Coating die head for slit coating equipment

Abstract

The utility model belongs to the technical field of solution method film deposition equipment, in particular to a coating die head for slit coating equipment, which is characterized in that a first die head, a gasket and a second die head are connected in sequence, the lower end of the gasket is provided with a notch, and a coating lip is formed between the lower ends of the first die head and the second die head; the face, facing the gasket, of the first die head is a liquid outlet end, a liquid storage groove and a liquid outlet channel are formed in the first die head, one end of the liquid outlet channel communicates with the liquid storage groove, and the other end of the liquid outlet channel communicates with the liquid outlet end of the first die head. A gas inlet cover is mounted on the first die head in a sealing manner, and gas is pumped into the liquid storage tank through the gas inlet cover for pressurization; the first die head is further provided with an ultrasonic generator used for removing bubbles of the precursor solution. According to the utility model, a low-pressure ultrasonic defoaming technology is adopted, the defect of'pinholes' in the film is effectively reduced, and meanwhile, residual precursor liquid in equipment such as pipelines, injection pumps and the like in the traditional coating technology is reduced through gas extrusion, so that the laboratory research cost is remarkably reduced.

Description

Technical Field

[0001] This utility model belongs to the field of slit coating equipment, thin film deposition preparation and solar cell preparation technology, specifically a coating die head for slit coating equipment. Background Technology

[0002] Perovskite solar cells have reportedly achieved a laboratory-certified efficiency of 27%, but high-quality, large-area production remains a major constraint on their large-scale commercialization. Compared to technologies such as vacuum deposition, blade coating, and inkjet printing, slot coating technology offers significant advantages in speed and precision. Its closed coating system prevents contaminant ingress and can adapt to varying coating liquid viscosities, making it one of the most suitable technologies for industrial production. Nevertheless, existing slot coating technologies still face several challenges in laboratory research, particularly regarding the defoaming treatment and utilization efficiency of the precursor solution.

[0003] In traditional slot coating processes, the precursor solution is typically drawn back into a syringe, which is then connected to the coating die via tubing. A pump is then activated to expel the precursor solution from the syringe and coat it onto the substrate through the coating lip. However, the precursor solution usually needs to be filtered before coating, and the use of porous filters often results in a large number of air bubbles in the solution. These air bubbles during coating often lead to pinhole defects on the film surface, affecting the film's quality and stability. Furthermore, the complex and lengthy piping system can not only cause uneven flow of the precursor solution but also increases the difficulty of equipment cleaning, further reducing research and production efficiency.

[0004] Furthermore, traditional slot coating equipment often suffers from precursor liquid residue. Because the precursor liquid in the syringe and tubing cannot be completely drained, some material is wasted, significantly increasing experimental costs and affecting the efficiency of the coating process. This problem is particularly pronounced in short-cycle laboratory studies. This issue leads to significant material waste and operational difficulties for researchers, necessitating improvements to existing technologies to increase material utilization and reduce experimental costs. Utility Model Content

[0005] In view of the above-mentioned problems of traditional slot coating, the purpose of this utility model is to provide a coating die head for slot coating equipment.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] This utility model includes an air inlet cap, a first die head, a gasket, and a second die head, which are connected in sequence. The gasket is sandwiched between the first and second die heads, and its lower end has a notch, thus forming a coating lip between the lower ends of the first and second die heads. The side of the first die head facing the gasket is the liquid outlet end. The interior of the first die head has a liquid storage tank and a liquid outlet channel. The liquid storage tank is used to hold the filtered precursor liquid. One end of the liquid outlet channel is connected to the liquid storage tank, and the other end is connected to the liquid outlet end of the first die head. An air inlet cap is sealed on the first die head. Gas is pumped into the liquid storage tank through the air inlet cap to pressurize it, thereby causing the precursor liquid in the liquid storage tank to be extruded through the liquid outlet channel, the liquid outlet end of the first die head, and the coating lip. An ultrasonic generator for defoaming the precursor liquid is also installed on the first die head.

[0008] Wherein: the top of the liquid storage tank extends to the top surface of the first mold head, the bottom of the liquid storage tank is an inclined surface, and one end of the liquid outlet channel is connected to the lowest point of the inclined surface.

[0009] The liquid outlet channel is U-shaped, with one end of the U-shaped opening connected to the liquid storage tank and the other end of the U-shaped opening connected to the liquid outlet end of the first mold head. The height of one end of the U-shaped opening is lower than the height of the other end.

