A multiplexed visual monitoring device and method for a multi-tube horizontal zone refining purification apparatus

Abstract

The application discloses a kind of multiplex visual monitoring device and method for multi-tube horizontal zone refining purification equipment, belong to semiconductor material purification equipment technical field.The device includes double-side symmetrical arrangement camera array, camera multiplex shooting structure, guide rail moving mechanism and high-temperature protection structure.Cameras are installed with oblique overhead shooting angle, and at least two adjacent heating units are covered simultaneously on the same side boundary area by single camera;Guide rail drives camera to move along the quartz tube axial direction to realize multi-station time-sharing full coverage;High-temperature protection structure includes heat dissipation module, air cooling channel and high-transparency glass insulation layer.The application realizes full-coverage visual monitoring to multi-tube multi-station with limited number of cameras, solves the shooting problem of heating unit shielding melting zone, and can work stably for a long time in high-temperature environment above 600 DEG C.

Description

Technical Field

[0001] This invention belongs to the technical field of semiconductor material purification equipment, specifically relating to a reusable visual monitoring device and method for multi-tube horizontal zone melting purification equipment, and particularly a visual monitoring device that achieves full coverage of multi-tube, multi-heating unit industrial-grade zone melting purification equipment through single-camera multi-station multiplexing and guide rail movement extension. Background Technology

[0002] Zone melting purification is a technique for the physical purification of semiconductor materials using the principle of segregation. In the horizontal zone melting purification process, the material to be purified is loaded into a carrier boat, which is placed inside a quartz tube. A heating unit moves axially along the quartz tube, forming a localized melting zone (i.e., a "melting zone") on the material ingot. This melting zone is then slowly moved from one end of the material to the other. Impurities have different solubilities in the solid and liquid phases, and after multiple zone melting movements, they are concentrated at both ends of the material, while the middle portion is purified.

[0003] The width of the melting zone is a key control parameter in the zone melting purification process. A melting zone that is too narrow will affect purification efficiency, while a melting zone that is too wide may lead to instability or "melting through" between adjacent melting zones. Therefore, the width of the melting zone corresponding to each heating unit needs to be monitored in real time throughout the entire zone melting purification process.

[0004] In existing technologies, there have been some attempts to monitor the molten zone visually. For example, CN118166421A discloses a method for determining the length of the molten zone based on zone melting purification. This method uses a transparent quartz crucible to hold polycrystalline material and directly observes and measures the length of the molten region formed after melting from the outside of the quartz crucible. However, this method relies on a transparent quartz crucible and direct external imaging of the entire molten zone, making it suitable for small laboratory devices. In industrial-grade equipment, the heating unit has a cuboid structure and is tightly attached to the outside of the quartz tube. Its shell severely obstructs the molten zone, making it impossible for the camera to capture the complete shape of the molten zone from any single angle. Therefore, this method cannot be directly applied to industrial-grade multi-tube zone melting purification equipment. For example, CN203187773U discloses a CCD real-time monitoring device for a zone melting furnace. This device includes a CCD camera, a displacement sensor, and a fixed bracket. The CCD camera includes a reflective glass, a reflective glass base, a CCD camera, and a CCD camera bracket. The displacement sensor includes a displacement sensor and a slider guide rail. The CCD camera monitors the area near the molten zone in real time during crystal pulling and transmits the image data to the operating terminal. The displacement sensor accurately detects the displacement of the molten zone center. Both the CCD camera and displacement sensor serve as reliable information sources for uploading single-crystal growth parameters to the automated crystal growth software. The entire device employs a flexible configuration, allowing the positions of the CCD camera and displacement sensor to be adjusted as needed. However, it still has the following shortcomings:

[0005] First, the device only performs fixed-point monitoring of a single melting zone and does not take into account the full-coverage monitoring requirements of multiple quartz tubes and multiple heating units operating in parallel in industrial-grade zone melting purification equipment. Simply replicating this solution and configuring a camera independently for each workstation would lead to a significant increase in hardware costs and serious space occupation of equipment.

[0006] Second, the device does not address the issue of photographing when the heating unit physically obstructs the molten zone. In industrial-grade horizontal zone melting purification equipment, the heating unit has a cuboid structure and is tightly attached to the outside of the quartz tube. Its shell severely obstructs the molten zone, making it impossible for the camera to capture the complete shape of the molten zone from a single angle. This patent does not provide any solution to this problem.

[0007] Third, the device lacks any high-temperature protection structure. The heating unit of the zone melting equipment can operate at temperatures exceeding 600℃, and the high-temperature heat radiation and convection would severely affect the long-term stable operation of the camera; this patent fails to consider this aspect.

