Conductive device of heater for single crystal furnace

Abstract

The utility model discloses a heater conductive device for a single crystal furnace. The heater conductive device comprises an upper electrode, a lower electrode, an upper insulating sheath, a lower insulating sheath and a heat preservation felt sheath, the upper electrode and the lower electrode are connected in a split manner; the lower insulating sheath is sleeved on the outer wall of the lower electrode; the upper insulating sheath is sleeved on the outer wall of the upper electrode; and the insulation felt sheath is sleeved at the joint of the upper insulation sheath and the lower insulation sheath. The heater conductive device effectively solves the problems of an existing device, can be flexibly matched with heat preservation layers with different thicknesses, achieves the function of adjusting the height of a thermal field, meets the crystal pulling requirements of different products, improves the heat preservation performance of the furnace bottom, reduces the production cost and improves the use safety.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the single crystal silicon preparation field, concretely relates to a heater electric conductive device for single crystal furnace. BACKGROUND

[0002] The existing single crystal furnace mainly adopts graphite electrode and furnace bottom copper electrode connection as the heater power supply. Because the heater size is big, the weight is heavy, in order to stabilize the support heater, the graphite electrode size will also increase, just because the graphite electrode size increases, the size of the insulation sheath matched with the electrode increases, the insulation sheath around the thermal blanket opening also needs to increase, which will lead to the furnace bottom heat loss, and the furnace bottom thermal insulation is insufficient. In addition, the electrode is an integrated graphite material processing and becomes the heat conduction coefficient, and the copper electrode is directly connected with the furnace bottom, the copper electrode is water-cooled structure and easy to absorb heat, the electrode heat is easy to directly conduct to the copper electrode, leading to heat loss. The graphite electrode is an integrated structure, once bumping occurs in the use process, or the thread is abraded, only can be scrapped, and the use cost is higher. The graphite electrode is a cylindrical structure, and the peripheral insulation sheath is annularly wrapped and directly contacted with the furnace bottom, and the heat is easy to conduct to the furnace bottom, leading to heat loss, and the gap formed between the sheath and the sheath is a through gap, which is directly connected to the furnace bottom. Once the silicon leakage occurs, the silicon liquid will flow along the gap to the furnace bottom, leading to the furnace bottom being scalded, and the cooling water of the furnace bottom is easy to leak and cause safety accidents. In addition, the thickness of the furnace bottom thermal insulation layer needs to be adjusted for different products during actual crystal pulling, and the optimal thermal insulation layer thickness is verified. Because the insulation sheath is an integrated structure design, the height of the insulation sheath cannot be adjusted, and the existing structure cannot flexibly match the thermal insulation layer of different thicknesses. SUMMARY

[0003] The utility model relates to a heater electric conductive device for single crystal furnace, effectively solve the problem existing in the prior art, can flexibly match the thermal insulation layer of different thicknesses, realize the height adjustable function of the thermal field, satisfy the crystal pulling demand of different products, improve the thermal insulation performance of the furnace bottom, reduce the production cost, and improve the use safety.

[0004] In order to realize the above-mentioned purpose, the technical scheme adopted by the utility model is as follows:

[0005] A heater electric conductive device for single crystal furnace, including upper electrode, lower electrode, upper insulation sheath, lower insulation sheath and thermal blanket sheath, the upper electrode and the lower electrode adopt split type connection, the lower insulation sheath is connected to the outer wall of the lower electrode, the upper insulation sheath is connected to the outer wall of the upper electrode, and the thermal blanket sheath is connected to the interface of the upper insulation sheath and the lower insulation sheath.

[0006] Furthermore, the lower electrode has a boss with external threads at its top and the upper electrode has a groove with internal threads at its bottom; the upper electrode and the lower electrode are connected separately through the threaded engagement of the groove and the boss.

[0007] Furthermore, the bottom of the lower electrode is provided with a connector for connecting to the copper electrode at the bottom of the furnace.

[0008] Furthermore, the outer diameter of the upper electrode is larger than the outer diameter of the lower electrode; the bottom of the upper insulating sleeve is tightly attached to the outer side of the top of the lower insulating sleeve.

[0009] Furthermore, the thermal insulation felt sheath is fitted over the outside of the upper insulating sheath, and the bottom of the thermal insulation felt sheath is provided with a step to support the bottom of the upper insulating sheath; the top of the upper insulating sheath is slightly higher than the top of the thermal insulation felt sheath.

