Insulation cylinder for silicon carbide crystal growth furnace

Abstract

This utility model discloses a heat-insulating cylinder for a silicon carbide crystal growth furnace, relating to the field of silicon carbide crystal growth furnace technology. Key technical features include splicing strips, which are arc-shaped structures. At least two splicing strips are equidistantly spliced ​​and arranged along the circumference to form a cylindrical main structure, with a gap reserved between adjacent splicing strips to reduce self-heating caused by circulating current. The heat-insulating cylinder body is fitted around the outer circumference of the splicing strips, and a stable connection is formed between the heat-insulating cylinder body and the splicing strips through a fixed connection. The heat-insulating cylinder body uses heat-insulating material to ensure heat insulation performance in the high-temperature environment of the silicon carbide crystal growth furnace. The effect is that the splicing strips cut off the continuous path of circulating current, significantly reducing self-heating.

Description

Technical Field

[0001] This utility model relates to the field of silicon carbide crystal growth furnace technology, and more specifically, it relates to a heat preservation cylinder for silicon carbide crystal growth furnaces. Background Technology

[0002] In the field of silicon carbide crystal growth, the crystal growth furnace is the core equipment for realizing silicon carbide crystal preparation, and the insulation cylinder, as a key thermal field component of the crystal growth furnace, has a profound impact on crystal growth quality and production efficiency. With the surge in demand for silicon carbide semiconductor devices, the requirements for crystal quality are becoming increasingly stringent, and traditional insulation cylinders have gradually revealed many shortcomings. Early crystal growth furnace insulation structures mostly adopted a single-material integral design, which lacked effective means to deal with the problem of circular current. During the operation of the crystal growth furnace, the electromagnetic environment is prone to generating circular current. If the conductive components of the insulation cylinder form a continuous circuit, the self-heating caused by the circular current will interfere with the thermal field stability, resulting in uneven temperature distribution inside the furnace, affecting the consistency of crystal growth, and even increasing crystal defects. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a heat preservation cylinder for silicon carbide crystal growth furnace.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] Insulation cylinder for silicon carbide crystal growth furnace, including:

[0006] The splicing strip has an arc-shaped structure. At least two splicing strips are spliced ​​and arranged at equal intervals along the circumference to form a cylindrical main structure, and a gap is reserved between two adjacent splicing strips to reduce self-heating caused by the circular current.

[0007] The insulation cylinder body is sleeved on the outer periphery of the splicing strip, and the insulation cylinder body and the splicing strip are stably connected by a fixed connection method;

[0008] The insulation cylinder body is made of insulation material to ensure insulation performance in the high-temperature environment of the silicon carbide crystal growth furnace.

[0009] Preferably, it also includes a carbon-carbon ring, which is fixedly connected to the end of the splicing strip.

[0010] Preferably, the carbon ring includes an annular plate and positioning blocks fixedly connected to the inner sidewall of the annular plate, and a plurality of positioning blocks are equidistant from the annular plate.

[0011] The end of the splicing strip is provided with a positioning groove, which corresponds to the positioning block.

[0012] Preferably, the carbon ring and the splicing strip are fixedly connected by screws.

[0013] Preferably, the gap between two adjacent splicing strips is 1mm.

[0014] Preferably, the outer circumferential wall of the heat-insulating cylinder body is wrapped with carbon sheets.

[0015] Preferably, the carbon sheet is fixed to the outer periphery of the insulation cylinder body by a carbon rope.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention relates to a heat insulation cylinder for silicon carbide crystal growth furnaces, which utilizes a carbon-carbon sheet design to create a highly efficient thermal barrier. During furnace operation, the high-temperature heat radiation and conduction generated inside the furnace first contact the carbon-carbon sheet. The carbon-carbon sheet can withstand heat impacts and, through reasonable thermal resistance, weakens the intensity of heat transfer, preventing direct erosion of the insulation cylinder body by high temperatures and slowing down the rate of thermal degradation of the insulation material, thereby significantly extending the overall service life of the insulation cylinder. Furthermore, it reduces heat loss to the outside, maintaining a stable high-temperature environment inside the furnace required for silicon carbide crystal growth, thus laying a solid temperature foundation for crystal growth.

[0018] The splicing strip design in this application interrupts the continuous path of the circular current, significantly reducing self-heating. This not only reduces unnecessary energy loss and saves on the electricity costs of the crystal growth furnace, but also prevents structural deformation and performance degradation of the splicing strip itself due to localized overheating, ensuring long-term stable operation of the splicing strip. The insulation cylinder effectively blocks heat transfer from the furnace to the outside, reducing energy loss from heat radiation and conduction. By reducing the rate of heat loss, the temperature range inside the crystal growth furnace is maintained suitable for silicon carbide crystal growth, ensuring the consistency and quality of crystal growth. Attached Figure Description

[0019] Figure 1 A schematic diagram of the heat insulation cylinder for a silicon carbide crystal growth furnace proposed in this utility model;

[0020] Figure 2 This utility model provides a schematic diagram showing the connection of carbon rings at both ends of the splicing strip 1 in the heat insulation cylinder for a silicon carbide crystal growth furnace.

