Photovoltaic cell aluminum oxide passivation deposition air inlet device
By adding bypass argon gas pipes to the passivation deposition intake device of alumina in the photovoltaic cell, the damage and safety hazards of controllable evaporation mixer caused by the backflow of compressed air in the process chamber are solved, and the safety and reliability of the equipment are improved.
Patent Information
- Application Number
- CN202421809993.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-29
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-07-29
AI Technical Summary
The compressed air in the process chamber flows back into the controllable evaporation mixer, causing water or oxygen to react with the residual TMA, resulting in a powdery substance, causing blockage, damage to the controllable evaporation mixer, and increasing safety hazards.
Add a bypass argon gas pipe between the argon gas intake pipe and the process chamber to skip the controllable evaporation mixer to divert the argon gas and control the argon flow at the front and rear ends of the CEM. Run the purge and leak detection process before maintenance, and purge the bypass argon gas pipe to open to prevent the residual process gas from flowing back to the controllable evaporation mixer.
Through the design of the bypass argon gas pipe, the reaction damage caused by compressed air backflow is avoided, safety hazards are reduced, the service life of the controllable evaporation mixer is extended, the equipment is started up, and the production capacity is avoided.
Smart Images
Figure CN222861630U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of photovoltaic cells, and in particular relates to an air intake device for aluminum oxide passivation deposition of photovoltaic cells. Background Art
[0002] In order to improve the conversion efficiency of crystalline silicon cells and reduce the surface load of the cells, the key technology is to prepare a thin layer of aluminum oxide on the front of the cell. One of the commonly used methods for preparing aluminum oxide is PECVD. The PECVD method mostly uses a plate coating method. N2O (laughing gas) and TMA (trimethylaluminum) are introduced into the process chamber, and microwave discharge is used to generate plasma for chemical vapor deposition to generate Al2O3, which is deposited on the back of the silicon wafer to form an anti-reflection film with a passivation effect, increase the absorption of the long-wave band of sunlight, and passivate the back of the silicon wafer.
[0003] The current process chamber air intake method is that liquid TMA enters the CEM (controlled evaporation mixer), where it is mixed with argon and heated. The gas mixture is finally transferred to the process chamber, and microwave discharge is used to generate plasma to achieve chemical vapor deposition. Since the pressure of argon is generally 2.5 bar (atmospheric pressure is about 1 bar), when maintaining the process chamber, it is currently necessary to fill the process chamber with compressed air to make the process chamber become normal pressure before opening the chamber cover for maintenance. When the control valve leaks, the compressed air in the process chamber will enter the controlled evaporation mixer CEM, and the water or oxygen in the compressed air will react with the residual TMA to generate powdery substances, causing blockage and damage to the CEM, and the controlled evaporation mixer CEM needs to be replaced.
[0004] To replace the controlled evaporator mixer CEM, all special gas inlet pipelines need to be purged to ensure that there is no special gas residue and replacement can be performed under the premise of ensuring safety. This operation will seriously affect normal production and reduce production capacity. If the equipment is not stopped and cleaned and repaired in time, an explosive decomposition reaction will occur and methane will be generated, posing a risk of fire. Utility Model Content
[0005] The embodiment of the utility model provides an air intake device for alumina passivation deposition of photovoltaic cells, which is intended to solve the problem of compressed air in the process chamber flowing back into a controllable evaporation mixer, causing water or oxygen in the compressed air to react with residual TMA to generate powdery substances that cause blockage and damage the controllable evaporation mixer, necessitating the replacement of the controllable evaporation mixer and bringing about safety hazards.
[0006] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide an air intake device for alumina passivation deposition of photovoltaic cells, comprising: a controllable evaporation mixer and a process chamber; the controllable evaporation mixer is provided with a trimethylaluminum liquid inlet pipe and an argon gas inlet pipe, a mixture gas inlet pipe is provided between the process chamber and the controllable evaporation mixer, and the process chamber is provided with a first gas inlet pipe for balancing the internal and external pressures; the argon gas inlet pipe is also provided with a bypass argon gas pipe directly connected to the process chamber.
