Monocrystalline silicon cell production line and cell production plant environment control method

Abstract

The application discloses a monocrystalline silicon cell production line and an environment control method in a cell production workshop. The monocrystalline silicon cell production line comprises a workshop, four circulating air paths are formed in the workshop and are independent of each other, a texturing and cleaning area, a CVD area, a TCO area and a screen printing area are formed in the four circulating air paths respectively, and a fan, a coarse filter, a medium filter, a humidifying module, a dehumidifying module and a first chemical filter for removing ozone are sequentially connected in the four circulating air paths. Heating modules, refrigeration modules and temperature sensors are arranged in the four circulating air paths. An ozone generator is connected in series in the circulating air path where the CVD area is located, and an ozone tester is arranged in the CVD area. The monocrystalline silicon cell production line has the advantages that the performance stability of the produced monocrystalline silicon cells is high, and the yield is high.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cell technology, specifically to a monocrystalline silicon cell production line and an environmental control method for the cell production workshop. Background Technology

[0002] Monocrystalline silicon (HJT) cells are a fusion of monocrystalline silicon wafer solar cell technology and thin-film photovoltaic technology, combining the advantages of both. They feature high open-circuit voltage and high conversion efficiency. The production of monocrystalline silicon cells mainly involves four processes: silicon wafer texturing and cleaning → amorphous silicon thin film deposition → transparent conductive oxide (TCO) thin film deposition → screen printing of conductive grid lines. Silicon wafer texturing typically uses anisotropic etching with alkaline solution to form a pyramidal surface structure. Amorphous silicon deposition usually employs plasma-enhanced chemical vapor deposition (PECVD) or hot-wire chemical vapor deposition (HWCVD). TCO deposition typically uses magnetron sputtering physical vapor deposition (PVD) or reactive plasma deposition (RPD). Conductive grid lines are typically created by screen printing low-temperature silver paste followed by drying and curing. These four processes have different requirements for the surrounding air quality, necessitating the control of various parameters. Appropriate air quality indicators can improve the electrical performance and quality stability of monocrystalline silicon cells.

[0003] However, for the above-mentioned processes, the relevant technologies only control temperature, humidity and cleanliness, and cannot control the testing and adjustment of other gases in the air. As a result, under the influence of other gases, the performance of the produced monocrystalline silicon cells is unstable and the yield is low. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a monocrystalline silicon cell production line, which has the advantages of producing monocrystalline silicon cells with high performance stability and high yield.

[0006] Embodiments of the present invention also propose an environmental control method for battery production workshops.

[0007] The monocrystalline silicon solar cell production line of this invention includes a workshop with four independent circulating air paths. Each of the four circulating air paths forms a texturing and cleaning area, a CVD area, a TCO area, and a screen printing area. Each of the four circulating air paths is sequentially connected in series with a fan, a coarse filter, a medium-efficiency filter, and a first chemical filter for ozone removal. Each of the four circulating air paths is equipped with a heating module, a cooling module, and a temperature sensor. An ozone generator is connected in series in the circulating air path containing the CVD area, and an ozone meter is installed within the CVD area.

[0008] According to an embodiment of the present invention, the monocrystalline silicon solar cell production line divides the internal space of the workshop into four independent circulating air paths. Independent fans, coarse filters, medium-efficiency filters, humidification modules, dehumidification modules, and a first chemical filter for ozone removal are used to independently regulate the temperature, humidity, and ozone concentration in the texturing and cleaning area, CVD area, TCO area, and screen printing area. This ensures that the parameters adapt to the working requirements of each process, thereby guaranteeing more stable performance of the final solar cells. Furthermore, by connecting an ozone generator in series in the circulating air path of the CVD area and installing an ozone meter in the CVD area, accurate detection of the ozone concentration in the CVD area is achieved, ensuring that it remains within a set range. This effectively reduces leakage current caused by doped layer plating, increases the parallel resistance of the solar cells, thereby improving solar cell efficiency. Simultaneously, it reduces the proportion of leakage failure and parallel resistance failure, further improving the performance stability and yield of the solar cells.

