Wiring board, electronic unit, electronic device, and imaging apparatus

Abstract

To provide a wiring board which has small radiation noise and excellent signal transmission characteristics even when a high-speed data signal is transmitted.SOLUTION: The wiring layer includes a wiring layer having a differential signal line including a pair of signal lines and an adjacent wiring to the differential signal line, outlines of a plurality of openings provided in the conductive layer overlap an intermediate region between the differential signal line and the adjacent wiring on both sides of the differential signal line, and a conductor portion extending from the outline of the opening in the conductive layer overlaps at least one of the adjacent wirings on both sides of the differential signal line.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a wiring board used in an electronic device, and more particularly to a technique for reducing noise generated from the wiring board. [Background technology]

[0002] Between two semiconductor devices mounted on electronic devices, data communication is performed using digital signals via a wiring board such as a flexible printed wiring board. As electronic devices become more powerful and functional, the amount of data handled by these devices is also increasing dramatically. To transmit the increasing amount of data at high speed, a differential transmission method is commonly used, in which one signal is converted into two signals, one in phase and one out of phase, and each signal is transmitted using two parallel signal wirings. However, as transmission speeds increase, unwanted electromagnetic noise generated from the signal wiring is also increasing.

[0003] In response to this, Patent Document 1 discloses a wiring board having a ground layer, ground wiring, and a conductive layer with shielding properties as a countermeasure against electromagnetic noise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-212439 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the wiring board disclosed in Patent Document 1 cannot meet the increasing speeds required for electronic devices in recent years due to the ever-increasing data communication speeds, and cannot adequately suppress the generated noise.

[0006] Therefore, the present invention provides a wiring board that allows high-speed transmission and suppresses noise. [Means for solving the problem]

[0007] The means for solving the above problem is a wiring board comprising: a substrate; a wiring layer supported by the substrate and including a plurality of wirings; and a conductive layer supported by the substrate and provided with an opening made up of a plurality of openings, wherein the wiring layer includes a first differential signal line configured with a pair of signal wirings consisting of a first signal wiring and a second signal wiring; a second differential signal line configured with a pair of signal wirings consisting of a third signal wiring and a fourth signal wiring; a first adjacent wiring adjacent to the first signal wiring; a second adjacent wiring adjacent to the second signal wiring and the third signal wiring; and a third adjacent wiring adjacent to the fourth signal wiring, wherein a first intermediate region is provided between the first signal wiring and the first adjacent wiring, and a second intermediate region is provided between the second signal wiring and the second adjacent wiring. a third intermediate region is provided between the third signal wiring and the second adjacent wiring, and a fourth intermediate region is provided between the fourth signal wiring and the third adjacent wiring; an outline of a first opening of the plurality of openings overlaps the first intermediate region, the first signal wiring, the second signal wiring, and the second intermediate region; a conductor portion of the conductive layer extending from the outline of the first opening overlaps at least one of the first adjacent wiring and the second adjacent wiring; an outline of a second opening of the plurality of openings overlaps the third intermediate region, the third signal wiring, the second signal wiring, and the fourth intermediate region; and a conductor portion of the conductive layer extending from the outline of the second opening overlaps at least one of the second adjacent wiring and the third adjacent wiring. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a wiring board that is capable of high-speed transmission and suppressing noise. [Brief explanation of the drawings]

[0009] [Figure 1](a) is an explanatory diagram of an electric module, (b) is a cross-sectional view of a partial region of a flexible wiring board, and (c) is an explanatory diagram showing the positional relationship between conductive layers and wiring layers. [Figure 2] FIG. 2 is an explanatory diagram showing the positional relationship between a conductive layer and a wiring layer. [Figure 3] FIG. 2 is an explanatory diagram showing the positional relationship between a conductive layer and a wiring layer. [Figure 4] FIG. 2 is an explanatory diagram showing the positional relationship between a conductive layer and a wiring layer. [Figure 5] FIG. 2 is an explanatory diagram showing the positional relationship between a conductive layer and a wiring layer. [Figure 6] FIG. 10 is a cross-sectional view of a partial region of a flexible wiring board according to a modified example. [Figure 7] FIG. 1 is a diagram of a system used to measure radiation noise. [Figure 8] FIG. 1 is a diagram of a system used for evaluating transmission characteristics. [Figure 9] FIG. 2 is an explanatory diagram showing the positional relationship of differential signal lines. [Figure 10] FIG. 1 is a schematic diagram of a digital camera. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, with reference to the drawings, an embodiment of the present invention will be described in detail, taking a flexible wiring board as an example of a wiring board. Note that in the following description and drawings, common reference numerals are used to designate components common to multiple drawings. In addition, common components may be described by mutual reference to multiple drawings without any explanation. In addition, descriptions of components with common reference numerals may be omitted.

[0011] Fig. 1(a) is an explanatory diagram of an electric module 100. Fig. 1(b) is an enlarged view of a portion of an AA cross section of a flexible wiring board 11. Fig. 1(c) is an explanatory diagram showing the positional relationship between a wiring layer 13 and a conductive layer 20 when the flexible wiring board 11 is viewed in plan from the second surface side of the substrate.

[0012] As shown in Figure 1(a), electric module 100 includes circuit board 101, circuit board 102, and one flexible wiring board 11 that electrically connects circuit board 101 and circuit board 102. Flexible wiring board 11 enables the wiring structure to be lighter than a coaxial cable. Circuit boards 101 and 102 can each be referred to as an electronic unit.

[0013] Circuit board 101 includes printed wiring board 110 and semiconductor device (first semiconductor device) 111 mounted on printed wiring board 110. Circuit board 102 includes printed wiring board 120 and semiconductor device 121 (second semiconductor device) mounted on printed wiring board 120. Printed wiring boards 110 and 120 can be rigid wiring boards, but may also be flexible wiring boards. Furthermore, wiring layer 13 and conductive layer 20 of flexible wiring board 11 may be configured using a rigid wiring board.

[0014] 1(a), a connector 112 is mounted on printed wiring board 110. Flexible wiring board 11 and semiconductor device 111 are electrically connected via connector 112 by conductors formed on printed wiring board 110. A connector 122 is mounted on printed wiring board 120. Flexible wiring board 11 and semiconductor device 121 are electrically connected via connector 122 by conductors formed on printed wiring board 120. In other words, semiconductor device 111 and semiconductor device 121 are electrically connected via printed wiring board 110, flexible wiring board 11, and printed wiring board 120, and can communicate with each other.

[0015] Furthermore, the electrical connection between flexible wiring board 11 and printed wiring board 110, or the electrical connection between flexible wiring board 11 and printed wiring board 120, may be achieved by direct bonding using a conductive bonding material such as a conductive adhesive or solder, rather than by a connector. Direct bonding reduces reflection loss at the connection compared to connector connection, and is therefore more suitable for high-speed transmission.

[0016] 1(b), flexible wiring board 11 includes substrate 12, wiring layer 13 that includes a plurality of wirings and is supported by substrate 12, and conductive layer 20 that is supported by substrate 12 and has an opening portion made up of a plurality of openings. In flexible wiring board 11, substrate 12 has first surface 12A and second surface 12B that faces the first surface.

[0017] The first surface 12A is provided with a wiring layer 13. In the wiring layer 13, differential signal lines 133 each formed of a pair of signal lines each consisting of a positive phase signal line 131 and a negative phase signal line 132, and adjacent lines 134 are laid alternately. The line width of the differential signal line 133 consisting of the positive phase signal line 131 and the negative phase signal line 132 is line width L1. Furthermore, the first surface 12A has a first insulating layer 15 for covering the differential signal lines 133 and the adjacent lines 134. When a ground potential is applied to the adjacent lines 134, the adjacent lines 134 can be referred to as ground lines.

[0018] A conductive layer 20 is provided on the second surface 12B. The conductive layer 20 has conductive portions 200 in which a conductive material is disposed and openings 201 in which no conductive material is disposed. The second surface 12B further has a second insulating layer 16 for covering the conductive layer 20.

[0019] When the wiring board is a flexible wiring board, the material of the substrate 12 is an insulating resin. Examples of resins include polyimide-based resins such as polyimide, polyamide, and polyamideimide; thermosetting resins such as epoxy; and thermoplastic resins such as liquid crystal polymers. Among these, polyimide or liquid crystal polymers are preferred. Polyimide has excellent heat resistance and mechanical properties and is readily available commercially. Liquid crystal polymers have a low dielectric constant, making them suitable for high-speed signal transmission applications, and also have low moisture absorption and excellent dimensional stability. The substrate 12 may be a single insulating layer, or may be a laminate of two or more functional layers, such as the wiring layer described above and an adhesive layer for adhering the conductive layer described below. The substrate 12 may also have holes for electrically connecting adjacent wiring 134 and the conductive portion 200. Although the adjacent wiring 134 and the conductive portion 200 can be electrically connected by a via conductor, even if the adjacent wiring 134 and the conductive portion 200 are not electrically connected by a via conductor, electrical coupling (electromagnetic coupling) can be formed between the wiring layer 13 and the conductive layer 20 by electromagnetic induction between the wiring layer 13 and the conductive layer 20. This embodiment is suitable for reducing noise in the adjacent wiring 134 that does not have a via conductor connected to the conductive portion 200, or in the adjacent wiring 134 that is 10 mm or more away from the via conductor connected to the conductive portion 200.

