WO2024141131A1 - Automatic silicon rod defect detection system, and detection method - Google Patents

Abstract

An automatic silicon rod defect detection system, and a detection method. The automatic silicon rod defect detection system comprises a silicon rod rotation module (1), an outline dimension measurement module (2), an internal defect detection module (3), a measurement mechanism motion module (4), a rack module (6) and a control module (5), wherein the silicon rod rotation module (1) is used for rotating a silicon rod (12); the outline dimension measurement module (2) is used for identifying the diameter, length and crystal line positions of the silicon rod (12); the internal defect detection module (3) is used for identifying internal defects such as hidden cracks, dislocation and twin crystals of the silicon rod (12); the measurement mechanism motion module (4) can make the outline dimension measurement module (2) and the internal defect detection module (3) move continuously and synchronously along an X axis, a Y axis and a Z axis.

Description

A silicon rod defect automatic detection system and detection method

Related Applications

This application claims priority to the Chinese patent application filed on December 28, 2022, with application number 202211692706.X and entitled “A Silicon Rod Defect Automatic Detection System and Detection Method”, the entire text of which is hereby incorporated by reference.

Technical Field

The present application relates to the technical field of optics and visual image analysis, and in particular to an automatic silicon rod defect detection system and detection method.

Background technique

At present, after the silicon rod is pulled from the crystal growth furnace, it is sent to the cooling area for cooling. The appearance defects of the silicon rod and the breakage of the crystal line are manually inspected and marked as the basis for the subsequent operation of the cutting machine. The internal defects of the silicon rod are not detected until they are processed into silicon wafers. Therefore, these processes will have the following problems: the initial inspection of the silicon rod adopts manual measurement and calibration, and the truncation length is determined according to experience. There is a situation where the truncation size is too long, resulting in waste of resources. In addition, manual measurement is carried out by naked eyes and tape measure, and the marking accuracy is low. The detailed inspection of silicon rods and silicon wafers is carried out only after the materials have undergone multiple production processes. In particular, internal defects such as hidden cracks and dislocations can only be detected when the silicon wafers are completed and about to be packaged. The unqualified products during this period cause a large waste of production resources. The above two problems seriously affect the production capacity and efficiency of silicon rods and silicon wafers. As the prices of upstream raw materials continue to rise, cost reduction and efficiency improvement in silicon wafer production is imminent. Therefore, a silicon rod detection system and detection method are proposed to achieve accurate detection of the external dimensions, crystal line integrity, and internal defects of silicon rods, which can save production and processing resources and improve production capacity and efficiency, and is of great value.

Summary of the invention

According to various embodiments of the present application, on the one hand, the present application proposes an automatic silicon rod defect detection system, comprising:

A silicon rod rotating module, the silicon rod rotating module comprising a rotating motor, a driving roller, a driven roller and a rotating base, the rotating motor provides a rotating power for the driving roller, the driving roller and the driven roller are rotatably arranged on the rotating base and axially distributed on both sides of the silicon rod to rotate and support the silicon rod;

A detection mechanism motion module, the detection mechanism motion module comprising an X-axis linear motion unit, a Y-axis linear motion unit, a Z-axis linear motion unit and a detection device holder, the detection device holder is used to install a variety of detection devices, the X-axis linear motion unit, the Y-axis linear motion unit and the Z-axis linear motion unit cooperate to achieve continuous synchronous motion of the detection device in three directions of X-axis, Y-axis and Z-axis;

An external dimension detection module, wherein the external dimension detection module comprises a first laser contour sensor and a second laser contour sensor, wherein the first laser contour sensor and the second laser contour sensor are symmetrically arranged on both sides of the silicon rod through the detection device holder;

An internal defect detection module, the internal defect detection module comprising a linear array camera and an infrared light source, the linear array camera The infrared light source is symmetrically arranged on both sides of the silicon rod through the detection device holder;

A control module, the control module comprising a detection mechanism motion controller, a light source controller, a shape dimension detection visual controller, an internal defect detection visual controller and a silicon rod rotation controller;

The rack module is a frame-type mechanism used to support the detection mechanism motion module, the external dimension detection module, the internal defect detection module and the silicon rod rotation module.

In some embodiments, a reducer is also provided on the rotating base, the rotating motor is connected to the reducer via a coupling, and the reducer is connected to the active roller via a synchronous belt.

