Bus module and battery pack

Abstract

A bus bar module (10) is provided on an electrode surface of a plurality of battery cells. A bus bar module is provided with: a substrate (50); a plurality of bus bars (80) each having a bus bar main body (60) and a connection piece (70); and a solder (100) which fixes the substrate and the connection piece. The connecting piece is provided with a guide structure (78), the guide structure is provided with a guide surface (79) for guiding the solder, and the solder adheres to at least a part of continuous surfaces (73, 75) which form the shell of the connecting piece and are continuous with the guide surface and the guide surface.

Description

Citation of related applications

[0001] This application is based on patent application No. 2023-022497 filed in Japan on February 16, 2023, and the contents of the basic application are incorporated herein by reference in their entirety. Technical Field

[0002] The disclosure recorded in this specification relates to a busbar module and a battery pack. Background Art

[0003] Patent document 1 describes a battery assembly equipped with a busbar module. The battery assembly is arranged so that the positive and negative electrodes of the single cells are alternately stacked. The busbar module has a circuit body, which is composed of a flexible substrate and is equipped with a busbar connected to the positive and negative electrodes of the single cells. The circuit body has: a main line arranged along the stacking direction above each single cell; and a first strip-shaped branch extending in a direction intersecting the length direction and thickness direction of the main line. At the front end of the first branch, a second strip-shaped branch extending in a direction parallel to the stacking direction of each battery body is provided. A connecting piece protruding from the busbar body toward the main line side is fixed to the second branch. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent No. 6793691 Summary of the Invention

[0005] The connecting piece is secured to the connecting portion at the front end of the second branch portion via solder. Solder is applied to the boundary between the connecting portion and the connecting piece. The solder adheres to the outer surface of the connecting piece along its edge. Due to the small amount of solder bonded to the connecting piece, there is a concern that when stress is applied to the solder, insufficient solder strength could damage the solder and prevent the connection between the connecting piece and the connecting portion from being maintained.

[0006] An object of the present disclosure is to provide a bus bar module and a battery pack that can easily maintain the connection between a substrate and a connection piece even when stress is applied to solder.

[0007] A busbar module according to one embodiment of the present disclosure, A busbar module is provided on the electrode surfaces of a plurality of battery cells stacked in the thickness direction and comprises: substrate; a plurality of busbars, each of the busbars having a busbar body and a connecting piece, the busbar body being connected to an electrode terminal connected to an electrode of a battery cell, the connecting piece extending from the busbar body and overlapping with and connected to a substrate; and Solder, which fixes the substrate and the connecting piece, The connecting piece is provided with a guiding structure, wherein the guiding structure has a guiding surface for guiding the solder. Solder is attached to at least a portion of a continuous surface that forms the outer shell of the connection piece and is continuous with the guide surface, and to the guide surface.

[0008] Solder adheres to both at least a portion of the continuous surface and the guide surface, increasing the amount of solder deposited on the connecting tab. This strengthens the connection between the substrate and the connecting tab, making it easier to maintain the connection even when stress is applied to the solder.

[0009] Furthermore, a battery pack according to another aspect of the present disclosure includes: A plurality of battery cells stacked in a thickness direction; and A busbar module is provided on the electrode surfaces of multiple battery cells. The busbar module has: substrate; a plurality of busbars, each of the busbars having a busbar body and a connecting piece, the busbar body being connected to an electrode terminal connected to an electrode of a battery cell, the connecting piece extending from the busbar body and overlapping with and connected to a substrate; and Solder, which fixes the substrate and the connecting piece, The connecting piece is provided with a guiding structure, wherein the guiding structure has a guiding surface for guiding the solder. Solder is attached to at least a portion of a continuous surface that forms the outer shell of the connection piece and is continuous with the guide surface, and to the guide surface.

[0010] The battery pack includes a busbar module. Solder adheres to at least a portion of the continuous surface and the guide surface, increasing the amount of solder applied to the connecting tab. This strengthens the connection between the substrate and the connecting tab. Even when stress is applied to the solder, the connection between the substrate and the connecting tab is easily maintained.

[0011] In addition, the reference numerals in parentheses in the appended claims merely indicate the correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is an exploded perspective view of the battery pack. Figure 2 This is a perspective view of the battery pack with the casing removed. Figure 3 This is a perspective view of the busbar module with the retainer removed. Figure 4 It is a perspective view showing the connection relationship between the terminal portion and the connecting piece. Figure 5 This is an enlarged view of the connection portion between the terminal and the connecting piece. Figure 6This is a schematic diagram illustrating one guide structure of the first embodiment. Figure 7 This is a schematic diagram illustrating another guide structure of the first embodiment. Figure 8 This is a schematic diagram illustrating the guide structure of the second embodiment. Figure 9 This is a cross-sectional view illustrating the guide structure of the second embodiment. Figure 10 This is a cross-sectional view illustrating a modified example of the guide structure of the second embodiment. Figure 11 This is a schematic diagram illustrating the guide structure of the third embodiment. Figure 12 This is a cross-sectional view illustrating the guide structure of the third embodiment. Figure 13 This is a schematic diagram illustrating a guide structure according to a fourth embodiment. Figure 14 This is a cross-sectional view illustrating a guide structure according to a fourth embodiment. DETAILED DESCRIPTION

[0013] Hereinafter, with reference to the accompanying drawings, a plurality of methods for implementing the present disclosure will be described. In each method, portions corresponding to matters described in a previous method may be denoted by the same reference numerals, and duplicate descriptions may be omitted. When only a portion of a structure is described in each method, the other methods described previously may be applied to the remaining portions of the structure.

[0014] Not only are combinations of parts that can be specifically combined clearly described in each embodiment, but embodiments, embodiments and modifications, and modifications may also be partially combined even without clear description, as long as there is no hindrance to the combination.

[0015] (First embodiment) based on Figures 1 to 7 , the battery pack 1 and the busbar module 10 are described. Figure 1 The various structural elements of the battery pack 1 are schematically described. Figures 2 to 7 The various structural elements of the busbar module 10 are schematically described in the figure. As an example, the battery pack 1 of the embodiment is applied to electric vehicles such as electric vehicles and plug-in hybrid vehicles. The battery pack 1 includes a plurality of battery cells 20. The battery cells 20 are secondary batteries. Examples of secondary batteries that can be used for the battery cells 20 include lithium-ion secondary batteries, nickel-metal hydride secondary batteries, and organic free radical batteries. These secondary batteries generate electromotive force through chemical reactions.

