A single crystal furnace

Abstract

The application discloses a single crystal furnace, and relates to the technical field of single crystal furnaces.The single crystal furnace comprises a furnace body, a heating cavity with an open top provided in the furnace body, and a support portion formed around the open top; a heat shield assembly movably arranged in the heating cavity; the heat shield assembly comprises a sealing portion located above the support portion, and the sealing portion moves away from or approaches the support portion along with the up-and-down movement of the heat shield assembly; and a gas sealing cylinder provided outside the sealing portion and abutting against the bottom of the support portion; wherein the inner wall of the gas sealing cylinder is provided with a displacement channel matched with the movement path of the sealing portion, and the displacement channel and the sealing portion are kept abutting against each other, so that the support portion and the sealing portion form a barrier for limiting the airflow or the support portion, the gas sealing cylinder and the sealing portion form a barrier for limiting the airflow during the movement of the sealing portion. The application has the advantage of significantly reducing the oxidation.

Description

Technical Field

[0001] This invention relates to the field of single crystal furnace technology, and specifically to a single crystal furnace. Background Technology

[0002] To reduce the cleaning frequency of the bottom thermal zone (insulation structure) in existing top-venting single crystal furnaces, an improved exhaust channel design is used: the exhaust port is located above the heater inside the furnace, allowing the exhaust channel to pass through the insulation layer of the furnace inner wall and connect to the ash collection bin, thereby changing the flow path of the protective gas. However, in practical applications, it has been found that this improved top-venting method leads to oxide adhesion on the inner wall of the upper components of the single crystal furnace, affecting the normal operation of the equipment.

[0003] Therefore, those skilled in the art need to develop a single-crystal furnace that can significantly reduce oxide adhesion problems. Summary of the Invention

[0004] This invention aims to address, to a certain extent, one of the technical problems in related technologies. To this end, this invention provides a single-crystal furnace that significantly reduces oxide content.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A single-crystal furnace includes: a furnace body having a heating chamber with a top opening inside, and a support portion formed around the top opening; a heat shield assembly movably disposed within the heating chamber; the heat shield assembly including a sealing portion located above the support portion, and the sealing portion moving away from or closer to the support portion relative to the support portion as the heat shield assembly moves up and down; and a sealing cylinder covering the sealing portion, with the bottom of the sealing cylinder abutting against the support portion; wherein the inner wall of the sealing cylinder has a displacement channel adapted to the movement path of the sealing portion, the displacement channel and the sealing portion remaining abutting against each other, such that during the movement of the sealing portion, the support portion and the sealing portion constitute a barrier restricting airflow, or the support portion, the sealing cylinder, and the sealing portion constitute a barrier restricting airflow.

[0007] Optionally, the support portion has a radial limiting portion on the end face that fits against the bottom of the sealing cylinder; the radial limiting portion includes one of a limiting groove or a limiting protrusion; the radial limiting portion cooperates with the bottom inner wall or outer wall of the sealing cylinder to limit the displacement of the sealing cylinder in the radial direction of the top opening.

[0008] Optionally, the displacement channel is provided with an axial limiting part on the movement path of the sealing part; relative to the axial limiting part, the sealing part has two states. In the first state, the sealing part is separated from the axial limiting part; in the second state, the sealing part abuts against the axial limiting part, and the sealing part causes the sealing cylinder to separate from the support part or has a tendency to separate through the axial limiting part.

[0009] Optionally, the center of the heat shield assembly has a crystal rod receiving space; the single crystal furnace also includes a furnace cover covering the upper part of the furnace body, the furnace cover having a top opening corresponding to the position of the crystal rod receiving space; the sealing cylinder includes an upper part of the cylinder body; the upper part of the cylinder body extends into the top opening, forming a channel connecting the top opening and the crystal rod receiving space.

[0010] Optionally, the sealing cylinder further includes: a lower part of the cylinder, wherein the inner wall of the lower part of the cylinder forms the displacement channel; the diameter of the lower part of the cylinder is larger than the diameter of the upper part of the cylinder; and a middle part of the cylinder, wherein the middle part of the cylinder has a variable diameter structure to connect the upper part of the cylinder and the lower part of the cylinder; and the periphery of the middle part of the cylinder connected to the inner wall of the lower part of the cylinder forms the axial limiting part.

[0011] Optionally, the inner wall of the sealing cylinder has a reflective surface, and the thermal radiation reflectance of the reflective surface is greater than or equal to 50%.

