Vacuum drying device

Abstract

The utility model relates to the technical field of solar cell manufacturing, and discloses a vacuum drying device, which is used for drying coating liquid on a product, and comprises a vacuum chamber, an exhaust port, a vacuum pump and a vacuum pump, the sealing cover is arranged in the vacuum chamber, and when the bearing plate is covered with the sealing cover, the sealing cover and the bearing plate jointly define a space used for containing a product; a first through hole is formed in the area, close to the exhaust port, of the sealing cover, a second through hole is formed in the area away from the exhaust port, and the size of the first through hole is smaller than that of the second through hole; and the vacuum pump is communicated with the exhaust port through a pipeline. According to the utility model, by increasing the size of the second through hole, the airflow velocity at the first through hole and the airflow velocity at the second through hole can be within a preset difference range, so that coating liquid on a product can be volatilized at basically the same evaporation velocity, and the uniformity of a final formed film is ensured.

Description

Technical Field

[0001] This utility model relates to the field of solar cell manufacturing technology, specifically to a vacuum drying device. Background Technology

[0002] Perovskite solar cells mainly consist of a transparent conductive oxide layer, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode. The perovskite layer is the core component of a perovskite solar cell. Currently, the most commonly used process for preparing the perovskite layer is the solution wet process. This process involves uniformly distributing a solution containing perovskite material onto a substrate, followed by a drying step to promote solvent evaporation and the formation of perovskite crystals.

[0003] However, the solvent evaporation rate varies greatly in different regions of the substrate during the drying process, resulting in poor uniformity of the final perovskite film and affecting the photoelectric conversion efficiency of subsequent perovskite solar cells. Utility Model Content

[0004] In view of this, the present invention provides a vacuum drying device to solve the problem of poor uniformity of perovskite films caused by the difference in solvent evaporation rate in different regions of the substrate.

[0005] This utility model provides a vacuum drying device for drying coating liquid on products, comprising:

[0006] A vacuum chamber, with an internal support plate for supporting the product, and an exhaust port;

[0007] A sealing cover is disposed within the vacuum chamber. When the sealing cover covers the support plate, it together with the support plate forms a space for placing the product. The sealing cover has a first through hole in the area near the exhaust port and a second through hole in the area away from the exhaust port. The size of the first through hole is smaller than the size of the second through hole.

[0008] A vacuum pump is connected to the exhaust port via a first pipeline.

[0009] Beneficial Effects: During vacuum drying, when the vacuum pump evacuates the vacuum chamber through the first pipeline connected to the exhaust port, gas flows outward from inside the vacuum chamber. Since the area near the exhaust port is closer to the vacuum pump's suction source, the airflow velocity in this area is faster than that further away from the exhaust port. This means the coating liquid near the exhaust port evaporates faster than that further away, leading to variations in crystallinity in the final product. To address this issue, this invention uses a sealing cover on the outside of the product, with a first and second through-hole to guide airflow. Furthermore, by making the first through-hole smaller near the exhaust port and the second through-hole larger further away, the problem of inconsistent evaporation rates of the coating liquid in different areas due to distance from the exhaust port is solved.

[0010] In one optional embodiment, the system further includes a controller and a vacuum pressure gauge electrically connected to the controller, the vacuum pressure gauge being located within the vacuum chamber; a valve electrically connected to the controller is provided on the first pipeline, the controller being used to control the opening angle of the valve based on the pressure information detected by the vacuum pressure gauge.

[0011] Beneficial effects: This vacuum pressure gauge not only monitors the pressure inside the vacuum chamber in real time, but also feeds back the monitored pressure information to the controller. Upon receiving this pressure data, the controller precisely controls the valve opening angle and opening time according to a pre-set intelligent control program. This reduces crystallization differences between wafers caused by fluctuations in the pumping process during production, ensuring product consistency.

[0012] In one optional embodiment, the carrier plate is provided with a plurality of spaced-apart support members, one end of which is used to support the product and the other end is detachably connected to the carrier plate.

[0013] Beneficial effects: The spaced-out supports effectively prevent large-area contact between the product and the support plate, ensuring that all surfaces of the product are fully exposed to the vacuum environment during drying. This facilitates uniform airflow around the product, promoting even drying of the coating liquid and improving drying quality. Simultaneously, the spaced-out supports allow for easy handling of the product by manual labor or robotic arms. Furthermore, the detachable connection between the supports and the support plate allows operators to easily remove the supports for processing, reducing maintenance costs and complexity.

