Circuit body and circuit body to which connector is attached

Abstract

The circuit body is a flexible substrate including a plurality of conductor layers having a plurality of conductor patterns, and a plurality of insulating layers arranged so as to sandwich the conductor layers therebetween. In each conductor pattern, a contact portion is disposed in the first conductor layer and exposed to the outside through an opening disposed in the first insulating layer. The plurality of contact portions includes a first contact portion belonging to a conductor pattern extending across the first conductor layer and a second conductor layer different from the first conductor layer, and a second contact portion belonging to a conductor pattern provided only on the first conductor layer and located further away from a terminal of the flexible substrate than the first contact portion. In the second conductor layer, a dummy pattern is arranged in the vicinity of the first contact portion.

Description

Technical Field

[0001] The present invention relates to a circuit body including a multi-layer flexible substrate and a circuit body to which a connector is attached. Background Art

[0002] Related art discloses that a flexible substrate (flexible printed circuit (FPC)) provided with a conductor pattern is used as wiring for connecting various electronic devices, etc. (for example, see Patent Documents 1 and 2). A flexible substrate generally has a structure in which a thin film conductor layer having a conductor pattern (i.e., a circuit) of a predetermined shape is inserted between insulating films (insulating layers), and the conductor layer and the insulating layer are bonded with an adhesive. A special feature of a flexible substrate is that the flexible substrate can be flexibly deformed, such as bent, while maintaining electrical characteristics.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: JP2022-089301A

[0006] Patent Document 2: JP2002-093995A Summary of the invention

[0007] In order to mount a connector or the like (e.g., a so-called SMT connector) on a flexible substrate, for example, an opening portion may be provided in an insulating layer of the flexible substrate, and a contact portion of a conductor pattern exposed from the opening portion (a so-called land portion) and an external terminal of the connector or the like may be connected by reflow soldering or the like. In this case, in order to appropriately connect a plurality of contact portions and a plurality of external terminals with solder, it is desirable that the interval between the mounting surface of the flexible substrate and the contact portion be as uniform as possible (i.e., the position of the contact portion in the thickness direction is uniform).

[0008] However, in a general manufacturing method of a flexible substrate, in which an insulating layer (so-called cover film) constituting a mounting surface is thermocompression-bonded with an adhesive, the thickness of the flexible substrate tends to differ between a portion provided with a conductor pattern and a portion not provided with a conductor pattern. Specifically, the thickness of the portion where no conductor pattern is provided tends to be thinner by an amount corresponding to the thinning of the adhesive layer. For example, in the case where a contact portion located in a first conductor layer belongs to a conductor pattern extending from the first conductor layer to a second conductor layer, when there is no conductor pattern on the back side of the contact portion (corresponding to the position of the contact portion in the second conductor layer), the thickness of the flexible substrate tends to be thinner at the periphery of the contact portion. As a result, the contact portion is not aligned with other contact portions in the thickness direction, and thus the spacing between the mounting surface of the flexible substrate and the contact portion may be uneven.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circuit body capable of making positions of a plurality of contact portions of a plurality of conductor patterns in the thickness direction consistent in the thickness direction of a flexible substrate.

[0010] In order to achieve the above-mentioned object, a circuit body and a connector-attached circuit body according to the present invention have the following features.

[0011] The circuit body of the present invention includes a multilayer flexible substrate. The multilayer flexible substrate includes a plurality of conductor layers having a plurality of conductor patterns for realizing a circuit configuration, and a plurality of insulating layers arranged in a manner of sandwiching the plurality of conductor layers therebetween. In each of the plurality of conductor patterns, a contact portion is provided in a first conductor layer adjacent to a first insulating layer in the plurality of conductor layers, and is exposed to the outside through an opening provided in the first insulating layer constituting a mounting surface of the flexible substrate in the plurality of insulating layers to be connected to an external terminal. The plurality of contact portions include a first contact portion belonging to a conductor pattern, the conductor pattern extending across the first conductor layer and a second conductor layer different from the first conductor layer, and a second contact portion different from the first contact portion and located at a position farther from the terminal of the flexible substrate than the first contact portion. In the second conductor layer, a dummy pattern is arranged on at least one of a corresponding position corresponding to the first contact portion and a vicinity of the corresponding position in the thickness direction of the flexible substrate, the dummy pattern being a conductor pattern that does not contribute to the circuit configuration.

