Silicon carbide annealing furnace

Abstract

The silicon carbide annealing furnace comprises a furnace body, a first furnace cover, a hoisting assembly, a second furnace cover, a tray assembly and a heating assembly, the furnace body is used for providing an annealing environment, and an opening is formed in the top of the furnace body; the first furnace cover hermetically covers the opening of the furnace body, and a material loading and unloading port is formed in the middle; the second furnace cover is hung on the hoisting assembly; the tray assembly is hung at the bottom of the second furnace cover and used for containing silicon carbide to be annealed. The heating assembly is arranged in the furnace body and is used for heating; the second furnace cover can carry the tray assembly to enter the heating range of the heating assembly through the lifting freedom degree of the hoisting assembly, and the second furnace cover covers the material loading and unloading opening of the first furnace cover or carries the tray assembly to be upwards away from the first furnace cover, so that the tray assembly is taken out from the material loading and unloading opening. The silicon carbide crystal ingot annealing device can be used for efficiently annealing silicon carbide crystal ingots in batches, so that stress in the silicon carbide crystal ingots is eliminated, defects are reduced, and the quality of wafers is improved.

Description

A silicon carbide annealing furnace Technical Field

[0001] This utility model belongs to the field of silicon carbide production technology, and relates to a silicon carbide production equipment, specifically a silicon carbide annealing furnace, which eliminates stress in silicon carbide ingots, reduces defects, and improves wafer quality by performing high-temperature annealing treatment on silicon carbide ingots. Background Technology

[0002] A silicon carbide annealing furnace is a high-temperature device that heats silicon carbide ingots in a graphite crucible to above 2200°C in a vacuum, argon, or nitrogen environment using graphite resistance heating to release thermal stress in the ingots and improve ingot quality. Due to the high operating temperature, it is difficult to design and has low efficiency in annealing production operations.

[0003] Existing technology CN217997414U discloses a batch high-temperature annealing device for silicon carbide crystals, including a graphite support and a graphite tube. The graphite support includes a base and a bracket connected to the upper end of the base. Several graphite boxes for placing silicon carbide crystals are placed parallel to each other along the axial direction inside the bracket. One side of the bracket is open for placing and removing the graphite boxes. The graphite tube is sleeved on the outside of the bracket, with its lower end detachably mounted on the base and its upper end detachably fitted with a cap. Although this technology can perform batch annealing, it does not specify how to feed and unload materials. During feeding, it can only be done manually or with the aid of external hoisting equipment. After annealing, it must be fully cooled before unloading, either manually or with the aid of external hoisting equipment. This results in low production efficiency and significant safety hazards.

[0004] Prior art CN217399047U discloses a silicon carbide crystal furnace, including a main furnace chamber, a furnace cover, and a base. The furnace cover is placed on the main furnace chamber, and the main furnace chamber is placed on the base. The furnace also includes: a furnace cover lifting system connected to the furnace cover for raising and lowering the furnace cover; a crucible hoisting system connected to the base, employing a flexible shaft winch structure for hoisting the crucible; the crucible lifting system including a roller screw drive mechanism and a hollow water-cooled structure for the crucible shaft; and a heat insulation system including an upper heat insulation plate, a heat insulation cavity, and a lower heat insulation plate, wherein the upper heat insulation plate, heat insulation cavity, and lower heat insulation plate together... The components are arranged into a hollow cylindrical cavity; the heating system includes heating electrodes, electrode connecting plates, and separate heaters; although the technology is designed with hoisting equipment, two hoisting devices are required during the loading and unloading process, one hoisting device to hoist the furnace cover and the other hoisting device to hoist the crucible. In order to meet the hoisting of the crucible, a complex crucible lifting system is also designed, which uses a roller screw transmission mechanism to drive the crucible to rise, and then connects to the crucible hoisting system for hoisting. The device has a complex structure, has two hoisting systems, and requires manual assistance to disassemble the hoisting system and the crucible when hoisting the crucible, so the efficiency is still not high.

