Flexible circuit board, acquisition assembly and battery module

Abstract

The utility model provides a flexible circuit board, an acquisition assembly and a battery module, the flexible circuit board comprises a substrate and an acquisition circuit, the acquisition circuit is arranged on one side of the substrate in a first direction, the acquisition circuit comprises an acquisition line and a fusing structure, the fusing structure is connected with the acquisition line and comprises a first fusing member and a second fusing member, and the first fusing member is connected with the second fusing member. The melting point of the first fuse link is larger than that of the second fuse link, the size of the first fuse link in the first direction is D1, and D1 is larger than or equal to 10 microns and smaller than or equal to 100 microns; the flexible circuit board provided by the embodiment of the utility model is suitable for a high-capacity module, and under the condition of low-voltage short circuit of the acquisition line, the fusing structure can utilize the M effect point to enable the fusing structure to be easy to fuse.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to a flexible circuit board, collection subassembly and battery module. BACKGROUND

[0002] In the related art, a fuse is etched on a collection harness in a battery module or a patch fuse is added to the collection harness to play a short-circuit protection function. However, due to the demand for large-capacity battery modules, the number of batteries in the battery module is increasing, which results in an increase in the number of collection harnesses, making it difficult to control the resistance of the collection harnesses within a specified fuse range. As a result, the collection harnesses cannot generate enough melting current when short-circuited, which makes it difficult for the fuses to melt. SUMMARY

[0003] Embodiments of the utility model provide a flexible circuit board, a collection subassembly and a battery module, which can improve the technical problem that the collection harness is not easy to melt when short-circuited in a large-capacity battery module.

[0004] In a first aspect, embodiments of the utility model provide a flexible circuit board, which includes:

[0005] a substrate;

[0006] a collection circuit arranged on one side of the substrate in a first direction, the collection circuit including a collection line and a melting structure, the melting structure being connected to the collection line and including a first melting component and a second melting component, the melting point of the first melting component being greater than the melting point of the second melting component;

[0007] wherein the size of the first melting component in the first direction is defined as D1, and D1 satisfies 10um≤D1≤100um.

[0008] In some embodiments, the first melting component includes a fuse, and the fuse is connected to the collection line.

[0009] In some embodiments, the first melting component is arranged on one side of the substrate in the first direction.

[0010] The second melting component is arranged on the side of the first melting component away from the substrate.

[0011] In some embodiments, the size of the first melting component in a second direction is defined as L1, and the second direction intersects the first direction; wherein L1 satisfies:

[0012] 4mm≤L1≤10mm.

[0013] In some embodiments, the size of the second melting component in the first direction is defined as D2; wherein D2 satisfies 5um≤D2≤500um.

[0014] In some embodiments, a dimension of the second fuse element in a second direction intersecting the first direction is defined as L2; wherein L2 satisfies:

[0015] 0.3mm≤L2≤3mm.

[0016] In some embodiments, a dimension of the second fuse element in a third direction perpendicular to the first direction and the second direction is defined as L3; wherein L3 satisfies:

[0017] 0.1mm≤L3≤0.5mm.

[0018] In some embodiments, the fuse includes a center region and two edge regions, the two edge regions are respectively located on two sides of the center region in the second direction, the first direction intersects the second direction;

[0019] wherein the second fuse element is located in the center region.

[0020] In some embodiments, a material of the first fuse element includes copper;

[0021] a material of the second fuse element includes tin or tin-silver alloy.

[0022] In some embodiments, a shape of the first fuse element includes linear or serpentine.

[0023] In a second aspect, embodiments of the utility model provide a kind of acquisition assembly, and acquisition assembly includes:

[0024] Flexible circuit board;

[0025] Multiple busbars are connected with flexible circuit board;And

[0026] Mounting bracket, flexible circuit board and busbar are all arranged on mounting bracket.

[0027] In a third aspect, embodiments of the utility model provide a kind of battery module, and battery module includes acquisition assembly.

[0028] The beneficial effects of the embodiments of the utility model are as follows:

[0029] The flexible circuit board provided in the embodiment of the present application comprises a substrate and a collection circuit, the collection circuit is arranged on one side of the substrate in a first direction, the collection circuit comprises a collection line and a fuse structure, the fuse structure is connected with the collection line, and comprises a first fuse element and a second fuse element, the melting point of the first fuse element is greater than the melting point of the second fuse element, and the size of the first fuse element in the first direction is D1, and D1 satisfies 10um≤D1≤100um; in this embodiment, the fuse structure is arranged in series with the collection line, the fuse structure comprises the first fuse element and the second fuse element with a smaller melting point than the first fuse element, and the size D1 of the first fuse element in the first direction satisfies the interval range of 10um≤D1≤100um, so that the flexible circuit board in the embodiment of the present application is suitable for use in a large-capacity module, and in the case of low-voltage short circuit of the collection line 20, the fuse structure 21 can use the M-effect point to make the fuse structure 21 easy to fuse.

