Flexible printed wiring board and battery module

Abstract

The present invention provides a flexible printed wiring board and a battery module, wherein the flexible printed wiring board includes: a main body; and a pair of branch parts, which branch into two from the main body and are both arranged on a battery having a plurality of arranged unit cells, and a bending process is performed on at least one of the branch parts of the pair of branch parts, and the bending process utilizes a pair of parallel bending lines that move away from the other branch part as they move away from the main body, and the at least one branch part is bent in such a way that the bending direction of one of the pair of parallel bending lines and the bending direction of the other bending line are opposite to each other.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Japanese Patent Application No. 2020-019076 filed with the Japan Patent Office on February 6, 2020, which is hereby incorporated by reference herein in its entirety. Technical Field

[0003] One embodiment of the present invention relates to a flexible printed wiring board and a battery module. Background Art

[0004] For example, a battery mounted on an electric vehicle or the like is provided with a voltage monitoring device for monitoring the voltage of the battery. The voltage monitoring device includes a battery module having a flexible printed wiring board (hereinafter referred to as FPC). Figure 8 as well as Fig. 9 A conventional voltage monitoring device will be described. Figure 8 It is a plan view showing a state where a battery module according to a conventional example is mounted on a battery. Fig. 9 This is a top view of a conventional FPC.

[0005] like Figure 8 As shown, a battery module 500 for monitoring voltage is mounted on the upper part of the battery 200. The battery module 500 includes: an FPC 510; a connector 530 fixed to the end of the FPC 510 and connected to a voltage monitoring device body (not shown); and a plurality of bus bars 540 electrically connected to the electrodes of the battery 200.

[0006] Furthermore, the FPC 510 includes: a main body 510X fixed to the connector 530 side; and a pair of branch parts 510Y and 510Z branched from the main body 510X and both arranged on the battery 200. In addition, a plurality of bus bars 540 are provided on each of the pair of branch parts 510Y and 510Z. Here, the width C of the main body 510X is determined by the width of the connector 530. The maximum width B of the pair of branch parts 510Y and 510Z is determined by the width of the battery 200. Therefore, even if the width of the connector 530 is narrow, the maximum width B must be expanded in the conventional configuration.

[0007] Generally, in the manufacturing process of FPC, a base material is used, and the base material includes a base film and a copper foil disposed on the base film to eventually become a circuit. In addition, the manufacturing process includes a process of cutting the base material to obtain an FPC of a desired shape. Fig. 9In the case of FPC 510 of the shape shown, the greater the maximum width B is relative to the width C of the main body 510X, the more the base material is discarded after the portion to be the FPC 510 is cut from the base material. In other words, the number of FPCs 510 obtained from one base material decreases.

[0008] In addition, the length L of the long side direction of FPC510 depends on the configuration of the battery 200 and the voltage monitoring device body. Ideally, when FPC510 is installed on the battery 200 and the connector 530 is connected to the voltage monitoring device body, the space portion of FPC510 between the battery 200 and the voltage monitoring device body is not loose. However, if the installation operability is taken into consideration, a surplus length is usually set for the above-mentioned length L. Therefore, FPC510 becomes loose. As a result, due to external vibrations, etc., FPC510 vibrates up and down, which may have a bad effect on various parts.

[0009] In addition, as prior art documents of the present invention, for example, Japanese Patent Laid-Open No. 2010-56035, Japanese Patent Laid-Open No. 2014-86246, Japanese Patent Laid-Open No. 2016-85930, Japanese Patent Laid-Open No. 2017-199804, and Japanese Patent Laid-Open No. 2018-142505 can be listed. Summary of the invention

[0010] An object of the present invention is to provide a flexible printed wiring board and a battery module capable of reducing waste materials.

[0011] The present invention adopts the following configuration.

[0012] That is, a flexible printed wiring board of one embodiment of the present invention includes: a main body; and a pair of branch portions, which branch into two from the main body, and are both arranged on a battery having a plurality of arranged unit cells, and a bending process is performed on at least one of the branch portions of the pair of branch portions, and the bending process uses a pair of parallel bending lines that move away from the other branch portion as they move away from the main body, and the at least one branch portion is bent in such a manner that the bending direction of the bending line of one of the pair of parallel bending lines and the bending direction of the other bending line are in opposite directions to each other.

