Vacuum flash evaporation film forming apparatus

Abstract

The application discloses a vacuum flash evaporation film forming device, which comprises a box body, an air extraction assembly and a baffle. An accommodating cavity for accommodating a substrate is formed in the box body. The air extraction assembly is arranged above the box body and connected with the box body, and is used for extracting gas in the accommodating cavity. The baffle is arranged around the periphery of the mounting position of the substrate, the highest end of the baffle is higher than the substrate, and the baffle blocks the edge position of the accommodating cavity and the mounting position of the substrate in the horizontal direction. The vacuum flash evaporation film forming device is used for reducing the influence of the gas flow rate difference in the box body on the drying effect of the liquid film on the substrate, and improving the consistency of drying and crystallization of the liquid film.

Description

Technical Field

[0001] This invention relates to the field of vacuum drying equipment technology, and in particular to a vacuum flash evaporation film forming device. Background Technology

[0002] In fields such as chip manufacturing, display manufacturing, solar cell manufacturing, and lithium battery manufacturing, a liquid film is coated onto a substrate, and then the substrate with the liquid film is vacuum dried to form the desired functional film layer. Maintaining consistent air pressure throughout the substrate during vacuum drying ensures uniform vacuum drying of the liquid film, thereby guaranteeing the quality of the final functional film layer.

[0003] When vacuum drying a substrate, the substrate is placed in a sealed chamber, and then the chamber is evacuated to achieve vacuum drying of the substrate. Existing vacuuming methods include top-mounted vacuuming and bottom-mounted vacuuming. However, in the bottom-mounted vacuuming method, the gas in the center of the substrate must first flow to the edge and then from the edge to the lower extraction port. This gas flow pattern can easily lead to inconsistent drying effects between the center and the edges of the substrate.

[0004] Therefore, one existing method for reducing pressure differences across a substrate is to employ a structure with top-mounted air extraction and a porous flow equalization plate. Gas flowing above the substrate is drawn out after being evenly distributed through the porous flow equalization plate. The damping effect of the porous flow equalization plate reduces the pressure difference across the substrate, thereby improving the drying uniformity of the liquid film on the substrate.

[0005] However, during the evacuation process, the difference in gas flow rate will also affect the drying effect of the liquid film on the substrate. The existing evacuation method only considers reducing the gas pressure difference at various parts of the substrate by forced flow equalization, without considering the impact of gas flow rate on the drying effect of the liquid film. The difference in gas flow rate during the evacuation process will reduce the uniformity of the drying and crystallization of the liquid film, and will affect the quality of some functional film layers with poor crystallization quality. Summary of the Invention

[0006] The purpose of this invention is to provide a vacuum flash evaporation film forming apparatus to reduce the impact of gas flow rate differences within the chamber on the drying effect of the liquid film on the substrate and to improve the consistency of drying and crystallization of the liquid film at various locations.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A vacuum flash film formation apparatus, comprising:

[0009] The housing has an internal cavity for accommodating the substrate;

[0010] An air extraction assembly is disposed above the housing and connected to the housing; the air extraction assembly is used to extract gas from the containment chamber.

[0011] A baffle is disposed around the outer periphery of the mounting position of the substrate, the highest end of the baffle being higher than the substrate, and the baffle horizontally blocking the edge of the receiving chamber from the mounting position of the substrate.

[0012] Preferably, the housing is provided with a support platform for supporting the substrate, and the baffle is installed on the support platform; the baffle is integrally formed or fixedly connected to the support platform.

[0013] Preferably, the inner side of the baffle forms a space between itself and the substrate, and the outer side of the baffle forms an edge space between itself and the side wall of the housing; in the vertical direction, the space includes a first disturbance region extending from the upper surface of the support platform to above the liquid film on the substrate, and the edge space includes a second disturbance region extending from the bottom wall of the housing to above the liquid film on the substrate; the volume of the first disturbance region is smaller than the volume of the second disturbance region; the airflow in the second disturbance region is blocked by the baffle and separated from the substrate.

[0014] Preferably, the baffle is 5mm to 10mm above the upper surface of the liquid film on the substrate.

[0015] Preferably, the horizontal distance D1 between the baffle and the substrate is 10mm~15mm.

[0016] Preferably, the thickness D3 of the baffle is 8mm to 12mm.

