Single crystal furnace thermal field

Abstract

The utility model discloses a single crystal furnace thermal field which comprises a thermal insulation cylinder, a guide cylinder arranged in the thermal insulation cylinder, a crucible arranged below the guide cylinder and a heater arranged between the crucible and the thermal insulation cylinder, the thermal insulation cylinder consists of an upper thermal insulation cylinder, a middle thermal insulation cylinder and a lower thermal insulation cylinder, a first cavity is formed in the inner side of the upper thermal insulation cylinder, and a second cavity is formed in the lower thermal insulation cylinder. A first cavity is formed in the middle heat preservation cylinder, a second cavity is formed in the inner side of the middle heat preservation cylinder and the inner side of the lower heat preservation cylinder, the first cavity is a heightened cavity, the second cavity is a lowered cavity, and the heater is located on the inner side of the second cavity and does not protrude out of the top of the crucible. According to the single crystal furnace thermal field, on the premise that the overall thermal field height is guaranteed, the heights of the middle thermal insulation cylinder and the lower thermal insulation cylinder are limited, the height of the heater is shortened, the second cavity becomes a material melting cavity, compared with an original thermal field, the second cavity is more compact, after the thermal field is compact, heat loss can be reduced, and after the squeezing space is supplied to the first cavity, the squeezing efficiency is improved. The temperature gradient of the whole thermal field can be increased.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaics, and particularly to a thermal field of a single crystal furnace. Background Art

[0002] The Czochralski method is a common method for growing single crystals at present. Its working principle is to place the raw materials constituting the crystal in a crucible and heat them to melt. A seed crystal is picked up on the surface of the melt, and under controlled conditions, the seed crystal and the melt continuously perform atomic or molecular rearrangement at the interface, and gradually solidify with the decrease of temperature to grow a single crystal. The thermal field is the place for single crystal growth.

[0003] At present, the heater for the single crystal thermal field mainly generates heat by the way of resistance energization and heating, and uses the crucible conduction to heat the silicon material in the crucible, and then generates the silicon liquid for growing single crystal silicon. In the prior art, as Figure 1 shown, the height of the heater is designed based on a specific proportional relationship between the heating area of the heater and the height of the crucible. Therefore, heaters with different heights need to be designed according to the height dimension of the crucible, and the above heaters are higher than the crucible, which makes a large part of the above heaters exposed on the upper surface of the melt level in the crucible during the temperature adjustment - equal diameter process. This not only easily causes high-temperature corrosion to the crucible wall, resulting in accelerated softening and collapse of the crucible edge, but also forms high-temperature radiation to the thermal shield and the molten silicon level, affecting the improvement of the pulling speed, and causing unnecessary heat loss, increasing the cost of the thermal field.

[0004] Therefore, it is very necessary to propose a thermal field of a single crystal furnace to solve the above problems. Content of the Utility Model

[0005] The main purpose of the utility model is to provide a thermal field of a single crystal furnace, which can effectively solve the problems in the background art.

[0006] To achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] A thermal field of a single crystal furnace includes a heat preservation cylinder, a flow guide cylinder arranged in the heat preservation cylinder, a crucible arranged below the flow guide cylinder, and a heater arranged between the crucible and the heat preservation cylinder. The heat preservation cylinder is composed of an upper heat preservation cylinder, a middle heat preservation cylinder, and a lower heat preservation cylinder. A first chamber is formed inside the upper heat preservation cylinder, a second chamber is formed inside the middle heat preservation cylinder and the lower heat preservation cylinder, and the first chamber is a heightened chamber, and the second chamber is a reduced chamber. The heater is located inside the second chamber, and the heater does not protrude above the top of the crucible.

[0008] Preferably, the lower end of the flow guide cylinder extends to the upper inner end of the crucible.

[0009] Preferably, the upper end of the crucible corresponds to the junction of the upper heat preservation cylinder and the middle heat preservation cylinder.

[0010] Preferably, the upper end of the heater is flush with the top of the crucible.

