Manufacturing method of battery cell connecting assembly, battery cell connecting assembly and battery cell connecting system

Abstract

A manufacturing method of a battery cell connecting assembly comprises the following steps: a first circuit board and a plurality of electric connecting pieces are arranged on the same side of an insulating substrate, the plurality of electric connecting pieces are arranged on the insulating substrate at intervals, and the first circuit board and each electric connecting piece are arranged at intervals. A slot is formed in one side, deviating from the insulating substrate, of each electric connecting piece, a thermosensitive element is arranged in each slot, and the thermosensitive elements are electrically isolated from the electric connecting pieces. A second circuit board is arranged on each electric connecting piece and the first circuit board, one end of each second circuit board covers the corresponding open groove and is electrically connected with the corresponding thermosensitive element, the other end of each second circuit board is electrically connected with the first circuit board, and each electric connecting piece is used for being electrically connected with one battery cell. In addition, the invention also provides a battery cell connecting assembly and a battery cell connecting system.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for manufacturing a battery cell connection assembly, a battery cell connection assembly, and a battery cell connection system. Background Art

[0002] With the rapid development of battery technology, the requirements for precision in battery module manufacturing and accurate temperature measurement are becoming increasingly stringent. As a core factor affecting battery performance and safety, temperature monitoring and management have become particularly critical. Negative temperature coefficient thermistors, as a commonly used temperature measurement component, play a crucial role in measuring and controlling temperature in battery modules.

[0003] However, in current battery module manufacturing, the thermistor is exposed on the outer layer of the busbar, exposing it to the risk of damage during the busbar soldering process, hot pressing, and subsequent packaging and transportation. This potential damage could not only reduce the accuracy of temperature measurement but also pose a serious threat to the overall performance and safety of the battery module. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a method for manufacturing a battery cell connection assembly.

[0005] In addition, it is necessary to provide a battery cell connection assembly.

[0006] In addition, it is necessary to provide a battery cell connection system.

[0007] A method for manufacturing a battery cell connection assembly comprises the following steps: disposing a first circuit board and a plurality of electrical connectors on the same side of an insulating substrate, the plurality of electrical connectors being spaced apart on the insulating substrate, and the first circuit board being spaced apart from each of the electrical connectors; disposing a slot on a side of each electrical connector facing away from the insulating substrate, disposing a thermistor in the slot, the thermistor being electrically isolated from the electrical connector; disposing a second circuit board between each of the electrical connectors and the first circuit board, one end of the second circuit board covering the slot and electrically connected to the thermistor, and the other end of the second circuit board being electrically connected to the first circuit board, wherein each of the electrical connectors is used to electrically connect a battery cell.

[0008] In some possible implementations, the further step is further included: filling the slot with insulating glue, wherein the insulating glue covers the thermal element.

[0009] In some possible implementations, the method further includes the step of connecting each of the electrical connectors and the second circuit board by ultrasonic welding technology.

[0010] In some possible implementations, before the step of “arranging a thermal element in the groove”, the step further includes: arranging an adhesive layer at the bottom of the groove.

[0011] The step of “arranging a thermosensitive element in the groove” further includes: arranging the thermosensitive element on the adhesive layer, and arranging a first solder on a side of the thermosensitive element away from the adhesive layer.

[0012] In some possible implementations, the first circuit board includes a first circuit substrate and a plurality of second solders disposed on the first circuit substrate, the second circuit board includes a second circuit board substrate and a plurality of third solders disposed on the second circuit substrate, the first solders correspond to a portion of the third solders, and the second solders correspond to another portion of the third solders, and the step of “providing a second circuit board on each of the electrical connectors and the first circuit board” includes:

[0013] The first solder and a portion of the third solder are soldered using a photon sintering technique, and the second solder and another portion of the third solder are soldered using the photon sintering technique.

[0014] In some possible implementations, the method for manufacturing the first circuit board includes the steps of:

[0015] A first copper clad laminate is provided. The first copper clad laminate includes a first transparent insulating layer, a first adhesive layer and a first copper foil layer. The first adhesive layer is connected between the first transparent insulating layer and the first copper foil layer.

