Battery management system and battery pack

Abstract

The utility model relates to the technical field of batteries, and provides a battery management system and a battery pack. The battery management system includes a circuit board and a busbar. The circuit board is provided with a connecting hole. The busbar includes a body portion and a connection portion. The connecting part and the body part are arranged at an angle. The connecting part passes through the connecting hole from the first side of the circuit board and is welded with the circuit board at the second side of the circuit board. Therefore, the welding difficulty can be reduced, and the welding strength is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery management system and a battery pack. Background Technology

[0002] In related technologies, battery management systems typically include a circuit board and busbars. The circuit board is primarily used for signal processing, logic control, and communication, enabling functions such as battery status monitoring, battery protection, and communication interaction. The busbars are mainly used for power transmission, enabling functions such as current collection and distribution, and low-impedance conductivity. Busbar pins are typically connected to the circuit board via soldering. The traditional method involves drilling holes in the circuit board, inserting the pins through the holes from the front, and soldering them on the same side. However, this soldering method is not only difficult to operate but also prone to insufficient solder strength. Utility Model Content

[0003] The present invention provides a battery management system and battery pack that facilitates welding operations and improves welding strength.

[0004] In a first aspect, embodiments of the present invention provide a battery management system, comprising:

[0005] The circuit board has connection holes;

[0006] The busbar includes a body and a connecting part, the connecting part being angled to the body, the connecting part passing through the connecting hole from a first side of the circuit board and being soldered to the circuit board on a second side of the circuit board.

[0007] In one embodiment, the connecting portion includes a through section extending out of the connecting hole, the connecting portion is welded to the circuit board to form a welding portion, the welding portion includes a first welding layer connected to the through section, the height of the first welding layer being H2, satisfying: 1 mm ≤ H2 ≤ 2 mm.

[0008] In one embodiment, the first weld layer is tapered along the direction from the first side to the second side.

[0009] In one embodiment, the connecting portion further includes a connecting segment located within the connecting hole, the connecting segment being connected to the through-section, wherein the connecting segment is spaced apart from the hole wall surface of the connecting hole.

[0010] In one embodiment, the welded portion further includes:

[0011] The second welding layer is connected between the connecting segment and the hole wall of the connecting hole, and the second welding layer is connected to the first welding layer.

[0012] In one embodiment, the distance between the connecting segment and the wall of the connecting hole is D1, which satisfies: 0 < D1 ≤ 0.4 mm.

[0013] In one embodiment, the distance between the connecting segment and the wall of the connecting hole is D1;

[0014] Wherein, the width of the connecting segment is D2, which satisfies that D1 and D2 are positively correlated;

[0015] And / or, the cross-sectional area of ​​the connecting segment in the plane parallel to the circuit board is S, satisfying that D1 is positively correlated with S.

[0016] In one embodiment, the distance between the connecting segment and the wall of the connecting hole is D1, the number of connecting parts is set to N, and the connecting parts correspond one-to-one with the connecting holes, wherein N≥1 and N is an integer, satisfying that D1 is positively correlated with N.

[0017] In one embodiment, the distance between the connecting segment and the wall of the connecting hole is D1, the connecting parts are spaced at least two, the connecting parts correspond one-to-one with the connecting holes, and the distance between two adjacent connecting parts is D3, satisfying that D1 and D3 are positively correlated.

[0018] In one embodiment, the body portion is spaced apart from the circuit board, and the welding portion further includes a third welding layer located between the facing surfaces of the body portion and the circuit board, wherein the third welding layer is connected to the end of the second welding layer away from the first welding layer.

[0019] In one embodiment, the circuit board is provided with pads, which are arranged around the connection hole. The connection portion is welded to the circuit board to form a welding portion, and the welding portion is connected to the pads.

[0020] In one embodiment, the connection hole spacing is set to at least two, and each connection hole is connected to a corresponding pad, wherein the spacing between each two adjacent pads is D4, satisfying: D4≥0.5 mm.

[0021] In one embodiment, the pad includes:

[0022] The first main body is located on the first side of the circuit board;

[0023] The second main body is circumferentially disposed on the wall surface of the connecting hole, and the second main body is connected to the first main body;

[0024] A third main body is disposed on the second side of the circuit board, and the third main body is connected to the end of the second main body away from the first main body.

[0025] In one embodiment, the connecting portion includes a protruding section extending out of the connecting hole and a connecting section located within the connecting hole, and the welding portion includes:

[0026] The first welding layer is connected to the through section and the third main body;

[0027] The second welding layer is located between the connecting section and the second main body, and the second welding layer is connected to the first welding layer;

[0028] The third welding layer is located between the body portion and the third main body portion, and the third welding layer is connected to the end of the second welding layer away from the first welding layer.

[0029] In one embodiment, the outer edge of the first weld layer does not exceed the outer edge of the third main body portion;

[0030] And / or, the outer edge of the third weld layer does not exceed the outer edge of the first main body portion.

[0031] In one embodiment, the width of the first main body is D5, which satisfies: D5≥1 mm;

[0032] And / or, the width of the third main body is D6, satisfying: D6≥1 mm.

[0033] In one embodiment, the connection surface between the connecting portion and the main body portion is set as an arc surface.

[0034] In one embodiment, the bus includes a positive input bus and a positive output bus, the positive input bus and the positive output bus are spaced apart on the circuit board, the circuit board is provided with a MOSFET, the MOSFET is located between the positive input bus and the positive output bus, and the opposite ends of the MOSFET are electrically connected to the positive input bus and the positive output bus, respectively.

[0035] And / or, the busbar includes a negative input busbar and a negative output busbar, the negative input busbar and the negative output busbar are spaced apart on the circuit board, the circuit board is provided with a shunt, the shunt is located between the negative input busbar and the negative output busbar, and the opposite ends of the shunt are electrically connected to the negative input busbar and the negative output busbar respectively.

[0036] In one embodiment, the body portion is provided with mounting holes configured to connect a battery module or a top cover.

[0037] Secondly, embodiments of the present invention provide a battery pack, including the battery management system as described above.

