JP2011114296A - Flexible board and manufacturing method of the flexible board - Google Patents

Abstract

The present invention provides a flexible substrate and a method for manufacturing the flexible substrate capable of improving signal transmission characteristics.
A strip-shaped first conductor layer 110 in which a plurality of conductors 111 inclined in the longitudinal direction are arranged in parallel and a side surface portion 112 crossing the plurality of conductors is formed, and has the same width as the first conductor layer. A strip-shaped second conductor layer 120 having a plurality of conductors 121 inclined in the longitudinal direction and arranged in parallel and having a side surface portion 122 that crosses the plurality of conductors, and the first and second conductor layers overlap each other. The first conductor layer in a state where the conductors of the first and second conductor layers intersect with each other through the insulating layer on the longitudinal center line CC ′ of the combined belt-like assembly. A first conductor 111 exposed on the side surface of the second conductor layer, and a conductor connecting portion 130 that is exposed on the side surface of the second conductor layer and connects the second conductor 121 paired with the first conductor.
[Selection] Figure 1

Description

  The present invention relates to a flexible substrate and a method for manufacturing a flexible substrate.

  As a countermeasure against signal noise of a flexible substrate (FPC), a flexible substrate having a shielding property improved by a twisted pair structure is known.

  For example, in Patent Documents 1 and 2 below, in a flexible substrate having two conductor layers, a twisted pair structure is configured by alternately connecting a circuit of one layer and a circuit of another layer by through holes and intermediate conductors. is doing. Further, in Patent Documents 3 and 4 below, a twisted pair structure is configured by winding a flexible substrate having a conductor layer or bending and joining.

JP-A-4-274405 JP 2003-13518 A JP-A-10-26732 JP 2003-77129 A

  However, in the prior arts of Patent Documents 1 and 2 described above, the width and thickness of the conductor greatly change in order to secure a connection margin at the conductor connection portion that connects the circuits with each other through a through hole or an intermediate conductor. For this reason, the impedance mismatch between the conductor connection portion and the other portion is increased, the signal quality is lowered during high-speed signal transmission, and the effect of suppressing EMI (electromagnetic interference) is also lowered. On the other hand, in the prior arts of Patent Documents 3 and 4, since the substrate is bent at an acute angle at the bent portion, the conductor is likely to be damaged, causing trouble in signal transmission. In addition, the winding portion and the bent portion are harder than the other portions, and it is difficult to bend the substrate in the longitudinal direction.

  Therefore, the present invention is intended to provide a flexible substrate and a method for manufacturing the flexible substrate that can improve the signal transmission characteristics.

  According to an aspect of the present invention, a plurality of conductors inclined in the longitudinal direction are arranged in parallel, and a strip-shaped first conductor layer having a side surface that crosses the plurality of conductors is the same as the first conductor layer. A strip-shaped second conductor layer having a width, a plurality of conductors inclined in the longitudinal direction arranged in parallel, and formed with side portions crossing the plurality of conductors, and the first and second conductor layers are overlapped In the state where the conductors of the first and second conductor layers intersect with each other through the insulating layer on the center line in the longitudinal direction of the strip-shaped assembly, the first conductor layer is exposed to the side surface portion. A flexible substrate is provided that includes a first conductor and a conductor connecting portion that is exposed on a side surface portion of the second conductor layer and connects the second conductor that forms a pair with the first conductor.

  According to such a configuration, the conductors exposed on the side surface portions are connected by the conductor connection portion, and therefore, the conductor connection portion and other portions can be formed to have the same width and thickness of the conductor. Further, since the substrate is not wound or bent, damage to the conductor can be prevented. Thereby, the transmission characteristic of the signal using a flexible substrate can be improved.

  The conductor connection portion may be a metal film that connects the first conductor and the second conductor.

  The first and second conductors may be exposed on the upper surface or the lower surface of the first and second conductor layers together with the side surfaces of the first and second conductor layers.

  The first and second conductors may be exposed on a top surface or a bottom surface of the first and second conductor layers with a predetermined width that is set according to a condition for forming the conductor connection portion.

  The first and second conductors may be opposed to each other through an insulating layer having a predetermined thickness set according to the formation conditions of the conductor connection portion.

  The insulating layer interposed between the first and second conductor layers may be formed thicker than the other portions at the portion where the conductors of the first and second conductor layers intersect with each other through the insulating layer. .