[0011] Preferably, the increased height of the first chamber is the same as the decreased height of the second chamber.

[0012] Preferably, a limiting component for limiting the crucible is arranged at the junction of the inner sides of the upper heat preservation cylinder and the middle heat preservation cylinder. The limiting component includes a fixing frame uniformly fixed on the inner wall of the connection of the upper heat preservation cylinder and the middle heat preservation cylinder. A notch is arranged on the side of the fixing frame facing the crucible, and a supporting roller corresponding to the outer wall of the crucible is rotatably connected to the inner side of the notch through a rotating component.

[0013] Preferably, the rotating component includes a rotating shaft fixed in the middle of the supporting roller, and both ends of the rotating shaft are rotatably connected to the inner wall of the notch through a sealing bearing.

[0014] Advantageous Effects

[0015] Compared with the prior art, the present utility model provides a thermal field of a single crystal furnace, having the following advantageous effects:

[0016] 1. For this thermal field of the single crystal furnace, on the premise of ensuring the overall height of the thermal field, the heights of the middle heat preservation cylinder and the lower heat preservation cylinder are extremely compressed, the height of the heater is shortened, and the second chamber becomes a material melting chamber. Compared with the original thermal field, the second chamber is more compact. After the thermal field becomes compact, heat loss can be reduced. After the compressed space is given to the first chamber, the temperature gradient of the entire thermal field can be increased. The reduction of the heater height can reduce the stress deformation degree of the legs of the heater, thereby prolonging the service life of the heater, and can reduce the influence of the heater on the uneven heating of the crucible.

[0017] 2. For this thermal field of the single crystal furnace, through the cooperation of the fixing frame, the notch, the supporting roller and the rotating component, the support for the upper side wall of the crucible can be conveniently realized, and the stability of the crucible during rotation can be improved. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the prior art of the present utility model;

[0019] Figure 2 is a schematic structural diagram of the present utility model;

[0020] Figure 3 is the present utility model Figure 2 enlarged view of part A.

[0021] In the figure: 1. upper heat preservation cylinder; 2. middle heat preservation cylinder; 3. lower heat preservation cylinder; 4. heater; 5. crucible; 6. guide cylinder; 7. fixing frame; 8. notch; 9. rotating shaft; 10. supporting roller; 11. sealing bearing. Detailed Embodiment

[0022] In order to make the technical means, creative features, achieved purposes and effects realized by the present utility model easy to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0023] As shown in Figures 1-3 Figure [not shown], a thermal field of a single crystal furnace includes a heat preservation cylinder, a diversion cylinder 6 arranged in the heat preservation cylinder, a crucible 5 arranged below the diversion cylinder 6, and a heater 4 arranged between the crucible 5 and the heat preservation cylinder. The lower end of the diversion cylinder 6 extends to the upper inner end of the crucible 5. The heat preservation cylinder is composed of an upper heat preservation cylinder 1, a middle heat preservation cylinder 2, and a lower heat preservation cylinder 3. A first chamber is formed inside the upper heat preservation cylinder 1, and a second chamber is formed inside the middle heat preservation cylinder 2 and the lower heat preservation cylinder 3. The first chamber is a chamber with increased height, and the second chamber is a chamber with decreased height. The increased height of the first chamber is the same as the decreased height of the second chamber. The upper end of the crucible 5 corresponds to the junction of the upper heat preservation cylinder 1 and the middle heat preservation cylinder 2. The heater 4 is located inside the second chamber, and the heater 4 does not protrude above the top of the crucible 5. Preferably, the upper end of the heater 4 is flush with the top of the crucible 5.

[0024] Furthermore, in order to increase the stability of the crucible 5, a limiting component for limiting the crucible 5 is arranged at the junction inside the upper heat preservation cylinder 1 and the middle heat preservation cylinder 2. The limiting component includes a fixing frame 7 uniformly fixed on the inner wall of the connection between the upper heat preservation cylinder 1 and the middle heat preservation cylinder 2. A notch 8 is arranged on the side of the fixing frame 7 facing the crucible 5. A support roller 10 corresponding to the outer wall of the crucible 5 is rotatably connected inside the notch 8 through a rotating component.

