Continuous Wire Bonding of Battery Modules

Abstract

The battery module includes: electrochemical cells arranged side by side with coplanar terminals, where the electrochemical cells include a first cell and a second cell; a busbar including coplanar interleaved fingers, where the first and second cells are located on opposite sides of a first coplanar interleaved finger of the coplanar interleaved fingers; and a first bonding wire having (i) a first wire bond at a first terminal of the first cell, (ii) a second wire bond at the first terminal of the second cell, and (iii) a first intermediate wire bond at the first coplanar interleaved finger between the first and second wire bonds.

Description

[Technical field]

[0001] [Cross-reference to related art] This application claims priority to U.S. patent application Ser. No. 17 / 651,474, filed Feb. 17, 2022, entitled “CONTINUOUS WIRE BONDING FOR BATTERY MODULES,” the disclosure of which is incorporated by reference in its entirety herein.

[0002] This document relates to continuous wire bonding of battery modules. [Background technology]

[0003] In recent years, global transportation has begun to transition away from primarily fossil fuel powered powertrains and toward more sustainable energy sources, particularly electric motors powered by on-board energy storage devices. Vehicle manufacturers strive to increase the efficiency and utility of such vehicles, including the performance of energy storage devices such as battery packs. Summary of the Invention

[0004] In a first aspect, a battery module includes: electrochemical cells arranged side by side with coplanar terminals, where the electrochemical cells include a first cell and a second cell; a busbar including coplanar interleaved fingers, where the first and second cells are located on opposite sides of a first coplanar interleaved finger of the coplanar interleaved fingers; and a first bonding wire having (i) a first wire bond at a first terminal of the first cell, (ii) a second wire bond at the first terminal of the second cell, and (iii) a first intermediate wire bond at the first coplanar interleaved finger between the first and second wire bonds.

[0005] The implementation may include any or all of the following features: the first terminal of the first cell and the first terminal of the second cell are center terminals; the first terminal of the first cell and the first terminal of the second cell are rim terminals; the first bonding wire has a plurality of intermediate wire bonds at the first coplanar interleaved fingers between the first and second wire bonds; the first bonding wire returns from the second wire bond to the first coplanar interleaved fingers; the electrochemical cell further includes a third cell adjacent to the first cell, the third cell being located on the same side of the first coplanar interleaved fingers as the first cell, where the first bonding wire continues from the first coplanar interleaved fingers and has a third wire bond at the first terminal of the third cell and has a second intermediate wire bond at the first coplanar interleaved fingers, where the second intermediate wire bond is between the second and third wire bonds; the first bonding wire returns from the third wire bond to the first coplanar interleaved fingers. The electrochemical cell further includes a fourth cell adjacent to the second cell, where the fourth cell is located on the same side of the first coplanar interleaved finger as the second cell, where a first bonding wire from a third wire bond back to the first coplanar interleaved finger continues from the first coplanar interleaved finger and has a fourth wire bond at a first terminal of the fourth cell and a third intermediate wire bond at the first coplanar interleaved finger, where the third intermediate wire bond is between the third and fourth wire bonds. The busbar further includes a second coplanar interleaved finger, where the second cell is adjacent to the second coplanar interleaved finger, where the electrochemical cells further include a third cell, where the third cell is adjacent to the second coplanar interleaved finger, where the second and third cells are located on opposite sides of the second coplanar interleaved finger, and the battery module further includes: (i) a first wire bond at the first terminal of the second cell, (ii) a second wire bond at the first terminal of the third cell, and (iii) a second bonding wire having an intermediate wire bond at the second coplanar interleaved finger between the first and second wire bonds.The busbar further includes an edge flush finger on an opposite side of the first cell from the first flush interleaved finger, where the first cell is an edge cell in the battery module such that none of the electrochemical cells are located on an opposite side of the edge flush finger from the first cell, and the battery module further includes (i) a third wire bond at the edge flush finger, (ii) a fourth wire bond at the second edge flush finger, and (iii) a second bonding wire having an intermediate wire bond at a second terminal of the first cell, where the intermediate wire bond is between the first and second wire bonds.

[0006] In a second aspect, a method of forming electrical connections for a battery module having electrochemical cells arranged side by side with terminals in a coplanar arrangement, the electrochemical cells including a first cell and a second cell, the method comprising: forming a first wire bond on a first bonding wire at a first terminal of the first cell using a wire bonder head; moving the wire bonder head from the first wire bond to a bus bar including coplanar interleaved fingers, where the first and second cells are located on opposite sides of the first coplanar interleaved fingers of the coplanar interleaved fingers; forming a first intermediate wire bond on the first bonding wire at the first coplanar interleaved finger using the wire bonder head; moving the wire bonder head from the first coplanar interleaved fingers to a first terminal of the second cell; and forming a second wire bond on the first bonding wire at the first terminal of the second cell using the wire bonder head.

