surface 181 and a main surface 182. The main surface 181 of the insulating layer 18 is in contact with the main surface 112 of the insulating layer 11. The main surface 182 of the insulating layer 18 is in contact with the first ground electrode 31. The first main surface 14 of the laminated substrate 1 is included in the main surface 182 of the insulating layer 18. 【0079】 The insulating layer 19 has a main surface 191 and a main surface 192. The main surface 191 of the insulating layer 19 is in contact with the main surface 122 of the insulating layer 12. The main surface 192 of the insulating layer 19 is in contact with the second ground electrode 32 and the signal electrode 20. The second main surface 15 of the laminated substrate 1 is included in the main surface 192 of the insulating layer 19. 【0080】 Each of the multiple hollow portions 6 is provided in the insulating layer 11, in the insulating layer 12, or spans both the insulating layer 11 and the insulating layer 12. In this embodiment, each of the multiple hollow portions 6 includes one of the multiple through holes 113 provided in the insulating layer 11 and one of the multiple through holes 123 provided in the insulating layer 12. In other words, neither the insulating layer 18 nor the insulating layer 19 is provided with any of the multiple hollow portions 6. 【0081】 In the multilayer substrate 100b according to Embodiment 4, it is also possible to improve the mountability of the multilayer substrate 100 onto the mounting substrate 530. In the multilayer substrate 100 according to Embodiment 1, the second region AR2 is more easily deformed than the first region AR1, so it is possible to make the multilayer substrate 100 conform to the main surface 531 of the mounting substrate 530. 【0082】 On the other hand, in the multilayer substrate 100b according to Embodiment 4, none of the multiple hollow portions 6 are provided in the insulating layer 18 in contact with the first ground electrode 31 and in the insulating layer 19 in contact with the second ground electrode 32 and the signal electrode 20. Therefore, in the multilayer substrate 100b according to Embodiment 4, the first main surface 14 and the second main surface 15 of the laminated substrate 1 are flat. As a result, the mountability of the multilayer substrate 100 on the mounting substrate 530 is further improved in the multilayer substrate 100b according to Embodiment 4. 【0083】 (Embodiment 5) The multilayer substrate 100d according to Embodiment 5 will be described with reference to Figure 9. With respect to the multilayer substrate 100d according to Embodiment 5, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0084】 The multilayer substrate 100d according to Embodiment 5 differs from the multilayer substrate 100 according to Embodiment 1 in that, when viewed from a plan view from the thickness direction D1 of the laminated substrate 1, the multiple hollow portions 6 do not overlap with the multiple (three in Figure 9) signal lines 2. 【0085】 In this embodiment, as shown in Figure 9, the multilayer substrate 100d is provided with a plurality of (four in Figure 9) hollow portions 6. The plurality of hollow portions 6 are arranged in each of the plurality of second regions AR2 of the multilayer substrate 100d. In a plan view from the thickness direction D1 of the laminated substrate 1 (see Figure 2), each of the plurality of hollow portions 6 does not overlap with the signal line 2. The multilayer substrate 100d according to Embodiment 5 also produces the same effects as the multilayer substrate 100 according to Embodiment 1. 【0086】(Embodiment 6) The multilayer substrate 100e according to Embodiment 6 will be described with reference to Figure 10. For the multilayer substrate 100e according to Embodiment 6, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their descriptions are omitted. 【0087】 (1) The multilayer substrate 100e according to Embodiment 6 differs from the multilayer substrate 100 according to Embodiment 1 in that, as shown in Figure 10, the line width d2 of the first portion 22 of the signal line 2 that overlaps with the hollow portion 6 in a plan view from the thickness direction D1 of the laminated substrate 1 is wider than the line width d1 of the second portion 21 that does not overlap with the hollow portion 6 in a plan view from the thickness direction D1 of the laminated substrate 1. 