[0012] Optionally, the reflective surface of the sealing cylinder has a multi-faceted structure; the multi-faceted structure includes multiple reflective zones distributed around the crystal rod receiving space; the multiple reflective zones extend along the axial direction of the crystal rod receiving space; in the circumferential direction along the crystal rod receiving space, the normal of the reflective surface is not parallel to the axis of the crystal rod receiving space.

[0013] Optionally, the reflective area is configured as a convex surface.

[0014] Optionally, the reflective area is configured as a reflective plane, wherein the angle between each reflective plane and the radial direction of the crystal rod receiving space is greater than or equal to 45° and less than 90°, so that the orthographic projection of the crystal rod located in the crystal rod receiving space on the reflective surface does not overlap with the reflective plane.

[0015] Optionally, the reflective areas are configured as paired and symmetrically arranged reflective planes; the interior angle between two adjacent symmetrical reflective planes along the circumference of the crystal rod accommodating space is greater than or equal to 90° and less than or equal to 180°.

[0016] Optionally, the heat shield assembly includes: a heat shield body; a fixing frame, the fixing frame being circumferentially disposed on the top of the heat shield body and protruding radially outward to form the sealing part; and a lifting connector, the lifting connector being inserted through the outside of the sealing cylinder and connected to the fixing frame, the lifting connector being used to drive the heat shield assembly to switch between different positions and lock.

[0017] Optionally, the furnace body includes: an outer furnace cylinder; a heat insulation layer structure disposed on the inner wall of the outer furnace cylinder, and the heat insulation layer structure forming the support portion at its end; the heating chamber forming the central region of the heat insulation layer structure; and an ash accumulation chamber disposed between the heat insulation layer structure and the outer furnace cylinder; wherein, the heat insulation layer structure is provided with an exhaust channel; the exhaust channel penetrates the heat insulation layer structure in the thickness direction and connects the heating chamber and the ash accumulation chamber respectively.

[0018] The single crystal furnace of this application has at least the following effects:

[0019] This single crystal furnace can effectively constrain the airflow around the sealing part of the heat shield assembly through the gas sealing cylinder, reducing the contact between volatiles in the furnace and the furnace cover and heat shield assembly, thereby significantly reducing the adhesion of oxides on the furnace cover and heat shield assembly and ensuring the stable operation of the equipment.

[0020] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of the present invention will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. In addition, each of these features, elements and components appearing in the following text and drawings is a plurality of, and different symbols or numbers are used for convenience of representation, but all represent parts with the same or similar construction or function. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] Figure 1 The following is an exploded view of the single crystal furnace described in some embodiments, showing the furnace body, heat shield assembly, and sealing gas cylinder.

[0023] Figure 2 This is a schematic diagram of the structure of the heat shield assembly of the single crystal furnace in the initial position in some embodiments.

[0024] Figure 3 This is a schematic diagram of the structure of the heat shield assembly of the single crystal furnace in a raised position in some embodiments.

[0025] Figure 4 This is a schematic diagram of the structure of the heat shield assembly of the single crystal furnace in the detached position in some embodiments.

[0026] Figure 5 The diagram below is a structural schematic of the single crystal furnace described in some other embodiments, showing the connection structure between the upper part of the sealing cylinder and the top opening of the furnace cover.

[0027] Figure 6 This is a structural schematic diagram of the heat shield assembly of the single crystal furnace in its initial position in some other embodiments.

[0028] Figure 7 This is a schematic diagram of the structure of the heat shield assembly of the single crystal furnace in a raised position in some other embodiments.

[0029] Figure 8 This is a schematic diagram of the structure of the heat shield assembly of the single crystal furnace in the detached position in some other embodiments.

[0030] Figure 9 This is a schematic diagram of the gas sealing cylinder on the furnace body in some embodiments.

[0031] Figure 10 This is a schematic diagram of the structure of the inner wall of the sealing cylinder in some embodiments.

[0032] Figure 11 This is a cross-sectional schematic diagram of the sealing cylinder described in some embodiments, showing the inner wall reflective surface structure in the shape of a regular polygon.

[0033] Figure 12 The image shows the path of light reflected from the inner wall of a conventionally circular cylindrical sealing cylinder.

[0034] Figure 13 This is a cross-sectional schematic diagram of the sealing cylinder described in some embodiments, showing that the reflective surface adopts a reflective convex surface.

[0035] Figure 14 The image shows a cross-sectional view of the sealing cylinder at the bottom straight cylinder in some embodiments, illustrating a special configuration of the reflective surface on the inner wall of the bottom straight cylinder.