[0007] The implementation may include any or all of the following features: The first terminal of the first cell and the first terminal of the second cell are center terminals. The first terminal of the first cell and the first terminal of the second cell are edge terminals. The method further includes forming a plurality of intermediate wire bonds on the first coplanar interleaved fingers between the first and second wire bonds. The method further includes moving the wire bonder head from the second wire bond back to the first coplanar interleaved fingers. The electrochemical cell further includes a third cell adjacent to the first cell, the third cell being located on the same side of the first coplanar interleaved finger as the first cell, and the method further comprises: forming a second intermediate wire bond on the first bonding wire at the first coplanar interleaved finger using the wire bonder head after returning the wire bonder head from the second wire bond to the first coplanar interleaved finger; after forming the second intermediate wire bond, moving the wire bonder head from the first coplanar interleaved finger to the first terminal of the third cell; and forming a third wire bond on the first bonding wire at the first terminal of the third cell using the wire bonder head, where the second intermediate wire bond is between the second and third wire bonds. The method further comprises returning the wire bonder head from the third wire bond to the first coplanar interleaved finger. The electrochemical cell further includes a fourth cell adjacent to the second cell, where the fourth cell is located on the same side of the first coplanar interleaved finger as the second cell, and the method further comprises: forming a third intermediate wire bond on the first bonding wire at the first coplanar interleaved finger using the wire bonder head after moving the wire bonder head from the third wire bond back to the first coplanar interleaved finger; after forming the third intermediate wire bond, moving the wire bonder head from the first coplanar interleaved finger to the first terminal of the fourth cell; and forming a fourth wire bond on the first bonding wire at the first terminal of the fourth cell using the wire bonder head, where the third intermediate wire bond is between the third and fourth wire bonds.The busbar further includes a second coplanar interleaved finger, the second cell adjacent to the second coplanar interleaved finger, the electrochemical cell further includes a third cell, the third cell adjacent to the second coplanar interleaved finger, the second and third cells located on opposite sides of the second coplanar interleaved finger, and the method further includes: forming a third wire bond at a second terminal of the second cell on the second bonding wire using a wire bonder head; moving the wire bonder head from the third wire bond to the second coplanar interleaved finger. The method includes using a wire bonder head to form a second intermediate wire bond on the second bonding wire at the second coplanar interleaved fingers; moving the wire bonder head from the second coplanar interleaved fingers to a second terminal of a third cell; and using the wire bonder head to form a fourth wire bond on the second bonding wire at the second terminal of the third cell. The busbar further includes an edge flush finger opposite the first cell from the first flush interleaved finger, the first cell being an edge cell in the battery module such that none of the electrochemical cells are located opposite the edge flush finger from the first cell, and the method further includes: forming a first edge wire bond on the edge flush finger on the second bonding wire using a wire bonder head; moving the wire bonder head from the first edge wire bond to a second terminal of the first cell; forming a third wire bond on the second bonding wire at the second terminal of the first cell using the wire bonder head; moving the wire bonder head from the third wire bond to the edge flush finger; and forming a second edge wire bond on the edge flush finger on the second bonding wire using the wire bonder head. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a perspective view of an example battery module.

[0009] [Figure 2A] FIG. 1 illustrates a top view of an example battery module. [Figure 2B] FIG. 1 illustrates a top view of an example battery module.

[0010] [Diagram 3] FIG. 2 shows a perspective view of another example of a battery module.

[0011] [Figure 4] 1 illustrates an example of a wire bonder head that may be used in forming the wire bonds.

[0012] [Diagram 5] 1A-1C are schematic diagrams illustrating examples of bonding wires and bonding operations;

[0013] [Figure 6] An example of the method is given below.

[0014] [Figure 7] FIG. 2 shows a perspective view of another example of a battery module.

[0015] Like reference numbers in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] This document describes examples of systems and techniques that simplify and streamline the installation of bond wires in battery modules by forming a bond wire that continues from a cell onto an intermediate bus bar and from there onto the next cell. This can be done between pairs of cells or more than two cells that are adjacently positioned on a bus bar that has the shape of coplanar interleaved fingers. The wire bonding machine can accomplish the task of establishing a conductive bond more efficiently because it may not need to change direction (e.g., move back or sideways) as much as in most existing approaches.

[0017] In the examples herein, reference is made to forming a bond between two or more conductive materials. As used herein, a bond may be formed by any technique that bonds materials together so that an electrical current can flow between them. To name just two examples, ultrasonic wire bonding and / or laser wire bonding may be used. The presence of a bond between materials indicates that the materials are electrically connected (herein referred to as connected) to one another.

[0018] Examples herein refer to electrochemical cells. As used herein, an electrochemical cell is a device that generates electrical energy from a chemical reaction, or uses electrical energy to cause a chemical reaction, or both. An electrochemical cell may include an electrolyte and two electrodes to store energy and deliver it when in use. In some implementations, an electrochemical cell may be a rechargeable cell. For example, an electrochemical cell may be a lithium-ion cell. In some implementations, an electrochemical cell may act as a galvanic cell when discharged and as an electrolytic cell when charged. An electrochemical cell may have at least one terminal for each electrode. The terminal, or at least a portion thereof, may be located at one end of the electrolytic cell. For example, if the electrochemical cell is cylindrical in shape, one of the terminals may be provided at the center of the end of the cell, and the can that forms the cylinder may constitute the other terminal and thus may also be at the end. Other shapes of electrochemical cells may be used, including but not limited to prismatic shapes.

