Bus bar module and battery pack

Abstract

To provide a bus bar module in which a substrate and a connection piece are easily held even if a stress is applied to a solder, and provide a battery pack.SOLUTION: A bus bar module 10 is a bus bar module provided to an electrode surface of a plurality of battery cells, comprising: a substrate 50; a bus bar main body 60 that is connected to electrode terminals 24 and 25 connected to the electrode of each battery cell; a plurality of bus bars 80 that is overlapped to the substrate so as to be extended from the bus bar main body, and includes a connection piece 70 connected to the substrate; and a solder 100 that fixes the substrate with the connection piece. A guide structure 78 having a guide surface 79 to which the solder is guided is provided to the connection piece, and an outer shell of the connection piece is formed, and the solder is attached to at least one part of connection surfaces 73 and 75 that are continued to the guide surface and the guide surface.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The disclosure herein relates to a busbar module and a battery pack. [Background technology]

[0002] Patent Document 1 describes a battery assembly to which a busbar module is attached. In the battery assembly, positive and negative electrodes of the cells are arranged so as to be stacked alternately. The busbar module is made of a flexible substrate and has a circuit body to which a busbar connected to the positive and negative electrodes of the cells is attached. The circuit body has a main line arranged along the stacking direction on each cell, and a belt-shaped first branch line portion extending in a direction intersecting the longitudinal direction and thickness direction of the main line. A belt-shaped second branch line portion extending in a direction parallel to the stacking direction of each battery body is provided at the tip of the first branch line. A connection piece protruding from the busbar body toward the main line is fixed to the second branch line portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6793691 Summary of the Invention [Problem to be solved by the invention]

[0004] A connection piece is fixed to the connection part at the tip of the second branch line via solder. Solder is provided at the boundary between the connection part and the connection piece. The solder is attached to the outer surface of the connection piece so as to follow the edge of the connection piece. Because the amount of adhesion between the solder and the connection piece is small, if stress is applied to the solder, the solder may be damaged due to insufficient strength, and the connection between the connection piece and the connection part may not be able to be maintained.

[0005] Therefore, an object of the present disclosure is to provide a bus bar module and a battery pack in which the connection between the substrate and the connection piece is likely to be maintained even when stress is applied to the solder. [Means for solving the problem]

[0006] A busbar module according to one aspect of the present disclosure includes: A bus bar module (10) provided on electrode surfaces (20A) of a plurality of battery cells (20) stacked in a thickness direction (TD), A substrate (50); a busbar body (60) connected to electrode terminals (24, 25) that are connected to electrodes of the battery cells, and a plurality of busbars (80) each having a connection piece (70) extending from the busbar body, overlapping with the substrate and connected to the substrate; and a solder (100) for fixing the substrate and the connection piece. A guide structure (78; 278; 378; 478) having a guide surface (79A; 279A; 379A; 479A) along which the solder is guided is provided on the connecting piece, Solder is applied to at least a portion of the continuous surface (73, 75) that forms the outer shell of the connection piece and is continuous with the guide surface, and to the guide surface.

[0007] Since the solder (100) adheres to at least a portion of the continuous surfaces (73, 75) and to the guide surfaces (79A; 279A; 379A; 479A), the amount of solder (100) adhered to the connection piece (70) is increased. This strengthens the connection between the substrate (50) and the connection piece (70). Even if stress is applied to the solder (100), the connection between the substrate (50) and the connection piece (70) is likely to be maintained.

[0008] A battery pack according to another aspect of the present disclosure includes: A plurality of battery cells (20) stacked in a thickness direction (TD); a bus bar module (10) provided on electrode surfaces (20A) of a plurality of battery cells; The busbar module is A substrate (50); a busbar body (60) connected to electrode terminals (24, 25) that are connected to electrodes of the battery cells, and a plurality of busbars (80) each having a connection piece (70) extending from the busbar body, overlapping with the substrate and connected to the substrate; and a solder (100) for fixing the substrate and the connection piece. A guide structure (78; 278; 378; 478) having a guide surface (79A; 279A; 379A; 479A) along which the solder is guided is provided on the connecting piece, Solder is applied to at least a portion of the continuous surface (73, 75) that forms the outer shell of the connection piece and is continuous with the guide surface, and to the guide surface.

[0009] The battery pack includes a bus bar module (10). Since the solder (100) adheres to at least a portion of the continuous surfaces (73, 75) and to the guide surfaces (79A; 279A; 379A; 479A), the amount of solder (100) adhered to the connection piece (70) is large. This strengthens the connection between the substrate (50) and the connection piece (70). Even if stress is applied to the solder (100), the connection between the substrate (50) and the connection piece (70) is likely to be maintained.

[0010] It should be noted that the reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments described below, and do not in any way limit the technical scope. [Brief description of the drawings]

[0011] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view of the battery pack with the case removed. [Diagram 3] FIG. 2 is a perspective view of the bus bar module excluding the holder. [Figure 4] 4 is a perspective view showing a connection relationship between a terminal portion and a connection piece. FIG. [Diagram 5] FIG. 2 is an enlarged view of a connection portion between a terminal portion and a connection piece; [Figure 6] FIG. 2 is a schematic diagram illustrating one of the guide structures of the first embodiment. [Figure 7] 6 is a schematic diagram illustrating another guide structure in the first embodiment. FIG. [Figure 8] 13 is a schematic diagram illustrating a guide structure in a second embodiment. FIG. [Figure 9] FIG. 11 is a cross-sectional view illustrating a guide structure according to a second embodiment. [Figure 10] 13 is a cross-sectional view illustrating a modified example of the guide structure of the second embodiment. FIG. [Figure 11] FIG. 13 is a schematic diagram illustrating a guide structure according to a third embodiment. [Figure 12] FIG. 11 is a cross-sectional view illustrating a guide structure according to a third embodiment. [Figure 13] 13 is a schematic diagram illustrating a guide structure according to a fourth embodiment. FIG. [Figure 14] FIG. 13 is a cross-sectional view illustrating a guide structure according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other embodiment described previously may be applied to the other parts of the configuration.

[0013] In addition to combinations of parts that are specifically specified as being possible in each embodiment, it is also possible to partially combine embodiments, embodiments and variations, and variations together, even if not specified, provided that no problems arise with the combination.

[0014] (First embodiment) A battery pack 1 and a busbar module 10 will be described with reference to Figs. 1 to 7. Fig. 1 shows a schematic diagram of various components of the battery pack 1. Figs. 2 to 7 show a schematic diagram of various components of the busbar module 10. The battery pack 1 of the embodiment is applied to an electric vehicle such as an electric vehicle or a plug-in hybrid vehicle, for example. The battery pack 1 includes a plurality of battery cells 20. The battery cells 20 are secondary batteries. Secondary batteries that can be used for the battery cells 20 include, for example, lithium ion secondary batteries, nickel-metal hydride secondary batteries, and organic radical batteries. These secondary batteries generate electromotive voltage through chemical reactions.

