Heterojunction battery piece edge etching and coating integrated equipment and control method thereof

Abstract

The invention discloses heterojunction battery piece edge etching and film coating integrated equipment and a control method thereof.The equipment comprises an outer cavity, an inner cavity, an air inlet assembly, a discharging assembly, a piece clamping mechanism and a vacuumizing assembly, the outer cavity and the inner cavity are arranged in an embedded mode, and the outer cavity and the inner cavity are separated through a separation cover plate; the vacuumizing assembly is connected with the outer cavity and the inner cavity so as to vacuumize the cavities. The gas inlet assembly penetrates through the top of the outer cavity and extends to the upper portion of the inner cavity so as to convey process gas into the inner cavity. The piece clamping mechanism is arranged at the lower part of the inner cavity and is used for bearing a battery piece; and the discharge assembly is located in the nesting gap between the outer cavity and the inner cavity, is connected with the inner cavity and an external radio frequency power supply, and is used for exciting ionization of the process gas in the inner cavity so as to realize edge etching or film coating of the heterojunction battery piece. The device has the advantages of being compact in structure, convenient to operate, high in reliability and the like, etching and deposition film forming of the battery piece are completed in the same device, and the production efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy battery preparation, and particularly relates to an integrated device for edge etching and coating of heterojunction battery wafers and a control method thereof. Background Art

[0002] The performance of heterojunction battery wafers not only depends on the characteristics of the active layer itself, but is also affected by interface engineering. As an important part of interface engineering, the quality of the edge insulating layer is directly related to the overall performance of the battery. The manufacturing process of HJT batteries mainly includes four steps: texturing, amorphous silicon deposition, TCO deposition, and screen printing. During the entire process, amorphous silicon intrinsic layers, doped layers, and TCO film layers are also deposited on the sides of the silicon wafers. Without insulation treatment, it will cause short circuits between the front and back sides of the battery, affecting the power generation efficiency of the bifacial battery. Therefore, the edge layer of the silicon wafer is usually etched later to remove the deposits. However, etching will cause damage and interface defects on the surface of the battery wafer, and these damages and defects become effective recombination centers for carriers, thereby affecting the efficiency and yield of the battery wafer. The above damages and surface defects cannot be processed in the same chamber, and it is necessary to transfer the target battery wafer to the next process to add a surface protection layer, which greatly increases the manufacturing cost of the battery wafer.

[0003] Chinese Patent Application CN202211700090.6 discloses a plasma edge etching device, in which a movable upper electrode assembly or a lower electrode assembly is provided in a vacuum reaction chamber. The lower electrode assembly is used to support the substrate, and a plasma confinement unit and an air extraction channel around the substrate are combined, so that the plasma confinement unit is used to limit the plasma around the substrate. After the process gas enters the reaction chamber and is ionized, the edge of the substrate is etched.

[0004] The above solution has obvious disadvantages: the movable electrode makes the manufacturing and maintenance costs of the device relatively high, and this solution can only achieve the etching effect on the edge layer of the substrate, and cannot process the etched surface layer. It is still necessary to add process steps to add a protection layer to the edge and surface of the substrate after etching, further increasing the manufacturing cost of the battery. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to solve the problem of edge carrier recombination caused by etching of heterojunction batteries, and provide an integrated device for edge etching and coating of heterojunction battery wafers with a compact structure, convenient operation, precise control and high stability and a control method thereof.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A heterojunction cell edge etching and coating integrated device, comprising: an outer cavity and an inner cavity nested, as well as an air inlet assembly, a discharge assembly, a wafer clamping mechanism, and a vacuum pumping assembly. The outer cavity and the inner cavity are separated by a partition cover plate; the vacuum pumping assembly is respectively connected to the outer cavity and the inner cavity to evacuate the outer cavity and the inner cavity; the air inlet assembly penetrates through the top of the outer cavity and extends to the upper part of the inner cavity to transport process gas into the inner cavity; the wafer clamping mechanism is arranged at the lower part of the inner cavity to carry the cell; the discharge assembly is located in the nested gap between the outer cavity and the inner cavity. The discharge assembly is respectively connected to the inner cavity and an external radio frequency power supply. The discharge assembly is used to excite the ionization of the process gas in the inner cavity to achieve edge etching or coating of the heterojunction cell.

