JP7239902B2 - Flexible wiring board and dimming unit - Google Patents

Description

The present disclosure relates to a flexible wiring board having terminals facing opposite directions, and a light control unit having the flexible wiring board.

A light control sheet comprising two transparent electrode layers is applied with a voltage between the transparent electrode layers, thereby exhibiting a different light transmittance than before the application. Each transparent electrode layer is connected to an external power supply via a flexible wiring board (see Patent Documents 1 and 2, for example). An example of a flexible wiring substrate includes adhered terminals facing in opposite directions, and electrode terminals facing each other in a light control sheet are connected to the two adhered terminals.

For example, as shown in FIG. 7, the light control sheet 70 includes a light control layer 71, a first transparent electrode sheet 75, and a second transparent electrode sheet . The first transparent electrode sheet 75 includes a first support film 75A and a first transparent electrode layer 75B. The second transparent electrode sheet 76 includes a second support film 76A and a second transparent electrode layer 76B. A voltage applied between the first transparent electrode layer 75B and the second transparent electrode layer 76B drives the dimming layer 71 located between the first transparent electrode layer 75B and the second transparent electrode layer 76B.

The light control sheet 70 has one sheet edge 70E. The sheet edge portion 70E includes a first electrode terminal 75P and a second electrode terminal 72P. The dimming layer 71 does not partially cover the first transparent electrode layer 75B, and exposes the first electrode terminal 75P in the first transparent electrode layer 75B toward the second transparent electrode layer 76B. The light control layer 71 does not partially cover the second transparent electrode layer 76B, and exposes the second electrode terminal 72P in the second transparent electrode layer 76B toward the first transparent electrode layer 75B. The first electrode terminal 75P and the second electrode terminal 72P face each other at the sheet edge portion 70E.

The light control sheet 70 is connected to an external power supply 97 (see FIG. 8) through the flexible wiring board 90 . The flexible wiring board 90 includes an intermediate insulating layer 91 , a first covering insulating layer 92 , a second covering insulating layer 93 , a first wiring layer 95 and a second wiring layer 96 . The first wiring layer 95 is located between the intermediate insulating layer 91 and the first cover insulating layer 92 . The second wiring layer 96 is positioned between the intermediate insulating layer 91 and the second covering insulating layer 93 . The first covering insulating layer 92 does not cover the end portion of the first wiring layer 95 and exposes the first bonded terminal 95P in the first wiring layer 95 toward the first electrode terminal 75P. The second covering insulating layer 93 does not cover the end portion of the second wiring layer 96 and exposes the second bonded terminal 96P in the second wiring layer 96 toward the second electrode terminal 72P. The first to-be-bonded terminal 95P and the second to-be-bonded terminal 96P are arranged back-to-back and face opposite directions. The first adhered terminal 95P is adhered to the first electrode terminal 75P via the conductive adhesive 85. As shown in FIG. The second adhered terminal 96P is adhered to the second electrode terminal 72P via the conductive adhesive 85. As shown in FIG.

As shown in FIG. 8, the flexible wiring board 90 includes first external connection terminals 95B and second external connection terminals 96B. The first external connection terminal 95B electrically connects the external power supply 97 to the first adhered terminal 95P through the first wiring layer 95 . The second external connection terminal 96B electrically connects the external power supply 97 to the second bonded terminal 96P via the second wiring layer 96 . The first bonded terminal 95P is a comb-shaped terminal. The first bonded terminal 95P has a plurality of tooth terminals arranged at intervals in the first direction D1, which is one direction, for the purpose of enhancing adhesiveness with the first electrode terminal 75P. As shown in FIG. 9, the second bonded terminal 96P is also a comb-shaped terminal, and includes a plurality of tooth terminals arranged at intervals in the first direction D1, like the first bonded terminal 95P.

As shown in FIG. 10, the first tooth terminals 95PE constituting the first bonded terminals 95P have a terminal width WP in the first direction D1, and are arranged one by one at the terminal pitch PP in the first direction D1. . The second tooth terminals 96PE constituting the second bonded terminals 96P also have a terminal width WP in the first direction D1, and are arranged one by one at the terminal pitch PP in the first direction D1. In the thickness direction of the intermediate insulating layer 91, the first to-be-bonded terminal 95P is arranged with respect to the second to-be-bonded terminal 96P so that the first toothed terminal 95PE overlaps the second toothed terminal 96PE.

JP 2007-57925 A JP 2020-38265 A

As shown in FIG. 11, when bonding the flexible wiring board 90, the flexible wiring board 90 is arranged between the first transparent electrode layer 75B and the second transparent electrode layer 76B. Then, while pressing the first transparent electrode layer 75B against the flexible wiring board 90 and pressing the second transparent electrode layer 76B against the flexible wiring board 90 via the conductive adhesive 85, the conductive adhesive 85 is heated. As a result, the first tooth terminal 95PE is connected to the first electrode terminal 75P via the conductive adhesive 85, and the second tooth terminal 96PE is connected to the second electrode terminal 72P via the conductive adhesive 85. be.