[0036] Figure 15 This is a schematic diagram illustrating the principle of thermal radiation reflection from the reflective surface inside the sealing cylinder in some embodiments.

[0037] in,

[0038] 100. Furnace body; 101. Outer furnace cylinder; 102. Insulation layer structure; 103. Ash accumulation chamber; 104. Exhaust channel; 110. Top opening; 120. Heating chamber; 121. Exhaust port; 130. Support part; 131. Radial limiting part; 200. Heat shield assembly; 201. Sealing part; 202. Crystal rod receiving space; 210. Heat shield body; 220. Fixing frame; 230. Lifting connector; 300. Gas sealing cylinder; 301. Displacement channel; 302. Axial limiting part; 310. Upper part of cylinder; 320. Lower part of cylinder; 330. Middle part of cylinder; 340. Reflection zone; 400. Furnace cover; 410. Top opening; 500. Crystal rod. Detailed Implementation

[0039] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain the present invention and should not be construed as limiting the invention.

[0040] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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 invention 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 invention.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, and "several" means one or more.

[0043] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this invention. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0044] The inventors of this application discovered through research that during the operation of a single crystal furnace, especially during re-feeding operations, the heat shield assembly 200 inside the furnace body 100 needs to be raised by approximately 200 mm and maintained for a considerable period (usually more than one hour). This operation creates a large gap between the periphery of the sealing part 201 (located at the top) of the heat shield assembly and the top opening 110 of the heating chamber 120 of the furnace body 100. Due to this gap, volatile gases inside the furnace body 100 can freely escape through this gap to the top of the furnace body 100. These volatile gases will then contact the inner wall of the furnace cover 400 or bypass the heat shield assembly 200 and contact the inner wall of the heat shield body 210. Since the furnace cover 400 and the heat shield body 210 are equipped with cooling components, their temperature is relatively low. When the volatiles come into contact with these cooling surfaces, they will quickly solidify and adhere to these surfaces, thereby affecting the overall performance of the thermal field and indirectly affecting the stability of the overall production process.

[0045] To maintain the thermal field performance within a preset range, the cleaning frequency of the furnace cover 400 and the heat shield assembly 200 must be increased. However, frequent cleaning not only increases maintenance time but also affects production efficiency. This is especially true for single-crystal furnaces using top-venting systems, where oxide adhesion to the inner walls of the furnace cover 400 and the heat shield body 210 is more severe. Since the exhaust port 121 of the exhaust channel 104 is located on the upper part of the inner wall of the furnace body 100, turbulent airflow may form within the furnace cover 400 when the heat shield assembly 200 is raised. This can cause dust from the exhaust port 121 to flow back into the furnace cover 400 through the gaps, further exacerbating the contamination problem.

[0046] To address the aforementioned issues, this embodiment proposes a single-crystal furnace. This furnace effectively constrains internal airflow during re-injection, reducing contact between volatiles and the furnace cover 400 and heat shield assembly 200, thereby significantly reducing oxide adhesion on the furnace cover 400 and heat shield assembly 200 and ensuring stable equipment operation.

[0047] like Figure 1-4 As shown, a single crystal furnace is illustrated, which mainly includes a furnace body 100, a heat shield assembly 200, and a sealing cylinder 300.

[0048] The furnace body 100 has a heating chamber 120 with a top opening 110 inside, and a support part 130 is formed around the top opening 110.

[0049] The heat shield assembly 200 is movably disposed within the heating chamber 120. The heat shield assembly 200 includes a sealing portion 201, which is located above the support portion 130, and the sealing portion 201 moves away from or closer to the support portion 130 as the heat shield assembly 200 moves up and down.

[0050] For example, when the sealing part 201 is close to the support part 130, it is in the initial position, in which the sealing part 201 is connected to the support part 130 and closes the top opening 110. When the sealing part 201 is away from the support part 130, it is in the raised position, in which the top opening 110 is separated from the support part 130.

[0051] The sealing cylinder 300 is placed outside the sealing part 201, and the bottom of the sealing cylinder 300 is in contact with the support part 130.

[0052] The inner wall of the sealing cylinder 300 has a displacement channel 301 adapted to the movement path of the sealing part 201. The displacement channel 301 and the sealing part 201 are kept in contact, so that during the movement of the sealing part 201, the support part 130 and the sealing part 201 form a barrier to restrict the flow of air, or the support part 130, the sealing cylinder 300 and the sealing part 201 form a barrier to restrict the flow of air.

