A method for rapid evacuation

Abstract

The application discloses a method for rapid vacuum pumping, which comprises the following steps: step one, providing a vacuum chamber, slow pumping valves are arranged on both sides of the vacuum chamber, a main pumping valve is arranged at a middle position, the main pumping valve and the slow pumping valves are connected in parallel through vacuum pipelines, the upper ends of the valves are connected with the vacuum chamber, and the lower ends of the parallel pipelines are connected with exhaust pump groups; step two, arranging one or more groups of air uniformizing plates between exhaust outlets of the vacuum chamber and a carrier plate; and step three, transmitting a carrier plate loaded with substrates into the vacuum chamber by transmission rollers, first opening the slow pumping valves on both sides, and discharging gas above and below the carrier plate through the air uniformizing plates for the first time, when the gas in the vacuum chamber is diluted, closing the slow pumping valves and opening the main pumping valve, and gathering the diluted gas above and below the carrier plate through the air uniformizing plates to the exhaust outlet of the main pumping valve for the second time. The method has the advantages that a stable and uniform exhaust structure is provided for a photovoltaic production line.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more specifically to a method for rapid vacuuming. Background Technology

[0002] With the rapid development of photovoltaic technology and the increasing market demand for photovoltaic cells, photovoltaic equipment is pursuing larger and thinner silicon wafers, reaching tens of micrometers, in order to meet market demands, with larger production capacity and increasing stacking quantities. This poses a greater challenge to the cycle time of photovoltaic production lines. Existing solutions for rapid vacuum chamber evacuation often involve changing the number and diameter of slow-release valves, increasing the diameter of the main release valve, and configuring large exhaust pump sets. While this increases costs, it cannot meet the requirements of the coating process in photovoltaic production lines. Specifically, during the evacuation process, the carrier plate naturally divides the gas in the chamber into upper and lower layers. The upper layer of gas, being farther from the exhaust port, has more gas molecules and higher pressure, while the lower layer, closer to the exhaust valve, is quickly expelled, becoming thinner with fewer gas molecules and lower pressure. This results in two gas layers with different pressures and an uneven airflow layer on the carrier plate. Even with slow-release valves, initially, a large amount of gas from the lower layer is rapidly expelled, while some of the upper layer gas converges around the carrier plate. As the exhaust time increases, the gas gradually decreases and dilutes around the exhaust port. Another portion of the gas on the upper layer of the carrier plate is impacted by the pressure difference during the exhaust process. Because the carrier plate is not only large but also very thin, the positioning grooves for stacking the substrates on the carrier plate are very shallow, reaching only a few tenths of a millimeter. Throughout the exhaust process, the carrier plate is always in an unstable and uneven airflow. This airflow layer will create a pressure difference on both sides of the carrier plate, which will impact the substrate and the carrier plate, causing the carrier plate to deform and the substrate to shift. At the same time, it will cause the substrate to generate certain internal stress. In severe cases, it will cause the substrate to fall off the carrier plate, resulting in transmission jamming. The internal stress of the substrate will also affect the uniformity and stability of the film layer in the later stage, which cannot meet the needs of photovoltaic production lines. Summary of the Invention

[0003] The invention proposes a rapid vacuuming method to solve the technical problems existing in the prior art.

[0004] According to one aspect of the present invention, a method for rapid vacuuming is provided, characterized by comprising: Step 1, providing a vacuum chamber, wherein slow-evacuation valves are arranged on both sides below the vacuum chamber, and a main evacuation valve is arranged in the middle position, the main evacuation valve and the slow-evacuation valve are connected in parallel through a vacuum pipe, the upper end of the valve is connected to the vacuum chamber, and the lower end of the parallel pipe is connected to an exhaust pump group; Step 2, placing one or more sets of gas equalization plates between the exhaust port of the vacuum chamber and the carrier plate, the gas equalization plates being used to maintain a consistent pressure above and below the carrier plate; Step 3, the carrier plate filled with substrates is introduced into the vacuum chamber by a transfer roller, the slow-evacuation valves on both sides are first opened, and the gas above and below the carrier plate is first discharged through the gas equalization plates, and after the gas in the vacuum chamber is diluted, the slow-evacuation valves are closed and the main evacuation valve is opened, the diluted gas above and below the carrier plate is collected through the gas equalization plates to the exhaust port of the main evacuation valve for a second evacuation.

[0005] Furthermore, the gas equalization plate is composed of an upper plate and four side plates, and the lower part of the gas equalization plate is fixed to the lower bottom plate of the vacuum chamber by screws.

[0006] Furthermore, the gas equalization plate is composed of an upper plate and four side plates, and the lower part of the gas equalization plate is fixed to the lower bottom plate of the vacuum chamber by screws.

