Battery pack safety valve dual-mode detection sensor and processing technology thereof

Abstract

The invention discloses a battery pack safety valve dual-mode detection sensor and a processing technology thereof, and the sensor comprises a PCB which is provided with a detection notch; a detection notch is formed in the PCB, the detection block is contained in the detection notch, a hard first micro-connection structure is connected between the first side of the detection block and the PCB, detection supporting feet are arranged on the first micro-connection structure, and the detection block can bear impact force generated when the safety valve is opened so that the first micro-connection structure and the detection supporting feet can be broken to form a first detection signal; a second micro-connection structure is connected between the first side or the second side opposite to the first side of the detection block and the PCB, the second micro-connection structure is flexible and deformable, and detection lines are densely distributed on the back face of the detection block and used for forming a second detection signal when making contact with the electrolyte. By combining two detection modes, the state of the battery pack in the early stage of thermal runaway can be effectively detected, and the accuracy and reference of detection are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery detection, and in particular to a dual-mode detection sensor for a battery pack safety valve and a processing technology thereof. Background Art

[0002] With the rapid development of energy storage technology, batteries are increasingly used, and the requirements for battery safety and reliability are becoming higher and higher. During the use of batteries, there may be serious overcharging, battery short circuit, serious overheating, thermal runaway, impact or extrusion deformation, and puncture. These problems may cause the internal temperature and pressure of the battery to continue to rise. When it exceeds its own safety threshold, it may cause the battery to explode.

[0003] The battery safety valve is the last explosion-proof barrier of the battery itself. When the internal pressure of the battery reaches the opening threshold of the safety valve, for example, the opening threshold of the safety valve of a lithium-ion battery is usually 600-800KPa, the battery safety valve is opened to release gas and reduce pressure to avoid battery explosion. When the battery safety valve opens, it means that the battery has a serious safety problem. Therefore, it is necessary to detect when the battery safety valve is opened to prevent the expansion of safety accidents.

[0004] At present, existing sensors usually determine whether the safety valve is in an open state by detecting the electrolyte splashed when the safety valve is opened. Since the splashing direction of the electrolyte has a certain uncertainty and there is a certain lag in detection after the electrolyte splashes onto the sensor, the detection effect is affected. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a battery pack safety valve dual-mode detection sensor and a processing technology thereof, which have the advantages of good detection effect and strong reference.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] According to a first aspect of an embodiment of the present disclosure, a battery pack safety valve dual-mode detection sensor is provided, comprising:

[0008] A PCB board, wherein the PCB board is provided with a detection notch corresponding to the safety valve to be detected;

[0009] A detection block is accommodated in the detection notch, a first hard micro-connection structure is connected between the first side of the detection block and the PCB board, so that the detection block is suspended in the detection notch, and detection legs are arranged on the first micro-connection structure. The detection block can bear the impact force of the opening of the safety valve to break the first micro-connection structure and the detection legs to form a first detection signal;

[0010] A second micro-connection structure is connected between the first side of the detection block or the second side opposite to the first side and the PCB board. The second micro-connection structure is flexible and deformable and can remain connected when subjected to impact force. The back of the detection block is densely covered with detection circuits connected to the second detection circuit, which are used to change the parallel detection resistance value of the second detection circuit when in contact with the electrolyte to form a second detection signal.

[0011] To implement the above technical solution, when in use, the PCB board is assembled to the battery, and the detection block is made to correspond to the safety valve, that is, the detection block is located directly above the safety valve and at a suitable distance. When a battery pack fails and causes the safety valve to open, an upward impact force will be generated and act on the detection block. The detection block will be deformed upward by the impact force, thereby causing the first micro-connection structure and the detection leg to break and generate a first detection signal. The first detection signal is the valve opening signal of the battery pack safety valve, thereby realizing the valve opening detection of the safety valve. At the same time, when the safety valve is opened, the electrolyte will be sprayed out at the same time. When the electrolyte is splashed on the back of the detection block, the detection circuit will contact the electrolyte. Since the electrolyte has good conductivity, the detection circuit will be The parallel detection resistance value of the second detection circuit is changed due to conduction, thereby causing the voltage change to form a second detection signal, and the second detection signal is the battery pack leakage detection signal. The second detection signal can further realize leakage detection and valve opening detection; because the impact force is directly borne by the detection block to realize the fracture of the first micro-connection structure for valve opening detection, the detection is faster, which significantly improves the timeliness of detection, provides a faster response for subsequent signal processing, and improves the detection effect. At the same time, through the second micro-connection structure and the detection circuit, leakage detection can be performed synchronously after the first micro-connection structure is fractured. The combination of the two detection methods can effectively detect the state of the battery pack in the early stage of thermal runaway, and improve the accuracy and reference of the detection.

