A vacuum film forming device and a film forming method

Abstract

The present invention discloses a vacuum film forming device and a film forming method, relating to the technical field of vacuum film forming. The device includes a vacuum chamber, which is connected with an air extraction pipeline, an air inlet pipeline and a pressure relief pipeline. One end of the air extraction pipeline far from the vacuum chamber is connected with a vacuum pump, and a proportional valve is arranged on the air extraction pipeline. One end of the air inlet pipeline far from the vacuum chamber is connected with an inert gas source, and the inert gas source can transport inert gas into the vacuum chamber. An air inlet regulating valve is arranged on the air inlet pipeline. One end of the pressure relief pipeline far from the vacuum chamber is connected with a pressure relief gas source, and the pressure relief gas source can transport pressure relief gas into the vacuum chamber. In the present invention, inert gas is introduced to keep the pressure position in the vacuum chamber at the initial film forming pressure for a period of time. Moreover, the number of vacuum pumps is small, the use cost is low, and the occupied space is relatively small.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum film forming, and particularly to a vacuum film forming device and a film forming method. Background Art

[0002] Vacuum crystal making is to place a substrate coated with a wet film in a chamber, and use a vacuum device to evacuate the chamber, thereby pumping out the moisture in the wet film, while the solid substances can be fixed on the substrate.

[0003] During the process of vacuum film forming, it takes a period of time (temporarily called invalid time) from atmospheric pressure (1×10 5 )to the actual film forming starting pressure, and the time from the film forming starting pressure to the film forming final pressure is the real effective time (temporarily called effective working time). The key point of film forming lies in forming the film as soon as possible within the expected effective working time (which is actually different for different solutions).

[0004] Existing vacuum film forming equipment basically adopts: 1. Evacuation system: including a vacuum pump group (mechanical pump, roots pump, dry pump, molecular pump, gate valve, globe valve, etc.); 2. Vacuum chamber: including a cavity, an upper cover, and an observation window. The working process is as follows: turn on multiple vacuum pumps - turn on the molecular pump - place the coated substrate into the vacuum chamber - open the valve between the vacuum pump and the chamber - then open the valve between the molecular pump and the vacuum chamber - pump to the ultimate vacuum and then close the valve between the molecular pump and the vacuum chamber - relieve the pressure in the chamber - take out the substrate.

[0005] However, the above existing vacuum film forming equipment can only simply evacuate to the ultimate vacuum. It cannot maintain a certain pressure at the film forming starting pressure and then continue to pump to the ultimate vacuum, because relying solely on a vacuum pump or other pump body structures, once the pipeline valve corresponding to the vacuum pump is closed, the pressure in the chamber will change more or less, so that the pressure in the chamber cannot be at the film forming starting pressure. If the film forming starting pressure cannot be guaranteed, the effective working time cannot be established. Of course, for the above existing technology, even if it cannot maintain the film forming starting pressure for a period of time, as long as it uses a large number of vacuum pumps with large power, it can still shorten the overall film forming working time (that is, both the invalid time and the effective working time will be shortened). However, in order to effectively pump out the moisture in the solution, the equipment needs to use pumps with a large pumping speed, such as a mechanical pump group, a dry pump, and a molecular pump, etc., and even needs to additionally increase a vacuum tank body, which not only increases the floor area of the equipment, but also greatly increases the cost of the equipment.

[0006] Therefore, there is an urgent need in the art for a new type of vacuum film forming device and a film forming method to solve the above problems. Summary of the Invention

[0007] The object of the present invention is to provide a vacuum film forming device and a film forming method to solve the problems existing in the above-mentioned prior art, realizing crystal film forming with a smaller number of pumps, having lower usage cost and manufacturing cost, and occupying a smaller area.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] The present invention discloses a vacuum film forming device, including a vacuum chamber, which is connected with an exhaust gas pipeline, an intake gas pipeline and a pressure relief pipeline. One end of the exhaust gas pipeline far from the vacuum chamber is connected with a vacuum pump, and a proportional valve is arranged on the exhaust gas pipeline. One end of the intake gas pipeline far from the vacuum chamber is connected with an inert gas source, and the inert gas source can transport inert gas into the vacuum chamber. An intake gas regulating valve is arranged on the intake gas pipeline. One end of the pressure relief pipeline far from the vacuum chamber is connected with a pressure relief gas source, and the pressure relief gas source can transport pressure relief gas into the vacuum chamber.

[0010] Preferably, a pipeline valve is arranged on the exhaust gas pipeline, and the pipeline valve is closer to the vacuum pump than the proportional valve.