In some embodiments, a roller support is fixedly disposed on the rotating base, and the active roller and the driven roller are rotatably disposed on the rotating base through the roller support.

In some embodiments, the X-axis linear motion unit includes a first X-axis linear motion unit and a second X-axis linear motion unit, the Y-axis linear motion unit includes a first Y-axis linear motion unit and a second Y-axis linear motion unit, and the Z-axis linear motion unit includes a first Z-axis linear motion unit and a second Z-axis linear motion unit. The base of the first Y-axis linear motion unit is fixedly mounted on the slider of the first X-axis linear motion unit, the base of the first Z-axis linear motion unit is fixedly mounted on the slider of the first Y-axis linear motion unit, the base of the second Y-axis linear motion unit is fixedly mounted on the slider of the second X-axis linear motion unit, and the base of the second Z-axis linear motion unit is fixedly mounted on the slider of the second Y-axis linear motion unit.

In some embodiments, the detection device holder includes a first detection device holder and a second detection device holder, and the first detection device holder and the second detection device holder are respectively fixed on the sliders of the first Z-axis linear motion unit and the second Z-axis linear motion unit, and a group of opposing-type photoelectric sensors are arranged on the first detection device holder and the second detection device holder.

In some embodiments, the first laser profile sensor is disposed on the first detection device holder, the second laser profile sensor is disposed on the second detection device holder, and the first laser profile sensor and the second laser profile sensor are symmetrically disposed.

In some embodiments, the infrared light source is disposed on a holder of the first detection device, the line array camera is disposed on a holder of the second detection device, and the infrared light source and the line array camera are symmetrically disposed.

In some embodiments, the X-axis linear motion unit, the Y-axis linear motion unit, the Z-axis linear motion unit and the through-beam photoelectric sensor are all electrically connected to the detection mechanism motion controller, the infrared light source is electrically connected to the light source controller, the linear array camera is electrically connected to the internal defect detection vision controller, the first laser contour sensor and the second laser contour sensor are both electrically connected to the external dimension detection vision controller, and the rotating motor is electrically connected to the silicon rod rotation controller.

In some embodiments, the control module further includes an image acquisition card, through which the linear array camera The card uploads the image to the control module.

On the other hand, the present application proposes a method for automatically detecting silicon rod defects, comprising the following steps:

(1) The detection mechanism motion controller drives the detection device holders on both sides to move along the X-axis to the initial detection position, and the detection device holders move from top to bottom along the Z-axis. The first laser profile sensor and the second laser profile sensor measure the diameter data of the silicon rod for the first time according to the boundary mutation of the silicon rod along the Z-axis direction, and obtain the diameter of the silicon rod as D;

(2) The encoder on the motor of the Z-axis linear motion unit senses that the holder moves along the Z-axis to 1/2 of the silicon rod diameter and stops. The silicon rod rotation controller drives the rotation motor of the silicon rod rotation module to rotate slowly. At the same time, the laser profile sensors on both sides of the shape and size detection module identify the positions of the four crystal lines of the silicon rod.

(3) When two crystal lines are perpendicular to the transmitting and receiving optical paths of the two laser profile sensors, the first laser profile sensor and the second laser profile sensor identify the two crystal lines of the silicon rod, and the silicon rod rotating module stops moving;

(4) The detection mechanism motion controller controls the detection mechanism motion module to move from the starting position along the X-axis, driving the laser profile sensor to scan the two crystal line profiles of the silicon rod and generate point cloud data. The internal defect detection module moves synchronously with the external dimension detection module through the detection device holder. The linear array camera receives the image after the light source transmits the silicon rod and uploads it to the control module through the image acquisition card. The through-beam photoelectric sensor senses the X-axis position of the detection mechanism motion module relative to the silicon rod in real time. When it senses that the detection mechanism motion module moves to the end boundary of the silicon rod, the detection mechanism motion controller controls the X-axis linear motion unit to stop moving and completes the measurement of the silicon rod length to obtain the silicon rod length L.

(5) A three-dimensional model of the two crystal lines of the silicon rod is constructed through point cloud data, and the images collected by the internal defect detection module are output, and the first silicon rod detection process is completed;

(6) Using the silicon rod rotating module, rotate the silicon rod 90° and then stop, repeat steps (4) and (5) to complete the second silicon rod inspection process, and summarize the inspection data.

