Coating and drying device

Abstract

A coating and drying device, comprising a bearing base platform (1), a bearing substrate (2), a coating die head (3), a first air-knife drying assembly (5) and a blocking component (6). The first air-knife drying assembly (5) is configured to blow gas in a coating direction (X) from an initial coating position (P) of the substrate (2) to a coating material (4) that has been applied to the surface of the substrate (2), so as to thin the coating material (4) with a preset thickness. The blocking component (6) is arranged in the coating direction (X) between the first air-knife drying assembly (5) and the coating die head (3); the first surface of the blocking component (6) that faces the first air-knife drying assembly (5) is a curved surface; and the blocking component (6) is configured to block the excess coating material (4) blown by the first air-knife drying assembly (5) from gathering towards the side of the coating die head (3). The coating and drying device can reduce the area of uneven drying and improve the uniformity of a liquid film.

Description

A coating drying device

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410666619.X, filed on May 27, 2024, entitled "A Coating and Drying Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of display technology, and more particularly to a coating and drying apparatus. Background Technology

[0004] Organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs) have advantages such as self-illumination, low power consumption, and high color gamut, and have received widespread attention from academia and industry. The application prospects of OLEDs and QLEDs in the display field are becoming increasingly bright.

[0005] In OLED and QLED optoelectronic display devices, inkjet printing or other solution coating methods, such as spraying, blade coating, and plating, are typically used to form organic functional layer thin films. An essential step in these wet film deposition processes is the removal of excess solvent through subsequent processes, followed by drying to form the desired thin film. This solvent removal and drying process determines the morphology of the formed film. For optoelectronic display devices, poor morphology and uniformity of the dried film significantly impact device lifespan and display performance. Furthermore, in the display field, substrates are typically pixelated. On these patterned substrates, after coating using all-around coating techniques such as slot coating, a coffee ring effect is often observed within the pixels, resulting in poor morphology. Therefore, efficiently and reproducibly fabricating uniform film layers on pixelated substrates is a necessary prerequisite for the mass production of OLED and QLED devices. Summary of the Invention

[0006] This disclosure provides a coating and drying apparatus for forming a stable and uniform dried film. The specific solution is as follows:

[0007] This disclosure provides a coating and drying apparatus, comprising:

[0008] Support base, used to support the substrate;

[0009] A coating die head is disposed above the side of the substrate away from the support base. The coating die head is used to coat the surface of the substrate with a coating material of a preset thickness from the initial coating position of the substrate along the coating direction.

[0010] The first air knife drying assembly is disposed above the side of the substrate away from the support base. The first air knife drying assembly is used to blow gas from the initial coating position of the substrate along the coating direction to the coating material already coated on the surface of the substrate to reduce the coating material of the preset thickness.

[0011] A blocking component is disposed above the side of the substrate away from the support base. The blocking component is disposed between the first air knife drying assembly and the coating die head along the coating direction. The first surface of the blocking component facing the first air knife drying assembly is curved. The blocking component is used to prevent excess coating material blown by the first air knife drying assembly from accumulating on the side of the coating die head.

[0012] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the bottom edge of the first surface of the blocking member near the substrate is arranged parallel to the air outlet of the first air knife drying assembly, and the width of the blocking member perpendicular to the coating direction is the same as the width of the first air knife drying assembly perpendicular to the coating direction.

[0013] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the included angle between the first surface of the blocking member and the bottom surface of the blocking member is less than 10°.

[0014] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the distance between the end of the first surface closest to the substrate and the bottom surface of the blocking member is less than 50 μm.

[0015] Optionally, the coating and drying apparatus provided in the embodiments of this disclosure further includes an exhaust assembly fixed to the first surface of the blocking member, the exhaust assembly being used to remove the gas blown onto the first surface and the excess coating material.

[0016] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the exhaust assembly has an overall curved structure, and the second side of the exhaust assembly near the blocking member is in contact with the first side of the blocking member.

[0017] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the exhaust assembly includes: an air inlet near the substrate, an air outlet opposite to the air inlet, and an exhaust channel for connecting the air inlet and the air outlet; wherein,

[0018] The distance between the air inlet and the substrate is greater than the distance between the bottom surface of the blocking member near the substrate and the substrate.

[0019] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the gap height between the bottom surface of the blocking member near the substrate and the surface of the coating material of the preset thickness is 20μm to 100μm.

[0020] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the distance between the air outlet of the first air knife drying component and the substrate is greater than the distance between the material outlet of the coating die head and the substrate, and the distance between the material outlet of the coating die head and the substrate is greater than the distance between the bottom surface of the blocking member near the substrate and the substrate.