[0015] Hereinafter, the thickness direction of the battery cell 20 may be referred to as the thickness direction TD. The thickness direction TD corresponds to the stacking direction of the multiple battery assemblies 21. The width direction of the battery cell 20 may be referred to as the width direction WD. The height direction of the battery cell 20 may be referred to as the height direction HT. The thickness direction TD, width direction WD, and height direction HT are mutually perpendicular. In the drawings, the thickness direction TD may be simply referred to as "TD." The width direction WD may be simply referred to as "WD." The height direction HT may be simply referred to as "HD."

[0016] The drawings will now be described. FIG. 1 is an exploded perspective view of a battery pack 1. FIG. 2 is a perspective view of the battery pack 1 without the case 160. FIG. 3 is a perspective view of the busbar module without the holder. FIG. 4 is a perspective view showing the connection relationship between the terminal portion 40 and the connection piece 70. FIG. 5 is an enlarged view of the connection portion between the terminal portion 40 and the connection piece 70. FIG. 6 is a schematic view illustrating one of the guide structures 78 of the first embodiment. FIG. 7 is a schematic view illustrating another of the guide structures 78 of the first embodiment.

[0017] <Car battery> The battery pack 1 is mounted on an electric vehicle and constitutes an on-board power supply. The on-board power supply serves to supply power to the electric loads of the vehicle. The on-board power supply may be located, for example, in the space under the front seats, the space under the rear seats, or the space between the rear seats and the trunk.

[0018] The battery pack 1 includes a bus bar module 10, a plurality of battery cells 20, a resin frame 110, a cover 120, nuts 130, end plates 140, shims 150, and a case 160 that houses these components. First, the case 160 will be described.

[0019] <Case> The case 160 has a box-like shape with a bottom formed by die casting, for example. Aluminum or the like is used as the material of the case 160. The case 160 has a bottom wall 161 and a side wall 162. The bottom wall 161 and the side wall 162 are integrally connected. The bottom wall 161 has a flat shape with a small thickness in the height direction HT. The side wall 162 stands upright in the height direction HT from the inner bottom surface of the bottom wall 161. The side wall 162 extends along the edge of the inner bottom surface and forms an annular shape in the circumferential direction around the height direction HT. The bottom wall 161 and the side wall 162 form a storage space 163 of the case 160.

[0020] A plurality of battery cells 20 are stored in the storage space 163. The plurality of battery cells 20 are stored in the storage space 163 in two rows in the width direction WD. The case 160 has an opening at one end in the height direction HT. The plurality of battery cells 20 are stored in the case 160 so that the electrode surfaces 20A of each battery cell 20 correspond to the opening side. The battery cells 20 are stacked in the thickness direction TD so that the main surfaces 20C overlap each other.

[0021] <Battery cell> The battery cell 20 has a generally rectangular parallelepiped shape that is thin in the thickness direction TD. The battery cell 20 has an electrode surface 20A having a positive electrode terminal 24 and a negative electrode terminal 25, and two main surfaces 20C along a plane perpendicular to the thickness direction TD. The electrode surface 20A is provided between the two main surfaces 20C so as to connect the two main surfaces 20C. The battery cell 20 has a positive electrode and a negative electrode at both ends of the electrode surface 20A in the width direction WD. The battery cells 20 are stacked in the thickness direction TD such that the positive electrodes and the negative electrodes are alternately arranged with respect to the thickness direction TD.

[0022] <Resin frame> A resin frame 110 is disposed between two adjacent ones of the stacked battery cells 20. The battery cells 20 and the resin frames 110 are alternately arranged in the stacking direction. The battery assembly 21 is formed by alternately stacking the battery cells 20 and the resin frames 110. The resin frame 110 is formed, for example, from a resin member having electrical insulation properties. The resin frame 110 is disposed between adjacent battery cells 20 as an insulating member.

[0023] The resin frame 110 has a central body 111 that faces the main surface 20C of the battery cell 20, and a ring-shaped frame body 112 that is integrally connected to the periphery of the central body 111. The battery cell 20 is housed in a space defined by the central body 111 and the frame body 112, and its position is fixed. A positive electrode terminal 24 that is electrically connected to the positive electrode and a negative electrode terminal 25 that is electrically connected to the negative electrode are provided on the wall of the frame body 112 that faces the electrode surface 20A. The positive electrode terminal 24 and the negative electrode terminal 25 may be collectively referred to as electrode terminals 24, 25.

[0024] <End plates and shims> 1, an end plate 140 is attached from the outside to the battery cell 20 located at the end in the thickness direction TD so as to cover this battery cell 20. As an example, the end plate 140 is made of an electrically insulating resin material. Furthermore, a shim 150 is provided between the end plate 140 and the side wall 162 to adjust the relative positions of the various components. As an example, the shim 150 is made of a metal material.

[0025] <Busbar module> A busbar module 10 is disposed above a battery assembly 21 so as to cover the electrode surfaces 20A of the multiple battery cells 20. The busbar module 10 has a substrate 50, a busbar 80, solder 100, and a holder 170. The substrate 50 is electrically connected to the electrode terminals 24, 25 of the battery cells 20 via the busbar 80. The substrate 50 and the busbar 80 are held and stored in the holder 170. The substrate 50 is a flexible substrate that can flexibly deform. A wiring pattern is provided on the substrate 50. A resin layer that covers the wiring pattern is provided on the front and back surfaces of the substrate 50.

[0026] <Substrate> The substrate 50 has a base 30 and a plurality of terminal portions 40. The base 30 is provided above the battery assembly 21 so as to cover a region between a positive electrode terminal 24 and a negative electrode terminal 25 that are spaced apart in the width direction WD. The base 30 extends in the thickness direction TD. The electrode terminals 24, 25 are provided outside the base 30 in the width direction WD. The base 30 and the electrode terminals 24, 25 are spaced apart in the width direction WD. A voltage detection line that detects the voltage of the battery cell 20 is provided on the base 30.

[0027] <Terminal part> The multiple terminal portions 40 are provided at both ends of the base 30 in the width direction WD. The terminal portions 40 have a first extension portion 41 and a second extension portion 42. The first extension portion 41 extends in the width direction WD from an end portion of the base 30 in the width direction WD toward each of the electrode terminals 24, 25. The second extension portion 42 is provided at an end portion of the first extension portion 41 on the side away from the base 30. The second extension portion 42 is provided on an edge in the width direction WD of the end portion of the first extension portion 41 on the side away from the base 30.

[0028] The second extension 42 extends away from the first extension 41 and toward the electrode surface 20A. It can also be said that the second extension 42 extends in the height direction HT toward the electrode surface 20A. The base 30 is provided above the electrode surface 20A by about the length of the second extension 42 in the height direction HT. The second extension 42 is bent in a substantially S-shape midway along its extension in the height direction HT toward the electrode surface 20A. It can also be said that the second extension 42 has two bent portions 42A that bend in opposite directions. The two bent portions 42A are continuously lined up in the height direction HT. One of the two bent portions 42A is bent in a mountain shape, and the other of the two bent portions 42A is bent in a valley shape.