【0088】 In this embodiment, as shown in Figure 10, the signal line 2 overlaps with a plurality of hollow portions 6. More specifically, the signal line 2 includes a plurality of first portions 22, a plurality of second portions 21, and a plurality of third portions 23. In a plan view from the thickness direction D1 of the laminated substrate 1, the plurality of first portions 22 overlap with the hollow portions 6. Each of the plurality of second portions 21 is located in the first region AR1. In a plan view from the thickness direction D1 of the laminated substrate 1, the plurality of second portions 21 do not overlap with the hollow portions 6. Each of the plurality of third portions 23 is located between one first portion 22 and one second portion 21. In this embodiment, in a plan view from the thickness direction D1 of the laminated substrate 1, each of the plurality of third portions 23 overlaps with the boundary between the first region AR1 and the second region AR2. Each of the multiple third parts 23 may be entirely contained within the first region AR1, or entirely contained within the second region AR2. 【0089】The line width d2 of the first portion 22 of the signal line 2 is wider than the line width d1 of the second portion 21 of the signal line 2. As a result, the impedance of the signal line 2 is designed to be 50Ω. In the second region AR2, because of the presence of the hollow portion 6, the dielectric constant of the laminated substrate 1 between the signal line 2 and the first ground electrode 31 is smaller than that of the laminated substrate 1 between the signal line 2 and the first ground electrode 31 in the first region AR1. Also, in the second region AR2, because of the presence of the hollow portion 6, the dielectric constant of the laminated substrate 1 between the signal line 2 and the second ground electrode 32 is smaller than that of the laminated substrate 1 between the signal line 2 and the second ground electrode 32 in the first region AR1. In contrast, because the line width d2 of the first portion 22 is wider than the line width d1 of the second portion 21, it is possible to reduce the difference in impedance of the signal line 2 between the first region AR1 and the second region AR2. In addition, in the multilayer substrate 100e according to Embodiment 6, the Z-axis thickness of the second portion 21 of the signal line 2 may be greater than the Z-axis thickness of the first portion 22. 【0090】 The third portion 23 of the signal line 2 has a tapered shape, for example, with a width that changes along the Y-axis. The line width of the third portion 23 of the signal line 2 is equal to the line width of the first portion 22 of the signal line 2 in the portion where it is in contact with the first portion 22 of the signal line 2. Also, the line width of the third portion 23 of the signal line 2 is equal to the line width of the second portion 21 of the signal line 2 in the portion where it is in contact with the second portion 21 of the signal line 2. Furthermore, the line width of the third portion 23 of the signal line 2 becomes monotonically wider or monotonically narrower along the X-axis. This makes it possible to reduce signal reflection due to abrupt changes in the impedance of the signal line 2 at the boundary between the first portion 22 and the third portion 23, and at the boundary between the third portion 23 and the second portion 21. 【0091】 (2) In the multilayer substrate 100e according to the effect embodiment 6, the line width d2 of the first portion 22 of the signal line 2 that overlaps with the hollow portion 6 in a plan view from the thickness direction D1 of the laminated substrate 1 is wider than the line width d1 of the second portion 21 that does not overlap with the hollow portion 6 in a plan view from the thickness direction D1 of the laminated substrate 1. 【0092】According to the above configuration, it is possible to reduce the difference in impedance of the signal line 2 between the first region AR1 and the second region AR2. 【0093】 (Embodiment 7) The multilayer substrate 100f according to Embodiment 7 will be described with reference to Figure 11. For the multilayer substrate 100f according to Embodiment 7, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their descriptions are omitted. 【0094】 (1) The multilayer substrate 100f according to Embodiment 7 differs from the multilayer substrate 100 according to Embodiment 1 in that, when viewed in plan from the thickness direction D1 of the laminated substrate 1, the ratio of the area occupied by the first ground electrode 31 and the second ground electrode 32 in the second region AR2 is smaller than the ratio of the area occupied by the first region AR1. 【0095】 In this embodiment, as shown in Figure 11, a plurality of slits 311 are provided in the first ground electrode 31 in the second region AR2. In a plan view from the thickness direction D1 of the laminated substrate 1, the plurality of slits 311 do not overlap with the signal line 2. This reduces the influence of the position and area of the plurality of slits 311 on the impedance of the signal line 2. Furthermore, it is preferable that the plurality of slits 311 are located near the center in the direction along the Y axis of the plurality of hollow portions 6. This reduces the influence of the position of the plurality of slits 311 on the impedance of the signal line 2. As a result, in a plan view from the thickness direction D1 of the laminated substrate 1, the ratio of the area of the first ground electrode 31 to the area of the second region AR2 is smaller than the ratio of the area of the second ground electrode 32 to the area of the first region AR1. 