[0017] Preferably, the pumping assembly includes a vacuum pipeline and a rectifier plate, the rectifier plate being disposed above the substrate and located upstream of the vacuum pipeline along the gas flow direction; the rectifier plate is provided with a plurality of uniformly distributed rectifier holes.

[0018] Preferably, a heat insulation ring is further provided on the support platform. The heat insulation ring is made of heat insulation material and is disposed between the support platform and the substrate to block heat transfer between the support platform and the substrate.

[0019] Preferably, the support platform is provided with an installation groove, and the heat insulation ring is embedded in the installation groove.

[0020] Preferably, the heat insulation ring is provided with a recessed groove, the recessed groove is adapted to the substrate and is used for substrate mounting, and the depth of the recessed groove is less than the thickness of the substrate.

[0021] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0022] By setting a baffle to block the edge of the receiving chamber from the mounting position of the substrate, the high-speed airflow generated at the edge of the receiving chamber during evacuation will be forcibly guided by the baffle and flow to the upper end of the baffle while separated from the substrate, that is, flow to the upper end of the substrate. The gas flowing to the upper end of the substrate is difficult to move down and affect the edge of the liquid film on the substrate, thereby preventing the high airflow from affecting the drying effect at the edge of the liquid film, ensuring the uniformity of gas flow rate at all parts of the liquid film, and making the drying and crystallization effect at the edge and the middle of the liquid film more consistent, thereby ensuring the quality of the dried functional film layer. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the vacuum flash evaporation film-forming apparatus according to an embodiment of the present invention;

[0024] Figure 2 This is an exploded view of the vacuum flash film forming apparatus according to an embodiment of the present invention;

[0025] Figure 3 This is a cross-sectional view of the vacuum flash film forming apparatus according to an embodiment of the present invention;

[0026] Figure 4 This is a partial cross-sectional view of the vacuum flash evaporation film-forming apparatus according to an embodiment of the present invention;

[0027] Figure 5 This is an exploded view of a portion of the structure of the vacuum flash film forming apparatus according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the gas flow state of the vacuum flash evaporation film forming apparatus according to an embodiment of the present invention when no baffle is provided;

[0029] Figure 7 This is a schematic diagram of the gas flow state of the vacuum flash film forming apparatus according to an embodiment of the present invention after the baffle is set;

[0030] Figure 8 This is a schematic diagram of the gas flow state of the vacuum flash film forming apparatus according to an embodiment of the present invention when the horizontal distance between the baffle and the substrate is greater than 15 mm.

[0031] In the diagram: 1. Housing; 11. Receiving chamber; 12. Cover plate; 13. Base plate; 2. Vacuum extraction assembly; 21. Vacuum pipeline; 22. Rectifier plate; 221. Rectifier hole; 222. Combination channel; 3. Support platform; 31. Mounting groove; 32. Heat insulation ring; 321. Recessed groove; 4. Baffle; 41. Spacing space; 411. First disturbance area; 42. Edge space; 421. Second disturbance area; 100. Base plate. Detailed Implementation

[0032] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0033] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.

[0034] like Figures 1 to 5 As shown, this invention provides a vacuum flash film deposition apparatus for drying a liquid film on a substrate 100 using a vacuum drying method. The substrate 100 can be a substrate used in fields such as chip manufacturing, display manufacturing, solar cell manufacturing, or lithium battery manufacturing. After drying, the liquid film on the substrate 100 can form the desired functional film layer. Specifically, the liquid film can be a perovskite liquid film or a PI (Polyimide) liquid film, and the substrate 100 can be a glass substrate 100.

[0035] The vacuum flash film forming device includes a housing 1, an air extraction assembly 2, a support platform 3, and a baffle 4.

[0036] Reference Figure 2 and Figure 3 The housing 1 forms a receiving chamber 11 for accommodating the substrate 100. When the substrate 100 needs to be dried, the receiving chamber 11 inside the housing 1 is evacuated to achieve vacuum drying of the substrate 100 located inside the housing 1, thereby drying the liquid film on the substrate 100 into the required functional film layer.

