Protection circuit module and battery

Abstract

The utility model relates to the technical field of batteries, in particular to a protection circuit module and a battery, the protection circuit module comprises a circuit board, a circuit device and a precision resistor, the circuit board is provided with a mounting surface, and an accommodating cavity is formed in the circuit board; the circuit device is arranged on the mounting surface of the circuit board; the precision resistor is embedded in the accommodating cavity of the circuit board and is provided with a detection point connected with the circuit device, and the detection point is used for detecting current flowing through the precision resistor; the protection circuit module can effectively reduce the overall size, reduces the occupation of the battery space, and facilitates the further improvement of the electric quantity of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a protection circuit module and a battery. Background Art

[0002] To meet user requirements, the design goal of most current mobile phones is to enable the battery to charge quickly (charge as much power as possible in a short time). To increase the charging current, the maximum current-carrying requirement of the current mobile phone battery protection board has reached more than 12A. As the current increases, the temperature of the PCB will increase significantly, and it is very easy to have the phenomenon of overheating when the mobile phone is charging. High temperature has a great impact on the battery and there is a risk of explosion. The current protection circuit module PCM (Protection Circuit Module) of the mobile phone battery is used to detect the charging and discharging current of the battery, which directly affects the electrical performance and the safety of the battery.

[0003] In many current design solutions, there are relatively high requirements for the battery thickness, and all components of the protection circuit are designed on the same side of the PCB. The precision resistor used to detect the magnitude of the charging and discharging current is attached to the current-carrying main line of the PCB through solder paste using surface mount technology, making the overall size of the circuit protection module relatively large, occupying more battery space, and being unfavorable for the battery to further increase the power. Summary of the Utility Model

[0004] The purpose of the present application is to provide a protection circuit module and a battery. The protection circuit module can effectively reduce the overall size, reduce the occupation of battery space, and is beneficial for the battery to further increase the power.

[0005] To this end, in a first aspect, an embodiment of the present application provides a protection circuit module, including: a circuit board having an installation surface, and an accommodation cavity is provided inside the circuit board; circuit components are arranged on the installation surface of the circuit board; and a precision resistor is embedded in the accommodation cavity of the circuit board. The precision resistor has a detection point connected to the circuit components, and the detection point is used to detect the current flowing through the precision resistor.

[0006] In a possible implementation, the extending direction of the precision resistor is parallel to the thickness direction of the circuit board.

[0007] In a possible implementation, the detection point includes a first detection point, and the first detection point is electrically connected to the circuit components through copper plating.

[0008] In a possible implementation, a first via hole communicating with the accommodation cavity is provided inside the circuit board. The first via hole is located on the side of the precision resistor away from the circuit components, and the detection point further includes a second detection point, and the second detection point is electrically connected to the circuit components through the first via hole.

[0009] In a possible implementation, the first via hole extends along the thickness direction of the circuit board.

[0010] In a possible implementation, a plurality of second detection points are provided, and the plurality of second detection points are arranged at intervals along the surface of the precision resistor.

[0011] In a possible implementation, a second via hole communicating with the accommodation cavity is provided inside the circuit board. The second via hole is parallel to the mounting surface. The detection point further includes a third detection point, and the third detection point is electrically connected to the circuit device through the second via hole.

[0012] In a possible implementation, a copper plating layer is provided inside the first via hole and the second via hole.

[0013] In a possible implementation, the protection circuit module further includes a nickel sheet disposed on the circuit device, and the projection of the accommodation cavity along the thickness direction of the circuit board is within the coverage of the nickel sheet.

[0014] In a second aspect, an embodiment of the present application provides a battery, including: a battery body; and the above-mentioned protection circuit module, the protection circuit module is connected to the electrodes of the battery body for protecting the battery body.

[0015] According to a protection circuit module and a battery provided by an embodiment of the present application, by embedding the precision resistor into the accommodation cavity inside the circuit board, compared with the prior art in which the precision resistor is mounted on the circuit device through solder paste and the extending direction of the precision resistor is parallel to the circuit board, not only can the occupied space be reduced by avoiding the exposed setting of the precision resistor, but also the volume of the precision resistor can be effectively reduced. Furthermore, the overall size can be effectively reduced, the occupation of the battery space can be reduced, which is beneficial to further improving the battery power. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts. In addition, in the drawings, the same components are denoted by the same reference numerals, and the drawings are not drawn to actual scale.