[0005] In summary, due to the high-temperature working environment of silicon carbide annealing furnaces, the production efficiency of existing technologies is relatively low. Therefore, it is necessary to develop a high-efficiency silicon carbide annealing furnace. Summary of the Invention

[0006] The purpose of this invention is to address the problem of low efficiency in existing silicon carbide annealing furnaces by providing a silicon carbide annealing furnace that improves automatic feeding and discharging efficiency through a split furnace cover.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A silicon carbide annealing furnace, comprising:

[0009] The furnace body, designed to provide an annealing environment, has an opening at the top;

[0010] The first furnace cover is a sealed cover over the opening of the furnace body, with a material loading and unloading port in the middle.

[0011] The hoisting assembly must have at least one degree of freedom for lifting.

[0012] The second furnace cover is suspended on the hoisting assembly and can be detachably connected to the first furnace cover via fasteners.

[0013] A tray assembly, suspended from the bottom of the second furnace lid, is used to hold silicon carbide awaiting annealing; and

[0014] Heating components, located inside the furnace, are used for heating;

[0015] The lifting freedom of the hoisting component allows the second furnace cover to carry the pallet assembly into the heating range of the heating component, and the second furnace cover to cover the material loading and unloading port of the first furnace cover, or to carry the pallet assembly upward away from the first furnace cover, thereby removing the pallet assembly from the material loading and unloading port.

[0016] Furthermore, the tray assembly is suspended from the bottom of the second furnace cover by a hanger.

[0017] Furthermore, the upper part of the lifting rod is provided with a first limiting protrusion and a second limiting protrusion spaced apart in the vertical direction, and the bottom of the second furnace cover is provided with an annular support member that cooperates with the first limiting protrusion. The lifting rod can be suspended and fixed on the annular support member through the first limiting protrusion. The annular support member is provided with a notch that allows the lifting rod to slide out laterally, and the second limiting protrusion is a clamping part that allows the lifting rod to slide out laterally.

[0018] Further, the tray assembly includes:

[0019] Lifting components are located at the bottom of the lifting rod;

[0020] Several pallet racks are stacked at intervals below the lifting components in the vertical direction, and each pallet rack is provided with at least two connection holes;

[0021] Interval adjustment cylinders are installed between pallet frames or between pallet frames and lifting components to adjust the interval;

[0022] At least two connecting rods are used to sequentially pass through the connecting holes of the pallet frame and the spacer adjustment cylinder to secure all pallet frames to the underside of the lifting device.

[0023] The tray is placed on a tray rack.

[0024] Furthermore, the furnace body is a sandwiched water-cooled furnace body, and an insulation layer is provided inside the furnace body, which forms an annealing space.

[0025] Furthermore, the insulation layer includes at least a side wall insulation layer and a top cover insulation layer, wherein the top cover insulation layer is installed on the hanger rod via connectors.

[0026] Furthermore, the heating assembly is disposed within the annealing space, and the heating assembly includes a heat spreader assembly, the heat spreader assembly comprising:

[0027] A heat spreader is mounted at the bottom of the furnace body via a support assembly; and

[0028] The heat spreader cover is installed on the boom via a connector and rises and falls with the boom.

[0029] Furthermore, the support component includes:

[0030] Support rods, fixed to the bottom of the furnace body; and

[0031] The heat spreader tray is fixed to the support rod by connectors and is used to support the heat spreader.

[0032] Furthermore, the heating assembly includes an electric heating cylinder, the two electrodes of which are connected to the furnace body via an electrode connection assembly.

[0033] Furthermore, the hoisting assembly includes

[0034] Lifting base;

[0035] The lifting platform is installed on the hoisting base via a lifting mechanism.

[0036] A cantilever arm, one end of which is rotatably mounted on a lifting platform via a vertical axis, and the other end being a suspended end; and

[0037] The clamping mechanism, installed at the suspension end, is used to clamp the second furnace cover.

[0038] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0039] (1) The main structure of the flower basket graphite heater assembly adopts a flower basket structure and adopts the side electrode entry method. It is installed by extending two ears (electrodes) on both sides to cooperate with the electrode assembly. The electrode entry method is relatively convenient for disassembly and assembly.