[0012] In some exemplary embodiments, the first micro-connection structure includes two separately arranged connecting legs, the detection legs include a first leg and a second leg respectively arranged on the two connecting legs, the first leg and the second leg are connected to a first detection circuit, and when the first leg and / or the second circuit is broken, the resistance value of the first detection circuit is changed to form a first detection signal.

[0013] In some exemplary embodiments, the first detection circuit includes a first detection resistor, and the first leg and the second leg are connected in parallel with the first detection resistor to change the resistance value of the first detection circuit when the first leg and / or the second leg is broken.

[0014] To implement the above technical solution, when the first leg and / or the second leg is broken, the resistor connected thereto can be disconnected, so that the resistance value of the entire first detection circuit changes, thereby forming a first detection signal to complete the valve opening detection.

[0015] In some exemplary embodiments, the detection circuit includes a first circuit and a second circuit, and the first circuit and the second circuit are close to each other but not in contact with each other;

[0016] The first line includes a first main line and a plurality of first branch lines connected to the first main line, the second line includes a second main line and a plurality of second branch lines connected to the second main line, the first main line basically surrounds the second line and encloses a detection area, the first branch lines are located on the inner side of the first main line, and the first branch lines and the second branch lines are arranged in sequence and alternately, the first branch lines and the second branch lines are densely distributed in the detection area, the second main line is located in the middle of the detection area, and the second branch lines are located on both sides of the second main line.

[0017] To implement the above technical solution, when a battery pack fails and causes the safety valve to open, the electrolyte will splash outward onto the detection area, and the electrolyte will change the resistance impedance between the first circuit and the second circuit, thereby changing the resistance value of the second detection circuit, and then causing the voltage to change to form a second detection signal. The second detection signal can be used as an alarm trigger signal, and leakage detection and valve opening detection can be realized; since the first main circuit surrounds the second circuit to form a detection area, and the first branch circuit and the second branch circuit are densely distributed in the detection area, when the electrolyte contacts any position in the detection area, the impedance change between the first circuit and the second circuit can be realized, thereby improving the detection efficiency and detection effect, and through the arrangement of the first branch circuit and the second branch circuit, the circuit arrangement can be made more compact, thereby realizing leakage detection as long as a small amount of electrolyte contacts the detection area, thereby improving the detection accuracy.

[0018] In some exemplary embodiments, a first terminal is formed at one end of the first main line, the second main line extends out of the first main line and forms a second terminal, the first terminal and the second terminal are connected to the second detection circuit, and when the electrolyte is contacted in the detection area, the resistance impedance between the first line and the second line changes to change the parallel detection resistance value of the second detection circuit to form a second detection signal.

[0019] In some exemplary embodiments, the second main line is linear and located at the central axis of the first main line, and multiple second branch lines are symmetrically arranged on both sides of the second main line, one end of the second branch line is connected to the second main line, and the other end extends close to the first main line.

[0020] In some exemplary embodiments, the second detection circuit includes a second detection resistor, which is connected in parallel with the second detection resistor via a second micro-connection structure to change the parallel detection resistance value of the second detection circuit to form a second detection signal when the detection area contacts the electrolyte.

[0021] By implementing the above technical solution, when the detection area contacts the electrolyte, the impedance between the first circuit and the second circuit can be changed. At the same time, the changed resistance value is made more obvious through the parallel second detection resistor, thereby realizing leakage detection and improving detection accuracy.

[0022] In some exemplary embodiments, the second micro-connection structure uses a pressing plate process to achieve a soft connection between the detection block and the PCB board, and the thickness of the second micro-connection structure is 0.2-0.5 mm.