[0016] Hereinafter, the thickness direction of the battery cell 20 is sometimes referred to as the thickness direction TD. Furthermore, the thickness direction TD corresponds to the stacking direction of the plurality of battery assemblies 21. The width direction of the battery cell 20 is sometimes referred to as the width direction WD. The height direction of the battery cell 20 is sometimes referred to as the height direction HT. The thickness direction TD, the width direction WD, and the height direction HT are orthogonal to one another. Furthermore, in the accompanying drawings, the thickness direction TD is sometimes abbreviated as "TD." The width direction WD is sometimes abbreviated as "WD." The height direction HT is sometimes abbreviated as "HD."

[0017] Next, the drawings will be described. Figure 1 It is an exploded perspective view of the battery pack 1. Figure 2 This is a perspective view of the battery pack 1 with the case 160 removed. Figure 3 This is a perspective view of the busbar module with the retainer removed. Figure 4 It is a perspective view showing the connection relationship between the terminal portion 40 and the connection piece 70 . Figure 5 This is an enlarged view showing the connection portion between the terminal portion 40 and the connection piece 70 . Figure 6 This is a schematic diagram illustrating one of the guide structures 78 according to the first embodiment. Figure 7 This is another schematic diagram illustrating the guide structure 78 of the first embodiment.

[0018] <Car Battery> The battery pack 1 is installed in an electric vehicle and constitutes an onboard power supply. The onboard power supply supplies power to the vehicle's electrical loads. The onboard power supply can be appropriately located in, for example, the space under the front seats, the space under the rear seats, or the space between the rear seats and the trunk.

[0019] The battery pack 1 includes a bus bar module 10, a plurality of battery cells 20, a resin frame 110, a cover 120, a nut 130, an end plate 140, a gasket 150, and a case 160 for housing these. First, the case 160 will be described.

[0020] <Housing> As an example, the housing 160 is in the shape of a box with a bottom formed by die casting. The components of the housing 160 are made of aluminum or the like. The housing 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 is flat and thin in the height direction HT. The side wall 162 rises from the inner bottom surface of the bottom wall 161 in the height direction HT. The side wall 162 extends along the edge of the inner bottom surface and is annular in the circumferential direction around the height direction HT. The storage space 163 of the housing 160 is formed by the bottom wall 161 and the side wall 162.

[0021] Multiple battery cells 20 are housed in the storage space 163. The multiple battery cells 20 are stored in two rows in the width direction WD within the storage space 163. The housing 160 has an opening at one end in the height direction HT. The multiple battery cells 20 are housed in the housing 160 so that the electrode surface 20A of each battery cell 20 is aligned with the opening. The battery cells 20 are stacked in the thickness direction TD with their main surfaces 20C overlapping.

[0022] Battery Cell The battery cell 20 has a generally rectangular parallelepiped shape that is relatively thin in the thickness direction TD. The battery cell 20 includes an electrode surface 20A having a positive electrode terminal 24 and a negative electrode terminal 25, and two main surfaces 20C extending along a plane perpendicular to the thickness direction TD. The electrode surface 20A is disposed between the two main surfaces 20C so as to connect them. 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, with the positive and negative electrodes alternately arranged in the thickness direction TD.

[0023] <Resin frame> Resin frames 110 are positioned between adjacent pairs of stacked battery cells 20. The battery cells 20 and resin frames 110 are arranged alternately in the stacking direction. By alternating the battery cells 20 and resin frames 110, a battery assembly 21 is formed. Resin frames 110 are formed, for example, from an electrically insulating resin member. Resin frames 110 serve as an insulating member between adjacent battery cells 20.

[0024] The resin frame 110 includes a central body 111 facing the main surface 20C of the battery cell 20, and a ring-shaped frame body 112 integrally connected to the periphery of the central body 111. The battery cell 20 is housed and fixed in position within the space defined by the central body 111 and the frame body 112. The wall of the frame body 112 facing the electrode surface 20A is provided with a positive electrode terminal 24 electrically connected to the positive electrode, and a negative electrode terminal 25 electrically connected to the negative electrode. The positive and negative terminals 24, 25 are sometimes collectively referred to as electrode terminals 24, 25.

[0025] <End plates and gaskets> In addition, if Figure 1 As shown, end plates 140 are attached to the battery cells 20 at the ends in the thickness direction TD from the outside, covering the battery cells 20. As an example, end plates 140 are made of an electrically insulating resin member. Furthermore, spacers 150 are provided between end plates 140 and side walls 162 to adjust the relative positions of the various components. As an example, spacers 150 are made of a metal material.

[0026] Busbar module The busbar module 10 is arranged above the battery assembly 21 so as to cover the electrode surfaces 20A of the plurality of battery cells 20. The busbar module 10 includes a substrate 50, busbars 80, solder 100, and a retainer 170. The substrate 50 is electrically connected to the electrode terminals 24 and 25 of the battery cells 20 via the busbars 80. The substrate 50 and busbars 80 are held and stored in the retainer 170. The substrate 50 is a flexible substrate that can be flexibly deformed. The substrate 50 is provided with a wiring pattern. Resin layers covering the wiring pattern are provided on the front and back surfaces of the substrate 50.

[0027] <Substrate> The substrate 50 includes a base 30 and a plurality of terminal portions 40. The base 30 is positioned above the battery assembly 21, covering the area between the positive electrode terminal 24 and the negative electrode terminal 25, which are spaced apart in the width direction WD. The base 30 extends in the thickness direction TD. The electrode terminals 24 and 25 are positioned outside the base 30 in the width direction WD. The base 30 and the electrode terminals 24 and 25 are spaced apart in the width direction WD. The base 30 is provided with voltage detection lines for detecting the voltage of the battery cells 20.

[0028] Terminals Multiple terminal portions 40 are provided at both ends of the base portion 30 in the width direction WD. The terminal portion 40 includes a first extension portion 41 and a second extension portion 42. The first extension portion 41 extends in the width direction WD from the end of the base portion 30 in the width direction WD toward the electrode terminals 24 and 25. The second extension portion 42 is provided at the end of the first extension portion 41 away from the base portion 30. The second extension portion 42 is provided at the edge of the end of the first extension portion 41 away from the base portion 30 in the width direction WD.

[0029] The second extension portion 42 leaves the first extension portion 41 and extends toward the electrode surface 20A. It can also be said that the second extension portion 42 extends in the height direction HT toward the electrode surface 20A. The base 30 is arranged above the electrode surface 20A to the extent of the length of the second extension portion 42 in the height direction HT. The second extension portion 42 is bent in a roughly S-shape in the middle of extending in the height direction HT toward the electrode surface 20A. It can also be said that the second extension portion 42 has two bends 42A that are bent in opposite directions to each other. The two bends 42A are arranged continuously in the height direction HT. One of the two bends 42A is bent in a mountain shape, and the other of the two bends 42A is bent in a valley shape.