[0012] The connector-attached circuit of the present invention includes the above-mentioned circuit body and a connector to be mounted on a mounting surface of the circuit body and having a plurality of external terminals to be connected to a plurality of contact portions.

[0013] According to the circuit body of the present invention and the circuit body with a connector attached, the first contact portion belongs to a conductor pattern arranged in a manner extending across the first conductor layer and the second conductor layer among a plurality of conductor patterns arranged in a multilayer flexible substrate. In addition, a dummy pattern is arranged in the second conductor layer at a corresponding position corresponding to the first contact portion and at least one near the corresponding position. Therefore, compared with the case where there is no dummy pattern in the second conductor layer, the flexible substrate at the position corresponding to the first contact portion is less likely to be thinned in the thickness direction. Therefore, even when the positions of the first contact portion and the second contact portion may not overlap in the thickness direction, such as in the case where the first contact portion is closer to the terminal portion of the flexible substrate than the other second contact portion, the positions of the first contact portion and the second contact portion can be made consistent. Therefore, in the circuit body having the present configuration and the circuit body with a connector attached, the positions of the plurality of contact portions of the plurality of conductor patterns can be made consistent in the thickness direction of the flexible substrate.

[0014] The present invention has been briefly described above. The details of the present invention can be clarified by reading the following mode for carrying out the present invention (hereinafter referred to as "embodiment") described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a perspective view of a circuit body according to an embodiment of the present invention.

[0016] Figure 2 It is shown Figure 1 A top view of the circuit body is shown.

[0017] Figure 3 It is along Figure 2 A cross-sectional view taken along line AA in FIG.

[0018] Figure 4 It is along Figure 2 A cross-sectional view taken along line BB in FIG.

[0019] Figure 5 It is along Figure 2 Cross-sectional view taken along line CC in FIG.

[0020] Figure 6 It is shown that according to the corresponding Figure 2 A view of the modified circuit body.

[0021] Figure 7 It is shown that according to the corresponding Figure 2 FIG. 2 is a view of another modified circuit body. DETAILED DESCRIPTION

[0022] Example

[0023] Hereinafter, a circuit body 1 according to an embodiment of the present invention (this embodiment) will be described with reference to the accompanying drawings. For the convenience of description, "front-rear direction", "left-right direction" and "up-down direction" are defined as follows: Figure 1 The "front-rear direction", "left-right direction" and "up-down direction" are orthogonal to each other. The front-rear direction, left-right direction and up-down direction correspond to the longitudinal direction, lateral direction and thickness direction of the circuit body 1, respectively.

[0024] like Figures 1 to 5 As shown, the circuit body 1 according to the present embodiment is implemented by a multilayer substrate (flexible printed circuit (FPC)) including a pair of upper and lower conductor layers 10A and 10B having a conductor pattern 11 formed of a thin film conductor for realizing a circuit configuration, and a plurality of insulating layers 20A, 20B, and 20C arranged in a manner sandwiching the conductor layers 10A and 10B.

[0025] Specifically, Figures 3 to 5As shown, the upper conductor layer 10A is interposed between the insulating layer 20A constituting the flexible substrate mounting surface (upper surface) 1a and the insulating layer 20B located below the insulating layer 20A, and the lower conductor layer 10B is interposed between the insulating layer 20B and the insulating layer 20C located below the insulating layer 20B and constituting the lower surface of the flexible substrate. The adhesive 12 having the function of bonding the insulating layers 20A and 20B to each other exists in the space of the conductor layer 10A except for the space occupied by the conductor pattern 11. Similarly, the adhesive 12 having the function of bonding the insulating layers 20B and 20C to each other exists in the space of the conductor layer 10B except for the space occupied by the conductor pattern 11.

[0026] The circuit body 1 includes, as the conductor patterns 11 , a plurality of conductor patterns 11A provided only in the conductor layer 10A, and a plurality of conductor patterns 11B provided in a manner extending on the conductor layer 10A and the conductor layer 10B.

