Battery protection plate and battery assembly

Abstract

The application discloses a battery protection plate and a battery assembly, and relates to the technical field of battery design. The battery protection plate comprises a protection plate main body and a current source. The protection plate main body is provided with a plurality of electrically connected holes arranged at intervals. The plurality of electrically connected holes comprise a first electrically connected hole group and a second electrically connected hole group arranged side by side along a first direction. The current source is arranged on one side of the first electrically connected hole group away from the second electrically connected hole group. Each electrically connected hole in the first electrically connected hole group and each electrically connected hole in the second electrically connected hole group are arranged at intervals along a second direction in sequence. Each electrically connected hole in the first electrically connected hole group and each electrically connected hole in the second electrically connected hole group are arranged in a staggered manner in the second direction. The first direction is perpendicular to the second direction, and the first direction and the second direction are both perpendicular to the thickness direction of the protection plate main body. The scheme can solve the problem of poor heat dissipation performance of the current battery protection plate.

Description

Technical Field

[0001] This application belongs to the field of battery design technology, specifically relating to a battery protection board and a battery assembly. Background Technology

[0002] Battery modules, as power supply devices for electronic devices, provide electrical energy for the normal operation of these devices. A battery module mainly consists of battery cells, a protection board, and a casing. The battery cells store and release electrical energy, the protection board provides overcharge, over-discharge, and short-circuit protection for the battery module, and the casing protects both the battery cells and the protection board.

[0003] With the increasing demand from users for fast charging of electronic devices, high-current fast charging electronic devices have been launched on the market. However, as the power supply device for electronic devices, the battery pack also faces the problem of heat dissipation difficulties for the protection board while achieving fast charging. Utility Model Content

[0004] The purpose of this application is to provide a battery protection board and battery assembly that can solve the problem of poor heat dissipation performance of current battery protection boards.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a battery protection board, including a protection board body and a current source. The current source is disposed on the protection board body, and the protection board body has a plurality of spaced-apart electrical connection holes, the central axis of which extends along the thickness direction of the protection board body. The plurality of electrical connection holes includes a first electrical connection hole group and a second electrical connection hole group arranged side by side along a first direction. The current source is disposed on the side of the first electrical connection hole group opposite to the second electrical connection hole group. Each electrical connection hole in the first electrical connection hole group and each electrical connection hole in the second electrical connection hole group are arranged sequentially at intervals along a second direction, and each electrical connection hole in the first electrical connection hole group and each electrical connection hole in the second electrical connection hole group are staggered in the second direction. Wherein, the first direction is perpendicular to the second direction, and both the first direction and the second direction are perpendicular to the thickness direction of the protective plate body. Optionally, the distance between adjacent electrical connection holes in the first electrical connection hole group is equal, the distance between adjacent electrical connection holes in the second electrical connection hole group is equal, and the distance between each electrical connection hole in the first electrical connection hole group and the electrical connection holes in and adjacent to it in the second electrical connection hole group is equal.

[0006] Optionally, each of the electrical connection holes is provided with a conductive filling structure, the conductive filling structure being located at the opening of the electrical connection hole, and the conductive filling structure being at least one of conductive ink and conductive epoxy resin.

[0007] Optionally, all of the electrical connection holes are located on the same side of the current source, and the two ends of each electrical connection hole extend to opposite sides of the main body of the protection plate. Each of the aforementioned electrical connection holes has a first annular ring at its end. The outer diameter of the first annular ring is greater than or equal to 0.55 mm and less than or equal to 0.6 mm, and the inner diameter of the first annular ring is greater than or equal to 0.3 mm and less than or equal to 0.35 mm; and / or, The first electrical connection hole group has a first distance between the central axes of adjacent electrical connection holes, the second electrical connection hole group has a second distance between the central axes of adjacent electrical connection holes, and each electrical connection hole in the first electrical connection hole group has a third distance between its central axis and the central axis of the electrical connection hole in the second electrical connection hole group and its adjacent central axis. The first distance, the second distance, and the third distance are all equal, and each of these distances is greater than 0.6 mm and less than 0.7 mm; and / or, Each of the electrical connection holes has a first annular metal layer on its inner wall, and the thickness of the first annular metal layer is greater than or equal to 15 μm and less than or equal to 25 μm.