[0008] Furthermore, if the conventional approach is to configure an independent camera for each workstation, taking an industrial device with 4 tubes and 12 workstations as an example, at least 12 cameras would be required (more if dual-side shooting is considered). This not only leads to a significant increase in hardware costs, but the installation and deployment of multiple cameras will also seriously occupy equipment space, change the original structural layout of the equipment, and even disrupt the uniformity of the internal temperature field, affecting the normal operation of the purification process.

[0009] To improve purification efficiency, industrial-grade zone melting purification equipment typically employs a parallel structure with multiple tubes and multiple stations. Taking a typical 4-tube system as an example, the equipment has four quartz tubes arranged in parallel, each corresponding to three independently controlled heating units, for a total of 12 heating units (i.e., 12 stations) operating simultaneously. In the traditional manual operation mode, operators need to visually observe the melting zone of each of the 12 stations through observation windows in a high-temperature environment and manually adjust the temperature of each heating unit based on experience. This manual monitoring method suffers from problems such as high workload, low monitoring accuracy, and slow response.

[0010] Therefore, how to achieve full-coverage visual monitoring of multi-tube, multi-station zone melting and purification equipment under limited camera hardware investment, while solving the problem of heating units blocking the melting zone and ensuring the normal operation of cameras in high-temperature industrial environments, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0011] The technical problem to be solved by this invention is: addressing the lack of suitable automated visual monitoring methods for industrial-grade multi-tube zone melting purification equipment in the prior art, this invention provides a reusable visual monitoring device for multi-tube zone melting purification equipment. Through a hardware architecture that reuses a single camera for multiple workstations, a shooting scheme with symmetrical arrangement on both sides, and a guide rail movement expansion mechanism, it achieves full-coverage visual monitoring of multiple tubes and multiple workstations with a limited number of cameras. At the same time, it solves the problem that the melting zone cannot be directly captured due to physical obstruction of the heating unit, and ensures the long-term stable operation of the camera in high-temperature industrial environments.

[0012] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0013] A reusable visual monitoring device for a multi-tube horizontal zone melting purification equipment is installed on the equipment, which has multiple quartz tubes and multiple heating units. The quartz tubes are arranged parallel to each other horizontally, and each quartz tube corresponds to at least one heating unit. Each heating unit has a cuboid structure with a through-hole in the center for the quartz tube to pass through. The heating unit can move axially along the quartz tubes. The reusable visual monitoring device includes:

[0014] A symmetrically arranged camera array comprises at least two sets of industrial cameras, symmetrically arranged on both sides of the quartz tube in the zone melting purification equipment. The cameras are mounted at an upward-sloping shooting angle, with their optical axes pointing towards the corresponding heating unit area, to acquire images of the molten zone boundary lines within the heating unit area. This upward-sloping shooting angle ensures that the camera's field of view avoids the main obstruction area of ​​the heating unit housing, clearly capturing the lateral boundary lines of the molten zone within the quartz tube.

[0015] Camera multiplexing structure: The position and field of view of each camera are designed so that a single camera can simultaneously cover the same-side boundary area of ​​at least two adjacent heating units. Specifically, along the axial direction of the quartz tube, the field of view of one camera simultaneously includes one side boundary area of ​​the first heating unit and the same-side boundary area of ​​the second heating unit. The dual cameras work together to acquire boundary line images of both sides of each heating unit, and the complete width of each melting zone is obtained through subsequent geometric fitting calculations.

[0016] The guide rail moving mechanism includes a guide rail arranged along the axial direction of the quartz tube and a slide table mounted on the guide rail. The camera is fixed to the slide table by a bracket, and the slide table can slide along the guide rail, thereby moving the camera along the axial direction of the quartz tube to different shooting positions. For situations where the number of heating units exceeds the static field of view coverage of a single camera, the camera can be dispatched to different workstations by moving the guide rail, achieving time-sharing full coverage of all workstations.

[0017] High-temperature protection structure: Installed in each camera, it includes a heat dissipation module, an air-cooling channel, and a high-transparency glass insulation layer. The heat dissipation module includes a heat-conducting substrate attached to the back of the camera housing, and an array of heat dissipation fins disposed on the heat-conducting substrate, used to quickly dissipate the heat generated by the camera and the ambient heat absorbed during operation. The airflow path of the air-cooling channel passes through the surface of the heat dissipation fin array, enhancing heat dissipation efficiency through forced convection. The high-transparency glass insulation layer is disposed between the high-temperature heating zone and the camera, located in the camera's imaging optical path, used to isolate the upward heat convection from the high-temperature heating zone, while allowing the camera to clearly capture the boundary of the molten zone below through this glass layer. Through the three-layer composite protection of the heat dissipation module, the air-cooling channel, and the high-transparency glass insulation layer, the long-term stable operation of the camera in the high-temperature environment of the zone melting equipment is ensured.

