Low-stress silicon carbide crystal annealing device and process

Abstract

The invention discloses a low-stress silicon carbide crystal annealing device and process, and particularly relates to the technical field of silicon carbide crystal preparation, the low-stress silicon carbide crystal annealing device comprises an annealing furnace, and a charging structure is arranged in the annealing furnace; the charging structure comprises a heat conduction cylinder, a pair of fixing supports fixedly mounted on the two sides in the heat conduction cylinder and a plurality of discharging grooves formed in the outer ring surface of the heat conduction cylinder; the fixing support is rotationally connected into the annealing furnace through a rotating shaft, and the rotating shaft end is connected with a driving motor. The device further comprises a limiting cover, a heating element, a sealing furnace cover, a pair of wheel disc action assemblies, a discharging plate, a plurality of feeding boxes, a furnace baffle and a sealing opening and closing assembly. The technical problems that feeding and discharging of the silicon carbide crystals in the annealing furnace need to be manually interfered by means of annealing of the silicon carbide crystals, heat loss is large when the furnace door of the annealing furnace is in a normally-open state, manual operation safety is low, the heating quality is affected by heating aging, and the timeliness of taking out the silicon carbide crystals is insufficient are solved.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide crystal preparation technology, and more specifically, to a low-stress silicon carbide crystal annealing apparatus and process. Background Technology

[0002] Silicon carbide crystals possess excellent physical properties such as a large bandgap, high electron saturation drift velocity, high critical breakdown field strength, and high thermal conductivity. They also exhibit high chemical stability and radiation resistance. These unique physicochemical properties make silicon carbide materials suitable for a wide range of applications, including high-temperature, high-frequency, high-power, radiation-resistant, corrosion-resistant devices, and optoelectronic integrated devices. Annealing methods include laser annealing and traditional baking. The purpose of annealing is to reduce hardness, improve machinability, eliminate residual stress, stabilize dimensions, reduce deformation and cracking tendency, refine grains, adjust microstructure, and eliminate structural defects. More precisely, annealing is a heat treatment process for materials. Currently, silicon carbide crystals require annealing in an annealing furnace to reduce internal stress within the crystal.

[0003] Currently, when annealing silicon carbide crystals, it is quite difficult to efficiently and accurately load and unload the crystals in the furnace while reducing heat loss. Existing methods require manual intervention to load and unload the silicon carbide crystals in the annealing furnace. With the furnace door constantly open, heat loss is high, manual operation is unsafe, and the timely removal of silicon carbide crystals is affected by heating aging. In other words, heating and annealing too much or too little silicon carbide crystals will affect the heating quality. Summary of the Invention

[0004] To overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a low-stress silicon carbide crystal annealing apparatus and process. The technical problem to be solved by the present invention is that the current method of silicon carbide crystal annealing requires manual intervention in the loading and unloading of silicon carbide crystals in the annealing furnace. The furnace door is always open, resulting in large heat loss, low safety of manual operation, and insufficient timeliness of silicon carbide crystal removal due to the influence of heating aging. In other words, heating and annealing with too much or too little silicon carbide crystal will affect the heating quality.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a low-stress silicon carbide crystal annealing apparatus, comprising an annealing furnace, wherein a charging structure is provided inside the annealing furnace, the charging structure comprising a heat-conducting cylinder, a pair of fixed supports fixedly installed on both sides inside the heat-conducting cylinder, and a plurality of discharge slots formed on the outer circumferential surface of the heat-conducting cylinder; the fixed supports are rotatably connected inside the annealing furnace via a rotating shaft, and a drive motor is connected to the end of the rotating shaft;

[0006] Also includes:

[0007] A limiting cover is fixedly connected inside the annealing furnace and disposed on the outside of the heat-conducting cylinder; a first discharge port is provided at the bottom of the limiting cover and a first loading port is provided at the top of the limiting cover; a second discharge port is provided at the bottom of the annealing furnace and below the first discharge port, and a second loading port is provided at the top of the annealing furnace and above the first loading port.

[0008] A heating element is disposed between the limiting cover and the annealing furnace;

[0009] A sealed furnace cover is disposed inside the second discharge port; a first torsion spring shaft is rotatably connected to the sealed furnace cover and the second discharge port.

