Bottom heater and thermal field

Abstract

The embodiment of the utility model provides a bottom heater and a thermal field. The bottom heater comprises a first heating body and a second heating body, one end of the first heating body is connected to the second heating body in the circumferential direction of the second heating body; the end, away from the second heating body, of the first heating body inclines towards the upper portion of the second heating body, and the first heating body is higher than the second heating body in the axial direction of the second heating body. And the distance between the bottom heater and the crucible upper is conveniently shortened, so that the heat radiated by the bottom heater is efficiently utilized.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a bottom heater and a thermal field. Background Art

[0002] With the promotion of large-size silicon wafers, a larger thermal field is required. The large thermal field has a more serious impact on power consumption. Therefore, reducing operating power consumption in the production of large-size CZ-type single crystal silicon is a key link in reducing costs and increasing efficiency.

[0003] In the prior art, a flat bottom heater is used to heat the bottom of the crucible. However, the flat bottom heater is far away from the crucible, and the heat radiated by the flat bottom heater cannot be efficiently utilized. Utility Model Content

[0004] In view of the above problems, embodiments of the present utility model are proposed to provide a bottom heater and a thermal field that overcome the above problems or at least partially solve the above problems.

[0005] In order to solve the above problems, in a first aspect, an embodiment of the utility model discloses a bottom heater, comprising a first heating body and a second heating body; along the circumference of the second heating body, one end of the first heating body is connected to the second heating body;

[0006] One end of the first heat-generating body away from the second heat-generating body is inclined toward the upper side of the second heat-generating body, and along the axial direction of the second heat-generating body, the height of the first heat-generating body is higher than the height of the second heat-generating body.

[0007] Optionally, the first heat-generating body comprises a plurality of heat-generating petals; along the circumference of the second heat-generating body, one end of the plurality of heat-generating petals is connected to the second heat-generating body, and the other end of the plurality of heat-generating petals extends away from the second heat-generating body in a radial shape.

[0008] Optionally, the second heating body is a circular ring structure; the first heating body and the second heating body are integrally formed or the first heating body and the second heating body are detachably connected.

[0009] Optionally, the first heating body is a bowl-shaped structure, and the inner surface of the bowl-shaped structure is an arc-shaped surface or a conical surface.

[0010] Optionally, along the direction from the second heat generating body to the first heat generating body, the first heat generating body

[0011] A slit is provided in the middle of the heating petal of the heat body.

[0012] In a second aspect, an embodiment of the utility model further discloses a thermal field, comprising the above-mentioned bottom heater.

[0013] Optionally, it includes a crucible side, which includes a transition portion and a flat portion connected to each other, wherein the transition portion has a transition surface on the side facing the bottom heater, and the transition surface is arranged opposite to the first heating body of the bottom heater; the flat portion is arranged opposite to the second heating body of the bottom heater.

[0014] Optionally, a shape of a transition surface of the transition portion is the same as a shape of an inner surface of the first heat-generating body.

[0015] Optionally, the distance between the first heating body and the transition portion is 20-25 mm;

[0016] The distance between the second heating body and the flat portion is 20-25 mm.

[0017] Optionally, the thermal field includes a thermal insulation felt plate, which is located below the bottom heater, and has a first thermal insulation surface arranged opposite to the outer surface of the first heating body, and the first thermal insulation surface is an arc surface or a conical surface.

[0018] Optionally, the thermal field further includes a heat preservation tube and an air-conducting heat-insulating tube;

[0019] The air-conducting heat-insulating cylinder is arranged in the heat-insulating cylinder, and the bottom heater is located in the air-conducting heat-insulating cylinder;

[0020] There is a gap between the outer wall of the air-conducting and heat-insulating cylinder and the inner wall of the heat-insulating cylinder, and the gap forms a first airflow channel.

[0021] Optionally, a protective shell is provided at the lower portion of the air-conducting and heat-insulating cylinder, and a second airflow channel is formed in the protective shell; the second airflow channel is connected to the first airflow channel and is used to change the flow direction of the airflow.

[0022] Optionally, an insulation felt plate is provided at the lower part of the bottom heater, and stepped holes are provided on the insulation felt plate to form a third airflow channel; the third airflow channel is connected to the exhaust through hole at the bottom of the single crystal furnace; the third airflow channel is connected to the first airflow channel.

[0023] Optionally, the difference between the outer diameter of the air-conducting heat-insulating cylinder and the inner diameter of the heat-insulating cylinder is 20-25 mm;

[0024] And / or, the distance between the air-conducting heat-insulating cylinder and the first heating body in the radial direction of the heat-insulating cylinder is 20-25 mm;

[0025] And / or, the distance between the air-conducting heat-insulating cylinder and the crucible ridge in the heat field in the axial direction of the heat-insulating cylinder is 20-25 mm.

