CN115156083A

CN115156083A - Single crystal silicon wafer sorting device and method

Info

Publication number: CN115156083A
Application number: CN202210767643.3A
Authority: CN
Inventors: 缪云
Original assignee: Individual
Current assignee: Suzhou Akeydrive Information Technology Co ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2022-10-11

Abstract

The invention provides a monocrystalline silicon piece sorting device and a monocrystalline silicon piece sorting method. The invention can classify and move 4 types of single crystal silicon wafers which are missed in the cutting device and are not cut, single crystal silicon fragments and different wafer types and crystal orientations to the subsequent processing step, has high automation degree in the whole process, avoids low yield and low separation efficiency caused by further crushing when the single crystal silicon wafers are artificially separated, can complete the classification of the wafer types and the crystal orientations at one time, improves the accuracy of the subsequent processing, and can remove the fragments.

Description

Single crystal silicon wafer sorting device and method

Technical Field

The invention belongs to the technical field of monocrystalline silicon wafer preparation, and particularly relates to a monocrystalline silicon wafer sorting device and method.

Background

Since the global petroleum energy crisis appeared in the seventies of the last century, the technology taking the emerging energy forms of solar energy, wind energy and the like as the core is gradually highly concerned by western countries, and a series of policy measures related to solar photovoltaic power generation are comprehensively established from the aspects of environmental problems, long-term utilization of energy and the like of countries and related institutions in various regions, so as to further promote the healthy development of the global photovoltaic industry, and therefore, a plurality of styles of solar cell technologies are born. Compared with the traditional petroleum energy, the solar energy is cleaner and recyclable, and becomes one of the best schemes for replacing the traditional energy. With research and technical development for many years, the price of the solar photovoltaic module has been greatly reduced, and the solar energy conversion efficiency has also been improved, so that the commercial development and application of solar photovoltaic power generation are possible.

Meanwhile, as the scale of integrated circuits is continuously enlarged, silicon material has become a semiconductor material which is most widely used in the manufacture thereof, and the semiconductor material is the core of the manufacture of semiconductor devices and is the foundation of the chip and electronic device manufacturing industry. The integrated circuit industry has become the core of the information technology industry, and the importance of the integrated circuit industry as an important foundation for supporting the development of the economic society and ensuring the strategic and basic safety of the country and the guiding industry and the construction of the information society is self-evident, and the importance of the single crystal silicon as the substrate material is also highlighted.

Silicon wafers are the most basic component of solar cell fabrication or integrated circuit chip fabrication.

The wafer is a silicon wafer used for manufacturing a silicon semiconductor integrated circuit, and is called a wafer because the outline of the shape is mostly circular. The preparation and processing processes of the monocrystalline silicon wafer generally comprise the following steps: growing a single crystal into a single crystal silicon ingot, cutting off, rolling and grinding the outer diameter of the single crystal silicon ingot, and then slicing the single crystal silicon ingot to obtain a single crystal silicon wafer, and further chamfering, grinding, corroding, polishing, cleaning and packaging the single crystal silicon wafer.

In the prior art, a preparation device for a monocrystalline silicon wafer is a device for separating cutting, feeding, sorting, blanking, subsequent chamfering, grinding and other steps of a monocrystalline silicon rod, the monocrystalline silicon rod is generally cut by using a monocrystalline silicon rod cutting machine and a monocrystalline silicon rod cutting method disclosed in Chinese patent 201510617988.0, then an intelligent silicon wafer sorting machine disclosed in Chinese patent 202011402246.3 is used for feeding, sorting and blanking, after blanking, a wafer positioning edge and an edge of a wafer can be detected and positioned by using a wafer pre-alignment system positioning method, a positioning device and a positioning circuit system disclosed in Chinese patent 201711059609.6, so that the processes of positioning the wafer again and detecting the edge after sorting are increased, the processing time of the whole wafer is prolonged, and the wafer pre-alignment system positioning method disclosed in the prior art can only position and identify the wafer screened with one positioning edge, and can not achieve the classification determination of different wafer types and crystal orientations of the cut wafer and screen the fragments and the omission of the cut wafer when the whole wafer is cut.