[0053] For example, the furnace body 100 adopts a vertical cylindrical structure, with a cylindrical heating chamber 120 in the middle. The heating chamber 120 has a top opening 110 at the top and is closed at the bottom. Specifically, the top opening 110 is located on the upper end face of the furnace body 100, and a support portion 130 is formed around the top opening 110 to support the heat shield assembly 200. The support portion 130 can be a horizontal end face or a stepped surface with decreasing height from the outside to the inside. It can be assembled from separate parts or be a single piece.

[0054] Under normal operating conditions, the hotspot component 200 is in its initial position (e.g., Figure 2 As shown, its sealing part 201 is close to and tightly fitted with the support part 130 to seal the top opening 110. Alternatively, if there is a gap between the sealing part 201 and the support part 130, the top opening 110 is sealed by the sealing part 201 sealing the inner wall of the displacement channel 301, and by the bottom wall of the displacement channel 301 sealing the support part 130.

[0055] The lower end of the heat shield assembly 200 is suspended inside the heating chamber 120, maintaining an appropriate distance from the inner wall of the chamber to form an airflow channel. Typically, a liftable crucible assembly is also located inside the furnace body 100 below the heat shield assembly 200; this channel also provides space for the liftable crucible assembly to move. For some single-crystal furnaces with an upward exhaust structure, an exhaust port 121 is also provided inside the heating chamber 120. When the crucible is raised to its highest position, the edge of its rim is flush with or slightly lower than the exhaust port 121 located inside the heating chamber 120.

[0056] During re-projection, the hot screen component 200 needs to be raised to a certain height. At this time, the hot screen component 200 is in the raised position (e.g., Figure 3As shown, in this position, the lower end of the heat shield assembly 200 is still mostly located within the heating chamber 120, with only the sealing part 201 suspended above the support part 130. The sealing part 201 is separated from the support part 130. Furthermore, an annular gap space of at least 100 mm is formed between the heat shield assembly 200 and the support part 130 or the top opening of the furnace body 100.

[0057] At this time, the displacement channel 301 and the sealing part 201 remain in contact, and the barrier formed can dynamically seal the annular space.

[0058] It should be noted that the "fitting" mentioned here refers not only to contact fitting but also to non-contact fitting. The specific explanation of non-contact fitting is as follows: In this embodiment, the inner diameter of the displacement channel 301 is slightly larger than the diameter of the sealing portion 201 of the heat shield assembly. Specifically, a gap of less than 10mm between the inner wall of the displacement channel 301 and the periphery of the sealing portion 201 of the heat shield assembly is considered a non-contact fit. Preferably, it is 1-5mm. Sealing refers to the ability to effectively restrict airflow by setting the gap within this range, thus preventing wear caused by accidental contact during movement. Dynamic sealing refers to maintaining fit throughout the movement of the sealing portion 201 within the displacement channel 301.

[0059] The presence of this barrier effectively maintains the original airflow path of the heating chamber 120, preventing the re-operation from interfering with the normal operation of the exhaust system. Experiments show that this structure can reduce airflow disturbance by more than 80%.

[0060] Secondly, this barrier forms independent gas spaces inside and outside the heat shield assembly 200, confining volatiles within the heating chamber 120 and effectively preventing their diffusion into the space above the heat shield assembly 200, thus significantly reducing the risk of oxide deposition. Test data shows that the concentration of volatiles in the space above the heat shield assembly 200 is reduced to less than 15% of the initial value, significantly reducing oxide deposition.

[0061] Meanwhile, the non-contact sealing between the heat shield assembly 200 and the displacement channel 301, achieved through a non-contact bonding method, avoids particulate contamination caused by motion wear. Long-term operation data shows that this structure extends the equipment maintenance cycle by 3 times and improves operational stability by 40%.

[0062] More importantly, the barrier effectively blocks heat exchange between the upper and lower regions of the heat shield assembly 200, keeping the thermal field fluctuations of the heating cavity 120 within a small range and reducing the power consumption to maintain the thermal field.

[0063] In some embodiments, see Figure 2The support portion 130 has a radial limiting portion 131 on the end face that is in contact with the bottom of the sealing cylinder 300. The radial limiting portion 131 includes either a limiting groove or a limiting protrusion. The radial limiting portion 131 cooperates with the inner wall or outer wall of the bottom of the inner sealing cylinder 300 to limit the displacement of the sealing cylinder 300 in the radial direction of the top opening 110.

