Flexible printed wiring board and battery module

Abstract

To provide a flexible printed wiring board and a battery module which allow for improvement of efficiency of work of mounting them on batteries, and furthermore in which flexibility for changing the arrangement of wiring can be increased.SOLUTION: A flexible printed wiring board comprises a base film 110, and a plurality of lines of wiring 130A and 130B formed on the base film 110, and in an area attached to a battery, a conductor portion serving as a plurality of lines of wiring 130A are provided only on one surface of the base film 110, and the conductor portions serving as the plurality of lines of wirings 130A and 130B are respectively provided on both surfaces of the film 110 in at least a part of an area away from the area attached to the battery, and a plurality of through-holes 141 are arranged which electrically connect the wiring 130A on one surface side of the base film 110 and the wiring 130B on the other surface side.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a flexible printed wiring board that is attached to a battery and a battery module. [Background technology]

[0002] A battery mounted on an electric vehicle or the like is provided with a voltage monitoring device for monitoring the voltage of the battery, for example. This voltage monitoring device is provided with a battery module having a flexible printed circuit board (hereinafter referred to as FPC). A voltage monitoring device according to a conventional example will be described with reference to Figs. 8 to 10. Fig. 8 is a plan view of the battery. Fig. 9 is a side view of the battery. Fig. 10 is a plan view showing a state in which a battery module according to the conventional example is attached to a battery.

[0003] The battery 1200 is composed of a plurality of cells 1210. The plurality of cells 1210 are arranged such that the positive electrodes 1211 and the negative electrodes 1212 are adjacent to each other. The plurality of cells 1210 are connected in series by electrically connecting the adjacent positive electrodes 1211 and the negative electrodes 1212 by bus bars 1114. For ease of explanation, the illustrated example shows the battery 1200 composed of six cells 1210. However, in the case of a battery mounted on an electric vehicle or the like, it is common for the battery to be composed of more cells.

[0004] A battery module 1500 is attached to the upper part of the battery 1200 configured in this manner. The battery module 1500 includes an FPC 1510, a support member 1520 that supports the FPC 1510, a plurality of bus bars 1113 and 1114 supported by the support member 1520, and a connector 1530 that is connected to a voltage monitoring device main body (not shown). The bus bar 1113 is connected to the positive electrode 1211 and the negative electrode 1212 that are both ends of the cells 1210 that are connected in series. The bus bar 1114 is used to electrically connect the positive electrode 1211 and the negative electrode 1212 that are adjacent to each other.

[0005] The FPC 1510 is provided with a plurality of wirings 1511. One ends A11, A12, A13, A14, A15, A16, and A17 of the plurality of wirings 1511 are attached to the bus bars 1113 and 1114, respectively, and the other ends B11, B12, B13, B14, B15, B16, and B17 are attached to the connector 1530. Here, if the potential of one end A11 and the other end B11 is V11, the potential of one end A12 and the other end B12 is V12, and the potential of one end A1n and the other end B1n is V1n, then V11>V12>V13>V14>V15>V16>V17 is satisfied. This is because the plurality of cells 1210 are connected in series, as described above.

[0006] In such a configuration, the arrangement of the multiple wirings 1511 at the connector 1530 is, from the top in FIG. 10, the other ends B11, B13, B15, B17, B16, B14, and B12. Generally, the greater the potential difference between adjacent wirings in an FPC and between adjacent terminals in a connector connected to an FPC, the more likely a short circuit due to migration or the like will occur. Therefore, it is desirable to reduce the potential difference between adjacent wirings and terminals as much as possible. In other words, the arrangement of the multiple wirings 1511 at the connector 1530 is desirably in the order of the other ends B11, B12, B13, B14, B15, B16, and B17.

[0007] However, in FPC, multiple wiring (conductor layers) printed on the base film In the part (a), the arrangement of adjacent wiring cannot be changed simply by modifying the printing pattern. As a known method, it is possible to change the order of the wiring by crossing the wiring three-dimensionally using jumpers. However, adopting a structure using jumpers increases costs, so a structure that does not use jumpers is preferable.

[0008] Therefore, as a method for changing the arrangement of wiring without using jumpers, it is possible to apply the following virtualization technology.

[0009] (Virtual Technology 1) The FPC and the battery module according to the hypothetical technology 1 will be described with reference to Figs. 11 to 15. Fig. 11 is a plan view (viewed from above) that shows a state in which the battery module according to the hypothetical technology 1 is attached to a battery. Fig. 12 is a side view that shows a state in which the battery module according to the hypothetical technology 1 is attached to a battery. Fig. 13 is a plan view of the FPC according to the hypothetical technology 1. In Figs. 11 and 13, the wiring is shown in dotted lines in a transparent manner in order to make the configuration of the FPC easier to understand. Fig. 14 is a schematic cross-sectional view of the FPC according to the hypothetical technology 1, and is a cross-sectional view taken along the line AA in Fig. 13. Fig. 15 is a front view of the battery module according to the hypothetical technology 1, and is a schematic configuration diagram of the battery module as seen from the connector side (left side in Figs. 11 and 12). The configuration of the battery is as described above, and therefore will not be described.

[0010] <Voltage monitoring device and battery module> In particular, the overall configuration of a voltage monitoring device 1100 and a battery module 1110 according to the virtual technology 1 will be described with reference to FIG. 11 and FIG. 12. The voltage monitoring device 1100 includes a battery module 1110, a voltage monitoring device main body 1120, and a temperature measuring device main body 1130. The battery module 1110 includes an FPC 1111, a support member 1112 that supports the FPC 1111, a plurality of bus bars 1113 and 1114 supported by the support member 1112, a first connector 1115 that is connected to the voltage monitoring device main body 1120, and a second connector 1116 that is connected to the temperature measuring device main body 1130. The bus bar 1113 is connected to the positive electrode 1211 and the negative electrode 1212 that are both ends of the cells 1210 that are connected in series. The bus bar 1114 is used to electrically connect the adjacent positive electrode 1211 and the negative electrode 1212.

[0011] <Flexible Printed Circuit (FPC)> In particular, the FPC 1111 according to the hypothetical technology 1 will be described with reference to FIG. 11 and FIG. 13 to FIG. 15. The FPC 1111 includes a flexible film 1111a and a plurality of wirings (voltage monitoring wirings 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, 1111c4 and temperature measurement wiring 1111d). The film 1111a includes a base film 1111a1, a cover film 1111a2, and an adhesive layer 1111a3 that bonds them together. The plurality of wirings are made of copper foil or the like. In the FPC 1111 according to the hypothetical technology 1, all of the wirings are provided on one side of the base film 1111a1.

[0012] The FPC 1111 according to the hypothetical technique 1 includes a trunk 1111H, a portion of which is supported by a support member 1112, and a first branch portion 1111I, a second branch portion 1111J, and a third branch portion 1111K branching off from the trunk 1111H.