[0020] The thickness of the substrate 12 is not particularly limited, but is preferably in the range of 10 μm to 100 μm. If the thickness is less than 10 μm, the distance between the differential signal line and the conductive layer 20 will be short, which may increase the characteristic impedance value. On the other hand, if the thickness exceeds 100 μm, the rigidity of the resin will be high, which may result in insufficient flexibility. A more preferred range is 12 μm to 75 μm.

[0021] When the wiring board is a rigid substrate, the material of the substrate 12 is a fiber substrate. Examples of the fiber substrate include glass fiber substrates such as woven glass cloth and nonwoven glass cloth, and inorganic fiber substrates such as woven or nonwoven cloth containing inorganic compounds other than glass. Other examples include organic fiber substrates made of organic fibers such as aromatic polyamide, polyamide, aromatic polyester, polyester, polyimide, and fluororesin. Among these, glass fiber substrates are preferred because of their excellent strength and low water absorption.

[0022] In the wiring layer 13, differential signal lines 133, which are transmission lines for differential signals, and adjacent lines 134 are laid alternately. A data signal, which is a digital signal representing imaging data, is transmitted through the differential signal line 133. The adjacent line 134 is a line grounded to the ground, and serves to dissipate a return current that occurs when electromagnetic noise radiated from the differential signal line is received by the conductive layer 20. The adjacent line 134 also serves to suppress crosstalk noise that occurs between the two differential signal lines. In addition to the differential signal lines, the wiring layer 13 may also have lines that transmit single-ended signals such as control signals and response signals, and lines for power supply.

[0023] The method for manufacturing the wiring layer 13 is not particularly limited, and it can be formed by known methods such as laminating metal foil, metal plating, and inkjet process. When copper foil is used as the metal foil, a film laminated with an adhesive or the like can be used to form the required transmission line pattern by a photolithography and etching process. When an inkjet process is used, the required pattern can be drawn using a polymer ink containing conductive metal particles and then baked at a temperature below the glass transition point (Tg) of the substrate 12. The thickness of the wiring layer (thickness of the differential signal wiring) is not particularly limited, but is, for example, in the range of 0.1 μm to 20 μm.

[0024] However, when the average lengths of the positive-phase and negative-phase signals transmitted through a differential signal line differ, mode conversion occurs, in which part of the differential signal is converted into a common-mode signal, inducing common-mode noise. When common-mode noise resonates on a wiring board, large radiated noise is generated at the frequency of the common-mode noise. Furthermore, with the recent increase in data volume, differential signals with high transmission speeds on the order of Gbps, e.g., 5 Gbps (Gigabits per Second) or higher, are transmitted through differential signal lines. The relationship R = 2f holds between the signal transmission speed R [bps] and the signal frequency f [Hz]. Generally, the higher the frequency of the differential signal being transmitted, the greater the time change in the current flowing through the transmission line, resulting in more radiated noise. Because the generated radiated noise is close to the communication frequency band of a wireless communication device, it can be superimposed on the communication data when a wireless communication IC communicates wirelessly with an external device (e.g., a PC or wireless router) via an antenna.

[0025] Conventionally, in a wiring board in which a substrate and a conductor layer are laminated, the conductor layer on one side of the substrate serves as a wiring layer to form a transmission line, and the conductor layer on the other side serves as a ground layer (shield layer) to suppress radiated noise. Also known is a wiring board that includes a shield layer with an opening in addition to a ground layer, as disclosed in Patent Document 1. However, after investigations by the inventors of the present application, it was found that the technology disclosed in Patent Document 1 results in large transmission loss and distorted signal waveforms when high-speed signals are applied to differential signal lines, making high-speed transmission impossible. It was also found that the technology disclosed in Patent Document 1 cannot sufficiently suppress electromagnetic noise generated when high-speed signals are applied.

[0026] In this embodiment, the conductive layer 20 of the flexible wiring board 11 has an opening 201 consisting of a plurality of openings arranged continuously in a two-dimensional space on the second surface 12B of the substrate 12. The conductive layer 20 has a first wire portion 202 made of a conductive material that extends in a diagonal direction D2 relative to the extension direction D1 in which the signal wiring extends. The conductive layer 20 also has a second wire portion 203 that extends in a diagonal direction D3 relative to the extension direction D1. The diagonal direction D2 and the diagonal direction D3 intersect. The conductive material 20 has an opening 201 that consists of a single region surrounded by the first wire portion 202 and the second wire portion 203.

[0027] A first wire portion 202, a second wire portion 203, an intersection 204 between the first wire portion 202 and the second wire portion 203, and an opening 201 are arranged on the differential signal line 133 via the substrate 12, and the shape of the opening 201 is set according to the shape of the wiring layer 13. Here, when the flexible wiring board 11 is viewed in a plan view, the width of the opening 201 in the X direction of the conductive layer 20 is defined as an opening length R1, and the width in the Y direction is defined as an opening width R2. The width of the differential signal line 133 composed of the positive phase signal conductor 131 and the negative phase signal conductor 132 is defined as a line width L1. The line width L1 is the sum of the line widths of the positive phase signal conductor 131 and the negative phase signal conductor 132 plus the distance between the positive phase signal conductor 131 and the negative phase signal conductor 132.

[0028] 1(c) shows the relationship between the opening width R2, opening length R1, and line width L1 in the first embodiment. It is preferable that the opening width R2 is larger than the line width L1. It is also preferable that the opening length R1 is larger than the opening width R2. From FIG. 1(c), it can be seen that the conductive layer 20 has an opening 201 consisting of a plurality of openings, and the opening shapes are two-dimensionally patterned continuously.

[0029] Because the opening width R2 is larger than the line width L1, one opening of the openings 201 in the conductive layer 20 can include the entire width (line width L1) of the differential signal lines 133 when the flexible wiring board 11 is viewed in a plan view. By providing an area (opening 201) on the differential signal lines 133 where the conductive layer 20 is not present, when a return current is generated in the conductive layer 20 due to electromagnetic noise radiated from the differential signal lines 133, impedance mismatch between the positive phase signal line 131 and the negative phase signal line 132 of each differential signal line 133 is suppressed, thereby suppressing electromagnetic noise caused by signal waveform distortion due to transmission loss. Furthermore, the electromagnetic noise from the signal lines is converted into a return current in the conductive layer 20. The return current is coupled to the adjacent line 134 adjacent to the differential signal line 133 via the conductive layer 20 via electromagnetic coupling. That is, the return current is induced in the adjacent line 134 by the current flowing in the wiring layer 13 and is then released to the adjacent line 134. By adopting such a configuration in which the opening width R2 is larger than the line width L1, the path of the return current converted in the conductive layer 20 to the adjacent wiring 134 can be shortened, thereby making it possible to further suppress electromagnetic noise even when transmitting high-speed signals.

[0030] As described above, when the aperture width R2, aperture length R1, and line width L1 satisfy the above relationship, radiation noise generated from the differential signal line can be suppressed even when high-speed differential signals on the order of Gbps are transmitted.

[0031] The wiring layer 13 and the conductive layer 20 will be described in detail with reference to FIG. 2. The wiring layer 13 includes differential signal lines 133a and 133b as differential signal lines 133. The differential signal line 133a is configured with a pair of signal lines 131a and 132a. The differential signal line 133b is configured with a pair of signal lines 131b and 132b. The wiring layer 13 includes adjacent lines 134a, 134b, and 134c as adjacent lines 134. The adjacent line 134a is adjacent to the signal line 131a, and the adjacent line 134b is adjacent to the signal line 132a and the signal line 131b. The adjacent line 134c is adjacent to the signal line 132b.

[0032] An intermediate region 130a is provided between the signal wiring 131a and the adjacent wiring 134a. An intermediate region 130b is provided between the signal wiring 132a and the adjacent wiring 134b. An intermediate region 130c is provided between the signal wiring 131b and the adjacent wiring 134b. An intermediate region 130d is provided between the signal wiring 132b and the adjacent wiring 134c. An intermediate region 130e is provided between the signal wiring 131a and the signal wiring 132a. An intermediate region 130f is provided between the signal wiring 131b and the signal wiring 132b. These intermediate regions a to f are regions where no conductor portion of the wiring layer 13 exists, and can also be called non-wiring regions.

[0033] The direction in which the signal wiring 131a and the signal wiring 132a extend is defined as extension direction X1, and the direction in which the signal wiring 131b and the signal wiring 132b extend is defined as extension direction X2. The extension direction X1 and the extension direction X2 may be non-parallel but are typically parallel. The extension direction X1 and the extension direction X2 are shown as the X direction in FIG. 2 and as direction D1 in FIG. 1(c). The extension direction X1 may be parallel to at least one of the edge of the signal wiring 131a on the signal wiring 132a side and the edge of the signal wiring 132a on the signal wiring 131a side. The arrangement direction Y1 may be perpendicular to at least one of the edge of the signal wiring 131a on the signal wiring 132a side and the edge of the signal wiring 132a on the signal wiring 131a side.

[0034] The direction in which the signal wiring 131a and the signal wiring 132a are aligned is referred to as arrangement direction Y1, and the direction in which the signal wiring 131b and the signal wiring 132b are aligned is referred to as arrangement direction Y2. The arrangement direction Y1 and the arrangement direction Y2 may be non-parallel but are typically parallel, and are shown as the Y direction in FIG. 2. The arrangement direction Y1 may be perpendicular to at least one of the edge of the signal wiring 131a on the signal wiring 132a side and the edge of the signal wiring 132a on the signal wiring 131a side. The arrangement direction Y2 may be perpendicular to at least one of the edge of the signal wiring 131b on the signal wiring 132b side and the edge of the signal wiring 132b on the signal wiring 131b side. Typically, the extension direction X1 and the arrangement direction Y1 are perpendicular, and the extension direction X2 and the arrangement direction Y2 are perpendicular.