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a structural schematic diagram of a collection assembly provided by an exemplary embodiment of the present application;

[0032] Figure 2 is Figure 1 is an enlarged schematic diagram of A in FIG.

[0033] Figure 3 is a partial sectional structural schematic diagram of a flexible circuit board provided by an exemplary embodiment of the present application;

[0034] Figure 4 is a structural schematic diagram of a flexible circuit board provided by an exemplary embodiment of the present application;

[0035] Figure 5 is a structural schematic diagram of a first fuse element provided by an exemplary embodiment of the present application.

[0036] Explanation of Reference Signs:

[0037] 1000, collection assembly; 100, flexible circuit board; 200, bus bar; 300, mounting bracket;

[0038] 1, substrate; 20, collection line; 21, fuse structure; 211, first fuse element; 212, second fuse element; 21A, central region; 21B, edge region. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application. In addition, it should be understood that the specific implementation described herein is only used to illustrate and explain the present application, and is not used to limit the present application. In the present application, the orientation words such as "upper" and "lower" generally refer to the upper and lower of the device in the actual use or working state, and specifically refer to the drawing direction in the drawings. The "inner" and "outer" refer to the outline of the device.

[0040] The present application provides a flexible circuit board, Figures 1 to 5 For some embodiments of the present application. As shown in the drawings, the Z direction is the first direction, the Y direction is the second direction, and the X direction is the third direction. The first direction intersects the second direction, and the third direction is perpendicular to the first direction and the second direction. In the following, the first direction Z, the second direction Y and the third direction X are described and explained.

[0041] Please refer to Figures 1 to 3 In some embodiments of the present application, the flexible circuit board 100 includes a substrate 1 and a collection circuit. The collection circuit is arranged on one side of the substrate 1 in the first direction Z. The collection circuit includes a collection line 20 and a fuse structure 21. The fuse structure 21 is connected with the collection line 20 and includes a first fuse element 211 and a second fuse element 212. The melting point of the first fuse element 211 is higher than that of the second fuse element 212. When the collection line 20 is in a short circuit state, the current through the collection line 20 increases, causing the temperature of the fuse structure 21 connected with the collection line 20 to rise until the fuse structure 21 reaches the melting point and is fused.

[0042] The fuse structure 21 includes the first fuse element 211 and the second fuse element 212. The melting point of the second fuse element 212 is lower than that of the first fuse element 211. The M-effect point is used to make the first fuse element 211 break at a lower current than the preset, so as to protect the circuit. The working principle of the M-effect point is as follows: when the current passes through the first fuse element 211 in a short circuit state, the second fuse element 212 with a lower melting point than the first fuse element 211 will melt first. The melted second fuse element 212 will remain at the initial position arranged on the first fuse element 211, thereby forming a local high temperature, causing the impedance of the first fuse element 211 in the region where the second fuse element 212 is arranged to increase, further accelerating the melting of the first fuse element 211.

[0043] In an embodiment of the present application, the fuse structure 21 is connected to the collection line 20 through the first fuse element 211; in another embodiment of the present application, the fuse structure 21 is connected to the collection line 20 through other lines.

[0044] It needs to be explained that, according to Ohm's law: I = U / R, when the collection line 20 is short-circuited, if the voltage is low, the current intensity generated by the short circuit is also low on the basis of the unchanged resistance, which in turn makes the temperature of the fuse structure 21 connected in series with the collection line 20 not easy to reach the fuse temperature of the fuse structure 21. However, the flexible circuit board 100 in the embodiment of the present application can make the fuse structure 21 connected in series with the collection line 20 fuse when the voltage is low and short-circuit occurs, thereby ensuring the safety performance of the battery module.

[0045] In some embodiments of the present application, the thickness of the first fuse element 211 in the first direction Z is D1, which satisfies: 10um≤D1≤100um; that is, the size of the first fuse element 211 in the first direction Z is set to satisfy this interval range, so that the first fuse element 211 in the flexible circuit board 100 applied in a longer battery module can fuse when low-voltage short-circuit occurs. If the value of D1 does not satisfy the interval range of 10um≤D1≤100um, there may be a situation that the first fuse element 211 cannot fuse under low-voltage short-circuit condition.

