BMS heat dissipation structure and BMS assembly

Abstract

The utility model provides a BMS heat dissipation structure comprising a heat dissipation base body, and at least one part of the outer surface of the heat dissipation base body is coated with a graphene heat dissipation layer. The utility model further provides a BMS assembly, the BMS assembly comprises a BMS circuit board and the BMS heat dissipation structure, and the BMS heat dissipation structure is connected with the BMS circuit board. According to the BMS heat dissipation structure and the BMS assembly provided by the utility model, the graphene heat dissipation layer is coated on at least one part of the outer surface of the heat dissipation base body, and the heat conduction capability of the graphene is far higher than that of the heat dissipation base body made of an aluminum alloy material, so that the graphene attached to the outer surface of the aluminum alloy can obviously improve the heat dissipation capability of the heat dissipation base body; the BMS heat dissipation structure is improved, and the heat dissipation efficiency of the unit area is improved. Therefore, on the premise that the same heat dissipation efficiency is achieved, the size of the BMS heat dissipation structure can be reduced, and the equipment is more compact.

Description

Technical Field

[0001] This application relates to the field of electronic systems, and more specifically, to a BMS heat dissipation structure. Background Technology

[0002] A Battery Management System (BMS) is an electronic system used to monitor and manage battery packs, especially lithium-ion battery packs. BMS plays a central role in electric vehicles, hybrid vehicles, energy storage systems, portable electronic devices, and other applications requiring high-performance battery packs. Its main functions include: 1. Battery status monitoring, 2. Battery protection, 3. Balance management, 4. Communication, 5. Fault diagnosis and alarms, and 6. Thermal management.

[0003] The basic components of a Battery Management System (BMS) include: a BMS circuit board, a battery connector, a heat sink, battery voltage acquisition terminals, and battery temperature acquisition terminals. Because the MOSFETs in a BMS have internal resistance, they generate heat when a large current flows through them. If the temperature exceeds a certain value, the MOSFETs will be damaged, and the BMS will become ineffective. Therefore, proper heat dissipation for the BMS is crucial.

[0004] Traditional heat dissipation methods include adding heat sinks to heat-generating components and silicone pads between them to conduct heat from the MOS to the heat sink for heat exchange with the outside environment. When the current is large, additional teeth are added to the heat sink to improve heat dissipation capacity, or aluminum alloy is used as the BMS circuit board to increase its own heat dissipation capacity.

[0005] When a BMS needs to handle high current, the heat dissipation effect of ordinary aluminum sheets is insufficient, requiring the addition of serrated heat sinks. However, small heat sinks have insufficient heat dissipation capacity, so large heat sinks are usually used to meet the high current requirements, resulting in an excessively large overall BMS size and high cost. When using aluminum alloy as the circuit board, to meet the circuit design and handle high current, the overall circuit board size becomes too large, leading to an excessively large overall BMS size. Furthermore, the heat from the MOSFETs is transferred to the MCU, causing the MCU to reach its temperature threshold and malfunction, thus preventing the MOSFETs from performing at their full potential.

[0006] During long-term use, heat sinks undergo chemical or electrochemical reactions on their surface due to various factors, leading to corrosion. Corrosion significantly reduces the heat dissipation performance of the heat sink, causing the overall BMS temperature to rise excessively, thus affecting the normal operation of the equipment and shortening its lifespan.

[0007] From the perspective of thermal radiation, aluminum has a relatively low emissivity. In comparison, the thermal radiation heat dissipation coefficient of aluminum heat sinks is relatively low, ranging from 0.02 to 0.1. Heat sinks can only enhance their thermal radiation dissipation effect by increasing the radiating area. To meet circuit requirements, this results in an excessively large overall BMS size. Utility Model Content

[0008] The main technical problem to be solved by this utility model is to provide a BMS heat dissipation structure that improves the heat dissipation efficiency per unit area and reduces the volume of the heat dissipation structure.

[0009] To address the aforementioned technical problems, this utility model provides a BMS heat dissipation structure, including a heat dissipation substrate for abutting against a BMS circuit board, wherein at least a portion of the outer surface of the heat dissipation substrate is coated with a graphene heat dissipation layer.