[0014] In one optional embodiment, the support plate is a heating plate, and a heater is provided on the side wall of the vacuum chamber away from the support plate, with a heat insulation structure provided on the outside of the heater.

[0015] Beneficial effects: The support plate, acting as a heating plate, can directly heat the product placed on it from the bottom, making the product heated more evenly. It can effectively accelerate the evaporation rate of the solvent in the coating liquid, significantly shorten the drying time, and improve production efficiency.

[0016] Furthermore, using the support plate as a heating plate facilitates the application of thicker films on the product. Understandably, applying a thicker film requires coating the product with a thicker layer of coating solution. However, during vacuum drying, the evaporation rate of the solution at the bottom and inside is slower than that of the solution on the outer surface. Therefore, the solution on the outer surface evaporates first and crystallizes. This crystallization not only hinders further evaporation of the internal solution, leading to prolonged drying time, but may also leave internal solution residue, affecting the thoroughness and uniformity of product drying. Thus, by using a heating plate, it is possible to ensure uniform heating of the product in a vacuum environment, avoiding defects caused by uneven evaporation and improving product quality.

[0017] In one alternative embodiment, the vacuum chamber includes a first half and a second half connected together, and a sealing ring is provided at the connection between the first half and the second half.

[0018] Beneficial effects: The split-type vacuum chamber design provides ample operating space in its separate state, facilitating product handling and maintenance. The sealing ring effectively ensures a tight seal at the connection between the first and second halves, preventing reduced drying efficiency and product quality due to insufficient vacuum.

[0019] In one alternative embodiment, the device further includes a drive member and a transmission member, wherein one of the first half and the second half is connected to the drive member via the transmission member and is adapted to move toward or away from the other under the drive of the drive member.

[0020] Beneficial effects: Compared with manual operation, the cooperation of the drive and transmission components allows one of the first and second halves to move closer to or further away from the other. This not only effectively avoids problems such as collisions between the two halves or poor sealing caused by human factors, but also makes the operation more labor-saving and convenient.

[0021] In one optional embodiment, the first half is located above the second half, and when the first half covers the second half, the first half and the second half together form the vacuum chamber; the side of the sealing cover away from the support plate is connected to the inner wall of the first half.

[0022] Beneficial Effects: Compared to other layouts, the vertical arrangement of the first and second halves fully utilizes the longitudinal space while reducing the horizontal space occupied. This not only improves space utilization but also makes the overall structure of the device more compact. Furthermore, taking the connection between the first half and the drive component as an example, connecting the sealing cover to the inner wall of the first half allows the sealing cover and the first half to maintain the same state of motion. Therefore, when the first half covers the second half, the sealing cover will also accurately cover the support plate, forming a space for placing the product. This arrangement eliminates the need for additional adjustments to the sealing cover, improving work efficiency. Similarly, when the dried product needs to be removed, the sealing cover will follow the first half away from the support plate, creating an easy-to-access operating space for product removal.

[0023] In one optional embodiment, the driving component is a servo motor, and the transmission component includes a lead screw connected to the servo motor and a slider that slides with the lead screw. The slider is connected to one of the first half and the second half. The lead screw is located on one side of the vacuum chamber and is arranged along the movement direction of the first half or the second half. A slide rail is also provided on one side of the lead screw and is arranged side by side with the lead screw. The side of the slider away from the vacuum chamber is slidably connected to the slide rail.

[0024] Beneficial effects: The servo motor enables high-precision speed and torque control. Combined with the transmission characteristics of the lead screw, it can precisely control the moving distance, speed, and positioning accuracy of the first or second half, ensuring the accuracy of the movement of the first and second halves as they approach or move away, effectively avoiding the impact of opening and closing position deviations on the sealing of the vacuum chamber. Furthermore, the slide rail further enhances the stability and guidance of the slider movement, reducing the impact of vibration and swaying on the accuracy of the first or second half's position.

[0025] In one optional embodiment, there are multiple first through holes distributed on the top periphery of the sealing cover and corresponding to the periphery region of the product; there is at least one second through hole located in the top center region of the sealing cover and corresponding to the center region of the product; the diameters of the first and second through holes are adjustable.