[0025] Furthermore, as a preferred embodiment, the rotating component includes a rotating shaft 9 fixed in the middle of the support roller 10. Both ends of the rotating shaft 9 are rotatably connected to the inner wall of the notch 8 through a sealed bearing 11.

[0026] It should be noted that the present utility model is a thermal field of a single crystal furnace. When in use, on the premise of ensuring the overall height of the thermal field, the heights of the middle heat preservation cylinder 2 and the lower heat preservation cylinder 3 are extremely compressed, the height of the heater 4 is shortened, and the second chamber becomes a material melting chamber. Compared with the original thermal field, the second chamber is more compact. After the thermal field is compacted, heat loss can be reduced. After the compressed space is given to the first chamber, the temperature gradient of the entire thermal field can be increased. The reduction of the height of the heater 4 can reduce the stress deformation degree of the legs of the heater 4, thereby prolonging the service life of the heater 4, and can reduce the influence of the heater 4 on the uneven heating of the crucible 5;

[0027] In addition, when the crucible 5 rotates in actual use, the upper side wall is supported by the support roller 10. When the crucible 5 rotates, it can drive the rotation of the support roller 10, which can improve the stability of the crucible 5 during rotation and will not increase too much friction to the crucible 5.

[0028] The foregoing has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above-mentioned embodiments, and what is described in the above-mentioned embodiments and the specification only illustrates the principles of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and all these changes and improvements fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A thermal field of a single crystal furnace, comprising a heat preservation cylinder, a diversion cylinder (6) arranged in the heat preservation cylinder, a crucible (5) arranged below the diversion cylinder (6), and a heater (4) arranged between the crucible (5) and the heat preservation cylinder, characterized in that: The heat preservation cylinder is composed of an upper heat preservation cylinder (1), a middle heat preservation cylinder (2), and a lower heat preservation cylinder (3). A first chamber is formed inside the upper heat preservation cylinder (1), and a second chamber is formed inside the middle heat preservation cylinder (2) and the lower heat preservation cylinder (3). The first chamber is a heightened chamber, and the second chamber is a lowered chamber. The heater (4) is located inside the second chamber, and the heater (4) does not protrude above the top of the crucible (5).

2. The single crystal furnace thermal field according to claim 1, wherein: The lower end of the flow guide cylinder (6) extends to the upper inner end of the crucible (5).

3. A thermal field of a single crystal furnace according to claim 2, characterized in that: The upper end of the crucible (5) corresponds to the junction of the upper heat preservation cylinder (1) and the middle heat preservation cylinder (2).

4. A single crystal furnace thermal field according to claim 3, characterized in that: The upper end of the heater (4) is flush with the top of the crucible (5).

5. A single crystal furnace thermal field according to claim 4, characterized in that: The height by which the first chamber is heightened is the same as the height by which the second chamber is lowered.

6. The thermal field of a single crystal furnace according to claim 5, characterized in that: A limiting component for limiting the crucible (5) is provided at the junction inside the upper heat preservation cylinder (1) and the middle heat preservation cylinder (2). The limiting component includes a fixing frame (7) uniformly fixed to the inner wall of the connection between the upper heat preservation cylinder (1) and the middle heat preservation cylinder (2). A notch (8) is provided on the side of the fixing frame (7) facing the crucible (5). A support roller (10) corresponding to the outer wall of the crucible (5) is rotatably connected to the inside of the notch (8) through a rotating component.

7. A thermal field of a single crystal furnace according to claim 6, characterized in that: The rotating component includes a rotating shaft (9) fixed to the middle of the support roller (10). Both ends of the rotating shaft (9) are rotatably connected to the inner wall of the notch (8) through a sealed bearing (11).

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