[0010] A pair of wheel actuation components are mirror-arranged at both ends of the annealing furnace and fixedly connected to the rotating shaft of the fixed support; a pull rod is fixedly connected to the sealing furnace cover. When the wheel actuation components on the rotating shaft of the fixed support rotate and first contact and then disengage from the pull rod, the sealing furnace cover rotates back and forth once at the second discharge port through the first torsion spring shaft.

[0011] A feeding plate is disposed below the second feeding port;

[0012] Multiple feeding boxes are arranged in a ring around the outer surface of the annealing furnace; each feeding box has a push rod fixedly connected to both ends; the end of the push rod facing away from the feeding box is fixedly connected to the fixing ring; each feeding box is provided with a material cavity; the length of the material cavity is less than the length of the second feeding port, and the cavity of the material cavity is a sloping groove structure.

[0013] A baffle plate is provided at the top of the inner ring wall of the annealing furnace and below the second feeding port.

[0014] A sealing and opening / closing assembly is disposed on the annealing furnace and connected to the furnace baffle plate. When the wheel actuation assembly based on the rotating shaft of the fixed support rotates and first contacts and then disengages from the sealing and opening / closing assembly, the furnace baffle plate rotates back and forth once around the axis of the annealing furnace.

[0015] In a preferred embodiment, the limiting cover has a plurality of first heat-conducting holes.

[0016] In a preferred embodiment, the heat-conducting cylinder is provided with a plurality of second heat-conducting holes, and the second heat-conducting holes are connected to the discharge trough.

[0017] In a preferred embodiment, a pair of baffles are mirror-imagely disposed on the limiting cover, and the pair of baffles are disposed on both sides of the first feeding port.

[0018] In a preferred embodiment, each wheel actuation assembly includes a rotating disk fixedly connected to the rotating shaft of the fixed support, a plurality of levers fixedly connected to the rotating disk, and a fixing ring fixedly connected to the plurality of levers.

[0019] In a preferred embodiment, the number of levers is the same as the number of feeding slots, and the number of feeding slots is the same as the number of feeding boxes.

[0020] In a preferred embodiment, when the lever contacts and then disengages from the pull rod, the sealed furnace cover rotates back and forth once on the second discharge port via the first torsion spring shaft, at which time one of the discharge slots is vertically aligned with the second discharge port.

[0021] In a preferred embodiment, the sealing opening and closing assembly includes a through groove formed on the outer surface of the annealing furnace, an arc-shaped slide rod fixedly connected in the through groove, a movable slider slidably connected to the arc-shaped slide rod, a spring sleeved on the arc-shaped slide rod, a rotating groove formed on the movable slider, a rotating rod disposed in the rotating groove, and a second torsion spring shaft rotatably connected to the rotating groove and the rotating rod; the furnace baffle is fixedly connected to the bottom position of the movable slider, and the movable slider is slidably connected in the through groove.

[0022] In a preferred embodiment, when the push rod contacts and then disengages from the rotating rod, the baffle plate rotates back and forth once around the axis of the annealing furnace, at which time the feeding box passes through the second feeding port.

[0023] To address the aforementioned technical problems, the present invention also provides a low-stress silicon carbide crystal annealing process, which is applied to the aforementioned low-stress silicon carbide crystal annealing apparatus, and includes the following steps:

[0024] S1. By loading silicon carbide crystal rods into the loading boxes near the side of the annealing furnace, the drive motor is controlled to drive the loading structure to cooperate with the heating element for rotary annealing heating. At this time, several loading boxes can rotate around the surface of the annealing furnace.

[0025] S2. When the push rod makes contact with the rotating rod, the rotating rod can drive the baffle plate fixed on the sliding block to move in a circumferential direction. At this time, the second feeding port can be in the open state, and the silicon carbide crystal rod in the feeding box can pass through the second feeding port and the first feeding port in sequence and then enter one of the discharge slots. The rotating discharge slot will rotate in conjunction with the heating element to perform annealing heat treatment to reduce residual stress until the spring is in the maximum compression state. At this time, the rotating rod can rotate around the axis of the second torsion spring until the push rod disengages from the rotating rod. In this way, the second feeding port can be blocked by the baffle plate.

