CN216017272U - Circuit board and battery pack - Google Patents

Abstract

The embodiment of the application discloses circuit board and group battery, wherein, the circuit board includes the base plate, sets up the functional module on the base plate and sets up the unit of fusing on the base plate, and the unit of fusing includes the fuse and wraps in the insulating layer of fuse, and the unit of fusing is connected with the functional module electricity, and the insulating layer is formed through locating the peripheral postcure of fuse with insulating material, and the insulating layer wraps at least partial structure of fuse, insulating layer bonding fuse and base plate. By the above mode, a simpler fuse structure can be provided.

Description

Circuit board and battery pack

Technical Field

The application relates to the technical field of circuit protection equipment, in particular to a circuit board and a battery pack.

Background

With the development of the electronic industry, the requirements for miniaturization and integration of elements in the field of electronic products are higher and higher, namely, the volume of a circuit board is greatly reduced. Meanwhile, as the circuit board is reduced, the number of protection elements disposed on the circuit board is also reduced.

In the prior art, a common protection element is a fuse, and the fuse has a structure composed of a melt portion, an electrode portion, and a housing portion, wherein the housing portion is used for supporting and connecting the fuse, and the housing portion is used for accumulating heat to the fuse and ensuring fusing when the melt portion of the fuse is subjected to arc extinction.

The shell part of the existing fuse usually needs to adopt structures such as a ceramic shell and the like, and the structure is complex.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application aims at providing a circuit board and a battery pack, and a simpler fuse structure can be provided.

In order to achieve the above object, in a first aspect, the present application provides a circuit board, which includes a substrate, a functional module and a conductive wire disposed on the substrate, and a fuse unit disposed on the substrate. The fusing unit comprises a fuse wire and an insulating layer coated on the fuse wire, the fusing unit is electrically connected with the functional module through a wire, the insulating layer is formed by arranging insulating materials on the periphery of the fuse wire and then solidifying the insulating materials, the insulating layer coats at least part of the structure of the fuse wire, and the insulating layer is bonded with the fuse wire and the substrate.

Under the abnormal condition, the fusing unit can be used for disconnecting the input power supply from the functional module, namely disconnecting the power supply source of the functional module, and protecting the functional module.

In an optional manner, the fuse unit further includes a first electrode and a second electrode, wherein the first electrode and the second electrode are both soldered on the substrate, and the fuse is disposed between the first electrode and the second electrode.

In an alternative mode, a gap exists between the fuse and the substrate, the gap is larger than 0 and smaller than or equal to 2mm, and the insulating layer is at least partially arranged in the gap.

The abnormal conditions of burning, explosion and carbonization of the substrate caused by explosion and cracking generated when the fuse wire is fused can be reduced, and the function of protecting the substrate can be achieved.

In an alternative form, the fuse includes at least one of a linear type, an S-type, or a spiral type.

In an alternative form, the insulating layer includes at least one air bubble. The oxygen in the air helps the fuse to blow faster.

In an alternative form, at least one air bubble is included between the insulating layer and the fusible link. The fusing of the fuse can be further improved.

In an alternative way, the edge of the insulating layer extends 2-4 mm beyond the edge of the fuse in the length direction of the fuse, and/or 3-5 mm beyond the edge of the fuse in the width direction of the fuse, and/or 2-4 mm above the fuse in the height direction of the fuse.

By defining the size relationship between the insulating layer and the fuse in the length, width and height directions of the fuse, respectively, it is possible to achieve that the fuse is completely covered by the insulating layer. On one hand, the fuse wire can be well protected through the insulating layer, and the possibility that the fuse wire is damaged due to external conditions is reduced; on the other hand, when the fuse wire is fused, the impact force caused by the explosion of the fuse wire can be reduced to a greater extent, and the safety is improved.

In an alternative form, the insulating layer has a middle portion and two end portions, the middle portion having a thickness greater than the two end portions, and a difference in thickness between the middle portion and the two end portions being greater than or equal to 2 millimeters.

Wherein, the breakdown voltage intensity of the insulating layer can be set to be more than or equal to 18 kilovolts/millimeter so as to improve the safety of the circuit on the circuit board. Further, if the thermal conductivity of the insulating layer is set to 0.3W/m.degree or less, the heat accumulation when a large current passes through the fuse can be increased, which is advantageous for fusing the fuse. Further, the tensile strength of the insulating layer may be set to 1.5 mpa or more, and thus, when the fuse is blown, the slag inside the fuse is prevented from being broken or cracked. In addition, the insulating layer may be provided with an elongation at break of eighty percent or more, which reduces arcing after the fuse is blown. Meanwhile, the fuse wire can be provided with the functions of water resistance, mildew resistance, static electricity resistance and the like, so that the fuse wire can be used under different working conditions. Further, the insulating layer can be made of transparent material, so that the actual state of the fuse can be known more conveniently.

