Heater for single crystal furnace

Abstract

The utility model discloses a heater for a single crystal furnace. The heater comprises a special-shaped heating body, a bolt and a foot plate, the special-shaped heating body is in a circular ring shape, the special-shaped heating body and the foot plate are designed in a separated mode, and the special-shaped heating body and the foot plate are fixed through bolts. A group of inclined seams are formed in the wall surface of the special-shaped heating body along the longitudinal direction; the foot plates are divided into a group, are symmetrically arranged at the bottom of the special-shaped heating body respectively and are used for supporting the special-shaped heating body; a long-strip-shaped kidney-shaped counter bore is formed in the top of the foot plate, and the height of the special-shaped heating body is adjusted through cooperation of a bolt and the long-strip-shaped kidney-shaped counter bore. According to the heater, airflow blocking driven by crucible rotation is avoided, the temperature stability is improved, the main heating height adjusting function is achieved, and cost waste caused by foot plate replacement when the cover distance is adjusted is avoided.

Description

Technical Field

[0001] The utility model belongs to the field of single crystal silicon production, and particularly relates to a heater for a single crystal furnace. Background Art

[0002] The heater of the single crystal furnace is an important component of the single crystal thermal field. During the single crystal pulling process, it continuously and stably supplies heat to the molten silicon liquid surface to ensure that the temperature of the crystallization interface is stable to meet the growth of single crystal silicon. The existing heater resistance adopts a uniformly distributed slotted design. Since there is no heating element at the slotted part, the existing main heating ring-shaped heating elements are distributed at intervals with the slotted parts, and the temperature uniformity of the ring circumference is relatively poor. The slotted part points vertically towards the center of the heater. There are crucible supports and quartz crucibles arranged at the center of the heater, and the three are installed concentrically. During the crystal pulling process, after the crucible rotation is started, the crucible supports and quartz crucibles rotate, driving the airflow. The slotted part of the heater is perpendicular to the airflow direction, resulting in blocked airflow, affecting the stability of the furnace table temperature, and further affecting the growth of single crystal silicon. In addition, during the actual crystal pulling process, it is necessary to adjust different distances between the cover and the heater to meet the pulling requirements of single crystal silicon rods of different sizes. The most direct way to adjust the distance between the cover and the heater is to adjust the height of the main heating foot plate. Since the existing main heating foot plate cannot adjust the height, when pulling crystals with different distances between the cover and the heater, it is only possible to repurchase the heater foot plate, resulting in cost waste. Summary of the Invention

[0003] Purpose of the utility model: The technical problem to be solved by the utility model is to provide a heater aiming at the deficiencies of the existing technology, which can avoid blocked airflow, realize the height adjustability of the heater, and improve the stability and economy of the heater temperature.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0005] A heater for a single crystal furnace includes a heating element, bolts, and a foot plate; the heating element is circular, and is designed in a separated manner from the foot plate, and the heating element is fixed to the foot plate through bolts; a group of inclined slotted parts are arranged along the longitudinal direction on the wall surface of the heating element; the foot plates are a group, and are symmetrically arranged at the bottom of the heating element respectively for supporting the heating element; long strip-shaped kidney-shaped counterbores are arranged at the top of the foot plate, and the height adjustment of the heating element is realized by the cooperation of the bolts and the long strip-shaped kidney-shaped counterbores.

[0006] Further, the angle between the inclined slotted part and the tangent of the circular wall surface of the heating element at the inclined slotted part is 30 - 49 degrees, preferably 45 degrees.

[0007] Further, the inclined slotted part includes a front wall surface and a rear wall surface, and the front and rear wall surfaces are parallel to each other; in the cross section, the front wall surface intersects with the outer wall of the heating element at point a, and the rear wall surface intersects with the inner wall of the heating element at point b. The connecting line between point a and the center of the heating element passes through the rear wall surface, and the connecting line between point b and the center of the heating element passes through the front wall surface.

[0008] Preferably, the three points of point a, point b, and the center of the heating element are connected on the same circular diameter.