  The insulating layer interposed between the first and second conductor layers may be formed of a material different from the other parts at the portion where the conductors of the first and second conductor layers intersect via the insulating layer. Good.

  In the longitudinal direction of the assembly, the periphery of the portion where the first and second conductors are exposed may be formed thinner than the other portions.

  The first conductor layer may be composed of a conductor of a first flexible substrate, and the second conductor layer may be composed of a conductor of a second flexible substrate bonded to the first flexible substrate. Good.

  The first and second conductor layers may be configured to include a first layer conductor and a second layer conductor of the flexible substrate.

  According to another aspect of the present invention, a strip-shaped first conductor layer in which a plurality of conductors inclined in the longitudinal direction are arranged in parallel and a side surface portion that crosses the plurality of conductors is formed, and the first conductor Providing a strip-shaped second conductor layer having a plurality of conductors having the same width as the layer and inclined in the longitudinal direction and formed with side portions crossing the plurality of conductors; The first and second conductor layers are overlapped so that the conductors of the first and second conductor layers intersect via the insulating layer on the longitudinal center line of the assembly in which the two conductor layers are overlapped. Connecting the first conductor exposed at the side surface of the first conductor layer and the second conductor exposed at the side surface of the second conductor layer and paired with the first conductor; A method for manufacturing a flexible substrate is provided.

  The step of connecting the first and second conductors forms a pair with the plurality of first conductors exposed on the side surface portion of the first conductor layer and the plurality of first conductors. You may include the step which forms simultaneously the metal film which connects the some 2nd conductor exposed to the side part for every one side.

  As described above, according to the present invention, it is possible to provide a flexible substrate and a method for manufacturing the flexible substrate capable of improving signal transmission characteristics.

It is a perspective view which shows the structure of the twist board | substrate which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the twist board | substrate shown in FIG. It is a schematic diagram which shows an example of the manufacturing method of the twist board | substrate shown in FIG. It is a schematic diagram which shows an example of the manufacturing method of the twist board | substrate shown in FIG. It is a figure which shows the structure of the modification a of a twist board | substrate. It is a figure which shows the structure of the modification b of a twist board | substrate. It is a figure which shows the structure of the modification c of a twist board | substrate. It is a figure which shows the structure of the twist board | substrate which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the twist board | substrate shown in FIG.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<First Embodiment>
First, a flexible substrate 100 having a twisted pair structure (hereinafter also referred to as a twisted substrate 100) according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the configuration of the twisted substrate 100, and FIG. 2 is a diagram showing the configuration of the twisted substrate 100 shown in FIG. 3A and 3B are schematic views showing a method for manufacturing the twisted substrate 100 shown in FIG.

(Configuration of twisted substrate 100)
As shown in FIG. 1, the twisted substrate 100 according to the first embodiment is formed by combining first and second single-layer flexible substrates 110 and 120. The twisted substrate 100 has a twisted pair structure including a conductor 111 (first conductor layer) formed on the first flexible substrate 110 and a conductor 121 (second conductor layer) formed on the second flexible substrate 120. Have. In the following description, the first and second flexible substrates 110 and 120 are also referred to as first and second substrates 110 and 120 for convenience of explanation.

  The first and second substrates 110 and 120 are strip-shaped substrates having the same width. A plurality of conductors 111 and 121 inclined in the longitudinal direction are arranged in parallel on the first and second substrates 110 and 120. Side surfaces 112 and 122 (first and second conductors) crossing the plurality of conductors 111 and 121 are formed on both sides along the longitudinal direction of the first and second substrates 110 and 120. A first conductor exposed portion 113 made of a plurality of exposed conductors 111 is formed on the side surface portion 112 of the first substrate 110, and a plurality of exposed conductors are formed on the side surface portion 122 of the second substrate 120. A second conductor exposed portion 123 made of 121 is formed.

  The twisted substrate 100 includes a first substrate 110 and a second substrate 120 bonded to the first substrate 110. The first and second substrates 110 and 120 are formed on the center line CC ′ in the longitudinal direction of the twisted substrate 100, and the conductors 111 and 121 of the first and second substrates 110 and 120 are insulating layers (covers described later). Material 116, 126 and adhesive layer 135 (not shown in FIG. 1). Here, the crossing angle Θ of the conductors 111 and 121 is appropriately designed according to the specifications of the twisted substrate 100. Hereinafter, a portion where the conductors 111 and 121 of the first and second substrates 110 and 120 intersect with each other via the insulating layer other than the side surface portions 112 and 122 is also referred to as a conductor intersection portion 131.

