Double-heater chemical vapor deposition equipment suitable for annular workpiece

Abstract

The utility model discloses double-heating rapid chemical vapor deposition equipment suitable for an annular workpiece. The double-heating rapid chemical vapor deposition equipment comprises a furnace body, a heat preservation layer, a resistance heater, a direct-current power supply, an outer isolation barrel, an inner isolation barrel, an induction heater and an alternating-current power supply, wherein the heat preservation layer, the resistance heater and the direct-current power supply are arranged in the furnace body; the inner isolation barrel is arranged in the central area of the outer isolation barrel; the resistance heater is arranged between the outer isolation barrel and the heat preservation layer; a deposition chamber used for machining the annular workpiece is formed between the outer isolation barrel and the inner isolation barrel. By arranging the outer isolation barrel and the inner isolation barrel, the deposition chamber for machining the annular workpiece is formed, so that the space in the whole equipment is compact, the utilization rate of process gas is increased, and the production cost is reduced; the resistance heater electrically connected with the direct-current power supply and the induction heater electrically connected with the alternating-current power supply in the inner isolation barrel are arranged, so that different heaters are used at different stages, the deposition speed is increased, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of silicon carbide semiconductor technology, and in particular to a dual-heating rapid chemical vapor deposition apparatus suitable for ring-shaped workpieces. Background Technology

[0002] Chemical vapor infiltration (CVI) is a coating process that deposits a coating into the interior space of a porous preform under controlled conditions. The process involves placing the preform in a dedicated CVI furnace, heating it to the desired temperature under vacuum, and then introducing a precursor gas of a specific composition. This precursor gas is pyrolyzed into different charged ions, which are deposited on the pore surface to fill the pores in the preform. Because CVI produces a matrix with a tight bond between the matrix and the preform fibers, and its structural thickness is adjustable, it is the preferred method for preparing high-performance carbon-carbon and carbon-ceramic composite materials. Commonly used CVI processes include isothermal CVI (ICVI), differential pressure CVI, thermal gradient CVI (TGCVI), forced flow CVI (FCVI), and direct heating CVI (HCVI). Electromagnetic field CVI (ECVI), on the other hand, introduces an electromagnetic field into ICVI. Beneficial intermediate phase charged particles generated by the process gas under hot conditions can be significantly promoted by the electromagnetic field to adsorb and capture the intermediate phase charged particles in the workpiece to be deposited, thereby accelerating the deposition efficiency and shortening the preparation cycle of composite materials. It is a promising low-cost and rapid deposition CVI technology.

[0003] For annular workpieces, the large hollow area in the center provides ample space for process gas diffusion during deposition. This results in a relatively low probability of charged ions from the intermediate phase after pyrolysis of the process gas adhering to the inner surface of the annular workpiece, with most being discharged with the exhaust gas. This leads to low gas utilization and inconsistent deposition quality. Patent CN108060409A discloses a deposition chamber and chemical vapor deposition system suitable for annular workpieces. This system creates a deposition space between the main body of the insulation chamber and the inner insulation layer, reducing the deposition space, lowering equipment heating energy consumption, and improving process gas utilization. However, its heating element still uses traditional resistance heating, and since the heating element is exposed in the deposition chamber, it is easily contaminated by the process gas.

[0004] Currently, in medium-frequency induction heating deposition furnaces, the induced current generated by an alternating magnetic field produced by an induction coil positioned outside the insulation layer, under the influence of alternating current, heats the induction crucible located inside the insulation layer within the furnace. Heat is then transferred to the workpiece via radiation from the crucible. These induction coils are often made of hollow copper tubing and contain cooling water. This type of induction coil heating device cannot be directly placed inside the furnace body, otherwise it would be melted and damaged by the high temperatures inside the furnace. The magnetic field generated by this induction coil still needs to pass through the insulation layer and the induction crucible, resulting in a weakened induced electromagnetic field and limited impact on the movement of charged ions.

