A PECVD reaction chamber structure for edge passivation coating

Abstract

This invention discloses a PECVD reaction chamber structure for edge passivation coating, comprising: a reaction chamber, a discharge backplate, a cathode assembly, an anode carrier, and a power supply component. The reaction chamber contains an anode carrier for placing solar cells, and an extraction port is located at the rear of the reaction chamber. The discharge backplate and the reaction chamber form a vacuum chamber required for the passivation coating reaction. A power supply component is located on the atmospheric side of the discharge backplate, connecting the discharge backplate to an RF power supply. The vacuum side of the discharge backplate contains the cathode assembly, and a gas feed pipe is provided on the discharge backplate to introduce the coating reaction gas into the cathode assembly and uniformly diffuse it into the reaction chamber. The cathode assembly and the anode carrier form a capacitively coupled substrate, generating plasma under the alternating electric field of the RF power supply. This invention features a compact structure, convenient operation, and high reliability, meeting the process requirements of different types of thin film deposition and achieving good passivation effects.

Description

Technical Field

[0001] This utility model relates to the field of coating technology for solar cells, and specifically to a PECVD reaction chamber structure for edge passivation coating. Background Technology

[0002] Half-cell module technology has become a consensus in the industry for improving module efficiency. It has advantages such as reducing internal resistance loss by half, reducing module temperature, increasing power generation, and reducing module mismatch losses in low power generation or shading scenarios. It is one of the mainstream technologies for modules at present, and there will be demand for three-cell and four-cell modules in the future.

[0003] Existing TOPCON battery production lines, driven by the need to reduce overall production costs and increase single-unit capacity to lower operating costs, mostly employ large-size silicon wafers. However, direct encapsulation of large-size silicon wafers impacts efficiency, making laser cutting of finished cells into smaller sizes the optimal option. After cutting, moisture adheres to the cut surfaces, and the cutting process causes dangling bonds in the silicon lattice, making the new cut surfaces prone to carrier recombination. This increases the recombination rate, affecting cell efficiency and reliability. To address this, equipment for depositing passivation films on the cut surfaces of cells has been developed to improve the overall efficiency and reliability of battery modules. This equipment, used for depositing passivation films on the edges of half-cells, is called edge passivation equipment.

[0004] Existing edge passivation equipment primarily uses ALD (Alternating Layer Deposition) to deposit thin films. Since ALD production is based on surface reactions, a film will grow on any reactive active sites. However, because the edge passivation rack needs to stack a large number of solar cells together, the coating area inevitably exhibits unevenness from a microscopic perspective, leading to film growth in non-deposition areas and resulting in wrap-around deposition. This wrap-around deposition increases the adhesion between solar cells, causing them to stick together. Furthermore, conventional edge passivation equipment can only grow single-layer films, unable to grow multiple films in the same reaction chamber, and requires annealing treatment in other equipment to achieve a good passivation effect. Excessively high annealing temperatures affect solar cell performance, while excessively low annealing temperatures result in poor passivation. Utility Model Content

[0005] The technical problem to be solved by this invention is the low conversion efficiency of battery cells after laser cutting in the prior art. It provides a PECVD reaction chamber structure for edge passivation coating that is compact, can achieve non-winding plating, maintenance-free, single-reaction-chamber multi-film deposition, and high battery efficiency.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0007] A PECVD reaction chamber structure for edge passivation coating includes: a reaction chamber, a discharge backplate, a cathode assembly, an anode carrier, and a power supply assembly; the reaction chamber contains an anode carrier for placing solar cells, and the rear of the reaction chamber has an exhaust port; the discharge backplate serves as a cover plate for the reaction chamber, and the discharge backplate and the reaction chamber together form a vacuum chamber required for the passivation coating reaction; the atmospheric side of the discharge backplate is provided with a power supply assembly to connect the discharge backplate to an RF power supply, the vacuum side of the discharge backplate contains a cathode assembly, and the discharge backplate is provided with a gas feed pipe to introduce the coating reaction gas into the cathode assembly and uniformly diffuse it into the reaction chamber; the cathode assembly and the anode carrier form a capacitively coupled substrate, which generates plasma under the alternating electric field of the RF power supply.

[0008] As a further improvement of this utility model, a heating component is also provided in the reaction chamber, which surrounds the outer periphery of the anode carrier.

[0009] As a further improvement of this utility model, the heating assembly includes a first heater and a second heater, the first heater being symmetrically arranged on both sides of the anode carrier, and the second heater being located at the bottom of the anode carrier.

[0010] As a further improvement of this utility model, the reaction chamber is also provided with a support assembly, which is used to support the anode carrier and adjust the distance between the anode carrier and the cathode assembly.