[0019] Examples herein refer to battery modules, which are individual components configured to hold and manage multiple electrochemical cells during charging, storage, and use. A battery module may be intended as the sole power source for one or more loads (e.g., electric motors), or more than one battery module of the same or different types may be used. Two or more battery modules may be implemented within a system separately or as part of a larger energy storage unit. For example, a battery pack may include two or more battery modules of the same or different types. The battery modules may include control circuits for managing the charging, storage, and / or use of electrical energy in the electrochemical cells, or the battery modules may be controlled by external components. For example, the battery management system may be implemented on one or more circuit boards (e.g., printed circuit boards).

[0020] Examples herein refer to bus bars, and a battery module may have at least one bus bar. The bus bar is electrically conductive and is used to conduct electricity to the electrochemical cells during charging or from the cells during discharging. The bus bar is made of an electrically conductive material (e.g., metal) and has suitable dimensions taking into account the characteristics and intended use of the electrochemical cells. In some implementations, the bus bar includes aluminum (e.g., an aluminum alloy). The bus bar may be planar (e.g., flat) or may have one or more bends, depending on the shape and intended use of the battery module. The bus bar may be configured to arrange the electrochemical cells in a series or parallel arrangement, or in a series and parallel arrangement.

[0021] Examples herein relate to bonding wires (e.g., ribbon-like bonding wires, or ribbon-like wires, or other electrical conductors). As used herein, a bonding wire may have any number of different geometric shapes and may include one or more materials with respective electrical conductivities. For example, a bonding wire may be a single-layered bonding wire, or may be a multi-layered bonding wire having multiple layers, each with a respective electrical conductivity. In some implementations, a bonding wire may be a ribbon-like wire having a rectangular cross-section and one or more layers. The one or more layers may include one or more conductive materials, such as one or more metals and / or metal alloys. A bonding wire may include, but is not limited to, copper, aluminum, copper alloys, aluminum alloys, and / or combinations thereof. As used herein, a bonding wire being coupled to a surface (e.g., a conductive surface, an electrical contact surface, etc.) refers to the bonding wire being electrically and / or physically coupled to the surface, unless otherwise indicated.

[0022] Examples herein refer to top or bottom. These and similar expressions identify things or aspects relative to one another based on an explicit or arbitrary notion of perspective. That is, these terms are merely examples used for illustrative purposes and do not necessarily indicate the only possible positions, orientations, or the like.

[0023] 1 shows a perspective view of an example of a battery module 100. The battery module 100 may be used with one or more other examples described elsewhere herein. The battery module 100 may include one or more housings and / or other surrounding or otherwise protective layers, which are omitted here for simplicity. Only a portion of the battery module 100 is shown in this example.

[0024] The battery module 100 includes electrochemical cells 102 that may be arranged side by side within the battery module 100. Here, the battery module 100 includes, among others, cells 102A-102F. For example, cells 102A and 102C may be arranged adjacent (e.g., side by side) to one another. As another example, cells 102E, 102B, and 102D may be arranged adjacent (e.g., side by side) to one another. The electrochemical cells 102 may have any shape or form. Here, the electrochemical cells 102 are cylindrical and arranged such that their respective cylindrical axes are parallel to one another.

[0025] The electrochemical cells 102 may be arranged such that the terminals are flush with each other, where each of the cells 102A-102F includes a central terminal at an end surface of the cylindrical shape. For example, the central terminal may be a positive terminal of the electrochemical cell 102. Here, each of the cells 102A-102F includes a rim terminal at the same end surface of the cylindrical shape where the central terminals are located. For example, the rim terminal may be a negative terminal of the electrochemical cell 102. In some implementations, the central terminals and / or the rim terminals may be oriented flush with each other (e.g., as shown).

[0026] The battery module 100 includes a busbar 104 including coplanar fingers. Some of the coplanar fingers may be interleaved with one another. Here, the busbar 104 includes at least coplanar interleaved fingers 104A-104B that are interleaved with one another. The cells 102A-102B are located on opposite sides of the coplanar interleaved finger 104A. The cells 102C-102D are located on opposite sides of the coplanar interleaved finger 104A.

[0027] One or more of the flush fingers can be edge flush fingers, where the busbar 104 includes an edge flush finger 104C that is located on an opposite side of the cell 102A from the flush interleaved fingers 104A. The cell 102A can be referred to as an edge cell in the battery module 100. For example, none of the electrochemical cells 102 are located on an opposite side of the edge flush finger 104C from the cell 102A.

[0028] The battery module 100 may include one or more bonding wires. Here, bonding wires 106A-106E are shown. For example, bonding wire 106A is coupled to a central terminal of cell 102A, coplanar interleaved fingers 104A, and a central terminal of cell 102B. As another example, bonding wire 106B is coupled to a central terminal of cell 102C, coplanar interleaved fingers 104A, and a central terminal of cell 102D. As another example, bonding wire 106C is coupled to a rim terminal and coplanar interleaved fingers 104B of each of cells 102B and 102D. As another example, bonding wire 106D is coupled to a rim terminal and to edge coplanar fingers 104C of each of cells 102A and 102C. As another example, bond wire 106E is coupled to a rim terminal of cell 102E, to coplanar interleaved fingers 104B, and to a rim terminal of cell 102F. Other approaches may be pursued.