[0023] Implementing the above technical solution can ensure that the second micro-connection structure can be freely bent within a range of at least 90° without breaking, and that leakage detection can still be performed after the first micro-connection structure breaks, thereby achieving a dual-mode detection effect.

[0024] According to a second aspect of an embodiment of the present disclosure, a processing technology for a dual-mode detection sensor for a battery pack safety valve is provided, comprising:

[0025] Taking a PCB substrate of suitable size, performing groove processing on the PCB substrate according to a predetermined process size to form a plurality of detection notches, and forming a detection block and a first micro-connection structure corresponding to each of the detection notches;

[0026] A second micro-connection structure is formed between the detection block and the PCB substrate by using a lamination process;

[0027] A first detection circuit and a second detection circuit are printed on the PCB substrate, and a detection circuit is printed on the detection block, wherein a detection foot connected to the first detection circuit is arranged on the first micro-connection structure, and the second detection circuit is connected to the detection circuit through the second micro-connection structure;

[0028] The PCB substrate is cut into pieces to form a single sensor or a detection board group including a plurality of sensors.

[0029] In some exemplary embodiments, the second micro-connection structure has a thickness of 0.2-0.5 mm to form a soft connection with the PCB substrate.

[0030] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0031] The embodiment of the present invention provides a battery pack safety valve dual-mode detection sensor and a processing technology thereof. When in use, the PCB board is assembled to the battery, and the detection block is made to correspond to the safety valve, that is, the detection block is located directly above the safety valve and at a suitable distance. When the battery pack fails and causes the safety valve to open, an upward impact force will be generated and act on the detection block. The detection block will be deformed upward by the impact force, thereby causing the first micro-connection structure and the detection leg to break and generate a first detection signal. The first detection signal is the battery pack safety valve opening signal, thereby realizing the safety valve opening detection. At the same time, when the safety valve is opened, the electrolyte will be sprayed out at the same time. When the electrolyte is splashed on the back of the detection block, the detection circuit will contact the electrolyte. Since the electrolyte has Good conductivity, the detection circuit will be turned on and change the resistance value of the second detection circuit, thereby causing the voltage change to form a second detection signal, and the second detection signal is the battery pack leakage detection signal. The second detection signal can further realize leakage detection and valve opening detection; because the detection block directly bears the impact force to realize the fracture of the first micro-connection structure for valve opening detection, the detection is faster, which significantly improves the timeliness of detection, provides a faster response for subsequent signal processing, and improves the detection effect. At the same time, through the second micro-connection structure and the detection circuit, leakage detection can be performed synchronously after the first micro-connection structure is broken. The combination of the two detection methods can effectively detect the state of the battery pack in the early stage of thermal runaway, and improve the accuracy and reference of the detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the structure of the dual-mode detection sensor for the battery pack safety valve in an embodiment of the present invention.

[0033] Figure 2 Schematic diagram of the structure of the first detection circuit in an embodiment of the present invention.

[0034] Figure 3 Schematic diagram of the structure of the second detection circuit in an embodiment of the present invention.

[0035] Figure 4 It is a schematic diagram of the structure of a dual-mode detection sensor for a battery pack safety valve in another embodiment of the present invention.

[0036] The numbers and letters in the figure represent the corresponding component names:

[0037] 10. PCB board; 11. Detection notch; 20. Detection block; 21. First micro-connection structure; 211. Connection leg; 22. Detection leg; 221. First leg; 222. Second leg; 30. Second micro-connection structure; 40. Detection circuit; 41. First circuit; 411. First main circuit; 412. First branch circuit; 413. First terminal; 42. Second circuit; 421. Second main circuit; 422. Second branch circuit; 423. Second terminal; 50. First detection circuit; 51. First detection resistor; 60. Second detection circuit; 61. Second detection resistor. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figures 1 to 3 As shown, a first aspect of an embodiment of the present invention provides a dual-mode detection sensor for a battery pack safety valve, comprising: a PCB board 10, a detection slot 11 corresponding to the safety valve to be detected is opened on the PCB board 10; a detection block 20 accommodated in the detection slot 11, a hard first micro-connection structure 21 is connected between the first side of the detection block 20 and the PCB board 10, so that the detection block 20 is suspended in the detection slot 11, and detection legs 22 are arranged on the connecting legs 211, and the detection block 20 can bear the impact force of the opening of the safety valve to break the first micro-connection structure 21 and the detection legs 22 to form a first detection signal; a second micro-connection structure 30 is connected between the second side of the detection block 20 opposite to the first side and the PCB board 10, and the second micro-connection structure 30 is flexible and deformable, and can maintain a connection state when subjected to impact force, and the back of the detection block 20 is densely covered with detection circuits 40 connected to the second detection circuit 60, which are used to change the parallel detection resistance value of the second detection circuit 60 when contacting the electrolyte to form a second detection signal.