[0010] In a preferred embodiment, the thickness of the graphene heat dissipation layer is 10µm to 30µm.

[0011] In a preferred embodiment: the heat dissipation substrate includes a base plate and a plurality of heat dissipation fins, one side of the heat dissipation fins is connected to the base plate, and the other side of the heat dissipation fins extends away from the base plate; a heat dissipation channel is formed between two adjacent heat dissipation fins.

[0012] This utility model also provides a BMS component, including: a BMS circuit board and a BMS heat dissipation structure as described above, wherein the BMS heat dissipation structure is connected to the BMS circuit board.

[0013] In a preferred embodiment: the BMS circuit board includes a circuit board body and power components. The circuit board body is divided into a power area and a control area, and the power components are installed in the power area.

[0014] In a preferred embodiment: the circuit board body has a partition hole between the power region and the control region.

[0015] In a preferred embodiment: the partition hole is a strip-shaped hole.

[0016] In a preferred embodiment: a thermally conductive layer is provided between the power element and the substrate, and the thermally conductive layer is in thermal contact with both the power element and the substrate.

[0017] In a preferred embodiment: the circuit board body and the base plate are provided with a first mounting hole and a second mounting hole at corresponding positions. The circuit board body and the base plate are connected and fixed through the mounting holes and connectors to form a space between the circuit board body and the base plate to accommodate the power element and the heat-conducting layer; the height of the space is less than the sum of the height of the power element and the thickness of the heat-conducting pad.

[0018] In a preferred embodiment: the connector includes a single-ended copper stud and a fixing screw; the upper end of the single-ended copper stud passes through the second mounting hole, and the lower end abuts against the base plate; the upper end of the fixing screw passes through the first mounting hole and is fixedly connected to the lower end of the single-ended copper stud.

[0019] Compared with the prior art, the technical solution of this utility model has the following beneficial effects:

[0020] This invention provides a BMS (Body Management System) heat dissipation structure. By coating at least a portion of the outer surface of the heat dissipation substrate with a graphene heat dissipation layer, the graphene's thermal conductivity, significantly exceeding that of aluminum alloy substrates, enhances the heat dissipation capacity of the substrate, thereby improving the BMS heat dissipation structure and increasing heat dissipation efficiency per unit area. This allows for a reduction in the size of the BMS heat dissipation structure while maintaining the same heat dissipation efficiency, resulting in a more compact device.

[0021] This invention provides a BMS heat dissipation structure. In addition to improving thermal conductivity, the graphene heat dissipation layer can also form a protective layer on the heat dissipation substrate, which can block the erosion of moisture, oxygen and various corrosive substances, so that the heat dissipation performance of the heat dissipation substrate remains stable and there is no need to worry about the BMS failing due to excessive temperature caused by corrosion.

[0022] This utility model provides a BMS component, which can form a space for placing power components and heat-conducting layers between the circuit board body and the base plate by setting a single-headed copper stud between the circuit board body and the base plate, and the back of the base plate can be made into a plane. Attached Figure Description

[0023] Figure 1 This is an exploded view of a BMS component according to an embodiment of this application;

[0024] Figure 2 This is a three-dimensional assembly drawing of the BMS component according to an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the heat dissipation structure of some embodiments of this application;

[0026] Figure 4 This is a top view of the heat dissipation structure of some embodiments of this application;

[0027] Figure 5 This is a top view of a BMS circuit board according to some embodiments of this application;

[0028] Figure 6 This is a bottom view of a BMS circuit board according to some embodiments of this application;

[0029] Figure 7 This is a schematic diagram of the circuit board body according to some embodiments of this application;

[0030] Figure 8 This is a side view of a BMS component according to some embodiments of this application;

[0031] Figure 9This is a schematic diagram of a BMS component and a battery module according to embodiments of this application;

[0032] Figure 10 This is a top view of a BMS component according to an embodiment of this application.