[0029] As described above, the substrate 50 is a flexible substrate. Therefore, the base 30, the first extension 41, and the second extension 42 are each flexibly deformable. The base 30 and the first extension 41 are particularly flexibly deformable in the height direction HT. The second extension 42 is particularly flexibly deformable in the height direction HT and the thickness direction TD. As shown in FIG. 3, the tip of the second extension 42 away from the first extension 41 extends in the thickness direction TD. It can also be said that the tip of the second extension 42 away from the first extension 41 has a length in the thickness direction TD. It can also be said that the second extension 42 has an axis 43 extending in the height direction HT so as to move away from the first extension 41, and a tip 44 extending in the thickness direction TD from the tip of the axis 43 away from the first extension 41.

[0030] <Tip> The tip portion 44 has a plate-like shape with a small thickness in the height direction HT. The tip portion 44 is provided between the base portion 30 and the battery assembly 21 in the height direction HT. The tip portion 44 is provided above the electrode surface 20A in the height direction HT. The tip portion 44 is a portion electrically connected to the electrode terminals 24, 25 via the bus bar 80. The tip portion 44 has a surface 44A located on the base portion 30 side and a back surface 44B on the back side thereof. The surface 44A is a surface to which the bus bar 80 is connected. The surface 44A extends flat along a plane perpendicular to the height direction HT. The connection piece 70 of the bus bar 80 is connected to the surface 44A, whereby the voltage detection wiring provided on the base portion 30 is electrically connected to the electrode terminals 24, 25.

[0031] A connector 31 is attached to the end of the base 30. The connector 31 is connected to a voltage detection line and can be connected to an external voltage detection device. A current flows in the voltage detection line when the tip 44 is electrically connected to the electrode terminals 24, 25 via the bus bar 80. The current that flows through the voltage detection line flows via the connector 31 to the external voltage detection device. The voltage detection device detects the voltage of the battery cell 20 based on this current.

[0032] <Busbar> The busbar 80 is a metal plate-shaped member that is flat in the height direction HT. As an example, the busbar 80 is made mainly of copper. The busbar 80 has a busbar body 60 and a connection piece 70 that protrudes from the busbar body 60. The busbar 80 is provided above the battery cell 20 so as to overlap the electrode surface 20A. The busbar body 60 is a portion that is electrically connected to the electrode terminals 24, 25. The connection piece 70 extends from the busbar body 60 toward the tip portion 44 in the width direction WD. The connection piece 70 is a portion that is electrically connected to the tip portion 44. The connection piece 70 may be a separate member from the busbar body 60.

[0033] The busbar body 60 has two through holes 61 through which the positive electrode terminal 24 and the negative electrode terminal 25 adjacent to each other in the thickness direction TD are respectively passed. The positive electrode terminal 24 and the negative electrode terminal 25 are respectively passed through the two through holes 61. Nuts 130 are passed through the positive electrode terminal 24 and the negative electrode terminal 25 from above the busbar body 60. The nuts 130 are fixed to the positive electrode terminal 24 and the negative electrode terminal 25, respectively. This electrically and mechanically connects the electrode terminals 24, 25 to the busbar body 60.

[0034] As described above, the terminal portion 40 is provided at the end of the base portion 30 in the width direction WD. The bus bar 80 is provided on the outer side of the terminal portion 40 in the width direction WD. The terminal portion 40 has a first extension portion 41 extending in the width direction WD from the end of the base portion 30 in the width direction WD, and a second extension portion 42 extending in the height direction HT from the end of the first extension portion 41. The second extension portion 42 has a shaft portion 43 extending in the height direction HT so as to move away from the first extension portion 41, and a tip portion 44 extending in the thickness direction TD from a tip of the shaft portion 43 away from the first extension portion 41. The bus bar main body 60 of the bus bar 80 is provided on the electrode terminals 24, 25. The connection piece 70 of the bus bar 80 extends from the bus bar main body 60 toward the tip portion 44 in the width direction WD. The connection piece 70 is connected to the tip portion 44 via the solder 100.

[0035] <Holder> The holder 170 is a holding and housing structure for holding and housing the substrate 50 and the bus bar 80. The holder 170 is formed of, for example, an electrically insulating resin. The holder 170 has a main body housing section 171, a terminal housing section 172, and a lid section 173. The main body housing section 171 is provided on the battery cell 20 side of the base section 30. The main body housing section 171 holds the base section 30 from below. The terminal housing sections 172 are provided on both ends of the main body housing section 171 in the width direction WD. The terminal section 40 is held and housed in the terminal housing section 172. The terminal section 40 is exposed from the terminal housing section 172. The substrate 50 is covered by a lid section 173 made of an electrically insulating resin on the opposite side of the main body housing section 171.

[0036] <Cover and nut> In addition, cover 120 made of an electrically insulating resin is attached to holder 170. Cover 120 is attached from above holder 170 to protect the live parts from the outside. By attaching cover 120 to holder 170 in this manner, contact between tip portion 44 and connection piece 70 and moisture or dust from the outside is prevented.

[0037] <Connection piece> The connection piece 70 has a frame shape that forms a ring around the axis in the height direction HT. The connection piece 70 has a substantially rectangular shape when viewed in the height direction HT. The connection piece 70 has four edges 71 that form a frame. Hereinafter, the edge 71 that continues from the busbar body 60 may be referred to as a first edge 71A. The edge 71 that is provided so as to face the first edge 71A may be referred to as a third edge 71C. The edge 71 that connects one end of the first edge 71A and one end of the third edge 71C may be referred to as a second edge 71B. The edge 71 that connects the other end of the first edge 71A and the other end of the third edge 71C may be referred to as a fourth edge 71D. The first edge 71A, the second edge 71B, the third edge 71C, and the fourth edge 71D are provided in this order in the clockwise direction on the busbar body 60. A space 72 is defined by the four edges 71. It can also be said that the space 72 is defined by the inner surfaces 73 of the four edges 71. The battery pack 1 further includes a chip fuse 82. The chip fuse 82 is disposed in the space 72. Although details are omitted, wiring such as a voltage detection wiring provided in the base 30 is electrically connected to the connection piece 70 via the chip fuse 82.

[0038] Each of the four edge portions 71 has an outer side surface 74, an opposing surface 75, and an upper surface 76 in addition to the inner side surface 73. In other words, the connection piece 70 has the inner side surface 73, the outer side surface 74, the opposing surface 75, and the upper surface 76. The outer side surface 74 is a surface that is provided on the outer side of the inner side surface 73 in a direction perpendicular to the height direction HT. The opposing surface 75 is a surface that faces the surface 44A of the tip portion 44. The opposing surface 75 is a surface that is connected to one end of the inner side surface 73 in the height direction HT and one end of the outer side surface 74 in the height direction HT. The opposing surface 75 is a surface that is spaced apart from the surface 44A in the height direction HT at a constant distance. The upper surface 76 is a surface that is connected to the other end of the inner side surface 73 in the height direction HT and the other end of the outer side surface 74 in the height direction HT. The outer side surface 74 of the first edge portion 71A is integrally connected to the busbar body 60.