[0009] In some embodiments, the circulating air path corresponding to the screen printing area is further connected in series with a second chemical filter for removing sulfides.

[0010] In some embodiments, the screen printing area is provided with a humidification module, a dehumidification module, and a humidity sensor.

[0011] In some embodiments, the workshop is provided with four compartments, each of which forms one of the four circulating air paths. Each of the four compartments includes a first partition forming the inner wall of the texturing and cleaning area, a second partition forming the inner wall of the CVD area, a third partition forming the inner wall of the TCO area, and a fourth partition forming the screen printing area. The first partition, the second partition, the third partition, and the fourth partition are all provided with openable and closed doors.

[0012] The workshop also includes a first channel between the first partition and the second partition, a second channel between the second partition and the third partition, and a third channel between the third partition and the fourth partition. The first channel can switch the texturing and cleaning area and the CVD area by opening and closing the door. The second channel can switch the CVD area and the TCO area by opening and closing the door. The third channel can switch the TCO area and the screen printing area by opening and closing the door.

[0013] In some embodiments, the first channel, the second channel, and the third channel are all provided with conveyor lines, and the texturing and cleaning area, the CVD area, the TCO area, and the screen printing area are all provided with transfer robots for transferring batteries.

[0014] In some embodiments, the workshop also includes a peripheral area surrounding the four circulating air ducts, and the peripheral area is equipped with air filtration devices, including high-efficiency filters.

[0015] The environmental control method for a battery production workshop according to an embodiment of the present invention includes the following steps:

[0016] Independent control is implemented for the air quality in the texturing and cleaning area, CVD area, TCO area, and screen printing area.

[0017] By using a first chemical filter to remove ozone and an ozone meter, the ozone concentration in the CVD area is maintained between 5 ppb and 15 ppb.

[0018] The environmental control method in the battery production workshop according to the present invention also has the advantages of high performance stability and high yield of the produced monocrystalline silicon batteries.

[0019] In some embodiments, the method further includes maintaining the ozone concentration in the texturing cleaning area below 5 ppb, maintaining the ozone concentration in the TCO area below 20 ppb, and maintaining the ozone concentration in the screen printing area below 20 ppb.

[0020] In some embodiments, the method further includes maintaining the sulfide concentration in the screen-printed area at 5 μg / m². 3 the following.

[0021] In some embodiments, the method further includes maintaining the air humidity in the texturing cleaning area, the CVD area, and the TCO area between 40% and 70%, and maintaining the air humidity in the screen printing area between 50% and 60%.

[0022] The temperatures in the texturing cleaning area, CVD area, TCO area, and screen printing area were maintained between 20°C and 26°C. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a monocrystalline silicon solar cell production line according to an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the circulating air path in the screen printing area of ​​a monocrystalline silicon cell production line according to an embodiment of the present invention.

[0025] Figure label:

[0026] 1. Workshop; 11. Circulating air duct; 12. Texturing and cleaning area; 13. CVD area; 14. TCO area; 15. Screen printing area; 16. Fan; 17. Coarse filter; 18. Medium-efficiency filter; 19. First chemical filter; 20. Second chemical filter; 21. Ozone meter; 22. Ozone generator; 23. Humidity sensor; 24. First channel; 25. Second channel; 26. Third channel. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] The following is combined Figure 1 and Figure 2 A monocrystalline silicon solar cell production line according to an embodiment of the present invention is described.

[0029] The monocrystalline silicon cell production line of this invention includes a workshop 1, which contains four independent circulating air paths 11. Each of the four circulating air paths 11 contains a texturing and cleaning area 12, a CVD area 13, a TCO area 14, and a screen printing area 15. Each of the four circulating air paths 11 is connected in series with a fan 16, a coarse filter 17, a medium-efficiency filter 18, and a first chemical filter 19 for ozone removal. Each of the four circulating air paths 11 is equipped with a heating module, a cooling module, and a temperature sensor. An ozone generator 22 is connected in series on the circulating air path 11 where the CVD area 13 is located, and an ozone meter 21 is installed in the CVD area 13.