[0010] The first mold head has a liquid leveling groove on the side facing the gasket, and the other end of the liquid outlet channel is connected to the liquid leveling groove.

[0011] The uniform liquid groove is an arc-shaped groove, and the bottom of the uniform liquid groove is provided with a liquid outlet. The other end of the liquid outlet channel is connected to the liquid outlet.

[0012] The air inlet cover is sealed and installed on the top surface of the first mold head, and the air inlet cover has an air inlet hole that communicates with the liquid storage tank; the ultrasonic generator is installed on the other side of the first mold head opposite to the liquid equalization groove.

[0013] The lower end of the gasket is in the shape of an inverted "U", and the opening of the inverted "U" is the notch. The projection of the liquid equalization groove on the gasket is located inside the inverted "U".

[0014] The lower end of the first die head that contacts the gasket extends downward to form an extension A, and the lower end of the second die head that contacts the gasket extends downward to form an extension B. The extension A, extension B and the notch at the lower end of the gasket together form a coating lip.

[0015] The advantages and positive effects of this utility model are as follows:

[0016] 1. Effective defoaming and reduction of film defects. This invention utilizes low-pressure ultrasonic defoaming technology to effectively remove air bubbles from the precursor solution before coating. The ultrasonic waves generated by the ultrasonic generator, combined with the low-pressure environment in the storage tank, can destroy the bubble structure, thereby potentially alleviating the formation of "pinhole" defects during the coating process and improving the uniformity and quality of the film.

[0017] 2. Improve the utilization rate of precursor liquid and reduce material waste. Through a reasonable storage tank structure design and gas pressurization extrusion method, this invention effectively reduces the problem of precursor liquid residue in traditional coating processes. Compared with traditional coating equipment, this invention can significantly reduce the waste of unused precursor liquid in pipelines and syringes, which not only reduces experimental costs but also improves material utilization efficiency, which is particularly important for laboratory research.

[0018] 3. Simplified equipment cleaning and reduced operational difficulty. The coating die head structure of this utility model is relatively simple, and the design of the tightly fitting gasket and die head connection avoids the complex piping system in traditional equipment, thereby simplifying the cleaning and maintenance of the equipment; in addition, it reduces the residue of precursor liquid in the pipeline, improves cleaning efficiency, and reduces the cost and time of equipment maintenance.

[0019] 4. Stability and Sustainability. The air inlet cover used in this invention can pressurize the liquid storage tank by pumping in gas, making the flow of the precursor liquid more stable and uniform, thus ensuring high precision in the coating process. Compared with traditional slot coating technology, this invention reduces the risk of contamination while ensuring liquid supply, greatly reduces the difficulty of cleaning the coating die and liquid flow pipes, and ensures the consistency and long-term stability of film coating.

[0020] 5. High adaptability and wide application. This invention is not only applicable to the coating of perovskite solar cells, but can also be widely used in other thin film preparation fields requiring high-precision coating, such as OLEDs, photoelectric sensors, and displays. Its high efficiency, energy saving, and low cost make it a coating technology with great potential for large-scale industrial production. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0022] Figure 2 This is one of the exploded views of this utility model;

[0023] Figure 3 This is the second exploded view of this utility model;

[0024] Figure 4 This is one of the three-dimensional structural schematic diagrams of the first mold head of this utility model;

[0025] Figure 5 This is the second three-dimensional structural schematic diagram of the first mold head of this utility model;

[0026] Figure 6 This is a front view of the structure of the first mold head of this utility model;

[0027] Figure 7 for Figure 6 The right view;

[0028] Figure 8 for Figure 7 This is a top view;

[0029] Figure 9 for Figure 6 Sectional view A-A;