[0026] Optionally, a heat preservation tube and a side heater are provided in the heat field, a groove is provided on the inner wall of the heat preservation tube, and at least a part of the side heater is provided in the groove.

[0027] The utility model embodiment includes the following advantages:

[0028] In an embodiment of the utility model, along the circumference of the second heating body, one end of the first heating body is connected to the second heating body, and the other end of the first heating body can be inclined toward the upper side of the second heating body, and along the axial direction of the second heating body, the height of the first heating body is higher than the height of the second heating body. In this way, the bottom heater is set at the bottom of the crucible side, and the distance between the first heating body and the crucible side can be close to the distance between the second heating body and the crucible side, so that the shape of the bottom heater can be adapted to the shape of the crucible side, which is convenient for shortening the distance between the bottom heater and the crucible side, and then efficiently utilizing the heat radiated by the bottom heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a thermal field of the utility model;

[0030] Figure 2 It is a structural schematic diagram of a bottom heater of the utility model;

[0031] Figure 3 It is a cross-sectional view of a bottom heater of the utility model;

[0032] Figure 4 It is a structural schematic diagram of a protective shell of the utility model.

[0033] Description of reference numerals:

[0034] 1-crucible assembly, 11-crucible, 12-crucible side, 121-transition surface, 13-crucible support, 2-bottom heater, 21-first heating body, 211-inner surface, 212-outer surface, 213-heating petal, 214-slit, 22-second heating body, 3-insulation tube, 31-upper insulation tube, 32-middle insulation tube, 33-lower insulation tube, 34-first accommodating space, 35-second accommodating space, 4-insulation felt board, 41-first insulation part, 411-second through hole, 42-second insulation part, 421-first insulation surface, 422-second insulation surface, 423-first sub-insulation part, 424-second sub-insulation part, 43-protective shell, 431-annular plate, 432-annular connecting plate, 5-air guide insulation tube, 51-first air flow channel, 6-side heater, 7-air barrier. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0036] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this utility model, unless otherwise specified, "multiple" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the thermal environment where the bottom heater 2 is used, the bottom heater 2 cooperates with the crucible side 12 so that the bottom heater 2 can radiate heat to the crucible side 12, and then the crucible side 12 transfers the heat to the crucible 11 to heat the silicon material in the crucible 11 and pull a single crystal silicon rod.

[0040] One of the core concepts of the embodiment of the utility model is to disclose a bottom heater 2, including a first heating body 21 and a second heating body 22; along the circumference of the second heating body 22, one end of the first heating body 21 is connected to the second heating body 22; one end of the first heating body 21 away from the second heating body 22 is inclined toward the upper side of the second heating body 22, and along the axial direction of the second heating body 22, the height of the first heating body 21 is higher than the height of the second heating body 22.

[0041] In this embodiment, by adjusting the height of the first heating body 21, the heat of the bottom heater 2 can be radiated more on the upper side. In the actual single crystal furnace thermal field environment, the heat of the bottom heater 2 can be radiated more to the crucible 11 through the crucible side 12; moreover, the height of one side of the bottom heater 2 is raised, and a part of the space can be left empty, and more insulation felts can be arranged on the lower side of the bottom heater 2, so as to improve the insulation performance of the thermal field insulation component, reduce the heat radiation downward, and reduce the loss caused by the heat being transmitted from the bottom of the single crystal furnace.

[0042] In the present invention, the first heating body 21 may include a plurality of heating petals 213; wherein, along the circumference of the second heating body 22, one end of the plurality of heating petals 213 is connected to the second heating body 22; one end of the heating petal 213 away from the second heating body 22 is inclined toward the upper side of the second heating body 22, and along the axial direction of the second heating body 22, the height of the heating petal 213 is higher than the height of the second heating body 22.

[0043] In the embodiment of the utility model, along the circumference of the second heating body 22, one end of the heating petal 213 is connected to the second heating body 22, and the other end of the heating petal 213 can be inclined toward the upper side of the second heating body 22, and along the axial direction of the second heating body 22, the height of the heating petal 213 is higher than the height of the second heating body 22. In this way, the bottom heater 2 is arranged at the bottom of the crucible side 12, and the shape of the heating petal 213 can be adapted to the shape of the crucible side 12, so as to shorten the distance between the heating petal 213 and the crucible side 12, thereby efficiently utilizing the heat radiated by the heating petal 213.

[0044] Furthermore, along the circumference of the second heating body 22 , one end of the plurality of heating petals 213 is connected to the second heating body 22 , and the other end of the plurality of heating petals 213 extends away from the second heating body 22 in a radiating manner, which can improve the uniformity of heat radiated from the bottom heater 2 to the crucible side 12 .

[0045] Specifically, the bottom heater 2 may be a carbon-carbon or graphite heater.