[0007] Furthermore, the upper plate is provided with uniformly dense small holes.

[0008] Furthermore, the four side plates are provided with uniformly distributed elongated holes.

[0009] Furthermore, the gas equalization plate is a rectangular box, a polygonal box, or a multi-faceted spherical box.

[0010] As can be seen from the technical solution provided by the present invention, by employing the present invention, one or more sets of gas equalization plate structures are arranged between the chamber exhaust port and the carrier plate. The gas equalization plate is rectangular box-shaped, consisting of an upper plate and four side plates. The upper plate is provided with uniformly dense small holes, and the four side plates are distributed with uniformly elongated holes. The gas equalization plate is fixed to the lower bottom plate of the vacuum chamber by screws. Whether the slow extraction valve is opened to vent the chamber or the main extraction valve is opened to vent the chamber, the upper and lower parts of the carrier plate are always in a constant pressure, uniform, and stable airflow layer during the exhaust process. This provides a stable and uniform exhaust structure for the photovoltaic production line, ensuring the continuity and stability of substrate transmission, reducing the internal stress of the substrate film, and providing a guarantee for the preparation of high-quality film layers in the photovoltaic production line. It solves the problems caused by the impact of existing chamber exhaust structures on the substrate and carrier plate, carrier plate deformation, substrate displacement and detachment, transmission jamming, and the influence of substrate internal stress on the uniformity and stability of the subsequent film layer.

[0011] The above description is merely an overview of the technology of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0012] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0013] Figure 1 This is a schematic diagram of an embodiment of the rapid vacuuming method of the present invention.

[0014] Figure 2 for Figure 1 A top view of the structure shown.

[0015] Figure 3 This is a schematic diagram of an embodiment of the substrate carrier of the present invention.

[0016] Figure 4 This is a schematic diagram of an embodiment of the air distribution plate of the present invention.

[0017] In the attached drawings, 1—sealing ring, 2—upper flange of chamber, 3—substrate, 4—carrier plate, 5—vacuum chamber, 6—transfer roller, 7—slow extraction valve, 8—main extraction valve, 9—exhaust pump group, 10—gas equalization plate. Detailed Implementation

[0018] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0019] The present invention provides a rapid vacuuming method. Details not described in detail in the embodiments of the present invention are prior art known to those skilled in the art. Unless otherwise specified in the embodiments of the present invention, conditions are as per conventional conditions or manufacturer's recommendations.

[0020] See Figures 1 to 4The present invention provides a method for rapid vacuuming, comprising: Step 1, providing a vacuum chamber, wherein slow-evacuation valves are arranged on both sides below the vacuum chamber, and a main evacuation valve is arranged in the middle position. The main evacuation valve and the slow-evacuation valve are connected in parallel through a vacuum pipe. The upper end of the valve is connected to the vacuum chamber, and the lower end of the parallel pipe is connected to an exhaust pump group; Step 2, placing one or more gas equalization plates between the exhaust port of the vacuum chamber and the carrier plate. The gas equalization plates are used to keep the pressure above and below the carrier plate consistent; Step 3, the carrier plate filled with substrates is introduced into the vacuum chamber by a transfer roller. First, the slow-evacuation valves on both sides are opened, and the gas above and below the carrier plate is discharged for the first time through the gas equalization plates. After the gas in the vacuum chamber is diluted, the slow-evacuation valves are closed, and the main evacuation valve is opened. The diluted gas above and below the carrier plate is collected at the exhaust port of the main evacuation valve through the gas equalization plates for a second evacuation.

[0021] In a specific embodiment, the vacuum chamber 5 is a large-sized chamber. Multiple sets of magnetohydrodynamic (MHD) sealed transmission rollers 6 are installed on the vertical plates on both sides of the vacuum chamber 5. One or more sets of gas equalization plates 10 are installed on the lower inner side of the vacuum chamber 5, located between the exhaust port of the vacuum chamber and the carrier plate. The gas equalization plate 10 is rectangular box-shaped, consisting of an upper plate and four side plates. The upper plate has uniformly dense small holes, and the four side plates have uniformly distributed elongated holes. The gas equalization plate 10 is fixed to the lower bottom plate of the vacuum chamber by screws. Slow-pulling valves 7 are installed on both sides of the lower part of the vacuum chamber 5, and a main-pulling valve 8 is installed in the middle. The main-pulling valve 8 and the slow-pulling valve 7 are connected in parallel through a vacuum pipe. The upper end of the valve is connected to the vacuum chamber, and the lower end of the parallel pipe is connected to the exhaust pump group. The upper flange of the vacuum chamber is connected to the upper part of the vacuum chamber through a sealing ring. The substrate is stacked on the carrier plate. In order to pursue production capacity, the carrier plate is often processed to be large and thin. During operation, the exhaust pump group is in the on state, and the gas in the vacuum chamber is emptied by opening and closing the slow-pulling valve and the main-pulling valve.