[0037] The housing 1 may include a cover plate 12 and a bottom plate 13. The cover plate 12 and the bottom plate 13 are sealed together to form a receiving chamber 11 for accommodating the substrate 100. When the substrate 100 needs to be replaced, the cover plate 12 can be separated from the bottom plate 13 to facilitate the placement and removal of the substrate 100. When the substrate 100 needs to be vacuum dried, the cover plate 12 and the bottom plate 13 are sealed together. The sealing between the cover plate 12 and the bottom plate 13 can be achieved by using a sealing ring or other sealing structure.

[0038] A support platform 3 is disposed within the housing 1 and is used to support and carry the substrate 100. The support platform 3 can be fixedly connected to the base plate 13, or it can be integrally formed with the base plate 13, protruding from the surface of the base plate 13. The area of ​​the upper surface of the support platform 3 that supports the substrate 100 is larger than the area of ​​the lower surface of the substrate 100, and the support platform 3 is spaced apart from the sidewall of the cover plate 12. Specifically, the support platform 3 can be a metal support platform made of metal material.

[0039] The vacuum pump assembly 2 is connected to the housing 1, and the vacuum pumping channel within the vacuum pump assembly 2 communicates with the receiving chamber 11 within the housing 1, allowing the gas in the receiving chamber 11 to be extracted by the vacuum pump assembly 2 through the vacuum pumping channel. When the receiving chamber 11 within the housing 1 is evacuated, the gas pressure in the receiving chamber 11 decreases, and the boiling point of the solvent in the liquid film to be dried decreases synchronously with the gas pressure. The decrease in the boiling point of the solvent accelerates evaporation, thus drying the liquid film to form the desired functional film layer. The vacuum pump assembly 2 can be installed above the substrate 100, allowing the vacuum flash evaporation film forming apparatus to perform vacuuming using a top-mounted vacuum method.

[0040] The vacuum pumping assembly 2 specifically includes a vacuum line 21 and a rectifier plate 22. One end of the vacuum line 21 is connected to the housing 1 so that the internal channel of the vacuum line 21 communicates with the receiving chamber 11 of the housing 1. The other end of the vacuum line 21 is connected to a vacuum pump so that the vacuum line 21 can generate suction through the vacuum pump to extract the gas from the housing 1. The rectifier plate 22 is located at the end of the vacuum line 21 connected to the housing 1, and the rectifier plate 22 is located upstream of the vacuum line 21 along the gas flow direction. When the vacuum pumping assembly 2 pumps gas, the gas first flows to the rectifier plate 22, and the gas passing through the rectifier plate 22 flows into the vacuum line 21 and is extracted. The rectifier plate 22 is provided with a plurality of uniformly distributed rectifier holes 221. When the gas flows through the rectifier plate 22, the uniformity of the gas flow is improved by the flow equalization effect of the plurality of rectifier holes 221, and the damping effect of the rectifier holes 221 is used to reduce the pressure gradient difference at various points on the substrate 100. The flow channel from the rectifier hole 221 to the vacuum line 21 can serve as the pumping channel for the pumping assembly 2.

[0041] One or more rectifier plates 22 can be provided. When multiple rectifier plates 22 are provided, they are arranged sequentially along the gas flow direction to perform multi-stage rectification of the gas. The number of holes in the multiple rectifier plates 22 can be gradually reduced along the gas flow direction so that the gas is gradually converged to the vacuum line 21 after passing through multiple rectifier plates 22. When only one rectifier plate 22 is provided, multiple rectification holes 221 can be provided on the side of the rectifier plate 22 facing the substrate 100, and multiple converging channels 222 can be provided on the side of the rectifier plate 22 facing away from the substrate 100. The converging channels 222 are connected to the rectification holes 221 so that the converging channels 222 can converge the gas flow from the multiple rectification holes 221 to the vacuum line 21.