In an optional manner, the function module includes a power supply unit, a logic control unit, and an execution unit, where the logic control unit is electrically connected to the execution unit, the power supply unit is electrically connected to an external input power supply, the logic control unit, and the execution unit, and the fusing unit is disposed between the input power supply and the power supply unit, and specifically, the execution unit is configured to execute a corresponding function according to a control signal of the logic control unit, and the power supply unit is configured to provide a working voltage for the logic control unit and the execution unit according to the input power supply.

In a second aspect, the present application provides a battery pack, including a cell module and the circuit board as in the first aspect above. The battery cell module is electrically connected with the circuit board and is used for providing an input power supply for the circuit board.

In an optional mode, the total positive pole and the total negative pole of the battery cell module are connected to the circuit board, and the fusing unit in the circuit board is arranged between the total positive pole and the total negative pole.

When the cell module is abnormal, the total positive electrode and the total negative electrode which can be disconnected by the fusing unit are connected, the cell module stops charging or discharging, the performance of the cell module is favorably improved,

in an optional manner, the circuit board further includes a first fuse unit, a first switch tube, a second switch tube, and a first resistor. The first end of the first fusing unit is electrically connected with the battery cell module, the second end of the first fusing unit is electrically connected with the third end of the first switch tube, the second end of the first switch tube is electrically connected with the second end of the second switch tube, the third end of the second switch tube is electrically connected with external equipment, and the two ends of the first resistor are electrically connected with the battery cell module and the external equipment respectively.

In an optional mode, the circuit board further includes a battery sampling chip and at least one voltage sampling branch, and the voltage sampling branch corresponds to the cells in the cell module one to one. The voltage sampling branch circuit comprises a second fusing unit, a second resistor, a first capacitor and a third switching tube. The first end of the second fusing unit is electrically connected with the anode of the corresponding battery core, the second end of the second fusing unit is electrically connected with the second end of the third switching tube and the first end of the second resistor, the first end of the third switching tube is electrically connected with the battery core acquisition chip, the third end of the third switching tube is electrically connected with the cathode of the corresponding battery core, the second end of the second resistor is electrically connected with the first end of the first capacitor and the battery acquisition chip, and the second end of the first capacitor is grounded.

In an optional manner, the circuit board further includes a third fuse unit and a first zener diode. The third fusing unit is connected with the first voltage stabilizing diode in series, and a circuit formed by the third fusing unit and the first voltage stabilizing diode is connected with external equipment.

In an optional manner, the circuit board further includes a fourth fuse unit, a first diode, a second zener diode, a second capacitor, and a voltage conversion unit. The first end of the fourth fusing unit is electrically connected with the battery cell module, the second end of the fourth fusing unit is electrically connected with the anode of the first diode, the cathode of the first diode is electrically connected with the cathode of the second voltage stabilizing diode, the first end of the second capacitor and the first end of the voltage conversion unit, and the anode of the second voltage stabilizing diode and the second end of the second capacitor are all grounded.

One or more embodiments of the present application include the following advantageous effects: the application provides a circuit board, including the base plate, set up functional module and wire on the base plate, and set up in basic fusing unit, at first, fusing unit sets up between input power and functional module, fusing unit plays the guard action promptly, and secondly, fusing unit includes fuse and cladding in the insulating layer of fuse, and wherein, the insulating layer is formed through the peripheral postcure of locating the insulating material fuse, and the at least partial structure of cladding fuse, simple structure.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a schematic structural diagram of a circuit board provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a circuit board according to another embodiment of the present application;

FIG. 3 is a schematic structural diagram of a fuse unit according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a fuse unit according to another embodiment of the present disclosure;

FIG. 5 is a schematic diagram illustrating a front view and a top view of a fuse unit according to an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of a fuse unit according to another embodiment of the present disclosure;

FIG. 7 is a schematic diagram illustrating a fuse unit according to another embodiment of the present disclosure;

fig. 8 is a flowchart of a method for manufacturing a circuit board according to an embodiment of the present disclosure;

fig. 9 is a schematic circuit structure diagram of a circuit board according to an embodiment of the present disclosure;

fig. 10 is a schematic circuit diagram of a circuit board according to another embodiment of the present application;

fig. 11 is a schematic circuit diagram of a circuit board according to another embodiment of the present application;

fig. 12 is a schematic circuit structure diagram of a circuit board according to yet another embodiment of the present application.

Detailed Description

In order to make the objects, 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 drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a circuit board according to an embodiment of the present disclosure. As shown in fig. 1, the circuit board 100 includes a substrate 10, a fuse unit 20 disposed on the substrate 10, and a functional module 30 and a conductive wire W1 disposed on the substrate 10.

It is understood that, in fig. 1, the substrate 10 is illustrated as a rectangular parallelepiped structure, but in other embodiments, the substrate 10 may also be other structures, such as a cube, and the like, which is not limited herein.

