A real-time monitoring device for a crystal growth process

Abstract

This invention discloses a real-time monitoring device for crystal growth. The device includes a crystal growth furnace, heating equipment and thermocouples located inside the furnace, a crucible rotation and lifting device, a collimated white light source, a camera, and an image recognition device housed in an electrical control cabinet. The crucible rotation and lifting device holds the crystal growth crucible. Two light-transmitting windows, A and B, matching the crystal growth height, are opened on the side wall of the crystal growth furnace. The collimated white light source, light-transmitting windows A and B, and the camera are arranged in parallel. The camera is communicatively connected to the image recognition device. This invention uses a collimated white light source to illuminate the crystal growth location and uses the camera to capture images in real time, obtaining clear images of the growth interface and the intensity ratios of the three primary colors of the crystal image. The image recognition device then identifies and analyzes the images to provide real-time information about the growth process.

Description

Technical Field

[0001] This utility model belongs to the field of crystal growth technology, and in particular relates to a real-time monitoring device for crystal growth process. Background Technology

[0002] The crucible lowering method is an important method for preparing large-size single crystals. Scintillation crystals such as cesium iodide (CsI), sodium iodide (NaI), and lanthanum bromide (LaBr3) are all prepared using this method. However, during crystal growth using the crucible lowering method, the interface shape inside the crucible cannot be observed due to the shielding effect of the insulation layer and heating element. Therefore, it is impossible to adjust the growth conditions in real time according to the evolution of the crystallization interface. Currently, it is only possible to know whether a single crystal has been grown after the crystal growth is completed and the crystal is cooled and removed. Real-time monitoring of the growth process is not possible, which affects the cost and efficiency of crystal growth.

[0003] To address these issues, some attempts have been made in existing technologies, such as using ultrasonic testing to monitor the crystal growth process. Ultrasonic waves can infer the location of the crystallization interface by measuring changes in the propagation speed of sound waves in the melt and crystal. However, the application of ultrasonic testing in crystal growth also faces several challenges. On the one hand, the propagation characteristics of ultrasound vary greatly in different media and are easily interfered with by impurities and bubbles in the melt, leading to signal attenuation and distortion, affecting detection accuracy. On the other hand, ultrasonic testing requires installing sensors on the crucible wall, which can compromise the structural integrity of the crucible, increasing the risk of leakage. Furthermore, the high-temperature resistance and long-term stability of the sensors are difficult to meet the requirements of the crystal growth process.

[0004] Although existing technologies have attempted to overcome the inability to monitor the crucible-lowering crystal growth process in real time through various methods, many shortcomings still remain. Therefore, there is an urgent need for a new technology or device that can effectively overcome these shortcomings and achieve high-precision, stable, and real-time monitoring of the crucible-lowering crystal growth process, in order to improve the success rate and efficiency of crystal growth and reduce production costs. Utility Model Content

[0005] Based on the above analysis, this utility model aims to provide a real-time monitoring device for crystal growth process, which solves the problem of the inability to monitor the growth process in real time, affecting the cost and efficiency of crystal growth.

[0006] The objective of this utility model is mainly achieved through the following technical solutions: This invention provides a real-time monitoring device for crystal growth process, including: a crystal growth furnace 1, a heating device 2 and a thermocouple 3 located inside the crystal growth furnace 1, a crucible rotation and lifting device 4, a collimated white light source 5, a camera 6, and an image recognition device 7 installed in an electrical control cabinet. The crucible rotation and lifting device 4 is equipped with a crystal growth crucible. A light-transmitting window A and a light-transmitting window B, which match the crystal growth height, are opened on the side wall of the crystal growth furnace 1. The light-transmitting windows A and B are symmetrically arranged in the direction perpendicular to the crystal growth height. A collimated white light source 5 is arranged outside the crystal growth furnace 1 corresponding to the light-transmitting window A. A camera 6 is arranged outside the crystal growth furnace 1 corresponding to the light-transmitting window B. The collimated white light source 5, the light-transmitting window A, the light-transmitting window B, and the camera 6 are arranged in parallel. The camera 6 is communicatively connected to the image recognition device 7.

[0007] Furthermore, the camera 6 is a high-resolution digital camera, and the camera 6 is connected to the image recognition device 7 via a wired communication interface.

[0008] Furthermore, the widths of the light-transmitting window A and the light-transmitting window B are each independently not less than the width of the crystal growth crucible.

