Dispersion exhaust device for chemical vapor deposition furnace

Abstract

The utility model provides a dispersed exhaust device for a chemical vapor deposition furnace, and relates to the technical field of chemical vapor deposition furnaces. The device specifically comprises a flow guide cover buckled at a gas outlet of a bottom plate of the chemical vapor deposition furnace, the flow guide cover comprises a flow guide part of a conical structure, the upper end of the flow guide part is provided with a closed end part, the flow guide part is provided with a vent hole, and the axis of the vent hole is in an inclined state. According to the dispersing exhaust device for the chemical vapor deposition furnace, the uniformity of atmosphere in the muffle cylinder can be obviously improved, so that the uniformity of a coating on the surface of a deposited product is improved, the quality of the product is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical vapor deposition furnaces, in particular to a dispersed exhaust device used for chemical vapor deposition furnaces. Background Art

[0002] Chemical vapor deposition (CVD) is a material surface modification technology. It can use the reaction between the gas phase to give the material surface some special properties without changing the composition of the base material or weakening the strength of the base material. At present, materials prepared by chemical vapor deposition technology, such as pyrolytic carbon coating (PyC), silicon carbide coating (SiC), tantalum carbide coating (TaC), boron nitride coating (BN), etc., are not only used in the fields of tool materials, wear-resistant, heat-resistant and corrosion-resistant materials, special composite materials in the aerospace industry, atomic reactor materials and biomedical materials, but also widely used in the preparation and synthesis of various powder materials, bulk materials, new crystal materials, ceramic fibers and diamond films. It is even more indispensable in the thin film preparation technology of ferroelectric materials, insulating materials, magnetic materials, and optoelectronic materials as large-scale integrated circuit technology.

[0003] The chemical vapor deposition furnace is one of the important equipment for realizing the chemical vapor deposition process. It is mainly composed of an electronic control system, an air intake system, an exhaust system, a lifting system, a vacuum system, a furnace shell, an insulation layer, a heater, a muffle tube and other parts. Among them, the muffle tube is an important component for carrying the product to deposit CVD coatings, and plays an important role in providing a closed environment, average temperature, conductive airflow and a stable atmosphere.

[0004] However, most vertical chemical vapor deposition furnaces on the market currently use a technical solution of multiple air intakes at the bottom of the muffle and a single exhaust at the top. The advantage of this is that the furnace structure is simple and easy to maintain, but the disadvantage is that the air flow velocity at the axis of the air intake hole is high. As a result, eddy currents are generated at the bottom of the muffle, and the atmosphere in the muffle is uneven, resulting in uneven thickness of the CVD coating on the surface of some products, and the coating is blooming, which seriously affects the service life and surface appearance of the product. Utility Model Content

[0005] In response to the above problems, the present application provides a dispersed exhaust device for a chemical vapor deposition furnace, which can significantly improve the uniformity of the atmosphere in the muffle, thereby improving the uniformity of the coating on the surface of the deposited product, and improving the product quality and service life.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] A dispersed exhaust device for a chemical vapor deposition furnace comprises a guide cover buckled at the gas outlet of the bottom plate of the chemical vapor deposition furnace, the guide cover comprises a guide portion with a conical structure, a closed end is arranged at the upper end of the guide portion, and a diffuser hole is arranged on the guide portion, and the axis of the diffuser hole is in an inclined state.

[0008] Furthermore, a positioning tube is arranged in the guide cover, and the lower end of the positioning tube is inserted into the air outlet.

[0009] Furthermore, the positioning tube includes a positioning portion, and the lower end of the positioning portion is inserted into the air outlet, the upper end of the positioning portion is provided with a guide portion, and the lower end of the guide portion is provided with a guide support portion that cooperates with the guide portion, and through the cooperation between the guide portion and the guide support portion, the positioning tube can slide up and down along the guide support portion of the guide cover.

[0010] Furthermore, a plurality of stop columns for supporting the positioning tube are arranged on the guide support portion, and the stop columns are connected to the guide support portion in a detachable manner.

[0011] Furthermore, the blocking column is threadedly connected to the guide support portion.

[0012] Furthermore, four blocking columns are evenly distributed along the circumferential direction on the guide support portion.

[0013] Furthermore, the closed end is recessed toward the interior of the air guide cover and has a conical structure.

[0014] Furthermore, a transition connection portion is provided between the positioning portion and the guide portion, and the transition connection portion and the closed end portion together form an annular flow channel with a conical structure.

[0015] Furthermore, a cover plate is provided at the upper end of the guide cover.

