Monocrystalline silicon battery production line and environment control method in battery production workshop

Abstract

The invention discloses a monocrystalline silicon battery production line and a battery production workshop internal environment control method, the monocrystalline silicon battery production line comprises a workshop, four mutually independent circulating air paths are formed in the workshop, and a texturing cleaning area, a CVD area, a TCO area and a screen printing area are respectively formed in the four circulating air paths; a fan, a low-efficiency filter, a medium-efficiency filter, a humidifying module, a dehumidifying module and a first chemical filter used for removing ozone are sequentially connected in series with the four circulating air paths, a heating module, a refrigerating module and a temperature sensor are arranged in each circulating air path, an ozone generator is connected in series with the circulating air path where the CVD area is located, and the ozone generator is connected in series with the circulating air path where the CVD area is located. And an ozone tester is arranged in the CVD area. The monocrystalline silicon battery production line provided by the invention has the advantages of high performance stability and high yield of produced monocrystalline silicon batteries.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a single crystal silicon cell production line and an environment control method within a cell production workshop. Background Art

[0002] The monocrystalline silicon (HJT) cell is a fusion of solar cell technology based on monocrystalline silicon wafers and thin-film photovoltaic technology, and has the advantages of both. It has the advantages of high open circuit voltage and high conversion efficiency. The production of monocrystalline silicon cells mainly includes four processes: silicon wafer texturing and cleaning → amorphous silicon thin film deposition → transparent conductive oxide (TCO) thin film deposition → screen printing conductive grid lines. Silicon wafer texturing usually uses alkaline anisotropic corrosion to form a pyramid structure surface, amorphous silicon deposition usually uses plasma enhanced chemical vapor deposition (PECVD) or hot wire chemical vapor deposition (HWCVD), TCO deposition usually uses magnetron sputtering physical vapor deposition (PVD) or reactive plasma deposition (RPD), and conductive grid lines usually use screen printing of low-temperature silver paste and then drying and curing. These four processes have different requirements for the air quality of the surrounding environment, and various parameter controls are required. Appropriate air quality indicators can improve the electrical performance and quality stability of monocrystalline silicon cells.

[0003] However, for the above process, the relevant technology only controls the 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 rate is low. Summary of the invention

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

[0005] To this end, an embodiment of the present invention proposes a single crystal silicon cell production line, which has the advantages of high performance stability and high yield of the produced single crystal silicon cells.

[0006] An embodiment of the present invention further provides a method for controlling the environment in a battery production workshop.

[0007] The monocrystalline silicon cell production line of an embodiment of the present invention includes a workshop, in which four independent circulating air paths are formed, and a texturing and cleaning area, a CVD area, a TCO area and a screen printing area are respectively formed in the four circulating air paths, and a fan, a coarse-efficiency filter, a medium-efficiency filter and a first chemical filter for removing ozone are sequentially connected in series in the four circulating air paths, and a heating module, a cooling module and a temperature sensor are provided in the four circulating air paths, wherein an ozone generator is connected in series to the circulating air path where the CVD area is located, and an ozone tester is provided in the CVD area.

[0008] According to the monocrystalline silicon cell production line of the embodiment of the present invention, the internal space of the workshop is divided into four independent circulating air paths, and the temperature, humidity and ozone concentration in the velvet cleaning area, CVD area, TCO area and screen printing area are independently adjusted through independent fans, coarse-effect filters, medium-efficiency filters, humidification modules, dehumidification modules and the first chemical filter for removing ozone, so as to ensure that the above parameters are adaptive to the working requirements of each process, and then ensure that the final obtained battery cell has more stable performance. By connecting an ozone generator in series to the circulating air path where the CVD area is located, and providing an ozone tester in the CVD area, accurate detection of the ozone concentration in the CVD area is achieved to ensure that it remains within the set range, which can effectively reduce the leakage current caused by the plating of the doping layer, increase the parallel resistance of the battery cell, thereby improving the efficiency of the battery cell, and at the same time reduce the proportion of leakage failure and parallel resistance failure of the battery cell, thereby further improving the performance stability and yield rate of the battery cell.

