Circuit board assembly for battery device

Abstract

The present invention relates to the technical field of circuit boards, and specifically proposes a circuit board assembly for a battery device, which includes a circuit board main body, a branch structure and a fixed plate. The circuit board main body includes a plurality of parallel wires, and the branch structure includes a branch connection part and a sampling part, and the sampling part is used to collect battery information; the branch connection part is provided with a through hole, and at least one through hole is formed with a solder point and welded to the wire; the fixed plate is connected to the branch connection part and its width is W1, and the through hole diameter is R, then 0.01≤R / W1≤2. In the present invention, the branch connection part is welded to the main wire of the circuit board through the solder point through hole, and is reinforced by a fixed plate to avoid the branch connection part from bending and warping due to heat during welding; in addition, the ratio of the through hole diameter to the fixed plate width is appropriately designed, which can not only play a sufficient fixing effect on the branch connection part, eliminate bending or even folding, but also make the welding firm and avoid large local resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and specifically proposes a circuit board assembly for a battery device. Background Art

[0002] At present, the low-voltage collection harnesses used in battery devices mainly include FPC (Flexible Printed Circuit) and FFC (Flat Flexible Cable).

[0003] Among them, FPC is made of etched copper wire as the core and encapsulated by insulating material as a protective film. It has the advantages of thin thickness and small volume, but its production cost is relatively high, and more core material needs to be cut off when forming branches during the forming process.

[0004] FFC is made of tin-plated copper as the core and is encapsulated by a protective film. It has the advantage of being soft and bendable, but it usually uses a stamped fuse, which will produce sparks when it blows, increasing the risk of short circuit in the battery pack. Although the use of an etched fuse does not have the spark problem, the cost is higher. Summary of the invention

[0005] The purpose of the present invention is to solve at least part of the technical problems mentioned above, and this purpose is achieved through the following technical solutions:

[0006] In the first aspect, the present invention proposes a circuit board assembly for a battery device, which includes a circuit board body, a branch structure and a fixed plate. The circuit board body includes a plurality of wires arranged in parallel, the wires include a first metal and a second metal coated on the outer surface of the first metal, and the hardness of the second metal is less than that of the first metal; the branch structure includes a branch connection part formed by the first metal and a sampling part connected to the branch connection part, and the sampling part is used to connect to the battery and collect battery information; the branch connection part is provided with at least two rows of through holes along the arrangement direction of the plurality of wires, the positions of the through holes correspond to the positions of the wires, and a soldering point is formed in at least one through hole, and the soldering point is welded to the wire; the fixed plate is connected to the branch connection part, the size of the fixed plate along the arrangement direction of the plurality of wires is W1, and the size of the through hole along the arrangement direction of the plurality of wires is R, then 0.01≤R / W1≤2.

[0007] The technical solution proposed by the present invention has at least the following technical effects:

[0008] In the present invention, the branch connection part is welded to the main conductor of the circuit board through the solder point through hole, and is reinforced by the fixing plate to prevent the branch connection part from bending and warping due to heat during welding; in addition, the ratio of the through hole diameter to the fixing plate width is properly designed, which can not only have a sufficient fixing effect on the branch connection part and eliminate the occurrence of bending or even folding, but also make the welding firm and avoid large local resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to better combine the contents shown in the drawings of the specification with the contents described in the specific implementation methods, the drawings of the specification are briefly introduced below. It can be understood that the drawings of the specification mentioned below only schematically show some embodiments of the relevant technical solutions and the technical solutions of the present invention. Without paying creative labor, those skilled in the art can also make drawings showing other embodiments.

[0010] Specifically, the annotations of the drawings in the specification are as follows:

[0011] Figure 1 It is a schematic diagram of the structure of the circuit board assembly for the battery device according to some embodiments of the present invention;

[0012] Figure 2 for Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0013] Figure 3 It is a structural schematic diagram of the branch structure described in some embodiments of the present invention;

[0014] Figure 4 It is a schematic diagram of the connection between the branch structure and the fixing plate described in some embodiments of the present invention;

[0015] Figure 5 It is a schematic structural diagram of a circuit board body described in some embodiments of the present invention.