[0022] When the substrate-laden carrier is transferred into the vacuum chamber by the transfer rollers, the chamber is initially atmospheric, with the pressure above and below the carrier being the same. To transfer the carrier to the adjacent process chamber, the vacuum chamber needs to be rapidly emptied to bring the pressure inside the vacuum chamber within the allowable range compared to the adjacent chamber. First, the slow-release valves on both sides are opened. At this point, the gas above and below the carrier is evenly and systematically drained through the uniformly dense small holes on the upper plate of the gas equalization plate and the uniformly elongated holes on the surrounding side plates. Once the gas in the chamber is diluted, the slow-release valves are closed, and the main release valve is opened. The diluted gas above and below the carrier then passes through the gas equalization plate. The small holes and elongated holes on the side plates are evenly and orderly gathered at the exhaust port of the main exhaust valve and quickly vented. During the entire venting process, due to the setting of the gas equalization plate, the gas in the upper and lower layers of the carrier plate is always in a uniform and stable airflow. The pressure above and below the carrier plate remains consistent, avoiding the impact of gas on the substrate and carrier plate, as well as the deformation of the carrier plate, substrate displacement, detachment, and transmission jamming. This meets the requirements of photovoltaic production lines for operational stability and coating process, ensures the uniformity of the film thickness deposited on the substrate, the density of the film structure, and reduces the internal stress of the film, thus ensuring the quality of the film.

[0023] Using this invention, one or more gas equalization plate structures are provided between the chamber exhaust port and the carrier plate. The gas equalization plate is rectangular box-shaped, consisting of an upper plate and four side plates. The upper plate is provided with uniformly dense small holes, and the four side plates are provided with uniformly distributed elongated holes. The gas equalization plate is fixed to the lower bottom plate of the vacuum chamber by screws. Whether the slow extraction valve is opened to vent the chamber or the main extraction valve is opened to vent the chamber, the upper and lower parts of the carrier plate are always in a constant pressure, uniform and stable airflow layer during the exhaust process.

[0024] By employing this invention, the pressure above and below the carrier plate remains consistent due to the gas equalization plate, thus avoiding the impact of gas on the substrate and carrier plate caused by pressure differences, as well as the deformation of the carrier plate, displacement and detachment of the substrate, and transmission jamming caused by the impact.

[0025] Using this invention, during the exhaust process, the carrier plate is always in a constant pressure, uniform and stable airflow layer, and the substrate will not be subjected to excessive airflow impact force, thus avoiding excessive internal stress on the substrate.

[0026] By employing this invention, the reduction of internal stress in the substrate itself directly leads to a reduction in internal stress in the thin film deposited on the substrate later, ensuring the stability of photovoltaic production line operation and the requirements of coating process, guaranteeing the uniformity of film thickness and the compactness of film structure deposited on the substrate, and ensuring film quality.

[0027] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

Claims

1. A method for rapid vacuuming, characterized in that, include: Step 1: Provide a vacuum chamber. Slow-release valves are installed on both sides of the lower part of the vacuum chamber, and a main-release valve is installed in the middle. The main-release valve and the slow-release valve are connected in parallel through a vacuum pipe. The upper end of the valve is connected to the vacuum chamber, and the lower end of the parallel pipe is connected to an exhaust pump group. Step 2: Place multiple gas equalization plates between the exhaust port of the vacuum chamber and the carrier plate. The gas equalization plates are used to keep the pressure above and below the carrier plate consistent. Step 3: The carrier plate filled with substrates is fed into the vacuum chamber by a transfer roller. First, open the slow-release valves on both sides. The gas above and below the carrier plate is discharged for the first time through the gas equalization plates. After the gas in the vacuum chamber is diluted, close the slow-release valves and open the main-release valve. The diluted gas above and below the carrier plate is collected at the exhaust port of the main-release valve through the gas equalization plates for a second venting. The gas equalization plate consists of an upper plate and four side plates. The lower part of the gas equalization plate is fixed to the lower bottom plate of the vacuum chamber by screws. The air distribution plate is rectangular box-shaped, polygonal box-shaped, or multi-faceted spherical box-shaped. The slow-pulling valve is located below the internal space of the side plate of the gas equalization plate, and the main-pulling valve is located below the central channel of the vacuum chamber outside the side plate of the gas equalization plate. The upper plate is provided with uniformly dense small holes; The four side plates are provided with uniformly distributed elongated holes.

2. The rapid vacuuming method according to claim 1, characterized in that, The vacuum chamber is a large-sized chamber.

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