[0021] Figure 3 This utility model proposes a schematic diagram showing that one end of the splicing strip 1 in the heat insulation cylinder for silicon carbide crystal growth furnace is connected to a carbon ring;

[0022] Figure 4 A schematic diagram of the carbon-carbon ring in the heat insulation cylinder for a silicon carbide crystal growth furnace proposed in this utility model;

[0023] Figure 5 The diagram shows the temperature rise curves of this utility model with and without an insulation cylinder body under the same process.

[0024] In the diagram: 1. Splicing strip; 2. Insulation cylinder body; 3. Carbon ring; 4. Annular plate; 5. Positioning block; 6. Positioning groove. Detailed Implementation

[0025] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0028] Reference Figures 1-5 As shown.

[0029] The embodiments further illustrate the heat preservation cylinder for the silicon carbide crystal growth furnace proposed in this utility model.

[0030] Insulation cylinder for silicon carbide crystal growth furnace, including:

[0031] Splicing strip 1, which is an arc-shaped structure, consists of at least two splicing strips 1 arranged at equal intervals along the circumference to form a cylindrical main structure, with a gap reserved between two adjacent splicing strips 1 to reduce self-heating caused by the circular current;

[0032] The insulation cylinder body 2 is sleeved on the outer periphery of the splicing strip 1, and the insulation cylinder body 2 and the splicing strip 1 are stably connected by a fixed connection method.

[0033] The insulation cylinder body 2 is made of insulation material to ensure insulation performance in the high-temperature environment of the silicon carbide crystal growth furnace.

[0034] The splicing strip 1 is an arc-shaped structure. At least two splicing strips 1 are arranged at equal intervals along the circumference to form a cylindrical main structure. During operation, the internal environment of the silicon carbide crystal growth furnace generates circular currents due to electromagnetic factors. If these circular currents are conducted within a continuous conductive structure, they can cause self-heating, potentially affecting the performance of the insulation cylinder and even the crystal growth process. By using at least two arc-shaped splicing strips 1 arranged at equal intervals along the circumference, with a pre-existing gap between adjacent splicing strips 1, the circular currents can be effectively blocked. The circular currents are unlikely to form a complete and smooth path along the circumference formed by the splicing strips 1, thus reducing the self-heating generated by the circular currents on the splicing strips 1. This prevents damage to the insulation cylinder structure due to localized overheating and also helps maintain a stable temperature environment within the crystal growth furnace, creating suitable conditions for silicon carbide crystal growth.

[0035] The insulation cylinder body 2 is fitted around the outer periphery of the splicing strip 1, forming a stable connection with it through a fixed connection method. In the high-temperature environment of the silicon carbide crystal growth furnace, heat spontaneously transfers from the high-temperature area to the low-temperature area. The insulation cylinder body 2 is made of insulation material, which has low thermal conductivity and can effectively suppress heat transfer through conduction and radiation. Once the insulation cylinder body 2 is stably connected to the outer periphery of the splicing strip 1, it can prevent the high-temperature heat inside the crystal growth furnace from dissipating to the outside, reducing heat loss and ensuring that the high-temperature environment required for silicon carbide crystal growth can be maintained inside the furnace.

[0036] The splicing strip 1 and the insulation cylinder body 2 work together to maintain the temperature and ensure stable operation of the silicon carbide crystal growth furnace. The splicing strip 1, through its splicing structure, reduces self-heating caused by the circular current, protecting its own structure and helping to maintain the furnace's internal temperature. The insulation cylinder body 2 relies on the structure formed by the splicing strip 1. Together, they create a stable and suitable high-temperature environment for silicon carbide crystal growth by suppressing internal heat sources and preventing external heat loss, thus ensuring the efficiency and quality of silicon carbide crystal growth.

[0037] It also includes a carbon ring 3, which is fixedly connected to the end of the splicing strip 1.

[0038] The carbon ring 3 includes an annular plate 4 and positioning blocks 5 fixedly connected to the inner sidewall of the annular plate 4. Several positioning blocks 5 are equidistant from the annular plate 4.

[0039] The end of the splicing strip 1 is provided with a positioning groove 6, which corresponds to the positioning block 5.