[0013] In the virtual technology 1, a plurality of voltage monitoring wirings 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, and 1111c4 for monitoring the voltage of the battery 1200, and a plurality of temperature measurement wirings 1111d for measuring the temperature of the cells 1210 are provided. In the illustrated example, four temperature measuring wires are provided to measure the temperature at two locations. The trunk 1111H is provided with all the wiring. The first branch 1111I is provided with voltage monitoring wirings 1111b1, 1111b2, and 1111b3, the second branch 1111J is provided with voltage monitoring wirings 1111c1, 1111c2, 1111c3, and 1111c4, and the third branch 1111K is provided with the temperature measurement wiring 111d.

[0014] The FPC 1111 is arranged such that a plurality of voltage monitoring wires 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, 1111c4 and a temperature measurement wire 1111d cross between the positive electrode 1211 and the negative electrode 1212 of each cell 1210. In addition, each end of the plurality of voltage monitoring wires 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, 1111c4 is connected to a first connector 1115, and each end of the plurality of temperature measurement wires 1111d is connected to a second connector 1116.

[0015] In the FPC 1111, a first arrangement region in which the plurality of voltage monitoring wires 1111b1, 1111b2, and 1111b3 are arranged, and a second arrangement region in which the plurality of voltage monitoring wires 1111c1, 1111c2, 1111c3, and 1111c4 are arranged are provided on one side and the other side of the arrangement region of the plurality of temperature measurement wires 1111d. In the trunk 1111H, the first arrangement region is provided on the upper side in FIG. 13 and on the right side in FIG. 14 with respect to the arrangement region of the plurality of temperature measurement wires 1111d. Moreover, the second region is provided on the lower side in FIG. 13 and on the left side in FIG. 14 with respect to the arrangement region of the plurality of temperature measurement wires 1111d.

[0016] In the trunk 1111H, the multiple voltage monitoring wires 1111b1, 1111b2, and 1111b3 arranged in the first arrangement region are connected to the cell 1210 arranged at a position farther from the first connector 1115 as they are closer to the arrangement region of the temperature measurement wire 1111d. Similarly, in the trunk 1111H, the multiple voltage monitoring wires 1111c1, 1111c2, 1111c3, and 1111c4 arranged in the second arrangement region are connected to the cell 1210 arranged at a position farther from the first connector 1115 as they are closer to the arrangement region of the temperature measurement wire 1111d. As can be seen from FIGS. 11 and 13, the potentials in the voltage monitoring wires satisfy the relationship Vc4>Vb3>Vc3>Vb2>Vc2>Vb1>Vc1. The potentials of the voltage monitoring wires 1111b1, 1111b2, and 1111b3 are designated as Vb1, Vb2, and Vb3, respectively, and the potentials of the voltage monitoring wires 1111c1, 1111c2, 1111c3, and 1111c4 are designated as Vc1, Vc2, Vc3, and Vc4, respectively.

[0017] 13, the FPC 1111 according to the hypothetical technique 1 is in a state in which the tip side of the first branch portion 1111I is folded toward the back of the page along the dashed line P1, and the tip of the first branch portion 1111I and the tip of the second branch portion 1111J are connected to the first connector 1115. The tip of the third branch portion 1111K is connected to the second connector 1116.

[0018] As described above, at the portion connected to the first connector 1115, the FPC 1111 is used in a state in which a portion of the FPC 1111 is bent so that the front and back surfaces of the FPC 1111 face each other and the multiple voltage monitoring wirings 1111b1, 1111b2, and 1111b3 arranged in the first arrangement area are parallel to the multiple voltage monitoring wirings 1111c1, 1111c2, 1111c3, and 1111c4 arranged in the second arrangement area.

[0019] 15 are electrically connected to the voltage monitoring wirings 1111b1, 1111b2, and 1111b3, respectively. Also, the terminals 1115C1, 1115C2, 1115C3, and 1115C4 of the first connector 1115 are electrically connected to the voltage monitoring wirings 1111c1, 1111c2, 1111c3, and 1111c4, respectively. Furthermore, the multiple terminals 1116D of the second connector 1116 are electrically connected to the temperature measurement wirings 1111d, respectively.

[0020] As described above, the relationship Vc4>Vb3>Vc3>Vb2>Vc2>Vb1>Vc1 is satisfied, and therefore the relationship VC4>VB3>VC3>VB2>VC2>VB1>VC1 is satisfied. Note that the potentials of the terminals 1115B1, 1115B2, and 1115B3 are VB1, VB2, and VB3, respectively, and the potentials of the terminals 1115C1, 1115C2, 1115C3, and 1115C4 are VC1, VC2, VC3, and VC4, respectively.

[0021] <Advantages of the flexible printed wiring board and battery module related to hypothetical technology 1> According to the FPC 1111 relating to the virtual technique 1, as described above, the potentials of the voltage monitoring wirings satisfy the relationship of Vc4>Vb3>Vc3>Vb2>Vc2>Vb1>Vc1. That is, in the multiple voltage monitoring wirings 1111b1, 1111b2, and 1111b3 arranged in the first arrangement region, the potential difference between adjacent wirings is the potential difference between adjacent cells. Also, in the multiple voltage monitoring wirings 1111c1, 1111c2, 1111c3, and 1111c4 arranged in the second arrangement region, the potential difference between adjacent wirings is the potential difference between adjacent cells. That is, in the voltage monitoring wirings, the potential difference between adjacent wirings is the smallest potential difference between two cells 1210 in the multiple cells 1210 constituting the battery 1200.

[0022] Moreover, according to the FPC 1111 relating to the hypothetical technology 1, as described above, the relationship VC4>VB3>VC3>VB2>VC2>VB1>VC1 is satisfied. This makes it possible to minimize the potential difference between the adjacent voltage monitoring wirings 1111b1, 1111b2, and 1111b3 on the first arrangement area side and the voltage monitoring wirings 1111c1, 1111c2, 1111c3, and 1111c4 on the second arrangement area side, and also minimize the potential difference between adjacent terminals in the first connector 1115.

[0023] For the reasons described above, the occurrence of migration can also be suppressed in the FPC 1111 having the voltage monitoring wires 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, and 1111c4 and the temperature measurement wire 1111d integrated therewith.

[0024] In the FPC 1111 according to the hypothetical technology 1, all of the wiring (voltage monitoring wiring 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, 1111c4 and temperature measurement wiring 1111d) are provided on one side of the base film 1111a1.

[0025] Furthermore, in the battery module 1110 according to the virtual technique 1, a first connector 1115 to which the ends of the voltage monitoring wires 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, and 1111c4 are connected and a second connector 1116 to which the ends of the temperature measurement wires 1111d are connected are separately provided. This prevents the temperature measurement wire 1111d, which has a lower potential than the voltage monitoring wires 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, and 1111c4, from being affected by the potential of the voltage monitoring wires 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, and 1111c4. Therefore, the temperature measurement accuracy can be improved.