[0030] As described above, the substrate 50 is a flexible substrate. Therefore, the base 30, the first extension 41, and the second extension 42 can be flexibly deformed. The base 30 and the first extension 41 can be flexibly deformed in the height direction HT. The second extension 42 can be flexibly deformed in the height direction HT and the thickness direction TD. Figure 3 As shown, the front end of the second extension portion 42, which is away from the first extension portion 41, extends in the thickness direction TD. The front end of the second extension portion 42, which is away from the first extension portion 41, has a length in the thickness direction TD. Alternatively, the second extension portion 42 includes a shaft portion 43 extending in the height direction HT away from the first extension portion 41, and a front end portion 44 extending in the thickness direction TD from the front end of the shaft portion 43, which is away from the first extension portion 41.

[0031] <Front end> The front end portion 44 is in the shape of a plate having a relatively thin thickness in the height direction HT. The front end portion 44 is arranged between the base 30 and the battery assembly 21 in the height direction HT. The front end portion 44 is arranged above the electrode surface 20A in the height direction HT. The front end portion 44 is a portion electrically connected to the electrode terminals 24 and 25 via the bus bar 80. The front end portion 44 has a surface 44A located on the side of the base 30 and a back surface 44B on the back side. The surface 44A is a surface connected to the bus bar 80. The surface 44A extends flatly along a plane perpendicular to the height direction HT. The connecting piece 70 of the bus bar 80 is connected to the surface 44A, so that the voltage detection wiring arranged on the base 30 is electrically connected to the electrode terminals 24 and 25.

[0032] Furthermore, a connector 31 is attached to the end of the base 30. Connector 31 can be connected to a voltage detection line and to an external voltage detection device. By electrically connecting the front end 44 to the electrode terminals 24 and 25 via the busbar 80, current flows through the voltage detection line. The current flowing through the voltage detection line flows through 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.

[0033] Busbar The busbar 80 is a plate-shaped member made of metal that is flat in the height direction HT. As an example, the busbar 80 is constructed with copper as the main material. The busbar 80 has a busbar body 60 and a connecting piece 70 protruding from the busbar body 60. The busbar 80 is arranged above the battery cell 20 in a manner overlapping with the electrode surface 20A. The busbar body 60 is a portion electrically connected to the electrode terminals 24 and 25. The connecting piece 70 extends in the width direction WD from the busbar body 60 toward the front end portion 44. The connecting piece 70 is a portion electrically connected to the front end portion 44. In addition, the connecting piece 70 can also be separated from the busbar body 60.

[0034] The busbar body 60 is provided with two through-holes 61 for the positive and negative terminals 24, 25, which are adjacent in the thickness direction TD. The positive and negative terminals 24, 25 are inserted through the two through-holes 61. Nuts 130 are inserted through the positive and negative terminals 24, 25 from above the busbar body 60. Nuts 130 are fixed to the positive and negative terminals 24, 25. This electrically and mechanically connects the electrode terminals 24, 25 to the busbar body 60.

[0035] As described above, the terminal portion 40 is provided at the end portion in the width direction WD of the base portion 30. The busbar 80 is provided on the outside of the terminal portion 40 in the width direction WD. The terminal portion 40 includes: a first extension portion 41 extending in the width direction WD from the end portion in the width direction WD of the base portion 30; and a second extension portion 42 extending in the height direction HT from the end portion of the first extension portion 41. The second extension portion 42 includes: a shaft portion 43 extending in the height direction HT away from the first extension portion 41; and a front end portion 44 extending in the thickness direction TD from the front end of the shaft portion 43 away from the first extension portion 41. The busbar body 60 of the busbar 80 is provided at the electrode terminals 24 and 25. The connecting piece 70 of the busbar 80 extends in the width direction WD from the busbar body 60 toward the front end portion 44. The connecting piece 70 and the front end portion 44 are connected via solder 100.

[0036] <Retaining parts> The retaining member 170 is a retaining and storing structure for retaining and storing the substrate 50 and the busbar 80. The retaining member 170 is formed of, for example, an electrically insulating resin. The retaining member 170 has a main body storing portion 171, a terminal storing portion 172, and a cover portion 173. The main body storing portion 171 is provided on the battery cell 20 side of the base 30. The main body storing portion 171 holds the base 30 from below. Terminal storing portions 172 are provided at both ends of the main body storing portion 171 in the width direction WD. The terminal portion 40 is retained and stored in the terminal storing portion 172. Furthermore, the terminal portion 40 is exposed from the terminal storing portion 172. In addition, the substrate 50 is covered by a cover portion 173 made of an electrically insulating resin on the opposite side of the main body storing portion 171.

[0037] <Cover and nut> Furthermore, an electrically insulating resin cover 120 is assembled to the holder 170. The cover 120 is assembled from above the holder 170 to protect the live parts from the outside. By assembling the cover 120 to the holder 170, moisture and dust are prevented from reaching the connection between the front end portion 44 and the connecting piece 70 from the outside.

[0038] <Connector> The connecting piece 70 has a frame shape formed in a ring around the height direction HT. When viewed from above along the height direction HT, the connecting piece 70 has a roughly rectangular shape. The connecting piece 70 has four edges 71 forming a frame. Hereinafter, the edge 71 extending from the busbar body 60 will sometimes be referred to as the first edge 71A. The edge 71 disposed opposite the first edge 71A will sometimes be referred to as the third edge 71C. The edge 71 connecting one end of the first edge 71A and one end of the third edge 71C will sometimes be referred to as the second edge 71B. The edge 71 connecting the other end of the first edge 71A and the other end of the third edge 71C will sometimes be referred to as the fourth edge 71D. The first edge 71A, the second edge 71B, the third edge 71C, and the fourth edge 71D are arranged in a clockwise direction on the busbar body 60. A space 72 is defined by the four edges 71. Alternatively, the space 72 can be described as being defined by the inner side surfaces 73 of the four edges 71. The battery pack 1 also includes a chip fuse 82. The chip fuse 82 is disposed in the space 72. Wires such as the voltage detection wire provided on the base 30 are electrically connected to the connection piece 70 via the chip fuse 82, although details thereof are omitted.