[0008] As a further improvement of the present invention, the inner cavity includes a first inner cavity and a second inner cavity. The second inner cavity is nested in the first inner cavity. A partition cover plate is provided between the top of the first inner cavity and the inner side of the top of the outer cavity to separate the outer cavity from the inner cavity.

[0009] As a further improvement of the present invention, the wall thickness of the first inner cavity is greater than that of the second inner cavity.

[0010] As a further improvement of the present invention, the wafer clamping mechanism includes a wafer clamping assembly and a rotary heating assembly. The rotary heating assembly is arranged at the lower inner side of the second inner cavity. The wafer clamping assembly is arranged on the rotary heating assembly. The wafer clamping assembly is used to clamp the cell.

[0011] As a further improvement of the present invention, the wafer clamping assembly includes a stud, an upper top plate, and a bottom plate. The bottom plate is arranged on the rotary heating assembly. A stud is provided between the upper top plate and the bottom plate. The cell is placed between the upper top plate and the bottom plate and locked by the stud.

[0012] As a further improvement of the present invention, the rotary heating assembly includes a graphite plate, an insulating tray, a rotary heating plate, a shielding insulating cover, and a support flange. The support flange is installed at the lower inner side of the second inner cavity. The rotary heating plate is nested in the support flange, and a shielding insulating cover is provided between the rotary heating plate and the support flange. The insulating tray is arranged on the rotary heating plate. The graphite plate is arranged on the insulating tray. The bottom plate is placed on the graphite plate to realize rotary heating of the cell.

[0013] As a further improvement of the present invention, the air inlet assembly includes an air inlet pipe, a flow equalizing plate, and a spray plate. One end of the air inlet pipe is connected to a process gas source. The other end of the air inlet pipe penetrates through the top of the outer cavity and extends into the second inner cavity and is connected to the flow equalizing plate. The spray plate is arranged at the top inner side of the second inner cavity and covers the periphery of the flow equalizing plate.

[0014] As a further improvement of the present invention, the discharge assembly includes an electrode extension rod, an electrode rod, and a copper coil. The copper coil is wound around the outer periphery of the first inner cavity. The electrode rod is disposed in the nested gap between the outer cavity and the first inner cavity. One end of the electrode rod is connected to the copper coil through the electrode extension rod, and the other end of the electrode rod penetrates through the bottom of the outer cavity and is connected to an external radio frequency power supply.

[0015] As a further improvement of the present invention, the vacuum pumping assembly includes an outer cavity exhaust pipe and a tee support pipe. The tee support pipe is respectively connected to a vacuum molecular pump and the second inner cavity. The outer cavity exhaust pipe is respectively connected to the outer cavity and the tee support pipe to evacuate the outer cavity and the second inner cavity; the outer cavity exhaust pipe is also connected to an outer cavity gas filling pipe to fill the outer cavity with an inert gas.

[0016] As a general technical concept, the present invention also provides a control method applicable to the above-mentioned integrated device for edge etching and coating of heterojunction solar cells, including the following steps:

[0017] Step S1: Clamp the solar cell between the upper top plate and the bottom plate, place it on the graphite plate, and evacuate the outer cavity and the second inner cavity through the tee support pipe and the vacuum molecular pump;

[0018] Step S2: In a vacuum state, introduce NF 3 / Cl 2 gas into the second inner cavity uniformly through the inlet pipe, the flow equalizing plate, and the spray plate, and introduce N 2 from the outer cavity gas filling pipe into the outer cavity;

[0019] Step S3: Drive the solar cell to rotate uniformly in the second inner cavity by rotating the heating plate, heat the solar cell, turn on the external radio frequency power supply, and NF 3 / Cl 2 gas generates glow discharge in the second inner cavity, ionizes NF 3 / Cl 2 into active plasma, and bombards the exposed edge layer surface of the solar cell in the second inner cavity;

[0020] Step S4: Extract the volatile waste gas generated by the reaction from the second inner cavity through the vacuum molecular pump and the tee support pipe to etch the edge of the solar cell;

[0021] Step S5: After the etching is completed, turn off the external radio frequency power supply, introduce N 2 into the second inner cavity through the inlet pipe for purging, and extract N 2 from the second inner cavity through the vacuum molecular pump and the tee support pipe;

