Flexible substrate and bus bar module

Abstract

A flexible substrate includes an electronic component, a base film, a conductor circuit, and a cover layer. The electronic component has an electrode. The conductor circuit is formed on a second surface (a lower surface in the vertical direction) of the base film, and has a bonding region to which the electrode is bonded with a bonding material. The cover layer covers at least a portion of a second surface (a lower surface in the vertical direction) of the conductor circuit, and has an opening that exposes the bonding region to the outside.

Description

Technical Field

[0001] The invention relates to a flexible substrate and a bus bar module. Background Art

[0002] Conventionally, there is known a flexible substrate in which electronic components are mounted on a flexible printed circuit (hereinafter referred to as FPC).

[0003] In the FPC, a conductor circuit is formed on a surface of a base film, and at least a portion of the surface of the conductor circuit is covered with an insulating cover layer.

[0004] In such a configuration, when the electronic component is mounted on the FPC, the electrode or terminal of the electronic component is joined to the joining region of the conductor circuit exposed to the outside in the opening of the cover layer using a joining material such as solder.

[0005] Patent document JP2017-27831A discloses a configuration in which, in a flexible substrate for mounting an electronic component on an FPC, a resin is applied to an opening of a cover layer, and the opening is covered with a resin film.

[0006] By such a configuration, in the opening of the cover layer, the joint between the electronic component and the conductor circuit is covered by the resin film, thereby increasing the moisture resistance of the joint. The joint includes the electrode of the electronic component, the bonding material and the bonding area of ​​the conductor circuit. Therefore, even when condensation occurs in the opening of the FPC, a short circuit of the electronic component caused by condensation water can be avoided. Summary of the invention

[0007] However, in general, when a resin is applied to form a resin film, it is difficult to control the film thickness. For example, when a thin resin film is formed, there is a possibility that condensation water enters the joint between the electronic component and the conductor circuit, which may cause the electronic component to short-circuit.

[0008] Therefore, when the moisture resistance of the joint is increased by coating the resin to form a resin film, the yield during manufacturing may be reduced. Therefore, it is necessary to further improve the moisture resistance of the joint between the electronic component and the conductor circuit while suppressing the reduction of the yield during manufacturing.

[0009] The present invention has been made in view of the problems in the conventional technology. An object of the present invention is to provide a flexible substrate and a bus bar module capable of increasing moisture resistance of a joint portion between an electronic component and a conductor circuit while suppressing a reduction in yield at the time of manufacturing.

[0010] A flexible substrate according to a first aspect of the present invention includes: an electronic component having an electrode; a base film; a conductor circuit formed on a lower surface of the base film in a vertical direction and having a first bonding area, the electrode being bonded to the first bonding area using a bonding material; and a covering layer covering at least a portion of the lower surface of the conductor circuit in the vertical direction and having a first opening that exposes the first bonding area to the outside.

[0011] The busbar module according to the second aspect of the present invention includes: a housing assembled to a battery module having a plurality of cells; a busbar supported by the housing and electrically connecting positive electrode terminals and negative electrode terminals of adjacent cells among the plurality of cells; and a flexible substrate accommodated in the housing. The flexible substrate has: a trunk; and a branch portion branching from the trunk, folding back to cross the trunk in a plan view, and electrically connected to the busbar. The end of the branch portion has: an electronic component having an electrode; a base film; a conductor circuit formed on the lower side surface of the base film in the vertical direction and having a first bonding area and a second bonding area; a covering layer covering at least a portion of the lower side surface of the conductor circuit in the vertical direction and having a first opening for exposing the first bonding area to the outside and a second opening for exposing the second bonding area to the outside; and a metal plate. In addition to the area exposed to the outside in the first opening, the covering layer also covers a portion of the lower side surface of the base film in the vertical direction. The metal plate is disposed on the lower surface of the cover layer in the vertical direction and surrounds the electronic component. In the first opening, the electrode is bonded to the first bonding area using a bonding material. In the second opening, one end of the metal plate is bonded to the second bonding area. The other end of the metal plate is bonded to the bus bar. The electronic component is electrically connected to the bus bar via the conductor circuit and the metal plate.

[0012] According to the present invention, it is possible to provide a flexible substrate and a bus bar module capable of increasing the moisture resistance of a joint portion between an electronic component and a conductor circuit while suppressing a reduction in yield during manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a bottom view of the flexible substrate according to the first embodiment.

[0014] Figure 2 It is along Figure 1 End view of line II-II.

[0015] Figure 3 is an end view of a flexible substrate according to a first modification example of the first embodiment.

[0016] Figure 4 is a diagram for explaining a state of a flexible substrate according to a second modification example of the first embodiment before electronic components are mounted on a flexible printed circuit.

[0017] Figure 5 is a diagram for explaining a state of the flexible substrate according to the second modification example of the first embodiment after the electronic component is mounted on the flexible printed circuit.

[0018] Figure 6 is a cross-sectional view of a flexible substrate according to a second embodiment.

[0019] Figure 7 is a cross-sectional view of a flexible substrate according to a modified example of the second embodiment.

[0020] Figure 8 is a plan view of a bus bar module including a flexible substrate according to a third embodiment.

[0021] Fig. 9 It is along Figure 8 Cross-sectional view along line IX-IX.

[0022] Fig.10 : is a diagram for explaining a state of the flexible substrate according to the third embodiment before folding back a plurality of branch portions branched from a trunk portion of a flexible printed circuit.

[0023] Fig.11 : is a diagram for explaining a state of the flexible substrate according to the third embodiment after folding back a plurality of branch portions branched from a trunk portion of a flexible printed circuit.

[0024] Fig.12 is a diagram for explaining a state of the flexible substrate according to the third embodiment before an electronic component is mounted on an end portion of a branch portion of a flexible printed circuit.

[0025] Fig.13 : is a diagram for explaining a state of the flexible substrate according to the third embodiment after an electronic component is mounted on an end portion of a branch portion of a flexible printed circuit.

[0026] Fig.14 is a plan view of a flexible substrate according to a modified example of the third embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, the flexible substrate according to the first to third embodiments will be described in detail with reference to the accompanying drawings. For the convenience of explanation, the size ratio of the accompanying drawings is enlarged and may be different from the actual ratio. In addition, the same functions and elements are identified by the same or similar reference numerals, and the description thereof will be omitted as appropriate.

[0028] (First embodiment)

[0029] (Flexible substrate structure)

[0030] First, the configuration of the flexible substrate 1 according to the present embodiment will be described. Figure 1 is a bottom view of the flexible substrate 1 . Figure 2 It is along Figure 1 End view of line II-II. Figure 1 and 2 In order to clearly show the mounting portion of the electronic component 10, only a portion of the flexible substrate 1 is shown.

[0031] Figure 1 and Figure 2 The X direction shown corresponds to the length direction of the flexible substrate 1 . Figure 1 and Figure 2 The Y direction shown corresponds to the width direction of the flexible substrate 1 and is orthogonal to the X direction. Figure 1 and Figure 2 The Z direction shown corresponds to the height direction of the flexible substrate 1 and is orthogonal to the X direction and the Y direction. In the present embodiment, the Z direction corresponds to the vertical direction.

[0032] The X direction and the Y direction may correspond to a width direction and a length direction of the flexible substrate 1 , respectively.

[0033] Figure 1 and Figure 2 The +X side and the −X side shown in correspond to the front side and the back side of the flexible substrate 1, respectively. Figure 1 and Figure 2 The +Y side and the −Y side shown in respectively correspond to the left side and the right side of the flexible substrate 1 when it faces the front side of the flexible substrate 1 . Figure 1 and Figure 2 The +Z side and the −Z side shown in correspond to the upper side and the lower side of the flexible substrate 1 , respectively.

[0034] like Figure 1 and Figure 2 As shown, the flexible substrate 1 includes an electronic component 10 and a flexible printed circuit (hereinafter referred to as FPC) 20. The electronic component 10 has a body 11 and electrodes 12a and 12b. The electronic component 10 is, for example, a fuse. The electronic component 10 is not limited to a fuse, and may be a resistor, a capacitor, a coil, a semiconductor, etc.

