Shielded flat cable

Abstract

A shielded flat cable has: a plurality of ground wires disposed on a first side; a pair of signal wires disposed between the plurality of ground wires and disposed on the first side; an insulating layer covering the plurality of ground wires and the pair of signal wires; and a shielding layer covering the insulating layer. In a cross-section of the shielded flat cable perpendicular to its longitudinal direction, the plurality of ground wires includes a ground wire adjacent to one of the signal wires in the pair of signal wires, and the shortest distance between the pair of signal wires is smaller than the shortest distance between the adjacent ground wire and the signal wire.

Description

Technical Field

[0001] This disclosure relates to a shielded flat cable.

[0002] This application claims priority based on Japanese Application No. 2020-114586, filed on July 2, 2020, and incorporates all the contents of that Japanese application. Background Technology

[0003] Shielded flat cables are known as cables for high-speed transmission of differential signals. In shielded flat cables, for example, two signal lines for transmitting differential signals are sometimes arranged between two ground wires (e.g., Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-207835 Summary of the Invention

[0007] The shielded flat cable disclosed herein comprises: a plurality of ground wires disposed on a first surface; a pair of signal wires disposed between the plurality of ground wires and disposed on the first surface; an insulating layer covering the plurality of ground wires and the pair of signal wires; and a shielding layer covering the insulating layer. In a cross-section of the shielded flat cable perpendicular to its longitudinal direction, the plurality of ground wires includes a ground wire adjacent to one of the signal wires in the pair of signal wires, and the shortest distance between the pair of signal wires is smaller than the shortest distance between the adjacent ground wire and the signal wire. Attached Figure Description

[0008] Figure 1 This is a top view showing the shielded flat cable of the first embodiment.

[0009] Figure 2 This is a cross-sectional view showing the shielded flat cable of the first embodiment.

[0010] Figure 3 This is a cross-sectional view showing the shielded flat cable of the second embodiment.

[0011] Figure 4 This is a cross-sectional view showing the shielded flat cable of the third embodiment.

[0012] Figure 5 This is a cross-sectional view showing the shielded flat cable of the fourth embodiment. Detailed Implementation

[0013] [The problem this disclosure aims to solve]

[0014] The shielded flat cable described in Patent Document 1 can achieve the desired purpose, but as the signal becomes more frequent, crosstalk may occur.

[0015] The purpose of this disclosure is to provide a shielded flat cable that can further reduce crosstalk.

[0016] [The Effects of This Disclosure]

[0017] According to this disclosure, crosstalk can be further reduced.

[0018] The following describes the implementation method.

[0019] [Description of embodiments of this disclosure]

[0020] First, the implementation plan disclosed herein will be listed for illustration.

[0021] [1] A shielded flat cable of one embodiment of the present disclosure has: a plurality of ground wires disposed on a first surface; a pair of signal wires disposed between the plurality of ground wires and disposed on the first surface; an insulating layer covering the plurality of ground wires and the pair of signal wires; and a shielding layer covering the insulating layer, wherein in a cross section of the shielded flat cable perpendicular to the longitudinal direction, the plurality of ground wires includes a ground wire adjacent to one of the signal wires in the pair of signal wires, and the shortest distance between the pair of signal wires is smaller than the shortest distance between the adjacent ground wire and the signal wire.

[0022] In a cross-section perpendicular to the longitudinal direction of a shielded flat cable, the shortest distance between a pair of signal lines is smaller than the shortest distance between the ground wire adjacent to one of the signal lines in the pair and that signal line. Therefore, the capacitance between the adjacent ground wire and that signal line can be reduced, thereby reducing crosstalk caused by capacitive noise.

[0023] [2] In [1], it is also possible that, in the cross-section, the maximum dimension of the adjacent ground wire in the direction parallel to the first surface is smaller than the maximum dimension of the signal wire in the direction parallel to the first surface. In this case, it is easier to further reduce crosstalk.

[0024] [3] In [1] or [2], it is also possible that, in the cross-section, the center-to-center distance between the pair of signal lines is smaller than the center-to-center distance between the adjacent ground line and the center of one signal line. In this case, it is easier to further reduce crosstalk.

[0025] [4] In [1] to [3], it is also possible that, in the cross-section, the cross-sectional area of ​​the adjacent ground wire is smaller than the cross-sectional area of ​​the signal wire. In this case, it is easier to further reduce crosstalk.