[0033] Figure label:

[0034] BMS component 10, battery module 20, BMS circuit board 1, circuit board body 11, partition hole 111, body part 112, conductive layer 113, external power supply hole 114, power area 115, control area 116, second mounting hole 117, power element 12, MOSFET 121, sampling resistor 122, first side 13, second side 14, heat dissipation structure 2, heat dissipation substrate 21, substrate plate 211, groove 2111, heat sink 212, first mounting hole 213, third mounting hole 214, heat dissipation layer 22, thermally conductive layer 3, fixing screw 4, single-headed copper stud 5. Detailed Implementation

[0035] To make the technical solution and features of this utility model clearer, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only for illustrating this utility model and are not intended to limit the scope of this utility model. After reading this utility model, any modifications of this utility model by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

[0036] The following is combined with Figures 1-10 A detailed description of the BMS component 10 according to an embodiment of this application.

[0037] Reference Figures 1-3 , Figure 10As shown, the BMS component 10 according to an embodiment of this application includes a BMS circuit board 1 and a BMS heat dissipation structure 2. The BMS heat dissipation structure 2 includes a heat dissipation substrate 21, and at least a portion of the outer surface of the heat dissipation substrate 21 is coated with a graphene heat dissipation layer 22. The BMS heat dissipation structure 2 is connected to the BMS circuit board 1. Since the thermal conductivity of the graphene heat dissipation layer 22 is much higher than that of the heat dissipation substrate 21, the graphene heat dissipation layer 22 attached to the outer surface of the heat dissipation substrate 21 can significantly improve the heat dissipation capacity of the BMS heat dissipation structure 2, thereby improving the overall performance of the BMS component 10. For example, in this embodiment, if only an aluminum heat dissipation substrate 21 is used, the thermal radiation heat dissipation coefficient of aluminum is relatively low, ranging from 0.02 to 0.1. The aluminum heat dissipation substrate 21 can only enhance the thermal radiation heat dissipation effect by increasing the radiation area. To meet the circuit requirements, this would result in an excessively large overall BMS volume. The graphene heat dissipation layer 22 has a thermal radiation coefficient greater than 0.95, which improves the heat dissipation efficiency of the BMS heat dissipation structure 2 per unit area, significantly improves the heat dissipation capacity of the BMS heat dissipation structure 2, avoids the BMS component 10 from being too hot and thus affecting the performance of the BMS circuit board 1, and reduces the volume of the BMS heat dissipation structure 2 while meeting the heat dissipation requirements, thereby reducing the volume of the BMS component 10 and reducing the space occupation rate of the BMS component 10 in the battery pack.

[0038] In this embodiment, all outer surfaces of the heat dissipation substrate 21 are coated with a graphene heat dissipation layer 22. In some embodiments not shown in the figures, only a portion of the outer surface of the heat dissipation substrate 21 is coated with the graphene heat dissipation layer 22, for example, only the upper surface of the heat dissipation substrate 21 is coated with the graphene heat dissipation layer 22. It is understood that the graphene heat dissipation layer 22 can be coated at any location on the heat dissipation substrate 21, and the shape and size of the graphene heat dissipation layer 22 can be changed according to actual needs. In addition, the graphene heat dissipation layer 22 can be coated using conventional metal spraying technology or 360° high-speed rotating automatic spraying technology to control the thickness of the graphene heat dissipation layer 22 to be between 10 μm and 30 μm.

[0039] See Figure 1 , Figure 2 , Figure 4 , Figure 10As shown, the heat dissipation substrate 21 includes a substrate plate 211 and heat sinks 212. One side of the heat sink 212 is connected to the substrate plate 211, and the other side of the heat sink 212 extends towards the side of the substrate plate 211 away from the BMS circuit board 1. A heat dissipation channel is formed between two adjacent heat sinks 212. Thus, the heat generated by the BMS circuit board 1 is transferred to the heat sink 212 through the substrate plate 211. The substrate plate 211 and the heat sink 212 together disperse excess heat to the outside, preventing the BMS component 10 from overheating and affecting the performance of the BMS circuit board 1. The extension of the heat sink 212 away from the BMS circuit board 1 increases the contact space between the heat sink 212 and the surrounding environment, effectively improving the heat dissipation capacity of the heat sink 212. At the same time, the arrangement of the heat sink 212 does not interfere with the BMS circuit board 1.

[0040] In some embodiments not shown in the figures, the heat sink 212 may extend in other directions besides extending toward the side of the base plate 211 away from the BMS circuit board 1, such as extending toward the side of the base plate 211 facing the BMS circuit board 1, that is, the heat sink 212 extends toward the lower side of the base plate 211, or the heat sink 212 extends in a direction parallel to the BMS circuit board 1.