【0096】 Furthermore, the multiple slits 311 are provided so as not to divide the first ground electrode 31 in the Y-axis direction. The multiple slits 311 do not penetrate the first ground electrode 31 in the direction along the X-axis. 【0097】Furthermore, the second ground electrode 32 may be provided with a slit similar to that of the first ground electrode 31. Also, in the multilayer substrate 100f according to Embodiment 7, the first ground electrode 31 may not have a slit, while the second ground electrode 32 may have a slit. 【0098】 (2) The multilayer substrate 100f according to the effect embodiment 7 further comprises ground electrodes 31 and 32. The ground electrodes 31 and 32 are formed on at least one of the first main surface 14 and the second main surface 15. In a plan view from the thickness direction D1 of the laminated substrate 1, the proportion of the area occupied by the ground electrodes 31 and 32 in the second region AR2 is smaller than the proportion of the area occupied by the ground electrodes 31 and 32 in the first region AR1. 【0099】 According to the above configuration, it is possible to improve the mountability of the multilayer substrate 100f onto the mounting substrate 530. More specifically, in the multilayer substrate 100f according to Embodiment 7, the second region AR2 is more easily deformed than the first region AR1, so it is possible to make the multilayer substrate 100f conform to the main surface shape of the mounting substrate 530 (see Figure 3). 【0100】 (Embodiment 8) The multilayer substrate 100g according to Embodiment 8 will be described with reference to Figure 12. For the multilayer substrate 100g according to Embodiment 8, components that are the same as those in the multilayer substrate 100f according to Embodiment 7 (see Figure 11) are denoted by the same reference numerals and their description is omitted. 【0101】 (1) The multilayer substrate 100g according to embodiment 8 differs from the multilayer substrate 100f according to embodiment 7 in that the second connecting conductor 7 (see Figure 12) connecting the first ground electrode 31 and the second ground electrode 32 is not arranged in the second region AR2. 【0102】 In this embodiment, as shown in Figure 12, a plurality of second connecting conductors 7 are arranged in a plurality of first regions AR1. As described above, the plurality of second connecting conductors 7 penetrate the insulating layers 11 and 12 and connect the first ground electrode 31 and the second ground electrode 32. 【0103】Two or more second connecting conductors 7, among the multiple second connecting conductors 7, are located in one of the first regions AR1, and are spaced apart from each other within the first region AR1. None of the multiple second connecting conductors 7 are located in any of the multiple second regions AR2. 【0104】 (2) The multilayer substrate 100g according to the effect embodiment 8 further comprises a second connecting conductor 7. The second connecting conductor 7 is connected to ground electrodes 31 and 32. The second connecting conductor 7 is not arranged in each of the multiple second regions AR2. 【0105】 According to the above configuration, it is possible to improve the mountability of the multilayer substrate 100g onto the mounting substrate 530. More specifically, in the multilayer substrate 100g according to Embodiment 8, the second region AR2 where the second connecting conductor 7 is not located is more easily deformed than the first region AR1, so that the multilayer substrate 100f can conform to the main surface shape of the mounting substrate 530. 【0106】 (Embodiment 9) The multilayer substrate 100h according to Embodiment 9 will be described with reference to Figure 13. With respect to the multilayer substrate 100h according to Embodiment 9, components that are the same as those in the multilayer substrate 100g according to Embodiment 8 (see Figure 12) are denoted by the same reference numerals and their description is omitted. 【0107】 (1) The multilayer substrate 100h according to embodiment 9 differs from the multilayer substrate 100g according to embodiment 8 in that recesses 131 are formed on the side surface 13 of the outer surface of the laminated substrate 1 that is aligned in the Y-axis direction in a plurality of second regions AR2. 