[0022] Step S6: Introduce SiH 4 and NH 3The gas is introduced through the intake pipe and evenly enters the second inner cavity after passing through the flow equalizing plate and the spraying plate;

[0023] Step S7: Turn on the radio frequency power supply, and SiH 4 and NH 3 gases generate glow discharge in the second inner cavity and undergo a chemical reaction to form Si x N y which is deposited on the edge of the battery cell to form a Si x N y thin film protection layer;

[0024] Step S8: Extract the waste gas generated by the reaction from the second inner cavity through the vacuum molecular pump and the three-way support pipe to achieve the deposition coating on the edge of the battery cell.

[0025] Compared with the prior art, the advantages of the present invention are as follows:

[0026] 1. For the integrated device for edge etching and coating of the heterojunction battery cell of the present invention, the outer cavity and the inner cavity arranged in a nested manner are separated from each other through the partition cover plate, avoiding power loss of the power supply caused by the discharge of the outer cavity during the process and damage to the cavity; the vacuum pumping assembly is used to achieve vacuum pumping of the outer cavity and the inner cavity, and the battery cell is placed in the inner cavity through the clip mechanism. Moreover, the inner cavity is also connected to the discharge assembly, and process gas is transported into the inner cavity through the intake assembly. Under the excitation of the discharge assembly, the process gas in the inner cavity is ionized, that is, the edge etching or coating of the heterojunction battery cell is realized. The etching process and the deposition coating process of the heterojunction battery cell can be seamlessly connected in the same process chamber. First, the etching process is carried out in the reaction chamber, which can effectively remove the redundant metal deposits on the edge of the battery cell and prevent short circuit of the battery cell edge. Then, a silicon nitride or silicon oxide thin film is deposited on the etched edge layer in the same vacuum reaction chamber, effectively reducing the edge carrier recombination and improving the battery edge passivation performance, which not only improves the power generation efficiency of the battery cell but also greatly reduces the battery manufacturing cost.

[0027] 2. For the control method of the integrated device for edge etching and coating of the heterojunction battery cell of the present invention, the battery cell is placed in the clip assembly and rotated and heated by the rotating heating assembly. By separating the outer cavity from the inner cavity and filling N 2 into the outer cavity, the outer cavity discharge is avoided. Different process gases enter the second inner cavity through the flow equalizing plate and the spraying plate, and discharge in the second inner cavity through the radio frequency discharge assembly, that is, the ionization or chemical reaction of the process gas is realized; by changing the type of the process gas entering the second inner cavity, the conversion of the etching or coating process is realized; by adjusting the radio frequency power supply power, the rotation speed of the rotating heating plate, the process gas flow rate or the gas ratio, the corresponding process effects are realized, and the operation is simple. Description of the Drawings

[0028] Figure 1 Schematic diagram of the structural principle of the integrated equipment for edge etching and coating of heterojunction solar cells in a specific embodiment of the present invention;

[0029] Figure 2 Process flow chart of edge etching and coating of heterojunction solar cells in a specific embodiment of the present invention;

[0030] Legend: 10, inlet pipe; 11, flow equalizing plate; 12, spraying plate; 20, outer cavity; 21, separating cover plate; 30, electrode extension rod; 31, electrode rod; 32, copper coil; 33, first inner cavity; 34, second inner cavity; 40, stud; 41, upper top plate; 42, bottom plate; 43, solar cell; 50, graphite plate; 51, insulating tray; 52, rotating heating plate; 53, shielding insulating cover; 54, support flange; 60, outer cavity exhaust pipe; 61, tee support pipe; 62, outer cavity filling pipe. Detailed implementation manners

[0031] The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0032] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "side", "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0033] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0034] Embodiment