[0038] The beneficial effects of the embodiments of this utility model are as follows:

[0039] In embodiments of this invention, by forming connection holes on the circuit board, the bus includes a body and a connecting portion. The body can be held by hand or clamped using a jig, robotic arm, etc., thereby efficiently and conveniently passing the connecting portion through the connection hole from the first side of the circuit board, improving the pre-assembly efficiency of the bus and the circuit board. The connecting portion is soldered to the circuit board on the second side. When the soldering gun is soldering the connecting portion, the body will not interfere with the operation of the soldering gun, thereby reducing the soldering difficulty. Furthermore, the soldering gun can ensure that the molten solder sprayed from the soldering nozzle completely covers the connecting portion, thereby improving the soldering strength and current carrying capacity. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the battery management system provided in an embodiment of the present invention;

[0042] Figure 2 This is a top view of the battery management system provided in an embodiment of the present invention;

[0043] Figure 3 This is a top view of the circuit board provided in an embodiment of this utility model;

[0044] Figure 4 This is a schematic diagram of the busbar structure provided in an embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of a partial connection structure between the busbar and the circuit board before soldering, provided in an embodiment of this utility model.

[0046] Figure 6 This is one of the schematic diagrams of a partial connection structure between the busbar and the circuit board after soldering, provided in an embodiment of this utility model;

[0047] Figure 7 This is the second schematic diagram of the partial connection structure between the busbar and the circuit board after soldering, provided in an embodiment of this utility model.

[0048] Explanation of reference numerals in the attached figures:

[0049] 1. Circuit board; 11. Connecting holes;

[0050] 2. Busbar; 21. Connecting part; 211. Through section; 212. Connecting section; 22. Mounting hole; 23. Body part;

[0051] 3. Welding section; 31. First weld layer; 32. Second weld layer; 33. Third weld layer;

[0052] 4. Solder pads; 41. First main body section; 42. Second main body section; 43. Third main body section;

[0053] 51. Positive input busbar; 52. Positive output busbar; 53. Negative input busbar; 54. Negative output busbar; 55. MOSFET; 56. Shunt. Detailed Implementation

[0054] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0055] like Figures 1 to 7 As shown, this application embodiment provides a battery management system. The battery management system includes a circuit board 1 and a busbar 2. The circuit board 1 has a connection hole 11. The busbar 2 includes a body portion 23 and a connecting portion 21. The connecting portion 21 is angled to the body portion 23. The connecting portion 21 passes through the connection hole 11 from a first side of the circuit board 1 and is soldered to the circuit board 1 on a second side of the circuit board 1.

[0056] In this embodiment, by forming a connection hole 11 on the circuit board 1, the busbar 2 includes a body portion 23 and a connecting portion 21. The body portion 23 can be held by hand or clamped using a jig, robotic arm, etc., thereby efficiently and conveniently passing the connecting portion 21 through the connection hole 11 from the first side of the circuit board 1, improving the pre-assembly efficiency of the busbar 2 and the circuit board 1. The connecting portion 21 is soldered to the circuit board 1 on the second side. When the soldering gun is soldering the connecting portion 21, the body portion 23 will not interfere with the operation of the soldering gun, thereby reducing the soldering difficulty. Furthermore, the soldering gun can ensure that the molten solder sprayed from the soldering nozzle can completely cover the connecting portion 21, thereby improving the soldering strength and current carrying capacity.

[0057] In some embodiments, to facilitate the insertion of the connecting portion 21, the end of the connecting portion 21 away from the body portion 23 may be configured as tapered. For example, the end of the connecting portion 21 away from the body portion 23 may be configured as a pyramid or frustum shape.

[0058] In some embodiments, the busbar 2 is integrally bent or integrally stamped to form a body portion 23 and a connecting portion 21 that are angled together. For example, the connecting portion 21 is perpendicular to the body portion 23. Alternatively, the connecting portion 21 is at an obtuse angle to the body portion 23. Alternatively, the connecting portion 21 is at an acute angle to the body portion 23.

[0059] In some embodiments, the connection portion 21 is soldered to the circuit board 1 by wave soldering. By using wave soldering to solder the connection portion 21 to the circuit board 1, compared to reflow soldering, the resulting solder joint 3 can fill the gap between them, and molten solder can overflow from the second side to the first side through the gap, so that the solder joint 3 can effectively connect the body portion 23 and the circuit board 1 on both opposite sides of the circuit board 1. This significantly improves the soldering strength and current carrying capacity.

[0060] like Figure 5 As shown, in some embodiments, the connecting portion 21 includes a protruding section 211 that extends through the connecting hole 11. The height of the protruding section 211 is H1, satisfying: 1 mm ≤ H1 ≤ 2 mm.

[0061] Understandably, during the soldering process, the soldering gun nozzle is fitted onto the through-hole section 211, and then solder is applied outwards. The molten solder adheres to the through-hole section 211 and the circuit board 1 before solidifying, thus achieving soldering between the connection part 21 and the circuit board 1. Setting the height H1 of the through-hole section 211 to between 1 mm and 2 mm ensures soldering strength while preventing insufficient solder coating.

[0062] When the height H1 of the through-section 211 is less than 1 mm, the height of the through-section 211 is too small, resulting in a small soldering area and insufficient soldering strength. Simultaneously, it causes the solder layer on the side of the through-section 211 furthest from the circuit board 1 to be too tall, making it easier for air bubbles to form inside this solder layer, affecting the current flow of the busbar 2, and making the solder layer more prone to solder spikes. When solder spikes appear in the solder layer, they easily detach and form solder balls that can roll around on the surface of the circuit board 1. If a solder ball rolls between two adjacent components and forms an electrical connection, it will cause a short circuit between the two adjacent components. Alternatively, if a solder ball rolls between two pins of a component, it will cause a short circuit in that single component.