[0041] The heat sink 212 can be a flat plate structure, which is simple in structure and easy to manufacture. The heat sink 212 can also be a plate structure with teeth, which can increase the surface area of ​​the heat sink 212 and thus improve the heat dissipation capacity.

[0042] like Figure 1 , Figure 5 , Figure 6 As shown, the BMS circuit board 1 includes a circuit board body 11 and a power component 12. The power component 12 is mounted on the side surface of the circuit board body 11 facing the BMS heat dissipation structure 2. A heat-conducting layer 3 is provided between the power component 12 and the substrate 211. One side of the heat-conducting layer 3 is attached to the power component 12, and the other side of the heat-conducting layer 3 is attached to the substrate 211.

[0043] In other words, the BMS circuit board has a first side 13 and a second side 14. The first side 13 faces the BMS heat dissipation structure 2, and the second side 14 faces away from the BMS heat dissipation structure 2. That is, the upper surface of the BMS circuit board is the first side 13, and the lower surface is the second side 14. The above-mentioned "power component 12 is mounted on the side surface of the circuit board body 11 facing the BMS heat dissipation structure 2" means that the power component 12 is mounted on the first side 13.

[0044] Specifically, by mounting the power element 12 on the first side 13, the power element 12 is brought closer to the BMS heat dissipation structure 2. This allows the heat generated by the power element 12 to be more easily dispersed to the BMS heat dissipation structure 2 and then to the surrounding environment, thus improving the heat dissipation efficiency of the BMS assembly 10. Furthermore, by providing a thermally conductive layer 3 between the power element 12 and the substrate 211, the heat generated by the power element 12 is dispersed more quickly onto the substrate 211 and then to the surrounding environment via the heat sink 212. This improves the heat exchange efficiency between the BMS circuit board 1 and the BMS heat dissipation structure 2, further enhancing the heat dissipation efficiency of the BMS assembly 10.

[0045] In this embodiment, the thermally conductive layer 3 can be a highly thermally conductive silicone pad, thermal grease, or the like. To enhance thermal conductivity, the distance between the substrate 211 and the circuit board body 11 should be less than the sum of the height of the power component 12 and the thickness of the thermally conductive layer 3. This ensures a tight fit between the thermally conductive layer 3 and the power component 12, as well as with the substrate 211.

[0046] See Figure 5 As shown, the circuit board body 11 includes a power region 115 and a control region 116, which are separated by a partition hole 111. A power component 12 is mounted in the power region 115. Therefore, separating the power region 115 and the control region 116 by the partition hole 111 reduces the heat transfer from the power region 115 to the control region 116, thus reducing the impact of the high temperature in the power region 115 on the MCU (Microcontroller Unit) in the control region 116. This allows for an increase in the temperature threshold of the power component 12 without affecting its lifespan, improving the high-current carrying time of the BMS circuit board 1 and enhancing its overall performance. The control region 116 can contain logic circuits, data acquisition circuits, etc.

[0047] See Figure 5 As shown, the power region 41 and the control region 42 are arranged spaced apart in the first direction. The partition hole 111 is an elongated hole. In this embodiment, there are two partition holes 111, but the number of partition holes 111 can be increased or decreased as needed. The length extension direction of the partition hole 111 is the second direction, and the angle between the second direction and the first direction is 70°~110°. This helps to block heat transfer between the power region 41 and the control region 42, preventing the control region 42 from affecting its performance due to excessive temperature.

[0048] In this embodiment, the first direction is the F1-F2 direction, and the second direction is the F3-F4 direction. The angle between the first and second directions is 90°. It is understood that the angle between the first and second directions can also be 70°, 80°, 100°, 110°, or any other angle between 70° and 110°. There can be one, two, three, or more partition holes 111. These will not be listed individually here.

[0049] The partition hole 111 can also be a matrix arrangement of round holes, square holes, or other shapes of holes.