[0021] Optionally, the coating and drying apparatus provided in the embodiments of this disclosure further includes a movable component that can move along the coating direction. The first air knife drying component, the exhaust component, the blocking component, and the coating die head are all connected to the movable component, and the first air knife drying component, the exhaust component, the blocking component, and the coating die head all move along the coating direction through the movable component.

[0022] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the distance between the first air knife drying assembly and the blocking component is adjustable, and the distance between the blocking component and the substrate is adjustable.

[0023] Optionally, the coating drying apparatus provided in the embodiments of this disclosure further includes a second air knife drying assembly disposed on the side of the first air knife drying assembly away from the coating die head. The second air knife drying assembly is used to blow gas onto the thinned coating material, and the speed at which the second air knife drying assembly blows gas is less than the speed at which the first air knife drying assembly blows gas.

[0024] Optionally, the coating and drying apparatus provided in the embodiments of this disclosure further includes a third air knife drying component disposed on the side of the second air knife drying component away from the coating die head, wherein the directions of the gas blown out by the first air knife drying component, the direction of the gas blown out by the second air knife drying component, and the direction of the gas blown out by the third air knife drying component are all different.

[0025] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the first angle between the direction of the gas blown out by the first air knife drying component and the coating direction, the second angle between the direction of the gas blown out by the second air knife drying component and the coating direction, and the third angle between the direction of the gas blown out by the third air knife drying component and the coating direction are all obtuse angles.

[0026] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the first angle between the direction of the gas blown out by the first air knife drying component and the coating direction, the second angle between the direction of the gas blown out by the second air knife drying component and the coating direction, and the third angle between the direction of the gas blown out by the third air knife drying component and the coating direction gradually increase.

[0027] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the first angle between the direction of the gas blown out by the first air knife drying component and the coating direction, the second angle between the direction of the gas blown out by the second air knife drying component and the coating direction are both obtuse angles, and the third angle between the direction of the gas blown out by the third air knife drying component and the coating direction is an acute angle.

[0028] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the direction of the gas blown out by the second air knife drying component is perpendicular to the direction of the gas blown out by the third air knife drying component.

[0029] Optionally, in the coating and drying apparatus provided in the embodiments of this disclosure, the first air knife drying component adopts a continuous blowing method, and the second air knife drying component and the third air knife drying component adopt a pulse blowing method. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the structure of a coating and drying apparatus provided in an embodiment of the present disclosure at a certain angle;

[0031] Figure 2 is a schematic diagram of the structure of a coating and drying apparatus provided in an embodiment of the present disclosure at a certain angle;

[0032] Figure 3 is a schematic diagram of the structure of a coating and drying apparatus provided in an embodiment of this disclosure from another angle;

[0033] Figure 4 is a schematic diagram of the blocking component in Figure 3;

[0034] Figure 5 is a schematic diagram of the side view (F2S2S3F5F3) in Figure 4;

[0035] Figure 6 is an enlarged view of the area within the dashed box in Figure 5;

[0036] Figure 7A is a schematic diagram of the simulated airflow field distribution on the substrate surface when no obstruction is placed between the first air knife drying assembly and the coating die head;

[0037] Figure 7B is a schematic diagram of the simulated airflow field distribution on the substrate surface when a blocking component is set between the first air knife drying assembly and the coating die head;

[0038] Figure 8 is a schematic diagram of the structure of another coating and drying apparatus provided in an embodiment of the present disclosure at a certain angle;

[0039] Figure 9 is a three-dimensional structural diagram of the blocking component 6 and the exhaust assembly 7 in Figure 8;

[0040] Figure 10A is a schematic diagram of the simulated airflow field distribution on the substrate surface when a blocking component and an exhaust component are set between the first air knife drying assembly and the coating die head;

[0041] Figure 10B is a schematic diagram of the simulated airflow field distribution on the substrate surface when a blocking component and an exhaust component are set between the first air knife drying assembly and the coating die head.

