Single crystal furnace heat shield

Abstract

A single crystal furnace heat shield comprises an outer heat shield body and an inner heat shield body, the top of the outer heat shield body is fixedly connected with a first edge placed on a heat shield supporting ring of a single crystal furnace, the bottom of the outer heat shield body shrinks inwards to form a mounting bottom ring, an extension ring is fixedly arranged on the mounting bottom ring, and a plurality of anti-disengaging strips are distributed on the inner side wall of the extension ring in the circumferential direction of the extension ring. A channel is formed between every two adjacent anti-disengaging strips, anti-disengaging space is formed between the anti-disengaging strips and the installation bottom ring, the top of the inner heat shield is fixedly connected with a second edge placed on a heat preservation ring cover of the single crystal furnace, and a plurality of protruding strips matched with the anti-disengaging strips are fixedly arranged on the outer wall of the inner heat shield. The protruding strip can penetrate through the channel and rotate to enter the anti-disengaging space. According to the utility model, the weight needing to be borne by the heat shield supporting ring is reduced, and the heat shield supporting ring is prevented from being broken.

Description

TECHNICAL FIELD

[0001] The utility model relates to single crystal furnace technical field, concretely is a single crystal furnace heat shield. BACKGROUND

[0002] The direct pulling method is the production method of the traditional silicon single crystal, along with the development of production equipment, process condition, energy saving and consumption reduction demand, the heat field structure needed by the matching also gradually develops optimization. As one part of the heat field structure, the heat shield plays a key role in single crystal pulling. The most intuitive performance is that the heat shield can provide guidance for the argon gas flow direction in the single crystal furnace, so it is also called the flow guide cylinder. In addition, the use of the heat shield can shield the heat radiation of the melt to the crystal bar, providing guarantee for high-speed crystal pulling and stable growth of the crystal. Therefore, the stability of the heat shield becomes a factor that needs to be focused on in the single crystal pulling process.

[0003] However, with the gradual increase of the size of the furnace table heat field from 16 inches, 18 inches, 20 inches, 22 inches, 24 inches, 28 inches, 32 inches and 36 inches, the size of the heat shield is also gradually increasing, which has higher requirements for the temperature shielding and structural stability of the heat shield. In order to improve the performance of the heat shield, the current method is to enlarge the size of the heat shield to meet the use demand, but the increase of the size of the heat shield also brings some problems.

[0004] The heat shield in the prior art, as shown in Figure 10 When in use, the inner flow guide cylinder 22, the outer flow guide cylinder 24 and the heat preservation piece 23 are stably placed as a whole on the heat shield support ring, and rely on the edge part of the heat shield support ring for bearing. However, when the size of the heat shield is enlarged, the overall weight will increase, which will greatly shorten the service life of the heat shield support ring, and in severe cases, the heat shield support ring may suddenly break during use. UTILITY MODEL CONTENTS

[0005] In order to solve the problem of sudden breakage of the heat shield support ring in the prior art during use, the utility model provides a single crystal furnace heat shield, which disperses the weight of the heat shield and does not concentrate on the heat shield support ring, avoiding the breakage of the heat shield support ring.

[0006] The utility model discloses a technical scheme that solves the above technical problem is adopted: a single crystal furnace heat shield, including outer heat shield and inner heat shield, the top of outer heat shield is fixedly connected with the first brim of placing on the heat shield support ring of single crystal furnace, and the bottom of outer heat shield contracts inwards and forms the installation bottom ring, and the installation bottom ring is fixedly provided with the extension ring, and the inboard wall of extension ring is distributed with a plurality of anti -drop strips along its circumferential direction, and forms the passageway between the adjacent anti -drop strip, and forms the anti -drop space between anti -drop strip and installation bottom ring, and the top of inner heat shield is fixedly connected with the second brim of placing on the heat preservation ring cover of single crystal furnace, and the outer wall of inner heat shield is fixedly provided with a plurality of with the convex strip of anti -drop strip cooperation, and the convex strip can pass through the passageway and rotate and enter the anti -drop space.

[0007] As the further optimization of the utility model single crystal furnace heat shield: the anti -drop strip and the installation bottom ring are connected with the stopper.

[0008] As the further optimization of the utility model single crystal furnace heat shield: the installation bottom ring is set up with the clamping slot adjacent with the stopper, and the bottom of convex strip is provided with the positioning block with the clamping slot cooperation, and the convex strip contacts the stopper in the rotation process of inner heat shield, and the positioning block is aligned with the clamping slot.