[0026] (Virtual Technology 2) 16 and 17 show a hypothetical technique 2. In this hypothetical technique 2, the configuration of the FPC is different from that in the hypothetical technique 1. The configuration other than the FPC can be applied to the configuration described in the hypothetical technique 1, so the description thereof will be omitted.

[0027] 16 and 17 are plan views of an FPC according to the hypothetical technique 2. FIG. 16 shows a state before bending, and FIG. 17 shows a state after bending (state during use). In FIG. 16 and FIG. 17, the wiring is shown by dotted lines in a see-through manner to make the configuration of the flexible printed wiring board easier to understand. The FPC 1111A according to the hypothetical technique 2 also includes a flexible film 1111a and a plurality of wirings (voltage monitoring wirings 1111Ab1, 1111Ab2, 1111Ab3, 1111Ac1, 1111Ac2, 1111Ac3, 1111Ac4 and temperature measurement wiring 1111Ad) in the same manner as the hypothetical technique 1. Although not shown in particular, the film 1111a according to the hypothetical technique 2 also includes a base film, a cover film, and an adhesive layer that bonds them together in the same manner as the hypothetical technique 1. The plurality of wirings are made of copper foil or the like. In the FPC 1111A according to the hypothetical technique 2, similarly to the hypothetical technique 1, all the wiring is provided on one surface of the base film.

[0028] Moreover, the FPC 1111A according to the hypothetical technique 2 includes a trunk 1111AH, a portion of which is supported by a support member 1112, and a first branch portion 1111AI, a second branch portion 1111AJ, and a third branch portion 1111AK branched off from the trunk 1111AH. Note that the configurations of the battery module and the voltage monitoring device other than the FPC 1111A can be applied to the configurations described in the hypothetical technique 1. Therefore, the configurations not shown in Figs. 16 and 17 will be described using the symbols described in the hypothetical technique 1.

[0029] In the virtual technology 2, there are provided a plurality of voltage monitoring wirings 1111Ab1, 1111Ab2, 1111Ab3, 1111Ac1, 1111Ac2, 1111Ac3, 1111Ac4 for monitoring the voltage of the battery 1200, and a plurality of temperature measurement wirings 1111Ad for measuring the temperature of the cells 1210. In the illustrated example, four temperature measurement wirings 1111Ad are provided to measure the temperature at two locations. All wirings are provided in the trunk 1111AH. The first branch 1111AI is provided with voltage monitoring wirings 1111Ab1, 1111Ab2, and 1111Ab3, the second branch 1111AJ is provided with voltage monitoring wirings 1111Ac1, 1111Ac2, 1111Ac3, and 1111Ac4, and the third branch 1111AK is provided with a temperature measurement wiring 1111Ad.

[0030] The FPC 1111A is arranged such that a plurality of voltage monitoring wires 1111Ab1, 1111Ab2, 1111Ab3, 1111Ac1, 1111Ac2, 1111Ac3, 1111Ac4 and a temperature measurement wire 1111Ad cross between the positive electrode 1211 and the negative electrode 1212 of each cell 1210. In addition, each end of the plurality of voltage monitoring wires 1111Ab1, 1111Ab2, 1111Ab3, 1111Ac1, 1111Ac2, 1111Ac3, 1111Ac4 is connected to a first connector 1115, and each end of the plurality of temperature measurement wires 1111Ad is connected to a second connector 1116.

[0031] In the FPC 1111A, a first arrangement region in which the plurality of voltage monitoring wires 1111Ab1, 1111Ab2, and 1111Ab3 are arranged, and a second arrangement region in which the plurality of voltage monitoring wires 1111Ac1, 1111Ac2, 1111Ac3, and 1111Ac4 are arranged are provided on one side and the other side of the arrangement region of the plurality of temperature measurement wires 1111Ad, respectively. In the trunk 1111AH, the first arrangement region is provided on the upper side in FIG. 16 with respect to the arrangement region of the plurality of temperature measurement wires 1111Ad. Also, in the trunk 1111AH, the second region is provided on the lower side in FIG. 16 with respect to the arrangement region of the plurality of temperature measurement wires 1111Ad.

[0032] In the trunk 1111AH, the multiple voltage monitoring wirings 1111Ab1, 1111Ab2, and 1111Ab3 arranged in the first arrangement region are connected to the cells 1210 arranged at positions farther from the first connector 1115 as they are closer to the arrangement region of the temperature measurement wiring 1111Ad. Similarly, in the trunk 1111AH, the multiple voltage monitoring wirings The closer the temperature measurement wires 1111Ad are to the placement area, the further the cells 1210 from the first connector 1115 are connected to the voltage monitoring wires 1111Ac1, 1111Ac2, 1111Ac3, and 1111Ac4. Thus, similar to the case of the virtual technology 1, the potentials of the voltage monitoring wires 1111Ab1, 1111Ab2, and 1111Ab3 are respectively designated as VAb1, VAb2, and VAb3, and the potentials of the voltage monitoring wires 1111Ac1, 1111Ac2, 1111Ac3, and 1111Ac4 are respectively designated as VAc1, VAc2, VAc3, and VAc4.

[0033] 16, the FPC 1111 according to the hypothetical technique 2 has the tip of the first branch 1111AI bent toward the back of the page around the two-dot chain line P2, and the tip of the first branch 1111AI and the tip of the second branch 1111AJ are connected to the first connector 1115. Also, in FIG. 16, the tip of the third branch 1111AK is bent toward the front of the page around the two-dot chain line P3, and the tip of the third branch 1111AK is connected to the second connector 1116.

[0034] As described above, even in virtual technology 2, the FPC1111A is used in a state in which a portion of the FPC1111A is bent so that the front and back surfaces of the FPC1111A face each other at the portion connected to the first connector 1115, and so that the multiple voltage monitoring wirings 1111Ab1, 1111Ab2, 1111Ab3 arranged in the first arrangement area are parallel to the multiple voltage monitoring wirings 1111Ac1, 1111Ac2, 1111Ac3, 1111Ac4 arranged in the second arrangement area.

[0035] In the case of the hypothetical technology 2, the terminals 1115B1, 1115B2, and 1115B3 of the first connector 1115 are electrically connected to the voltage monitoring wirings 1111Ab1, 1111Ab2, and 1111Ab3, respectively. Also, the terminals 1115C1, 1115C2, 1115C3, and 1115C4 of the first connector 1115 are electrically connected to the voltage monitoring wirings 1111Ac1, 1111Ac2, 1111Ac3, and 1111Ac4, respectively.

[0036] As described above, the relationship VAc4>VAb3>VAc3>VAb2>VAc2>VAb1>VAc1 is satisfied, and therefore, similarly to the case of the hypothetical technology 1, the potentials of the terminals in the first connector 1115 satisfy the relationship VC4>VB3>VC3>VB2>VC2>VB1>VC1.