[0029] The battery module 100 is an example of an electrical component that includes electrochemical cells (e.g., electrochemical cell 102) arranged side by side with coplanar terminals. The electrochemical cells include a first cell (e.g., cell 102A) and a second cell (e.g., cell 102B). The battery module includes a bus bar (e.g., bus bar 104) including coplanar interleaved fingers, where the first and second cells are located on opposite sides of a first coplanar interleaved finger (e.g., coplanar interleaved finger 104A) of the coplanar interleaved fingers. The battery module includes a first bonding wire (e.g., bonding wire 106A) having (i) a first wire bond at a first terminal of the first cell, (ii) a second wire bond at a first terminal of the second cell, and (iii) a first intermediate wire bond at the first coplanar interleaved finger between the first and second wire bonds.

[0030] 2A-2B show top views of examples of battery modules 200 and 250. Battery modules 200 and / or 250 may be used with one or more other examples described elsewhere herein. Battery module 200 includes cells 202A-202D and busbar 204. In some implementations, busbar 204 may be coplanar interleaved fingers of a larger busbar. For example, cells 202A-202B are located on opposite sides of busbar 204. As another example, cells 202C-202D are located on opposite sides of busbar 204. As another example, cells 202A and 202C are adjacent to one another. As another example, cells 202B and 202D are adjacent to one another.

[0031] Each of the cells 202A-202D may have a plurality of terminals. Here, the cells 202A-202D have a terminal at at least one of their ends (e.g., an end of a cylindrical shape). The cell 202A may have a center terminal 202A1 (e.g., a positive terminal) and a rim terminal 202A2 (e.g., a negative terminal). The cell 202B may have a center terminal 202B1 (e.g., a positive terminal) and a rim terminal 202B2 (e.g., a negative terminal). The cell 202C may have a center terminal 202C1 (e.g., a positive terminal) and a rim terminal 202C2 (e.g., a negative terminal). The cell 202D may have a center terminal 202D1 (e.g., a positive terminal) and a rim terminal 202D2 (e.g., a negative terminal).

[0032] The battery module 200 may include one or more bonding wires. Here, the battery module 200 includes a bonding wire 206A coupling at least the cells 202A-202B to each other and to the bus bar 204. The bonding wire 206A has a wire bond 208A at a central terminal 202A1. The bonding wire 206A has a wire bond 208B at a central terminal 202B1. The bonding wire 206A has at least one intermediate wire bond 208C at the bus bar 204 between the wire bonds 208A-208B. Here, the battery module 200 includes a bonding wire 206B coupling at least the cells 202C-202D to each other and to the bus bar 204. The bonding wire 206B has a wire bond 210A at a central terminal 202C1. The bonding wire 206B has a wire bond 210B at a central terminal 202D1. Bonding wire 206B has at least one intermediate wire bond 210C between wire bonds 210A-210B at bus bar 204. Other approaches may be used.

[0033] Battery module 250 includes cells 252A-252D and a bus bar 254. In some implementations, bus bar 254 can be coplanar interleaved fingers of a larger bus bar. For example, cells 252A-252B are located on opposite sides of bus bar 254. As another example, cells 252C-252D are located on opposite sides of bus bar 254. As another example, cells 252A and 252C are adjacent to one another. As another example, cells 252B and 252D are adjacent to one another.

[0034] Each of the cells 252A-252D may have a plurality of terminals. Here, the cells 252A-252D have a terminal at least at one of their ends (e.g., an end of a cylindrical shape). The cell 252A may have a center terminal 252A1 (e.g., a positive terminal) and a rim terminal 252A2 (e.g., a negative terminal). The cell 252B may have a center terminal 252B1 (e.g., a positive terminal) and a rim terminal 252B2 (e.g., a negative terminal). The cell 252C may have a center terminal 252C1 (e.g., a positive terminal) and a rim terminal 252C2 (e.g., a negative terminal). The cell 252D may have a center terminal 252D1 (e.g., a positive terminal) and a rim terminal 252D2 (e.g., a negative terminal).

[0035] The battery module 250 may include one or more bonding wires. Here, the battery module 250 includes a bonding wire 256A coupling at least the cells 252A-252B to each other and to the bus bar 254. The bonding wire 256A has a wire bond 258A at a central terminal 252A1. The bonding wire 256A has a wire bond 258B at a central terminal 252B1. The bonding wire 256A has at least one intermediate wire bond 258C at the bus bar 254 between the wire bonds 258A-258B. Here, the battery module 250 includes a bonding wire 256B coupling at least the cells 252C-252D to each other and to the bus bar 254. The bonding wire 256B has a wire bond 260A at a rim terminal 252C2. The bonding wire 256B has a wire bond 260B at a rim terminal 252D2. Wire bond 256B has at least one intermediate wire bond 260C between wire bonds 260A-260B at bus bar 254. Other approaches may be used.

[0036] 3 shows a perspective view of another example of a battery module 300. The battery module 300 may be used with one or more other examples described elsewhere herein. The battery module 300 may include one or more housings and / or other surrounding or otherwise protective layers, which are omitted here for simplicity. Only a portion of the battery module 300 is shown in this example.