[0026] S3. Continuing from step S2, when the rotary motion assembly drives the push rod to rotate in a ring, the lever can rotate to the pull rod position and make contact. By pushing the pull rod, the sealed furnace cover can rotate around the axis of the first torsion spring shaft, so that the first discharge port can be in the open state. When rotated to the discharge trough vertically corresponding to the first discharge port, the silicon carbide crystal rod inside can fall out through the first discharge port and be discharged and collected by the discharge plate until the lever disengages from the pull rod. The sealed furnace cover can be reset and closed in the first discharge port by the elastic potential energy of the torsion spring of the first torsion spring shaft. At this time, the first discharge port is in the closed state.

[0027] The technical effects and advantages of this invention are as follows:

[0028] 1. This invention, by setting up a loading structure, a limiting cover, and a first discharge port, drives a motor to drive a heat-conducting cylinder filled with silicon carbide crystal rods to rotate at a low speed. The limiting cover provides spatial isolation to the outside of the heat-conducting cylinder, and the first discharge port provides an independent discharge channel for the heat-conducting cylinder. In this way, the silicon carbide crystal rods are rotated to perform annealing treatment. Under the heat treatment conditions of uniform annealing and controllable discharge position, the discharge effect can be achieved in a timely manner without manual intervention. This effectively avoids the silicon carbide crystal rods being heated too much or too little, which would affect the heat treatment quality, thereby achieving a precise heat treatment control effect.

[0029] 2. This invention, by setting up a sealed furnace cover, a wheel actuation assembly, and a pull rod, allows the wheel actuation assembly to rotate synchronously with the charging structure. This enables the wheel actuation assembly to respond to the feeding state of the silicon carbide crystal rods at the first feeding port and engage with the sealed furnace cover. Specifically, through the lever and the squeeze pull rod, the sealed furnace cover can rotate back and forth once at the second feeding port via the first torsion spring shaft. This single opening and closing action of the second feeding port maximizes the reduction of heat loss within the annealing furnace while ensuring effective and timely feeding of the silicon carbide crystal rods, achieving accurate and timely feeding of the silicon carbide crystal rods.

[0030] 3. This invention, by setting up a feeding box, a rotary motion assembly, a push rod, a baffle plate, and a sealing opening and closing assembly, utilizes the rotational property of the rotary motion assembly to load silicon carbide crystal rods into the feeding box. This drives several feeding boxes to perform circular motion outside the annealing furnace. The push rod at the end of the feeding box can move and contact the rotating rod until it pushes the baffle plate to open the second feeding port. In this way, the feeding box can cooperate with the second feeding port to put silicon carbide crystal rods into the feeding process. Because the baffle plate has a resettable property, the second feeding port can be sealed in time to reduce heat loss. In this way, by performing a single opening and closing action on the second feeding port, the heat loss rate in the annealing furnace can be minimized while meeting the requirements of rapid silicon carbide crystal rod feeding. This achieves timely and accurate feeding of silicon carbide crystal rods. Therefore, how to efficiently and accurately process silicon carbide crystals in the furnace while reducing heat loss is a difficult problem. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a low-stress silicon carbide crystal annealing apparatus according to the present invention.

[0032] Figure 2 For the present invention Figure 1 A sectional view.

[0033] Figure 3 For the present invention Figure 2 Enlarged view of part A.

[0034] Figure 4 This is a schematic diagram of the loading structure and the limiting cover of the present invention.

[0035] Figure 5 This is a cross-sectional view of the annealing furnace and the rotary disc actuation assembly of the present invention.

[0036] Figure 6 For the present invention Figure 5 Enlarged view of part B.

[0037] Figure 7 For the present invention Figure 5 A bottom view.

[0038] The attached diagram is labeled as follows: 1. Annealing furnace; 2. Baffle.