[0063] When the height H1 of the through-hole section 211 is greater than 2 mm, the height of the through-hole section 211 is too large. Since the height of the solder nozzle for the same product is usually fixed, the height of the solder layer covering the through-hole section 211 will be too thin, resulting in insufficient solder coating and affecting the soldering effect. At the same time, it will also cause the distance between the through-hole section 211 and the metal part below the circuit board 1 to be too small, resulting in insufficient electrical clearance between the through-hole section 211 and the metal part below the circuit board 1. This may cause the through-hole section 211 to come into contact with the circuit board 1 due to vibration, processing errors, cumulative assembly errors, etc., resulting in a short circuit.

[0064] In some embodiments, the height H1 of the protruding section 211 is set to 1 mm, 1.5 mm, 2 mm, or any value between the two.

[0065] like Figure 6 and Figure 7 As shown, in some embodiments, the connecting portion 21 is soldered to the circuit board 1 to form a solder portion 3. The solder portion 3 includes a first solder layer 31 connected to the through section 211. The height of the first solder layer 31 is H2, satisfying: 1 mm ≤ H2 ≤ 2 mm.

[0066] It is understandable that the first welding layer 31 of the welding part 3 formed by welding the connecting part 21 to the circuit board 1 will completely cover the through section 211 in the height direction. Thus, the first welding layer 31 can completely cover the periphery of the through section 211, ensuring a good welding effect.

[0067] When the height H2 of the first welding layer 31 is less than 1 mm, the height of the first welding layer 31 is too small, resulting in a small welding area and insufficient welding strength. When the height H2 of the first welding layer 31 is greater than 2 mm, the height of the first welding layer 31 is too large, resulting in a small gap between the first welding layer 31 and the metal part below the circuit board 1. This leads to insufficient electrical clearance between the first welding layer 31 and the metal part below the circuit board 1, which may cause the first welding layer 31 to come into contact with the circuit board 1 due to vibration, processing errors, cumulative assembly errors, etc., resulting in a short circuit.

[0068] In some embodiments, the height H2 of the first weld layer 31 is set to 1 mm, 1.5 mm, 2 mm, or any value between the two.

[0069] In some embodiments, the height H2 of the first solder layer 31 is greater than or equal to the height H1 of the through-hole section 211. When the height H2 of the first solder layer 31 is equal to the height H1 of the through-hole section 211, the first solder layer 31 completely covers the outer surface of the through-hole section 211. On the side away from the circuit board 1, the first solder layer 31 is flush with the through-hole section 211. This ensures the soldering effect between the through-hole section 211 and the circuit board 1, reducing the problem of reduced current carrying capacity caused by poor soldering such as voids in the first solder layer 31. When the height H2 of the first solder layer 31 is greater than the height H1 of the through-hole section 211, the first solder layer 31 also covers the surface of the through-hole section 211 away from the circuit board 1. This improves the soldering strength between the through-hole section 211 and the circuit board 1, ensuring reliable soldering of the through-hole section 211 by the soldering nozzle.

[0070] In some embodiments, the following condition is satisfied: H2-H1≤0.2 mm.

[0071] Understandably, when the difference between the height H2 of the first solder layer 31 and the height H1 of the through section 211 exceeds 0.2 mm, the height of the first solder layer 31 on the side of the through section 211 away from the circuit board 1 will be too large. In this case, air bubbles are more likely to form inside the first solder layer 31, affecting the current flow of the busbar 2. Furthermore, an excessively thick first solder layer 31 is also prone to solder spikes. When solder spikes appear in the first solder layer 31, they are easy to fall off and form solder balls that can roll around on the surface of the circuit board 1. If a solder ball rolls between two adjacent components and forms an electrical connection between them, it will cause a short circuit between the two adjacent components. Alternatively, if a solder ball rolls between two pins of a component, it will cause a short circuit in that single component.

[0072] In some embodiments, the height of the first weld layer 31 above H2 is equal to the height of the through section 211 above H1.

[0073] In some embodiments, the height H2 of the first weld layer 31 is 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm higher than the height H1 of the through section 211, or any value between the two.

[0074] Please continue reading. Figure 6 and Figure 7 In some embodiments, the first weld layer 31 is tapered along the direction from the first side to the second side.

[0075] It is understandable that the direction from the first side to the second side is the extension direction of the through-section 211, and the direction perpendicular to the extension direction of the through-section 211 is the thickness direction of the first solder layer 31. The first solder layer 31 tapers along the direction from the busbar 2 to the circuit board 1. Since the through-section 211 is not gradual, the thickness of the first solder layer 31 decreases. Therefore, the thickness of the first solder layer 31 is greatest near the circuit board 1, ensuring good soldering strength and current flow between the circuit board 1 and the through-section 211; the thickness of the first solder layer 31 is smallest away from the circuit board 1, reducing the possibility of air bubbles forming inside the first solder layer 31 and preventing solder spikes from appearing in the first solder layer 31.

[0076] It should be noted that the first solder layer 31 can be tapered based on the design of the solder nozzle. Alternatively, the tapering of the first solder layer 31 can be achieved through the combined effects of gravity and the surface tension between the molten solder and the connecting section 212 and the solder pad 4.

[0077] It should be noted that the first side and the second side are opposite sides of the circuit board 1. For example, the first side is the front side of the circuit board 1, and the second side is the back side of the circuit board 1.

[0078] In some embodiments, the cross-section of the through-hole section 211 is square along the extension direction perpendicular to the through-hole section 211. In this case, the first weld layer 31 is annular along the extension direction perpendicular to the through-hole section 211. Alternatively, the cross-section of the through-hole section 211 is circular along the extension direction perpendicular to the through-hole section 211. In this case, the first weld layer 31 is annular along the extension direction perpendicular to the through-hole section 211.

[0079] Please continue reading. Figures 5 to 7 In some embodiments, the connecting portion 21 further includes a connecting segment 212 located within the connecting hole 11. The connecting segment 212 is connected to the through portion 211. The connecting segment 212 is spaced apart from the wall surface of the connecting hole 11.

[0080] Based on the spacing between the connecting section 212 and the hole wall of the connecting hole 11, when the soldering nozzle is sleeved on the through section 211 and solder is dispensed, some of the molten solder will adhere to the surface of the through section 211, and some of the molten solder will overflow into the gap between the connecting section 212 and the hole wall of the connecting hole 11, thereby improving the soldering strength between the connecting part 21 and the circuit board 1.