[0026] [5] Another aspect of the shielded flat cable disclosed herein comprises: a first ground wire, a second ground wire, and a third ground wire, disposed on a first surface; a pair of first signal lines and a second signal line, disposed between the first ground wire and the second ground wire, and disposed on the first surface; a pair of third signal lines and a fourth signal line, disposed between the second ground wire and the third ground wire, and disposed on the first surface; an insulating layer covering the first ground wire, the second ground wire, the third ground wire, the first signal line, the second signal line, the third signal line, and the fourth signal line; and a shielding layer covering the insulating layer, wherein the second signal line is configured to be closer to the second ground wire than the first signal line, and the fourth signal line is configured to be closer to the third ground wire than the third signal line, wherein in a cross-section perpendicular to the longitudinal direction of the shielded flat cable, the shortest distance between the first signal line and the second signal line is greater than the distance between the first ground wire and the first signal line. The shortest distance between the first ground line and the second signal line is smaller than the shortest distance between the second ground line and the second signal line. The shortest distance between the third signal line and the fourth signal line is smaller than the shortest distance between the second ground line and the third signal line and the shortest distance between the third ground line and the fourth signal line. The maximum dimension of each of the first ground line, the second ground line, and the third ground line in the direction parallel to the first surface is smaller than the maximum dimension of each of the first signal line, the second signal line, the third signal line, and the fourth signal line in the direction parallel to the first surface. The center-to-center distance between the first signal line and the second signal line is smaller than the center-to-center distance between the first ground line and the first signal line and the center-to-center distance between the second ground line and the second signal line. The center-to-center distance between the third signal line and the fourth signal line is smaller than the center-to-center distance between the second ground line and the third signal line and the center-to-center distance between the third ground line and the fourth signal line.

[0027] It can reduce the capacitance between the first ground line and the first signal line, the capacitance between the second ground line and the second signal line, the capacitance between the second ground line and the third signal line, and the capacitance between the third ground line and the fourth signal line, thereby reducing crosstalk caused by capacitive noise.

[0028] [Details of the embodiments of this disclosure]

[0029] The embodiments of this disclosure will now be described in detail, but these embodiments are not limited thereto. It should be noted that in this specification and accompanying drawings, sometimes repeated descriptions are omitted by labeling constituent elements having substantially the same functional configuration with the same reference numerals. In each figure, an XYZ orthogonal coordinate system is provided for ease of explanation.

[0030] (First Implementation)

[0031] The first embodiment will be described. Figure 1 This is a top view showing the shielded flat cable of the first embodiment. Figure 2 This is a cross-sectional view showing the shielded flat cable of the first embodiment. Figure 2 It is along Figure 1 A sectional view along line II-II.

[0032] like Figure 1 and Figure 2 As shown, the shielded flat cable 100 of the first embodiment has a plurality of ground wires 110 arranged along a first surface 101 parallel to the XY plane. The shielded flat cable 100 also has a plurality of signal lines 120 arranged along the ground wires 110 in the first surface 101 between the ground wires 110. The ground wires 110 and signal lines 120 extend, for example, in the X-axis direction. The shielded flat cable 100 includes, for example, three ground wires 110 and four signal lines 120. The ground wires 110 and signal lines 120 are formed, for example, of a metal such as copper foil or tin-plated soft copper foil.

[0033] The three ground wires 110 include a first ground wire 111, a second ground wire 112, and a third ground wire 113. The second ground wire 112 is disposed on the +Y side of the first ground wire 111, and the third ground wire 113 is disposed on the +Y side of the second ground wire 112. That is, in the Y-axis direction, the second ground wire 112 is disposed between the first ground wire 111 and the third ground wire 113.

[0034] The four signal lines 120 include a first signal line 121, a second signal line 122, a third signal line 123, and a fourth signal line 124. In the Y-axis direction, the first signal line 121 and the second signal line 122 are disposed between the first ground line 111 and the second ground line 112. The second signal line 122 is disposed on the +Y side of the first signal line 121. Therefore, the first signal line 121 is adjacent to the first ground line 111, and the second signal line 122 is adjacent to the second ground line 112. In the Y-axis direction, the third signal line 123 and the fourth signal line 124 are disposed between the second ground line 112 and the third ground line 113. The fourth signal line 124 is disposed on the +Y side of the third signal line 123. Therefore, the third signal line 123 is adjacent to the second ground line 112, and the fourth signal line 124 is adjacent to the third ground line 113. The first signal line pair 126, consisting of the first signal line 121 and the second signal line 122, is used for the transmission of the first differential signal, and the second signal line pair 127, consisting of the third signal line 123 and the fourth signal line 124, is used for the transmission of the second differential signal.

