Thermal insulation structure of single crystal furnace and single crystal furnace

Abstract

The utility model provides a thermal insulation structure of a single crystal furnace and the single crystal furnace, the thermal insulation structure comprises a lower thermal insulation cylinder, the lower thermal insulation cylinder comprises a cylinder body and a convex edge part, the convex edge part protrudes out of the outer side surface of the cylinder body, the convex edge part is provided with an insertion groove, the insertion groove is used for accommodating a foot plate of a main heater of the single crystal furnace, and the insertion groove is provided with a through hole; the upper end of the inserting groove extends upwards to the upper end face of the lower heat preservation cylinder, and an upper opening is formed in the upper end face of the lower heat preservation cylinder. The inner diameter of the cylinder body is set to be smaller than the outer diameter of the foot plate and does not interfere with the foot plate of the main heater, so that the inner diameter of the cylinder body can be set to be smaller, and correspondingly, the outer diameter of the cylinder body can also be smaller, so that more space can be provided for accommodating the lower heat preservation felt layer on the premise of not replacing the furnace body; therefore, the thickness of the lower heat preservation felt layer can be set to be thicker, the heat preservation performance is better, and the production energy consumption and the production cost are lower.

Description

Technical Field

[0001] The present application relates to the technical field of crystal pulling production, and in particular to a heat preservation structure of a single crystal furnace and a single crystal furnace. Background Art

[0002] The CZ method (also known as the CZ method or the Czochralski method) is a commonly used crystal pulling production method that can be used to produce single crystal silicon and other crystalline materials. The principle of the CZ method is to heat the raw material above the melting point, then melt it, and then put a small rod with a seed crystal attached to the head into the melt. Due to the presence of the seed crystal, the atoms in the melt will gradually arrange into a crystal structure outside the seed crystal, and a material with a single crystal structure will be formed through rapid stretching.

[0003] Single crystal furnaces are used in the CZ production process. A heat preservation tube is set inside the furnace body of the single crystal furnace, and a heat preservation felt layer is set around the outside of the heat preservation tube. Crucibles, main heaters and other components are installed inside the heat preservation tube. The thicker the heat preservation felt layer, the better the heat preservation, and the more conducive to reducing production energy consumption and production costs. The thickness of the heat preservation felt layer is limited by the inner diameter of the furnace body, and the cost of replacing the furnace body is high. If the furnace body with a larger inner diameter is replaced in order to increase the thickness of the heat preservation felt layer, it will not be conducive to reducing production costs.

[0004] In view of this, how to increase the thickness of the thermal insulation felt layer without replacing the furnace body is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0005] In order to solve the above-mentioned technical problems, the present application provides an insulation structure of a single crystal furnace, wherein the insulation structure includes a lower insulation tube, wherein the lower insulation tube includes a tube body and a convex ridge portion, wherein the convex ridge portion protrudes outward from the outer side surface of the tube body, and the convex ridge portion is provided with a slot, wherein the slot is used to accommodate the foot plate of the main heater of the single crystal furnace, and the upper end of the slot extends upward to the upper end surface of the lower insulation tube, and an upper opening is formed on the upper end surface of the lower insulation tube.

[0006] An implementation manner of a heat preservation structure of a single crystal furnace, the heat preservation structure comprises a middle heat preservation cylinder, and the outer diameter of the cylinder body is smaller than the inner diameter of the middle heat preservation cylinder.

[0007] An embodiment of the insulation structure of a single crystal furnace, the lower insulation tube includes an annular support portion, the annular support portion is arranged on the tube body and the upper end of the convex ridge portion, the outer diameter of the annular support portion is larger than the inner diameter of the middle insulation tube, and the lower end face of the middle insulation tube is supported on the upper end face of the annular support portion.

[0008] In one implementation manner of the thermal insulation structure of the single crystal furnace, the axial thickness of the annular support portion is in the range of ≥10 mm and ≤20 mm.