[0030] Wherein: 1 is the air inlet cover, 11 is the air inlet hole, 2 is the first mold head, 21 is the ultrasonic generator, 22 is the liquid storage tank, 23 is the liquid outlet channel, 24 is the liquid outlet, 25 is the liquid equalization groove, 26 is the extension A, 3 is the gasket, 31 is the coating lip, 4 is the second mold head, and 41 is the extension B. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] like Figures 1-9 As shown, this utility model provides a low-cost, high-utilization coating die head for a slot coating equipment. The equipment base is a slot coating equipment, and the coating die head is installed on a liftable support of the slot coating equipment. The coating die head includes an air inlet cover 1, a first die head 2, a gasket 3, and a second die head 4. The first die head 2, gasket 3, and second die head 4 are connected in sequence. The gasket 3 is sandwiched between the first die head 2 and the second die head 4. The lower end of the gasket 3 has a notch, thus forming a coating lip 31 between the lower ends of the first die head 2 and the lower ends of the second die head 4. The side of the first die head 2 facing the gasket 3 is the liquid outlet end. The interior of the first die head 2 is provided with a liquid storage tank 22 and a liquid outlet channel 23. The liquid storage tank 22 is used to hold the filtered precursor liquid. One end of the liquid outlet channel 23 is connected to the liquid storage tank 22, and the other end is connected to the liquid outlet end of the first die head 2. An air inlet cover 1 is sealed on the first die head 2. The air inlet cover 1 has an air inlet hole 11 that communicates with the liquid storage tank 22. Gas is pumped into the liquid storage tank 22 through the air inlet hole 11. An ultrasonic generator 21 for defoaming the precursor liquid is also installed on the first die head 2.

[0033] In this embodiment, both the first mold head 2 and the second mold head 4 are cuboids. The first mold head 2, the gasket 3 and the second mold head 4 are provided with multiple bolt holes. The first mold head 2, the gasket 3 and the second mold head 4 are fixed together by bolts inserted through the bolt holes. The gasket 3 is tightly fitted with the first mold head 2 and the second mold head 4 respectively.

[0034] In this embodiment, the top of the liquid storage tank 22 extends to the top surface of the first mold head 2, the bottom of the liquid storage tank 22 is a slope, and one end of the liquid outlet channel 23 is connected to the lowest point of the slope.

[0035] In this embodiment, the air inlet cover 1 is a cuboid, with a volume smaller than that of the first mold head 2. A square sealing groove is provided on the bottom surface of the air inlet cover 1 around the air inlet hole 11. A sealing ring is placed inside the sealing groove, and the size of the sealing groove is larger than the size of the liquid storage tank 22 on the top surface of the first mold head 2. Bolt holes are respectively provided on the top surfaces of the air inlet cover 1 and the first mold head 2. The air inlet cover 1 is fixed to the first mold head 2 by bolts inserted through the bolt holes, and a seal is achieved by the sealing ring.

[0036] In this embodiment, a liquid leveling groove 25 is provided on the side of the first mold head 2 facing the gasket 3. The liquid leveling groove 25 is an arc-shaped groove, and a liquid outlet 24 is provided at the bottom of the groove. In this embodiment, the liquid outlet channel 23 is U-shaped. One end of the U-shaped opening is connected to the liquid storage tank 22, and the other end of the U-shaped opening is connected to the liquid outlet 24. The height of one end of the U-shaped opening is lower than the height of the other end. The ultrasonic generator 21 is installed on the opposite side of the surface where the liquid leveling groove 25 is located, and generates ultrasonic waves with a frequency of 20-120 kHz.

[0037] In this embodiment, the lower end of the gasket 3 is inverted "U" shape. The thickness of the gasket 3 is 20-500 micrometers. The material of the gasket 3 includes, but is not limited to, polyimide, polydimethylsiloxane, and polytetrafluoroethylene. The opening of the inverted "U" shape is the notch, and the projection of the liquid distribution groove 25 on the gasket 3 is located within the inverted "U" shape. In this embodiment, the lower end of the side of the first die head 2 that contacts the gasket 3 extends downward to form an extension A26, and the lower end of the side of the second die head 4 that contacts the gasket 3 extends downward to form an extension B41. The extensions A26 and B41, together with the notch at the lower end of the gasket 3, form the coating lip 31.

[0038] The coating method of this utility model includes the following steps:

[0039] Step A: Seal the coating lip 31 and add the filtered precursor liquid to the storage tank 22;

[0040] Step B: Install the air inlet cover 1 on the first mold head 2, and connect the air inlet 11 to the injection pump;

[0041] Step C: Start the ultrasonic generator 21 on the first mold head 2 and start the injection pump in reverse to keep the liquid storage tank 22 under low pressure. Treat the precursor liquid in the liquid storage tank 22 by low-pressure ultrasonic defoaming to remove the air bubbles in the precursor liquid.

[0042] Step D: After defoaming, the injection pump operates in the forward direction, pumping gas into the storage tank 22 through the air inlet 11, pressurizing the storage tank 22, and uniformly squeezing the precursor liquid. The precursor liquid in the storage tank 22 flows out through the liquid outlet 23, the liquid outlet 24, and the liquid leveling groove 25 to the coating lip 31 and is then uniformly squeezed out. With the cooperation of substrate movement, the precursor liquid is uniformly coated on the substrate surface to form a wet film, and then the next drying process is carried out.