[0026] Beneficial Effects: This invention positions the second through-hole at the center of the product and the first through-hole at the periphery, ensuring that the coating liquid in the center and periphery maintains a similar evaporation rate. This prevents significant differences in crystallization between the center and periphery, improving the uniformity of drying and overall quality. Furthermore, by making the first and second through-holes adjustable, operators can flexibly adjust the gas flow rate and velocity in each area based on the coating liquid's composition and thickness, allowing for more precise control of evaporation in different areas. For example, when the coating liquid has a low proportion of volatile components and a thicker thickness, the through-hole diameter can be increased to accelerate airflow in the corresponding area, increasing the evaporation rate and ensuring drying efficiency. Conversely, if the coating liquid is thin and has a high volatile content, the through-hole diameter can be decreased to prevent uneven drying or other quality problems caused by excessively rapid evaporation.

[0027] In one optional embodiment, the vacuum chamber has an opening communicating with its interior, and a sealing baffle is provided at the opening. The sealing baffle is slidably connected to the side wall of the vacuum chamber and is adapted to seal the opening. The side of the sealing cover away from the support plate is connected to the inner wall of the first half through a telescopic member. The vacuum chamber is also provided with a second pipeline communicating with its interior, and the second pipeline is used to transport inert gas.

[0028] Beneficial effects: Compared to a split design, the product enters and exits the vacuum chamber through an opening, eliminating the need to fully open the chamber. This allows the chamber to maintain an inert gas atmosphere to some extent during product movement, shortening the time the product is exposed to air before drying and ensuring product quality. Furthermore, because the inert gas atmosphere inside the chamber is well-preserved, only a small amount of inert gas needs to be replenished subsequently. Compared to methods that require large-scale refilling of inert gas each time, this method reduces the amount of inert gas used and lowers costs. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a vacuum drying device according to an embodiment of the present invention;

[0031] Figure 2This is a diagram showing the pressure changes inside the vacuum chamber at different stages according to an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Vacuum chamber; 101. First half; 102. Second half; 103. Exhaust port; 2. Support plate; 3. Sealing cover; 301. First through hole; 302. Second through hole; 4. Vacuum pump; 5. First pipeline; 6. Controller; 7. Vacuum pressure gauge; 8. Valve; 9. Support component; 10. Heater; 11. Heat insulation structure; 12. Sealing ring; 13. Drive component; 14. Transmission component; 1401. Lead screw; 1402. Slider; 15. Slide rail; 16. Second pipeline. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] To address the problem of poor uniformity in perovskite films caused by differences in solvent evaporation rates in different regions of the substrate, this invention provides a vacuum drying device.

[0036] The following is combined with Figure 1 and Figure 2 The following describes embodiments of the present invention.

[0037] According to embodiments of the present invention, such as Figure 1 As shown, a vacuum drying apparatus is provided for drying coating liquid on a product, including: a vacuum chamber 1, a sealing cover 3, and a vacuum pump 4.

[0038] Specifically, the vacuum chamber 1 is provided with a support plate 2 for carrying products, and the vacuum chamber 1 is provided with an exhaust port 103; a sealing cover 3 is provided in the vacuum chamber 1, and when the sealing cover 3 covers the support plate 2, it together with the support plate 2 to form a space for placing products; the area of ​​the sealing cover 3 near the exhaust port 103 is provided with a first through hole 301, and the area away from the exhaust port 103 is provided with a second through hole 302, the size of the first through hole 301 is smaller than the size of the second through hole 302; the vacuum pump 4 is connected to the exhaust port 103 through a first pipe 5.

[0039] During the vacuum drying process, when the vacuum pump 4 is connected to the exhaust port 103 through the first pipe 5 to evacuate the vacuum chamber 1, gas flows outward from inside the vacuum chamber 1. Since the area near the exhaust port 103 is closer to the suction source of the vacuum pump 4, the airflow velocity in this area is faster than that in areas farther from the exhaust port 103. This means that the evaporation rate of the coating liquid near the exhaust port 103 is faster than that farther away, leading to potential crystallinity differences in the final product. To address this issue, this embodiment uses a sealing cover 3 on the outside of the product, with a first through-hole 301 and a second through-hole 302 to guide airflow. Furthermore, by setting the size of the first through-hole 301 near the exhaust port 103 to be smaller, and the size of the second through-hole 302 farther away to be larger, the problem of inconsistent evaporation rates of the coating liquid in different areas due to distance from the exhaust port 103 can be resolved.