【0108】 In this embodiment, as shown in Figure 13, the second region AR2 includes a portion in which the width in the X-axis direction (second direction) perpendicular to the Y-axis direction (first direction) is shorter than the width in the X-axis direction (second direction) of the first region AR1. More specifically, in each of the plurality of second regions AR2, recesses 131 are formed on two side surfaces 13 of the outer surface of the laminated substrate 1 that are aligned with the Y-axis direction. The second region AR2 includes a portion in which the width in the X-axis direction is narrower than the width of the laminated substrate 1 in the X-axis direction in the first region AR1. 【0109】(2) In the multilayer substrate 100h according to the effect embodiment 9, the second region AR2 includes a portion in which the width in the X-axis direction (second direction) perpendicular to the Y-axis direction (first direction) is shorter than the width of the first region AR1 intersecting the X-axis direction (second direction). 【0110】 According to the above configuration, it is possible to improve the mountability of the multilayer substrate 100h onto the mounting substrate 530. More specifically, in the multilayer substrate 100h according to Embodiment 9, since the second region AR2 includes a portion with a smaller width in the X-axis direction than the first region AR1, it is possible to make the multilayer substrate 100f conform to the main surface shape of the mounting substrate 530. 【0111】 (Embodiment 10) The multilayer substrate 100i according to Embodiment 10 will be described with reference to Figure 14. With respect to the multilayer substrate 100i according to Embodiment 10, components that are the same as those in the multilayer substrate 100h according to Embodiment 9 (see Figure 12) are denoted by the same reference numerals and their description is omitted. 【0112】 (1) The multilayer substrate 100i according to the configuration embodiment 10 differs from the multilayer substrate 100h according to embodiment 9 in that, in a plurality of second regions AR2, a hollow portion 6 is formed in place of a recess 131 on the side surface 13 of the outer surface of the laminated substrate 1 that extends along the Y-axis direction. 【0113】 In this embodiment, as shown in Figure 14, a hollow portion 6 is formed in the second region AR2 so as to communicate with the side surface 13 of the laminated substrate 1. More specifically, in each of the multiple second regions AR2, a hollow portion 6 is formed so as to communicate with two side surfaces 13 of the outer surface of the laminated substrate 1 that are aligned in the Y-axis direction. 【0114】 (2) In the multilayer substrate 100i according to the effect embodiment 10, hollow portions 6 are formed on the side surfaces 13 of the laminated substrate 1 in a plurality of second regions AR2. 【0115】 According to the above configuration, it is possible to improve the mountability of the multilayer substrate 100i onto the mounting substrate 530. More specifically, in the multilayer substrate 100i according to embodiment 10, since the second region AR2 includes a hollow portion 6, it is possible to make the multilayer substrate 100f conform to the main surface shape of the mounting substrate 530. 【0116】(Embodiment 11) The multilayer substrate 100j according to Embodiment 11 will be described with reference to Figure 15. With respect to the multilayer substrate 100j according to Embodiment 11, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0117】 (1) The multilayer substrate 100j according to Embodiment 11 differs from the multilayer substrate 100 according to Embodiment 1 in that, in a plan view from the thickness direction D1 of the laminated substrate 1, it includes an elongated main body portion 84 and one or more elongated branch portions 85 in contact with the main body portion 84. Note that in Figure 15, the boundary line between the first region AR1 and the second region AR2 indicates the boundary of the region and is not a line indicating the structure. 【0118】 In this embodiment, as shown in Figure 15, the main body 84 has an elongated shape in the direction along the Y-axis when viewed from the thickness direction D1 of the laminated substrate 1. In the main body 84, the signal line 2 has an elongated shape in the direction along the Y-axis. The branching section 85a has an elongated shape in the direction along the X-axis when viewed from the thickness direction D1 of the laminated substrate 1. In the branching section 85a, the signal line 2 has an elongated shape in the direction along the X-axis. The branching section 85b has an elongated shape in the direction along the Y-axis when viewed from the thickness direction D1 of the laminated substrate 1. In the branching section 85b, the signal line 2 has an L-shape, similar to the outer shape of the branching section 85b. 