[0009] Furthermore, the inclined slot includes a lower inclined slot and an upper inclined slot that are respectively grooved upward and downward, and the lower inclined slot and the upper inclined slot are arranged at intervals in sequence.

[0010] Furthermore, the inner diameter of the heating element is 1036 - 1048 mm, and the wall thickness of the heating element is 20 - 28 mm. The slot widths of the lower inclined slot and the upper inclined slot are respectively 14 - 24 mm.

[0011] Furthermore, the distance between the top notch of the lower inclined slot and the extension of the upper arm of the heating element is 220 - 240 mm; the distance between the bottom notch of the upper inclined slot and the extension of the lower arm of the heating element is 220 - 240 mm.

[0012] Furthermore, the foot plates are a pair, both are L-shaped plates, the tops are fixed on the outer wall of the heating element by a set of bolts, and the bottoms are fixed on the power electrodes by bolts.

[0013] Furthermore, there are a pair of long strip-shaped waist-shaped counterbores on the tops of the foot plates, and each long strip-shaped waist-shaped counterbore is fixed on the heating element by two bolts.

[0014] Furthermore, both the bolts and the foot plates are made of carbon-carbon material. Beneficial Effects

[0015] (1) The heater of the present invention adopts a 45-degree slotting design, which avoids the blockage of the airflow driven by the crucible rotation and improves the temperature stability. Ensure that the heating element is completely blocked in the vertical direction of the outer circle of the main heater at any slotted position, realize the annular band heating of the entire heating element, and improve the uniformity of the heating temperature. At the same time, the special slotting design is adopted to increase the area of the heating zone and improve the heating efficiency.

[0016] (2) The foot plate of the heater of the present invention adopts a long strip-shaped waist-shaped counterbore design, which realizes the function of adjustable main heater height and avoids the cost waste caused by replacing the foot plate when adjusting the cover distance. Description of the Drawings

[0017] The following further specifically describes the present invention in conjunction with the drawings and specific embodiments, and the above and / or other advantages of the present invention will become clearer.

[0018] Figure 1 It is a three-dimensional structural schematic diagram of the bottom heater.

[0019] Figure 2 It is a side view of the bottom heater.

[0020] Figure 3 This is a schematic structural diagram of the bottom heater foot plate.

[0021] Figure 4 This is a schematic structural diagram of the heating element.

[0022] Figure 5 This is a top view of the oblique seam of the heating element and its wall surface.

[0023] Figure 6 This is a state diagram when the line connecting point a and point b passes through the center of the heating element.

[0024] Figure 7 This is a working state diagram of the heater.

[0025] Among them, each reference numeral represents respectively:

[0026] 1 - heating element; 2 - foot plate; 201 - long strip-shaped waist-shaped counterbore; 3 - oblique seam; 301 - front wall surface; 302 - rear wall surface; 303 - lower oblique seam; 304 - upper oblique seam; 4 - bolt; 5 - quartz crucible; 6 - crucible wall; 7 - crucible bottom; 8 - power electrode. Detailed implementation manners

[0027] According to the following embodiments, the present utility model can be better understood.

[0028] The structures, ratios, sizes, etc. shown in the accompanying drawings of the specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "front", "rear", "middle", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the scope for the implementation of the present utility model. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope for the implementation of the present utility model.

[0029] Combined with Figure 1 and Figure 2 as shown, the heater for single crystal furnace of the present utility model includes a heating element 1, a bolt 4 and a foot plate 2; the heating element 1 is circular ring-shaped, and adopts a separated design from the foot plate 2, and the heating element 1 and the foot plate 2 are fixed through the bolt 4; a group of oblique seams 3 are arranged longitudinally on the wall surface of the heating element 1; the foot plate 2 is a group, which are symmetrically arranged at the bottom of the heating element 1 respectively for supporting the heating element 1; a long strip-shaped waist-shaped counterbore 201 is arranged at the top of the foot plate 2, and the height adjustment of the heating element 1 is realized by the cooperation of the bolt 4 and the long strip-shaped waist-shaped counterbore 201.