[0040] It should be noted that the coating solution in this embodiment may be, but is not limited to, a perovskite precursor solution.

[0041] According to one embodiment of the present invention, such as Figure 1 As shown, it also includes a controller 6 and a vacuum pressure gauge 7 electrically connected to the controller 6. The vacuum pressure gauge 7 is located inside the vacuum chamber 1. A valve 8 electrically connected to the controller 6 is provided on the first pipeline 5. The controller 6 is used to control the opening angle of the valve 8 according to the pressure information detected by the vacuum pressure gauge 7.

[0042] In this embodiment, a vacuum pressure gauge 7 monitors the pressure information inside the vacuum chamber 1 in real time and feeds it back to the controller 6. The controller 6 precisely controls the opening angle of the valve 8 based on this pressure data, enabling precise control of the vacuum level inside the vacuum chamber 1. This ensures that the vacuum environment remains suitable for drying the product coating liquid throughout the drying process, avoiding any impact on drying efficiency and product quality due to excessively high or low vacuum levels.

[0043] It should be noted that, as Figure 2As shown, the vacuum chamber 1 typically undergoes the following stages: ① slow evacuation stage → ② fast evacuation stage → ③ vacuum pressure maintenance stage → ④ evacuation to low pressure → ⑤ slow inflation to break the vacuum → ⑥ rapid vacuum breaking to atmospheric pressure. The first four stages are achieved by controlling the opening degree and opening time of valve 8. Therefore, if the opening degree and opening time of valve 8 are manually adjusted, differences in crystallization between products during production may occur, affecting product consistency. To solve this problem, this embodiment is equipped with a vacuum pressure gauge 7 and a controller 6 electrically connected to the vacuum pressure gauge 7. The vacuum pressure gauge 7 can not only monitor the pressure information within the vacuum chamber 1 in real time, but also feed back the monitored pressure information to the controller 6. After receiving this pressure data, the controller 6 will precisely control the opening angle and opening time of valve 8 according to a pre-set intelligent control program. This reduces the crystallization differences between wafers caused by fluctuations in the evacuation process during production, ensuring product consistency.

[0044] The performance of the perovskite solar cell module prepared by the vacuum drying apparatus of this embodiment will be described below with reference to some embodiments and comparative examples.

[0045] The fabrication process of the perovskite solar cell module in this embodiment is as follows:

[0046] A comprehensive cleaning process is performed on the FTO glass. After cleaning, nickel oxide is deposited on the FTO glass substrate. A perovskite precursor layer is prepared using slot coating technology. The FTO glass with the perovskite precursor layer is placed in the vacuum drying device of this invention and processed according to the set evacuation conditions. Specifically, the valve angle is first set at 45° and held for 5 seconds, then adjusted to 90° and held for 10 seconds. An oxide layer is deposited on the processed structure using plasma deposition. ITO / Cu electrodes are sputtered. After completing all the above front-end process steps, the process proceeds to the back-end encapsulation stage to complete the fabrication of the perovskite solar cell module.

[0047] The fabrication process of the comparative perovskite solar cell module is similar to that of the example, with the following differences:

[0048] The FTO glass coated with the perovskite precursor layer was placed in a conventional vacuum drying apparatus and processed according to specific pressure and time settings: first, it was held at a pressure of 10000 Pa for 5 seconds, then at a pressure of 500 Pa for 10 seconds, and finally at a pressure of 25 Pa for 3 seconds.

[0049] The performance tests of the perovskite solar modules of Examples 1-8 and Comparative Examples 1-8 are shown in Table 1 below:

[0050] Table 1

[0051]

[0052]

[0053] As can be seen from the comparison between the examples and the comparative examples in Table 1, the photoelectric conversion efficiency of the sample from the examples and the sample from the comparative examples prepared under the same conditions is similar, and they have good repeatability. Compared with the comparative examples, the perovskite solar cell modules of the examples have better performance and can also improve the product consistency of perovskite solar cell modules in the same batch.

[0054] According to one embodiment of the present invention, such as Figure 1 As shown, the support plate 2 is equipped with multiple spaced-apart support members 9. One end of each support member 9 supports the product, and the other end is detachably connected to the support plate 2. The spaced-apart support members 9 effectively prevent large-area contact between the product and the support plate 2, ensuring that all surfaces of the product are fully exposed to the vacuum environment during the drying process. This facilitates uniform airflow around the product, promoting even drying of the coating liquid and improving drying quality. Simultaneously, the spaced-apart support members allow for easy handling of the product by manual labor or robotic arms. Furthermore, the detachable connection between the support member 9 and the support plate 2 allows operators to easily remove the product from the support plate 2 for processing, reducing the maintenance cost and difficulty of the device.