[0011] Preferably, a plurality of vacuum pumps are provided. When there are two or more vacuum pumps, the plurality of vacuum pumps are arranged in parallel.

[0012] Preferably, a pressure relief valve is arranged on the pressure relief pipeline.

[0013] Preferably, the inert gas source is a nitrogen gas tank.

[0014] Preferably, the pressure relief gas source is an air compression bottle or a nitrogen gas tank.

[0015] Preferably, a vacuum gauge is arranged in the vacuum chamber.

[0016] Preferably, the intake gas regulating valve is an internal thread micro regulating valve.

[0017] The present invention discloses a film forming method for a vacuum film forming device, including the following steps:

[0018] S1. Turn on the vacuum pump;

[0019] S2. Open the vacuum chamber, put in the substrate to be film formed with a coated wet film, and close the vacuum chamber;

[0020] S3. Set the internal pressure value of the vacuum chamber according to requirements, open the pipeline valve, and adjust the internal pressure of the vacuum chamber by adjusting the intake gas regulating valve and the proportional valve;

[0021] S4. Close the intake gas regulating valve and fully open the proportional valve, thereby completing the film forming process of the substrate;

[0022] S5. Close the proportional valve and open the pressure relief valve to make the vacuum chamber reach atmospheric pressure and take out the substrate.

[0023] The present invention has achieved the following technical effects compared with the prior art:

[0024] During the air extraction process of the present invention, inert gas is also filled into the vacuum chamber, so that the pressure in the vacuum chamber can be accurately maintained at the initial film-forming pressure for a period of time, and the filled inert gas can also carry out the moisture in the wet film, so as to realize that a smaller number of vacuum pumps can quickly form a film on the wet film on the substrate within the expected effective working time. The key point in the crystallization and film formation of the perovskite solution is to quickly crystallize from the wet film to the dry film, so as to ensure the key nucleation quality such as the crystal grain growth direction and crystal grain size of the perovskite film. Finally, the whole device has a simple structure, low manufacturing cost, small floor area, good practicability and applicability. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic structural diagram of the vacuum film-forming device in Embodiment 1;

[0027] In the figure: 1 - vacuum chamber; 2 - air extraction pipeline; 3 - vacuum pump; 4 - intake pipeline; 5 - intake regulating valve; 6 - pressure relief pipeline; 7 - pressure relief valve; 8 - vacuum gauge; 9 - proportional valve; 10 - pipeline valve. Detailed Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0029] The purpose of the present invention is to provide a vacuum film-forming device and a film-forming method to solve the problems existing in the above-mentioned prior art, realize crystal film formation with a smaller number of pump bodies, have less use cost and manufacturing cost, and have a smaller floor area.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0031] Example 1

[0032] As Figure 1 shown, this embodiment provides a vacuum film forming device, which includes a vacuum chamber 1. The vacuum chamber 1 is a closed chamber, and its side is provided with a switch door and an observation window. The vacuum chamber 1 is connected with an exhaust gas pipeline 2, an intake gas pipeline 4 and a pressure relief pipeline 6. One end of the exhaust gas pipeline 2 far away from the vacuum chamber 1 is connected with a vacuum pump 3. The vacuum pump 3 is used to extract the gas in the vacuum chamber 1, and a proportional valve 9 is arranged on the exhaust gas pipeline 2. The proportional valve 9 is used to adjust the exhaust rate. One end of the intake gas pipeline 4 far away from the vacuum chamber 1 is connected with an inert gas source. The inert gas source can transport inert gas into the vacuum chamber 1, and an intake gas regulating valve 5 is arranged on the intake gas pipeline 4. The intake gas regulating valve 5 is used to adjust the intake rate of the inert gas. One end of the pressure relief pipeline 6 far away from the vacuum chamber 1 is connected with a pressure relief gas source. The pressure relief gas source can transport pressure relief gas into the vacuum chamber 1, and after the pressure relief gas source is input, the air pressure in the vacuum chamber 1 can be restored to the normal pressure state.