[0040] (2) This utility model is designed with a unique combination tray assembly, which can hold 5 crystal ingots for annealing at one time. It can simultaneously accommodate 6-inch and 8-inch crystal ingots for annealing. It is also very convenient to use. The operator only needs to put the tray containing the crystal ingots and powder into the graphite tray in sequence. This structure can make the crystal ingots heat evenly. In addition, more crystal ingots can be placed for annealing by adjusting the size of the furnace body and other components along the axis.

[0041] (3) The lifting rod on the tray assembly is equipped with two arc-shaped structures (first limiting protrusion and second limiting protrusion). The first limiting protrusion is installed in conjunction with the annular support at the bottom of the second furnace cover. The tray assembly is hoisted into the furnace body for annealing. After the ingot is annealed, the chamber is removed and the second limiting protrusion is clamped by the lifting tool. The tray assembly can then be removed from the bottom of the second furnace cover, thereby removing the ingot.

[0042] (4) The ingot is removed by top discharge. The second furnace cover, tray assembly, heat-spreading cylinder cover and the second protective layer top cover are lifted, rotated and removed together to remove the ingot. The structure is stable and reliable. Attached Figure Description

[0043] Figure 1 is a schematic diagram of the silicon carbide annealing furnace in an embodiment of this utility model.

[0044] Figure 2 is an overall cross-sectional view of the silicon carbide annealing furnace in an embodiment of this utility model.

[0045] Figure 3 is a schematic diagram of the furnace body in an embodiment of this utility model.

[0046] Figure 4 is a schematic diagram of the installation of the inner tray assembly and the second furnace cover in an embodiment of this utility model.

[0047] Figure 5 is a magnified view of part A in Figure 4.

[0048] Figure 6 is a perspective view of the tray assembly in an embodiment of this utility model.

[0049] Figure 7 is a magnified view of part of Figure 6 (B).

[0050] Figure 8 is a schematic diagram of a single pallet rack structure.

[0051] Figure 9 is a schematic diagram of the installation of the heating components and heat spreader components inside the furnace.

[0052] Figure 10 is a three-dimensional schematic diagram of the heating component.

[0053] 100-Furnace body, 101-Bottom cover, 102-Cylinder body, 103-Reserved hole, 104-Mounting hole, 105-Inlet / outlet hole, 106-Interlayer;

[0054] 110-First furnace cover, 111-Material loading and unloading port, 112-Vertical elbow clamp, 120-Second furnace cover, 121-Annular support, 122-Notch, 123-Connector, 124-Upright pole, 125-; 130-Furnace body base;

[0055] 200-Lifting assembly, 210-Lifting base, 220-Lifting seat, 230-Cantilever, 240-Clamping mechanism, 250-Rotating shaft;

[0056] 300-Pallet assembly, 310-Hanging rod, 311-First limiting protrusion, 312-Second limiting protrusion;

[0057] 321-Lifting component, 322-Pallet frame, 323-Fixing lug, 324-Interval adjusting cylinder, 325-Pallet, 326-Connecting rod;

[0058] 400-Heating component, 410-Basket-shaped graphite heating cylinder, 420-Electrode, 430-Electrode connection component, 431-Inner electrode, 432-Outer electrode;

[0059] 500 - Insulation layer, 510 - Insulation layer bottom cover, 520 - Insulation layer cylinder, 530 - First insulation layer top cover, 540 - Second protective layer top cover;

[0060] 600-Hot vapor chamber assembly, 610-Hot vapor chamber, 620-Hot vapor chamber cover, 630-Support assembly, 631-Support rod, 632-Hot vapor chamber tray, 633-Layer;

[0061] 700-Silicon carbide ingot. Detailed Implementation

[0062] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0063] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0064] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0065] As shown in Figures 1 and 2, this utility model provides a silicon carbide annealing furnace, comprising:

[0066] The furnace body 100 is used to provide an annealing environment and has an opening at the top;

[0067] The first furnace cover 110 is sealed over the opening of the furnace body 100, and a material loading and unloading port 111 is provided in the middle of it;

[0068] The hoisting assembly 200 has at least one degree of freedom for lifting;

[0069] The second furnace cover 120 is suspended on the hoisting assembly 200 and can be detachably connected to the first furnace cover 110 by means of fasteners.