[0016] Specifically, the annotations of the accompanying drawings in the specification are as follows:

[0017] 100. Circuit board assembly for battery device; 110. Circuit board body; 111. Wire; 120. Branch structure; 121. Branch connection part; 122. Sampling part; 123. Buffer arm; 130. Fixing plate; 140. Connector seat; 150. Battery aluminum row; a. Through hole; g. Fuse structure; B1. First main body layer; B2. Second main body layer; E1. First branch structure; E2. Second branch structure; K1. First fixing plate; K2. Second fixing plate; X. First direction; Y. Second direction; Z. Third direction. DETAILED DESCRIPTION

[0018] In order to make the contents of the embodiments of the present invention clearer, the following description will be made in conjunction with the accompanying drawings. It can be understood that the contents mentioned below are only some embodiments of the present invention, and all embodiments are listed in detail. Therefore, without paying creative work, other embodiments obtained based on the following embodiments fall within the protection scope of the present invention.

[0019] It should be understood that the terms used herein are only for the purpose of describing specific embodiments and are not intended to strictly limit the technical solutions unless the context clearly indicates otherwise. For example, the use of "a", "an" and "the" to modify a feature does not exclude that the feature may also be plural in other embodiments.

[0020] It should be understood that the terms "include", "comprises", and "have" are open ended, indicating the presence of the stated features, but not excluding the possibility that the embodiment may have other features. Similarly, the use of the terms first, second, etc. in the text to describe multiple features only means to distinguish one feature from another, and unless the context clearly indicates otherwise, such terms do not imply an order or sequence.

[0021] It should be understood that, unless the context clearly indicates otherwise, the terms "dispose", "connect", and "install" should be understood in a broad sense, for example, they can be fixedly connected, detachably connected, or integrally connected; they can be directly connected or indirectly connected through a medium. For those skilled in the art, the specific meanings of the above terms in the text can be understood according to the specific circumstances.

[0022] In addition, for the convenience of description, the text will use terms of spatial relative relationships to illustrate the position of one feature relative to another feature, for example, "inside", "outside", "end", "side", "top", "middle", "bottom", "high", "low", "axial", "circumferential", "radial", "horizontal", "vertical", "first direction", "second direction", etc. It can be understood that the spatial relative relationship between two features should include other specific situations in addition to those shown in the drawings of the specification.

[0023] The embodiments of the present invention are described below in conjunction with the accompanying drawings.

[0024] Reference Figures 1 to 5The present invention provides a circuit board assembly 100 for a battery device, which includes a circuit board body 110, a branch structure 120 and a fixing plate 130. Among them, the circuit board body 110 includes a plurality of wires 111 arranged in parallel, the wires 111 include a first metal and a second metal coated on the outer surface of the first metal, and the hardness of the second metal is less than that of the first metal; the branch structure 120 includes a branch connection part 121 formed by the first metal and a sampling part 122 connected to the branch connection part 121, and the sampling part 122 is used to connect to the battery and collect battery information; the branch connection part 121 is provided with at least two rows of through holes a along the arrangement direction of the plurality of wires 111, the position of the through hole a corresponds to the position of the wire 111, and a solder joint is formed in at least one through hole a, and the solder joint is welded to the wire 111; the fixing plate 130 is connected to the branch connection part 121, the dimension of the fixing plate 130 along the arrangement direction of the plurality of wires 111 is W1, and the dimension of the through hole a along the arrangement direction of the plurality of wires 111 is R, then 0.01≤R / W1≤2.

[0025] In the present invention, the branch connection part 121 is welded to the wire 111 of the circuit board body 110 by using the solder joint in the through hole a, and a fixing plate 130 is provided for reinforcement to prevent the branch connection part 121 from bending and warping due to heat during welding; in addition, the ratio of the diameter of the through hole a to the width of the fixing plate 130 is appropriately designed, and the fixing plate 130 can not only have a sufficient fixing effect on the branch connection part 121 to eliminate bending or even folding, but also ensure that the solder joint in the through hole a and the wire 111 are firmly welded, thereby avoiding large local resistance.