[0039] In addition to the inner side surface 73, the four edge portions 71 also have an outer side surface 74, an opposing surface 75, and an upper surface 76. In other words, the connecting piece 70 has an inner side surface 73, an outer side surface 74, an opposing surface 75, and an upper surface 76. The outer side surface 74 is a surface located on the outside of the inner side surface 73 in a direction perpendicular to the height direction HT. The opposing surface 75 is a surface opposite to the surface 44A of the front end portion 44. The opposing surface 75 is a surface 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 separated from the surface 44A by a fixed distance from the surface 44A and is a surface separated from the surface 44A in the height direction HT. The upper surface 76 is a surface 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. In addition, the outer side surface 74 of the first edge portion 71A is integrally connected to the busbar body 60.

[0040] The facing surfaces 75 of the four edges 71 of the connecting surface 70 are arranged on the front end portion 44 so as to overlap with the surface 44A in the height direction HT. Solder 100 is provided between the edges 71 and the front end portion 44. The connecting piece 70 and the front end portion 44 are fixed via the solder 100. Surface 44A is the portion of the front end portion 44 to which the solder 100 is connected, and is therefore sometimes also referred to as a solder connection portion. The resin layer is removed from the overlapping region 45 of the solder connection portion that overlaps with the first edge 71A and the third edge 71C, as well as from the continuous region 46 of the solder connection portion that extends slightly from the overlapping region 45 toward the space 72.

[0041] Solder 100 is provided in overlapping region 45 overlapping first edge 71A and third edge 71C, and in continuous region 46 extending slightly from overlapping region 45 toward space 72. Solder 100 provided in overlapping region 45 overlapping first edge 71A and in continuous region 46 extending from overlapping region 45 electrically connects and secures first edge 71A to front end portion 44. Solder 100 provided in overlapping region 45 overlapping third edge 71C and in continuous region 46 extending from overlapping region 45 electrically connects and secures third edge 71C to front end portion 44.

[0042] As described above, the first edge portion 71A and the third edge portion 71C are spaced apart in the width direction WD. Therefore, it can be said that the connection piece 70 and the front end portion 44 are fixed together at two locations spaced apart in the width direction WD by the solder 100. Since the solder 100 is provided in the continuous region 46, it can also be said that the solder 100 is provided in an area outside the projection area of ​​the edge portion 71 onto the surface 44A. Therefore, the solder 100 can be visually confirmed when viewed from above along the height direction HT.

[0043] <Guidance structure> Furthermore, a guide structure 78 is provided on the inner side of the space 72 of the edge portion 71. The guide structure 78 has a guide surface 79A for guiding the solder 100. The guide structure 78 has a guide surface 79A connecting the opposing surface 75 and the inner side surface 73. The guide structure 78 is an inclined portion 79 having an inclined surface connecting the opposing surface 75 and the inner side surface 73 as the guide surface 79A. The guide structure 78 is not limited to the inclined portion 79. Alternatively, the guide structure 78 may be a recessed portion 279 recessed from the opposing surface 75, a recessed portion 379 recessed from the inner side surface 73, a curved portion 479 having a curved surface connecting the opposing surface 75 and the inner side surface 73, or the like, as described below.

[0044] The inclined portion 79 extends and inclines in such a manner that the guide surface 79A moves away from the solder connection portion of the front end portion 44, that is, the surface 44A. The inclined portion 79 is inclined so as to be inclined sideways as it approaches the front end portion 44 from the inner side surface 73 toward the outer side surface 74. The inclined portion 79 is provided at an imaginary corner 77 formed by the collision of the inner side surface 73 and the opposite surface 75. The guide surface 79A is a surface connecting the inner side surface 73 and the opposite surface 75. The opposite surface 75 overlaps with the surface 44A of the terminal portion 40 and is continuous at one end with the guide surface 79A. The inner side surface 73 is continuous from the end opposite to the end of the guide surface 79A that is continuous with the opposite surface 75, and extends in the height direction HT in such a manner as to move away from the opposite surface 75.

[0045] The guide structure 78 is formed on the first edge portion 71A and the third edge portion 71C. The guide structure 78 formed on the first edge portion 71A will be described first. The inclined portion 79 is provided at an imaginary corner 77 where the inner side surface 73 of the first edge portion 71A and the opposing surface 75 meet. The guide surface 79A of the inclined portion 79 connects the inner side 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 side surface 73 of the first edge portion 71A are continuous. Furthermore, the solder 100 is attached to the above-mentioned opposing surface 75 and the guide surface 79A. In addition, the solder 100 may also be attached to the inner side 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 continuous from the opposing surface 75. Because inner side surface 73 and / or opposing surface 75 are continuous with guide surface 79A, they are sometimes referred to as continuous surfaces 73 and 75. Furthermore, continuous surfaces 73 and 75 form a portion of the outer shell of connector 70. The outer shell refers to the outer surface excluding guide surface 79A. For example, the outer shell includes inner side surface 73, outer side surface 74, opposing surface 75, and upper surface 76.

[0046] The solder 100 attached to the guide surface 79A of the first edge portion 71A smoothly bends downward toward the surface 44A. The solder 100 that has expanded downward 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 of solder 100 when viewing from above along the height direction HT during inspection.

[0047] Similarly, inclined portion 79 is provided at imaginary corner 77 where inner side surface 73 and opposing surface 75 of third edge portion 71C meet. Guide surface 79A of inclined portion 79 connects inner side surface 73 of third edge portion 71C and opposing surface 75 of third edge portion 71C. Opposing surface 75 of third edge portion 71C, guide surface 79A of inclined portion 79, and inner side surface 73 of third edge portion 71C are continuous. Furthermore, solder 100 is attached to the opposing surface 75 and guide surface 79A continuous from opposing surface 75. Alternatively, solder 100 may be attached to inner side surface 73 of third edge portion 71C in addition to opposing surface 75 of third edge portion 71C and guide surface 79A continuous from opposing surface 75.

[0048] In addition, in the third edge portion 71C, the inner side surface 73 and / or the opposing surface 75 are also continuous with the guide surface 79A, and therefore, are sometimes referred to as continuous surfaces 73 and 75. Continuous surfaces 73 and 75 are surfaces that form the outer shell of the connecting piece 70. The solder 100 attached to the guide surface 79A of the third edge portion 71C is smoothly bent toward the surface 44A in a downwardly extending manner. The solder 100 that has expanded in a downwardly extending manner 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. As a result, during inspection, the presence or absence of the solder 100 can be easily confirmed when observing from above along the height direction HT.

[0049] The busbar module 10 also includes a metal film 81 for improving the wetting and diffusion of the solder 100. An example of the metal film 81 is a plating layer. The metal film 81 is provided on the four edges 71 of the connecting piece 70. The metal film 81 is provided on the facing surfaces 75, the upper surface 76, and the guide surface 79A of the four edges 71. The metal film 81 does not need to be provided on the guide surface 79A.

