Device for treating TMA in coating process tail gas

Abstract

The utility model discloses a device for treating TMA in coating process tail gas, which comprises a process cavity and a vacuum pump, a cooling mechanism and an adsorption mechanism are arranged between the process cavity and the vacuum pump, the cooling mechanism is connected with the process cavity, the adsorption mechanism is connected with the vacuum pump, and the cooling mechanism is connected with the adsorption mechanism. The adsorption mechanism comprises an adsorption shell and an adsorption frame arranged in the adsorption shell. According to the utility model, the cooling mechanism and the adsorption mechanism are arranged, so that gaseous TMA is converted into liquid after entering the cooling mechanism, and the liquid TMA is adsorbed by the adsorption mechanism. And the gaseous TMA which cannot be directly converted into the liquid state reacts with water vapor to promote the conversion of the gaseous TMA. The method ensures that gaseous TMA can be completely converted into liquid TMA, the TMA content in the tail gas is effectively reduced, and pollution caused by the fact that TMA is filtered and enters a vacuum pump is prevented to the maximum extent, so that corrosion and damage to equipment are avoided, the service life of the equipment is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of coating process exhaust gas treatment technology, specifically a device for treating TMA in coating process exhaust gas. Background Art

[0002] Solar photovoltaic (PV) cells are a new type of battery that directly converts sunlight into electrical energy. They typically use silicon as a substrate and operate based on the photovoltaic effect of the PN junction in semiconductor physics. To reduce the recombination loss of minority carriers within the PN junction and increase sunlight absorption to improve the cell's photoelectric conversion efficiency, a passivation coating is applied to the silicon substrate. Passivation film materials include alumina and silicon nitride. These coating deposition processes generate exhaust gas and dust, requiring vacuum pump equipment to stabilize the voltage in the process chamber and extract the exhaust gas.

[0003] Taking ALD as an example, ALD atomic layer deposition equipment is a special process equipment used for coating on the surface of silicon wafers. Its working principle is to alternately introduce gaseous precursor TMA (trimethylaluminum) and O3 (ozone) or water vapor pulses into the reaction chamber, and deposit Al2O3 thin film on the surface of silicon substrate through continuous and self-limiting reaction. Only one atomic layer is deposited at a time. This process involves the generation of various precursor gases and reaction products.

[0004] The exhaust gas consists of precursor residues, reaction byproducts, carrier gas, and possible dopant gases. It is extracted from the process chamber by a vacuum pump. Due to the large amount of dust it carries, a particulate filter is installed between the vacuum pump and the process chamber for filtration. The filtered exhaust gas then enters the vacuum pump. If the dust content is too high, or if it carries too much unreacted TMA, it will contaminate the vacuum pump body, accumulating dust particles on the pump rotor and reducing the lifespan of the vacuum pump. Therefore, a device for treating TMA in the exhaust gas from the coating process is proposed. Utility Model Content

[0005] The purpose of this invention is to provide an apparatus for treating TMA in the exhaust gas of a coating process, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a device for treating TMA in coating process exhaust gas, comprising a process chamber and a vacuum pump, wherein a cooling mechanism and an adsorption mechanism are provided between the process chamber and the vacuum pump, the cooling mechanism is connected to the process chamber, the adsorption mechanism is connected to the vacuum pump, the cooling mechanism and the adsorption mechanism are connected, the adsorption mechanism comprises an adsorption shell and an adsorption rack disposed within the adsorption shell, wherein adsorption material is provided on the adsorption rack in a gap arrangement.

[0007] As a further embodiment of this invention, the adsorbent material is activated carbon, but silica gel or activated alumina may also be used.

[0008] As a further embodiment of this invention: the adsorption shell is connected to the vacuum pump via an exhaust pipe.

[0009] As a further embodiment of this invention, a gas guiding structure is provided between the cooling mechanism and the adsorption mechanism.

[0010] As a further embodiment of this utility model: the cooling mechanism includes a housing, which is connected to the exhaust gas pipe and the adsorption housing respectively, and a heat exchanger is installed inside the housing.

[0011] As a further embodiment of this utility model: the process chamber and the shell are connected by an exhaust gas pipe.

[0012] As a further embodiment of this utility model, a water vapor pipe is installed on the outer peripheral surface of the shell.