【0119】The length of the main body 84 is longer than the length of any of the multiple branch sections 85. Here, the length of the main body 84 is the length along the longitudinal direction of the main body 84, and in this embodiment, it is the length along the Y-axis direction. The length of each of the multiple branch sections 85 is the length along the longitudinal direction of each of the multiple branch sections 85. In this embodiment, the length of branch section 85a is the length along the X-axis direction of branch section 85a. The length of branch section 85b is the length along the Y-axis direction of branch section 85b. In this embodiment, the length of the main body 84 is longer than the length of branch section 85a and the length of branch section 85b. The main body 84 includes at least one second region AR2. The main body 84 includes a third region AR2 which is one of the multiple second regions AR2. In this embodiment, one of the two second regions AR2 included in the main body 84 corresponds to the third region AR2. 【0120】 The branching section 85 includes a fourth region AR2, which is one of a plurality of second regions AR2. The fourth region AR2 is connected to the main body 84. More specifically, the second region AR2 of branching section 85a is connected to the main body 84. Also, the second region AR2 of branching section 85b is connected to the main body 84. In this embodiment, the second region AR2 included in branching sections 85a and 85b each correspond to the fourth region AR2. 【0121】 (2) The multilayer substrate 100j according to the effect embodiment 11 includes, in a plan view from the thickness direction D1 (see Figure 2) of the laminated substrate 1, an elongated main body portion 84 and an elongated branch portion 85 in contact with the main body portion 84. The length of the main body portion 84 is longer than the length of the branch portion 85. The main body portion 84 includes the third region AR2 of a plurality of second regions AR2. The branch portion 85 includes the fourth region AR2 of a plurality of second regions AR2. The fourth region AR2 is connected to the main body portion 84. 【0122】The above configuration makes it possible to improve the mountability of the multilayer substrate 100i onto the mounting substrate 530. More specifically, since the longest main body portion 84 includes the second region AR2, the mountability of the main body portion 84 onto the mounting substrate 530 (see Figure 3) is improved. In addition, since the second region AR2 is located at the connection portion of the branch portion 85 to the main body portion 84, the mountability of the connection portion between the branch portion 85 and the main body portion 84 onto the mounting substrate 530 is improved. 【0123】 (Embodiment 12) The multilayer substrate 100k according to Embodiment 12 will be described with reference to Figures 16 and 17. With respect to the multilayer substrate 100k according to Embodiment 12, components that are the same as those in the multilayer substrate 100 according to Embodiment 1 (see Figures 1 to 3) are denoted by the same reference numerals and their description is omitted. 【0124】 (1) Configuration (1.1) Multilayer substrate The multilayer substrate 100k according to embodiment 12 differs from the multilayer substrate 100 according to embodiment 1 in that it has multiple signal lines 2a and 2b instead of multiple signal lines 2, and further comprises insulating layers 16 and 17 and a third ground electrode 33. 【0125】 As shown in Figure 17, the laminated substrate 1 has a plurality of (four in the illustrated example) insulating layers 11, 12, 16, and 17, and the plurality of insulating layers 11, 12, 16, and 17 are stacked on top of each other. 【0126】 Each of the multiple insulating layers 16, 17 is made of, for example, a thermoplastic resin. The thickness of each of the multiple insulating layers 16, 17 is, for example, 10 μm or more and 120 μm or less. 【0127】 The insulating layer 16 has a main surface 161 and a main surface 162. The main surface 161 of the insulating layer 16 is the main surface in contact with the signal line 2b. The main surface 162 of the insulating layer 16 is the main surface facing the third ground electrode 33 in the thickness direction D1 of the laminated substrate 1. The insulating layer 16 has through holes 163 in each of the plurality of second regions AR2. 【0128】The insulating layer 17 has a main surface 171 and a main surface 172. The main surface 171 of the insulating layer 17 is the main surface that is in contact with the insulating layer 16 in the thickness direction D1 of the laminated substrate 1. The main surface 172 of the insulating layer 17 is the main surface that is in contact with the second ground electrode 32 in the thickness direction D1 of the laminated substrate 1. The insulating layer 17 has through holes 173 in each of the plurality of second regions AR2. 