[0007] In one achievable manner, a one-way valve, a first pressure buffer and a third control valve are sequentially provided on the mixture inlet pipe from the controllable evaporation mixer to the process chamber.
[0008] In a feasible manner, a second pressure buffer is further provided on the mixture intake pipe, and the third control valve is provided between the first pressure buffer and the second pressure buffer.
[0009] In one practicable manner, a filter is further provided on the argon gas inlet pipe.
[0010] In one achievable manner, a first flow meter and a first control valve are provided on the argon gas inlet pipe and between the filter and the controllable evaporation mixer.
[0011] In one achievable manner, one end of the bypass argon gas pipe is connected to the argon gas inlet pipe, and the other end is connected to the mixture gas inlet pipe.
[0012] In one achievable manner, one end of the bypass argon gas tube is connected between the filter and the first flow meter.
[0013] In one achievable manner, the other end of the bypass argon gas pipe is connected between the one-way valve and the first pressure buffer.
[0014] In one achievable manner, a second flow meter and a second control valve are provided on the bypass argon gas pipe.
[0015] Compared with the prior art, the photovoltaic cell aluminum oxide passivation deposition air intake device provided by the utility model has the beneficial effect that: a bypass argon gas pipe that skips the controllable evaporation mixer CEM is added between the argon gas inlet pipe and the process chamber to divert the argon gas, and the argon gas flow at the front and rear ends of the CEM can be controlled. Before maintenance, the purging and leak detection process is run, and the bypass argon gas pipe is opened for purging first, so that the residual gas in the mixture inlet pipe is blown out, and then the main pipeline is purged and leak-checked through the argon gas inlet pipe to avoid any residual process gas from flowing back into the controllable evaporation mixer and damaging it. After purging and leak detection, even if the environment in the process chamber reaches normal pressure, the valve has a gas leak. At this time, since there is no residual trimethylaluminum liquid in the pipeline after clean purging and leak detection, the risk of oxygen or water reacting with the residual trimethylaluminum to damage the CEM and the risk of explosion and fire caused by the generated flammable gas is avoided. This not only reduces the safety hazards caused by TMA operation, but also improves the service life of the controllable evaporation mixer, ensures the start-up rate of the equipment, and avoids the loss of production capacity. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 A schematic diagram of the structure of an air intake device for aluminum oxide passivation deposition of photovoltaic cells provided by an embodiment of the utility model;
[0017] Figure 2 A schematic diagram of the structure of the interior of a process chamber provided by an embodiment of the utility model;
[0018] Description of reference numerals:
[0019] 1. Filter; 2. One-way valve; 3. First pressure buffer; 4. First pressure gauge; 5. Second pressure buffer; 6. Second pressure gauge; 7. Process chamber; 8. Electrode; 9. Microwave generator; 10. Cover plate; 11. Graphite boat; 12. Conveying device; 13. Heater; MFC1, first flow meter; MFC2, second flow meter; EV1, first control valve; EV2, second control valve; EV3, third control valve; CEM, controllable evaporation mixer. DETAILED DESCRIPTION
[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0021] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.
[0022] See also Figure 1 , the photovoltaic cell aluminum oxide passivation deposition gas inlet device provided by the utility model is now described. The photovoltaic cell aluminum oxide passivation deposition gas inlet device comprises: a controllable evaporation mixer CEM and a process chamber 7; a trimethyl aluminum liquid inlet pipe and an argon gas inlet pipe are arranged on the controllable evaporation mixer CEM, a mixture gas inlet pipe is arranged between the process chamber 7 and the controllable evaporation mixer CEM, and the process chamber 7 is provided with a first gas inlet pipe (nitrogen or CDA compressed air) for balancing the internal and external pressures; the argon gas inlet pipe is also provided with a bypass argon gas pipe directly connected to the process chamber 7.