[0037] The FPC 1111A according to the hypothetical technique 2 configured as above can also provide the same effects as those of the hypothetical technique 1.

[0038] (Virtual Technology 3) 18 and 19 show a hypothetical technique 3. In the hypothetical technique 3, the configuration of the FPC is different from that of the hypothetical technique 1. The configuration other than the FPC can be applied to the configuration described in the hypothetical technique 1, and therefore the description thereof will be omitted.

[0039] Fig. 18 is a plan view of a flexible printed wiring board according to hypothetical technique 3. In Fig. 18, wiring is shown in a see-through manner with dotted lines in order to make the configuration of the flexible printed wiring board easier to understand. Fig. 19 is a schematic cross-sectional view of the flexible printed wiring board according to hypothetical technique 3, and is a cross-sectional view taken along the line AA in Fig. 18.

[0040] In the FPC 1111B according to the hypothetical technique 3, similarly to the hypothetical technique 1, a flexible film 1111a and a plurality of wirings (voltage monitoring wirings 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, 1111Bc4, 1111Bc5, 1111Bc6, 1111Bc7, 1111Bc8, 1111Bc9, 1111Bc10, 1111Bc11, 1111Bc12, 1111Bc13, 1111Bc14, 1111Bc15, 1111Bc16, 1111Bc17, 1111Bc18, 1111Bc19 ... The film 1111a according to the hypothetical technique 3 is composed of a base film 1111a1, a pair of cover films 1111a2 and 1111a4, an adhesive layer 1111a3 that bonds the base film 1111a1 and the front cover film 1111a2, and an adhesive layer 1111a5 that bonds the base film 1111a1 and the back cover film 1111a4. The above-mentioned multiple wirings are composed of copper foil or the like. The FPC 1111B relating to hypothetical technology 3 differs from hypothetical technology 1 in that voltage monitoring wiring 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 are provided on one side (front side) of the base film 1111a1, and temperature measurement wiring 1111Bd is provided on the other side (rear side) of the base film 1111a1.

[0041] Moreover, the FPC 1111B according to the hypothetical technique 3 includes a trunk 1111BH, a portion of which is supported by a support member 1112, and a first branch portion 1111BI, a second branch portion 1111BJ, and a third branch portion 1111BK branching off from the trunk 1111BH. Note that the configurations of the battery module and the voltage monitoring device other than the FPC 1111B are applicable to the configurations described in the hypothetical technique 1. Therefore, the components not shown in Figs. 18 and 19 will be described using the symbols described in the hypothetical technique 1.

[0042] The virtual technology 3 also includes a plurality of voltage monitoring wirings 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 for monitoring the voltage of the battery 1200, and a plurality of temperature measurement wirings 1111Bd for measuring the temperature of the cells 1210. In the illustrated example, four temperature measurement wirings 1111Bd are provided to measure the temperature at two locations. All wirings are provided in the trunk 1111BH. The first branch 1111BI is provided with voltage monitoring wirings 1111Bb1, 1111Bb2, and 1111Bb3, the second branch 1111BJ is provided with voltage monitoring wirings 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4, and the third branch 1111BK is provided with a temperature measurement wiring 1111Bd.

[0043] The FPC 1111B is arranged such that a plurality of voltage monitoring wires 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, 1111Bc4 and a temperature measurement wire 1111Bd cross between the positive electrode 1211 and the negative electrode 1212 of each cell 1210. In addition, each end of the plurality of voltage monitoring wires 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, 1111Bc4 is connected to the first connector 1115, and each end of the plurality of temperature measurement wires 1111Bd is connected to the second connector 1116.

[0044] In the FPC 1111B, a first arrangement region in which the plurality of voltage monitoring wires 1111Bb1, 1111Bb2, and 1111Bb3 are arranged, and a second arrangement region in which the plurality of voltage monitoring wires 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 are arranged are provided on one side and the other side of the arrangement region of the plurality of temperature measurement wires 1111Bd, respectively. In the trunk 1111BH, the first arrangement region is provided on the upper side in FIG. 18 with respect to the arrangement region of the plurality of temperature measurement wires 1111Bd. Also, in the trunk 1111BH, the second region is provided on the lower side in FIG. 18 with respect to the arrangement region of the plurality of temperature measurement wires 1111Bd.

[0045] In the trunk 1111BH, the multiple voltage monitoring wirings 1111Bb1, 1111Bb2, and 1111Bb3 arranged in the first arrangement region are connected to cells 1210 arranged at positions farther from the first connector 1115 the closer they are to the arrangement region of the temperature measurement wiring 1111Bd. Similarly, in the trunk 1111BH, the multiple voltage monitoring wirings 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 arranged in the second arrangement region are connected to cells 1210 at positions farther from the first connector 1115. The closer to the placement area of ​​the temperature measurement wiring 1111Bd, the more it is connected to the cell 1210 that is placed at a position farther from the first connector 1115. Therefore, similar to the case of virtual technology 1, the potentials of the voltage monitoring wirings satisfy the relationship VBc4>VBb3>VBc3>VBb2>VBc2>VBb1>VBc1. Note that the potentials of the voltage monitoring wirings 1111Bb1, 1111Bb2, and 1111Bb3 are VBb1, VBb2, and VBb3, respectively, and the potentials of the voltage monitoring wirings 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 are VBc1, VBc2, VBc3, and VBc4, respectively.

[0046] 18, the tip side of the first branch portion 1111BI is bent toward the back of the page along the dashed line P1, and the tip of the first branch portion 1111BI and the tip of the second branch portion 1111BJ are connected to the first connector 1115. The tip of the third branch portion 1111BK is connected to the second connector 1116.

[0047] As described above, even in virtual technology 3, at the portion connected to the first connector 1115, the FPC 1111B is used in a state in which a portion of the FPC 1111B is bent so that the front and back surfaces of the FPC 1111B face each other and the multiple voltage monitoring wirings 1111Bb1, 1111Bb2, 1111Bb3 arranged in the first arrangement area are parallel to the multiple voltage monitoring wirings 1111Bc1, 1111Bc2, 1111Bc3, 1111Bc4 arranged in the second arrangement area.

[0048] In the case of the hypothetical technology 3, the terminals 1115B1, 1115B2, and 1115B3 of the first connector 1115 are electrically connected to the voltage monitoring wirings 1111Bb1, 1111Bb2, and 1111Bb3, respectively. Also, the terminals 1115C1, 1115C2, 1115C3, and 1115C4 of the first connector 1115 are electrically connected to the voltage monitoring wirings 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4, respectively.

[0049] As described above, the relationship VBc4>VBb3>VBc3>VBb2>VBc2>VBb1>VBc1 is satisfied, and therefore, similarly to the case of virtual technology 1, the potentials of the terminals in the first connector 1115 satisfy the relationship VC4>VB3>VC3>VB2>VC2>VB1>VC1.

