Gas drainage mechanism for forming silicon carbide crystals

Abstract

The utility model relates to the technical field of silicon carbide crystal forming, and discloses a gas drainage mechanism for silicon carbide crystal forming, which comprises a heat insulation outer cylinder, an induction heating coil is arranged in the heat insulation outer cylinder, and a graphite crucible is arranged in the heat insulation outer cylinder. A top cover is installed between the top end of the heat insulation outer cylinder and the top end of the graphite crucible, an air inlet pipe is fixedly installed at the top end of the top cover, a porous graphite layer is installed at the bottom end of the interior of the graphite crucible, an exhaust pipe is fixedly connected to the bottom end of the porous graphite layer, and the exhaust pipe is inserted into the bottom end of the exterior of the heat insulation outer cylinder. A porous graphite layer is arranged at the bottom end of the heat insulation outer cylinder, a transverse groove is formed in the bottom end of the heat insulation outer cylinder, a rectangular groove is formed in the top end of the transverse groove, and a limiting mechanism used for fixing an exhaust pipe is arranged in the rectangular groove. When the porous graphite layer is damaged, the porous graphite layer is convenient to replace.

Description

TECHNICAL FIELD

[0001] The utility model relates to silicon carbide crystal forming technical field, specifically, relate to a kind of gas drainage mechanism for silicon carbide crystal forming. BACKGROUND

[0002] The heater around the crucible in the furnace cavity of the general silicon carbide crystal growth furnace generates heat during the crystal growth process, heating the silicon carbide raw material in the crucible, causing the silicon carbide raw material to sublimate, and then recrystallizing on the seed crystal bonded to the crucible cover to form a silicon carbide single crystal. One of the reasons for the hydrogen gas passing through the silicon carbide crystal growth furnace is that hydrogen gas has a low density. After the hydrogen gas enters the furnace, it moves upward. This characteristic forces the nitrogen gas remaining in the raw material to move downward. An exhaust hole is provided below the position where the hydrogen gas is introduced, which helps to exhaust the nitrogen gas. The porous graphite layer is located above the exhaust hole and is connected to the graphite crucible, further guiding the gas exhaust. The design of the porous graphite layer blocks the exhaust hole in the inner cavity, ensuring that the gas can only be exhausted from the porous graphite layer. The design of this gas drainage structure effectively removes the residual nitrogen gas in the inner cavity, providing a pure atmosphere for the growth of silicon carbide crystals.

[0003] The porous graphite layer in the existing gas drainage structure for silicon carbide crystal forming is installed inside the graphite crucible, so it is not convenient to assemble or disassemble the porous graphite layer. When the porous graphite layer is damaged, it is not convenient to replace it. Therefore, a gas drainage mechanism for silicon carbide crystal forming is needed to solve the above problems. UTILITY MODEL CONTENTS

[0004] The utility model aims to provide a kind of gas drainage mechanism for silicon carbide crystal forming, solve the problem that the existing porous graphite layer in prior art is installed inside graphite crucible, so it is not convenient to assemble or disassemble the porous graphite layer, when the porous graphite layer is damaged, it is not convenient to replace it.

[0005] The utility model provides the following technical scheme: a kind of gas drainage mechanism for silicon carbide crystal forming, including heat-insulating outer cylinder, induction heating coil is installed in the inside of the heat-insulating outer cylinder, graphite crucible is installed in the inside of the heat-insulating outer cylinder, top cap is installed between the top end of the heat-insulating outer cylinder and the top end of graphite crucible, the top end of the top cap is fixedly installed with air inlet pipe, the inside bottom end of the graphite crucible is installed with porous graphite layer, the bottom end of the porous graphite layer is fixedly connected with exhaust pipe, the exhaust pipe is inserted to the outside bottom end of heat-insulating outer cylinder, the bottom end of the heat-insulating outer cylinder is equipped with horizontal groove, the top end of the horizontal groove is equipped with rectangular slot, the inside of the rectangular slot is equipped with the limiting mechanism for fixed exhaust pipe.

[0006] As a preferred embodiment of the above technical solution, a hole is formed in the side end of the exhaust pipe, and a limiting groove is formed in the bottom side end of the exhaust pipe.