[0018] Mounting bracket: Used to fix the guide rail and camera to the frame of the zone melting purification equipment. The mounting bracket is structurally designed to avoid the original critical components of the equipment and does not change the internal temperature field distribution characteristics of the equipment.

[0019] Furthermore, the camera is an industrial-grade CMOS or CCD camera with a resolution of no less than 12 megapixels and a lens focal length of 12mm. The guide rail is a linear guide rail, and the slide is driven manually or electrically.

[0020] Furthermore, the aforementioned bilateral symmetrical arrangement refers to the following: with a vertical plane passing through the axis of the quartz tube as the plane of symmetry, the cameras on the left and right sides are symmetrically arranged in space, and the shooting angles are symmetrically set. The angle between the optical axis of each camera and the axis of the quartz tube ranges from 30° to 80°.

[0021] Furthermore, the heat dissipation module's thermally conductive substrate is made of a high thermal conductivity metal material and is tightly bonded to the camera housing using thermally conductive grease or adhesive; the heat dissipation fins are arranged along the airflow direction to increase the heat dissipation area. The air-cooling channel has an air inlet and an air outlet, with the air inlet connected to a compressed air source or a cooling fan.

[0022] Furthermore, the high-transparency glass insulating layer is made of tempered glass or quartz glass with high temperature resistance and high light transmittance, and is horizontally positioned above the high-temperature heating zone and below the camera. Its lower surface faces the high-temperature heating zone to isolate heat convection and volatiles, while its upper surface faces the camera to provide an unobstructed shooting light path. The high-transparency glass insulating layer isolates heat convection without altering the temperature field distribution inside and above the heating zone.

[0023] The present invention also provides a method for visually monitoring a multi-tube horizontal zone melting purification equipment using the reusable visual monitoring device described in the present invention, comprising the following steps:

[0024] S1: Shooting is performed using the camera array, wherein the field of view of each camera is configured to simultaneously cover the same-side boundary area of ​​at least two adjacent heating units, with the left camera acquiring the left boundary line image of each heating unit and the right camera acquiring the right boundary line image of each heating unit.

[0025] S2: Control the slide to move the camera along the guide rail to the next shooting position, so that the camera's field of view covers the same side boundary area of ​​the next group of adjacent heating units;

[0026] S3: Repeat steps S1 to S2 until the boundary images of all heating units are acquired;

[0027] S4: Process the images of the left and right boundary lines of each heating unit, and calculate the actual width of each melting zone by fitting.

[0028] During the shooting process, the camera is continuously protected by a high-temperature protection structure: the heat-conducting substrate conducts the heat generated by the camera to the heat dissipation fins, the forced airflow in the air-cooling channel flows over the surface of the heat dissipation fins to carry away the heat, and at the same time, the high-transparency glass insulation layer blocks the upward heat convection of the high-temperature heating area to prevent the hot airflow from directly impacting the camera.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. Achieve full workstation coverage with limited hardware costs. By adopting a reused architecture where a single camera covers the same side boundary of multiple heating units, taking a typical industrial equipment with 4 tubes and 12 workstations as an example, only 4 cameras (symmetrically arranged on both sides) are needed to achieve boundary image acquisition of all workstations. Compared with the solution of configuring a camera independently for each workstation, the hardware cost is significantly reduced.

[0031] 2. The problem of photographing the molten zone obstructed by the heating unit has been solved. Addressing the severe physical obstruction of the molten zone by the rectangular shell of the heating unit, a symmetrical oblique shooting method is adopted. The camera only needs to capture the boundary line of the molten zone, without needing to capture the entire molten zone. By combining the positions of the two boundary lines with the fixed geometric parameters of the heating unit, the width of the complete molten zone can be calculated. This solution fundamentally overcomes the limitation of existing methods for directly photographing transparent crucibles, which cannot be applied to industrial equipment.

[0032] 3. The original temperature field of the equipment is not disrupted. The mounting bracket is specially designed to avoid key components and hot areas of the equipment. The installation of the camera and guide rail does not change the internal temperature distribution characteristics of the equipment and does not affect the normal operation of the purification process.

[0033] 4. Capable of long-term stable operation in high-temperature industrial environments. Through a three-layer composite protective structure consisting of a heat dissipation module, an air-cooling channel, and a high-transparency glass insulation layer, the camera can operate continuously and stably in environments where the heating unit operates at temperatures exceeding 600℃, meeting the full-process monitoring needs of industrial-grade zone melting purification equipment (where a single batch process typically takes several weeks). Simultaneously, the high-transparency glass insulation layer prevents material volatiles from contaminating the camera lens, reducing maintenance frequency.