[0035] The shielded flat cable 100 has an insulating layer 130 sandwiching a first surface 101 covering a ground wire 110 and a signal wire 120. For example, the insulating layer 130 has a first insulating layer 131 on the -Z side of the first surface 101 and a second insulating layer 132 on the +Z side of the first surface 101. The first insulating layer 131 has a second surface 131A on the side opposite to the first surface 101. The second insulating layer 132 has a second surface 132A on the side opposite to the first surface 101. The second surfaces 131A and 132A are an example of an outer surface.

[0036] The shielded flat cable 100 has a shielding layer 140 covering the insulation layer 130. The shielding layer 140 has: a first shielding layer 141, covering a second surface 131A of the first insulation layer 131; and a second shielding layer 142, covering a second surface 132A of the second insulation layer 132. Only one of the first shielding layer 141 or the second shielding layer 142 is required; the other may be omitted to improve the flexibility of the shielded flat cable 100. The first shielding layer 141 and the second shielding layer 142 may also cover the side of the insulation layer 130 parallel to the ZX plane.

[0037] For example, ground wire 110 and signal wire 120 are flat conductors, and the shielded flat cable 100 has a cross-section perpendicular to its long dimension ( Figure 2 The ground wire 110 and signal wire 120 in the cross-section shown are rectangular in shape. Figure 2 In the cross-section shown, for example, the thickness (dimension in the Z-axis direction) of the ground wire 110 and the signal wire 120 is more than 0.01 mm and less than 0.10 mm.

[0038] The first ground wire 111 has a side 111A on the -Y side and a side 111B on the +Y side. The second ground wire 112 has a side 112A on the -Y side and a side 112B on the +Y side. The third ground wire 113 has a side 113A on the -Y side and a side 113B on the +Y side. The first signal wire 121 has a side 121A on the -Y side and a side 121B on the +Y side. The second signal wire 122 has a side 122A on the -Y side and a side 122B on the +Y side. The third signal wire 123 has a side 123A on the -Y side and a side 123B on the +Y side. The fourth signal wire 124 has a side 124A on the -Y side and a side 124B on the +Y side.

[0039] exist Figure 2 In the cross-section shown, the widths of the first ground wire 111, the second ground wire 112, and the third ground wire 113 are all equal, each being a width Wg. The width of the first ground wire 111 is the distance between side surface 111A and side surface 111B, the width of the second ground wire 112 is the distance between side surface 112A and side surface 112B, and the width of the third ground wire 113 is the distance between side surface 113A and side surface 113B. Figure 2 In the cross-section shown, the widths of the first signal line 121, the second signal line 122, the third signal line 123, and the fourth signal line 124 are all equal, each being a width Ws. The width of the first signal line 121 is the distance between side 121A and side 121B; the width of the second signal line 122 is the distance between side 122A and side 122B; the width of the third signal line 123 is the distance between side 123A and side 123B; and the width of the fourth signal line 124 is the distance between side 124A and side 124B. For example, the width Wg of the ground line 110 is 0.10mm or more and 0.20mm or less, and the width Ws of the signal line 120 is 0.20mm or more and 0.30mm or less. The width Wg is smaller than the width Ws. That is to say, in Figure 2 In the cross-section shown, the maximum dimension of the ground wire 110 along the direction of the first surface 101 (Y-axis direction) is smaller than the maximum dimension of the signal wire 120 along the direction of the first surface 101 (Y-axis direction). Furthermore, in Figure 2 In the cross-section shown, the cross-sectional area of ​​ground wire 110 is smaller than that of signal wire 120.