[0008] Optionally, the protection board body is an HDI board, and the plurality of electrical connection holes include multiple rings of electrical connection holes arranged at intervals along a third direction. Each ring of electrical connection holes surrounds the current source. The multiple rings of electrical connection holes include a first ring of electrical connection holes and a second ring of electrical connection holes. The first ring of electrical connection holes includes a first group of electrical connection holes, and the second ring of electrical connection holes includes a second group of electrical connection holes. Wherein, the third direction is the direction in which the current source extends along the edge of the main body of the protection plate.

[0009] Optionally, the first ring of electrical connection holes further includes a third group of electrical connection holes, the third group of electrical connection holes and the first group of electrical connection holes being located on different sides of the current source; the second ring of electrical connection holes further includes a fourth group of electrical connection holes, the fourth group of electrical connection holes and the second group of electrical connection holes being located on different sides of the current source; the third group of electrical connection holes is located between the fourth group of electrical connection holes and the current source; and each electrical connection hole in the third group of electrical connection holes is opposite to each electrical connection hole in the fourth group of electrical connection holes in the third direction.

[0010] Optionally, the protective board body includes a stacked substrate and a wiring layer group. Each of the electrical connection holes is located in and electrically connected to the wiring layer group. The length of each electrical connection hole is less than the thickness of the wiring layer group, and the first end of each electrical connection hole extends to the side of the wiring layer group opposite to the substrate. Each of the aforementioned electrical connection holes has a second annular ring at its end. The outer diameter of the second annular ring is greater than or equal to 0.3 mm and less than or equal to 0.35 mm, and the inner diameter of the second annular ring is greater than or equal to 0.1 mm and less than or equal to 0.15 mm; and / or, Each of the electrical connection holes has a second annular metal layer on its inner wall, the thickness of which is greater than or equal to 15 μm and less than or equal to 20 μm.

[0011] Optionally, the protection board body further includes a plurality of spaced-apart overcurrent holes, the central axis of each overcurrent hole extending along the thickness direction of the protection board body, each overcurrent hole being located within the wiring layer group, and each overcurrent hole being electrically connected to the wiring layer group, each overcurrent hole forming the current source. Each of the aforementioned flow passages is provided with a third perforated ring at its end. The outer diameter of the third perforated ring is greater than 0.5 mm and less than 0.6 mm, and the inner diameter of the third perforated ring is greater than 0.25 mm and less than 0.5 mm; and / or, Each of the aforementioned flow holes has a third annular metal layer on its inner wall, the thickness of which is greater than or equal to 49 μm and less than or equal to 55 μm.

[0012] Optionally, the protective board body further includes an electrical connection groove located on a first surface of the protective board body. The electrical connection groove extends to and is electrically connected to the wiring layer group of the protective board body. The electrical connection groove is elongated and has a first metal filling structure located at the groove opening, flush with the first surface; and / or, The main body of the protection board is also provided with a flow guide hole and a pad. The flow guide hole is located on the pad. One end of the flow guide hole extends to the wiring layer group of the main body of the protection board and is electrically connected to the wiring layer group. A second metal filling structure is provided in the flow guide hole. The second metal filling structure is located at the opening of the flow guide hole and is flush with the side of the pad facing away from the wiring layer group.

[0013] Secondly, embodiments of this application also provide a battery assembly, including a battery cell, a housing, and the aforementioned battery protection plate. The housing encloses the battery cell, and the battery protection plate is disposed on the outer surface of the housing and electrically connected to the tabs of the battery cell.

[0014] In this embodiment, the plurality of electrical connection holes include a first electrical connection hole group and a second electrical connection hole group arranged side by side along a first direction. The current source is disposed on the side of the first electrical connection hole group away from the second electrical connection hole group. Each electrical connection hole in the first electrical connection hole group and each electrical connection hole in the second electrical connection hole group are arranged sequentially at intervals along a second direction. The electrical connection holes in the first electrical connection hole group and each electrical connection hole in the second electrical connection hole group are staggered in the second direction. The first direction is perpendicular to the second direction, and both the first direction and the second direction are perpendicular to the thickness direction of the protective plate body.