[0034] 5. Excellent scalability. The guide rail moving mechanism allows the camera position to be adjusted as needed, adapting to equipment configurations with different numbers of workstations and different pipe spacings, exhibiting high versatility and scalability. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall installation of the reusable visual monitoring device provided in an embodiment of the present invention on a 4-tube zone melting and purification equipment.

[0036] Figure 2 for Figure 1 Top view of the device shown.

[0037] Figure 3 This is a schematic diagram illustrating the principle of multiplexing with a single camera.

[0038] Figure 4 This is a schematic diagram illustrating the principle of guide rail movement to extend coverage.

[0039] Figure 5 This is a diagram illustrating the shooting angle from a slightly upward angle.

[0040] Figure 6 This is a schematic cross-sectional view of a three-layer composite high-temperature protection structure.

[0041] Figure 7 This is a schematic diagram of the heat dissipation fins for a camera.

[0042] In the picture:

[0043] 101 - First quartz tube, 102 - Second quartz tube, 103 - Third quartz tube, 104 - Fourth quartz tube;

[0044] 201 - First heating unit, 202 - Second heating unit, 203 - Third first heating unit;

[0045] 301 - First left-side camera, 302 - Second left-side camera, 303 - Third right-side camera, 304 - Fourth right-side camera, 305 - Optical axis;

[0046] 401-Guide rail, 402-Slide table, 403-Bracket, 404-First shooting position, 405-Second shooting position, 406-Second shooting position;

[0047] 501- Thermally conductive substrate, 502- Heat dissipation fins, 503- Air cooling channel, 504- Air inlet, 505- Air outlet, 506- High-transparency glass insulation layer, 507- Support frame;

[0048] 600-Cargo Boat;

[0049] α - Angle between the optical axis and the axial direction of the quartz tube. Detailed Implementation

[0050] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0051] Figure 1 This diagram illustrates the overall installation of a reusable visual monitoring device on a four-tube zone melting purification equipment. The diagram shows the symmetrical arrangement of four quartz tubes 101-104, three heating units 201-203 corresponding to each quartz tube, and four cameras 301-304 on both sides of the equipment. The cameras are mounted on slides 402 via brackets 403, and the slides 402 can slide along guide rails 401. The diagram also shows the positional relationship of the high-temperature protection structure between the cameras and the heating units.

[0052] Figure 2 From a top-down view, four quartz tubes 101, 102, 103, and 104 are arranged horizontally in parallel. Cameras 301 and 302 on the left and 303 and 304 on the right are symmetrically arranged with a plane perpendicular to the axis of the quartz tubes as their plane of symmetry. The angle α between the optical axis 305 of each camera and the axis of the quartz tubes ranges from 30° to 80°.

[0053] Figure 3 Taking the first left-side camera 301 as an example, it is shown that the field of view of a camera simultaneously covers the left boundary region of the first heating unit 201 and the left boundary region of the second heating unit 202 along the axial direction of the quartz tube.

[0054] Figure 4 The diagram illustrates the principle of a camera moving axially along guide rail 401 to different shooting positions. In the diagram, the first shooting position 404 covers the first heating unit 201; the second shooting position 405 covers the second heating unit 202; and the third shooting position 406 covers the third heating unit 203. The slide table 402 moves the camera along guide rail 401, thus switching the shooting positions.

[0055] Figure 5In a cross-section perpendicular to the axis of the quartz tube, the camera is installed on the upper side of the quartz tube, and the optical axis 305 forms an included angle α with the axis of the quartz tube. A through hole for the quartz tube to pass through is provided in the middle of the heating unit housing, a material carrying boat 600 is arranged inside the quartz tube, and a melting zone is located above the material carrying boat 600. When the camera shoots from the obliquely upper side, the field of view passes through the gap between the through hole of the heating unit and the quartz tube, so as to capture the lateral boundary line of the melting zone.

[0056] Figure 6 and Figure 7 show the specific structure of the high-temperature protection structure arranged between the heating unit and the camera, and the arrangement mode of the array of heat dissipation fins 502 on the heat conduction substrate 501. The high-temperature protection structure comprises: a heat conduction substrate 501 attached to the back of the camera housing; an array of heat dissipation fins 502 arranged on the heat conduction substrate 501; an air cooling channel 503 passing over the surfaces of the heat dissipation fins 502, wherein the air cooling channel 503 is provided with an air inlet 504 and an air outlet 505; and a high-transmittance glass isolation layer 506 arranged between the high-temperature heating zone and the camera, wherein the high-transmittance glass isolation layer 506 is fixed on the equipment frame through a support frame 507. The heat dissipation fins 502 are arranged along the direction of the air cooling airflow to increase the heat dissipation area. The direction of the arrow in the figure indicates the airflow path in the air cooling channel 503.