[0040] exist Figure 2 In the cross-section shown, the distance between the side surface 121B of the first signal line 121 and the side surface 122A of the second signal line 122, and the distance between the side surface 123B of the third signal line 123 and the side surface 124A of the fourth signal line 124, are equal to each other, both being distance L1ss. Figure 2 In the cross-section shown, the distances between the side 111B of the first ground wire 111 and the side 121A of the first signal wire 121, the distances between the side 112A of the second ground wire 112 and the side 122B of the second signal wire 122, the distances between the side 112B of the second ground wire 112 and the side 123A of the third signal wire 123, and the distances between the side 113A of the third ground wire 113 and the side 124B of the fourth signal wire 124 are all equal, and are all distances L1sg. For example, distance L1ss is 0.25mm or more and 0.45mm or less, distance L1sg is 0.35mm or more and 0.55mm or less, and distance L1ss is smaller than distance L1sg. That is to say, in Figure 2 In the cross-section shown, the shortest distance (distance in the Y-axis direction) between two adjacent signal lines 120 is smaller than the shortest distance (distance in the Y-axis direction) between the adjacent ground line 110 and the signal line 120.

[0041] exist Figure 2 In the cross-section shown, the distance between the center of the first signal line 121 and the center of the second signal line 122, and the distance between the center of the third signal line 123 and the center of the fourth signal line 124, are equal to each other, both being a distance L2ss. Figure 2 In the cross-section shown, the distances between the center of the first ground line 111 and the center of the first signal line 121, the distances between the center of the second ground line 112 and the center of the second signal line 122, the distances between the center of the second ground line 112 and the center of the third signal line 123, and the distances between the center of the third ground line 113 and the center of the fourth signal line 124 are all equal, and are all distances L2sg. For example, distance L2ss is 0.55mm or more and 0.65mm or less, distance L2sg is 0.60mm or more and 0.70mm or less, and distance L2ss is smaller than distance L2sg. That is to say, in Figure 2 In the cross-section shown, the center-to-center distance (distance in the Y-axis direction) between two adjacent signal lines 120 is smaller than the center-to-center distance (distance in the Y-axis direction) between the adjacent ground line 110 and the signal line 120.

[0042] The ground wire 110 and the signal wire 120 are covered by the insulating layer 130, so the above-described arrangement of the ground wire 110 and the signal wire 120 is maintained.

[0043] Materials used for the insulating layer 130 include, for example, polyester resin, polyphenylene sulfide resin, and polyimide resin. Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, and polybutylene naphthalate resin. It should be noted that, among these resins, polyethylene terephthalate resin is preferred from the viewpoints of electrical properties, mechanical properties, and cost. The thicknesses of the first insulating layer 131 and the second insulating layer 132 are, for example, 9 μm or more and 100 μm or less.

[0044] The first shielding layer 141 and the second shielding layer 142 each include an adhesive layer, a resin layer, and a metal layer arranged sequentially from the insulating layer 130 side. For example, aluminum foil is used as the metal layer. Examples of materials for the resin layer include polyethylene terephthalate and low-dielectric-constant polyethylene. If the resin layer is adhesive, the adhesive layer may not be included. The thickness of the first shielding layer 141 and the second shielding layer 142 is, for example, 30 μm or more and 90 μm or less.

[0045] In the shielded flat cable 100 of the first embodiment, the distance L1ss is smaller than the distance L1sg. Therefore, the capacitance between adjacent ground wires 110 and signal lines 120 can be reduced, thereby reducing crosstalk caused by capacitive noise. For example, crosstalk between the first differential signal transmitted using the first signal pair 126 and the second differential signal transmitted using the second signal pair 127 can be reduced.

[0046] (Second Implementation)

[0047] The second embodiment will be described. Figure 3This is a cross-sectional view showing the shielded flat cable according to the second embodiment. The second embodiment differs from the first embodiment mainly in the arrangement of the signal line 120.

[0048] like Figure 3 As shown, in the shielded flat cable 200 of the second embodiment, the distance L2ss and the distance L2sg are equal. On the other hand, similar to the first embodiment, the distance L1ss is smaller than the distance L1sg, the width Wg is smaller than the width Ws, and the cross-sectional area of ​​the ground wire 110 is smaller than the cross-sectional area of ​​the signal wire 120. For example, the width Wg of the ground wire 110 is 0.10 mm or more and 0.20 mm or less, and the width Ws of the signal wire 120 is 0.20 mm or more and 0.30 mm or less. For example, the distance L1ss is 0.25 mm or more and 0.50 mm or less, and the distance L1sg is 0.30 mm or more and 0.55 mm or less. For example, the distances L2ss and L2sg are 0.55 mm or more and 0.70 mm or less.

[0049] The other components are the same as in the first embodiment.