[0039] The connecting piece 70 is provided at the tip 44 such that the opposing surfaces 75 of the four edges 71 overlap the surface 44A in the height direction HT. Solder 100 is provided between the edges 71 and the tip 44. The connecting piece 70 and the tip 44 are fixed via the solder 100. The surface 44A is sometimes also referred to as the solder connection portion because it is the portion of the tip 44 where the solder 100 is connected. Note that the resin layer has been removed from an overlapping region 45 that overlaps the first edge 71A and the third edge 71C in the solder connection portion, and from a continuous region 46 that continues slightly from the overlapping region 45 toward the space 72 in the solder connection portion.

[0040] Solder 100 is provided in overlapping region 45 overlapping first edge 71A and third edge 71C, and in continuous region 46 slightly continuing from overlapping region 45 toward space 72. First edge 71A and tip 44 are electrically connected and fixed by solder 100 provided in overlapping region 45 overlapping first edge 71A and continuous region 46 continuing from overlapping region 45. Third edge 71C and tip 44 are electrically connected and fixed by solder 100 provided in overlapping region 45 overlapping third edge 71C and continuous region 46 continuing from overlapping region 45.

[0041] As described above, the first edge 71A and the third edge 71C are spaced apart in the width direction WD. Therefore, it can be said that the connection piece 70 and the tip 44 are fixed by the solder 100 at two points spaced apart in the width direction WD. Also, since the solder 100 is provided in the continuous region 46, it can be said that the solder 100 is provided in a region outside the projection region of the edge 71 onto the surface 44A. Therefore, the solder 100 is visible when viewed from the height direction HT.

[0042] <Guide structure> Also, a guide structure 78 having a guide surface 79A along which the solder 100 is guided is provided on the inside of the edge portion 71, which is on the side of the space 72. The guide structure 78 has the guide surface 79A connected to the opposing surface 75 and the inner surface 73. The guide structure 78 is an inclined portion 79 having an inclined surface connecting the opposing surface 75 and the inner surface 73 as the guide surface 79A. Note that the guide structure 78 is not limited to the inclined portion 79. Note that, as will be described later, the guide structure 78 may be a recess 279 recessed from the opposing surface 75, a recess 379 recessed from the inner surface 73, a curved portion 479 having a curved surface connecting the opposing surface 75 and the inner surface 73, or the like.

[0043] The inclined portion 79 is inclined such that the guide surface 79A extends away from the surface 44A which is the solder connection portion of the tip portion 44. The inclined portion 79 is inclined so as to approach the tip portion 44 as it moves from the inner surface 73 to the outer surface 74. The inclined portion 79 is provided at an imaginary corner portion 77 formed by the collision of the inner surface 73 and the opposing surface 75. The guide surface 79A is a surface that connects the inner surface 73 and the opposing surface 75. The opposing surface 75 overlaps with the surface 44A of the terminal portion 40, and its end continues to the guide surface 79A. The inner surface 73 continues from the end of the guide surface 79A opposite to the end that continues to the opposing surface 75, and extends in the height direction HT so as to move away from the opposing surface 75.

[0044] The guide structure 78 is formed on the first edge portion 71A and the third edge portion 71C. First, the guide structure 78 formed on the first edge portion 71A will be described. An inclined portion 79 is provided at a virtual corner portion 77 where the inner surface 73 and the opposing surface 75 of the first edge portion 71A collide. The guide surface 79A of the inclined portion 79 connects the inner surface 73 of the first edge portion 71A and the opposing surface 75 of the first edge portion 71A. The opposing surface 75 of the first edge portion 71A, the guide surface 79A of the inclined portion 79, and the inner surface 73 of the first edge portion 71A are continuous. Solder 100 is attached to the opposing surface 75 and the guide surface 79A. The solder 100 may be attached to the inner surface 73 of the first edge portion 71A in addition to the opposing surface 75 of the first edge portion 71A and the guide surface 79A continuing from the opposing surface 75. The inner surface 73 and / or the opposing surface 75 are sometimes referred to as continuous surfaces 73, 75 because they are continuous with the guide surface 79A. The continuous surfaces 73, 75 are surfaces that form part of the outer shell of the connecting piece 70. The outer shell refers to the outer surface excluding the guide surface 79A. For example, the outer shell refers to the inner surface 73, the outer surface 74, the opposing surface 75, and the top surface 76.

[0045] The solder 100 attached to the guide surface 79A of the first edge portion 71A curves smoothly and flares out toward the surface 44A. The solder 100 that spreads out at the bottom enters the continuous region 46. In other words, the solder 100 attached to the guide surface 79A forms a fillet shape. This makes it easy to check the presence or absence of the solder 100 when viewed from the height direction HT during inspection.

[0046] Similarly, an inclined portion 79 is provided at a virtual corner 77 where the inner surface 73 and the opposing surface 75 of the third edge portion 71C collide. A guide surface 79A of the inclined portion 79 connects the inner surface 73 of the third edge portion 71C to the opposing surface 75 of the third edge portion 71C. The opposing surface 75 of the third edge portion 71C, the guide surface 79A of the inclined portion 79, and the inner surface 73 of the third edge portion 71C are continuous. Solder 100 is attached to the opposing surface 75 and the guide surface 79A continuing from the opposing surface 75. The solder 100 may be attached to the inner surface 73 of the third edge portion 71C in addition to the opposing surface 75 of the third edge portion 71C and the guide surface 79A continuing from the opposing surface 75.

[0047] In addition, in the third edge portion 71C, the inner surface 73 and / or the opposing surface 75 are also referred to as continuous surfaces 73, 75 because they are surfaces that are continuous with the guide surface 79A. The continuous surfaces 73, 75 are surfaces that form the outer shell of the connection piece 70. The solder 100 attached to the guide surface 79A of the third edge portion 71C smoothly curves toward the surface 44A. The solder 100 that spreads out at the bottom enters the continuous region 46. In other words, it can be said that the solder 100 attached to the guide surface 79A forms a fillet shape. This makes it easy to check the presence or absence of the solder 100 when viewed from the height direction HT during inspection.

[0048] The busbar module 10 further has a metal film 81 for improving the wetting and spreading of the solder 100. One example of the metal film 81 is plating. The metal film 81 is provided on the four edge portions 71 of the connection piece 70. The metal film 81 is provided on the opposing surface 75, the upper surface 76, and the guide surface 79A of each of the four edge portions 71. Note that the metal film 81 does not necessarily have to be provided on the guide surface 79A.

[0049] Generally, busbars are formed by punching out a metal plate such as copper, on whose surface a metal film such as plating has been applied in advance, in the thickness direction. Therefore, at the fracture surface perpendicular to the thickness direction, the base metal material such as copper, which is not covered with the metal film, is exposed. It is generally known that the solder wettability and spreadability is inferior to that of a surface covered with a metal film. Therefore, even if solder is to be applied to the fracture surface, it is difficult for the solder to creep up to the fracture surface, and there is a concern that the solder cannot be applied over a wide area of ​​the fracture surface.