[0009] Furthermore, the heights of the light-transmitting windows A and B are not less than the height of the crystal growth in the crystal growth crucible.

[0010] Furthermore, the collimated white light source 5 includes an LED light source with adjustable light intensity.

[0011] Furthermore, the device also includes a temperature signal receiver.

[0012] Furthermore, the device also includes an alarm device, which is communicatively connected to an image recognition device and / or a temperature signal receiver.

[0013] Furthermore, the light-transmitting window A and the light-transmitting window B are each independently made of at least two layers of hollow quartz glass or sapphire, and the thickness of the light-transmitting window A and the light-transmitting window B is each independently 2-5mm.

[0014] Furthermore, the heating device 2 is a resistance heating element, which is spirally distributed on the inner wall of the crystal growth furnace 1.

[0015] Furthermore, there are multiple thermocouples 3, located on the side wall of the crystal growth furnace 1 and at the bottom of the crystal growth crucible.

[0016] Furthermore, the crucible rotation and lifting device 4 includes a motor and a lifting mechanism with adjustable rotation speed and lifting speed.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: (1) This utility model uses collimated white light source to illuminate the crystal growth position and uses a camera to collect images in real time to obtain clear growth interface images and the intensity ratio of the three primary color signals of the crystal image. The images are then identified and analyzed by an image recognition device to understand the growth process information in real time.

[0018] (2) This utility model sets the number of thermocouples to multiple, located on the side wall of the crystal growth furnace and the bottom of the crystal growth crucible, respectively. This enables multi-point temperature monitoring and correction, accurately reflects the actual temperature of the crystallization interface, and avoids the problem of low monitoring accuracy caused by interference from factors such as ambient temperature fluctuations at a single location.

[0019] (3) This utility model can promptly detect problems in the crystal growth process, such as abnormal interface shape and uneven crystal growth rate, based on the images collected in real time by the camera and the analysis results of the image recognition device. When a problem occurs, the system can also immediately issue an alarm and then regulate the crystal growth process to improve the yield of crystals.

[0020] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1 This is a schematic diagram of the device of this utility model.

[0023] Figure label: 1. Crystal growth furnace; 2. Heating equipment; 3. Thermocouple; 4. Crucible rotation and lifting equipment; 5. Collimated white light source; 6. Camera; 7. Image recognition device. Detailed Implementation

[0024] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0025] This utility model provides a real-time monitoring device for crystal growth, including: a crystal growth furnace 1, a heating device 2 and a thermocouple 3 located inside the crystal growth furnace 1, a crucible rotation and lifting device 4, a collimated white light source 5, a camera 6, and an image recognition device 7 installed in an electrical control cabinet. The crucible rotation and lifting device 4 is equipped with a crystal growth crucible. A light-transmitting window A and a light-transmitting window B, which match the crystal growth height, are opened on the side wall of the crystal growth furnace 1. The light-transmitting windows A and B are symmetrically arranged in the direction perpendicular to the crystal growth height. A collimated white light source 5 is arranged outside the crystal growth furnace 1 corresponding to the light-transmitting window A. A camera 6 is arranged outside the crystal growth furnace 1 corresponding to the light-transmitting window B. The collimated white light source 5, the light-transmitting window A, the light-transmitting window B, and the camera 6 are arranged in parallel. The camera 6 is communicatively connected to the image recognition device 7.

[0026] By illuminating the crystal growth site with collimated white light and using a camera to acquire clear images of the crystal growth interface and the intensity ratios of the three primary colors in the crystal image in real time, an image recognition device is used to identify, analyze, and control the image and the intensity ratios of the three primary colors. If a problem is detected during the growth process (such as an increase or decrease in the intensity ratio of the three primary colors), the device can immediately issue an alarm and promptly notify the operator to adjust the growth parameters, thereby achieving precise control of the crystal growth process and improving the crystal yield.

[0027] In this invention, it is understood that the camera 6 is equipped with a beam splitter to decompose the incident light of the acquired image into the three primary colors of red, green and blue and project them onto three independent sensors, which are located in the camera 6.

[0028] In this invention, the light-transmitting window is located on the side wall of the crystal growth furnace 1, and the collimated white light source 5, light-transmitting window A, light-transmitting window B, and camera 6 are arranged in parallel, rather than the light-transmitting window being directly located on the top of the crystal growth furnace 1. The camera directly captures the image of the crystal growth interface through the top window. This is because the collimated white light emitted by the collimated white light source 5 penetrates the entire crystal, thereby collecting and analyzing the image of the crystal and the intensity ratio of the three primary color signals of the image color. This improves the timely control of defects that occur during the crystal growth process, and increases the accuracy of monitoring and the yield of crystals.