On the other hand, the patterning of the first bonded terminals 95P requires a predetermined tolerance for the terminal width WP and the terminal pitch PP of the first toothed terminals 95PE. The patterning of the second bonded terminals 96P also requires a predetermined margin for the terminal width WP and the terminal pitch PP of the second toothed terminals 96PE. The tolerance required for each patterning causes variation in the degree of overlap between the first toothed terminal 95PE and the second toothed terminal 96PE. For example, as shown in FIG. 11, the comb-shaped terminal may overlap the entire first tooth terminal 95PE over the second tooth terminal 96PE, or as shown in FIG. A portion of the terminal 95PE may overlap only a portion of the second tooth terminal 96PE.

Here, as shown in FIG. 12, when a portion of the first toothed terminal 95PE overlaps only a portion of the second toothed terminal 96PE, the portion of the first toothed terminal 95PE that does not overlap the second toothed terminal 96PE is , the force with which the first tooth terminal 95PE adheres to the first electrode terminal 75P is weakened. Similarly, in the other portion of the second tooth terminal 96PE that does not overlap the first tooth terminal 95PE, the force with which the second tooth terminal 96PE adheres to the second electrode terminal 72P is weakened. Thus, in the flexible wiring board described above, which requires the entire tooth terminals to overlap each other, the contact resistance between the electrode terminals and the terminals to be bonded is reduced by a single flexible wiring board inside the flexible wiring board. Variation occurs between the flexible wiring board and another flexible wiring board.

A flexible wiring board for solving the above problems is provided by: an insulating layer having a first supporting surface; and a second supporting surface opposite to the first supporting surface; The flexible wiring board includes a first comb-shaped terminal and a second comb-shaped terminal located on the second support surface. The first comb-shaped terminals include a plurality of first fine-toothed terminals arranged in a first direction and a plurality of first thick-toothed terminals arranged in the first direction. The second comb-tooth-shaped terminal has a width smaller than that of the first thick-toothed terminal, a plurality of second fine-toothed terminals arranged in the first direction, and a width larger than that of the first fine-toothed terminal. and a plurality of second thick-tooth terminals arranged in the first direction. In the thickness direction of the insulating layer, a portion of the first thick-toothed terminal overlaps the entirety of the second thin-toothed terminal, and a portion of the second thick-toothed terminal overlaps the entirety of the first thin-toothed terminal. , the first thick-toothed terminal does not overlap the second thick-toothed terminal.

A light control sheet unit for solving the above problems is a light control unit including a light control sheet and a flexible wiring board adhered to the light control sheet. The light control sheet includes a first transparent electrode layer having a first electrode terminal on a first electrode surface, a second transparent electrode layer having a second electrode terminal on a second electrode surface, and a a light control layer positioned between the first electrode surface and the second electrode surface such that two electrode terminals are exposed from the light control layer, wherein the first electrode terminal is connected to the second electrode terminal; Face to face. The flexible wiring board is bonded to the first electrode terminal via an insulating layer having a first support surface and a second support surface opposite to the first support surface, and a conductive adhesive. a first comb-shaped terminal positioned on the first support surface; a second comb-shaped terminal bonded to the second electrode terminal via a conductive adhesive and positioned on the second support surface; Prepare. The first comb-tooth-shaped terminal includes a plurality of first fine-tooth terminals arranged in a first direction and a plurality of first thick-tooth terminals arranged in the first direction, and the second comb-tooth-shaped terminal includes: a plurality of second fine-toothed terminals having a width smaller than that of the first thick-toothed terminals and arranged in the first direction; and a plurality of second fine-toothed terminals having a width larger than that of the first fine-toothed terminals and arranged in the first direction. and a second thick-toothed terminal of In the thickness direction of the insulating layer, a portion of the first thick-toothed terminal overlaps the entirety of the second thin-toothed terminal, and a portion of the second thick-toothed terminal overlaps the entirety of the first thin-toothed terminal. , the first thick-toothed terminal does not overlap the second thick-toothed terminal.

According to each of the above configurations, the first thick-toothed terminals are arranged in the first direction so that the first thick-toothed terminals having a width larger than that of the second thin-toothed terminals overlap the second thin-toothed terminals. Further, the first fine-toothed terminals are arranged in the first direction such that the first fine-toothed terminals having a smaller width than the second thick-toothed terminals overlap the second thick-toothed terminals. Then, the terminal width of the first thick-toothed terminal is larger than the terminal width of the second fine-toothed terminal, or the terminal width of the second thick-toothed terminal is larger than the terminal width of the first fine-toothed terminal, This increases the margin for the first comb-shaped terminal to overlap the second comb-shaped terminal. This suppresses variations in contact resistance caused by the fact that the first comb-shaped terminals do not overlap the second comb-shaped terminals.

