Flexible substrate and battery connection structure

Abstract

The flexible substrate includes a plate-shaped substrate main body disposed perpendicular to the vertical direction, and an elongated and extended connection portion. The connecting part comprises a taking-out part, a bending part, a first extending part extending from the bending part along the front side of the x direction, a folding part, a second extending part parallel to the first extending part and extending in the reverse direction, and a fixing part. The first extension portion is inclined downward toward the front side of the x-direction. The second extension portion is inclined downward toward the negative side in the x direction. Even if the inclination angle of the first extension part and the second extension part is set to be small, the fixing part can be made lower than the substrate main body.

Description

Technical Field

[0001] This disclosure relates to a structure of a flexible substrate for battery cells, etc., and a battery connection structure using the flexible substrate. Background Technology

[0002] In battery cells used in automobiles and the like, a large current output is taken from an assembly comprising multiple batteries, and these outputs are connected in series, for example. Therefore, a substrate including terminals connected to the electrodes of each battery is mounted onto such a battery cell (battery assembly). At this time, the positions of the terminals on the battery side may change due to heat generated during battery use, thermal expansion caused by ambient temperature, and expansion of the battery itself. On the other hand, since each battery outputs a large current, it is necessary to reliably connect the substrate and each battery with low resistance.

[0003] To address this positional change, a flexible substrate (flexible printed circuit board) as described in Patent Document 1 is used, for example. In the flexible substrate, a wiring pattern through which current flows is formed on a substrate made of a thin flexible resin material. A connection portion with the wiring pattern extends from the substrate body and is fixed to the electrode on the battery side.

[0004] Figure 7A This is a top view showing the configuration in which the flexible substrate 300 is mounted onto the battery 50. Figure 7B This is a cross-sectional view along its AA direction. Here, the flexible substrate 300 is connected to the electrode (positive electrode or negative electrode) 55 in the battery 50. In the flexible substrate 300, a plate-shaped substrate body 310 and a connecting portion 320 extending from the substrate body 310 are connected to the electrode 55. Wiring patterns are suitably formed on the substrate body 310 and the connecting portion 320, and their description is omitted. The substrate body 310 is configured such that current is extracted to the outside.

[0005] like Figure 7A As shown, the connecting portion 320, which is connected to the substrate body 310 at one end, has a curved shape in the horizontal direction (the plane direction of the flexible substrate 300). A rectangular plate-shaped connecting terminal 40 made of metal is connected to a fixing portion 330 provided at the other end, and the connecting terminal 40 is connected via a metal bonding layer 57 on the electrode 55. With this structure, the connection with the electrode 55 on the battery 50 side can be maintained even when the position of the battery 50 (electrode 55) changes.

[0006] Citation List

[0007] Patent documents

[0008] Patent Document 1: JP2022-97917A Summary of the Invention

[0009] With the above structure, the connection with electrode 55 can be stably maintained even when the position of battery 50 (electrode 55) changes. However, the positional change of battery 50... Figure 7A It occurs in both the left-right and up-down directions, and sometimes both simultaneously.

[0010] Figure 8 This corresponds to the case in which... Figure 7A A top view. In this case, although the connection between the connection terminal 300 and the electrode 55 is stably maintained, the connection portion 300 may deform, and the connection portion 320 and the substrate body 310 may interfere as in region B, or different parts of the bent connection portion 320 may interfere with each other as in region C. At this time, even in the state before deformation ( Figure 7A and 7B Particularly in region C, interference may occur due to manufacturing tolerances in the smaller intervals. Therefore, the connector 320 and the substrate body 310 may be damaged, and problems may arise when drawing current from the battery 50.

[0011] This disclosure is made in view of the above circumstances, and its purpose is to resolve the above problems.

