Protection device of pressure control device for silicon carbide powder synthesis system

Abstract

The utility model relates to the technical field of silicon carbide powder synthesis, in particular to a protection device of a pressure control device for a silicon carbide powder synthesis system, which comprises a chamber, a filter arranged in the chamber and close to the top of the chamber, and an air inlet pipeline and an air outlet pipeline arranged above the chamber and extending into the chamber, the filter is parallel to the upper end surface or the bottom surface of the cavity; the air inlet pipeline extends to the lower part of the filter sheet; and the air outlet pipeline extends to the upper part of the filter sheet. The protection device can be used for condensing, depositing and filtering tail gas discharged from the deposition chamber, so that substances such as methyl trichlorosilane, silicon powder, carbon powder and silicon carbide powder mixed in the tail gas are deposited in the chamber, and the tail gas discharged from the deposition chamber is prevented from directly entering and exiting the pressure control device to cause impact and corrosion to the pressure control device; the problem that in the prior art, substances mingled in tail gas cause erosion and damage to a tail gas pipeline and a pressure control device is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon carbide powder synthesis, in particular to a protection device for a pressure control device of a silicon carbide powder synthesis system. Background Art

[0002] Silicon carbide (SiC) single crystal is a third-generation semiconductor material developed after Si and GaAs. It has the characteristics of wide bandgap, high thermal conductivity, high breakdown field strength, high carrier saturation and high radiation resistance. In recent years, silicon carbide crystal materials have rapidly penetrated into every corner of lighting, electronic power devices and other fields; and its market size is still increasing rapidly, becoming one of the directions of future new energy development.

[0003] At present, silicon carbide substrates are usually prepared by physical vapor transport (PVT). When using physical vapor transport (PVT) to prepare silicon carbide single crystals, the growth source of silicon carbide single crystals comes from silicon carbide powder. Therefore, the purity and particle size of the silicon carbide powder play a vital role in the growth of silicon carbide single crystals and will directly affect the crystal quality of the grown single crystals.

[0004] Currently, silicon carbide powder is commonly synthesized using the self-propagating method (SHP), which involves uniformly mixing high-purity silicon powder with carbon powder and then heating it to a high temperature to cause the two powders to react. However, due to the high production costs of high-purity graphite and silicon powders, the cost of synthesizing silicon carbide powder is also high. Furthermore, due to the limitations of the SHP synthesis process, it is difficult to synthesize large-particle, high-purity silicon carbide powder. In order to reduce the synthesis cost of silicon carbide powder and synthesize silicon carbide powder with large particle size, some companies have tried to use chemical vapor deposition process to synthesize silicon carbide powder. Although this synthesis method has the application prospects of low cost, high purity and high production capacity, the processes and equipment supporting this synthesis method are still in the exploratory stage. For example, in the process of improving the production capacity of chemical vapor deposition, problems such as incomplete reaction of carbon source and silicon source and homogeneous reaction caused by excessive air intake rate will be faced. This will cause the exhaust gas discharged from the deposition chamber to be mixed with unreacted methyltrichlorosilane (MTS), silicon powder or carbon powder produced by homogeneous reaction, and silicon carbide powder. These atmospheres or powders will inevitably cause erosion and damage to the exhaust pipeline and pressure control device.

[0005] The utility model provides a protective device for a pressure control device of a synthetic silicon carbide powder system, so as to solve the problem in the prior art that substances such as methyltrichlorosilane, silicon powder, carbon powder, and silicon carbide powder mixed in the tail gas cause erosion and damage to the tail gas pipeline and the pressure control device. Utility Model Content

[0006] The purpose of the utility model is to provide a protective device for a pressure control device of a synthetic silicon carbide powder system, so as to solve the problem in the prior art that substances such as methyltrichlorosilane, silicon powder, carbon powder, and silicon carbide powder mixed in the tail gas cause erosion and damage to the tail gas pipeline and the pressure control device.

[0007] The technical solution of the utility model is: a protective device for a pressure control device for a synthetic silicon carbide powder system, comprising a chamber, a filter disc arranged inside the chamber and near the top of the chamber, an air inlet pipe and an air outlet pipe arranged above the chamber and extending into the chamber; the filter disc is parallel to the upper end surface or bottom surface of the chamber; the air inlet pipe extends to the bottom of the filter disc; and the air outlet pipe extends to the top of the filter disc.