[0011] As a further improvement of this utility model, the support assembly includes a support panel, a spacing adjustment plate, and a support column. One end of the support column is fixed in the reaction chamber, and the other end of the support column is connected to the support panel through the spacing adjustment plate. The support panel is connected to the anode carrier. The spacing adjustment plate is provided with multiple mounting holes along the vertical direction to adjust the spacing between the support panel and the end of the support column, thereby adjusting the spacing between the anode carrier and the cathode assembly.

[0012] As a further improvement of this utility model, a conductive strip is provided between the support panel and the end of the support column.

[0013] As a further improvement of this utility model, a cleaning spray pipe is also provided in the reaction chamber. The cleaning spray pipe is located in the upper part of the reaction chamber and is used to transport cleaning gas.

[0014] As a further improvement of this utility model, the cathode assembly includes a flow equalization plate, a spray plate, and a flow equalization box. The flow equalization plate is connected to the discharge backplate via a connecting column, and a primary flow equalization zone is formed between the flow equalization plate and the discharge backplate. The gas feed pipe is connected to the primary flow equalization zone. One end of the flow equalization box is connected to the discharge backplate, and the other end of the flow equalization box is connected to the spray plate. The flow equalization plate is located inside the flow equalization box, and a secondary flow equalization zone is formed between the flow equalization plate and the spray plate. The flow equalization plate is provided with multiple flow equalization holes, and the spray plate is provided with multiple spray holes.

[0015] As a further improvement of this utility model, the cross-sectional area of ​​the flow equalization hole is smaller than the cross-sectional area of ​​the spray hole, and the volume of the primary flow equalization zone is smaller than the volume of the secondary flow equalization zone.

[0016] As a further improvement of this utility model, the anode carrier includes a conductive dielectric plate, a boat support, and a material box. The boat support is fixed in the reaction chamber, and multiple material boxes are placed side by side on the boat support. The material boxes are loaded with battery cells, and the top of the material boxes is covered by the conductive dielectric plate. The conductive dielectric plate has a notch, and the position of the notch coincides with the passivation surface of the battery cell. The passivation surface and the conductive dielectric plate together form the anode substrate.

[0017] Compared with the prior art, the advantages of this utility model are:

[0018] This invention discloses a PECVD reaction chamber structure for edge passivation coating. A discharge backplate serves as the cover of the reaction chamber, and the discharge backplate and the reaction chamber together form a vacuum chamber required for the passivation coating reaction. The atmospheric side of the discharge backplate is connected to an RF power supply, while a cathode assembly is located on the vacuum side of the discharge backplate. The coating reaction gas is introduced into the cathode assembly through a gas feed pipe on the discharge backplate and then uniformly diffused into the reaction chamber. Simultaneously, an anode carrier for loading the solar cells is placed within the reaction chamber. The cathode assembly and the anode carrier form a capacitively coupled substrate with upper and lower plates. Under vacuum conditions, glow discharge is performed using an alternating electric field provided by the RF power supply, ionizing the coating process gas to form plasma. This achieves uniform passivation coating on the cut surfaces of the solar cells, avoiding the problem of coating around the edges. Furthermore, this PECVD reaction chamber structure exhibits excellent scalability, enabling the superposition of multiple processes such as silicon nitride deposition, amorphous silicon deposition, and annealing, while achieving superior passivation effects. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram of the PECVD reaction chamber structure used for edge passivation coating in a specific embodiment of this utility model.

[0020] Figure 2This is a side view schematic diagram of the PECVD reaction chamber structure used for edge passivation coating in a specific embodiment of this utility model;

[0021] Figure 3 This is a schematic diagram of the cross-sectional structure of the cathode assembly in a specific embodiment of this utility model;

[0022] Figure 4 This is a schematic diagram of the three-dimensional structure of the cathode assembly in a specific embodiment of this utility model;

[0023] Figure 5 This is a schematic diagram of the cross-sectional structure of the anode carrier in a specific embodiment of this utility model;

[0024] Figure 6 This is a schematic diagram of the three-dimensional structure of the anode carrier in a specific embodiment of this utility model;

[0025] Figure 7 This is a schematic diagram of the three-dimensional structure of the support component in a specific embodiment of this utility model;