[0039] 3. Loading structure; 31. Heat-conducting cylinder; 32. Fixing support; 33. Discharge chute; 4. Drive motor;

[0040] 5. Limiting cover; 51. First discharge port; 52. First loading port; 6. Second discharge port; 61. Second loading port; 7. Heating element;

[0041] 8. Sealed furnace cover; 81. First torsion spring shaft;

[0042] 9. Wheel actuation assembly; 91. Rotating disc; 92. Lever; 93. Fixed ring; 10. Pull rod;

[0043] 11. Material cutting plate;

[0044] 12. Feeding box; 121. Material cavity; 13. Push rod;

[0045] 14. Furnace baffle; 15. Sealing and opening / closing assembly; 151. Through groove; 152. Arc-shaped slide bar; 153. Moving slider; 154. Spring; 155. Rotating groove; 156. Rotating rod; 157. Second torsion spring shaft;

[0046] 16. First heat conduction hole; 17. Second heat conduction hole. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] This invention provides a low-stress silicon carbide crystal annealing apparatus, including an annealing furnace 1, a charging structure 3, a limiting cover 5, a heating element 7, a sealed furnace cover 8, a pair of wheel actuation components 9, a feeding plate 11, multiple feeding boxes 12, a furnace baffle 14, and a sealing opening and closing component 15; in this invention, silicon carbide crystals can be annealed in the annealing furnace 1 with a rod-shaped structure to reduce residual stress.

[0050] See also Figure 4 The charging structure 3 includes a heat-conducting cylinder 31 disposed in the annealing furnace 1, a pair of fixed supports 32 fixedly installed on both sides inside the heat-conducting cylinder 31, and a plurality of discharge slots 33 opened on the outer ring surface of the heat-conducting cylinder 31; the fixed supports 32 are rotatably connected to the annealing furnace 1 via a rotating shaft, and a drive motor 4 is connected to the end of the rotating shaft; in this application, the drive motor 4 can be fixed on the mounting surface; in this application, the discharge slots 33 are composed of semi-arc and rectangular shapes, which facilitates the entry and exit of silicon carbide crystal rods, and at the same time facilitates heat transfer contact to achieve the effect of annealing heat treatment.

[0051] The heat-conducting cylinder 31 is provided with several second heat-conducting holes 17, and the second heat-conducting holes 17 are connected to the feeding trough 33. The advantage of this design is that when heating is achieved in the annealing furnace 1, the second heat-conducting holes 17 can achieve the effect of heat transfer, which can ensure that the silicon carbide crystal rod in the feeding trough 33 can be effectively heated.

[0052] Continue reading Figure 4 The limiting cover 5 is fixedly connected inside the annealing furnace 1 and is located outside the heat conduction cylinder 31. The limiting cover 5 can effectively prevent the silicon carbide crystal rod in the feeding trough 33 from moving and falling when the heat conduction cylinder 31 rotates. The bottom of the limiting cover 5 is provided with a first feeding port 51 and the top of the limiting cover 5 is provided with a first feeding port 52. The first feeding port 51 can provide a feeding channel for the feeding trough 33. The first feeding port 52 can provide a feeding channel for the feeding trough 33. The bottom of the annealing furnace 1 and below the first feeding port 51 is provided with a second feeding port 6, and the top of the annealing furnace 1 and above the first feeding port 52 is provided with a second feeding port 61. The second feeding port 6 can provide a feeding channel for the first feeding port 51. The second feeding port 61 can provide a feeding channel for the first feeding port 52.

[0053] The limiting cover 5 has several first heat conduction holes 16; the first heat conduction holes 16 can achieve the effect of heat transfer, so that the heat source at the position of the heating element 7 can be easily passed through the heat conduction cylinder 31 to increase the effect of heat treatment.

[0054] A pair of baffles 2 are mirror-mounted on the limiting cover 5, and the pair of baffles 2 are located on both sides of the first feeding port 52. The advantage of the design of the pair of baffles 2 is that when the silicon carbide crystal rod is fed into the second feeding port 61, the baffles 2 can ensure that the silicon carbide crystal rod can reliably enter the first feeding port 52.

[0055] See also Figure 3 The heating element 7 is disposed between the limiting cover 5 and the annealing furnace 1. The heating element 7 in this application can be an electric heating component. Multiple sets of heating elements 7 can be provided and fixedly connected to the inner wall of the annealing furnace 1. The high heat generated can be used for the heat treatment of silicon carbide crystal rods.

[0056] See also Figure 2 A sealing furnace cover 8 is disposed inside the second discharge port 6; a first torsion spring shaft 81 is rotatably connected to the sealing furnace cover 8 and the second discharge port 6; the sealing furnace cover 8 is used for sealing and opening / closing the position of the second discharge port 6; the first torsion spring shaft 81 may be composed of a first shaft and a first torsion spring; the first torsion spring enables the sealing furnace cover 8 to have elastic restoring property through the rotation of the first shaft.