[0070] A tray assembly 300, suspended from the bottom of the second furnace cover 120, is used to hold silicon carbide awaiting annealing; and

[0071] Heating component 400 is located inside furnace body 100 and is used for heating;

[0072] The lifting freedom of the hoisting component 200 allows the second furnace cover 120 to carry the pallet assembly 300 into the heating range of the heating component 400, and the second furnace cover 120 covers the material loading and unloading port 111 of the first furnace cover 110, or carries the pallet assembly 300 upward away from the first furnace cover 110, thereby removing the pallet assembly 300 from the material loading and unloading port 111.

[0073] This utility model creatively designs a split furnace cover and a matching hoisting component 200, which allows the pallet component 300 to be hoisted into and out of the furnace body 100 without hoisting the entire furnace cover, thus greatly improving the efficiency of silicon carbide material feeding and unloading.

[0074] In some embodiments, as shown in FIG3, the furnace body 100 is a jacketed water-cooled furnace body, with cooling water circulating through the jacket to prevent the furnace body 100 from overheating; the furnace body 100 has a cylindrical structure, with a bottom cover 101 and a surrounding cylindrical body 102, the jacket of the bottom cover 101 and the cylindrical body 102 are separated and cooled water is introduced through it, the cylindrical body 102 is also provided with mounting holes 104 for installing electrodes, inlet and outlet holes 105 for cooling water circulation and several reserved holes 103, the reserved holes 103 are used for air intake, air exhaust, sensor installation, etc., and can be added or removed according to the prior art, and unused reserved holes 103 can be sealed by blind plates, which will not be described in detail in this utility model. The entire furnace body 100 can be supported by the furnace body base 130.

[0075] As shown in Figure 2, the tray assembly 300 is suspended from the bottom of the second furnace cover 120 by the hanger 310. This allows the tray assembly 300 to move in and out with the second furnace cover 120 and facilitates assembly and disassembly.

[0076] In some embodiments, as shown in FIG2, a heat insulation layer 500 is provided inside the furnace body 100, which forms an annealing space. The heating component 400 and the tray component 300 are both located in the heating space. Through the heat insulation function of the heat insulation layer 500, the required temperature for annealing is ensured, and the high temperature environment of annealing can be prevented from causing the furnace body 100 to become too hot, resulting in heat energy loss, safety hazards, and reduced lifespan of the furnace body 100.

[0077] For example, as shown in Figure 2, the insulation layer 500 is made of graphite hard felt and can be divided into multiple sub-blocks for installation according to its internal structure, ensuring both insulation effect and ease of assembly and disassembly. Specifically, according to the furnace body structure, the insulation layer 500 includes a bottom cover 510, an insulation cylinder 520, a first top cover 530, and a second top cover 540. The bottom cover 510 is located at the bottom of the furnace body 100, the insulation cylinder 520 is tightly fitted against the inner wall of the furnace body 100, the first top cover 530 is located at the top of the insulation cylinder 520, and the first top cover 530 has a through hole (or countersunk hole) in the middle that is smaller than the material loading and unloading port 111. The outer diameter of the second top cover 540 is smaller than the material loading and unloading port 111. The outer diameter of the second insulation layer top cover 540 is smaller than or slightly smaller than the diameter of the material loading and unloading port 111, allowing it to pass smoothly through the material loading and unloading port 111. The second insulation layer top cover 540 covers the through hole in the middle of the first insulation layer top cover 530, thus forming a relatively independent annealing space. The second insulation layer top cover 540 itself is fixed to the lifting rod 310 by a connector (adhesive or fixing sleeve), so that the second insulation layer top cover 540 moves up and down with the lifting rod 310, thereby realizing that the second insulation layer top cover 540 automatically opens and closes during the loading and unloading process, without the need for additional operation to close the insulation layer 500. The various sub-blocks of the insulation layer 500 are interlocked, making the joint a zigzag line, which improves the protective performance of the insulation layer 500 after splicing.