[0009] In one embodiment of the insulation structure of a single crystal furnace, the outer diameter of the annular support portion is the same as the outer diameter of the middle insulation tube, the outer diameter of the ridge portion is the same as the outer diameter of the middle insulation tube, and the outer diameter of the slot is the same as the inner diameter of the middle insulation tube.

[0010] In one embodiment of the insulation structure of a single crystal furnace, the lower insulation cylinder is an integrally formed structure, the inner diameter of the annular support portion is the same as the inner diameter of the cylinder body, and the lower end surface of the convex ridge portion is coplanar with the lower end surface of the cylinder body.

[0011] An embodiment of the insulation structure of a single crystal furnace, wherein the slot extends downward to the lower end surface of the convex ridge portion, thereby forming a lower opening on the lower end surface of the convex ridge portion, and the slot extends inward to the inner side surface of the lower insulation tube, thereby forming a side opening on the inner side surface of the lower insulation tube.

[0012] In addition, the present application also provides a single crystal furnace, including a furnace body, an insulation structure, a crucible and a main heater, the insulation structure is the insulation structure described in any one of the above items, the insulation structure is located in the furnace body, the main heater includes a heating element arranged around the outside of the crucible and a foot plate arranged at the lower end of the heating element, the foot plate extends downward through the upper opening of the slot into the slot, and there is a gap of ≥20 mm between the foot plate and the slot wall of the slot.

[0013] An implementation manner of the single crystal furnace is characterized in that there is a gap of ≥20 mm between the inner side surface of the lower insulation cylinder and the outer side surface of the crucible.

[0014] In one implementation manner of the single crystal furnace, there is a gap of ≥20 mm between the upper end surface of the lower insulation cylinder and the lower edge of the heating element.

[0015] In the present application, since the lower heat-insulating cylinder has a convex ridge portion protruding outward from the outer side surface of the cylinder body, and the convex ridge portion is provided with a slot capable of accommodating the foot plate of the main heater, the inner diameter of the cylinder body is set smaller than the outer diameter of the foot plate and will not interfere with the foot plate of the main heater, so the inner diameter of the cylinder body can be set smaller, and correspondingly, the outer diameter of the cylinder body can also be smaller. The inner diameter of the furnace body remains unchanged, and the outer diameter of the cylinder body of the lower heat-insulating cylinder is smaller, so there is more space to accommodate the lower heat-insulating felt layer, so the thickness of the lower heat-insulating felt layer can be set thicker (can be thickened by more than 35%), so the heat-insulating structure has better heat-insulating performance, and the production energy consumption and production cost are lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A cross-sectional view of a portion of the structure of the single crystal furnace provided in this application;

[0017] Figure 2 for Figure 1 A three-dimensional diagram of the middle and lower insulation cylinder;

[0018] The following are the descriptions of the reference numerals:

[0019] 10 lower heat-insulating cylinder, 11 cylinder body, 12 annular support portion, 13 convex ridge portion, 14 slot, 14a upper opening, 14b side opening, 14c lower opening;

[0020] 20 middle insulation cylinder, 30 lower insulation felt layer, 40 middle insulation felt layer, 50 upper insulation cylinder, 60 upper insulation felt layer, 70 insulation board, 80 crucible, 90 crucible plate, 100 main heater, 101 heating element, 110 support rod shaft. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] like Figure 1 As shown, the single crystal furnace provided in the present application includes a furnace body (not shown in the figure), a crucible 80, a crucible bond 90, a heat preservation structure, a main heater 100 and a support rod shaft 110.

[0023] The insulation structure is located in the furnace body, and the insulation structure includes a lower insulation tube 10, a middle insulation tube 20 located above the lower insulation tube 10, an upper insulation tube 50 located above the middle insulation tube 20, a lower insulation felt layer 30 surrounded by the outside of the lower insulation tube 10, a middle insulation felt layer 40 surrounded by the outside of the middle insulation tube 20, an upper insulation felt layer 60 surrounded by the outside of the upper insulation tube 50, and an insulation board 70 located below the lower insulation tube 10.