In some embodiments, the fuse unit 20 is electrically connected to the functional module 30 through a wire W1, and the fuse unit 20 can be used to control whether the functional module 30 is powered. For example, when the functional module 30 is in a normal operating state, that is, parameters such as current or temperature in the functional module 30 are in a normal state, the fusing unit 20 may only function as a wire, and the functional module 30 is normally powered; when the functional module 30 is abnormal (e.g., overcurrent), the fuse module 20 may disconnect the input power 200 from the functional module 30, and may disconnect the power source of the functional module 30, so that the functional module 30 loses power, thereby protecting the functional module 30.

In one embodiment, as shown in fig. 2, the functional module 30 includes a power unit 31, a logic control unit 32, and an execution unit 33. The logic control unit 32 is electrically connected to the execution unit 33, the power supply unit 31 is electrically connected to the external input power supply 200 through the fuse unit 20, and the power supply unit 31 is further connected to the logic control unit 32 and the execution unit 33, respectively.

Specifically, the execution unit 33 is controlled by the logic control unit 32, that is, the logic control unit 32 outputs a control signal to the execution unit 33, so that the execution unit 33 executes the corresponding function. The power supply unit 31 is used for converting the input power 200 to output an operating voltage suitable for the logic control unit 32 and the execution unit 33. For example, in one embodiment, the logic control unit 32 includes a controller with 3.3V as an operating voltage, and the battery pack is used as the input power source 200, which provides 24V, and the power source unit 31 is used to convert 24V into 3.3V to provide the operating voltage for the controller. The fusing unit 20 is used for controlling the connection state between the input power 200 and the power unit 31, when the fusing unit 20 is not fused, the input power 200 is communicated with the power unit 31, and the power unit 31 obtains the input voltage, that is, the functional module 30 is normally powered; when the fusing unit 20 is fused, the input power 200 is disconnected from the power unit 31, and the power unit 31 loses the input voltage, i.e., the functional module 30 loses power.

Referring to fig. 1 and 3 together, fig. 3 is a schematic structural diagram of a fuse unit 20 according to an embodiment of the present disclosure. The blowing unit 20 includes a fuse 21 and an insulating layer 22 covering the fuse. In practical applications, the fuse 21 may be soldered on the substrate 10, an insulating material may be disposed on the periphery of the fuse 21, such as on the surface of the fuse 21, and the insulating layer 22 may be formed after the insulating material is cured. The insulating layer 22 covers at least a part of the fuse 21, for example, as shown in fig. 3, the insulating layer 22 covers the whole fuse 21, which is beneficial to better protecting the fuse 21 and reducing the damage of other foreign objects to the fuse 21. The insulating layer 22 also serves to adhere the fuse 21 to the substrate 10, so that the fuse 21 can be more firmly fixed to the substrate 10, which is advantageous for reducing the separation between the fuse 21 and the substrate 10.

It should be noted that, in the embodiment shown in fig. 3, the fuse 21 has a linear structure, and in other embodiments, the fuse 21 may also have other structures, for example, the fuse 21 shown in fig. 4 has an S-shaped structure, and for example, the fuse 21 may also have a spiral structure, and the like, which is not limited herein. In some embodiments, the melting point of the fuse 21 itself is higher than the temperature of the soldering process, for example, if the fuse 21 is soldered by a reflow soldering process, which is about 300 ℃, the melting point of the fuse 21 should be higher than 300 ℃ to reduce the fusing of the fuse 21 during soldering.

In some embodiments, the insulating layer 22 has good insulating properties. Optionally, the breakdown voltage of the insulating layer 22 is greater than or equal to 18 kv/mm, which may improve the safety of the lines on the circuit board. The breakdown voltage strength is also called dielectric breakdown strength, which means that the material is prevented from being damaged (broken down) under the action of an electric field, and can bear the highest electric field strength.

In some embodiments, the insulating layer 22 has good thermal insulation properties, for example, the insulating layer 22 has a thermal conductivity less than or equal to 0.3W/m.degree, which can improve the heat accumulation when a large current passes through the fuse 21, and facilitate the fusing of the fuse 21. Thermal conductivity, also called thermal conductivity or thermal conductivity, is a physical quantity representing the magnitude of the thermal conductivity of a material.

In some embodiments, the tensile strength of the insulating layer 22 is greater than or equal to 1.5 mpa, which can limit the molten slag inside the fuse 21 from breaking or bursting when the fuse 21 is blown. Wherein, the tensile strength generally refers to the tensile strength, the tensile strength is the resistance which represents the maximum uniform plastic deformation of the material, the deformation of the tensile sample is uniform and consistent before the tensile sample bears the maximum tensile stress, but after the maximum tensile stress is exceeded, the metal begins to generate necking phenomenon, namely concentrated deformation, and for the brittle material without (or with small) uniform plastic deformation, the metal reflects the fracture resistance of the material.