[0040] Specifically, the detection block 20 is elliptical, and the detection slot 11 as a whole is also elliptical corresponding to the detection block 20. The outer edge of the detection block 20 is 1-3 mm away from the edge of the detection slot 11, and the area of ​​the detection block 20 is 1.1-1.3 times the switch area of ​​the safety valve, and in a normal state, the distance between the detection block 20 and the safety valve is 1-3 mm; preferably, the outer edge of the detection block 20 is 2 mm away from the edge of the detection slot 11, and the area of ​​the detection block 20 is 1.2 times the switch area of ​​the safety valve, and in a normal state, the distance between the detection block 20 and the safety valve is 2 mm.

[0041] The first micro-connection structure 21 includes two separately arranged connecting legs 211, the width of the connecting legs 211 is 1-2 mm, preferably set to 1.6 mm, and the detection leg 22 includes a first leg 221 and a second leg 222 respectively arranged on the two connecting legs 211, the first leg 221 and the second leg 222 are connected to the first detection circuit 50, and when the first leg 221 and / or the second leg 222 are broken, the resistance value of the first detection circuit 50 is changed to form a first detection signal.

[0042] It can be understood that the first detection circuit 50 is printed on the PCB board 10 and the detection block 20, and the first detection circuit 50 includes a first detection resistor 51. The first leg 221 and the second leg 222 are connected in parallel with the first detection resistor 51. When the first leg 221 and / or the second leg 222 are broken, the first detection resistor 51 can be disconnected, so that the resistance value of the entire first detection circuit 50 changes, thereby forming a first detection signal to complete the valve opening detection.

[0043] The thickness of the PCB board 10 is 1.4-1.8 mm. Preferably, the thickness of the PCB board 10 is set to 1.6 mm. Since the connecting leg 211 is directly formed in the PCB board 10, the thickness of the PCB board 10 is the same as the thickness of the connecting leg 211. By setting a suitable board thickness, the connecting leg 211 has a suitable load-bearing performance, so that the detection block 20 can break after being subjected to a suitable impact force to achieve valve opening detection.

[0044] The second micro-connection structure 30 adopts a pressed plate process to achieve a soft connection between the detection block 20 and the PCB board 10, and the thickness of the second micro-connection structure 30 is 0.2-0.5mm. Preferably, the thickness of the second micro-connection structure 30 is set to 0.3mm, which can ensure that the second micro-connection structure 30 can be freely bent within a range of at least 90° without breaking, so that leakage detection can still be achieved after the first micro-connection structure 21 is broken, thereby achieving a dual-mode detection effect.

[0045] The detection circuit 40 includes a first circuit 41 and a second circuit 42, and the first circuit 41 and the second circuit 42 are close to each other but do not touch each other; the first circuit 41 includes a first main circuit 411 and a plurality of first branch circuits 412 connected to the first main circuit 411, and the second circuit 42 includes a second main circuit 421 and a plurality of second branch circuits 422 connected to the second main circuit 421, the first main circuit 411 basically surrounds the second circuit 42 and encloses to form a detection area, the first branch circuit 412 is located on the inner side of the first main circuit 411, and each first branch circuit 412 and each second branch circuit 422 are arranged in sequence and alternately, the first branch circuit 412 and the second branch circuit 422 are densely distributed in the detection area, the second main circuit 421 is located in the middle of the detection area, and the second branch circuit 422 is located on both sides of the second main circuit 421.