[0035] As Figure 1As shown in the figure, the integrated equipment for etching and coating the edges of the heterojunction cell of the present invention includes: an outer cavity 20 and an inner cavity nested, as well as an air inlet assembly, a discharge assembly, a wafer clamping mechanism, and a vacuum pumping assembly; the outer cavity 20 and the inner cavity are separated by a partition cover plate 21, and there is no interference between them. The vacuum pumping assembly is respectively connected to the outer cavity 20 and the inner cavity to achieve vacuum pumping of the outer cavity 20 and the inner cavity, and at the same time, the gas in the outer cavity 20 and the inner cavity can also be pumped out. The air inlet assembly penetrates through the top of the outer cavity 20 and extends to the upper part of the inner cavity to be used for transporting process gas into the inner cavity; by transporting different types of process gas, different processes can be carried out. The wafer clamping mechanism is arranged at the lower part of the inner cavity to be used for carrying the cell 43. The discharge assembly is located in the nested gap between the outer cavity 20 and the inner cavity. The discharge assembly is respectively connected to the inner cavity and an external radio frequency power supply / bias power supply. The discharge assembly is used to excite the ionization of the process gas in the inner cavity to achieve edge etching or coating of the heterojunction cell.

[0036] In this embodiment, the outer cavity 20 and the inner cavity which are nested are separated from each other by the partition cover plate 21, avoiding power loss of the power supply caused by discharge in the outer cavity 20 during the process and damage to the cavity; the vacuum pumping assembly is used to achieve vacuum pumping of the outer cavity 20 and the inner cavity. The cell 43 is placed in the inner cavity through the wafer clamping mechanism. Moreover, the inner cavity is also connected to the discharge assembly. Process gas is transported into the inner cavity through the air inlet assembly. Under the excitation of the discharge assembly, the process gas in the inner cavity is ionized, that is, edge etching or coating of the heterojunction cell is achieved. The etching process and the deposition coating process of the heterojunction cell are seamlessly connected in the same process chamber. First, the etching process is carried out in the reaction chamber, which can effectively remove the excess metal deposits on the edge of the cell 43 and prevent short circuit at the edge of the cell 43. Then, a silicon nitride or silicon oxide film is deposited on the etched edge layer in the same vacuum reaction chamber, effectively reducing the edge carrier recombination and improving the edge passivation performance of the cell, which not only improves the power generation efficiency of the cell 43 but also greatly reduces the manufacturing cost of the cell.

[0037] As Figure 1 shown in the figure, the inner cavity includes a first inner cavity 33 and a second inner cavity 34. The second inner cavity 34 is nested in the first inner cavity 33. Both ends of the second inner cavity 34 are in sealed contact with both ends of the outer cavity 20. The bottom of the first inner cavity 33 is in sealed contact with the bottom of the outer cavity 20. A partition cover plate 21 is provided between the top of the first inner cavity 33 and the inner side of the top of the outer cavity 20 to separate the outer cavity 20 from the inner cavity, and a cavity gap is formed between the outer cavity 20 and the first inner cavity 33.

[0038] Furthermore, the wall thickness of the first inner cavity 33 is greater than that of the second inner cavity 34, and both the first inner cavity 33 and the second inner cavity 34 are made of quartz material to ensure the structural stability of the inner cavity, facilitate the layout of the discharge component, and also ensure effective isolation between the inner cavity and the outer cavity 20.

[0039] In this embodiment, the clip mechanism includes a clip assembly and a rotary heating assembly. The rotary heating assembly is arranged at the lower inner part of the second inner cavity 34, and the clip assembly is arranged on the rotary heating assembly. The clip assembly is used to hold the battery slice 43. This not only realizes the fixation of the battery slice 43 in the second inner cavity 34 but also realizes the rotary heating of the battery slice 43 to improve the efficiency of edge etching and deposition coating of the battery slice.

[0040] As Figure 1 shown, the clip assembly includes a stud 40, an upper top plate 41, and a bottom plate 42. The bottom plate 42 is arranged on the rotary heating assembly. There is a stud 40 between the upper top plate 41 and the bottom plate 42. The battery slice 43 is placed between the upper top plate 41 and the bottom plate 42 and is locked by the stud 40. Further, the stud 40, the upper top plate 41, and the bottom plate 42 are all made of polytetrafluoroethylene material, which has the characteristics of high temperature resistance and insulation.