In some embodiments, the insulating layer 22 has an elongation at break of eighty percent or greater, which reduces arcing after the fuse 21 is blown. Wherein, the elongation at break refers to the ratio of the elongation length before and after stretching to the length before stretching when the fiber is broken by external force, and is called the elongation at break.

In some embodiments, the insulating layer 22 has waterproof, mildew-proof and antistatic functions, so that the fuse 21 can be used under different working conditions.

As an illustrative example, the insulating material of the insulating layer may be formed by mixing an epoxy system glue with a curing agent, an arc extinguishing agent, and water, wherein the arc extinguishing agent is sulfur hexafluoride, for example.

Further, the insulating layer 22 includes a transparent material, so that the state of the fuse 21 can be directly observed through the insulating layer 22. On one hand, the safety of the circuit is ensured by observing whether the fuse 21 is blown or not in real time and replacing the fuse 21 in time when the fuse 21 is blown. On the other hand, it is helpful to quickly find out where the fault is located when the functional module 30 is abnormal. For example, in the case of an abnormal power failure of the functional module 30, if the fuse 21 is observed not to be blown through the insulating layer 22, the power failure due to the blown fuse 21 may be excluded, whereas if the fuse 21 is observed to be blown and the functional module 30 returns to normal operation after the fuse 21 is replaced, the abnormal power failure due to the blown fuse 21 may be determined.

In one embodiment, there is a gap between the fuse 21 and the substrate 10, and during the process of coating the fuse 21 with the insulating material, the insulating material can cover the gap between the fuse 21 and the substrate 10, i.e., the insulating layer after the insulating material is cured is at least partially disposed in the gap between the fuse 21 and the substrate 10, so as to reduce the occurrence of abnormal situations of burning, explosion and carbonization of the substrate 10 caused by explosion when the fuse 21 is fused, and to protect the substrate 10. For example, when the substrate 10 is horizontally placed, the fuse 21 is soldered along the vertical direction of the substrate 10 and at a distance of 0-2mm from the substrate 10, and the gap between the fuse 21 and the substrate 10 is greater than 0 and less than or equal to 2 mm.

Optionally, the fusing element comprises at least one air bubble provided in the insulating layer 22, the oxygen in the air facilitating a faster fusing of the fuse 21. In another embodiment, the air bubble is formed between the fuse 21 and the insulating layer 22, which can further promote the fusing of the fuse 21.

Further, in another embodiment, the fuse 21 is completely covered by the insulating layer 22, which further reduces the effect of the fuse 21 that may be cracked when being blown.

The fuse unit 20 shown in fig. 3 will be described as an example. Referring to fig. 5 in conjunction with fig. 3, fig. 5 is a front view and a top view of the fuse unit 20 shown in fig. 3, wherein a in fig. 5 is a front view and b in fig. 5 is a top view.

As shown in fig. 5, in the length direction of the fuse 21, the lengths of two portions of the edge of the insulating layer 22 protruding beyond the edge of the fuse 21 are L1 and L2, respectively, i.e., the lengths between two positions where the insulating layer 22 and the fuse 21 are closest in the length direction are L1 and L2, respectively. The values of L1 and L2 are both 2-4 mm, which can reduce the influence caused by the possibility of explosion in the length direction when the fuse 21 is blown. And L1 and L2 may be the same size or different sizes.

The distance between the insulating layer 22 and the fuse 21 in the height direction of the fuse 21 is L3. The value range of L3 is 2-4 mm, which can reduce the effect of the fuse 21 that may be cracked in the height direction when it is blown. Meanwhile, in an embodiment, the insulating layer 22 may be further divided into a middle portion and two end portions, wherein the portion between the dotted line S1 and the dotted line S2 is the middle portion, and the remaining portions are the two end portions, and the height from the middle portion to the two end portions tends to decrease. The thickness of the middle part is L42, and the thickness of the two end parts is L41, so that the thickness difference between the middle part and the two end parts is L4-L42-L41, and the value range of L4 is greater than or equal to 2mm, which is beneficial to reducing the influence caused by the excessive reaction in the middle of the fuse 21 during fusing.

The lengths of the two portions of the edge of the insulating layer 22 protruding beyond the edge of the fuse 21 in the width direction of the fuse 21 are L6 and L7, respectively. The values of L6 and L7 are both 3-5 mm, which can reduce the influence caused by the possibility of explosion in the width direction when the fuse 21 is blown. And L6 and L7 may be the same size or different sizes.

The fuse 21 is completely covered with the insulating layer 22 in three directions of length, width, and height. On one hand, the fuse 21 can be well protected by the insulating layer 22, and the fuse 21 is ensured not to be damaged by external conditions; on the other hand, when the fuse 21 is blown, the impact force due to the explosion of the fuse can be reduced to a greater extent, and the safety is improved.

As can be seen from the above embodiments, the gap between the fuse 21 and the substrate 10 is greater than 0 and less than or equal to 2mm, the distance between the insulating layer 22 and the fuse 21 is L5, and L5 can cover the entire gap, so the value range of L5 is also greater than 0 and less than or equal to 2 mm.