[0046] Specifically, the bottom heater 2 includes a first heating body 21 and a second heating body 22. The first heating body 21 and the second heating body 22 can be spliced ​​together, and the first heating body 21 and the second heating body 22 can be detachably connected to facilitate replacement and reduce costs. As an implementation mode, in this embodiment, the second heating body 22 can be electrically connected to the electrode.

[0047] Alternatively, the first heating body 21 and the second heating body 22 may be integrally formed, which may improve the structural stability of the bottom heater 2 .

[0048] Specifically, Figure 1As shown, the axial direction of the second heating body 22 is the vertical direction, and along the axial direction of the second heating body 22, the height of the heating petal 213 is higher than the height of the second heating body 22, so that the end of the heating petal 213 away from the first heating body 21 is inclined toward the upper side of the second heating body 22, so as to shorten the distance between the heating petal 213 and the crucible side 12. The distance between the heating petal 213 and the crucible side 12 can be close to the distance between the second heating body 22 and the crucible side 12.

[0049] Specifically, the bottom heater 2 can be disposed below the crucible rib 12, and the axis of the bottom heater 2 can coincide with the axis of the crucible rib 12. Specifically, the crucible rib 12 can be wrapped around the crucible 11, and the axes of the crucible 11 and the crucible rib 12 coincide with each other.

[0050] Optionally, the second heating body 22 is a circular ring structure; along the circumference of the second heating body 22, multiple heating petals 213 radiate outward along the second heating body 22, so that there is an angle between the first heating body 21 and the second heating body 22, which can adapt to the outer contour shape of the crucible side 12, and can further shorten the distance between the first heating body 21 and the crucible side 12, as well as the distance between the second heating body 22 and the crucible side 12, so as to effectively utilize the heat radiated by the bottom heater 2.

[0051] Specifically, the second heating body 22 is a circular ring structure; along the circumference of the second heating body 22, a plurality of heating petals radiate outward from the second heating body 22, so that the extension direction of the second heating body 22 is different from the extension direction of the first heating body 21.

[0052] Optionally, the first heating body 21 composed of a plurality of heating petals 213 may be a bowl-shaped structure, and the inner surface 211 of the bowl-shaped structure may be an arc-shaped surface or a conical surface. In the embodiment of the utility model, the inner surface 211 of the first heating body 21 may be an arc-shaped surface or a conical surface, which may be close to the outer contour shape of the crucible side 12, so as to shorten the distance between the first heating body 21 and the crucible side 12, and effectively utilize the heat radiated by the first heating body 21.

[0053] Specifically, taking the second heating body 22 as a circular ring structure and the inner surface 211 of the first heating body 21 as a conical surface as an example, the first heating body 21 can be in the shape of a truncated cone, and the diameter of the inner surface 211 of the first heating body 21 gradually decreases from one end of the first heating body 21 away from the second heating body 22 to the end of the first heating body 21 close to the second heating body 22, so as to improve the uniformity of the heat radiated by the first heating body 21 to the crucible side 12.

[0054] Specifically, the first heating body 21 is a bowl-shaped structure with a first avoidance hole, and the first avoidance hole can be arranged at the center of the first heating body 21; the second heating body 22 can be arranged in the first avoidance hole.

[0055] Specifically, the first heating body 21 is a bowl-shaped structure. Correspondingly, the first heating body 21 can have relative concave sides and convex sides. The inner surface of the first heating body 21 is the concave surface of the first heating body, and the outer surface of the first heating body 21 can be the convex surface of the first heating body 21.

[0056] Alternatively, if Figure 3 As shown, the first heating body 21 extends away from the second heating body 22 along the first direction, and the second heating body 22 extends away from the first heating body 21 along the second direction, and the angle between the first direction and the second direction is an obtuse angle. In this way, the distance between the first heating body 21 and the crucible side 12 can be close to the distance between the second heating body 22 and the crucible side 12, and the heat radiated by each part of the bottom heater 2 can be effectively utilized.

[0057] like Figure 3 As shown, the first direction is arrow S 1 The second direction is the direction indicated by arrow S 2 Direction indicated.

[0058] Alternatively, if Figure 2 As shown, along the direction from the second heating body 22 to the first heating body 21, a slit 214 is opened in the middle of the heating petal 213 of the first heating body 21; the resistance of the bottom heater 2 can be adjusted by adjusting the length or width of the slit 214, so as to facilitate the first heating body 21 to radiate heat when powered on.

[0059] The bottom heater described in the embodiment of the utility model has at least the following advantages:

[0060] In the embodiment of the utility model, along the circumference of the second heating body, one end of the first heating body is connected to the second heating body, and the other end of the first heating body can be inclined toward the upper side of the second heating body, and along the axial direction of the second heating body, the height of the first heating body is higher than the height of the second heating body. In this way, the bottom heater is set at the bottom of the crucible side, and the distance between the first heating body 21 and the crucible side can be close to the distance between the second heating body and the crucible side, so that the shape of the bottom heater can be adapted to the shape of the crucible side, which is convenient for shortening the distance between the bottom heater and the crucible side, and then efficiently utilizing the heat radiated by the bottom heater.