[0008] Preferably, a support platform is provided on the inner side wall of the chamber, and the filter plate is provided on the support platform.

[0009] Preferably, the chamber comprises a cavity and an upper cover; the upper cover is connected to the cavity via a twisted buckle structure or a threaded connection;

[0010] A support pad is provided in the upper cover and on the inner peripheral side of the side wall of the upper cover, and is used to interact with the support platform after the upper cover is fixedly connected to the cavity to constrain and fix the filter plate.

[0011] Preferably, the air intake pipeline includes an air intake pipe and a first cooling water pipe which are coaxially arranged; the first cooling water pipe is arranged on the outside of the air intake pipe;

[0012] The first cooling water pipe is provided with a first water inlet at the upper end and a first water outlet at the lower end;

[0013] The air outlet pipe includes a coaxially arranged air outlet pipe and a second cooling water pipe; the second cooling water pipe is arranged on the outside of the air outlet pipe; the upper end of the second cooling water pipe is provided with a second water outlet, and the lower end is provided with a second water inlet; the first water outlet and the second water inlet are connected through a water flow pipe.

[0014] Preferably, a protective inner sleeve is provided in the air intake pipe;

[0015] The protective inner sleeve is arranged on the inner side of the air intake pipe and is arranged in contact with the inner wall of the air intake pipe.

[0016] Preferably, the air intake pipe includes an upper air intake pipe and a lower air intake pipe connected through a sealing sleeve; the first cooling water pipe includes a first upper cooling water pipe and a first lower cooling water pipe connected through a sealing sleeve;

[0017] The first water inlet is provided at the upper end of the first upper cooling water pipe; the first water outlet is provided at the lower end of the first lower cooling water pipe;

[0018] The air outlet pipe includes an upper air outlet pipe and a lower air outlet pipe connected through a sealing sleeve; the second cooling water pipe includes a second upper cooling water pipe and a second lower cooling water pipe connected through a sealing sleeve;

[0019] The second water outlet is arranged at the upper end of the second upper cooling water pipe; the second water inlet is arranged at the lower end of the second lower cooling water pipe.

[0020] Preferably, sealing gaskets are provided at positions of the air inlet pipe and the air outlet pipe that contact the upper cover.

[0021] Preferably, a liquid outlet is provided on the side wall of the chamber and near the bottom of the chamber.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] The utility model provides a protective device for a pressure control device of a system for synthesizing silicon carbide powder. The protective device can condense, deposit, and filter the tail gas discharged from a deposition chamber of the silicon carbide powder, so that substances such as methyltrichlorosilane, silicon powder, carbon powder, and silicon carbide powder mixed in the tail gas are deposited in the chamber, thereby preventing the tail gas discharged from the deposition chamber from directly entering and exiting the pressure control device and causing impact and corrosion thereto. The problem in the prior art that substances such as methyltrichlorosilane, silicon powder, carbon powder, and silicon carbide powder mixed in the tail gas cause erosion and damage to the tail gas pipeline and the pressure control device is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0025] Figure 1 This is an example diagram of the three-dimensional structure of the protective device of the present invention;

[0026] Figure 2 This is a structural example diagram of the protection device of the present utility model;

[0027] Figure 3 This is a structural example diagram of the air intake pipe of the present invention;

[0028] Figure 4 This is a structural example diagram of the air outlet pipeline of the utility model;

[0029] Among them: 1. Chamber; 11. Cavity; 12. Upper cover; 2. Filter; 3. Air inlet pipe; 31. Air inlet pipe; 311. Upper air inlet pipe; 312. Lower air inlet pipe; 32. First cooling water pipe; 321. First upper cooling water pipe; 322. First lower cooling water pipe; 33. First water inlet; 34. First water outlet; 4. Air outlet pipe; 41. Air outlet pipe; 411. Upper air outlet pipe; 412. Lower air outlet pipe; 42. Second cooling water pipe; 421. Second upper cooling water pipe; 422. Second lower cooling water pipe; 43. Second water inlet; 44. Second water outlet; 5. Support platform; 6. Support pad; 7. Sealing gasket; 8. Liquid outlet; 9. Sealing sleeve. DETAILED DESCRIPTION