[0035] The openings of the opening portion 201 include an opening 201a, an opening 201b, an opening 201c, an opening 201d, and an opening 201e. In Fig. 2, the outline of each opening is indicated by a thick line.

[0036] 2, the opening 201a has one end 208a and the other end 209a as its opposite ends in the extension direction X1, and one end 206a and the other end 207a as its opposite ends in the arrangement direction Y1. The opening length R1 of the opening 201a is the distance in the extension direction X1 between one end 208a and the other end 209 of the opening 201a in the conductive layer 20. The opening width R2 of the opening 201a is the distance in the arrangement direction Y1 between one end 206a and the other end 207a of the opening 201a in the conductive layer 20.

[0037] 2, opening 201b has one end 208b and the other end 209b as its opposite ends in extension direction X2, and one end 206b and the other end 207b as its opposite ends in arrangement direction Y2. An opening length R1 of opening 201b is the distance in extension direction X2 between one end 208b and the other end 209 of opening 201b in conductive layer 20. An opening width R2 of opening 201b is the distance in arrangement direction Y1 between one end 206b and the other end 207b of opening 201b in conductive layer 20.

[0038] The line segment (diagonal) connecting one end 208a and the other end 209a of the opening 201a and the line segment (diagonal) connecting one end 206a and the other end 207a are preferably perpendicular to each other, but may be oblique. The line segment connecting one end 208a and the other end 209a is preferably parallel to the extension direction X1, but may be non-parallel to the extension direction X1. The line segment connecting one end 206a and the other end 207a is preferably parallel to the arrangement direction Y1, but may be non-parallel to the arrangement direction Y1. The same applies to the opening 201b.

[0039] The contour of opening 201a of the plurality of openings overlaps intermediate region 130a, signal wiring 131a, signal wiring 132a, and intermediate region 130b. A conductor portion of conductive layer 20 extending from the contour of opening 201a overlaps at least one of adjacent wiring 134a and adjacent wiring 134b.

[0040] The contour of opening 201b of the plurality of openings overlaps with intermediate region 130c, signal wiring 131b, signal wiring 132a, and intermediate region 130d. A conductor portion (e.g., intersection 204) extending from the contour of opening 201b in conductive layer 20 overlaps with at least one of adjacent wiring 134b and adjacent wiring 134c.

[0041] The contour of the opening 201c of the plurality of openings overlaps the intermediate region 130a, the signal wiring 131a, the signal wiring 132a, and the intermediate region 130b. A conductor portion (e.g., the intersection 204) extending from the contour of the opening 201c in the conductive layer 20 overlaps at least one of the adjacent wiring 134a and the adjacent wiring 134b.

[0042] The contour of opening 201d of the plurality of openings overlaps with intermediate region 130c, signal wiring 131b, signal wiring 132a, and intermediate region 130d. A conductor portion (e.g., intersection 204) extending from the contour of opening 201d in conductive layer 20 overlaps with at least one of adjacent wiring 134b and adjacent wiring 134c.

[0043] In this way, openings 201a-201d that overlap differential signal lines 133a, 133b also overlap adjacent intermediate regions 130a-130d. This increases the value of the characteristic impedance, improving the transmission characteristics of differential signal lines 133a, 133b. Furthermore, by providing the same configuration to both differential signal lines 133a, 133b, it is possible to reduce variations in the characteristic impedance of differential signal line 133a and differential signal line 133b, thereby achieving high transmission characteristics.

[0044] Furthermore, the conductor portions extending from the contours of the openings 201a-201d that overlap the differential signal lines 133a and 133b overlap the adjacent wirings 134a-c. This allows the return current flowing in the conductive layer 20 due to electromagnetic noise radiated from the differential signal lines 133a and 133b to escape to the adjacent wirings 134a-c. Therefore, for example, the return current due to electromagnetic noise radiated from the differential signal line 133a can be prevented from flowing into the differential signal line 133b.

[0045] The distance Wr between the adjacent wiring 134a and the signal wiring 131a and the distance Wr between the signal wiring 132a and the adjacent wiring 134b are preferably smaller than the line width L1 of the differential signal line 133a. The distance Wr between the adjacent wiring 134a and the signal wiring 131a and the distance Wr between the adjacent wiring 134b and the signal wiring 132a are preferably smaller than the line width L1 of the differential signal line 133b. By placing the adjacent wirings 134a to 134c closer to the differential signal lines 133a and 133b in this manner, the return current flowing through the conductive layer 20 can be more easily released to the adjacent wirings 134a to 134c.

[0046] The line width L1 of the differential signal line 133a is the sum of the width Ws of the signal wiring 131a, the width Ws of the signal wiring 132a, and the distance Wd between the signal wirings 131a and 132a. The line width L1 of the differential signal line 133b is the sum of the width Ws of the signal wiring 131b, the width Ws of the signal wiring 132b, and the distance Wd between the signal wirings 131b and 132b.

[0047] The distance Wr between the signal wiring 132a and the adjacent wiring 134b and the distance Wr between the adjacent wiring 134b and the signal wiring 131b are preferably smaller than the width Wg of the adjacent wiring 134b. By placing the adjacent wirings 134a to 134c closer to the differential signal lines 133a and 133b in this manner, the return current flowing through the conductive layer 20 can be more easily released to the adjacent wirings 134a to 134c.

[0048] The distance Wd between the signal wiring 131a and the signal wiring 132a is preferably smaller than the distance Wr between the adjacent wiring 134a and the signal wiring 131a and the distance Wr between the adjacent wiring 134b and the signal wiring 132a. The distance Wd between the signal wiring 131b and the signal wiring 131b is preferably smaller than the distance Wr between the adjacent wiring 134a and the signal wiring 131a and the distance Wr between the adjacent wiring 134b and the signal wiring 132a. By strengthening the coupling between the signal wiring 131a and the signal wiring 132a and between the signal wiring 131a and the signal wiring 132a in this way, the transmission characteristics can be improved.

[0049] 2 shows a distance L7 between the edge of adjacent wiring 134a opposite to signal wiring 131a and the edge of adjacent wiring 134c opposite to signal wiring 131b. It is preferable that the opening width R2 of opening 201a in arrangement direction Y1 and the opening width R2 of opening 201b in arrangement direction Y2 are smaller than distance L7. In this way, noise caused by differential signal lines other than differential signal lines 133a and 133b is less likely to flow to differential signal lines 133a and 133b in the conductor portions defining openings 201a and 201b.

[0050] Furthermore, it is also preferable that the opening width R2 of opening 201a in arrangement direction Y1 and the opening width R2 of opening 201b in arrangement direction Y2 are equal to or less than the interval L6 between adjacent wirings 134a and 134c. In this way, noise caused by differential signal lines other than differential signal lines 133a and 133b is less likely to flow to differential signal lines 133a and 133b.

[0051] Furthermore, it is preferable that the opening width R2 of the opening 201a in the arrangement direction Y1 is smaller than the distance L5 between the edge of the adjacent wiring 134a opposite to the signal wiring 131a side and the edge of the adjacent wiring 134b opposite to the signal wiring 132a side. Similarly, it is preferable that the width of the opening 201b in the arrangement direction Y2 is smaller than the distance L5 between the edge of the adjacent wiring 134b opposite to the signal wiring 131b side and the edge of the adjacent wiring 134c opposite to the signal wiring 131b side.

[0052] The opening width R2 of the opening 201a in the arrangement direction Y1 is preferably at least twice the line width L1 of the differential signal line 133a. The opening width R2 of the opening 201b in the arrangement direction Y2 is preferably at least two times but not more than four times the line width L1 of the differential signal line 133b.

[0053] The opening width R2 of the opening 201a in the arrangement direction Y1 may be larger than the distance L4 between the edge of the signal wiring 131a on the side of the adjacent wiring 134a and the edge of the signal wiring 131a on the side of the adjacent wiring 134b.

[0054] The distance L2 between the signal wiring 132a and the signal wiring 131b is preferably larger than the line width L1 of the differential signal line 133a and the line width L1 of the differential signal line 133b. By sufficiently separating the differential signal line 133a and the differential signal line 133b, crosstalk between the differential signal lines 133 can be suppressed.

[0055] The opening width R2 of the opening 201a in the arrangement direction Y1 is preferably equal to or greater than the distance L3 between the adjacent wirings 134a and 134b. The opening width R2 of the opening 201b in the arrangement direction Y2 is preferably equal to or greater than the distance L3 between the adjacent wirings 134b and 134c.

[0056] It is preferable that the outline of the opening 201a overlaps with at least one of the adjacent wirings 134a and 134b, and / or the outline of the opening 201b overlaps with at least one of the adjacent wirings 134a and 134b.

[0057] It is preferable that the opening width R2 of the opening 201a in the arrangement direction Y1 and the opening width R2 of the opening 201b in the arrangement direction Y2 are greater than the distance L2 between the signal wiring 132a and the signal wiring 131b.

[0058] The width Wg of the adjacent wiring 134b is preferably smaller than the line width L1 of the differential signal line 133a and the line width L1 of the differential signal line 133b.