[0030] According to an embodiment of the present invention, the monocrystalline silicon solar cell production line divides the internal space of workshop 1 into four independent circulating air paths 11. Independent fans 16, coarse filters 17, medium-efficiency filters 18, humidification modules, dehumidification modules, and a first chemical filter 19 for ozone removal are used to independently regulate the temperature, humidity, and ozone concentration in the texturing and cleaning area 12, CVD area 13, TCO area 14, and screen printing area 15. This ensures that the parameters adapt to the working requirements of each process, thereby guaranteeing more stable performance of the final solar cells. Furthermore, by connecting an ozone generator 22 in series on the circulating air path 11 in the CVD area 13 and installing an ozone meter 21 in the CVD area 13, accurate detection of the ozone concentration in the CVD area 13 is achieved, ensuring it remains within a set range. This effectively reduces leakage current caused by doped layer plating, increases the parallel resistance of the solar cells, thereby improving solar cell efficiency. Simultaneously, it reduces the proportion of leakage failure and parallel resistance failure, further improving the performance stability and yield of the solar cells.

[0031] It should be noted that by setting coarse filter 17 and medium filter 18, the cleanliness level in the four circulating air paths 11 can be controlled at or above Class 1000 (or ISO Class 6).

[0032] In some embodiments, such as Figure 1 and Figure 2 As shown, a second chemical filter 20 for removing sulfides is also connected in series in the circulating air path 11 corresponding to the screen printing area 15.

[0033] This setting effectively reduces the sulfide content in the screen printing area 15, thereby effectively reducing the yellowing or blackening of the silver grid lines due to the oxidation of sulfides to produce silver sulfide, effectively ensuring the appearance and welding performance of the battery cells, and also effectively reducing the probability of poor conductivity of the silver grid lines.

[0034] Specifically, the sulfides are mainly SO2 and H2S. The second chemical filter 20 ensures that the sulfide concentration in the screen printing area 15 is below 5 μg / m³. 3 .

[0035] In some embodiments, such as Figure 1 As shown, the screen printing area 15 is equipped with a humidification module, a dehumidification module and a humidity sensor 23.

[0036] The printing and curing properties of low-temperature curing silver paste are affected by air humidity. When the air humidity is below 40%, the silver paste tends to dry out and become more viscous, which is not conducive to printing. When the air humidity is above 70%, the curing rate of the silver paste slows down, which also has adverse effects. By setting up a humidification module, a dehumidification module, and a humidity sensor 23, the air humidity in the screen printing area 15 can be maintained between 50% and 60%, effectively avoiding the above-mentioned defects.

[0037] Specifically, the humidity value measured by the humidity meter is fed back to the control system to control the working efficiency of the humidification module or the dehumidification module in order to maintain the air humidity in the screen printing area 15 within a suitable range.

[0038] In some embodiments, such as Figure 1As shown, workshop 1 is equipped with four compartments, each forming a circulating air passage 11. Each compartment includes a first partition on the inner wall of a portion of the forming and cleaning area 12, a second partition on the inner wall of a portion of the forming CVD area 13, a third partition on the inner wall of a portion of the forming TCO area 14, and a fourth partition on the inner wall of the forming screen printing area 15. Each of the first, second, third, and fourth partitions is equipped with a door. Workshop 1 also contains a first channel 24 located between the first and second partitions, a second channel 25 located between the second and third partitions, and a third channel 26 located between the third and fourth partitions. The first channel 24 allows the connection between the forming and cleaning area 12 and the CVD area 13 to be opened and closed by the opening and closing of its door; the second channel 25 allows the connection between the CVD area 13 and the TCO area 14 to be opened and closed by the opening and closing of its door; and the third channel 26 allows the connection between the TCO area 14 and the screen printing area 15 to be opened and closed by the opening and closing of its door.