[0035] The body 11 includes an element (not shown) therein. The element is electrically connected to the electrode 12a at one end (-X side) of the body 11, and is electrically connected to the electrode 12b at the other end (+X side) of the body 11. If the electronic component 10 is a fuse, the body 11 includes a fuse resistor therein.

[0036] The electrodes 12a and 12b are bonded to the conductor circuit 22 of the FPC 1 using a bonding material such as solder. Fillets 13a, 13b on which the bonding material is accumulated are formed respectively at portions where the electrodes 12a and 12b are bonded to the conductor circuit 22 using the bonding material. Since the electrodes 12a and 12b are electrically connected to the conductor circuit 22 via the fillets 13a and 13b, the fillets 13a and 13b are also referred to as connecting portions.

[0037] The FPC 20 has flexibility and includes a base film 21, a conductor circuit 22, and a cover layer 23. The base film 21 has flexibility and is formed in a planar shape. The base film 21 is a base material of the FPC 20 and defines the overall shape of the FPC 20. The base film 21 is formed of, for example, a polyimide resin having excellent heat resistance.

[0038] The base film 21 has a first surface 21a and a second surface 21b extending along the length direction of the flexible substrate 1. The first surface 21a and the second surface 21b face opposite directions to each other. In a state where the flexible substrate 1 is mounted on a product, the first surface 21a and the second surface 21b face the upper side (+Z side) and the lower side (-Z side) of the flexible substrate 1, respectively (see FIG. Figure 1 and Figure 2 ). Therefore, the first surface 21a and the second surface 21b are also referred to as an upper side surface in the vertical direction and a lower side surface in the vertical direction, respectively.

[0039] The conductor circuit 22 is formed on the second surface 21b of the base film 21. Specifically, a pattern layer constituting the conductor circuit 22 is stacked on the base film 21 on the second surface 21b side of the base film 21 (see Figure 2 ).

[0040] The conductor circuit 22 has a first surface 22a and a second surface 22b extending along the length direction of the flexible substrate 1. The first surface 22a and the second surface 22b face opposite directions to each other. In a state where the flexible substrate 1 is mounted on a product, the first surface 22a and the second surface 22b face the upper side (+Z side) and the lower side (-Z side) of the flexible substrate 1, respectively (see FIG. Figure 1 and Figure 2 ). Therefore, the first surface 22a and the second surface 22b are also referred to as an upper side surface in the vertical direction and a lower side surface in the vertical direction.

[0041] In a state where the conductor circuit 22 is stacked on the base film 21, the first surface 22a of the conductor circuit 22 abuts against the second surface 21b of the base film 21. The conductor circuit 22 is also called a Cu pattern.

[0042] In the present embodiment, the conductor circuit 22 extends along the length direction of the flexible substrate 1 in the portion where the electronic component 10 is mounted on the FPC 20; however, the present embodiment is not limited thereto. Depending on the use state of the flexible substrate 1, the conductor circuit 22 may extend in a direction other than the length direction of the flexible substrate 1.

[0043] The conductor circuit 22 has pads 31 and 32. The pads 31 and 32 are physically separated from each other, and constitute a bonding region 30 of the conductor circuit 22. The electrode 12a of the electronic component 10 is bonded to the pad 31. The electrode 12b of the electronic component 10 is bonded to the pad 32.

[0044] The cover layer 23 is an insulating protective film, and covers the second surface 21b of the base film 21 and the second surface 22b of the conductor circuit 22 except for a region of the second surface 21b of the base film 21 and a region of the second surface 22b of the conductor circuit 22 (joining region 30) which are exposed to the outside in the opening 24a to be described later (see FIG. Figure 1 and Figure 2 ). Therefore, the cover layer 23 is laminated on a part of the base film 21 and a part of the conductor circuit 22 on the second surface 21b side of the base film 21 and the second surface 22b side of the conductor circuit 22.

[0045] With this configuration, the cover layer 23 covers at least a portion of the second surface 22b of the conductor circuit 22. As a result, a portion of the conductor circuit 22 is insulated and protected by the cover layer 23.

[0046] The cover layer 23 has a first surface 23a and a second surface 23b extending along the length direction of the flexible substrate 1. The first surface 23a and the second surface 23b face opposite directions to each other. In a state where the flexible substrate 1 is mounted on a product, the first surface 23a and the second surface 23b face the upper side (+Z side) and the lower side (-Z side) of the flexible substrate 1, respectively (see FIG. Figure 1 and Figure 2 ). Therefore, the first surface 23a and the second surface 23b are also referred to as an upper side surface in the vertical direction and a lower side surface in the vertical direction.

[0047] With cover layer 23 laminated on a portion of base film 21 and a portion of conductor circuit 22 , first surface 23a of cover layer 23 is bonded to a portion of second surface 21b of base film 21 and a portion of second surface 22b of conductor circuit 22 .

[0048] The cover layer 23 has an opening 24a at a portion where the electronic component 10 is mounted on the FPC 20. In the opening 24a, the bonding area 30 (pads 31, 32) of the conductor circuit 22 bonded to the electrodes 12a and 12b of the electronic component 10 is exposed to the outside. In the opening 24a, the pad 31 forms the -X side end of the conductor circuit 22, and the pad 32 forms the +X side end of the conductor circuit 22. The opening 24a is also referred to as a first opening. The bonding area 30 is also referred to as a first bonding area.

[0049] In the present embodiment, the opening 24a is formed in a rectangular shape, and the long side and the short side of the opening 24a extend along the length direction and the width direction of the flexible substrate 1, respectively; however, the present embodiment is not limited thereto. Depending on the shape of the bonding area 30 of the conductor circuit 22, the opening 24a may be formed in a shape other than a rectangle. In addition, even when the opening 24a is formed in a rectangular shape, depending on the arrangement of the bonding area 30 of the conductor circuit 22, the long side may extend in a direction other than the length direction of the flexible substrate 1, and the short side may extend in a direction other than the width direction of the flexible substrate 1.

[0050] The opening 24a is surrounded by a metal plate 40 provided on the second surface 23b of the cover layer 23. The metal plate 40 has a first portion 41, a second portion 42, a third portion 43, and a fourth portion 44. The first portion 41 is provided to protrude from the second surface 23b of the cover layer 23 along the width direction of the flexible substrate 1 at the -X side relative to the opening 24a. The second portion 42 is provided to protrude from the second surface 23b of the cover layer 23 along the width direction of the flexible substrate 1 at the +X side relative to the opening 24a.

[0051] The third portion 43 is provided so as to protrude from the second surface 23b of the cover layer 23 on the +Y side relative to the opening 24a along the length direction of the flexible substrate 1. The fourth portion 44 is provided so as to protrude from the second surface 23b of the cover layer 23 on the -Y side relative to the opening 24a along the length direction of the flexible substrate 1. The -X side end portion and the +X side end portion of the third portion 43 are connected to the +Y side end portion of the first portion 41 and the +Y side end portion of the second portion 42, respectively. The -X side end portion and the +X side end portion of the fourth portion 44 are connected to the -Y side end portion of the first portion 41 and the -Y side end portion of the second portion 42, respectively.

[0052] With such a configuration, the metal plate 40 surrounds the electronic component 10. In the present embodiment, since the rigidity of the FPC 20 can be improved by providing the metal plate 40, no reinforcing plate is provided on the first surface 21a of the base film 21.

[0053] (Installation of electronic components)

[0054] Next, a description will be given of a method for mounting the electronic component 10 on the FPC 20. As an example, a description will be given of a method for mounting the electronic component 10 on the FPC 20 when solder is used as a bonding material.

[0055] First, solder paste is printed on the pads 31 and 32 exposed to the outside in the opening 24a of the cover layer, with the second surface 23b of the cover layer 23 facing the upper side (+Z side) of the flexible substrate 1. When the printing of the solder paste is completed, the electrodes 12a and 12b of the electronic component 10 are placed on the pads 31 and 32, respectively.

[0056] Next, the flexible substrate 1 is placed in a reflow oven. When the flexible substrate 1 is placed in the reflow oven, the pads 31 and 32 are heated and soldered in the reflow oven. As a result, the electrodes 12a and 12b are bonded to the pads 31 and 32, respectively, and the electronic component 10 is mounted on the FPC 20.