[0037] The battery module 300 includes electrochemical cells 302 that may be arranged side-by-side within the battery module 300. Here, the battery module 300 includes, among other things, cells 302A-302B. For example, the cells 302A and 302B may be arranged on opposite sides of coplanar interleaved fingers of a busbar. The electrochemical cells 302 may have any shape or form. Here, the electrochemical cells 302 are cylindrical and arranged such that their respective cylindrical axes are parallel to one another.

[0038] The electrochemical cells 302 may be arranged in a coplanar terminal configuration, where each of the cells 302A-302B includes a central terminal at an end surface of the cylindrical shape. For example, the central terminal may be a positive terminal of the electrochemical cell 302. Here, each of the cells 302A-302B includes a rim terminal at the same end surface of the cylindrical shape as the central terminal. For example, the rim terminal may be a negative terminal of the electrochemical cell 302. In some implementations, the central terminal and / or the rim terminal may be in a coplanar orientation (e.g., as shown).

[0039] The battery module 300 includes a busbar 304 that includes coplanar fingers. Some of the coplanar fingers may be interleaved with one another. Here, the busbar 304 includes coplanar interleaved fingers 304A-304B. For example, the cells 302A-302B are located on opposite sides of the coplanar interleaved finger 304A.

[0040] The battery module 300 may include one or more bonding wires. Here, a bonding wire 306 is shown. For example, the bonding wire 306 is coupled to a central terminal of the cell 302A, to the bus bar 304, and to a central terminal of the cell 302B. The bonding wire 306 has a wire bond to the central terminal of the cell 302A. The bonding wire 306 has a wire bond to the central terminal of the cell 302B. The bonding wire 306 has at least one intermediate wire bond (e.g., multiple intermediate wire bonds) in the coplanar interleaved fingers 304A between the wire bonds of each of the cells 302A-302B. The bonding wire 306 may have an intermediate wire bond 308-1 and at least one additional intermediate wire bond (collectively referred to herein as intermediate wire bond 308-N, where N≧2). Other approaches may be used.

[0041] 4 illustrates an example of a wire bonder head 400 that may be used in forming a wire bond. The wire bonder head 400 may operate using a supply of bonding wire 402. The wire bonder head 400 and / or the bonding wire 402 may be used with one or more other examples described elsewhere herein. The wire bonder head 400 includes a wire guide 404. The wire guide 404 is used to guide (e.g., feed) the bonding wire 402 in a bonding operation. The wire guide 404 may be made of one or more materials, including but not limited to metal or synthetic materials. A supply 406 of bonding wire 402 is seen passing through the wire guide 404. In some implementations, the supply 406 of bonding wire 402 may be provided from a spool 408. For example, a spool 408 may be rotatably suspended relative to the wire bonder head 400 so that the bonding wire 402 has a specific orientation relative to an electrochemical cell for bonding and to allow a supply 406 of bonding wire 402 to be obtained in a continuous or intermittent manner.

[0042] The wire bonder head 400 includes a wedge 410. The wedge 410 can be used to bond the bonding wire 402 to an electrochemical cell (not shown). For example, the wedge 410 can be made of a metal.

[0043] The wire bonder head 400 includes a cutter 412. The cutter 412 can be used to cut the bonding wire 402 before, during, or after bonding. For example, the cutter 412 can be made of metal.

[0044] 5 illustrates a schematic diagram of an example bonding wire and bonding operation 500. Example 500 or aspects thereof may be used with one or more other examples described elsewhere herein. The bonding operation of example 500 may be used to perform wire bonding, such as with example implementations described herein. Here, a bonding wire 506 (e.g., a ribbon wire, a bonding wire, or a wire) may be fed through a wedge wire bonder head such that the bonding wire 506 is positioned under a wedge 516. In some implementations, the wedge may include steel or another metal.

[0045] Bonding wire 506 is shown in a front view with the end of bonding wire 506 visible. A portion of an electrochemical cell 508 is shown; electrochemical cell 508 may be included in a battery module. Bonds to electrochemical cell 508 may be formed in a wire bonding operation. Also shown in FIG. 5 are arrows 504 and 505, which indicate clockwise rotation of wedge 516 (and associated wedge bonder head) and counterclockwise rotation of wedge 516, respectively. Such rotation may be used to change the direction of movement of wedge 516 and the corresponding direction in which bonding wire 506 is fed or deployed when performing a wire bonding operation.

[0046] In an exemplary implementation, the bonding wire 506 may be formed (e.g., as a result of forming a wire bond, wire loop or segment, and / or bend) into a shape that is suitable for its intended use of forming a wire bond between separate electrical contact surfaces or conductive surfaces (e.g., any or all of the terminals and / or bus bars described herein). In some implementations, the shape of the bonding wire 506 may result from a process in which the bonding wire 506 is placed to electrically connect associated terminals or other conductive surfaces. In some implementations, the bonding wire 506 may initially be stored as a stock material on a spool, and a suitable length of the bonding wire 506 may be placed to assume a suitable shape for forming wire bonds that provide electrical connections between two or more conductive surfaces, thereby connecting those surfaces. For example, one or more non-planar segments of the bonding wire (sometimes referred to as wire loops) may be formed between each wire bond formed on the conductive surfaces. Such non-planar segments may include, but are not limited to, bends to change direction.