[0013] In addition, a battery module of one embodiment of the present invention includes: a flexible printed wiring board installed on a battery having a plurality of arranged unit cells; a plurality of bus bars electrically connected to a plurality of wirings of the flexible printed wiring board, and electrically connected to each electrode provided on the plurality of unit cells; and a connector fixed to an end of the flexible printed wiring board, the flexible printed wiring board including: a main body; and a pair of branch portions branched from the main body, both of which are arranged on the battery, a bending process is performed on at least one of the pair of branch portions, the bending process utilizes a pair of parallel bending lines that move away from the other branch portion as they move away from the main body, and the at least one branch portion is bent in such a manner that the bending direction of one of the pair of parallel bending lines and the bending direction of the other bending line are opposite to each other.

[0014] According to these inventions, at least one of a pair of branch portions is subjected to bending processing on a flexible printed wiring board. Thus, the maximum width of the pair of branch portions after the bending processing becomes wider than before the bending processing. Therefore, even if the maximum width of the pair of branch portions before the bending processing is narrower than the desired width, the maximum width of the pair of branch portions after the bending processing can be made to be the desired width. Thus, the maximum width of the pair of branch portions before the bending processing can be made narrower than the desired width, so that waste materials can be reduced.

[0015] As described above, according to the aspects of the present invention, waste materials can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a top view of the battery.

[0017] Figure 2 is a side view of the battery.

[0018] Figure 3 It is a side view showing a state where a battery module according to this embodiment is mounted with batteries.

[0019] Figure 4 It is a plan view showing a state where batteries are mounted on the battery module of this embodiment.

[0020] Figure 5A as well as Figure 5B 1 is a top view of a flexible printed wiring board according to an embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram showing an example of a state when the flexible printed wiring board according to the embodiment of the present invention is transported.

[0022] Fig. 7A as well as Figure 7BIt is a top view of a flexible printed wiring board according to a modified example of the present invention.

[0023] Figure 8 It is a plan view showing a state where a battery module according to a conventional example is mounted on a battery.

[0024] Fig. 9 It is a top view of a conventional flexible printed wiring board. DETAILED DESCRIPTION

[0025] In the detailed description below, for the purpose of illustration, in order to provide a thorough understanding of the disclosed embodiments, many specific details are set forth. However, it is apparent that one or more embodiments may be implemented without these specific details. In other cases, in order to simplify drawing, well-known structures and devices are schematically represented.

[0026] Hereinafter, the method for implementing the technology of the present invention will be described in detail by way of example with reference to the accompanying drawings. However, unless otherwise specified, the scope of the present invention is not limited to the size, material, shape and relative arrangement of the components described in the embodiments.

[0027] (Example)

[0028] Reference Figure 1 to Figure 6 , a flexible printed wiring board and a battery module according to an embodiment of the present invention are described. Figure 1 This is a top view of the battery. Figure 2 is a side view of the battery. Figure 3 It is a side view showing a state where a battery module according to this embodiment is mounted with batteries. Figure 4 It is a plan view showing a state where batteries are mounted on the battery module of this embodiment. Figure 5A as well as Figure 5B 1 is a top view of a flexible printed wiring board according to an embodiment of the present invention. Figure 5A This shows the state of a flexible printed wiring board before the bending process. Figure 5B This shows the state of a flexible printed wiring board after being bent. Figure 6 This is a schematic diagram showing an example of a state when the flexible printed wiring board according to the embodiment of the present invention is transported.

[0029] <Battery>

[0030] Reference Figure 1 as well as Figure 2, a battery 200 equipped with a flexible printed wiring board and a battery module of this embodiment is described. The battery 200 has a plurality of arranged unit cells 210. Electrodes (a positive electrode 211 and a negative electrode 212) are provided on each of the unit cells 210. Moreover, these plurality of unit cells 210 are arranged in such a manner that the positive electrode 211 and the negative electrode 212 are adjacent to each other on adjacent unit cells 210. In addition, these plurality of unit cells 210 are connected in series by electrically connecting adjacent positive electrodes 211 and negative electrodes 212 through a bus bar provided on the battery module. Figure 1 In the example shown in the figure, for the convenience of explanation, a battery 200 including six cells 210 is shown. However, a battery mounted on an electric vehicle or the like generally includes more cells.

[0031] <Battery Module>

[0032] In particular, refer to Figure 3 as well as Figure 4 , the overall structure of the battery module 100 of this embodiment is described. The battery module 100 includes: a flexible printed wiring board (hereinafter referred to as "FPC110"); a support member 120 that supports the FPC110; a plurality of bus bars 141 and 142 that are supported on the support member 120; and a connector 130 that is fixed to the end of the FPC110.