[0041] As Figure 1 shown, the rotary heating assembly includes a graphite plate 50, an insulating tray 51, a rotary heating plate 52, a shielding insulating cover 53, and a support flange 54. Among them, the shielding insulating cover 53 is made of polytetrafluoroethylene material and has good insulation performance. The support flange 54 is installed at the lower inner part of the second inner cavity 34. The rotary heating plate 52 is nested in the support flange 54, and there is a shielding insulating cover 53 between the rotary heating plate 52 and the support flange 54. The insulating tray 51 is arranged on the rotary heating plate 52, the graphite plate 50 is arranged on the insulating tray 51, and the bottom plate 42 is placed on the graphite plate 50 to realize the rotary heating of the battery slice 43.

[0042] As Figure 1 shown, the air inlet assembly includes an air inlet pipe 10, a flow equalizing plate 11, and a spray plate 12. One end of the air inlet pipe 10 is connected to the process gas source. The other end of the air inlet pipe 10 penetrates through the top of the outer cavity 20 and extends into the second inner cavity 34 and is connected to the flow equalizing plate 11. The spray plate 12 is arranged at the inner top of the second inner cavity 34 and covers the outer periphery of the flow equalizing plate 11 to realize the uniform distribution of the process gas in the second inner cavity 34. Further, two air inlet pipes 10 are provided to simultaneously transport two different types of process gases. The cross-sectional dimension of the spray plate 12 is slightly smaller than the cross-section of the second inner cavity 34 to improve the uniformity of the process gas distribution as much as possible.

[0043] As Figure 1As shown, the discharge assembly includes an electrode extension rod 30, an electrode rod 31, and a copper coil 32. The copper coil 32 is wound around the outer periphery of the first inner cavity 33. The electrode rod 31 is disposed in the nested gap between the outer cavity 20 and the first inner cavity 33. One end of the electrode rod 31 is connected to the copper coil 32 through the electrode extension rod 30, and the other end of the electrode rod 31 penetrates through the bottom of the outer cavity 20 and is connected to an external radio frequency power source to form an ICP radio frequency discharge assembly.

[0044] By arranging the copper coil 32 around the outer wall of the first inner cavity 33, during discharge, the electric field in the second inner cavity 34 is evenly distributed, enabling NF 3 / Cl 2 to be fully ionized. The plasma can fully bombard the edge of the battery cell 43, or during film coating, enable SiH 4 and NH 3 to fully react, such that the Si x N y film can be evenly deposited on the edge of the battery cell 43.

[0045] As Figure 1 shown, the vacuum pumping assembly includes an outer cavity vacuum pumping pipe 60 and a tee support pipe 61. The tee support pipe 61 is respectively connected to a vacuum molecular pump and the second inner cavity 34, and the outer cavity vacuum pumping pipe 60 is respectively connected to the outer cavity 20 and the tee support pipe 61; the outer cavity 20 and the second inner cavity 34 are evacuated through the tee support pipe 61 and the vacuum molecular pump. Further, the outer cavity vacuum pumping pipe 60 is also connected to an outer cavity gas charging pipe 62 to fill the outer cavity 20 with an inert gas to prevent ionization in the outer cavity 20.

[0046] As Figure 2 shown, in this embodiment, a control method applicable to the above-mentioned integrated device for edge etching and coating of heterojunction battery cells is further provided, including the following steps:

[0047] Step S1: Clamp the battery cell 43 between the upper top plate 41 and the bottom plate 42, place it on the graphite plate 50, and evacuate the outer cavity 20 and the second inner cavity 34 through the tee support pipe 61 and the vacuum molecular pump.

[0048] Step S2: In a vacuum state, introduce the NF 3 / Cl 2 gas into the second inner cavity 34 evenly through the inlet pipe 10, after passing through the flow equalizing plate 11 and the spray plate 12. Introduce N 2 into the outer cavity 20 from the outer cavity gas charging pipe 62 to avoid discharge in the outer cavity 20.

[0049] Step S3: Drive the battery cell 43 to rotate evenly in the second inner cavity 34 by rotating the heating plate 52, heat the battery cell 43, turn on the external radio frequency power source, NF 3 / Cl2 Glow discharge is generated by the gas within the second inner cavity 34 to ionize NF 3 / Cl 2 into active plasma, which bombards the surface of the exposed edge layer of the cell 43 within the second inner cavity 34. By adjusting the power of the power supply, the temperature and rotation speed of the rotating heating plate 52, the electric potential energy of the plasma and its contact with the edge of the cell 43 are increased, enabling the plasma to fully bombard the edge coating layer of the cell 43.