[0042] Figure 11 is a schematic diagram of the structure of another coating and drying apparatus provided in an embodiment of the present disclosure at a certain angle;

[0043] Figure 12 is a schematic diagram of the structure of another coating and drying apparatus provided in an embodiment of the present disclosure at a certain angle;

[0044] Figure 13 is a schematic diagram of the structure of another coating and drying apparatus provided in the embodiments of this disclosure at a certain angle. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0046] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "comprising" or "including," and similar terms as used in this disclosure, mean that an element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "inner," "outer," "upper," and "lower" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0047] As used in this disclosure, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0048] As used in this disclosure, "parallel," "perpendicular," and "equal" include the described situation and situations that are similar to the described situation, within an acceptable deviation range, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein an acceptable deviation range for approximate parallelism may be, for example, within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein an acceptable deviation range for approximate perpendicularity may also be, for example, within 5°. "Equal" includes absolute equality and approximate equality, wherein an acceptable deviation range for approximate equality may be, for example, a difference between the two equals being less than or equal to 10% of either one.

[0049] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0050] This disclosure describes exemplary embodiments with reference to cross-sectional views and / or plan views as idealized exemplary drawings. In the drawings, for clarity, the thickness of layers and the area of ​​regions are enlarged. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0051] In this disclosure, circles, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined, but can be approximate circles, triangles, rectangles, trapezoids, pentagons, or hexagons. Small deformations due to tolerances may exist, and chamfers, curved edges, and other deformations may exist.

[0052] In related technologies, the drying process after large-area coating of liquid film generally employs the air knife blowing method. The conventional air knife blowing method accelerates the evaporation of the liquid film solvent by blowing air, forming an orderly and well-formed thin film while evaporating rapidly.

[0053] Air knife drying methods for liquid films generally include simultaneous coating and air drying, and coating followed by air drying. However, in the simultaneous coating and air drying method, the cumulative effect of air blowing on the liquid film between the air knife and the coating die is gradual, which may lead to different drying morphologies in different parts of the liquid film. When coating followed by air drying, the liquid film at the end of the drying process is subject to the longest cumulative air blowing time from the air knife, resulting in the longest combined time for natural evaporation and drying. This can also easily lead to inconsistencies in morphology and thickness between the liquid film and the middle part of the substrate.

[0054] Depending on the characteristics of the substrates used in the OLED / QLED display field (with micron-level pixelation structure), film thickness (requiring film thickness below 100 nanometers), and technical requirements (the dried film within the pixel must be sufficiently flat, and the area of ​​the portion with undulations less than 10nm usually needs to account for more than 80%), special processes must be used for liquid film drying to achieve uniform film thickness after drying.

[0055] In view of this, in order to achieve a uniformly thick film after liquid film coating, this disclosure provides a coating drying apparatus, as shown in Figures 1-3. Figures 1 and 2 are schematic diagrams of the coating drying apparatus from one angle, and Figure 3 is a schematic diagram of the coating drying apparatus from another angle. The coating drying apparatus includes:

[0056] Supporting base 1, used to support substrate 2;

[0057] The coating die 3 is disposed above the side of the substrate 2 away from the support base 1. The coating die 3 is used to coat the surface of the substrate 2 with a coating material 4 of a preset thickness from the initial coating position P of the substrate 2 along the coating direction X.

[0058] The first air knife drying assembly 5 is disposed above the side of the substrate 2 away from the support base 1. The first air knife drying assembly 5 is used to blow gas from the initial coating position P of the substrate 2 along the coating direction X toward the coating material 4 already coated on the surface of the substrate 2 to reduce the coating material 4 of a preset thickness.

[0059] The blocking component 6 is disposed above the side of the substrate 2 away from the support base 1. The blocking component 6 is disposed between the first air knife drying assembly 5 and the coating die head 3 along the coating direction X. The first surface (F1F2F3F4, i.e. the windward surface) of the blocking component 6 facing the first air knife drying assembly 5 is curved. The blocking component 6 is used to prevent the excess coating material 4 blown by the first air knife drying assembly 5 from accumulating on the side of the coating die head 3.

[0060] The coating drying apparatus provided in this embodiment not only accelerates the airflow across the surface of the coating material 4 (hereinafter referred to as the liquid film) to cause solvent evaporation, but also reduces (or "shears") the thickness of the liquid film. For example, if the initial thickness of the coating material 4 is H1, the thickness of the coating material 4 after being reduced by the blown gas is H2. That is, the air blown from the first air knife drying assembly 5 must be strong enough to push the liquid on the surface of the substrate 2 using the air knife blade, thereby achieving the purpose of thinning and controlling the uniformity of the liquid film thickness. However, liquid in the coated areas is pushed towards the uncoated areas. The process of liquid film accumulation in the uncoated area causes inconsistencies in the initial liquid film thickness across different areas. Therefore, this disclosure adds a blocking component 6 between the first air knife drying assembly 5 and the coating die 3. This blocking component 6 can, on the one hand, prevent excess liquid 40 blown by the first air knife drying assembly 5 from continuously accumulating towards the coating die 3, thus increasing the unevenness of the liquid film and avoiding the problem of inconsistent initial liquid film thickness across different areas of the uncoated area. On the other hand, the blocking component 6 can also improve the problem of uneven film thickness caused by inconsistent cumulative time of airflow blowing on the liquid film in different areas between the first air knife drying assembly 5 and the coating die 3. Therefore, the coating drying apparatus provided in this embodiment can dry and form a stable and uniform film.