Disclosure of Invention

Aiming at the defects, the invention provides a single crystal silicon wafer sorting device and a single crystal silicon wafer sorting method. The invention can classify and move 4 types of monocrystalline silicon wafers which are missed in a cutting device and are not cut, monocrystalline silicon fragments generated in the transfer process after cutting and 4 types of monocrystalline silicon wafers with different wafer types and crystal orientations to the subsequent processing step, has high automation degree in the whole process, does not need manual processing, reduces the situations of low yield caused by further crushing during manual sorting of the monocrystalline silicon wafers and low sorting efficiency caused by long sorting time, can complete the classification of the wafer types and the crystal orientations at one time, improves the accuracy of the subsequent processing, and can remove the fragments.

The invention provides the following technical scheme: the monocrystalline silicon piece sorting device comprises a first carrying platform, a second carrying platform and a third carrying platform, wherein the third carrying platform is used for continuously conveying monocrystalline silicon pieces obtained after cutting to the second carrying platform, the second carrying platform is used for screening monocrystalline silicon pieces, and the first carrying platform is used for classifying the monocrystalline silicon pieces of different wafer types and crystal orientations obtained after screening into different vacant monocrystalline silicon piece output baskets;

a second support frame is fixedly arranged on the second carrying platform, a size detection unit for detecting the size of the wafer is fixedly arranged on the second support frame, and the size detection unit comprises a main control module, an ultrasonic generator and an ultrasonic receiver; the first carrying platform and the third carrying platform are both fixedly provided with a sorting mechanical arm for moving monocrystalline silicon wafers and a plurality of groups of first limiting blocks, a turntable for conveying the monocrystalline silicon wafer output basket to one side of the first carrying platform is rotatably sleeved on the first carrying platform, and the first carrying platform is fixedly provided with a plurality of first electric push rods for pushing the monocrystalline silicon wafer output basket to the turntable and an empty basket pushing mechanism for pushing the empty basket to the inner side of the turntable to be abutted against any one group of the plurality of groups of first limiting blocks on the first carrying platform for limiting;

the third carrying platform and the first electric push rod are both fixedly provided with monitoring modules for detecting the number of the monocrystalline silicon wafers stored in the basket in real time, the second carrying platform is fixedly provided with a third supporting frame, one side of the third supporting frame is rotatably connected with a control panel, and the control panel is in wireless communication connection with the size detection unit, the first electric push rod, the third carrying platform and the monitoring modules on the first electric push rod, the turntable and the vacant basket pushing mechanism.

Further, the method for screening the monocrystalline silicon wafer obtained after cutting by the size detection unit comprises the following steps:

s1: the control panel sends an instruction to the main control module, the main control module controls the ultrasonic generator to sequentially send out ultrasonic waves in real time from a point right above the center of the detected monocrystalline silicon piece to the edge of the monocrystalline silicon piece, and the ultrasonic receiver which is positioned on the same horizontal plane with the ultrasonic generator receives the ultrasonic waves reflected in real time;

s2: judging whether the detected monocrystalline silicon piece has a main positioning edge or not according to the change condition of an included angle theta (t) between the wafer circle center O axis of the monocrystalline silicon piece detected by the ultrasonic receiver in real time and a connecting line between the edge point of the monocrystalline silicon piece receiving the ultrasonic waves and the ultrasonic wave transmitting point in the step S1, and if the included angle theta (t) between the wafer circle center O axis of the monocrystalline silicon piece detected in real time and the connecting line between the edge point of the monocrystalline silicon piece receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one period of transmitting the ultrasonic waves in real time along the edge of the monocrystalline silicon piece for one circle _s If the silicon wafer is changed, the detected monocrystalline silicon wafer has a main positioning edge, and the step S3 is carried out; otherwise, judging that the detected monocrystalline silicon wafer has no positioning edge, and entering the step S4;

s3: according to the judgment result of the step S2, if a main positioning edge exists, a positioning edge recognition calculation model is constructed to determine the main positioning edge and the secondary positioning edge and determine the wafer type and the crystal orientation of the monocrystalline silicon wafer;

s4: and according to the judgment result of the step S2, if no main positioning edge exists, determining whether the single crystal silicon wafer fragments exist, if so, sending an instruction to the control panel by the main control module, and controlling the sorting mechanical arm on the first carrying platform to throw the fragments into the single crystal silicon wafer output basket for collecting the fragments by the control panel.