[0007] As the preferred technical scheme of the above, the limiting mechanism comprises a spring, the spring is fixedly connected to the inner side end of the rectangular groove, the side end of the spring is fixedly connected with a rectangular plate, the side end of the rectangular plate is fixedly connected with a plug rod, and the side end of the plug rod is inserted into one of the plug holes.

[0008] As the preferred technical scheme of the above, the bottom end of the rectangular plate is fixedly connected with a limiting plate, and the limiting plate is located in the horizontal groove.

[0009] As the preferred technical scheme of the above, the limiting plate is L-shaped in shape, and the bottom side end of the limiting plate is inserted into one of the limiting grooves.

[0010] As the preferred technical scheme of the above, the middle part of the top cover is rotatably provided with a rotating shaft, and the bottom end of the rotating shaft is fixedly connected with a crystal tray.

[0011] As the preferred technical scheme of the above, the bottom end of the graphite crucible to the bottom end of the heat-insulating outer cylinder is provided with a vent, and the bottom end of the heat-insulating outer cylinder is fixedly connected with a vent valve pipe at the position of the vent.

[0012] Compared with the prior art, the utility model has the advantages of:

[0013] The utility model discloses a limiting mechanism, porous graphite layer and the setting of exhaust pipe, through the opening of top cover, through the pulling limiting plate, make limiting plate leave limiting groove, when the movement of limiting plate drives rectangular plate to move, at this moment, rectangular plate can drive plug rod to leave the plug hole, so that limiting mechanism whole no longer position and fix exhaust pipe, at this moment, through the pushing exhaust pipe, can conveniently assist porous graphite layer to dismantle from graphite crucible, so as to be convenient for the replacement of damaged porous graphite layer, when installation, through the alignment of exhaust pipe between the aperture of heat-insulating outer cylinder and graphite crucible, through the placement of multilayer graphite layer to graphite crucible, at this moment, exhaust pipe is inserted between heat-insulating outer cylinder and graphite crucible after the aperture, at this moment, through the pulling limiting plate, make plug rod not sheltered at the bottom end of aperture, at this moment, continue to move down porous graphite layer, make exhaust pipe be located at the outer bottom end of heat-insulating outer cylinder, at this moment, the plug hole of exhaust pipe side end just aligns the position of plug rod, at this moment, after the loosening of limiting plate, spring is pressed against rectangular plate and drives plug rod to rebound, make plug rod insert into plug hole, make the bottom side end of limiting plate insert into limiting groove, so as to realize the installation and fixation of exhaust pipe and porous graphite layer, so as to facilitate the assembly or disassembly of porous graphite layer, when porous graphite layer is damaged, it is convenient to replace. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a kind of whole structure schematic diagram of gas drainage mechanism for silicon carbide crystal forming;

[0015] Figure 2 Fig. 2 is a sectional view of a gas flow mechanism for forming a silicon carbide crystal;

[0016] Figure 3 Fig. 1 is a sectional view of a gas flow mechanism for forming a silicon carbide crystal; Figure 2 Fig. 3 is a partial enlarged view of A in Fig. 1;

[0017] Figure 4 Fig. 4 is a perspective view of a porous graphite layer of the gas flow mechanism for forming a silicon carbide crystal.