[0026] Furthermore, when the ratio of R / W1 is too large, it means that the welding spot is large and the fixing plate 130 is narrow, the fixing effect on the branch connection part 121 is insufficient, and the branch connection part 121 may still bend or even fold; when the ratio of R / W1 is too small, it means that the welding spot is small and the fixing plate 130 is too wide. Although the fixing effect is sufficient, the small welding spot may lead to loose welding and large local resistance, and the fixing plate 130 is too wide and will occupy more space in the battery pack. Therefore, the ratio of R / W1 should be moderate, for example, it can be 0.01, 1, or 2.

[0027] It should be noted that the fixing plate 130 can be a whole piece or a plurality of small pieces. In some embodiments, the length of a whole piece of the fixing plate 130 or the total length of the overlapping pieces of the fixing plate 130 is substantially equal to the length of the straight section of the circuit board body 110. In addition, in some embodiments, R is the diameter of the through hole a, W1 is the width of the fixing plate 130, and the fixing plate 130 is a hot pressing film.

[0028] Particularly, in some embodiments, the direction in which the plurality of wires 111 are arranged in parallel is the first direction X, the direction in which the guides extend is the second direction Y, the thickness direction of the fixing plate 130 is the third direction Z, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0029] In some embodiments, the distance between the wire 111 provided with the welding spot and its adjacent wire 111 is H1, and 0.3 mm≤H1≤2 mm.

[0030] In the above embodiment, if the spacing between the wires 111 is too small, short circuit is easy to occur. If the spacing is too large, the number of wires that can be arranged in the circuit board body 110 is too small, and it is impossible to match the collection of multiple strings of batteries. In addition, the spacing between the wires 111 also determines the spacing between the through holes a. If the through holes a are too close, the strength of the branch connection part 121 is insufficient. Therefore, the value of the spacing H1 of the wires 111 should be moderate, for example, it can be 0.3mm, 1mm, or 2mm.

[0031] In some embodiments, reference Figure 3 Each branch connection portion 121 is provided with a plurality of rows of through holes a along the extending direction of the conductive wire 111 .

[0032] In some embodiments, the dimension of the branch connection portion 121 along the extending direction of the conductive line 111 is L1, the number of through holes a is n, and the area of ​​the through holes a is S, then 0.3≤L1 / (n*S)≤0.6.

[0033] In the above embodiment, if the value of L1 / (n*S) is too small, it means that the proportion of through holes a in the branch connection part 121 is too large, and the branch connection part 121 is easily broken and damaged during transportation, molding and welding; if the value of L1 / (n*S) is too large, it means that the through holes a in the branch connection part 121 are fewer and / or smaller, and the corresponding solder joints are also fewer and / or smaller, which is not conducive to the reliability of welding and will cause large local resistance. Therefore, the ratio of L1 / (n*S) should be moderate, for example, it can be 0.3, 0.5, or 0.6.

[0034] It should be noted that each branch connection portion 121 is provided with at least two columns of through holes a, the multiple through holes a in each column are arranged at intervals along the second direction Y, and the multiple through holes a in each row are arranged at intervals along the first direction X.

[0035] In some embodiments, along the extension direction of the conductive wire 111 , the spacing between two adjacent rows of through holes a is P, and 0.5 mm≤P≤1.5 mm.

[0036] In some embodiments, the thickness of the fixing plate 130 is d, then d≥0.03 mm, and P≤1.2 mm.

[0037] In the above embodiment, if the through hole a is too close, the branch connection portion 121 will be insufficiently strong and easily warp, and the fixing plate 130 needs to be thicker.

[0038] It should be noted that the shape of the through hole a is not necessarily circular, and may also be rectangular or other shapes, which is not limited here.

[0039] In some embodiments, the dimension of the fixing plate 130 along the extending direction of the conductive wire 111 is L2, and thus 0.01≤L1 / L2≤1.

[0040] In the above embodiment, if the ratio of L1 / L2 is too small, it means that the width of the branch connection part 121 is too small, so the number of welding points or the size of welding points are also small, which is not conducive to improving welding reliability and current carrying capacity; while if the ratio of L1 / L2 is too large, it means that the width of the branch connection part 121 is large and the fixing plate 130 is small, and the fixing plate 130 is cumbersome to position when installing and fixing, and if the positioning is not accurate, it is easy to fail to press the branch structure 120. Therefore, the ratio of L1 / L2 should be moderate, for example, it can be 0.01, 0.5, 1.