[0017] Figure 1 Showing a schematic cross-sectional structure diagram of a protection circuit module provided by an embodiment of the present application;

[0018] Figure 2 Showing a schematic cross-sectional structure diagram of a protection circuit module in the prior art;

[0019] Description of the reference numerals:

[0020] 1. Circuit board; 11. Mounting surface; 12. First via; 13. Second via;

[0021] 2. Circuit device;

[0022] 3. Precision resistor; 31. First detection point; 32. Second detection point; 33. Third detection point;

[0023] 4. Nickel sheet;

[0024] 5. Solder;

[0025] 6. Protective layer;

[0026] 7. Electrode. Specific implementation manner

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0028] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present application. To simplify the disclosure of the embodiments of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the embodiments of the present application. In addition, the embodiments of the present application may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0029] For ease of description, spatial relative relationship terms may be used in the text to describe the relative position or movement of one element or feature shown in the figure with respect to another element or feature. These relative relationship terms are, for example, "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", "front", "rear", etc. Such spatial relative relationship terms are intended to include different orientations of the device in use or operation other than the orientations depicted in the figure. For example, if the device in the figure undergoes a position flip, attitude change, or motion state change, then these directional indications will also change accordingly. For example, an element described as "below" or "beneath" other elements or features will then be oriented as "above" or "over" other elements or features. Thus, the exemplary term "below" can include both the upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used in the text are interpreted accordingly.

[0030] To solve the problems in the prior art, the present application provides a protection circuit module and a battery. The protection circuit module can effectively reduce the overall size, reduce the occupation of the battery space, and is beneficial for the battery to further increase the power.

[0031] As Figure 1 shown, an embodiment of the present application provides a protection circuit module, including: a circuit board 1, a circuit device 2, and a precision resistor 3.

[0032] The circuit board 1 has a mounting surface 11, and a receiving cavity is provided inside the circuit board 1.

[0033] The circuit device 2 is disposed on the mounting surface 11 of the circuit board 1. Specifically, the circuit device 2 is an electronic circuit and / or a power electronic device.

[0034] The precision resistor 3 is embedded in the receiving cavity of the circuit board 1. The precision resistor 3 has a detection point connected to the circuit device 2, and the detection point is used to detect the current flowing through the precision resistor 3. Specifically, the precision resistor 3 is made of an alloy and has a specific resistance value. By detecting the current flowing through it, the voltage across its two ends can be determined, and then the magnitude of the charging and discharging current of the battery can be detected.

[0035] In this application, by embedding the precision resistor 3 into the accommodation cavity within the circuit board 1 and setting the extension direction of the precision resistor 3 at an angle to the thickness direction X of the circuit board 1, compared with the prior art where the precision resistor 3 is mounted on the circuit device 2 through solder paste and the extension direction of the precision resistor 3 is parallel to the circuit board 1, not only can the occupied space be reduced by avoiding the exposed setting of the precision resistor 3, but also the volume of the precision resistor 3 can be effectively reduced. Furthermore, the overall size can be effectively reduced, the occupation of the battery space can be reduced, which is conducive to further increasing the battery power.

[0036] As Figure 2 shown, in the related art, the precision resistor 3 for detecting the magnitude of the charging and discharging current is attached to the main current-carrying line of the PCB through solder 5 using surface mount technology. The precision resistor 3 is located outside the circuit board 1, and the solder 5 also has a certain thickness. Protective layers 6 need to be provided on both sides of the precision resistor 3, resulting in a large occupied space. Moreover, the width of the precision resistor 3 is limited by the width of the circuit board 1 and cannot be made too wide, which will affect the battery capacity. The height is limited by the thickness of the battery and cannot be made too thick, and the length cannot be made too short for the following main reasons: in the surface mount process, the precision resistor 3 has two current-carrying electrodes 7. To ensure the accuracy of the resistance value, the detection circuit needs to be designed from the center direction of the inner spacing between the two electrodes 7, and a certain safety distance needs to be reserved between the electrodes 7; in addition, the two electrodes 7 also need to occupy the length dimension of the precision resistor 3 body. Moreover, the precision resistor 3 is exposed, which is not convenient for protecting the precision resistor 3.

[0037] In the embodiment of this application, by embedding the precision resistor 3 into the accommodation cavity of the circuit board 1, the space outside the circuit board 1 will not be occupied. Moreover, the extension direction of the precision resistor 3 is changed from being perpendicular to the thickness direction X of the circuit board 1 to forming an angle a with the thickness direction X of the circuit board 1. According to R = ρ * L / S, the volume of the precision resistor 3 can be made smaller, further reducing the space occupied by the precision resistor 3. The area of the circuit board 1 can be reduced, and thus the overall volume of the protection circuit module can be reduced, reducing the occupation of the battery space. Moreover, by embedding the precision resistor 3 into the accommodation cavity of the circuit board 1, the precision resistor 3 can be well protected.

[0038] Specifically, the current in the precision resistor 3 flows along the extension direction of the precision resistor 3.

[0039] Preferably, the extension direction of the precision resistor 3 is parallel to the thickness direction X of the circuit board 1.