[0012] The flexible substrate disclosed herein is a thin, sheet-like substrate made of a flexible material and formed with a wiring pattern serving as a path for current from a battery. The flexible substrate includes: a substrate body having a surface perpendicular to the vertical direction; and a connecting portion extending from a protrusion portion of the substrate body in a top view, the front end of the connecting portion serving as a fixing portion for attachment to an electrode of the battery. The connecting portion bends at multiple locations in the top view from the protrusion portion to the fixing portion to change its extension direction. The connecting portion is inclined such that the distance between it and the substrate body along the vertical direction increases as the connecting portion extends along the extension direction from the protrusion portion to the fixing portion, so that the fixing portion and the substrate body are not positioned at the same height in the vertical direction. In other words, the connecting portion is inclined in the vertical direction to space it from the substrate body, such that the fixing portion and the substrate body are positioned at different heights in the vertical direction.

[0013] Furthermore, the connection portion may include a first extension and a second extension extending in the opposite direction to a second direction perpendicular to the first direction, wherein the first direction is the direction from the substrate body toward the battery in a top view.

[0014] Furthermore, in the battery connection structure using the flexible substrate in this disclosure, the fixing part and the electrode are connected by a plate-shaped connection terminal.

[0015] The substrate body can be disposed above the electrode, and the connection terminal can be engaged with the lower side of the fixing part.

[0016] Because of the configuration described above, it is possible to obtain a flexible substrate that can stably extract the output from the connected electrodes even when the position of the electrodes changes. Attached Figure Description

[0017] Figure 1 This is a top view showing a first mode (electrode connection structure) when using a flexible substrate according to an embodiment;

[0018] Figures 2A to 2C This is a cross-sectional view showing a first mode (electrode connection structure) when using a flexible substrate according to this embodiment;

[0019] Figure 3 This is a top view showing the second mode (electrode connection structure) when using the flexible substrate according to this embodiment;

[0020] Figures 4A to 4C This is a cross-sectional view showing the second mode (electrode connection structure) when using a flexible substrate according to this embodiment;

[0021] Figure 5 This is a top view showing the mode when using a first modified example of the flexible substrate according to this embodiment;

[0022] Figure 6 This is a top view showing a configuration when using a second modified example of the flexible substrate according to this embodiment;

[0023] Figure 7A and 7B This is a top view showing the configuration when using a flexible substrate from the prior art; and

[0024] Figure 8 This is a cross-sectional view showing a pattern when using a flexible substrate in the prior art. Detailed Implementation

[0025] A flexible substrate according to an embodiment of the present disclosure will be described. The flexible substrate also includes connection portions for electrical connection with the electrodes of a battery cell (battery), and the connection between them remains unchanged even when the position of the battery (electrode) changes due to the flexibility of the flexible substrate. Furthermore, in the flexible substrate, even if the battery (electrode) moves, the connection portions connecting the battery and the substrate body, or different portions of the connection portions, are unlikely to interfere with each other.

[0026] Figure 1This is a top view showing the configuration (battery connection structure) when the flexible substrate 10 is mounted to the battery 50. Here, the x, y, and z directions are defined as shown here. The y direction (first direction) is the direction connecting the substrate body 20 and the battery 50 in the top view, the x direction (second direction) is the direction in the horizontal plane perpendicular to the y direction, and the z direction is the vertical direction.

[0027] and Figure 7A and 7B The structure is the same as that in the previous example. Here, the flexible substrate 10 is further provided with a plate-shaped substrate body 20 perpendicular to the vertical direction (z direction) and a connecting portion 30 extending from the substrate body 20. The flexible substrate 10 is also provided with a metal connection terminal 40 for connecting the metal bonding layer 57 on the electrode 55 and the connecting portion 30. Figure 1 The top view shown is the same as Figure 7A The top view shown is basically the same. Here, the connecting part 30 includes a part that is taken out from the substrate body 20 toward the negative side in the y direction, namely the taking-out part 31; a bending part 32 that changes the extension direction by 90° (along the x direction) from the taking-out part 31; a first extension part 33 that extends from the bending part 32 toward the positive side in the x direction; a folding part 34 that is provided on the positive side of the first extension part 33 in the x direction and changes the extension direction by 180°; a second extension part 35 that extends parallel to and in the opposite direction to the first extension part 33; and a fixing part 36 that is provided at the front end of the second extension part 35 and connected to the connecting terminal 40. Figure 1 The top view shown is the same as Figure 7A The top views shown are basically the same.