[0046] Among them, a first terminal 413 is formed at one end of the first main line 411, and the second main line 421 extends from the first main line 411 and forms a second terminal 423. The first terminal 413 and the second terminal 423 are connected to the second detection circuit 60. When the electrolyte is contacted in the detection area, the resistance impedance between the first line 41 and the second line 42 changes to change the parallel detection resistance value of the second detection circuit 60 to form a second detection signal.

[0047] When a battery pack fails and the safety valve opens, the electrolyte will splash outward onto the detection area. The electrolyte will change the resistance impedance between the first circuit 41 and the second circuit 42, thereby changing the resistance value of the second detection circuit 60, and then causing the voltage to change to form a second detection signal. The second detection signal can be used as an alarm trigger signal to realize leakage detection and valve opening detection. Since the first main circuit 411 surrounds the second circuit 42 to form a detection area, and the first branch circuit 412 and the second branch circuit 422 are densely distributed in the detection area, when the electrolyte contacts any position in the detection area, the impedance change between the first circuit 41 and the second circuit 42 can be realized, thereby improving the detection efficiency and detection effect. Through the arrangement of the first branch circuit 412 and the second branch circuit 422, the circuit arrangement can be made more compact, thereby realizing leakage detection as long as a small amount of electrolyte contacts the detection area, thereby improving the detection accuracy.

[0048] The second main line 421 is linear and located at the central axis of the first main line 411. Specifically, the second main line 421 can be straight or wavy. In this embodiment, the second main line 421 is set to be straight, and multiple second branch lines 422 are symmetrically arranged on both sides of the second main line 421. One end of the second branch line 422 is connected to the second main line 421, and the other end extends to the vicinity of the first main line 411.

[0049] The second detection circuit 60 includes a second detection resistor 61, which is connected in parallel with the second detection resistor 61 through the second micro-connection structure 30 to change the parallel detection resistance value of the second detection circuit 60 when the detection area contacts the electrolyte to form a second detection signal. When the detection area contacts the electrolyte, the impedance between the first circuit and the second circuit can be changed. At the same time, the changed resistance value is made more obvious through the parallel second detection resistor 61, thereby realizing leakage detection and improving detection accuracy.

[0050] At the same time, in some embodiments, the first detection resistor 51 and the second detection resistor 61 can be connected to a number of precision adjustment resistors to further adjust the detection accuracy. It can be understood that the first detection circuit 50 and the second detection circuit 60 are connected to the central processing unit to upload to the battery management system when the detection signal is formed.

[0051] When in use, the PCB board 10 is assembled to the battery, and the detection block 20 is made to correspond to the safety valve, that is, the detection block 20 is located directly above the safety valve and at a suitable distance. When a battery pack fails and causes the safety valve to open, an upward impact force will be formed and act on the detection block 20. The detection block 20 will be deformed upward by the impact force, thereby causing the first micro-connection structure 21 and the detection leg 22 to break and generate a first detection signal. The first detection signal is the valve opening signal of the battery pack safety valve, thereby realizing the valve opening detection of the safety valve. At the same time, when the safety valve is opened, the electrolyte will be sprayed out at the same time. When the electrolyte splashes on the back of the detection block 20, the detection circuit 40 will contact the electrolyte. Since the electrolyte has good conductivity, the detection circuit 40 will The conduction occurs and changes the resistance value of the second detection circuit 60, thereby causing a voltage change to form a second detection signal, which is the battery pack leakage detection signal. The second detection signal can be used to further realize leakage detection and valve opening detection. Since the detection block 20 directly bears the impact force to realize the break of the first micro-connection structure 21 for valve opening detection, the detection is faster, which significantly improves the timeliness of the detection, provides a faster response for subsequent signal processing, and improves the detection effect. At the same time, through the second micro-connection structure 30 and the detection circuit 40, leakage detection can be performed synchronously after the first micro-connection structure 21 is broken. The combination of the two detection methods can effectively detect the state of the battery pack in the early stage of thermal runaway, and improve the accuracy and reference of the detection.