[0013] As a further embodiment of this utility model, a liquid nitrogen inlet pipe and a liquid nitrogen exhaust pipe are also installed on the outer peripheral surface of the shell.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] This application incorporates a cooling mechanism and an adsorption mechanism to transform gaseous TMA into a liquid state upon entering the cooling mechanism, where it is then adsorbed by the adsorption mechanism. For gaseous TMA that cannot be directly transformed into a liquid state, its transformation is induced by reaction with water vapor. This method ensures that gaseous TMA is completely converted into a liquid state, effectively reducing the TMA content in the exhaust gas, minimizing contamination caused by TMA filtration entering the vacuum pump, thereby avoiding corrosion and damage to the equipment, extending its service life, and reducing maintenance costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the gas guiding structure of this utility model;

[0018] Figure 3 This is a schematic diagram of the adsorption rack of this utility model;

[0019] In the diagram: 1. Process chamber; 2. Vacuum pump; 3. Cooling mechanism; 3-1. Shell; 3-2. Heat exchanger; 4. Adsorption mechanism; 4-1. Adsorption shell; 4-2. Adsorption rack; 4-3. Adsorption material; 5. Tail gas pipe; 6. Exhaust pipe; 7. Water vapor pipe; 8. Liquid nitrogen inlet pipe; 9. Liquid nitrogen exhaust pipe; 10. Gas flow guiding structure. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] Please see Figure 1-3 In this embodiment of the invention, an apparatus for treating TMA in coating process exhaust gas includes a process chamber 1 and a vacuum pump 2. A cooling mechanism 3 and an adsorption mechanism 4 are provided between the process chamber 1 and the vacuum pump 2. The cooling mechanism 3 and the adsorption mechanism 4 filter the process exhaust gas entering the vacuum pump 2 from the process chamber 1 to prevent excessive dust from entering the interior of the vacuum pump 2. The cooling mechanism 3 is connected to the process chamber 1, and the adsorption mechanism 4 is connected to the vacuum pump 2. The cooling mechanism 3 and the adsorption mechanism 4 are connected, so that the process exhaust gas can enter the vacuum pump 2 after passing through multiple layers of treatment by the cooling mechanism 3 and the adsorption mechanism 4 in sequence. Inside the pump 2, the adsorption mechanism 4 includes an adsorption housing 4-1 and an adsorption frame 4-2 located inside the adsorption housing 4-1. The adsorption frame 4-2 is provided with adsorption materials 4-3 arranged in a gap. The outer diameter of the adsorption frame 4-2 is adapted to the inner diameter of the adsorption housing 4-1, which can provide a more stable installation for the adsorption frame 4-2 and ensure that the process exhaust gas will inevitably pass through the adsorption frame 4-2 when passing through the inside of the adsorption housing 4-1. Secondly, the adsorption housing 4-1 can also play the role of guiding the exhaust gas. The setting of the adsorption frame 4-2 facilitates the intermittent arrangement of the adsorption materials 4-3 and allows for the replacement of the entire structure when it is saturated with adsorption.

[0022] Please see Figure 3 In one embodiment, preferably, the adsorbent 4-3 is activated carbon, but silica gel or activated alumina may also be used.

[0023] Specifically, when the adsorbent material 4-3 is activated carbon, activated carbon is an adsorbent material with both physical and chemical adsorption characteristics. It has a well-developed pore structure, a large specific surface area, unique surface characteristics, stable chemical properties, easy regeneration, and strong adsorption capacity. It also has a huge specific surface area and a fine porous surface structure, including micropores and mesopores, making it suitable for adsorbing various substances. It can effectively adsorb liquid TMA. To ensure sufficient contact between activated carbon and liquid TMA, the activated carbon layer is filled with granular activated carbon, and multiple layers of activated carbon are used to increase the adsorption area and gaps of the activated carbon, thereby improving the adsorption effect. The large gaps are also suitable for the adsorption of liquid TMA. The gap structure of the activated carbon is used to achieve airflow dispersion, so that the exhaust gas forms turbulence in the particulate filter, increasing the collision opportunities between liquid TMA and activated carbon.

[0024] When the adsorbent 4-3 is silica gel, it can interact with liquid trimethylaluminum. On the one hand, the porous structure of silica gel can physically adsorb and contain liquid trimethylaluminum molecules. On the other hand, silanol groups may chemically adsorb with trimethylaluminum, such as forming coordinate bonds. This adsorption method has a good effect on removing liquid trimethylaluminum.

[0025] When the adsorbent 4-3 is activated alumina, it can also be used to adsorb liquid trimethylaluminum. Activated alumina, as a porous and highly dispersed solid material, possesses a large specific surface area and various pore structures, making it widely applicable in the adsorption field. Specifically regarding the adsorption of liquid trimethylaluminum, although research directly targeting this specific application may be limited, considering the good affinity of activated alumina for other organic and inorganic pollutants, it also exhibits a certain adsorption capacity for liquid trimethylaluminum.

[0026] Please see Figure 1 In one embodiment, preferably, the adsorption shell 4-1 is connected to the vacuum pump 2 via an exhaust pipe 6. Furthermore, the filtered process exhaust gas can enter the interior of the vacuum pump 2 through the exhaust pipe 6.