[0042] Although the use of rectifier plate 22 can reduce the pressure gradient difference at various points on substrate 100 to a certain extent, due to the limited space inside the housing 1, the gap between rectifier plate 22 and substrate 100 is small. When the solvent vapor generated by the liquid film on substrate 100 flows to rectifier plate 22, the solvent vapor is converted into a gas flow state that passes through rectifier hole 221 in the vertical direction within the small gap between rectifier plate 22 and substrate 100. This conversion of gas within the small gap will cause the velocity gradient of gas in the vertical direction to increase sharply. At the edge of the substrate 100, due to the large gap between the edge of the substrate 100 and the side wall of the housing 1, the airflow at the edge of the substrate 100 is forcibly compressed and accelerated when it converges to the rectifier hole 221 corresponding to the rectifier plate 22. The airflow velocity at the edge of the substrate 100 is significantly greater than the gas velocity in the middle of the substrate 100. This results in the fluid tearing shear force borne by the edge region of the substrate 100 being much greater than that borne by the center region of the substrate 100. The excessive fluid tearing shear force at the edge of the substrate 100 will destroy the lattice interface at the edge of the liquid film on the substrate 100, which is in a critical nucleation state, and thus lead to the microscopic thermodynamic imbalance of the liquid film flash evaporation interface. Furthermore, when a large fluid tearing shear force acts directly on the gas-liquid interface at the edge of the liquid film, it disrupts the micro-interface equilibrium of the flash evaporation process. The desorption rate of solvent molecules at the liquid film edge far exceeds the lattice self-assembly rate during liquid film drying. Volatile organic components in the liquid film are preferentially stripped away, leading to severe concentration gradient distortion and consequently, a large number of non-coordination defect states within the final dried functional film. For example, when the liquid film is a perovskite liquid film, organic components such as methylamine and formic acid are preferentially stripped away, resulting in a large number of non-coordination defect states within the perovskite lattice formed after the perovskite liquid film dries.

[0043] Furthermore, under the negative pressure state during vacuum flash evaporation, solvent molecules at the center of the liquid film diffuse and escape only in the vertical direction, while solvent molecules at the edge of the liquid film diffuse in multiple directions, including both vertical and horizontal, resulting in a higher solvent diffusion flux at the edge than at the center. Simultaneously, the gas phase concentration boundary layer at the edge of the liquid film is thinner, leading to lower mass transfer resistance and further increasing the solvent evaporation rate. Therefore, the solute concentration at the edge of the liquid film rises rapidly during flash evaporation, and the supersaturation quickly exceeds the critical nucleation upper limit, entering the explosive nucleation region and instantly generating a large number of fine crystal nuclei. After explosive nucleation at the edge of the liquid film, the solvent is rapidly depleted, and the small crystal nuclei do not have time to merge and grow through Ostwald ripening, ultimately forming a thin film morphology with small grains, high grain boundary density, and high defect density. Meanwhile, solvent escape is slower at the center of the liquid film, and the supersaturation gently crosses the nucleation window, forming a small number of large grains. This results in a significantly higher central mass than edge mass in the final functional film.

[0044] In this application, to balance the drying and crystallization quality of the liquid film at its center and edges, a baffle 4 can be disposed around the substrate 100, with the uppermost point of the baffle 4 higher than the substrate 100. In this case, the inner side of the baffle 4 serves as the mounting space for the substrate 100, and horizontally, the inner side of the baffle 4 can be spaced from the substrate 100 to form a gap space 41; the outer side of the baffle 4 can be spaced from the sidewall of the housing 1 to form an edge space 42. During the evacuation process, the airflow that easily affects the liquid film on the substrate 100 mainly comes from the gas below the liquid film. This gas flows upwards and may affect the drying and crystallization quality of the liquid film. The volume of gas that can affect the liquid film within the gap space 41 is much smaller than the volume of gas that can affect the liquid film within the edge space 42.

[0045] Reference Figure 3 and Figure 4The edge space 42 has a relatively large volume. When the gas in the edge space 42 is extracted, a large amount of gas will converge towards the rectifier hole 221, resulting in gas vortices and a relatively high flow velocity. The large volume of the edge space 42 reduces the resistance to gas flow, thus creating a preferential airflow channel for rapid gas flow. By setting the baffle 4, the airflow in the edge space 42 is blocked when it flows towards the substrate 100. The baffle 4 forces the gas to flow vertically to the top of the substrate 100, and then the gas continues to flow upward and is extracted. The airflow basically does not flow to the liquid film on the substrate 100 and affect the liquid film. This prevents the fluid tearing shear force generated by the high-velocity gas from acting on the edge of the substrate 100, and also prevents microscopic thermodynamic imbalance during flash evaporation or the presence of a large number of non-coordination defect states in the functional film layer formed during final drying. Furthermore, by blocking the preferential airflow channels (airflow channels in the edge space 42) formed around the accommodating chamber 11 due to the low gas flow resistance by the baffle 4, the high-speed airflow flowing through the edge of the substrate 100 in the edge space 42 is eliminated, so that the edge region of the substrate 100 is in a similar airflow condition to the center region. The edge position of the liquid film no longer suffers additional fluid shear and forced convection to accelerate evaporation, and the solvent evaporation rate at the edge position of the liquid film approaches the solvent evaporation rate at the center position of the liquid film.