[0043] In step D, by controlling the speed of the gas pumped into the air inlet cover 1, the liquid outlet speed of the coating lip 31 can be adjusted, thereby controlling the film thickness.

[0044] The gas pumped into the storage tank 22 by this invention can be one of nitrogen, argon, oxygen, air or dry air, and the minimum gas pumping rate into the storage tank 22 by the injection pump is 0.001 mL / min.

[0045] This invention employs low-pressure ultrasonic defoaming technology to effectively reduce pinhole defects in the film. Simultaneously, it reduces residual precursor liquid in pipes, injection pumps, and other equipment used in traditional coating techniques through gas extrusion, thereby significantly lowering laboratory research costs.

Claims

1. A coating die for a slot coating apparatus, characterized by: The application relates to a coating device, which comprises an air inlet cover (1), a first die head (2), a gasket (3) and a second die head (4), wherein the first die head (2), the gasket (3) and the second die head (4) are sequentially connected, the gasket (3) is clamped between the first die head (2) and the second die head (4), the lower end of the gasket (3) is provided with an opening, and a coating lip (31) is formed between the lower end of the first die head (2) and the lower end of the second die head (4); one side of the first die head (2) facing the gasket (3) is a liquid outlet end, the inner part of the first die head (2) is respectively provided with a liquid storage groove (22) and a liquid outlet channel (23), the liquid storage groove (22) is used for containing filtered precursor liquid, one end of the liquid outlet channel (23) is communicated with the liquid storage groove (22), and the other end of the liquid outlet channel (23) is communicated with the liquid outlet end of the first die head (2); the air inlet cover (1) is sealingly mounted on the first die head (2), gas is pumped into the liquid storage groove (22) through the air inlet cover (1) to pressurize, and then the precursor liquid in the liquid storage groove (22) is extruded through the liquid outlet channel (23), the liquid outlet end of the first die head (2) and the coating lip (31); the first die head (2) is further provided with an ultrasonic generator (21) for removing bubbles of the precursor liquid.

2. The coating die for a slot die coater according to claim 1, characterized by: The top end of the liquid storage groove (22) extends to the top surface of the first die head (2), the groove bottom of the liquid storage groove (22) is a slope, and one end of the liquid outlet channel (23) is communicated with the lowest part of the slope.

3. The coating die for a slot-die coating apparatus according to claim 1, wherein: The liquid outlet channel (23) is in a "U" shape, one end of the "U" shape opening is communicated with the liquid storage groove (22), the other end of the "U" shape opening is communicated with the liquid outlet end of the first die head (2), and the height of the one end of the "U" shape opening is lower than that of the other end.

4. The coating die for a slot-die coating apparatus according to claim 1, characterized by: One side of the first die head (2) facing the gasket (3) is provided with a liquid uniformizing groove (25), and the other end of the liquid outlet channel (23) is communicated with the liquid uniformizing groove (25).

5. The coating die for a slot coating apparatus according to claim 4, wherein: The liquid uniformizing groove (25) is an arc-shaped groove, the groove bottom in the liquid uniformizing groove (25) is provided with a liquid outlet (24), and the other end of the liquid outlet channel (23) is communicated with the liquid outlet (24).

6. The coating die for a slot coating apparatus according to claim 4, wherein: The air inlet cover (1) is sealingly mounted on the top surface of the first die head (2), the air inlet cover (1) is provided with an air inlet hole (11) communicated with the liquid storage groove (22); and the ultrasonic generator (21) is mounted on the other side of the first die head (2) opposite to the liquid uniformizing groove (25).

7. The coating die for a slot coating apparatus according to claim 4, wherein: The lower end of the gasket (3) is in an inverted "U" shape, the opening of the inverted "U" shape is the opening, and the projection of the liquid uniformizing groove (25) on the gasket (3) is located in the inverted "U" shape.

8. The coating die for a slot coating apparatus according to claim 1, wherein: The lower end of the one side of the first die head (2) contacting the gasket (3) extends downward to form an extension A (26), the lower end of the one side of the second die head (4) contacting the gasket (3) extends downward to form an extension B (41), and the extension A (26), the extension B (41) and the opening of the lower end of the gasket (3) jointly form the coating lip (31).

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