[0057] Embodiment: Reusable visual monitoring device for 4-tube 12-station industrial zone melting purification equipment

[0058] This embodiment takes a typical industrial horizontal zone melting purification equipment with 4 tubes × 3 heating units as an example, and describes in detail the specific implementation of the present invention.

[0059] 1. Overall structure of the equipment

[0060] Referring to Figure 1 , the horizontal zone melting purification equipment in this embodiment is provided with four quartz tubes, which are respectively a first quartz tube 101, a second quartz tube 102, a third quartz tube 103 and a fourth quartz tube 104. The four quartz tubes are arranged in parallel along the horizontal direction in a "field" shape or in a linear arrangement. A material carrying boat 600 (the material carrying boat 600 holds semiconductor materials to be purified, such as tellurium, cesium aluminum bromide, etc.) is placed in each quartz tube. Each quartz tube corresponds to three heating units, which are respectively a first heating unit 201, a second heating unit 202 and a third heating unit 203. The heating unit has a cuboid structure, a through hole for the quartz tube to pass through is formed in the middle, and the heating unit can be driven by a motor to move slowly along the axial direction of the quartz tube at a preset speed (for example, 8mm / h).

[0061] The reusable visual monitoring device of this embodiment includes four industrial cameras, numbered as First Left Camera 301, Second Left Camera 302, First Right Camera 303, and Second Right Camera 304. The First Left Camera 301 and Second Left Camera 302 are arranged on the left side of the quartz tube array, while the First Right Camera 303 and Second Right Camera 304 are symmetrically arranged on the right side. The cameras are mounted on a slide table 402 via brackets 403, and the slide table 402 is mounted on a guide rail 401, allowing the cameras to move along the guide rail 401 in the axial direction of the quartz tube. The guide rail 401 and the cameras are fixed to the frame of the zone melting purification equipment via mounting brackets 403. The mounting brackets 403 structurally avoid obstructing the original critical components of the equipment and do not alter the internal temperature field distribution characteristics of the equipment.

[0062] II. Symmetrical Layout Scheme

[0063] Reference Figure 2 With the vertical plane containing the axis of the quartz tube as the plane of symmetry, cameras 301 and 302 on the left and cameras 303 and 304 on the right are symmetrically arranged in space. Specifically:

[0064] The first left-side camera 301 and the second left-side camera 302 are mounted on the guide rail 401 on the left side of the device, with their optical axes 305 pointing towards the quartz tube area. The first right-side camera 303 and the second right-side camera 304 are symmetrically mounted on the guide rail 401 on the right side of the device, with their optical axes 305 angles mirror-symmetrical to the corresponding cameras on the left.

[0065] Each camera uses an industrial-grade CMOS or CCD sensor with a resolution of at least 12 megapixels and a lens focal length of 12mm. The angle α between the camera's optical axis 305 and the quartz tube's axis ranges from 30° to 80°. The camera's installation height and angle are precisely calculated to ensure its field of view covers the molten area within the quartz tube from an obliquely upward direction (the distance between the camera lens and the upper surface of the heating unit, as well as the α angle, are adjusted according to actual on-site testing needs to meet the field of view coverage requirements). Due to the obstruction of the quartz tube by the heating unit housing, the camera cannot directly capture the complete morphology of the molten area, but it can clearly capture the boundary lines between the molten area and the unmelted material, namely the left and right boundary lines of the molten area.

[0066] III. Single-camera multiplexing principle

[0067] Reference Figure 3The principle of single-camera multiplexing is explained using the first left-side camera 301 as an example. The installation position of the first left-side camera 301 allows its field of view to simultaneously cover the left boundary area of ​​the heating unit along the first quartz tube 101 and the second quartz tube 102, meaning that one camera can simultaneously capture images of the same side boundary of two adjacent heating units.

[0068] The specific implementation method is as follows:

[0069] (1) Based on the center distance D between adjacent heating units and the field of view of the camera, determine the installation position and working distance of the camera so that twice the center distance D between adjacent heating units is less than the effective field of view of the camera, that is, 2D is less than the effective field of view of the camera, so as to ensure that the same side boundary of the two heating units can be within the field of view at the same time.

[0070] (2) The single-frame image captured by the first left camera 301 contains the boundary information of the two heating unit regions of the first heating unit 201 of the first quartz tube 101 and the first heating unit 201 of the second quartz tube 102.

[0071] (3) In subsequent image processing, the boundary sub-images of the first heating unit 201 of the first quartz tube 101 and the boundary sub-images of the first heating unit 201 of the second quartz tube 102 are extracted respectively through the pre-labeled ROI (region of interest). The ROI can be labeled by visually viewing the image after image acquisition and cropping a target box from it, and using the box as the ROI.