[0015] Compared to the array arrangement of electrical connection holes in the prior art, this application staggers the electrical connection holes in the first electrical connection hole group and the electrical connection holes in the second electrical connection hole group, which are located on the same side of the current source, in the second direction, and increases the distance between adjacent electrical connection holes. This allows some current to pass through the gaps between adjacent electrical connection holes in the first electrical connection hole group and be transmitted to the second electrical connection hole group, thus avoiding the majority of the current being concentrated in the first electrical connection hole group and reducing the current density of the first electrical connection hole group. This is beneficial for increasing the effective conductive contact area of ​​each electrical connection hole in the battery protection board, thereby increasing the heat dissipation area of ​​each electrical connection hole and improving the heat dissipation performance of the battery protection board. Attached Figure Description

[0016] Figure 1 This is a partial structural schematic diagram of the battery protection board disclosed in an embodiment of this application; Figure 2 This is a partial structural schematic diagram of the battery protection board disclosed in an embodiment of this application; Figure 3 This is a partial structural schematic diagram of a battery protection board disclosed in another embodiment of this application; Figure 4 This is a partial structural schematic diagram of a battery protection board disclosed in another embodiment of this application; Figure 5 This is a partial structural schematic diagram of the battery protection board disclosed in an embodiment of this application.

[0017] Explanation of reference numerals in the attached figures: 100 - Protective board body, 110 - Electrical connection hole, 111 - First electrical connection hole group, 112 - Second electrical connection hole group, 113 - First hole ring, 114 - First ring of electrical connection holes, 114a - Third electrical connection hole group, 115 - Second ring of electrical connection holes, 115a - Fourth electrical connection hole group, 116 - Fifth electrical connection hole group, 117 - Second hole ring, 120 - Flow hole, 121 - Third hole ring, 130 - Electrical connection groove, 140 - Guide hole, 150 - Solder pad; 200- Current source. Detailed Implementation The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0019] The battery protection board and battery assembly provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0020] like Figures 1 to 5 As shown in the figure, this application embodiment provides a battery protection board, which includes a protection board body 100 and a current source 200. The current source 200 is disposed on the protection board body 100 and is used to transmit current to its surroundings. The protection board body 100 is provided with a plurality of spaced electrical connection holes 110, the central axis of each electrical connection hole 110 extending along the thickness direction of the protection board body 100, and each electrical connection hole 110 can be used for electrical connection with electronic components. Multiple electrical connection holes 110 include those along a first direction (e.g.) Figure 2 A first electrical connection hole group 111 and a second electrical connection hole group 112 are arranged side by side in the Y direction. A current source 200 is located on the side of the first electrical connection hole group 111 away from the second electrical connection hole group 112, meaning the first electrical connection hole group 111 and the second electrical connection hole group 112 are located on the same side of the current source 200. Each electrical connection hole 110 in the first electrical connection hole group 111 and each electrical connection hole 110 in the second electrical connection hole group 112 are along the second direction (e.g., in the Y direction). Figure 2The electrical connection holes 110 of the first electrical connection hole group 111 and the electrical connection holes 110 of the second electrical connection hole group 112 are staggered in the second direction, wherein the first direction is perpendicular to the second direction, and both the first direction and the second direction are perpendicular to the thickness direction of the protective plate body 100.

[0021] Compared to the array arrangement of electrical connection holes 110 in the prior art, this application staggers the electrical connection holes 110 of the first electrical connection hole group 111 and the electrical connection holes 110 of the second electrical connection hole group 112 located on the same side of the current source 200 in the second direction, and increases the distance between adjacent electrical connection holes 110. This allows some current to pass between adjacent electrical connection holes 110 in the first electrical connection hole group 111 and be transmitted to the second electrical connection hole group 112, avoiding the majority of current concentration in the first electrical connection hole group 111 and reducing the current density of the first electrical connection hole group 111. This increases the effective conductive contact area of ​​each electrical connection hole 110 of the battery protection board, thereby increasing the heat dissipation area of ​​each electrical connection hole 110 and improving the heat dissipation performance of the battery protection board. Therefore, the embodiments of this application can solve the problem of poor heat dissipation performance of current battery protection boards.

[0022] In one optional embodiment, the distance between adjacent electrical connection holes 110 in the first electrical connection hole group 111 is equal, and the distance between adjacent electrical connection holes 110 in the second electrical connection hole group 112 is equal. The distances between each electrical connection hole 110 in the first electrical connection hole group 111 and its adjacent electrical connection holes 110 in the second electrical connection hole group 112 are also equal, so that the current density transmitted to the second electrical connection hole group 112 is more uniform, thereby further improving the heat dissipation performance of the battery protection board. Of course, the distances between each electrical connection hole 110 in the first electrical connection hole group 111 and its adjacent electrical connection holes 110 in the second electrical connection hole group 112 may not be equal.