[0016] The first copper foil layer is etched to form a first circuit layer, wherein the first circuit layer includes a plurality of first connection pads arranged at intervals.

[0017] A first covering film is provided on the first circuit layer, the first covering film includes a second adhesive layer and a first protective layer provided on the second adhesive layer, the second adhesive layer connects the first circuit layer and the first protective layer, a plurality of first openings are provided through the first covering film, and the first connection pads are exposed in the first openings.

[0018] The second solder is disposed in the first opening, and the second solder is connected to the first connection pad to obtain the first circuit board.

[0019] In some possible implementations, the method for manufacturing the second circuit board includes the steps of:

[0020] A second copper clad laminate is provided. The second copper clad laminate includes a second transparent layer, a third adhesive layer, and a second copper foil layer. The third adhesive layer is connected between the second transparent insulating layer and the second copper foil layer.

[0021] The second copper foil layer is etched to form a second circuit layer, wherein the second circuit layer includes a plurality of second connection pads arranged at intervals.

[0022] A second covering film is provided on the second circuit layer, the second covering film includes a fourth adhesive layer and a second protective layer provided on the fourth adhesive layer, the fourth adhesive layer connects the second circuit layer and the second protective layer, a plurality of second openings are provided through the second covering film, and the second connection pads are exposed in the second openings.

[0023] The third solder is provided in the second opening, and the third solder is connected to the second connection pad to obtain the second circuit board.

[0024] A battery cell connection assembly includes an insulating substrate, a first circuit board, multiple electrical connectors, multiple thermistors, and multiple second circuit boards, wherein the first circuit board and the multiple electrical connectors are arranged on the same side of the insulating substrate, and the multiple electrical connectors are arranged at intervals on the insulating substrate. The first circuit board is spaced apart from each of the electrical connectors, and a groove is provided on the side of each electrical connector facing away from the insulating substrate. The thermistor is provided in the groove, and the thermistor is electrically isolated from the electrical connector. The second circuit board is provided on each of the electrical connectors and the first circuit board, one end of the second circuit board covers the groove and is electrically connected to the thermistor, and the other end of the second circuit board is electrically connected to the first circuit board, wherein each of the electrical connectors is used to electrically connect a battery cell.

[0025] In some possible implementations, the battery cell connection assembly further includes insulating glue, the insulating glue is filled in the groove, and the insulating glue covers the thermal element.

[0026] A battery cell connection system comprises a plurality of battery cells and the battery cell connection assembly as described above, wherein the plurality of battery cells are arranged side by side, and each of the battery cells is connected to one of the electrical connectors.

[0027] Compared to the prior art, the battery cell connection assembly provided in this application embeds a thermal element into a slot in an electrical connector, then covers the slot with a second circuit board, and electrically connects the second circuit board to the thermal element. In this way, the thermal element is installed in the electrical connector, which not only helps reduce the impact of the hot pressing process on the thermal element, but also helps improve the stability and reliability of the battery cell connection assembly during packaging, transportation, and battery packaging, thereby improving the durability and stability of the battery cell connection assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a cross-sectional schematic diagram of an electrical connector provided in an embodiment of the present application after being grooved.

[0029] Figure 2 for Figure 1 The cross-sectional diagram of the groove after the adhesive layer is set in the groove is shown.

[0030] Figure 3 for Figure 2 The cross-sectional diagram shown is a diagram of a bonding layer after a thermal-sensitive element is provided.

[0031] Figure 4 for Figure 3 The cross-sectional view of the thermal element after the first solder is provided is shown.

[0032] Figure 5 This is a schematic cross-sectional view of an electrical connector, a first circuit board, and an insulating substrate layer provided in one embodiment of the present application before lamination.

[0033] Figure 6 for Figure 5 The diagram shows a cross-sectional view of an intermediate body obtained by laminating the electrical connector, the first circuit board and the insulating substrate layer.

[0034] Figure 7 for Figure 6 The intermediate body shown is a schematic cross-sectional view after a second circuit board is provided.

[0035] Figure 8 for Figure 7 The cross-sectional schematic diagram of the battery cell connection assembly obtained after the intermediate body is welded to the second circuit board is shown.

[0036] Figure 9 for Figure 8 The cross-sectional schematic diagram shown is a diagram of a battery cell connection assembly after a first insulating adhesive is provided in the groove.