[0046] When the accommodating chamber 11 is evacuated, the gas volume in the space 41 that can affect the liquid film is small. The small gas flow will not generate a large fluid tearing shear force, and thus will not have much impact on the edge position of the liquid film.

[0047] Furthermore, the baffle 4 can also block the horizontal diffusion at the edge of the liquid film, thus causing the liquid film edge to mainly diffuse in the vertical direction. At this time, the solvent diffusion flux at the edge and center of the liquid film is basically the same. In addition, the baffle 4 blocks the area with a thin gas phase concentration boundary layer in the accommodating chamber 11, which can further balance the solvent evaporation rate at the edge and center of the liquid film, so that the solvent escape speed at the edge and center of the substrate 100 is relatively slow, and the supersaturation can pass through the nucleation window in a gentle manner. Large grains can be formed at both the edge and center of the liquid film, ensuring that the amount of dry crystallization at the center and edge of the liquid film is consistent.

[0048] In some specific embodiments, the baffle 4 can be disposed on the support platform 3. In this case, along the vertical direction, the gas that can affect the liquid film in the interval space 41 is mainly the first disturbance region 411 extending from the upper surface of the support platform 3 to the upper surface of the liquid film on the substrate 100; the gas that can affect the liquid film in the edge space 42 is mainly the second disturbance region 421 extending from the bottom wall of the housing 1 (the upper surface of the bottom plate 13) to the upper surface of the liquid film on the substrate 100. The second disturbance region 421 is deeper and its volume is much larger than that of the first disturbance region 411.

[0049] In the vertical direction, the first disturbance region 411 extends upward from the upper surface of the support platform 3. The height of the first disturbance region 411 is only the same as or similar to the height of the substrate 100 protruding from the support platform 3. Because the height of the first disturbance region 411 is relatively small, even if the gas in the first disturbance region 411 flows inside the baffle 4, the flow path of the gas in the first disturbance region 411 to the rectifier plate 22 is similar to the flow path of the gas above the liquid film to the rectifier plate 22. Therefore, the flow velocity of the gas in the first disturbance region 411 is similar to the flow velocity of the gas above the liquid film, and the influence of the gas in the first disturbance region 411 on the liquid film is small, thus ensuring the drying and crystallization quality at the edge of the liquid film. For the airflow in the deeper second disturbance region 421, it flows obliquely upward to the baffle 4 and is restricted by the baffle 4, making it difficult to flow to the substrate 100. This prevents the high-speed airflow generated by the second disturbance region 421 from affecting the edge of the liquid film on the substrate 100, ensuring the uniformity of drying and crystallization at the edge and center of the liquid film.

[0050] Reference Figure 6 , Figure 6 This is a schematic diagram of the gas flow state in the accommodating chamber 11 without baffle 4. It can be seen that when the rectifier plate 22 is used directly for rectification, the gas at the edge of the accommodating chamber 11 flows rapidly and generates eddies. The eddies will act on the edge of the liquid film, thereby reducing the drying and crystallization quality of the liquid film edge.

[0051] Reference Figure 7 , Figure 7 This is a schematic diagram of the gas flow state when a baffle 4 is set on the outside of the substrate 100. It can be seen that the setting of the baffle 4 allows the gas in the edge space 42 to flow directly along the baffle 4 to the rectifier plate 22. The gas in the edge space 42 will not have much impact on the edge position of the liquid film. This effectively reduces the impact of the gas flow rate difference in the box 1 on the drying effect of the liquid film on the substrate 100 and improves the consistency of drying and crystallization in various parts of the liquid film.