[0081] In some embodiments, the welding part 3 further includes a second welding layer 32 connected between the connecting section 212 and the hole wall of the connecting hole 11. The second welding layer 32 is connected to the first welding layer 31.

[0082] Understandably, based on the spacing between the connecting segment 212 and the hole wall of the connecting hole 11, when the soldering nozzle is sleeved on the through segment 211 and solder is dispensed, some of the molten solder will adhere to the surface of the through segment 211, and some of the molten solder will overflow into the gap between the connecting segment 212 and the hole wall of the connecting hole 11, forming a second solder layer 32 between the connecting segment 212 and the hole wall of the connecting hole 11. This second solder layer 32 connects the connecting segment 212 and the connecting hole 11, increasing the connection area between the connecting part 21 and the circuit board 1 and improving the reliability of the soldering.

[0083] It should be noted that the second solder layer 32 also allows the connecting section 212 to directly form an electrical connection with the copper layer between the layers of the circuit board 1. Therefore, the busbar 2 can conduct current to the circuit board 1 through the connecting part 21, eliminating the need for current conduction between the layers of the circuit board 1. Since the impedance of the circuit board 1 conducting current across the various functional layers along its thickness direction to the copper layer is significantly greater than the impedance of the path through which the connecting section 212 directly conducts current to the copper layer of the circuit board 1, the current carrying capacity is improved. Thus, both soldering strength and current carrying capacity are improved.

[0084] In some embodiments, the cross-section of the connecting segment 212 is square. In this case, the connecting hole 11 is a square hole, and the second welding layer 32 is a square annular shape. Alternatively, the cross-section of the connecting segment 212 is circular. In this case, the connecting hole 11 is a circular hole, and the second welding layer 32 is an annular shape.

[0085] It should be noted that the connecting segment 212 and the through segment 211 have the same cross-sectional dimensions. Based on the spacing between the connecting segment 212 and the wall of the connecting hole 11, it is also convenient for the through segment 211 and the connecting segment 212 to pass through the connecting hole 11, preventing the through segment 211 from failing to pass through the connecting hole 11 due to insufficient size. In this embodiment, the gap between the connecting segment 212 and the wall of the connecting hole 11 is filled using the second solder layer 32, which can prevent insufficient solder filling between them from causing excessive impedance in the connection area. Excessive impedance at this location can lead to severe heat generation, causing product functional degradation or even damage.

[0086] Since both the first welding layer 31 and the second welding layer 32 are formed by solidifying molten tin, the first welding layer 31 and the second welding layer 32 are integrally formed.

[0087] Please continue reading. Figure 5 In some embodiments, the distance between the connecting segment 212 and the hole wall of the connecting hole 11 is D1, which satisfies: 0 < D1 ≤ 0.4 mm.

[0088] Understandably, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is greater than 0 to ensure that there is a gap between them. This facilitates the insertion of the through segment 211 and the connecting segment 212 through the connecting hole 11, and allows molten tin to penetrate into the gap, thereby forming the second solder layer 32. The distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is less than or equal to 0.4 mm to prevent the second solder layer 32 from being too thick and forming air bubbles inside, which would affect the current flow effect, impedance, and solder strength.

[0089] It is understandable that the distance D1 between the connecting section 212 and the wall of the connecting hole 11 corresponds to the difference between the inner and outer diameters of the second welding layer 32, i.e., the thickness of the second welding layer 32. If the distance D1 between the connecting section 212 and the wall of the connecting hole 11 is greater than 0.4 mm, on the one hand, it will cause the thickness of the second welding layer 32 to be too large, resulting in air bubbles inside, affecting the current flow effect, impedance, and welding strength. On the other hand, it will also make it more difficult to align the connecting part 21 with the connecting hole 11, making it difficult to install the busbar 2 in the preset position on the circuit board 1, resulting in excessive installation error of the busbar 2, which will affect the subsequent installation of the battery management system.

[0090] In some embodiments, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or any value between the two.

[0091] In some embodiments, the distance between the connecting segment 212 and the wall of the connecting hole 11 is D1. The width of the connecting segment 212 is D2, satisfying that D1 and D2 are positively correlated.

[0092] Understandably, the larger the width of the connecting segment 212, the larger the size of the connecting hole 11, and the greater the manufacturing tolerances for both during production. Therefore, increasing the distance between the connecting segment 212 and the wall of the connecting hole 11 ensures that both the through segment 211 and the connecting segment 212 can be inserted into the connecting hole 11. For example, the width D2 of the connecting segment 212 is set to 7 mm, and the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.2 mm. Alternatively, the width D2 of the connecting segment 212 can be set to 10 mm, and the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 can be set to 0.3 mm.

[0093] It should be noted that the width direction of the connecting segment 212 can be the width direction of the circuit board 1. Alternatively, the width direction of the connecting segment 212 can also be the length direction of the circuit board 1.

[0094] In some embodiments, the distance between the connecting segment 212 and the wall of the connecting hole 11 is D1. The cross-sectional area of ​​the connecting segment 212 in the plane parallel to the circuit board 1 is S, satisfying that D1 is positively correlated with S.

[0095] Understandably, in the direction parallel to the plane of circuit board 1, the larger the cross-sectional area of ​​the connecting segment 212, the larger the size of the connecting hole 11, and the greater the manufacturing tolerances for both during production. Therefore, a larger distance between the connecting segment 212 and the wall of the connecting hole 11 ensures that both the through segment 211 and the connecting segment 212 can pass through the connecting hole 11. For example, if the cross-sectional area S of the connecting segment 212 is set to 80 square millimeters, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.2 millimeters. If the cross-sectional area S of the connecting segment 212 is set to 100 square millimeters, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.3 millimeters.

[0096] It should be noted that the connecting segment 212 can be square or circular. When the connecting segment 212 is square, it is consistent with the positive correlation between the width of the connecting segment 212 and the diameter of the connecting segment 212 in the previous embodiment. When the connecting segment 212 is circular, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is positively correlated with the diameter of the connecting segment 212.