[0061] Specifically, as shown in Figure 1, the blocking component 6 divides the area between the coating die head 3 and the first air knife drying assembly 5 into area A and area B. Area B is no longer affected by the gas blown out by the first air knife drying assembly 5 due to the blocking effect of the blocking component 6, thus blocking the continuous drying effect of the air force (especially the horizontal component) of the first air knife drying assembly 5 on the liquid film in area B. Furthermore, by controlling the size of area A, the area of ​​uneven drying can be reduced.

[0062] In some embodiments, in the coating and drying apparatus provided in the present disclosure, as shown in FIG4, FIG4 is a structural schematic diagram of the blocking member 6 in FIG3. In this disclosure, the first surface (F1F2F3F4) of the blocking member 6 facing the first air knife drying assembly 5 is set as a curved surface. This is beneficial to reduce the vortex-like phenomenon caused by the blocking effect on the first surface (F1F2F3F4) of the gas blown out by the first air knife drying assembly 5, thereby avoiding uneven film formation on the surface of the substrate 2. The curvature of the curved surface can be designed by simulation calculation according to actual needs.

[0063] In some embodiments, in the coating and drying apparatus provided in this disclosure, as shown in FIG3, the bottom edge (F1F2) of the first surface (F1F2F3F4) of the blocking member 6 near the substrate 2 is arranged parallel to the air outlet 51 of the first air knife drying assembly 5, and the width L1 of the blocking member 6 perpendicular to the coating direction X is the same as the width L2 of the first air knife drying assembly 5 perpendicular to the coating direction X. In this way, excess liquid blown by the first air knife drying assembly 5 can be almost completely blocked by the blocking member 6, preventing it from accumulating on the coating die head 3 side.

[0064] In some embodiments of the coating and drying apparatus provided in this disclosure, as shown in FIG4, the blocking member 6 has a flat bottom surface. For example, the flatness fluctuation of the lines (S1S2, S2S3, S3S4, S4S1) and the bottom surface (S1S2S3S4) is less than 5μm. This can ensure that the flatness fluctuation of the liquid film surface after drying is less than 5μm, thereby improving the uniformity of the liquid film.

[0065] In some embodiments, in the coating and drying apparatus provided in this disclosure, as shown in Figures 4 and 5, Figure 5 is a schematic diagram of the side surface (F2S2S3F5F3) in Figure 4. The angle θ between the first surface (F1F2F3F4) of the blocking member 6 and the bottom surface (S1S2S3S4) of the blocking member 6 (i.e. the angle between the side surface F2F3 and the bottom surface S2S3) is less than 10°. This can further reduce the vortex-like phenomenon caused by the blocking effect on the first surface (F1F2F3F4) of the gas blown out by the first air knife drying assembly 5.

[0066] In some embodiments, in the coating and drying apparatus provided in the present disclosure, as shown in Figures 3-6, Figure 6 is an enlarged schematic diagram within the dashed frame in Figure 5. The distance h (i.e., the height of F2S2) between the end of the first surface (F1F2F3F4) closest to the substrate 2 (i.e., the bottom edge F1F2) and the bottom surface (S1S2S3S4) of the blocking member 6 is less than 50 μm. This ensures that the edges of F1-F2 are thin enough, further reducing the vortex-like phenomenon caused by the blocking effect on the first surface (F1F2F3F4) by the gas blown out by the first air knife drying assembly 5.