[0005] In addition, during the CVI process, the workpiece density is low in the initial stage. If the deposition rate is too fast, it is easy to cause a crust to form on the workpiece surface, making it impossible to continue to increase the density. In the later stage, as the workpiece density gradually increases, the porosity inside the workpiece gradually decreases. If only conventional deposition processes are used, the ability of the process gas network to penetrate is weak, requiring a longer deposition time and resulting in low production efficiency. Utility Model Content

[0006] The technical problem to be solved by this invention is that the single heating device of the existing chemical vapor deposition equipment cannot meet the deposition process requirements at different stages. The invention provides a dual-heating rapid chemical vapor deposition equipment suitable for ring-shaped workpieces.

[0007] The technical solution to this problem is as follows: A dual-heating rapid chemical vapor deposition (CVD) device suitable for annular workpieces is constructed. The device includes a furnace body, an insulation layer disposed within the furnace body, a resistance heater disposed within the furnace body, and a DC power supply electrically connected to the heater. An outer isolation chamber is disposed inside the insulation layer, an inner isolation chamber is disposed in the central region of the outer isolation chamber, a spiral induction heater is disposed within the inner isolation chamber, and an AC power supply is disposed outside the furnace body and electrically connected to the induction heater. The resistance heater is disposed between the outer isolation chamber and the insulation layer. A deposition chamber for processing annular workpieces is formed between the outer and inner isolation chambers.

[0008] Furthermore, the furnace body includes a furnace shell and an upper furnace cover; the insulation layer includes an intermediate insulation cylinder disposed on the inner side wall of the furnace shell, an upper insulation cover disposed on the top of the intermediate insulation cylinder, and a lower insulation cover disposed on the bottom of the intermediate insulation cylinder.

[0009] Furthermore, the outer insulation barrel is configured with an open bottom, the open end of which covers the top of the lower insulation cover.

[0010] Furthermore, the top of the outer isolation cylinder is provided with a through hole that matches the inner isolation cylinder, and the inner isolation cylinder is configured with an open top. The open end of the inner isolation cylinder extends through the through hole of the outer isolation cylinder and the upper insulation cover to the bottom of the upper furnace cover.

[0011] Furthermore, the upper furnace cover is equipped with an induction heating terminal, and the induction heater is electrically connected to the AC power supply through the induction heating terminal.

[0012] Furthermore, an insulating pad is provided between the induction heater and the bottom of the inner isolation barrel.

[0013] Furthermore, an insulation ring is provided between the upper insulation cover and the middle insulation cylinder. The insulation ring is embedded between the outer isolation barrel and the furnace shell. An exhaust pipe is provided on the top side of the outer isolation barrel. The exhaust pipe passes through the insulation ring and the furnace shell and extends to the outside of the furnace body.

[0014] Furthermore, a receiving cavity is provided between the outer insulating cylinder and the intermediate insulation cylinder, and the resistance heater is disposed in the receiving cavity.

[0015] Furthermore, the furnace shell is provided with a resistance heating terminal, and the resistance heater is electrically connected to the DC power supply through the resistance heating terminal.

[0016] Furthermore, the bottom of the furnace body is fixedly provided with multiple air inlets that pass through the lower insulation cover and the furnace body. The air inlets are located between the inner isolation barrel and the outer isolation barrel, and the air inlets are connected to the external process air intake system.

[0017] The dual-heating rapid chemical vapor deposition equipment for annular workpieces described in this utility model has the following advantages: By setting up an outer isolation tank and an inner isolation tank, a deposition chamber for processing annular workpieces is formed, making the entire equipment space compact, requiring only a small amount of process gas, improving the utilization rate of process gas, and reducing production costs; by setting up a resistance heater electrically connected to a DC power supply and an induction heater electrically connected to an AC power supply in the inner isolation tank, it is possible to use only the resistance heater to densify the annular workpiece in the initial stage, while in the later stage, the induction heater connected to the AC power supply introduces an electromagnetic field to rapidly densify the interior of the annular workpiece. This allows for the use of different heaters at different stages to accelerate the deposition speed and improve production efficiency. Attached Figure Description

[0018] Figure 1 The diagram shown is a preferred embodiment of the dual-heating rapid chemical vapor deposition equipment for ring-shaped workpieces described in this utility model.