[0097] In some embodiments, the distance between the connecting segment 212 and the wall surface of the connecting hole 11 is D1. The number of connecting parts 21 is set to N. Each connecting part 21 corresponds to a connecting hole 11. Wherein, N≥1, and N is an integer, satisfying that D1 is positively correlated with N.

[0098] It is understandable that the number of connecting parts 21 corresponds one-to-one with the number of connecting holes 11. The more connecting parts 21 there are, the more connecting holes 11 there are. During manufacturing, there is a cumulative tolerance between the multiple connecting parts 21 and the multiple connecting holes 11; the more connecting parts 21 there are, the larger the cumulative tolerance becomes. In this case, making the distance between the connecting segment 212 and the wall of the connecting hole 11 larger ensures that the through segment 211 and the connecting segment 212 can be inserted into the connecting hole 11. For example, if the number of connecting parts 21 is set to 5, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.1 mm. If the number of connecting parts 21 is set to 8, the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.2 mm.

[0099] like Figure 3 As shown, in some embodiments, the distance between the connecting segment 212 and the wall surface of the connecting hole 11 is D1. The connecting portions 21 are spaced at least two apart. Each connecting portion 21 corresponds one-to-one with a connecting hole 11. The distance between two adjacent connecting portions 21 is D3, satisfying the condition that D1 and D3 are positively correlated.

[0100] It is understandable that the number of connecting parts 21 corresponds one-to-one with the number of connecting holes 11. The larger the distance D3 between two adjacent connecting parts 21, the larger the distance between two adjacent connecting holes 11. During manufacturing, the tolerance for a larger distance will be greater than the tolerance for a smaller distance. In this case, making the distance between the connecting segment 212 and the wall of the connecting hole 11 larger ensures that the through segment 211 and the connecting segment 212 can be inserted into the connecting hole 11. For example, the distance D3 between two adjacent connecting parts 21 is set to 2 mm, and the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.1 mm. The distance D3 between two adjacent connecting parts 21 is set to 4 mm, and the distance D1 between the connecting segment 212 and the wall of the connecting hole 11 is set to 0.2 mm.

[0101] Please continue reading. Figure 6 and Figure 7 In some embodiments, the body portion 23 is spaced apart from the circuit board 1. The soldering portion 3 further includes a third soldering layer 33 located between the facing surfaces of the body portion 23 and the circuit board 1. The third soldering layer 33 is connected to the end of the second soldering layer 32 away from the first soldering layer 31.

[0102] It is understandable that the connecting segment 212 and the hole wall of the connecting hole 11 are spaced apart, and the body 23 and the circuit board 1 are spaced apart. At this time, the gap between the connecting segment 212 and the hole wall of the connecting hole 11 can communicate with the gap between the body 23 and the circuit board 1. When the soldering nozzle is fitted onto the exit segment 211 and solder is dispensed, a portion of the molten solder will adhere to the surface of the exit segment 211, and a portion of the molten solder will overflow into the gap between the connecting segment 212 and the hole wall of the connecting hole 11, forming a second solder layer 32 between the connecting segment 212 and the hole wall of the connecting hole 11. Another portion of the molten solder will overflow into the gap between the body 23 and the circuit board 1, forming a third solder layer 33 between the body 23 and the circuit board 1. Thus, the third solder layer 33 can connect the body 23 and the circuit board 1, increasing the connection area between the connecting segment 21 and the circuit board 1 and improving the reliability of the soldering.

[0103] The first welding layer 31, the second welding layer 32, and the third welding layer 33 are all formed by solidifying molten tin, and the first welding layer 31, the second welding layer 32, and the third welding layer 33 are integrally formed.

[0104] The third welding layer 33 is located between the body part 23 and the circuit board 1, and the thickness of the third welding layer 33 is the same as the height of the gap between the body part 23 and the circuit board 1.

[0105] The third welding layer 33 is annular and is arranged around the connection hole 11 and the connection part 21. This further increases the connection area between the main body 23 and the circuit board 1, and between the connection part 21 and the circuit board 1, thereby improving the reliability of the welding.

[0106] like Figure 2 and Figure 6 As shown, in some embodiments, the circuit board 1 is provided with pads 4. The pads 4 are arranged around the connection holes 11. The connection portion 21 is soldered to the circuit board 1 to form a solder portion 3. The solder portion 3 is connected to the pads 4.

[0107] Understandably, the solder joint 3 is positioned between the pad 4 and the bus 2, and between the pad 4 and the connector 21, to achieve electrical connection between the bus 2 and the circuit board 1. Forming the solder joint 3 on the pad 4 ensures solder strength, guarantees a reliable solder joint, and provides good conductivity. If the solder joint 3 were formed directly on the circuit board 1, molten solder might diffuse across the circuit board 1. When this molten solder diffuses between other components, it could cause short circuits or bridging, resulting in electrical faults.

[0108] In some embodiments, if the connection hole 11 is a square hole, then the pad 4 is a square annular pad 4. Alternatively, if the connection hole 11 is a circular hole, then the pad 4 is a circular annular pad 4.

[0109] In some embodiments, the pad 4 may also have an isolation portion on its periphery away from the connection hole 11. The isolation portion can prevent molten solder from flowing out of the pad 4, further avoiding short circuits or bridging between components.

[0110] In some embodiments, the pad 4 may be made of materials such as copper, tin, tin-plated copper, tin-lead alloy, lead-free solder, nickel, etc.

[0111] Please continue reading. Figure 3 In some embodiments, the connection holes 11 are spaced at least two apart. Each connection hole 11 corresponds to a pad 4. The spacing between any two adjacent pads 4 is D4, which satisfies: D4 ≥ 0.5 mm.

[0112] Understandably, a bus 2 has multiple connectors 21, each connector 21 corresponding to a connector hole 11. To enable soldering of the connectors 21 to the circuit board 1, a solder pad 4 is provided at each connector hole 11. The spacing D4 between two adjacent solder pads 4 is greater than or equal to 0.5 mm to prevent adjacent solder joints 3 from sticking together. Sticking between adjacent solder joints 3 may cause electrical connections to components surrounding the solder joint 3. Furthermore, it can lead to solder waste due to solder buildup, affecting the aesthetics of the circuit board 1.