[0050] Typically, busbars are formed by punching a copper or other metal sheet pre-coated with a metal film, such as a coating, along the thickness direction. Therefore, at the fracture surface perpendicular to the thickness direction, the copper or other metal material, which is the base material without the metal film, is exposed. It is known that solder generally has poorer wetting and diffusibility on fracture surfaces than on surfaces coated with a metal film. Therefore, even if solder were to adhere to the fracture surface, it would be difficult for the solder to reach the fracture surface, raising concerns that solder would not be able to adhere to the fracture surface over a large area.

[0051] This makes it difficult to increase the area of ​​adhesion between the busbar and the solder at the fracture surface, and thus to enhance the connection strength between the busbar and the object to which it is fixed. Therefore, to improve the wetting and diffusibility of the solder at the fracture surface, one approach is to re-apply a metal film to the fracture surface after the busbar is formed. However, this requires a new metal film for the fracture surface, which raises concerns about excessive material costs and the need for a new process for re-applying the metal film to the fracture surface.

[0052] In this embodiment, during the manufacturing process, the corner 77 between the opposing surface 75 and the inner side surface 73 of the connecting busbar 80 is crushed to form an inclined portion 79 as a guide structure 78. This process of crushing the corner 77 to form the inclined portion 79 as the guide structure 78 is also known as C-face chamfering. This forms a guide surface 79A from the opposing surface 75 on at least a portion of the inclined portion 79. Therefore, a metal film can be provided on at least a portion of the guide surface 79A. This improves the wettability and diffusivity of the solder 100 on the guide surface 79A, allowing for a greater amount of solder 100 to adhere to the connecting piece 70.

[0053] In addition, while the example in which the connecting piece 70 is in a frame shape has been described above, the shape of the connecting piece 70 is not limited to a frame shape. The connecting piece 70 may also be in the shape of a plate that encloses the space 72. In this case, the connecting piece 70 has a facing surface 75, an upper surface 76, and an outer side surface 74. In this case, the inclined portion 79 is provided at an imaginary corner 77 of the connecting piece 70 where the facing surface 75 and the outer side surface 74 meet. The solder 100 is attached to the facing surface 75 and the guide surface 79A. In this case, the solder 100 may also be attached to the outer side surface 74. This can increase the amount of solder 100 attached to the connecting piece 70.

[0054] Effects The busbar module 10 of this embodiment includes a substrate 50, a busbar 80, and solder 100. The substrate 50 includes a base 30 and a plurality of terminal portions 40 extending from the base 30 toward the electrode terminals 24 and 25 of the plurality of battery cells 20. The busbar 80 includes: a busbar body 60 connected to the electrode terminals 24 and 25; and a connecting piece 70 extending from the busbar body 60 and connected to the terminal portion 40. The terminal portion 40 and the connecting piece 70 overlap in the height direction HT of the battery cell 20, and the terminal portion 40 and the connecting piece 70 are fixed by the solder 100. In addition, the substrate 50 may not have the terminal portion 40. The substrate 50 may also have only the base 30. In this case, the connecting piece 70 and the base 30 are fixed by the solder 100.

[0055] Connecting piece 70 is formed with a guide structure 78 having a guide surface 79A for guiding solder 100. Solder 100 adheres to continuous surfaces 73 and 75, which form part of the outer shell of connecting piece 70 and are continuous with guide surface 79A, as well as to guide surface 79A. Continuous surfaces 73 and 75 and guide surface 79A adhere to solder 100, thereby increasing the adhesion between solder 100 and connecting piece 70. This strengthens the fixation between terminal portion 40 and connecting piece 70. For example, even if battery cell 20 expands or contracts, exerting stress on solder 100, the connection between terminal portion 40 and connecting piece 70 is easily maintained.

[0056] During the manufacture of the battery pack 1, the electrode terminals 24 and 25 are inserted through the through-holes 61 of the busbar 80. Nuts 130 are then inserted through the electrode terminals 24 and 25. The nuts 130 are rotated about the electrode terminals 24 and 25, thereby securing the busbar 80 and the electrode terminals 24 and 25. However, at this point, the torque generated by the rotation of the nuts 130 may apply stress to the solder 100 connecting the terminal portion 40 and the connecting tab 70.

[0057] In addition, the battery cells 20 used in the battery pack 1 expand and contract in the thickness direction TD according to changes in the external environment, etc. At this time, there is a situation where the relative positions of the terminal portion 40 and the connecting piece 70 are offset. Along with this, there is a situation where stress is applied to the solder 100 connecting the terminal portion 40 and the connecting piece 70. In this embodiment, as described above, the guide surface 79A and the continuous surfaces 73 and 75 are fixed by the solder 100, so the fixation of the terminal portion 40 and the connecting piece 70 becomes stronger. Due to the unique structure of the above-mentioned battery pack 1, even if stress is applied to the solder 100, according to this embodiment, the connection between the terminal portion 40 and the connecting piece 70 can be maintained.

[0058] The guide structure 78 is an inclined portion 79 extending so that the guide surface 79A is away from the solder connection portion of the terminal portion 40, that is, the surface 44A. The connecting piece 70 has an inner side surface 73, an outer side surface 74, an opposing surface 75, and an upper surface 76. The opposing surface 75, the guide surface 79A, and the inner side surface 73 are continuous. The opposing surface 75 is opposite to the surface 44A of the terminal portion 40 and its end is continuous with the guide surface 79A. The inner side surface 73 is continuous from the end of the guide surface 79A opposite to the end continuous with the opposing surface 75 and extends in the height direction HT away from the opposing surface 75. The solder 100 is attached to the opposing surface 75 and the guide surface 79A.

[0059] 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 structure in which the guide structure 78 is provided at the imaginary corner 77 where the inner side surface 73 and the opposite surface 75 meet, the amount of solder 100 adhered tends to be greater than in a structure in which the guide structure 78 is not provided. Therefore, even if stress is applied to the solder 100, the connection between the connecting piece 70 and the terminal portion 40 tends to become stronger, and the connection between the two tends to be maintained. Alternatively, even if shear stress is applied to the solder 100 in the height direction HT, the connection between the connecting piece 70 and the terminal portion 40 tends to be maintained. In addition, since the guide structure 78 is an inclined portion 79, it is easy to alleviate the stress applied to the solder 100 due to changes in temperature, etc.

[0060] The busbar module 10 includes a metal film 81, such as a plating layer, to enhance the wetting and diffusion of solder 100. The metal film 81 is provided on the guide surface 79A. This facilitates the wetting and diffusion of solder 100 from the opposing surface 75 to the guide surface 79A. This increases the amount of solder 100 adhering to the guide surface 79A. This helps maintain the connection between the connecting piece 70 and the terminal portion 40 even when stress is applied to the solder 100.