It will be appreciated that the insulating layer 22 may take on different shapes due to the different manner in which the insulating material is applied to the fuse 21. For example, the insulating layer shown in FIG. 3 may exhibit a different shape than the insulating layer 22 shown in FIG. 6.

In one embodiment, the fuse unit 20 further includes a first electrode and a second electrode. Referring to fig. 7 together with the example of the fuse unit 20 shown in fig. 2, the fuse unit 20 further includes a first electrode 23 and a second electrode 24. Wherein, the electrode refers to a component in an electronic or electrical device and equipment and is used as two ends for inputting or outputting current in a conductive medium (solid, gas, vacuum or electrolyte solution).

Specifically, the first electrode 23 and the second electrode 24 are also soldered to the substrate, and the fuse 21 is provided between the first electrode 23 and the second electrode 24. The first electrode 23 and the second electrode 24 may have a circular, square, or annular structure, and the first electrode 23 and the second electrode 24 may be the same or different, for example, as shown in fig. 7, the first electrode 23 and the second electrode 24 are the same annular structure.

The first electrode 23 and the second electrode 24 may be made of metal, and may be used as the first electrode 23 and the second electrode 24 as long as the process of exchanging electrons is achieved.

Meanwhile, the fuse 21 can be partially connected to the first electrode 23 and the second electrode 24. The fuse 21 may be connected to the first electrode 23 or the second electrode 24 at its edge in the longitudinal direction, or may be connected to the first electrode 23 or the second electrode 24 at its intermediate position, that is, the fuse 21 may partially protrude from the first electrode 23 or the second electrode 24. Optionally, the insulating layer 22 covers at least a portion of the first electrode 23 and/or at least the second electrode 24, further protecting the first electrode 23 and/or the electrode 24. Optionally, the insulating layer 22 covers all of the first electrode 23 and/or all of the second electrode 24.

Referring to fig. 8, fig. 8 is a flowchart of a method for manufacturing a circuit board according to an embodiment of the present application, where the method includes:

step 801: and welding the fuse unit on the substrate of the circuit board.

In one embodiment, the fuse unit includes a fuse, and in this embodiment, the fuse is soldered on the substrate. In another embodiment, the fuse unit includes a fuse, a first electrode and a second electrode, and the fuse is disposed between the first electrode and the second electrode, for example, one edge of the fuse in the length direction is connected to the first electrode, and the other edge is connected to the second electrode.

Optionally, in practical applications, the fuse, the first electrode, and the second electrode may be respectively soldered on the substrate by a reflow soldering process, a wave soldering process, or spot welding with an electric welder.

Step 802: an insulating material is applied to the surface of the fuse unit.

Step 803: and the insulating material is solidified to form an insulating layer which covers at least part of the fuse unit.

In one embodiment, the insulating material may be applied to the surface of the fuse by dispensing. During dispensing, the insulating material may be a glue, which is cured within a period of time after being coated on the fuse surface to form an insulating layer for protecting the fuse. And the insulating layer can cover at least part of the fuse.

Step 804: and after the insulating material is solidified, welding the functional module.

The functional module is arranged and welded after the insulating material is solidified, so that the insulating material is solidified more fully, and the fuse wire is better coated.

An embodiment of the present application further provides a battery pack, where the battery pack includes a battery cell module and a circuit board (not shown) as in any of the above embodiments, and optionally, the circuit board includes a battery management system.

Specifically, the battery cell module is electrically connected with the circuit board, and the battery cell module is used for providing an input power supply for the circuit board. In some embodiments, total positive pole and total negative pole of electric core module are connected to the circuit board, and fusing unit in the circuit board sets up between total positive pole and the total negative pole, and when electric core module was unusual, fusing unit breakable total positive pole and total negative pole were connected, and electric core module stops to charge or discharges, is favorable to promoting the performance of electric core module, for example when electric core module charging current was too big, fusing unit fusing, total positive pole and total negative pole disconnection, and electric core module stops to charge.

In an embodiment, as shown in fig. 9, the circuit board further includes a first fuse unit 910, a first switch (in the figure, an NMOS transistor Q1), a second switch (in the figure, a PMOS transistor Q2), a first resistor R1 and a control unit 920. A first end of the first fuse unit 910 is electrically connected to the positive electrode B + of the cell module 200, a second end of the first fuse unit 910 is electrically connected to the drain of the NMOS transistor Q1, the source of the NMOS transistor Q1 is electrically connected to the source of the PMOS transistor Q2, the drain of the PMOS transistor Q2 is electrically connected to the interface P +, the interface P + and the interface P-are respectively used for electrically connecting to the positive electrode and the negative electrode of the external device 300, the control unit 920 is electrically connected to the gate of the NMOS transistor Q1 and the gate of the NMOS transistor Q2, a first end of the first resistor R1 is electrically connected to the negative electrode B-of the cell module 200 and the control unit 920, and a second end of the first resistor R1 is electrically connected to the interface P-and the control unit 920.