[0041] In some embodiments, the width of the conductive line 111 is W2, and 0.5 mm ≤ R / W2 ≤ 2 mm.

[0042] In the above embodiment, if the ratio of R / W2 is too large, it means that the width of the solder joint is too large compared to the wire 111. If the spacing between the wires 111 is small, it is easy to overlap the adjacent wires 111 and cause acquisition errors; if the ratio of R / W2 is too small, it means that the width of the solder joint is too small compared to the wire 111, which may cause insufficient overcurrent. Therefore, the ratio of R / W2 should be moderate, for example, it can be 0.5mm, 1mm, 2mm.

[0043] It should be noted that the first metal in the wire 111 can be flat, and its width direction is the first direction X. The function of the second metal is to facilitate welding. It can completely cover the first metal along the circumference of the first metal, or it can incompletely cover the first metal along the circumference of the first metal. In addition, the second metal can also cover the first metal continuously or intermittently along the second direction Y; the wire 111 as a whole can also be flat, and its width direction is along the first direction X.

[0044] In some embodiments, the thickness of the fixing plate 130 is d, then 0.03 mm≤d≤0.1 mm, and 0.0006≤d / W1≤0.05.

[0045] In some embodiments, if the fixing plate 130 is too thin, the fixing effect is insufficient and the fixing plate 130 is easy to fold, while if the fixing plate 130 is too thick, it will occupy more space in the third direction Z and be heavier. Therefore, the thickness d of the fixing plate 130 should be moderate, for example, 0.03 mm, 0.05 mm, or 0.1 mm.

[0046] In addition, if the ratio of d / W1 is too large, it means that the fixing plate 130 is too thick and narrow, which is not conducive to saving space, reducing weight and positioning the fixing plate 130; while if the ratio of d / W1 is too small, it means that the fixing plate 130 is thin and wide, and the fixing plate 130 itself is more likely to bend or break due to insufficient strength. Therefore, the ratio of d / W1 should be moderate, for example, it can be 0.0006, 0.01, 0.05.

[0047] In some embodiments, the dimension of the branch connection portion 121 along the arrangement direction of the plurality of conductive wires 111 is W2, then W2≤W1, and 0.03mm≤d≤0.06mm.

[0048] In the above embodiment, in the first direction X, the size of the fixing plate 130 is larger than the size of the branch connection portion 121, and the fixing plate 130 completely covers and exceeds the branch connection portion 121 to ensure that the branch connection portion 121 does not warp. Then, the thickness of the fixing plate 130 can be set slightly thinner, for example, d can be 0.03 mm, 0.05 mm, or 0.06 mm.

[0049] In some embodiments, the branch connection portion 121 is provided with fixing plates 130 at both ends in the thickness direction thereof, and 0.03 mm ≤ d ≤ 0.05 mm.

[0050] In the above embodiment, both side surfaces of the branch connection portion 121 in the third direction Z are fixed by the fixing plate 130, so the strength of the overall structure is sufficient, and the thickness of the fixing plate 130 can be further set to be thinner, for example, d can be 0.03mm, 0.04mm, or 0.05mm.

[0051] In some embodiments, the fixing plate 130 is bonded and fixed to the branch connection portion 121 and the circuit board body 110 .

[0052] In some embodiments, the plurality of conductive wires 111 are respectively connected to the plurality of branch connection portions 121 in a one-to-one correspondence, and each branch connection portion 121 is welded to the conductive wire 111 via a welding point formed by a through hole a corresponding to the conductive wire 111 .

[0053] In some embodiments, the fixing plate 130 covers the welding points on the plurality of branch connection portions 121 .

[0054] In the above embodiment, the fixing plate 130 is directly pressed against the solder joint, which fixes the branch connection part 121 to prevent it from warping and ensures the insulation, dustproof and dewproof effects of the solder joint.

[0055] In some embodiments, reference Figure 2The circuit board body 110 includes a first main layer B1 and a second main layer B2 which are stacked, and the first main layer B1 is connected to a first branch structure E1, and the second main layer B2 is connected to a second branch structure E2; the first branch structure E1 and the second branch structure E2 are distributed on both sides of the extension direction of the circuit board body 110.