[0052] like Figure 4As shown, in another embodiment, the second micro-connection structure 30 is arranged between the first side of the detection block 20 and the PCB board 10. Specifically, the two separately arranged connecting legs 211 are spaced a sufficient distance apart, and the second micro-connection structure 30 is located between the two connecting legs 211, so that there is no connection between the second side of the detection block 20 and the PCB board and it is in a suspended state. When the safety valve opens and impacts the detection block 20, the detection block 20 bends upward to break the connecting legs 211. It can be understood that, compared with the above embodiment, since the second micro-connection structure 30 is located on the opposite side, the direction in which the detection block 20 is impacted and bent upward is also opposite. Taking the illustrated direction as an example, in the above embodiment, the detection block 20 is along Figure 1 In the embodiment, the detection block 20 is bent upward from left to right. Figure 4 Bend upward from right to left.

[0053] A second aspect of an embodiment of the present invention provides a processing technology for a dual-mode detection sensor for a battery pack safety valve, including:

[0054] S100, take a PCB substrate of suitable size, perform groove processing on the PCB substrate according to a predetermined process size to form a plurality of detection notches 11, and form a detection block 20 and a first micro-connection structure 21 corresponding to each detection notch 11, wherein the first micro-connection structure 21 includes two spaced-apart connecting legs 211, the connecting legs 211 are located on one side of the detection block 20 so that the detection block 20 is suspended in the detection notch 11, the outer edge of the detection block 20 is 1-3 mm away from the edge of the detection notch 11, the area of ​​the detection block 20 is 1.1-1.3 times the switch area of ​​the safety valve, and the width of the connecting legs 211 is 1-2 mm.

[0055] Specifically, the thickness of the PCB substrate is selected to be 1.4-1.8 mm, and a PCB substrate with a thickness of 1.6 mm is preferably used. During the groove processing, the detection block 20 and the connecting leg 211 are formed at the same time as the detection notch 11, and the area for processing the second micro-connection structure 30 is formed at the same time; preferably, the outer edge of the detection block 20 is 2 mm away from the edge of the detection notch 11, the area of ​​the detection block 20 is 1.2 times the area of ​​the safety valve switch, and the width of the connecting leg 211 is 1.6 mm.

[0056] S200, forming a second micro-connection structure 30 between the detection block 20 and the PCB substrate by a lamination process, wherein the lamination process can be to add a soft connection structure between the PCB substrate and the detection block 20 by lamination, and the soft connection structure has conductivity. Preferably, the thickness of the second micro-connection structure 30 is 0.2-0.5 mm to form a soft connection with the PCB substrate, and the upper surface of the second micro-connection structure 30 is substantially flush with the surface of the PCB substrate. The second micro-connection structure 30 can be located on the side of the detection block 20 opposite to the first micro-connection structure 21, or on the same side of the detection block 20 and the first micro-connection structure 21. The specific selection can be made according to actual needs. Preferably, the second micro-connection structure is located on the side of the detection block 20 opposite to the first micro-connection structure 21.

[0057] S300, printing a first detection circuit 50 and a second detection circuit 60 on a PCB substrate, and printing a detection circuit 40 on a detection block 20, wherein a detection foot 22 connected to the first detection circuit 50 is arranged on the first micro-connection structure 21, and the second detection circuit 60 is connected to the detection circuit 40 via a second micro-connection structure 30.

[0058] Among them, the detection circuit 40 includes a first circuit 41 and a second circuit 42, the first circuit 41 and the second circuit 42 are close to each other but not in contact with each other; the first circuit 41 includes a first main circuit 411 and a plurality of first branch circuits 412 connected to the first main circuit 411, the second circuit 42 includes a second main circuit 421 and a plurality of second branch circuits 422 connected to the second main circuit 421, the first main circuit 411 basically surrounds the second circuit 42 and encloses to form a detection area, the first branch circuit 412 is located on the inner side of the first main circuit 411, and each first branch circuit 412 and each second branch circuit 422 are arranged in sequence and alternately, the first branch circuit 412 and the second branch circuit 422 are densely distributed in the detection area, the second main circuit 421 is located in the middle of the detection area, and the second branch circuit 422 is located on both sides of the second main circuit 421, and the spacing between the first branch circuit 412 and the second branch circuit 422 is 0.2-0.6mm, preferably set to 0.5mm.