[0023] In another optional embodiment, each electrical connection hole 110 is provided with a conductive filling structure. The conductive filling structure is located at the opening of the electrical connection hole 110. The conductive filling structure is at least one of conductive ink and conductive epoxy resin. Optionally, the thermal conductivity of the conductive ink can be 0.319 W / mK, and the thermal conductivity of the conductive epoxy resin can be 2.691 W / mK. Of course, it can also be selected according to actual needs, and this application embodiment does not impose specific limitations on this. By providing a conductive filling structure in each electrical connection hole 110, the impedance that hinders the flow of current to the conductive filling structure is reduced, thereby reducing the Joule heating of the via and thus reducing the heat generation of the battery protection board. In addition, the conductive filling structure can prevent impurities from entering the electrical connection hole 110, thereby reducing the risk of contamination or corrosion. Furthermore, the conductive epoxy resin in the electrical connection hole 110 can also increase the mechanical strength of the protection board body 100. Of course, the conductive filling structure can also be electrolytic copper.

[0024] In another optional embodiment, each electrical connection hole 110 is located on the same side of the current source 200, and the two ends of each electrical connection hole 110 extend to the opposite sides of the protection plate body 100, that is, each electrical connection hole 110 is a through hole structure. Optionally, the plurality of electrical connection holes 110 may further include a fifth electrical connection hole group 116, wherein each electrical connection hole 110 in the fifth electrical connection hole group 116 is staggered from each electrical connection hole 110 in the second electrical connection hole group 112 in the second direction, so that each electrical connection hole 110 in the fifth electrical connection hole group 116 is opposite to each electrical connection hole 110 in the first electrical connection hole group 111 in the second direction. At this time, some current can pass through between adjacent electrical connection holes 110 in the second electrical connection hole group 112, thereby transmitting to the fifth electrical connection hole group 116, thereby reducing the current density of the first electrical connection hole group 111 and the second electrical connection hole group 112, thereby further increasing the effective conductive contact area of ​​each electrical connection hole of the battery protection board, thereby further increasing the heat dissipation area of ​​each electrical connection hole and improving the heat dissipation performance of the battery protection board.

[0025] Optionally, each electrical connection hole 110 has a first annular ring 113 at its end. If the outer and inner diameters of the first annular ring 113 are too small, the heat dissipation area of ​​the electrical connection hole 110 will be reduced; if the outer and inner diameters of the first annular ring 113 are too large, the number of electrical connection holes 110 will be reduced if the space for the battery protection board is limited. Optionally, the outer diameter of the first annular ring 113 is greater than or equal to 0.55 mm and less than or equal to 0.6 mm, and the inner diameter of the first annular ring 113 (i.e., the diameter of the electrical connection hole 110) is greater than or equal to 0.3 mm and less than or equal to 0.35 mm. This increases the heat dissipation area of ​​each electrical connection hole 110 while ensuring the number of electrical connection holes 110, thereby improving the heat dissipation performance of the battery protection board. It should be noted that the above values ​​can be selected according to actual needs, and this embodiment does not impose specific limitations on them.

[0026] Optionally, there is a first distance between the central axes of adjacent electrical connection holes 110 in the first electrical connection hole group 111, a second distance between the central axes of adjacent electrical connection holes 110 in the second electrical connection hole group 112, and a third distance between the central axes of each electrical connection hole 110 in the first electrical connection hole group 111 and its adjacent electrical connection holes 110 in the second electrical connection hole group 112. The first, second, and third distances are similar. If the distance between adjacent electrical connection holes 110 is too small, the current density in the first electrical connection hole group 111 will be relatively low. The first electrical connection hole group 111 has a large current density, while the second electrical connection hole group 112 has a small current density, resulting in a low utilization rate of the second electrical connection hole group 112. If the distance between adjacent electrical connection holes 110 is too large, the number of electrical connection holes 110 will be small given the limited size of the battery protection board, thus affecting the multifunctionality of the battery protection board. Therefore, optionally, the first distance, the second distance, and the third distance are all greater than 0.6 mm and less than 0.7 mm to reduce the current density of the first electrical connection hole group 111 and increase the current density of the second electrical connection hole group 112, while ensuring the number of electrical connection holes 110, thereby satisfying the multifunctionality of the battery protection board.