[0061] The connecting piece 70 is in the shape of a frame with the height direction HT as an axis and formed in a ring around it. The connecting piece 70 has four edges 71 that form a frame. The four edges 71 divide a space 72. A guide structure 78 is provided on the side of the space 72 of the edge 71, that is, on the inner side. The solder 100 is provided in the overlapping area 45 of the terminal portion 40 with the connecting piece 70 and the continuous area 46 of the terminal portion 40 that continues from the overlapping area 45 to the inner side. The solder 100 attached to the guide surface 79A is smoothly bent toward the front end portion 44 in a manner that expands downward. The solder 100 that expands in a manner that expands downward enters the continuous area 46. As a result, the solder 100 can be visually confirmed when viewed from above along the height direction HT. During inspection, the presence or absence of the solder 100 can be easily confirmed when viewed from above along the height direction HT.

[0062] The connecting piece 70 is roughly rectangular when viewed from above along the height direction HT. The connecting piece 70 has four edges 71 forming a frame. As the edges 71, the first edge 71A, the second edge 71B, the third edge 71C and the fourth edge 71D are arranged in a clockwise order. The guide structure 78 is formed on the first edge 71A and the third edge 71C arranged in the width direction WD. In addition, 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. Therefore, even if the guide structure 78 vibrates in the arrangement direction, the amount of solder 100 attached increases, and therefore, it is easy to maintain the connection between the terminal portion 40 and the connecting piece 70. It is easy to suppress the positional deviation of the terminal portion 40 and the connecting piece 70.

[0063] The substrate 50 is a flexible substrate. As described above, the substrate 50 includes a base portion 30 and a terminal portion 40. The terminal portion 40 includes a first extension portion 41 and a second extension portion 42. The first extension portion 41 extends in the width direction WD from the end portion of the base portion 30 in the width direction WD toward the electrode terminals 24 and 25. The second extension portion 42 is provided at the end portion of the first extension portion 41 in the width direction WD on the side away from the base portion 30. The second extension portion 42 extends away from the first extension portion 41 and toward the electrode surface 20A. The base portion 30, the first extension portion 41, and the second extension portion 42 are capable of flexible deformation. The base portion 30 and the first extension portion 41 are particularly capable of flexible deformation in the height direction HT. The second extension portion 42 is particularly capable of flexible deformation in the height direction HT and the thickness direction TD.

[0064] When the battery cell 20 expands or 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, allowing it to follow the tension. Therefore, when the battery cell 20 expands or 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, in a twisting manner, due to expansion or contraction of the battery cell 20, vibration, or the like. In this case, significant stress is expected to be applied to the solder 100. To address this issue, in this embodiment, the amount of solder 100 adhered to the connecting tab 70 is increased. Even when significant stress is applied to the solder 100, the connection between the terminal portion 40 and the connecting tab 70 is securely 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 guide structure 78 is provided on two of the four edge portions 71 aligned in the width direction WD, thus minimizing stress.

[0065] <Second embodiment> In the first embodiment, the guide structure 78 is described as the inclined portion 79, but the guide structure 78 is not limited to the inclined portion 79. In the second embodiment, the guide structure 278 is the recessed portion 279. The second embodiment is similar to the first embodiment except for the attachment method of the guide structure 278 and the solder 100. Figure 8 This is a schematic diagram illustrating the guide structure 278 according to the second embodiment. Figure 9 It is along Figure 8 A cross-sectional view taken along line IX-IX is shown. Figure 10 This is a modified example of the guide structure 278 of the second embodiment. Figures 8 to 10 Schematic diagram and cross-sectional view representatively show the guide structure 278 provided at the third edge portion 71C. Figure 8 In FIG. 1 , the second edge 71B and the fourth edge 71D connected to the third edge 71C are omitted, and only the third edge 71C is extracted and shown.

[0066] The guide structure 278 of the second embodiment, i.e., the recess 279, is a through hole that penetrates the upper surface 76 and the opposing surface 75. The recess 279 is divided by a guide surface 279A that connects the upper surface 76 and the opposing surface 75. The guide surface 279A is continuous with the upper surface 76 and the opposing surface 75. The 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 with the solder 100 interposed therebetween. The solder 100 enters the recess 279. The solder 100 that has entered the recess 279 climbs up the guide surface 279A. The solder 100 adheres to the opposing surface 75, the guide surface 79A, and the inner side surface 73.

[0067] The guide structure 278 provided on the third edge portion 71C is 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 side surface 73 of the third edge portion 71C. In the second embodiment, the guide surface 279A and the continuous surfaces 73 and 75 are also fixed by the solder 100. The adhesion amount of the solder 100 to the connecting piece 70 is increased. The fixation of the terminal portion 40 and the connecting piece 70 becomes stronger. Even if stress is applied to the solder 100, it is easy to maintain the connection between the terminal portion 40 and the connecting piece 70. In addition, the recess 279 can also be provided on the first edge portion 71A in addition to the third edge portion 71C. In addition, the recess 279 can also be provided on the plate-shaped connecting piece 70.

[0068] In addition, the recess 279 is not limited to a through hole that passes through the upper surface 76 and the opposite surface 75. The recess 279 can also be a pit that is recessed from the opposite surface 75 toward the upper surface 76. In this case, the guide structure 278 has a guide surface 279A that divides the pit on the inner side. The guide surface 279A is continuous with the opposite surface 75. The solder 100 is attached to the opposite surface 75, the guide surface 279A and the inner side surface 73. In this way, the same effect can be achieved. In addition, as another example, for example, a through hole can be formed as the recess 279 in the first edge 71A, and a pit can be formed as the recess 279 in the third edge 71C. In addition, the guide structure 278 of the second embodiment is not limited to being provided with one for each edge 71. A plurality of guide structures 278 can also be provided for each edge 71. In addition, the guide structure 278 can be provided on the connecting piece.

[0069] <Third embodiment> The guide structure 378 of the third embodiment is a recess 379. In the third embodiment, except for the attachment method of the guide structure 378 and the solder 100, the other structures are the same as those of the first embodiment. Figure 11 This is a schematic diagram illustrating a guide structure 378 according to the third embodiment. Figure 12 It is along Figure 11 The cross-sectional view of the line XII-XII is shown. Figure 11 and Figure 12 Schematic diagram and cross-sectional view representatively show the guide structure 378 provided on the third edge portion 71C. Figure 11 In FIG. 1 , the second edge 71B and the fourth edge 71D connected to the third edge 71C are omitted, and only the third edge 71C is extracted and shown.