[0055] In one embodiment, the support member 9 is a support pin, which includes a support rod and a pin cap. One end of the support rod is threadedly connected to the pin cap, and the other end is detachably connected to the carrier plate 2; the end of the pin cap away from the support rod is used to support the product.

[0056] According to one embodiment of this utility model, the support plate 2 is a heating plate, and a heater 10 is provided on the side wall of the vacuum chamber 1 away from the support plate 2. A heat insulation structure 11 is provided on the outside of the heater 10. As a heating plate, the support plate 2 can directly heat the product placed on it from the bottom, making the product more evenly heated, effectively accelerating the evaporation rate of the solvent in the coating liquid, significantly shortening the drying time, and improving production efficiency.

[0057] Furthermore, setting the support plate 2 as a heating plate facilitates the application of thicker films on the product. Understandably, to apply a thicker film, a thicker coating liquid needs to be applied. However, during vacuum drying, the evaporation rate of the solution at the bottom and inside is slower than that of the solution on the outer surface. Therefore, the solution on the outer surface evaporates first and crystallizes. This crystallization not only hinders further evaporation of the internal solution, leading to prolonged drying time, but may also leave internal solution residue, affecting the thoroughness and uniformity of product drying. Thus, by setting a heating plate, the product can be ensured to be heated uniformly in a vacuum environment, avoiding defects caused by uneven evaporation and improving product quality. Additionally, to avoid excessive contact between the needle cap and the product, leading to uneven heating, the diameter of the needle cap is generally made as small as possible; typically, the diameter of the support rod is 15-25 mm, and the diameter of the needle cap is 1-2 mm.

[0058] Understandably, when the heating plate is working, there will be a temperature difference between the side of the product away from the heating plate and the side where the heating plate is located. Therefore, a heater 10 is installed on the side wall of the vacuum chamber 1 away from the support plate 2 to ensure temperature uniformity. Furthermore, by providing a heat insulation structure 11 outside the heater 10, the rate at which heat dissipates from the vacuum chamber 1 can be reduced, allowing the temperature inside the vacuum chamber 1 to be maintained for a longer period of time. In this way, the starting speed of the heater 10 can be reduced, as well as the damage to the heater 10 caused by repeated starts.

[0059] It should be noted that the heating temperature of the heating plate and heater 10 can be flexibly set as needed. Taking the coating solution as a perovskite solution as an example, the heating temperature range of the heating plate and heater 10 can be from room temperature to 150°C.

[0060] According to one embodiment of the present invention, such as Figure 1 As shown, the vacuum chamber 1 includes a first half 101 and a second half 102 connected together, with a sealing ring 12 at the connection between the first half 101 and the second half 102. The split-type design of the vacuum chamber 1 provides ample operating space in its split state, facilitating product handling and maintenance by operators. The sealing ring 12 effectively ensures the sealing performance at the connection between the first half 101 and the second half 102, preventing problems such as reduced drying efficiency and decreased product quality due to insufficient vacuum.

[0061] According to one embodiment of the present invention, such as Figure 1As shown, it also includes a driving component 13 and a transmission component 14. One of the first half 101 and the second half 102 is connected to the driving component 13 through the transmission component 14, and is adapted to move towards or away from the other under the drive of the driving component 13. Compared with manual operation, the cooperation of the driving component 13 and the transmission component 14 to move one of the first half 101 and the second half 102 towards or away from the other can not only effectively avoid problems such as collision between the two halves or poor sealing caused by human factors, but also make the operation more labor-saving and convenient.