[0030] The following is a further detailed description of the present invention in conjunction with specific embodiments:

[0031] A protective device for a pressure control device used in a silicon carbide powder synthesis system, such as Figure 1 As shown, it includes a chamber 1, a filter 2, an air inlet pipe 3 and an air outlet pipe 4; wherein, as Figure 2As shown, the filter 2 is arranged inside the chamber 1 and is arranged near the top of the chamber 1 to filter the silicon powder, carbon powder, silicon carbide powder and other dust in the exhaust gas; and the filter 2 is parallel to the upper end surface or bottom surface of the chamber 1; the air inlet pipe 3 and the air outlet pipe 4 are both arranged above the chamber 1, and one end of the air inlet pipe 3 and the air outlet pipe 4 extends into the interior of the chamber 1, the other end of the air inlet pipe 3 is connected to the deposition chamber of the synthetic silicon carbide powder, and the other end of the air outlet pipe 4 is connected to the deposition chamber of the synthetic carbon powder. The pressure control device used in the silicon powder system is connected and is used to transport the exhaust gas flowing out of the deposition chamber into the chamber 1, where it is condensed, deposited, filtered, and other processes are carried out. The treated gas in the chamber 1 is then transported to the pressure control device. At the same time, in order to better condense, deposit, filter, and other processes of the exhaust gas, the inlet pipe 3 needs to extend to the bottom of the filter 2, and the outlet pipe 4 only needs to extend to the top of the filter 2. The filter 2 is provided with a hole for the inlet pipe 3 to pass through. The diameter of the filter 2 is slightly smaller than the inner diameter of the chamber 1, so that the filter 2 can be easily installed in the chamber 1 and filter the exhaust gas transported into the chamber 1. A support platform 5 is provided on the inner wall of the chamber 1 for placing the filter 2 on the support platform 5, which supports and limits the filter 2 and prevents it from falling. In this embodiment, the support platform 5 is an annular platform coaxially arranged with the chamber 1, and the outer side of the annular platform is fixedly connected to the inner wall of the chamber 1; in other embodiments, the support platform 5 can be two or more support blocks, and the two or more support blocks are all arranged at the same height on the inner wall of the chamber 1 and are evenly distributed on the inner wall of the chamber 1 to support and limit the filter 2. In this embodiment or other embodiments, the main material of the chamber 1 is preferably 316L; the material of the air inlet pipe 3 and the air outlet pipe 4 is preferably polytetrafluoroethylene or 316L; the material of the filter 2 is 316L, porous graphite or porous ceramic, and the mesh number of the filter 2 is ≥300 mesh.

[0032] The chamber 1 includes a cavity 11 and an upper cover 12; the upper cover 12 is connected to the cavity 11 by a threaded connection, so that the chamber 1 is in a sealed state; wherein, a support pad 6 is provided in the upper cover 12; the support pad 6 is provided on the inner peripheral side of the side wall of the upper cover 12, and is used to interact with the support platform 5 after the upper cover 12 is fixedly connected to the cavity 11, so as to realize the constraint and fixation of the filter plate 2; the upper cover 12 is also provided with a through hole for the air inlet pipe 3 and the air outlet pipe 4 to pass through.