[0027] Optionally, each electrical connection hole 110 has a first annular metal layer on its inner wall. If the thickness of the first annular metal layer is too small, the heat dissipation performance of the electrical connection hole 110 will be poor; if the thickness of the first annular metal layer is too large, it will increase the difficulty of setting the first annular metal layer when the diameter of the electrical connection hole 110 is limited. Therefore, optionally, the thickness of the first annular metal layer can be greater than or equal to 15 μm and less than or equal to 25 μm to improve the heat dissipation performance of the electrical connection hole 110 and facilitate the setting of the first annular metal layer. It should be noted that the thickness of the first annular metal layer can also be selected according to actual needs, and this embodiment does not impose specific limitations on it.

[0028] In another optional embodiment, the protection board body 100 is an HDI board (High Density Interconnector), and the plurality of electrical connection holes 110 include multiple rings of electrical connection holes arranged at intervals along a third direction. Each ring of electrical connection holes surrounds the current source 200. The multiple rings of electrical connection holes include a first ring of electrical connection holes 114 and a second ring of electrical connection holes 115. The first ring of electrical connection holes 114 includes a first group of electrical connection holes 111, and the second ring of electrical connection holes 115 includes a second group of electrical connection holes 112. The third direction is the direction in which the current source 200 extends along the edge of the protection board body 100 (e.g., Figure 4 (Z direction in the diagram). This design employs an encircling perforation pattern to disperse the current around the current source 200, thereby increasing the current flow area, reducing the current density around the current source 200, and ultimately improving the heat dissipation performance of the battery protection board. Alternatively, each electrical connection hole 110 can be arranged in an arc shape around the current source 200, i.e., in a semi-encircling manner.

[0029] In a further optional embodiment, the first ring of electrical connection holes 114 further includes a third electrical connection hole group 114a, which is located on different sides of the current source 200, and the second ring of electrical connection holes 115 further includes a fourth electrical connection hole group 115a, which is located on different sides of the current source 200, and the third electrical connection hole group 114a is located between the fourth electrical connection hole group 115a and the current source 200. Each electrical connection hole 110 of the third electrical connection hole group 114a is opposite to each electrical connection hole of the fourth electrical connection hole group 115a in a third direction. That is, the third electrical connection hole group 114a and the fourth electrical connection hole group 115a are arranged in an array. In this case, with the size of the battery protection board fixed, the array arrangement can accommodate more electrical connection holes 110 to meet the usage requirements of the HDI board. Of course, if the size of the HDI board is large, the electrical connection holes 110 of the first ring of electrical connection holes 114 and the electrical connection holes 110 of the second ring of electrical connection holes 115 can be arranged in a staggered manner in the circumference of the current source 200 to improve the heat dissipation performance of the battery protection board.

[0030] Optionally, all the multiple rings of electrical connection holes in the above scheme can be rectangular in structure. In this case, the first electrical connection hole group 111 and the third electrical connection hole group 114a of the first ring of electrical connection holes 114 can be arranged adjacent to each other, and the second electrical connection hole group 112 and the fourth electrical connection hole group 115a of the second ring of electrical connection holes 115 can be arranged adjacent to each other; or, the first electrical connection hole group 111 and the third electrical connection hole group 114a of the first ring of electrical connection holes 114 are respectively arranged on opposite sides of the current source 200, and similarly, the second electrical connection hole group 112 and the fourth electrical connection hole group 115a of the second ring of electrical connection holes 115 are respectively arranged on opposite sides of the current source 200.

[0031] In another optional embodiment, the protection board body 100 includes a stacked substrate and a wiring layer group. Each electrical connection hole 110 is located in the wiring layer group and is electrically connected to the wiring layer group. The length of each electrical connection hole 110 is less than the thickness of the wiring layer group. The first end of each electrical connection hole 110 extends to the side of the wiring layer group away from the substrate, that is, each electrical connection hole 110 is a blind hole. Optionally, when the size of the HDI board is large, some electrical connection holes 110 can be set as through holes to improve their effective current-carrying contact area and the space utilization of the protection board body 100.