[0052] Reference Figure 4The size of the first disturbance region 411 is also related to the distance between the baffle 4 and the substrate 100. When the distance between the baffle 4 and the substrate 100 is small, the space enclosed by the baffle 4 is small, which increases the difficulty of placing the substrate 100 in the space inside the baffle 4. In addition, the liquid film on the substrate 100 is in a flowing state before it dries. If the distance between the baffle 4 and the substrate 100 is too small, it is easy to affect the liquid film due to scratches, etc., which will affect the coating effect of the liquid film on the substrate 100. When the distance between the baffle 4 and the substrate 100 is too large, the gas content in the space 41 between the baffle 4 and the substrate 100 increases. In addition, the airflow outside the baffle 4 (the airflow between the baffle 4 and the cover plate 12) is also prone to bypassing the edge of the liquid film after flowing above the baffle 4, which will affect the drying effect of the edge of the liquid film. To ensure the drying effect at the edge of the liquid film, the coating effect of the liquid film on the substrate 100, and to reduce the difficulty of installation operation of the substrate 100, the distance D1 between the baffle 4 and the substrate 100 is 10mm~15mm.

[0053] Furthermore, when the distance D1 between the baffle 4 and the substrate 100 is large, eddies are more likely to be generated at a greater distance from the substrate 100 within this larger distance. The generation of these eddies affects the flow of gas within the distance, thereby influencing the edge position of the substrate 100. (Refer to...) Figure 8 , Figure 8 When the distance between the middle baffle 4 and the substrate 100 is greater than 15 mm, a swirling vortex is generated in the area adjacent to the baffle 4. The generation of this swirling vortex will cause the flow velocity at the edge of the substrate 100 to increase, thereby affecting the drying uniformity of the liquid film at the edge and middle positions on the substrate 100.

[0054] Reference Figure 7 , Figure 7 The distance between the baffle 4 and the substrate 100 is 10mm~15mm. At this time, the gas between the baffle 4 and the substrate 100 flows uniformly and no vortex is generated, which can make the gas flow rate at the edge and middle of the substrate 100 uniform, thereby improving the drying uniformity of the liquid film at the edge and middle of the substrate 100.

[0055] Furthermore, when the distance D1 between the baffle 4 and the substrate 100 is set to 10mm~15mm, the installation of the substrate 100 is more convenient, and the baffle 4 has virtually no impact on the coating effect of the liquid film. The airflow outside the baffle 4, after flowing above the baffle 4, cannot circulate within a distance of 10mm~15mm to bypass the edge of the liquid film, thus preventing the airflow outside the baffle 4 from affecting the edge position of the substrate 100. The distance between the baffle 4 and the substrate 100 can be the same at different positions, or the distance can be different at different positions.

[0056] The height of the baffle 4 needs to be greater than the thickness of the substrate 100 to ensure that the highest point of the baffle 4 can be higher than the substrate 100. At this time, the airflow outside the baffle 4 (the airflow in the second disturbance region 421) is guided by the baffle 4 and flows vertically to the top of the substrate 100, thereby preventing the airflow outside the baffle 4 from affecting the liquid film on the substrate 100. However, when the height of the baffle 4 is high, the high baffle 4 will affect the placement of the substrate 100.

[0057] When the baffle 4 is high enough to contact the rectifier plate 22, the connection between the baffle 4 and the support platform 3, and the connection between the baffle 4 and the rectifier plate 22, need to be sealed. Furthermore, to facilitate the placement and removal of the substrate 100, the baffle 4 needs to be separable from at least one of the support platform 3 and the rectifier plate 22. Additionally, the baffle 4 separates the space inside containing the substrate 100 from the space outside the baffle 4. Since the space inside the baffle 4 is occupied by the substrate 100, the support platform 3, etc., while the space outside the baffle 4 is relatively empty, and the rectifier holes 221 of the rectifier plate 22 are mainly corresponding to the substrate 100, the number of rectifier holes 221 corresponding to the space outside the baffle 4 is relatively small. This may result in inconsistent air extraction rates inside and outside the baffle 4, leading to a pressure difference between the inside and outside of the baffle 4.

[0058] When the baffle 4 and the rectifier plate 22 are sealed in a separable manner, if gas outside the baffle 4 fails to seal at the connection between the baffle 4 and the rectifier plate 22 and flows laterally into the baffle 4, this laterally flowing airflow will interfere with the vertical suction effect of the gas inside the baffle 4, thereby affecting the vacuum drying effect of the substrate 100. When the baffle 4 and the support platform 3 are sealed in a separable manner, if gas outside the baffle 4 flows laterally into the baffle 4 due to a seal failure between the baffle 4 and the support platform 3, this laterally flowing airflow will directly blow towards and affect the substrate 100, thereby affecting the vacuum drying effect of the liquid film on the substrate 100. That is, when the height of the baffle 4 is relatively high and extends to contact the rectifier plate 22, it will place higher demands on the sealing performance and introduce the risk of seal failure affecting the vacuum drying effect of the liquid film.