[0050] Step S4: The volatile waste gas generated by the reaction is extracted from the second inner cavity 34 through the vacuum molecular pump and the three-way support pipe 61 to etch the edge of the cell 43.

[0051] Step S5: After the etching is completed, the external radio frequency power supply is turned off, and N 2 is introduced into the second inner cavity 34 through the air inlet pipe 10 for purging, and N 2 is extracted from the second inner cavity 34 through the vacuum molecular pump and the three-way support pipe 61.

[0052] Step S6: SiH 4 and NH 3 gases are introduced through the air inlet pipe 10, and after passing through the flow equalizing plate 11 and the spray plate 12, they are uniformly introduced into the second inner cavity 34.

[0053] Step S7: The radio frequency power supply is turned on. SiH 4 and NH 3 gases generate glow discharge within the second inner cavity 34 and undergo a chemical reaction to form Si x N y which is deposited on the edge of the cell 43 to form a Si x N y thin film protective layer. By adjusting the flow rate of the introduced gases, the gas ratio, the power of the power supply, the temperature and rotation speed of the rotating heating plate 52, SiH 4 and NH 3 react fully and are uniformly deposited at the edge of the cell 43.

[0054] Step S8: The waste gas generated by the reaction is extracted from the second inner cavity 34 through the vacuum molecular pump and the three-way support pipe 61 to deposit a coating on the edge of the cell 43. After the coating process is completed, the rotating heating plate 52 stops operating, and then the cell 43 is taken out.

[0055] The above description is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. An integrated device for etching and coating the edge of a heterojunction cell, characterized in that: include: The outer cavity (20) and the inner cavity, as well as the air intake component, the discharge component, the clamping mechanism and the vacuum component are nested, and the outer cavity (20) and the inner cavity are separated by a partition cover (21); the vacuum component is respectively connected to the outer cavity (20) and the inner cavity to realize vacuuming of the outer cavity (20) and the inner cavity; the air intake component passes through the top of the outer cavity (20) and extends to the upper part of the inner cavity to be used for conveying process gas to the inner cavity; the clamping mechanism is arranged at the lower part of the inner cavity to be used for carrying the battery cell (43); the discharge component is located in the nested gap between the outer cavity (20) and the inner cavity, the discharge component is respectively connected to the inner cavity and an external radio frequency power supply, and the discharge component is used to excite the process gas in the inner cavity to ionize, so as to realize edge etching or coating of the heterojunction battery cell.

2. The integrated equipment for heterojunction cell edge etching and coating according to claim 1, characterized in that: The inner cavity comprises a first inner cavity (33) and a second inner cavity (34), wherein the second inner cavity (34) is nested in the first inner cavity (33), and a partition cover plate (21) is provided on the top of the first inner cavity (33) and the inner side of the top of the outer cavity (20) to separate the outer cavity (20) from the inner cavity.

3. The integrated equipment for heterojunction cell edge etching and coating according to claim 2, characterized in that: The wall thickness of the first inner cavity (33) is greater than the wall thickness of the second inner cavity (34).

4. The integrated equipment for heterojunction cell edge etching and coating according to claim 2, characterized in that: The clamping mechanism comprises a clamping assembly and a rotating heating assembly, wherein the rotating heating assembly is arranged at the lower inner part of the second inner cavity (34), and the clamping assembly is arranged on the rotating heating assembly, and the clamping assembly is used to clamp the battery cell (43).

5. The integrated equipment for heterojunction cell edge etching and coating according to claim 4, characterized in that: The clip assembly comprises a stud (40), an upper plate (41) and a bottom plate (42); the bottom plate (42) is arranged on the rotary heating assembly; a stud (40) is arranged between the upper plate (41) and the bottom plate (42); the battery cell (43) is placed between the upper plate (41) and the bottom plate (42) and is locked by the stud (40).

6. The integrated equipment for heterojunction cell edge etching and coating according to claim 5, characterized in that: The rotary heating assembly comprises a graphite plate (50), an insulating tray (51), a rotary heating plate (52), a shielding insulating cover (53) and a supporting flange (54); the supporting flange (54) is installed at the lower inner side of the second inner cavity (34); the rotary heating plate (52) is nested in the supporting flange (54); a shielding insulating cover (53) is provided between the rotary heating plate (52) and the supporting flange (54); the insulating tray (51) is arranged on the rotary heating plate (52); the graphite plate (50) is arranged on the insulating tray (51); and the bottom plate (42) is placed on the graphite plate (50) to realize rotary heating of the battery cell (43).