[0040] In this application, by setting the extending direction of the precision resistor 3 to be parallel to the thickness direction X of the circuit board 1, the precision resistor 3 can be made into a relatively regular shape. L is the thickness of the precision resistor 3, and S is the cross-sectional area of the precision resistor 3 perpendicular to L. This not only facilitates controlling the resistance value of the precision resistor 3 and embedding the precision resistor 3 into the circuit board 1, but also, according to R = ρ*L / S, can minimize the volume of the precision resistor 3 to the greatest extent.

[0041] Optionally, the precision resistor 3 can also be set into other irregular shapes according to needs, such as a boss structure, a cone structure, a frustum structure, etc., as long as the current direction flowing through the precision resistor 3 is consistent with the thickness direction X of the circuit board 1.

[0042] In some embodiments, the detection point includes a first detection point 31, and the first detection point 31 is electrically connected to the circuit device 2 through copper plating.

[0043] In this application, the accommodating cavity on the circuit board 1 is open on the side facing the mounting surface 11, and the first detection point 31 of the precision resistor 3 is directly electrically connected to the circuit device 2 through copper plating, which facilitates embedding the precision resistor 3 into the circuit board 1 and simplifies the assembly process.

[0044] In a specific embodiment, the thickness of the precision resistor 3 is the same as the thickness of the circuit board 1, that is, the precision resistor 3 penetrates the circuit board 1. One end of the precision resistor 3 is directly electrically connected to the circuit device 2, and the other end is also electrically connected to the circuit device 2 through a circuit.

[0045] In another embodiment, a first via 12 communicating with the accommodating cavity is provided inside the circuit board 1. The first via 12 is located on the side of the precision resistor 3 away from the circuit device 2. The detection point further includes a second detection point 32, and the second detection point 32 is electrically connected to the circuit device 2 through the first via 12.

[0046] In this application, the thickness of the precision resistor 3 is less than the thickness of the circuit board 1. One end of the precision resistor 3 is directly electrically connected to the circuit device 2 through the first detection point 31, and the other end is electrically connected to the circuit device 2 through the first via 12.

[0047] As Figure 2 described, in the related art, the precision resistor 3 is mounted on the surface of the circuit device 2 through solder 5. The solder 5 not only has a certain thickness, increasing the size, but also introduces the resistance of the solder paste, thus reducing the detection accuracy. In this application, the precision resistor 3 is embedded in the circuit board 1. One end of the precision resistor 3 is directly electrically connected to the circuit device 2, and the other end is electrically connected through the first via 12, without introducing the resistance of solder paste, etc., so that the voltage across the precision resistor 3 can be detected more accurately.

[0048] In some embodiments, the first via 12 extends along the thickness direction X of the circuit board 1.

[0049] In this application, by setting the extending direction of the first via 12 to the thickness direction X of the circuit board 1, the length of the first via 12 can be minimized as much as possible, and the influence of the first via 12 on the precision resistor 3 can be minimized as much as possible.

[0050] In some embodiments, a plurality of second detection points 32 are provided, and the plurality of second detection points 32 are arranged at intervals along the surface of the precision resistor 3.

[0051] In this application, by providing a plurality of second detection points 32, different second detection points 32 are used in cooperation with the first detection point 31, and different parts of the precision resistor 3 can be selected for detection, that is, the parts of the precision resistor 3 through which the current flows are different, and the actual resistance of the precision resistor 3 used is also different, improving the practicability.

[0052] In some embodiments, a copper plating layer is provided inside the first via 12.

[0053] In this application, by providing a copper plating layer inside the first via 12, one end of the copper plating layer of the first via 12 is electrically connected to the second detection point 32 of the precision resistor 3, and the other end is electrically connected to the circuit device 2. The connection of the copper plating layer to the circuit device 2 can be in the form of an electronic circuit, which is not limited here.

[0054] In some embodiments, a second via 13 communicating with the accommodation cavity is provided inside the circuit board 1. The second via 13 is parallel to the mounting surface 11. The detection point further includes a third detection point 33, and the third detection point 33 is electrically connected to the circuit device 2 through the second via 13.

[0055] In this application, in order to further expand the utilization rate of the precision resistor 3, the third detection point 33 of the precision resistor 3 can also be electrically connected to the circuit device 2 through the second via 13. The second via 13 is parallel to the mounting surface 11, so as to select a section of the precision resistor 3 in the thickness direction X for use, and the second via 13 is far from the first via 12, which can ensure a safety distance and improve safety.

[0056] Specifically, the second via 13 can be provided at one end of the precision resistor 3 away from the first detection point 31, or can be provided at the middle position of the precision resistor 3 in the thickness direction X.

[0057] In this application, one second via 13 is provided, or multiple second vias 13 can be provided according to needs.

[0058] In some embodiments, a copper plating layer is provided inside the second via 13.

[0059] In this application, one end of the copper plating layer in the second via 13 is electrically connected to the precision resistor 3, and the other end is electrically connected to the circuit device 2. The copper plating layer has a small resistance, which can minimize the influence on the resistance value of the precision resistor 3 as much as possible.