[0019] Figure 2 As shown Figure 1 Enlarged view of part I. Detailed Implementation

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] It should also be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0023] like Figure 1 , 2 As shown, in a preferred embodiment of the dual-heating rapid chemical vapor deposition equipment for ring-shaped workpieces described in this utility model, it mainly includes a furnace body 10, an insulation layer 20, a resistance heater 30, a DC power supply 1, an induction heater 40, an AC power supply 2, an inner isolation tank 50, and an outer isolation tank 60.

[0024] The insulation layer 20 is disposed inside the furnace body 10, preferably in close contact with the furnace body 10; the outer isolation barrel 60 is disposed on the inner side wall of the insulation layer 20, and the inner isolation barrel 50 is disposed in the central area of ​​the outer isolation barrel 60, forming a deposition chamber 3 between the outer isolation barrel 60 and the inner isolation barrel 50 that is adapted to the annular workpiece 6; the resistance heater 30 is disposed between the insulation layer 20 and the outer isolation barrel 60 and is electrically connected to the external DC power supply 1; the induction heater 40 is disposed inside the inner isolation barrel 50 and is electrically connected to the external AC power supply 2.

[0025] In this preferred embodiment, the insulation layer 20 preferably includes an intermediate insulation cylinder 21, an upper insulation cover 22, and a lower insulation cover 23; the furnace body 10 includes a furnace shell 11 and an upper furnace cover 12. The upper furnace cover 12 covers the upper opening of the furnace shell, forming a hollow area inside the furnace shell. The intermediate insulation cylinder 21 is disposed on the inner wall of the furnace shell 11, the upper insulation cover 22 is disposed on the top of the intermediate insulation cylinder 21, and the lower insulation cover 23 is disposed at the bottom of the intermediate insulation cylinder 21 and located at the bottom inner side of the furnace shell 11.

[0026] In this preferred embodiment, a through hole 61 is preferably provided at the top of the outer isolation barrel 60, and the outer contour of the inner isolation barrel 50 matches the through hole 61, so that the inner isolation barrel 50 is perfectly fitted into the through hole 61. Preferably, the top of the inner isolation barrel 50 is open, with its open end 52 passing through the through hole 61 of the outer isolation barrel and the upper insulation cover 22, and extending to below the upper furnace cover 12. Preferably, an induction heating terminal 41 is provided on the upper furnace cover 12, and the induction heater 40 is electrically connected to the external AC power supply 2 through the induction heating terminal 41; this makes wiring the induction heater 40 built into the inner isolation barrel 50 more convenient, eliminating the need for frequent removal of the induction heater 40. Preferably, an insulating pad 42 is provided between the induction heater 40 and the bottom of the inner isolation barrel, and a gap is left between the induction heater 40 and the side wall of the inner isolation barrel 50 to prevent current from passing through the inner isolation barrel 50.

[0027] Preferably, a receiving cavity 4 is provided between the outer isolation barrel 60 and the intermediate insulation cylinder, and the resistance heater 30 is positioned in the receiving cavity 4, thereby avoiding process gas contamination of the resistance heater 30. Specifically, it is best to provide a resistance heating terminal 31 on the furnace shell 11, and the resistance heater 30 is electrically connected to the external DC power supply 1 through the resistance heating terminal 31.