[0061] In a second aspect, an embodiment of the utility model further discloses a thermal field, which includes the above-mentioned bottom heater 2.

[0062] Optionally, the hot field includes a crucible assembly 1, the crucible assembly 1 includes a crucible 11, a crucible side 12 and a crucible support 13, the crucible side 12 is wrapped around the periphery of the crucible 11, and is used to improve the supporting strength of the crucible 11; the crucible support 13 is connected to the bottom of the crucible 11, and is used to support the crucible 11; the crucible side 12 includes a transition portion and a flat portion that are connected to each other, and the crucible support 13 is connected to the flat portion of the crucible side 12.

[0063] Optionally, the transition portion of the crucible side 12 has a transition surface 121 on the side facing the bottom heater 2 , and the transition surface 121 is arranged opposite to the first heating body 21 of the bottom heater 2 ; the flat portion of the crucible side 12 is arranged opposite to the second heating body 22 of the bottom heater 2 .

[0064] In an embodiment of the utility model, the first heating body 21 of the bottom heater 2 can be arranged corresponding to the transition part of the crucible side 12, and the second heating body 22 can be arranged corresponding to the flat part of the crucible side 12, which can balance the distance between the bottom heater 2 and the crucible side 12, thereby improving the heating uniformity of the crucible side 12.

[0065] Specifically, the first heating body 21 is opposite to the transition part, so that the first heating body 21 can radiate heat to the transition part of the crucible side 12; the second heating body 22 is opposite to the flat part, so that the second heating body 22 can radiate heat to the flat part of the crucible side 12. In this way, both the transition part and the flat part of the crucible side 12 can be heated, which is convenient for improving the heating uniformity of the crucible side 12.

[0066] Specifically, the bottom of the crucible side 12 includes a transition portion and a flat portion connected to each other, and the transition surface 121 of the transition portion can be an arc surface or a conical surface; the shape of the transition surface 121 and the inner surface 211 of the first heating body 21 can be completely the same, or can also be approximately the same.

[0067] Optionally, the shape of the inner surface 211 of the first heating body 21 is the same as that of the transition surface 121 , so that the transition parts of the first heating body 21 and the crucible side 12 are evenly spaced, and the heat radiated by the first heating body 21 can be utilized to the maximum extent.

[0068] In the embodiment of the utility model, the bottom heater 2 is arranged at the bottom of the crucible side 12, so that the bottom heater 2 can radiate heat from the bottom to the crucible side 12 to melt the silicon material in the crucible 11 for crystal pulling operation. Since the bottom of the crucible side 12 includes a transition portion, the transition portion has a transition surface 121 on the side facing the bottom heater 2, and the bottom heater 2 includes a first heating body 21, and the first heating body 21 has an inner surface 211 on the side facing the crucible side 12. Since the inner surface 211 of the first heating body 21 and the transition surface 121 of the transition portion are arranged relative to each other, the shape of the first heating body 21 can be adapted to the shape of the crucible side 12 at the transition portion, which is convenient for shortening the distance between the first heating body 21 and the crucible side 12, thereby efficiently utilizing the heat radiated by the bottom heater 2.

[0069] Specifically, the shapes of the inner surface 211 of the first heating body 21 and the transition surface 121 of the transition part are close, which facilitates shortening the distance between the inner surface 211 of the first heating body 21 and the transition surface 121. In this way, the heat radiation distance of the first heating body 21 can be shortened, so that the first heating body 21 can radiate more heat to the crucible 11, and the heat radiated by the bottom heater 2 can be efficiently utilized.

[0070] Optionally, the distance between the first heating body 21 and the transition part is 20-25 mm, and the distance between the second heating body 22 and the flat part is 20-25 mm, so that there is a certain gap between the bottom heater 2 and the crucible side 12 to avoid sparking of the bottom heater 2.

[0071] Optionally, the thermal field also includes an insulation felt board 4, which is located below the bottom heater 2. The insulation felt board 4 has a first insulation surface 421 that is arranged opposite to the outer surface 212 of the first heating body 21. The first insulation surface 421 can be an arc-shaped surface or a conical surface, which is convenient for the first insulation surface 421 of the insulation felt board 4 to adapt to the shape of the first heating body 21, and can shorten the distance between the insulation felt board 4 and the first heating body 21, thereby increasing the thickness of the insulation felt board 4, and effectively improving the insulation effect at the bottom of the thermal field.