[0010] Furthermore, the conductive device for the heater of the single crystal furnace also includes, from bottom to top, a lower graphite felt insulation layer, a curing felt insulation layer, an upper graphite felt insulation layer, and an insulation layer protective plate, which are sequentially sleeved on the outside of the upper and lower electrodes.

[0011] Furthermore, the lower graphite felt insulation layer is sleeved on the outside of the lower insulating sleeve, and its top height is lower than the top of the lower insulating sleeve.

[0012] Furthermore, the cured felt insulation layer, the upper graphite felt insulation layer, and the insulation layer protective plate are all sleeved on the outside of the insulation felt cover; a platform is provided inside the cured felt insulation layer to support the bottom step of the insulation felt cover.

[0013] Furthermore, the lower electrode is made of carbon-carbon material with an outer diameter of 65-70mm and a low thermal conductivity, which can effectively slow down the downward conduction of heat from the upper part.

[0014] Furthermore, the upper electrode is made of graphite with an outer diameter of 90-100mm to further slow down the corrosion rate and improve the electrode's service life.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] (1) The electrodes of the heater's conductive device adopt a split structure design, with a combination of carbon and graphite materials. The combination of thick and thin materials effectively slows down the heat conduction to the furnace bottom, reduces heat loss, and improves the heat preservation of the furnace bottom.

[0017] (2) The electrode of the conductive device of the heater is designed with a separate structure. If a single part is bumped or the threads are worn out, it can be replaced separately, avoiding the need to replace the whole part and reducing the cost of using graphite parts.

[0018] (3) The conductive device of the heater adopts a two-section insulating sleeve design, which can effectively avoid direct contact between the integrated structure and the furnace bottom, and the high temperature at the top is directly conducted to the furnace bottom, thus slowing down the heat conduction.

[0019] (4) The insulating sleeve of the conductive device of the heater adopts a split structure design with a ring installation scheme, so that the height of the insulating sleeve can be flexibly adjusted to meet the actual needs of different products for the thickness of the furnace bottom insulation layer and select the optimal insulation layer thickness.

[0020] (5) The conductive device of the heater is designed with a combination of insulating sheath and heat insulation felt sheath with a countersunk hole, which effectively seals the gaps and prevents the liquid silicon from flowing directly down to the bottom of the furnace through the gap in the sheath when silicon leakage occurs, thus avoiding the furnace bottom being scalded through and avoiding the occurrence of safety accidents. Attached Figure Description

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0022] Figure 1 This is a schematic diagram of the split upper and lower electrode structure of the heater's conductive device.

[0023] Figure 2 This is a schematic diagram of the overall structure of the conductive device of the heater.

[0024] Figure 3 This is an enlarged view of the structure of the insulation felt sheath in the conductive device of the heater.

[0025] In the diagram, the various reference numerals represent:

[0026] 1-Upper electrode; 2-Lower electrode; 3-Upper insulating sleeve; 4-Lower insulating sleeve; 5-Insulation felt sleeve; 6-Insulation layer protective plate; 7-Upper graphite felt insulation layer; 8-Curing felt insulation layer; 9-Lower graphite felt insulation layer; 10-Furnace bottom copper electrode. Detailed Implementation

[0027] The present invention can be better understood from the following embodiments.

[0028] The structures, proportions, and sizes shown in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, terms such as "upper," "lower," "front," "rear," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0029] Combination Figure 1 and Figure 2 As shown, the conductive device for a heater in a single-crystal furnace of this utility model includes an upper electrode 1, a lower electrode 2, an upper insulating sleeve 3, a lower insulating sleeve 4, and a heat-insulating felt sleeve 5. The upper electrode 1 and the lower electrode 2 are connected separately; the lower insulating sleeve 4 is fitted onto the outer wall of the lower electrode 2; the upper insulating sleeve 3 is fitted onto the outer wall of the upper electrode 1; and the heat-insulating felt sleeve 5 is fitted onto the interface between the upper insulating sleeve 3 and the lower insulating sleeve 4.

[0030] The lower electrode 2 has a boss with external threads at its top, and the upper electrode 1 has a groove with internal threads at its bottom; the upper electrode 1 and the lower electrode 2 are connected separately through the threaded engagement of the groove and the boss.

[0031] The bottom of the lower electrode 2 is provided with an interface for connecting to the furnace bottom copper electrode 10.

[0032] The outer diameter of the upper electrode 1 is larger than the outer diameter of the lower electrode 2; the bottom of the upper insulating sleeve 3 is tightly attached to the outer side of the top of the lower insulating sleeve 4.