[0067] As shown in Figures 7A and 7B, Figure 7A is a simulation diagram of the airflow field distribution on the surface of substrate 2 when no obstruction component 6 is placed between the first air knife drying assembly 5 and the coating die 3. Figure 7B is a simulation diagram of the airflow field distribution on the surface of substrate 2 when the obstruction component 6 is placed between the first air knife drying assembly 5 and the coating die 3. The vertical axis represents height, and the color depth represents flow velocity. The redder the color (C1 area) represents a higher flow velocity, and the bluer the color (C2 area) represents a lower velocity. It can be seen that without the obstruction component 6, the gas blown by the first air knife drying assembly 5 across the entire coating film surface (horizontally) has a high flow velocity, which means rapid evaporation of the film surface. However, when the obstruction component 6 is added, the wind speed on the side of the obstruction component 6 facing away from the first air knife drying assembly 5 decreases, and the first surface (F1F2F3F4, i.e., the windward side) of the obstruction component 6 will generate vortices under higher wind speeds. These vortices will cause uneven film formation on the surface of substrate 2. Furthermore, when there is a large amount of excess coating material, it is very likely that the coating material will flow back, causing liquid to accumulate on the surface of the substrate 2 below the blocking component 6.

[0068] To address the issues of vortex formation and backflow of excess coating material on the windward side of the blocking component 6, as shown in FIG8, the coating drying apparatus provided in this embodiment further includes an exhaust assembly 7 fixed on the first surface (F1F2F3F4, i.e., the windward side) of the blocking component 6. The exhaust assembly 7 is used to remove gas and excess coating material blown onto the first surface (F1F2F3F4). This exhaust assembly 7 can quickly remove gas blown onto the windward side from the system, reducing the probability of vortex formation and thus helping to maintain stable airflow on the substrate 2 surface, improving film uniformity.

[0069] In some embodiments, in the coating and drying apparatus provided in this disclosure, as shown in Figures 8 and 9, Figure 9 is a three-dimensional structural schematic diagram of the blocking component 6 and the exhaust assembly 7 in Figure 8. The exhaust assembly 7 has a curved surface structure, and the second surface 71 of the exhaust assembly 7 near the blocking component 6 is in contact with the first surface (F1F2F3F4) of the blocking component 6. This can almost completely remove excess coating material blown onto the windward surface of the blocking component 6 from the system, avoiding incomplete adhesion between the second surface 71 and the windward surface, which could cause gas to flow back to the surface of the substrate 2.

[0070] In some embodiments, in the coating and drying apparatus provided in this disclosure, as shown in Figures 8 and 9, the exhaust assembly 7 includes: an air inlet 72 near the substrate 2, an air outlet 73 opposite to the air inlet 72, and an exhaust channel (within the exhaust assembly 7) for connecting the air inlet 72 and the air outlet 73; wherein,

[0071] The distance between the air inlet 72 and the substrate 2 is greater than the distance between the bottom surface (S1S2S3S4) of the blocking member 6 near the substrate 2 and the substrate 2. In this way, the excess coating material 4 first climbs to the lower end of the windward side of the blocking member 6 (i.e. the lower end that is not in contact with the exhaust assembly 7), and then is discharged out of the system through the exhaust assembly 7.

[0072] In some embodiments, in the coating and drying apparatus provided in the present disclosure, as shown in Figures 8 and 9, the suction force and rate of the exhaust port 73 of the exhaust assembly 7 can be optimized and adapted to the gas content blown out by the first air knife drying assembly 5. That is, when the gas blowing rate of the first air knife drying assembly 5 is large (its air volume component on the liquid film surface will also increase), the exhaust rate of the exhaust port 73 of the exhaust assembly 7 should also be appropriately increased.

[0073] In some embodiments, in the coating and drying apparatus provided in this disclosure, as shown in Figures 1 and 8, the distance D1 between the air outlet of the first air knife drying assembly 5 and the substrate 2 is greater than the distance D2 between the discharge port of the coating die 3 and the substrate 2, and the distance D2 between the discharge port of the coating die 3 and the substrate 2 is greater than the distance D3 between the bottom surface of the blocking member 6 near the substrate 2 and the substrate 2. This ensures that excess liquid blown by the first air knife drying assembly 5 can be blocked by the blocking member 6 and discharged out of the system by the exhaust assembly 7.

[0074] In some embodiments, the coating and drying apparatus provided in this disclosure, as shown in Figures 1 and 8, further includes a movable component (not shown) that can move along the coating direction X. The first air knife drying component 5, the exhaust component 7, the blocking component 6, and the coating die 3 are all connected to the movable component, and the first air knife drying component 5, the exhaust component 7, the blocking component 6, and the coating die 3 all move along the coating direction X via the movable component. In this way, the distance between the first air knife drying component 5 and the blocking component 6, and the distance between the blocking component 6 and the substrate 2 can be dynamically adjusted. Therefore, during the coating process of the coating die 3, the distance between the first air knife drying component 5 and the blocking component 6, and the distance between the blocking component 6 and the substrate 2 can be adjusted in real time to obtain a stable and uniform liquid film.