[0046] It can be understood that if the value of D1 is less than 10um, the resistance of the first fuse element 211 will be too large, so that the heat generated by the fuse structure 21 under short-circuit or overload condition may not easily make the fuse structure 21 fuse; if the value of D1 is greater than 100um, the resistance of the first fuse element 211 is too small, at this time, even if the current passing through the fuse structure 21 is large, the fuse structure 21 is not easy to generate enough heat to fuse within a period of time, thereby easily leading to other parts or devices in the battery module to fuse first and catch fire, thereby making the fuse structure 21 lose its protection effect.

[0047] In addition, if the resistance of the fuse structure 21 is too small, the fuse structure 21 may not be able to withstand the normal load current, affecting the normal use of the battery module.

[0048] The value of D1 can be 10 um, 12 um, 14 um, 16 um, 18 um, 20 um, 22 um, 24 um, 26 um, 28 um, 30 um, 32 um, 34 um, 36 um, 38 um, 40 um, 42 um, 44 um, 46 um, 48 um, 50 um, 52 um, 54 um, 56 um, 58 um, 60 um, 62 um, 64 um, 66 um, 68 um, 70 um, 72 um, 74 um, 76 um, 78 um, 80 um, 82 um, 84 um, 86 um, 88 um, 90 um, 92 um, 94 um, 96 um, 98 um, 100 um. The value of D1 is not limited to the listed values, and other values in the range also apply.

[0049] In the technical solution of the present application, the fuse structure 21 is provided, the fuse structure 21 is connected in series with the collection line 20, the fuse structure 21 includes a first fuse element 211 and a second fuse element 212 with a lower melting point than the first fuse element 211, and the size D1 of the first fuse element 211 in the first direction Z satisfies the range of 10 um≤D1≤100 um, so that the flexible circuit board 100 in the embodiment is suitable for use in a large-capacity module. In the case of low-voltage short circuit of the collection line 20, the fuse structure 21 can use the M-effect point to make the fuse structure 21 easy to fuse.

[0050] It should be noted that the flexible circuit board 100 in the embodiment of the present application is also suitable for use in a Cell to Pack (CTP) battery pack.

[0051] In some embodiments of the present application, the first fuse element 211 includes a fuse, and the fuse is connected with the collection line 20. That is, in this embodiment, the fuse structure 21 uses the combination of the fuse and the second fuse element 212 with a lower melting point than the fuse, so that the flexible circuit board 100 can cause the fuse structure 21 connected in series with the collection line 20 to fuse when the voltage is low and a short circuit occurs, thereby ensuring the safety performance of the battery module.

[0052] In some embodiments of the present application, the first fuse element 211 is arranged on one side of the substrate 1 in the first direction Z, and the second fuse element 212 is arranged on the side of the first fuse element 211 away from the substrate 1. In this way, it is convenient for an operation tool or an operator to form the fuse structure 21 on the substrate 1.

[0053] In some embodiments of the present application, the first fuse element 211 is etched on the substrate 1, and the second fuse element is formed on the first fuse element 211 by electroplating.

[0054] It should be noted that the size D1 of the first fusing member 211 in the first direction Z can be designed according to the rated current of the battery module.

[0055] It should be noted that the size D1 of the first fusing member 211 in the first direction Z can be designed according to the rated current of the battery module. Figure 4 In some embodiments of the present application, the size L1 of the first fusing member 211 in the second direction Y is defined; L1 satisfies: 4mm≤L1≤10mm; wherein the size L1 of the first fusing member 211 in the second direction Y satisfying this interval range is set according to the specific requirements of the circuit in the flexible circuit board 100, to ensure that the battery module can effectively cut off the current when a fault occurs, and ensure the safety of the circuit and equipment inside the battery module.

[0056] In addition, the size L1 of the first fusing member 211 in the second direction Y affects the fusing time and breaking capacity of the fusing structure 21, and further affects the safety protection effect of the fusing structure 21; if the value of L1 is less than 4mm, it may cause the fusing structure 21 to fail to fuse in time when the circuit is short-circuited or overloaded, thereby failing to effectively cut off the fault current, thereby increasing the safety risk of thermal runaway of the battery module; if the value of L1 is greater than 10mm, it may cause the fusing time of the fusing structure 21 to be prolonged, thereby failing to cut off the current within a certain period of time, and further prolonging the damage time of the internal parts and circuit of the battery module, thereby possibly causing greater safety hazards.

[0057] If the value of L1 is greater than 10mm, it will also increase the resistance of the fusing structure 21, thereby generating additional heat to increase the risk of damage to the internal parts and circuit of the battery module.