[0040] The splicing strip 1 in this application serves as a basic structural component of the insulation cylinder, with its ends fixedly connected to the carbon-carbon ring 3. It lays the foundation for the coordinated operation of all components of the insulation cylinder within the overall structure of the silicon carbide crystal growth furnace. The splicing strip 1 forms a cylindrical body through its own arc-shaped structure and multiple segments, while the carbon-carbon ring 3 connects to its ends. From the end position, it provides auxiliary positioning and reinforcement for the splicing strip 1 and the subsequently assembled insulation cylinder body 2, ensuring the overall structural stability of the insulation cylinder under the high-temperature and complex operating conditions of the crystal growth furnace.

[0041] The carbon-carbon ring 3 includes an annular plate 4 and positioning blocks 5 fixedly connected to the inner wall of the annular plate 4. Several positioning blocks 5 are equidistant from the annular plate 4. When the carbon-carbon ring 3 is connected to the splicing strip 1, the positioning groove 6 opened at the end of the splicing strip 1 corresponds to the positioning block 5. During assembly, the positioning block 5 is embedded in the positioning groove 6. The equidistant positioning blocks 5 cooperate with the corresponding positioning groove 6 to facilitate the circumferential positioning of the splicing strip 1, ensuring that multiple splicing strips 1 are evenly distributed in the circumferential direction. This avoids the problem of uneven distribution of annular current due to the positional deviation of the splicing strip 1, thereby ensuring the stable performance of the function of reducing the self-heating of annular current and the heat preservation function. Through the mechanical connection between the positioning block 5 and the positioning groove 6, the connection strength between the carbon-carbon ring 3 and the splicing strip 1 can be enhanced, preventing loosening between the splicing strip 1 and the carbon-carbon ring 3, and ensuring the reliability of the overall structure of the heat preservation cylinder.

[0042] Figure 5 The graph shows the temperature rise curves of the insulated and non-insulated bodies under the same process. The horizontal axis represents time (in minutes), and the vertical axis represents temperature (in degrees Celsius). Under the same process, the insulated and non-insulated bodies 2 show similar temperature rise trends in the early stages. Before 81 minutes, the temperatures of both are low and rise slowly, and then they begin to rise rapidly. As time progresses, the temperatures of both continue to rise, with the non-insulated body 2 rising slightly faster. However, the difference narrows in the later stages, and finally, at 221 minutes, the temperature of the insulated body 2 exceeds that of the non-insulated body 2. This indicates that although the insulated body 2 has little impact on the temperature rise rate in the early stages, its long-term effect is beneficial to temperature stability and heat retention, and it plays a role in the thermal stability of the silicon carbide crystal growth furnace.

[0043] The carbon-carbon ring 3 and the splicing strip 1 are fixedly connected by screws. In the overall structure of the silicon carbide crystal growth furnace insulation cylinder, the splicing strip 1 is a key component constituting the cylindrical main body, and its end is fixed to the carbon-carbon ring 3.

[0044] The gap between two adjacent splicing strips 1 is 1mm.

[0045] A 1mm gap is left between two adjacent splicing strips 1, which can physically block the loop current. When the loop current attempts to conduct along the circumference of the splicing strip 1, the presence of the 1mm gap makes it difficult to form a complete and continuous current path.

[0046] The 1mm gap between two adjacent splicing strips 1 allows the splicing strip 1 to play a key role in suppressing the self-heating of the circular current, reducing energy waste and structural hazards caused by its own heating.

[0047] The outer circumferential wall of the heat-insulating cylinder body 2 is wrapped with carbon sheets.

[0048] The carbon sheet is fixed to the outer periphery of the insulation cylinder body 2 by carbon rope.

[0049] The carbon-carbon sheet is fixed to the outer periphery of the insulation cylinder body 2 by carbon-carbon rope. The carbon-carbon rope serves as a connecting medium to accommodate the thermal expansion and contraction of the insulation cylinder body 2 at high temperatures. When the crystal growth furnace is working, the insulation cylinder body 2 expands due to heat, and the carbon-carbon rope will not generate excessive stress due to structural deformation. Instead, it can buffer the stress through its own slight deformation, ensuring that the carbon-carbon sheet is firmly wrapped around the outside of the insulation cylinder body 2.

[0050] The way the carbon fiber rope is fixed allows the carbon fiber sheet to be evenly and tightly attached to the outer circumference of the insulation cylinder body 2. This even attachment ensures the protective and auxiliary function of the carbon fiber sheet for the insulation cylinder body 2, enabling the carbon fiber sheet to function continuously and stably when facing heat transfer inside the furnace.