[0057] See also Figure 1A pair of wheel actuation components 9 are mirror images of each other at both ends of the annealing furnace 1 and are fixedly connected to the rotating shaft of the fixed support 32. A pull rod 10 is fixedly connected to the sealing furnace cover 8. When the wheel actuation components 9 on the rotating shaft of the fixed support 32 rotate and first contact and then disengage from the pull rod 10, the sealing furnace cover 8 rotates back and forth once on the second discharge port 6 through the first torsion spring shaft 81. Each wheel actuation component 9 includes a rotating disk 91 fixedly connected to the rotating shaft of the fixed support 32, several levers 92 fixedly connected to the rotating disk 91, and a fixing ring 93 fixedly connected to the levers 92. The number of levers 92 is the same as the number of discharge troughs 33, and the number of discharge troughs 33 is the same as the number of feeding boxes 12. The same number of these components ensures that the discharge and retrieval of silicon carbide crystal rods in the discharge troughs 33 are consistent.

[0058] When the lever 92 contacts and then disengages from the pull rod 10, the sealing furnace cover 8 rotates back and forth once on the second discharge port 6 via the first torsion spring shaft 81. At this time, one of the discharge troughs 33 is vertically aligned with the second discharge port 6.

[0059] Specifically, when the drive motor 4 drives the heat-conducting cylinder 31 to rotate, that is, when the silicon carbide crystal rod is driven to perform circumferential heat treatment in the heating cylinder 1, the wheel actuation assembly 9 can rotate with the heat-conducting cylinder 31 on the same rotating shaft until the lever 92 rotates to a position close to the pull rod 10 and makes contact, that is, when the lever 92 slides into contact with the side of the pull rod 10, the pull rod 10 is forced to push the sealing furnace cover 8. After being forced, the sealing furnace cover 8 can rotate around the first shaft of the first torsion spring shaft 81, and the second discharge port 6 can gradually open. During this process, one of the discharge troughs 33 can contact the first discharge port. With vertical alignment at 51, the heated silicon carbide crystal rods in the feeding trough 33 can be discharged sequentially through the first feeding port 51 and the second feeding port 6 until the silicon carbide crystal rods are discharged. At this point, the pull rod 10 can disengage from the end of the lever 92, allowing the sealing furnace cover 8 to be reset by the elastic traction force of the first torsion spring. This allows the second feeding port 6 to be sealed by the sealing furnace cover 8. Therefore, by performing a single opening and closing action on the second feeding port 6, the effective discharge and collection of silicon carbide crystal rods can be achieved, and the heat loss rate in the annealing furnace 1 can be minimized, thus achieving the effect of accurate and timely discharge of silicon carbide crystal rods.

[0060] The feeding plate 11 is positioned below the second feeding port 6; when the silicon carbide crystal rod falls through the second feeding port 6, the feeding plate 11 can receive the silicon carbide crystal rod and change its falling direction in order to collect the heat-treated silicon carbide crystal rod.

[0061] See also Figure 5Multiple feeding boxes 12 are arranged in a ring around the outer surface of the annealing furnace 1. Each feeding box 12 has a push rod 13 fixedly connected to both ends. The end of the push rod 13 facing away from the feeding box 12 is fixedly connected to a fixing ring 93. Each feeding box 12 is provided with a material cavity 121. The length of the material cavity 121 is less than the length of the second feeding port 61, and the cavity of the material cavity 121 is a sloping groove structure. When the feeding box 12 is located on the right side of the annealing furnace 1, the sloping groove of the material cavity 121 can prevent the material from slipping out after the silicon carbide crystal rod is placed into the material cavity 121. The push rod 13 fixed to the fixing ring 93 can provide fixed support for the feeding box 12. The length of the material cavity 121 is less than the length of the second feeding port 61, which can ensure that the silicon carbide crystal rod in the material cavity 121 effectively falls into the second feeding port 61. In this application, the feeding of silicon carbide crystal rods in the material cavity 121 can be completed by a robot.

[0062] The baffle plate 14 is located at the top of the inner ring wall of the annealing furnace 1 and below the second feeding port 61. The baffle plate 14 can block the second feeding port 61, that is, when the baffle plate 14 is located below the second feeding port 61, it can reduce the heat loss rate inside the annealing furnace 1.