[0032] Optionally, each electrical connection hole 110 has a second annular ring 117 at its end. If the outer and inner diameters of the second annular ring 117 are too small, the heat dissipation area of ​​the electrical connection hole 110 will be reduced. If the outer and inner diameters of the second annular ring 117 are too large, the number of electrical connection holes 110 will be reduced if the space for the battery protection board is limited. Optionally, the outer diameter of the second annular ring 117 is greater than or equal to 0.3 mm and less than or equal to 0.35 mm, and the inner diameter of the second annular ring 117 (i.e., the diameter of the electrical connection hole 110) is greater than or equal to 0.1 mm and less than or equal to 0.15 mm. This increases the heat dissipation area of ​​each electrical connection hole 110 while ensuring the number of electrical connection holes 110, thereby improving the heat dissipation performance of the battery protection board. It should be noted that the above values ​​can be selected according to actual needs, and this embodiment does not impose specific limitations on them.

[0033] Optionally, a second annular metal layer is provided on the inner wall of each electrical connection hole 110. If the thickness of the second annular metal layer is too small, the heat dissipation performance of the electrical connection hole 110 will be poor; if the thickness of the second annular metal layer is too large, it will increase the difficulty of setting the second annular metal layer when the diameter of the electrical connection hole 110 is limited. Therefore, the thickness of the second annular metal layer can be greater than or equal to 15 μm and less than or equal to 20 μm to improve the heat dissipation performance of the electrical connection hole 110 and facilitate the setting of the second annular metal layer. It should be noted that the thickness of the second annular metal layer can also be selected according to actual needs, and this embodiment does not impose specific limitations on it.

[0034] In another optional embodiment, the protection board body 100 is further provided with a plurality of spaced-apart overcurrent holes 120. The central axis of each overcurrent hole 120 extends along the thickness direction of the protection board body 100. Each overcurrent hole 120 is located within the wiring layer group, that is, each overcurrent hole 120 is a buried via. Each overcurrent hole 120 is electrically connected to the wiring layer group and forms a current source 200. Optionally, the number of overcurrent holes 120 and electrical connection holes 110 can be matched with each other, such as one overcurrent hole 120 corresponding to multiple electrical connection holes 110, so as to improve the space current carrying capacity of the protection board body 100.

[0035] Optionally, each flow passage 120 has a third ring 121 at its end. If the outer and inner diameters of the third ring 121 are too small, the current carrying capacity of the flow passage 120 will be reduced. If the outer and inner diameters of the third ring 121 are too large, the number of flow passages 120 will be reduced due to limited space in the battery protection board. Optionally, the outer diameter of the third ring 121 is greater than 0.5 mm and less than 0.6 mm, and the inner diameter is greater than 0.25 mm and less than 0.5 mm. Increasing the thickness of the metal plating on the inner diameter of the third ring 121 while ensuring the number of flow passages 120 can improve the thermal conductivity of the passages. It should be noted that the above values ​​can be selected according to actual needs, and this application embodiment does not impose specific limitations on them.

[0036] Optionally, a third annular metal layer is provided on the inner wall of each flow passage 120. If the thickness of the third annular metal layer is too small, the current carrying and heat conduction capacity of the metal layer of the flow passage 120 will be weakened, affecting the heat dissipation performance. If the thickness of the third annular metal layer is too large, the difficulty of setting the third annular metal layer will increase when the aperture of the flow passage 120 is limited. Based on this, the thickness of the third annular metal layer is optionally greater than or equal to 49 μm and less than or equal to 55 μm to improve the heat dissipation performance of the flow passage 120 and facilitate the setting of the third annular metal layer. It should be noted that the thickness of the third annular metal layer can also be selected according to actual needs, and this embodiment does not impose specific limitations on it.

[0037] In another optional embodiment, the protection board body 100 is further provided with an electrical connection groove 130. The electrical connection groove 130 is located on the first surface of the protection board body 100, extends to the wiring layer group of the protection board body 100, and is electrically connected to the wiring layer group. The electrical connection groove 130 is a long strip structure, that is, the electrical connection groove 130 can be a slot groove to release thermal stress and allow the heat of the inner layer to be directly conducted along the inner side of the groove, thereby reducing the thermal resistance on the heat conduction path and improving the heat dissipation rate of the protection board body 100; and can also enhance the transmission performance of current and signals. Optionally, the electrical connection groove 130 is penetrated by a through-hole and formed into a blind via slot groove by copper filling. The electrical connection groove 130 is provided with a first metal filling structure, which is located at the groove opening of the electrical connection groove 130 and is flush with the first surface, which can improve the structural strength of the protection board body 100.