In the flexible wiring board described above, the first comb-shaped terminal has a tooth terminal at each first interval in the first direction, and the second comb-shaped terminal has a tooth terminal arranged at the first interval in the first direction. One tooth terminal may be provided at each interval.

According to the above configuration, the interval at which the tooth terminals are arranged in the first comb-shaped terminal and the interval at which the tooth terminals are arranged in the second comb-shaped terminal are equal to each other. Therefore, the first comb-tooth-shaped terminal and the second comb-tooth-shaped terminal are arranged such that the first thick-toothed terminal overlaps the second thin-toothed terminal, and the first thin-toothed terminal overlaps the second thick-toothed terminal. Cheap.

In the flexible wiring board, the first fine-toothed terminals and the first thick-toothed terminals are alternately arranged in the first direction among the first comb-shaped terminals, and the second comb-toothed terminals are arranged alternately. The second fine-toothed terminals and the second thick-toothed terminals may be alternately arranged in the first direction among the terminals.

According to the flexible wiring board, the first thick-toothed terminals and the first thin-toothed terminals are alternately arranged in the first direction at the first intervals. Therefore, the narrow terminal interval due to the mutually adjacent first wide-toothed terminals continues in the first direction, and the wide terminal interval due to the mutually adjacent first fine-toothed terminals continues in the first direction. is suppressed. Similarly, the narrow terminal spacing due to the second thick-toothed terminals adjacent to each other continues in the first direction, and the wide terminal spacing due to the mutually adjacent second fine-toothed terminals continues in the first direction. can be suppressed. As a result, uniform contact resistance is achieved over the entire range in which the first thick-toothed terminals and the first thin-toothed terminals are aligned, and over the entire range in which the second thick-toothed terminals and the second thin-toothed terminals are aligned. .

In the above flexible wiring board, the shape of the first comb-shaped terminal is the same as the shape of the second comb-shaped terminal, and the position of the first comb-shaped terminal is opposed to the first supporting surface. From the point of view, it may be displaced by the first distance in the first direction with respect to the position of the second comb-like terminal.

According to the flexible wiring board, since the shape of the first comb-shaped terminal is the same as the shape of the second comb-shaped terminal, it is more flexible than the configuration in which the comb-shaped terminals have mutually different shapes. This reduces the load required to design and manufacture a flexible wiring board.

FIG. 1 is a cross-sectional view showing an enlarged arrangement of electrode terminals on a light control sheet. FIG. 2 is a plan view showing the configuration of the flexible wiring board viewed from a viewpoint facing the first adhered terminals. FIG. 3 is a plan view showing the configuration of the flexible wiring board viewed from a viewpoint facing the second adherend terminals. FIG. 4 is a cross-sectional view taken along line IV--IV in FIG. FIG. 5 is a cross-sectional view showing the arrangement of tooth terminals with respect to the transparent electrode layer. FIG. 6 is a cross-sectional view showing the arrangement of tooth terminals with respect to the transparent electrode layer. FIG. 7 is a cross-sectional view showing an enlarged arrangement of electrode terminals on the light control sheet. FIG. 8 is a plan view showing the configuration of the first terminal to be bonded. FIG. 9 is a plan view showing the configuration of the second bonded terminal. FIG. 10 is a cross-sectional view showing the arrangement of the first tooth terminal and the second tooth terminal. FIG. 11 is a cross-sectional view showing the arrangement of tooth terminals with respect to the transparent electrode layer. FIG. 12 is a cross-sectional view showing the arrangement of tooth terminals with respect to the transparent electrode layer.

An embodiment embodying a flexible wiring board and a light control unit will be described. First, the structure of the light control sheet to which the flexible wiring board is adhered will be described. Next, the configuration of the flexible wiring board will be described. Then, a light control unit including a light control sheet and a flexible wiring board adhered to the light control sheet will be described.

[Light control sheet]
As shown in FIG. 1 , the light control sheet 10 includes a light control layer 21 , a first transparent electrode sheet 11 and a second transparent electrode sheet 12 . The light control layer 21 is positioned between the first transparent electrode sheet 11 and the second transparent electrode sheet 12 . The light control sheet 10 divides the space in which the light control sheet 10 is positioned into two. Of the two spaces separated by the light control sheet 10, the space in contact with the first transparent electrode sheet 11 is the first space. Of the two spaces separated by the light control sheet 10, the space in contact with the second transparent electrode sheet 12 is the second space.

The first transparent electrode sheet 11 includes a first support film 11A and a first transparent electrode layer 11B. The second transparent electrode sheet 12 includes a second support film 12A and a second transparent electrode layer 12B. The dimming layer 21 located between the first transparent electrode layer 11B and the second transparent electrode layer 12B is driven by the voltage applied between the first transparent electrode layer 11B and the second transparent electrode layer 12B. . The light control sheet 10 may further include an orientation layer between the first transparent electrode layer 11B and the light control layer 21 . The light control sheet 10 may further include an orientation layer between the second transparent electrode layer 12B and the light control layer 21 .