[0028] on the other hand, Figure 2A It is along Figure 1 A cross-sectional view taken along the DD direction in the image. Figure 2B It is along Figure 1 A cross-sectional view taken along the EE direction in the image. Figure 2C It is along Figure 1 A cross-sectional view taken along the FF direction. Specifically, Figure 2C Corresponding to Figure 7B .like Figure 2A As shown, the first extension 33 slopes downward toward the positive side in the x-direction (toward the negative side in the z-direction). As... Figure 2B As shown, the second extension 35 slopes downward toward the negative side of the x-direction (or toward the negative side of the z-direction). Figure 1 In this context, the slanted portion is indicated by an arrow with the front end located on the lower side. Therefore, as... Figure 2C As shown, the fixing part 36 is located below the substrate body 20 (negative side in the z direction). In this case, the distance between the lower surface of the substrate body 20 and the upper surface of the connecting terminal 40 in the z direction is L.

[0029] In particular, by providing a bending portion 32 and a folding portion 34 in the connecting portion 30, the effective length from the taking-out portion 31 to the fixing portion 36 (connecting terminal 40) can be increased, and even when Figure 2A and 2B Even when the tilt angle of the first extension 33 and the second extension 35 is set to be small, the fixing part 36 can be made sufficiently low to the substrate body 20.

[0030] exist Figure 1 In, with Figure 8 In region B, the portion of the connecting portion 30 (first extension 33) and the substrate body 20 that are opposite to each other is shown as region B0, and the portion of the first extension 33 and the fixing portion 36 that are opposite to each other, corresponding to region C, is shown as region C0. With this configuration, since the first extension 33 is located below the substrate body 20 in region B0, and the fixing portion 36 is located below the first extension 33 in region C0, even if an accident occurs in the connecting portion 30 (flexible substrate 10)... Figure 8 When the same deformation occurs, interference in regions B0 and C0 can also be prevented.

[0031] exist Figure 1 and Figures 2A to 2C In this structure, it is evident that even when the electrode 55 (battery 50) moves slightly along the z-direction, the deformation of the connecting portion 30 can follow the slight movement. Therefore, even when the position of the connected electrode 55 changes, the output of the electrode can be stably extracted.

[0032] Figure 1 The diagram illustrates a structure where one flexible substrate 10 is connected to a single battery 50, and in practice, another flexible substrate is connected to another battery 50 adjacent to it in the same manner. In this case, the substrate bodies of the flexible substrates can be shared or separate. In the case of separate substrate bodies, the height of the substrate body can vary depending on the battery, and... Figures 2A to 2C The tilt angle can be changed accordingly.

[0033] Figure 3 and Figures 4A to 4C It shows the relationship with Figure 1 and Figures 2A to 2C Different modes utilize the structure (electrode connection structure) of the flexible substrate 10, and correspond to... Figure 1 and Figures 2A to 2C .exist Figure 1 and Figures 2A to 2C In the example, the connecting terminal 40 is connected to the upper side (positive side in the z-direction) of the fixing part 36, and in this structure, the connecting terminal 40 is connected to the lower side of the fixing part 36. Here, in the installed state, the connecting terminal 40 remains horizontal, as... Figure 4C As shown.

[0034] like Figure 4C As shown, when Figure 2C The distance between the substrate body 20 and the connecting terminal 40 in the z-direction is L, and... Figure 3 and Figures 4A to 4C In this structure, when the distance remains constant, the height of the fixing part 36 can exceed the thickness of the connecting terminal 40. Therefore, Figure 4A and 4B The tilt angle of the first extension 33 and the second extension 35 in the middle can be greater than Figure 2A and 2B The tilt angle is gentler.

[0035] like Figures 2A to 2C As shown in 4A to 4C, the resin material that forms the main body of the flexible substrate 10 is made thinner than the connecting terminal 40, etc. Therefore, it is evident that this construction also prevents interference between the connecting portion 30 and the substrate body 20, as well as interference between the first extension 33 and the fixing portion 36. On the other hand, when using this construction, the entire connecting portion 30 can be shortened by the amount that makes the inclination gentler, and the overall strength can also be improved.