[0009] As the further optimization of the utility model single crystal furnace heat shield: the single crystal furnace heat shield includes the first closed ring, and the first closed ring is arranged on the inner wall of the heat preservation ring cover, and the first closed ring is placed on the heat shield support ring, and the two ends of the first closed ring are respectively attached with the second brim and heat shield support ring.

[0010] As the further optimization of the utility model single crystal furnace heat shield: the top of the first closed ring is provided with the flared portion that expands outward, and the inner diameter of the small end of the flared portion is greater than the outer diameter of the first brim.

[0011] As the further optimization of the utility model single crystal furnace heat shield: the single crystal furnace heat shield includes the heat preservation layer and the second closed ring, and the heat preservation layer is filled between the outer heat shield and the inner heat shield, and the two ends of the second closed ring are respectively in contact with the first brim and the second brim to seal the heat preservation layer between the outer heat shield and the inner heat shield.

[0012] As the further optimization of the utility model single crystal furnace heat shield: the inner wall of the first closed ring and the outer wall of the second closed ring are in contact or have a distance.

[0013] As the further optimization of the utility model single crystal furnace heat shield: two groups of hoisting holes axially symmetrical about the inner heat shield are set up on the second brim, and each group of hoisting holes is set up as three.

[0014] As a further optimization of the utility model kind of single crystal furnace heat shield: the single crystal furnace heat shield includes two lifting pieces, lifting piece includes the mounting plate and connecting plate parallel up and down, the mounting plate and connecting plate are connected through the inclined plate, the connecting plate corresponds with a group of the hoisting hole, and the connecting plate is connected with the second brim through the connecting bolt.

[0015] As a further optimization of the utility model kind of single crystal furnace heat shield: the second brim's thickness is greater than the first brim's thickness.

[0016] Compared with the prior art, the utility model has the beneficial effects that:

[0017] 1) the utility model discloses a first brim is fixedly connected with the heat shield support ring of single crystal furnace and is placed on the top of the outer heat shield, and a second brim is fixedly connected with the heat shield support ring of single crystal furnace and is placed on the top of the inner heat shield, and the inner heat shield is mainly supported by the heat preservation ring cover, and the outer heat shield is mainly supported by the heat shield support ring, and the heat shield support ring of the utility model only bears the weight of the outer heat shield, greatly reduces the weight that the heat shield support ring needs to bear, and avoids the fracture of the heat shield support ring.

[0018] 2) the utility model discloses an extension ring, and the inner side wall of the extension ring is distributed with a plurality of anti-drop strips along the circumferential direction, and the anti-drop strips are formed with channels between adjacent anti-drop strips, and the anti-drop space is formed between the anti-drop strip and the installation bottom ring, and the outer wall of the inner heat shield is fixedly provided with a plurality of convex strips matched with the anti-drop strip, and the convex strip can pass through the channel and rotate into the anti-drop space, and in the pulling crystal process, the convex strip of the inner heat shield also supports the anti-drop strip of the outer heat shield to a certain extent, which can disperse a part of the weight that the heat shield support ring needs to bear, and also plays a protective role to the heat shield support ring, avoiding the fracture of the heat shield support ring. ACCURACY OF DRAWINGS

[0019] Figure 1 It is the assembly schematic drawing of the utility model;

[0020] Figure 2 It is the extension ring, the stop block, the clamping groove, the anti-drop strip and the installation bottom ring cooperation schematic drawing;

[0021] Figure 3 It is the inner heat shield structure schematic drawing;

[0022] Figure 4 It is the inner heat shield and outer heat shield assembly schematic drawing;

[0023] Figure 5 It is the A place partial enlarged view;

[0024] Figure 6 It is the B place partial enlarged view;

[0025] Figure 7 It is the C place partial enlarged view;

[0026] Figure 8 is the schematic diagram of outer heat shield structure;

[0027] Figure 9 is the schematic diagram of lifting hole distribution;

[0028] Figure 10 is the schematic diagram of prior art;

[0029] Marked in the figure: 1, outer heat shield, 2, extension ring, 3, stop block, 4, clamping groove, 5, anti-off strip, 6, installation bottom ring, 7, inner heat shield, 8, first edge, 9, lifting hole, 10, convex strip, 11, positioning block, 12, gap, 13, heat preservation ring cover, 14, heat shield support ring, 15, installation plate, 16, first closed ring, 17, second closed ring, 18, heat preservation layer, 19, second edge, 20, flared part, 21, distance, 22, inner flow guide cylinder, 23, heat preservation piece, 24, outer flow guide cylinder, 25, anti-off space, 26, inclined plate, 27, connecting plate. DETAILED DESCRIPTION

[0030] The technical scheme of the utility model will be further described in detail in combination with specific embodiments, and the parts not described and disclosed in the following embodiments of the utility model should be understood as the prior art known or known by the person skilled in the art, such as the structure of the single crystal furnace, the material of the heat shield support ring 14, how the heat shield support ring 14 is placed in the single crystal furnace, the material of the outer heat shield 1 and the inner heat shield 7, etc.