The support films 11A and 12A each have a light transmittance of transmitting visible light and an electrical insulation. Materials constituting the support films 11A and 12A are organic polymer compounds or inorganic polymer compounds. An example of the organic polymer compound is at least one selected from the group consisting of polyesters, polyacrylates, polycarbonates and polyolefins. An example of the inorganic polymer compound is at least one selected from the group consisting of silicon dioxide, silicon oxynitride, and silicon nitride.

The transparent electrode layers 11B and 12B each have optical transparency to transmit visible light and electrical conductivity. Examples of materials constituting the transparent electrode layers 11B and 12B are at least selected from the group consisting of indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, and poly-3,4-ethylenedioxythiophene. is one.

The light modulating layer 21 makes the light transmittance after voltage application different from the light transmittance before voltage application. An example of the light modulating layer 21 includes a transparent organic polymer layer and a liquid crystal composition. The transparent organic polymer layer defines a gap to be filled with the liquid crystal composition between the first transparent electrode layer 11B and the second transparent electrode layer 12B. The liquid crystal composition is filled in the voids of the transparent organic polymer layer. A liquid crystal composition includes a liquid crystal compound. Examples of liquid crystal compounds include Schiff base compounds, azo compounds, azoxy compounds, biphenyl compounds, terphenyl compounds, benzoic acid ester compounds, tolan compounds, pyrimidine compounds, cyclohexanecarboxylic acid ester compounds, phenyl It is at least one selected from the group consisting of cyclohexane compounds and dioxane compounds.

An example of the retention type of the liquid crystal composition in the light modulating layer 21 is any one selected from the group consisting of a polymer network type, a polymer dispersion type, and a capsule type. The polymer network type has a three-dimensional mesh-like transparent polymer network, and holds the liquid crystal composition in the interconnected mesh-like voids. A polymer network is an example of a transparent organic polymer layer. The polymer-dispersed type has a large number of isolated voids in the transparent organic polymer layer, and holds the liquid crystal composition in the voids dispersed in the polymer layer. In the capsule type, a liquid crystal composition having a capsule shape is held in a transparent organic polymer layer. In addition to the liquid crystal compound described above, the liquid crystal composition may contain a monomer for forming a transparent organic polymer layer and a dichroic dye.

The light control sheet 10 includes a first electrode terminal 11P and a second electrode terminal 12P. The surface of the first transparent electrode layer 11B facing the light control layer 21 is the first electrode surface. The light control layer 21 does not cover a part of the first electrode surface of the first transparent electrode layer 11B, and exposes the first electrode terminal 11P in the first transparent electrode layer 11B toward the second transparent electrode layer 12B. . The surface of the second transparent electrode layer 12B facing the light control layer 21 is the second electrode surface. The light control layer 21 does not partially cover the second electrode surface of the second transparent electrode layer 12B, and exposes the second electrode terminal 12P in the second transparent electrode layer 12B toward the first transparent electrode layer 11B. . The first electrode terminal 11P and the second electrode terminal 12P face each other.

[Flexible wiring board 40]
The light control sheet 10 is connected to an external power source through the flexible wiring board 40 . The flexible wiring board 40 is a flexible printed circuit board (FPC: Flexible Printed Circuits). The flexible wiring board 40 includes an intermediate insulating layer 41 , a first covering insulating layer 42 , a second covering insulating layer 43 , a first wiring layer 45 and a second wiring layer 46 . The first wiring layer 45 is located between the intermediate insulating layer 41 and the first covering insulating layer 42 . The second wiring layer 46 is located between the intermediate insulating layer 41 and the second cover insulating layer 43 .

Materials forming the intermediate insulating layer 41, the first insulating covering layer 42, and the second insulating covering layer 43 are insulating organic polymer compounds or insulating inorganic-organic composite materials. An example of the material constituting the intermediate insulating layer 41, the first covering insulating layer 42, and the second covering insulating layer 43 is at least one selected from the group consisting of polyimide and polyester. An example of the material forming the first wiring layer 45 and the second wiring layer 46 is at least one selected from the group consisting of a copper thin film, an aluminum thin film, and a nickel thin film.

The first supporting surface 41S1 of the intermediate insulating layer 41 supports the entire first wiring layer 45. As shown in FIG. The second support surface 41S2 of the intermediate insulating layer 41 supports the second wiring layer 46 as a whole. The first covering insulating layer 42 does not cover the end portion of the first wiring layer 45, and exposes the first bonded terminal 45P in the first wiring layer 45 toward the first electrode terminal 11P. The first bonded terminal 45P is an example of a first comb-like terminal. The second covering insulating layer 43 does not cover the end portion of the second wiring layer 46 and exposes the second adhered terminal 46P in the second wiring layer 46 toward the second electrode terminal 12P. The second bonded terminal 46P is an example of a second comb-shaped terminal. The first to-be-bonded terminal 45P and the second to-be-bonded terminal 46P are arranged back to back and face opposite directions. The first adhered terminal 45P is adhered to the first electrode terminal 11P via the conductive adhesive 25. As shown in FIG. The second adhered terminal 46P is adhered to the second electrode terminal 12P via the conductive adhesive 25. As shown in FIG.