[0059] The distance L2 between the signal wiring 132a and the signal wiring 131b is preferably smaller than the distance L3 between the adjacent wiring 134a and the adjacent wiring 134b and the distance L3 between the adjacent wiring 134b and the adjacent wiring 134c.

[0060] The width Ws of the signal wiring 131a and the width Ws of the signal wiring 132a are preferably larger than the distance Wd between the signal wiring 131a and the signal wiring 132a. The width Ws of the signal wiring 131b and the width Ws of the signal wiring 132b are preferably larger than the distance Wd between the signal wiring 131b and the signal wiring 132b.

[0061] The opening length R1 of the opening 201a in the direction perpendicular to the arrangement direction Y1 (extension direction X1) is preferably greater than the opening width R2 of the opening 201a in the arrangement direction Y1. The opening length R1 of the opening 201b in the direction perpendicular to the arrangement direction Y2 (extension direction X2) is preferably greater than the opening width R2 of the opening 201b in the arrangement direction Y2.

[0062] The opening length R1 of the opening 201a in the direction perpendicular to the arrangement direction Y1 (extension direction X1) is preferably at least two times and at most eight times the opening width R2 of the opening 201a in the arrangement direction Y1. The opening length R1 of the opening 201b in the direction perpendicular to the arrangement direction Y2 (extension direction X2) is preferably at least two times and at most eight times the opening width R2 of the opening 201a in the extension direction X2.

[0063] The opening length R1 of the opening 201a in the direction (extension direction X1) perpendicular to the arrangement direction Y1 is preferably greater than the distance L3 between the adjacent wirings 134a and 134b. The opening length R1 of the opening 201b in the direction (extension direction X2) perpendicular to the arrangement direction Y2 is preferably greater than the distance L3 between the adjacent wirings 134b and 134c.

[0064] The opening length R1 of the opening 201a in the direction orthogonal to the arrangement direction Y1 (extension direction X1) is preferably greater than the distance L4 between the edge of the signal wiring 131a on the side of the adjacent wiring 134a and the edge of the signal wiring 131a on the side of the adjacent wiring 134b. The opening length R1 of the opening 201b in the direction orthogonal to the arrangement direction Y2 (extension direction X2) is preferably greater than the distance L4 between the edge of the signal wiring 131a on the side of the adjacent wiring 134a and the edge of the signal wiring 131a on the side of the adjacent wiring 134b.

[0065] The opening length R1 of the opening 201a in the direction orthogonal to the arrangement direction Y1 (extension direction X1) is preferably greater than the distance L5 between the edge of the adjacent wiring 134a opposite to the signal wiring 131a side and the edge of the adjacent wiring 134b opposite to the signal wiring 132a side. The opening length R1 of the opening 201b in the direction orthogonal to the arrangement direction Y2 (extension direction X2) is preferably greater than the distance L5 between the edge of the adjacent wiring 134b opposite to the signal wiring 131b side and the edge of the adjacent wiring 134c opposite to the signal wiring 131b side.

[0066] The opening length R1 of the opening 201a in the direction (extension direction X1) perpendicular to the arrangement direction Y1 is preferably greater than the distance L6 between the adjacent wirings 134a and 134c. The opening length R1 of the opening 201b in the direction (extension direction X2) perpendicular to the arrangement direction Y2 is preferably greater than the distance L6 between the adjacent wirings 134a and 134c.

[0067] The opening length R1 of the opening 201a in the direction orthogonal to the arrangement direction Y1 (extension direction X1) is preferably greater than the distance L7 between the edge of the adjacent wiring 134a opposite to the signal wiring 131a side and the edge of the adjacent wiring 134c opposite to the signal wiring 131b side. The opening length R1 of the opening 201b in the direction orthogonal to the arrangement direction Y2 (extension direction X2) is preferably greater than the distance L7 between the edge of the adjacent wiring 134a opposite to the signal wiring 131a side and the edge of the adjacent wiring 134c opposite to the signal wiring 131b side.

[0068] It is preferable that the distance G1 between the openings 201a and 201b is smaller than the interval L6 between the adjacent wiring 134a and the adjacent wiring 134c. It is preferable that the distance G1 between the openings 201a and 201b is smaller than the width Wg of the adjacent wiring 134b. It is also preferable that the openings 201a and 201b overlap the adjacent wiring 134b. It is preferable that the distance G1 between the openings 201c and 201d is smaller than the width Wg of the adjacent wiring 134b. It is also preferable that the openings 201c and 201d overlap the adjacent wiring 134b. In this way, it is preferable to place the openings 201a to 201d close to the adjacent wiring 134b in order to allow noise components to escape to the adjacent wiring 134b.

[0069] It is preferable that opening 201c, which has a similar shape to opening 201a, overlaps differential signal line 133a, as does opening 201a. It is preferable that opening 201d, which has a similar shape to opening 201b, overlaps differential signal line 133b, as does opening 201b. Below, several features of openings 201c and 201d will be described.

[0070] Of the plurality of openings, the outline of opening 201c preferably overlaps at least one of signal wiring 132a and signal wiring 131b and adjacent wiring 134b.

[0071] It is preferable that the line width L1 of the opening 201c in the arrangement direction Y1 in which the signal wiring 132a and the signal wiring 131b are aligned is equal to or smaller than the distance L6 between the adjacent wiring 134a and the adjacent wiring 134c.

[0072] The openings 201a and 200c overlapping the signal wiring 131a and the signal wiring 132a, respectively, are preferably closer to each other. The openings 201b and 200d overlapping the signal wiring 131b and the signal wiring 132b, respectively, are preferably closer to each other. The distance G2 between the openings 201a and 200c is preferably smaller than the opening length R1 of the opening 201a, and the distance G2 between the openings 201b and 201d is preferably smaller than the opening length R1 of the opening 201b. The distance G2 between the openings 201a and 200c and the distance G2 between the openings 201b and 201d are preferably 10 mm or less, and more preferably 5 mm or less. Arranging the openings 201a to 201d that satisfy a suitable relationship with the differential signal line 133 at closer intervals on the differential signal line 133 is effective in reducing noise at multiple locations in the extension directions X1 and X2 of the differential signal line 133.

[0073] Of the plurality of apertures, the contour of aperture 201c preferably overlaps with signal wiring 131a and signal wiring 132a, and the aperture width R2 of aperture 201c in arrangement direction Y1 is greater than the line width L1 of differential signal line 133a. Of the plurality of apertures, the contour of aperture 201d preferably overlaps with signal wiring 131b and signal wiring 132b, and the aperture width R2 of aperture 201d in arrangement direction Y2 is greater than the line width L1 of differential signal line 133b.

[0074] The area of ​​the conductor portion of wiring layer 13 that occupies a first target region from the edge of signal wiring 132a on the side of signal wiring 131b to the edge of signal wiring 131b on the side of signal wiring 132a is defined as A. The area of ​​conductive layer 20 that occupies a second target region that overlaps the first target region in the direction in which wiring layer 13 and conductive layer 20 overlap is defined as B. It is preferable that area A is larger than area B. It is also preferable that area B of conductive layer 20 that occupies the second target region is 90% or less of the area of ​​the second target region.

[0075] Among the multiple openings, opening 201e is adjacent to openings 201a-d and can therefore be referred to as an adjacent opening. The contour of opening 201e among the multiple openings overlaps adjacent wiring 134b, intermediate region 130b, and intermediate region 130d. Furthermore, the contour of opening 201e overlaps at least one of signal wiring 132a and signal wiring 131b. Opening 201e does not need to overlap at least one of signal wiring 131a and signal wiring 132b, and preferably does not overlap both.

[0076] The width of the opening 201e in the direction in which the signal wiring 132a and the signal wiring 131b are aligned (Y direction) is preferably equal to or larger than the distance L2 between the signal wiring 132a and the signal wiring 131b. The width of the opening 201e in the direction in which the signal wiring 132a and the signal wiring 131b are aligned (Y direction) is preferably equal to or smaller than the distance L6 between the adjacent wiring 134a and the adjacent wiring 134c. The dimensions of the opening 201e may be similar to those of the openings 201a to 201d.

[0077] Considering the above, the preferred relationship is Wg>Ws≧Wr>Wd. The preferred relationship is L7>L6>L5>L4>L3>L2>L1. Furthermore, it is preferable that L1>Wg. Since it is preferable that L5>R2, R2>L4, and R1>L7, it is preferable that R1>L7>L6>L5>R2>L4>L3>L2>L1>Wg>Ws≧Wr>Wd. The width Wg can be 100 μm or more, and the width Ws can be less than 100 μm. The distance L7 can be 1000 μm or more and 2000 μm or less. The interval L6 can be less than 1000 μm.

[0078] It is desirable that the opening width R2 be 150 μm or more. If the opening width R2 is smaller than 150 μm, when flexible wiring board 11 is viewed in a plan view, the area covered by conductive layer 20 that overlaps signal wiring 131, 132 becomes too large, which may easily cause impedance mismatching and reduce transmission performance. A more preferable opening width is 300 μm or more.