[0062] According to one embodiment of the present invention, such as Figure 1 As shown, the first half 101 is located above the second half 102. When the first half 101 covers the second half 102, the first half 101 and the second half 102 together form a vacuum chamber 1. The side of the sealing cover 3 away from the support plate 2 is connected to the inner wall of the first half 101. Compared with other layouts, the vertical arrangement of the first half 101 and the second half 102 makes full use of the space in the longitudinal direction and reduces the space occupied in the horizontal direction. This not only improves the space utilization rate but also makes the overall structure of the device more compact. Furthermore, taking the connection between the first half 101 and the driving component 13 as an example, connecting the sealing cover 3 to the inner wall of the first half 101 allows the sealing cover 3 and the first half 101 to maintain the same state of motion. Therefore, when the first half 101 covers the second half 102, the sealing cover 3 will also accurately cover the support plate 2 and form a space for placing the product. It can be seen that this arrangement can save the step of adjusting the sealing cover 3 and improve work efficiency. Similarly, when the dried product needs to be removed, the sealing cover 3 will also leave the support plate 2 along with the first half 101, forming an operating space that facilitates the removal of the product.

[0063] According to one embodiment of the present invention, such as Figure 1As shown, the driving component 13 is a servo motor, and the transmission component 14 includes a lead screw 1401 connected to the servo motor and a slider 1402 slidably engaged with the lead screw 1401. The slider 1402 is connected to one of the first half 101 and the second half 102. The lead screw 1401 is located on one side of the vacuum chamber 1 and is arranged along the movement direction of the first half 101 or the second half 102. A slide rail 15 is also provided on one side of the lead screw 1401, arranged parallel to the lead screw 1401. The side of the slider 1402 away from the vacuum chamber 1 is slidably engaged with the slide rail 15. The servo motor can achieve high-precision speed and torque control. Combined with the transmission characteristics of the lead screw 1401, it can accurately control the moving distance, speed, and positioning accuracy of the first half 101 or the second half 102, ensuring the accuracy of the movement of the first half 101 and the second half 102 as they approach or move away, and effectively avoiding the impact on the sealing of the vacuum chamber 1 due to deviations in the opening and closing positions. The slide rail 15 further enhances the stability and guidance of the slider 1402's movement, reducing the impact of vibration and swaying on the accuracy of the first half 101 or the second half 102's movement position.

[0064] According to one embodiment of the present invention, such as Figure 1 As shown, there are multiple first through holes 301, distributed on the top periphery of the sealing cover 3 and corresponding to the periphery of the product; there is at least one second through hole 302, located in the top center of the sealing cover 3 and corresponding to the center of the product; the apertures of the first through holes 301 and 302 are adjustable. In this embodiment, the second through hole 302 is positioned to correspond to the center of the product, and the first through hole 301 is positioned to correspond to the periphery of the product. This ensures that the coating liquid in the center and periphery of the product maintains a substantially similar evaporation rate, preventing significant differences in crystallization between the center and periphery, thus improving the uniformity of drying and overall quality. Furthermore, by setting the first through holes 301 and 302 to adjustable sizes, operators can flexibly adjust the gas flow rate and airflow velocity in each area based on factors such as the composition and thickness of the coating liquid, thereby more accurately controlling the evaporation of different areas of the product. For example, when the volatile components in the coating liquid are relatively low and the thickness is relatively high, the aperture of the through holes can be appropriately increased to accelerate the airflow in the corresponding area, improve the evaporation rate, and ensure drying efficiency. On the other hand, if the coating liquid is relatively thin and the volatile component content is high, the aperture of the through holes can be appropriately reduced to avoid uneven drying or other quality problems caused by excessively rapid evaporation.

[0065] According to one embodiment of the present invention, a vacuum chamber 1 is provided with an opening communicating with its interior, and a sealing baffle is provided at the opening. The sealing baffle is slidably connected to the side wall of the vacuum chamber 1 and is adapted to seal the opening. The side of the sealing cover 3 away from the support plate 2 is connected to the inner wall of the first half 101 through a telescopic member. The vacuum chamber 1 is also provided with a second pipeline 16 communicating with its interior, and the second pipeline 16 is used to transport inert gas.

[0066] Compared to a split design, the product enters and exits the vacuum chamber 1 through an opening, eliminating the need to fully open the entire chamber. This allows the chamber to maintain an inert gas atmosphere to some extent during product movement, shortening the product's contact time with air before drying and ensuring product quality. Furthermore, because the inert gas atmosphere inside the chamber is well-preserved, only a small amount of inert gas needs to be replenished subsequently. Compared to methods that require large-scale refilling of inert gas each time, this method reduces the amount of inert gas used and lowers costs.