[0038] Optionally, the protection board body 100 also includes a flow guide hole 140 and a pad 150. The flow guide hole 140 is located on the pad 150, and one end of the flow guide hole 140 extends to and is electrically connected to the wiring layer group of the protection board body 100. A second metal filling structure is provided inside the flow guide hole 140. The second metal filling structure is located at the opening of the flow guide hole 140 and is flush with the side of the pad 150 facing away from the wiring layer group. This design uses a hole in the pad to increase the heat dissipation area of ​​the flow guide hole 140 and reduce the internal resistance of the flow guide hole 140, thereby enhancing the physical heat dissipation effect of the protection board body 100. In addition, by providing a second metal filling structure inside the flow guide hole 140, the structural strength of the protection board body 100 is enhanced, and impurities are prevented from entering the flow guide hole 140. Optionally, the first annular metal layer, the second annular metal layer, and the third annular metal layer described above can all be copper structures, which have good electrical conductivity and heat dissipation performance. Of course, they can also be other types of metal structures, and this application embodiment does not impose specific limitations on them.

[0039] Based on the battery protection board disclosed in the embodiments of this application, the embodiments of this application also disclose a battery assembly, which includes a battery cell, a housing, and the battery protection board described in any of the above embodiments. The housing encloses the battery cell, the battery protection board is disposed on the outer surface of the housing, and the battery protection board is electrically connected to the tabs of the battery cell. The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A battery protection board, characterized in that, The device includes a protection board body (100) and a current source (200). The current source (200) is disposed on the protection board body (100). The protection board body (100) has a plurality of spaced electrical connection holes (110). The central axis of each electrical connection hole (110) extends along the thickness direction of the protection board body (100). The plurality of electrical connection holes (110) includes a first electrical connection hole group (111) and a second electrical connection hole group (112) arranged side by side along a first direction. The current source (200) is disposed on the side of the first electrical connection hole group (111) away from the second electrical connection hole group (112). Each electrical connection hole (110) in the first electrical connection hole group (111) and each electrical connection hole (110) in the second electrical connection hole group (112) are arranged sequentially at intervals along a second direction, and each electrical connection hole (110) in the first electrical connection hole group (111) and each electrical connection hole (110) in the second electrical connection hole group (112) are staggered in the second direction. Wherein, the first direction is perpendicular to the second direction, and both the first direction and the second direction are perpendicular to the thickness direction of the protective plate body (100).

2. The battery protection board according to claim 1, characterized in that, The distance between adjacent electrical connection holes (110) in the first electrical connection hole group (111) is equal, the distance between adjacent electrical connection holes (110) in the second electrical connection hole group (112) is equal, and the distance between each electrical connection hole (110) in the first electrical connection hole group (111) and the electrical connection hole (110) in the second electrical connection hole group (112) and its adjacent electrical connection hole (110) is equal.

3. The battery protection board according to claim 1, characterized in that, Each of the electrical connection holes (110) is provided with a conductive filling structure, which is located at the opening of the electrical connection hole (110). The conductive filling structure is at least one of conductive ink and conductive epoxy resin.

4. The battery protection board according to claim 1, characterized in that, Each of the electrical connection holes (110) is located on the same side of the current source (200), and both ends of each electrical connection hole (110) extend to opposite sides of the protective plate body (100). Each of the electrical connection holes (110) has a first annular ring (113) at its end. The outer diameter of the first annular ring (113) is greater than or equal to 0.55 mm and less than or equal to 0.6 mm, and the inner diameter of the first annular ring (113) is greater than or equal to 0.3 mm and less than or equal to 0.35 mm; and / or, There is a first distance between the central axes of adjacent electrical connection holes (110) in the first electrical connection hole group (111), a second distance between the central axes of adjacent electrical connection holes (110) in the second electrical connection hole group (112), and a third distance between each electrical connection hole (110) in the first electrical connection hole group (111) and the central axis of the electrical connection hole (110) in the second electrical connection hole group (112) and its adjacent one. The first distance, the second distance, and the third distance are all equal, and the first distance, the second distance, and the third distance are all greater than 0.6 mm and less than 0.7 mm; and / or, Each of the electrical connection holes (110) has a first annular metal layer on its inner wall, the thickness of which is greater than or equal to 15 μm and less than or equal to 25 μm.