【0129】 The laminated substrate 1 is provided with multiple (two in Figures 16 and 17) hollow portions 6d and multiple (two in Figures 16 and 17) hollow portions 6e. Each of the multiple hollow portions 6d and the multiple hollow portions 6e is provided in each of the multiple regions AR2 of the multilayer substrate 100. 【0130】 In this embodiment, each of the multiple hollow portions 6d includes a through hole 113 provided in the insulating layer 11 and a through hole 123 provided in the insulating layer 12. Also in this embodiment, each of the multiple hollow portions 6e includes a through hole 163 provided in the insulating layer 16 and a through hole 173 provided in the insulating layer 17. 【0131】 (1.2) As shown in the signal line diagrams 16 and 17, the signal line 2a and signal line 2b are arranged within the laminated substrate 1. More specifically, as shown in Figure 17, the signal line 2a is formed on the main surface 111 of the insulating layer 11. As shown in Figure 17, the signal line 2b is formed on the main surface 161 of the insulating layer 16. 【0132】 The third ground electrode 33 is positioned between the insulating layer 12 and the insulating layer 16. In the thickness direction D1 of the laminated substrate 1, the third ground electrode 33 faces the signal line 2a and the first ground electrode 31. The third ground electrode 33 also faces the signal line 2b and the second ground electrode 32 in the thickness direction D1 of the laminated substrate 1. 【0133】 (2) The multilayer substrate 100k according to Embodiment 12 also provides the same effects as the multilayer substrate 100 according to Embodiment 1. 【0134】(Modifications) Embodiments 1 to 12 described above are merely one of many embodiments of the present invention. Embodiments 1 to 12 described above can be modified in various ways depending on the design, etc., as long as the objective of the present invention is achieved, and may be combined as appropriate. 【0135】 For example, multilayer substrates 100, 100a to 100k may be provided with only one of the first ground electrode 31 or the second ground electrode 32. Also, multilayer substrates 100, 100a to 100e may not be provided with either the first ground electrode 31 or the second ground electrode 32. 【0136】 Furthermore, multilayer substrates 100a and 100c to 100k may also be provided with an insulating layer 18 in contact with the first ground electrode 31, similar to multilayer substrate 100b. Additionally, multilayer substrates 100a and 100c to 100k may also be provided with an insulating layer 19 in contact with the second ground electrode 32 and the signal electrode 20, similar to multilayer substrate 100b. 【0137】 Furthermore, the electronic device 500 may include any of the multilayer substrates 100a to 100k instead of the multilayer substrate 100. 【0138】100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k Multilayer substrate 1 Laminated substrate 11 Insulating layer 14 First main surface 15 Second main surface 111 Main surface 112 Main surface 113 Through hole 114 Hole 12 Insulating layer 121 Main surface 122 Main surface 123 Through hole 124 Hole 13 Side surface 131 Recess 18 Insulating layer 181, 182 Main surface 19 Insulating layer 191, 192 Main surface 16 Insulating layer 161 Main surface 162 Main surface 163 Through hole 17 Insulating layer 171 Main surface 172 Main surface 173 Through holes 2, 2a, 2b Signal lines 21 Second part 22 First part 23 Third part 24, 25 Main surface 31 First ground electrode (ground electrode) 311 Slit 32 Second ground electrode (ground electrode) 33 Third ground electrode 20 Signal electrode 4 External connection electrode 4a First connection electrode 4b Second connection electrode 51 First resist layer 52 Second resist layer 520 Openings 6, 6a, 6c Hollow part 7 Second connecting conductor (connecting conductor) 71 First connecting conductor 84 Main body part 85, 85a, 85b Branch part 500 Electronic equipment 530 Mounting substrate 531 Main surface 532 Electrode 533 Solder AR1 First region AR2 Second region d1 Line width d2 Line width D1 Thickness direction
Claims
1. A multilayer substrate comprising: a laminated substrate having a first main surface and a second main surface; a signal line disposed within the laminated substrate; and a plurality of external connection electrodes disposed on the first main surface of the laminated substrate, wherein the laminated substrate is elongated along a first direction perpendicular to the thickness direction of the laminated substrate; the plurality of external connection electrodes are provided in each of a plurality of first regions spaced apart from each other; the laminated substrate has hollow portions in each of a plurality of second regions spaced apart from each other; and the plurality of first regions and the plurality of second regions are arranged alternately in the first direction.