[0079] The aperture length R1 is the length of the longest diagonal line of the aperture 201 in the conductive layer 20. The aperture length R1 can be determined depending on the transmission speed of the applied signal. For example, to achieve a transmission speed of 5 to 6 Gbps, electromagnetic noise with a frequency of 5 GHz (wavelength λ≈60 mm) to 6 GHz (wavelength λ≈50 mm) is generated. In this case, λ / 4 is 12.5 to 15.0 mm, so the aperture length R1 is preferably 12.5 mm or less. Since λ / 8 is 6.25 to 7.50 mm, the aperture length R1 is preferably 6.25 mm or less. If the aperture length R1 is greater than 12.5 mm, noise leakage from the aperture 201 increases the possibility of affecting wireless communication devices in electronic devices. Furthermore, electromagnetic noise includes not only the fundamental frequency but also second and third harmonics, although their intensity is reduced. Therefore, it is preferable to be able to respond to electromagnetic noise of these harmonics. In practice, the aperture length R1 is preferably equal to or less than λ / 4, or even λ / 8, of the tripled wave. The tripled wave of 5 GHz is 15 GHz (wavelength λ=20 mm), and λ / 4 is 5.0 mm and λ / 8 is 2.5 mm, so the aperture width R2 can be equal to or less than 5.0 mm, or even 2.5 mm. The tripled wave of 6 GHz is 18 GHz (wavelength λ=16.7 mm), and λ / 4 is 4.2 mm and λ / 8 is 2.1 mm, so the aperture width R2 can be equal to or less than 4.2 mm, or even 2.1 mm.

[0080] The line width of the first line portion 202 or the second line portion 203 is preferably 20 μm or more. If the line width is thinner than 20 μm, the electrical resistance of the first line portion 202 or the second line portion 203 increases, reducing the efficiency of electromagnetic noise conversion by the conductive layer and potentially impairing shielding performance. Furthermore, the line width of the first line portion 202 or the second line portion 203 is preferably 200 μm or less. A line width of 200 μm or less allows the area covered by the conductive layer for each signal line to be more uniform, suppressing impedance mismatch and reducing transmission failures of transmitted signals.

[0081] 3(a), the line width of the first line portion 202 and / or the second line portion 203 at an intersection 204 where the first line portion 202 and the second line portion 203 of the conductive layer 20 intersect may be narrower than the line width of the first line portion 202 and / or the second line portion 203 at a non-intersection portion. In other words, the first line portion 202 and / or the second line portion 203 at the non-intersection portion may be a thick line portion, and the first line portion 202 and / or the second line portion 203 at the intersection 204 may be a thin line portion. Here, a thin line portion has a line width smaller than that of a thick line portion.

[0082] By narrowing the intersecting area in this way, the overlapping area of ​​first line portion 202 and second line portion 203 is reduced, thereby improving the flexibility of flexible wiring board 11. In order to minimize the overlapping area of ​​first line portion 202 and second line portion 203, they may be made to intersect at right angles from a direction different from diagonal direction D2 or diagonal direction D3, as shown in FIG. 3(b).

[0083] In the opening of the conductive layer 20, the direction in which a straight line connecting both ends in the extending directions X1 and X2 extends is defined as the axial direction D4. When R1 > R2, it is the long-axis direction of the opening, and when R1 < R2, it is the short-axis direction of the opening. This axial direction D4 and the extending direction D1 in which the signal wiring extends may be the same as shown in FIG. 1(c), or may be different as shown in FIG. 4. It is more preferable that the acute angle θ formed by the extending direction D1 and the axial direction D4 is greater than 0 degrees. The acute angle θ formed by the extending direction D1 and the axial direction D4 may be less than 45 degrees, may be less than 30 degrees, and preferably less than 15 degrees, may be less than 10 degrees, and may be less than 5 degrees. Thereby, variations in the impedance of each signal wiring can be suppressed, and transmission failures of the transmitted digital signals can be reduced. The angle θ formed by the extending direction D1 and the axial direction D4 is preferably 0 degrees or more and 10 degrees or less. Incidentally, electromagnetic wave noise radiated from the signal wiring occurs in a direction exactly opposite to the current direction in the signal wiring. When the angle θ formed by the extending direction D1 and the axial direction D4 becomes more than 30 degrees, the angle formed with the first line portion 202 or the second line portion 203 in the conductive layer 20 with respect to the signal wiring becomes too large, making it difficult for the return current to occur. As a result, there is a risk of degrading the shielding performance.

[0084] The thickness of the conductive layer 20 is preferably in the range of 1 μm or more and 20 μm or less. If the thickness is less than 1 μm, the resistance value of the conductive layer 20 becomes large. Therefore, it becomes difficult for the return current to flow when electromagnetic wave noise occurs, and there is a risk of an increase in the amount of radiated noise. On the other hand, when the thickness of the conductive layer 20 is thicker than 20 μm, it becomes difficult to smooth the surface shape with the second insulating layer 16. More preferably, it is in the range of 2 μm or more and 15 μm or less.

[0085] The aperture ratio, which is the area ratio of the openings in the conductive layer 20, is preferably in the range of 40% or more and 90% or less. That is, the aperture ratio is the ratio of the area of the openings 201 to the total area of the openings 201 in the conductive layer 20 in an arbitrary area when the flexible wiring board 11 is viewed in plan. A more preferable range of the aperture ratio is 50% or more and 85% or less.

[0086] If the aperture ratio is less than 40%, the characteristic impedance value will decrease, and depending on the speed of the transmitted signal, transmission characteristics may deteriorate. Also, the rigidity of the conductive layer will increase, and if wiring board 11 is made into a flexible wiring board, there is a risk that its flexibility will be insufficient. On the other hand, if the aperture ratio is greater than 90%, radiation noise will not be sufficiently suppressed, increasing the possibility of affecting communication in wireless communication devices.

[0087] The aperture ratio can be measured, for example, by the following method. An image of the conductive layer 20 is obtained from a direction perpendicular to the second surface 12B of the substrate 12 using any observation method. The obtained image should include 10 or more openings. Using the obtained rectangular image, portions corresponding to the conductive portions 200 and openings 201 are extracted and binarized, and their respective areas are calculated from the pixel count. The rectangular area including 10 or more openings is defined as S1. The opening area in the rectangular area including 10 or more openings (the sum of the areas of the 10 or more openings) is defined as S1. The aperture ratio (%) can be calculated by 100 × S2 / S1. The observation method can be any method, such as an optical microscope, a stereo microscope, a digital microscope, or a scanning electron microscope (SEM). Alternatively, the shape of the conductive layer can be measured and analyzed using a laser microscope, a contact shape measuring instrument, an optical interference shape measuring instrument, or the like, and the aperture ratio can be calculated from information corresponding to the conductive portions 200 and openings 201.

[0088] The image size to be acquired at this time is preferably 500 pixels x 500 pixels or more. The aforementioned opening width R2 and opening length R1 can also be calculated using the image. The conductive portion 200 and the opening 201 are binarized and separated, the pixel length is measured, and after correcting for actual size, the opening width R2 and opening length R1 values ​​for 10 openings are averaged.

[0089] The opening 201 can have any shape as long as it satisfies the relationship between the opening width R2, the opening length R1, and the line width L1.

[0090] The opening 201 may be a diamond shape as shown in FIG. 1(c) or an approximately diamond shape as shown in FIGS. 3(a) and 3(b). It may also be a rectangle or a parallelogram, or a circle, ellipse, or hexagon as shown in FIGS. 5(a), (b), and (c). It may also be a shape in which the first line portion or the second line portion is discontinuous as shown in FIG. 5(d). It may also be a shape in which a plurality of these shapes are selected and arranged. Among these, polygons such as squares and hexagons are preferred. A polygonal shape of the opening 201 can reduce variations in the width of non-opening portions, which makes the return path of radiated noise uniform and more efficiently suppresses radiated noise.

[0091] The method for forming the conductive layer 20 is not particularly limited. For example, methods for forming a conductive layer on the second surface 12B of the substrate 12 include subtractive methods, electroless plating methods, electrolytic plating methods, and physical vapor deposition methods such as vacuum deposition and sputtering. Also, known coating film formation methods such as bar coating, slit coating, and screen printing methods can be used. Of these, the method for forming a patterned conductive layer on the second surface 12B of the substrate 12 is preferably screen printing, which can be performed at room temperature and atmospheric pressure and involves applying a pattern of a conductive material and heating it to form a dried coating film.

[0092] The electrical resistivity of the conductive layer 20 is preferably 10 Ω·cm or less from the viewpoint of electromagnetic noise shielding ability, and 1×10 -5 [Ω·cm] or less is more preferable. Materials constituting the conductive layer include metal materials such as gold, silver, copper, aluminum, and nickel; conductive resin compositions in which conductive fillers such as metal particles, metal fibers, and carbon nanotubes are mixed into resin; and conductive polymers such as polythiophene and polypyrrole. Of these, a silver paste consisting of silver particles with high conductivity and a resin binder is particularly suitable as a material for forming a coating film. In addition to silver paste, gold paste, copper paste, carbon paste, etc. may also be used.

[0093] When forming a conductive layer using silver paste, the viscosity of the silver paste is preferably 1 Pa·s or more and 500 Pa·s or less at a shear rate of 10 / s. A viscosity of 1 Pa·s or more prevents the line width of the conductive portion 200 from changing after formation, allowing for a conductive layer 20 of stable quality to be obtained. Furthermore, a viscosity of 500 Pa·s or less allows for the formation of conductive portion 200 lines without interruption. From these perspectives, the viscosity of the silver paste is more preferably 5 to 100 Pa·s at a shear rate of 10 / s.

[0094] Within the housing of the electronic device, the distance between the wireless communication unit 150 and the conductive layer 20 is preferably shorter than the distance between the wireless communication unit 150 and the wiring layer 13. In other words, the conductive layer 20 is preferably disposed in a position closer to the wireless communication unit 150 than the wiring layer 13. By locating the conductive layer 20 closer to the wireless communication unit 150 than the wiring layer 13, it is possible to prevent radiation noise generated from the wiring layer 13 from being superimposed on radio waves of external communication performed by the wireless communication unit 150.