[0039] When the doors are closed, the air quality of the texturing and cleaning area 12, CVD area 13, TCO area 14, and screen printing area 15 remains independent. When it is necessary to transfer the solar cells to the next process, simply open the door at the current process location, transfer the solar cells to the corresponding channel, close the door at the current process location, open the door at the next process location, and close the door at the next process location once the solar cells have been transferred from the channel to the next process location. This completes the transfer of the solar cells. This setup effectively prevents the connection between two adjacent circulating air paths 11, effectively ensuring the stability of their respective air parameters, and thus effectively ensuring the performance stability and yield of the produced solar cells.

[0040] Specifically, the first channel 24, the second channel 25, and the third channel 26 are preferably closed channels, or, when the environmental cleanliness, temperature, and humidity outside the four circulating air ducts meet the requirements for storing the battery cells, the first channel 24, the second channel 25, and the third channel 26 can also be open channels.

[0041] In some embodiments, conveyor lines are provided in the first channel 24, the second channel 25 and the third channel 26, and transfer robots for transferring batteries are provided in the texturing and cleaning area 12, the CVD area 13, the TCO area 14 and the screen printing area 15.

[0042] The installation of conveyor lines and rotating robotic arms effectively improves the automation level of solar cell production, resulting in higher production efficiency and lower labor costs.

[0043] Specifically, the transfer robot can be a three-degree-of-freedom robot with a suction cup. The conveyor line is preferably a belt conveyor line.

[0044] In some embodiments, a peripheral area surrounding four circulating air passages 11 is also formed within the workshop 1, and an air filtration device, including a high-efficiency filter, is provided within the peripheral area.

[0045] Therefore, when the solar cells are removed to the outer area, the air cleanliness of the outer area ensures that the solar cells will not be contaminated, further guaranteeing the performance stability and yield of the produced solar cells.

[0046] Specifically, with the help of high-efficiency filters, the air cleanliness level in the surrounding area is controlled at or above Class 10,000 (or ISO Class 7).

[0047] The environmental control method for a battery production workshop 1 according to an embodiment of the present invention includes the following steps:

[0048] The air quality in the texturing cleaning area 12, CVD area 13, TCO area 14 and screen printing area 15 is controlled independently.

[0049] The ozone concentration in the CVD zone 13 is maintained between 5 ppb and 15 ppb by using the first chemical filter 19 for ozone removal and the ozone meter 21.

[0050] The environmental control method in the battery production workshop 1 according to the present invention also has the advantages of high performance stability and high yield of the produced monocrystalline silicon batteries.

[0051] In some embodiments, the method further includes maintaining the ozone concentration in the texturing cleaning zone 12 below 5 ppb, maintaining the ozone concentration in the TCO zone 14 below 20 ppb, and maintaining the ozone concentration in the screen printing zone 15 below 20 ppb.

[0052] Silicon wafers are easily oxidized by ozone in the air during the drying process, which reduces minority carrier lifetime. Therefore, it is necessary to minimize the ozone concentration. Controlling the ozone concentration below 5 ppb can effectively improve the minority carrier lifetime. The silicon wafers in TCO region 14 and screen printing region 15 have already completed amorphous silicon deposition, reducing their sensitivity to ozone concentration. Controlling the ozone concentration below 20 ppb can reduce the requirements for the first chemical filter 19 and save plant costs.

[0053] In some embodiments, the method further includes maintaining the sulfide concentration within the screen-printed area 15 below 5 μg / m3.

[0054] This setting effectively reduces the sulfide content in the screen printing area 15, thereby effectively reducing the yellowing or blackening of the silver grid lines due to the oxidation of sulfides to produce silver sulfide, effectively ensuring the appearance and welding performance of the battery cells, and also effectively reducing the probability of poor conductivity of the silver grid lines.