[0036] In particular, the planar shape of the connecting portion can be appropriately changed in the flexible substrate 10. Figure 5 In the flexible substrate 110 shown (first modified example), a bent connecting portion 130, as shown, is formed on the substrate body 120. In the connecting portion 30, the extending direction changes in two parts (bent portion 32, folded-back portion 34), and in the connecting portion 130, bent portions 131, 132, 133, and 134 are provided, each changing the extending direction by 90°, and a fixing portion 135 is provided at the front end. By providing multiple bent portions in this manner, and as... Figure 5 As shown by the arrow in the image, between the bends, and Figure 2A and 2B Similarly, by tilting the connecting portion 130 towards the front end, the output can be stably extracted from the electrode 55 in the same manner. Also in this case, the connecting terminal 40 is connected to the lower side of the fixing portion 135, which is consistent with... Figure 3 and Figures 4A to 4C The structures are the same.

[0037] exist Figure 6 In the flexible substrate 210 shown (second modified example), a connecting portion 230 with the shape shown in the figure is formed on the substrate body 220. The connecting portion 230 includes curved portions 231, 232, and 233 that respectively change the extension direction by 90°, and a curved portion 234 with an arc shape is provided between curved portions 232 and 233. Thus, by combining the curved portion and the curved portion with a curved shape, and as shown in the figure... Figure 6 As indicated by the arrows, tilting these parts towards the front end (fixed part 235) achieves the same effect. Similarly, in this case, the connecting terminal 40 is connected to the lower side of the fixed part 235, which is consistent with... Figure 3 and Figures 4A to 4C The structures are the same.

[0038] In this way, by setting multiple bends and folds, and between the bends and folds, and... Figure 2A and 2B Similarly, by tilting the connection towards the front end, the output can be stably extracted from electrode 55 in the same manner.

[0039] In the example above, the fixing part is located below the substrate body (on the negative side in the z-direction). Alternatively, depending on the positional relationship between the substrate body (flexible substrate) and the battery, the fixing part may be located above the substrate body. In this case, Figure 2A and 2B The inclination directions of the connecting portions (first extension 33, second extension 35) shown can be opposite. That is, the area of ​​the connecting portion can be inclined in the vertical direction relative to the side of the substrate body facing the front end where the fixing portion is provided.

[0040] The structure of the substrate body is appropriately set according to the method of extracting current from the battery, and the connection part is appropriately constructed to ensure that the current path starts from the fixing part.

[0041] The present disclosure has been described above based on embodiments. These embodiments are merely examples, and those skilled in the art will understand that various modifications can be made to the combination of components in these embodiments, and these modifications are also within the scope of this disclosure.

Claims

1. A flexible substrate, which is a thin, sheet-like substrate made of a flexible material and formed with wiring patterns serving as paths for current from a battery, said flexible substrate comprising: The substrate body has a surface perpendicular to the vertical direction; A connecting portion, which extends from and from the removal portion of the substrate body in the top view, has a front end serving as a fixing portion for fixing to the electrodes of the battery, wherein... The connecting portion bends at multiple locations in the top view from the extraction portion to the fixing portion to change its extension direction. The connecting portion is inclined such that the distance between it and the substrate body along the vertical direction increases as the connecting portion extends from the extraction portion to the fixing portion along the extending direction, and The fixing part and the substrate body are not set at the same height in the vertical direction.

2. The flexible substrate according to claim 1, wherein, The connecting portion includes a first extension and a second extension extending in the opposite direction to a second direction perpendicular to the first direction, wherein the first direction is the direction from the substrate body toward the battery in the top view.

3. A battery connection structure using a flexible substrate according to claim 1 or 2, wherein, The fixing part and the electrode are connected via plate-shaped connecting terminals.

4. The battery connection structure according to claim 3, wherein, The substrate body is disposed above the electrode, and The connecting terminal engages with the lower side of the fixing part.

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