[0056] In the above embodiment, the first branch structure E1 and the second branch structure E2 are symmetrically arranged to reduce branch warping; in addition, the first main body layer B1 and the second main body layer B2 are stacked, so the output end does not need to be bent, and two output ends are arranged on the two layers respectively to facilitate the subsequent direct insertion of the connector seat 140 of the BMS (Battery Management System).

[0057] It should be noted that, in some embodiments, the straight sections of the two main layers are stacked in the third direction Z, and the two branch structures 120 in the first direction X can be staggered or symmetrically distributed.

[0058] In some embodiments, reference Figure 2 The first main body layer B1 and the second main body layer B2 are disposed between two layers of fixing plates 130 , and the total thickness between the two layers of fixing plates 130 is D, then D≤150 μm.

[0059] In the above embodiment, the first fixing plate K1 and the second fixing plate K2 are respectively arranged on both sides of the two main body layers in the third direction Z to form a stacked structure as a whole. If the total thickness is too large, it will occupy too much space and the sides will be prone to cracking.

[0060] In some embodiments, the electrical conductivity of the first metal is greater than the electrical conductivity of the second metal, and the thickness of the first metal is d1, and the thickness of the second metal is d2, then 1≤d1 / d2≤2.5.

[0061] In the above embodiment, the second metal plating layer is mainly used to increase the weldability of the welding point between the first metal and the branch connection portion 121 and to prevent oxidation.

[0062] If the ratio of d1 / d2 is too large, it means that the thickness of the second metal is insufficient, and the effect will be insufficient; however, the conductivity of the second metal is not as good as the first metal. If the ratio of d1 / d2 is too small, that is, the thickness of the second metal is too large, the current flow of the wire 111 will be poor. In some embodiments, d1 / d2 can be 1, 2, or 2.5.

[0063] It should be noted that the first metal may be flat copper with a rectangular cross section and a thickness direction of the third direction Z. The second metal may be a tin layer coated on the surface of the first metal.

[0064] In addition, the actual product's tin brush thickness is 0.2mm, and the copper wire thickness is 0.1mm, thus ensuring that the tin can overflow from through hole a and increase welding strength.

[0065] In some embodiments, the melting point of the first metal is greater than the melting point of the second metal, and 0.1≤R / W1≤2.

[0066] In the above embodiment, the welding spot of the second metal is relatively low, which is convenient for welding. In this case, the welding spot can be set larger to reduce the occurrence of warping. For example, R / W1 is preferably 0.1, 1, or 2.

[0067] In some embodiments, reference Figure 3 A fuse structure g is provided on the branch structure 120 .

[0068] In the above embodiment, the branch structure 120 is provided with a fuse structure g, which can be closer to the sampling portion 122, because when the battery temperature is too high and the electrical connection needs to be disconnected, the fuse structure g has a shorter reaction time, thereby responding faster and having a better protection effect.

[0069] In some embodiments, reference Figure 3 A buffer arm 123 is provided between the branch connection portion 121 and the sampling portion 122, and the fuse structure g is provided on the buffer arm 123. The minimum distance between the fuse structure g and the sampling portion 122 is H2, and 1mm≤H2≤25mm. In some embodiments, H2 can be 1mm, 10mm, or 25mm.

[0070] In the above embodiment, due to battery expansion, the battery row is elongated along its arrangement direction, and the main size of the wiring harness assembly is fixed, and the sampling portion 122 and the battery aluminum row 150 are welded and fixed, that is, the relative positions of the branch connection portion 121 and the sampling portion 122 are fixed, so an S-shaped buffer arm 123 is designed between the two to absorb the displacement through its deformation, thereby avoiding the risk of breaking the branch connection portion 121 due to the expansion and contraction displacement of the battery.

[0071] It should be noted that the expansion and contraction direction of the battery pack when doing work is to move from the center point of the battery pack to both sides along the second direction Y; in addition, the buffer arm 123 has a curved structure.

[0072] In some embodiments, the distance between the fuse structure g and the welding point is H3, and H3≥5mm.

[0073] In the above embodiment, if the distance between the fuse structure g and the welding point is too close, the fuse structure g may fail during welding of the welding point.