[0057] When manufacturing a product, the FPC 20 is turned over, and the flexible substrate 1 is mounted on the product in a state where the second surface 23b of the cover layer 23 faces the lower side (-Z side) of the flexible substrate 1. The region of the FPC 20 including the portion where the electronic component 10 is mounted may be folded back so that the second surface 23b of the cover layer 23 faces the lower side (-Z side) of the flexible substrate 1.

[0058] The electrodes 12a and 12b of the electronic component 10, the bonding material, and the bonding area 30 of the conductor circuit 22 constitute a bonding portion 33 between the electronic component 10 and the conductor circuit 22. Specifically, the electrodes 12a of the electronic component 10, the fillet 13a, and the pad 31 of the conductor circuit 22 constitute a bonding portion 33a between the electronic component 10 and the conductor circuit 22. Similarly, the electrodes 12b of the electronic component 10, the fillet 13b, and the pad 32 of the conductor circuit 22 constitute a bonding portion 33b between the electronic component 10 and the conductor circuit 22.

[0059] (Function and Effect)

[0060] According to the present embodiment, the flexible substrate 1 includes an electronic component 10, a base film 21, a conductor circuit 22, and a cover layer 23. The electronic component 10 has electrodes 12a and 12b. The conductor circuit 22 is formed on the second surface (lower side surface in the vertical direction) 21b of the base film 21, and has a bonding area 30, and the electrodes 12a and 12b are bonded to the bonding area 30 using a bonding material. The cover layer 23 covers at least a portion of the second surface (lower side surface in the vertical direction) 22b of the conductor circuit 22, and has an opening 24a that exposes the bonding area 30 to the outside.

[0061] In the present embodiment, by the above-mentioned construction, the electrodes 12a and 12b of the electronic component 10, the bonding material, and the bonding area 30 of the conductor circuit 22 are arranged on the second surface 21b of the base film 21, which are included in the bonding portion 33 between the electronic component 10 and the conductor circuit 22. Here, the second surface 21b of the base film 21 faces the lower side in the vertical direction.

[0062] Therefore, even if condensation occurs in the opening 24a of the FPC 20, the condensation water is discharged to the lower side (ground side) in the vertical direction. Therefore, with a simple structure, it is possible to prevent condensation water from accumulating in the joint portion 33, thereby reliably avoiding a short circuit of the electronic component 10. Thus, in the flexible substrate 1, it is possible to improve the moisture resistance of the joint portion 33 between the electronic component 10 and the conductor circuit 22 while suppressing a decrease in yield during manufacturing.

[0063] According to the present embodiment, the flexible substrate 1 further includes a metal plate 40. The cover layer 23 covers a portion of the second surface (lower side surface in the vertical direction) 21b of the base film 21, except for the region exposed to the outside in the opening 24a. The metal plate 40 is provided on the second surface (lower side surface in the vertical direction) 23b of the cover layer 23, and surrounds the electronic component 10. No reinforcing plate is provided on the first surface (upper side surface in the vertical direction) 21a of the base film 21.

[0064] Generally, in the case where electronic components are mounted on an FPC, the FPC has excellent flexibility, and therefore when external force acts on the FPC due to vibration, contact, etc., the FPC is bent. As a result, mechanical stress is applied to the electronic components and the joint between the electronic components and the conductor circuit. Therefore, there is a possibility of disconnection and connection failure in the flexible substrate.

[0065] In order to solve such a problem, when the electronic component is mounted on the FPC, the reinforcing plate is attached to the surface opposite to the surface on which the electronic component is mounted in the FPC. Therefore, the rigidity of the portion where the electronic component is mounted on the FPC can be increased. Therefore, even if an external force acts on the FPC due to vibration, contact, etc., the FPC hardly bends, thereby reducing the mechanical stress applied to the electronic component and the joint between the electronic component and the conductor circuit.

[0066] However, since the size of the reinforcing plate is large, a certain size is required to attach the reinforcing plate to the FPC. Therefore, when the number of electronic components is small, workability deteriorates. In addition, when the electronic components are mounted on the FPC in a state of being separated from each other, the number of reinforcing plates to be attached to the FPC increases, thereby increasing the manufacturing cost.

[0067] At the same time, in the present embodiment, with the above-mentioned configuration, since the metal plate 40 is provided on the second surface of the cover layer 23 and surrounds the electronic component 10, it is possible to increase the rigidity of the portion where the electronic component 10 is mounted on the FPC 20. Thus, it is possible to reduce the mechanical stress applied to the electronic component 10 and the joint 33 between the electronic component 10 and the conductor circuit 22.

[0068] In addition, since the rigidity of the portion where the electronic component 10 is mounted on the FPC 20 can be increased by the metal plate 40, it is not necessary to attach the reinforcing plate separately to the FPC 20. Since the metal plate 40 can be processed flexibly, it can be made smaller in size than the reinforcing plate. Thus, by providing the metal plate 40, the processability can be improved, and the increase in manufacturing cost can be suppressed.

[0069] (First Modification)

[0070] In the first embodiment described above, the joint 33 between the electronic component 10 and the conductor circuit 22 is directly exposed to the outside in the opening 24 a of the cover layer 23 ; however, the present embodiment is not limited thereto. For example, a surface treatment may be applied to the opening 24 a of the cover layer 23 .

[0071] Figure 3 FIG. 1 is an end view of the flexible substrate 1 according to the present modification. Figure 3 As shown, surface treatment is applied to the opening 24a of the cover layer 23, and the opening 24a is covered with insulating oil 50. Therefore, in the opening 24a, the joint 33 between the electronic component 10 and the conductor circuit 22 is covered with the insulating oil 50 and is not directly exposed to the outside.

[0072] In the present modification, by adopting the above-described configuration, the insulation of the joint portion 33 and the moisture resistance of the joint portion 33 can be improved.

[0073] (Second Modification)

[0074] In the first embodiment described above, only the electronic component 10 is bonded to the conductor circuit 22 ; however, the present embodiment is not limited thereto. For example, in addition to the electronic component 10 , the metal plate 40 may also be bonded to the conductor circuit 22 .

[0075] Figure 4 1 is a diagram for explaining a state of the flexible substrate 1 according to the present modification before the electronic component 10 is mounted on the FPC 20 . Figure 5 1 is a diagram for explaining a state of the flexible substrate 1 according to the present modification example after the electronic component 10 is mounted on the FPC 20 .

[0076] In this modification, in the FPC 20, a conductor circuit 22A is formed on the base film 21 instead of the conductor circuit 22 (see Figure 4). The conductor circuit 22A includes a first circuit 25a and a second circuit 25b. The first circuit 25a terminates at a pad 31 which forms a -X side end portion of the conductor circuit 22A in the opening 24a.

[0077] The second circuit 25b branches into three branches, and the first branch terminates at a pad 32 that forms the +X side end of the conductor circuit 22A in the opening 24a. The second branch terminates at a pad 61 (described later) that forms the +Y side end of the conductor circuit 22A in the opening 24b described later. The third branch terminates at a pad 62 (described later) that forms the -Y side end of the conductor circuit 22A in the opening 24c described later.

[0078] The conductor circuit 22A has a bonding region 60 in addition to the bonding region 30. The pads 31 and 32 constitute the bonding region 30. The electrodes 12a and 12b of the electronic component 10 are bonded to the pads 31 and 32, respectively. The pads 61 and 62 constitute the bonding region 60. The third portion 43 and the fourth portion 44 of the metal plate 40 are bonded to the pads 61 and 62, respectively (see FIG. Figure 5 ).

[0079] The cover layer 23 has openings 24b and 24c at the portions where the third portion 43 and the fourth portion 44 of the metal plate 40 are provided. In the openings 24b and 24c, the bonding region 60 (pads 61, 62) of the conductor circuit 22A bonded to the third portion 43 and the fourth portion 44 of the metal plate 40 is exposed to the outside. The openings 24b and 24c are also referred to as second openings. In addition, the bonding region 60 is also referred to as a second bonding region.