[0070] In the third embodiment, a recess 379 that is recessed from the inner side surface 73 toward the outer side surface 74 is provided on the connecting piece 70 as a guide structure 378. The recess 379 is divided by a guide surface 379A that is continuous with the inner side surface 73. The guide surface 379A is continuous with the inner side surface 73. The 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 with the solder 100 interposed therebetween. The solder 100 climbs up the inner side surface 73 and enters the recess 379. The solder 100 that has entered the recess 379 adheres to the guide surface 379A. The solder 100 adheres to the opposing surface 75, the guide surface 79A, and the inner side surface 73.

[0071] The guide structure 378 provided at the third edge 71C is described. The solder 100 is attached to the opposing surface 75 of the third edge 71C, the guide surface 379A of the guide structure 378 provided at the third edge 71C, and the inner side surface 73 of the third edge 71C. In the third embodiment, the guide surface 379A and the continuous surfaces 73 and 75 are also fixed by the solder 100. The adhesion amount between the solder 100 and the connecting piece 70 is increased. The fixation of the terminal portion 40 and the connecting piece 70 becomes stronger. Even if the battery cell 20 expands and contracts and stress is applied to the solder 100, it is easy to maintain the connection between the terminal portion 40 and the connecting piece 70. In addition, in addition to the third edge 71C, the recess 379 can also be provided at the first edge 71A. In addition, the recess 379 can also be provided on the plate-shaped connecting piece 70.

[0072] <Fourth embodiment> The guide structure 478 of the fourth embodiment is a curved portion 479 . Figure 13 This is a schematic diagram illustrating a guide structure 478 according to the fourth embodiment. Figure 14 It is along Figure 13 A cross-sectional view taken along line XIV-XIV is shown. In the fourth embodiment, the connecting piece 70 is, for example, in the shape of a plate. The connecting piece 70 has an upper surface 470A and a lower surface 470B separated in the plate thickness direction. The upper surface 470A and the lower surface 470B are provided with a metal film 81. The connecting piece 70 is bent in a substantially L-shape so that a portion thereof rises from the terminal portion 40. The portion of the connecting piece 70 that is bent so as to gradually rise from the terminal portion 40 has a curved surface.

[0073] A portion of the connecting piece 70 extends along the terminal portion 40. The portion of the connecting piece 70 extending along the terminal portion 40 overlaps with the terminal portion 40. The lower surface 470B of the portion of the connecting piece 70 overlapping with the terminal portion 40 corresponds to the opposing surface 75. The remaining portion of the connecting piece 70 extends away from the terminal portion 40. The lower surface 470B of the portion of the connecting piece 70 extending away from the terminal portion 40 corresponds to the inner surface 73.

[0074] A guide surface 479A connecting 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 portion of the lower surface 470B. The 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 with the solder 100 interposed therebetween. The solder 100 climbs from the lower surface 470B corresponding to the opposing surface 75 to the lower surface 470B corresponding to the inner side surface 73 via the guide surface 479A.

[0075] In the fourth embodiment, the connecting piece 70 and the terminal portion 40 are also fixed via the solder 100. The solder 100 is attached to the lower surface 470B corresponding to the opposing surface 75, the guide surface 79A, and the lower surface 470B corresponding to the inner side surface 73. The guide surface 79A and the continuous surfaces 73 and 75 are fixed by the solder 100. The adhesion amount between the solder 100 and the connecting piece 70 is increased. Therefore, the fixation of the terminal portion 40 and the connecting piece 70 becomes stronger. Even if the battery cell 20 expands and contracts and stress is applied to the solder 100, it is easy to maintain the connection between the terminal portion 40 and the connecting piece 70. In addition, according to the fourth embodiment, there are the following advantages: the metal film 81 can be reliably provided on the guide surface 479A without unnecessary costs and processes, and the wetting and diffusion of the solder 100 is improved.

[0076] Although the present disclosure is described based on the embodiments, it should be understood that the present disclosure is not limited to the above-described embodiments and structures. The present disclosure also includes various modifications and variations within the scope of equivalents. In addition, although various combinations and methods are shown in the present disclosure, other combinations and methods that include only one element, or more or less than these elements, also fall within the scope and scope of the present disclosure.

[0077] (Disclosure of technical ideas) This specification discloses multiple technical concepts described in the following multiple items. Some items are sometimes described by selectively citing a multiple dependent form of a previous item in a subsequent item. In addition, some items are sometimes described by referring to a multiple dependent form of another multiple dependent form. These items described in multiple dependent forms define multiple technical concepts.

[0078] (Technical Thought 1) A busbar module, A busbar module (10) is provided on electrode surfaces (20A) of a plurality of battery cells (20) stacked in a thickness direction (TD), and comprises: base(50); a plurality of busbars (80), each having a busbar body (60) and a connecting piece (70), wherein the busbar body is connected to electrode terminals (24, 25) of the battery cells connected to electrodes, and the connecting piece extends from the busbar body and overlaps with and is connected to the substrate; and Solder (100), the solder fixing the substrate and the connecting piece, The connecting piece is provided with a guiding structure (78, 278, 378, 478), and the guiding structure has a guiding surface (79A, 279A, 379A, 479A) for guiding the solder. The solder is attached to at least a portion of a 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.

[0079] (Technical Thought 2) In the busbar module according to technical concept 1, the guide structure is an inclined portion (79) or a curved portion (479) in which the guide surface extends away from a portion of the substrate to which the solder is connected. The continuous surface comprises: an opposing surface (75) opposing the substrate and having an end continuous with the guide surface; and a side surface (73) continuous from an end of the guide surface opposite to the end continuous with the opposing surface and extending away from the opposing surface. At least the solder is attached to the opposing surface and the guide surface.

[0080] (Technical Thought 3) The busbar module according to the technical idea 1 or 2 further comprises a metal film (81) for improving the wetting and diffusion of the solder. The metal film is provided on at least a portion of the guide surface.

[0081] (Technical Thought 4) In the busbar module according to technical idea 2 or 3, the connecting piece has a plurality of edges (71) forming a ring-shaped frame around the height direction (HT) of the battery cell as an axis. A space (72) is divided by the plurality of edges, The guide structure is provided on the inner side of the space side of the edge. The substrate has: an overlapping region (45) overlapping with the edge portion; and a continuous region (46) continuous from the overlapping region toward the space side. The portion of the solder attached to the guide surface expands downwardly toward the continuous region.