Further, the rule of judging whether the detected monocrystalline silicon piece has the main positioning edge in the step S2 is as follows:

if the included angle theta (t) between the wafer center O axis of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one cycle of transmitting the ultrasonic waves in real time along one circle of the edge of the monocrystalline silicon wafer _s The included angle theta (t) between the axis of the center O of the wafer of the monocrystalline silicon wafer and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point is theta _max If the measured value is the fixed value, the detected monocrystalline silicon wafer is a complete wafer with the radius of r and has no main positioning edge or secondary positioning edge;

if the included angle theta (t) between the wafer center O axis of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one cycle of transmitting the ultrasonic waves in real time along one circle of the edge of the monocrystalline silicon wafer _s The internal change is irregular, and the time t of one period of real-time ultrasonic wave emission in one circle along the edge of the monocrystalline silicon wafer is not met _s And judging that the monocrystalline silicon wafer is a fragment of the monocrystalline silicon wafer if the condition of no change in the monocrystalline silicon wafer does not meet the condition of having a main positioning edge.

Further, the step S3 of constructing a positioning edge recognition computation model includes the following steps:

s301: according to the step S1, the center O axis of the wafer circle of the monocrystalline silicon wafer detected in real timeAn included angle theta (t) between a line and a connecting line between an edge point of the monocrystalline silicon piece receiving the ultrasonic waves and an ultrasonic wave transmitting point is within the time t of one cycle of real-time transmission of the ultrasonic waves along the edge of the monocrystalline silicon piece _s Judging the condition that the detected monocrystalline silicon wafer has a main positioning edge and a secondary positioning edge at the moment of the internal change time point; if the change time points are only three, the detected monocrystalline silicon wafer is the monocrystalline silicon wafer only with the main positioning edge, and the monocrystalline silicon wafer is the P type monocrystalline silicon wafer<111>A crystal orientation monocrystalline silicon wafer; if the change time points are six, the detected monocrystalline silicon wafer is a monocrystalline silicon wafer with a primary positioning edge and a secondary positioning edge, the primary positioning edge corresponds to one group of change time points, and the secondary positioning edge corresponds to the other group of change time points;

s302: when the change time points are six, a positioning edge recognition calculation model is constructed, and a first angle alpha corresponding to the ultrasonic wave in the horizontal plane of the monocrystalline silicon piece along the path of the monocrystalline silicon piece edge in the first group of change time points is calculated ₁ And a second angle alpha corresponding to the path in the horizontal plane of the monocrystalline silicon wafer at the second set of change time points ₂ ：

Wherein the first group of change time points is

And

to be at

And

the time in between; | is calculated as an absolute value;

to detect a first minimum angle

At the time of the day,

for detecting included angle theta (t) from a fixed value theta _max Initially gradually towards a first minimum angle

The initial moment of time of the decrease is,

for detecting included angle theta (t) from a first minimum angle

Gradually increases to a fixed value theta _max The final time of (2);

wherein the second group of change time points is

And

to be at

And

the time in between;

to detect a second minimum angle

At the time of the day,

for detecting included angle theta (t) from a fixed value theta _max Initially gradually towards a second minimum angle

The initial moment of time of the decrease is,

for detecting angle theta (t) from a second minimum angle

Gradually increases to a fixed value theta _max The final time of (d);

s303: according to the result obtained by the calculation in the step S32, the corresponding first angle alpha in the horizontal plane of the monocrystalline silicon piece is judged ₁ The path of the corresponding ultrasonic wave in the first group of change time points along the edge of the monocrystalline silicon piece is a main positioning edge or a secondary positioning edge: if α is ₁ >α ₂ Then from

To

The linear edge at the edge of the monocrystalline silicon detected within the moment is the main positioning edge A if alpha ₁ <α ₂ Then from

To

The linear edge at the edge of the single crystal silicon detected at the moment is the secondary positioning edge B.