[0113] In some embodiments, the spacing D4 between any two adjacent pads 4 is the same. For example, D4 ​​can be set to 0.5 mm, 1 mm, 2 mm, etc.

[0114] In some embodiments, the spacing D4 between each pair of adjacent pads 4 is different. For example, D4 ​​can be set to 0.5 mm, 1 mm, 2 mm, etc.

[0115] like Figure 5 As shown, in some embodiments, the pad 4 includes a first body portion 41, a second body portion 42, and a third body portion 43. The first body portion 41 is disposed on a first side of the circuit board 1. The second body portion 42 is disposed around the wall of the connecting hole 11. The second body portion 42 is connected to the first body portion 41. The third body portion 43 is disposed on a second side of the circuit board 1. The third body portion 43 is connected to the end of the second body portion 42 away from the first body portion 41.

[0116] It is understood that the first side of circuit board 1 is the top surface (front side) of circuit board 1, and the second side of circuit board 1 is the bottom surface (back side) of circuit board 1. A first main body 41 is disposed on the front side of circuit board 1 and is used to connect the busbar 2 to the solder joint 3 on the front side of circuit board 1. A second main body 42 is disposed on the wall of the connecting hole 11 and is used to connect the connecting section 212 to the solder joint 3 on the wall of the connecting hole 11. A third main body 43 is disposed on the back side of circuit board 1 and is used to connect the through section 211 to the solder joint 3 on the back side of circuit board 1.

[0117] In some embodiments, the first main body portion 41, the second main body portion 42, and the third main body portion 43 are integrally formed.

[0118] In some embodiments, both the first main body portion 41 and the third main body portion 43 are configured in a U-shape. The inner edge dimensions of the first main body portion 41 and the third main body portion 43 are the same. The outer edge dimensions of the first main body portion 41 and the third main body portion 43 may be the same or different.

[0119] like Figure 6 and Figure 7 As shown, in some embodiments, the connecting portion 21 includes a through section 211 extending out of the connecting hole 11 and a connecting section 212 located within the connecting hole 11. The welding portion 3 includes a first welding layer 31, a second welding layer 32, and a third welding layer 33. The first welding layer 31 is connected to the through section 211 and the third main body portion 43. The second welding layer 32 is located between the connecting section 212 and the second main body portion 42. The second welding layer 32 is connected to the first welding layer 31. The third welding layer 33 is located between the main body portion 23 and the third main body portion 43. The third welding layer 33 is connected to the end of the second welding layer 32 away from the first welding layer 31.

[0120] Understandably, the first solder layer 31 covers the periphery of the through section 211 and is connected to the third main body 43 located on the back of the circuit board 1. The second solder layer 32 is used to connect the second main body 42 and the connecting section 212. The third solder layer 33 is used to connect the first main body 41 and the main body 23 located on the front of the circuit board 1. Thus, the top surface, back surface and the area of ​​the connecting hole 11 wall of the circuit board 1 can be soldered to the main body 23 and the connecting part 21, ensuring that the circuit board 1 and the busbar 2 have a sufficiently large soldering area, improving the soldering strength, and ensuring the reliability and stability of the soldering.

[0121] In some embodiments, the shape of the first welding layer 31 is adapted to the shape of the third main body portion 43, the shape of the second welding layer 32 is adapted to the shape of the second main body portion 42, and the shape of the third welding layer 33 is adapted to the shape of the first main body portion 41.

[0122] Please continue reading. Figure 6 and Figure 7 In some embodiments, the outer edge of the first weld layer 31 does not exceed the outer edge of the third body portion 43.

[0123] It is understandable that by ensuring that the outer edge of the first solder layer 31 does not exceed the outer edge of the third main body 43, solder can be prevented from overflowing from the third main body 43 and directly adhering to the surface of the circuit board 1. On the one hand, this avoids solder waste and improves the aesthetics of the product. On the other hand, it can prevent overflowing solder from forming solder balls or beads that roll on the circuit board 1 and cause short circuits in other components on the circuit board 1.

[0124] In some embodiments, the outer edge of the first weld layer 31 is flush with the outer edge of the third body portion 43.

[0125] In some embodiments, the outer edge of the first welding layer 31 is spaced apart from the outer edge of the third body portion 43.

[0126] Please continue reading. Figure 6 and Figure 7 In some embodiments, the outer edge of the third welding layer 33 does not exceed the outer edge of the first body portion 41.

[0127] It is understandable that by ensuring that the outer edge of the third solder layer 33 does not exceed the outer edge of the first main body 41, solder can be prevented from overflowing from the first main body 41 and directly adhering to the surface of the circuit board 1. On the one hand, this avoids solder waste and improves the aesthetics of the product. On the other hand, it can prevent overflowing solder from forming solder balls or beads that roll on the circuit board 1 and cause short circuits in other components on the circuit board 1.

[0128] In some embodiments, the outer edge of the third welding layer 33 is flush with the outer edge of the first body portion 41.

[0129] In some embodiments, the outer edge of the third welding layer 33 is spaced apart from the outer edge of the first body portion 41.

[0130] Please continue reading. Figure 6 and Figure 7 In some embodiments, the width of the first main body portion 41 is D5, which satisfies: D5≥1 mm.

[0131] Understandably, if the width D5 of the first main body portion 41 is less than 1 mm, molten solder can easily leak from the outer edge of the first main body portion 41 during the soldering process. This leaked solder may cause short circuits in surrounding components, or it may form solder balls or beads that roll on the circuit board 1, causing short circuits in other components on the circuit board 1. A width D5 of less than 1 mm also results in insufficient solder filler between the busbar 2 and the back of the circuit board 1, affecting soldering strength and reducing soldering reliability. Therefore, in this embodiment, the width D5 of the first main body portion 41 is greater than or equal to 1 mm to prevent molten solder from leaking from the outer edge of the first main body portion 41 and to ensure sufficient solder filler between the busbar 2 and the back of the circuit board 1, thus ensuring soldering strength.