[0047] In example 500, the bonding operation may include electrically bonding a bond wire 506 to a portion of an electrochemical cell 508 of a battery module. For simplicity, only an end 510 of the electrochemical cell 508 is shown here. In some implementations, the end 510 may be referred to as a top of the electrochemical cell 508. For example, the electrochemical cell 508 may include a can (not shown) for holding active materials, and the end 510 may be formed by a cap that seals an opening of the can.

[0048] The electrochemical cell 508 can have multiple terminals. Terminal 512 is shown here as a centrally located structure at end 510. For example, terminal 512 can be a positive terminal for the electrochemical cell 508, where end 510 includes a rim 514 that is at least a portion of another terminal for the electrochemical cell 508. For example, rim 514 (and the remainder of the can material, including the bottom of the can) can function as a negative terminal for the electrochemical cell 508. In such an approach, terminal 512 and rim 514 can be electrically isolated from one another.

[0049] The bonding operation may include the use of one or more tools. In some implementations as described herein, a wedge wire bond head may be used, where a wedge 516 may be included within the wedge wire bond head. For example, in this example, the wedge 516 may be used to bond the bonding wire 506 to the terminal 512 or the rim 514. In an implementation, the wedge 516 may be made of metal. In an implementation, after formation of a first wire bond, relative lateral translation between the battery module and the wedge 516 (and associated bonder head, optionally including rotation) may occur to facilitate formation of another wire bond at a different location. For example, the wedge bonder head may move to a subsequent electrical contact surface (e.g., another cell or bus bar) and the bonding wire 506 (e.g., continuing from the previous wire bond) may be bonded to that subsequent electrical contact surface.

[0050] In some implementations, the bonding wire 506 may be wedge bonded to the rim 514 or terminal 512 of the electrochemical cell 508 as part of a wire bonding operation. In such implementations, the bonding wire 506 may have any suitable orientation relative to the rim 514 or terminal 512. For example, in some implementations, the orientation of the bonding wire 506 (e.g., the length of the corresponding bonding wire segment) may be substantially radial relative to the rim 514 or terminal 512. In other implementations, the bonding wire 506 may be substantially tangential relative to the rim 514 or terminal 512. In still other implementations, other orientations of the bonding wire 506 relative to the rim 514 or terminal 512 may be used.

[0051] 6 illustrates an example of a method 600. The method 600 may be used with one or more other examples described elsewhere herein. More or fewer operations may be performed than shown. Unless otherwise indicated, two or more operations may be performed in a different order.

[0052] At operation 602, the method 600 may include forming a first wire bond at a first terminal of a first cell using a wire bonder head on a first bonding wire. For example, wire bond 208A or 258A (FIGS. 2A-2B) may be formed.

[0053] At operation 604, method 600 may include moving a wire bonder head from the first wire bond to a bus bar including coplanar interleaved fingers. The first and second cells may be located on opposite sides of the coplanar interleaved fingers from the first coplanar interleaved fingers. For example, the wire bonder head may be moved to bus bar 204 or 254 (FIGS. 2A-2B).

[0054] At operation 606, the method 600 may include forming at least a first intermediate wire bond in the first coplanar interleaved finger using a wire bonder head on the first bonding wire. In some implementations, multiple intermediate wire bonds may be formed in the first coplanar interleaved finger. For example, N intermediate wire bonds, referred to as intermediate wire bonds 308-1 and 308-N (FIG. 3), may be formed.

[0055] At operation 608, the method 600 can include moving a wire bonder head from the first coplanar interleaved finger to a first terminal of a second cell. For example, the wire bonder head can be moved to cell 202B or 252B (FIGS. 2A-2B).

[0056] At operation 610, the method 600 may include forming a second wire bond at a first terminal of a second cell using a wire bonder head on the first bonding wire. For example, wire bond 208B or 258B (FIGS. 2A-2B) may be formed.

[0057] At operation 612, the method 600 may include forming a zigzag pattern of wire bonds. For example, one or more of the wire bonds described below with reference to FIG.

[0058] At operation 614, method 600 may include forming a wire bond at another terminal of one or more cells. For example, if bond wire 206A is bonded by operations 602-610, then bond wire 256A may be bonded at operation 614, or vice versa.

[0059] In operation 616, the method 600 may include forming one or more edge wire bonds. For example, bond wire 106D may be bonded.

[0060] None, one, or more than one operation may be performed at operation 618. In some implementations, method 600 may end after performing some or all of operations 602-616. In some implementations, some or all of operations 602-616 may be performed at operation 618 associated with another cell or busbar. Other approaches may be used.

[0061] 7 shows a perspective view of another example of a battery module 700. The battery module 700 may be used with one or more other examples described elsewhere herein. The battery module 700 may include one or more housings and / or other surrounding or otherwise protective layers, which are omitted here for simplicity. Only a portion of the battery module 700 is shown in this example.

[0062] The battery module 700 includes electrochemical cells 702 that may be arranged side-by-side within the battery module 700. Here, the battery module 700 includes, among other things, cells 702A-D. For example, cells 702A and 702C may be arranged adjacent (e.g., side-by-side) to one another. As another example, cells 702B and 702D may be arranged adjacent (e.g., side-by-side) to one another. The electrochemical cells 702 may have any shape or form. Here, the electrochemical cells 702 are cylindrical and arranged such that their respective cylindrical axes are parallel to one another.