[0050] In the shielded flat cable 200 of the second embodiment, the distance L1ss is also smaller than the distance L1sg. Therefore, the capacitance between adjacent ground wires 110 and signal lines 120 can be reduced, thereby reducing crosstalk caused by capacitive noise. For example, crosstalk between the first differential signal transmitted using the first signal pair 126 and the second differential signal transmitted using the second signal pair 127 can be reduced.

[0051] (Third Implementation)

[0052] The third embodiment will be described. Figure 4 This is a cross-sectional view showing the shielded flat cable of the third embodiment. The third embodiment differs from the first embodiment mainly in the cross-sectional shapes of the ground wire and signal wire.

[0053] like Figure 4 As shown, the shielded flat cable 300 of the third embodiment has three ground wires 310 and four signal wires 320 instead of three ground wires 110 and four signal wires 120.

[0054] The three ground wires 310 include a first ground wire 311, a second ground wire 312, and a third ground wire 313. The second ground wire 312 is disposed on the +Y side of the first ground wire 311, and the third ground wire 313 is disposed on the +Y side of the second ground wire 312. That is, in the Y-axis direction, the second ground wire 312 is disposed between the first ground wire 311 and the third ground wire 313.

[0055] The four signal lines 320 include a first signal line 321, a second signal line 322, a third signal line 323, and a fourth signal line 324. In the Y-axis direction, the first signal line 321 and the second signal line 322 are disposed between the first ground line 311 and the second ground line 312. The second signal line 322 is disposed on the +Y side of the first signal line 321. Therefore, the first signal line 321 is adjacent to the first ground line 311, and the second signal line 322 is adjacent to the second ground line 312. In the Y-axis direction, the third signal line 323 and the fourth signal line 324 are disposed between the second ground line 312 and the third ground line 313. The fourth signal line 324 is disposed on the +Y side of the third signal line 323. Therefore, the third signal line 323 is adjacent to the second ground line 312, and the fourth signal line 324 is adjacent to the third ground line 313. The first signal line pair 326, consisting of the first signal line 321 and the second signal line 322, is used for the transmission of the first differential signal, and the second signal line pair 327, consisting of the third signal line 323 and the fourth signal line 324, is used for the transmission of the second differential signal.

[0056] For example, ground wire 310 and signal wire 320 are circular conductors, and the shielded flat cable 300 has a cross-section perpendicular to its long dimension. Figure 4 The ground wire 310 and signal wire 320 in the cross-section shown are circular in shape. Figure 4 In the cross-sections shown, for example, the diameter Dg of the ground wire 310 is 0.10 mm or more and 0.20 mm or less, and the diameter Ds of the signal wire 320 is 0.20 mm or more and 0.30 mm or less. That is to say, in Figure 4 In the cross-section shown, the maximum dimension of the ground wire 310 along the direction of the first surface 101 (Y-axis direction) is smaller than the maximum dimension of the signal wire 320 along the direction of the first surface 101 (Y-axis direction). Furthermore, in Figure 4 In the cross-section shown, the cross-sectional area of ​​ground wire 310 is smaller than that of signal wire 320.

[0057] exist Figure 4 In the cross-section shown, the shortest distance between the first signal line 321 and the second signal line 322, and the shortest distance between the third signal line 323 and the fourth signal line 324, are equal, both being distance L1ss. Figure 4 In the cross-section shown, the shortest distances between the first ground wire 311 and the first signal wire 321, the second ground wire 312 and the second signal wire 322, the second ground wire 312 and the third signal wire 323, and the third ground wire 313 and the fourth signal wire 324 are all equal, both being distance L1sg. For example, distance L1ss is 0.25mm or more and 0.45mm or less, distance L1sg is 0.35mm or more and 0.55mm or less, and distance L1ss is smaller than distance L1sg. That is to say, in Figure 4In the cross-section shown, the shortest distance (distance in the Y-axis direction) between two adjacent signal lines 320 is smaller than the shortest distance (distance in the Y-axis direction) between the adjacent ground line 310 and the signal line 320.