  In addition, the first and second substrates 110 and 120 are formed of the conductor 121 of the second conductor exposed portion 123 in which the conductor 111 of the first conductor exposed portion 113 is paired with the conductor 111 of the first conductor exposed portion 113. It is arranged to be located above or below. Here, the pair of conductors means conductors connected to each other via a conductor connecting portion 130 described later in a state where the first and second substrates 110 and 120 are bonded.

  The twist substrate 100 is formed by connecting the first conductor exposed portion 113 and the second conductor exposed portion 123. Between the first conductor exposed portion 113 and the second conductor exposed portion 123, a pair of conductors are connected via a conductor connecting portion 130 made of a metal film or the like. As a result, the plurality of conductors 111 and 121 of the first and second substrates 110 and 120 are connected by the conductor connecting portion 130, whereby the twisted substrate 100 having a twisted pair structure is formed.

  Here, in the twisted substrate 100 shown in FIG. 1, the first and second substrates 110 and 120 are symmetrical with respect to the center line CC ′ in the longitudinal direction so that the conductors 111 and 121 are line symmetric. And the 2nd board | substrates 110 and 120 are bonded. However, the conductors 111 and 121 of the first and second substrates 110 and 120 do not necessarily have line symmetry.

  Further, in the twisted substrate 100 shown in FIG. 1, one conductor intersecting portion 131 is formed on the same cross section orthogonal to the longitudinal direction of the twisted substrate 100. Hereinafter, a case where one conductor intersection 131 is formed on the twisted substrate 100 will be described. However, two or more conductor intersections 131 may be formed on the same cross section.

  FIG. 2 shows a plan view (2a) of the twisted substrate 100, a cross-sectional view (2b) along the line 2b-2b 'on the plan view (2a), and a cross-sectional view (2c) along the line 2c-2c'. )It is shown.

  As shown in FIG. 2, the first and second substrates 110 and 120 include base materials 115 and 125, conductors 111 and 121 arranged on the base materials 115 and 125, base materials 115 and 125, and a conductor 111. , 121 covering the cover material 116, 126. The cover materials 116 and 126 of the first and second substrates 110 and 120 are bonded via an adhesive layer 135.

  Here, the base materials 115 and 125 and the cover materials 116 and 126 are made of a polyimide film or the like, the conductors 111 and 121 are made of electrolytic copper foil, rolled copper foil, or the like, and the adhesive layer 135 is a thermosetting adhesive or the like. Consists of. The base materials 115 and 125, the cover materials 116 and 126, and the adhesive layer 135 are formed with substantially the same width.

  In the cross-sectional view (2b), a conductor intersecting portion 131 composed of the conductors 111 and 121 of the first and second substrates 110 and 120 is shown. In the first and second substrates 110 and 120, the conductors 111 and 121 are located in the center portions on the base materials 115 and 125. The conductors 111 and 121 of the first and second substrates 110 and 120 are opposed to each other with the cover materials 116 and 126 and the adhesive layer 135 interposed therebetween.

  In the cross-sectional view (2c), a conductor connecting portion 130 for connecting the conductors 111 and 121 of the first and second substrates 110 and 120 is shown. In the first and second substrates 110 and 121, the conductors 111 and 121 are located on the side surface portions on both sides of the bases 115 and 125, respectively. The conductors 111 and 121 of the first and second substrates 110 and 120 are opposed to each other with the cover materials 116 and 126 and the adhesive layer 135 interposed therebetween. In addition, first and second conductor exposed portions 113 and 123 (side surfaces of the conductors 111 and 121 covered by the conductor connecting portion 130) are formed on the side portions of the first and second substrates 110 and 120. Has been.

  The first and second conductor exposed portions 113 and 123 are connected by a conductor connecting portion 130. The conductor connection portion 130 is formed so as to cover the side surfaces of the first and second conductor exposed portions 113 and 123, the cover materials 116 and 126, and the adhesive layer 135. For this reason, in the conductor connection part 130, the width of the twisted substrate 100 is increased by the thickness of the conductor connection part 130.

  The conductor connection portion 130 is preferably formed as a metal film by plating or the like. However, the conductor connection part 130 may be formed as a conductive adhesive or a sheet material. Further, an insulating layer may be formed outside the conductor connection portion 130 so that the conductor connection portions 130 adjacent in the longitudinal direction are not electrically connected to each other.