[0050] See Figure 5 , Figure 7 As shown, the circuit board body 11 includes a body portion 112 and multiple conductive layers 113. The multiple conductive layers 113 are embedded in the body portion 112. The circuit board body 11 has an exposed conductive layer area. Specifically, the exposed conductive layer area is located on the first side 13, where the conductive layers 113 are exposed. Power components 12 are disposed in the exposed conductive layer area. In particular, the provision of multiple conductive layers 113 improves the current carrying capacity of the BMS circuit board 1, enhances the flexibility of board layout and wiring, and exposes part of the conductive layers 113, thereby improving the heat exchange capacity between the BMS circuit board 1 and the outside environment, as well as the heat dissipation efficiency of the conductive layers 3.

[0051] The number of conductive layers 113 can be two, three, four or more. The conductive layers 113 can be copper foil, aluminum foil, etc.

[0052] In this embodiment, the body part 112 can be made of epoxy resin board or plastic board.

[0053] See Figure 6 , Figure 7 As shown, on the surface of the circuit board body 11 facing away from the BMS heat dissipation structure 2, i.e., on the second side 14, the conductive layer 113 in the area facing away from the power component 12 is exposed. This improves the heat exchange capability between the BMS circuit board 1 and the external environment, as well as the heat dissipation efficiency of the BMS circuit board 1.

[0054] See Figure 4 , Figure 9 As shown, the substrate 211 has a first mounting hole 213 and a third mounting hole 214. The first mounting hole 213 is used to connect the substrate 211 to the circuit board body 11, and the third mounting hole 214 is used to connect the substrate 211 to the battery module 20. Specifically, the first mounting hole 213, in conjunction with a connector, is used to fix the substrate 211 to the circuit board body 11. The third mounting hole 214, in conjunction with a connector, is used to fix the BMS assembly 10 to the battery module 20.

[0055] The first mounting hole 213 can be a threaded hole or a smooth hole. There can be one, two, three, or more first mounting holes 213. For example... Figure 4 As shown, there are six first mounting holes 213. The third mounting hole 214 is either a threaded hole or a smooth hole. There can be one, two, three, or more third mounting holes 214. For example... Figure 4 As shown, there are four third mounting holes 214.

[0056] The connection between the substrate 211 and the battery module 20 at the third mounting hole 214 can be a fixing screw connection, a stud connection, a rivet connection, or other connection methods. For example, in an embodiment not shown in the figures of this application, the substrate 211 and the battery module 20 are connected at the third mounting hole 214 by fixing screws.

[0057] Specifically, the circuit board body 11 is provided with a second mounting hole 117, which is used to connect the circuit board body 11 to the base plate 211. The number of first mounting holes 213 and second mounting holes 117 are the same, and they correspond one-to-one in space. For example Figure 2 , Figure 4 , Figure 5 As shown, there are six first mounting holes 213 and six third mounting holes. The connection between the substrate 211 and the circuit board body 11 through the first mounting holes 213 can be achieved through screw connection, rivet connection, bolt connection, or other connection methods. For example... Figure 2 As shown, the substrate 211 and the circuit board body 11 are connected at the first mounting hole 213 by a single-ended copper stud 5 and a fixing screw 4; the upper end of the single-ended copper stud 5 passes through the second mounting hole 117, and the lower end abuts against the substrate 211; the upper end of the fixing screw 4 passes through the first mounting hole 213 and is fixedly connected to the lower end of the single-ended copper stud 5.

[0058] In some embodiments, see Figure 1 , Figure 2 , Figure 8 As shown, the substrate 211 has a groove 2111, which is recessed in a direction away from the circuit board body 11, such as... Figure 8As shown, the groove 2111 is recessed upwards. The power element 12 is at least partially located within the groove 2111, and a heat-conducting layer 3 is provided between the power element 12 and the substrate 211. Therefore, by partially positioning the power element 12 within the groove 2111, the total thickness of the BMS circuit board 1 and the BMS heat dissipation structure 2 is reduced. The heat-conducting layer 3, positioned between the power element 12 and the substrate 211, effectively transfers the heat generated by the power element 12 to the substrate 211, which is then dissipated through the BMS heat dissipation structure 2. This optimizes the heat conduction path and improves heat dissipation efficiency. Simultaneously, the design of the groove 2111 allows the power element 12 to be partially placed within it, bringing the circuit board body 11 closer to the substrate 211. This increases the heat conduction efficiency between the circuit board body 11 and the substrate 211, reduces the distance between the circuit board body 11 and the heat dissipation substrate 21, and makes the structure of the BMS assembly 10 more compact, reducing the space occupied by the BMS assembly 10.