[0033] In this embodiment, if Figure 2As shown, the air intake pipe 3 includes a coaxially arranged air intake pipe 31 and a first cooling water pipe 32; and the first cooling water pipe 32 is arranged on the outside of the air intake pipe 31; the upper end of the first cooling water pipe 32 is provided with a first water inlet 33, and the lower end is provided with a first water outlet 34; a protective inner sleeve 35 is also provided in the air intake pipe 3; and the protective inner sleeve 35 is provided on the inner side of the air intake pipe 31 and fits with the inner side wall of the air intake pipe 31 to reduce the thermal shock and corrosion of methyltrichlorosilane, silicon powder, carbon powder, silicon carbide powder and other substances in the exhaust gas to the air intake pipe 31, thereby extending the service life of the air intake pipe 31; the protective inner sleeve 35 can use Si C. Alumina, silicon nitride or graphite. In addition, since the gas temperature in the process of synthesizing silicon carbide powder by chemical vapor deposition is higher than 900°C, the gas and dust in the exhaust gas cause thermal erosion to the pipeline. Therefore, a high-temperature resistant graphite protective inner sleeve 35 is preferably used to protect the intake pipe 31. The outlet pipe 4 includes a coaxially arranged outlet pipe 41 and a second cooling water pipe 42; the second cooling water pipe 42 is arranged on the outside of the outlet pipe 41; and a second water outlet 44 is provided at the upper end of the second cooling water pipe 42, and a second water inlet 43 is provided at the lower end; at the same time, the first water outlet 34 on the intake pipe 3 is connected to the second water inlet 43 on the outlet pipe 4 through a water flow pipe; the cooling medium enters the first cooling water pipe 32 from the first water inlet 33 on the intake pipe 3 to cool the exhaust gas in the intake pipe 31, and the cooling medium in the first cooling water pipe 32 flows into the second cooling water pipe 42 through the first water outlet 34, the water flow pipe and the second water inlet 43, and then flows out from the second water outlet 44 at the upper end of the outlet pipe 4.

[0034] In this embodiment, the air inlet pipe 31, the air outlet pipe 41, the first and second cooling water pipes 42, etc. are all integrally formed pipes; in other embodiments, the air inlet pipe 31, the air outlet pipe 41, the first and second cooling water pipes 42, etc. can be composed of multiple sections of pipes connected by a sealing sleeve 9; for example, Figure 3 As shown, the air intake pipe 31 includes an upper air intake pipe 311 and a lower air intake pipe 312 connected through a sealing sleeve 9; the first cooling water pipe 32 includes a first upper cooling water pipe 321 and a first lower cooling water pipe 322 connected through a sealing sleeve 9; and the upper air intake pipe 311 and the first upper cooling water pipe 321 are arranged outside the chamber 1, and the lower air intake pipe 312 and the first lower cooling water pipe 322 are arranged inside the chamber 1; the first water inlet 33 is arranged at the upper end of the first upper cooling water pipe 321, and the first water outlet 34 is arranged at the lower end of the first lower cooling water pipe 322; similarly, as Figure 4As shown, the air outlet pipe 41 includes an upper air outlet pipe 411 and a lower air outlet pipe 412 which are connected through a sealing sleeve 9; the second cooling water pipe 42 includes a second upper cooling water pipe 421 and a second lower cooling water pipe 422 which are connected through a sealing sleeve 9; the upper air outlet pipe 411 and the second upper cooling water pipe 421 are arranged outside the chamber 1, and the lower air outlet pipe 412 and the second lower cooling water pipe 422 are arranged inside the chamber 1; the second water outlet 44 is arranged at the upper end of the second upper cooling water pipe 421; and the second water inlet 43 is arranged at the lower end of the second lower cooling water pipe 422.

[0035] Sealing gaskets 7 are also provided at the positions where the outer sides of the air inlet pipe 3 and the air outlet pipe 4 contact the upper cover 12, so that the air inlet pipe 3 and the air outlet pipe 4 are in sealed contact with the upper cover 12, thereby improving the sealing performance of the chamber 1.

[0036] In addition, a liquid outlet 8 is provided on the side wall of the chamber 1 and near the bottom of the chamber 1 for regularly discharging dust particles such as liquid methyltrichlorosilane, silicon powder, carbon powder, and silicon carbide powder deposited in the chamber 1.

[0037] Filling particles are also provided in the chamber 1 of the protection device; and the filling particles are preferably silicon carbide particles, which are used to separate methyltrichlorosilane and dust such as silicon powder, carbon powder, silicon carbide powder, etc. in the tail gas from other gases.