The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better describe and illustrate the embodiments and/or examples of the inventions disclosed herein, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed inventions, the embodiments and/or examples currently described, and any of the best modes of these inventions currently understood.

FIG. 1 is a schematic diagram of the structure of the automatic silicon rod defect detection system.

FIG. 2 is a schematic structural diagram of a silicon rod rotating module.

FIG. 3 is a schematic structural diagram of a motion module of a detection mechanism.

FIG. 4 is a top view of the silicon rod defect automatic detection system.

FIG. 5 is a schematic diagram of a method for detecting external dimensions.

FIG. 6 is a schematic diagram of an internal defect detection method.

FIG. 7 is a schematic diagram of the structure of a control module in an embodiment.

FIG8 is a schematic diagram of the structure of the automatic silicon rod defect detection system applied to the wire body.

FIG. 9 is a diagram showing an example of the basic characteristics of infrared transmission imaging of silicon rods.

FIG10 is a diagram showing an example of basic feature extraction of silicon rod infrared transmission imaging.

FIG. 11 is a diagram showing an example of a hidden crack defect inside a silicon rod.

FIG. 12 is a diagram showing an example of a dislocation defect inside a silicon rod.

FIG. 13 is a schematic diagram of the process of the automatic silicon rod defect detection method in one embodiment of the present application.

Description of reference numerals:
1. Silicon rod rotation module; 2. Dimension detection module; 3. Internal defect detection module; 4. Detection mechanism motion module; 5. Control module; 51. Detection mechanism motion controller; 52. Light source controller; 53. Dimension detection visual controller; 54. Internal defect detection visual controller; 55. Silicon rod rotation controller; 56. Image acquisition card; 6. Rack module; 7. Rotating motor; 8. Speed reducer; 9. Active roller; 10. Driven roller; 11. Rotating base; 12. Silicon rod; 13. First laser profile sensor; 14. Second laser profile sensor; 15. Linear array camera; 16. Infrared light source; 101. X-axis linear motion unit; 17. First X-axis linear motion unit; 18. Second X-axis linear motion unit; 102. Y-axis linear motion unit; 19. First Y-axis linear motion unit; 20. Second Y-axis linear motion unit; 103. Z-axis linear motion unit; 21. First Z-axis linear motion unit; 22. Second Z-axis linear motion unit; 104. Detection device holder; 23. First detection device holder; 24. Second detection device holder; 25. Roller support; 26. Through-beam photoelectric sensor.

Detailed ways

The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

The following describes a silicon rod defect automatic detection system and detection method proposed according to an embodiment of the present application with reference to the accompanying drawings.

As shown in FIGS. 1 to 4 , the silicon rod defect automatic detection system of the present application includes a silicon rod rotation module 1 , a detection mechanism motion module 4 , an external dimension detection module 2 , an internal defect detection module 3 , a control module 5 and a rack module 6 .

The silicon rod rotating module 1 includes a rotating motor 7, a driving roller 9, a driven roller 10, a reducer 8 and a rotating base 11. The rotating motor 7 provides a rotating power for the driving roller 9. The driving roller 9 and the driven roller 10 are rotatably arranged on the rotating base 11 and are axially distributed on both sides of the silicon rod 12 to rotate and support the silicon rod 12. The rotating motor 7 is connected to the reducer 8 through a coupling, and the reducer 8 is connected to the driving roller 9 through a synchronous belt. A roller support 25 is fixedly arranged on the rotating base 11, and the driving roller 9 and the driven roller 10 are rotatably arranged on the rotating base 11 through the roller support 25.

Specifically, the silicon rod rotating module 1 is used to rotate the silicon rod 12 to be detected, and the auxiliary shape dimension detection module 2 and the internal defect detection module 3 determine the positions of the four crystal lines of the silicon rod. The silicon rod rotating module 1 includes a rotating motor 7, an active roller 9, a driven roller 10, a reducer 8 and a rotating base 11. Among them, a roller support 25 is provided on the rotating base 11, and the active roller 9 and the driven roller 10 are rotatably arranged on the rotating base 11 through bearings and the roller support 25. The active roller 9 and the driven roller 10 are distributed on both sides of the silicon rod 12 along the axial direction, and the active roller 9 and the driven roller 10 are located below the silicon rod 12, which play a role in rotating and supporting the silicon rod 12. The rotating motor 7 provides rotating power for the active roller 9. The rotating motor 7 is connected to the reducer 8 through a coupling, and the reducer 8 is connected to the active roller 9 through a synchronous belt. The rotating motor 7 transmits the rotating power to the reducer 8 through the coupling, and the reducer 8 transmits the rotating power to the active roller 9 through the synchronous belt, thereby driving the active roller 9 to rotate. When the active roller 9 rotates, the silicon rod 12 is driven to rotate, and the driven roller 10 is further driven to rotate.