[0026] Legend: 1. Reaction chamber; 2. Discharge backplate; 3. Cathode assembly; 4. Anode carrier; 5. Power supply assembly; 6. Support assembly; 7. First heater; 8. Second heater; 9. Exhaust port; 10. Cleaning spray pipe; 20. Primary flow equalization zone; 21. Secondary flow equalization zone; 22. Gas feed pipe; 23. Connecting column; 24. Flow equalization plate; 25. Flow equalization hole; 26. Spray plate; 27. Spray hole; 28. Flow equalization box; 29. ​​Planar insulating component; 30. Vertical insulating component; 41. Conductive dielectric plate; 42. Grab; 43. Boat support; 44. Material box; 61. Support panel; 62. Conductive strip; 63. Spacing adjustment plate; 64. Support column; 631. Mounting hole. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0028] In the description of this utility model, it should be understood that 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., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0030] Example

[0031] like Figure 1 and Figure 2 As shown, the PECVD reaction chamber structure for edge passivation coating of this utility model includes: a reaction chamber 1, a discharge backplate 2, a cathode assembly 3, an anode carrier 4, and a power supply assembly 5. The reaction chamber 1 is equipped with an anode carrier 4 for placing solar cells. The anode carrier 4 can be inserted into and removed from the reaction chamber 1 via a loading mechanism. An exhaust port 9 is provided at the rear of the reaction chamber 1 to provide the responsive vacuum conditions for the CVD reaction. The discharge backplate 2 serves as a cover plate for the reaction chamber 1, and the discharge backplate 2 and the reaction chamber 1 together form the vacuum chamber required for the passivation coating reaction. A power supply feed assembly 5 is provided on the atmospheric side of the discharge backplate 2 to connect the discharge backplate 2 to the radio frequency power supply. A cathode assembly 3 is provided on the vacuum side of the discharge backplate 2, and a gas feed pipe 22 is provided on the discharge backplate 2 to introduce the coating reaction gas into the cathode assembly 3 and uniformly diffuse it into the reaction chamber 1. The cathode assembly 3 and the anode carrier 4 form a capacitively coupled substrate. Under the alternating electric field of the radio frequency power supply, the process gas is ionized to generate plasma, thereby achieving passivation coating on the cut surface of the battery cell. In this embodiment, two discharge backplates 2 are provided on the top of the reaction chamber 1 as cover plates, which can effectively improve the standing wave effect caused by excessive discharge backplates 2, and ensure the overall glow uniformity within an effective range.

[0032] In this embodiment, a discharge backplate 2 is used as the cover plate of the reaction chamber 1, and the discharge backplate 2 and the reaction chamber 1 together form a vacuum chamber required for the passivation coating reaction. The atmospheric side of the discharge backplate 2 is connected to the radio frequency power supply, and the cathode assembly 3 is set on the vacuum side of the discharge backplate 2. The coating reaction gas is introduced into the cathode assembly 3 through the gas feed pipe 22 on the discharge backplate 2, and then diffused uniformly into the reaction chamber 1. At the same time, an anode carrier 4 for loading the battery cells is also set in the reaction chamber 1. The cathode assembly 3 and the anode carrier 4 form a capacitively coupled substrate in the form of upper and lower plates. Under vacuum conditions, glow discharge is performed using the alternating electric field provided by the radio frequency power supply, which ionizes the coating process gas to form plasma, achieving uniform passivation coating on the cut surface of the battery cells and avoiding the problem of coating around the surface. Meanwhile, the PECVD reaction chamber structure of this invention also has excellent scalability, enabling the superposition of multiple processes such as silicon nitride deposition, amorphous silicon, and annealing, and achieving a better passivation effect.

[0033] In this embodiment, a heating component is also provided inside the reaction chamber 1. The heating component surrounds the anode carrier 4 and uses resistance heating to heat the anode carrier 4 through convection, radiation and other means to provide the temperature conditions required for the reaction.

[0034] like Figure 1 and Figure 2 As shown, the heating assembly includes a first heater 7 and a second heater 8. The first heater 7 is symmetrically arranged on the left and right sides of the anode carrier 4, and the second heater 8 is located at the bottom of the anode carrier 4 to achieve uniform heating of the anode carrier 4.

[0035] like Figure 1 and Figure 2 As shown, the reaction chamber 1 is also provided with a support assembly 6, which is used to support the anode carrier 4 and adjust the distance between the anode carrier 4 and the cathode assembly 3 according to the actual process requirements, so as to improve the effect of edge passivation coating.

[0036] like Figure 3 and Figure 4 As shown, the cathode assembly 3 includes a flow equalization plate 24, a spray plate 26, and a flow equalization box 28. The flow equalization plate 24 is connected to the discharge backplate 2 via a connecting post 23, and a primary flow equalization zone 20 is formed between the flow equalization plate 24 and the discharge backplate 2. The gas feed pipe 22 is connected to the primary flow equalization zone 20. The top end of the flow equalization box 28 is connected to the discharge backplate 2, and the bottom end of the flow equalization box 28 is connected to the spray plate 26. The flow equalization plate 24 is located inside the flow equalization box 28, and a secondary flow equalization zone 21 is formed between the flow equalization plate 24 and the spray plate 26. The flow equalization plate 24 is provided with multiple flow equalization holes 25, and the spray plate 26 is provided with multiple spray holes 27.