  According to the twisted substrate 100 according to the first embodiment, the conductors 111 and 121 exposed at the side surface portions 112 and 122 are connected to each other by the conductor connecting portion 130. The thickness can be formed to the same level. In addition, since the substrates 110 and 120 are not wound or bent, the conductors 111 and 121 can be prevented from being damaged. Thereby, the transmission characteristic of the signal using the flexible substrate 100 can be improved.

(Method for manufacturing twisted substrate 100)
Next, a manufacturing method of the twisted substrate 100 according to the first embodiment will be described with reference to FIGS. 3A and 3B. 3A and 3B are schematic views showing an example of a method for manufacturing the twisted substrate 100. FIG.

  First, as shown in the state (3a), first and second substrates 110 and 120 made of a single-layer flexible substrate are prepared. The first and second substrates 110 and 120 are prepared as band-shaped or plate-shaped substrates in which a plurality of conductors 111 and 121 are arranged in parallel along the longitudinal direction.

  Secondly, as shown in the state (3b), the first and second substrates 110 and 120 are bonded together through the adhesive layer 135. The first and second substrates 110, 120 are arranged on the center line CC ′ in the longitudinal direction of the twisted substrate 100, and the conductors 111, 121 of the first and second substrates 110, 120 are insulating layers (cover material 116 126, 126 and the adhesive layer 135) so as to intersect at a predetermined angle Θ.

  Thirdly, as shown in the state (3c), a strip-shaped substrate to be the twisted substrate 100 is cut out from the first and second substrates 110 and 120. The first and second substrates 110 and 120 are cut out so that side surfaces 112 and 122 that cross the plurality of conductors 111 and 121 are formed. The first and second conductor exposed portions 113 and 123 are formed on the side surface portions 112 and 122 of the first and second substrates 110 and 120, respectively.

  Fourth, as shown in the state (3d), the side surfaces 112 and 122 of the first and second substrates 110 and 120 are plated on each side. In the plating process, for example, the side surfaces 112 and 122 of the substrates 110 and 120 are immersed in a plating agent. Here, in the first and second substrates 110 and 120, the plurality of conductors 111 and 121 of the first and second conductor exposed portions 113 and 123, in particular, the conductors 111 and 121 on all one side are subjected to plating simultaneously. The

  As shown in the state (3e) by plating, the conductor exposed portions 113 and 123 of the side surfaces 112 and 122 of the first and second substrates 110 and 120 are covered with a metal film between the conductors 111 and 121. A conductor connecting portion 130 is formed. Since the insulating layers (base materials 115 and 125, cover materials 116 and 126, and adhesive layer 135) are exposed at portions other than the conductor exposed portions 113 and 123, the conductor connecting portion 130 is not formed.

  Thereby, the twisted substrate 100 including the first and second substrates 110 and 120 is manufactured. According to the manufacturing method, the twisted substrate 100 can be manufactured easily and inexpensively using the two single-layer flexible substrates 110 and 120. In particular, in the above manufacturing method, the conductor connection portion 130 can be easily formed by plating.

  In the above manufacturing method, the cutting process is performed after the bonding process of the substrates 110 and 120, but the bonding process may be performed after the cutting process of the substrates 110 and 120. In the manufacturing method, the first and second substrates 110 and 120 are prepared as a substrate in which a plurality of conductors 111 and 121 are arranged in parallel along the longitudinal direction. However, the first and second substrates 110 and 120 may be prepared as substrates on which a plurality of conductors 111 and 121 inclined in the longitudinal direction are arranged in parallel. Moreover, in the said manufacturing method, although the conductor connection part 130 consists of metal films, the conductive connection part 130 may be a conductive adhesive material or a sheet material.

<Modification of Twist Substrate 100>
Next, a modification of the twisted substrate 100 according to the first embodiment will be described with reference to FIGS. 4 to 6 are diagrams showing configurations of modified examples a to c of the twisted substrate.

(Modification a)
Modification a shown in FIG. 4 improves the peripheral configuration of the conductor connection portion in the twisted substrate 100 according to the first embodiment. FIG. 4 shows a plan view (4a) of a twisted substrate 100a according to Modification A and a cross-sectional view (4b) along the line 4b-4b ′ on the plan view (4a). The cross-sectional view 4b shows the peripheral configuration of the conductor connecting portion 130a.