[0132] In some embodiments, the width D5 of the first main body portion 41 is set to 1 mm, 1.5 mm, 2 mm, etc.

[0133] Please continue reading. Figure 6 and Figure 7 In some embodiments, the width of the third main body 43 is D6, which satisfies: D6≥1 mm.

[0134] Understandably, if the width D6 of the third main body 43 is less than 1 mm, molten solder will easily leak out from the outer edge of the third main body 43 after overflowing during the soldering process. This leaked solder may cause short circuits in surrounding components, or it may form solder balls or beads that roll on the circuit board 1, causing short circuits in other components. A width D6 of less than 1 mm will also result in insufficient solder filler between the busbar 2 and the front side of the circuit board 1, affecting soldering strength and reducing soldering reliability. Therefore, in this embodiment, the width D6 of the third main body 43 is greater than or equal to 1 mm to prevent molten solder from leaking out from the outer edge of the third main body 43 and to ensure sufficient solder filler between the busbar 2 and the front side of the circuit board 1, thus ensuring soldering strength.

[0135] In some embodiments, the width D6 of the third body portion 43 is set to 1 mm, 1.5 mm, 2 mm, etc.

[0136] like Figure 4 As shown, in some embodiments, the connection surface between the connecting portion 21 and the body portion 23 is set as an arc surface.

[0137] It is understandable that by setting the connecting surface between the connecting part 21 and the main body 23 as an arc surface, and considering the limitations of the actual processing technology, a gap can be formed between the main body 23 and the circuit board 1 after the connecting part 21 passes through the connecting hole 11. This gap can be used to accommodate the third solder layer 33, thereby ensuring reliable soldering between the main body 23 and the circuit board 1.

[0138] It should be noted that the curvature and arc length of the arc surface are positively correlated with the dimensions of the connecting part 21. The larger the cross-sectional area of ​​the connecting part 21, the larger the curvature and arc length of the arc surface can be.

[0139] like Figure 2 As shown, in some embodiments, bus 2 includes a positive input bus 51 and a positive output bus 52. The positive input bus 51 and the positive output bus 52 are spaced apart on circuit board 1. A MOSFET 55 is provided on circuit board 1. The MOSFET 55 is located between the positive input bus 51 and the positive output bus 52, and the opposite ends of the MOSFET 55 are electrically connected to the positive input bus 51 and the positive output bus 52, respectively.

[0140] Understandably, the two ends of the MOSFET 55 are electrically connected to the positive input busbar 51 and the positive output busbar 52, respectively, thereby carrying the large current conduction at the positive input and positive output of the battery management system. The MOSFET 55 can be soldered to the circuit board 1 via reflow soldering.

[0141] Please continue reading. Figure 2 In some embodiments, bus 2 includes a negative input bus 53 and a negative output bus 54. The negative input bus 53 and the negative output bus 54 are spaced apart on circuit board 1. Circuit board 1 is provided with a shunt 56. The shunt 56 is located between the negative input bus 53 and the negative output bus 54, and the opposite ends of the shunt 56 are electrically connected to the negative input bus 53 and the negative output bus 54, respectively.

[0142] It is understandable that the two ends of the shunt 56 are electrically connected to the negative input busbar 53 and the negative output busbar 54, respectively, thereby carrying the large current conduction of the negative input and negative output of the battery management system. The shunt 56 can be soldered to the circuit board 1 via reflow soldering.

[0143] In some embodiments, the positive input busbar 51, positive output busbar 52, negative input busbar 53, and negative output busbar 54 are all formed by stamping and bending of metal sheets, and can all be made of metals with high conductivity such as copper and aluminum. The number and cross-sectional dimensions of the connection portions 21 on each busbar can be selected based on the product's current output requirements, the number and distribution of MOSFETs 55.

[0144] Please continue reading. Figure 4 In some embodiments, the body portion 23 is provided with mounting holes 22. The mounting holes 22 are configured to connect a battery module or a top cover.

[0145] It is understandable that by providing mounting holes 22 on the main body 23 and connecting the busbar 2 to the battery module or top cover by passing fasteners through the mounting holes 22, it is not necessary to use fasteners to fix the circuit board 1. As a result, it is not necessary to make holes in the circuit board 1, and the installation efficiency of the circuit board 1 can be improved.

[0146] In some embodiments, the body 23 may have at least two mounting holes 22. The at least two mounting holes 22 are spaced apart. Each mounting hole 22 is fixed to the battery module or top cover by a fastener, thereby serving as a mechanical connection point between the circuit board 1 and the busbar 2, ensuring reliable fixation of the battery management system.

[0147] Specifically, the positive input busbar 51, the positive output busbar 52, the negative input busbar 53, and the negative output busbar 54 are all provided with mounting holes 22.

[0148] The positive input busbar 51 and the negative input busbar 53 are connected to the positive and negative terminals of the battery module through their respective mounting holes 22. This achieves electrical connection and mechanical fixation between the positive input busbar 51 and the positive terminal of the battery module, and electrical connection and mechanical fixation between the negative input busbar 53 and the negative terminal of the battery module.

[0149] The top cover is provided with a positive output terminal and a negative output terminal. The positive output busbar 52 and the negative output busbar 54 are respectively connected to the positive output terminal and the negative output terminal through their respective mounting holes 22. Thus, the positive output busbar 52 is electrically connected and mechanically fixed to the positive output terminal, and the negative output busbar 54 is electrically connected and mechanically fixed to the negative output terminal.

[0150] The positive input busbar 51, positive output busbar 52, negative input busbar 53, and negative output busbar 54 are electrically connected and mechanically fixed in the manner described above, so as to realize the charging and external discharge of the battery module. In the process of electrical connection of the busbar, the circuit board 1 is fixed to the battery module and the top cover of the battery pack, without the need to fix the circuit board 1 with screws.