[0037] Furthermore, the cross-sectional area of ​​the flow equalization orifice 25 is smaller than that of the spray orifice 27, which allows the gas pressure in the primary flow equalization zone 20 to be greater than that in the secondary flow equalization zone 21, thus facilitating gas diffusion. Correspondingly, the smaller volume of the primary flow equalization zone 20 compared to the secondary flow equalization zone 21 also serves the same purpose. In this embodiment, the volume of the primary flow equalization zone 20 is 2 / 3 the volume of the secondary flow equalization zone 21.

[0038] The coating reaction gas enters the primary flow equalization zone 20, which is composed of the discharge back plate 2 and the flow equalization plate 24, through the gas feed pipe 22 on the discharge back plate 2. It then enters the secondary flow equalization zone 21, which is composed of the flow equalization plate 24 and the spray plate 26, through the flow equalization hole 25 on the flow equalization plate 24. Finally, it is evenly fed into the reaction chamber 1 through the spray hole 27 on the spray plate 26.

[0039] like Figure 3 and Figure 4 As shown, during the glow discharge process, only the spray plate 26 in the cathode assembly 3 participates in the discharge as a substrate. The bottom of the discharge back plate 2 is provided with a planar insulating component 29 and a vertical insulating component 30 to cover the cathode assembly 3. Furthermore, the insulating component can be made of high-temperature insulating materials, such as ceramics or high-performance polymers, to suit the high temperature inside the reaction chamber 1 and the circuit insulation effect. Considering the thermal expansion caused by high temperature, the insulating component can be divided into multiple small insulating parts to reduce the risk of breakage caused by thermal expansion.

[0040] like Figure 5 and Figure 6 As shown, the anode carrier 4 includes a conductive dielectric plate 41, a boat support 43, and a collection box 44. The boat support 43 is fixed inside the reaction chamber 1, and multiple collection boxes 44 are placed side by side on the boat support 43. Each collection box 44 contains a solar cell, with the passivated surface of the solar cell facing the plasma glow discharge region. The top of each collection box 44 is covered by the conductive dielectric plate 41, which has a notch. The notch coincides with the passivated surface of the solar cell edge. The passivated surface and the conductive dielectric plate 41 together form the anode substrate. Specifically, the conductive dielectric plate 41 can be made of a material with excellent conductivity and high temperature resistance, such as graphite, to meet the requirements of glow discharge.

[0041] In this embodiment, in order to improve the ease of handling the anode carrier 4, grippers 42 are symmetrically provided on both sides of the boat support 43.

[0042] like Figure 7As shown, the support assembly 6 includes a support panel 61, a spacing adjustment plate 63, and a support column 64. The top end of the support column 64 is fixed inside the reaction chamber 1, and the bottom end of the support column 64 is connected to the support panel 61 via the spacing adjustment plate 63. The support panel 61 is connected to the anode carrier 4. Further, the spacing adjustment plate 63 has multiple mounting holes 631 along the vertical direction. These mounting holes 631 at different heights are connected to the ends of the support column 64 to adjust the spacing between the support panel 61 and the ends of the support column 64, thereby adjusting the spacing between the anode carrier 4 and the cathode assembly 3. Specifically, the adjustment range of the anode carrier 4 and the cathode assembly 3 is between 10mm and 80mm, depending on the type of deposited thin film.

[0043] To ensure that the anode carrier 4 has good electrical performance connection, a conductive strip 62 is provided between the support panel 61 and the end of the support column 64. The conductive strip 62 has a grounding function.

[0044] like Figure 2 As shown, a cleaning spray pipe 10 is also provided inside the reaction chamber 1. The cleaning spray pipe 10 is located above the first heater 7 and is connected to the gas inlet pipe at the furnace opening of the reaction chamber 1. During the cleaning process of the reaction chamber 1, the cleaning gas is supplied by the cleaning spray pipe 10. Spray holes are evenly distributed on the cleaning spray pipe 10, and the spray holes face the glow discharge area. By separating the coating gas and the cleaning gas into two parts for delivery, the erosion damage of the cleaning gas to the spray holes 27 on the spray plate 26 during the glow discharge process can be effectively reduced, extending the service life of the spray plate 26 and the equipment maintenance cycle.