[0050] As described above, it is difficult to increase the adhesion area between the busbar and the solder on the fractured surface, and it is also difficult to increase the connection strength of the solder between the busbar and the object to which the busbar is fixed. Therefore, in order to improve the wettability and spreadability of the solder on the fractured surface, it is possible to provide a new metal film on the fractured surface after forming the busbar. However, in that case, there is a concern that the new metal film for the fractured surface will require additional material costs or a process for providing a new metal film on the fractured surface will be required.

[0051] In this embodiment, in the manufacturing process, the corner 77 connecting the facing surface 75 and the inner surface 73 of the bus bar 80 is crushed to form the inclined portion 79 as the guide structure 78. The process of crushing the corner 77 to form the inclined portion 79 as the guide structure 78 is also called C-face stamping. As a result, a guide surface 79A originating from the facing surface 75 is formed on at least a part of the inclined portion 79. For this reason, a metal film can be provided on at least a part of the guide surface 79A. As a result, the wetting and spreading property of the solder 100 on the guide surface 79A can be improved. The amount of the solder 100 attached to the connection piece 70 can be increased.

[0052] Although an example in which the connecting piece 70 has a frame shape has been described so far, the shape of the connecting piece 70 is not limited to a frame shape. The connecting piece 70 may be in a plate shape with the space 72 closed. In this case, the connecting piece 70 has an opposing surface 75, an upper surface 76, and an outer surface 74. In this case, an inclined portion 79 is provided at an imaginary corner 77 where the opposing surface 75 and the outer surface 74 of the connecting piece 70 collide. The solder 100 adheres to the opposing surface 75 and the guide surface 79A. Even in this case, the solder 100 may further adhere to the outer surface 74. The amount of solder 100 adhered to the connecting piece 70 can be increased.

[0053] <Action and effect> The busbar module 10 of this embodiment has a substrate 50, a busbar 80, and solder 100. The substrate 50 has a base 30 and a plurality of terminal portions 40 extending from the base 30 toward the electrode terminals 24, 25 of the plurality of battery cells 20. The busbar 80 has a busbar main body 60 connected to the electrode terminals 24, 25, and a connection piece 70 extending from the busbar main body 60 and connected to the terminal portion 40. The terminal portion 40 and the connection piece 70 overlap in the height direction HT of the battery cell 20, and the connection piece 70 and the terminal portion 40 are fixed by the solder 100. It is to be noted that the substrate 50 does not have to have the terminal portion 40. The substrate 50 may have only the base 30. In that case, the connection piece 70 and the base 30 are fixed by the solder 100.

[0054] A guide structure 78 having a guide surface 79A along which the solder 100 is guided is formed on the connection piece 70. The solder 100 is attached to the guide surface 79A and to continuous surfaces 73, 75 which form part of the outer shell of the connection piece 70 and are continuous with the guide surface 79A. Because the continuous surfaces 73, 75 and the guide surface 79A are attached to the solder 100, the amount of adhesion between the solder 100 and the connection piece 70 is increased. The connection between the terminal portion 40 and the connection piece 70 is strengthened. For example, even if the battery cell 20 expands and contracts and stress is applied to the solder 100, the connection between the terminal portion 40 and the connection piece 70 is more likely to be maintained.

[0055] When the battery pack 1 is manufactured, the electrode terminals 24, 25 are passed through the through holes 61 of the bus bar 80. Thereafter, the nut 130 is passed through the electrode terminals 24, 25, and the nut 130 is rotated around the electrode terminals 24, 25 to fix the bus bar 80 and the electrode terminals 24, 25. However, at this time, the torque caused by the rotation of the nut 130 may apply stress to the solder 100 connecting the terminal portion 40 and the connection piece 70.

[0056] Furthermore, the battery cells 20 applied to the battery pack 1 expand and contract individually in the thickness direction TD in response to changes in the external environment. At this time, the relative positions of the terminal portion 40 and the connection piece 70 may shift. As a result, stress may be applied to the solder 100 connecting the terminal portion 40 and the connection piece 70. In this embodiment, the guide surface 79A and the continuous surfaces 73 and 75 are fixed by the solder 100 as described above, so that the terminal portion 40 and the connection piece 70 are firmly fixed. Even if stress is applied to the solder 100 due to such a structure unique to the battery pack 1, the connection between the terminal portion 40 and the connection piece 70 is easily maintained according to this embodiment.

[0057] The guide structure 78 is an inclined portion 79 in which the guide surface 79A extends away from the surface 44A, which is the solder connection site of the terminal portion 40. The connection piece 70 has an inner surface 73, an outer surface 74, an opposing surface 75, and an upper surface 76. The opposing surface 75, the guide surface 79A, and the inner surface 73 are continuous. The opposing surface 75 faces the surface 44A of the terminal portion 40, and its end continues to the guide surface 79A. The inner surface 73 continues from the end of the guide surface 79A opposite to the end continuing to the opposing surface 75, and extends in the height direction HT away from the opposing surface 75. Solder 100 is attached to the opposing surface 75 and the guide surface 79A.

[0058] Since the guide structure 78 is an inclined portion 79, the area of ​​the guide surface 79A is larger than the projected area of ​​the guide surface 79A onto the surface 44A. In a configuration in which the guide structure 78 is provided at the imaginary corner portion 77 where the inner surface 73 and the opposing surface 75 collide, the amount of solder 100 attached is likely to be greater than in a configuration in which the guide structure 78 is not provided. Therefore, even if stress is applied to the solder 100, the connection between the connection piece 70 and the terminal portion 40 is likely to be strong and the connection between the two is likely to be maintained. Also, even if a shear stress that shears in the height direction HT is applied to the solder 100, the connection between the connection piece 70 and the terminal portion 40 is likely to be maintained. Furthermore, since the guide structure 78 is an inclined portion 79, stress applied to the solder 100 due to changes in temperature and the like is likely to be alleviated.

[0059] The bus bar module 10 has a metal film 81, such as a plating film, for improving the wetting and spreading of the solder 100. The metal film 81 is provided on the guide surface 79A. This allows the solder 100 to easily spread from the opposing surface 75 to the guide surface 79A. The amount of the solder 100 adhering to the guide surface 79A increases. Even if stress is applied to the solder 100, the connection between the connection piece 70 and the terminal portion 40 is easily maintained.

[0060] The connection piece 70 has a frame shape that forms a ring around the axis in the height direction HT. The connection piece 70 has four edges 71 that form a frame. The four edges 71 define a space 72. A guide structure 78 is provided on the inside of the edge 71, which is the side of the space 72. Solder 100 is provided in the overlapping area 45 with the connection piece 70 in the terminal portion 40 and in the continuous area 46 that continues from the overlapping area 45 in the terminal portion 40 to the inside. The solder 100 attached to the guide surface 79A smoothly curves toward the tip portion 44. The solder 100 that spreads out at the bottom enters the continuous area 46. This makes it possible to visually check the solder 100 when viewed from the height direction HT. The presence or absence of the solder 100 can be easily confirmed when viewed from the height direction HT during inspection.