[0033] The thermal insulation felt cover 5 is fitted over the outside of the upper insulating cover 3, and the bottom of the thermal insulation felt cover 5 is provided with a step to support the bottom of the upper insulating cover 3; the top of the upper insulating cover 3 is slightly higher than the top of the thermal insulation felt cover 5.

[0034] The conductive device for the heater in the single crystal furnace also includes, from bottom to top, a lower graphite felt insulation layer 9, a curing felt insulation layer 8, an upper graphite felt insulation layer 7, and an insulation layer protective plate 6, which are sequentially fitted onto the outside of the upper and lower electrodes.

[0035] The lower graphite felt insulation layer 9 is fitted onto the outside of the lower insulating sleeve 4, and its top height is lower than the top of the lower insulating sleeve 4.

[0036] The cured felt insulation layer 8, the upper graphite felt insulation layer 7, and the insulation layer protective plate 6 are all sleeved on the outside of the insulation felt cover 5; the cured felt insulation layer 8 is provided with a platform for supporting the bottom step of the insulation felt cover 5.

[0037] The lower electrode 2 is made of carbon material with an outer diameter of 65-70mm. It has a low thermal conductivity, which can effectively slow down the downward conduction of heat from the upper part.

[0038] The upper electrode 1 is made of graphite and has an outer diameter of 90-100mm to further slow down the corrosion rate and improve the service life of the electrode.

[0039] The assembly method of the conductive device of the heater is as follows: The upper part of the bottom copper electrode 10 has an external thread structure, which matches the internal thread of the lower electrode 2. The lower insulating sleeve 4 is fitted around the lower electrode 2, and the bottom is completely in contact with the upper end face of the bottom copper electrode 10. The lower graphite felt insulation layer 9, the curing felt insulation layer 8, the upper graphite felt insulation layer 7, and the insulation layer guard plate 6 are installed in sequence from bottom to top. The insulation felt sleeve 5 is installed in the countersunk hole formed between the insulation layer guard plate 6, the upper graphite felt insulation layer 7, the curing felt insulation layer 8 and the lower insulating sleeve 4. Then, the upper insulating sleeve 3 is placed inside the insulation felt sleeve 5. The inner diameter of the upper insulating sleeve 3 is slightly larger than the outer diameter of the lower insulating sleeve 4, so that it can completely wrap the lower insulating sleeve 4. Finally, the internal thread of the small end of the upper electrode 1 is connected to the external thread of the upper part of the lower electrode 2 to form an integral structure (e.g., Figure 2 ).

[0040] The conductive device of this heater has the following characteristics:

[0041] The upper electrode 1 and lower electrode 2 adopt a split structure design, connected by threads. The lower electrode 2 is made of carbon-carbon material, which has a low thermal conductivity, effectively slowing down the conduction of heat from the upper part to the copper electrode 10 at the furnace bottom. Because the lower electrode 2 is made of carbon-carbon material, it has higher strength and a longer service life than graphite, allowing its outer diameter to be reduced to 65-70mm. This design and the introduction of carbon-carbon material effectively reduce the outer diameter of the lower electrode 2, and correspondingly, the opening size of its outer insulation felt is also reduced, improving the insulation performance of the furnace bottom. Meanwhile, the upper electrode 1 retains the graphite portion, with an outer diameter of 90-100mm. The temperature here is much higher than in the lower part, and graphite has higher corrosion resistance. The increased diameter further slows down the corrosion rate and improves the electrode's service life. The split structure design of the upper electrode 1 and lower electrode 2, with different materials and varying thicknesses, effectively slows down the conduction of heat to the furnace bottom, reducing heat loss.

[0042] The heater's conductive device features a two-section upper insulating sleeve 3 and a lower insulating sleeve 4 surrounding the upper electrode 1 and lower electrode 2. This structural design effectively prevents direct contact between the integrated structure and the furnace bottom, allowing the high temperature from the upper part to be directly conducted to the furnace bottom, thus slowing down heat transfer. Simultaneously, an insulating felt sleeve 5 is installed around the upper insulating sleeve 3, effectively preventing high-temperature erosion of the upper graphite felt insulation layer 7 and the cured felt insulation layer 8 by the high temperature from the upper part, thereby improving the service life of the insulation layer. Furthermore, the upper insulating sleeve 3 and lower insulating sleeve 4 adopt a split structure design with a ring-type installation scheme. When the thickness of the lower graphite felt insulation layer 9 increases or decreases, the upper insulating sleeve 3 and the insulating felt sleeve 5 can be raised or lowered synchronously. This meets the actual needs of different products for the thickness of the furnace bottom insulation layer, allowing for the selection of the optimal insulation layer thickness.