The conductive adhesive 25 includes conductive particles and thermosetting resin. The conductive adhesive 25 is, for example, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), an isotropic conductive film (ICF: Isotropic Conductive Film), and It is at least one selected from the group consisting of isotropic conductive pastes (ICP: Isotropic Conductive Paste).

As shown in FIG. 2, the flexible wiring board 40 includes first external connection terminals 45B and second external connection terminals 46B. The first external connection terminal 45B electrically connects an external power supply to the first bonded terminal 45P through the first wiring layer 45 . The second external connection terminal 46B electrically connects an external power source to the second bonded terminal 46P via the second wiring layer 46 .

The first bonded terminal 45</b>P is one comb-like terminal located on the first supporting surface 41</b>S 1 of the intermediate insulating layer 41 . The first bonded terminal 45P includes a plurality of first tooth terminals 45PE arranged at intervals in the first direction D1, which is one direction. The first to-be-bonded terminal 45P composed of a plurality of first toothed terminals 45PE has a surface area larger than that of the flat terminal, and the first to-be-bonded terminal 45P and the first electrode terminal 11P are connected to each other via the conductive adhesive. Improves adhesion.

As shown in FIG. 3, the second bonded terminal 46P is one comb-like terminal positioned on the second supporting surface 41S2 of the intermediate insulating layer 41. As shown in FIG. The second bonded terminal 46P includes a plurality of second tooth terminals 46PE arranged at intervals in the first direction D1, which is one direction. The second to-be-bonded terminal 46P, which is composed of a plurality of second tooth terminals 46PE, has a larger surface area than the flat terminal, and the second to-be-bonded terminal 46P and the second electrode terminal 12P are connected via the conductive adhesive. Improves adhesion.

As shown in FIG. 4, the plurality of first tooth terminals 45PE includes a plurality of first thick tooth terminals 45E1 and a plurality of first fine tooth terminals 45E2. The first thick tooth terminal 45E1 has a wide tooth width WP1, which is the terminal width in the first direction D1. The first fine tooth terminal 45E2 has a fine tooth width WP2, which is the terminal width in the first direction D1. The first tooth terminals 45PE are positioned one by one at the terminal pitch PP, which is an example of the first spacing, in the first direction D1.

The plurality of second tooth terminals 46PE includes a plurality of second thick tooth terminals 46E1 and a plurality of second fine tooth terminals 46E2. The second thick-tooth terminal 46E1 has a wide tooth width WP1, which is the terminal width in the first direction D1, like the first thick-tooth terminal 45E1. The second fine-tooth terminal 46E2 has a fine tooth width WP2, which is the terminal width, in the first direction D1, like the second fine-tooth terminal 46E2. The second tooth terminals 46PE are positioned one by one at the terminal pitch PP in the first direction D1.

The first tooth terminal 45PE and the second tooth terminal 46PE satisfy the following conditions (A) to (C) in the thickness direction of the intermediate insulating layer 41.
(A) Part of the first thick-toothed terminal 45E1 overlaps the entire second fine-toothed terminal 46E2.
(B) Part of the second thick-toothed terminal 46E1 overlaps the entire first fine-toothed terminal 45E2.
(C) The first thick-toothed terminal 45E1 does not overlap the second thick-toothed terminal 46E1.

As an example that satisfies the above conditions (A) to (C), the shape of the first to-be-bonded terminal 45P is the same as the shape of the second to-be-bonded terminal 46P. The positions of the first bonded terminals 45P are displaced from the positions of the second bonded terminals 46P by the terminal pitch PP in the first direction D1 when viewed from the viewpoint facing the first support surface 41S1.

The wide tooth width WP1 is, for example, 1.5 times or more and 2.0 times or less the thin tooth width WP2. When the margin in the first direction D1 in the patterning of the first bonded terminal 45P is about 0.1 times the narrow tooth width WP2, the wide tooth width WP1 is 1.5 times or more the narrow tooth width WP2. makes it possible to make the wide face width WP1 sufficiently larger than the narrow face width WP2. The configuration in which the wide tooth width WP1 is 2.0 times or less the narrow tooth width WP2 increases the accuracy of electrically connecting the first fine tooth terminal 45E2 to the first electrode terminal 11P.