[0033] During actual use, first place the substrate coated with a wet film into the vacuum chamber 1, close the switch door of the vacuum chamber 1 to make its interior in a sealed state. Start the vacuum pump 3 to evacuate the vacuum chamber 1, so that the pressure in the vacuum chamber 1 gradually decreases until it is less than the initial film forming pressure (for example, when the initial film forming pressure is 100 Pa, it can be pumped to 1 Pa at this time). Then open the intake gas regulating valve 5 and adjust the opening degrees of the proportional valve 9 and the intake gas regulating valve 5 so that the intake rate is the same as the exhaust rate, thereby maintaining the pressure in the vacuum chamber 1 at 1 Pa, and remember the scale value of the intake gas regulating valve 5 at this time. Then, adjust the opening degree of the intake gas regulating valve 5 again so that the intake rate is greater than the exhaust rate, so the air pressure in the vacuum chamber 1 gradually increases until it reaches 100 Pa (i.e., the initial film forming pressure). At this time, quickly adjust the intake gas regulating valve 5 to the just-recorded scale position again, so that the internal pressure of the vacuum chamber 1 can be maintained at this value. Then close the intake gas regulating valve 5 to make the substrate officially enter the film forming working process. And under the carrying action of the inert gas and the exhaust action of the vacuum pump 3, the wet film can remove moisture within the effective working time to complete the film forming process. Finally, use the pressure relief pipeline 6 to input pressure relief gas into the vacuum chamber 1 until the air pressure in the vacuum chamber 1 is restored to the normal pressure state, and then the switch door can be opened and the substrate can be taken out.

[0034] In this embodiment, a pipeline valve 10 is arranged on the exhaust gas pipeline 2. The pipeline valve 10 is closer to the vacuum pump 3 than the proportional valve 9, and the gas flow on the exhaust gas pipeline 2 is controlled by the pipeline valve 10.

[0035] In this embodiment, there are several vacuum pumps 3. Figure 1The vacuum pump 3 in [it] is provided with one. Although the area of the substrate gradually increases and the demand for negative pressure also increases accordingly, the number of vacuum pumps 3 will also increase accordingly. When there are two or more vacuum pumps 3, and several vacuum pumps 3 are arranged in parallel, that is, a pipeline valve 10 can control the opening or closing of all the vacuum pumps 3.

[0036] In this embodiment, a pressure relief valve 7 is provided on the pressure relief pipeline 6, and the pressure relief valve 7 is used to control the flow of the pressure relief pipeline 6.

[0037] In this embodiment, the inert gas source is a nitrogen gas cylinder, so the inert gas is nitrogen. The reason for using inert gas is that its chemical properties are stable and it is not easy to undergo chemical reactions, so as to maintain stable air pressure.

[0038] During the air extraction process, an appropriate proportion of inert gas is introduced through the intake regulating valve 5, which can make the wet film on the substrate achieve nucleation crystallization faster. And according to the process requirements, different wet film coatings adopt different pumping speeds by adjusting the proportion valve 9, and more suitable film-forming effects can be obtained by stabilizing different pressures in the vacuum chamber 1.

[0039] In this embodiment, the pressure relief gas source is an air compression bottle or a nitrogen gas cylinder, so the pressure relief gas is air or nitrogen, which is selected according to the actual use cost of the user.

[0040] In this embodiment, a vacuum gauge 8 is provided in the vacuum chamber 1, and the pressure in the vacuum chamber 1 can be monitored in real time through the vacuum gauge 8.

[0041] In this embodiment, the intake regulating valve 5 adopts an existing internal thread micro-regulating valve, which can finely adjust the flow rate. Specifically, the straight-through ferrule diameter of the internal thread micro-regulating valve is 10 mm, the outer diameter of the inserted tube is 10 mm, and high-purity nitrogen is passed through the tube, and the pressure is 0.2 ± 0.05 MPa.

[0042] Embodiment 2

[0043] This embodiment provides a film-forming method for a vacuum film-forming device. Based on the vacuum film-forming device disclosed in Embodiment 1, it includes the following steps:

[0044] S1. Turn on the vacuum pump 3. It should be noted that the pipeline valve 10 is not turned on at this time, which only preheats the vacuum pump 3 so that it can reach the working state as soon as possible.

[0045] S2. Open the vacuum chamber 1, put in the substrate to be film-formed with a coated wet film, and close the vacuum chamber 1.

[0046] S3. Set the internal pressure value of the vacuum chamber 1 according to requirements. Open the pipeline valve 10 and adjust the internal pressure of the vacuum chamber 1 by adjusting the intake regulating valve 5 and the proportional valve 9. The specific process is as follows: First, start the vacuum pump 3 to evacuate the vacuum chamber 1, so that the pressure in the vacuum chamber 1 gradually decreases until it is less than the initial film-forming pressure (for example, when the initial film-forming pressure is 100 Pa, it can be pumped to 1 Pa at this time). Then open the intake regulating valve 5 and adjust the opening degrees of the proportional valve 9 and the intake regulating valve 5 so that the intake rate is the same as the exhaust rate, thereby maintaining the pressure in the vacuum chamber 1 at 1 Pa, and remember the scale value of the intake regulating valve 5 at this time. Then, adjust the opening degree of the intake regulating valve 5 again so that the intake rate is greater than the pumping rate, so the air pressure in the vacuum chamber 1 gradually increases until it reaches 100 Pa (i.e., the initial film-forming pressure). At this time, quickly adjust the intake regulating valve 5 to the just-recorded scale position, so that the internal pressure of the vacuum chamber 1 can be maintained at this value.