[0095] In addition to the wiring layer 13, a first insulating layer 15 may be provided on the first surface 12A of the substrate 12. In addition to the conductive layer 20, a second insulating layer 16 may be provided on the second surface 12B of the substrate 12. The first insulating layer 15 and the second insulating layer 16 serve as protective layers that act as a deterrent to prevent current from flowing to other components within the electronic device. Therefore, it is preferable that the first insulating layer 15 and the second insulating layer 16 have high electrical insulation properties.

[0096] The volume resistivity of the first insulating layer 15 and the second insulating layer 16 is 10 9 [Ω·cm] or more is preferable, and 10 13 [Ω·cm] or more.

[0097] The first insulating layer 15 and the second insulating layer 16 are made of resin, such as a flexible cover film or an insulating resin coating layer. Plastics can be used as the cover film. Examples include polypropylene (PP), high-density polyethylene, polyester, polyethylene terephthalate (PET), polybenzimidazole, polyamide (PA), polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), and polyether ether ketone (PEEK). Polyester film is preferred from the perspective of low cost. Polyphenylene sulfide film is preferred from the perspective of excellent flame retardancy, and aramid film or polyimide film is preferred when heat resistance is required.

[0098] The insulating resin used for the coating may be any resin having insulating properties, such as a thermosetting resin or an ultraviolet-curing resin. Examples of thermosetting resins include phenolic resins, acrylic resins, epoxy resins, melamine resins, silicone resins, and acrylic-modified silicone resins. Examples of ultraviolet-curing resins include epoxy acrylate resins, polyester acrylate resins, and methacrylate-modified versions thereof. The curing mode may be any of thermosetting, ultraviolet curing, and electron beam curing. If necessary, other known additives such as coloring pigments, flame retardants, antioxidants, lubricants, dust-preventing agents, and curing accelerators may be added.

[0099] The first insulating layer 15 and the second insulating layer 16 may be a single layer, or may be configured with two or more layers each having functional properties such as adhesion and wiring conformability during coating. For example, the adhesive layer may be made of a cured product of a known adhesive. Examples include acrylonitrile butadiene rubber (NBR) adhesives, polyamide adhesives, polyester adhesives, acrylic adhesives, polyester polyurethane adhesives, and silicone adhesives. For example, the wiring conformable layer may be made of a known flexible resin such as rubber. Examples of rubber include silicone rubber, butadiene rubber, nitrile rubber, acrylic rubber, urethane rubber, styrene rubber, styrene-butadiene rubber, and butyl rubber.

[0100] The first insulating layer 15 and the second insulating layer 16 do not need to cover the entire wiring layer 13 and the conductive layer 20, respectively, and there may be some areas of the first insulating layer 15 and the second insulating layer 16 that are not covered.

[0101] The thickness of the first insulating layer 15 and the second insulating layer 16 is not particularly limited, but it is desirable that they sufficiently cover the wiring layer 13 and the conductive layer 20 and be smooth. Specifically, a thickness of 2 μm to 50 μm is preferable, and a thickness of 5 μm to 30 μm is particularly preferable. If the thickness is less than 2 μm, the spaces between the wirings in the wiring layer 13 or the openings 201 in the conductive layer 20 will not be sufficiently filled, which may result in peeling or the like during use of the electronic device. Furthermore, in the case of a flexible wiring board, a thickness exceeding 50 μm will reduce flexibility.

[0102] There are no particular limitations on the method for forming the first insulating layer 15 and the second insulating layer 16, and any known method can be used, such as a method of laminating a cover film having an adhesive, a method of applying an adhesive and then laminating and curing a cover film, or a method of applying a liquid resin using a dispenser or printing method and then curing it by heat or ultraviolet irradiation.

[0103] In this embodiment, the conductive layer 20 is provided on the second surface 12B of the base material 12, but the position of the conductive layer 20 is not limited thereto. The conductive layer 20 only needs to face the wiring layer 13 via an insulating layer, and for example, as shown in FIG. 6, the conductive layer 20 may be provided on a first insulating layer 15 provided on the wiring layer 13. In this modification, the first insulating layer 15, which is a covering portion formed on the wiring layer 13, may have an adhesive function. Furthermore, the conductive layer 20 may be provided on the first insulating layer 15 side while facing the wiring layer 13 via the base material 12.

[0104] 10 is an explanatory diagram of a digital camera 600 as an example of an electronic device. The digital camera 600 is an interchangeable lens digital camera and includes a camera body 601. A lens unit (lens barrel) 602 including a lens can be attached to the camera body 601. The camera body 601 includes a housing 611, and an electric module 100 and a wireless communication unit 150 housed inside the housing 611. The camera body 601 and the lens unit 602 are also electronic devices.

[0105] Camera body 601 includes circuit board 101, which is an electronic unit, circuit board 102, which is also an electronic unit, and one flexible wiring board 11, which is a wiring board, that electrically connects circuit board 101 and circuit board 102. Housing 611 stores circuit board 101 and circuit board 102. Flexible wiring board 11 is bent within housing 611, which allows camera body 601 to be made smaller. Flexible wiring board 11 allows the wiring structure to be lighter than a coaxial cable.

[0106] Circuit board 101 includes a printed wiring board 110 and a semiconductor device 111 mounted on printed wiring board 110. Circuit board 102 includes a printed wiring board 120 and a semiconductor device 121 mounted on printed wiring board 120.

[0107] The semiconductor device 111 is an image sensor serving as an imaging element. The image sensor is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The image sensor has a function of converting light incident via the lens unit 602 into an electrical signal. The semiconductor device 121 is a digital signal processor serving as a processing circuit. The digital signal processor has a function of acquiring an electrical signal representing image data from the image sensor, correcting the acquired electrical signal, and generating corrected image data.

[0108] The wireless communication unit 150 is a modularized wireless communication module that performs wireless communication in the GHz band. The wireless communication unit 150 includes a printed wiring board 151 provided with an antenna (not shown) and a wireless communication IC 152 mounted on the printed wiring board 151. The antenna is provided on the same plane as the wireless communication IC 152 and is located close to the housing 611 to facilitate communication with the outside. The wireless communication IC 152 transmits and receives image data by wirelessly communicating with an external device (such as a PC or a wireless router) via the antenna. That is, the wireless communication IC 152 modulates a digital signal representing the image data and transmits it from the antenna as radio waves at a communication frequency of a wireless standard. The wireless communication IC 152 also demodulates the radio waves received by the antenna into a digital signal representing the image data. The wireless communication IC 152 communicates wirelessly with the external device in accordance with standards such as Wi-Fi (registered trademark) and Bluetooth (registered trademark). The flexible wiring board 11 of this embodiment has a wiring layer 13 and a conductive layer 20 arranged in consideration of the effects of noise, and therefore can suppress mutual influence between the flexible wiring board 11 and the wireless communication unit 150 provided within the housing 611.

[0109] Although the electronic device is described as a digital camera as an example, the present invention is not limited to this. For example, the electronic device may be a mobile communication device. For example, the electronic device may be an information device such as a smartphone or a personal computer, or a communication device such as a modem or a router. Alternatively, the electronic device may be office equipment such as a printer or a copier, medical equipment such as a radiographic device, a magnetic imaging device, an ultrasound imaging device, or an endoscope, industrial equipment such as a robot or a semiconductor manufacturing device, or transportation equipment such as a vehicle, an airplane, or a ship. The wiring board of the present invention is applicable to all electronic devices. [Example]

[0110] The present embodiment will be described in more detail with reference to an example, but the present invention is not limited to this example. The measurement method in this example is as follows.

[0111] (Examples 1 to 10) A wiring board 11 having the shape shown in FIG. 1(b) is fabricated. A 25 μm-thick polyimide film (Kapton 100H manufactured by DuPont-Toray Co., Ltd.) is prepared as the substrate 12. A 12 μm-thick copper foil is laminated on the first surface 12A of this substrate 12 as the wiring layer 13, and signal wirings 131, 132 and adjacent wiring 134, each with a total length of 120 mm, are formed by etching. A pair of differential signal lines 133 consisting of two signal lines 131, 132 is arranged between two adjacent wirings 134 at a pitch of 500 μm (corresponding to L4). There are 20 pairs of differential signal lines 133 in the wiring board. The signal wirings 131 and 132 have a line width Ws = 75 μm and a signal wiring spacing Wd = 55 μm, the adjacent wiring 134 has a line width Wg = 150 μm and a spacing Wr = 72.5 μm between the adjacent wiring 134 and the signal wiring 131 or the signal wiring 132. The inspection specifications for the circuit appearance and tolerance are in accordance with the JPCA standard (JPCA-DG02).

[0112] Next, a conductive layer 20 is formed by screen printing on the second surface 12B of the substrate 12. The conductive layer 20 is printed using a silver paste (product name: DD2630L-245) manufactured by Kyoto Elex Co., Ltd. with a screen printer (MT-320T manufactured by Micro-Tec Co., Ltd.) under conditions such that the thickness is 5 μm. The conductive layer 20 is formed in the form shown in FIG. 1(c).