[0043] The lower part of the insulation felt sheath 5 contacts the bottom of the countersunk hole of the cured insulation layer 8, and the lower part of the upper insulation sheath 3 contacts the upper edge of the lower step inside the insulation felt sheath 5 (e.g., Figure 3 The gaps between the upper insulating sleeve 3 and the heat insulation felt sleeve 5, as well as the gaps between the heat insulation felt sleeve 5 and the curing felt insulation layer 8, are completely sealed at the bottom. Furthermore, the upper part of the upper insulating sleeve 3 is higher than the heat insulation felt sleeve 5, effectively preventing molten silicon from flowing directly down to the furnace bottom through the gaps between the insulating sleeve and the insulation layer, and between the insulating sleeve and the heat insulation felt sleeve, in the event of silicon leakage, thus preventing the furnace bottom from being burned through and causing a safety accident. The upper electrode 1 and the lower electrode 2 adopt a split structure design, connected by threads. If a single component is damaged or the threads age and wear, it can be replaced individually, avoiding the need for complete replacement and reducing the cost of using graphite components.

[0044] This utility model provides a concept and method for a conductive device for a heater in a single crystal furnace. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. All components not explicitly stated in this embodiment can be implemented using existing technology.

Claims

1. A conductive device for a heater in a single crystal furnace, characterized in that, It includes an upper electrode (1), a lower electrode (2), an upper insulating sleeve (3), a lower insulating sleeve (4), and a thermal insulation felt sleeve (5); the upper electrode (1) and the lower electrode (2) are connected separately; the lower insulating sleeve (4) is fitted onto the outer wall of the lower electrode (2); the upper insulating sleeve (3) is fitted onto the outer wall of the upper electrode (1); and the thermal insulation felt sleeve (5) is fitted onto the interface between the upper insulating sleeve (3) and the lower insulating sleeve (4).

2. The conductive device for a heater in a single crystal furnace according to claim 1, characterized in that, The lower electrode (2) is provided with a boss with external threads at the top, and the upper electrode (1) is provided with a groove with internal threads at the bottom; the upper electrode (1) and the lower electrode (2) are connected separately through the threaded engagement of the groove and the boss.

3. The conductive device for a heater in a single crystal furnace according to claim 1, characterized in that, The bottom of the lower electrode (2) is provided with an interface for connecting to the bottom copper electrode (10).

4. The conductive device for a heater in a single crystal furnace according to claim 1, characterized in that, The outer diameter of the upper electrode (1) is larger than the outer diameter of the lower electrode (2); the bottom of the upper insulating sleeve (3) is closely attached to the outer side of the top of the lower insulating sleeve (4).

5. The conductive device for a heater in a single crystal furnace according to claim 4, characterized in that, The heat insulation felt cover (5) is fitted over the outside of the upper insulating cover (3), and the bottom of the heat insulation felt cover (5) is provided with a step to support the bottom of the upper insulating cover (3); the top of the upper insulating cover (3) is higher than the top of the heat insulation felt cover (5).

6. The conductive device for a heater in a single crystal furnace according to claim 5, characterized in that, It also includes a lower graphite felt insulation layer (9), a cured felt insulation layer (8), an upper graphite felt insulation layer (7), and an insulation layer protective plate (6) that are sequentially fitted onto the outside of the upper and lower electrodes from bottom to top.

7. The conductive device for a heater in a single crystal furnace according to claim 6, characterized in that, The lower graphite felt insulation layer (9) is fitted onto the outside of the lower insulating sleeve (4), and its top height is lower than the top of the lower insulating sleeve (4).

8. The conductive device for a heater in a single crystal furnace according to claim 6, characterized in that, The curing felt insulation layer (8), the upper graphite felt insulation layer (7) and the insulation layer protective plate (6) are all sleeved on the outside of the insulation felt cover (5); the curing felt insulation layer (8) is provided with a platform for supporting the bottom step of the insulation felt cover (5).

9. The conductive device for a heater in a single crystal furnace according to claim 1, characterized in that, The lower electrode (2) is made of carbon carbon material and has an outer diameter of 65-70mm.

10. The conductive device for a heater in a single crystal furnace according to claim 1, characterized in that, The upper electrode (1) is made of graphite and has an outer diameter of 90-100mm.

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