[0072] Similarly, the first right-side camera 303 simultaneously covers the right boundary areas of both the first heating unit 201 of the first quartz tube 101 and the first heating unit 201 of the second quartz tube 102. By using one camera on each side, image acquisition of the two heating units (i.e., the four boundary points of the first heating unit 201 of the first quartz tube 101 and the first heating unit 201 of the second quartz tube 102 - two boundaries on each side) can be completed.

[0073] IV. Guide Rail Mobility Extension Coverage Solution

[0074] Reference Figure 4 For the third heating unit 203 on the quartz tube, since it exceeds the static field of view coverage of the first left-side camera 301 and the first right-side camera 303, it needs to be covered by moving the guide rail.

[0075] The specific scheduling plan is as follows:

[0076] 1) At the start of the process, the camera is positioned at the first shooting position 404, which covers the first heating unit 201 in its field of view.

[0077] 2) Triggering the movement of the guide rail: The slide table 402 drives the camera to move along the guide rail 401 to the second shooting position 405, which makes its field of view cover the second heating unit 202.

[0078] 3) This process is repeated to achieve time-sharing full coverage of all heating units throughout the entire process.

[0079] The guide rail 401 is a linear guide rail, and the slide table 402 is driven by a stepper motor-driven lead screw for electric or manual adjustment.

[0080] V. Shooting angle from a slightly above

[0081] Reference Figure 5 The angle of the camera, shooting from a slightly above oblique angle, is one of the key design parameters of this invention. Looking at a cross-section perpendicular to the axis of the quartz tube:

[0082] The camera is installed within 500mm to 700mm above the side of the quartz tube. The optical axis 305 forms an angle α with the quartz tube. The value of α ranges from 30° to 80°. The specific parameters are adjusted according to the actual scene.

[0083] The heating unit housing is located outside the quartz tube, and its side partially obscures the area of ​​the quartz tube. The heating unit housing has a cuboid structure with a through hole in the middle for the quartz tube to pass through.

[0084] The melting zone is located inside the quartz tube, above the material carrier boat 600. The material carrier boat 600 contains the semiconductor material to be purified.

[0085] When the camera shoots from an oblique angle above, its field of view is just able to pass through the gap between the heating unit's through-hole and the quartz tube, capturing the lateral boundary line of the molten zone. Specifically, cameras 301 and 302 on the left capture the left boundary line of the molten zone, while cameras 303 and 304 on the right capture the right boundary line of the molten zone.

[0086] In subsequent processing, the distance between the left boundary line and the left boundary of the heating unit is calculated and recorded as d1, and the distance between the right boundary line and the left boundary of the heating unit is calculated and recorded as d2. Then, combined with the known thickness H of the heating unit, the actual width of the molten zone W = H + d1 + d2 is obtained by fitting through geometric model calculation.

[0087] The principle for choosing a shooting angle from a slightly above is:

[0088] a) When the angle is too small (too horizontal), the heating unit housing is severely obstructed, making it impossible to capture the boundary line.

[0089] b) When the angle is too large (too vertical), the field of view is limited, and the installation space conflicts with the equipment rack.

[0090] In this embodiment, the angle α between the optical axis 305 and the axial direction of the quartz tube is preferably 60°.

[0091] VI. High-Temperature Protection Structure

[0092] Reference Figure 6 The heating unit of the zone melting purification equipment can operate at temperatures exceeding 600℃, with the high-temperature heat waves primarily transferred upwards through convection and radiation. The camera needs to operate in this high-temperature environment for extended periods. This embodiment employs a three-layer composite high-temperature protection structure consisting of a heat dissipation module, an air-cooling channel, and a high-transparency glass insulation layer, specifically including:

[0093] 1. Heat dissipation module: comprising a thermally conductive substrate 501 and an array of heat dissipation fins 502. The thermally conductive substrate 501 is made of a high thermal conductivity metal material (such as copper or aluminum) and has a preset thickness (e.g., 3–10 mm). It is tightly attached to the back of the camera housing (the area of ​​concentrated heat generation) using thermally conductive grease or adhesive. The heat dissipation fins 502 are integrally formed or welded to the thermally conductive substrate 501 and are arranged vertically to maximize the heat dissipation area within a limited space. The heat generated by the camera during operation is conducted through the thermally conductive substrate 501 to the heat dissipation fins 502 and dissipated into the environment through natural convection and forced convection cooling.