[0037] Figure 10 for Figure 9 The cross-sectional view of the second circuit board of the battery cell connection assembly after welding to the pad connector is shown.

[0038] Figure 11 A schematic cross-sectional view of a first copper clad laminate provided in one embodiment of the present application.

[0039] Figure 12 For etching Figure 11 The diagram shows a cross-sectional view of the first copper foil layer of the first copper clad laminate after forming the first circuit layer.

[0040] Figure 13 for Figure 12 The diagram shows a cross-sectional view of the first circuit layer after the first protective film is provided.

[0041] Figure 14 for Figure 13 The diagram shows a cross-sectional view of the first circuit board obtained after the second solder is provided on the first connection pad.

[0042] Figure 15 A schematic cross-sectional view of a second copper clad laminate provided in one embodiment of the present application.

[0043] Figure 16 For etching Figure 15 The diagram shows a cross-sectional view of the second copper foil layer of the second copper clad laminate after forming the second circuit layer.

[0044] Figure 17 for Figure 16 The diagram shows a cross-sectional view of the second circuit layer after the second protective film is provided.

[0045] Figure 18 for Figure 17 The diagram shows a cross-sectional view of the second circuit board obtained after the third solder is provided on the second connection pad.

[0046] Description of main component symbols

[0047] Battery cell connection assembly 100

[0048] Electrical connection assembly 15

[0049] Electrical connector 10

[0050] Slot 11

[0051] Adhesion layer 12

[0052] Thermal element 13

[0053] First solder 14

[0054] Insulating substrate 20

[0055] Intermediate 21

[0056] First circuit board 30

[0057] First circuit substrate 31

[0058] Second solder 32

[0059] First copper clad plate 33

[0060] First transparent insulating layer 331

[0061] First adhesive layer 332

[0062] First copper foil layer 333

[0063] First circuit layer 334

[0064] First connection pad 335

[0065] First covering film 336

[0066] Second adhesive layer 336a

[0067] First protective layer 336b

[0068] First window 336c

[0069] Second circuit board 40

[0070] Second circuit substrate 41

[0071] The third solder 42

[0072] First electrical connection body 43

[0073] Second electrical connection body 44

[0074] Second copper clad plate 45

[0075] Second transparent insulating layer 451

[0076] The third adhesive layer 452

[0077] Second copper foil layer 453

[0078] Second circuit layer 454

[0079] Second connection pad 455

[0080] Second covering film 456

[0081] Fourth adhesive layer 456a

[0082] Second protective layer 456b DETAILED DESCRIPTION

[0083] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application.

[0084] In addition, in this application, descriptions such as "first" and "second" are only used for descriptive purposes and do not specifically refer to the order or ranking, nor are they used to limit this application. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0085] See Figures 1 to 10 One embodiment of the present application provides a method for manufacturing a battery cell connection assembly 100, comprising the steps of:

[0086] S1: See Figure 4 An electrical connection assembly 15 is provided, comprising an electrical connector 10, an adhesive layer 12, a thermal element 13, and a first solder 14. A slot 11 is provided on one side of the electrical connector 10, the adhesive layer 12 is provided at the bottom of the slot 11, and the thermal element 13 is provided in the slot 11 and connected to the adhesive layer 12. The first solder 14 is provided on a side of the thermal element 13 facing away from the adhesive layer 12. The thermal element 13 is electrically isolated from the electrical connector 10.

[0087] In this embodiment, the manufacturing method of the electrical connection assembly 15 includes the following steps:

[0088] S11: See Figure 1 The slot 11 is provided on one side of the electrical connector 10. Specifically, the slot 11 is formed by mechanical drilling. The electrical connector 10 includes an aluminum busbar, a copper busbar, an iron busbar, and the like.

[0089] S12: See Figure 2 The adhesive layer 12 is provided in the groove 11 and is provided at the bottom of the groove 11. The adhesive layer 12 is made of epoxy resin, phenolic resin and the like.