The rotating motor 7 is electrically connected to the silicon rod rotation controller 55 , specifically, the rotating motor 7 is electrically connected to the silicon rod rotation controller 55 of the control module 5 , so that the rotation speed of the rotating motor 7 is automatically controlled by the silicon rod rotation controller 55 , and the rotation speed and rotation angle of the silicon rod 12 are further controlled.

The detection mechanism motion module 4 includes an X-axis linear motion unit 101, a Y-axis linear motion unit 102, a Z-axis linear motion unit 103 and a detection device holder 104. The detection device holder 104 is used to install a variety of detection devices. The X-axis linear motion unit 101, the Y-axis linear motion unit 102 and the Z-axis linear motion unit 103 cooperate to realize continuous and synchronous movement of the detection device in three directions of X-axis, Y-axis and Z-axis.

Specifically, the X-axis linear motion unit 101 includes a first X-axis linear motion unit 17 and a second X-axis linear motion unit 18, the Y-axis linear motion unit 102 includes a first Y-axis linear motion unit 19 and a second Y-axis linear motion unit 20, and the Z-axis linear motion unit 103 includes a first Z-axis linear motion unit 21 and a second Z-axis linear motion unit 22. The base of the first Y-axis linear motion unit 19 is fixedly mounted on the slider of the first X-axis linear motion unit 17, the base of the first Z-axis linear motion unit 21 is fixedly mounted on the slider of the first Y-axis linear motion unit 19, the base of the second Y-axis linear motion unit 20 is fixedly mounted on the slider of the second X-axis linear motion unit 18, and the base of the second Z-axis linear motion unit 22 is fixedly mounted on the slider of the second Y-axis linear motion unit 20. A variety of detection devices can be installed on the detection device holder 104, and the detection device holder 104 includes a first detection device holder 23 and a second detection device holder 24, which are respectively fixedly arranged on the sliders of the first Z-axis linear motion unit 21 and the second Z-axis linear motion unit 22. In some embodiments, a group of through-beam photoelectric sensors 26 are arranged on the first detection device holder 23 and the second detection device holder 24, and the through-beam photoelectric sensors 26 are used to dynamically monitor the relative position of the detection mechanism motion module 4 and the silicon rod 12 along the X-axis direction.

It can be understood that the first detection device holder 23 and the second detection device holder 24 can also be arranged on the sliders of other linear motion units, so that the detection devices are arranged in different directions.

The X-axis linear motion unit 101, the Y-axis linear motion unit 102, the Z-axis linear motion unit 103 and the through-beam photoelectric sensor 26 are all electrically connected to the detection mechanism motion controller 51. Specifically, the X-axis linear motion unit 101, the Y-axis linear motion unit 102, and the Z-axis linear motion unit 103 all include a motor, a ball screw, a linear guide, a slider and a base, and the motors of the X-axis linear motion unit, the Y-axis linear motion unit, and the Z-axis linear motion unit are all externally connected to the detection mechanism motion controller of the control module 5, and the control instructions of the detection mechanism motion controller can realize the synchronous motion of the X-axis, Y-axis and Z-axis.

The dimension detection module 2 includes a first laser profile sensor 13 and a second laser profile sensor 14, which are symmetrically arranged on both sides of the silicon rod 12 through a detection device holder. The first laser profile sensor 13 and the second laser profile sensor 14 are both electrically connected to the dimension detection visual controller.