2. In a plan view from the thickness direction of the laminated substrate, the hollow portion overlaps with a part of the signal line, as described in claim 1.
3. The multilayer substrate according to claim 2, wherein a portion of the signal line is exposed in the hollow portion.
4. The multilayer substrate according to claim 1 or 2, wherein the hollow portion penetrates the laminated substrate in a direction intersecting the first direction.
5. The multilayer substrate according to any one of claims 1 to 4, wherein the plurality of external connection electrodes are not provided in any of the plurality of second regions.
6. The multilayer substrate according to any one of claims 1 to 5, wherein the line width of the first portion of the signal line that overlaps with the hollow portion in a plan view from the thickness direction of the laminated substrate is wider than the line width of the second portion that does not overlap with the hollow portion in a plan view from the thickness direction of the laminated substrate.
7. A multilayer substrate according to any one of claims 1 to 6, further comprising a ground electrode formed on at least one of the first main surface and the second main surface, wherein, in a plan view from the thickness direction of the laminated substrate, the proportion of the area occupied by the ground electrode in the second region is smaller than the proportion of the area occupied by the ground electrode in the first region.
8. The multilayer substrate according to claim 7, further comprising a connecting conductor connected to the ground electrode, wherein the connecting conductor is not disposed in each of the plurality of second regions.
9. The multilayer substrate according to any one of claims 1 to 8, wherein the second region includes a portion in which the width in the second direction perpendicular to the first direction is shorter than the width of the first region in the second direction.
10. The multilayer substrate according to any one of claims 1 to 9, wherein the hollow portion is formed on the side surface of the laminated substrate in the plurality of second regions.
11. A multilayer substrate according to any one of claims 1 to 10, wherein, in a plan view from the thickness direction of the laminated substrate, it includes an elongated main body portion and an elongated branch portion in contact with the main body portion, the length of the main body portion is longer than the length of the branch portion, the main body portion includes a third region which is one of the plurality of second regions, and the branch portion includes a fourth region which is one of the plurality of second regions connected to the main body portion.
12. The multilayer substrate according to any one of claims 1 to 11, wherein the material of the insulating layer included in the laminated substrate includes a thermoplastic liquid crystal polymer.
13. Electronic device comprising: a mounting substrate; and a multilayer substrate disposed on the main surface of the mounting substrate, wherein the multilayer substrate includes: a laminated substrate having a first main surface; a signal line disposed within the laminated substrate; and a plurality of external connection electrodes disposed on the first main surface of the laminated substrate, wherein the laminated substrate is elongated along a first direction perpendicular to the thickness direction of the laminated substrate; the plurality of external connection electrodes are provided in each of a plurality of first regions of the multilayer substrate that are spaced apart from each other; the plurality of external connection electrodes are connected to the mounting substrate by solder; the laminated substrate has hollow portions in one or more second regions of the multilayer substrate that are spaced apart from each other; and the plurality of first regions and the one or more second regions are arranged alternately in the first direction.