[0023] Compared with the prior art, the photovoltaic cell aluminum oxide passivation deposition air intake device provided by the utility model has the beneficial effect of adding a bypass argon gas pipe skipping the controllable evaporation mixer CEMCEM between the argon gas intake pipe and the process chamber 7, so that the argon gas is diverted and the argon gas flow at the front end and the rear end of the CEM can be controlled. Before maintenance, the purging and leak detection process is run, and the bypass argon pipe is opened for purging first, which will blow out the residual gas in the mixture inlet pipe, and then the main pipeline is purged and leak-checked through the argon inlet pipe to prevent any residual process gas from flowing back into the controllable evaporator mixer CEM and damaging it. After purging and leak detection, even if the environment in the process chamber 7 reaches normal pressure and the valve has a gas leak, at this time, there is no residual trimethylaluminum liquid after the clean purging and leak detection in the pipeline, which avoids the risk of oxygen or water reacting with the residual trimethylaluminum to damage the CEM and the risk of explosion and fire caused by the generated flammable gas. This not only reduces the safety hazards caused by TMA operation, but also improves the service life of the controllable evaporator mixer CEM, ensures the equipment start-up rate, and avoids the loss of production capacity.
[0024] For the sake of clarity, some terms in this application are explained as follows:
[0025] Trimethylaluminum: Trimethylaluminum, referred to as TMA, is an organic compound with the chemical formula C3H9Al. It is a colorless, transparent liquid. It is mainly used as an olefin polymerization catalyst and ignition fuel. It is also used to prepare straight-chain primary alcohols and olefins, etc. It can also be used for the vapor deposition of metal organic compounds.
[0026] TOPCon battery: It is a tunneling oxide passivation contact battery. The main purpose of this application is to solve the problem that when the PECVD method is used to prepare N-type TOPCon battery alumina, the gas from the process chamber 7 of the alumina equipment flows back into the CEM, resulting in safety hazards caused by TMA operation, short life of the CEM mixing box, long equipment failure time, and low start-up rate.
[0027] PECVD: It is the abbreviation of plasma enhanced chemical vapor deposition. Plasma enhanced chemical vapor deposition technology is a technology that uses plasma energy to form solid deposits by chemical reactions in gaseous or vaporous chemical substances in the gas phase or gas-solid interface in the reactor. Chemical vapor deposition is a process method in which gaseous substances react chemically on the surface of the workpiece, and the reaction products form a solid film layer on the surface of the workpiece. It uses substances containing film-forming elements to deposit single crystal, polycrystalline or amorphous thin films, and is used in microelectronics, optoelectronics and other industries.
[0028] CEM: is the abbreviation of Controlled Evacuate Mixer, which is an evaporation control and mixing system, also known as a controlled evaporation mixer CEM. It is a new liquid delivery system that can be used in atmospheric or vacuum industrial processing. It is a device that can produce mixed gas containing water vapor. It can produce gas mixed with water vapor and another gas in any proportion, and the flow rate and temperature of the gas can be continuously adjusted. Applicable to models such as CEM3002, CEM3020 and CEM3080.
[0029] CDA: Compressed air, full name is compressed air.
[0030] MFC: Mass Flow Controller
[0031] EV: stands for electric control valve. All valves in this application are EV valves. EV valve, that is, EV series electric control valve, is an electric control device with a simple and reliable working principle. It does not require a servo amplifier, and can be easily controlled by directly inputting control signals and single-phase power supply to achieve the adjustment of process parameters such as pressure, flow, temperature, and liquid level. The design of this valve makes it very useful in a variety of industrial applications, especially in situations where precise control of fluid flow is required. In addition, the application of EV valves is not limited to electric adjustment, it can also be used for other types of electric adjustment equipment, such as EV / NC series "A" class gas safety solenoid valves, etc. These devices play an important role in the field of gas safety. For different types of control system output voltages, the connection method of EV valves is also different. For example, for a 220Vac control system, it is necessary to connect the power supply and ground wires according to specific steps to ensure the normal operation and safe use of the valve.