[0063] The electrochemical cells 702 may be arranged in a coplanar terminal configuration, where each of the cells 702A-702D includes a central terminal at an end surface of the cylindrical shape. For example, the central terminal may be a positive terminal of the electrochemical cell 702. Here, each of the cells 702A-702D includes a rim terminal at the same end surface of the cylindrical shape as the central terminal. For example, the rim terminal may be a negative terminal of the electrochemical cell 702. In some implementations, the central terminal and / or the rim terminal may be in a coplanar orientation (e.g., as shown).

[0064] The battery module 700 includes a busbar 704 that includes coplanar fingers. Some of the coplanar fingers may be interleaved with one another. Here, the busbar 704 includes coplanar interleaved fingers 704A-704B that are interleaved with one another. For example, the cells 702A-702B are located on opposite sides of the coplanar interleaved finger 704A. As another example, the cells 702C-702D are located on opposite sides of the coplanar interleaved finger 704A.

[0065] The battery module 700 may include one or more bonding wires. Here, a bonding wire 706 is shown. For example, the bonding wire 706 may be coupled to a central terminal of cell 702A, coupled to a coplanar interleaved finger 704A, coupled to a central terminal of cell 702B, coupled back to a coplanar interleaved finger 704A, coupled to a central terminal of cell 702C, coupled back to a coplanar interleaved finger 704A, and finally coupled to a central terminal of cell 702D. Thus, the bonding wire 706 forms a zigzag pattern about the coplanar interleaved finger 704A for cells 702A-D. Thus, the bonding wire 706 may be placed based on a series of wire bonder operations that involve forming a bond, then moving a wedge, then forming another bond, and so on. In some implementations, the bonding wire 706 may instead form a corresponding zigzag pattern with the rim terminals of some or all of the cells. In some implementations, a zigzag pattern may be used for the wire bonds of both the center and rim terminals. Other approaches may be used.

[0066] The terms "substantially" and "about" used throughout this specification are used to describe and report small variations, such as those due to processing variations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Also, as used herein, indefinite articles such as "a" or "an" mean "at least one".

[0067] It should be understood that all combinations of the above concepts, and additional concepts discussed in more detail below (provided that such concepts are not mutually inconsistent), are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein.

[0068] Although several implementations have been described, it will be understood that various modifications may be made without departing from the spirit and scope of the specification.

[0069] Additionally, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Additionally, other processes may be provided or processes may be eliminated from the described flows, and other components may be added to or removed from the described systems. Accordingly, other implementations are within the scope of the following claims.

[0070] While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It should therefore be understood that the appended claims are intended to cover all such modifications and changes that fall within the scope of these implementations. It should be understood that they have been presented by way of example only, and not by way of limitation, and that various changes in form and details may be made. Any part of the apparatus and / or methods described herein may be combined in any combination, except in mutually exclusive combinations. The implementations described herein may include various combinations and / or subcombinations of the functions, components, and / or features of the different implementations described.

Claims

1. side-by-side electrochemical cells having coplanar terminals, the electrochemical cells including a first cell and a second cell; a busbar including coplanar interleaved fingers, wherein the first cell and the second cell are located on opposite sides of a first coplanar interleaved finger of the coplanar interleaved fingers; and a first bonding wire having (i) a first wire bond at a first terminal of the first cell, (ii) a second wire bond at a first terminal of the second cell, and (iii) a first intermediate wire bond at the first coplanar interleaved finger between the first wire bond and the second wire bond; A battery module comprising:

2. The battery module of claim 1 , wherein the first terminal of the first cell and the first terminal of the second cell are center terminals.

3. The battery module according to claim 1 , wherein the first terminal of the first cell and the first terminal of the second cell are rim terminals.

4. 4. The battery module of claim 1, wherein the first bonding wire has a plurality of intermediate wire bonds in the first coplanar interleaved fingers between the first wire bond and the second wire bond.

5. 4. The battery module of claim 1, wherein the first bond wire returns from the second wire bond to the first coplanar interleaved finger.

6. 6. The battery module of claim 5, wherein the electrochemical cells further include a third cell adjacent to the first cell, the third cell being located on the same side of the first coplanar interleaved finger as the first cell, and wherein the first bonding wire from the second wire bond back to the first coplanar interleaved finger continues from the first coplanar interleaved finger and has a third wire bond at a first terminal of the third cell and a second intermediate wire bond at the first coplanar interleaved finger, wherein the second intermediate wire bond is between the second and third wire bonds.

7. 7. The battery module of claim 6, wherein the first bond wire returns from the third wire bond to the first coplanar interleaved finger.

8. 8. The battery module of claim 7, wherein the electrochemical cells further include a fourth cell adjacent to the second cell, the fourth cell being located on the same side of the first coplanar interleaved finger as the second cell, and wherein the first bonding wire from the third wire bond back to the first coplanar interleaved finger continues from the first coplanar interleaved finger and has a fourth wire bond at a first terminal of the fourth cell and a third intermediate wire bond at the first coplanar interleaved finger, the third intermediate wire bond being between the third wire bond and the fourth wire bond.