Further, the step S3 of determining the type and the crystal orientation of the single crystal silicon wafer includes the following steps:

s311: according to the primary positioning edge and the secondary positioning edge determined in the step S303, a calculation formula of an included angle beta between the middle point of the primary positioning edge and the middle point of the secondary positioning edge is constructed:

wherein i =1,2,j =1,2,i ≠ j, i.e. if

Is composed of

Then

Is composed of

If it is

Is composed of

Then

Is composed of

And

respectively transmitting ultrasonic waves clockwise or anticlockwise along the edge of the monocrystalline silicon piece to the middle points of the two corresponding positioning edges;

s312: judging the wafer type and the crystal orientation of the monocrystalline silicon wafer with the primary positioning edge and the secondary positioning edge according to the included angle beta calculated in the step S311:

if the beta is 90 degrees or 270 degrees, judging that the detected monocrystalline silicon piece is a P-type <100> crystal orientation monocrystalline silicon piece;

if the beta is 45 degrees or 315 degrees, judging that the detected monocrystalline silicon wafer is an N-type <111> crystal orientation monocrystalline silicon wafer;

and if the beta is 180 degrees, judging that the detected monocrystalline silicon piece is an N-type <100> crystal orientation monocrystalline silicon piece.

Furthermore, a first support frame is fixedly arranged on the first carrying platform, and the vacant basket pushing mechanism is fixedly arranged on the first support frame; the vacant basket pushing mechanism comprises a servo motor fixedly arranged on the first support frame, a second electric push rod arranged at the output end of the servo motor, and a second push plate fixedly arranged at the output end of the second electric push rod; the equal fixedly connected with fourth baffle in second push pedal both sides, fixed mounting has a plurality of second strengthening ribs on the second push pedal, the second fabrication hole has been seted up to one side of second push pedal, the both sides inner wall fixed mounting in second fabrication hole has a plurality of connecting plates.

Furthermore, two second baffle plates are fixedly mounted on the first carrying platform, one ends of the second baffle plates extend to the turntable in an inclined manner, and one ends of the second baffle plates, which extend to the turntable, are bent inwards to be close to the circle center of the turntable; the first fixed angle iron is fixedly mounted on one side of the second baffle, the second baffle is fixedly connected with the first carrying platform through the first fixed angle iron, an arc-shaped section is arranged on the second baffle, a plurality of first reinforcing ribs are fixedly arranged on one side of the second baffle where the first fixed angle iron is mounted, and a plurality of first process holes are formed in the gaps of the plurality of first reinforcing ribs of the second baffle.

Furthermore, a plurality of third fixed angle irons are fixedly mounted on one side of the first carrier, a same supporting plate is fixedly mounted on the plurality of third fixed angle irons, a third baffle is fixedly mounted on one side, away from the first carrier, of the supporting plate, a supporting rod is fixedly connected to one side, away from the first carrier, of the third fixed angle irons, one end, away from the third fixed angle irons, of the supporting rod is fixedly mounted with the third baffle, a second fixed angle iron is fixedly mounted on one side of the supporting plate, and the second fixed angle iron is fixedly mounted with the second baffle.

The invention also provides a single crystal silicon wafer sorting method adopting the device, which comprises the following steps;

1) The control panel controls a mechanical arm of the feeding device to place a feeding basket containing monocrystalline silicon wafers which are not classified and screened after being cut at the first limiting block of the third carrying platform for limiting, and the control panel controls a sorting mechanical arm on the third carrying platform to sequentially move the monocrystalline silicon wafers in the feeding basket to the second carrying platform;

2) The control panel controls the size detection unit in the second carrying platform to be started, sequentially identifies whether the monocrystalline silicon wafer moved to the second carrying platform is a fragment or not, identifies the type and the crystal orientation of the monocrystalline silicon wafer, and transmits an identified result to the control panel;

3) After receiving the recognition result, the control panel sends an instruction to a sorting mechanical arm on the first carrying platform, controls the sorting mechanical arm on the first carrying platform to throw the detected monocrystalline silicon wafer into a corresponding monocrystalline silicon wafer output basket arranged on the inner side of the turntable according to the wafer type and the crystal orientation of the monocrystalline silicon wafer recognized by the sorting mechanical arm, and throws the fragments into the monocrystalline silicon wafer output basket which independently holds the fragments;