[0075] As shown in Figures 10A and 10B, both are simulation diagrams of the airflow field distribution on the surface of the substrate 2 when a blocking component 6 and an exhaust component 7 are set between the first air knife drying assembly 5 and the coating die head 3. The difference between Figures 10A and 10B is that the distance between the bottom surface of the blocking component 6 and the substrate 2 in Figure 10A is greater than that in Figure 10B. The vertical axis represents height, and the color depth represents flow velocity; the redder the color (C1 area), the higher the flow velocity, and the bluer the color (C2 area), the lower the velocity. It can be seen that, compared to Figure 7B without the exhaust component 7, the vortex on the windward side of the blocking component 6 in Figures 10A and 10B disappears. Comparing Figures 7B, 10A, and 10B, it can be seen that as the gap height between the bottom surface of the blocking member 6 near the substrate 2 and the surface of the coating material 4 gradually decreases (e.g., 1mm → 0.5mm → 0.05mm), the airflow velocity on the surface of the coating material 4 below the side of the blocking member 6 facing away from the coating die 3 gradually decreases, and the thickness of the high-velocity layer below the bottom surface of the blocking member 6 also gradually decreases. When the gap is as small as 0.05mm as shown in Figure 10B, it essentially completely blocks the high-velocity gas from passing below the bottom surface of the blocking member 6. Therefore, by employing the coordinated action of the blocking member 6 and the exhaust assembly 7, and by reasonably setting the gap G height between the bottom surface of the blocking member 6 near the substrate 2 and the surface of the coating material 4 of a preset thickness, a stable and uniform liquid film can be obtained in this embodiment.

[0076] In some embodiments, in the coating and drying apparatus provided in the present disclosure, as shown in Figures 1 and 8, the gap G height between the bottom surface of the blocking member 6 near the substrate 2 and the surface of the coating material 4 of a preset thickness can be 20 μm to 100 μm.

[0077] In some embodiments, the coating drying apparatus provided in this disclosure, as shown in 11, further includes a second air knife drying component 8 disposed on the side of the first air knife drying component 5 away from the coating die head 3. The second air knife drying component 8 is used to blow gas onto the thinned coating material 4, and the speed at which the second air knife drying component 8 blows gas is less than the speed at which the first air knife drying component 5 blows gas. In this way, the first air knife drying component 5 uses strong air blowing to thin the initially coated coating material 4, so that the thinned coating material 4 no longer has macroscopic fluidity. However, in the actual drying process, the liquid evaporation rate may be slow, and it may not be able to dry completely in one air blowing. Therefore, the second air knife drying component 8 is used to blow dry the thinned coating material 4. By providing a continuous airflow, the liquid can evaporate quickly. In this way, for film formation on the pixelated substrate, the horizontal shear component of the wind can suppress the various coffee ring effects of the liquid in the pixels on the pixelated substrate, thereby improving the film uniformity on the pixelated substrate.

[0078] In some embodiments, the coating and drying apparatus provided in this disclosure, as shown in Figures 12 and 13, further includes a third air knife drying assembly 9 disposed on the side of the second air knife drying assembly 8 away from the coating die head 3. The directions of the gas blown out by the first air knife drying assembly 5 (Y1), the second air knife drying assembly 8 (Y2), and the third air knife drying assembly 9 (Y3) are all different. This addresses the issue of film formation on pixelated substrates, where the substrate has a pixelated surface with micron-level height undulations. Liquid on this surface is prone to forming coffee rings due to pinning forces. This disclosure improves upon this by employing multi-stage air knife drying assemblies, such as the first air knife drying assembly 5, the second air knife drying assembly 8, and the third air knife drying assembly 9. Each air knife drying assembly blows out gas in a different direction, allowing the airflow direction to correspond to the undulations of the substrate surface, thereby preventing the formation of coffee rings on the liquid surface.

[0079] In some embodiments, in the coating and drying apparatus provided in the present disclosure, as shown in 12, the first angle β1 between the direction Y1 of the gas blown out by the first air knife drying component 5 and the coating direction X, the second angle β2 between the direction Y2 of the gas blown out by the second air knife drying component 8 and the coating direction X, and the third angle β3 between the direction Y3 of the gas blown out by the third air knife drying component 9 and the coating direction X can all be obtuse angles.