[0063] Continue reading Figure 6 The sealing and opening / closing assembly 15 is mounted on the annealing furnace 1 and connected to the baffle plate 14. In this application, two sets of sealing and opening / closing assemblies 15 can be provided, so that a pair of push rods 13 can simultaneously cooperate with the sealing and opening / closing assembly 15 to operate, thus the baffle plate 14 can be more stably controlled by the sealing and opening / closing assembly 15. When the wheel actuation assembly 9 based on the rotating shaft on the fixed support 32 rotates and first contacts and then disengages from the sealing and opening / closing assembly 15, the baffle plate 14 rotates back and forth once around the axis of the annealing furnace 1. The sealing and opening / closing assembly 15 includes a through groove 151 opened on the outer surface of the annealing furnace 1, an arc-shaped slide rod 152 fixedly connected in the through groove 151, and a moving part slidably connected to the arc-shaped slide rod 152. The system comprises a slider 153, a spring 154 sleeved on an arc-shaped slide rod 152, a rotating groove 155 formed on the movable slider 153, a rotating rod 156 disposed in the rotating groove 155, and a second torsion spring shaft 157 rotatably connected to the rotating groove 155 and the rotating rod 156; the movable slider 153 is slidably connected in the through groove 151; the baffle plate 14 is fixedly connected to the bottom position of the movable slider 153; in this application, the design position of the through groove 151, when the baffle plate 14 is set at the position of the second discharge port 6, the baffle plate 14 can also be used to block the position of the through groove 151 to reduce heat loss; in this application, the second torsion spring shaft 157 is composed of a second shaft and a second torsion spring.

[0064] When the push rod 13 contacts and then separates from the rotating rod 156, the baffle plate 14 rotates back and forth once around the axis of the annealing furnace 1. At this time, the feeding box 12 passes through the second feeding port 61.

[0065] Specifically, when the heat-conducting cylinder 31 rotates, the fixing ring 93 can simultaneously drive the feeding box 12 to rotate via the push rod 13. That is, multiple feeding boxes 12 rotate around the axis of the annealing furnace 1 until the push rod 13 rotates close to the position of the rotating rod 156 and contacts the push. When the pushing force is less than the torque of the second torsion spring, the push rod 13 can drive the moving slider 153 to correspond on the arc-shaped sliding rod 152 via the rotating rod 156. At this time, the spring 154 can be in a compressed state, and the position of the second feeding port 61 can be opened by the furnace baffle 14. In this way, when the feeding box 12 moves to the position of the second feeding port 61, and one of the discharge slots 33 is vertically aligned with the first feeding port 52, the silicon carbide crystal rod in the material cavity 121 can pass through the second feeding port 61 and the first feeding port 52 in sequence. The feed port 52 enters the corresponding feeding trough 33, thus completing the feeding process for heating silicon carbide crystal rods. When the spring 154 is in its maximum compressed state, the pressure on the moving slider 153 from the rotating rod 156 is greater than the torque of the second torsion spring. Thus, the rotating rod 156 can rotate through the second shaft until it disengages from the push rod 13. Under the elastic force of the spring 154, the moving slider 153 can drive the baffle plate 14 to return to the bottom of the second feeding port 61, thus closing the second feeding port 61. Therefore, by performing a single opening and closing action on the second feeding port 61, the heat loss rate in the annealing furnace 1 can be minimized while meeting the requirements for rapid feeding of silicon carbide crystal rods, achieving timely and accurate feeding of silicon carbide crystal rods.

[0066] Example 2

[0067] This invention provides a low-stress silicon carbide crystal annealing apparatus process, which is applied in Example 1 and includes the following steps:

[0068] S1. By loading silicon carbide crystal rod aluminum alloy into the loading box (12) near the side of the annealing furnace (1), the drive motor (4) is controlled to drive the loading structure (3) to cooperate with the heating element (7) for rotary annealing heating. At this time, several loading boxes (12) can rotate around the surface of the annealing furnace (1).