[0033] The busbars of this embodiment are electrically connected to the plurality of wirings provided in the FPC 110, and are electrically connected to the electrodes provided on the plurality of unit cells 210. The busbars 141 are electrically connected to the positive electrodes 211 and the negative electrodes 212 at both ends of the unit cells 210 connected in series. In addition, the busbars 142 are used to electrically connect the adjacent positive electrodes 211 and negative electrodes 212. Figure 3 As shown, the connector 130 is connected to the voltage monitoring device body 300 , for example.

[0034] <Flexible Printed Circuit Board (FPC)>

[0035] Reference Figure 4 5, the FPC 110 of this embodiment is described in more detail. Generally, the FPC has a base film, a copper foil that forms a circuit, and a cover film. As their structures are well-known technologies, their description is omitted. Figure 4 5 , a wiring (circuit) 118 formed by etching the copper foil is indicated by a dotted line. The wiring 118 is omitted in FIG.

[0036] The FPC 110 of this embodiment comprises: a main body 110X; a pair of branch parts (hereinafter referred to as the first branch part 110Y and the second branch part 110Z for convenience) branching from the main body 110X. The above-mentioned connector 130 is fixed to the end of the main body 110X. In addition, the first branch part 110Y and the second branch part 110Z are both arranged on the battery 200. In addition, a plurality of small branch parts 110Y1, 110Y2, 110Y3, and 110Y4 are arranged on the first branch part 110Y. A plurality of small branch parts 110Z1, 110Z2, and 110Z3 are also arranged on the second branch part 110Z.

[0037] In this embodiment, seven wirings 118 are provided on the FPC 110. All the wirings 118 are arranged on the main body 110X. Moreover, four wirings 118 among the seven wirings 118 are arranged in the first branch portion 110Y. The remaining three wirings 118 are arranged in the second branch portion 110Z. In addition, the ends of the four wirings 118 arranged in the first branch portion 110Y are arranged in the small branch portions 110Y1, 110Y2, 110Y3, and 110Y4, respectively. Moreover, the ends of each wiring 118 are electrically connected to the bus bar 141 or the bus bar 142 respectively provided in each small branch portion 110Y1, 110Y2, 110Y3, and 110Y4. Similarly, the ends of the three wirings 118 arranged in the second branch portion 110Z are arranged in the small branch portions 110Z1, 110Z2, and 110Z3, respectively. Furthermore, the ends of the respective wirings 118 are electrically connected to the bus bars 142 provided at the respective small branch portions 110Z1 , 110Z2 , and 110Z3 .

[0038] Furthermore, the first branch portion 110Y is subjected to a bending process using a pair of parallel bending lines 111a and 111b (see FIG. 111b ) that are farther away from the second branch portion 110Z as they are farther away from the main body portion 110X. Figure 5A ). The portion where the bending process using these bending lines 111a and 111b is performed is called the first bending portion 111. The first bending portion 111 is bent in such a way that the bending direction of the bending line 111a of one of a pair of parallel bending lines 111a and 111b is opposite to the bending direction of the other bending line 111b. In the example shown in the figure, at the bending line 111a, the front end side of the first branch portion 110Y is bent about 180° from the front of the paper surface of FIG. 5 to the back direction (refer to Figure 5B ). In addition, at the bending line 111b, the front end side of the first branch portion 110Y is bent about 180° from the back side of the paper surface of FIG. 5 toward the front side (refer to Figure 5B). In addition, the first bending portion 111 (first branch portion 110Y) may also be configured as shown below. That is, at the bending line 111a, the front end side of the first branch portion 110Y may also be bent about 180° from the back side of the paper surface of FIG. 5 to the front side of the paper surface of FIG. 5 . In addition, at the bending line 111b, the front end side of the first branch portion 110Y may also be bent about 180° from the front side of the paper surface of FIG. 5 to the back side of the paper surface of FIG.