[0059] S400, cutting the PCB substrate to form a single sensor or a detection board group including multiple sensors. Specifically, the cutting process can be performed to form a single sensor or a detection board group according to actual application requirements. A single sensor can be suitable for a single battery, and the detection board group is suitable for a battery pack composed of multiple batteries.

[0060] Furthermore, when in use, a single sensor or a detection plate group is assembled on the battery pack so that the detection block 20 corresponds to the safety valve, and under normal conditions, the distance between the detection block 20 and the safety valve is 1-3mm, preferably, the distance between the detection block 20 and the safety valve is 2mm; by setting a suitable distance between the detection block 20 and the safety valve, coordinating the valve opening distance of the safety valve, a suitable impact force can be applied to the detection block 20 when the valve is opened, thereby realizing valve opening detection, and ensuring that the electrolyte can splash into the detection area when the valve is opened.

[0061] By directly bearing the impact force through the detection block 20, the first micro-connection structure 21 is broken to perform valve opening detection, which makes the detection faster, significantly improves the timeliness of the detection, provides a faster response for subsequent signal processing, and improves the detection effect. At the same time, through the second micro-connection structure 30 and the detection circuit 40, leakage detection can be performed synchronously after the first micro-connection structure 21 is broken. The combination of the two detection methods can effectively detect the status of the battery pack in the early stage of thermal runaway, and improve the accuracy and reference of the detection.

[0062] In order to verify the specific detection functions of different sensor size structures, the following comparative experiments are provided for illustration:

[0063] Comparative Experiment 1

[0064] The probability of breaking of the connecting leg was tested by setting different size ratios of the detection block and the safety valve. Specifically, the size ratios of the detection block and the safety valve were set to 0.8:1, 1:1, and 1.2:1, respectively. Then, the sensor and the safety valve were set accordingly, and the valve opening test was performed to determine the probability of breaking of different sensors. The specific test results are as follows:

[0065] Dimensional ratio of the detection block and the safety valve 0.8:1 1:1 1.2:1 Breakout probability 70％ 90％ 100％

[0066] According to the test results, when the size ratio of the detection block to the safety valve is greater than 1.2, it can be guaranteed that the detection block will be triggered to open 100%.

[0067] Comparative Experiment 2

[0068] Different PCB board thicknesses were set to test the breaking force of the connecting legs. Specifically, PCB boards with thicknesses of 0.8mm, 1.0mm, 1.5mm, and 2.0mm were set respectively. Then the sensor and the safety valve were set accordingly, and the valve opening test was performed to determine the breaking force of different sensors. The specific test results are as follows:

[0069] PCB board thickness 0.8mm 1.0mm 1.6mm 2.0mm Breaking force 5N 12N 20N 40N

[0070] According to the test results, when the PCB board thickness is 1.6mm, it can ensure that the connecting legs are effectively broken under the action of 20N breaking force, and at the same time it will not cause the sensor to trigger a short circuit too easily. In actual applications, since the second micro-connection structure can also form a connecting force, a thinner PCB board can also be set, so that the connecting legs will not be easily broken during transportation.

[0071] Comparative Experiment 3

[0072] The leakage detection accuracy was tested by setting different spacings between the first branch line and the second branch line. Specifically, spacings of 1mm, 0.8mm, 0.5mm, and 0.2mm were set respectively. Then the sensor and the safety valve were set accordingly and the valve opening test was performed to determine the leakage detection accuracy of different sensors. The specific test results are as follows:

[0073] spacing 1mm 0.8mm 0.5mm 0.2mm High humidity misjudgment rate 30％ 50％ 60％ 90％ Leakage detection accuracy 50％ 70％ 90％ 100％

[0074] According to the test results, when the distance between the first branch line and the second branch line is in the range of 0.5mm±0.1mm, high-precision leakage detection can be guaranteed, and the high humidity misjudgment rate is also within a reasonable range.

[0075] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which are equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of them belong to the protection scope of the present invention.