[0064] For example, the surface of the support 130 is provided with a groove surrounding the top opening 110. The inner diameter of the groove is slightly larger than the outer diameter of the sealing part 201, and the width of the groove is larger than the wall thickness of the sealing cylinder 300. This allows the bottom of the sealing cylinder 300 to be placed in the groove, and the inner wall of the sealing cylinder 300 to cooperate with the inner side wall of the groove, or the outer wall of the sealing cylinder 300 to cooperate with the outer side wall of the groove. This achieves radial limiting of the sealing cylinder 300 and ensures that the gap between the inner wall of the sealing cylinder 300 and the periphery of the sealing part 201 is controlled within a preset range.

[0065] In some embodiments, the displacement channel 301 is provided with an axial limiting portion 302 on the movement path of the sealing portion 201. The sealing portion 201 has two states relative to the axial limiting portion 302. In a first state, the sealing portion 201 is separated from the axial limiting portion 302; in a second state, the sealing portion 201 abuts against the axial limiting portion 302, and the sealing portion 201, through the axial limiting portion 302, causes the sealing cylinder 300 to separate from the support portion 130 or has a tendency to separate.

[0066] like Figure 4 As shown, with the support portion 130 as a reference point, in the direction of movement of the sealing portion 201, that is, in the opening direction of the top opening 110, the sealing portion 201 is provided with an initial position, a raised position, and a disengaged position from near to far. Within the displacement channel 301, the axial limiting portion 302 is specifically located between the raised position and the disengaged position, and compared to the disengaged position, the axial limiting portion 302 is closer to the raised position.

[0067] The first state of the sealing part 201 corresponds to the process of it moving from the initial position to the raised position, and the second state of the sealing part 201 corresponds to the process of it moving from the raised position to the disengaged position.

[0068] For example, the axial limiting part 302 is a protrusion on the inner wall surface of the sealing cylinder 300. When the heat shield assembly 200 is raised to a position greater than the lifting position, it continues to be raised until the periphery of the sealing part 201 abuts against the protrusion, thereby lifting the sealing cylinder 300 and separating the bottom of the sealing cylinder 300 from the support part 130. In this position, the sealing cylinder 300 no longer restricts the airflow between the heat shield assembly 200 and the support part 130.

[0069] In other embodiments, such as Figure 5 , Figure 6 and Figure 7 As shown, a crystal rod receiving space 202 is formed at the center of the heat shield assembly 200. The crystal rod receiving space 202 extends along the axial direction of the furnace body 100 and has a lower opening with an upper opening opposite to the upper opening in the extending direction, so that the crystal rod can pass through and the airflow can pass through.

[0070] The single crystal furnace also includes a furnace cover 400 that covers the upper part of the furnace body 100, and the furnace cover 400 has a top opening 410 at the position corresponding to the position of the crystal rod receiving space 202.

[0071] Specifically, the top opening 410, the upper opening of the ingot receiving space 202, and the lower opening are coaxially arranged. The cavity inside the furnace cover 400 is connected to the ingot receiving space 202 of the heat shield assembly 200. The top opening 410 leads directly to the ingot receiving space 202, and the ingot can extend into the top opening 410 as it grows. The furnace cover 400 can inject protective gas into the furnace through the top opening 410.

[0072] like Figure 6 , Figure 7 and Figure 8 As shown, the sealing cylinder 300 includes an upper cylinder 310, a lower cylinder 320, and a middle cylinder 330 connecting the two. The upper cylinder extends into the top opening 410, so that the sealing cylinder 300 communicates with both the top opening 410 and the crystal rod receiving space 202. Specifically, the diameter of the upper cylinder 310 is slightly smaller than the diameter of the top opening 410, so that the outer wall of the upper cylinder 310 intermittently fits the top opening 410.

[0073] A displacement channel 301 is formed on the inner wall of the lower part 320 of the cylinder. The diameter of the lower part 320 of the cylinder is much larger than the diameter of the top opening 410 of the furnace cover 400. The middle part 330 of the cylinder has a variable diameter structure, which connects the two parts.

[0074] The axial limiting part 302 is formed around the inner wall of the middle part 330 of the cylinder and the lower part 320 of the cylinder.

[0075] Normally, when the heat shield assembly 200 is in the initial position to the raised position, the lower part 320 of the cylinder remains in contact with the support part 130. Because the middle part 330 of the cylinder has a variable diameter structure, when it is lifted by the sealing part 201, the lower part 320 of the cylinder remains separated from the support part 130. Furthermore, because the middle part 330 of the cylinder has a variable diameter structure, a two-stage sealing cylinder 300 can be compactly arranged inside the furnace cover 400, ensuring that the lower part 320 of the cylinder has sufficient upward space without touching the furnace cover 400.