[0078] In some embodiments, as shown in Figures 2, 4, and 5, the upper part of the lifting rod 310 is provided with a first limiting protrusion 311 and a second limiting protrusion 312 spaced apart in the vertical direction. The bottom of the second furnace cover 120 is provided with an annular support member 121 that cooperates with the first limiting protrusion 311. The lifting rod 310 can be suspended and fixed on the annular support member 121 through the first limiting protrusion 311. As shown in Figure 6, the annular support member 121 is provided with a notch 122 that allows the lifting rod 310 to slide out laterally. The second limiting protrusion 312 is a clamping part that allows the lifting rod to slide out laterally.

[0079] For example, as shown in Figure 6, the first limiting protrusion 311 and the second limiting protrusion 312 are similar in shape, both being inverted cones surrounding the lifting rod 310. The annular support member 121 is a support ring, which is fixed to the bottom of the second furnace cover 120 by a screw or other connecting member. The support ring has a notch 122 on its side, the width of which is greater than the outer diameter of the lifting rod 310 and smaller than the outer diameter of the first limiting protrusion 311. Thus, under the action of gravity, the lifting rod 310 is firmly clamped to the support ring by the first limiting protrusion 311. Inside, and automatically centered through the adaptive action of the inverted cone; when the lifting rod 310 is lifted by external force, the first limiting protrusion 311 moves away from the support ring. At this time, the lifting rod 310 is moved laterally, and the lifting rod 310 can be removed from the support ring through the notch 122. The pallet assembly 300 can then be removed from the second furnace cover 120. A new pallet assembly 300 can be directly replaced and hoisted onto the second furnace cover 120 for the next annealing. The annealed pallet assembly 300 can be processed in other processes, which can greatly improve production efficiency.

[0080] The second limiting protrusion 312 is designed to cooperate in lifting and laterally moving the boom 310. External equipment (such as a multi-axis robotic arm) is provided with a structure similar to the support ring or a gripper assembly. The boom 310 below the second limiting protrusion 312 can be clamped to complete the function of lifting and laterally moving it. The relevant external equipment is not the core utility model point of this utility model, and will not be described in detail here.

[0081] This utility model can use any existing pallet assembly 300 to achieve rapid material loading and unloading in silicon carbide, or it can use a specially designed pallet 325 for single-batch production. For example, as shown in Figures 5 and 7, this utility model provides a pallet assembly 300 comprising:

[0082] Lifting component 321 is installed at the bottom of lifting rod 310;

[0083] Several pallet racks 322 are stacked at intervals below the lifting component 321 in the vertical direction, and each pallet rack 322 is provided with at least two connection holes;

[0084] The interval adjustment cylinder 324 is installed between pallet frames 322 or between pallet frames 322 and lifting components 321 to adjust the interval;

[0085] At least two connecting rods 326 are used to sequentially pass through the connecting holes and spacing adjustment cylinders of the pallet frames 322 and then fix all the pallet frames 322 under the lifting member 321.

[0086] Pallet 325 is mounted on pallet rack 322.

[0087] In this utility model, the shape of the lifting component 321 is not limited and can be any shape, as long as it can be installed with the pallet frame 322 and the lifting rod 310; the number of pallet frames 322 is not limited and can be designed according to the annealing space and the size of the silicon carbide ingot. Generally, there can be 3-10, and in this embodiment there are 5. The pallet frame 322 itself is disc-shaped and has a countersunk hole or groove in the middle for positioning the pallet 325; the connecting rod 326 is a screw, and the number is not limited, but at least 2, and generally there can be 3-6.