[0080] In the present modification, each of the openings 24b and 24c is formed in a rectangular shape, and its long side and short side extend along the length direction and the width direction of the flexible substrate 1, respectively; however, the present embodiment is not limited thereto. Depending on the shape of the bonding area 60 of the conductor circuit 22A, each of the openings 24b and 24c may be formed in a shape other than a rectangular shape. In addition, even when each of the openings 24b and 24c is formed in a rectangular shape, depending on the arrangement of the bonding area 60 of the conductor circuit 22, the long side may extend in a direction other than the length direction of the flexible substrate 1, and the short side may extend in a direction other than the width direction of the flexible substrate 1.

[0081] Since the method for bonding the third and fourth portions 43 and 44 of the metal plate 40 to the pads 61 and 62 , respectively, is the same as the method for bonding the electrodes 12 a and 12 b of the electronic component 10 to the pads 31 and 32 , respectively, a description thereof will be omitted.

[0082] According to the present modification, the conductor circuit 22A has the bonding region 60 to which a part (the third portion 43 and the fourth portion 44) of the metal plate 40 is bonded. The cover layer 23 has the openings 24b and 24c that expose the bonding region 60 to the outside.

[0083] In the present modification, for example, when the flexible substrate 1 needs to be electrically connected to a portion as a measurement object, by bonding the metal plate 40 to the measurement object, the measurement object can be electrically connected to the conductor circuit 22A of the flexible substrate 1. Therefore, when the flexible substrate 1 is electrically connected to the measurement object, there is no need to provide a separate component, thereby further improving workability and further suppressing an increase in manufacturing cost.

[0084] (Second embodiment)

[0085] (Flexible substrate structure)

[0086] The configuration of the flexible substrate 1A according to the present embodiment will be described below. Figure 6 is a cross-sectional view of the flexible substrate 1A. Figure 6 In order to clearly show the mounting portion of the connector 110 , only a portion of the flexible substrate 1A is shown.

[0087] Figure 6 The X direction shown corresponds to the length direction of the flexible substrate 1A. Figure 6 The Y direction shown corresponds to the width direction of the flexible substrate 1A and is orthogonal to the X direction. Figure 6 The Z direction shown corresponds to the height direction of the flexible substrate 1A, and is orthogonal to the X direction and the Y direction. In the present embodiment, the Z direction corresponds to the vertical direction.

[0088] The X direction and the Y direction may correspond to the width direction and the length direction of the flexible substrate 1A, respectively.

[0089] Figure 6 The +X side and the -X side shown correspond to the front side and the back side of the flexible substrate 1A, respectively. Figure 6 The +Y side and the −Y side shown correspond to the left side and the right side, respectively, of the flexible substrate 1A when it faces the front side of the flexible substrate 1A. Figure 6 The +Z side and the −Z side shown correspond to the upper side and the lower side of the flexible substrate 1A, respectively.

[0090] like Figure 6 As shown, the flexible substrate 1A includes a connector 110, an FPC 120, a connection portion 130, and a reinforcing plate 140. The flexible substrate 1A includes the connector 110 as an electronic component mounted on the FPC 120.

[0091] In the flexible substrate 1A, the connector 110 is provided at an end of the FPC 120. The connector 110 is mated with a mating connector (not shown) at the end of the FPC 120, thereby electrically connecting the mating connector to the FPC 120.

[0092] The connector 110 has a plurality of terminals 111. Figure 6 , only one terminal 111 is shown. One end of the plurality of terminals 111 is accommodated in the connector 110, and contacts with a plurality of terminals of the mating connector when the connector 110 is mated with the mating connector. The other end of the plurality of terminals 111 is bonded to the FPC 120 using a bonding material.

[0093] The FPC 120 has the same structure as the FPC 20 in the first embodiment. The FPC 120 has a first surface 120a and a second surface 120b extending in the length direction of the flexible substrate 1A. The first surface 120a and the second surface 120b face opposite directions to each other.

[0094] When the flexible substrate 1A is mounted on a product, the first surface 120a and the second surface 120b face the upper side (+Z side) and the lower side (-Z side) of the flexible substrate 1A, respectively (see FIG. Figure 1 and Figure 2 ). Therefore, the first surface 120a and the second surface 120b are also referred to as an upper side surface in the vertical direction and a lower side surface in the vertical direction, respectively.

[0095] The first surface 120a of the FPC 120 corresponds to one surface of a base film of the FPC 120. The second surface 120b of the FPC 120 corresponds to one surface of a cover layer of the FPC 120.

[0096] The connector 110 is mounted on the second surface 120b of the FPC 120. An opening is formed in the second surface 120b of the FPC 120, and a bonding area of ​​a conductor circuit of the FPC 120 is exposed to the outside in the opening. The other ends of the plurality of terminals 111 of the connector 110 are bonded to the bonding area of ​​the conductor circuit of the FPC 120 in the opening of the second surface 120b. As in the first embodiment, the bonding area of ​​the conductor circuit is constituted by a pad of the conductor circuit.

[0097] Since the method for joining the other ends of the plurality of terminals 111 of the connector 110 to the pads of the conductor circuit of the FPC 120 is the same as the method for joining the electrodes 12a and 12b of the electronic component 10 to the pads 31 and 32 respectively in the first embodiment, its description will be omitted.

[0098] The connection portion 130 is made of a bonding material accumulated at the other end of the plurality of terminals 111 of the connector 110. The plurality of terminals 111 of the connector 110 are electrically connected to a bonding area of ​​a conductor circuit of the FPC 120 through the connection portion 130.

[0099] The other ends of the plurality of terminals 111 of the connector 110 , the connection portion 130 (joining material), and the joining region of the conductor circuit of the FPC 120 constitute a joining portion between the connector 110 and the conductor circuit of the FPC 120 .

[0100] The reinforcing plate 140 is attached to the first surface 120a of the FPC 120. Viewed from a plane (XY plane) orthogonal to the height direction of the flexible substrate 1, the region where the reinforcing plate 140 is provided includes the region where the connector 110 is provided. As a result, the reinforcing plate 140 can increase the rigidity of the region where the connector 110 is mounted to the FPC 120.

[0101] In this embodiment, the connector 110 is disposed at the end of the FPC 120 and is mated with a mating connector (not shown). Therefore, since the connector 110 cannot be surrounded by a metal plate, the reinforcing plate 140 is used to increase the rigidity of the portion where the connector 110 is mounted on the FPC 120.

[0102] (Function and Effect)

[0103] According to the present embodiment, the flexible substrate 1A includes a connector 110 and an FPC 120. The connector 110 has a plurality of terminals 111. The FPC 120 has a bonding area to which the plurality of terminals 111 are bonded using a bonding material. The second surface 120b (the lower side surface in the vertical direction) of the FPC 120 has an opening for exposing the bonding area to the outside.

[0104] In the present embodiment, with the above-described configuration, the other ends of the plurality of terminals 111 of the connector 110, the connection portion 130 (joining material), and the joining area of ​​the conductor circuit of the FPC 120 are arranged on the second surface 120b side of the FPC 120, and the other ends of the plurality of terminals 111 of the connector 110, the connection portion 130 (joining material), and the joining area of ​​the conductor circuit of the FPC 120 are included in the joining portion between the connector 110 and the conductor circuit of the FPC 120. Here, the second surface 120b of the FPC 120 faces the lower side in the vertical direction.

[0105] Therefore, even if condensation occurs in the opening of the second surface 120b of the FPC 120, the condensation water is discharged to the lower side (ground side) in the vertical direction. Therefore, by a simple structure, it is possible to prevent condensation water from accumulating in the joint between the connector 110 and the conductor circuit of the FPC 120, thereby reliably avoiding a short circuit between the terminals 111 of the connector 110. Therefore, it is possible to improve the moisture resistance of the joint between the connector 110 and the conductor circuit of the FPC 120 while suppressing a decrease in yield during manufacturing. In addition, it is possible to prevent foreign matter from adhering to the second surface 120b of the FPC 120.