[0076] In this embodiment, the sealing cylinder 300 adopts an innovative two-section structural design. The upper part 310 of the cylinder is structurally connected to the top opening 410 of the furnace cover 400, dividing the space between the inner side of the furnace cover 400 and the top opening 110 of the furnace body 100 into two independent areas: an inner cylinder space and an outer cylinder space. The inner cylinder space is directly connected to the top opening 410 and the upper opening of the ingot receiving space 202 of the heat shield assembly 200, while the outer cylinder space is formed in a relatively closed area between the outer side of the sealing cylinder 300 and the inner side of the furnace cover 400.

[0077] This unique spatial division allows the lower part 320 of the cylinder to not only dynamically constrain the airflow between the heat shield assembly 200 and the support part 130, but more importantly, to form an effective thermal barrier layer between the inner and outer spaces of the cylinder, thereby reducing axial heat loss in the thermal field. Especially during the constant diameter growth stage, the heater power fluctuation can be controlled within ±2%.

[0078] Specifically, this design reduces the heat load on the cooling system within the furnace cover 400 by more than 30% by delaying heat transfer to the cover, significantly improving the stability of the thermal field. Simultaneously, the independent spatial division ensures that the thermal environment of the crystal rod housing 202 is unaffected by external interference, providing ideal conditions for the growth of high-quality single crystals. Compared to traditional structures, this design achieves 15-20% energy savings while maintaining crystal growth quality, demonstrating significant economic benefits.

[0079] To further improve the stability of the thermal field and reduce energy consumption in the constant-diameter stage, in some embodiments, the inner wall of the sealing cylinder 300 has a reflective surface with a thermal radiation reflectance coefficient greater than or equal to 50%. For example, the sealing cylinder 300 is made of molybdenum. Alternatively, the inner wall of the sealing cylinder 300 is coated with molybdenum.

[0080] In some embodiments, see Figure 9 , Figure 10 , Figure 11 , Figure 13 and Figure 14 As shown, the reflective surface of the sealing cylinder 300 has a multi-faceted structure. The multi-faceted structure includes multiple reflective regions 340 distributed around the crystal rod receiving space 202. The multiple reflective regions 340 extend along the axial direction of the crystal rod receiving space 202. In the circumferential direction along the crystal rod receiving space 202, the normal of the reflective region 340 is out of plane with the axis of the crystal rod receiving space 202.

[0081] It should be noted that the fact that the normal of the reflective region 340 is not parallel to the axis of the crystal rod housing space 202 means that most of the normals on the reflective region 340 are not parallel to the axis of the crystal rod housing space 202. For a symmetrical reflective region 340, its center of symmetry will pass through the axis of the crystal rod housing space 202, resulting in a normal in the middle of the reflective region 340 being collinear with the axis of the crystal rod housing space 202, which can be ignored.

[0082] Specifically, the inner wall of the lower part 320 of the cylinder is configured with a multi-faceted structure. Correspondingly, the outer contour shape of the sealing part 201 of the heat shield assembly is adapted to the shape formed by the multiple reflective areas 340, so that the part of the sealing part 201 of the heat shield assembly corresponding to the multiple reflective areas 340 can always fit in close contact with the corresponding reflective areas 340.

[0083] like Figure 11 As shown, the sealing cylinder 300 has a cross-section in the horizontal direction that is a thin-walled regular polygonal structure. The crystal rod 500 is positioned along the axis of the crystal rod receiving space 202, with the axis of the crystal rod 500 collinear with the axis of the crystal rod receiving space 202. The inner wall of the sealing cylinder 300 has multiple reflective planes facing the crystal rod. This design offers certain advantages in thermal management.

[0084] Since the lower part 320 of the cylinder is arranged around the crystal rod, if a cylindrical inner wall is used (such as...) Figure 12 As shown in the figure, its concave structure will produce a converging effect on thermal radiation. Specifically, when the thermal radiation from the crystal rod shines on the side of the cylinder, the reflected light will focus on a local area on the surface of the crystal rod, causing the temperature in that area to rise abnormally, which will seriously affect the uniform heat dissipation of the crystal rod.

[0085] In this embodiment, the multifaceted structure adopts a regular polygonal inner wall structure (such as...). Figure 11 (As shown). Its design with multiple reflective zones ensures that thermal radiation can return along its original path, avoiding the converging effect of thermal radiation.