[0072] Among them, the outer surface of the first heating body 21 refers to the convex surface of the first heating body 21, that is, the surface of the first heating body 21 away from its axis; the inner surface of the first heating body 21 refers to the concave surface of the first heating body 21, that is, the surface of the first heating body 21 close to its axis.

[0073] Optionally, the shape of the first heat-insulating surface 421 may be the same as the shape of the outer surface 212 of the first heat-generating body 21 , so that the heat-insulating felt board 4 and the first heat-generating body 21 may be evenly spaced, further improving the heat-insulating effect on the thermal field.

[0074] Optionally, the thermal field also includes an insulation tube 3 and an air-conducting insulation tube 5, the air-conducting insulation tube 5 is arranged in the insulation tube 3, and the bottom heater 2 is located in the air-conducting insulation tube 5; there is a gap between the outer wall of the air-conducting insulation tube 5 and the inner wall of the insulation tube 3, and the gap forms a first air flow channel 51, which is convenient for smoothly discharging the gas in the insulation tube 3, and the air-conducting insulation tube 5 can protect the insulation felt board 4 and the bottom heater 2, so as to extend the service life of the insulation felt board 4 and the bottom heater 2.

[0075] During the crystal pulling process, corrosive volatiles are generated, and the airflow in the thermal field will drive the volatiles to scour and corrode many thermal field components in the thermal field. For example, the scouring and corroding of the bottom insulation component will increase the powdering rate of the bottom insulation component, and the scouring and corroding of the bottom heater 2 will cause the bottom heater 2 to be seriously damaged and cause failure. In the embodiment of the utility model, the insulation tube 3 is sleeved on the outer periphery of the gas-conducting insulation tube 5, and the gas-conducting insulation tube 5 is arranged at the bottom of the insulation tube 3, and a first airflow channel 51 is formed between the gas-conducting insulation tube 5 and the insulation tube 3. The setting of the first airflow channel 51 plays a role in guiding the airflow in the thermal field device, and in the crystal pulling process, the thermal field device is evacuated through the through hole at the bottom of the single crystal furnace body, so that the airflow with volatile substances flows along the first airflow channel 51 to the through hole at the bottom of the furnace body, until it flows out of the thermal field device through the through hole, thereby avoiding the airflow with volatile substances from scouring and surrounding the thermal field components in the thermal field, such as the bottom heater 2 and the bottom insulation component.

[0076] Specifically, the material of the air-conducting heat-insulating tube 5 can be graphite or carbon-carbon.

[0077] Optionally, the bottom heater 2 is disposed in the air-conducting and heat-insulating tube 5 , so that the air-conducting and heat-insulating tube 5 can block the airflow from scouring the bottom heater 2 , thereby protecting the bottom heater 2 .

[0078] Specifically, the radial distance between the air-conducting insulation tube 5 and the first heating body 21 in the heat-insulating tube 3 is 20-25 mm, which can effectively prevent the air-conducting insulation tube 5 from contacting the first heating body 21 and causing ignition in the bottom heater 2 .

[0079] Optionally, the distance between the gas-conducting insulation tube 5 and the crucible side 12 in the hot field in the axial direction of the heat-insulating tube 3 is 20-25 mm, which can avoid direct contact between the gas-conducting insulation tube 5 and the crucible side 12 to improve the stability during the crystal pulling process.

[0080] Optionally, the bottom insulation component is an insulation felt board 4, which may include a first insulation part 41 and a second insulation part 42; the first insulation part 41 is connected to the bottom of the insulation tube 3, and the second insulation part 42 is arranged in the insulation tube 3; the air-conducting insulation tube 5 is sleeved on the outer periphery of the second insulation part 42, and the air-conducting insulation tube 5 can also protect the second insulation part 42.

[0081] Specifically, the thermal insulation felt board 4 may be formed by integrally forming the first thermal insulation part 41 and the second thermal insulation part 42 , or may be formed by assembling and splicing the first thermal insulation part 41 and the second thermal insulation part 42 .

[0082] Optionally, the first insulation part 41 of the insulation felt board 4 is connected to the bottom of the insulation tube 3, and is enclosed with the inner wall of the insulation tube 3 to form a first accommodating space 34; the second insulation part 42, the bottom heater 2 and the crucible side 12 are all arranged in the first accommodating space 34, and the bottom heater 2 is arranged between the crucible side 12 and the second insulation part 42 of the insulation felt board 4.

[0083] Specifically, the insulation tube 3 and the insulation felt board 4 can play a role in heat insulation. The bottom heater 2 and the crucible side 12 are arranged in the first accommodating space 34, which can improve the insulation performance of the thermal field environment and reduce the heat loss in the thermal field environment.

[0084] Specifically, the heat-insulating cylinder 3 may include a cylinder body, and the outer periphery of the cylinder body may be wrapped with a layer of solid felt or soft felt. Specifically, the material of the heat-insulating felt board 4 may be solid felt or soft felt.