[0080] In some embodiments, in the coating and drying apparatus provided in this disclosure, as shown in 12, the first angle β1 between the direction Y1 of the gas blown out by the first air knife drying component 5 and the coating direction X, the second angle β2 between the direction Y2 of the gas blown out by the second air knife drying component 8 and the coating direction X, and the third angle β3 between the direction Y3 of the gas blown out by the third air knife drying component 9 and the coating direction X gradually increase. In this way, a stable and uniform thin film without coffee rings can be obtained while drying the liquid film.

[0081] In some embodiments, due to the unevenness and surface pinning of the pixelated substrate, the coating liquid is prone to edge climbing and coffee ring effect during the drying process. When the air knife drying component is used for air drying, the continuous unidirectional force in the later stage of drying can easily cause the film morphology at the edge of the pixel defining layer of the pixelated substrate to be asymmetrical. Therefore, in the coating drying apparatus provided in the embodiments of this disclosure, as shown in 13, the first angle β1 between the direction Y1 of the gas blown out by the first air knife drying component 5 and the coating direction X, and the second angle β2 between the direction Y2 of the gas blown out by the second air knife drying component 8 and the coating direction X are both obtuse angles, while the third angle β3 between the direction Y3 of the gas blown out by the third air knife drying component 9 and the coating direction X is an acute angle. By changing the direction Y3 of the gas blown out by the third air knife drying component 9 to an acute angle with the coating direction X, which is opposite to the air outlet direction of the second air knife drying component 8, the film surface bias phenomenon caused by the unidirectional air blowing of the second air knife drying component 8 can be improved, making the film morphology at the edge of the pixel defining layer of the pixelated substrate symmetrical.

[0082] In some embodiments, in the coating and drying apparatus provided in the present disclosure, as shown in 13, the direction Y2 of the gas blown out by the second air knife drying component 8 is perpendicular to the direction Y3 of the gas blown out by the third air knife drying component 9, which can further improve the film morphology and make the film surface uniform.

[0083] It should be noted that the "vertical" mentioned above refers to approximate verticality. Due to manufacturing processes, there may be some deviation, which may be slightly less than 90° or slightly greater than 90°.

[0084] In some embodiments, as shown in FIG1, FIG8, FIG11-FIG13, the first air knife drying component 5 adopts a continuous blowing method, the main purpose of which is to reduce the thickness of the coating material.

[0085] In some embodiments, as shown in Figures 12 and 13, the second air knife drying assembly 8 and the third air knife drying assembly 9 adopt a pulsed blowing method, which can increase the counterforce between the wind force and surface tension and other coffee ring forming factors, thereby improving the film morphology.

[0086] It should be noted that Figures 12 and 13 of this embodiment use three air knife drying components as an example, but it is not limited to this. There can also be four or more air knife drying components, depending on actual needs and cost requirements.

[0087] This disclosure provides a coating drying apparatus in which the gas blown by the first air knife drying component not only accelerates the airflow across the surface of the coating material (hereinafter referred to as the liquid film) to evaporate the solvent, but also reduces (or "shears") the thickness of the liquid film. Specifically, the air blown from the first air knife drying component must be sufficiently strong to push the liquid on the substrate surface using the air knife blade, thereby thinning and controlling the uniformity of the liquid film thickness. However, there is a process where liquid in the coated areas is pushed towards the uncoated areas and continuously accumulates, causing inconsistent initial liquid film thicknesses in the uncoated areas. Therefore, this disclosure adds a blocking component between the first air knife drying component and the coating die. This blocking component, on the one hand, prevents excess liquid blown by the first air knife drying component from continuously accumulating towards the coating die side, thus increasing the unevenness of the liquid film and avoiding the problem of inconsistent initial liquid film thicknesses in the uncoated areas. On the other hand, the blocking component also improves the problem of uneven film uniformity caused by inconsistent cumulative airflow time affecting the liquid film in the area between the first air knife drying component and the coating die. Therefore, the coating drying apparatus provided in this disclosure can dry and form a stable and uniform film.

[0088] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A coating and drying apparatus, wherein, include: Support base, used to support the substrate; A coating die head is disposed above the side of the substrate away from the support base. The coating die head is used to coat the surface of the substrate with a coating material of a preset thickness from the initial coating position of the substrate along the coating direction. The first air knife drying assembly is disposed above the side of the substrate away from the support base. The first air knife drying assembly is used to blow gas from the initial coating position of the substrate along the coating direction to the coating material already coated on the surface of the substrate to reduce the coating material of the preset thickness. A blocking component is disposed above the side of the substrate away from the support base. The blocking component is disposed between the first air knife drying assembly and the coating die head along the coating direction. The first surface of the blocking component facing the first air knife drying assembly is curved. The blocking component is used to prevent excess coating material blown by the first air knife drying assembly from accumulating on the side of the coating die head.