[0051] The carbon-carbon sheet is 0.8mm thick. In the high-temperature environment of the crystal growth furnace, its high-temperature resistance allows it to form an effective thermal protection layer. Its moderate thickness prevents excessive heat storage due to its large heat capacity, thus avoiding negatively impacting the furnace temperature environment. Simultaneously, it assists the insulation cylinder body 2 in preventing heat leakage, thereby enhancing the overall insulation effect. In the heat transfer path, the carbon-carbon sheet acts as an outer barrier, weakening the heat transfer intensity without causing heat accumulation due to excessive thickness, thus ensuring a stable and controllable temperature inside the crystal growth furnace.

[0052] A method for preparing an insulation cylinder for a silicon carbide crystal growth furnace. The method includes the following steps:

[0053] At least two splicing strips 1 are spliced ​​and arranged at equal intervals along the circumference to form a cylindrical main structure;

[0054] A gap is reserved between adjacent splicing strips 1;

[0055] The insulation cylinder body 2 is fixedly connected to the outer periphery of the splicing strip 1.

[0056] The manufacturing process of the heat preservation cylinder body 2 is as follows:

[0057] Carbon fibers, resin, dispersant, and water are mixed in the following manner: the length of the carbon fibers is 0.1-5 mm; the resin is phenolic resin, epoxy resin, or furan resin; the dispersant includes, but is not limited to, hydroxymethyl cellulose, hydroxyethyl cellulose, and polyacrylamide; the proportion of carbon fibers is 0.2%-5%; the weight of the resin is 0.2-1.5 times the weight of the carbon fibers; and the proportion of the dispersant is 0.01%-1%.

[0058] The wet blank is made by vacuum filtration or centrifugal molding.

[0059] The curing process is carried out in an oven at a temperature of 80-130℃.

[0060] Carbonization is carried out in a high-temperature furnace at a temperature of 1700-2200℃.

[0061] The insulation cylinder body 2 is processed into the required size using a precision engraving machine.

[0062] Carbon fibers with a length of 0.1-5mm are selected to form a thermally conductive and structurally supportive skeleton in subsequent processes. Phenolic resin, epoxy resin, or furan resin serves as the bonding and molding matrix. A dispersant ensures that the carbon fibers and resin are uniformly dispersed in the aqueous solution, thus preventing agglomeration. A wet blank is obtained by filtration or centrifugation. External force is used to shape the solid components in the mixed slurry, initially determining the macroscopic shape of the insulation cylinder. During curing in an oven at 80-130℃, the resin undergoes a cross-linking reaction, forming a three-dimensional network structure that bonds the carbon fibers, enhancing the strength and stability of the blank. High-temperature carbonization at 1700-2200℃ allows residual carbon-containing substances to work with the carbon fibers to construct a porous, high-temperature resistant skeleton dominated by carbon, significantly optimizing high-temperature resistance and thermal insulation performance. Finally, precision machining is used to accurately control the dimensions, thus adapting to the requirements of the crystal growth furnace.

[0063] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A heat retaining cylinder for a silicon carbide crystal growing furnace, characterized by comprising: include: The splicing strip (1) is an arc-shaped structure. At least two splicing strips (1) are spliced ​​and arranged at equal intervals along the circumferential direction to form a cylindrical main structure. An interval is reserved between two adjacent splicing strips (1) to reduce self-heating caused by the ring current. The heat insulation cylinder body (2) is sleeved on the outer periphery of the splicing strip (1) and the heat insulation cylinder body (2) and the splicing strip (1) are connected in a stable manner by a fixed connection method. The insulation cylinder body (2) is made of insulation material to ensure insulation performance in the high-temperature environment of the silicon carbide crystal growth furnace.

2. The heat retaining cylinder for a silicon carbide crystal growing furnace according to claim 1, wherein It also includes a carbon ring (3), which is fixedly connected to the end of the splicing strip (1).

3. The heat retaining cylinder for a silicon carbide crystal growing furnace according to claim 2, wherein The carbon ring (3) includes an annular plate (4) and a positioning block (5) fixedly connected to the inner sidewall of the annular plate (4). Several positioning blocks (5) are equidistant from the annular plate (4). The end of the splicing strip (1) is provided with a positioning groove (6), which corresponds to the positioning block (5).

4. The heat retaining cylinder for a silicon carbide crystal growing furnace according to claim 2, wherein The carbon ring (3) and the splicing strip (1) are fixedly connected by screws.

5. The heat retaining cylinder for a silicon carbide crystal growing furnace according to claim 1, wherein The gap between two adjacent splicing strips (1) is 1mm.

6. The heat retaining cylinder for a silicon carbide crystal growing furnace according to claim 5, wherein The outer circumferential wall of the heat-insulating cylinder body (2) is wrapped with carbon sheets.

7. The heat retaining cylinder for a silicon carbide crystal growing furnace according to claim 6, wherein The carbon sheet is fixed to the outer periphery of the heat insulation cylinder body (2) by carbon rope.

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