[0085] Optionally, the second insulation part 42 has a first insulation surface 421 on the side facing the bottom heater 2, shortening the distance between the first insulation surface 421 and the outer surface 212 of the bottom heater 2, facilitating increasing the thickness of the second insulation part 42 and effectively improving the insulation effect at the bottom of the heat field.

[0086] In some embodiments of the utility model, the second heating body 22 can be a circular ring structure, and the corresponding second insulation part 42 also has a second insulation surface 422 on the side facing the bottom heater 2. The second insulation surface 422 can be a circular ring surface. The second insulation surface 422 is opposite to the second heating body 22, which can effectively shorten the distance between the second insulation surface 422 of the second insulation part 42 and the second heating body 22, facilitate increasing the thickness of the second insulation part 42, and can have a better insulation effect on the thermal field.

[0087] Optionally, the distance between the first insulation surface 421 of the insulation felt board 4 and the first heating body 21 can be 20-25mm, and the distance between the second insulation surface 422 of the insulation felt board 4 and the second heating body 22 is 20-25mm; it can effectively ensure that the distance between the second insulation part 42 and each area of ​​the bottom heater 2 is close, and then increase the thickness of the second insulation part 42 as much as possible, which can improve the insulation effect of the thermal field.

[0088] Optionally, the difference between the outer diameter of the air-conducting heat-insulating cylinder 5 and the inner diameter of the heat-insulating cylinder 3 is 20-25 mm, so that the outer wall of the air-conducting heat-insulating cylinder 5 and the inner wall of the heat-insulating cylinder 3 are enclosed to form a first airflow channel 51. The first airflow channel 51 provides a space for the airflow with volatile substances to flow freely, and has the beneficial effect of increasing the flow rate of the airflow with volatile substances in the first airflow channel 51. As the thermal field device is evacuated, when the width of the first airflow channel 51 is less than 20 mm, the airflow with volatile substances may have a low flow rate due to the small size of the first airflow channel 51, resulting in a long residence time in the thermal field device, and it is possible to overflow from the first airflow channel 51 to cause erosion and corrosion to the thermal field parts. Therefore, setting the width of the first airflow channel 51 of the thermal field device to be greater than or equal to 20 mm has the beneficial effect of facilitating the airflow with volatile substances to quickly flow out of the thermal field device. However, the width of the first airflow channel 51 cannot be too large, as it will cause heat loss.

[0089] Optionally, the thermal field further includes a protective shell 43, which is located at the lower part of the air-conducting heat-insulating cylinder 5, and a second airflow channel is formed in the protective shell 43; the second airflow channel is connected to the first airflow channel 51, so as to facilitate the discharge of the airflow in the heat-insulating cylinder 3. In addition, the second airflow channel can change the flow direction of the airflow, and can also prevent heat from being directly radiated to the bottom of the single crystal furnace through the second airflow channel, so as to reduce heat loss in the thermal field.

[0090] Specifically, the material of the protective shell 43 may be carbon or graphite. Figure 4 As shown, the protective shell 43 includes two annular plates 431 arranged in parallel at intervals, the inner circumferences of the two annular plates 431 are connected by an annular connecting plate 432, and a first through hole is arranged on the lower annular plate 431; a second through hole can be arranged on the thermal insulation felt located at the lower part of the protective shell. The interval between the two annular plates 431, the first through hole and the second through hole are connected to form a second airflow channel. Among them, the gap between the outer circumference of the upper annular plate 431 and the inner wall of the thermal insulation tube 3 can form an air inlet of the second airflow channel, and the second through hole 411 on the thermal insulation felt at the lower part of the protective shell 43 can form an air outlet of the second airflow channel.

[0091] Specifically, the air inlet and the air outlet of the second air flow channel are not coaxially arranged, which can prevent the air flow from being discharged straightly in the second air flow channel, further reduce the heat flowing out of the second air flow channel, and reduce heat loss.

[0092] Optionally, an insulating felt plate 4 is provided at the lower part of the bottom heater 2, and a stepped hole may be provided on the insulating felt plate 4 to form a third airflow channel, which is connected to the exhaust through hole at the bottom of the single crystal furnace; the third airflow channel is connected to the first airflow channel 51.

[0093] In the embodiment of the utility model, a stepped hole is provided on the heat-insulating felt plate 4 to form a third air flow channel, and the third air flow channel is connected with the first air flow channel to facilitate the discharge of the air flow in the heat-insulating cylinder 3.

[0094] Specifically, the third airflow channel can change the direction of airflow, which can prevent heat from being directly radiated to the bottom of the single crystal furnace through the third airflow channel, and can reduce heat loss in the thermal field. Furthermore, the air inlet and the air outlet of the third airflow channel are not coaxially arranged, which can prevent the airflow from being discharged directly in the third airflow channel, further reduce the heat from flowing out of the third airflow channel, and reduce heat loss.