7. The integrated equipment for heterojunction cell edge etching and coating according to any one of claims 2 to 6, characterized in that: The air intake assembly comprises an air intake pipe (10), a flow equalizer plate (11) and a spray plate (12); one end of the air intake pipe (10) is connected to a process gas source; the other end of the air intake pipe (10) passes through the top of the outer cavity (20) and extends into the second inner cavity (34), and is connected to the flow equalizer plate (11); the spray plate (12) is arranged at the top of the inner side of the second inner cavity (34) and covers the outer periphery of the flow equalizer plate (11).

8. The integrated equipment for heterojunction cell edge etching and coating according to any one of claims 2 to 6, characterized in that: The discharge assembly comprises an electrode extension rod (30), an electrode rod (31) and a copper coil (32); the copper coil (32) is wound around the outer periphery of the first inner cavity (33); the electrode rod (31) is arranged in a nested gap between the outer cavity (20) and the first inner cavity (33); one end of the electrode rod (31) is connected to the copper coil (32) via the electrode extension rod (30); and the other end of the electrode rod (31) passes through the bottom of the outer cavity (20) and is connected to an external radio frequency power source.

9. The integrated equipment for heterojunction cell edge etching and coating according to any one of claims 2 to 6, characterized in that: The vacuum pumping assembly comprises an outer cavity exhaust pipe (60) and a three-way support pipe (61), wherein the three-way support pipe (61) is respectively connected to a vacuum molecular pump and a second inner cavity (34), and the outer cavity exhaust pipe (60) is respectively connected to the outer cavity (20) and the three-way support pipe (61) to realize vacuum pumping of the outer cavity (20) and the second inner cavity (34); the outer cavity exhaust pipe (60) is also connected to an outer cavity filling pipe (62) to realize filling of the outer cavity (20) with an inert gas.

10. A control method applicable to the heterojunction cell edge etching and coating integrated equipment according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, clamping the battery cell (43) between the upper top plate (41) and the bottom plate (42), and placing it on the graphite plate (50), and evacuating the outer cavity (20) and the second inner cavity (34) through a three-way support tube (61) and a vacuum molecular pump; Step S2, under vacuum, NF3 / Cl2 gas is introduced from the air inlet pipe (10), passed through the flow equalizer plate (11) and the spray plate (12), and then uniformly introduced into the second inner cavity (34), and N2 is introduced into the outer cavity (20) from the outer cavity charging pipe (62); Step S3, the battery cell (43) is driven to rotate evenly in the second inner cavity (34) by rotating the heating plate (52), and the battery cell (43) is heated, and the external radio frequency power supply is turned on, and the NF3 / Cl2 gas generates a glow discharge in the second inner cavity (34), and the NF3 / Cl2 gas is heated. 3 / Cl2 is ionized into active plasma, which bombards the exposed edge layer surface of the battery sheet (43) in the second inner cavity (34); Step S4, extracting the volatile waste gas generated by the reaction out of the second inner cavity (34) through a vacuum molecular pump and a three-way support tube (61), so as to etch the edge of the battery cell (43); Step S5: After etching is completed, turn off the external radio frequency power supply, pass N2 from the air inlet pipe (10) into the second inner cavity (34) for purging, and pump N2 out of the second inner cavity (34) through the vacuum molecular pump and the three-way support pipe (61); Step S6, introducing SiH4 and NH3 gases from the air inlet pipe (10), passing through the flow equalizer plate (11) and the spray plate (12), and then uniformly introduced into the second inner cavity (34); Step S7: Turn on the radio frequency power supply, and the SiH4 and NH3 gases generate glow discharge in the second inner cavity (34), and chemically react to generate Si x N y Deposited on the edge of the cell (43) to form Si x N y Thin film protective layer; Step S8, exhaust gas generated by the reaction is pumped out of the second inner cavity (34) through a vacuum molecular pump and a three-way support tube (61), so as to achieve deposition and coating of the edge of the battery cell (43).

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