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

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

[0011] In some embodiments, four compartments are provided in the workshop, and four circulating air paths are respectively formed in the four compartments, and the four compartments respectively include a first partition for forming a portion of the inner wall surface of the velveting and cleaning area, a second partition for forming a portion of the inner wall surface of the CVD area, a third partition for forming a portion of the inner wall surface of the TCO area, and a fourth partition for forming the screen printing area, and the first partition, the second partition, the third partition, and the fourth partition are all provided with a switch door;

[0012] The workshop also has 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 realize the connection and disconnection of the texturing cleaning area and the CVD area by opening and closing the switch door, the second channel can realize the connection and disconnection of the CVD area and the TCO area by opening and closing the switch door, and the third channel can realize the connection and disconnection of the TCO area and the screen printing area by opening and closing the switch door.

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

[0014] In some embodiments, a peripheral area surrounding the four circulating air paths is formed in the workshop, and an air filtering device is provided in the peripheral area, and the air filtering device includes a high-efficiency filter.

[0015] The method for controlling the environment in a battery production workshop according to an embodiment of the present invention comprises the following steps:

[0016] Independently control the air quality in the texturing and cleaning area, CVD area, TCO area and screen printing area;

[0017] The ozone concentration in the CVD area was maintained between 5 ppb and 15 ppb by a first chemical filter to remove ozone and an ozone tester.

[0018] The method for controlling the environment in a battery production workshop according to an embodiment of the present invention also has the advantages of high performance stability and high yield rate of the produced single crystal silicon batteries.

[0019] In some embodiments, it also includes: maintaining the ozone concentration in the texturing and 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 comprises: maintaining the sulfide concentration in the screen printing area at 5 μg / m 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 temperature in the texturing cleaning area, CVD area, TCO area and screen printing area was maintained between 20°C and 26°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a single crystal silicon cell production line according to an embodiment of the present invention.

[0024] Figure 2 It is a schematic diagram of a circulating air path where a screen printing area is located in a single crystal silicon cell production line according to an embodiment of the present invention.

[0025] Reference numerals:

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

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

[0028] Combine the following Figure 1 and Figure 2 A single crystal silicon cell production line according to an embodiment of the present invention is described.

[0029] The monocrystalline silicon cell production line of the embodiment of the present invention includes a workshop 1, in which four independent circulating air paths 11 are formed, and a texturing and cleaning area 12, a CVD area 13, a TCO area 14 and a screen printing area 15 are respectively formed in the four circulating air paths 11, and a fan 16, a coarse-efficiency filter 17, a medium-efficiency filter 18 and a first chemical filter 19 for removing ozone are connected in series in sequence in the four circulating air paths 11, and a heating module, a cooling module and a temperature sensor are provided in the four circulating air paths 11, wherein an ozone generator 22 is connected in series to the circulating air path 11 where the CVD area 13 is located, and an ozone tester 21 is provided in the CVD area 13.

[0030] According to the monocrystalline silicon cell production line of the embodiment of the present invention, the internal space of the workshop 1 is divided into four independent circulating air paths 11, and the temperature, humidity and ozone concentration in the velvet cleaning area 12, the CVD area 13, the TCO area 14 and the screen printing area 15 are independently adjusted through independent fans 16, coarse filters 17, medium filters 18, humidification modules, dehumidification modules and the first chemical filter 19 for removing ozone, so as to ensure that the above parameters are adaptive to the working requirements of each process, and then ensure that the final obtained battery cell has more stable performance. By connecting an ozone generator 22 in series on the circulating air path 11 where the CVD area 13 is located, and providing an ozone tester 21 in the CVD area 13, accurate detection of the ozone concentration in the CVD area 13 is achieved to ensure that it remains within the set range, which can effectively reduce the leakage current caused by the plating of the doping layer, increase the parallel resistance of the battery cell, thereby improving the efficiency of the battery cell, and at the same time reduce the proportion of leakage failure and parallel resistance failure of the battery cell, thereby further improving the performance stability and yield rate of the battery cell.

[0031] It should be noted that by providing the coarse-effect filter 17 and the medium-effect filter 18 , the cleanliness in the four circulation air passages 11 can be controlled to be above Class 1000 (or ISO Class 6).