[0032] In some embodiments, see Figure 1 A one-way valve 2, a first pressure buffer 3 and a third control valve EV3 are sequentially arranged on the mixture inlet pipe from the controllable evaporation mixer CEM to the process chamber 7.
[0033] In some embodiments, see Figure 1 A second pressure buffer 5 is also provided on the mixture intake pipe, and the third control valve EV3 is provided between the first pressure buffer 3 and the second pressure buffer 5 .
[0034] The present application sets a bypass argon pipe that skips the CEM between the argon inlet pipe and the process chamber 7, so that the argon gas is diverted and the argon flow rate at the front / rear end of the CEM can be controlled. At the same time, a one-way valve 2, a first pressure buffer 3, a third control valve EV3, a second pressure buffer 5, etc. are sequentially added behind the main road of the CEM to form a purge protection device (which may also include a bypass argon pipe). The one-way valve 2 prevents any gas from flowing back to the CEM and causing damage to it. Before maintenance, the purge and leak detection process is run. The bypass argon pipe is opened for purge first, which will blow out the residual gas in the pipe, and then the main road mixture inlet pipe is purged to avoid any residual process gas flowing back into the mixing box and damaging it. Through the setting of the bypass argon pipe and the purge protection device, even if the process chamber 7 reaches normal pressure and the third control valve EV3 has a gas leak, there is also a pressure buffer protection to avoid damage to the CEM, which increases the service life of the CEM, reduces the safety hazards caused by TMA operation, and ensures the start-up rate of the equipment.
[0035] In some embodiments, see Figure 1 A filter 1 is also provided on the argon gas inlet pipe to filter the incoming argon gas.
[0036] In some embodiments, see Figure 1 A first flow meter MFC1 and a first control valve EV1 are arranged on the argon gas inlet pipe and between the filter 1 and the controllable evaporation mixer CEM.
[0037] In some embodiments, see Figure 1 One end of the bypass argon tube is connected to the argon inlet pipe, and the other end is connected to the mixture inlet pipe.
[0038] In some embodiments, see Figure 1 One end of the bypass argon gas pipe is connected between the filter 1 and the first flowmeter MFC1.
[0039] In some embodiments, see Figure 1 The other end of the bypass argon gas pipe is connected between the one-way valve 2 and the first pressure buffer 3 .
[0040] In some embodiments, see Figure 1 A second flow meter MFC2 and a second control valve EV2 are provided on the bypass argon gas pipe.
[0041] The process of the photovoltaic cell aluminum oxide passivation deposition air intake device provided by the utility model is as follows:
[0042] The purpose of the purge process is mainly to run the purge process when the process chamber 7 needs to be opened due to equipment failure, leak detection or shutdown, to purge the residual TMA in the process chamber 7, and then introduce nitrogen or CDA gas to balance the pressure inside and outside the process chamber 7 so that the cover 10 on the process chamber 7 can be opened.
[0043] (1) See Figure 1 , open the second control valve EV2 on the bypass argon pipe, and introduce argon to purge the bypass (this process ensures that the pressure value of the first pressure gauge 4 on the first pressure buffer 3 is greater than the pressure value of the second pressure gauge 6 on the second pressure buffer 5, and the third control valve EV3 can be opened. At this time, the vacuum pump valve of the process chamber 7 is in an open vacuum state) to the process chamber 7, the time is controlled at 5-10 minutes, and then the second control valve EV2 on the bypass is closed.
[0044] (2) Open the first control valve EV1 on the argon inlet pipe, the one-way valve 2 on the mixture inlet pipe, and the third control valve EV3, bypass the second control valve EV2 on the argon pipe and the second flow meter MFC2 (closed, and argon is introduced into the main pipeline for purging. During this process, the third control valve EV3 can be opened only after ensuring that the pressure value of the first pressure gauge 4 is greater than the pressure value of the second pressure gauge 6. At this time, the vacuum pump of the process chamber 7 is in the open state, and the pressure in the process chamber 7 is maintained at a negative pressure. The purging time is controlled within 5-10 minutes, and then stop introducing argon to allow the vacuum pump to evacuate until the pressure in the process chamber 7 is as low as possible. The time is controlled within 5-10 minutes, and then close the first control valve EV1, the one-way valve 2, and the third control valve EV3.