[0090] S13: See Figure 3 The thermal element 13 is disposed in the slot 11 and is electrically isolated from the electrical connector 10. The adhesive layer 12 is used to secure the thermal element 13 within the slot 11, thereby protecting the thermal element 13 from damage during subsequent processing, transportation, or use. The thermal element 13 comprises a negative temperature coefficient thermistor.

[0091] S14: See Figure 4 The first solder 14 is provided on the side of the thermosensitive element 13 facing away from the adhesive layer 12 , and the first solder 14 is used to connect other elements (see below).

[0092] S2: See Figure 5 and Figure 6A first circuit board 30 and a plurality of the electrical connection components 15 are spaced apart on one side of an insulating substrate 20 to produce an intermediate product 21. The plurality of electrical connection components 15 are symmetrically distributed on opposite sides of the first circuit board 30. The opening of the slot 11 faces away from the insulating substrate 20. The insulating substrate 20 is a PET hot-pressed film. The first circuit board 30 is a flexible circuit board. The first circuit board 30 includes a first circuit substrate 31 and a plurality of second solders 32 disposed on the first circuit substrate 31.

[0093] In this embodiment, step S2 specifically includes:

[0094] S21: See Figure 5 According to the size and requirements of the first circuit board 30 and the multiple electrical connection components 15, a suitable hot pressing film material is selected and cut to obtain the insulating substrate 20, so that the size of the insulating substrate 20 matches the first circuit board 30 and the multiple electrical connection components 15.

[0095] S22: See Figure 5 , the insulating substrate 20 is placed in a hot press (not shown), and then the first circuit board 30 and the plurality of electrical connection components 15 are spaced apart and arranged on one side of the insulating substrate 20 .

[0096] S23: See Figure 6 , set the parameters of the hot press, and then press the first circuit board 30 and the plurality of electrical connection components 15 together. Under high temperature and high pressure, the insulating substrate 20, the first circuit board 30, and the plurality of electrical connection components 15 are bonded together. After cooling and solidification, the intermediate body 21 is obtained.

[0097] In this example, see Figures 11 to 14 The manufacturing method of the first circuit board 30 includes the following steps:

[0098] S24: See Figure 11 A first copper-clad laminate 33 is provided. The first copper-clad laminate 33 includes a first transparent insulating layer 331, a first adhesive layer 332, and a first copper foil layer 333. The first adhesive layer 332 is connected between the first transparent insulating layer 331 and the first copper foil layer 333. The first transparent insulating layer 331 includes one of polyester film (PET), polyimide (PI), and polytetrafluoroethylene (PTFE). The first adhesive layer 332 is made of a material including epoxy resin, acrylic resin, polyimide (PI), and silicone.

[0099] S25: See Figure 12, the first copper foil layer 333 is etched to form a first circuit layer 334 , wherein the first circuit layer 334 includes a plurality of first connection pads 335 arranged at intervals.

[0100] S23: See Figure 13 A first covering film 336 is provided on the first circuit layer 334. The first covering film 336 includes a second adhesive layer 336a and a first protective layer 336b provided on the second adhesive layer 336a. The second adhesive layer 336a connects the first circuit layer 334 and the first protective layer 336b. A plurality of first openings 336c are provided through the first covering film 336. The first connection pads 335 are exposed in the first openings 336c to obtain the first circuit substrate 31.

[0101] S26: See Figure 14 The second solder 32 is set in the first window 336 c, and the second solder 32 is connected to the first connection pad 335 to obtain the first circuit board 30.

[0102] S3: See Figure 7 and Figure 8 A second circuit board 40 is provided between each of the electrical connectors 10 and the first circuit board 30. One end of the second circuit board 40 covers the slot 11 and is electrically connected to the thermistor 13. The other end of the second circuit board 40 is electrically connected to the first circuit board 30, thereby obtaining the battery cell connection assembly 100. The second circuit board 40 includes a second circuit substrate 41 and a plurality of third solders 42 provided on the second circuit substrate 41. The first solder 14 corresponds to connecting part of the third solders 42, and the second solder 32 corresponds to connecting another part of the third solders 42. In this way, the electrical connection between the thermistor 13 and the second circuit board 40 and the electrical connection between the second circuit board 40 and the first circuit board 30 are achieved.