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

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

[0034] Specifically, sulfides are mainly SO2 and H2S. The second chemical filter 20 can ensure that the sulfide concentration in the screen printing area 15 is less than 5 μg / m 3 .

[0035] In some embodiments, Figure 1 As shown, a humidification module, a dehumidification module and a humidity sensor 23 are provided in the screen printing area 15 .

[0036] The printing performance and curing performance of low-temperature curing silver paste will be affected by air humidity. When the air humidity is lower than 40%, the silver paste is easy to dry and the viscosity becomes larger, which is not conducive to printing; when the air humidity is higher than 70%, the curing rate of the silver paste slows down, which will also cause adverse effects. By providing 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%, so as to effectively avoid the above defects.

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

[0038] In some embodiments, Figure 1As shown, four compartments are provided in the workshop 1, and four circulating air paths 11 are formed in the four compartments respectively. The four compartments respectively include a first partition on a part of the inner wall of the forming velvet cleaning area 12, a second partition on a part of the inner wall of the forming CVD area 13, a third partition on a part of the inner wall of the forming TCO area 14, and a fourth partition on the forming screen printing area 15. The first partition, the second partition, the third partition, and the fourth partition are all provided with a switch door. The workshop 1 also has a first channel 24 located between the first partition and the second partition, a second channel 25 located between the second partition and the third partition, and a third channel 26 located between the third partition and the fourth partition. The first channel 24 can realize the connection and disconnection of the velvet cleaning area 12 and the CVD area 13 by opening and closing the switch door, the second channel 25 can realize the connection and disconnection of the CVD area 13 and the TCO area 14 by opening and closing the switch door, and the third channel 26 can realize the connection and disconnection of the TCO area 14 and the screen printing area 15 by opening and closing the switch door.

[0039] When the switch door is in the closed state, the independence of the air quality of the texturing and cleaning area 12, the CVD area 13, the TCO area 14 and the screen printing area 15 can be guaranteed. When it is necessary to transfer the battery cell to the next process, it is only necessary to open the switch door at the process first, transfer the battery cell to the corresponding channel, and then close the switch door at the process, open the switch door at the next process, and when the battery cell is transferred from the channel to the next process, close the opened switch door to complete the transfer of the battery cell. This setting effectively avoids the connection between the two adjacent circulating air paths 11, effectively ensures the stability of each air parameter, and thus effectively ensures the performance stability and yield rate of the produced battery 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 battery cell storage requirements, the first channel 24, the second channel 25 and the third channel 26 can also be open channels.

[0041] In some embodiments, conveying 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 setting of conveyor lines and speed manipulators has effectively improved the degree of automation in battery cell production, making battery cell production more efficient and reducing 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 the four circulating air paths 11 is formed in the workshop 1, and an air filtering device is provided in the peripheral area, and the air filtering device includes a high-efficiency filter.

[0045] Therefore, when the battery cells are taken out to the peripheral area, the air cleanliness in the peripheral area is guaranteed not to contaminate the battery cells, further ensuring the performance stability and yield rate of the produced battery cells.

[0046] Specifically, under the filtration of high-efficiency filters, the air cleanliness in the peripheral area is controlled to be above Class 10,000 (or ISO Class 7).

[0047] The method for controlling the environment in a battery production workshop 1 according to an embodiment of the present invention comprises the following steps:

[0048] Independently control the air quality of the texturing and cleaning area 12, the CVD area 13, the TCO area 14 and the screen printing area 15;

[0049] The ozone concentration in the CVD area 13 is maintained between 5 ppb and 15 ppb by the first chemical filter 19 and the ozone tester 21 for removing ozone.

[0050] The method for controlling the environment in the battery production workshop 1 according to the embodiment of the present invention also has the advantages of high performance stability and high yield rate of the produced single crystal silicon batteries.

[0051] In some embodiments, it also includes: maintaining the ozone concentration in the texturing cleaning area 12 below 5 ppb, maintaining the ozone concentration in the TCO area 14 below 20 ppb, and maintaining the ozone concentration in the screen printing area 15 below 20 ppb.