4) When monitoring that one or more monocrystalline silicon wafer output baskets on the turntable are full of monocrystalline silicon wafers in real time, a monitoring unit in the first electric push rod sends a signal to the control panel, the control panel controls the first electric push rod to push the monocrystalline silicon wafer output baskets full of monocrystalline silicon wafers to the first turntable, then controls the turntable to rotate to the discharging side of the monocrystalline silicon wafer output baskets, the control panel continuously controls a mechanical arm of a discharging device to move the classified monocrystalline silicon wafer output baskets out of the first carrying platform and controls the vacant basket pushing mechanism to push the vacant monocrystalline silicon wafer output baskets to the inner side of the turntable, so that each vacant monocrystalline silicon wafer output basket abuts against any two first limiting blocks on the first carrying platform to limit and wait for the screened monocrystalline silicon wafers to enter delivery;

5) After the monitoring module in the third carrying platform monitors the empty basket in the feeding flower basket filled with the cut monocrystalline silicon wafers, the control panel receives the signal, and the control panel continuously controls the mechanical arm of the feeding device to move the feeding flower basket filled with the monocrystalline silicon wafers which are not classified and screened after being cut into the third carrying platform, so that screening and fragment removal in the continuous preparation process of the monocrystalline silicon wafers are completed.

Further, the size detection unit in step 2) sequentially identifies the wafer type and the crystal orientation of the single crystal silicon wafer moved to the second stage, and includes the following steps:

2.1 A main control module of the size detection unit controls an ultrasonic generator to sequentially emit ultrasonic waves to a point on the edge of the monocrystalline silicon wafer right above the center of the monocrystalline silicon wafer in real time and controls an ultrasonic receiver to receive ultrasonic signals reflected by the monocrystalline silicon wafer;

2.2 The main control module of the size detection unit judges whether the detected monocrystalline silicon piece has a main positioning edge or not according to the data acquired in the step 2.1), and further judges whether the detected monocrystalline silicon piece is a complete wafer without a main positioning edge or a secondary positioning edge or a fragment of the monocrystalline silicon piece;

2.3 According to the judgment result in the step 2.2), under the condition that the detected monocrystalline silicon wafer is confirmed to have a main positioning edge, determining the main positioning edge and a secondary positioning edge of the detected monocrystalline silicon wafer, and determining the type and the crystal orientation of the monocrystalline silicon wafer;

2.4 And then the main control module of the size detection unit sends an instruction to a control panel, and the control panel controls a sorting mechanical arm on the first carrying platform to sort and deliver the monocrystalline silicon fragments and the monocrystalline silicon pieces of different types obtained by identification to different monocrystalline silicon piece output baskets.

The beneficial effects of the invention are as follows:

1. the monocrystalline silicon piece sorting device provided by the invention has the advantages that through arranging the two material loading baskets which alternately limit and abut against the cut monocrystalline silicon piece wafers, the cut monocrystalline silicon wafer can be continuously and uninterruptedly conveyed to the second carrying platform with the size detection unit through the sorting mechanical arm on the third carrying platform, then, the size detection unit is used for transmitting ultrasonic waves clockwise or anticlockwise along the edge of the cut monocrystalline silicon wafer in real time and receiving the transmitted ultrasonic waves, further, the detected monocrystalline silicon piece can be judged to be a complete wafer without a main positioning edge and a secondary positioning edge or a monocrystalline silicon piece fragment, and determining the main positioning edge and the secondary positioning edge under the condition of confirming that the wafer has the main positioning edge, and determining the type and the crystal orientation of the monocrystalline silicon wafer, classifying intact wafers which are left out of the cutting device and are not cut, monocrystalline silicon fragments generated in the transfer process after cutting and 4 monocrystalline silicon wafers with different wafer types and crystal orientations, can be respectively put into a plurality of monocrystalline silicon wafer output baskets which are clamped and connected in the first carrying platform and limited by a plurality of groups of first limiting blocks, when the monitoring unit arranged in the first electric push rod monitors that one or more monocrystalline silicon pieces output from the basket on the turntable are full of monocrystalline silicon pieces in real time, the control panel can control the output basket filled with the sorted monocrystalline silicon wafers to be pushed to the first rotating disc and rotate to the joint with the blanking device, a mechanical arm of the blanking device is controlled to output a plurality of single crystal silicon wafers which are classified out of the basket of flowers and move out of the first carrying platform, and controlling the vacant basket pushing mechanism to push a plurality of vacant monocrystalline silicon wafer output baskets to the inner side of the turntable so as to continuously receive the classified monocrystalline silicon wafers. The invention has simple structure, can continuously and uninterruptedly classify and move 4 types of monocrystalline silicon wafers which are missed in a monocrystalline silicon wafer cutting device and are not cut, fragments of the monocrystalline silicon wafer generated in the transfer process after cutting and 4 types of monocrystalline silicon wafers with different wafer types and crystal orientations to the subsequent processing step, has high automation degree in the whole process, does not need manual processing, reduces the occurrence of low yield caused by further crushing when the monocrystalline silicon wafers are artificially sorted and low sorting efficiency caused by long sorting time, can simultaneously complete the classification of the wafer types and the crystal orientations at one time, improves the accuracy of the subsequent processing, and can remove the fragments.