  In the twisted substrate 100 shown in FIG. 2, the base materials 115 and 125, the cover materials 116 and 126, and the adhesive layer 135 are formed with substantially the same width. On the other hand, in the modified example a, the cover materials 116 a and 126 a and the adhesive layer 135 a are formed with a shorter width than the cover materials 115 and 125. As a result, a substantially rectangular space is formed on the sides of the cover materials 116a and 126a and the adhesive layer 135a, and at least a part of the upper surface or the lower surface of the conductors 111 and 121 is exposed with the exposed width b along with the side surfaces of the conductors 111 and 121. Is done.

  Therefore, by appropriately setting the exposure width b, it is possible to enlarge the connection surface between the conductor connection portion 130a and the conductors 111 and 121 as compared to the twisted substrate 100 shown in FIG. Further, the width of the twisted substrate 100a does not have to be increased by the thickness of the conductor connection portion 130a around the conductor connection portion 130a. Here, the exposed width b of the upper surface or the lower surface of the conductors 111 and 121 is appropriately set according to the formation conditions of the conductor connection portion 130a.

  Further, in the twisted substrate 100a, the thicknesses of the cover materials 116a and 126a and the adhesive layer 135a may be adjusted. Thereby, the height h of the space formed in the side part of the cover materials 116a and 126a and the adhesive layer 135a is adjusted. Therefore, the height of the conductor connection part 130a can be adjusted. Here, the thicknesses of the cover members 116a and 126a and the adhesive layer 135a are also appropriately set according to the formation conditions of the conductor connection portion 130a.

  According to the twisted substrate 100a according to the modified example a, the connectivity between the conductors 111 and 121 by the conductor connecting portion 130a can be improved and the signal transmission characteristics can be improved by improving the peripheral configuration of the conductor connecting portion.

(Modification b)
The modification b shown in FIG. 5 improves the peripheral configuration of the conductor intersection in the twisted substrate 100 according to the first embodiment. FIG. 5 includes a plan view (5a) of a twisted substrate 100b according to the modification b, and cross-sectional views (5b) and (5c) along lines 5b-5b ′ and 5c-5c ′ on the plan view (5a). It is shown. In the cross-sectional views (5b) and (5c), the conductor intersecting portion 131b of the first and second substrates 110 and 120 is shown. Cross-sectional views (5b) and (5c) show two configuration examples according to the modification b.

  In the twisted substrate 100 shown in FIG. 2, the cover materials 116 and 126 are formed of a uniform material with a constant thickness. On the other hand, in the modified example b, the cover members 116b and 126b are formed with different thicknesses and / or different materials in the conductor intersecting portion 131b and other portions.

  Specifically, in the configuration example 1 shown in the cross-sectional view (5b), the cover members 116b and 126b are formed in a lamp shape so as to be thicker at the conductor intersection portion 131b than the other portions. In the cross-sectional view (5b), the surfaces of the base materials 115b and 125b are formed as flat surfaces, but they may be formed as lamp surfaces as with the cover materials 116b and 126b. Further, in the configuration example 2 shown in the cross-sectional view (5c), the cover materials 116b 'and 126b' of the conductor intersecting portion 131b cause signal noise between the conductors 111 and 121 of the first substrate and the second substrates 110 and 120. It is formed of cover materials 117 and 127 made of a material that can suppress generation.

  According to the twisted substrate 100b according to the modified example b, signal noise generated between the conductors 111 and 121 of the first substrate and the second substrates 110b and 120b is suppressed by improving the peripheral configuration of the conductor intersection, The transmission characteristics can be improved. In addition, by combining the configuration example 1 and the configuration example 2, the cover materials 115b and 125b may be formed of different materials with different thicknesses at the conductor intersecting portion 131b and other portions.

(Modification c)
Modification c shown in FIG. 6 improves the peripheral configuration of the conductor connecting portion in the twist substrate 100 according to the first embodiment. FIG. 6 shows a plan view (6a) of a twisted substrate 100c according to modification c, and a longitudinal sectional view (6b) along line 6b-6b ′ on the plan view (6a). FIG. 6 b shows a peripheral configuration of the conductor connecting portion 130.

  In the twisted substrate 100 shown in FIG. 2, the base materials 115 and 125 are formed with a constant thickness. On the other hand, in the modified example c, the base materials 115c and 125c are formed with different thicknesses in the periphery of the conductor connecting portion 130 and in other portions. Specifically, as shown in the longitudinal sectional view (6 b), the base materials 115 c and 125 c are formed in a lamp shape so as to be thinner around the conductor exposed portion 130 than other portions. Here, the lamp-shaped base materials 115c and 125c are formed by cutting using a roller or the like, for example, for the region RA shown in the plan view (6a). The region RA is repeatedly formed along the longitudinal direction of the twisted substrate 100c.