[0069] S2. When the push rod (13) comes into contact with the moving rotating rod (156), the rotating rod (156) can drive the baffle plate (14) fixed on the moving slider (153) to move in a circumferential direction. At this time, the second feeding port (61) can be in an open state. The silicon carbide crystal rod in the feeding box (12) can pass through the second feeding port (61) and the first feeding port (52) in sequence and then enter one of the feeding grooves (33). The rotating feeding groove (33) is annealed in a rotating manner in conjunction with the heating element (7) to reduce residual stress until the spring (154) is in the maximum compression state. At this time, the rotating rod (156) can rotate around the axis of the second torsion spring shaft (157) until the push rod (13) disengages from the rotating rod (156). In this way, the second feeding port (61) can be blocked by the baffle plate (14).

[0070] S3. Continuing with the processing steps of S2, when the wheel actuation assembly (9) drives the push rod (13) to rotate in a ring, the lever (92) can rotate to the position of the pull rod (10) and make contact. By pushing the pull rod (10), the sealed furnace cover (8) can rotate around the axis of the first torsion spring shaft (81), so that the first discharge port (51) can be in the open state. When rotated to the discharge trough (33) vertically corresponding to the first discharge port (51), the silicon carbide crystal rod inside can fall out through the first discharge port (51) and be discharged and collected by the discharge plate (11) until the lever (92) disengages from the pull rod (10). The sealed furnace cover (8) can be reset and closed in the first discharge port (51) by the elastic potential energy of the torsion spring of the first torsion spring shaft (81). At this time, the first discharge port (51) is in the closed state.

Claims

1. A low-stress silicon carbide crystal annealing apparatus, comprising an annealing furnace (1), wherein a charging structure (3) is provided inside the annealing furnace (1); characterized in that: The charging structure (3) includes a heat-conducting cylinder (31), a pair of fixed supports (32) fixedly installed on both sides inside the heat-conducting cylinder (31), and a plurality of discharge slots (33) opened on the outer ring surface of the heat-conducting cylinder (31); the fixed supports (32) are rotatably connected to the annealing furnace (1) through a rotating shaft, and a drive motor (4) is connected to the end of the rotating shaft; Also includes: A limiting cover (5) is fixedly connected inside the annealing furnace (1) and is located on the outside of the heat-conducting cylinder (31). The bottom of the limiting cover (5) is provided with a first discharge port (51) and the top of the limiting cover (5) is provided with a first loading port (52). The bottom of the annealing furnace (1) and below the first discharge port (51) is provided with a second discharge port (6), and the top of the annealing furnace (1) and above the first loading port (52) is provided with a second loading port (61). A heating element (7) is disposed between the limiting cover (5) and the annealing furnace (1); A sealed furnace cover (8) is provided inside the second discharge port (6); a first torsion spring shaft (81) is rotatably connected to the sealed furnace cover (8) and the second discharge port (6); A pair of wheel actuation components (9) are mirror images of the two ends of the annealing furnace (1) and are fixedly connected to the rotating shaft of the fixed support (32); a pull rod (10) is fixedly connected to the sealing furnace cover (8). When the wheel actuation components (9) on the rotating shaft of the fixed support (32) rotate and first contact and then disengage with the pull rod (10), the sealing furnace cover (8) rotates back and forth once on the second discharge port (6) through the first torsion spring shaft (81); A feeding plate (11) is disposed below the second feeding port (6); Multiple feeding boxes (12) are arranged around the outer surface of the annealing furnace (1); each feeding box (12) has a push rod (13) fixedly connected to both ends; the end of the push rod (13) facing away from the feeding box (12) is fixedly connected to the fixing ring (93); each feeding box (12) is provided with a material cavity (121); the length of the material cavity (121) is less than the length of the second feeding port (61), and the cavity of the material cavity (121) is a sloping groove structure; A baffle plate (14) is located at the top of the inner ring wall of the annealing furnace (1) and below the second feeding port (61); A sealing and opening / closing assembly (15) is disposed on the annealing furnace (1) and connected to the baffle plate (14). When the wheel actuation assembly (9) on the rotating shaft of the fixed support (32) rotates and first contacts and then disengages from the sealing and opening / closing assembly (15), the baffle plate (14) rotates back and forth once around the axis of the annealing furnace (1).

2. The low-stress silicon carbide crystal annealing apparatus according to claim 1, characterized in that: The limiting cover (5) has several first heat conduction holes (16).

3. The low-stress silicon carbide crystal annealing apparatus according to claim 1, characterized in that: The heat-conducting cylinder (31) is provided with a plurality of second heat-conducting holes (17), and the second heat-conducting holes (17) are connected to the discharge trough (33).