The gate of the NMOS transistor Q1 is the first end of the second switch transistor, the source of the NMOS transistor Q1 is the second end of the second switch transistor, and the drain of the NMOS transistor Q1 is the third end of the second switch transistor.

The grid electrode of the PMOS tube Q2 is the first end of the third switching tube, the source electrode of the PMOS tube Q2 is the second end of the third switching tube, and the drain electrode of the PMOS tube Q2 is the third end of the third switching tube.

Under normal operation, the NMOS transistor Q1 and the PMOS transistor Q1 are normally closed, and the first fuse unit 910 only serves as a conductive line. When an abnormal condition such as an overcurrent or an overvoltage occurs, the control unit 920 controls the NMOS transistor Q1 to be disconnected from the PMOS transistor Q2, so as to disconnect the battery cell module 200 from the external device 300. On the other hand, in the case where the NMOS transistor Q1 and the PMOS transistor Q2 are not disconnected, the first fuse unit 910 can be fused due to a short circuit to further disconnect the cell module 200 from the external device 300. Therefore, the possibility of explosion of the battery cell module 200 due to factors such as overcharge, overcurrent, overvoltage or overtemperature can be reduced.

It is understood that the first fuse unit 910 may include the same materials and structures as the fuse unit 20 in any of the above embodiments. For example, the first blowing unit 910 may include a fuse 911 and an insulating layer 912 covering the fuse 911. Moreover, the type and practical application of the first blowing unit 910 may be similar to the blowing unit 20, and will not be described herein again.

In addition, in this embodiment, the first fusing unit 910 is disposed between the positive electrode B + of the cell module 200 and the interface P +. In another embodiment, the first fuse unit 910 may be disposed between the negative electrode B-and the interface P-of the battery cell module 200. Similarly, the circuit formed by the NMOS transistor Q1 and the PMOS transistor Q1, and the first resistor R1 may be disposed between the positive electrode B + of the cell module 200 and the interface P +, or between the negative electrode B-of the cell module 200 and the interface P-.

In an embodiment, the circuit board further includes a battery sampling chip and at least one voltage acquisition circuit, and the voltage acquisition circuits correspond to the battery cells in the battery cell modules one to one. As shown in fig. 10, the battery pack further includes a battery sampling chip 1020, a first path of voltage acquisition circuit 1000, a second path of voltage acquisition circuit 1010 … …, and an nth path of voltage acquisition circuit, where N is a positive integer. The first path of voltage acquisition circuit 1000 is configured to acquire a voltage of a first electrical core in the electrical core module 200, and the second path of voltage acquisition circuit 1010 is configured to acquire a voltage … … of a second electrical core in the electrical core module 200, and the nth path of voltage acquisition circuit is configured to acquire a voltage of an nth electrical core in the electrical core module 200.

It can be understood that, in other embodiments, a voltage acquisition circuit may also be used to detect voltages of a plurality of battery cells in the battery cell module, which is not limited in this application embodiment.

In an embodiment, the Battery sampling chip may be an AFE (Analog Front End) chip in a BMS (Battery Management System), and the AFE chip may be used to collect cell voltage, temperature, and the like.

Any one of the voltage acquisition circuits comprises a second fusing unit, a second resistor, a first capacitor and a third switching tube. Taking the first voltage collecting circuit 1000 as an example, the first voltage collecting circuit 1000 includes a second fuse unit 1001, a second resistor R21, a first capacitor C11, and an NMOS transistor Q31 (i.e., a third switch transistor). The first end of the second fuse unit 1001 is electrically connected to the positive electrode of the corresponding cell (i.e. the first cell), the second end of the second fuse unit 1001 is electrically connected to the source of the NMOS transistor Q31 and the first end of the second resistor R21, the gate of the NMOS transistor Q31 is electrically connected to the cell acquisition chip 1020, the drain of the NMOS transistor Q31 is electrically connected to the negative electrode of the corresponding cell through the second fuse unit 1011 of the second voltage acquisition circuit 1010, the second end of the second resistor R21 is electrically connected to the first end of the first capacitor C11 and the battery acquisition chip 1020, and the second end of the first capacitor C11 is grounded.

The second resistor R21 is used for limiting the current, which is beneficial to reducing the risk that the battery sampling chip 1020 is damaged due to the excessive input current. The first capacitor C11 is used for filtering to filter out high-frequency interference in the signal sampled by the battery sampling chip 1020, which is beneficial to obtaining more accurate sampling signal, thereby improving the sampling accuracy. The battery acquisition chip 1020 controls the NMOS pipe Q31 to be closed, when surge appears in the battery core, the second fusing unit 1001 can be fused by a loop formed by the second fusing unit 1001, the NMOS pipe Q31 and the battery core, so that the input voltage of the battery acquisition chip 1020 is cut off, and the battery acquisition chip 1020 plays a role in protecting. Among them, a Surge (Electrical Surge), i.e., a peak value of a voltage or a current which instantaneously exceeds a stable value, includes a Surge voltage and a Surge current.