[0016] The beneficial effects of the utility model are:

[0017] The embodiment of the present application provides a dispersed exhaust device for a chemical vapor deposition furnace, which adopts a conical structure with a closed top. By setting diffuser holes on the inclined conical surface, the axial velocity of the gas can be partially converted into a radial velocity, offsetting the vortex phenomenon of the atmosphere, and avoiding the phenomenon that the atmosphere of the traditional chemical vapor deposition furnace goes straight up and down without diffusing to the surroundings. In this way, the uniformity of the atmosphere in the muffle can be effectively optimized, so that the gas rises evenly from bottom to top without causing gas concentration, improving the thickness uniformity and surface aesthetics of the CVD coating on the product surface, thereby improving product quality and service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the installation structure of a dispersed exhaust device for a chemical vapor deposition furnace provided in an embodiment of the present application;

[0019] Figure 2 for Figure 1 A schematic diagram of the enlarged structure of part A;

[0020] Figure 3 A cross-sectional view of an installation structure of a dispersed exhaust device for a chemical vapor deposition furnace provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of the three-dimensional structure of a dispersed exhaust device for a chemical vapor deposition furnace provided in an embodiment of the present application;

[0022] Figure 5 An exploded view of a dispersed exhaust device for a chemical vapor deposition furnace provided in an embodiment of the present application;

[0023] Figure 6 This is a cross-sectional view of the guide cover.

[0024] In the figure: 1. Air outlet;

[0025] 21. flow guide cover; 211. flow guide portion; 2111. air diffusion hole; 212. closed end portion; 213. guide support portion; 2131. threaded through hole;

[0026] 22, positioning cylinder; 221, positioning portion; 222, guide portion; 223, transition connection portion;

[0027] 23. stop column; 231. plug-in slot;

[0028] 24. Cover plate. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application, and the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by those skilled in the art without creative work on the basis of the embodiments of the present application shall belong to the protection scope of the present application.

[0030] like Figure 1 , Figure 2 and Figure 3As shown, a dispersed exhaust device for a chemical vapor deposition furnace includes a guide cover 21 that is buckled at the gas outlet 1 of the bottom plate of the chemical vapor deposition furnace, and the guide cover 21 is made of graphite material. The guide cover 21 includes a guide portion 211 with a conical structure, and the guide portion 211 is open at both ends, and the open end with a smaller diameter is located at the top. The upper end of the guide portion 211 is provided with a closed end portion 212 for closing the small end opening of the guide portion 211. The guide portion 211 is evenly distributed with diffuser holes 2111, and the axis of the diffuser holes 2111 is in an inclined state.

[0031] By providing inclined diffuser holes 2111 on the guide part 211, and the upper end opening of the guide part 211 is closed, the airflow can be dispersed. In this way, the airflow ejected from the gas outlet 1 of the bottom plate of the chemical vapor deposition furnace flows out through the diffuser holes 2111, and the axial velocity of the gas is partially converted into a radial velocity, and the radial velocities of adjacent dispersed exhaust devices will offset each other, so that the airflow is spread out at the bottom of the chemical vapor deposition furnace and rises evenly, which can offset the atmosphere vortex phenomenon, optimize the atmosphere uniformity in the muffle tube, and make the gas rise evenly from bottom to top without causing gas concentration.

[0032] Furthermore, in order to facilitate installation, the coaxiality between the guide cover 21 and the air outlet 1 is ensured. Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, a positioning tube 22 coaxially arranged with the guide cover 21 is disposed in the guide cover 21 , and the lower end of the positioning tube 22 is inserted into the air outlet 1 .

[0033] As a specific implementation, the positioning cylinder 22 described in this embodiment includes a positioning portion 221 with a cylindrical tube-shaped structure, and the lower end of the positioning portion 221 is inserted into the air outlet 1, and a guide portion 222 is provided at the upper end of the positioning portion 221, and the outer edge of the guide portion 222 is connected to the inner wall of the guide cover 21, and the air diffusion hole 2111 is located above the guide portion 222.

[0034] Furthermore, if Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, a guide support portion 213 is provided at the large end opening of the guide portion 211. The guide support portion 213 is a cylindrical tube structure and is coaxially arranged with the guide portion 211. The guide portion 222 of the positioning cylinder 22 cooperates with the guide support portion 213 of the guide cover 21, and through the cooperation between the guide portion 222 and the guide support portion 213, the positioning cylinder 22 can slide up and down along the guide support portion 213 of the guide cover 21.

[0035] The reasons for this design are: first, the positioning cylinder 22 can move up and down relative to the guide cover 21 to adapt to different depths of the air outlet 1, and the lower end surface of the positioning cylinder 22 always rests on the step surface of the air outlet 1, thereby preventing the airflow from passing through the gap between the positioning portion 221 of the positioning cylinder 22 and the side wall of the air outlet 1 and entering the space between the lower side of the guide portion 222 and the guide cover 21, causing the guide cover 21 to be lifted. Second, the positioning cylinder 22 adopts a detachable connection method, which can be easily replaced, so as to be suitable for air outlets 1 of different diameters, thereby improving the versatility of the decentralized exhaust device.