[0055] In some embodiments, the method further includes maintaining the air humidity in the texturing cleaning zone 12, CVD zone 13, and TCO zone 14 between 40% and 70%, and maintaining the air humidity in the screen printing zone 15 between 50% and 60%. The temperature in the texturing cleaning zone 12, CVD zone 13, TCO zone 14, and screen printing zone 15 is maintained between 20°C and 26°C.

[0056] The printing and curing properties of low-temperature curing silver paste are affected by air humidity. When the air humidity is below 40%, the silver paste tends to dry out and become more viscous, which is not conducive to printing. When the air humidity is above 70%, the curing rate of the silver paste slows down, which also has an adverse effect. Setting the air humidity of the screen printing area 15 to 50%-60% better ensures the printing performance of the grid lines on the solar cells.

[0057] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0058] 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 at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0059] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0061] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0062] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A single crystal silicon cell production line, characterized by, The workshop comprises four independent circulating air paths, each of which forms a texturing cleaning area, a CVD area, a TCO area and a screen printing area, and each of which is sequentially connected with a fan, a coarse filter, a medium filter and a first chemical filter for removing ozone, and each of which is provided with a heating module, a refrigeration module and a temperature sensor, wherein the circulating air path of the CVD area is connected with an ozone generator, and the CVD area is provided with an ozone tester.

2. The single crystal silicon cell production line according to claim 1, characterized in that, The circulating air path corresponding to the screen printing area is further connected with a second chemical filter for removing sulfides.

3. The single crystal silicon cell production line according to claim 1, characterized by The screen printing area is provided with a humidification module, a dehumidification module and a humidity sensor.

4. The single crystal silicon cell production line according to claim 1, characterized by The workshop is provided with four separate boxes, each of which forms one of the four circulating air paths, and each of which comprises a first partition forming a part of the inner wall of the texturing cleaning area, a second partition forming a part of the inner wall of the CVD area, a third partition forming a part of the inner wall of the TCO area, and a fourth partition forming the screen printing area, and each of the first, second, third and fourth partitions is provided with a switch door. The workshop is further provided with a first channel between the first and second partitions, a second channel between the second and third partitions, and a third channel between the third and fourth partitions, and the first channel can be switched on and off by the switch door to switch the texturing cleaning area and the CVD area, the second channel can be switched on and off by the switch door to switch the CVD area and the TCO area, and the third channel can be switched on and off by the switch door to switch the TCO area and the screen printing area.

5. The single crystal silicon cell production line according to claim 4, characterized in that, Each of the first, second and third channels is provided with a conveying line, and each of the texturing cleaning area, the CVD area, the TCO area and the screen printing area is provided with a transfer robot for transferring batteries.

6. The single crystal silicon cell production line according to claim 1, wherein The workshop is further provided with a peripheral area surrounding the four circulating air paths, and the peripheral area is provided with an air filtration device comprising a high-efficiency filter.

7. A method of controlling the environment in a battery production plant, characterized by, The method comprises the following steps: Independently controlling the air quality of the texturing cleaning area, the CVD area, the TCO area and the screen printing area; Maintaining the ozone concentration in the CVD area between 5ppb and 15ppb by the first chemical filter for removing ozone and the ozone tester.

8. The battery plant in-plant environment control method according to claim 7, characterized by, Further comprising: maintaining the ozone concentration in the texturing cleaning area below 5ppb, maintaining the ozone concentration in the TCO area below 20ppb, and maintaining the ozone concentration in the screen printing area below 20ppb.

9. The method of controlling the environment within a battery production plant according to claim 7, wherein, Further comprising: The concentration of sulfides within the screen printed area was maintained at 5 μg / m 3 The following.

10. The method of controlling the environment within a battery production plant according to claim 7, wherein, Further comprising: Maintaining the air humidity in the texturing cleaning area, the CVD area and the TCO area between 40% and 70%, and maintaining the air humidity in the screen printing area between 50% and 60%; The temperature within the texturing cleaning area, CVD area, TCO area and screen printing area is maintained between 20°C and 26°C. The temperature within the texturing cleaning area, CVD area, TCO area and screen printing area is maintained between 20°C and 26°C.

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