[0059] Power element 12 generates a significant amount of heat during operation. In some embodiments, see [reference needed]. Figure 1 , Figure 2 , Figure 5 , Figure 8 As shown, the power component 12 may include a MOSFET 121 and a sampling resistor 122. The MOSFET 121 is at least partially located within some recesses 2111, and a thermally conductive layer 3 is provided between the MOSFET 121 and the substrate 211. The sampling resistor 122 is at least partially located within other recesses 2111, and a thermally conductive layer 3 is provided between the sampling resistor 122 and the substrate 211. Therefore, the heat generated by the MOSFET 121 and the sampling resistor 122 can be more effectively transferred to the substrate 211 and then dissipated through the BMS heat dissipation structure 2, optimizing the heat conduction path and improving heat dissipation efficiency. The design of the recesses 2111 allows both the MOSFET 121 and the sampling resistor 122 to be partially placed within the recesses 2111, making the circuit board body 11 closer to the substrate 211, increasing the thermal conductivity between the circuit board body 11 and the substrate 211, reducing the distance between the circuit board body 11 and the heat dissipation substrate 21, making the structure of the BMS component 10 more compact, and reducing the space occupied by the BMS component 10.

[0060] In other embodiments, the power element 12 may also be other types of heating elements.

[0061] See Figure 5 , Figure 7As shown, the circuit board body 11 includes a body portion 112 and multiple conductive layers 113. The multiple conductive layers 113 are embedded in the body portion 112, stacked and spaced apart from each other. An external power supply hole 114 is provided on the circuit board body 11, and the external power supply hole 114 connects to the multiple conductive layers 113. Specifically, the external power supply hole 114 is used for soldering power lines. The external power supply hole 114 allows the power lines to contact the multiple conductive layers 113, increasing the contact area between the power lines and the multiple conductive layers 113, thereby improving the conductivity of the conductive layers 113. The power lines can provide the voltage required for the operation of the BMS circuit board 1.

[0062] The above is only one specific embodiment of the present utility model, but the design concept of the present utility model is not limited thereto. Any non-substantial modifications made to the present utility model using this concept shall be deemed as an infringement of the protection scope of the present utility model.

Claims

1. A BMS assembly comprising The application relates to a BMS (Battery Management System) heat dissipation structure. The BMS heat dissipation structure comprises a heat dissipation base body for abutting against a BMS circuit board, at least a part of the outer surface of the heat dissipation base body is coated with a graphene heat dissipation layer, the thickness of the graphene heat dissipation layer is 10-30 um, the heat dissipation base body comprises a base plate and a plurality of heat dissipation fins, one side of the heat dissipation fin is connected with the base plate, the other side of the heat dissipation fin extends away from the base plate, and a heat dissipation channel is formed between two adjacent heat dissipation fins. The BMS circuit board comprises a circuit board body and a power element, the circuit board body is divided into a power area and a control area, the power element is arranged in the power area, and a partition hole is arranged between the power area and the control area of the circuit board body. The partition hole is a strip-shaped hole.

2. The BMS assembly of claim 1, wherein, A heat conduction layer is arranged between the power element and the base plate, and the heat conduction layer is in heat conduction contact with the power element and the base plate respectively.

3. The BMS assembly of claim 1, wherein, First and second mounting holes are arranged at corresponding positions of the circuit board body and the base plate, the circuit board body and the base plate are connected and fixed through the mounting holes and connecting pieces, so as to form a space for accommodating the power element and the heat conduction layer between the circuit board body and the base plate, and the height of the space is less than the sum of the height of the power element and the thickness of the heat conduction pad.

4. The BMS assembly of claim 3, wherein: The connecting piece comprises a single-end copper stud and a fixing screw, the upper end of the single-end copper stud penetrates through the second mounting hole and abuts against the base plate, and the upper end of the fixing screw penetrates through the first mounting hole and is fixedly connected with the lower end of the single-end copper stud.

5. The BMS assembly of claim 4, wherein: ​

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