[0027] The plurality of conductor patterns 11A are arranged at intervals in the left-right direction and extend in the front-back direction only in the conductor layer 10A (see FIG. Figure 2 ). The terminal portions of the rear portions of the plurality of conductor patterns 11A are positioned in front of the terminal portion of the circuit body 1 at a predetermined distance and are arranged at intervals in the left-right direction. An opening portion 21A is formed in the insulating layer 20A at the upper side of the terminal portion of the rear portion of each conductor pattern 11A, and the terminal portion of the rear portion of each conductor pattern 11A is exposed to the outside through the corresponding opening portion 21A (see Figure 2 ). A terminal portion at the rear of each conductor pattern 11A serves as a contact portion (so-called land portion) 13A.

[0028] The plurality of conductor patterns 11B are located between the plurality of conductor patterns 11A in the left-right direction and extend across the conductor layer 10A and the conductor layer 10B in the front-rear direction (see FIG. Figure 2 ). Specifically, Figure 2 and Figure 3As shown, in an area located in the rear of the contact portion 13A of the conductor pattern 11A and in front of the through hole 22 formed in the insulating layer 20B and extending in the up-down direction, each conductor pattern 11B extends in the front-to-back direction in the conductor layer 10B, at the position of the through hole 22 extending in the front-to-back direction, each conductor pattern 11B extends in the up-to-down direction to pass through the through hole 22 and connect the conductor layer 10B and the conductor layer 10A, and in the rear area of ​​the through hole 22, each conductor pattern 11B extends in the front-to-back direction in the conductor layer 10A. The terminal portions in the rear of the plurality of conductor patterns 11B (located in the conductor layer 10A) are located near the rear end of the circuit body 1 at the position of the rear of the contact portion 13A of the conductor pattern 11A (at a position closer to the rear end of the circuit body 1 than the contact portion 13A), and are arranged at intervals in the left-right direction. An opening portion 21B is formed in the insulating layer 20A on the upper side of the terminal portion in the rear portion of each conductor pattern 11B, and the terminal portion in the rear portion of each conductor pattern 11B is exposed to the outside through the corresponding opening portion 21B (see Figure 2 ). A terminal portion at the rear of each conductor pattern 11B serves as a contact portion (so-called land portion) 13B.

[0029] In the conductor layer 10B located below the plurality of contact portions 13B arranged in the left-right direction, a plurality of dummy patterns 14 formed of a thin film conductor that does not contribute to the circuit configuration are arranged in the left-right direction at positions where the plurality of conductor patterns 11A are arranged (see Figure 2 ). In other words, the plurality of dummy patterns 14 are arranged at positions adjacent to the plurality of contact portions 13B in the board surface direction (left-right direction) of the circuit body 1 (flexible substrate). Therefore, when the flexible substrate is manufactured, the conductor layer 10B located below the plurality of contact portions 13B is less likely to become thinner than in the case where the dummy patterns 14 are not provided in the conductor layer 10B. Therefore, when the position in the thickness direction of the mounting surface 1a around the peripheral edge of the opening portion 21A where the second contact portion 13A is exposed is defined as the reference plane position, the interval HB in the up-down direction between the contact portion 13B and the reference plane position (see Figure 4 ) and the vertical distance HA between the contact portion 13A and the reference surface position (see Figure 5 In other words, the positions of the plurality of contact portions 13A and the plurality of contact portions 13B in the up-down direction (the thickness direction of the circuit body 1 ) are made consistent.

[0030] For the plurality of contact portions 13A and 13B exposed from the plurality of opening portions 21A and 21B of the circuit body 1 configured as described above, for example, corresponding to the surface mount (SMT) connector 2 (see Figure 1 ) of the plurality of contact portions 13A and 13B are arranged to connect the plurality of terminals 2a by soldering or the like using a reflow method (see Figures 3 to 5 Here, as described above, since the positions of the plurality of contact portions 13A and the plurality of contact portions 13B in the up-down direction (the thickness direction of the circuit body 1) are made consistent by arranging the plurality of dummy patterns 14 in the conductor layer 10B in this embodiment, the plurality of contact portions 13A and 13B of the connector 2 and the plurality of terminals 2a are easily connected by more appropriate welding.