[0106] (Revision)

[0107] In the second embodiment described above, in a state where the flexible substrate 1A is mounted on a product, the first surface 120a and the second surface 120b of the FPC 120 face the upper side in the vertical direction and the lower side in the vertical direction, respectively; however, the present embodiment is not limited thereto. For example, the flexible substrate 1A may be raised in a manner that the connector 110 is located at the upper end, and each of the first surface 120a and the second surface 120b may face a direction perpendicular to the vertical direction.

[0108] Figure 7 1 is a cross-sectional view of the flexible substrate 1A according to the present modification. In the present modification, since the flexible substrate 1A is elevated in such a manner that the connector 110 is located at the upper end, the X direction corresponds to the vertical direction.

[0109] like Figure 7 As shown, when the flexible substrate 1A is mounted on a product, each of the first surface 120 a and the second surface 120 b of the FPC 120 faces a direction perpendicular to the vertical direction.

[0110] With such a configuration, even when condensation occurs in the opening of the second surface 120b of the FPC 120, the condensation water is discharged to the lower side (+X side, ground side) in the vertical direction. Therefore, with a simple configuration, it is possible to prevent condensation water from accumulating in the joint between the connector 110 and the conductor circuit of the FPC 120, and reliably avoid a short circuit between the terminals 111 of the connector 110. In addition, it is possible to prevent foreign matter from adhering to the second surface 120b of the FPC 120.

[0111] (Third Embodiment)

[0112] (Overall structure of busbar module)

[0113] First, the configuration of the bus bar module 201 including the flexible substrate 1B according to the present embodiment will be described. Figure 8 is a plan view of the bus bar module 201 . Fig. 9 It is along Figure 8The cross-sectional view of the line IX-IX. Note that Fig. 9 No shading is shown.

[0114] Figure 8 and Fig. 9 The X direction shown corresponds to the length direction of the flexible substrate 1B. Figure 8 and Fig. 9 The Y direction shown corresponds to the width direction of the flexible substrate 1B and is orthogonal to the X direction. Figure 8 and Fig. 9 The Z direction shown corresponds to the height direction of the flexible substrate 1B, and is orthogonal to the X direction and the Y direction. In the present embodiment, the Z direction corresponds to the vertical direction.

[0115] Figure 8 and Fig. 9 The +X side and the -X side shown in correspond to the front side and the rear side of the flexible substrate 1B, respectively. Figure 8 and Fig. 9 The +Y side and the -Y side shown in respectively correspond to the left side and the right side of the flexible substrate 1B when it faces the front side of the flexible substrate 1B. Figure 8 and Fig. 9 The +Z side and the -Z side shown in correspond to the upper side and the lower side of the flexible substrate 1B, respectively.

[0116] like Figure 8 As shown, the bus bar module 201 is included in the battery module 200 and assembled to the upper part of the plurality of cells 210. The battery module 200 is installed in a vehicle such as an electric vehicle as a power source. The electric vehicle includes, for example, a battery electric vehicle, a hybrid vehicle, and a plug-in hybrid vehicle.

[0117] The battery module 200 includes a bus bar module 201, a plurality of battery cells 210, and a smoke exhaust duct 250. Hereinafter, for the sake of convenience, the plurality of battery cells 210, the smoke exhaust duct 250, and the bus bar module 201 will be described in sequence.

[0118] In the battery module 200, a plurality of cells 210 are arranged along the length direction of the flexible substrate 1B. Thus, the length direction of the flexible substrate 1B corresponds to the arrangement direction of the cells 210. Figure 8 , ten battery cells 210 are shown, but the number of battery cells 210 is not limited thereto, and may be two to nine, or eleven or more.

[0119] Each battery cell 210 is, for example, a lithium ion battery. Electrode terminals 211 and 212 are provided to protrude from upper surfaces of both ends of each battery cell 210. One of the electrode terminals 211 and 212 is a positive electrode, and the other of the electrode terminals 211, 212 is a negative electrode.

[0120] In a state where a plurality of cells 210 are arranged, a plurality of electrode terminals 211 are arranged on the +Y side to form a first electrode terminal group. In the first electrode terminal group, electrode terminals 211 as positive electrodes and electrode terminals 211 as negative electrodes are arranged alternately. Thus, in adjacent cells 210, one of the two electrode terminals 211 is a positive electrode, and the other is a negative electrode.

[0121] Similarly, when a plurality of cells 210 are arranged, a plurality of electrode terminals 212 are arranged on the -Y side to form a second electrode terminal group. In the second electrode terminal group, electrode terminals 212 as positive electrodes and electrode terminals 212 as negative electrodes are arranged alternately. Thus, in adjacent cells 210, one of the two electrode terminals 212 is a positive electrode, and the other is a negative electrode.

[0122] The smoke exhaust duct 250 is a duct for exhausting the gas exhausted to the outside when the gas pressure in each single cell 210 exceeds a predetermined value to the outside of the battery module 200. The smoke exhaust duct 250 extends along the arrangement direction of the single cells 210 and is placed on the upper surface between the electrode terminals 211 and 212 in each single cell 210.

[0123] The bus bar module 201 includes a flexible substrate 1B, a housing 220, and a plurality of bus bars 230a to 230c. For convenience, the plurality of bus bars 230a to 230c, the flexible substrate 1B, and the housing 220 will be described in sequence.

[0124] Each of the plurality of bus bars 230a to 230c is made of a conductive metal material and is formed into a plate shape. The plurality of bus bars 230a and 230b are arranged on the +Y side relative to the smoke exhaust duct 250. The plurality of bus bars 230c are arranged on the -Y side relative to the smoke exhaust duct 250. In the present embodiment, according to the number of the single cells 210 (ten), the number of the bus bars 230a is four, the number of the bus bars 230b is two, and the number of the bus bars 230c is five.

[0125] Each bus bar 230a is connected to adjacent electrode terminals 211 in the first electrode terminal group by welding, etc. In the case of the first electrode terminal group, adjacent electrode terminals 211 do not include two electrode terminals 211 arranged at both ends thereof. As a result, adjacent electrode terminals 211 are electrically connected to each other via the bus bars 230a.

[0126] Each bus bar 230 b is connected to the electrode terminals 211 arranged at both ends of the first electrode terminal group by welding or the like.

[0127] Each bus bar 230c is connected to the adjacent electrode terminal 212 in the second electrode terminal group by welding, etc. Therefore, the adjacent electrode terminals 212 are electrically connected to each other via the bus bar 230c.

[0128] With such a configuration, in the battery module 200 , a plurality of single cells 210 are electrically connected in series to form a battery pack.

[0129] The flexible substrate 1B includes an FPC 240. The FPC 240 has a trunk portion 241 and a plurality of branch portions 242a and 242b. The trunk portion 241 is formed in a substantially U shape and has a first extending portion 241a, a second extending portion 241b, and a connecting portion 241c.

[0130] The first extension portion 241a is arranged at the +Y side relative to the smoke exhaust duct 250 and extends along the length direction of the flexible substrate 1B. The second extension portion 241b is arranged at the -Y side relative to the smoke exhaust duct 250 and extends along the length direction of the flexible substrate 1B. Therefore, the second extension portion 241b extends in parallel with the first extension portion 241a.

[0131] The connecting portion 241c connects the +X side end of the first extending portion 241a and the +X side end of the second extending portion 241b at the -X side end of the connecting portion 241c. The connector 410 is attached to the +X side end of the connecting portion 241c.

[0132] Each of the plurality of branch portions 242a branches from the first extension portion 241a of the trunk portion 241 in a direction approaching the second extension portion 241b, and then turns back in a direction away from the second extension portion 241b to intersect with the first extension portion 241a in a plan view (XY plan view). Specifically, each of the plurality of branch portions 242a branches from a lateral portion on the -Y side of the first extension portion 241a of the trunk portion 241, and then turns back to intersect with the first extension portion 241a in a plan view (XY plan view) (see FIG. 2 ). Fig. 9 ).