[0094] 2. Air-cooled channel 503: Located on the back of the camera, this rectangular channel covers the entire array of heat dissipation fins 502. One end of the air-cooled channel 503 has an air inlet 504 connected to an external compressed air source or cooling fan; the other end has an air outlet 505 leading to the outside of the equipment. Cool air flows at a certain velocity (e.g., 5–15 m / s) across the surface of the heat dissipation fins 502, undergoing forced convection heat exchange with the fins before being discharged through the air outlet 505. The inner wall of the air-cooled channel 503 is equipped with guide vanes to guide the airflow evenly across all the gaps between the heat dissipation fins 502, avoiding localized hot spots.

[0095] 3. High-transparency glass insulating layer 506: Made of high-temperature resistant and high-transparency tempered glass or quartz glass, it is horizontally installed above the high-temperature heating zone and below the camera. The high-transparency glass insulating layer 506 is fixed to the equipment frame by a support frame 507, with its lower surface facing the heating unit and its upper surface facing the camera. The function of this high-transparency glass insulating layer 506 is:

[0096] a) Physical barrier to heat convection: The hot air generated in the heating zone rises and is blocked by the high-transparency glass insulation layer 506, preventing it from directly impacting the camera lens and body.

[0097] b) Maintaining a stable temperature field: The high-transparency glass insulating layer 506 confines the heat flow within the heating zone, preventing external hot and cold air exchange from disturbing the temperature field of the melting zone.

[0098] c) Prevention of lens contamination: Trace amounts of volatile substances generated by the material at high temperatures condense on the lower surface of the high-transparency glass barrier layer 506, rather than on the camera lens. The high-transparency glass barrier layer 506 can be periodically removed for cleaning or replacement, with maintenance costs far lower than replacing the camera lens protective window.

[0099] The high-transparency glass insulating layer 506 isolates heat convection without changing the temperature field distribution inside and above the heating zone.

[0100] Verified in actual industrial environments, the camera, with its three-layer composite protective structure, can operate stably for 500 hours without significant degradation in image quality.

[0101] VII. 4-pipe 12-station full coverage solution

[0102] This embodiment uses four cameras to achieve full coverage of four quartz tubes and three heating units (a total of 12 workstations). The correspondence between the cameras and workstations is as follows:

[0103] First left-side camera 301: Covers the left edge of the first heating unit 201 and the left edge of the second heating unit 202 of the first quartz tube 101, as well as the left edge of the first heating unit 201 and the left edge of the second heating unit 202 of the second quartz tube 102 (the field of view covers two adjacent quartz tubes).

[0104] The second left-side camera 302 covers the left edge of the first heating unit 201 and the left edge of the second heating unit 202 of the third quartz tube 103, as well as the left edge of the first heating unit 201 and the left edge of the second heating unit 202 of the fourth quartz tube 104.

[0105] First right-side camera 303: covers the right boundary of the first heating unit 201 and the right boundary of the second heating unit 202 of the first quartz tube 101, and the right boundary of the first heating unit 201 and the right boundary of the second heating unit 202 of the second quartz tube 102.

[0106] Second right-side camera 304: covers the right boundary of the first heating unit 201 and the right boundary of the second heating unit 202 of the third quartz tube 103, and the right boundary of the first heating unit 201 and the right boundary of the second heating unit 202 of the fourth quartz tube 104.

[0107] The third heating unit 203 of each quartz tube achieves time-sharing coverage by moving along the guide rail. This configuration scheme achieves boundary image acquisition of all 12 workstations with a minimum of 4 cameras, giving full play to the low-cost advantage of the "reusable" architecture.

[0108] VIII. Other Embodiments

[0109] The above embodiments are illustrated using a 4-tube, 12-station equipment as an example, but the scope of protection of this invention is not limited thereto. For equipment with different configurations:

[0110] a) If the equipment contains only 1 or 2 quartz tubes, 2 cameras (1 on the left and 1 on the right) can be used to achieve full coverage.

[0111] b) If the equipment contains 6 quartz tubes, 6 cameras (3 on each side) can be used to achieve full coverage.

[0112] c) If the number of heating units in a single quartz tube exceeds 3, full coverage can be achieved by increasing the travel and adjustment position of guide rail 401.

[0113] The core architecture of "single camera multiple station reuse" and the technical concept of "double-sided symmetrical oblique shooting + guide rail movement expansion" adopted in this invention can be flexibly adjusted according to the actual configuration of the equipment, and both are within the protection scope of this invention.