[0058] Wherein, the value of L1 can be 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5mm, 5.2mm, 5.4mm, 5.6mm, 5.8mm, 6mm, 6.2mm, 6.4mm, 6.6mm, 6.8mm, 7mm, 7.2mm, 7.4mm, 7.6mm, 7.8mm, 8mm, 8.2mm, 8.4mm, 8.6mm, 8.8mm, 9mm, 9.2mm, 9.4mm, 9.6mm, 9.8mm, 10mm. The value of L1 is not limited to the listed values, and other values not listed in this range are also applicable.

[0059] In some embodiments of the present application, the size D2 of the second fusing member 212 in the first direction Z is defined; D2 satisfies: 5um≤D2≤500um. Designing the value of D2 to satisfy this interval range makes the second fusing member 212 suitable for application on the first fusing member 211 that satisfies 10um≤D1≤100um and L1 satisfies 4mm≤L1≤10mm, so that the fusing structure 21 is easy to fuse under low-voltage short-circuit conditions.

[0060] wherein the value of D1 can be 10um, 12um, 14um, 16um, 18um, 20um, 22um, 24um, 26um, 28um, 30um, 32um, 34um, 36um, 38um, 40um, 42um, 44um, 46um, 48um, 50um, 52um, 54um, 56um, 58um, 60um, 62um, 64um, 66um, 68um, 70um, 72um, 74um, 76um, 78um, 80um, 82um, 84um, 86um, 88um, 90um, 92um, 94um, 96um, 98um, 100um. The value of D1 is not limited to the listed values, other values within the range are also applicable.

[0061] In some embodiments of the present application, the second fusing member 212 has a dimension L2 in the second direction Y, and L2 satisfies: 0.3mm≤L2≤3mm. The value of L2 is designed to satisfy the interval range, so that the second fusing member 212 is suitable for being applied on the first fusing member 211 satisfying 10um≤D1≤100um and 4mm≤L1≤10mm, so that the fusing structure 21 is easy to fuse under low-voltage short-circuit conditions.

[0062] wherein the value of L2 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm. The value of L2 is not limited to the listed values, other values within the range are also applicable.

[0063] In some embodiments of the present application, the second fusing member 212 has a dimension L3 in the third direction X; wherein L3 satisfies: 0.1mm≤L3≤0.5mm. The value of L3 is designed to satisfy the interval range, so that the second fusing member 212 is suitable for being applied on the first fusing member 211 satisfying 10um≤D1≤100um and 4mm≤L1≤10mm, so that the fusing structure 21 is easy to fuse under low-voltage short-circuit conditions.

[0064] The value of L3 can be 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm, 0.4 mm, 0.41 mm, 0.42 mm, 0.43 mm, 0.44 mm, 0.45 mm, 0.46 mm, 0.47 mm, 0.48 mm, 0.49 mm, 0.5 mm. The value of L3 is not limited to the listed values, and other values in the range are also applicable.

[0065] In some embodiments of the present application, the shape of the second fusing member 212 is not limited, and the shape of the second fusing member 212 can be square, circular, spherical, or the like.

[0066] In some embodiments of the present application, the shape of the second fusing member 212 is square.

[0067] In some embodiments of the present application, the shape of the second fusing member 212 is square, and the size D2 of the second fusing member 212 in the first direction Z, the size L2 of the second fusing member 212 in the second direction Y, and the size L3 of the second fusing member 212 in the third direction X satisfy 5 um≤D2≤500 um, 0.3 mm≤L2≤3 mm, and 0.1 mm≤L3≤0.5 mm, respectively.

[0068] Please refer to Figure 5 In some embodiments of the present application, the first fusing member 211 includes a central region 21A and two edge regions 21B located on both sides of the central region 21A in the second direction Y; wherein the heat of the central region 21A of the first fusing member 211 is the largest when the collection line 20 is short-circuited, and the second fusing member 212 is located in the central region 21A, that is, when the collection line 20 is open-circuited, the second fusing member 212 located in the central region 21A of the first fusing member 211 is easily melted, so that the first fusing member 211 is easily fused.

[0069] In some embodiments of the present application, the second fusing member 212 is located at the midpoint of the first fusing member 211.

[0070] In some embodiments of the present application, the material of the first fuse 211 comprises copper; the material of the second fuse 212 comprises tin or tin-silver alloy; in this embodiment, the melting point of tin or tin-silver alloy is lower than that of copper, so that the first fuse 211 is also easy to melt in the case of low-voltage short circuit.