It is understood that the second fuse unit 1001 may include the same material and structure as the fuse unit 20 in any of the above embodiments. The second fuse unit 1001 may be similar to the fuse unit 20 in the selection and practical application, and will not be described herein again.

In one embodiment, as shown in fig. 11, the circuit board further includes a third fuse unit 1100 and a first zener diode DW1, wherein the third fuse unit 1100 is connected in series with the first zener diode DW1, and a first end of a circuit formed by the third fuse unit 1100 and the first zener diode DW1 is electrically connected to the interface P +, and a second end thereof is electrically connected to the interface P-.

In this embodiment, the non-series connection terminal of the third fuse unit 1100 is electrically connected to the interface P +, and the anode of the first zener diode DW1 is electrically connected to the interface P-. In another embodiment, the non-serial connection terminal of the third fuse unit 1100 is electrically connected to the interface P-and the anode of the first zener diode DW1 is electrically connected to the interface P +.

The first voltage stabilizing diode DW1 is arranged between the interface P + and the interface P-, so that the impact of the surge generated at the moment of connecting the external equipment 300 to the components in the main loop is reduced. Secondly, the third fuse unit 1100 is arranged in series with the first zener diode DW1, which is beneficial to reduce the risk of breakdown or breakdown of the zener diode caused by large current or large voltage.

In this embodiment, the battery pack further includes an NMOS transistor Q4 and an NMOS transistor Q5, which are disposed between the positive electrode B + of the cell module 200 and the interface P +, and the NMOS transistor Q4 and the NMOS transistor Q5 are used for controlling the connection state between the positive electrode B + of the cell module 200 and the interface P +.

It is understood that the third fuse unit 1100 may include the same materials and structures as the fuse unit 20 of any of the above embodiments. Moreover, the type and practical application of the third fuse unit 1100 may be similar to the fuse unit 20, and will not be described herein.

In an embodiment, as shown in fig. 12, the circuit board further includes a fourth fuse unit 1210, a first diode D1, a second zener diode DW2, a second capacitor C2, and a voltage converting unit 1220. The first end of the fourth fuse unit 1210 is electrically connected to the positive electrode B + of the cell module 200, the second end of the fourth fuse unit 1210 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the cathode of the second zener diode DW2, the first end of the second capacitor C2 and the first end of the voltage conversion unit 1220, and the anode of the second zener diode DW2 and the second end of the second capacitor C2 are both grounded to GND.

Wherein, through set up first diode D1 between anodal B + at electric core module 200 and voltage conversion unit 1220, first diode D1 can play the effect of preventing the back pressure to play the guard action to electric core module 200. The second zener diode DW2 is used for voltage stabilization, the second capacitor C2 is used for filtering, and the combination of the second zener diode DW2 and the second capacitor C2 is beneficial to providing a more stable input voltage for the voltage converting unit 1220.

When the voltage converting unit 1220 is in a normal operation state, the fourth fusing unit 1210 only functions as a conductive line. When the voltage converting unit 1220 is short-circuited, the fourth fusing unit 1210 can also be fused due to the short-circuit, which is beneficial to reducing the risk of explosion of the battery cell module due to over-current.

In one embodiment, the voltage converting unit 1220 includes a total voltage converting unit U1, a first sub-voltage converting unit U2, and a second sub-voltage converting unit U3. The total voltage conversion unit U1 is configured to convert the voltage of the battery cell module 200 into a first voltage, the first sub-voltage conversion unit U2 is configured to convert the first voltage into a second voltage, and the second sub-voltage conversion unit U3 is configured to convert the second voltage into a third voltage. For example, in one embodiment, the supply voltage of the control unit in the BMS is 3.3V, the supply voltage of the digital circuit is 5V, and the voltage of the cell module 200 is 20V. Furthermore, the total voltage converting unit U1 can convert 20V into 12V, and the first sub-voltage converting unit U2 and the second sub-voltage converting unit U3 convert 12V into 3.3V and 5V, respectively, to supply power to the control unit and the digital circuit, respectively.

In another embodiment, the voltage converting unit may include K sub-voltage converting units, where K is a positive integer. Each sub-voltage conversion unit is used for outputting different voltages so as to provide different power supply voltages according to the requirements of each component in the circuit board, and the stability of the work of each component is improved.