[0088] As a specific embodiment, the pallet assembly 300 is entirely made of graphite or other high-temperature resistant materials. For example, as shown in Figures 7 and 8, five graphite pallet frames 322 are spaced apart, and each pallet frame 322 has three fixing ears 323 evenly distributed around its perimeter. Each fixing ear 323 has an ear hole. The lifting component 321 is a graphite disc with a shape similar to that of the pallet frame 322. Graphite adjusting cylinders are set between the corresponding fixing ears 323 of two adjacent pallet frames 322. A graphite adjusting cylinder is also provided between the topmost pallet frame 322 and the fixing ears 323 of the lifting component 321. Three graphite screws are sequentially connected to the corresponding ear holes and graphite adjusting cylinders, and are fastened at both ends by graphite nuts to form the pallet assembly 300. The lifting component 321 has a screw hole in the middle, which is threadedly connected to the lifting rod 310.

[0089] In some embodiments, as shown in Figures 9 and 10, the heating assembly 400 is a basket-shaped graphite heater assembly, specifically a basket-shaped graphite heating cylinder 410, having two opposing electrodes 420. The two electrodes 420 are connected to the outside of the furnace body 100 through an electrode connection assembly 430. Specifically, the electrode connection assembly 430 includes an inner electrode 431 and an outer electrode 432. The furnace body 100 is provided with mounting holes for installing the electrode connection assembly 430. The inner electrode 431 is fixed to the side wall of the furnace body 100 by a connector. The inner end of the inner electrode 431 passes through a hole opened in the insulation layer 500 and is fixedly connected to the electrode 420 by screws or other fixing methods. The outer end of the inner electrode 431 extends out of the mounting hole, and the outer electrode 432 is installed in the threaded hole provided at the outer end of the inner electrode 431 by threaded engagement.

[0090] This invention provides power to the heating component 400 by setting up an internal and external separate electrode connection assembly 430, without affecting the sealing and heat preservation performance of the furnace body 100.

[0091] In some embodiments, as shown in FIG9, the heating assembly 400 includes a heat spreader assembly 600, the heat spreader assembly 600 comprising:

[0092] The heat spreader 610 is installed at the bottom of the furnace body 100 via a support assembly 630; and

[0093] The heat spreader cover 620 is installed on the boom 310 via a connector and rises and falls with the boom 310.

[0094] This utility model, by setting a split heat spreader structure, not only satisfies the material loading and unloading of the tray assembly 300, but also satisfies the need to form a relatively independent heat spreader space during annealing, thereby improving the uniformity of heating temperature; the heat spreader assembly 600 itself is made of high temperature resistant materials such as graphite.

[0095] In some embodiments, as shown in FIG9, the support component 630 includes:

[0096] Support rod 631, fixed to the bottom of the furnace body 100; and

[0097] The heat spreader tray 632 is fixed to the support rod 631 by a connector and is used to support the heat spreader 610.

[0098] This utility model supports the heat spreader tray 632 with a support rod 631, preventing the heat from the heat spreader 610 from being directly transferred to the furnace body 100. In a more preferred embodiment, the support rod 631 is threadedly installed on the bottom cover 101 of the furnace body 100, and a sandwich layer 106 is provided at a corresponding position on the bottom cover 101 to cool the lower end of the support rod 631 and prevent the high temperature of the support rod 631 from overflowing outside the furnace body 100.

[0099] In some embodiments, as shown in Figures 1 and 2, the hoisting assembly 200 includes

[0100] Lifting base 210;

[0101] The lifting platform 220 is installed on the hoisting base 210 via a lifting mechanism;

[0102] The cantilever 230 has one end rotatably mounted on the lifting base 220 via a vertical axis, and the other end is a suspension end; and

[0103] The clamping mechanism 240 is installed at the suspension end and is used to clamp the second furnace cover 120.

[0104] This utility model installs the lifting seat 220 on the hoisting base 210 via a lifting mechanism (not shown in Figures 1 and 2), and the cantilever 230 is installed on the lifting seat 220 via a rotating shaft 250, which can realize the lifting and rotation of the cantilever 230. In use, the lifting mechanism drives the cantilever 230 to rise, which drives the second furnace cover 120 and the tray assembly 300 below it to rise to the material loading and unloading port 111 that is separated from the furnace body 100. Then, the cantilever 230 is rotated so that the tray assembly 300 moves away from the furnace body 100 in the horizontal direction. This makes it easier to pick up and put down the tray assembly 300 from the second furnace cover 120, and also ensures safety by preventing the tray assembly 300 from bumping into the furnace body 100 during the picking and putting process.