[0086] For further optimized thermal radiation management. In some embodiments, such as Figure 13 As shown, the reflective region 340 is configured as a reflective convex surface. Through its divergent properties, the reflective convex surface can diffuse thermal radiation, allowing the crystal rod to receive only a portion of the reflected energy.

[0087] In other embodiments, to prevent the thermal radiation from the crystal rod from being absorbed again after the initial reflection by the reflective region, the reflective region 340 is configured as a reflective plane. For example... Figure 14 and 15 As shown, the angle between each reflective plane and the radial direction of the crystal rod receiving space 202 is greater than or equal to 45° and less than 90°, so that the orthographic projection of the crystal rod located in the crystal rod receiving space 202 on the reflective surface does not overlap with the reflective plane.

[0088] Typically, when the reflecting plane is directly opposite the crystal rod, there is a maximum radial angle between the reflecting plane and the crystal rod, which is 90 degrees. See also Figure 14 As shown, taking one reflecting plane AB as an example, the angles between the two ends of the reflecting plane AB and the radial direction are ∠a and ∠b, respectively, both of which are between 45° and 90°. See also... Figure 15 The projection of the crystal rod onto the reflecting plane AB is a line segment L. Line segment L does not overlap with the reflecting plane AB, thus deflecting the thermal radiation after reflection and preventing it from directly returning to the crystal rod surface. The deflected thermal radiation is gradually absorbed during multiple reflections within the inner wall of the sealing cylinder 300, achieving effective energy dissipation.

[0089] In other embodiments, the reflective regions 340 are configured as paired and symmetrically arranged reflective planes. Along the circumference of the crystal rod housing space 202, the interior angle between two adjacent symmetrical reflective planes is greater than or equal to 90° and less than or equal to 180°.

[0090] Example, Figure 14 The two reflective planes AB and BC are symmetrically arranged, with an obtuse angle ∠c between them. This structure firstly avoids multiple reflections of thermal radiation in local areas between adjacent reflective planes; secondly, it extends the reflection path of thermal radiation within the sealing cylinder 300, thus improving energy absorption efficiency.

[0091] In some embodiments, such as Figure 8 As shown, the hot screen assembly 200 includes a hot screen body 210, a fixing frame 220, and a lifting connector 230.

[0092] A fixing frame 220 is circumferentially disposed on the top of the heat shield body 210 and protrudes radially outward to form a sealing part 201 of the heat shield assembly. A lifting connector 230 passes through the sealing cylinder 300 and connects to the fixing frame 220, and is used to drive the heat shield assembly 200 to switch and lock between different positions.

[0093] In some embodiments, an exhaust port 121 is provided within the heating chamber 120, the exhaust port 121 communicating with the heating chamber 120 and used to exhaust air to the outside of the heating chamber 120. The furnace body 100 includes an outer furnace cylinder 101, a heat insulation layer structure 102, and an ash collection chamber 103. The heat insulation layer structure 102 is disposed on the inner wall of the outer furnace cylinder 101. The heat insulation layer structure 102 has a certain thickness to form a support portion 130 at its end. The heating chamber 120 is formed in the central region of the heat insulation layer structure 102. The ash collection chamber 103 is disposed between the heat insulation layer structure 102 and the inner wall of the outer furnace cylinder 101. An exhaust channel 104 is provided within the heat insulation layer structure 102, the exhaust channel 104 penetrating the heat insulation layer structure 102 in the thickness direction and communicating with the heating chamber 120 and the ash collection chamber 103 respectively. The exhaust port 121 is the through-hole of the exhaust channel 104 inside the heat insulation layer structure.

[0094] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A single crystal furnace, characterized in that, include: The furnace body (100) has a heating chamber (120) with a top opening (110) inside, and a support part (130) is formed around the top opening (110); A heat shield assembly (200) is movably disposed within the heating chamber (120); the heat shield assembly (200) includes a sealing portion (201) located above the support portion (130), and the sealing portion (201) moves away from or closer to the support portion (130) relative to the heating portion (130) as the heat shield assembly (200) moves up and down; and, A sealing cylinder (300) is provided, which covers the sealing part (201), and the bottom of the sealing cylinder (300) is in contact with the support part (130); The inner wall of the sealing cylinder (300) has a displacement channel (301) adapted to the movement path of the sealing part (201). The displacement channel (301) and the sealing part (201) are kept in contact, so that the supporting part (130) and the sealing part (201) form a barrier to restrict the airflow during the movement of the sealing part (201), or the supporting part (130), the sealing cylinder (300) and the sealing part (201) form a barrier to restrict the airflow.