[0133] Similarly, each of the plurality of branch portions 242b branches from the second extension portion 241b of the trunk portion 241 in a direction approaching the first extension portion 241a, and then turns back in a direction away from the first extension portion 241a to intersect with the second extension portion 241b in a plan view (XY plan view). Specifically, each of the plurality of branch portions 242b branches from a lateral portion on the +Y side of the second extension portion 241b of the trunk portion 241, and then turns back to intersect with the second extension portion 241b in a plan view (XY plan view) (see FIG. 2 ). Fig. 9 ).

[0134] The electronic component 10 and the metal plate 340 are mounted on the (+Y side) end 300 of each folded-back branch portion 242a, as will be described later. The end 300 of each folded-back branch portion 242a is electrically connected to the bus bar 230a or the bus bar 230b via the metal plate 340, and the bus bar 230a or the bus bar 230b is arranged on the +Y side relative to the smoke exhaust duct 250.

[0135] Similarly, the electronic component 10 and the metal plate 340 are mounted on the (-Y side) end 300 of each folded-back branch portion 242b, as will be described later. The end 300 of each folded-back branch portion 242b is electrically connected to the bus bar 230c via the metal plate 340, and the bus bar 230c is arranged on the -Y side relative to the smoke exhaust duct 250.

[0136] like Figure 8 As shown, the housing 220 is assembled to the upper part of the plurality of cells 210. Fig. 9 As shown, the housing 220 has a plurality of terminal insertion holes 221a, a bus bar support portion 222a, a trunk accommodating portion 223a, and a branch support portion 224a on the +Y side relative to the smoke exhaust duct 250. Fig. 9 , only one terminal insertion hole 221a is shown.

[0137] The plurality of electrode terminals 211 are respectively inserted into the plurality of terminal insertion holes 221a. The bus bar support portion 222a, the trunk accommodating portion 223a, and the branch support portion 224a extend along the arrangement direction of the single cells 210. The bus bar support portion 222a supports the plurality of bus bars 230a and 230b. The trunk accommodating portion 223a accommodates the first extension portion 241a of the trunk portion 241 of the FPC 240. The branch support portion 224a supports the branch portion 242a of the FPC 240.

[0138] Similarly, the housing 220 has a plurality of terminal insertion holes 221b, a bus bar support portion 222b, a trunk accommodating portion 223b, and a branch support portion 224b on the -Y side relative to the smoke exhaust duct 250. Fig. 9 , only one terminal insertion hole 221b is shown.

[0139] The plurality of electrode terminals 212 are respectively inserted into the plurality of terminal insertion holes 221b. The bus bar support portion 222b, the trunk accommodating portion 223b, and the branch support portion 224b extend along the arrangement direction of the single cells 210. The bus bar support portion 222b supports the plurality of bus bars 230c. The trunk accommodating portion 223b accommodates the second extension portion 241b of the trunk portion 241 of the FPC 240. The branch support portion 224b supports the branch portion 242b of the FPC 240.

[0140] In this embodiment, the length of each folded branch portion 242a is greater than the width of the first extension portion 241a of the trunk portion 241 (see Fig. 9 ); however, the present embodiment is not limited thereto. The length of each folded-back branch portion 242a may be smaller than the width of the first extension portion 241a of the trunk portion 241. In this case, the branch support portion 224a is arranged in a position where each folded-back branch portion 242a can be supported.

[0141] Similarly, the length of each folded branch portion 242b is greater than the width of the second extension portion 241b of the trunk portion 241 (see Fig. 9 ); however, the present embodiment is not limited thereto. The length of each folded-back branch portion 242b may be smaller than the width of the second extension portion 241b of the trunk portion 241. In this case, the branch support portion 224b is arranged in a position where each folded-back branch portion 242b can be supported.

[0142] (Flexible substrate structure)

[0143] Next, the configuration of the flexible substrate 1B will be described. Fig.10 1 is a diagram for explaining a state of the flexible substrate 1B before the plurality of branch portions 242 a and 242 b branched from the trunk portion 241 of the FPC 240 are folded back. Fig.11 1 is a diagram for explaining a state of the flexible substrate 1B after folding back a plurality of branch portions 242 a and 242 b branched from a trunk portion 241 of an FPC 240 . Fig.12 1 is a diagram for explaining a state of the flexible substrate 1B before the electronic component 10 is mounted on the end portion 300 of the branch portion 242 a or the branch portion 242 b of the FPC 240 . Fig.13 1 is a diagram for explaining a state of the flexible substrate 1B after the electronic component 10 is mounted on the end portion 300 of the branch portion 242 a or the branch portion 242 b of the FPC 240 .

[0144] The flexible substrate 1B includes a plurality of electronic components 10, an FPC 240, a plurality of metal plates 340, and a connector 410. As described above, the plurality of electronic components 10 and the plurality of metal plates 340 are mounted to the ends 300 of the plurality of branches 242a and 242b in the FPC 240. The configuration of the ends 300 of the respective branches will be described later.

[0145] As described above, the FPC 240 has the trunk portion 241 and the plurality of branch portions 242a and 242b. The trunk portion 241 has the first extending portion 241a, the second extending portion 241b, and the connecting portion 241c.

[0146] In the present embodiment, the FPC 240 includes a base film 21, a plurality of conductor circuits 22B, and a cover layer 23. The base film 21 is a base material of the FPC 240, and defines the overall shape of the FPC 240.

[0147] A plurality of conductor circuits 22B are formed on the second surface 21b of the base film 21. Each of the plurality of conductor circuits 22B has one end electrically connected to the metal plate 340 mounted on the end portion 300 of each branch portion via the electronic component 10, and the other end electrically connected to the connector 410 mounted on the trunk portion 241. As described above, each metal plate 340 is electrically connected to each bus bar.

[0148] In the present embodiment, each conductor circuit 22B is used as a voltage detection line. For example, an ECU (Electronic Control Unit) (not shown) is connected to the connector 410. The ECU can detect the voltage of each single cell 210 by acquiring the voltage from the plurality of conductor circuits 22B.

[0149] The cover layer 23 covers the second surface 21b of the base film 21 and the second surface 22b of the conductor circuit 22, except for one area of ​​the second surface 21b of the base film 21 and one area of ​​the second surface 22b of the conductor circuit 22 (joining areas 30 and 60) exposed to the outside in the openings 24a to 24c at the end portions 300 of each branch portion. Therefore, the cover layer 23 is laminated on a portion of the base film 21 and a portion of the conductor circuit 22 on the second surface 21b side of the base film 21 and the second surface 22b side of the conductor circuit 22.

[0150] Next, a description will be given of the folding back of the plurality of branch portions 242 a and 242 b in the FPC 240 .

[0151] like Fig.10 As shown, in the state before folding back the plurality of branch portions 242a, each of the plurality of branch portions 242a branches from the first extension portion 241a of the trunk portion 241 and extends in a direction approaching the second extension portion 241b. Specifically, each of the plurality of branch portions 242a branches from a lateral portion of the first extension portion 241a of the trunk portion 241 on the -Y side and extends on the -Y side along the width direction of the flexible substrate 1B. In this state, the electronic component 10 and the metal plate 340 are mounted on the end portion 300 of each branch portion 242a.

[0152] Similarly, in the state before the plurality of branch portions 242b are folded back, each of the plurality of branch portions 242b branches from the second extension portion 241b of the trunk portion 241 and extends in a direction approaching the first extension portion 241a. Specifically, each of the plurality of branch portions 242b branches from a lateral portion of the second extension portion 241b of the trunk portion 241 on the +Y side and extends on the +Y side along the width direction of the flexible substrate 1B. In this state, the electronic component 10 and the metal plate 340 are mounted on the end portion 300 of each branch portion 242b.

[0153] like Fig.11 As shown, when the electronic component 10 and the metal plate 340 are installed at the end 300 of each branch portion 242a, each of the multiple branch portions 242a is folded back in a direction away from the second extension portion 241b to intersect with the first extension portion 241a in a plan view (XY plan view).

[0154] Similarly, with the electronic component 10 and the metal plate 340 mounted on the end 300 of each branch portion 242b, each of the multiple branch portions 242b is folded back in a direction away from the first extension portion 241a to intersect with the second extension portion 241b in a plan view (XY plan view).