[0151] The battery management system in this embodiment, based on the selection of the soldering position, the shape of the soldering part 3, and the selection of various dimensions, can effectively reduce the risks of solder bridging, solder spikes, and incomplete solder filling after soldering of the circuit board 1, thereby improving the yield rate and reducing production costs. At the same time, it can also effectively improve the soldering strength and enhance mechanical properties such as tensile strength and vibration resistance.

[0152] This application also provides a battery pack. The battery pack includes the battery management system as described in the foregoing embodiments.

[0153] By forming a connection hole 11 on the circuit board 1, the connection portion 21 of the busbar 2 passes through the connection hole 11 from the first side of the circuit board 1, and the connection portion 21 is soldered to the circuit board 1 on the second side of the circuit board 1. Therefore, when the soldering gun is soldering the connection portion 21, the busbar 2 will not interfere with the operation of the soldering gun, thereby reducing the soldering difficulty. Furthermore, the soldering gun can completely fit the solder nozzle onto the connection portion 21, allowing molten solder to completely cover the connection portion 21, thereby improving the soldering strength.

[0154] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery management system, characterized in that, include: The circuit board has connection holes; The busbar includes a body and a connecting part, the connecting part being angled to the body, the connecting part passing through the connecting hole from a first side of the circuit board and being soldered to the circuit board on a second side of the circuit board.

2. The battery management system according to claim 1, characterized in that, The connecting part includes a through section extending out of the connecting hole. The connecting part is welded to the circuit board to form a welding part. The welding part includes a first welding layer connected to the through section. The height of the first welding layer is H2, which satisfies: 1 mm ≤ H2 ≤ 2 mm.

3. The battery management system according to claim 2, characterized in that, Along the direction from the first side to the second side, the first weld layer is tapered.

4. The battery management system according to claim 2, characterized in that, The connecting part further includes a connecting segment located inside the connecting hole, the connecting segment being connected to the through section, wherein the connecting segment is spaced apart from the hole wall surface of the connecting hole.

5. The battery management system according to claim 4, characterized in that, The welding section also includes: The second welding layer is connected between the connecting segment and the hole wall of the connecting hole, and the second welding layer is connected to the first welding layer.

6. The battery management system according to claim 4, characterized in that, The distance between the connecting segment and the wall of the connecting hole is D1, which satisfies: 0 < D1 ≤ 0.4 mm.

7. The battery management system according to claim 4, characterized in that, The distance between the connecting segment and the wall of the connecting hole is D1; Wherein, the width of the connecting segment is D2, which satisfies that D1 and D2 are positively correlated; And / or, the cross-sectional area of ​​the connecting segment in the plane parallel to the circuit board is S, satisfying that D1 is positively correlated with S.

8. The battery management system according to claim 4, characterized in that, The distance between the connecting segment and the wall of the connecting hole is D1, and the number of connecting parts is set to N. The connecting parts correspond one-to-one with the connecting holes, where N≥1 and N is an integer, satisfying that D1 is positively correlated with N.

9. The battery management system according to claim 4, characterized in that, The distance between the connecting segment and the wall of the connecting hole is D1. The connecting parts are spaced at least two apart. The connecting parts correspond one-to-one with the connecting holes. The distance between two adjacent connecting parts is D3, satisfying that D1 and D3 are positively correlated.

10. The battery management system according to claim 5, characterized in that, The body portion is spaced apart from the circuit board, and the welding portion further includes a third welding layer located between the facing surfaces of the body portion and the circuit board, wherein the third welding layer is connected to the end of the second welding layer away from the first welding layer.

11. The battery management system according to any one of claims 1 to 10, characterized in that, The circuit board is provided with solder pads, which are arranged around the connection holes. The connection part is soldered to the circuit board to form a solder part, and the solder part is connected to the solder pads.

12. The battery management system according to claim 11, characterized in that, The connection holes are spaced at least two apart, and each connection hole is connected to a pad. The spacing between any two adjacent pads is D4, which satisfies the condition that D4 ≥ 0.5 mm.

13. The battery management system according to claim 11, characterized in that, The pads include: The first main body is located on the first side of the circuit board; The second main body is circumferentially disposed on the wall surface of the connecting hole, and the second main body is connected to the first main body; A third main body is disposed on the second side of the circuit board, and the third main body is connected to the end of the second main body away from the first main body.

14. The battery management system according to claim 13, characterized in that, The connecting portion includes a protruding section extending out of the connecting hole and a connecting section located within the connecting hole; the welding portion includes: The first welding layer is connected to the through section and the third main body; The second welding layer is located between the connecting section and the second main body, and the second welding layer is connected to the first welding layer; The third welding layer is located between the body portion and the third main body portion, and the third welding layer is connected to the end of the second welding layer away from the first welding layer.

15. The battery management system according to claim 14, characterized in that, The outer edge of the first weld layer does not exceed the outer edge of the third main body portion; And / or, the outer edge of the third weld layer does not exceed the outer edge of the first main body portion.

16. The battery management system according to claim 13, characterized in that, The width of the first main body is D5, which satisfies: D5≥1 mm; And / or, the width of the third main body is D6, satisfying: D6≥1 mm.

17. The battery management system according to any one of claims 1 to 10, characterized in that, The connection surface between the connecting part and the main body part is set as an arc surface.

18. The battery management system according to any one of claims 1 to 10, characterized in that, The busbar includes a positive input busbar and a positive output busbar, which are spaced apart on the circuit board. A MOSFET is provided on the circuit board, which is located between the positive input busbar and the positive output busbar, and the opposite ends of the MOSFET are electrically connected to the positive input busbar and the positive output busbar, respectively. And / or, the busbar includes a negative input busbar and a negative output busbar, the negative input busbar and the negative output busbar are spaced apart on the circuit board, the circuit board is provided with a shunt, the shunt is located between the negative input busbar and the negative output busbar, and the opposite ends of the shunt are electrically connected to the negative input busbar and the negative output busbar respectively.

19. The battery management system according to any one of claims 1 to 10, characterized in that, The main body has mounting holes configured to connect to a battery module or a top cover.

20. A battery pack, characterized in that, Includes the battery management system as described in any one of claims 1 to 19.

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