[0074] In some embodiments, the branch connection portion 121 is an FPC branch structure packaged by a hot pressing film, and 0.2≤R / W1≤2.

[0075] In the above embodiment, the hardness of the branch encapsulated by the hot pressing film is enhanced and the probability of warping is reduced, so R / W1 can be preferably 0.2, 1, or 2.

[0076] In some embodiments, the circuit board body 110 is an FFC main layer structure, and the peeling force after welding the FPC branch structure and the FFC main layer structure is F, then F≥8N.

[0077] In the above-mentioned embodiment, if the peeling force is too small, the film is easily peeled off.

[0078] In summary, in some embodiments, the present invention provides a circuit board assembly 100 for a battery device, which uses FFC (tinned copper) as the circuit board body 110, uses FPC (etched copper wire) as the branch structure 120, and is then packaged with a fixing plate 130; the overall softness of the FFC is taken into account, and the production cost is reduced; at the same time, the fuse structure g formed by the etched FPC is located closer to the sampling part 122, which is safer and will not generate sparks; moreover, a stacked main layer can be formed, such as the upper and lower layers of FFC to collect batteries on both sides, and form a two-layer plug-in structure that is directly plugged into the BMS, thereby reducing the overall width of the wiring harness and adapting to more space inside the battery pack.

[0079] It should be noted that the embodiments of the present invention only describe the structure of the circuit board assembly 100 for a battery device that is related to the improvement points of the present application, but it does not mean that it does not have other structures. For example, the circuit board assembly 100 for a battery device also includes a connector seat 140 electrically plugged into the circuit board body 110, and / or a battery aluminum row 150 electrically connected to the sampling portion 122, etc. Other structures will not be described one by one here.

[0080] In particular, the term "and / or" in the present invention should be understood as follows:

[0081] In the first case, the term "and / or" located between a first subject and a second subject includes any one of the following meanings: (1) only the first subject; (2) only the second subject; and (3) the first subject and the second subject.

[0082] In the second case, the term "and / or" between the last two subjects among three or more subjects means including at least any one of the multiple subjects. For example, "the first subject, the second subject and / or the third subject" has the same meaning as "the first subject and / or the second subject and / or the third subject", specifically including the following combinations: (1) only the first subject; (2) only the second subject; (3) only the third subject; (4) the first subject and the second subject but not the third subject; (5) the first subject and the third subject but not the second subject; (6) the second subject and the third subject but not the first subject; and (7) the first subject, the second subject and the third subject.

[0083] In addition, although the above content describes the embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art can also make various modifications and variations without departing from the concept of the present invention, and such modifications and variations all fall within the scope of protection of the present invention.

Claims

1. A circuit board assembly for a battery device, characterized in that: include: A circuit board body (110), the circuit board body (110) comprising a plurality of wires (111) arranged in parallel, the wires (111) comprising a first metal and a second metal coated on an outer surface of the first metal, the second metal having a lower hardness than the first metal; A branch structure (120), the branch structure (120) comprising a branch connection portion (121) formed of the first metal and a sampling portion (122) connected to the branch connection portion (121), the sampling portion (122) being used to collect battery information; the branch connection portion (121) is provided with at least two rows of through holes (a) along the arrangement direction of the plurality of wires (111), the positions of the through holes (a) corresponding to the positions of the wires (111), a welding spot formed in at least one of the through holes (a), the welding spot being welded to the wire (111); A fixing plate (130), the fixing plate (130) covering the surface of the solder joint and fixedly connected to the branch connection portion (121), the size of the fixing plate (130) along the arrangement direction of the plurality of wires (111) being W1, the size of the through hole (a) along the arrangement direction of the plurality of wires (111) being R, and 0.01≤R / W1≤2.

2. The circuit board assembly for a battery device according to claim 1, characterized in that: The distance between the wire (111) provided with the welding point and the adjacent wire (111) is H1, and 0.3 mm≤H1≤2 mm.

3. The circuit board assembly for a battery device according to claim 1, characterized in that: Each of the branch connection portions (121) is provided with a plurality of rows of through holes (a) along the extension direction of the conductive wire (111).