[0155] After folding back the plurality of branch portions 242a and 242b, the FPC 240 is assembled to the housing 220, and is electrically connected to the plurality of bus bars 230a to 230c via the plurality of metal plates 340 (see FIG. 24A ). Fig. 9 ).

[0156] Next, the configuration of the end portions 300 of the plurality of branch portions 242a and 242b in the FPC 240 will be described. The configuration of the end portions 300 of the respective branch portions in the FPC 240 is similar to the configuration of the FPC 20 according to the second modified example of the first embodiment (see FIG. Figure 4 In the FPC 240, the length direction (Y direction) and the width direction (X direction) of each branch portion correspond to the width direction (Y orientation) and the length direction (X orientation) of the FPC 20 according to the second modified example of the first embodiment, respectively.

[0157] In this embodiment, if Fig.12 As shown, in the FPC 20, a conductor circuit 22B is formed on the base film 21 in place of the conductor circuit 22. The conductor circuit 22B has a first circuit 25a1, an auxiliary circuit 25a2, and a second circuit 25b.

[0158] The configuration of the first circuit 25a1 is the same as that of the first circuit 25a according to the second modification of the first embodiment except that it is electrically connected to the auxiliary circuit 25a2 formed on the first surface 21a of the base film 21 via the hole 25a3.

[0159] On the first surface 21a side of the base film 21, an insulating cover layer (not shown) is separately provided to cover at least the auxiliary circuit 25a2. When extending a predetermined length, the auxiliary circuit 25a2 is electrically connected to a circuit (not shown) of the conductor circuit 22B formed on the second surface 21b of the base film 21 via a hole (not shown).

[0160] The configuration of the second circuit unit 25 b is the same as that of the second circuit unit 25 b according to the second modification example of the first embodiment, and thus a description thereof will be omitted.

[0161] like Fig.13 As shown, the opening 24a is surrounded by the metal plate 340 provided in the cover layer 23 at one end 341 of the metal plate 340. Therefore, the electronic component 10 is surrounded by the metal plate 340. The metal plate 340 is bonded to the bonding region 60 (pads 61, 62) of the conductor circuit 22B using a bonding material.

[0162] The metal plate 340 extends from the end 300 of each branch portion along the length direction of the branch portion by a predetermined length. The metal plate 340 is joined to each bus bar (see FIG. 1 ) at the other end 342 of the metal plate 340 by welding or the like. Fig. 9 ). With such a configuration, the electronic component 10 is electrically connected to each bus bar via the second circuit 25 b of the conductor circuit 22B and the metal plate 340 .

[0163] In the present embodiment, by providing the metal plate 340 , the rigidity of the end portion 300 of each branch portion can be improved, and therefore no reinforcing plate is provided on the first surface 21 a of the base film 21 in the end portion 300 .

[0164] (Function and Effect)

[0165] According to the present embodiment, the flexible substrate 1B is included in the bus bar module 201. The bus bar module 201 has: a plurality of bus bars 230a, each of which electrically connects the positive electrode terminal 211 and the negative electrode terminal 211 of the adjacent single cells 210 and 210; and a plurality of bus bars 230c, each of which electrically connects the positive electrode terminal 212 and the negative electrode terminal 212 of the adjacent single cells 210 and 210. The metal plate 340 is bonded to one of the bus bars 230a and 230c. The electronic component 10 is electrically connected to the one bus bar via the conductor circuit 22B and the metal plate 340.

[0166] In the present embodiment, with the above configuration, the bus bar can be electrically connected to the conductor circuit 22B by bonding the metal plate 340 to the bus bar. Thus, when the conductor circuit 22B is electrically connected to the bus bar, there is no need to provide a separate component, thereby further improving workability and further suppressing an increase in manufacturing cost.

[0167] According to the present embodiment, the flexible substrate 1B includes a trunk portion 241 and a plurality of branch portions 242a and 242b branched from the trunk portion 241. Each of the branch portions 242a and 242b is folded back to intersect the trunk portion 241 in a plan view. An end portion 300 of each of the branch portions 242a and 242b has the electronic component 10, the base film 21, the conductor circuit 22B, the cover layer 23, and the metal plate 340.

[0168] In the present embodiment, with the above-described configuration, since each of the branch portions 242a and 242b is folded back so as to intersect with the trunk portion 241 in a plan view, the protrusion amount of each branch portion in the width direction of the flexible substrate 1B (the expansion of each branch portion in the width direction of the flexible substrate 1B) can be reduced, and the length of each branch portion can be ensured. Thus, even when thermal expansion occurs in the battery module 200, tolerances can be easily absorbed in each branch portion.

[0169] According to the present embodiment, the trunk portion 241 is formed in a substantially U-shape and has a first extension portion 241a, a second extension portion 241b and a connecting portion 241c. The second extension portion 241b extends parallel to the first extension portion 241a. The connecting portion 241c connects the end of the first extension portion 241a and the end of the second extension portion 241b.

[0170] When each of the plurality of branch portions 242a branches from the first extension portion 241a in a direction approaching the second extension portion 241b, each branch portion 242 turns back in a direction away from the second extension portion 241b to intersect with the first extension portion 241a in a plan view. When each of the plurality of branch portions 242b branches from the second extension portion 241b in a direction approaching the first extension portion 241a, each branch portion 242 turns back in a direction away from the first extension portion 241a to intersect with the second extension portion 241b in a plan view.

[0171] In the present embodiment, with the above configuration, the plurality of branch portions 242a branch from the first extension portion 241a in a direction approaching the second extension portion 241b. Thus, compared with a case where the plurality of branch portions 242a branch from the first extension portion 241a in a direction away from the second extension portion 241b, the number of regions in the FPC 240 that are not used as branch portions can be reduced, thereby reducing the amount of waste.

[0172] Similarly, the plurality of branch portions 242b branch from the second extension portion 241b in a direction approaching the first extension portion 241a. Thus, compared with the case where the plurality of branch portions 242b branch from the second extension portion 241b in a direction away from the first extension portion 241a, the number of regions in the FPC 240 that are not used as branch portions can be reduced, thereby reducing the amount of waste.

[0173] According to the present embodiment, the bus bar module 201 includes a housing 220, a plurality of bus bars 230a and 230c, and an FPC 240. The housing 220 is assembled to the battery module 200 having a plurality of cells 210. Each of the plurality of bus bars 230a is supported by the housing 220, and electrically connects the positive electrode terminal 211 and the negative electrode terminal 211 of the adjacent cells 210 and 210 of the plurality of cells 210. Each of the plurality of bus bars 230c is supported by the housing 220, and electrically connects the positive electrode terminal 212 and the negative electrode terminal 212 of the adjacent cells 210 and 210 of the plurality of cells 210. The FPC 240 is accommodated in the housing 220.

[0174] The FPC 240 includes a trunk portion 241 and a plurality of branch portions 242a and 242b branched from the trunk portion 241. The plurality of branch portions 242a and 242b are folded back to cross the trunk portion 241 in a plan view and are electrically connected to the plurality of bus bars 230a and 230c, respectively.

[0175] Each end 300 of the branch portions 242a and 242b has an electronic component 10, a base film 21, a conductor circuit 22B, a cover layer 23, and a metal plate 340. The electronic component 10 has electrodes 12a and 12b. The conductor circuit 22B is formed on the second surface (the lower side surface in the vertical direction) 21b of the base film 21, and has a bonding area 30 and a bonding area 60. The cover layer 23 covers at least a portion of the second surface (the lower side surface in the vertical direction) 22b of the conductor circuit 22b, and has openings 24a to 24c. The opening 24a exposes the bonding area 30 to the outside. The openings 24b and 24c expose the bonding area 60 to the outside. The metal plate 340 is arranged on the second surface (the lower side surface in the vertical direction) 23b of the cover layer 23, and surrounds the electronic component 10.

[0176] In the opening 24a, the electrodes 12a and 12b are bonded to the bonding region 30 using a bonding material. In the openings 24b and 24c, one end 341 of the metal plate 340 is bonded to the bonding region 60. The other end 342 of the metal plate 340 is bonded to each of the plurality of bus bars 230a and 230c. The electronic component 10 is electrically connected to each of the plurality of bus bars 230a and 230c via the conductor circuit 22B and the metal plate 340.