  In the vicinity of the conductor connecting portion 130, the formation of the conductor connecting portion 130 increases the rigidity, and the flexibility of the twisted substrate 100 is likely to be lowered. When the twisted substrate 100 is bent in the longitudinal direction, the bendability becomes uneven at the periphery of the conductor exposed portion 130 and other portions, and stress concentration may occur at the boundary portion between the two. However, the increase in rigidity around the conductor connection portion 130 is suppressed by reducing the thickness of the base materials 115c and 125c.

  According to the twist substrate 100c according to the modified example c, the occurrence of stress concentration during the bending of the twist substrate 100c is suppressed by improving the peripheral configuration of the conductor exposed portion. Since the conductors 111 and 121 are prevented from being damaged, it is difficult for signal transmission to occur, and signal transmission characteristics can be improved.

<Second Embodiment>
Next, a flexible substrate 200 having a twisted pair structure according to a second embodiment of the present invention (hereinafter also referred to as a twisted substrate 200) will be described with reference to FIGS. In addition, the description which overlaps with 1st Embodiment is abbreviate | omitted. FIG. 7 is a perspective view showing the configuration of the twist substrate 200, and FIG. 8 is a diagram showing the configuration of the twist substrate 200 shown in FIG.

(Configuration of twisted substrate 200)
As shown in FIG. 7, the twisted substrate 200 according to the second embodiment is composed of a two-layer flexible substrate. The twisted substrate 200 has a twisted pair structure including first and second conductor layers 210 and 220 formed on a two-layer flexible substrate. Hereinafter, for convenience of explanation, the two-layer flexible substrate is also referred to as a two-layer substrate.

  In the first and second conductor layers 210 and 220, a plurality of conductors 211 and 221 are arranged in parallel and inclined in the longitudinal direction. The first and second conductor layers 210 and 220 are formed with side portions 212 and 222 that cross the plurality of conductors 211 and 221 (first and second conductors) on both sides along the longitudinal direction. The first and second conductor exposed portions 213 and 223 including the exposed plurality of conductors 211 and 221 are formed on the side surface portions 212 and 222 of the first and second conductor layers 210 and 220, respectively. Yes.

  The twisted substrate 200 is configured by a two-layer substrate on which first and second conductor layers 210 and 220 are formed. The first and second conductor layers 210 and 220 are conductors 211 and 221 of the first and second conductor layers 210 and 220 on the center line CC ′ in the longitudinal direction of the two-layer substrate. Base member 235 (not shown in FIG. 7), the conductor crossing portion 231 is formed at a predetermined angle Θ.

  Further, the first and second conductor layers 210 and 220 include the conductor 221 of the second conductor exposed portion 223 in which the conductor 211 of the first conductor exposed portion 213 is paired with the conductor 211 of the first conductor exposed portion 213. It is formed to be located above or below.

  The twist substrate 200 is formed by connecting the first conductor exposed portion 213 and the second conductor exposed portion 223. Between the first conductor exposed portion 213 and the second conductor exposed portion 223, the paired conductors 211 and 221 are connected via a conductor connecting portion 230 made of a metal film or the like. Accordingly, the plurality of conductors 211 and 221 of the first and second conductor layers 210 and 220 are connected by the conductor connection portion 230, whereby the twist substrate 200 having a twisted pair structure is formed.

  FIG. 8 includes a plan view (8a) of the twisted substrate 200, a cross-sectional view (8b) along the line 8b-8b ′ on the plan view (8a), and a cross-sectional view along the line 8c-8c ′ (8c). )It is shown.

  As shown in FIG. 8, the two-layer substrate covers the base material 235, the conductors 211 and 221 arranged on both surfaces of the base material 235, and the base material 235 and the conductors 211 and 221 on both surfaces of the base material 235. It consists of cover materials 215 and 225.

  In the cross-sectional view (8b), a conductor intersection 231 composed of the conductors 211 and 221 of the first and second conductor layers 210 and 220 is shown. In the first and second conductor layers 210 and 220, the conductors 211 and 221 are located at the center of both surfaces on the base material 235. The conductors 211 and 221 of the first and second conductor layers 210 and 220 are opposed to each other with the base material 235 interposed therebetween.