4. The circuit board assembly for a battery device according to claim 3, characterized in that: The dimension of the branch connection portion (121) along the extension direction of the wire (111) is L1, and the dimension of the fixing plate (130) along the extension direction of the wire (111) is L2, and then 0.01≤L1 / L2≤1.

5. The circuit board assembly for a battery device according to claim 3, characterized in that: Along the extension direction of the conductive wire (111), the spacing between two adjacent rows of through holes (a) is P, and 0.5 mm ≤ P ≤ 1.5 mm.

6. The circuit board assembly for a battery device according to claim 5, characterized in that: The thickness of the fixing plate (130) is d, then d≥0.03 mm, and P≤1.2 mm.

7. The circuit board assembly for a battery device according to claim 1, characterized in that: The width of the conductive line (111) is W2, then 0.5≤R / W2≤2.

8. The circuit board assembly for a battery device according to claim 1, characterized in that: The thickness of the fixing plate (130) is d, then 0.03 mm≤d≤0.1 mm, and 0.0006≤d / W1≤0.

05.

9. The circuit board assembly for a battery device according to claim 8, characterized in that: The dimension of the branch connection portion (121) along the arrangement direction of the plurality of wires (111) is W2, then W2≤W1, and 0.03mm≤d≤0.06mm.

10. The circuit board assembly for a battery device according to claim 8, characterized in that: The branch connection portion (121) is provided with the fixing plates (130) at both ends in the thickness direction thereof, respectively, and 0.03 mm ≤ d ≤ 0.05 mm.

11. The circuit board assembly for a battery device according to claim 1, characterized in that: The fixing plate (130) is bonded and fixed to the branch connection portion (121) and the circuit board body (110).

12. The circuit board assembly for a battery device according to claim 1, characterized in that: The plurality of conductive wires (111) are respectively connected to the plurality of branch connection portions (121) in a one-to-one correspondence, and each branch connection portion (121) is welded to the conductive wire (111) via a welding point formed by a through hole (a) corresponding to a conductive wire (111) thereon.

13. The circuit board assembly for a battery device according to claim 12, characterized in that: The fixing plate (130) covers a plurality of welding points on the branch connection parts (121).

14. The circuit board assembly for a battery device according to claim 1, characterized in that: The circuit board body (110) comprises a first main body layer (B1) and a second main body layer (B2) which are stacked, and the first main body layer (B1) is connected to a first branch structure (E1), and the second main body layer (B2) is connected to a second branch structure (E2); The first branch structure (E1) and the second branch structure (E2) are distributed on both sides of the extension direction of the circuit board body (110).

15. The circuit board assembly for a battery device according to claim 14, characterized in that: The first main body layer (B1) and the second main body layer (B2) are arranged between two layers of the fixing plates (130), and the total thickness between the two layers of the fixing plates (130) is D, and D is ≤150 μm.

16. The circuit board assembly for a battery device according to claim 1, characterized in that: The electrical conductivity of the first metal is greater than the electrical conductivity of the second metal, and the thickness of the first metal is d1, and the thickness of the second metal is d2, then 1≤d1 / d2≤2.

5.

17. The circuit board assembly for a battery device according to claim 1, characterized in that: The melting point of the first metal is greater than the melting point of the second metal, and 0.1≤R / W1≤2.

18. The circuit board assembly for a battery device according to claim 1, characterized in that: The branch structure (120) is provided with a fuse structure (g).

19. The circuit board assembly for a battery device according to claim 18, characterized in that: A buffer arm (123) is provided between the branch connection portion (121) and the sampling portion (122); the fuse structure (g) is provided on the buffer arm (123); the minimum distance between the fuse structure (g) and the sampling portion (122) is H2, and 1mm≤H2≤25mm.

20. The circuit board assembly for a battery device according to claim 19, characterized in that: The distance between the fuse structure (g) and the welding point is H3, and H3 is ≥ 5 mm.

21. The circuit board assembly for a battery device according to any one of claims 1 to 20, characterized in that: The branch connection portion (121) is an FPC branch structure formed by hot pressing film packaging, and 0.2≤R / W1≤2.

22. The circuit board assembly for a battery device according to claim 21, characterized in that: The circuit board body (110) is an FFC main layer structure, and the peeling force after welding the FPC branch structure and the FFC main layer structure is F, then F≥8N.

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