[0103] In this embodiment, step S3 specifically includes: welding the first solder 14 and part of the third solder 42 by photon sintering technology, and welding the second solder 32 and another part of the third solder 42 by photon sintering technology. The photon sintering technology is also called intense pulsed light (IPL) sintering technology. Its principle is to use a focused high-energy light source to irradiate the target (for example, the first solder 14 and part of the third solder 42, or the second solder 32 and another part of the third solder 42) in a very short time, so that the target obtains high energy, thereby achieving the purpose of sintering and connection. The first solder 14 and part of the third solder 42 form a first electrical connector 43 after sintering and cooling, and the second solder 32 and another part of the third solder 42 form a second electrical connector 44 after sintering and cooling.

[0104] In this example, see Figures 15 to 18 The manufacturing method of the second circuit board 40 includes the following steps:

[0105] S31: See Figure 15 A second copper clad laminate 45 is provided, and the second copper clad laminate 45 includes a second transparent insulating layer 451, a third adhesive layer 452, and a second copper foil layer 453. The third adhesive layer 452 is connected between the second transparent insulating layer 451 and the second copper foil layer 453.

[0106] S32: See Figure 16 , etching the second copper foil layer 453 to form a second circuit layer 454 , wherein the second circuit layer 454 includes a plurality of second connection pads 455 arranged at intervals;

[0107] S33: See Figure 17 A second cover film 456 is disposed on the second circuit layer 454. The second cover film 456 includes a fourth adhesive layer 456a and a second protective layer 456b disposed on the fourth adhesive layer 456a. The fourth adhesive layer 456a connects the second circuit layer 454 and the second protective layer 456b. A plurality of second openings 456c are provided through the second cover film 456. The second connection pads 455 are exposed through the second openings 456c, thereby forming the second circuit substrate 41.

[0108] S34: See Figure 17 and Figure 18 The third solder 42 is set in the second window 456c, and the third solder 42 is connected to the second connection pad 455 to obtain the second circuit board 40.

[0109] Among them, the second transparent insulating layer 451 and the third adhesive layer 452 are both light-transmissive. During the photon sintering process in step S3, the high-energy light source penetrates the local second transparent insulating layer 451 and the third adhesive layer 452 in a very short time and acts on one side of the second connecting pad 445, so that the third solder 42 connected to the other side of the second connecting pad 445 is sintered with the first solder 14 to form the first electrical connector 43, and the third solder 42 connected to the other side of the second connecting pad 445 is sintered with the second solder 32 to form the second electrical connector 44.

[0110] In this embodiment, the manufacturing method of the battery cell connection assembly 100 further includes the steps of:

[0111] S4: See Figure 9 A first insulating glue 50 is filled in the groove 11, and the first insulating glue 50 covers the thermistor 13 and the first electrical connector 43. A second insulating glue 51 is filled between the first circuit substrate 31 and the second circuit substrate 41, and the second insulating glue 51 covers the second electrical connector 44.

[0112] S5: See Figure 10 , each of the electrical connectors 10 and the second circuit board 40 is connected by ultrasonic welding technology. The ultrasonic welding technology (UW) is a technology that uses high-frequency mechanical vibration energy to combine the electrical connector 10 and the second circuit board 40 to be welded by compression, melting, and vibration, forming a weld seam caused by molecular interaction. Its principle is to utilize the characteristics of ultrasound - the cavitation effect. When ultrasound propagates in a medium, negative pressure is generated around it, causing the medium to boil locally, thereby generating a large number of tiny bubbles, which rapidly expand and burst. The strong impact and destructive effect generated is sufficient to cause the contact surface of the welded electrical connector 10 and the second circuit board 40 to rub violently and heat up. At the same time, due to the effect of the ultrasonic field, the molecular bonds in the surface layer are continuously connected, thereby achieving the purpose of welding. In this way, the connection between the electrical connector 10 and the second circuit board 40 is further stabilized, making the electrical connection between the second circuit board 40 and the thermal element 13 more stable.