Specifically, the shape and size detection module 2 is used to identify the position of the silicon rod crystal line, detect the integrity of the crystal line, and measure the diameter and length of the silicon rod. The first laser profile sensor 13 is set on the first detection device holder 23, and the second laser profile sensor 14 is set on the second detection device holder 24. The first laser profile sensor 13 and the second laser profile sensor 14 are symmetrically arranged. The laser profile sensor can emit a strip laser and generate diffuse reflection on the surface of the silicon rod 12. The reflected light is then received by the laser profile sensor, and the control module 5 generates three-dimensional point cloud data, thereby realizing the recognition of the shape and size of the silicon rod and the crystal line. The first laser profile sensor 13 and the second laser profile sensor 14 are both externally connected to the shape and size detection visual controller 53 of the control module 5.

The internal defect detection module 3 includes a line array camera 15 and an infrared light source 16, which are symmetrically arranged on both sides of the silicon rod 12 through a detection device holder. The infrared light source 16 is electrically connected to a light source controller 52, and the line array camera 15 is electrically connected to an internal defect detection visual controller 54. The control module 5 also includes an image acquisition card 56, and the line array camera 15 uploads images to the control module 5 through the image acquisition card 56.

Specifically, the internal defect detection module 3 includes a linear array camera 15 and an infrared light source 16, which can identify internal defects such as silicon rod cracks, dislocations, and twins. The infrared light source 16 is arranged on the first detection device holder 23, and the linear array camera 15 is arranged on the second detection device holder 24. The infrared light source 16 and the linear array camera 15 are symmetrically arranged. The infrared light source 16 is connected to the light source controller 52 in the control module 5, and the linear array camera 15 is connected to the internal defect detection visual controller 54 in the control module 5. The linear array camera 15 uploads the image to the control module 5 through the image acquisition card 56.

According to the above description, the first laser profile sensor 13 and the infrared light source 16 used for internal defect detection are installed on both sides of the first detection device holder 23, and the first detection device holder 23 is connected to the slider of the first Z-axis linear motion unit 21, thereby realizing the movement of the first laser profile sensor 13 and the infrared light source 16 along the Z-axis, and the second laser profile sensor 14 and the linear array camera 15 used for internal defect detection are installed on both sides of the second detection device holder 24, and the second detection device holder 24 is connected to the slider of the second Z-axis linear motion unit 22, thereby realizing the movement of the second laser profile sensor 14 and the linear array camera 15 along the Z-axis.

Referring to FIG7 , the control module 5 includes a detection mechanism motion controller 51, a light source controller 52, a dimension detection visual controller 53, an internal defect detection visual controller 54, and a silicon rod rotation controller 55. The control module 5 includes but is not limited to an industrial computer, a programmable controller with a visual controller, etc. The control module 5 is responsible for the motion control of the silicon rod rotation module 1 and the detection mechanism motion module 4, as well as the visual image acquisition, processing, analysis, recognition, judgment, and marking functions of the dimension detection module 2 and the internal defect detection module 3.

The rack module 6 is a frame-type structure, used to support the detection mechanism motion module 4, the external dimension detection module 2, the internal defect detection module 3 and the silicon rod rotation module 1. In some embodiments, the rack module 6 is a metal frame-type structure.

Referring to FIG. 13 , the silicon rod online detection method using the silicon rod defect automatic detection system proposed in the present application includes the following steps:

(1) The detection mechanism motion controller drives the detection device holders on both sides to move along the X-axis to the initial detection position, and the detection device holders move from top to bottom along the Z-axis. The first laser profile sensor 13 and the second laser profile sensor 14 measure the diameter data of the silicon rod 12 for the first time according to the boundary mutation of the silicon rod 12 along the Z-axis direction, and obtain the diameter of the silicon rod 12 as D;

(2) The encoder carried by the motor of the Z-axis linear motion unit senses that the holder moves along the Z-axis to 1/2 of the silicon rod diameter and stops, that is, the movement stroke is D/2, and the silicon rod rotation controller 55 drives the rotation motor 7 of the silicon rod rotation module 1 to rotate slowly. At the same time, the laser profile sensors on both sides of the shape dimension detection module 2 identify the positions of the four crystal lines of the silicon rod, as shown in FIG5 ;

(3) When two crystal lines are perpendicular to the transmitting and receiving optical paths of the two laser profile sensors, the first laser profile sensor 13 and the second laser profile sensor 14 identify the two crystal lines of the silicon rod 12, and the silicon rod rotating module 1 stops moving;