[0031] <Operations and Effects>

[0032] As described above, according to the circuit body 1 in the present embodiment, the contact portion 13B belongs to the conductor pattern 11B extending across the conductor layer 10A and the conductor layer 10B among the plurality of conductor patterns 11A and 11B provided in the multilayer flexible substrate. In addition, the dummy pattern 14 is arranged near the contact portion 13B in the conductor layer 10B. Therefore, when the flexible substrate is manufactured, the thickness of the flexible substrate at the position corresponding to the contact portion 13B is less likely to be reduced compared to the case where the dummy pattern 14 is not provided in the conductor layer 10B. Therefore, even when the positions of the contact portion 13A and the contact portion 13B may not be aligned in the thickness direction, the positions of the contact portion 13A and the contact portion 13B may be consistent, as in the present embodiment, where the contact portion 13B is closer to the terminal portion of the flexible substrate than the contact portion 13A belonging to the conductor pattern 11A provided only in the conductor layer 10A. Therefore, in the circuit body 1 according to the present embodiment, the positions of the plurality of contact portions 13A and 13B of the plurality of conductor patterns 11A and 11B can be made consistent in the thickness direction of the flexible substrate.

[0033] <Other embodiments>

[0034] The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. can be appropriately made. In addition, the materials, shapes, sizes, quantities, arrangement positions, etc. of the components in the above-described embodiments are freely selected and are not limited as long as the present invention can be implemented.

[0035] For example, in the above-described embodiment, in the conductor layer 10B located below the plurality of contact portions 13B, the plurality of dummy patterns 14 are arranged in the left-right direction at positions where the plurality of conductor patterns 11A are arranged (positions adjacent to the plurality of contact portions 13B in the left-right direction) (see Figure 2 ). On the other hand, Figure 6 As shown, in the conductor layer 10B located below the plurality of contact portions 13B, one dummy pattern 14 elongated in the left-right direction may be arranged in a manner extending over a range in the left-right direction including all of the plurality of contact portions 13B. Figure 7As shown, in the conductor layer 10B located below the plurality of contact portions 13B, the plurality of dummy patterns 14 may be arranged so as to overlap with the lower sides of the plurality of contact portions 13B (at the same position as the plurality of contact portions 13B in the left-right direction).

[0036] Here, the features of the embodiments of the circuit body 1 and the circuit body (1+2) with a connector attached according to the present invention described above are briefly summarized and listed in the following [1] to [3].

[0037] [1] A circuit body (1) implemented by a multi-layer flexible substrate includes a plurality of conductor layers (10A and 10B) having conductor patterns (11) for implementing a circuit configuration, and a plurality of insulating layers (20A, 20B, and 20C) arranged in a manner sandwiching the plurality of conductor layers (10A and 10B). In a first conductor layer (10A) adjacent to a first insulating layer (20A) among the plurality of conductor layers, each of the plurality of conductor patterns (11) has a contact portion (13A, 13B) which is exposed to the outside through an opening portion (21A, 21B) provided in the first insulating layer (20A) constituting a mounting surface (1A) of the flexible substrate among the plurality of insulating layers and is to be connected to an external terminal (2a).

[0038] Multiple contact parts include

[0039] a first contact portion (13B) belonging to a conductor pattern (11B) extending across the first conductor layer (10A) and a second conductor layer (10B) different from the first conductor layer (10A), and

[0040] The second contact portion (13A) is different from the first contact portion (13B) and is located farther from the terminal portion of the flexible substrate than the first contact portion (13B).

[0041] In the second conductor layer (10B), a dummy pattern (14) is arranged at least one of a corresponding position corresponding to the first contact portion (13B) and a position near the corresponding position in the thickness direction of the flexible substrate. The dummy pattern is a conductor pattern that does not contribute to the circuit configuration.

[0042] According to the circuit body having the above-mentioned configuration [1], the first contact portion belongs to a conductor pattern extending through the first conductor layer and the second conductor layer among a plurality of conductor patterns arranged in the multilayer flexible substrate. In addition, a dummy pattern is arranged at least one of a corresponding position corresponding to the first contact portion and a position near the corresponding position in the second conductor layer. Therefore, compared with a case where there is no dummy pattern in the second conductor layer, the flexible substrate at the position corresponding to the first contact portion is less likely to become thinner in the thickness direction. Therefore, even when the positions of the first contact portion and the second contact portion may not overlap in the thickness direction, such as in a case where the first contact portion is closer to the terminal portion of the flexible substrate than the other second contact portion, the positions of the first contact portion and the second contact portion can be made consistent. Therefore, in the circuit body having the present configuration, the positions of the plurality of contact portions of the plurality of conductor patterns can be made consistent in the thickness direction of the flexible substrate.