[0113] Next, first insulating layer 15 and second insulating layer 16 are formed on wiring layer 13 and conductive layer 20, respectively. Specifically, a coverlay (CISV1215 manufactured by Nikkan Industries Co., Ltd.) is attached with a polyimide film as an insulating portion having a thickness of 12.5 μm and an adhesive portion having a thickness of 15 μm, to obtain the wiring boards of Examples 1 to 10. The differential signal lines are designed with a target differential impedance of 100 Ω±10 Ω.

[0114] The wiring boards of Examples 1 to 10 have a wiring configuration in which a pair of differential signal lines 133 consisting of two signal lines 131 and 132 is arranged between two adjacent lines 134. For each of the 20 pairs of differential signal lines 133, the midpoints of both ends in the Y direction of at least two openings located within a range of 10 mm overlap with the midpoint between the signal lines 131 and 132 (a position Wg / 2 from the signal lines 131 and 132).

[0115] (Examples 11 and 12) The wiring boards in Examples 11 and 12 are configured so that adjacent wiring 134 is not placed between differential signal lines 133. The signal wirings 131 and 132 have a line width Ws of 50 μm and a signal wiring interval Wd of 140 μm.

[0116] (Example 13) The signal wirings 131 and 132 have a line width Ws=50 μm and a signal wiring interval Wd=65 μm, the adjacent wiring 134 has a line width Wg=50 μm and an interval Wr between the adjacent wiring 134 and the signal wiring 131 or 132=92.5 μm.

[0117] (Evaluation 1) Radiation noise measurement The amount of radiated noise from wiring board 11 is evaluated using a system configured as shown in Fig. 7. As a reference example, the amount of radiated noise from a wiring board having the same wiring layer configuration as in Examples 1 to 10 but without a conductive layer is measured.

[0118] Next, the wiring board is connected to a connection board 35. A signal generator 31 (Keysight M8041A) is used to transmit a pseudo-random signal (PRBS23) with a data pattern at a bit rate of 5.3 Gbps. The waveform of the common mode voltage is then observed with an oscilloscope 32 (Agilent Technologies 92504A), and the input amplitude is adjusted so that the common mode voltage is 150 mV.

[0119] Next, the wiring board 11 (Examples 1 to 13) to be measured is connected to a connection board 35, and a signal generator 31 is used to transmit a pseudorandom signal (PRBS23) with a data pattern at a bit rate of 5.3 Gbps. The signal is then sent with an adjusted input amplitude using a reference differential wiring board without a conductive layer. The 5.3 GHz radiated noise 36 generated from the wiring board 11 is detected with a pen-shaped, 110 mm long near-field probe 34 (manufactured by Electrometrics) and measured with a spectrum analyzer 33 (Keysight E4440A). The near-field probe 34 is placed 5 mm above the wiring board, and each point is scanned five times. The average value obtained by scanning all points at 1 mm intervals with the near-field probe 34 in the area where the ground layer is formed is taken as the radiated noise. The lower the radiated noise, the better the shielding of the radiated noise, indicating a wiring board with good shielding properties. The radiated noise was measured in an atmosphere with a temperature of 25°C and a relative humidity of 23 to 50% in the frequency range of 300 kHz to 20 GHz. The evaluation criteria are as follows, with the lower the noise, the better the evaluation. A: Less than 20dBμV B: 20dBμV or more, less than 25dBμV C:25dBμV or more (Evaluation 2) Transmission characteristics evaluation (eye pattern) The output waveform characteristics of the wiring board are evaluated using a system configured as shown in Figure 8. This system consists of a signal generator 41 (Keysight M8041A), an oscilloscope 42 (Agilent Technologies 92504A), and a pair of connection boards 35. The connection boards 35 have input and output terminals, and the wiring board 11 to be measured is connected between the pair of connection boards 35 in a floating state. Furthermore, the signal generator 41 is connected to one of the connection boards 35, and a PRBS23 pseudo-random signal with a bit rate of 5.3 Gbps is input. The amplitude of the input signal is 150 mV / side (differential 300 mV). An oscilloscope 42 is connected to the other connection board 35, and the opening amplitude of the signal eye pattern output from the connection board 35 is observed. The measurement was performed in an atmosphere with a temperature of 25°C and a relative humidity of 30 to 50%. The larger the opening amplitude, the better the evaluation. A: Aperture amplitude 110mV or more B: Opening amplitude 100mV or more, less than 110mV C: Opening amplitude less than 100mV Tables 1 and 2 show the evaluations 1 and 2 for the wiring boards in Examples 1 to 13.

[0120] [Table 1]

[0121] [Table 2]

[0122] As shown in Tables 1 and 2, the wiring boards of Examples 1 to 9 and 13 all had low levels of electromagnetic noise at 5.3 GHz, and all had very good aperture amplitudes, ranked B or higher. In particular, Examples 1 to 3 and 5 to 9, in which the aperture width R2 is larger than the spacing L3, can obtain better aperture amplitudes than Examples 4 and 13, in which the aperture width R2 is smaller than the spacing L3.

[0123] Examples 10 and 11, in which the opening width R2 is less than the line width L1, have low opening amplitudes. Figure 9 shows the wiring board of Example 10. As shown in Figure 9, in the wiring boards of Examples 10 and 11, compared to Examples 1 to 9, in which the opening width R2 is greater than the line width L1, signal wiring 131 and signal wiring 132 are not aligned in the area corresponding to the conductive layer opening in a planar view of the wiring board. Therefore, each signal line continues to be affected by the conductive layer, resulting in uneven impedance and impaired transmission performance. In Examples 11 and 12, because there is no ground line between the differential signal lines, the return current generated in the conductive layer affects other signal wirings due to electromagnetic coupling when passing over them, resulting in transmission loss in the other signal wiring and degrading transmission performance. For the same reason, the signal waveforms of the other signal wirings are disrupted, increasing the amount of radiated noise and ultimately reducing the noise suppression effect.

[0124] The present disclosure is not limited to the above-described embodiments, and many modifications of the embodiments are possible within the technical concept of the present disclosure. For example, at least two of the above-described embodiments and modifications may be combined. Furthermore, the effects described in the present embodiments are merely a list of the most preferable effects resulting from the embodiments of the present disclosure, and the effects of the embodiments of the present disclosure are not limited to those described in the present embodiments.

[0125] The disclosure of this specification includes the following items 1 to 20.

[0126] [Matter 1] A substrate; a wiring layer supported by the base material and including a plurality of wirings; a conductive layer supported by the substrate and having a plurality of openings; A wiring board comprising: the wiring layer includes a wiring layer having a first differential signal line configured with a pair of signal wirings consisting of a first signal wiring and a second signal wiring, a second differential signal line configured with a pair of signal wirings consisting of a third signal wiring and a fourth signal wiring, a first adjacent wiring adjacent to the first signal wiring, a second adjacent wiring adjacent to the second signal wiring and the third signal wiring, and a third adjacent wiring adjacent to the fourth signal wiring; a first intermediate region is provided between the first signal wiring and the first adjacent wiring, a second intermediate region is provided between the second signal wiring and the second adjacent wiring, a third intermediate region is provided between the third signal wiring and the second adjacent wiring, and a fourth intermediate region is provided between the fourth signal wiring and the third adjacent wiring; an outline of a first opening of the plurality of openings overlaps a first intermediate region, the first signal wiring, the second signal wiring, and the second intermediate region; a conductor portion of the conductive layer extending from the outline of the first opening overlaps at least one of the first adjacent wiring and the second adjacent wiring; an outline of a second opening of the plurality of openings overlaps a third intermediate region, the third signal wiring, the second signal wiring, and the fourth intermediate region, and a conductor portion of the conductive layer extending from the outline of the second opening overlaps at least one of the second adjacent wiring and the third adjacent wiring; A wiring board characterized by:

[0127] [Matter 2] a width of the first opening in a first direction in which the first signal wiring and the second signal wiring are aligned is larger than a width of the first differential signal line; a width of the second opening in a second direction in which the third signal wiring and the fourth signal wiring are aligned is larger than a width of the second differential signal line; Item 1. The wiring board according to item 1.

[0128] [Matter 3] a width of the first opening in the first direction is equal to or greater than a distance between the first adjacent wiring and the second adjacent wiring; a width of the second opening in the second direction that is equal to or greater than the distance between the second adjacent wiring and the third adjacent wiring; Item 1 or 2. The wiring board according to item 1 or 2.

[0129] [Matter 4] a width of the first opening in the first direction is smaller than a distance between an edge of the first adjacent wiring on an opposite side to the first signal wiring and an edge of the second adjacent wiring on an opposite side to the second signal wiring; a width of the second opening in the second direction is smaller than a distance between an edge of the second adjacent wiring on the opposite side to the third signal wiring and an edge of the third adjacent wiring on the opposite side to the fourth signal wiring; 4. The wiring board according to any one of items 1 to 3.

[0130] [Matter 5] a width of the first opening in a third direction perpendicular to the first direction is greater than a width of the first opening in the first direction; The width of the second opening in a fourth direction perpendicular to the second direction is larger than the width of the second opening in the second direction. 5. The wiring board according to any one of items 1 to 4.

[0131] [Matter 6] a distance between the first adjacent wiring and the first signal wiring and a distance between the second signal wiring and the second adjacent wiring are smaller than a width of the first differential signal line; a distance between the first adjacent wiring and the first signal wiring and a distance between the second adjacent wiring and the second signal wiring are smaller than a width of the second differential signal line; 6. The wiring board according to any one of items 1 to 5.

[0132] [Matter 7] a distance between the second signal wiring and the second adjacent wiring and a distance between the second adjacent wiring and the third signal wiring are smaller than a width of the second adjacent wiring; 7. The wiring board according to any one of items 1 to 6.