[0018] In the figure: 1, heat-insulating outer cylinder; 101, induction heating coil; 102, graphite crucible; 103, top cover; 104, gas inlet pipe; 105, air vent; 106, air vent valve pipe; 107, rectangular groove; 108, transverse groove; 2, rotating shaft; 201, crystal tray; 3, porous graphite layer; 301, exhaust pipe; 302, insertion hole; 303, limiting groove; 4, limiting mechanism; 401, spring; 402, rectangular plate; 403, insertion rod; 404, limiting plate. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0020] As Figures 1-4As shown, the utility model provides a technical scheme: a gas drainage mechanism for silicon carbide crystal forming, including heat preservation outer tube 1, the inside installation of heat preservation outer tube 1 has induction heating coil 101, the inside installation of heat preservation outer tube 1 has graphite crucible 102, induction heating coil 101 is convenient for heating graphite crucible 102 and the raw material of inside, the top of heat preservation outer tube 1 and the top of graphite crucible 102 between installation has top cover 103, the top of top cover 103 fixedly installed has inlet pipe 104, the middle part rotation of top cover 103 is provided with shaft 2, the bottom fixed connection of shaft 2 has crystal tray 201, and crystal tray 201 is used to carry the silicon carbide crystal of forming, the bottom of graphite crucible 102 to the bottom of heat preservation outer tube 1 is equipped with vent 105, and the bottom of heat preservation outer tube 1 is fixedly connected with vent valve pipe 106 in the position of vent 105, the inside bottom of graphite crucible 102 is installed with porous graphite layer 3, and the bottom of porous graphite layer 3 is fixedly connected with exhaust pipe 301, and exhaust pipe 301 is inserted to the outside bottom of heat preservation outer tube 1, in the implementation, when hydrogen gas enters graphite crucible 102 from inlet pipe 104, because the density of hydrogen gas is lower, so hydrogen gas moves upwards after entering graphite crucible 102, nitrogen gas remaining in the raw material is forced to move downwards, because the position below inlet pipe 104 is provided with porous graphite layer 3 and exhaust pipe 301 connection, nitrogen gas can be conveniently discharged from exhaust pipe 301 after passing through porous graphite layer 3, because the design of porous graphite layer 3 shields the pipe orifice of exhaust pipe 301, ensures that gas can only pass through porous graphite layer 3 and discharge, the structure for draining nitrogen gas out of graphite crucible 102, effectively removes residual nitrogen gas in the inner cavity of graphite crucible 102, provides pure atmosphere for the growth of silicon carbide crystal on crystal tray 201, by the setting of vent 105 and vent valve pipe 106, it is convenient to discharge the gas that is beneficial to the formation of silicon carbide crystal into graphite crucible 102.

[0021] Further, the side end of the exhaust pipe 301 is provided with a bushing 302, and the bottom side end of the exhaust pipe 301 is provided with a limiting groove 303. The bottom end of the heat preservation outer tube 1 is provided with a horizontal groove 108, and the top end of the horizontal groove 108 is provided with a rectangular groove 107. The rectangular groove 107 is provided with a limiting mechanism 4 for fixing the exhaust pipe 301. Through the setting of the limiting mechanism 4, the porous graphite layer 3, and the exhaust pipe 301, the porous graphite layer 3 can be conveniently assembled or disassembled. When the porous graphite layer 3 is damaged, it can be conveniently replaced.

[0022] As an embodiment in the present embodiment, as Figure 2 and Figure 3As shown, the limiting mechanism 4 includes a spring 401 fixedly connected to the inner side end of the rectangular groove 107, the side end of the spring 401 is fixedly connected with a rectangular plate 402, the side end of the rectangular plate 402 is fixedly connected with a plug rod 403, the side end of the plug rod 403 is inserted into one of the insertion holes 302, the bottom end of the rectangular plate 402 is fixedly connected with a limiting plate 404, the limiting plate 404 is located in the horizontal groove 108, the limiting plate 404 is provided in an L-shaped form, the bottom side end of the limiting plate 404 is inserted into one of the limiting grooves 303, in the implementation, after the top cover 103 is opened, the limiting plate 404 is pulled to make the limiting plate 404 leave the limiting groove 303, the rectangular plate 402 is moved when the limiting plate 404 is moved, at this time, the rectangular plate 402 is pressed against the spring 401 to shrink, the plug rod 403 can be moved out of the insertion hole 302, so that the limiting mechanism 4 as a whole no longer limits and fixes the exhaust pipe 301, at this time, after the exhaust pipe 301 is pushed, the porous graphite layer 3 can be conveniently and assistively disassembled from the graphite crucible 102, so that the damaged porous graphite layer 3 can be conveniently replaced.