[0060] Optionally, the copper plating layers in the first via 12 and the second via 13 can also be set to silver plating or the like.

[0061] In some embodiments, the protection circuit module further includes a nickel sheet 4 disposed on the circuit device 2, and the projection of the accommodation cavity along the thickness direction X of the circuit board 1 is located within the coverage of the nickel sheet 4.

[0062] In this application, by arranging the accommodation cavity below the nickel sheet 4, the area of the circuit board 1 can be further reduced, and thus the overall space of the protection circuit module can be reduced. Moreover, by arranging the precision resistor 3 below the nickel sheet 4, the protection of the precision resistor 3 can be further improved.

[0063] In some embodiments, the nickel sheet 4 is connected to the circuit device 2 by solder 5.

[0064] In this application, the nickel sheet 4 is electrically connected to the circuit device 2 by solder 5, which facilitates the assembly of the nickel sheet 4 and the circuit device 2. Optionally, the nickel sheet 4 can also be connected to the circuit device 2 in other ways.

[0065] By embedding the precision resistor 3 of the protection circuit module into the accommodation cavity in the circuit board 1 and setting the current flowing through the precision resistor 3 at an angle to the thickness direction X of the circuit board 1, compared with the prior art where the precision resistor 3 is mounted on the circuit device 2 by solder paste and the current flowing through the precision resistor 3 is parallel to the circuit board 1, not only can the occupied space be reduced by avoiding the exposed setting of the precision resistor 3, but also the volume of the precision resistor 3 can be effectively reduced, thereby effectively reducing the overall size and the occupied space of the battery, which is beneficial to further improving the battery power.

[0066] An embodiment of this application provides a battery, including: a battery body; and the above protection circuit module, and the protection circuit module is used to protect the battery body.

[0067] In this application, by embedding the precision resistor 3 of the protection circuit module into the circuit board 1, the overall thickness of the protection circuit module can be thinned, and the extending direction of the precision resistor 3 is set at an angle to the thickness direction X of the circuit board 1, which can effectively reduce the volume of the precision resistor 3, reduce the area of the circuit board 1 in the plane, and further reduce the occupied space of the battery, so that the battery body can have more space, thereby improving the power of the battery body.

[0068] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an" and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing" and "having" are inclusive and thus specify the presence of stated features, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0069] Although the terms first, second, third, etc. may be used herein to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer or section from another. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms when used herein do not imply an order or sequence. Thus, the first element, component, region, layer or section discussed below may be referred to as the second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0070] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A protection circuit module, characterized in that, Comprising: A circuit board (1) having a mounting surface (11), and an accommodation cavity is provided inside the circuit board (1); Circuit components (2) disposed on the mounting surface (11) of the circuit board (1); and A precision resistor (3) embedded in the accommodation cavity of the circuit board (1), the precision resistor (3) having a detection point connected to the circuit components (2), and the detection point being used for detecting the current flowing through the precision resistor (3).

2. The protection circuit module according to claim 1, wherein The extending direction of the precision resistor (3) is parallel to the thickness direction of the circuit board (1).

3. The protection circuit module according to claim 1, characterized in that, The detection point includes a first detection point (31), and the first detection point (31) is electrically connected to the circuit components (2) by copper plating.

4. The protection circuit module according to claim 3, wherein A first via hole (12) communicating with the accommodation cavity is provided inside the circuit board (1), the first via hole (12) is located on a side of the precision resistor (3) away from the circuit components (2), the detection point further includes a second detection point (32), and the second detection point (32) is electrically connected to the circuit components (2) through the first via hole (12).

5. The protection circuit module according to claim 4, wherein The first via hole (12) extends along the thickness direction of the circuit board (1).

6. The protection circuit module according to claim 4, wherein A plurality of the second detection points (32) are provided, and the plurality of second detection points (32) are spaced apart along the surface of the precision resistor (3).

7. The protection circuit module according to claim 4, wherein A second via hole (13) communicating with the accommodation cavity is provided inside the circuit board (1), the second via hole (13) is parallel to the mounting surface (11), the detection point further includes a third detection point (33), and the third detection point (33) is electrically connected to the circuit components (2) through the second via hole (13).

8. The protection circuit module according to claim 7, wherein A copper plating layer is provided inside the first via hole (12) and the second via hole (13).

9. The protection circuit module according to claim 1, characterized in that The protection circuit module further includes a nickel sheet (4) disposed on the circuit components (2), and the projection of the accommodation cavity along the thickness direction of the circuit board (1) is within the coverage of the nickel sheet (4).

10. A battery, characterized in that, Comprising: A battery body; And The protection circuit module according to any one of claims 1-9, the protection circuit module being connected to the electrodes of the battery body for protecting the battery body.

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