[0082] (Technical Thought 5) In the busbar module according to Technical Concept 4, the connecting piece has four edges for dividing the space. The guide structure is provided at two of the four edge portions that partition the space and are arranged in a width direction (WD) of the battery cell.

[0083] (Technical Thought 6) In the busbar module described in Technical Idea 4 or 5, the substrate is a flexible substrate. The substrate comprises: 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 comprises: a first extension portion (41), the first extension portion extending from the end portion in the width direction of the base portion toward the electrode terminal; and a second extension portion (42), the second extension portion being provided at the end portion of the first extension portion away from the base portion, extending toward the electrode surface and having the connecting piece connected to the front end thereof. The second extension portion is flexibly deformable in the height direction and the thickness direction.

[0084] (Technical Thought 7) In the busbar module described in Technical Concept 6, the second extension portion includes: an axis portion (43) bent in a mountain shape and a valley shape and extending in the height direction; and a front end portion (44) extending from the front end of the axis portion away from the first extension portion in the thickness direction and connected to the connecting piece.

[0085] (Technical Thought 8) In the busbar module according to technical concept 1, the guide structure is a recess (279) having the guide surface inside. The connecting piece has an opposing surface (75) facing the substrate, The recessed portion is provided on the connecting piece in such a manner that the guide surface and the opposing surface are continuous. The solder is attached to the opposing surface and the guide surface.

[0086] (Technical Thought 9) In the busbar module according to technical concept 1, the guide structure is a recess (379) having the guide surface inside. The connecting piece comprises: an opposing surface (75) opposing the substrate; and a side surface (73) extending away from the opposing surface. The recess is provided on the connecting piece in such a manner that the guide surface is continuous with the side surface. The solder is attached to the opposing surface, the side surface, and the guide surface.

[0087] (Technical Thought 10) A battery pack comprising: a plurality of battery cells (20) stacked in a thickness direction (TD); and A busbar module (10) is provided on the electrode surfaces (20A) of the plurality of battery cells, The busbar module has: base(50); a plurality of busbars (80), each having a busbar body (60) and a connecting piece (70), wherein the busbar body is connected to electrode terminals (24, 25) of the battery cells connected to electrodes, and the connecting piece extends from the busbar body and overlaps with and is connected to the substrate; and Solder (100), the solder fixing the substrate and the connecting piece, The connecting piece is provided with a guiding structure (78, 278, 378, 478), and the guiding structure has a guiding surface (79A, 279A, 379A, 479A) for guiding the solder. The solder is attached to at least a portion of a 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.

Claims

1. A busbar module (10) provided on electrode surfaces (20A) of a plurality of battery cells (20) stacked in a thickness direction (TD), comprising: base(50); a plurality of busbars (80), each having a busbar body (60) and a connecting piece (70), wherein the busbar body is connected to electrode terminals (24, 25) of the battery cells connected to electrodes, and the connecting piece extends from the busbar body and overlaps with and is connected to the substrate; and Solder (100), the solder fixing the substrate and the connecting piece, The connecting piece is provided with a guiding structure (78, 278, 378, 478), and the guiding structure has a guiding surface (79A, 279A, 379A, 479A) for guiding the solder. The solder is attached to at least a portion of a 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.

2. The busbar module according to claim 1, characterized in that: The guide structure is an inclined portion (79) or a curved portion (479) in which the guide surface extends away from a portion of the substrate to which the solder is connected. The continuous surface comprises: an opposing surface (75) opposing the substrate and having an end continuous with the guide surface; and a side surface (73) continuous from an end of the guide surface opposite to the end continuous with the opposing surface and extending away from the opposing surface. At least the solder is attached to the opposing surface and the guide surface.

3. The busbar module according to claim 2, characterized in that: It also includes a metal film (81) for improving the wetting and diffusion of the solder. The metal film is provided on at least a portion of the guide surface.

4. The busbar module according to claim 2 or 3, characterized in that: The connecting piece has a plurality of edge portions (71) forming a ring-shaped frame around the height direction (HT) of the battery cell as an axis. A space (72) is divided by the plurality of edges, The guide structure is provided on the inner side of the space side of the edge. The substrate has: an overlapping region (45) overlapping with the edge portion; and a continuous region (46) continuous from the overlapping region toward the space side. The portion of the solder attached to the guide surface expands downwardly toward the continuous region.

5. The busbar module according to claim 4, characterized in that: The connecting piece has four edges for dividing the space. The guide structure is provided at two of the four edge portions that partition the space and are arranged in a width direction (WD) of the battery cell.

6. The busbar module according to claim 5, characterized in that: The substrate is a flexible substrate, The substrate comprises: 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 comprises: a first extension portion (41), the first extension portion extending from the end portion in the width direction of the base portion toward the electrode terminal; and a second extension portion (42), the second extension portion being provided at the end portion of the first extension portion away from the base portion, extending toward the electrode surface and having the connecting piece connected to the front end thereof. The second extension portion is flexibly deformable in the height direction and the thickness direction.

7. The busbar module according to claim 6, characterized in that: The second extension portion comprises: an axis portion (43) bent in a mountain and valley shape and extending in the height direction; and a front end portion (44) extending from the front end of the axis portion away from the first extension portion in the thickness direction and connected to the connecting piece.

8. The busbar module according to claim 1, characterized in that: The guide structure is a recess (279) having the guide surface inside. The connecting piece has an opposing surface (75) facing the substrate, The recessed portion is provided on the connecting piece in such a manner that the guide surface and the opposing surface are continuous. The solder is attached to the opposing surface and the guide surface.

9. The busbar module according to claim 1, characterized in that: The guide structure is a recess (379) having the guide surface inside. The connecting piece comprises: an opposing surface (75) opposing the substrate; and a side surface (73) extending away from the opposing surface. The recess is provided on the connecting piece in such a manner that the guide surface is continuous with the side surface. The solder is attached to the opposing surface, the side surface, and the guide surface.

10. A battery pack comprising: a plurality of battery cells (20) stacked in a thickness direction (TD); and A busbar module (10) is provided on the electrode surfaces (20A) of the plurality of battery cells, The busbar module has: base(50); a plurality of busbars (80), each having a busbar body (60) and a connecting piece (70), wherein the busbar body is connected to electrode terminals (24, 25) of the battery cells connected to electrodes, and the connecting piece extends from the busbar body and overlaps with and is connected to the substrate; and Solder (100), the solder fixing the substrate and the connecting piece, The connecting piece is provided with a guiding structure (78, 278, 378, 478), and the guiding structure has a guiding surface (79A, 279A, 379A, 479A) for guiding the solder. The solder is attached to at least a portion of a 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.

Images