[0045] (3) When the third control valve EV3 and the CDA supply are closed, the vacuum pump valve of the process chamber 7 is opened to evacuate the chamber, and the pressure value of the second pressure buffer 5 is observed. When the vacuum pressure reaches the set requirement, the vacuum pump valve is closed and the pressure value is recorded.
[0046] (4) Open the second flow meter MFC2 and the second control valve EV2 to introduce argon into the first pressure buffer 3. When the first pressure gauge 4 reaches the process set value, close all bypass valves. This process ensures that the third control valve EV3 and the vacuum pump valve of the process chamber 7 are in the closed state.
[0047] (5) Observe the changes in the pressure values of the first pressure gauge 4 and the second pressure gauge 6. If the pressure value of the first pressure gauge 4 drops rapidly and the pressure value of the second pressure gauge 6 rises rapidly, it is determined that the third control is damaged and leaking and needs to be replaced. Otherwise, it is normal and the next step can be carried out.
[0048] See also Figure 2, wherein a conveyor 12 is provided in the process chamber 7, a heater 13 is provided below the conveyor 12, a graphite boat 11 is provided on the conveyor 12, an electrode 8 and a microwave generator 9 are provided on the top of the process chamber 7, and a cover plate 10 is provided on the top of the process chamber 7. The electrode 8 of the process chamber 7 is electrically connected to an external radio frequency power supply.
[0049] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A photovoltaic cell aluminum oxide passivation deposition air intake device, characterized in that: include: A controllable evaporation mixer (CEM) and a process chamber (7); the controllable evaporation mixer (CEM) is provided with a trimethylaluminum liquid inlet pipe and an argon gas inlet pipe, a mixture gas inlet pipe is provided between the process chamber (7) and the controllable evaporation mixer (CEM), and the process chamber (7) is provided with a first gas inlet pipe for balancing internal and external pressures; the argon gas inlet pipe is also provided with a bypass argon gas pipe directly connected to the process chamber (7).
2. The photovoltaic cell aluminum oxide passivation deposition air intake device according to claim 1, characterized in that: A one-way valve (2), a first pressure buffer (3) and a third control valve (EV3) are sequentially arranged on the mixture inlet pipe from the controllable evaporation mixer (CEM) to the process chamber (7).
3. The photovoltaic cell aluminum oxide passivation deposition air intake device according to claim 2, characterized in that: A second pressure buffer (5) is also provided on the mixture intake pipe, and the third control valve (EV3) is provided between the first pressure buffer (3) and the second pressure buffer (5).
4. The photovoltaic cell aluminum oxide passivation deposition air intake device according to claim 2, characterized in that: A filter (1) is also provided on the argon gas inlet pipe.
5. The photovoltaic cell aluminum oxide passivation deposition air inlet device according to claim 4, characterized in that: A first flow meter (MFC1) and a first control valve (EV1) are arranged on the argon gas inlet pipe and between the filter (1) and the controllable evaporation mixer (CEM).
6. The photovoltaic cell aluminum oxide passivation deposition air inlet device according to claim 5, characterized in that: One end of the bypass argon pipe is connected to the argon inlet pipe, and the other end is connected to the mixture inlet pipe.
7. The photovoltaic cell aluminum oxide passivation deposition gas inlet device according to claim 6, characterized in that: One end of the bypass argon gas pipe is connected between the filter (1) and the first flow meter (MFC1).
8. The photovoltaic cell aluminum oxide passivation deposition gas inlet device according to claim 6, characterized in that: The other end of the bypass argon gas pipe is connected between the one-way valve (2) and the first pressure buffer (3).
9. The photovoltaic cell aluminum oxide passivation deposition gas inlet device according to claim 1, characterized in that: The bypass argon gas pipe is provided with a second flow meter (MFC2) and a second control valve (EV2).