(4) The detection mechanism motion controller controls the detection mechanism motion module 4 to move from the starting position along the X-axis, driving the laser profile sensor to scan the two crystal line profiles of the silicon rod and generate point cloud data. The internal defect detection module 3 moves synchronously with the external dimension detection module 2 through the detection device holder. The linear array camera 15 receives the image after the light source transmits the silicon rod 12, and uploads it to the control module 5 through the image acquisition card. The through-beam photoelectric sensor 26 senses the X-axis position of the detection mechanism motion module 4 relative to the silicon rod 12 in real time. When it is sensed that the detection mechanism motion module 4 moves to the end boundary of the silicon rod 12, the detection mechanism motion controller controls the X-axis linear motion unit to stop moving, and completes the measurement of the silicon rod length to obtain the silicon rod length L. The schematic diagram of the internal defect detection method is shown in FIG6 .

(5) A three-dimensional model of two crystal lines of the silicon rod 12 is constructed through point cloud data, and the image collected by the internal defect detection module 3 is output, and the first silicon rod detection process is completed;

(6) Using the silicon rod rotating module 1, rotate the silicon rod 90° and then stop, repeat steps (4) and (5) to complete the second silicon rod detection process, and summarize the detection data.

Among them, step (6) specifically includes the following process: after the first silicon rod detection process is completed, the detection mechanism motion device is reset along the X-axis and returns to the starting position, the silicon rod rotating module 1 rotates slowly, and stops after rotating 90°, and the detection The mechanism moves along the X-axis, and the double-sided laser profile sensors scan the contours of the remaining two crystal lines of the silicon rod respectively to generate point cloud data. The internal defect detection module 3 moves synchronously with the external dimension detection module 2 through the detection device holder, and the linear array camera 15 receives the image after the light source transmits the silicon rod, and uploads it to the control module 5 through the acquisition card; the three-dimensional model of the remaining two crystal lines of the silicon rod is constructed through the point cloud data, and the image collected by the internal defect detection module 3 is superimposed and mapped in the control module 5, and the second silicon rod detection process is completed. The summary of the detection data is specifically to summarize the imaging results of the two silicon rod external dimension detection, crystal line integrity detection and internal defect detection, and to count the length data of the silicon rod 12. The outer cylindrical surface of the silicon rod is fitted by the three-dimensional model of the four crystal lines of the silicon rod, and the average diameter of the silicon rod is calculated from this. The internal defect detection image is analyzed based on the established judgment rules, and combined with the silicon rod length data, the hidden cracks, dislocations, and twin defects inside the silicon rod are located and marked along the X-axis direction, and the marking results of the silicon rod crystal line break and internal defects are summarized, and the results are transmitted to the next process using a specific communication protocol.

The calculation method of the average diameter of the silicon rod is as follows: the length L of the silicon rod is determined by the laser profile sensor, the number of collection points is set to n, and the diameter data of the silicon rod 12 after fitting is collected at every L/n along the X-axis direction. For example, the diameter of the silicon rod measured at the i-th collection point is Di, and the diameter of the silicon rod measured at the n-th collection point is Dn, then the average diameter of the silicon rod 12 is:

This application also provides several embodiments for identifying basic characteristics of silicon rods.

Based on the optoelectronic characteristics of silicon rods, the internal defect detection of this application adopts short-wave infrared light transmission combined with line scan camera imaging. The longitudinal stripes in Figure 9 are the surface texture features of the silicon rod, and the transverse stripes A are the crystal lines of the silicon rod 12. The above features will be predefined in the detection model to avoid interference with the defect detection process.

The upper boundary of the silicon rod generally presents a wavy curve, as shown in the B to F section of Figure 10, which is also a way of presenting its surface texture. Due to the characteristics of the silicon material itself and the arrangement of the light source, the closer to the top, the darker the image will be. Due to the arrangement of the silicon rod rotating module 1, the lower boundary of the silicon rod and the mechanism imaging are generally indistinguishable.

When the lens is focused on the center of the silicon rod, the thin horizontal line D is the crystal line imaging on the camera side, and the relatively blurred thick line C is the imaging on the light source side. In general, there may be multiple crystal lines of varying thicknesses. The two corner points at the upper left B and the upper right F are the imaging features of the cross-section of the silicon rod, which are close to right angles; the lower left E and the lower right G are the angle imaging between the silicon rod and the conveyor belt, which are close to right angles, but generally present an arc shape.