4. The low-stress silicon carbide crystal annealing apparatus according to claim 1, characterized in that: A pair of baffles (2) are mirror-imagely arranged on the limiting cover (5), and the pair of baffles (2) are arranged on both sides of the first feeding port (52).

5. The low-stress silicon carbide crystal annealing apparatus according to claim 1, characterized in that: Each wheel actuation assembly (9) includes a rotating disk (91) fixedly connected to the rotating shaft of the fixed support (32), a plurality of levers (92) fixedly connected to the rotating disk (91), and a fixing ring (93) fixedly connected to the plurality of levers (92).

6. The low-stress silicon carbide crystal annealing apparatus according to claim 5, characterized in that: The number of levers (92) is the same as the number of feed troughs (33), and the number of feed troughs (33) is the same as the number of feed boxes (12).

7. The low-stress silicon carbide crystal annealing apparatus according to claim 5, characterized in that: When the lever (92) contacts and then separates from the pull rod (10), the sealed furnace cover (8) rotates back and forth once on the second discharge port (6) via the first torsion spring shaft (81), at which time one of the discharge slots (33) is vertically aligned with the second discharge port (6).

8. The low-stress silicon carbide crystal annealing apparatus according to claim 5, characterized in that: The sealing and opening / closing assembly (15) includes a through groove (151) formed on the outer surface of the annealing furnace (1), an arc-shaped slide rod (152) fixedly connected in the through groove (151), a movable slider (153) slidably connected on the arc-shaped slide rod (152), a spring (154) sleeved on the arc-shaped slide rod (152), a rotating groove (155) formed on the movable slider (153), a rotating rod (156) set in the rotating groove (155), and a second torsion spring shaft (157) rotatably connected on the rotating groove (155) and the rotating rod (156); the furnace baffle (14) is fixedly connected to the bottom position of the movable slider (153); the movable slider (153) is slidably connected in the through groove (151).

9. The low-stress silicon carbide crystal annealing apparatus according to claim 8, characterized in that: When the push rod (13) contacts and then separates from the rotating rod (156), the baffle plate (14) rotates back and forth once around the axis of the annealing furnace (1), at which time the feeding box (12) passes through the second feeding port (61).

10. A low-stress silicon carbide crystal annealing process, applied to a low-stress silicon carbide crystal annealing apparatus as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. By loading silicon carbide crystal rod aluminum alloy into the loading box (12) near the side of the annealing furnace (1), the drive motor (4) is controlled to drive the loading structure (3) to cooperate with the heating element (7) for rotary annealing heating. At this time, several loading boxes (12) can rotate around the surface of the annealing furnace (1). S2. When the push rod (13) comes into contact with the moving rotating rod (156), the rotating rod (156) can drive the baffle plate (14) fixed on the moving slider (153) to move in a circumferential direction. At this time, the second feeding port (61) can be in an open state. The silicon carbide crystal rod in the feeding box (12) can pass through the second feeding port (61) and the first feeding port (52) in sequence and then enter one of the feeding grooves (33). The rotating feeding groove (33) is annealed in a rotating manner in conjunction with the heating element (7) to reduce residual stress until the spring (154) is in the maximum compression state. At this time, the rotating rod (156) can rotate around the axis of the second torsion spring shaft (157) until the push rod (13) disengages from the rotating rod (156). In this way, the second feeding port (61) can be blocked by the baffle plate (14). S3. Continuing with the processing steps of S2, when the wheel actuation assembly (9) drives the push rod (13) to rotate in a ring, the lever (92) can rotate to the position of the pull rod (10) and make contact. By pushing the pull rod (10), the sealed furnace cover (8) can rotate around the axis of the first torsion spring shaft (81), so that the first discharge port (51) can be in the open state. When rotated to the discharge trough (33) vertically corresponding to the first discharge port (51), the silicon carbide crystal rod inside can fall out through the first discharge port (51) and be discharged and collected by the discharge plate (11) until the lever (92) disengages from the pull rod (10). The sealed furnace cover (8) can be reset and closed in the first discharge port (51) by the elastic potential energy of the torsion spring of the first torsion spring shaft (81). At this time, the first discharge port (51) is in the closed state.

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