[0029] According to this invention, the camera 6 is a high-resolution digital camera, and the camera 6 is connected to the image recognition device 7 via a wired communication interface. The communication interface is either an HDMI interface or a USB interface to ensure high-speed transmission of image data and improve monitoring accuracy.

[0030] According to this invention, considering the ability to accurately acquire the entire image of the crystal growth process, the widths of the light-transmitting window A and the light-transmitting window B are each independently not less than the width of the crystal growth crucible. Furthermore, the heights of the light-transmitting windows A and B are not less than the height of the crystal growth within the crystal growth crucible, which further improves the accuracy of the detection process.

[0031] According to this utility model, the collimated white light source 5 includes an adjustable light intensity LED light source, which is electrically connected to the image recognition device 7, and the light intensity is adjusted through feedback from the image recognition device 7 to optimize image quality.

[0032] According to this utility model, considering the identification of the temperature of thermocouple 3 and the ability to adjust growth parameters in a timely manner, the device further includes a temperature signal receiver, which is electrically connected to thermocouple 3.

[0033] According to this invention, the device further includes an alarm device, which is communicatively connected to the image recognition device 7 and / or the temperature signal receiver. When an abnormality occurs in the temperature or image recognition result during the crystal growth process, the alarm device issues an alarm signal to remind the operator to handle the situation promptly.

[0034] According to this utility model, the light-transmitting window A and the light-transmitting window B are each independently made of at least two layers of hollow quartz glass or sapphire, and the thickness of the light-transmitting window A and the light-transmitting window B is 2-5mm, so as to ensure that they have both high light transmittance and good high temperature resistance, and avoid poor image quality and inaccurate image information due to poor light transmittance or insufficient heat insulation.

[0035] According to this utility model, in order to provide a uniform heating effect for the crystal growth process, the heating device 2 is a resistance heating element, and the resistance heating element is distributed in a spiral shape on the inner wall of the crystal growth furnace 1.

[0036] According to this invention, the thermocouples 3 are multiple, located on the side wall of the crystal growth furnace 1 and at the bottom of the crystal growth crucible. This enables multi-point temperature monitoring, accurately reflecting the actual temperature of the crystallization interface and avoiding the problem of low monitoring accuracy caused by interference from factors such as ambient temperature fluctuations at a single location.

[0037] According to this utility model, the crucible rotation and lifting device 4 includes a motor and a lifting mechanism with adjustable rotation speed and lifting speed, which are used to adjust the rotation speed and lifting position of the crucible according to real-time image feedback during the crystal growth process. Furthermore, the operator can adjust the rotation speed and lifting speed of the crucible rotation and lifting device 4 in real time by observing information from the image recognition device 7, thereby ensuring the normal operation of crystal growth.

[0038] In this invention, the distance between the camera 6 and the light-transmitting window B is at least 2cm, which isolates the camera from the high-temperature environment inside the furnace. The camera is installed in a relatively stable temperature zone, which greatly reduces the risk of equipment damage and improves the stability and reliability of the system.

[0039] The device will be described in detail below through embodiments.

[0040] Example 1 like Figure 1 As shown, the device includes a crystal growth furnace 1, a heating device 2 spirally distributed on the inner wall of the crystal growth furnace 1, thermocouples 3 located on the side wall of the crystal growth furnace 1 and the bottom of the crystal growth crucible, a crucible rotation and lifting device 4, a collimated white light source 5, a camera 6, and an image recognition device 7 and a temperature signal receiver installed in the electrical control cabinet. The thermocouples 3 and the temperature signal receiver are electrically connected. The crucible rotation and lifting device 4 is equipped with a crystal growth crucible. A light-transmitting window A and a light-transmitting window B, matching the crystal growth height, are opened on the side wall of the crystal growth furnace 1. The light-transmitting windows A and B are symmetrically arranged in a direction perpendicular to the crystal growth height. A collimated white light source 5 is installed outside the crystal growth furnace 1 corresponding to the light-transmitting window A. The collimated white light source 5 includes an LED light source with adjustable light intensity. A camera 6 is installed outside the crystal growth furnace 1 corresponding to the light-transmitting window B. The collimated white light source 5, light-transmitting window A, light-transmitting window B, and camera 6 are arranged in parallel. The distance between the collimated white light source 5 and light-transmitting window A is 2 cm, and the distance between light-transmitting window B and camera 6 is 2 cm. The camera 6 communicates with the image recognition device 7 via an HDMI interface.