The present application also provides several embodiments for identifying internal defect characteristics of silicon rods.

Different from the crystal lines and surface texture features of silicon rods, the hidden cracks inside silicon rods generally appear as thin black stripes or flaky shadows, as shown at H in Figure 11. They are irregular in shape and have no specific location. They extend from the inside to the outside and may extend to the outer surface of the silicon rod.

Dislocation is an internal defect of silicon rods and one of the most important crystal defects. The grayscale value difference is large, as shown at I in Figure 12, and the defect area is generally large.

The silicon rod defect automatic detection system proposed in this application can be independent of the silicon rod production and processing line, as shown in Figure 1, or it can be embedded in the silicon rod production line, as shown in Figure 8. In this case, it is only necessary to improve the mechanism design of the silicon rod rotation module 1 in the original system, change the roller structure of the silicon rod rotation module 1 to the structure of the transmission roller, and add a silicon rod lifting module, so that the silicon rod rotation module and the silicon rod lifting module can be compatible with the line body. The silicon rod lifting module mainly includes a servo electric cylinder, a lifting guide rod, a frame, and a rotating support. The silicon rod rotation mechanism is installed on the rotating support of the silicon rod lifting module. The lifting guide rod is used for auxiliary guidance when the servo electric cylinder performs the lifting movement. The two ends of the servo electric cylinder and the lifting guide rod are respectively connected to the frame and the rotating support. The power source can be in various forms such as motors, pneumatic transmission, and hydraulic transmission. There is no limit on the number of infrared light sources, cameras, and 3D laser profile sensors involved in the silicon rod defect automatic detection system proposed in this application.

Compared with the related art, the beneficial effects of this application are:

The silicon rod detection system and detection method proposed in this application can accurately detect the external dimensions and internal defects of silicon rods, thereby improving the production capacity and efficiency of silicon rods and silicon wafers.

The detection mechanism motion module of the silicon rod detection system proposed in the present application can realize the continuous and synchronous movement of the external dimension detection module and the internal defect detection module on the left and right sides of the silicon rod in three directions of X-axis, Y-axis and Z-axis.

The silicon rod detection system and detection method proposed in the present application can detect internal defects such as hidden cracks, dislocations, twins, etc. of the silicon rod before the silicon rod undergoes other production processes, thereby avoiding waste of production resources.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims (10)

1. A silicon rod defect automatic detection system, characterized by comprising:

   A silicon rod rotating module, the silicon rod rotating module comprising a rotating motor, a driving roller, a driven roller and a rotating base, the rotating motor provides a rotating power for the driving roller, the driving roller and the driven roller are rotatably arranged on the rotating base and axially distributed on both sides of the silicon rod to rotate and support the silicon rod;

   A detection mechanism motion module, the detection mechanism motion module comprising an X-axis linear motion unit, a Y-axis linear motion unit, a Z-axis linear motion unit and a detection device holder, the detection device holder is used to install a variety of detection devices, the X-axis linear motion unit, the Y-axis linear motion unit and the Z-axis linear motion unit cooperate to achieve continuous synchronous motion of the detection device in three directions of X-axis, Y-axis and Z-axis;

   An external dimension detection module, wherein the external dimension detection module comprises a first laser contour sensor and a second laser contour sensor, wherein the first laser contour sensor and the second laser contour sensor are symmetrically arranged on both sides of the silicon rod through the detection device holder;

   An internal defect detection module, the internal defect detection module comprising a linear array camera and an infrared light source, the linear array camera and the infrared light source being symmetrically arranged on both sides of the silicon rod through the detection device holder;

   A control module, the control module comprising a detection mechanism motion controller, a light source controller, a shape dimension detection visual controller, an internal defect detection visual controller and a silicon rod rotation controller;