[0059] In some specific embodiments, to facilitate the installation of the substrate 100, the height of the baffle 4 can be set to be 5mm to 10mm higher than the upper surface of the liquid film on the substrate 100, that is, the protrusion length D2 of the baffle 4 protruding from the upper surface of the liquid film on the substrate is 5mm to 10mm. In this case, the baffle 4 can effectively block the influence of the external airflow on the edge position of the liquid film, and the lower height of the baffle 4 can also facilitate the placement of the substrate 100. At the same time, the baffle 4 does not separate the inner and outer spaces, ensuring that the pressure in all parts of the receiving chamber 11 is basically the same. The sealing structure at the baffle 4 does not need to be affected by the pressure difference between the inside and outside, which can reduce the requirements of the sealing structure and avoid the risk of sealing failure affecting the vacuum drying effect of the liquid film. As a preferred embodiment, the baffle 4 can be integrally formed with the support platform 3, and no sealing structure needs to be set between the baffle 4 and the support platform 3.

[0060] When the airflow in the second disturbance region 421 flows obliquely upwards, there will be a certain amount of horizontal movement after the airflow reaches above the baffle 4. If the baffle 4 is thin, a small amount of airflow may cross the baffle 4 and move downwards, potentially affecting the edge region of the liquid film. However, if the baffle 4 is thick, it will result in a larger volume, making it inconvenient to install and increasing the cost. To further prevent the airflow in the second disturbance region 421 from affecting the edge region of the liquid film and to facilitate the installation of the baffle 4, the thickness D3 of the baffle 4 can be set to 8mm~12mm. In this case, the gas flowing horizontally above the baffle 4 will be restricted by the baffle 4. Within the 8mm~12mm path restricted by the baffle 4, the airflow will continuously be subjected to suction force from above. Therefore, the airflow is unlikely to have a downward flow area after flowing horizontally for 8mm~12mm, effectively preventing the airflow from affecting the edge region of the liquid film.

[0061] When the substrate 100 is mounted on the support stage 3, heat transfer occurs between the substrate 100 and the support stage 3, and the heat from the substrate 100 is dissipated to the outside through the support stage 3. The heat dissipation area at the edge of the support stage 3 is significantly larger than that at the center. This results in weaker heat dissipation at the center of the substrate 100, which is in contact with the center of the support stage 3, and stronger heat dissipation at the edge of the substrate 100, which is in contact with the edge of the support stage 3. This difference in heat dissipation leads to a temperature difference between the edge and the center of the substrate 100, which may reach 5~15℃. The temperature of the substrate 100 affects the saturated vapor pressure of the solvent and the solubility of the solute. The temperature difference between the edge and the center of the substrate 100 exacerbates the inconsistency between the crystallization conditions at the edge and the center of the liquid film.

[0062] Reference Figure 4 and Figure 5In some specific embodiments, to reduce the temperature difference between the edge and center of the substrate 100, a heat insulation ring 32 can be provided between the substrate 100 and the support stage 3. The heat insulation ring 32 is made of a material with low thermal conductivity, so that the thermal conductivity of the heat insulation ring 32 can be less than 2W / m·K. By using the heat insulation ring 32 to separate the substrate 100 and the support stage 3, the heat conduction path between the substrate 100 and the support stage 3 can be blocked, thereby preventing the temperature difference between the center and edge of the substrate 100 after the substrate 100 comes into thermal contact with the support stage 3. When the heat insulation ring 32 is provided, the heat of the substrate 100 will not be dissipated through the heat dissipation surface of the support stage 3. At this time, the heat dissipation effect is uniform throughout the substrate 100, thereby ensuring that the temperature of the substrate 100 is uniform throughout the substrate 100, and ensuring that the crystallization conditions of the liquid film on the substrate 100 are uniform throughout the substrate 100. The thickness of the heat insulation ring 32 can be set to 2~5mm.