[0047] S4. Close the intake regulating valve 5 and fully open the proportional valve 9, so that the pressure in the vacuum chamber 1 drops from the initial film-forming pressure to the final film-forming pressure, thereby completing the substrate film-forming process.

[0048] S5. Close the proportional valve 9 and open the pressure relief valve 7, so that the vacuum chamber 1 reaches atmospheric pressure and take out the substrate.

[0049] In this embodiment, the vacuum gauge 8 of the vacuum chamber 1 can display the pressure value in the vacuum chamber 1 in real time. According to the wet film coatings of different components, technical solutions with different pressures and pressure holding times can be adopted, as follows:

[0050] When the wet film uses a high-boiling-point solution (i.e., a solution added with high-boiling-point solvents such as DMF, NMP, DMSO, etc. with a boiling point higher than 150 °C), the pressure in step S3 is 1000 ± 100 Pa, hold for 10 seconds, then close the intake regulating valve 5 and continue to evacuate.

[0051] When the wet film uses a low-boiling-point solution (i.e., a solution using low-boiling-point solvents such as DME, ACE, THF, etc. with a boiling point lower than 70 °C), the pressure in step S3 is 300 ± 50 Pa, hold for 10 seconds, then close the intake regulating valve 5 and continue to evacuate.

[0052] If it is a wet film coating made of a special solution, it can be precisely controlled through the intake regulating valve 5 and the proportional valve 9, debug the appropriate process pressure, keep the pressure constant for 10 seconds, then close the intake and continue to evacuate.

[0053] This embodiment also provides four groups of control experiments, as follows:

[0054] Comparative case a: Conditions: A substrate of 120 mm × 120 mm, using a low-boiling-point solution.

[0055] For a conventional vacuum film forming device, it takes 4 seconds for 1 vacuum pump to evacuate and achieve the color change of the wet film (i.e., the film forming is completed), and it takes 2 seconds for 3 vacuum pumps to achieve the color change of the wet film.

[0056] However, for the vacuum film forming device provided in this embodiment, only 1 vacuum pump plus controlling the pressure of the vacuum chamber 1 by introducing inert gas can achieve the color change of the wet film in 2 seconds.

[0057] Therefore, for the experiment of low-boiling-point solution with the vacuum film forming device provided in this embodiment, using 1 vacuum pump can achieve the same effect as the device with 3 vacuum pumps in the conventional vacuum film forming equipment.

[0058] Comparative case b: Conditions: Substrate of 120mm×120mm, using high-boiling-point solution.

[0059] For a conventional vacuum film forming device, 1 vacuum pump cannot evacuate to achieve the color change of the wet film, and it takes 5 seconds for 3 vacuum pumps to achieve the color change of the wet film.

[0060] However, for the vacuum film forming device provided in this embodiment, only 1 vacuum pump plus controlling the pressure of the vacuum chamber 1 by introducing inert gas can achieve the color change of the wet film in 4 seconds.

[0061] Therefore, for the experiment of high-boiling-point solution with the vacuum film forming device provided in this embodiment, using 1 vacuum pump can achieve the same effect as the device with 3 vacuum pumps in the conventional vacuum film forming equipment.

[0062] Comparative case c: Conditions: Substrate of 600mm×600mm, using high-boiling-point solution.

[0063] For a conventional vacuum film forming device, 4 vacuum pumps cannot evacuate to achieve the color change of the wet film.

[0064] However, for the vacuum film forming device provided in this embodiment, only 2 vacuum pumps plus controlling the pressure of the vacuum chamber 1 by introducing inert gas can achieve the color change of the wet film in 15 seconds.

[0065] Therefore, for the experiment of high-boiling-point solution with the vacuum film forming device provided in this embodiment, using 2 vacuum pumps has a better effect than the device with 4 vacuum pumps in the conventional vacuum film forming equipment, and can complete tasks that the conventional vacuum film forming equipment cannot complete.

[0066] Comparative case d: Conditions: Substrate of 1200mm×600mm, using high-boiling-point solution.

[0067] For a conventional vacuum film forming device, 12 vacuum pumps cannot evacuate to achieve uniform color change of the wet film.

[0068] However, for the vacuum film forming device provided in this embodiment, only 4 vacuum pumps plus controlling the pressure of the vacuum chamber 1 by introducing inert gas can achieve uniform color change of the wet film in 17 seconds.