[0041] During operation, in order to facilitate the observation of crystal growth, the crystal growth crucible is arranged in parallel with the light-transmitting windows A and B on the side wall of the crystal growth furnace 1, the collimated white light source 5 outside the crystal growth furnace 1, and the camera 6. The collimated white light source 5 emits collimated white light, which passes through the light-transmitting window A, the material in the crystal growth crucible, and the light-transmitting window B in one pass. The camera 6 uses a beam splitter to decompose the incident light of the image into the three primary colors of red, green, and blue, and projects them onto three independent sensors. The sensors are set in the camera 6. The image recognition device 7 is communicatively connected to the camera 6. It receives the intensity ratio values ​​of the three primary colors of the incident light from the camera 6 and performs real-time analysis. The image recognition device 7 analyzes the acquired image and the intensity ratio of the three primary colors in real time. If the intensity ratio of the acquired three primary colors matches the intensity ratio of the three primary colors in the pre-calibrated target crystal melting state, it responds to the operator to start the growth program. If the intensity ratio of the acquired three primary colors matches the intensity ratio of the three primary colors in the pre-calibrated target crystal state, it responds to the operator to end the growth program and perform in-situ annealing. If the crystal growth temperature exceeds the set range, the temperature signal receiver receives the temperature signal from the thermocouple and alarms, promptly notifying the operator to adjust the temperature of the crystal growth process by operating the electrical control cabinet to ensure normal crystal growth.

[0042] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A real-time monitoring device for crystal growth process, characterized in that, include: Crystal growth furnace (1), heating equipment (2) and thermocouple (3) located inside the crystal growth furnace (1), crucible rotation and lifting equipment (4), collimated white light source (5), camera (6), and image recognition device (7) installed in the electrical control cabinet. The crucible rotation and lifting device (4) is equipped with a crystal growth crucible. A light-transmitting window A and a light-transmitting window B, which are matched with the crystal growth height, are opened on the side wall of the crystal growth furnace (1). The light-transmitting window A and the light-transmitting window B are symmetrically arranged in the direction perpendicular to the crystal growth height. A collimated white light source (5) is arranged outside the crystal growth furnace (1) corresponding to the light-transmitting window A. A camera (6) is arranged outside the crystal growth furnace (1) corresponding to the light-transmitting window B. The collimated white light source (5), the light-transmitting window A, the light-transmitting window B, and the camera (6) are arranged in parallel. The camera (6) is communicatively connected to the image recognition device (7).

2. The apparatus according to claim 1, characterized in that, The camera (6) is a high-resolution digital camera, and the camera (6) is connected to the image recognition device (7) via a wired communication interface.

3. The apparatus according to claim 1, characterized in that, The widths of the light-transmitting window A and the light-transmitting window B are each independently not less than the width of the crystal growth crucible; And / or, the height of the light-transmitting window A and the light-transmitting window B is not less than the height of the crystal growth in the crystal growth crucible.

4. The apparatus according to claim 1, characterized in that, The collimated white light source (5) includes an LED light source with adjustable light intensity.

5. The apparatus according to claim 1, characterized in that, The device also includes a temperature signal receiver.

6. The apparatus according to claim 1, characterized in that, The device also includes an alarm device, which is communicatively connected to an image recognition device and / or a temperature signal receiver.

7. The apparatus according to claim 1, characterized in that, The light-transmitting window A and the light-transmitting window B are each made of at least two layers of hollow quartz glass or sapphire, and the thickness of the light-transmitting window A and the light-transmitting window B is 2-5mm.

8. The apparatus according to any one of claims 1-7, characterized in that, The heating device (2) is a resistance heating element, which is spirally distributed on the inner wall of the crystal growth furnace (1).

9. The apparatus according to claim 8, characterized in that, The thermocouples (3) are multiple and are located on the side wall of the crystal growth furnace (1) and the bottom of the crystal growth crucible, respectively.

10. The apparatus according to any one of claims 1-7, characterized in that, The crucible rotation and lifting device (4) includes a motor and a lifting mechanism with adjustable rotation speed and lifting speed.

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