[0031] Embodiment 1

[0032] A single crystal furnace heat shield, such as Figures 1 to 4As shown, the single crystal furnace heat shield includes an outer heat shield 1 and an inner heat shield 7. The top of the outer heat shield 1 is fixedly connected with a first edge 8 placed on a heat shield support ring 14 of the single crystal furnace. The bottom of the outer heat shield 1 is inwardly tapered to form a mounting bottom ring 6. An extension ring 2 is fixedly arranged on the mounting bottom ring 6 and extends along the axial direction of the outer heat shield 1. A plurality of anti-disengagement strips 5 are distributed along the circumferential direction of the inner side wall of the extension ring 2. Channels are formed between adjacent anti-disengagement strips 5. Anti-disengagement spaces 25 are formed between the anti-disengagement strips 5 and the mounting bottom ring 6. The top of the inner heat shield 7 is fixedly connected with a second edge 19 placed on a heat preservation ring cover 13 of the single crystal furnace. A plurality of convex strips 10 are fixedly arranged on the outer wall of the inner heat shield 7 and cooperate with the anti-disengagement strips 5. The convex strips 10 can pass through the channels and rotate into the anti-disengagement spaces 25. When the inner heat shield 7 is assembled into the outer heat shield 1, the convex strips 10 are first placed in the channels, and then the inner heat shield 7 is rotated. At this time, the convex strips 10 on the inner heat shield 7 rotate together, pass through the channels, and enter the anti-disengagement spaces 25. The anti-disengagement strips 5 prevent the convex strips 10 from disengaging along the axial direction of the outer heat shield 1. The extension ring 2 prevents the convex strips 10 from disengaging along the radial direction of the outer heat shield 1. At this time, the assembly of the inner heat shield 7 and the outer heat shield 1 is completed. In order to facilitate assembly, as shown in Figure 3 、 Figure 4 and Figure 9 two groups of lifting holes 9 are arranged on the second edge 19 and are axially symmetrical about the inner heat shield 7. Each group of lifting holes 9 includes three lifting holes. Figure 1 and Figure 5 The single crystal furnace heat shield includes two lifting pieces. Each lifting piece includes an upper mounting plate 15 and a lower mounting plate 15 arranged in parallel and a connecting plate 27. The mounting plates 15 and the connecting plate 27 are connected by an inclined plate 26. The connecting plate 27 corresponds to a group of lifting holes 9 and is connected with the second edge 19 by a connecting bolt. The rotation of the lifting piece realizes the rotation of the inner heat shield 7 and the assembly between the inner heat shield 7 and the outer heat shield 1.

[0033] In order to avoid friction damage to the outer heat shield 1 and the inner heat shield 7, the convex strip 10 is not directly and completely in contact with the anti-drop strip 5, the mounting bottom ring 6 and / or the extension ring 2 during the rotation into the anti-drop space 25. However, due to the fact that the heat shield as a whole is in a hoisting state before the completion of the crystal pulling, the outer heat shield 1 is affected by gravity to make the anti-drop strip 5 contact with the convex strip 10, at this time, there is a gap 12 between the convex strip 10 and the mounting bottom ring 6; the overall weight of the outer heat shield 1 and the inner heat shield 7 is mainly supported by the lifting piece; during the crystal pulling process, the second edge 19 of the inner heat shield 7 is placed on the heat preservation ring cover 13, and the first edge 8 of the outer heat shield 1 is placed on the heat shield support ring 14 in the single crystal furnace, at this time, the gap 12 exists between the convex strip 10 and the anti-drop strip 5, the inner heat shield 7 is mainly supported by the heat preservation ring cover 13, and the outer heat shield 1 is mainly supported by the heat shield support ring 14. Compared with the prior art, the heat shield support ring 14 needs to support the overall weight of the outer heat shield 1 and the inner heat shield 7, the heat shield support ring 14 of the utility model can bear the weight of the outer heat shield 1 only, which greatly reduces the weight that the heat shield support ring 14 needs to bear, and the convex strip 10 of the inner heat shield 7 can also support the anti-drop strip 5 of the outer heat shield 1 to some extent, which can disperse part of the weight that the heat shield support ring 14 needs to bear, and also protects the heat shield support ring 14 from breaking. In order to ensure the service life of the second edge 19, the thickness of the second edge 19 is greater than that of the first edge 8.