[0024] The crucible 90 is located inside the middle insulation tube 20 and the lower insulation tube 10, and supports the crucible 80. The upper end of the support rod shaft 110 is connected to the crucible 90, and the lower end of the support rod shaft 110 passes through the insulation board 70 and is connected to the transmission mechanism (not shown in the figure). Under the power transmitted by the transmission mechanism, the support rod shaft 110 can drive the crucible 90 and the crucible 80 to rotate and rise and fall.

[0025] The main heater 100 is located inside the insulation structure. The main heater 100 includes a heating element 101 and a foot plate (not visible in the figure). The heating element 101 is surrounded by the outside of the crucible 90 and is located inside the middle insulation tube 20. The foot plate is arranged at the lower end of the heating element 101 and extends downward to the lower insulation tube 10. Two foot plates are usually arranged at the lower end of the heating element 101, and the two foot plates are arranged at 180 degrees with respect to the central axis of the lower insulation tube 10.

[0026] like Figure 2As shown, the lower heat-insulating barrel 10 includes a barrel body 11 and a convex ridge portion 13, and the convex ridge portion 13 protrudes outward from the outer side surface of the barrel body 11. The convex ridge portion 13 is provided with a slot 14, and the upper end of the slot 14 extends upward to the upper end surface of the lower heat-insulating barrel 10, and an upper opening 14a is formed on the upper end surface of the lower heat-insulating barrel 10. The slot 14 is used to accommodate the foot plate of the main heater 100. As mentioned above, the foot plate of the main heater 100 extends downward to the inside of the lower heat-insulating barrel 10. In more detail, the foot plate of the main heater 100 extends downward through the upper opening 14a of the slot 14 to the inside of the slot 14.

[0027] Specifically, the number of the ridges 13 and the number of the slots 14 are consistent with the number of the foot plates of the main heater 100, so that the slots 14 correspond to the foot plates one by one. For example, when two foot plates are arranged at the lower end of the heating element 101 and the two foot plates are arranged at 180 degrees with respect to the central axis of the lower heat-insulating tube 10, the lower heat-insulating tube 10 is provided with two ridges 13, the two ridges 13 are arranged at 180 degrees with respect to the central axis of the lower heat-insulating tube 10, and each ridge 13 is provided with a slot 14.

[0028] In the conventional structure, the lower heat-insulating tube 10 is a cylindrical structure with both inner and outer sides being cylindrical surfaces. The inner diameter of the lower heat-insulating tube 10 must be larger than the outer diameter of the foot plate, otherwise it will interfere with the foot plate.

[0029] In comparison, the lower insulation cylinder 10 of the above structure provided by the present application has a convex ridge portion 13 protruding outward from the outer side of the cylinder body 11, and the convex ridge portion 13 is provided with a slot 14 capable of accommodating the foot plate, so the inner diameter of the cylinder body 11 is set smaller than the outer diameter of the foot plate and will not interfere with the foot plate, so the inner diameter of the cylinder body 11 can be set smaller, and correspondingly, the outer diameter of the cylinder body 11 can also be smaller. The inner diameter of the furnace body remains unchanged, and the outer diameter of the cylinder body 11 of the lower insulation cylinder 10 is smaller, so there is more space to accommodate the lower insulation felt layer 30, so the thickness of the lower insulation felt layer 30 can be set thicker (can be thickened by more than 35%), so the insulation structure has better insulation performance, and the production energy consumption and production cost are lower.

[0030] Specifically, Figure 1 As shown, the outer diameter of the cylinder body 11 of the lower heat-insulating cylinder 10 is smaller than the inner diameter of the middle heat-insulating cylinder 20. In this way, the thickness of the lower heat-insulating felt layer 30 can be increased to a large extent.