[0177] In the present embodiment, by the above-mentioned construction, the electrodes 12a and 12b of the electronic component 10, the bonding material, and the bonding area 30 of the conductor circuit 22B are arranged on the second surface 21b of the base film 21, which are included in the bonding portion 33 between the electronic component 10 and the conductor circuit 22B. Here, the second surface 21b of the base film 21 faces the lower side in the vertical direction.

[0178] Therefore, even if condensation occurs in the openings 24a of each branch portion of the FPC 240, the condensation water is discharged to the lower side (ground side) in the vertical direction. Therefore, with a simple structure, it is possible to prevent condensation water from accumulating in the joint portion 33, thereby reliably avoiding a short circuit of the electronic component 10. Thus, in the bus bar module 201, it is possible to improve the moisture resistance of the joint portion 33 between the electronic component 10 and the conductor circuit 22 while suppressing a decrease in yield during manufacturing.

[0179] With the above configuration, the bus bar can be electrically connected to the conductor circuit 22B by bonding the metal plate 340 to the bus bar. Thus, when the conductor circuit 22B is electrically connected to the bus bar, there is no need to provide a separate component, thereby further improving workability and further suppressing an increase in manufacturing cost.

[0180] With the above configuration, since each of the plurality of branch portions 242a and 242b is folded back to intersect the trunk portion 241 in a plan view, the protrusion amount of each branch portion in the width direction of the flexible substrate 1B (the expansion of each branch portion in the width direction of the flexible substrate 1B) can be reduced, and the length of each branch portion can be ensured. Thus, even when thermal expansion occurs in the battery module 200, tolerances can be easily absorbed in each branch portion.

[0181] (Revision)

[0182] In the third embodiment described above, the trunk portion 241 of the FPC 240 is formed in a substantially U-shape because the smoke exhaust duct 250 is placed on the upper surface between the electrode terminals 211 and 212 in each of the single cells 210; however, the present embodiment is not limited thereto. For example, if the smoke exhaust duct 250 is not placed on the upper surface between the electrode terminals 211 and 212 in each of the single cells 210, the trunk portion may be formed in a straight line.

[0183] Fig.14 is a plan view of a flexible substrate 1B according to this modification. Fig.14 As shown, the flexible substrate 1B includes an FPC 240A. The FPC 240A has a trunk portion 243 and a plurality of branch portions 244a and 244b. The trunk portion 243 is formed in a straight line shape and has an extension portion 243a and a connection portion 243b.

[0184] The extension portion 243a extends along the length direction of the flexible substrate 1B. The connection portion 243b is connected to the +X side end of the extension portion 243a at the -X side end of the connection portion 243, and the connector 410 is mounted on the +X side end of the connection portion 243b.

[0185] Each of the plurality of branch portions 244a branches from one side (-Y side) of the extension portion 243a and then folds back toward the +Y side to intersect the extension portion 243a in a plan view (XY plan view). Similarly, each of the plurality of branch portions 244b branches from the other side (+Y side) of the extension portion 243a and then folds back toward the -Y side to intersect the extension portion 243a in a plan view (XY plan view). The branch portions 244a and 244b are alternately arranged along the length direction of the flexible substrate 1B.

[0186] If the flexible substrate 1B can be assembled to the upper side of the smoke exhaust duct 250 , the trunk portion can be formed linearly even if the smoke exhaust duct 250 is placed on the upper surface between the electrode terminals 211 and 212 in each of the single cells 210 .

[0187] With the above configuration, since each of the plurality of branch portions 244a and 244b is folded back to intersect the trunk portion 243 in a plan view, the protrusion amount of each branch portion in the width direction of the flexible substrate 1B (the expansion of each branch portion in the width direction of the flexible substrate 1B) can be reduced, and the length of each branch portion can be ensured. Thus, even when thermal expansion occurs in the battery module 200, tolerances can be easily absorbed in each branch portion.

[0188] (Other modifications)

[0189] Two or more of the first embodiment, the first and second modifications of the first embodiment, the second embodiment, the modification of the second embodiment, the third embodiment, and the modification of the third embodiment may be combined and applied to a flexible substrate and a bus bar module.

[0190] Although specific embodiments have been described, these embodiments are disclosed only by way of example and are not intended to limit the scope of the invention. Indeed, the novel embodiments described herein may be implemented in a variety of other forms; furthermore, various omissions, substitutions, and changes in the forms of the embodiments described herein may be made without departing from the spirit of the invention. The appended claims and their counterparts are intended to cover such forms or modifications that fall within the scope and spirit of the invention.

Claims

1. A flexible substrate, comprising: an electronic component having an electrode; Basement membrane; a conductor circuit formed on a lower surface of the base film in a vertical direction and having a first bonding region to which the electrode is bonded using a bonding material; as well as A cover layer covers at least a portion of a lower surface of the conductor circuit in a vertical direction and has a first opening for exposing the first bonding region to the outside.

2. The flexible substrate according to claim 1, wherein: The first opening is covered with insulating oil.

3. The flexible substrate according to claim 1 or 2, further comprising a metal plate, wherein: The cover layer covers a portion of the lower side surface of the base film in the vertical direction except for the area exposed to the outside in the first opening, The metal plate is disposed on the lower surface of the cover layer in the vertical direction and surrounds the electronic component, and No reinforcing plate is provided on the upper side surface of the base film in the vertical direction.

4. The flexible substrate according to claim 3, wherein: The conductor circuit has a second bonding area to which a portion of the metal plate is bonded, and The cover layer has a second opening, and the second opening exposes the second bonding area to the outside.

5. The flexible substrate according to claim 4, wherein: The flexible substrate is included in a bus bar module having a plurality of bus bars, each of the bus bars electrically connecting a positive electrode terminal and a negative electrode terminal of adjacent single cells, The metal plate is bonded to one of the plurality of bus bars, and The electronic component is electrically connected to the one bus bar via the conductor circuit and the metal plate.

6. The flexible substrate according to claim 5, further comprising: Main cadre; as well as A branch portion, the branch portion branches off from the main trunk, wherein: The branch portion is folded back to intersect the trunk portion in a plan view, and The end portion of the branch portion has the electronic component, the base film, the conductor circuit, the cover layer, and the metal plate.

7. The flexible substrate according to claim 6, wherein: The trunk portion is formed in a substantially U-shape and has a first extending portion, a second extending portion extending parallel to the first extending portion, and a connecting portion connecting an end portion of the first extending portion and an end portion of the second extending portion. When the branch portion branches from the first extension portion in a direction approaching the second extension portion, the branch portion turns back in a direction away from the second extension portion to intersect with the first extension portion in a plan view, and When the branch portion branches from the second extension portion in a direction approaching the first extension portion, the branch portion turns back in a direction away from the first extension portion to intersect with the second extension portion in a plan view.

8. A busbar module, comprising: a housing assembled to a battery module having a plurality of battery cells; a bus bar supported by the case and electrically connecting the positive electrode terminal and the negative electrode terminal of adjacent cells among the plurality of cells; as well as A flexible substrate is housed in the housing, wherein: The flexible substrate has: Main officers; and a branch portion branching from the trunk portion, folding back to intersect the trunk portion in a plan view, and electrically connected to the bus bar, and The end of the branch portion has: an electronic component having an electrode; Basement membrane; a conductor circuit formed on a lower surface of the base film in a vertical direction and having a first bonding area and a second bonding area; a cover layer covering at least a portion of a lower surface of the conductor circuit in a vertical direction and having a first opening for exposing the first bonding area to the outside and a second opening for exposing the second bonding area to the outside; and Metal sheet, and The cover layer covers a portion of the lower side surface of the base film in the vertical direction except for the area exposed to the outside in the first opening, The metal plate is disposed on the lower surface of the cover layer in the vertical direction and surrounds the electronic component. In the first opening, the electrode is bonded to the first bonding region using a bonding material, In the second opening, one end of the metal plate is bonded to the second bonding area, and the other end of the metal plate is bonded to the bus bar, and The electronic components are electrically connected to the bus bars via the conductor circuits and the metal plates.

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