[0036] Furthermore, if Figure 3 , Figure 5 and Figure 6 As shown, the guide support portion 213 of the guide cover 21 is provided with a plurality of blocking posts 23 for supporting the positioning cylinder 22, and the blocking posts 23 are made of graphite material. The blocking posts 23 are located below the guide portion 222 of the positioning cylinder 22, and the blocking posts 23 are threadedly connected to the guide support portion 213 of the guide cover 21, and the guide support portion 213 of the guide cover 21 is provided with threaded through holes 2131 for accommodating the blocking posts 23, and the guide posts are provided with external threads that match the threaded through holes 2131.

[0037] As a specific implementation, in this embodiment, four blocking columns 23 are evenly arranged along the circumferential direction on the guide support portion 213 of the deflector cover 21. The outer end surface of the blocking column 23 is provided with an inserting groove 231 that matches with a wrench.

[0038] Furthermore, if Figure 5 and Figure 6 As shown, the closed end 212 is recessed toward the inside of the air guide cover 21 and has a conical structure with a larger diameter at the upper end and a smaller diameter at the lower end. This can prevent the airflow ejected from the air outlet 1 from vertically impacting the closed end 212 and causing turbulence. The airflow can be guided by the conical closed end 212 so that the airflow can be blown toward the diffuser holes 2111.

[0039] Furthermore, if Figure 3 and Figure 5 As shown, a transition connection portion 223 with a conical structure having a larger diameter at the upper end and a smaller diameter at the lower end is provided between the positioning portion 221 and the guide portion 222 of the positioning cylinder 22, and the transition connection portion 223 of the positioning cylinder 22 and the closed end portion 212 of the guide cover 21 together form an annular flow channel with a conical structure, thereby guiding the airflow.

[0040] Furthermore, in order to prevent the concave structure of the closed end 212 of the guide cover 21 from disturbing the airflow, Figure 3 and Figure 5 As shown, a cover plate 24 is disposed at the upper end of the guide cover 21 , and the cover plate 24 blocks the concave structure of the closed end 212 .

[0041] Other embodiments obtained by those skilled in the art by combining, splitting, reorganizing, etc. the embodiments of the present application on the basis of the embodiments provided in the present application do not exceed the protection scope of the present application.

[0042] The above specific implementation methods have detailed the purpose, technical solutions and beneficial effects of the embodiments of the present application. The above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. That is, any modifications, equivalent substitutions, improvements, etc. made on the basis of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A dispersed exhaust device for a chemical vapor deposition furnace, characterized in that: The invention comprises a guide cover (21) which is buckled at the gas outlet (1) of the bottom plate of a chemical vapor deposition furnace, wherein the guide cover (21) comprises a guide portion (211) having a conical structure, wherein the upper end of the guide portion (211) is provided with a closed end portion (212), and the guide portion (211) is provided with air diffusion holes (2111), and the axis of the air diffusion holes (2111) is in an inclined state.

2. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 1, characterized in that: A positioning tube (22) is arranged inside the guide cover (21), and the lower end of the positioning tube (22) is inserted into the air outlet (1).

3. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 2, characterized in that: The positioning tube (22) includes a positioning portion (221), and the lower end of the positioning portion (221) is inserted into the air outlet (1), the upper end of the positioning portion (221) is provided with a guide portion (222), and the lower end of the guide portion (211) is provided with a guide support portion (213) that cooperates with the guide portion (222), and through the cooperation between the guide portion (222) and the guide support portion (213), the positioning tube (22) can slide up and down along the guide support portion (213) of the guide cover (21).

4. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 3, characterized in that: A plurality of blocking columns (23) for supporting the positioning cylinder (22) are arranged on the guide support portion (213), and the blocking columns (23) are connected to the guide support portion (213) in a detachable manner.

5. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 4, characterized in that: The blocking column (23) is threadedly connected to the guide support portion (213).

6. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 4, characterized in that: Four blocking columns (23) are evenly distributed along the circumferential direction on the guide support portion (213).

7. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 3, characterized in that: The closed end (212) is recessed toward the interior of the flow guide cover (21) and has a conical structure.

8. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 7, characterized in that: A transition connection portion (223) is provided between the positioning portion (221) and the guide portion (222), and the transition connection portion (223) and the closed end portion (212) together form an annular flow channel with a conical structure.

9. The dispersed exhaust device for a chemical vapor deposition furnace according to claim 7, characterized in that: A cover plate (24) is provided at the upper end of the guide cover (21).

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