[0039] Similarly, the second branch portion 110Z is provided with a pair of parallel bending lines 112a and 112b (see FIG. 1 ) which are farther away from the first branch portion 110Y as they are farther away from the main body portion 110X. Figure 5A ) is subjected to a bending process. The portion where the bending process using these bending lines 112a, 112b is implemented is referred to as the second bending portion 112. The second bending portion 112 is bent in such a manner that the bending direction of the bending line 112a of one of a pair of parallel bending lines 112a, 112b and the bending direction of the bending line 112b of the other are opposite to each other. In the illustrated example, at the bending line 112a, the front end side of the second branch portion 110Z is bent by approximately 180° from the front to the back of the paper surface of FIG. 5. In addition, at the bending line 112b, the front end side of the second branch portion 110Z is bent by approximately 180° from the back to the front of the paper surface of FIG. 5. In addition, the second bending portion 112 (second branch portion 110Z) may also be constructed as follows. That is, at the bending line 112a, the front end side of the second branch portion 110Z can also be bent about 180° from the back side of the paper surface of Figure 5 to the front side. In addition, at the bending line 112b, the front end side of the second branch portion 110Z can also be bent about 180° from the front side of the paper surface of Figure 5 to the back side.

[0040] It goes without saying that the width C of the main body 110X determined by the width of the connector 130 does not change before and after the bending process. The maximum width of the pair of branch portions (the first branch portion 110Y and the second branch portion 110Z) satisfies B>B1 if the maximum width before the bending process is set to B1 and the maximum width after the bending process is set to B. In addition, the maximum width B after the bending process is determined according to the width of the battery 200.

[0041] In addition, regarding the length of the long side direction of the FPC 110, if the length before the bending process is L and the length after the bending process is L1, L1<L is satisfied. In addition, it is desirable that the length L1 after the bending process is set so that the FPC 110 does not substantially sag when the FPC 110 is mounted on the battery 200 and the connector 130 is connected to the voltage monitoring device body 300. Furthermore, it is desirable that the length L before the bending process is set to a length including a surplus length portion in consideration of mounting workability.

[0042] <Advantages of the FPC and battery module of this embodiment>

[0043] According to the FPC110 and the battery module 100 of the present embodiment, for the FPC110, the first branch portion 110Y and the second branch portion 110Z are respectively provided with a first bending portion 111 and a second bending portion 112. As a result, the maximum width of a pair of branches (the first branch portion 110Y and the second branch portion 110Z) after the bending process becomes wider than before the bending process. That is, as described above, B>B1 is satisfied. Therefore, even if the maximum width B1 of a pair of branches before the bending process is narrower than the desired width, the maximum width B of a pair of branches after the bending process can be made to be the desired width. As a result, the maximum width B1 of a pair of branches before the bending process can be made narrower than the desired width, so that waste materials can be reduced. In other words, the number of FPC110 obtained from one base material can be increased.

[0044] In addition, in this embodiment, even if the length L1 of the long side direction of the FPC 110 after the bending process is set so that the FPC 110 does not substantially relax when the FPC 110 is mounted on the battery 200, the FPC 110 can be extended and retracted (in Figure 3 Refer to arrow S in the figure). Thus, obstacles to installation operability can be suppressed. That is, by setting the length L before the bending process to include a surplus length portion that takes installation operability into consideration, installation operability can be improved. Moreover, by setting the length L1 as described above, the up and down vibration of FPC110 can be suppressed, so the interference between FPC110 and other components can be suppressed. In addition, damage to FPC110 caused by up and down vibration can also be suppressed. In addition, since the effect of absorbing vibrations can be exerted by the first bent portion 111 and the second bent portion 112, the generation of resonance can also be suppressed. In addition, as Figure 6 As shown, the FPC 110 can also be folded back at the first bend portion 111 and the second bend portion 112. Therefore, when the battery module 100 is transported, the battery module 100 can be made compact as a whole. Therefore, the degree of freedom of the shape of the battery module 100 during transportation is increased. As a result, the handling performance of the battery module 100 can be improved.

[0045] (other)

[0046] In the configuration shown in the above-mentioned embodiment, both branch portions (the first branch portion 110Y and the second branch portion 110Z) of a pair of branch portions are provided with bending portions (the first bending portion 111 and the second bending portion 112).

[0047] However, the embodiment of the present invention is not limited to such a configuration. In the configuration of the embodiment of the present invention, a bending portion may be provided only on one of the pair of branch portions. Fig. 7A As shown in the FPC110A of the modification example 1 shown in , it is also possible to adopt a structure in which a bending portion (first bending portion 111) is provided only in the first branch portion 110Y, and no bending process is performed on the second branch portion 110Z. Even in this case, the maximum width of a pair of branch portions (first branch portion 110Y and second branch portion 110Z) after the bending process becomes wider than before the bending process. Therefore, even if the maximum width of a pair of branch portions before the bending process is narrower than the desired width, the maximum width B2 of the pair of branch portions after the bending process can be made the desired width. Thus, the maximum width of a pair of branch portions before the bending process can be made narrower than the desired width, so that waste materials can be reduced.