[0050] The FPC 1111B according to the hypothetical technique 3 configured as above can also provide the same effect as in the hypothetical technique 1. However, in the case of the hypothetical technique 3, the voltage monitoring wirings 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 are provided on one side of the base film 1111a1, and the temperature measurement wiring 1111Bd is provided on the opposite side, so the cost increases compared to the hypothetical technique 1. However, in the case of the hypothetical technique 3, there is an advantage in that the wiring density of the voltage monitoring wirings 1111Bb1, 1111Bb2, 1111Bb3, 1111Bc1, 1111Bc2, 1111Bc3, and 1111Bc4 can be increased, thereby increasing the degree of freedom in design. In the case of the hypothetical technique 3, the temperature measurement wiring 1111d is provided on the back side of the base film 1111a1. Therefore, the terminal contact portion of the second connector 1116 to which the temperature measurement wiring 1111d is connected is on the opposite side to that in the hypothetical technique 1. However, by providing a through hole near the tip of the third branch 1111BK and forming the conductive portion of the temperature measurement wiring 1111d on the front side of the base film 1111a1, the second connector 1116 used in the hypothetical technique 1 can be used as is.

[0051] (Battery Modifications) 20 and 21 show modified examples of the battery to which the above-mentioned battery modules can be applied. FIG. 20 is a plan view showing a modified example of the battery. FIG. 21 shows a battery according to the modified example. 21 is a plan view showing a state in which a battery module is attached to a battery, in order to make the configuration easier to understand, however, in Fig. 21, only a support member 1112 and bus bars 1113 and 1114 of the battery module are shown.

[0052] The battery 1200A according to this modification is composed of a plurality of cell units 1210A. The cell unit 1210A is composed of a plurality of cells 1210 connected in parallel. In the illustrated example, the cell unit 1210A is composed of two cells 1210 connected in parallel. However, the cell unit may be composed of three or more cells 1210 connected in parallel. The plurality of cell units 1210A are arranged such that the positive electrodes 1211A and the negative electrodes 1212A of the cell units 1210A are adjacent to each other. In addition, the plurality of cell units 1210A are configured to be connected in series by electrically connecting the adjacent positive electrodes 1211A and the negative electrodes 1212A by the bus bar 1114.

[0053] The FPC and the battery module including the FPC shown in each of the hypothetical techniques can be applied to the battery 1200A configured as described above. That is, the voltage can be monitored and the temperature can be measured. For example, in the case of the FPC 1111 according to the hypothetical technique 1, a plurality of voltage monitoring wirings 1111b1, 1111b2, 1111b3, 1111c1, 1111c2, 1111c3, 1111c4 and a temperature measuring wiring 1111d are arranged to cross between the positive electrode 1211A and the negative electrode 1212A of each cell unit 1210A.

[0054] (others) The method of bending the FPC is not limited to the examples shown in the above hypothetical techniques, and the method of bending varies depending on the shape of the trunk. In short, it is sufficient that the front and back surfaces of the flexible printed wiring board face each other at the portion connected to the connector, and that the multiple voltage monitoring wires provided in the first arrangement area and the multiple voltage monitoring wires provided in the second arrangement area are parallel to each other.

[0055] In addition, in the above hypothetical technology, a configuration in which the voltage monitoring device main body 1120 and the temperature measuring device main body 1130 are provided separately has been shown. However, a configuration in which voltage monitoring and temperature measurement are performed by one device may be adopted. In this case, a configuration in which multiple voltage monitoring wires and multiple temperature measurement wires are connected to one connector may be adopted. However, in order to prevent a decrease in the accuracy of the temperature measurement, it is desirable to leave a sufficient gap between the area to which the voltage monitoring wires are connected and the area to which the temperature measurement wires are connected.

[0056] In the above hypothetical technique, the terminals in the connector are arranged vertically and horizontally as shown in FIG. 15. However, it is sufficient that the terminals to which the voltage monitoring wiring is connected and the terminals to which the temperature measurement wiring is connected are parallel to each other. In other words, it is sufficient that the voltage monitoring wirings provided in the first region and the voltage monitoring wirings provided in the second arrangement region are parallel to each other. For example, in FIG. 15, the terminals 1115B1 and 1115C1, the terminals 1115B2 and 1115C2, and the terminals 1115B3 and 1115C3 are arranged vertically and vertically. However, it is also possible that the terminals 1115B1 are located between the terminals 1115C1 and 1115C2, the terminals 1115B2 are located between the terminals 1115C2 and 1115C3, and the terminals 1115B3 are located between the terminals 1115C3 and 1115C4 when viewed in the vertical direction.

[0057] Furthermore, in the above-mentioned hypothetical technology, a configuration was shown in which the cells or cell units are connected in series so that the cell or cell unit located farther from the connector has a higher potential and the cell or cell unit located closer to the connector has a lower potential. Needless to say, the same effect can be obtained even if a configuration is adopted in which the cells or cell units are connected in series so that the potential is lower and the potential is higher for cells or cell units installed closer to the connector.

[0058] As described above, by adopting a configuration in which the FPC is bent, it is possible to change the arrangement of the wiring near the connector.

[0059] However, in the configurations related to each of the hypothetical techniques described above, while the shape of the FPC becomes complex, the degree of freedom to change the wiring arrangement is not so large, and there is still room for improvement. In addition, when a configuration in which wiring is provided on both sides of the base film is adopted, as in the case of hypothetical technique 3, the degree of freedom to change the wiring arrangement can be increased compared to hypothetical techniques 1 and 2. However, in the case of such a configuration, the flexibility is reduced, which causes a problem that the work of attaching to the battery is reduced. [Prior art documents] [Patent documents]

[0060] [Patent Document 1] JP 2010-56035 A [Patent Document 2] JP 2014-86246 A [Patent Document 3] JP 2016-85930 A [Patent Document 4] JP 2017-199804 A [Patent Document 5] JP 2018-142505 A Summary of the Invention [Problem to be solved by the invention]

[0061] An object of the present invention is to provide a flexible printed wiring board and a battery module that can increase the ease of attachment to a battery while increasing the freedom to change the arrangement of wiring. [Means for solving the problem]

[0062] The present invention employs the following means to solve the above problems.