[0063] In some specific embodiments, the support platform 3 may be provided with a recessed mounting groove 31, the depth of which may be the same as the depth of the heat insulation ring 32. The heat insulation ring 32 may be embedded in the mounting groove 31 of the support platform 3, so that the heat insulation ring 32 and the support platform 3 remain relatively fixed. The upper surface of the heat insulation ring 32 may be flush with the lowermost end of the baffle 4.

[0064] A recessed groove 321 may be provided on the heat insulation ring 32. This recessed groove 321 can be used to accommodate the substrate 100, so that the substrate 100 can be relatively fixed to the heat insulation ring 32. The heat insulation ring 32 may be made of a flexible material. When the substrate 100 is mounted in the recessed groove 321 of the heat insulation ring 32, the recessed groove 321 of the heat insulation ring 32 can be appropriately deformed to facilitate the mounting of the substrate 100 within the recessed groove 321. The depth of the recessed groove 321 is less than the thickness of the substrate 100, ensuring that after the substrate 100 is mounted in the recessed groove 321, the liquid film coated on the substrate 100 can protrude from the heat insulation ring 32.

[0065] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A vacuum flash film forming apparatus, characterized in that, include: The housing (1) has an internal cavity (11) for accommodating the substrate (100). An air extraction assembly (2) is disposed above the housing (1) and connected to the housing (1). The air extraction assembly (2) is used to extract the gas in the receiving chamber (11). A baffle (4) is disposed around the mounting position of the substrate (100). The highest end of the baffle (4) is higher than the substrate (100). The baffle (4) blocks the edge of the receiving chamber (11) from the mounting position of the substrate (100) in the horizontal direction.

2. The vacuum flash evaporation film-forming apparatus according to claim 1, characterized in that, The housing (1) is provided with a support platform (3) for supporting the substrate (100), and the baffle (4) is installed on the support platform (3); the baffle (4) and the support platform (3) are integrally formed or fixedly connected.

3. The vacuum flash film forming apparatus according to claim 2, characterized in that, The inner side of the baffle (4) forms an interval space (41) spaced from the substrate (100), and the outer side of the baffle (4) forms an edge space (42) spaced from the side wall of the housing (1). In the vertical direction, the interval space (41) includes a first disturbance region (411) extending from the upper surface of the support platform (3) to above the liquid film of the substrate (100), and the edge space (42) includes a second disturbance region (421) extending from the bottom wall of the housing (1) to above the liquid film of the substrate (100). The volume of the first disturbance region (411) is smaller than the volume of the second disturbance region (421). The airflow in the second disturbance region (421) is blocked by the baffle (4) and separated from the substrate (100).

4. The vacuum flash film forming apparatus according to claim 1, characterized in that, The baffle (4) is 5 mm to 10 mm above the upper surface of the liquid film on the substrate (100).

5. The vacuum flash evaporation film-forming apparatus according to claim 1, characterized in that, The horizontal distance D1 between the baffle (4) and the substrate (100) is 10mm~15mm.

6. The vacuum flash evaporation film-forming apparatus according to claim 1, characterized in that, The thickness D3 of the baffle (4) is 8mm~12mm.

7. The vacuum flash evaporation film-forming apparatus according to claim 1, characterized in that, The pumping assembly (2) includes a vacuum line (21) and a rectifier plate (22). The rectifier plate (22) is disposed above the substrate (100) and upstream of the vacuum line (21) along the gas flow direction. The rectifier plate (22) is provided with a plurality of uniformly distributed rectifier holes.

8. The vacuum flash evaporation film-forming apparatus according to claim 2, characterized in that, The support platform (3) is also provided with a heat insulation ring (32), which is made of heat insulation material and is disposed between the support platform (3) and the substrate (100) to block the heat transfer between the support platform (3) and the substrate (100).

9. The vacuum flash film-forming apparatus according to claim 8, characterized in that, The support platform (3) is provided with an installation groove (31), and the heat insulation ring (32) is embedded in the installation groove (31).

10. The vacuum flash film-forming apparatus according to claim 8, characterized in that, The heat insulation ring (32) is provided with a recessed groove (321), the recessed groove (321) is adapted to the substrate (100) and is used for mounting the substrate (100), and the depth of the recessed groove (321) is less than the thickness of the substrate (100).

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