   The rack module is a frame-type mechanism used to support the detection mechanism motion module, the external dimension detection module, the internal defect detection module and the silicon rod rotation module.
2. The system as claimed in claim 1, wherein a reducer is also provided on the rotating base, the rotating motor is connected to the reducer via a coupling, and the reducer is connected to the active roller via a synchronous belt.
3. The system as claimed in claim 1, wherein a roller support is also fixedly disposed on the rotating base, and the active roller and the driven roller are rotatably disposed on the rotating base through the roller support.
4. The system of claim 1, wherein the X-axis linear motion unit includes a first X-axis linear motion unit and a second X-axis linear motion unit, the Y-axis linear motion unit includes a first Y-axis linear motion unit and a second Y-axis linear motion unit, the Z-axis linear motion unit includes a first Z-axis linear motion unit and a second Z-axis linear motion unit, the base of the first Y-axis linear motion unit is fixedly mounted on a slider of the first X-axis linear motion unit, and the base of the first Z-axis linear motion unit is fixedly mounted on a slider of the first Y-axis linear motion unit The base of the second Y-axis linear motion unit is fixedly mounted on the slider of the second X-axis linear motion unit, and the base of the second Z-axis linear motion unit is fixedly mounted on the slider of the second Y-axis linear motion unit.
5. The system as claimed in claim 4, wherein the detection device holder includes a first detection device holder and a second detection device holder, the first detection device holder and the second detection device holder are respectively fixedly arranged on the sliders of the first Z-axis linear motion unit and the second Z-axis linear motion unit, and a group of through-beam photoelectric sensors are arranged on the first detection device holder and the second detection device holder.
6. The system as claimed in claim 5, wherein the first laser profile sensor is arranged on the first detection device holder, the second laser profile sensor is arranged on the second detection device holder, and the first laser profile sensor and the second laser profile sensor are arranged symmetrically.
7. The system as claimed in claim 5, wherein the infrared light source is arranged on a holder of the first detection device, the line array camera is arranged on a holder of the second detection device, and the infrared light source and the line array camera are arranged symmetrically.
8. The system as claimed in claim 5, wherein the X-axis linear motion unit, the Y-axis linear motion unit, the Z-axis linear motion unit and the through-beam photoelectric sensor are all electrically connected to the detection mechanism motion controller, the infrared light source is electrically connected to the light source controller, the line array camera is electrically connected to the internal defect detection vision controller, the first laser profile sensor and the second laser profile sensor are both electrically connected to the external dimension detection vision controller, and the rotary motor is electrically connected to the silicon rod rotation controller.
9. The system as claimed in claim 1, wherein the control module further comprises an image acquisition card, and the line array camera uploads the image to the control module through the image acquisition card.
10. A method for online detection of silicon rods, characterized in that the method comprises the following steps, using the system according to any one of claims 1 to 9:

    (1) The detection mechanism motion controller drives the detection device holders on both sides to move along the X-axis to the initial detection position, and the detection device holders move from top to bottom along the Z-axis. The first laser profile sensor and the second laser profile sensor measure the diameter data of the silicon rod for the first time according to the boundary mutation of the silicon rod along the Z-axis direction, and obtain the diameter of the silicon rod as D;

    (2) The encoder on the motor of the Z-axis linear motion unit senses that the holder moves along the Z-axis to 1/2 of the silicon rod diameter and stops. The silicon rod rotation controller drives the rotation motor of the silicon rod rotation module to rotate slowly. At the same time, the shape dimension detection module Laser profile sensors on both sides identify the positions of the four crystal lines of the silicon rod;

    (3) When two crystal lines are perpendicular to the transmitting and receiving optical paths of the two laser profile sensors, the first laser profile sensor and the second laser profile sensor identify the two crystal lines of the silicon rod, and the silicon rod rotating module stops moving;

    (4) The detection mechanism motion controller controls the detection mechanism motion module to move from the starting position along the X-axis, driving the laser profile sensor to scan the two crystal line profiles of the silicon rod and generate point cloud data. The internal defect detection module moves synchronously with the external dimension detection module through the detection device holder. The linear array camera receives the image after the light source transmits the silicon rod and uploads it to the control module through the image acquisition card. The through-beam photoelectric sensor senses the X-axis position of the detection mechanism motion module relative to the silicon rod in real time. When it senses that the detection mechanism motion module moves to the end boundary of the silicon rod, the detection mechanism motion controller controls the X-axis linear motion unit to stop moving and completes the measurement of the silicon rod length to obtain the silicon rod length L.

    (5) A three-dimensional model of the two crystal lines of the silicon rod is constructed through point cloud data, and the images collected by the internal defect detection module are output, and the first silicon rod detection process is completed;

    (6) Using the silicon rod rotating module, rotate the silicon rod 90° and then stop, repeat steps (4) and (5) to complete the second silicon rod inspection process, and summarize the inspection data.