[0043] [2] In the circuit body (1) according to the above [1],

[0044] In the case where the mounting surface (1a) around the peripheral edge of the opening portion (21A) where the second contact portion (13A) is exposed is defined as a reference surface position,

[0045] The dummy pattern (14) is arranged so that the difference between the interval (HB) in the thickness direction between the first contact portion (13B) and the reference surface position and the interval (HA) in the thickness direction between the second contact portion (13A) and the reference surface position is close to zero.

[0046] According to the circuit body having the above configuration [2], the dummy pattern is arranged so that there is no difference between the interval between the second contact portion and the mounting surface at the position where the second contact portion is provided and the interval between the first contact portion and the mounting surface at the position where the first contact portion is provided. Therefore, in the circuit body having the present configuration, the positions of the plurality of contact portions of the plurality of conductor patterns can be made uniform in the thickness direction of the flexible substrate.

[0047] [3] In the circuit body (1) according to the above [1],

[0048] The dummy patterns (14) are arranged in a manner that sandwiches corresponding positions in the board direction of the flexible substrate.

[0049] According to the circuit body having the above configuration [3], by arranging the dummy pattern at a position adjacent to the first contact portion in the board surface direction of the flexible substrate, the positions of the plurality of contact portions of the plurality of conductor patterns can be made consistent in the thickness direction of the flexible substrate.

[0050] [4] A circuit body (1+2) with a connector attached, comprising:

[0051] The circuit body (1) according to any one of [1] to [3]; and

[0052] A connector (2) is to be mounted on a mounting surface (1a) of a circuit body (1) and has a plurality of external terminals (2a) to be connected to a plurality of contact portions (13A and 13B).

[0053] According to the circuit body with a connector attached having the above-mentioned configuration [4], the first contact portion belongs to a conductor pattern extending through the first conductor layer and the second conductor layer among a plurality of conductor patterns arranged in the multilayer flexible substrate. In addition, a dummy pattern is arranged at least one of a corresponding position corresponding to the first contact portion and a position near the corresponding position in the second conductor layer. Therefore, compared with a case where there is no dummy pattern in the second conductor layer, the flexible substrate at the position corresponding to the first contact portion is less likely to become thinner in the thickness direction. Therefore, even when the positions of the first contact portion and the second contact portion may not overlap in the thickness direction, such as in a case where the first contact portion is closer to the terminal portion of the flexible substrate than the other second contact portion, the positions of the first contact portion and the second contact portion can be made consistent. Therefore, in the circuit body with a connector attached having the present configuration, the positions of the plurality of contact portions of the plurality of conductor patterns can be made consistent in the thickness direction of the flexible substrate.

Claims

1. A circuit body implemented by a multi-layer flexible substrate, The multi-layer flexible substrate includes a plurality of conductor layers having a plurality of conductor patterns for realizing a circuit configuration, and a plurality of insulating layers arranged in a manner sandwiching the plurality of conductor layers, wherein In each of the plurality of conductor patterns, a contact portion is provided in a first conductor layer adjacent to a first insulating layer among the plurality of conductor layers and is exposed to the outside through an opening provided in a first insulating layer constituting a mounting surface of the flexible substrate among the plurality of insulating layers to be connected to an external terminal, Multiple contact parts include a first contact portion belonging to the conductor pattern, the conductor pattern extending across the first conductor layer and a second conductor layer different from the first conductor layer, and a second contact portion which is different from the first contact portion and is located farther from a terminal end of the flexible substrate than the first contact portion, and In the second conductor layer, a dummy pattern is arranged on at least one of a corresponding position corresponding to the first contact portion and a vicinity of the corresponding position in the thickness direction of the flexible substrate, the dummy pattern being a conductor pattern that does not contribute to the circuit configuration.

2. The circuit body according to claim 1, wherein In the case where the mounting surface around the peripheral edge of the opening portion where the second contact portion is exposed is defined as a reference surface position, The dummy pattern is arranged so that a difference between an interval in the thickness direction between the first contact portion and the reference surface position and an interval in the thickness direction between the second contact portion and the reference surface position is close to zero.

3. The circuit body according to claim 1, wherein The dummy patterns are arranged to sandwich the corresponding positions in a board direction of the flexible substrate.

4. A circuit body with a connector attached, comprising: The circuit body according to any one of claims 1 to 3; and A connector is to be mounted on the mounting surface of the circuit body and has a plurality of external terminals to be connected to the plurality of contact portions.

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