9. 4. The battery module of claim 1, wherein the busbar further comprises a second coplanar interleaved finger, where the second cell is adjacent to the second coplanar interleaved finger, where the electrochemical cells further comprise a third cell, where the third cell is adjacent to the second coplanar interleaved finger, where the second cell and the third cell are located on opposite sides of the second coplanar interleaved finger, and the battery module further comprises: (i) a first wire bond at a first terminal of the second cell, (ii) a second wire bond at a first terminal of the third cell, and (iii) a second bonding wire having an intermediate wire bond at the second coplanar interleaved finger between the first wire bond and the second wire bond.

10. 4. The battery module of claim 1, wherein the busbar further comprises an edge flush finger on an opposite side of the first cell from the first flush interleaved finger, where the first cell is an edge cell in the battery module such that none of the electrochemical cells are located on an opposite side of the edge flush finger from the first cell, and the battery module further comprises: (i) a third wire bond at the edge flush finger, (ii) a fourth wire bond at a second edge flush finger, and (iii) a second bonding wire having an intermediate wire bond at a second terminal of the first cell, where the intermediate wire bond is between the first wire bond and the second wire bond.

11. 1. A method of forming electrical connections in a battery module having side-by-side electrochemical cells with coplanar terminals, the electrochemical cells including a first cell and a second cell, the method comprising: forming a first wire bond at a first terminal of the first cell on a first bonding wire using a wire bonder head; moving the wire bonder head from the first wire bond to a bus bar including coplanar interleaved fingers, where the first cell and the second cell are located on opposite sides of a first coplanar interleaved finger of the coplanar interleaved fingers; forming a first intermediate wire bond on the first bonding wire at the first coplanar interleaved fingers using the wire bonder head; moving the wire bonder head from the first coplanar interleaved fingers to a first terminal of the second cell; and forming a second wire bond on the first bonding wire at the first terminal of the second cell using the wire bonder head. A method comprising:

12. The method of claim 11 , wherein the first terminal of the first cell and the first terminal of the second cell are center terminals.

13. The method of claim 11 , wherein the first terminal of the first cell and the first terminal of the second cell are edge terminals.

14. 14. The method of claim 11, further comprising forming a plurality of intermediate wire bonds in the first coplanar interleaved fingers between the first wire bonds and the second wire bonds.

15. 14. The method of claim 11, further comprising moving the wire bonder head from the second wire bond back to the first coplanar interleaved fingers.

16. The electrochemical cell further includes a third cell adjacent to the first cell, the third cell being on the same side of the first coplanar interleaved finger as the first cell, and the method further includes: forming a second intermediate wire bond on the first bonding wire at the first co-planar interleaved finger using the wire bonder head after returning the wire bonder head from the second wire bond to the first co-planar interleaved finger; after forming the second intermediate wire bond, moving the wire bonder head from the first coplanar interleaved fingers to a first terminal of the third cell; and forming a third wire bond at the first terminal of the third cell on the first bonding wire using the wire bonder head, where the second intermediate wire bond is between the second wire bond and the third wire bond. The method of claim 15 comprising:

17. 17. The method of claim 16, further comprising moving the wire bonder head from the third wire bond back to the first coplanar interleaved fingers.

18. The electrochemical cell further includes a fourth cell adjacent to the second cell, wherein the fourth cell is on the same side of the first coplanar interleaved finger as the second cell, and the method further includes: forming a third intermediate wire bond on the first bonding wire at the first co-planar interleaved finger using the wire bonder head after moving the wire bonder head from the third wire bond back to the first co-planar interleaved finger; after forming the third intermediate wire bond, moving the wire bonder head from the first coplanar interleaved fingers to a first terminal of the fourth cell; and forming a fourth wire bond at the first terminal of the fourth cell on the first bonding wire using the wire bonder head, where the third intermediate wire bond is between the third wire bond and the fourth wire bond.

20. The method of claim 17 comprising:

19. the busbar further comprises a second coplanar interleaved finger, the second cell adjacent the second coplanar interleaved finger, the electrochemical cell further comprises a third cell, the third cell adjacent the second coplanar interleaved finger, the second cell and the third cell located on opposite sides of the second coplanar interleaved finger, and the method further comprises: forming a third wire bond on a second bonding wire at a second terminal of the second cell using the wire bonder head; moving the wire bonder head from the third wire bond to the second coplanar interleaved fingers; forming a second intermediate wire bond at the second coplanar interleaved fingers on the second bonding wire using the wire bonder head; moving the wire bonder head from the second coplanar interleaved fingers to a second terminal of the third cell; and forming a fourth wire bond at the second terminal of the third cell on the second bonding wire using the wire bonder head.

14. The method of claim 11, comprising:

20. The busbar further includes an edge flush finger on an opposite side of the first cell from the first flush interleaved finger, the first cell being an edge cell in the battery module such that none of the electrochemical cells are located on an opposite side of the edge flush finger from the first cell, and the method further includes: forming a first edge wire bond on the edge flush finger on a second bonding wire using the wire bonder head; moving the wire bonder head from the first edge wire bond to a second terminal of the first cell; forming a third wire bond on the second bonding wire at the second terminal of the first cell using the wire bonder head; moving the wire bonder head from the third wire bond to the edge flush fingers; and forming a second edge wire bond at the edge flush finger on the second bonding wire using the wire bonder head.

14. The method of claim 11, comprising:

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