[0114] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A reusable visual monitoring device for a multi-tube horizontal zone melting purification equipment, wherein the horizontal zone melting purification equipment has multiple quartz tubes and multiple heating units, the quartz tubes are arranged parallel to each other in the horizontal direction, each quartz tube corresponds to at least one heating unit, the heating unit is a cuboid structure with a through hole in the middle for the quartz tube to pass through, and the heating unit can move along the axial direction of the quartz tube, characterized in that... The device includes: A symmetrically arranged camera array includes at least two industrial cameras, which are symmetrically arranged on both sides of the quartz tube of the zone melting purification equipment. The cameras are installed at an oblique upward shooting angle, with their optical axes pointing to the corresponding heating unit area, in order to acquire images of the boundary lines of the melting zone within the heating unit area. Camera multiplexing structure: The position and field of view of each camera are set so that a single camera can simultaneously cover the same side boundary area of ​​at least two adjacent heating units; The guide rail moving mechanism includes a guide rail (401) arranged along the axial direction of the quartz tube, and a slide (402) mounted on the guide rail (401); the camera is fixed on the slide (402) by a bracket (403), and the slide (402) can slide along the guide rail (401), thereby driving the camera to move along the axial direction of the quartz tube to different shooting positions; High-temperature protection structure: Installed in each camera to protect the camera from normal operation in high-temperature environments; Mounting bracket (403): used to fix the guide rail (401) and the camera to the frame of the zone melting purification equipment.

2. The reusable visual monitoring device according to claim 1, characterized in that, The high-temperature protection structure includes a heat dissipation module, an air-cooling channel (503), and a high-transparency glass insulation layer (506); the heat dissipation module includes a heat-conducting substrate (501) attached to the back of the camera housing and an array of heat dissipation fins (502) disposed on the heat-conducting substrate (501); the airflow path of the air-cooling channel (503) passes through the surface of the heat dissipation fin array (502); the high-transparency glass insulation layer (506) is disposed between the high-temperature heating zone and the camera, located in the camera's shooting optical path.

3. The reusable visual monitoring device according to claim 1, characterized in that, The bilateral symmetrical arrangement refers to the following: with the vertical plane passing through the axis of the quartz tube as the plane of symmetry, the cameras on the left and right sides are symmetrically arranged in space, and the shooting angles are symmetrically set; the angle α between the optical axis of each camera and the axis of the quartz tube is in the range of 30° to 80°.

4. The reusable visual monitoring device according to claim 1, characterized in that, The upward-sloping shooting angle allows the camera's field of view to avoid the main obstruction area of ​​the heating unit housing, clearly capturing the lateral boundary line of the molten zone inside the quartz tube; the dual cameras work together to acquire boundary line images on both sides of each heating unit, and the complete width of each molten zone is calculated through geometric fitting.

5. The reusable visual monitoring device according to claim 1, characterized in that, The camera is an industrial-grade CMOS or CCD camera with a resolution of no less than 12 million pixels and a lens focal length of 12mm; the guide rail (401) is a linear guide rail and the slide (402) is driven manually or electrically.

6. The reusable visual monitoring device according to claim 2, characterized in that, The heat dissipation module's heat-conducting substrate (501) is made of a high thermal conductivity metal material and is tightly attached to the camera housing by thermal grease or thermal adhesive; the heat dissipation fins (502) are arranged along the air cooling airflow direction; the air cooling channel (503) is provided with an air inlet (504) and an air outlet (505), and the air inlet (504) is connected to a compressed air source or a cooling fan.

7. The reusable visual monitoring device according to claim 2, characterized in that, The high-transparency glass insulation layer (506) is made of tempered glass or quartz glass with high temperature resistance and high light transmittance, and is horizontally set above the high-temperature heating zone and below the camera. Its lower surface faces the high-temperature heating zone to isolate heat convection and volatiles, while its upper surface faces the camera to provide an unobstructed light path for shooting.

8. The reusable visual monitoring device according to claim 1, characterized in that, The mounting bracket (403) avoids the original key components of the equipment in terms of structure and does not change the distribution characteristics of the internal temperature field of the equipment.

9. The reusable visual monitoring device according to any one of claims 1 to 8, characterized in that, For situations where the number of heating units exceeds the static field of view coverage of a single camera, the camera can be moved to different workstations via guide rail (401) to achieve time-sharing full coverage of all workstations.

10. A visual monitoring method using a reusable visual monitoring device for a multi-tube horizontal zone melting purification equipment according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Shooting is performed using the camera array, wherein the field of view of each camera is configured to simultaneously cover the same-side boundary area of ​​at least two adjacent heating units, with the left camera acquiring the left boundary line image of each heating unit and the right camera acquiring the right boundary line image of each heating unit. S2: Control the slide (402) to move the camera along the guide rail (401) to the next shooting position, so that the camera's field of view covers the same side boundary area of ​​the next group of adjacent heating units; S3: Repeat steps S1 to S2 until the boundary images of all heating units are acquired; S4: Process the images of the left and right boundary lines of each heating unit, and calculate the actual width of each melting zone by fitting.

Images