[0095] Optionally, the protective shell 43 may include two annular plates 431 arranged in parallel at an interval, the inner circumferences of the two annular plates 431 are connected by an annular connecting plate 432, the outer circumference of the upper annular plate 431 may have a gap with the inner wall of the insulation tube 3, and a first through hole is provided on the lower annular plate 431.

[0096] In one case, the second insulation part 42 includes a first sub-insulation part 423 and a second sub-insulation part 424, the first sub-insulation part 423 is connected between the first insulation part 41 and the second sub-insulation part 424, and the outer diameter of the first sub-insulation part 423 is smaller than the outer diameters of the first insulation part 41 and the second sub-insulation part 424; the annular connecting plate 432 is sleeved outside the first sub-insulation part 423, the first through hole is connected to the second through hole 411 on the first insulation part 41 on the lower side of the protective shell 43, and the gap between the two parallel annular plates 431 and the first through hole are connected to the second through hole to achieve gas discharge.

[0097] In another case, the second insulation part 42 is a cylindrical structure, and a stepped hole is provided on the first insulation part 41. The stepped hole may include a first opening and a second opening. The protective shell 43 may be provided in the first opening. The first insulation part 41 is protected by the protective shell 43. The first airflow channel, the gap of the protective shell and the second opening are connected to discharge the airflow.

[0098] In another case, the second insulation part 42 is a cylindrical structure, and the protective shell 43 itself encloses a step hole structure, and the second air flow channel is formed by the step hole structure; the protective shell 43 covers the inner wall of the step hole on the first insulation part 41, and the air flow is discharged through the second air flow channel formed by the protective shell 43.

[0099] Optionally, an insulation tube 3 and a side heater 6 are provided in the heat field, a groove is provided on the inner wall of the insulation tube 3, at least a portion of the side heater 6 is provided in the groove, the insulation tube 3 can block the longitudinal heat radiation of the side heating, can prevent the side heater 6 from radiating heat downward, and can reduce heat loss.

[0100] Specifically, Figure 1As described, the insulation tube 3 includes an upper insulation tube 31, a middle insulation tube 32 and a lower insulation tube 33, and the inner diameter of the middle insulation tube 32 is larger than the inner diameters of the upper insulation tube 31 and the lower insulation tube 33, so that the inner walls of the upper insulation tube 31, the middle insulation tube 32 and the lower insulation tube 33 can form a groove; in other cases, the insulation tube 3 may also only include a lower insulation tube 33 and a middle insulation tube 32, and the inner diameter of the middle insulation tube 32 is larger than the inner diameter of the lower insulation tube 33, so that the inner walls of the middle insulation tube 32 and the lower insulation tube 33 are enclosed to form a groove.

[0101] Optionally, the thermal field further includes an air barrier hood 7; the air barrier hood 7 is connected to the insulation tube 3 and blocks the groove, and the air barrier hood 7 and the groove enclose a second accommodating space 35; the side heater 6 is arranged in the second accommodating space 35, and the heat of the side heater 6 is radiated to the crucible 11 through the air barrier hood 7.

[0102] In the embodiment of the utility model, the side heater 6 is arranged around the periphery of the crucible side 12, so as to heat the crucible side 12 to melt the silicon material and pull the single crystal silicon rod. The air shield 7 is used to block between the side heater 6 and the crucible side 12, so as to avoid the air flow from eroding and corroding the side heater 6, and to improve the service life of the side heater 6.

[0103] Specifically, the material of the air baffle 7 can be carbon or graphite.

[0104] Specifically, the side heater 6 may be a carbon-carbon or graphite heater.

[0105] Optionally, the interval between the air barrier hood 7 and the side heater 6 is 20-25 mm, which can ensure the interval between the air barrier hood 7 and the side heater 6, avoid the air barrier hood 7 contacting the side heater 6 and causing ignition of the side heater 6, thereby increasing the service life of the side heater 6.

[0106] Optionally, the interval between the air shield 7 and the periphery of the crucible side 12 is 20-25 mm, which can prevent the air shield 7 from contacting the crucible side 12, thereby improving the stability during the crystal pulling process.

[0107] The thermal field described in the embodiment of the utility model has at least the following advantages:

[0108] In an embodiment of the utility model, the bottom heater is arranged at the bottom of the crucible side, and the distance between the first heating body and the crucible side can be close to the distance between the second heating body and the crucible side, so that the shape of the bottom heater can be adapted to the shape of the crucible side, which is convenient for shortening the distance between the bottom heater and the crucible side, and then efficiently utilizing the heat radiated by the bottom heater. Moreover, the height of one side of the bottom heater is raised, and a part of the space can be left empty, and more insulation felts are arranged on the lower side of the bottom heater to improve the insulation performance of the thermal field insulation component, reduce the heat radiation downward, and transmit from the bottom of the single crystal furnace to cause losses. An air-conducting insulation tube is added to the insulation tube, and the gap between the air-conducting insulation tube and the insulation tube can form a first airflow channel, which is convenient for discharging the gas in the insulation tube 3 and avoiding the erosion and corrosion of the thermal field component by the airflow. A groove is provided on the inner wall of the insulation tube, and the side heater is arranged in the groove, which can prevent the side heater from radiating heat downward and reduce heat loss.