The terminal pitch PP is, for example, 2.0 times or more the narrow tooth width WP2 and not more than the sum of the wide tooth width WP1 and the narrow tooth width WP2. When the terminal pitch PP is 2.0 times or more the fine tooth width WP2, the effect of increasing the adhesiveness between the first bonded terminal 45P and the first electrode terminal 11P by the surface area of the first bonded terminal 45P is sufficient. obtained in In addition, the effect of increasing the adhesiveness between the second bonded terminal 46P and the second electrode terminal 12P by the surface area of the second bonded terminal 46P can be sufficiently obtained. When the terminal pitch PP is equal to or less than the sum of the wide tooth width WP1 and the thin tooth width WP2, the interval between the first tooth terminals 45PE adjacent to each other is suppressed from being excessive, and the first bonded terminal 45P and the first electrode The contact resistance with the terminal 11P is sufficiently suppressed. Moreover, the interval between the second tooth terminals 46PE adjacent to each other is prevented from being excessive, and the contact resistance between the second adhered terminal 46P and the second electrode terminal 12P is sufficiently reduced.

As shown in FIG. 5, when bonding the flexible wiring board 40, the flexible wiring board 90 is arranged between the first transparent electrode layer 11B and the second transparent electrode layer 12B. Then, while pressing the first transparent electrode layer 11B against the flexible wiring board 40 and pressing the second transparent electrode layer 12B against the flexible wiring board 40 via the conductive adhesive 85, the conductive adhesive 25 is heated. As a result, the first tooth terminal 45PE is connected to the first transparent electrode layer 11B via the conductive adhesive 25, and the second tooth terminal 46PE is connected to the second transparent electrode layer 12B via the conductive adhesive 25. Connected.

Here, the flexible wiring board 40 satisfies the above conditions (A) and (C). As a result, when the conductive adhesive 25 is heated, the reaction force applied by the first thick-toothed terminal 45E1 to the first transparent electrode layer 11B is almost the same as the reaction force applied by the second fine-toothed terminal 46E2 to the second transparent electrode layer 12B. be equal. The force with which the first thick-toothed terminal 45E1 adheres to the first transparent electrode layer 11B is substantially equal to the force with which the second fine-toothed terminal 46E2 adheres to the second transparent electrode layer 12B.

Moreover, the flexible wiring board 40 satisfies the above conditions (B) and (C). As a result, when the conductive adhesive 25 is heated, the reaction force applied to the first transparent electrode layer 11B by the first fine-toothed terminal 45E2 is almost equal to the reaction force applied to the second transparent electrode layer 12B by the second thick-toothed terminal 46E1. be equal. The force with which the first fine-toothed terminal 45E2 adheres to the first transparent electrode layer 11B is approximately equal to the force with which the second thick-toothed terminal 46E1 adheres to the second transparent electrode layer 12B.

As shown in FIG. 6, the patterning of the first terminal to be bonded 45P is such that the wide tooth width WP1 of the first thick-toothed terminal 45E1, the narrow toothed width WP2 of the first fine-toothed terminal 45E2, and the terminal pitch PP have a predetermined margin. It takes degrees. The patterning of the second bonded terminal 46P also requires a predetermined tolerance for the wide tooth width WP1 of the second thick-toothed terminal 46E1, the narrow toothed width WP2 of the second fine-toothed terminal 46E2, and the terminal pitch PP. The tolerance required for each patterning causes variation in the degree of overlap between the first wide-toothed terminal 45E1 and the second fine-toothed terminal 46E2 and the degree of overlap between the first finely-toothed terminal 45E2 and the second wide-toothed terminal 46E1.

Here, the overlap between the first wide-toothed terminal 45E1 and the second fine-toothed terminal 46E2 has a margin of width obtained by subtracting the fine-tooth width WP2 from the large-tooth width WP1. The overlap between the first fine-toothed terminal 45E2 and the second wide-toothed terminal 46E1 also has a margin of width obtained by subtracting the fine-tooth width WP2 from the large-tooth width WP1. Even if the overlap between the first wide-toothed terminal 45E1 and the second fine-toothed terminal 46E2 varies by the width obtained by subtracting the narrowly-toothed width WP2 from the wide-toothed width WP1, the flexible wiring board 40 does not meet the above conditions. (A) to (C) are satisfied. The force with which the first thick-toothed terminal 45E1 adheres to the first transparent electrode layer 11B is substantially equal to the force with which the second fine-toothed terminal 46E2 adheres to the second transparent electrode layer 12B. Further, the force with which the first fine-toothed terminal 45E2 adheres to the first transparent electrode layer 11B is substantially equal to the force with which the second thick-toothed terminal 46E1 adheres to the second transparent electrode layer 12B.