[0113] Compared with the prior art, the manufacturing method of the battery cell connection assembly 100 provided in this application has the following advantages:

[0114] (1) The thermal element 13 is embedded in the slot 11 of the electrical connector 10, and then the slot 11 is covered with a second circuit board 40, and the second circuit board 40 is electrically connected to the thermal element 13. In this way, the thermal element 13 is installed in the electrical connector 10, which not only helps to reduce the impact of the hot pressing process on the thermal element 13, but also helps to improve the stability and reliability of the battery cell connection assembly 100 during packaging, transportation and battery packaging, thereby improving the durability and stability of the battery cell connection assembly 100.

[0115] (2) By using photon sintering technology, a high-energy pulse light beam is allowed to penetrate the local transparent insulating layer (the second transparent insulating layer 451) and the adhesive layer (the third adhesive layer 452) and act on the second connection pad 445, thereby reducing unnecessary heating caused by the use of the whole-plate reflow soldering technology (SMT), thereby facilitating the protection of the thermal sensitive element 13 and improving the production yield of the battery cell connection assembly 100.

[0116] See also Figure 10 One embodiment of the present application further provides a cell connection assembly 100, comprising an insulating substrate 20, a first circuit board 30, a plurality of electrical connectors 10, a plurality of thermistors 13, and a plurality of second circuit boards 40. The first circuit board 30 and the plurality of electrical connectors 10 are arranged on the same side of the insulating substrate 20, and the plurality of electrical connectors 10 are arranged at intervals on the insulating substrate 20. The first circuit board 30 is spaced apart from each of the electrical connectors 10, and a groove 11 is provided on the side of each electrical connector 10 facing away from the insulating substrate 20. The thermistor 13 is provided in the groove 11, and the thermistor 13 is electrically isolated from the electrical connector 10. The second circuit board 40 is provided on each of the electrical connectors 10 and the first circuit board 30, one end of the second circuit board 40 covers the groove 11 and is electrically connected to the thermistor 13, and the other end of the second circuit board 40 is electrically connected to the first circuit board 30, wherein each of the electrical connectors 10 is used to electrically connect a cell (not marked). The battery cell connection assembly 100 provided in the present application can improve the protection for the thermal element 13, facilitate the stable and reliable connection between the thermal element 13 and the second circuit board 40, and also improve space utilization.

[0117] In this embodiment, the battery cell connection assembly 100 further includes a first insulating adhesive 50, which fills the slot 11 and covers the thermal element 13. In this way, the thermal element 13 is fixed in the slot 11, making the battery cell connection assembly 100 more stable and durable.

[0118] In addition, an embodiment of the present application further provides a battery cell connection system (not marked), the battery cell connection system includes a plurality of battery cells (not marked) and the battery cell connection system, the plurality of battery cells are arranged side by side, and each of the battery cells is connected to one of the electrical connectors 10. The battery cell connection system can be applied to a wide range of applications, especially in the fields of electric vehicles, power tools, energy storage systems, etc. Its main application scenarios include but are not limited to: Electric vehicles: In the assembly of power batteries for electric vehicles, the battery cell connection system can be used to connect battery cells, ensure a stable connection and electrical connection between battery cells, and improve the performance and safety of the overall battery assembly. Energy storage system: In renewable energy storage systems such as solar energy and wind energy, the battery cell connection system can be used to connect energy storage batteries to achieve storage and release of electrical energy, improve energy utilization and system stability. Power tools: In various types of power tools, such as electric screwdrivers, electric drills, etc., the battery cell connection system can be used to connect battery modules, ensure a stable connection between the battery and the power tool and efficient transmission of electrical energy, and provide long-lasting working performance. Portable devices: In portable electronic devices such as smartphones and tablets, the battery cell connection system can be used to connect battery cells or battery modules to ensure continuous power supply and stable performance of the device.

[0119] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for manufacturing a battery cell connection assembly, characterized in that: Including steps: A first circuit board and a plurality of electrical connectors are arranged on one side of an insulating substrate, wherein the plurality of electrical connectors are arranged at intervals on the insulating substrate, and the first circuit board is arranged at intervals from each of the electrical connectors; A groove is provided on a side of each of the electrical connectors facing away from the insulating substrate; A thermal element is arranged in the slot, wherein the thermal element is electrically isolated from the electrical connector; A second circuit board is arranged between each of the electrical connectors and the first circuit board, one end of the second circuit board covers the slot and is electrically connected to the thermistor, and the other end of the second circuit board is electrically connected to the first circuit board, wherein each of the electrical connectors is used to electrically connect one battery cell.