5. The battery protection board according to claim 1, characterized in that, The main body (100) of the protection board is an HDI board. The plurality of electrical connection holes (110) include multiple rings of electrical connection holes arranged at intervals along a third direction. Each ring of electrical connection holes surrounds the current source (200). The multiple rings of electrical connection holes include a first ring of electrical connection holes (114) and a second ring of electrical connection holes (115). The first ring of electrical connection holes (114) includes a first group of electrical connection holes (111), and the second ring of electrical connection holes (115) includes a second group of electrical connection holes (112). Wherein, the third direction is the direction in which the current source (200) extends along the edge of the protection plate body (100).

6. The battery protection board according to claim 5, characterized in that, The first ring of electrical connection holes (114) further includes a third electrical connection hole group (114a), which is located on different sides of the current source (200) and the first electrical connection hole group (111). The second ring of electrical connection holes (115) further includes a fourth electrical connection hole group (115a), which is located on different sides of the current source (200) and the second electrical connection hole group (112). The third electrical connection hole group (114a) is located between the fourth electrical connection hole group (115a) and the current source (200). Each electrical connection hole (110) of the third electrical connection hole group (114a) is opposite to each electrical connection hole (110) of the fourth electrical connection hole group (115a) in the third direction.

7. The battery protection board according to claim 5, characterized in that, The protective board body (100) includes a stacked substrate and a wiring layer group. Each of the electrical connection holes (110) is located in the wiring layer group and is electrically connected to the wiring layer group. The length of each electrical connection hole (110) is less than the thickness of the wiring layer group. The first end of each electrical connection hole (110) extends to the side of the wiring layer group opposite to the substrate. Each of the electrical connection holes (110) has a second annular ring (117) at its end. The outer diameter of the second annular ring (117) is greater than or equal to 0.3 mm and less than or equal to 0.35 mm, and the inner diameter of the second annular ring (117) is greater than or equal to 0.1 mm and less than or equal to 0.15 mm; and / or, Each of the electrical connection holes (110) has a second annular metal layer on its inner wall, the thickness of which is greater than or equal to 15 μm and less than or equal to 20 μm.

8. The battery protection board according to claim 7, characterized in that, The protection board body (100) is also provided with a plurality of spaced-apart overcurrent holes (120). The central axis of each overcurrent hole (120) extends along the thickness direction of the protection board body (100). Each overcurrent hole (120) is located within the wiring layer group and is electrically connected to the wiring layer group. Each overcurrent hole (120) forms the current source (200). Each of the aforementioned flow passages (120) has a third perforated ring (121) at its end. The outer diameter of the third perforated ring (121) is greater than 0.5 mm and less than 0.6 mm, and the inner diameter of the third perforated ring (121) is greater than 0.25 mm and less than 0.5 mm; and / or, Each of the flow holes (120) has a third annular metal layer on its inner wall, the thickness of which is greater than or equal to 49 μm and less than or equal to 55 μm.

9. The battery protection board according to claim 1, characterized in that, The protective board body (100) is further provided with an electrical connection groove (130), the electrical connection groove (130) is located on the first surface of the protective board body (100), the electrical connection groove (130) extends to the wiring layer group of the protective board body (100) and is electrically connected to the wiring layer group, the electrical connection groove (130) is a long strip structure, the electrical connection groove (130) is provided with a first metal filling structure, the first metal filling structure is located at the groove opening of the electrical connection groove (130) and the first metal filling structure is flush with the first surface; and / or, The protection board body (100) is also provided with a flow guide hole (140) and a pad (150). The flow guide hole (140) is located on the pad (150). One end of the flow guide hole (140) extends to the wiring layer group of the protection board body (100) and is electrically connected to the wiring layer group. A second metal filling structure is provided in the flow guide hole (140). The second metal filling structure is located at the opening of the flow guide hole (140) and is flush with the side of the pad (150) facing away from the wiring layer group.

10. A battery assembly, characterized in that, The device includes a battery cell, a housing, and a battery protection board according to any one of claims 1 to 9, wherein the housing encloses the battery cell, the battery protection board is disposed on the outer surface of the housing, and the battery protection board is electrically connected to the tabs of the battery cell.

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