2. The coating and drying apparatus as described in claim 1, wherein, The bottom edge of the first surface of the blocking member near the substrate is arranged parallel to the air outlet of the first air knife drying assembly, and the width of the blocking member perpendicular to the coating direction is the same as the width of the first air knife drying assembly perpendicular to the coating direction.

3. The coating and drying apparatus as described in claim 1, wherein, The angle between the first surface of the blocking component and the bottom surface of the blocking component is less than 10°.

4. The coating and drying apparatus as described in claim 1, wherein, The distance between the end of the first surface closest to the substrate and the bottom surface of the blocking member is less than 50 μm.

5. The coating and drying apparatus according to any one of claims 1-4, wherein, It also includes an exhaust assembly fixed to the first surface of the blocking member, the exhaust assembly being used to expel gas blown onto the first surface and the excess coating material.

6. The coating and drying apparatus as described in claim 5, wherein, The exhaust assembly has a curved surface structure, and the second side of the exhaust assembly near the blocking component is in contact with the first side of the blocking component.

7. The coating and drying apparatus as described in claim 6, wherein, The exhaust assembly includes: an air inlet near the side of the substrate, an air outlet opposite to the air inlet, and an exhaust channel for connecting the air inlet and the air outlet; wherein, The distance between the air inlet and the substrate is greater than the distance between the bottom surface of the blocking member near the substrate and the substrate.

8. The coating and drying apparatus as described in claim 7, wherein, The gap height between the bottom surface of the blocking component near the substrate and the surface of the coating material of the preset thickness is 20μm to 100μm.

9. The coating and drying apparatus according to any one of claims 1-8, wherein, The distance between the air outlet of the first air knife drying assembly and the substrate is greater than the distance between the material outlet of the coating die head and the substrate, and the distance between the material outlet of the coating die head and the substrate is greater than the distance between the bottom surface of the blocking member near the substrate and the substrate.

10. The coating and drying apparatus according to any one of claims 5-8, wherein, It also includes a movable component that can move along the coating direction. The first air knife drying component, the exhaust component, the blocking component, and the coating die head are all connected to the movable component. The first air knife drying component, the exhaust component, the blocking component, and the coating die head can all move along the coating direction via the movable component.

11. The coating and drying apparatus as claimed in claim 10, wherein, The distance between the first air knife drying assembly and the blocking component is adjustable, and the distance between the blocking component and the substrate is adjustable.

12. The coating and drying apparatus according to any one of claims 1-11, wherein, It also includes a second air knife drying assembly disposed on the side of the first air knife drying assembly away from the coating die head. The second air knife drying assembly is used to blow gas onto the thinned coating material. The speed at which the gas is blown out by the second air knife drying assembly is less than the speed at which the gas is blown out by the first air knife drying assembly.

13. The coating and drying apparatus as described in claim 12, wherein, It also includes a third air knife drying assembly disposed on the side of the second air knife drying assembly away from the coating die head, wherein the directions of the gas blown out by the first air knife drying assembly, the second air knife drying assembly, and the third air knife drying assembly are all different.

14. The coating and drying apparatus as described in claim 13, wherein, The first angle between the direction of the gas blown out by the first air knife drying component and the coating direction, the second angle between the direction of the gas blown out by the second air knife drying component and the coating direction, and the third angle between the direction of the gas blown out by the third air knife drying component and the coating direction are all obtuse angles.

15. The coating and drying apparatus as described in claim 14, wherein, The first angle between the direction of the gas blown out by the first air knife drying component and the coating direction, the second angle between the direction of the gas blown out by the second air knife drying component and the coating direction, and the third angle between the direction of the gas blown out by the third air knife drying component and the coating direction gradually increase.

16. The coating and drying apparatus as claimed in claim 13, wherein, The first angle between the direction of the gas blown out by the first air knife drying component and the coating direction, the second angle between the direction of the gas blown out by the second air knife drying component and the coating direction are both obtuse angles, and the third angle between the direction of the gas blown out by the third air knife drying component and the coating direction is an acute angle.

17. The coating and drying apparatus as claimed in claim 16, wherein, The direction of the gas blown out by the second air knife drying component is perpendicular to the direction of the gas blown out by the third air knife drying component.

18. The coating and drying apparatus according to any one of claims 13-17, wherein, The first air knife drying assembly uses a continuous blowing method, while the second and third air knife drying assemblies use a pulse blowing method.

Images