[0031] Specifically, Figure 1 As shown, the inner diameter of the cylinder body 11 of the lower heat-insulating cylinder 10 can be consistent with the inner diameter of the heating element 101 .

[0032] Specifically, Figure 2As shown, the lower heat-insulating cylinder 10 includes an annular support portion 12, which is arranged on the upper ends of the cylinder body 11 and the convex ridge portion 13, and the upper opening 14a of the slot 14 is formed on the upper end surface of the annular support portion 12. The outer diameter of the annular support portion 12 is larger than the inner diameter of the middle heat-insulating cylinder 20, and the lower end surface of the middle heat-insulating cylinder 20 is supported on the upper end surface of the annular support portion 12. In this way, the lower heat-insulating cylinder 10 can support the middle heat-insulating cylinder 20.

[0033] Specifically, Figure 1 As shown, the outer diameter of the annular support portion 12 is preferably the same as the outer diameter of the middle insulation tube 20, so that the support reliability is higher and there can be a larger space between the outer side of the annular support portion 12 and the inner side of the furnace body for arranging the insulation felt layer, so that the thickness of the insulation felt layer surrounding the outer side of the annular support portion 12 will not be too thin.

[0034] Specifically, Figure 2 As shown, the lower insulation cylinder 10 can be an integrally formed structure, the inner diameter of the annular support portion 12 can be the same as the inner diameter of the cylinder body 11, and the lower end surface of the convex ridge portion 13 can be coplanar with the lower end surface of the cylinder body 11. With this arrangement, the integral forming of the lower insulation cylinder 10 is more convenient.

[0035] Specifically, the axial thickness of the annular support portion 12 is preferably in the range of ≥10 mm and ≤20 mm, so that the support reliability is high and the occupied axial space inside the furnace body is not too large.

[0036] Specifically, the outer diameter of the ridge portion 13 is the same as the outer diameter of the middle heat-insulating cylinder 20. Figure 2 A in the figure refers to the outer side of the ridge portion 13, and the outer diameter of the ridge portion 13 refers to the radial distance between a point on the outer side of the ridge portion 13 and the central axis of the lower insulation tube 10. The outer diameter of the slot 14 is the same as the inner diameter of the middle insulation tube 20. Figure 2 B refers to the outer wall of the slot 14, and the outer diameter of the slot 14 refers to the radial distance between a point on the outer wall of the slot 14 and the central axis of the middle insulation tube 20. In this way, the area of ​​the convex ridge portion 13 facing the middle insulation tube 20 is a solid structure rather than a cavity structure, so it can share the load from the middle insulation tube 20 on the annular support portion 12, making the support reliability higher.

[0037] Specifically, Figure 2 As shown, the slot 14 can extend downward to the lower end surface of the ridge portion 13, thereby forming a lower opening 14c on the lower end surface of the ridge portion 13, and the slot 14 can extend inward to the inner side surface of the lower heat-insulating tube 10, thereby forming a side opening 14b on the inner side surface of the lower heat-insulating tube 10. In this way, the slot 14 is easy to process, and the foot plate is easier to insert into the slot 14 during assembly.

[0038] Specifically, there is a gap of ≥20 mm between the slot wall of the slot 14 and the foot plate, and more preferably a gap of ≥25 mm. It should be noted that if the slot 14 has multiple slot walls, there is a gap of ≥20 mm between each slot wall and the foot plate, for example, Figure 2 In the embodiment, the slot 14 has three slot walls (indicated by B, C, and D), and there is a gap of ≥20 mm between the three slot walls and the foot plate. In this way, arcing and sparking can be prevented during the operation of the single crystal furnace, which is beneficial to the safe operation of the single crystal furnace.

[0039] Specifically, there is a gap of ≥20 mm between the inner side of the lower heat preservation tube 10 and the outer side of the crucible 90, and more preferably the gap is ≥25 mm. This is beneficial to the safe operation of the single crystal furnace.