[0038] When the protection device is in working condition, the exhaust gas flowing out of the silicon carbide powder deposition chamber can be transported into the chamber 1 through the air inlet pipe 31. Under the cooling of the cooling medium in the first cooling water pipe 32, the unreacted methyltrichlorosilane in the exhaust gas is condensed into liquid and deposited inside the chamber 1 together with dust particles such as silicon powder, carbon powder, and silicon carbide powder. The treated pure atmosphere, including hydrogen, argon, hydrogen chloride gas, etc., passes through the filter 2 under the action of the pressure difference and flows into the subsequent pressure control device from the air outlet pipe 41. This can effectively prevent the exhaust gas from directly entering the pressure control device and causing impact, corrosion and damage to the pressure control device.

[0039] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they are not intended to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A protective device for a pressure control device for a system for synthesizing silicon carbide powder, characterized in that: The invention comprises a chamber (1), a filter (2) arranged inside the chamber (1) and close to the top of the chamber (1), an air inlet pipe (3) and an air outlet pipe (4) arranged above the chamber (1) and extending into the chamber (1); the filter (2) is parallel to the upper end surface or bottom surface of the chamber (1); the air inlet pipe (3) extends to the bottom of the filter (2); the air outlet pipe (4) extends to the top of the filter (2); the air inlet pipe (3) comprises a coaxially arranged air inlet pipe (31) and a first cooling water pipe (32); the first cooling water pipe (32) is arranged outside the air inlet pipe (31); The first cooling water pipe (32) is provided with a first water inlet (33) at its upper end and a first water outlet (34) at its lower end; The air outlet pipe (4) comprises a coaxially arranged air outlet pipe (41) and a second cooling water pipe (42); the second cooling water pipe (42) is arranged outside the air outlet pipe (41); the upper end of the second cooling water pipe (42) is provided with a second water outlet (44), and the lower end is provided with a second water inlet (43); the first water outlet (34) and the second water inlet (43) are connected through a water flow pipe.

2. The protective device for a pressure control device for a silicon carbide powder synthesis system according to claim 1, characterized in that: A support platform (5) is provided on the inner side wall of the chamber (1), and the filter plate (2) is provided on the support platform (5).

3. The protective device for a pressure control device for a silicon carbide powder synthesis system according to claim 2, characterized in that: The chamber (1) comprises a cavity (11) and an upper cover (12); the upper cover (12) is connected to the cavity (11) via a twisting buckle structure or via a threaded connection; A support pad (6) is provided in the upper cover (12) and is arranged on the inner circumference of the side wall of the upper cover (12). The support pad is used to interact with the support platform (5) after the upper cover (12) is fixedly connected to the cavity (11) to constrain and fix the filter plate (2).

4. The protective device for a pressure control device for a silicon carbide powder synthesis system according to claim 3, characterized in that: A protective inner sleeve (35) is provided in the air intake pipe (3); The protective inner sleeve (35) is arranged on the inner side of the air intake pipe (31) and is arranged in contact with the inner side wall of the air intake pipe (31).

5. The protective device for a pressure control device for a system for synthesizing silicon carbide powder according to claim 3, characterized in that: The air intake pipe (31) includes an upper air intake pipe (311) and a lower air intake pipe (312) connected via a sealing sleeve (9); the first cooling water pipe (32) includes a first upper cooling water pipe (321) and a first lower cooling water pipe (322) connected via a sealing sleeve (9); The first water inlet (33) is provided at the upper end of the first upper cooling water pipe (321); the first water outlet (34) is provided at the lower end of the first lower cooling water pipe (322); The air outlet pipe (41) includes an upper air outlet pipe (411) and a lower air outlet pipe (412) connected via a sealing sleeve (9); the second cooling water pipe (42) includes a second upper cooling water pipe (421) and a second lower cooling water pipe (422) connected via a sealing sleeve (9); The second water outlet (44) is provided at the upper end of the second upper cooling water pipe (421); and the second water inlet (43) is provided at the lower end of the second lower cooling water pipe (422).

6. The protective device for a pressure control device for a silicon carbide powder synthesis system according to claim 3, characterized in that: Sealing gaskets (7) are sleeved on the positions of the air inlet pipe (3) and the air outlet pipe (4) that contact the upper cover (12).

7. The protective device for a pressure control device for a silicon carbide powder synthesis system according to claim 2, characterized in that: A liquid outlet (8) is provided on the side wall of the chamber (1) and near the bottom of the chamber (1).

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