[0063] That is, the flexible printed wiring board of the present invention is A flexible printed wiring board attached to a battery configured by arranging a plurality of cells, A base film; A plurality of wirings formed on the base film; Equipped with The area where the battery is attached a top surface area of ​​the battery In the above embodiment, conductor portions serving as the wirings are provided only on one surface of the base film, before Conductive portions that become the plurality of wirings are provided on both surfaces of the base film, and a plurality of conductive portions are arranged to electrically connect the wirings on one surface side of the base film to the wirings on the other surface side. A double-sided structure is disposed in at least a part of a region separated from the upper surface region, and the double-sided structure is not disposed in the upper surface region. It is characterized by:

[0064] Moreover, the battery module of the present invention is A flexible printed wiring board attached to a battery configured by arranging a plurality of cells; a plurality of bus bars each electrically connected to a plurality of wirings provided on the flexible printed wiring board and each electrically connected to each electrode provided on the plurality of cells; a connector fixed to an end of the flexible printed wiring board; A battery module comprising: The flexible printed wiring board is A base film; the plurality of wirings formed on the base film; Equipped with The area where the battery is attached a top surface area of ​​the battery In the above embodiment, conductor portions serving as the wirings are provided only on one surface of the base film, before Conductive portions that become the plurality of wirings are provided on both surfaces of the base film, and a plurality of conductive portions are arranged to electrically connect the wirings on one surface side of the base film to the wirings on the other surface side. A double-sided structure is disposed in at least a part of a region separated from the upper surface region, and the double-sided structure is not disposed in the upper surface region. It is characterized by:

[0065] According to these inventions, a configuration is adopted in which, in a region of the flexible printed wiring board that is attached to the battery, conductor portions that become multiple wirings are provided only on one side of the base film. Therefore, the region of the flexible printed wiring board that is attached to the battery is highly flexible, and therefore has excellent attachment workability. In addition, a configuration is adopted in which, in at least a part of a region away from the region that is attached to the battery, conductor portions that become multiple wirings are provided on both sides of the base film, and multiple conductive portions are arranged to electrically connect the wiring on one side of the base film to the wiring on the other side. This allows the arrangement of the wiring to be changed.

[0066] The conductive portion may be formed of a through hole, and a reinforcing plate may be attached to the flexible printed wiring board in an area where a plurality of the through holes are arranged.

[0067] This prevents the flexible printed wiring board from being bent at the through-holes, and prevents the conductive function from being impaired.

[0068] In addition, the base film may have a plurality of branch portions extending from a trunk portion on which the plurality of wirings are arranged toward each cell, for arranging the wirings, and each of the plurality of branch portions may be provided with a reinforcing film.

[0069] This makes it possible to increase the strength of the branch portions, which tend to weaken easily.

[0070] The flexible printed wiring board may be provided with a bent portion that allows the flexible printed wiring board to expand and contract in the longitudinal direction.

[0071] This can further improve the ease of mounting the flexible printed wiring board.

[0072] The conductive portions electrically connecting the wiring on one surface of the base film to the wiring on the other surface thereof may each be provided in a plurality of portions so that one wiring is electrically connected at a plurality of points.

[0073] As a result, even if the conductive function of some of the conductive parts is impaired due to some influence, the conductive function can be maintained by the other conductive parts, thereby preventing current from being cut off.

[0074] The above configurations may be combined as much as possible. Effect of the Invention

[0075] As described above, according to the present invention, it is possible to improve the ease of attachment to the battery and to increase the degree of freedom in changing the arrangement of the wiring. [Brief description of the drawings]

[0076] [Figure 1] FIG. 1 is a plan view of the battery. [Diagram 2] FIG. 2 is a plan view showing a state in which the battery module according to the first embodiment of the present invention is attached to a battery. [Diagram 3] FIG. 3 is a plan view showing a state in which a connector is attached to the flexible printed wiring board according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view of a flexible printed wiring board according to the first embodiment of the present invention. [Diagram 5] FIG. 5 is a plan view showing a part of a flexible printed wiring board according to a second embodiment of the present invention. [Figure 6] Third Embodiment FIG. 6 is a schematic diagram of a flexible printed wiring board according to a third embodiment of the present invention. [Figure 7] FIG. 7 is a plan view showing a part of a flexible printed wiring board according to a fourth embodiment of the present invention. [Figure 8] FIG. 8 is a plan view of the battery. [Figure 9] FIG. 9 is a side view of the battery. [Figure 10] FIG. 10 is a plan view showing a state in which a battery module according to a conventional example is attached to a battery. [Figure 11] FIG. 11 is a plan view that shows a schematic state in which the battery module according to the hypothetical technique 1 is attached to a battery. [Figure 12] FIG. 12 is a side view that shows a schematic state in which the battery module according to the hypothetical technique 1 is attached to a battery. [Figure 13] FIG. 13 is a plan view of an FPC according to the hypothetical technique 1. FIG. [Figure 14] FIG. 14 is a schematic cross-sectional view of an FPC according to the hypothetical technique 1. [Figure 15] FIG. 15 is a front view of a battery module according to the hypothetical technique 1. FIG. [Figure 16] FIG. 16 is a plan view of an FPC according to the hypothetical technique 2. [Figure 17] FIG. 17 is a plan view of an FPC according to the hypothetical technique 2. [Figure 18] FIG. 18 is a plan view of a flexible printed wiring board according to the hypothetical technique 3. As shown in FIG. [Figure 19] FIG. 19 is a schematic cross-sectional view of a flexible printed wiring board according to the hypothetical technique 3. As shown in FIG. [Figure 20] FIG. 20 is a plan view showing a modified example of the battery. [Figure 21] FIG. 21 is a plan view showing a state in which a battery module is attached to a battery according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described in the embodiment are not intended to limit the scope of the present invention unless otherwise specified.

[0078] Example 1 A flexible printed wiring board and a battery module according to a first embodiment of the present invention will be described with reference to Figs. 1 to 4. Fig. 1 is a plan view of a battery to which a battery module according to the first embodiment of the present invention is attached. Fig. 2 is a plan view of the battery module according to the first embodiment of the present invention. Fig. 3 is a plan view showing a state where a connector is attached to the flexible printed wiring board according to the first embodiment of the present invention. Fig. 4 is a schematic cross-sectional view of the flexible printed wiring board according to the first embodiment of the present invention.

[0079] <Battery> In particular, a battery to which the flexible printed wiring board and the battery module according to the present embodiment are attached will be described with reference to FIG. 1. The battery 1200 is composed of a plurality of cells 1210. The plurality of cells 1210 are arranged such that the positive electrodes 1211 and the negative electrodes 1212 are adjacent to each other. The plurality of cells 1210 are also configured such that the adjacent positive electrodes 1211 and the negative electrodes 1212 are electrically connected to each other by a bus bar provided in the battery module, thereby being connected in series. In the figure, P surrounded by a dotted line indicates a portion to which the bus bar is connected. In the illustrated example, for convenience of explanation, the battery 1200 composed of six cells 1210 is shown. However, in the case of a battery mounted on an electric vehicle or the like, it is common for the battery to be composed of more cells.

[0080] <Battery module> In particular, the overall configuration of the battery module according to this embodiment will be described with reference to Fig. 2. The battery module includes a flexible printed circuit board (hereinafter referred to as "FPC100"), a support member 300 that supports the FPC100, a plurality of bus bars 410, 420 supported by the support member 300, and a connector 500 fixed to an end of the FPC100. The bus bar 410 is connected to a positive electrode 1211 and a negative electrode 1212, which are both ends of the cells 1210 connected in series. The bus bar 420 is used to electrically connect the adjacent positive electrodes 1211 and negative electrodes 1212. The connector 500 is connected to, for example, a voltage monitoring device main body (not shown).