[0040] Specifically, there is a gap of ≥20 mm between the upper end surface of the lower heat-insulating cylinder 10 and the lower edge of the heating element 101, and more preferably the gap is ≥25 mm. This is beneficial to the safe operation of the single crystal furnace.

[0041] The above specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. The thermal insulation structure of the single crystal furnace is characterized by: The heat-insulating structure comprises a lower heat-insulating cylinder (10), wherein the lower heat-insulating cylinder (10) comprises a cylinder body (11) and a convex ridge portion (13), wherein the convex ridge portion (13) protrudes outward from the outer side surface of the cylinder body (11), and the convex ridge portion (13) is provided with a slot (14), wherein the slot (14) is used to accommodate a foot plate of a main heater of a single crystal furnace, and the upper end of the slot (14) extends upward to the upper end surface of the lower heat-insulating cylinder (10), and an upper opening (14a) is formed on the upper end surface of the lower heat-insulating cylinder (10).

2. The heat preservation structure of the single crystal furnace according to claim 1, characterized in that: The heat-insulating structure comprises a middle heat-insulating cylinder (20), and the outer diameter of the cylinder body (11) is smaller than the inner diameter of the middle heat-insulating cylinder (20).

3. The heat preservation structure of the single crystal furnace according to claim 2, characterized in that: The lower insulation tube (10) comprises an annular support portion (12), wherein the annular support portion (12) is arranged on the upper end of the tube body (11) and the convex ridge portion (13), the outer diameter of the annular support portion (12) is larger than the inner diameter of the middle insulation tube (20), and the lower end surface of the middle insulation tube (20) is supported on the upper end surface of the annular support portion (12).

4. The heat preservation structure of the single crystal furnace according to claim 3, characterized in that: The axial thickness of the annular support portion (12) is in the range of ≥10 mm and ≤20 mm.

5. The heat preservation structure of the single crystal furnace according to claim 3, characterized in that: The outer diameter of the annular support portion (12) is the same as the outer diameter of the middle insulation tube (20), the outer diameter of the ridge portion (13) is the same as the outer diameter of the middle insulation tube (20), and the outer diameter of the slot (14) is the same as the inner diameter of the middle insulation tube (20).

6. The heat preservation structure of the single crystal furnace according to claim 3, characterized in that: The lower heat-insulating cylinder (10) is an integrally formed structure, the inner diameter of the annular support portion (12) is the same as the inner diameter of the cylinder body (11), and the lower end surface of the convex ridge portion (13) is coplanar with the lower end surface of the cylinder body (11).

7. The heat preservation structure of a single crystal furnace according to any one of claims 1 to 6, characterized in that: The slot (14) extends downward to the lower end surface of the convex ridge portion (13), thereby forming a lower opening (14c) on the lower end surface of the convex ridge portion (13), and the slot (14) extends inward to the inner side surface of the lower heat-insulating tube (10), thereby forming a side opening (14b) on the inner side surface of the lower heat-insulating tube (10).

8. A single crystal furnace, comprising a furnace body, a heat preservation structure, a crucible (90) and a main heater (100), characterized in that: The thermal insulation structure is the thermal insulation structure described in any one of claims 1 to 7, and the thermal insulation structure is located in the furnace body. The main heater (100) includes a heating element (101) arranged around the outside of the crucible (90) and a foot plate arranged at the lower end of the heating element (101), and the foot plate extends downward through the upper opening (14a) of the slot (14) into the slot (14), and there is a gap of ≥20 mm between the foot plate and the slot wall of the slot (14).

9. The single crystal furnace according to claim 8, characterized in that: There is a gap of ≥20 mm between the inner side surface of the lower heat-insulating cylinder (10) and the outer side surface of the crucible (90).

10. The single crystal furnace according to claim 9, characterized in that: There is a gap of ≥20 mm between the upper end surface of the lower heat-insulating cylinder (10) and the lower edge of the heating element (101).

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