[0023] Working principle: after the top cover 103 is opened, the limiting plate 404 is pulled to make the limiting plate 404 leave the limiting groove 303, the rectangular plate 402 is moved when the limiting plate 404 is moved, at this time, the rectangular plate 402 is pressed against the spring 401 to shrink, the plug rod 403 can be moved out of the insertion hole 302, so that the limiting mechanism 4 as a whole no longer limits and fixes the exhaust pipe 301, at this time, after the exhaust pipe 301 is pushed, the porous graphite layer 3 can be conveniently and assistively disassembled from the graphite crucible 102, so that the damaged porous graphite layer 3 can be conveniently replaced, when installation, after the exhaust pipe 301 is aligned with the aperture between the heat-insulating outer cylinder 1 and the graphite crucible 102, the multi-layer graphite layer is placed into the graphite crucible 102, at this time, the exhaust pipe 301 is inserted between the heat-insulating outer cylinder 1 and the graphite crucible 102 after passing through the aperture, at this time, the plug rod 403 does not block the bottom end of the aperture after the limiting plate 404 is pulled, at this time, after the porous graphite layer 3 is continuously moved downward, the exhaust pipe 301 is located at the outer bottom end of the heat-insulating outer cylinder 1, at this time, the insertion hole 302 at the side end of the exhaust pipe 301 is just aligned with the position of the plug rod 403, at this time, the spring 401 is pressed against the rectangular plate 402 to drive the plug rod 403 to rebound after the limiting plate 404 is loosened, the plug rod 403 is inserted into the insertion hole 302, the bottom side end of the limiting plate 404 is inserted into the limiting groove 303, so that the installation and fixation of the exhaust pipe 301 and the porous graphite layer 3 are realized, so that the porous graphite layer 3 can be conveniently assembled or disassembled, and the damaged porous graphite layer 3 can be conveniently replaced.

[0024] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit them.

Claims

1. A gas flow guide mechanism for molding silicon carbide crystals, comprising an adiabatic outer cylinder (1) having an induction heating coil (101) installed inside, a graphite crucible (102) installed inside the adiabatic outer cylinder (1), and a top cover (103) installed between the top end of the adiabatic outer cylinder (1) and the top end of the graphite crucible (102), characterized in that: The top end of the top cover (103) is fixedly installed with an air inlet pipe (104), the inner bottom end of the graphite crucible (102) is installed with a porous graphite layer (3), the bottom end of the porous graphite layer (3) is fixedly connected with an exhaust pipe (301), the exhaust pipe (301) is inserted into the outer bottom end of the heat insulation outer cylinder (1), the bottom end of the heat insulation outer cylinder (1) is provided with a horizontal groove (108), the top end of the horizontal groove (108) is provided with a rectangular groove (107), and the inside of the rectangular groove (107) is provided with a limiting mechanism (4) for fixing the exhaust pipe (301).

2. The gas flow guide for forming a silicon carbide crystal according to claim 1, wherein: The side end of the exhaust pipe (301) is provided with a jack (302), and the bottom side end of the exhaust pipe (301) is provided with a limiting groove (303).

3. The gas flow guide for forming a silicon carbide crystal according to claim 2, wherein: The limiting mechanism (4) comprises a spring (401), the spring (401) is fixedly connected to the inner side end of the rectangular groove (107), the side end of the spring (401) is fixedly connected with a rectangular plate (402), the side end of the rectangular plate (402) is fixedly connected with a plug rod (403), and the side end of the plug rod (403) is inserted into one of the jacks (302).

4. The gas flow guide for forming a silicon carbide crystal according to claim 3, wherein: The bottom end of the rectangular plate (402) is fixedly connected with a limiting plate (404), and the limiting plate (404) is located in the horizontal groove (108).

5. The gas flow guide for forming a silicon carbide crystal according to claim 4, wherein: The limiting plate (404) is L-shaped, and the bottom side end of the limiting plate (404) is inserted into one of the limiting grooves (303).

6. The gas flow guide for forming a silicon carbide crystal according to claim 1, wherein: The middle part of the top cover (103) is rotatably provided with a rotating shaft (2), and the bottom end of the rotating shaft (2) is fixedly connected with a crystal tray (201).

7. The gas flow guide for forming a silicon carbide crystal according to Claim 1, wherein: The bottom end of the graphite crucible (102) to the bottom end of the heat insulation outer cylinder (1) is provided with a vent (105), and the bottom end of the heat insulation outer cylinder (1) is fixedly connected with a vent valve pipe (106) at the position of the vent (105).

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