[0030] In some embodiments, the angle between the inclined slit 3 and the tangent of the circumferential wall surface of the heating element 1 at the inclined slit 3 is 30 - 49 degrees. In a preferred embodiment, this angle is 45 degrees.

[0031] Combined with Figures 4 to 6 , the inclined slit 3 includes a front wall surface 301 and a rear wall surface 302, and the front and rear wall surfaces are parallel to each other; in a cross-section, the front wall surface 301 intersects the outer wall 101 of the heating element 1 at point a, and the rear wall surface 302 intersects the inner wall 102 of the heating element 1 at point b. The connection line between point a and the center of the heating element 1 passes through the rear wall surface 302, and the connection line between point b and the center of the heating element 1 passes through the front wall surface 301.

[0032] In a preferred embodiment, the three points of point a, point b, and the center of the heating element 1 are connected on the same circular diameter.

[0033] In this embodiment, the inclined slit 3 includes a lower inclined slit 303 and an upper inclined slit 304 that are respectively slotted upward and downward, and the lower inclined slit 303 and the upper inclined slit 304 are arranged at intervals in sequence.

[0034] In this embodiment, the inner diameter of the heating element 1 is 1039 mm, and the wall thickness of the heating element 1 is 26 mm. The slit widths of the lower inclined slit 303 and the upper inclined slit 304 are respectively 16 mm.

[0035] In this embodiment, the distance between the top notch of the lower inclined slit 303 and the extension of the upper arm of the heating element 1 is 220 - 240 mm; the distance between the bottom notch of the upper inclined slit 304 and the extension of the lower arm of the heating element 1 is 228 mm.

[0036] As Figure 3 shown, in some embodiments, there are a pair of the foot plates 2, both of which are L-shaped plates. The tops are fixed on the outer wall surface of the heating element 1 through a set of bolts 4, and the bottoms are fixed on the power electrodes 8 through bolts.

[0037] In a preferred embodiment, there are a pair of elongated waist-shaped counterbores 201 at the tops of the foot plates 2, and each elongated waist-shaped counterbore 201 is fixed on the heating element 1 through two bolts 4.

[0038] In a preferred embodiment, both the bolts 4 and the foot plates 2 are made of carbon-carbon material.

[0039] The bottom heater of the utility model adopts a split design of the circular ring-shaped heating element 1 and the foot plate 2. The heating element 1 symmetrically reserves two positions for installing the heater foot plates 2. Four screw holes are evenly distributed at the foot plates 2, which match the heater foot plates. Each single foot plate is fixed to the heating element 1 with four carbon-carbon bolts 4. The heating element 1 adopts a special slotted design. The slotted angle preferably forms a 45-degree angle with the tangent (the general range is 30-49 degrees). When the heating element 1 is actually in use, the heat emitted is circumferentially directed towards the center of the heater. When the 45-degree slotted design is adopted, points a and b can be completely coincident, which can ensure that the heating element 1 is completely blocked in the horizontal direction of the outer circle at any slotted position. On the one hand, it increases the area of the heating zone and improves the heating efficiency. On the other hand, it realizes the annular strip heating of the entire heating element 1 and improves the uniformity of the heating temperature. In addition, the 45-degree slotted design enables the crucible wall 6 and the quartz crucible 5 to rotate after the crucible rotation is started during the crystal pulling process, driving the air flow. The slotted opening of the heater forms a 45-degree angle with the air flow direction, and the air flow is smoothly discharged from the 45-degree slotted opening, avoiding the air flow driven by the crucible rotation from impacting the main heating slotted opening and causing the occurrence of air flow blockage, thereby achieving the purpose of improving the temperature stability of the furnace platform.