[0048] In addition, in the configuration shown in the above-described embodiment, one bending portion (the first bending portion 111 and the second bending portion 112 ) is provided in each of the first branch portion 110Y and the second branch portion 110Z.

[0049] However, the embodiments of the present invention are not limited to such a configuration. In the configuration of the embodiments of the present invention, a bending portion including a pair of parallel bending lines may be provided at multiple locations of each branch portion. Figure 7B As shown in the FPC110B of the modification example 2 shown in the figure, it is also possible to adopt a structure in which two bends (the first bend 111 and the third bend 113) are provided in the first branch 110Y, and two bends (the second bend 112 and the fourth bend 114) are provided in the second branch 110Z. In addition, since the structure and bending method of the third bend 113 and the fourth bend 114 are the same as the structure and bending method of the first bend 111 and the second bend 112, their description is omitted. Of course, even in the case of the FPC110B of the modification example 2, the same effect as the FPC110 of the above-mentioned embodiment can be obtained. In the case of the modification example 2, there is the following advantage: compared with the structure of the above-mentioned embodiment, it is easy to make the maximum width B3 of a pair of branch portions after the bending process wider relative to the maximum width of the pair of branch portions before the bending process.

[0050] In addition, three or more bends may be provided in one branch portion. In addition, the number of bends provided in the first branch portion 110Y and the number of bends provided in the second branch portion 110Z may be different from each other.

[0051] Furthermore, the flexible printed wiring board of the present invention may be the following first flexible printed wiring board.

[0052] A first flexible printed wiring board, characterized in that the first flexible printed wiring board is installed on a battery formed by arranging a plurality of unit cells, the first flexible printed wiring board includes: a main body; and a pair of branches, which are branched into two from the main body and are both arranged on the battery, and a bending process is performed on at least one of the pair of branches, and the bending process uses a pair of parallel bending lines that move away from the other branch as they move away from the main body, and the bending is performed in a manner such that the bending direction of one of the pair of parallel bending lines is opposite to the bending direction of the other branch.

[0053] The detailed description has been given for the purpose of example and illustration. In light of the above teachings, many variations and changes are possible. The detailed description is not exhaustive or intended to limit the subject matter described herein. Although the subject matter has been described in words with specific structural features and / or method processes, it should be understood that the subject matter defined in the claims is not necessarily limited to the specific features or specific processes described. More specifically, the specific features and specific processes are described as examples of implementing the claims.

Claims

1. A flexible printed wiring board, characterized in that include: Main body; as well as A pair of branch portions branching from the main body portion into two, both of which are arranged on a battery having a plurality of arranged unit cells, A bending process is performed on at least one of the pair of branch portions, wherein the bending process uses a pair of parallel bending lines that are farther away from the other branch portion as they are farther away from the main body portion. and the at least one branch portion is bent in such a manner that a bending direction of one of the pair of parallel bending lines and a bending direction of the other bending line are in opposite directions to each other, The branch portion that is closer to the main body than the pair of parallel bending lines before bending and the branch portion that is farther away from the main body than the pair of parallel bending lines have an overlapping portion after bending, thereby allowing at least one of the branch portions to be stretched and retracted in the long side direction of the branch portion.

2. A battery module, characterized in that: include: A flexible printed wiring board is mounted on a battery having a plurality of arranged unit cells; a plurality of bus bars electrically connected to the plurality of wirings provided on the flexible printed wiring board, respectively, and electrically connected to the respective electrodes provided on the plurality of unit cells, respectively; as well as A connector fixed to an end portion of the flexible printed wiring board, The flexible printed wiring board comprises: Main body; as well as A pair of branch parts, branching from the main body into two, both arranged on the battery, A bending process is performed on at least one of the pair of branch portions, wherein the bending process uses a pair of parallel bending lines that are farther away from the other branch portion as they are farther away from the main body portion. and the at least one branch portion is bent in such a manner that a bending direction of one of the pair of parallel bending lines and a bending direction of the other bending line are in opposite directions to each other, The branch portion that is closer to the main body than the pair of parallel bending lines before bending and the branch portion that is farther away from the main body than the pair of parallel bending lines have an overlapping portion after bending, thereby allowing at least one of the branch portions to be stretched and retracted in the long side direction of the branch portion.

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