Claims

1. A dual-mode detection sensor for a battery pack safety valve, characterized in that: include: A PCB board, wherein the PCB board is provided with a detection notch corresponding to the safety valve to be detected; A detection block is accommodated in the detection notch, a first hard micro-connection structure is connected between the first side of the detection block and the PCB board, so that the detection block is suspended in the detection notch, and detection legs are arranged on the first micro-connection structure. The detection block can bear the impact force of the opening of the safety valve to break the first micro-connection structure and the detection legs to form a first detection signal; A second micro-connection structure is connected between the first side of the detection block or the second side opposite to the first side and the PCB board. The second micro-connection structure is flexible and deformable and can remain connected when subjected to impact force. The back of the detection block is densely covered with detection circuits connected to the second detection circuit, which are used to change the parallel detection resistance value of the second detection circuit when in contact with the electrolyte to form a second detection signal.

2. The battery pack safety valve dual-mode detection sensor according to claim 1, characterized in that: The first micro-connection structure includes two separately arranged connecting legs, and the detection legs include a first leg and a second leg respectively arranged on the two connecting legs. The first leg and the second leg are connected to a first detection circuit. When the first leg and / or the second circuit is broken, the resistance value of the first detection circuit is changed to form a first detection signal.

3. The battery pack safety valve dual-mode detection sensor according to claim 2, characterized in that: The first detection circuit includes a first detection resistor, and the first leg and the second leg are connected in parallel with the first detection resistor to change the resistance value of the first detection circuit when the first leg and / or the second leg is broken.

4. The battery pack safety valve dual-mode detection sensor according to claim 1, characterized in that: The detection circuit includes a first circuit and a second circuit, wherein the first circuit and the second circuit are close to each other but do not contact each other; The first line includes a first main line and a plurality of first branch lines connected to the first main line, the second line includes a second main line and a plurality of second branch lines connected to the second main line, the first main line basically surrounds the second detection line and encloses a detection area, the first branch lines are located on the inner side of the first main line, and the first branch lines and the second branch lines are arranged in sequence and alternately, the first branch lines and the second branch lines are densely distributed in the detection area, the second main line is located in the middle of the detection area, and the second branch lines are located on both sides of the second main line.

5. The battery pack safety valve dual-mode detection sensor according to claim 4, characterized in that: A first terminal is formed at one end of the first main line, and the second main line extends out of the first main line and forms a second terminal. The first terminal and the second terminal are connected to the second detection circuit. When the electrolyte is contacted in the detection area, the resistance impedance between the first line and the second line changes to change the parallel detection resistance value of the second detection circuit to form a second detection signal.

6. The battery pack safety valve dual-mode detection sensor according to claim 5, characterized in that: The second main line is linear and located at the central axis of the first main line. Multiple second branch lines are symmetrically arranged on both sides of the second main line. One end of the second branch line is connected to the second main line and the other end extends close to the first main line.

7. The battery pack safety valve dual-mode detection sensor according to claim 6, characterized in that: The second detection circuit includes a second detection resistor, which is connected in parallel with the second detection resistor through a second micro-connection structure to change the parallel detection resistance value of the second detection circuit to form a second detection signal when the detection area contacts the electrolyte.

8. The battery pack safety valve dual-mode detection sensor according to claim 1, characterized in that: The second micro-connection structure uses a pressing plate process to achieve a soft connection between the detection block and the PCB board, and the thickness of the second micro-connection structure is 0.2-0.5mm.

9. A processing technology for a dual-mode detection sensor for a battery pack safety valve, characterized in that: include: Taking a PCB substrate of suitable size, performing groove processing on the PCB substrate according to a predetermined process size to form a plurality of detection notches, and forming a detection block and a first micro-connection structure corresponding to each of the detection notches; A second micro-connection structure is formed between the detection block and the PCB substrate by using a lamination process; A first detection circuit and a second detection circuit are printed on the PCB substrate, and a detection circuit is printed on the detection block, wherein a detection foot connected to the first detection circuit is arranged on the first micro-connection structure, and the second detection circuit is connected to the detection circuit through the second micro-connection structure; The PCB substrate is cut into pieces to form a single sensor or a detection board group including a plurality of sensors.

10. The processing technology of the dual-mode detection sensor for the battery pack safety valve according to claim 9, characterized in that: The thickness of the second micro-connection structure is 0.2-0.5 mm to form a soft connection with the PCB substrate.

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