[0105] The hoisting base 210 can be a vertically installed column or other high-level base (such as a wall or beam). A vertical guide rail (not shown in Figures 1 and 2) is provided on the hoisting base 210. The lifting seat 220 is installed on the guide rail, or the lifting seat 220 is directly guided and installed on the hoisting base 210 through a lifting mechanism. The implementation method of the lifting mechanism is not limited, such as a screw and nut mechanism, hydraulic lifting, pneumatic lifting, etc., which has no impact on the technical problem solved by this utility model. For example, a screw and nut mechanism can be used for lifting.

[0106] It should be noted that, as shown in Figure 1, the cantilever 230 is mounted on the lifting seat 220 via a rotating shaft 250 to enable the cantilever 230 to swing, which facilitates the loading and unloading of the pallet assembly 300. The rotating shaft 250 can be rotated manually or automatically, for example, by adding a motor drive or directly using a rotating mechanism such as a swing cylinder or a swing hydraulic cylinder.

[0107] In some embodiments, the clamping mechanism 240 is a common clamping mechanism in the prior art, such as a three-jaw chuck. The second furnace cover 120 is provided with a clamping component, as shown in FIG4. Specifically, it can be a vertical rod 124. The vertical rod 124 is provided with a clamping part 125 similar to the first limiting protrusion 311. The second furnace cover 120 is installed on the cantilever 230 by clamping the clamping part with the jaws.

[0108] In some embodiments, as shown in FIG1, the second furnace cover 120 is detachably fixed to the first furnace cover 110 by a snap fastener or a vertical elbow clamp 112. For example, the vertical elbow clamp 112 is installed on the first furnace cover 110 and can fix the second furnace cover 120 after it is closed. The vertical elbow clamp 112 is a commonly used and effective fixing component in the prior art.

[0109] In use, first assemble the tray assembly 300, or several tray assemblies 300 have already been assembled. Place the silicon carbide ingots to be returned into the trays 325 of the tray assembly 300, and select one or more trays 325 to hold toner as needed. In the initial inspection state, the cantilever 230 is in a high position and far from the furnace body 100. Move the tray assembly 300 containing the silicon carbide ingots manually or with external hoisting equipment to below the second furnace cover 120, and insert the lifting rod 310 into the support ring through the notch 122. The first limiting protrusion 311 limits the position, suspending the tray assembly 300 at the bottom of the second furnace cover 120. Then rotate the cantilever 230 so that the tray assembly 300 is directly above the material loading / unloading port 111, and then use a lift... The lowering cantilever 230 lowers the tray assembly 300 into the degradation space within the furnace body 100 until it reaches the second furnace cover 120 and the material loading / unloading port 111 of the second furnace cover 120. The second furnace cover 120 is then secured by a fixing component (vertical elbow clamp 112). The heating component 400 can then be activated to heat the annealing process (simultaneously driving a water-cooling circulation to cool the furnace body 100). After annealing, the heating component 400 is turned off, the fixing component (vertical elbow clamp 112) is opened, and the cantilever 230 is raised via the lifting mechanism. The tray assembly 300 rises and exits from the degradation space within the furnace body 100. Then, the cantilever 230 is lowered so that the tray assembly 300 is moved away from the furnace body 100, allowing for replacement of the tray assembly 300 or silicon carbide ingots. This cycle can be repeated to achieve continuous production.

[0110] It should be noted that when the pallet assembly 300 is replaced during production, each pallet assembly 300 needs to be equipped with a lifting rod 310, and each lifting rod 310 is equipped with a heat-spreading cylinder cover 620 and a second insulation layer top cover 540.