[0069] Therefore, the effect of using 4 vacuum pumps 3 in the high-boiling-point solution experiment of the vacuum film-forming device provided in this embodiment is better than that of 12 vacuum pumps 3 in the conventional vacuum film-forming equipment.

[0070] The present invention has the following advantages during actual use:

[0071] 1. Greatly reduce the manufacturing cost of the equipment and enable uniform film formation of high-boiling-point formulations that cannot be achieved by conventional equipment.

[0072] 2. Reduce the floor area of the equipment: For every two additional vacuum pumps 3 in the equipment, an additional 1 square meter of floor area is required.

[0073] 3. Greatly reduce the energy consumption of the equipment; for every two fewer vacuum pumps 3 used in the equipment, the equipment power is reduced by 6 kilowatts.

[0074] 4. Shorten the process time.

[0075] 5. Improve the film-forming quality; by combining the solution formulation scraped on the substrate to formulate the process curve of the film-forming process, the present invention can easily achieve precise control of the pressure in the vacuum chamber 1 of the equipment to improve the film-forming quality and ensure the consistency of crystal nucleus growth.

[0076] Specific examples are used in the present invention to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A film forming method of a vacuum film forming device, characterized in that: A vacuum film forming device is adopted. The vacuum film forming device includes a vacuum chamber, and the vacuum chamber is connected with an exhaust gas pipeline, an intake gas pipeline and a pressure relief pipeline. One end of the exhaust gas pipeline far away from the vacuum chamber is connected with a vacuum pump, and a proportional valve is arranged on the exhaust gas pipeline. One end of the intake gas pipeline far away from the vacuum chamber is connected with an inert gas source, and the inert gas source can transport inert gas into the vacuum chamber. An intake gas regulating valve is arranged on the intake gas pipeline. One end of the pressure relief pipeline far away from the vacuum chamber is connected with a pressure relief gas source, and the pressure relief gas source can transport pressure relief gas into the vacuum chamber; The film forming method of the vacuum film forming device comprises the following steps: S1. Turn on the vacuum pump; S2. Open the vacuum chamber, put in the substrate to be formed with a coated wet film, and then close the vacuum chamber; S3. Set the internal pressure value of the vacuum chamber according to requirements, open the pipeline valve, and adjust the internal pressure of the vacuum chamber by adjusting the intake gas regulating valve and the proportional valve, and maintain the pressure. The specific process is as follows: First, start the vacuum pump to evacuate the vacuum chamber, so that the pressure in the vacuum chamber gradually decreases until it is less than the initial film forming pressure. Then, open the intake gas regulating valve and adjust the opening degrees of the proportional valve and the intake gas regulating valve so that the intake gas rate is the same as the exhaust gas rate, thereby maintaining the pressure in the vacuum chamber unchanged, and remember the scale value of the intake gas regulating valve at this time. Then, adjust the opening degree of the intake gas regulating valve again so that the intake gas rate is greater than the exhaust gas rate, so the air pressure in the vacuum chamber gradually increases until the initial film forming pressure. At this time, adjust the intake gas regulating valve to the just-recorded scale position again, so that the internal pressure of the vacuum chamber can be maintained at this value; S4. When entering the film forming operation, close the intake gas regulating valve and fully open the proportional valve, so that the pressure in the vacuum chamber drops from the initial film forming pressure to the final film forming pressure, thereby completing the film forming process of the substrate; S5. Close the proportional valve and open the pressure relief valve, so that the vacuum chamber reaches normal pressure and take out the substrate.

2. The film forming method of the vacuum film forming device according to claim 1, characterized in that: A pipeline valve is arranged on the exhaust gas pipeline, and the pipeline valve is closer to the vacuum pump than the proportional valve.

3. The film forming method of the vacuum film forming apparatus according to claim 1, characterized in that: There are several vacuum pumps. When there are two or more vacuum pumps, several vacuum pumps are arranged in parallel.

4. The film forming method of the vacuum film forming apparatus according to claim 1, characterized in that: A pressure relief valve is arranged on the pressure relief pipeline.

5. The film forming method of the vacuum film forming apparatus according to claim 1, characterized in that: The inert gas source is a nitrogen gas cylinder.

6. The film forming method of the vacuum film forming device according to claim 1, characterized in that: The pressure relief gas source is an air compression bottle or a nitrogen gas cylinder.

7. The film forming method of the vacuum film forming apparatus according to claim 1, characterized in that: A vacuum gauge is arranged in the vacuum chamber.

8. The film forming method of the vacuum film forming apparatus according to claim 1, characterized in that: The intake gas regulating valve is an internal thread micro-regulating valve.

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