[0052] During the drying process, silicon wafers are easily oxidized by ozone in the air, which reduces the minority carrier lifetime. Therefore, it is necessary to reduce the ozone concentration as much as possible. Controlling the ozone concentration below 5ppb can effectively increase the minority carrier lifetime. The silicon wafers in the TCO area 14 and the screen printing area 15 have completed amorphous silicon deposition, and their sensitivity to ozone concentration is reduced. Controlling the ozone concentration below 20ppb can reduce the requirements for the first chemical filter 19 and save factory costs.

[0053] In some embodiments, the method further includes maintaining the sulfide concentration in the screen printing area 15 below 5 μg / m 3 .

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

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

[0056] The printing performance and curing performance of low-temperature curing silver paste will be affected by air humidity. When the air humidity is lower than 40%, the silver paste is easy to dry and the viscosity becomes larger, which is not conducive to printing. When the air humidity is higher than 70%, the curing rate of the silver paste slows down, which will also cause adverse effects. The air humidity of the screen printing area 15 is set to 50%-60%, which better guarantees the grid line printing performance on the battery cell.

[0057] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0062] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A single crystal silicon cell production line, characterized in that: The invention comprises a workshop, wherein four independent circulating air paths are formed in the workshop, wherein the four circulating air paths respectively form a velveting and cleaning area, a CVD area, a TCO area and a screen printing area, wherein the four circulating air paths are sequentially connected in series with a fan, a coarse-efficiency filter, a medium-efficiency filter and a first chemical filter for removing ozone, wherein the four circulating air paths are each provided with a heating module, a cooling module and a temperature sensor, wherein the circulating air path where the CVD area is located is connected in series with an ozone generator, and an ozone tester is provided in the CVD area.

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

3. The monocrystalline silicon cell production line according to claim 1, characterized in that: A humidification module, a dehumidification module and a humidity sensor are arranged in the screen printing area.

4. The monocrystalline silicon cell production line according to claim 1, characterized in that: Four compartments are provided in the workshop, and four circulating air paths are respectively formed in the four compartments. The four compartments respectively include a first partition for forming part of the inner wall surface of the velveting and cleaning area, a second partition for forming part of the inner wall surface of the CVD area, a third partition for forming part of the inner wall surface of the TCO area, and a fourth partition for forming the screen printing area. The first partition, the second partition, the third partition, and the fourth partition are all provided with a switch door. The workshop also has 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 realize the connection and disconnection of the texturing cleaning area and the CVD area by opening and closing the switch door, the second channel can realize the connection and disconnection of the CVD area and the TCO area by opening and closing the switch door, and the third channel can realize the connection and disconnection of the TCO area and the screen printing area by opening and closing the switch door.

5. The monocrystalline silicon cell production line according to claim 4, characterized in that: Conveying lines are provided in the first channel, the second channel and the third channel, and transfer robots for transferring batteries are provided in the texturing and cleaning area, the CVD area, the TCO area and the screen printing area.

6. The monocrystalline silicon cell production line according to claim 1, characterized in that: The workshop also has a peripheral area surrounding the four circulating air paths, and an air filtering device is arranged in the peripheral area, wherein the air filtering device includes a high-efficiency filter.

7. A method for controlling the environment in a battery production workshop, characterized in that: The following steps are involved: Independently control the air quality in the texturing and cleaning area, CVD area, TCO area and screen printing area; The ozone concentration in the CVD area was maintained between 5 ppb and 15 ppb by a first chemical filter to remove ozone and an ozone tester.

8. The method for controlling the environment in a battery production workshop according to claim 1, characterized in that: It also includes: maintaining the ozone concentration in the texturing and 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 for controlling the environment in a battery production workshop according to claim 1, characterized in that: Also includes: The sulfide concentration in the screen printing area was maintained at 5 μg / m 3 the following.

10. The method for controlling the environment in a battery production workshop according to claim 1, characterized in that: Also includes: Maintain the air humidity between 40% and 70% in the texturing cleaning area, CVD area and TCO area, and maintain the air humidity between 50% and 60% in the screen printing area; The temperature in the texturing cleaning area, CVD area, TCO area and screen printing area was maintained between 20°C and 26°C.

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