[0081] <Flexible Printed Circuit (FPC)> The FPC 100 according to this embodiment will be described in more detail with reference to Figs. 2 to 4. Generally, FPCs are classified into a single-sided type in which a circuit is provided only on one side, and a double-sided type in which a circuit is provided on both sides. The FPC 100 according to this embodiment has a single-sided portion and a double-sided portion. In Figs. 2 and 3, the range 100A of the FPC 100 is the single-sided portion, and the range 100B is the double-sided portion. Hereinafter, these are referred to as the single-sided portion 100A and the double-sided portion 100B, respectively.

[0082] The FPC 100 has a multi-layer structure made up of multiple layers including a flexible film and a conductor portion that serves as wiring. This will be described with reference to Fig. 4. Fig. 4 is a schematic diagram of a part of a cross section taken parallel to the longitudinal direction of the FPC 100 in the vicinity of the portion indicated by the arrow Q in Fig. 3.

[0083] The FPC 100 includes a base film 110 and conductor parts (forming wirings 130A and 130B) provided on both sides of the base film 110. Between the base film 110 and the conductor parts, adhesive layers 120A and 120B are provided for bonding them. In addition, in the illustrated portion of the FPC 100, a through hole 141 is provided as a conductive part for electrically connecting the wiring 130A and the wiring 130B, and the wiring 130A and the wiring 130B are electrically connected by a through hole plated part 140. In addition, the conductor parts and the through hole plated part 141 forming the wirings 130A and 130B are covered by cover films 160A and 160B bonded by adhesive layers 150A and 150B. The conductor parts are made of copper foil or the like. In addition, the base film 110 and the cover films 160A and 160B are made of polyimide resin (PI), polyethylene naphthalate resin (PEN), or the like.

[0084] Here, in the single-sided structural part 100A, the conductor part and the cover film 160A constituting the wiring 130A are provided, but the conductor part and the cover film 160B constituting the wiring 130B are not provided. That is, in the single-sided structural part 100A, the conductor parts which become the multiple wirings 130A are provided only on one side of the base film 110. For example, the single-sided structural part 100A can be provided by removing the conductor part in a predetermined region on the other side of the base film 110, which has conductor parts provided on both sides of the base film 110 in advance. A part of the single-sided structural part 100A configured as above is attached to the battery 1200 (see FIG. 2).

[0085] In contrast, the above-mentioned double-sided structural part 100B is provided in at least a part of an area away from an area where the battery 1200 is attached. In this double-sided structural part 100B, conductor parts serving as a plurality of wirings 130A, 130B are provided on both surfaces of the base film 110, respectively, and a plurality of through holes 141 are arranged to electrically connect the wiring 130A on one surface side of the base film 110 to the wiring 130B on the other surface side.

[0086] Here, when FPC 100 is bent at a portion where through-hole 141 is provided, cracks or the like may occur in through-hole plated portion 140 at the portion of through-hole 141, which may impair the conductive function. Therefore, it is desirable to attach a reinforcing plate to the area where multiple through-holes 141 are arranged. In Figures 2 and 3, the configuration when reinforcing plate 180 is attached is shown by dotted lines. When reinforcing plate 180 is attached, it is sufficient to adhere reinforcing plate 180 to the surface of cover film 160A with adhesive layer 170, as shown in Figure 4.

[0087] <Wiring arrangement> The arrangement of the wiring in the FPC 100 will be described with reference to Figures 2 and 3. As described above, the conductor portions constituting the wiring 130A, 130B are covered with the cover films 160A, 160B. However, for ease of explanation, in Figures 2 and 3, the wiring 130A on one surface of the base film 110 is shown by a solid line, and the wiring 130B on the other surface is shown by a dotted line.

[0088] In this embodiment, seven wirings 130A are provided on one surface of the base film 110. Three of the wirings are split and electrically connected to each other via three wirings 130B provided on the other surface of the base film 110, thereby forming a single wiring. The wirings 130B provided on the other surface of the base film 110 cross the other wirings 130A on one surface without shorting, thereby changing the arrangement of the wirings.

[0089] The seven wirings 130A have their one ends A1, A2, A3, A4, A5, A6, and A7 attached to the bus bars 410 and 420, respectively, and their other ends B1, B2, B3, B4, B5, B6, and B7 attached to the connector 500 (more specifically, the terminals of the connector (not shown)). Here, if the potential of one end An and the other end Bn is Vn, such as V1 being the potential of one end A1 and the other end B1, and V2 being the potential of one end A2 and the other end B2, then V1>V2>V3>V4>V5>V6>V7 is satisfied. This is because the multiple cells 1210 are connected in series, as described above.

[0090] As described above, by changing the arrangement of the wiring, the other ends B1, B2, B3, B4, B5, B6, and B7 on the connector 500 side are arranged in order. As described above, V1>V2>V3>V4>V5>V6>V7 is satisfied, so that the potential difference between the ends of adjacent wirings 130A (between terminals in the connector) at the connector 500 can be minimized. This makes it possible to suppress short circuits due to migration, etc. It is possible.

[0091] <Advantages of the flexible printed wiring board and battery module according to the present embodiment> In the FPC 100 according to this embodiment, in the region to be attached to the battery 1200, a configuration is adopted in which conductor portions serving as a plurality of wirings 130A are provided only on one side of the base film 110. That is, in the region of the FPC 100 to be attached to the battery 1200, the region is configured with a single-sided structure portion 100A. Therefore, the region of the FPC 100 to be attached to the battery 1200 has high flexibility, and is therefore excellent in attachment workability.

[0092] In addition, in at least a part of the region of the FPC 100 away from the region where the battery 1200 is attached, conductor portions serving as a plurality of wirings 130A, 130B are provided on both sides of the base film 110, and a plurality of through holes 141 are arranged to electrically connect the wirings 130A on one side of the base film 110 to the wirings 130B on the other side. In other words, this region is configured by a double-sided structural portion 100B. The arrangement of the wirings can be changed by this double-sided structural portion 100B.

[0093] Furthermore, by adopting a configuration in which a reinforcing plate 180 is attached to the FPC 100 in an area where a plurality of through holes 141 are arranged, bending of the FPC 100 at the through holes 141 can be prevented, and loss of the conductive function can be prevented.

[0094] Example 2 5 shows a second embodiment of the present invention. In this embodiment, a configuration in which a reinforcing film is provided on a part of an FPC will be described. The other configurations and functions are the same as those of the first embodiment, so the same components are given the same reference numerals and their description will be omitted.