[0027] Please see Figure 2-3 In one embodiment, preferably, a gas guiding structure 10 is provided between the cooling mechanism 3 and the adsorption mechanism 4. The gas guiding structure 10 is implemented by a spiral structure, which guides the exhaust gas flow through the inlet of the adsorption shell 4-1 to the structural inlet composed of the adsorption frame 4-2 and the adsorption material 4-3, ensuring that the cooled exhaust gas can be concentrated through the interior of the adsorption material 4-3.

[0028] Please see Figure 1In one embodiment, preferably, the cooling mechanism 3 includes a housing 3-1, which is connected to the exhaust gas pipe 5 and the adsorption housing 4-1 respectively. A heat exchanger 3-2 is installed inside the housing 3-1. The process chamber 1 is connected to the housing 3-1 through the exhaust gas pipe 5. Further, the process exhaust gas generated in the process chamber 1 enters the interior of the housing 3-1 through the exhaust gas pipe 5. Then, under the action of the heat exchanger 3-2, the gaseous TMA is converted into liquid TMA. The liquid is adsorbed by the adsorption material 3-3, and the gaseous state that has not yet been converted is reacted by water vapor.

[0029] Please see Figure 1 In one embodiment, preferably, a water vapor pipe 7 is installed on the outer peripheral surface of the shell 3-1. The water vapor pipe 7 can inject water vapor into the interior of the shell 3-1 to ensure that the interior of the shell 3-1 is filled with water vapor, so as to better react with the gaseous TMA.

[0030] Please see Figure 1 In one embodiment, preferably, the outer peripheral surface of the housing 3-1 is also equipped with a liquid nitrogen inlet pipe 8 and a liquid nitrogen exhaust pipe 9. The inlet of the liquid nitrogen inlet pipe 8 is connected to the inlet of the heat exchanger 3-2, and the liquid nitrogen exhaust pipe 9 is connected to the outlet of the heat exchanger 3-2. The heat exchanger 3-2 is arranged in a spiral shape, which can increase the contact area with the exhaust gas in a limited space.

[0031] The working principle and usage process of this utility model are as follows: The process exhaust gas generated in the process chamber 1 enters the shell 3-1 through the exhaust gas pipe 5. At the same time, water vapor enters the shell 3-1 through the water vapor pipe 7, filling the interior with water vapor. Liquid nitrogen enters the heat exchanger 3-2 through the liquid nitrogen inlet pipe 8 and is discharged through the liquid nitrogen exhaust pipe 9. Under the action of the heat exchanger 3-2, the process exhaust gas changes from gaseous TMA to liquid TMA. The unconverted gaseous TMA will also change after combining with water vapor. The converted TMA is adsorbed by the adsorption material 4-3. After the liquid TMA in the exhaust gas is adsorbed, the exhaust gas enters the interior of the vacuum pump 2 through the exhaust pipe 6.

[0032] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0033] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. An apparatus for treating TMA in the exhaust gas of a coating process, comprising a process chamber (1) and a vacuum pump (2), characterized in that, A cooling mechanism (3) and an adsorption mechanism (4) are provided between the process chamber (1) and the vacuum pump (2). The cooling mechanism (3) is connected to the process chamber (1), and the adsorption mechanism (4) is connected to the vacuum pump (2). The cooling mechanism (3) and the adsorption mechanism (4) are connected. The adsorption mechanism (4) includes an adsorption shell (4-1) and an adsorption rack (4-2) disposed in the adsorption shell (4-1). The adsorption rack (4-2) is provided with adsorption material (4-3) arranged in a gap.

2. The apparatus for treating TMA in coating process exhaust gas according to claim 1, characterized in that, The adsorbent material (4-3) is activated carbon, but silica gel or activated alumina may also be used.

3. The apparatus for treating TMA in coating process exhaust gas according to claim 1, characterized in that, The adsorption shell (4-1) is connected to the vacuum pump (2) through an exhaust pipe (6).

4. The apparatus for treating TMA in coating process exhaust gas according to claim 1, characterized in that, A gas guiding structure (10) is provided between the cooling mechanism (3) and the adsorption mechanism (4).

5. The apparatus for treating TMA in coating process exhaust gas according to claim 1, characterized in that, The cooling mechanism (3) includes a housing (3-1), which is connected to the exhaust pipe (5) and the adsorption housing (4-1) respectively. A heat exchanger (3-2) is installed inside the housing (3-1).

6. The apparatus for treating TMA in coating process exhaust gas according to claim 5, characterized in that, The process chamber (1) is connected to the shell (3-1) via an exhaust pipe (5).

7. The apparatus for treating TMA in coating process exhaust gas according to claim 5, characterized in that, A water vapor pipe (7) is installed on the outer circumferential surface of the shell (3-1).

8. The apparatus for treating TMA in coating process exhaust gas according to claim 5, characterized in that, The outer circumferential surface of the shell (3-1) is also equipped with a liquid nitrogen inlet pipe (8) and a liquid nitrogen exhaust pipe (9).

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