According to the above embodiment, the following effects can be obtained.
(1) The first thick-toothed terminals 45E1 are arranged in the first direction D1 such that the first thick-toothed terminals 45E1 having a width larger than that of the second thin-toothed terminals 46E2 overlap the second thin-toothed terminals 46E2. Further, the first fine-toothed terminals 45E2 are arranged in the first direction such that the first fine-toothed terminals 45E2 having a smaller width than the second thick-toothed terminals 46E1 overlap the second thick-toothed terminals 46E1. As a result, the wide tooth width WP1 of the first thick-toothed terminal 45E1 is greater than the narrow toothed width WP2 of the second thin-toothed terminal 46E2, or the wide toothed width WP1 of the second thick-toothed terminal 46E1 is greater than that of the first thin-toothed terminal 46E1. As the narrow tooth width WP2 of the terminal 45E2 is larger than the width WP2 of the terminal 45E2, the margin for the first bonded terminal 45P to overlap the second bonded terminal 46P increases. As a result, variations in contact resistance due to the first bonded terminal 45P not overlapping the second bonded terminal 46P are suppressed.

(2) Among the first bonded terminals 45P, the first toothed terminals 45PE are arranged at the terminal pitch PP, and among the second bonded terminals 46P, the second toothed terminals 46PE are arranged at the terminal pitch PP. Therefore, the first terminal to be bonded 45P and the second terminal to be bonded 46P are arranged so that the first thick-toothed terminal 45E1 overlaps the second thin-toothed terminal 46E2, and the first thin-toothed terminal 45E2 overlaps the second thick-toothed terminal 46E1. and easy to place.

(3) Since the shape of the first terminal to be bonded 45P is the same as the shape of the second terminal to be bonded 46P, the design of the flexible wiring board 40 and the design of the flexible wiring board 40 are relatively different compared to the configuration in which the comb-teeth-shaped terminals have mutually different shapes. The load required for manufacturing is reduced.

(4) The first thick-toothed terminals 45E1 and the first fine-toothed terminals 45E2 are alternately arranged in the first direction D1 at the terminal pitch PP. Therefore, the narrow space between the first thick-toothed terminals 45E1 adjacent to each other continues in the first direction D1, and the wide space between the first fine-toothed terminals 45E2 adjacent to each other continues in the first direction D1. can be suppressed. As a result, the contact resistance is made uniform over the entire range in which the first thick-toothed terminals 45E1 and the first fine-toothed terminals 45E2 are arranged.

(5) The second thick-toothed terminals 46E1 and the second fine-toothed terminals 46E2 are alternately arranged in the first direction D1 at the terminal pitch PP. Therefore, the narrow space between the second thick-toothed terminals 46E1 adjacent to each other continues in the first direction D1, and the wide space between the second fine-toothed terminals 46E2 adjacent to each other continues in the first direction D1. can be suppressed. As a result, uniform contact resistance is achieved over the entire range in which the second thick-toothed terminals 46E1 and the second fine-toothed terminals 46E2 are arranged.

The above embodiment can be implemented with the following modifications.
[Tooth terminal]
- Two or more first fine-toothed terminals 45E2 may be positioned between two first large-toothed terminals 45E1 adjacent in the first direction D1. Two or more second fine-tooth terminals 46E2 may be positioned between two second thick-tooth terminals 46E1 adjacent in the first direction D1. Even with such a configuration, if the configuration satisfies the conditions (A) to (C), the effects corresponding to the above (1) to (3) can be obtained.

A plurality of first fine-toothed terminals 45E2 arranged continuously in the first direction D1 constitute one first fine-toothed terminal group, and a plurality of second fine-toothed terminals 46E2 arranged continuously in the first direction D1 constitute one group of terminals. It may be a second fine-toothed terminal group. At this time, two or more first thick-toothed terminals 45E1 may be positioned between two groups of first thin-toothed terminals adjacent in the first direction D1. Also, two or more second thick-toothed terminals 46E1 may be positioned between two second fine-toothed terminal groups adjacent in the first direction D1. Even with such a configuration, if the configuration satisfies the conditions (A) to (C), the effects corresponding to the above (1) to (3) can be obtained.

- The shape of the first to-be-bonded terminal 45P may be different from that of the second to-be-bonded terminal 46P.
- The first to-be-bonded terminal 45P may include a first tooth terminal 45PE that does not overlap the second to-be-bonded terminal 46P in the thickness direction of the intermediate insulating layer 41 . The second bonded terminal 46P may include a second tooth terminal 46PE that does not overlap the first bonded terminal 45P in the thickness direction of the intermediate insulating layer 41 . Even with such a configuration, the effects corresponding to the above (1) to (2) can be obtained as much as the configuration that satisfies the conditions (A) to (C) is provided.

- The first to-be-bonded terminal 45P may include a first tooth terminal 45PE in which a part of the first tooth terminal 45PE overlaps a part of the second tooth terminal 46PE in the thickness direction of the intermediate insulating layer 41. . The second bonded terminal 46</b>P may include a second toothed terminal 46</b>PE that partially overlaps the first toothed terminal 45</b>PE in the thickness direction of the intermediate insulating layer 41 . Even with such a configuration, the effects corresponding to the above (1) to (2) can be obtained as much as the configuration that satisfies the conditions (A) to (C) is provided.