It is understood that the fourth fuse unit 1210 may include the same materials and structures as the fuse unit 20 of any of the above embodiments. Moreover, the type and practical application of the fourth fuse unit 1210 may be similar to the fuse unit 20, and are not described herein again.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; within the context of the present application, where technical features in the above embodiments or in different embodiments can also be combined, the steps can be implemented in any order and there are many other variations of the different aspects of the present application as described above, which are not provided in detail for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims (14)

1. A circuit board, comprising:

the circuit board comprises a substrate, a functional module and a lead, wherein the functional module and the lead are arranged on the substrate;

the fusing unit is arranged on the substrate and comprises a fuse wire and an insulating layer coated on the fuse wire, and the fusing unit is electrically connected with the functional module through the lead;

the insulating layer is formed by arranging an insulating material on the periphery of the fuse and then curing, the insulating layer covers at least part of the structure of the fuse, and the insulating layer is bonded with the fuse and the substrate.

2. The circuit board of claim 1,

the fusing unit further comprises a first electrode and a second electrode;

the first electrode and the second electrode are both welded on the substrate, and the fuse is arranged between the first electrode and the second electrode.

3. Circuit board according to claim 1 or 2,

a gap exists between the fuse wire and the substrate, the gap is larger than 0 and smaller than or equal to 2 millimeters, and the insulating layer is at least partially arranged in the gap.

4. Circuit board according to claim 1 or 2,

the insulating layer includes at least one air bubble.

5. Circuit board according to claim 1 or 2,

at least one air bubble is included between the insulating layer and the fuse.

6. Circuit board according to claim 1 or 2,

in the length direction of the fuse, the edge of the insulating layer extends out of the edge of the fuse by 2-4 mm;

and/or the edge of the insulating layer extends 3-5 mm beyond the edge of the fuse in the width direction of the fuse;

and/or the insulating layer is 2-4 mm higher than the fuse in the height direction of the fuse.

7. The circuit board of claim 6,

the insulating layer has a middle portion and two end portions, the thickness of the middle portion is greater than the thickness of the two end portions, and the difference in thickness between the middle portion and the two end portions is greater than or equal to 2 millimeters.

8. Circuit board according to claim 1 or 2,

the functional module comprises a power supply unit, a logic control unit and an execution unit;

the logic control unit is electrically connected with the execution unit, and the execution unit is configured to execute a corresponding function according to a control signal of the logic control unit;

the power supply unit is respectively electrically connected with an external input power supply, the logic control unit and the execution unit, and is used for providing working voltage for the logic control unit and the execution unit according to the input power supply;

the fusing unit is arranged between the input power supply and the power supply unit.

9. A battery pack, characterized by comprising a cell module and a circuit board according to any one of claims 1 to 8;

the battery cell module is electrically connected with the circuit board and is used for providing an input power supply for the circuit board.

10. The battery pack according to claim 9,

the battery cell module comprises a total positive electrode and a total negative electrode, the total positive electrode and the total negative electrode are connected to the circuit board, and a fusing unit in the circuit board is arranged between the total positive electrode and the total negative electrode.

11. The battery pack of claim 9, wherein the circuit board further comprises:

the fuse protector comprises a first fusing unit, a first switch tube, a second switch tube, a first resistor and a control unit;

the first end of the first fusing unit is electrically connected with the battery cell module, the second end of the first fusing unit is electrically connected with the third end of the first switch tube, the second end of the first switch tube is electrically connected with the second end of the second switch tube, the third end of the second switch tube is electrically connected with external equipment, the control unit is respectively electrically connected with the first end of the first switch tube and the first end of the second switch tube, the first end of the first resistor is electrically connected with the battery cell module and the control unit, and the second end of the first resistor is electrically connected with the external equipment and the control unit.

12. The battery pack of claim 9, wherein the circuit board further comprises:

a battery sampling chip and at least one voltage sampling branch,

the voltage sampling branch comprises a second fusing unit, a second resistor, a first capacitor and a third switching tube;

the first end of the second fusing unit is electrically connected with the positive electrode of the corresponding battery core, the second end of the second fusing unit is electrically connected with the second end of the third switch tube and the first end of the second resistor, the first end of the third switch tube is electrically connected with the battery core acquisition chip, the third end of the third switch tube is electrically connected with the negative electrode of the corresponding battery core, the second end of the second resistor is electrically connected with the first end of the first capacitor and the battery acquisition chip, and the second end of the first capacitor is grounded.

13. The battery pack of claim 9, wherein the circuit board further comprises:

the third fusing unit and the first voltage stabilizing diode;

the third fusing unit is connected with the first voltage stabilizing diode in series, and a circuit formed by the third fusing unit and the first voltage stabilizing diode is electrically connected with external equipment.

14. The battery pack of claim 9, wherein the circuit board further comprises:

the fourth fusing unit, the first diode, the second voltage stabilizing diode, the second capacitor and the voltage conversion unit;

the first end of the fourth fusing unit is electrically connected with the battery cell module, the second end of the fourth fusing unit is electrically connected with the anode of the first diode, the cathode of the first diode is electrically connected with the cathode of the second voltage stabilizing diode, the first end of the second capacitor and the first end of the voltage conversion unit, and the anode of the second voltage stabilizing diode and the second end of the second capacitor are all grounded.

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