  In the cross-sectional view (8c), a conductor connecting portion 230 that connects the conductors 211 and 221 of the first and second conductor layers 210 and 220 is shown. In the first and second conductor layers 210 and 220, the conductors 211 and 221 are located on the side surface portions 212 and 222 on both sides of the base material 235. The conductors 211 and 221 of the first and second conductor layers 210 and 220 are opposed to each other with the base material 235 interposed therebetween. Further, the side surface portions 212 and 222 of the first and second conductor layers 210 and 220 are exposed to the first and second conductor exposed portions 213 and 223 (the conductors 211 and 221 covered by the conductor connecting portion 230). Side) is formed.

  The first and second conductor exposed portions 213 and 223 are connected by a conductor connecting portion 230. The conductor connecting portion 230 is formed so as to cover the first and second conductor exposed portions 213 and 223 and the side surfaces of the base material 235. The conductor connection portion 230 is preferably formed as a metal film by plating or the like.

  According to the twisted substrate 200 according to the second embodiment, the conductors 211 and 221 exposed on the side surface portions 212 and 222 are connected by the conductor connecting portion 230, so that the conductors 211 and 221 are connected to the conductor connecting portion 230 and other portions. Can be formed to have the same width and thickness. Further, since the conductor layers 210 and 220 are not wound or bent, the conductors 211 and 221 can be prevented from being damaged. Thereby, the transmission characteristic of the signal using the flexible substrate 200 can be improved.

(Method of manufacturing twisted substrate 200)
Next, a method for manufacturing the twisted substrate 200 according to the second embodiment will be described.

  First, a two-layer flexible substrate (two-layer substrate) on which the first and second conductor layers 210 and 220 are formed is prepared. In the two-layer substrate, the first and second conductor layers 210 and 220 are arranged on the longitudinal center line CC ′ of the substrates 210 and 220, and the conductors 211 and 220 of the first and second conductor layers 210 and 220, respectively. 221 is formed to intersect at a predetermined angle Θ through the insulating layer 235. In the two-layer substrate, first and second conductor exposed portions 213 and 223 are respectively formed on the side surface portions 212 and 222 of the first and second conductor layers 210 and 220.

  Second, the side surfaces 212 and 222 of the first and second conductor layers 210 and 220 are plated on each side. In the plating process, for example, the side surfaces 212 and 222 of the conductor layers 210 and 220 are immersed in a plating agent. Here, in the first and second conductor layers 210 and 220, the plurality of conductors 211 and 221 of the first and second conductor exposed portions 213 and 223, in particular, all the conductors 211 and 221 on one side are simultaneously plated. Applied. Of the side surface portions 212 and 222 of the first and second conductor layers 210 and 220, a conductor connection portion 230 made of a metal film is formed between the conductors 211 and 221 by plating. The In addition, since the insulating layers (cover materials 215 and 225, base material 235) are exposed at portions other than the conductor exposed portions 213 and 223, the conductor connecting portion 230 is not formed.

  As a result, the twisted substrate 200 including the first and second conductor layers 210 and 220 is manufactured. According to the manufacturing method described above, the twisted substrate 200 can be manufactured easily and inexpensively using one two-layer flexible substrate. In particular, in the above manufacturing method, the conductor connecting portion 230 can be easily formed by plating.

<Summary>
As described above, according to the twisted substrates 100, 100a to 100c, and 200 (flexible substrate) according to the embodiment of the present invention, the conductors 111, 121, 211, and 221 exposed on the side surfaces 112, 122, 212, and 222 are used. Since the conductors are connected by the conductor connecting portions 130, 130a, and 230, the conductors 111, 121, 211, and 221 can be formed to have the same width and thickness at the conductor connecting portions 130, 130a, and 230 and other portions. . In addition, since the substrates 110, 120, 110a to 110c, 120a to 120c or the conductor layers 210 and 220 are not wound or bent, the conductors 111, 121, 211, and 221 can be prevented from being damaged. Thereby, the transmission characteristic of the signal using the twist board | substrate 100,100a-100c, 200 can be improved.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above description, the case where one conductor crossing portion 131, 131b, 231 is formed on the same cross section orthogonal to the longitudinal direction of the twist substrates 100, 100a to 100c, 200 has been described. Conductor intersections may be formed.