[0034] When the existing outer heat shield 1 and the inner heat shield 7 are assembled, it is necessary to ensure that the hoisting holes 9 on the outer heat shield 1 and the inner heat shield 7 are coaxially connected one by one. With the increase of the size of the outer heat shield 1 and the inner heat shield 7, the process of rotating the hoisting holes 9 one by one becomes relatively difficult. The utility model only has the hoisting hole 9 on the second edge 19 of the inner heat shield 7, and does not need to be one by one. The hoisting hole 9 is coaxially connected, and the operation is relatively simple.

[0035] As Figure 1 And Figure 5As shown, in order to seal the heat shield cover 13 with the outer heat shield 1 and the inner heat shield 7, the single crystal furnace heat shield comprises a first sealing ring 16 made of high-temperature-resistant and good heat-conducting materials such as graphite, silicon carbide or molybdenum. The first sealing ring 16 is arranged on the inner wall of the heat shield cover 13, and the first sealing ring 16 is placed on the heat shield support ring 14, and the two ends of the first sealing ring 16 are respectively attached to the second edge 19 and the heat shield support ring 14 to form a first sealing structure. The single crystal furnace heat shield comprises a heat insulation layer 18 and a second sealing ring 17, the heat insulation layer 18 is filled between the outer heat shield 1 and the inner heat shield 7, and the heat insulation layer 18 is made of solidified insulation felt or graphite soft felt. The two ends of the second sealing ring 17 are respectively in contact with the first edge 8 and the second edge 19 to seal the heat insulation layer 18 between the outer heat shield 1 and the inner heat shield 7 to form a second sealing structure, and the heat insulation layer 18 is sealed between the outer heat shield 1 and the inner heat shield 7 to prevent the heat insulation layer 18 from leaking. The inner wall of the first sealing ring 16 and the outer wall of the second sealing ring 17 are in contact or have a distance 21, but the distance 21 is beneficial to heat insulation and is affected by thermal expansion and cold contraction, so that the first sealing ring 16 and the second sealing ring 17 are not worn.

[0036] The above is the basic embodiment of the present application, which can be further improved, optimized and limited on the basis of the above to obtain the following embodiments:

[0037] Embodiment 2

[0038] This embodiment is an improved scheme based on embodiment 1, and the main structure is the same as that of embodiment 1. The improvement lies in that, as shown in Figure 1 、 Figure 2 and Figure 8 , when the inner heat shield 7 is rotated, a stop block 3 is connected between the anti-falling strip 5 and the mounting bottom ring 6 to remind the operator whether the rotation is in place. When the convex strip 10 hits the stop block 3 during rotation, it can be judged that the rotation position is appropriate, and the convex strip 10 has completely entered the anti-falling space 25. During assembly, in order to avoid the rotation of the convex strip 10 in the anti-falling space 25 affecting the stability between the outer heat shield 1 and the inner heat shield 7 during the process of lifting or placing the assembled inner heat shield 7 and outer heat shield 1 as a whole on the single crystal furnace, as shown in Figure 3 and Figure 7 , a clamping groove 4 adjacent to the stop block 3 is formed on the mounting bottom ring 6, and the bottom of the convex strip 10 is provided with a positioning block 11 matched with the clamping groove 4. During rotation of the inner heat shield 7, the convex strip 10 is in contact with the stop block 3, and the positioning block 11 is aligned with the clamping groove 4. After the positioning block 11 is aligned with the clamping groove 4, the inner heat shield 7 is lowered as a whole until the positioning block 11 enters the clamping groove 4. At this time, there is a gap 12 between the anti-falling strip 5 and the convex strip 10. When the inner heat shield 7 and the outer heat shield 1 are lifted as a whole, the positioning block 11 is located in the clamping groove 4, avoiding the rotation of the inner heat shield 7 again so that the convex strip 10 is pulled out of the anti-falling space 25, causing the outer heat shield 1 to fall off and resulting in damage to the outer heat shield 1.