[0061] The connection piece 70 is substantially rectangular in the height direction HT plane view. The connection piece 70 has four edges 71 forming a frame. The edges 71 are a first edge 71A, a second edge 71B, a third edge 71C, and a fourth edge 71D arranged in this order clockwise. The guide structure 78 is formed on the first edge 71A and the third edge 71C arranged in the width direction WD. The solder 100 is attached to the guide surface 79A provided on the first edge 71A and the guide surface 79A provided on the third edge 71C. With this, even if the guide structure 78 vibrates in the direction of arrangement, the connection between the terminal portion 40 and the connection piece 70 is easily maintained because the amount of the solder 100 attached is increased. The positional deviation between the terminal portion 40 and the connection piece 70 is easily suppressed.

[0062] The substrate 50 is a flexible substrate. As described above, the substrate 50 has a base 30 and a terminal portion 40. The terminal portion 40 has a first extension portion 41 and a second extension portion 42. The first extension portion 41 extends in the width direction WD from an end portion of the base 30 in the width direction WD toward each of the electrode terminals 24 and 25. The second extension portion 42 is provided at an end portion of the first extension portion 41 in the width direction WD on the side away from the base 30. The second extension portion 42 extends away from the first extension portion 41 and toward the electrode surface 20A. Each of the base 30, the first extension portion 41, and the second extension portion 42 is flexibly deformable. The base 30 and the first extension portion 41 are flexibly deformable, particularly in the height direction HT. The second extension portion 42 is flexibly deformable, particularly in the height direction HT and the thickness direction TD.

[0063] When the battery cell 20 expands and contracts in the thickness direction TD, the second extension portion 42 is pulled in the stacking direction. As described above, the second extension portion 42 can flexibly deform in the height direction HT and the thickness direction TD, so the second extension portion 42 can follow the tension. Therefore, when the battery cell 20 expands and contracts in the thickness direction TD, stress is less likely to be applied to the solder 100. On the other hand, the second extension portion 42 may be deformed, for example, twisted, due to the expansion and contraction or vibration of the battery cell 20. In that case, it is expected that a large stress will be applied to the solder 100. In response to this, in this embodiment, the amount of the solder 100 attached to the connection piece 70 is increased. Even if a large stress is applied to the solder 100, the connection between the terminal portion 40 and the connection piece 70 can be firmly maintained. Stress is less likely to be applied to the solder 100. Even if the second extension portion 42 is pulled in the width direction WD, the solder 100 is less likely to be subjected to stress because the guide structures 78 are provided on two of the four edges 71 that are aligned in the width direction WD.

[0064] <Second embodiment> In the first embodiment, the guide structure 78 is described as being the inclined portion 79, but the guide structure 78 is not limited to being the inclined portion 79. The guide structure 278 in the second embodiment is a recess 279. In the second embodiment, the other configurations except for the guide structure 278 and the attachment form of the solder 100 are the same as those in the first embodiment. FIG. 8 is a schematic diagram for explaining the guide structure 278 of the second embodiment. FIG. 9 is a cross-sectional view taken along the line IX-IX shown in FIG. 8. FIG. 10 is a modified example of the guide structure 278 of the second embodiment. Note that, as a representative example, FIG. 8 to FIG. 10 show a schematic diagram and a cross-sectional view in which the guide structure 278 is provided on the third edge portion 71C. In FIG. 8, the second edge portion 71B and the fourth edge portion 71D connected to the third edge portion 71C are omitted, and only the third edge portion 71C is shown.

[0065] The recess 279, which is the guide structure 278 in the second embodiment, is a through hole penetrating the upper surface 76 and the opposing surface 75. The recess 279 is defined by a guide surface 279A that connects the upper surface 76 and the opposing surface 75. The guide surface 279A is continuous with the opposing surface 75 and the upper surface 76. The solder 100 is provided between the connection piece 70 and the terminal portion 40. The connection piece 70 and the terminal portion 40 overlap in the height direction HT via the solder 100. The solder 100 enters the recess 279. The solder 100 that has entered the recess 279 creeps up the guide surface 279A. The solder 100 adheres to the opposing surface 75, the guide surface 79A, and the inner surface 73.

[0066] The guide structure 278 provided on the third edge portion 71C will be described. The solder 100 is attached to the opposing surface 75 of the third edge portion 71C, the guide surface 279A of the recess 279 provided on the third edge portion 71C, and the inner surface 73 of the third edge portion 71C. In the second embodiment, the guide surface 279A and the continuous surfaces 73 and 75 are fixed with the solder 100. The amount of adhesion between the solder 100 and the connection piece 70 is increased. The terminal portion 40 and the connection piece 70 are firmly fixed. Even if stress is applied to the solder 100, the connection between the terminal portion 40 and the connection piece 70 is easily maintained. The recess 279 may be provided on the first edge portion 71A in addition to the third edge portion 71C. Furthermore, the recess 279 may be provided on the plate-shaped connection piece 70.

[0067] The recess 279 is not limited to a through hole penetrating the upper surface 76 and the opposing surface 75. The recess 279 may be a recess recessed from the opposing surface 75 toward the upper surface 76. In this case, the guide structure 278 has a guide surface 279A that defines a recess on the inside. The guide surface 279A is continuous with the opposing surface 75. The solder 100 is attached to the opposing surface 75, the guide surface 279A, and the inner surface 73. This also produces the same effect. As another example, a through hole may be formed as the recess 279 in the first edge portion 71A, and a recess may be formed as the recess 279 in the third edge portion 71C. The guide structure 278 of the second embodiment is not limited to a form in which one guide structure 278 is provided per edge portion 71. A plurality of guide structures 278 may be provided per edge portion 71. The guide structure 278 may be provided in the connection piece 70.

[0068] <Third embodiment> The guide structure 378 in the third embodiment is a recess 379. In the third embodiment, the configuration other than the guide structure 378 and the attachment form of the solder 100 is the same as in the first embodiment. FIG. 11 is a schematic diagram for explaining the guide structure 378 in the third embodiment. FIG. 12 is a cross-sectional view taken along the line XII-XII shown in FIG. 11. Note that, as a representative example, FIG. 11 and FIG. 12 show a schematic diagram and a cross-sectional view in which the guide structure 378 is provided on the third edge portion 71C. In FIG. 11, the second edge portion 71B and the fourth edge portion 71D connected to the third edge portion 71C are omitted, and only the third edge portion 71C is shown.

[0069] In the third embodiment, a recess 379 recessed from the inner surface 73 toward the outer surface 74 is provided in the connecting piece 70 as a guide structure 378. The recess 379 is defined by a guide surface 379A continuing to the inner surface 73. The guide surface 379A is continuing to the inner surface 73. Solder 100 is provided between the connecting piece 70 and the terminal portion 40. The connecting piece 70 and the terminal portion 40 overlap in the height direction HT via the solder 100. The solder 100 creeps up the inner surface 73 and enters the recess 379. The solder 100 that has entered the recess 379 is attached to the guide surface 379A. The solder 100 is attached to the opposing surface 75, the guide surface 79A, and the inner surface 73.