  In addition, when many conductor intersections are formed on the same cross section, signal noise (crosstalk) may easily occur between adjacent conductor intersections. Therefore, the number of conductor intersections formed on the twist substrates 100, 100a to 100c, 200 is reduced, and the plurality of twist substrates 100, 100a to 100c, 200 are arranged in parallel to form the substrates 100, 100a to 100c, 200. You may integrate at the edge part of a longitudinal direction.

  Further, for example, in the above description, the case where the peripheral configuration of the conductor connecting portion and the peripheral configuration of the conductor intersecting portion are improved in the first embodiment, but the same improvement is also performed in the second embodiment. be able to.

100, 100a, 100b, 100c, 200 Twist substrate 110, 120, 110a-110c, 120a-120c, 210, 220 First and second substrates or conductor layers 111, 121, 211, 221 Conductors 112, 122, 212 , 222 Side surface portion 113, 123, 213, 223 Conductor exposed portion 115, 115b, 115c, 125, 125b, 125c, 235 Base material 116, 116a, 116b, 117, 126, 126a, 126b, 127, 215, 225 Cover material 130, 130a, 230 Conductor connection 131, 131b Conductor intersection 135, 135a Adhesive layer

Claims (12)

A plurality of conductors inclined in the longitudinal direction are arranged in parallel, and a strip-shaped first conductor layer in which a side surface portion that crosses the plurality of conductors is formed;
A strip-shaped second conductor layer having the same width as the first conductor layer, in which a plurality of conductors inclined in the longitudinal direction are arranged in parallel, and a side surface portion is formed across the plurality of conductors;
The conductors of the first and second conductor layers are formed so as to intersect with each other through an insulating layer on the longitudinal center line of the belt-like assembly in which the first and second conductor layers are overlapped. A first conductor exposed on the side surface of the first conductor layer and a second conductor exposed on the side surface of the second conductor layer and paired with the first conductor. A conductor connection to be connected;
A flexible substrate comprising:   The flexible substrate according to claim 1, wherein the conductor connection portion is a metal coating that connects the first conductor and the second conductor.   The flexible substrate according to claim 1, wherein the first and second conductors are exposed on an upper surface or a lower surface of the first and second conductor layers together with side surfaces of the first and second conductor layers. .   The said 1st and 2nd conductor is exposed to the upper surface or lower surface of the said 1st and 2nd conductor layer by the predetermined width set according to the formation conditions of the said conductor connection part. Flexible substrate.   5. The flexible substrate according to claim 1, wherein the first and second conductors are opposed to each other via an insulating layer having a predetermined thickness set in accordance with a formation condition of the conductor connection portion. .   The insulating layer interposed between the first and second conductor layers is formed thicker than the other portions at the portions where the conductors of the first and second conductor layers intersect via the insulating layer. The flexible substrate according to any one of claims 1 to 5.   The insulating layer interposed between the first and second conductor layers is formed of a material different from that of the other portions at a portion where the conductors of the first and second conductor layers intersect with each other through the insulating layer. The flexible substrate according to any one of claims 1 to 6.   The flexible substrate according to claim 1, wherein in the longitudinal direction of the assembly, the flexible substrate is formed thinner around the exposed portion of the first and second conductors than other portions.   The first conductor layer is composed of a conductor of a first flexible substrate, and the second conductor layer is composed of a conductor of a second flexible substrate bonded to the first flexible substrate. The flexible substrate according to any one of claims 1 to 8.   The flexible substrate according to claim 1, wherein the first and second conductor layers are configured to include a first layer conductor and a second layer conductor of the flexible substrate. A plurality of conductors inclined in the longitudinal direction are arranged in parallel, and have a strip-shaped first conductor layer in which side portions crossing the plurality of conductors are formed, and have the same width as the first conductor layer. Preparing a strip-shaped second conductor layer in which a plurality of conductors inclined to each other are arranged in parallel and a side surface portion is formed across the plurality of conductors;
The first and second conductor layers intersect with each other through an insulating layer on a longitudinal center line of the assembly in which the first and second conductor layers are overlapped. Overlaying the second conductor layer;
Connecting the first conductor exposed at the side surface portion of the first conductor layer and the second conductor exposed at the side surface portion of the second conductor layer and paired with the first conductor; When,
A method for manufacturing a flexible substrate.   The step of connecting the first and second conductors forms a pair with the plurality of first conductors exposed on the side surface portion of the first conductor layer and the plurality of first conductors, and The manufacturing method of the flexible substrate of Claim 11 including the step which forms simultaneously the metal film which connects the said some 2nd conductor exposed to the said side part of 2 conductor layers for every one side.

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