[0109] Although the preferred embodiments of the utility model embodiments have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the utility model embodiments.

[0110] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0111] The bottom heater and thermal field provided by the utility model are introduced in detail above. The principle and implementation mode of the utility model are explained in detail by using specific examples in this article. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. At the same time, for the general technical personnel in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

Claims

1. A bottom heater, characterized in that: It comprises a first heat-generating body and a second heat-generating body; along the circumference of the second heat-generating body, one end of the first heat-generating body is connected to the second heat-generating body; One end of the first heat-generating body away from the second heat-generating body is inclined toward the upper side of the second heat-generating body, and along the axial direction of the second heat-generating body, the height of the first heat-generating body is higher than the height of the second heat-generating body.

2. The bottom heater according to claim 1, characterized in that: The first heating body includes a plurality of heating petals; along the circumference of the second heating body, one end of the plurality of heating petals is connected to the second heating body, and the other end of the plurality of heating petals extends away from the second heating body in a radial shape.

3. The bottom heater according to claim 2, characterized in that: The second heating body is a circular ring structure; the first heating body and the second heating body are integrally formed or the first heating body and the second heating body are detachably connected.

4. The bottom heater according to claim 1 or 2, characterized in that: The first heating body is a bowl-shaped structure, and the inner surface of the bowl-shaped structure is an arc surface or a conical surface.

5. The bottom heater according to claim 2, characterized in that: Along the direction from the second heating body to the first heating body, a slit is opened in the middle of the heating petal of the first heating body.

6. A thermal field, characterized in that: The bottom heater comprises the bottom heater as claimed in any one of claims 1 to 5.

7. The thermal field according to claim 6, characterized in that It includes a crucible side, which includes a transition part and a flat part connected to each other. The transition part has a transition surface on the side facing the bottom heater, and the transition surface is arranged opposite to the first heating body of the bottom heater; the flat part is arranged opposite to the second heating body of the bottom heater.

8. The thermal field according to claim 7, characterized in that: The shape of the transition surface of the transition portion is the same as the shape of the inner surface of the first heat-generating body.

9. The thermal field according to claim 7, characterized in that: The distance between the first heating body and the transition part is 20-25 mm; the distance between the second heating body and the flat part is 20-25 mm. The distance is 20-25mm.

10. The thermal field according to claim 6, characterized in that The thermal field includes a thermal insulation felt plate, which is located below the bottom heater. The thermal insulation felt plate has a first thermal insulation surface that is arranged opposite to the outer surface of the first heating body, and the first thermal insulation surface is an arc surface or a conical surface.

11. The thermal field according to claim 6, characterized in that The thermal field also includes a heat preservation tube and an air-conducting heat-insulating tube; The air-conducting heat-insulating cylinder is arranged in the heat-insulating cylinder, and the bottom heater is located in the air-conducting heat-insulating cylinder; There is a gap between the outer wall of the air-conducting and heat-insulating cylinder and the inner wall of the heat-insulating cylinder, and the gap forms a first airflow channel.

12. The thermal field according to claim 11, characterized in that A protective shell is provided at the lower part of the air-conducting heat-insulating cylinder, and a second airflow channel is formed in the protective shell; the second airflow channel is connected to the first airflow channel and is used to change the flow direction of the airflow.

13. The thermal field according to claim 11, characterized in that A thermal insulation felt plate is provided at the lower part of the bottom heater, and stepped holes are provided on the thermal insulation felt plate to form a third airflow channel; the third airflow channel is connected to the exhaust through hole at the bottom of the single crystal furnace; the third airflow channel is connected to the first airflow channel.

14. The thermal field according to claim 11, characterized in that The difference between the outer diameter of the air-conducting heat-insulating cylinder and the inner diameter of the heat-insulating cylinder is 20-25 mm; And / or, the distance between the air-conducting heat-insulating cylinder and the first heating body in the radial direction of the heat-insulating cylinder is 20-25 mm; And or, the distance between the air-conducting heat-insulating cylinder and the crucible side in the heat field in the axial direction of the heat-insulating cylinder is 20-25 mm.

15. The thermal field according to claim 6, characterized in that A heat preservation tube and a side heater are arranged in the heat field, a groove is arranged on the inner wall of the heat preservation tube, and at least a part of the side heater is arranged in the groove.

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