[0070] The guide structure 378 provided on the third edge portion 71C will be described. The solder 100 is attached to the opposing surface 75 of the third edge portion 71C, the guide surface 379A of the guide structure 378 provided on the third edge portion 71C, and the inner surface 73 of the third edge portion 71C. In the third embodiment, the guide surface 379A and the continuous surfaces 73 and 75 are fixed with the solder 100. The amount of adhesion between the solder 100 and the connection piece 70 is increased. The terminal portion 40 and the connection piece 70 are firmly fixed. Even if the battery cell 20 expands and contracts and stress is applied to the solder 100, the connection between the terminal portion 40 and the connection piece 70 is easily maintained. The recess 379 may be provided on the first edge portion 71A in addition to the third edge portion 71C. Furthermore, the recess 379 may be provided on the plate-shaped connection piece 70.

[0071] <Fourth embodiment> The guide structure 478 in the fourth embodiment is a curved portion 479. FIG. 13 is a schematic diagram for explaining the guide structure 478 in the fourth embodiment. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13. In the fourth embodiment, the connection piece 70 has, for example, a plate-like shape. The connection piece 70 has an upper surface 470A and a lower surface 470B spaced apart in the plate thickness direction. A metal film 81 is provided on the upper surface 470A and the lower surface 470B. The connection piece 70 is bent in a substantially L-shape so that a portion of it rises from the terminal portion 40. The connection piece 70 has a curved surface at the bent portion that rises gently from the terminal portion 40.

[0072] A portion of the connection piece 70 extends along the terminal portion 40. The portion of the connection piece 70 that extends along the terminal portion 40 overlaps with the terminal portion 40. The lower surface 470B of the portion of the connection piece 70 that overlaps with the terminal portion 40 corresponds to the opposing surface 75. The remaining portion of the connection piece 70 extends away from the terminal portion 40. The lower surface 470B of the portion of the connection piece 70 that extends away from the terminal portion 40 corresponds to the inner surface 73.

[0073] A guide surface 479A that connects the lower surface 470B corresponding to the opposing surface 75 and the lower surface 470B corresponding to the side surface is provided at the bent portion. The guide surface 479A is a curved surface. The guide surface 479A is a part of the lower surface 470B. The solder 100 is provided between the connection piece 70 and the terminal portion 40. The connection piece 70 and the terminal portion 40 overlap in the height direction HT via the solder 100. The solder 100 creeps up from the lower surface 470B corresponding to the opposing surface 75 via the guide surface 479A to the lower surface 470B corresponding to the inner side surface 73.

[0074] In the fourth embodiment, the connection piece 70 and the terminal portion 40 are fixed via the solder 100. The solder 100 is attached to the lower surface 470B corresponding to the facing surface 75, the guide surface 79A, and the lower surface 470B corresponding to the inner surface 73. The guide surface 79A and the continuous surfaces 73 and 75 are fixed with the solder 100. The amount of adhesion between the solder 100 and the connection piece 70 is increased. Therefore, the terminal portion 40 and the connection piece 70 are firmly fixed. Even if the battery cell 20 expands and contracts and the solder 100 is subjected to stress, the connection between the terminal portion 40 and the connection piece 70 is easily maintained. In addition, according to the fourth embodiment, the metal film 81 is reliably provided on the guide surface 479A without any extra cost or process, which has the advantage of improving the wetting and spreading of the solder 100.

[0075] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and concept of the present disclosure.

[0076] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple dependent claims. Some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. Some of the claims may be described in a multiple dependent form, where the subsequent claim alternatively refers to the preceding claim. The multiple dependent form claims define multiple technical ideas.

[0077] (Technical thought 1) A bus bar module (10) provided on electrode surfaces (20A) of a plurality of battery cells (20) stacked in a thickness direction (TD), A substrate (50); a busbar body (60) connected to electrode terminals (24, 25) that are connected to electrodes of the battery cells, and a plurality of busbars (80) each having a connection piece (70) extending from the busbar body, overlapping with the substrate, and connected to the substrate; and a solder (100) for fixing the substrate and the connection piece, A guide structure (78; 278; 378; 478) having a guide surface (79A; 279A; 379A; 479A) along which the solder is guided is provided on the connecting piece, a busbar module in which the solder is attached to at least a portion of a continuous surface (73, 75) that forms an outer shell of the connection piece and is continuous with the guide surface, and to the guide surface;

[0078] (Technical thought 2) The guide structure is a sloped portion (79) or a curved portion (479) that extends such that the guide surface extends away from the portion of the board where the solder is connected, the continuous surface includes an opposing surface (75) that faces the substrate and whose end continues to the guide surface, and a side surface (73) that continues from an end of the guide surface opposite to the end that continues to the opposing surface and extends away from the opposing surface; The busbar module according to Technical Idea 1, wherein the solder is attached to at least the opposing surface and the guide surface.

[0079] (Technical Thought 3) Further comprising a metal film (81) for improving the wetting and spreading of the solder; The busbar module according to Technical Idea 1 or 2, wherein the metal film is provided on at least a portion of the guide surface.

[0080] (Technical Thought 4) The connection piece includes a plurality of edges (71) that form an annular frame around an axis in the height direction (HT) of the battery cell, A space (72) is defined by the plurality of edges, The guide structure is provided on an inner side of the edge portion, which is on the space side, The substrate has an overlapping region (45) that overlaps the edge portion and a continuous region (46) that continues from the overlapping region toward the space, The busbar module according to Technical Idea 2 or 3, wherein the portion of the solder that is attached to the guide surface widens toward the continuous region.

[0081] (Technical Thought 5) The connection piece has four edges that define the space, The busbar module according to Technical Idea 4, wherein the guide structure is provided on two of the four edges that partition the space and that are aligned in the width direction (WD) of the battery cell.

[0082] (Technical Thought 6) the substrate is a flexible substrate, the substrate has a base portion (30) overlying the electrode surface and a substrate (50) having a plurality of terminal portions (40) extending from the base portion toward the electrode surface; the terminal portion has a first extension portion (41) extending from an end portion in the width direction of the base portion toward the electrode terminal, and a second extension portion (42) provided at an end portion of the first extension portion away from the base portion, extending toward the electrode surface, and having a tip to which the connection piece is connected; The busbar module according to Technical Idea 4 or 5, wherein the second extension portion is flexibly deformable in the height direction and the thickness direction.

[0083] (Technical Thought 7) The busbar module according to Technical Idea 6, wherein the second extension portion has an axis portion (43) extending in the height direction while bending in a mountain shape and a valley shape, and a tip portion (44) extending in the thickness direction from a tip of the axis portion away from the first extension portion and connected to the connection piece.