2. The manufacturing method according to claim 1, wherein The method further comprises the steps of: filling the slot with insulating glue, and coating the thermal sensitive element with the insulating glue.

3. The manufacturing method according to claim 1, wherein The method further includes the step of connecting each of the electrical connectors and the second circuit board by ultrasonic welding technology.

4. The manufacturing method according to claim 1, wherein: Before the step of "arranging the thermal element in the slot", the method further includes: arranging an adhesive layer at the bottom of the slot; The step of "arranging a thermal element in the slot" further includes: arranging the thermal element on the adhesive layer, and arranging a first solder on a side of the thermal element away from the adhesive layer.

5. The manufacturing method according to claim 4, wherein: The first circuit board includes a first circuit substrate and a plurality of second solders disposed on the first circuit substrate, the second circuit board includes a second circuit board substrate and a plurality of third solders disposed on the second circuit substrate, the first solders corresponding to a portion of the third solders, and the second solders corresponding to another portion of the third solders, and the step of "arranging a second circuit board on each of the electrical connectors and the first circuit board" includes: The first solder and a portion of the third solder are soldered using a photon sintering technique, and the second solder and another portion of the third solder are soldered using the photon sintering technique.

6. The manufacturing method according to claim 5, wherein: The manufacturing method of the first circuit board comprises the steps of: Providing a first copper clad laminate, the first copper clad laminate comprising a first transparent insulating layer, a first adhesive layer and a first copper foil layer, wherein the first adhesive layer is connected between the first transparent insulating layer and the first copper foil layer; Etching the first copper foil layer to form a first circuit layer, wherein the first circuit layer includes a plurality of first connection pads spaced apart from each other; A first cover film is provided on the first circuit layer, the first cover film including a second adhesive layer and a first protective layer provided on the second adhesive layer, the second adhesive layer connecting the first circuit layer and the first protective layer, a plurality of first openings being provided through the first cover film, and the first connection pads being exposed in the first openings; The second solder is disposed in the first opening, and the second solder is connected to the first connection pad to obtain the first circuit board.

7. The manufacturing method according to claim 5, wherein: The manufacturing method of the second circuit board comprises the steps of: Providing a second copper clad laminate, the second copper clad laminate comprising a second transparent layer, a third adhesive layer, and a second copper foil layer, wherein the third adhesive layer is connected between the second transparent insulating layer and the second copper foil layer; etching the second copper foil layer to form a second circuit layer, wherein the second circuit layer includes a plurality of second connection pads spaced apart from each other; A second cover film is provided on the second circuit layer, the second cover film including a fourth adhesive layer and a second protective layer provided on the fourth adhesive layer, the fourth adhesive layer connecting the second circuit layer and the second protective layer, the second cover film having a plurality of second openings formed therethrough, the second connection pads being exposed in the second openings; The third solder is provided in the second opening, and the third solder is connected to the second connection pad to obtain the second circuit board.

8. A battery cell connection assembly, characterized in that: It includes an insulating substrate, a first circuit board, multiple electrical connectors, multiple thermistors and multiple second circuit boards, the first circuit board and the multiple electrical connectors are arranged on the same side of the insulating substrate, the multiple electrical connectors are arranged at intervals on the insulating substrate, the first circuit board is spaced apart from each electrical connector, each electrical connector is provided with a groove on the side facing away from the insulating substrate, the thermistor is arranged in the groove, the thermistor is electrically isolated from the electrical connector, the second circuit board is arranged on each electrical connector and the first circuit board, one end of the second circuit board covers the groove and is electrically connected to the thermistor, and the other end of the second circuit board is electrically connected to the first circuit board, wherein each electrical connector is used to electrically connect a battery cell.

9. The battery cell connection assembly according to claim 8, characterized in that: It also includes insulating glue, which is filled in the slot and covers the thermal element.

10. A battery cell connection system, characterized in that: It comprises a plurality of battery cells and the battery cell connection assembly as claimed in claim 8 or 9, wherein the plurality of battery cells are arranged side by side, and each of the battery cells is connected to one of the electrical connectors.

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