[0067] It should be noted that the inert gas in this embodiment can be nitrogen, helium, neon, argon, or other gases that do not react with the product or the apparatus; nitrogen is generally used. The inert gas is typically introduced into the vacuum chamber 1 after the vacuum pump 4 has completed the evacuation process in the hollow chamber, thereby breaking the vacuum environment. Furthermore, after the vacuum chamber 1 is filled with nitrogen, a pre-annealing operation can be performed by setting a suitable temperature, which reduces the time required for the subsequent formal annealing process and improves production cycle time.

[0068] It should be noted that the telescopic components in this embodiment include, but are not limited to, linear motors and telescopic cylinders.

[0069] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A vacuum drying apparatus for drying coating liquid on products, characterized in that, include: A vacuum chamber (1) is provided inside with a support plate (2) for carrying products, and the vacuum chamber (1) is provided with an exhaust port (103); A sealing cover (3) is disposed inside the vacuum chamber (1). When the sealing cover (3) covers the support plate (2), it together with the support plate (2) forms a space for placing the product. The sealing cover (3) has a first through hole (301) in the area near the exhaust port (103) and a second through hole (302) in the area away from the exhaust port (103). The size of the first through hole (301) is smaller than the size of the second through hole (302). The vacuum pump (4) is connected to the exhaust port (103) through the first pipeline (5).

2. The vacuum drying apparatus according to claim 1, characterized in that, It also includes a controller (6) and a vacuum pressure gauge (7) electrically connected to the controller (6), the vacuum pressure gauge (7) being located inside the vacuum chamber (1); a valve (8) electrically connected to the controller (6) is provided on the first pipeline (5), the controller (6) being used to control the opening angle of the valve (8) according to the pressure information detected by the vacuum pressure gauge (7).

3. The vacuum drying apparatus according to claim 1, characterized in that, The support plate (2) is provided with a plurality of spaced support members (9). One end of the support member (9) is used to support the product, and the other end is detachably connected to the support plate (2).

4. The vacuum drying apparatus according to claim 1, characterized in that, The support plate (2) is a heating plate, and a heater (10) is provided on the side wall of the vacuum chamber (1) away from the support plate (2). A heat insulation structure (11) is provided on the outside of the heater (10).

5. The vacuum drying apparatus according to any one of claims 1 to 4, characterized in that, The vacuum chamber (1) includes a first half (101) and a second half (102) connected to each other, and a sealing ring (12) is provided at the connection between the first half (101) and the second half (102).

6. The vacuum drying apparatus according to claim 5, characterized in that, It also includes a drive member (13) and a transmission member (14), one of the first half (101) and the second half (102) being connected to the drive member (13) via the transmission member (14) and adapted to move toward or away from the other under the drive of the drive member (13).

7. The vacuum drying apparatus according to claim 6, characterized in that, The first half (101) is located above the second half (102). When the first half (101) covers the second half (102), the first half (101) and the second half (102) together form the vacuum chamber (1); the side of the sealing cover (3) away from the support plate (2) is connected to the inner wall of the first half (101).

8. The vacuum drying apparatus according to claim 7, characterized in that, The driving component (13) is a servo motor, and the transmission component (14) includes a lead screw (1401) connected to the servo motor and a slider (1402) slidably engaged with the lead screw (1401). The slider (1402) is connected to one of the first half (101) and the second half (102). The lead screw (1401) is located on one side of the vacuum chamber (1) and is arranged along the movement direction of the first half (101) or the second half (102). A slide rail (15) is also provided on one side of the lead screw (1401) and is arranged side by side with the lead screw (1401). The side of the slider (1402) away from the vacuum chamber (1) is slidably engaged with the slide rail (15).

9. The vacuum drying apparatus according to any one of claims 1 to 4, characterized in that, There are multiple first through holes (301), which are distributed on the top periphery of the sealing cover (3) and correspond to the periphery of the product; there is at least one second through hole (302), which is located in the top center region of the sealing cover (3) and corresponds to the center region of the product; the aperture sizes of the first through holes (301) and the second through holes (302) are adjustable.

10. The vacuum drying apparatus according to claim 5, characterized in that, The vacuum chamber (1) is provided with an opening that communicates with its interior. A sealing baffle is provided at the opening. The sealing baffle is slidably connected to the side wall of the vacuum chamber (1) and is adapted to seal the opening. The sealing cover (3) is connected to the inner wall of the first half (101) on the side away from the support plate (2) through a telescopic member. The vacuum chamber (1) is also provided with a second pipeline (16) that communicates with its interior. The second pipeline (16) is used to transport inert gas.

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