- The terminal pitch PP between the first to-be-bonded terminals 45P and the second to-be-bonded terminals 46P may change continuously in the first direction D1, or may change periodically. For example, the terminal pitch PP between the first bonded terminals 45P and the second bonded terminals 46P may gradually increase or decrease in the first direction D1. For example, the terminal pitch PP between the first to-be-bonded terminals 45P and the second to-be-bonded terminals 46P may increase or decrease for each predetermined number of first thick-toothed terminals 45E1 that are continuous in the first direction D1. may Even with such a configuration, if the configuration satisfies the conditions (A) to (C), the effects corresponding to the above (1) to (2) can be obtained.

[unit]
- The light control unit may include one light control sheet 10 and a plurality of flexible wiring boards 40 bonded to the light control sheet 10 . At this time, the plurality of flexible wiring substrates 40 adhered to the first transparent electrode layer 11B are connected to one common potential, and the plurality of flexible wiring substrates 40 adhered to the second transparent electrode layer 12B are connected to one common potential. are connected to one common potential.

D1... First direction 10... Light control sheet 11B... First transparent electrode layer 11P... First electrode terminal 12B... Second transparent electrode layer 12P... Second electrode terminal 21... Light control layer 25, 85... Conductive adhesive 40 , 90 Flexible wiring board 41 Intermediate insulating layer 41S1 First supporting surface 41S2 Second supporting surface 45E1 First thick-toothed terminal 45E2 First fine-toothed terminal 46E1 Second thick-toothed terminal 46E2 Second fine tooth terminal

Claims (5)

an insulating layer having a first support surface and a second support surface opposite the first support surface;
a first comb-like terminal positioned on the first support surface;
a second comb-shaped terminal positioned on the second support surface, the flexible wiring board comprising:
The first comb-shaped terminal is
a plurality of first fine-toothed terminals arranged in a first direction;
a plurality of first thick-toothed terminals arranged in the first direction,
The second comb-shaped terminal is
a plurality of second fine-toothed terminals arranged in the first direction and having a width smaller than that of the first thick-toothed terminals;
a plurality of second thick-toothed terminals having a width larger than that of the first thin-toothed terminals and arranged in the first direction;
In the thickness direction of the insulating layer,
a portion of the first thick-toothed terminal overlaps the entirety of the second fine-toothed terminal;
A portion of the second thick-toothed terminal overlaps the entire first fine-toothed terminal,
A flexible wiring board, wherein the first thick-toothed terminal does not overlap the second thick-toothed terminal. the first comb-shaped terminal includes a tooth terminal at each first interval in the first direction;
2. The flexible wiring board according to claim 1, wherein the second comb-shaped terminal has one tooth terminal at each of the first intervals in the first direction. Among the first comb-shaped terminals, the first fine-toothed terminals and the first thick-toothed terminals are alternately arranged in the first direction,
3. The flexible wiring board according to claim 2, wherein said second thin-toothed terminals and said second thick-toothed terminals of said second comb-shaped terminals are alternately arranged one by one in said first direction. The shape of the first comb-shaped terminal is the same as the shape of the second comb-shaped terminal,
A position of the first comb-shaped terminal is displaced from a position of the second comb-shaped terminal in the first direction by the first distance when viewed from a viewpoint facing the first support surface. 4. The flexible wiring board according to Item 2 or 3. a light control sheet;
and a flexible wiring board adhered to the light control sheet,
The light control sheet is
a first transparent electrode layer having a first electrode terminal on a first electrode surface;
a second transparent electrode layer having a second electrode terminal on a second electrode surface;
a light control layer positioned between the first electrode surface and the second electrode surface such that the first electrode terminal and the second electrode terminal are exposed from the light control layer;
the first electrode terminal faces the second electrode terminal;
The flexible wiring board is
an insulating layer having a first support surface and a second support surface opposite the first support surface;
a first comb-like terminal adhered to the first electrode terminal via a conductive adhesive and located on the first supporting surface;
a second comb-shaped terminal adhered to the second electrode terminal via a conductive adhesive and located on the second support surface;
The first comb-shaped terminal is
a plurality of first fine-toothed terminals arranged in a first direction;
a plurality of first thick-toothed terminals arranged in the first direction,
The second comb-shaped terminal is
a plurality of second fine-toothed terminals arranged in the first direction and having a width smaller than that of the first thick-toothed terminals;
a plurality of second thick-toothed terminals having a width larger than that of the first thin-toothed terminals and arranged in the first direction;
In the thickness direction of the insulating layer,
a portion of the first thick-toothed terminal overlaps the entirety of the second fine-toothed terminal;
A portion of the second thick-toothed terminal overlaps the entire first fine-toothed terminal,
The light control unit, wherein the first thick-toothed terminal does not overlap the second thick-toothed terminal.

Images