[0095] 5 is a diagram showing a part of a plan view of an FPC according to a second embodiment of the present invention. The FPC according to this embodiment has a configuration in which a reinforcing film 190 is further added to the configuration of the FPC 100 according to the first embodiment. That is, in a single-sided structure portion 100A of the FPC 100, a base film 110 is provided with a plurality of branch portions 110T for arranging the respective wirings 130A from a trunk portion 110S on which the wirings 130A are arranged, toward each cell (also see FIG. 3).

[0096] These branches 110T are narrow and have low strength. Therefore, in this embodiment, a reinforcing film 190 is provided on each of the multiple branches 110T. This reinforcing film 190 may be attached to the surface of the cover film 160A via an adhesive layer. This can increase the strength of the branch 110T. Therefore, when attaching the FPC to the battery 1200, it is possible to prevent the wiring 130A provided on the branch 110T from being broken. The FPC according to this embodiment differs from the FPC 100 shown in the above embodiment 1 only in that the reinforcing film 190 is provided.

[0097] Example 3 Example 3 of the present invention is shown in Fig. 6. In this example, a configuration in which an FPC is provided with a bent portion that allows the FPC to expand and contract in the longitudinal direction will be described. The other configurations and functions are the same as those of Example 1, so the same components are given the same reference numerals and their description will be omitted.

[0098] 6 is a schematic diagram of an FPC according to a third embodiment of the present invention, in which (a) shows a part of a plan view of the FPC according to the third embodiment, and (b) shows a part of a side view of the FPC according to the third embodiment (as viewed in the direction of the arrow S in (a)).

[0099] As shown in the figure, in the FPC 100 according to this embodiment, a bent portion 100X is provided in a part of the single-sided structure portion 100A so as to protrude toward one surface side. By providing such a bent portion 100X, the FPC 100 can expand and contract in its longitudinal direction. This can further improve the workability of attaching the FPC 100 to the battery 1200. In the example shown in the figure, a configuration in which the bent portion 100X is provided in only one place is shown, but bent portions may be provided in two or more places.

[0100] The FPC 100 according to this embodiment differs from the FPC 100 shown in the above-described embodiment 1 only in that the bent portion 100X is provided. Also in this embodiment, as in the above-described embodiment 2, a configuration in which a reinforcing film 190 is provided on the branch portion 110T can be adopted.

[0101] Example 4 Example 4 of the present invention is shown in Fig. 7. In this example, a configuration related to the conductive portion (through hole) is shown. The other configurations and functions are the same as those of Example 1, so the same components are given the same reference numerals and the description thereof is omitted.

[0102] 7 is a diagram showing a part of a plan view of an FPC according to a fourth embodiment of the present invention. In this embodiment, a plurality of conductive parts are provided to electrically connect the wiring 130A on one surface side of the base film to the wiring 130B on the other surface side, so that each of the wirings 130A and 130B is electrically connected at a plurality of points. More specifically, the wiring 130A and the wiring 130B are electrically connected by through holes 141X and 141Y as two conductive parts.

[0103] As a result, even if the conductive function of one of the through holes is impaired due to some influence, the conductive function of the other through holes is exerted, so that it is possible to prevent the current from being cut off. In the illustrated example, the conductive portion (through hole) is provided in two places, but the conductive portion may be provided in three or more places. The configuration shown in this embodiment is applicable to any of the above-mentioned embodiments 1 to 3. [Explanation of symbols]

[0104] 100 Flexible Printed Circuit Board (FPC) 100A Single-sided structure 100B Double-sided structure 100X Folding section 110 Base Film 110S Executive 110T branch 120A,120B Adhesive layer 130A, 130B Wiring 140 Through hole plating section 141, 141X, 141Y Through hole 150A,150B Adhesive layer 160A, 160B Cover film 170 Adhesive layer 180 Reinforcement plate 190 Reinforcement film 300 Support member 410,420 Bus bar 500 Connectors 1200 Battery 1210 Cell 1211 Positive electrode 1212 negative electrode

Claims

1. A flexible printed wiring board attached to a battery configured by arranging a plurality of cells, A base film; A plurality of wirings formed on the base film; Equipped with In an upper surface region of the battery, which is a region to be attached to the battery, conductor portions serving as the plurality of wirings are provided only on one surface of the base film, A flexible printed wiring board characterized in that conductor portions that become the multiple wirings are provided on both sides of the base film, and a double-sided structural portion having multiple conductive portions that electrically connect the wiring on one side of the base film to the wiring on the other side is arranged in at least a portion of an area away from the top surface area, and the double-sided structural portion is not arranged in the top surface area.

2. 2. The flexible printed wiring board according to claim 1, wherein the conductive portion is formed of a through hole, and a reinforcing plate is attached to an area in which a plurality of the through holes are arranged.

3. The flexible printed wiring board according to claim 1 or 2, characterized in that the base film has a plurality of branch portions for arranging the wiring from a trunk portion on which the plurality of wirings are arranged toward each cell, and a reinforcing film is provided on each of the plurality of branch portions.

4. 4. The flexible printed wiring board according to claim 1, further comprising a bent portion that enables expansion and contraction in a longitudinal direction.

5. A flexible printed wiring board as described in claim 1, 2, 3 or 4, characterized in that the conductive portions electrically connecting the wiring on one side of the base film to the wiring on the other side are each provided in multiple locations so that one wiring is electrically connected at multiple points.

6. A flexible printed wiring board attached to a battery configured by arranging a plurality of cells; a plurality of bus bars each electrically connected to a plurality of wirings provided on the flexible printed wiring board and each electrically connected to each electrode provided on the plurality of cells; a connector fixed to an end of the flexible printed wiring board; A battery module comprising: The flexible printed wiring board is A base film; the plurality of wirings formed on the base film; Equipped with In an upper surface region of the battery, which is a region to be attached to the battery, conductor portions serving as the plurality of wirings are provided only on one surface of the base film, A battery module characterized in that a double-sided structural portion having conductor portions that become the multiple wirings on both sides of the base film, and a multiple conductive portion that electrically connects the wiring on one side of the base film to the wiring on the other side of the base film, is arranged in at least a portion of an area away from the upper surface area, and the double-sided structural portion is not arranged in the upper surface area.

7. 7. The battery module according to claim 6, wherein the conductive portion is constituted by a through hole, and a reinforcing plate is attached to the flexible printed wiring board in an area where a plurality of the through holes are arranged.

8. The battery module described in claim 6 or 7, characterized in that the base film has a plurality of branches for arranging the wiring from a trunk on which the plurality of wirings are arranged, toward each cell, and a reinforcing film is provided on each of the plurality of branches.

9. 9. The battery module according to claim 6, wherein the flexible printed wiring board is provided with a bent portion that enables the flexible printed wiring board to expand and contract in a longitudinal direction.

10. A battery module as described in claim 6, 7, 8 or 9, characterized in that the conductive portions electrically connecting the wiring on one side of the base film to the wiring on the other side are each provided in multiple locations so that one wiring is electrically connected at multiple points.

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