[0111] This invention discloses a silicon carbide annealing furnace, employing a double-layer water-cooled furnace shell structure and two electrode inlets on the side. A special graphite basket heater structure heats the internal chamber, and the ingot is placed in a basket structure for annealing. After annealing, the ingot is lifted out via a top-loading method. This annealing resistance furnace has a reasonable structural layout, good temperature uniformity, simple operation, and reliable performance. It can eliminate stress in silicon carbide ingots, reduce defects, and improve wafer quality.

[0112] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be covered within the scope of the claims of the present invention.

Claims

1. A silicon carbide annealing furnace, characterized in that, include: The furnace body provides an annealing environment and has an opening at the top; a first furnace cover seals over the opening in the furnace body and has a material loading / unloading port in its center; a hoisting assembly has at least one degree of freedom for lifting; a second furnace cover is suspended from the hoisting assembly and can be detachably connected to the first furnace cover via fasteners; a tray assembly is suspended from the bottom of the second furnace cover and is used to hold the silicon carbide to be annealed; and a heating assembly is located inside the furnace body for heating; the hoisting assembly's degree of freedom for lifting allows the second furnace cover to carry the tray assembly into the heating range of the heating assembly, and the second furnace cover covers the material loading / unloading port of the first furnace cover, or carries the tray assembly upward away from the first furnace cover, thereby removing the tray assembly from the material loading / unloading port.

2. The silicon carbide annealing furnace according to claim 1, characterized in that, The tray assembly is suspended from the bottom of the second furnace cover by a boom.

3. The silicon carbide annealing furnace according to claim 2, characterized in that, The upper part of the lifting rod is provided with a first limiting protrusion and a second limiting protrusion spaced apart in the vertical direction. The bottom of the second furnace cover is provided with an annular support member that cooperates with the first limiting protrusion. The lifting rod can be suspended and fixed on the annular support member through the first limiting protrusion. The annular support member is provided with a notch that allows the lifting rod to slide out laterally. The second limiting protrusion is a clamping part that allows the lifting rod to slide out laterally.

4. The silicon carbide annealing furnace according to claim 2, characterized in that, The pallet assembly includes: a lifting component disposed at the bottom of a lifting rod; a plurality of pallet frames stacked vertically at intervals below the lifting component, each pallet frame having at least two connection holes; an interval adjustment cylinder disposed between pallet frames or between a pallet frame and the lifting component for adjusting the interval; at least two connecting rods for sequentially passing through the connection holes of the pallet frames and the interval adjustment cylinders to fix all pallet frames below the lifting component; and a pallet disposed on the pallet frames.

5. The silicon carbide annealing furnace according to claim 2, characterized in that, The furnace body is a sandwiched water-cooled furnace body, and an insulation layer is provided inside the furnace body to form an annealing space.

6. The silicon carbide annealing furnace according to claim 4, characterized in that, The insulation layer includes at least a side wall insulation layer and a top cover insulation layer, and the top cover insulation layer is installed on the hanger rod by means of connectors.

7. The silicon carbide annealing furnace according to claim 2, characterized in that, The heating assembly is located within the annealing space. The heating assembly contains a heat spreader assembly, which includes: a heat spreader, which is installed at the bottom of the furnace body via a support assembly; and a heat spreader cover, which is installed on a lifting rod via a connector and moves up and down with the lifting rod.

8. The silicon carbide annealing furnace according to claim 7, characterized in that, The support assembly includes: a support rod, fixed to the bottom of the furnace body; and a heat spreader tray, fixed to the support rod by a connector, for supporting the heat spreader.

9. The silicon carbide annealing furnace according to claim 2, characterized in that, The heating assembly includes an electric heating cylinder, and the two electrodes of the electric heating cylinder are connected to the outside of the furnace body through an electrode connection assembly.

10. The silicon carbide annealing furnace according to claim 2, characterized in that, The hoisting assembly includes a hoisting base; a lifting seat, which is mounted on the hoisting base via a lifting mechanism; a cantilever, one end of which is rotatably mounted on the lifting seat via a vertical axis, and the other end of which is a suspension end; and a clamping mechanism, which is mounted on the suspension end and is used to clamp the second furnace cover.

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