[0040] The foot plate 2 of the heater adopts a design of two long strip-shaped kidney-shaped counterbores 201. Selecting carbon-carbon material can effectively ensure that its strength meets the use requirements. When the foot plate 2 is matched with the main heating element, four carbon-carbon bolts 4 are used for fixation, and the bottom of the pot 7 is located above the bottom of the foot plate 2. According to different height requirements, the relative positions of the kidney-shaped counterbores of the foot plate and the bolts can be adjusted to achieve the purpose of adjustable main heating height. It avoids the waste of cost caused by purchasing new heater foot plates when adjusting different distances between the lid and the heater, and effectively reduces the production cost.

[0041] The utility model provides an idea and method for a heater used in a single crystal furnace. There are many methods and ways to specifically implement this technical solution. The above is only the preferred embodiment of the utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the utility model, several improvements and retouches can still be made, and these improvements and retouches should also be regarded as the protection scope of the utility model. Each component not clearly defined in this embodiment can be realized by the existing technology.

Claims

1. A heater for a single crystal furnace, characterized in that: The heating element (1) comprises a heating element (1), a bolt (4) and a foot plate (2); the heating element (1) is in a circular shape and is separated from the foot plate (2), and the heating element (1) and the foot plate (2) are fixed by means of the bolt (4); a group of oblique slits (3) are provided on the wall surface of the heating element (1) along the longitudinal direction; the foot plates (2) are a group and are symmetrically arranged at the bottom of the heating element (1) for supporting the heating element (1); a long waist-shaped countersunk hole (201) is provided on the top of the foot plate (2), and the height of the heating element (1) can be adjusted by means of the bolt (4) cooperating with the long waist-shaped countersunk hole (201).

2. The single crystal furnace heater according to claim 1, characterized in that: The angle between the oblique slit (3) and the tangent line of the annular wall surface of the heating element (1) at the oblique slit (3) is 30-49 degrees.

3. The single crystal furnace heater according to claim 1, characterized in that: The oblique slit (3) comprises a front wall surface (301) and a rear wall surface (302), the front and rear wall surfaces being parallel to each other; in a cross section, the front wall surface (301) intersects with an outer wall (101) of the heating element (1) at point a, the rear wall surface (302) intersects with an inner wall (102) of the heating element (1) at point b, a line connecting point a and the center of the circle of the heating element (1) passes through the rear wall surface (302), and a line connecting point b and the center of the circle of the heating element (1) passes through the front wall surface (301).

4. The single crystal furnace heater according to claim 3, characterized in that: The point a, point b and the center of the heating element (1) are connected on the same circular diameter.

5. The single crystal furnace heater according to claim 1, characterized in that: The oblique slit (3) comprises a lower oblique slit (303) and an upper oblique slit (304) which are respectively grooved upward and downward, and the lower oblique slit (303) and the upper oblique slit (304) are arranged in sequence and at intervals.

6. The single crystal furnace heater according to claim 5, characterized in that: The inner diameter of the heating element (1) is 1036-1048 mm, and the wall thickness of the heating element (1) is 20-28 mm; the opening widths of the lower oblique slit (303) and the upper oblique slit (304) are respectively 14-24 mm.

7. The single crystal furnace heater according to claim 5, characterized in that: The distance between the top notch of the lower oblique slit (303) and the upper arm extension of the heating element (1) is 220-240 mm; the distance between the bottom notch of the upper oblique slit (304) and the lower arm extension of the heating element (1) is 220-240 mm.

8. The heater for a single crystal furnace according to claim 5, characterized in that: The foot plates (2) are a pair, both of which are L-shaped plates, with the top being fixed to the outer wall surface of the heating element (1) by a set of bolts (4), and the bottom being fixed to the power supply electrode (8) by bolts.

9. The single crystal furnace heater according to claim 5, characterized in that: There is a pair of long waist-shaped countersunk holes (201) on the top of the foot plate (2), and each long waist-shaped countersunk hole (201) is fixed to the heating element (1) via two bolts (4).

10. The heater for a single crystal furnace according to claim 1, characterized in that: The bolts (4) and the foot plate (2) are both made of carbon-carbon material.

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