2. The single crystal furnace according to claim 1, characterized in that, The support part (130) has a radial limiting part (131) on the end face that fits against the bottom of the sealing cylinder (300); The radial limiting part (131) includes either a limiting groove or a limiting protrusion; the radial limiting part (131) cooperates with the bottom inner wall or outer wall of the sealing cylinder (300) to limit the displacement of the sealing cylinder (300) in the radial direction of the top opening (110).

3. The single crystal furnace according to claim 1, characterized in that, The displacement channel (301) is provided with an axial limiting part (302) on the movement path of the sealing part (201); the sealing part (201) has two states relative to the axial limiting part (302). In the first state, the sealing part (201) is separated from the axial limiting part (302); in the second state, the sealing part (201) abuts against the axial limiting part (302), and the sealing part (201) causes the sealing cylinder (300) to separate from the support part (130) or has a tendency to separate through the axial limiting part (302).

4. The single crystal furnace according to claim 3, characterized in that, A crystal rod receiving space (202) is formed at the center of the heat shield assembly (200); The single crystal furnace also includes a furnace cover (400) covering the upper part of the furnace body (100), and the furnace cover (400) has a top opening (410) at the position corresponding to the crystal rod receiving space (202); The sealing cylinder (300) includes an upper part (310) of the cylinder body; the upper part (310) of the cylinder body extends into the top opening (410) so that the sealing cylinder (300) is connected to the top opening (410) and the crystal rod receiving space (202) respectively.

5. The single crystal furnace according to claim 4, characterized in that, The sealing cylinder (300) also includes: The lower part (320) of the cylinder, the inner wall of which forms the displacement channel (301); the diameter of the lower part of the cylinder is larger than the diameter of the upper part (310) of the cylinder; and, The middle part (330) of the cylinder is a variable diameter structure to connect the upper part (310) and the lower part (320) of the cylinder; and the axial limiting part (302) is formed around the inner wall of the middle part (330) of the cylinder and the inner wall of the lower part (320).

6. The single crystal furnace according to any one of claims 1-5, characterized in that, The inner wall of the sealing cylinder (300) has a reflective surface, and the thermal radiation reflectance of the reflective surface is greater than or equal to 50%.

7. The single crystal furnace according to claim 6, characterized in that, The reflective surface of the sealing cylinder (300) has a multi-faceted structure; the multi-faceted structure includes multiple reflective areas (340) distributed around the crystal rod receiving space (211); the multiple reflective areas (340) extend along the axial direction of the crystal rod receiving space (211); in the circumferential direction along the crystal rod receiving space (211), the normal of the reflective surface is not parallel to the axis (211) of the crystal rod receiving space.

8. The single crystal furnace according to claim 7, characterized in that, The reflective area (340) is configured as a convex surface; Alternatively, the reflective area (340) is configured as a reflective plane, with each reflective plane having an angle greater than or equal to 45° and less than 90° between it and the radial direction of the crystal rod receiving space (211), such that the orthographic projection of the crystal rod located in the crystal rod receiving space (211) on the reflective surface does not overlap with the reflective plane. Alternatively, the reflective areas are configured as paired and symmetrically arranged reflective planes; the interior angle between two adjacent symmetrical reflective planes is greater than or equal to 90° and less than or equal to 180° along the circumference of the crystal rod accommodating space (202).

9. The single crystal furnace according to any one of claims 1-5, characterized in that, The heat shield assembly (200) includes: Hot screen main body (210); A fixing frame (220) is provided around the top of the heat shield body and protrudes radially outward to form the sealing part (201); A lifting connector (230) is provided outside the sealing cylinder (300) and connected to the fixing frame (220). The lifting connector (230) is used to drive the heat shield assembly (200) to switch and lock between different positions.

10. The single crystal furnace according to any one of claims 1-5, characterized in that, The furnace body (100) includes: Outer furnace cylinder (101); A heat insulation layer structure (102) is disposed inside the outer furnace cylinder (101), and the heat insulation layer structure (102) forms the support part (130) on the end side; the heating cavity (120) is formed in the central region of the heat insulation layer structure (102); Ash collection chamber (103), the ash collection chamber (103) is disposed between the outer furnace cylinder (101) and the heat insulation layer structure (102); The insulation layer structure (102) is provided with an exhaust channel (104); the exhaust channel (104) penetrates the insulation layer structure (102) in the thickness direction and is connected to the heating chamber (120) and the ash accumulation chamber (103) respectively.

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