[0058] exist Figure 4 In the cross-section shown, the distance between the center of the first signal line 321 and the center of the second signal line 322, and the distance between the center of the third signal line 323 and the center of the fourth signal line 324, are equal, both being a distance L2ss. Figure 4 In the cross-section shown, the distances between the center of the first ground wire 311 and the center of the first signal line 321, the distances between the center of the second ground wire 312 and the center of the second signal line 322, the distances between the center of the second ground wire 312 and the center of the third signal line 323, and the distances between the center of the third ground wire 313 and the center of the fourth signal line 324 are all equal, and are all distances L2sg. For example, distance L2ss is 0.55mm or more and 0.65mm or less, distance L2sg is 0.60mm or more and 0.70mm or less, and distance L2ss is smaller than distance L2sg. That is to say, in Figure 4 In the cross-section shown, the center-to-center distance (distance in the Y-axis direction) between two adjacent signal lines 320 is smaller than the center-to-center distance (distance in the Y-axis direction) between the adjacent ground line 310 and the signal line 320.

[0059] The other components are the same as in the first embodiment.

[0060] In the shielded flat cable 300 of the third embodiment, the distance L1ss is also smaller than the distance L1sg. Therefore, the capacitance between adjacent ground wires 310 and signal lines 320 can be reduced, thereby reducing crosstalk caused by capacitive noise. For example, crosstalk between the first differential signal transmitted using the first signal pair 326 and the second differential signal transmitted using the second signal pair 327 can be reduced.

[0061] (Fourth Implementation)

[0062] The fourth embodiment will be described. Figure 5 This is a cross-sectional view showing the shielded flat cable according to the fourth embodiment. The fourth embodiment differs from the first embodiment mainly in the cross-sectional shape of the signal line.

[0063] like Figure 5As shown, the shielded flat cable 400 of the fourth embodiment has four signal lines 320 instead of four signal lines 120, the same as the shielded flat cable 300 of the third embodiment. The four signal lines 320 include a first signal line 321, a second signal line 322, a third signal line 323, and a fourth signal line 324. The arrangement of the first signal line 321, the second signal line 322, the third signal line 323, and the fourth signal line 324 is the same as in the third embodiment.

[0064] The other components are the same as in the first embodiment.

[0065] In the shielded flat cable 400 of the fourth embodiment, the same effect as in the first and third embodiments can also be obtained.

[0066] exist Figures 2-5 In the cross-section shown, when the maximum dimensions (width Wg, diameter Dg) of ground lines 110 and 310 along the direction of the first surface 101 are smaller than the maximum dimensions (width Ws, diameter Ds) of signal lines 120 and 320 along the direction of the first surface 101, it is easy to make the distance L1ss smaller than the distance L1sg. Therefore, it is easier to further reduce crosstalk.

[0067] exist Figures 2-5 In the cross-section shown, when the center-to-center distance L2ss between two adjacent signal lines 120 and 320 is smaller than the center-to-center distance L2sg between adjacent ground lines 110 and 310 and signal lines 120 and 320, it is easier to make the distance L1ss smaller than the distance L1sg. Therefore, it is easier to further reduce crosstalk.

[0068] exist Figures 2-5 In the cross-sections shown, when the cross-sectional areas of ground lines 110 and 310 are smaller than those of signal lines 120 and 320, it is easier to make the distance L1ss smaller than the distance L1sg. Therefore, it is easier to further reduce crosstalk.

[0069] In this disclosure, the ground wire and signal wire are not limited to flat or round conductors. For example, the shape of the cross-section of the ground wire and signal wire perpendicular to the longitudinal direction can be elliptical or other polygonal shapes. It should be noted that the center of the ground wire and signal wire is in the direction of the intersection of the cross-section perpendicular to the longitudinal direction of the shielded flat cable and the first surface (in...). Figures 2-5 The center is the point between the two furthest points on the ground line and signal line (in the Y-axis direction).

[0070] In the third and fourth embodiments, the distances L2ss and L2sg can be equal, as in the second embodiment.

[0071] The number of ground and signal wires included in a shielded flat cable is not limited. For example, two ground wires can be configured between two signal wire pairs.

[0072] The embodiments have been described in detail above, but are not limited to specific embodiments. Various modifications and alterations can be made within the scope of the claims.