[0133] [Matter 8] a distance between the first signal wiring and the second signal wiring is smaller than a distance between the first adjacent wiring and the first signal wiring and a distance between the second adjacent wiring and the second signal wiring; a distance between the third signal wirings is smaller than a distance between the first adjacent wiring and the first signal wiring and a distance between the second adjacent wiring and the second signal wiring; 8. The wiring board according to any one of items 1 to 7.

[0134] [Matter 9] an outline of the first opening overlaps with at least one of the first adjacent wiring and the second adjacent wiring, and / or an outline of the second opening overlaps with at least one of the first adjacent wiring and the second adjacent wiring; 9. The wiring board according to any one of items 1 to 8.

[0135] [Matter 10] a width of the second adjacent wiring is smaller than a width of the first differential signal line and a width of the second differential signal line; 10. The wiring board according to any one of items 1 to 9.

[0136] [Matter 11] a distance between the second signal wiring and the third signal wiring is smaller than a distance between the first adjacent wiring and the second adjacent wiring and a distance between the second adjacent wiring and the third adjacent wiring; 11. The wiring board according to any one of items 1 to 10.

[0137] [Matter 12] The distance between the first opening and the second opening is smaller than the width of the second adjacent wiring. 12. The wiring board according to any one of items 1 to 11.

[0138] [Matter 13] an outline of an adjacent opening adjacent to the first opening and the second opening among the plurality of openings overlaps at least one of the second signal wiring and the third signal wiring and the second adjacent wiring; 13. The wiring board according to any one of items 1 to 12.

[0139] [Matter 14] a width of the adjacent opening in a direction in which the second signal wiring and the third signal wiring are arranged side by side is equal to or smaller than a distance between the first adjacent wiring and the third adjacent wiring; Item 14. The wiring board according to item 13.

[0140] [Matter 15] an outline of a third opening among the plurality of openings overlaps the first signal wiring and the second signal wiring, and a width of the third opening in the first direction is larger than a width of the first differential signal line; an outline of a fourth opening among the plurality of openings overlaps the third signal wiring and the fourth signal wiring, and a width of the fourth opening in the second direction is larger than a width of the second differential signal line; The distance between the first opening and the third opening and the distance between the second opening and the fourth opening are 10 mm or less. 6. The wiring board according to any one of items 2 to 5.

[0141] [Matter 16] A wiring board according to any one of items 1 to 15, a first electronic unit; a second electronic unit, The device in which the wiring board connects the first electronic unit and the second electronic unit.

[0142] [Matter 17] the first electronic unit includes an image sensor; Item 16.

[0143] [Matter 18] a housing for storing the first electronic unit and the second electronic unit; The wiring board is bent within the housing. 18. Devices according to item 16 or 17.

[0144] [Matter 19] The transmission speed of the first differential signal line and the second differential signal line is 5 Gbps or more. 19. The device according to any one of items 16 to 18.

[0145] [Matter 20] a housing for storing the first electronic unit and the second electronic unit; a wireless communication unit provided in the housing, 20. The device according to any one of items 16 to 19.

[0146] The disclosure of this specification includes not only what is explicitly described in this specification, but also all matters that can be understood from this specification and the drawings attached hereto. The disclosure of this specification also includes the complement of the individual concepts described in this specification. In other words, if this specification states, for example, that "A is B," it can be said that this specification discloses that "A is not B," even if it omits the statement that "A is not B." This is because when "A is B," it is assumed that the case where "A is not B" is taken into consideration. [Explanation of symbols]

[0147] 11 Flexible wiring board 12 Base material 13 Wiring layer 20 Conductive layer 201 Opening 131 Positive phase signal wiring 132 Negative phase signal wiring 133 Differential Signal Line 134 Adjacent Wiring

Claims

1. A substrate; a wiring layer supported by the base material and including a plurality of wirings; a conductive layer supported by the substrate and having a plurality of openings; A wiring board comprising: the wiring layer includes a wiring layer having a first differential signal line configured with a pair of signal wirings consisting of a first signal wiring and a second signal wiring, a second differential signal line configured with a pair of signal wirings consisting of a third signal wiring and a fourth signal wiring, a first adjacent wiring adjacent to the first signal wiring, a second adjacent wiring adjacent to the second signal wiring and the third signal wiring, and a third adjacent wiring adjacent to the fourth signal wiring; a first intermediate region is provided between the first signal wiring and the first adjacent wiring, a second intermediate region is provided between the second signal wiring and the second adjacent wiring, a third intermediate region is provided between the third signal wiring and the second adjacent wiring, and a fourth intermediate region is provided between the fourth signal wiring and the third adjacent wiring; an outline of a first opening of the plurality of openings overlaps a first intermediate region, the first signal wiring, the second signal wiring, and the second intermediate region; a conductor portion of the conductive layer extending from the outline of the first opening overlaps at least one of the first adjacent wiring and the second adjacent wiring; an outline of a second opening of the plurality of openings overlaps a third intermediate region, the third signal wiring, the second signal wiring, and the fourth intermediate region, and a conductor portion of the conductive layer extending from the outline of the second opening overlaps at least one of the second adjacent wiring and the third adjacent wiring; A wiring board characterized by:

2. a width of the first opening in a first direction in which the first signal wiring and the second signal wiring are aligned is larger than a width of the first differential signal line; a width of the second opening in a second direction in which the third signal wiring and the fourth signal wiring are aligned is larger than a width of the second differential signal line; The wiring board according to claim 1 .

3. a width of the first opening in the first direction is equal to or greater than a distance between the first adjacent wiring and the second adjacent wiring; a width of the second opening in the second direction is equal to or greater than a distance between the second adjacent wiring and the third adjacent wiring; The wiring board according to claim 2 .

4. a width of the first opening in the first direction is smaller than a distance between an edge of the first adjacent wiring on an opposite side to the first signal wiring and an edge of the second adjacent wiring on an opposite side to the second signal wiring; a width of the second opening in the second direction is smaller than a distance between an edge of the second adjacent wiring on the opposite side to the third signal wiring and an edge of the third adjacent wiring on the opposite side to the fourth signal wiring; The wiring board according to claim 3 .

5. a width of the first opening in a third direction perpendicular to the first direction is greater than a width of the first opening in the first direction; a width of the second opening in a fourth direction perpendicular to the second direction is greater than a width of the second opening in the second direction; The wiring board according to claim 2 .

6. a distance between the first adjacent wiring and the first signal wiring and a distance between the second signal wiring and the second adjacent wiring are smaller than a width of the first differential signal line; a distance between the first adjacent wiring and the first signal wiring and a distance between the second adjacent wiring and the second signal wiring are smaller than a width of the second differential signal line; The wiring board according to claim 1 .

7. a distance between the second signal wiring and the second adjacent wiring and a distance between the second adjacent wiring and the third signal wiring are smaller than a width of the second adjacent wiring; The wiring board according to claim 1 .

8. a distance between the first signal wiring and the second signal wiring is smaller than a distance between the first adjacent wiring and the first signal wiring and a distance between the second adjacent wiring and the second signal wiring; a distance between the third signal wirings is smaller than a distance between the first adjacent wiring and the first signal wiring and a distance between the second adjacent wiring and the second signal wiring; The wiring board according to claim 1 .

9. an outline of the first opening overlaps with at least one of the first adjacent wiring and the second adjacent wiring, and / or an outline of the second opening overlaps with at least one of the first adjacent wiring and the second adjacent wiring; The wiring board according to claim 1 .

10. a width of the second adjacent wiring is smaller than a width of the first differential signal line and a width of the second differential signal line; The wiring board according to claim 1 .

11. a distance between the second signal wiring and the third signal wiring is smaller than a distance between the first adjacent wiring and the second adjacent wiring and a distance between the second adjacent wiring and the third adjacent wiring; The wiring board according to claim 1 .

12. the distance between the first opening and the second opening is smaller than the width of the second adjacent wiring; The wiring board according to claim 1 .

13. an outline of an adjacent opening adjacent to the first opening and the second opening among the plurality of openings overlaps at least one of the second signal wiring and the third signal wiring and the second adjacent wiring; The wiring board according to claim 1 .

14. a width of the adjacent opening in a direction in which the second signal wiring and the third signal wiring are arranged side by side is equal to or smaller than a distance between the first adjacent wiring and the third adjacent wiring; The wiring board according to claim 13 .

15. an outline of a third opening among the plurality of openings overlaps the first signal wiring and the second signal wiring, and a width of the third opening in the first direction is larger than a width of the first differential signal line; an outline of a fourth opening among the plurality of openings overlaps the third signal wiring and the fourth signal wiring, and a width of the fourth opening in the second direction is larger than a width of the second differential signal line; a distance between the first opening and the third opening and a distance between the second opening and the fourth opening are 10 mm or less; The wiring board according to claim 2 .

16. The wiring board according to claim 1; a first electronic unit; a second electronic unit, The device includes a wiring board that connects the first electronic unit and the second electronic unit.

17. the first electronic unit includes an image sensor; 17. The device of claim 16.

18. a housing for storing the first electronic unit and the second electronic unit; The wiring board is bent within the housing.

17. The device of claim 16.

19. the transmission speed of the first differential signal line and the second differential signal line is 5 Gbps or more; 17. The device of claim 16.

20. a housing for storing the first electronic unit and the second electronic unit; a wireless communication unit provided in the housing, 17. The device of claim 16.

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