[0028] In this preferred embodiment, an insulation ring 24 is preferably provided between the upper insulation cover 22 and the intermediate insulation cylinder 21, and the insulation ring 24 is embedded between the outer isolation cylinder 60 and the furnace shell 11. At the same time, an exhaust pipe 62 is preferably provided on the outer isolation cylinder 60, and the exhaust pipe 62 is preferably located at the top of the side of the outer isolation cylinder 60. The exhaust pipe 62 passes through the insulation ring 24 and the furnace shell 11 and extends to the outside of the furnace body 10, connecting with the external exhaust gas treatment system.

[0029] In this preferred embodiment, multiple air inlets 5 can also be fixedly installed at the bottom of the furnace body 10. The air inlets 5 pass through the lower insulation cover 23 and the furnace body 10, with their inner ends located between the inner isolation tank 50 and the outer isolation tank 60, and their outer ends connected to the external process air intake system 6. During operation, the process gas enters the deposition space between the inner isolation tank 50 and the outer isolation tank 60 through the air inlets 5.

[0030] Based on the embodiments of this utility model, any modifications, equivalent substitutions, improvements, etc., made by all other embodiments obtained by those skilled in the art without creative effort should be included within the protection scope of this utility model.

Claims

1. A double heater chemical vapor deposition apparatus for a ring-shaped workpiece, comprising a furnace body, a heat insulating layer provided in the furnace body, a resistance heater provided in the furnace body, and a direct current power source electrically connected to the heater, characterized in that, An outer isolation barrel is arranged inside the heat preservation layer, an inner isolation barrel is arranged in the central area of the outer isolation barrel, a spiral induction heater is arranged in the inner isolation barrel, and an alternating current power supply is electrically connected with the induction heater outside the furnace body; the resistance heater is arranged between the outer isolation barrel and the heat preservation layer; a deposition chamber for processing annular workpieces is formed between the outer isolation barrel and the inner isolation barrel.

2. The dual-heater chemical vapor deposition apparatus for a ring-shaped workpiece according to claim 1, wherein The furnace body comprises a furnace shell and an upper furnace cover; the heat preservation layer comprises a middle heat preservation cylinder arranged on the inner side wall of the furnace shell, an upper heat preservation cover arranged on the top of the middle heat preservation cylinder, and a lower heat preservation cover arranged on the bottom of the middle heat preservation cylinder.

3. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 2, wherein, The outer isolation barrel is arranged with an open bottom end, and the open end covers the top of the lower heat preservation cover.

4. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 3, wherein, The top of the outer isolation barrel is provided with a through hole matched with the inner isolation barrel, the inner isolation barrel is arranged with an open top end, and the open end of the inner isolation barrel extends below the upper furnace cover through the through hole of the outer isolation barrel and the upper heat preservation cover.

5. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 4, wherein, The upper furnace cover is provided with an induction heating terminal post, and the induction heater is electrically connected with the alternating current power supply through the induction heating terminal post.

6. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 1, wherein, An insulating pad is arranged between the induction heater and the bottom of the inner isolation barrel.

7. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 2, wherein, A heat preservation ring is further arranged between the upper heat preservation cover and the middle heat preservation cylinder, the heat preservation ring is embedded between the outer isolation barrel and the furnace shell, an exhaust pipe is arranged on the top of the side surface of the outer isolation barrel, and the exhaust pipe extends to the outside of the furnace body through the heat preservation ring and the furnace shell.

8. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 2, wherein, A containing cavity is arranged between the outer isolation barrel and the middle heat preservation cylinder, and the resistance heater is arranged in the containing cavity.

9. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 2, wherein, A resistance heating terminal post is arranged on the furnace shell, and the resistance heater is electrically connected with the direct current power supply through the resistance heating terminal post.

10. The dual-heater chemical vapor deposition apparatus for use with an annular workpiece of claim 7, wherein, A plurality of air inlet nozzles are fixedly arranged on the bottom of the furnace body and pass through the lower heat preservation cover and the furnace body, the air inlet nozzles are located between the inner isolation barrel and the outer isolation barrel, and the air inlet nozzles are connected with an external process air system.

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