[0073] Explanation of reference numerals in the attached figures

[0074] 100: Shielded flat cable

[0075] 101: First Page

[0076] 110: Ground wire

[0077] 111: First ground wire

[0078] 111A, 111B: Side view

[0079] 112: Second ground wire

[0080] 112A, 112B: Side view

[0081] 113: Third ground wire

[0082] 113A, 113B: Side view

[0083] 120: Signal line

[0084] 121: First signal line

[0085] 121A, 121B: Side view

[0086] 122: Second signal line

[0087] 122A, 122B: Side view

[0088] 123: Third signal line

[0089] 123A, 123B: Side view

[0090] 124: Fourth signal line

[0091] 124A, 124B: Side view

[0092] 126: First signal line pair

[0093] 127: Second signal line pair

[0094] 130: Insulation layer

[0095] 131: First insulating layer

[0096] 131A: Second page

[0097] 132: Second insulating layer

[0098] 132A: Second side

[0099] 140: Shielding layer

[0100] 141: First shielding layer

[0101] 142: Second shielding layer

[0102] 200: Shielded flat cable

[0103] 300: Shielded flat cable

[0104] 310: Ground wire

[0105] 311: First Ground Line

[0106] 312: Second ground wire

[0107] 313: Third Ground Line

[0108] 320: Signal line

[0109] 321: First signal line

[0110] 322: Second signal line

[0111] 323: Third signal line

[0112] 324: Fourth signal line

[0113] 326: First signal line pair

[0114] 327: Second signal line pair

[0115] 400: Shielded flat cable

[0116] Dg, Ds: Diameter

[0117] L1sg, L1ss, L2sg, L2ss: Distance

[0118] Wg, Ws: Width.

Claims

1. A shielded flat cable, comprising: Multiple ground wires are configured on the first surface; A first signal line pair and a second signal line pair are disposed between the plurality of ground lines and are arranged on the first surface; An insulating layer covers the plurality of ground wires, the first signal pair, and the second signal pair; as well as A shielding layer that covers the insulating layer. In the cross-section of the shielded flat cable perpendicular to its longitudinal direction, The first signal line pair includes: First signal line; and The second signal line is adjacent to the first signal line. The second signal line pair includes: The third signal line; and The fourth signal line is adjacent to the third signal line. The plurality of ground lines includes a first ground line adjacent to the first signal line, a second ground line sandwiched between the second signal line and the third signal line, and a third ground line adjacent to the fourth signal line. The shortest distance between the first signal line and the second signal line is smaller than the shortest distance between the first signal line and the first ground line. The shortest distance between the first signal line and the second signal line is smaller than the shortest distance between the second signal line and the second ground line. The shortest distance between the third signal line and the fourth signal line is smaller than the shortest distance between the third signal line and the second ground line. The shortest distance between the third signal line and the fourth signal line is smaller than the shortest distance between the fourth signal line and the third ground line.

2. The shielded flat cable according to claim 1, wherein, In the cross section, The center-to-center distance between the first signal line and the second signal line is smaller than the center-to-center distance between the second signal line and the second ground line. The center-to-center distance between the third signal line and the fourth signal line is smaller than the center-to-center distance between the third signal line and the second ground line. The center-to-center distance between the first signal line and the second signal line is smaller than the center-to-center distance between the first ground line and the first signal line. The center-to-center distance between the third signal line and the fourth signal line is smaller than the center-to-center distance between the third ground line and the fourth signal line.

3. The shielded flat cable according to claim 1, wherein, In the cross section, The center-to-center distances between the first ground line and the first signal line, the first signal line and the second signal line, the second signal line and the second ground line, the second ground line and the third signal line, the third signal line and the fourth signal line, and the fourth signal line and the third ground line are all equal.

4. The shielded flat cable according to any one of claims 1 to 3, wherein, The insulating layer is configured to be in contact with all surfaces of the first signal line, the second signal line, the third signal line, the fourth signal line, and the second ground line on its inner surface.

5. The shielded flat cable according to any one of claims 1 to 3, wherein, The first signal line, the second signal line, the third signal line, and the fourth signal line are circular conductors. The multiple ground wires are flat conductors.

6. The shielded flat cable according to any one of claims 1 to 3, wherein, In the cross section, The maximum dimensions of the first ground wire, the second ground wire, and the third ground wire along the direction of the first surface are all smaller than the maximum dimensions of the first signal line, the second signal line, the third signal line, and the fourth signal line along the direction of the first surface.

7. The shielded flat cable according to any one of claims 1 to 3, wherein, In the cross section, The cross-sectional area of ​​each of the first ground wire, the second ground wire, and the third ground wire is smaller than the cross-sectional area of ​​the first signal line, the second signal line, the third signal line, and the fourth signal line.

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