[0045] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A PECVD reactor chamber structure for edge passivation coating, characterized in that, include: The reaction chamber (1), discharge backplate (2), cathode assembly (3), anode carrier (4), and power supply feed assembly (5) are provided. The reaction chamber (1) is provided with an anode carrier (4) for placing the battery cells. The tail of the reaction chamber (1) is provided with an exhaust port (9). The discharge backplate (2) is used as a cover plate for the reaction chamber (1). The discharge backplate (2) and the reaction chamber (1) form a vacuum chamber required for passivation coating reaction. The atmospheric side of the discharge backplate (2) is provided with a power supply feed assembly (5) to realize the connection between the discharge backplate (2) and the radio frequency power supply. The vacuum side of the discharge backplate (2) is provided with a cathode assembly (3). The discharge backplate (2) is provided with a gas feed pipe (22) to realize the coating reaction gas is introduced into the cathode assembly (3) and diffused evenly into the reaction chamber (1). The cathode assembly (3) and the anode carrier (4) form a capacitively coupled substrate to generate plasma under the alternating electric field of the radio frequency power supply.

2. The PECVD reaction chamber structure for edge passivation coating according to claim 1, characterized in that, The reaction chamber (1) is also equipped with a heating component, which surrounds the anode carrier (4).

3. The PECVD reactor chamber structure for edge passivation coating according to claim 2, wherein, The heating assembly includes a first heater (7) and a second heater (8). The first heater (7) is symmetrically arranged on both sides of the anode carrier (4), and the second heater (8) is located at the bottom of the anode carrier (4).

4. The PECVD reactor chamber structure for edge passivation coating according to claim 1, wherein, The reaction chamber (1) is also provided with a support assembly (6), which is used to support the anode carrier (4) and adjust the distance between the anode carrier (4) and the cathode assembly (3).

5. The PECVD reaction chamber structure for edge passivation coating according to claim 4, characterized in that, The support assembly (6) includes a support panel (61), a spacing adjustment plate (63), and a support column (64). One end of the support column (64) is fixed inside the reaction chamber (1), and the other end of the support column (64) is connected to the support panel (61) through the spacing adjustment plate (63). The support panel (61) is connected to the anode carrier (4). The spacing adjustment plate (63) has multiple mounting holes (631) in the vertical direction to adjust the spacing between the ends of the support panel (61) and the support column (64), thereby adjusting the spacing between the anode carrier (4) and the cathode assembly (3).

6. The PECVD reactor chamber structure for edge passivation coating according to claim 5, wherein, A conductive strip (62) is provided between the end of the support panel (61) and the support column (64).

7. The PECVD reactor chamber structure for edge passivation coating according to any of claims 1 to 6, characterized in that, The reaction chamber (1) is also provided with a cleaning spray pipe (10), which is located at the upper part of the reaction chamber (1) for conveying cleaning gas.

8. The PECVD reactor chamber structure for edge passivation coating according to any of claims 1 to 6, characterized in that, The cathode assembly (3) includes a flow equalization plate (24), a spray plate (26), and a flow equalization box (28). The flow equalization plate (24) is connected to the discharge backplate (2) via a connecting post (23), and a primary flow equalization zone (20) is formed between the flow equalization plate (24) and the discharge backplate (2). The gas feed pipe (22) is connected to the primary flow equalization zone (20). One end of the flow equalization box (28) is connected to the discharge backplate (2), and the other end of the flow equalization box (28) is connected to the spray plate (26). The flow equalization plate (24) is located inside the flow equalization box (28), and a secondary flow equalization zone (21) is formed between the flow equalization plate (24) and the spray plate (26). The flow equalization plate (24) is provided with multiple flow equalization holes (25), and the spray plate (26) is provided with multiple spray holes (27).

9. The PECVD reactor chamber structure for edge passivation coating according to claim 8, wherein, The cross-sectional area of ​​the uniform flow hole (25) is smaller than that of the spray hole (27), and the volume of the primary uniform flow zone (20) is smaller than that of the secondary uniform flow zone (21).

10. The PECVD reactor chamber structure for edge passivation coating according to any of claims 1 to 6, characterized in that, The anode carrier (4) includes a conductive dielectric plate (41), a boat support (43), and a material box (44). The boat support (43) is fixed inside the reaction chamber (1). Multiple material boxes (44) are placed side by side on the boat support (43). The material boxes (44) are loaded with battery cells. The top of the material box (44) is covered by the conductive dielectric plate (41). The conductive dielectric plate (41) has a notch. The position of the notch coincides with the passivation surface of the battery cell. The passivation surface and the conductive dielectric plate (41) together form the anode substrate.

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