[0039] Example 3

[0040] This embodiment is an improved scheme based on example 1, and the main structure is the same as example 1, and the improvement point is that, as shown in Figure 1 and Figure 5 The top of the first closed ring 16 is provided with an outwardly expanding flared portion 20, and the inner diameter of the small end of the flared portion 20 is greater than the outer diameter of the first rim 8. When the outer heat shield 1 is placed downward into the single crystal furnace, the small end of the flared portion 20 does not interfere with the movement of the outer heat shield 1, and under the action of the flared portion 20, even if the outer heat shield 1 deviates during the descending process, so that the surface of the outer heat shield 1 is in contact with the flared portion 20, the outer heat shield 1 can slide down along the inner wall of the flared portion 20 to the predetermined position.

[0041] The above description of disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heat shield for a single crystal furnace, characterized by: The single crystal furnace heat shield comprises an outer heat shield (1) and an inner heat shield (7), the top of the outer heat shield (1) is fixedly connected with a first edge (8) placed on a heat shield support ring (14) of a single crystal furnace, the bottom of the outer heat shield (1) is inwardly contracted to form a mounting bottom ring (6), the mounting bottom ring (6) is fixedly provided with an extension ring (2), the inner side wall of the extension ring (2) is distributed with a plurality of anti-drop strips (5) along the circumferential direction thereof, channels are formed between adjacent anti-drop strips (5), anti-drop spaces (25) are formed between the anti-drop strips (5) and the mounting bottom ring (6), the top of the inner heat shield (7) is fixedly connected with a second edge (19) placed on a heat preservation ring cover (13) of the single crystal furnace, the outer wall of the inner heat shield (7) is fixedly provided with a plurality of convex strips (10) matched with the anti-drop strips (5), the convex strips (10) can pass through the channels and rotate into the anti-drop spaces (25).

2. The heat shield for a single crystal furnace as set forth in claim 1, wherein: The anti-drop strips (5) and the mounting bottom ring (6) are connected with a stop block (3).

3. The heat shield for a single crystal furnace as set forth in claim 2, wherein: The mounting bottom ring (6) is provided with a clamping groove (4) adjacent to the stop block (3), the bottom of the convex strip (10) is provided with a positioning block (11) matched with the clamping groove (4), in the rotating process of the inner heat shield (7), the convex strip (10) is in contact with the stop block (3), and the positioning block (11) is aligned with the clamping groove (4).

4. The heat shield for a single crystal furnace as set forth in claim 1, wherein: The single crystal furnace heat shield comprises a first closed ring (16), the first closed ring (16) is arranged on the inner wall of the heat preservation ring cover (13), and the first closed ring (16) is placed on the heat shield support ring (14), and the two ends of the first closed ring (16) are respectively attached to the second edge (19) and the heat shield support ring (14).

5. The heat shield for a single crystal furnace as set forth in claim 4, wherein: The top of the first closed ring (16) is provided with an expanding portion (20) expanding outward, and the inner diameter of the small end of the expanding portion (20) is greater than the outer diameter of the first edge (8).

6. The heat shield for a single crystal furnace as set forth in claim 4, wherein: The single crystal furnace heat shield comprises a heat preservation layer (18) and a second closed ring (17), the heat preservation layer (18) is filled between the outer heat shield (1) and the inner heat shield (7), and the two ends of the second closed ring (17) are respectively in contact with the first edge (8) and the second edge (19) to seal the heat preservation layer (18) between the outer heat shield (1) and the inner heat shield (7).

7. The heat shield for a single crystal furnace as set forth in claim 6, wherein: The inner wall of the first closed ring (16) and the outer wall of the second closed ring (17) are in contact or have a distance.

8. The heat shield for a single crystal furnace as set forth in claim 1, wherein: The second edge (19) is provided with two groups of hoisting holes (9) axially symmetrical about the inner heat shield (7), and each group of hoisting holes (9) is provided with three hoisting holes.

9. The heat shield for a single crystal furnace as set forth in claim 8, wherein: The single crystal furnace heat shield comprises two lifting pieces, each lifting piece comprises an upper and lower parallel mounting plate (15) and a connecting plate (27), the mounting plate (15) and the connecting plate (27) are connected through an inclined plate (26), the connecting plate (27) corresponds to a group of hoisting holes (9), and the connecting plate (27) is connected with the second edge (19) through a connecting bolt.

10. The heat shield for a single crystal furnace as set forth in claim 1, wherein: The thickness of the second edge (19) is greater than the thickness of the first edge (8).

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