[0071] In some embodiments of the present application, the shape of the first fuse 211 comprises a linear shape or a snake shape.

[0072] Please refer to Figure 5 In some embodiments of the present application, the shape of the first fuse 211 is a snake shape, so as to have a larger resistance and heat generation, which can be more easily melted in the case of overload or short circuit, thereby playing a role in protecting the circuit.

[0073] The flexible circuit board 100 in the embodiments of the present application is suitable for a larger size collection module, so as to reduce the melting current of the fuse structure 21 according to actual needs; compared with the fuse current of about 3.5A in the collection assembly in the related art, the melting current of the fuse structure 21 in the collection assembly 1000 in the embodiments of the present application can be controlled to be above 1A, that is, the fuse structure 21 in the embodiments of the present application is more easily melted.

[0074] The present application also proposes a collection assembly 1000, which comprises a flexible circuit board 100, a plurality of busbars 200 and a mounting bracket 300, the plurality of busbars 200 are connected with the flexible circuit board 100, and the flexible circuit board 100 and the busbars 200 are both arranged on the mounting bracket 300. Wherein, the flexible circuit board 100 is as described above, since the collection assembly 1000 adopts all the technical solutions of the above-mentioned embodiments, it at least has the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0075] Wherein, the busbar 200 is configured to connect the positive and negative poles of the battery in the battery module.

[0076] The present application also proposes a battery module, which comprises a collection assembly 1000, the collection assembly 1000 is as described above, and the battery module adopts all the technical solutions of the above-mentioned embodiments, so it at least has the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0077] The embodiments of the present application are described in detail above, and the principle and implementation mode of the present application are described by applying specific examples; the above embodiment description is only used to help understand the method and core idea of the present application; meanwhile, for those skilled in the art, the specific implementation mode and application range will be changed according to the idea of the present application; in conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A flexible circuit board, characterized by, Comprising: a substrate (1); a collection circuit, disposed on one side of the substrate (1) in a first direction, the collection circuit comprising a collection line (20) and a fuse structure (21), the fuse structure (21) being connected with the collection line (20) and comprising a first fuse element (211) and a second fuse element (212), the melting point of the first fuse element (211) being greater than the melting point of the second fuse element (212); wherein the size of the first fuse element (211) in the first direction is defined as D1, and the D1 satisfies: 10um≤D1≤100um.

2. The flexible circuit board of claim 1, wherein, The first fuse element (211) comprises a fuse, and the fuse is connected with the collection line (20).

3. The flexible circuit board of claim 1, wherein, The first fuse element (211) is disposed on one side of the substrate (1) in the first direction. The second fuse element (212) is disposed on the side of the first fuse element (211) away from the substrate (1).

4. The flexible circuit board of claim 1, wherein, The size of the first fuse element (211) in a second direction is defined as L1, and the second direction intersects the first direction; wherein the L1 satisfies: 4mm≤L1≤10mm.

5. The flexible circuit board according to any one of claims 1 to 4, characterized in that, The size of the second fuse element (212) in the first direction is defined as D2; wherein the D2 satisfies: 5um≤D2≤500um.

6. The flexible circuit board according to any one of claims 1 to 4, characterized in that, The size of the second fuse element (212) in a second direction is defined as L2, and the second direction intersects the first direction; wherein the L2 satisfies: 0.3mm≤L2≤3mm.

7. The flexible circuit board according to any one of claims 1 to 4, wherein, The size of the second fuse element (212) in a third direction is defined as L3, and the third direction is perpendicular to the first direction and the second direction; wherein the L3 satisfies: 0.1mm≤L3≤0.5mm.

8. The flexible circuit board according to any one of claims 1 to 4, characterized in that, The first fuse element (211) comprises a central region (21A) and two edge regions (21B), and the two edge regions (21B) are respectively located on both sides of the central region (21A) in a second direction, and the first direction intersects the second direction; wherein the second fuse element (212) is located in the central region (21A).

9. The flexible circuit board according to any one of claims 1 to 4, characterized in that, The material of the first fuse element (211) comprises copper; The material of the second fuse element (212) comprises tin or tin-silver alloy.

10. The flexible circuit board according to any one of claims 1 to 4, characterized in that, The shape of the first fuse element (211) comprises a linear shape or a serpentine shape.

11. A collection assembly comprising: Comprising: the flexible circuit board according to any one of claims 1 to 10; a plurality of bus bars connected with the flexible circuit board; and a mounting bracket, wherein the flexible circuit board and the bus bars are disposed on the mounting bracket. The collection assembly according to claim 9 is provided.

12. A battery module, characterized by ​

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