[0084] (Technical Thought 8) The guide structure is a recess (279) having the guide surface therein, The connection piece has an opposing surface (75) facing the substrate, The recess is provided in the connecting piece so that the guide surface is continuous with the opposing surface, The busbar module according to Technical Idea 1, wherein the solder is attached to the opposing surface and the guide surface.

[0085] (Technical Thought 9) The guide structure is a recess (379) having the guide surface therein, The connection piece has an opposing surface (75) facing the substrate and a side surface (73) extending away from the opposing surface, The recess is provided in the connecting piece so that the guide surface is continuous with the side surface, The busbar module according to Technical Idea 1, wherein the solder is attached to the opposing surface, the side surface, and the guide surface.

[0086] (Technical Thought 10) A plurality of battery cells (20) stacked in a thickness direction (TD); a bus bar module (10) provided on the electrode surfaces (20A) of the plurality of battery cells; The bus bar module includes: A substrate (50); a busbar body (60) connected to electrode terminals (24, 25) that are connected to electrodes of the battery cells, and a plurality of busbars (80) each having a connection piece (70) extending from the busbar body, overlapping with the substrate, and connected to the substrate; and a solder (100) for fixing the substrate and the connection piece, A guide structure (78; 278; 378; 478) having a guide surface (79A; 279A; 379A; 479A) along which the solder is guided is provided on the connecting piece, a battery pack in which the solder is attached to at least a portion of a continuous surface (73, 75) that forms an outer shell of the connection piece and is continuous with the guide surface, and to the guide surface; [Explanation of symbols]

[0087] 10 busbar module, 100 solder, 20 battery cell, 20A electrode surface, 24, 25 electrode terminal, 30 base portion, 40 terminal portion, 41 first extension portion, 42 second extension portion, 43 shaft portion, 44 tip portion, 45 overlapping region, 46 continuous region, 50 substrate, 60 busbar body, 70 connection piece, 71 edge portion, 72 space, 73 continuous surface, 73 side surface, 73, 75 continuous surface, 75 opposing surface, 75 continuous surface, 78 guide structure, 79 inclined portion, 79A guide surface, 80 bus bar, 81 metal film, 278 guide structure, 279 recess, 279A guide surface, 378 guide structure, 379 recess, 379A guide surface 478 guide structure, 479 curved portion, 479A guide surface, HT height direction, TD thickness direction, WD width direction.

Claims

1. A bus bar module (10) provided on an electrode surface (20A) of a plurality of battery cells (20) laminated in the thickness direction (TD), a substrate (50), a bus bar body (60) connected to electrode terminals (24, 25) connected to the electrodes of the battery cells, and a plurality of bus bars (80) having connection pieces (70) extending from the bus bar body, overlapping the substrate, and connected to the substrate, a solder (100) for fixing the substrate and the connection piece, and a guiding structure (78; 278; 378; 478) having a guiding surface (79A; 279A; 379A; 479A) for guiding the solder is provided on the connection piece, at least a part of continuous surfaces (73, 75) forming an outer shell of the connection piece and continuous with the guiding surface, and the solder adheres to the guiding surface, the substrate is a flexible substrate, having a base portion (30) overlapping the electrode surface and a plurality of terminal portions (40) extending from the base portion toward the electrode surface, the terminal portion has a first extension portion (41) extending from an end in the width direction (WD) of the battery cell in the base portion toward the electrode terminal, and a second extension portion (42) provided at an end of the first extension portion away from the base portion, extending toward the electrode surface, and having the connection piece connected to its tip, the second extension portion is a bus bar module that can be flexibly deformed in the height direction (HT) and the thickness direction of the battery cell.

2. The guiding structure is an inclined portion (79) or a curved portion (479) in which the guiding surface extends so as to be away from a portion of the substrate where the solder is connected, the continuous surface includes a facing surface (75) facing the substrate and having an end continuous with the guiding surface, and a side surface (73) continuing from an end opposite to the end of the guiding surface continuous with the facing surface and extending away from the facing surface, The bus bar module according to claim 1, wherein at least the solder adheres to the facing surface and the guiding surface.

3. Further comprising a metal film (81) for improving the wetting spread of the solder, The bus bar module according to claim 2, wherein the metal film is provided on at least a part of the guiding surface.

4. The connection piece includes a plurality of edge portions (71) forming an annular frame around the height direction as an axis, a space (72) is partitioned by the plurality of edge portions, The guiding structure is provided inside the inner side on the space side of the edge portion. The substrate has an overlapping region (45) overlapping the edge portion and a continuous region (46) continuous from the overlapping region to the space side. The bus bar module according to claim 2 or 3, wherein a portion of the solder adhering to the guiding surface spreads out like a skirt toward the continuous region.

5. The connecting piece has four edge portions partitioning the space. The bus bar module according to claim 4, wherein the guiding structure is provided on two of the four edge portions partitioning the space and arranged in the width direction.

6. The second extension portion has a shaft portion (43) extending in the height direction while bending into a mountain shape and a valley shape, and a tip portion (44) extending in the thickness direction from a tip of the shaft portion away from the first extension portion and connected to the connecting piece.

7. The guiding structure is a recess (279) having the guiding surface inside. The connecting piece has a facing surface (75) facing the substrate. The recess is provided in the connecting piece such that the guiding surface is continuous with the facing surface. The bus bar module according to claim 1, wherein the solder adheres to the facing surface and the guiding surface.

8. The guiding structure is a recess (379) having the guiding surface inside. The connecting piece has a facing surface (75) facing the substrate and a side surface (73) extending away from the facing surface. The recess is provided in the connecting piece such that the guiding surface is continuous with the side surface. The bus bar module according to claim 1, wherein the solder adheres to the facing surface, the side surface, and the guiding surface.

9. A plurality of battery cells (20) laminated in the thickness direction (TD). A bus bar module (10) provided on an electrode surface (20A) of the plurality of battery cells. The bus bar module includes: a substrate (50); a plurality of bus bars (80) having a bus bar body (60) connected to electrode terminals (24, 25) connected to electrodes of the battery cells and a connecting piece (70) extending from the bus bar body, overlapping the substrate, and connected to the substrate; a solder (100) fixing the substrate and the connecting piece; a guiding structure (78; 278; 378; 478) having a guiding surface (79A; 279A; 379A; 479A) for guiding the solder is provided on the connecting piece. forming the outer shell of the connection piece and at least a part of the continuous surfaces (73, 75) continuous with the guide surface, and the solder adheres to the guide surface, the substrate is a flexible substrate and has a base portion (30) overlapping the electrode surface and a plurality of terminal portions (40) extending from the base portion toward the electrode surface, the terminal portion has a first extension portion (41) extending from an end portion in the width direction (WD) of the battery cell in the base portion toward the electrode terminal, and a second extension portion (42) provided at an end portion of the first extension portion away from the base portion, extending toward the electrode surface and having the connection piece connected to the tip, the second extension portion is a battery pack that can be flexibly deformed in the height direction (HT) and the thickness direction of the battery cell.

Images