2. According to the device provided by the invention, the size detection unit comprising the main control module, the ultrasonic generator and the ultrasonic receiver is arranged on the second carrying platform, whether the detected monocrystalline silicon wafer has a main positioning edge or not is judged according to the change condition of an included angle theta (t) between an axis where the wafer circle center O of the monocrystalline silicon wafer where the ultrasonic generator is located and a connecting line between the edge point of the monocrystalline silicon wafer receiving ultrasonic waves and the ultrasonic wave sending point M, and then monocrystalline silicon wafers with 4 different wafer types and crystal orientations (the monocrystalline silicon wafer with the main positioning edge A in the P-type <111> crystal orientation, the monocrystalline silicon wafer with the main positioning edge A and the secondary positioning edge B in the P-type <100> crystal orientation, the monocrystalline silicon wafer with the main positioning edge A and the secondary positioning edge B in the N-type <111> crystal orientation, and the monocrystalline silicon wafer with the main positioning edge A and the secondary positioning edge B in the N-type <100> crystal orientation) are firstly finished products, or monocrystalline silicon wafer fragments which are not cut but are sorted for the cutting device, so that the monocrystalline silicon wafer types and the model is constructed and the monocrystalline silicon fragments are determined, and the sorting efficiency is further improved.

3. By the size detection unit of the device, through the method for constructing the positioning edge recognition calculation model comprising the steps of S301-S303, no matter the ultrasonic generator sequentially transmits ultrasonic waves to points on the edge of the monocrystalline silicon piece from the position right above the center of the monocrystalline silicon piece in a counterclockwise or clockwise manner, the obtained result is that the length of the main positioning edge A is greater than that of the corresponding secondary positioning edge B, and the specific positions of the main positioning edge A and the secondary positioning edge B can be determined. Therefore, the positioning edge identification calculation model provided by the invention is not limited to the direction of the ultrasonic wave generator emitting the ultrasonic waves along the edge of the detected monocrystalline silicon piece, and can accurately identify and position the main positioning edge and the secondary positioning edge.

4. When the type and the crystal orientation of the monocrystalline silicon wafer are determined, the size detection unit of the device can judge the type and the crystal orientation of the monocrystalline silicon wafer according to the calculation result of S312 without considering that the ultrasonic generator which is clockwise or anticlockwise emits along the edge of the monocrystalline silicon wafer in sequence or considering the sequence substituted into the step S311, and can effectively identify the detected monocrystalline silicon wafer and carry out classified delivery blanking in the next step.

5. According to the single-crystal-wafer sorting device, the flower basket is blocked by the two second baffles, interference between the flower basket and a sorting mechanical arm is avoided when the flower basket moves, and further the working precision of the device is influenced.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the embodiments of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

FIG. 1 is a schematic view of a first-view perspective structure of a single crystal silicon wafer sorting device provided by the present invention;

FIG. 2 is a schematic view of a second perspective structure of the single crystal silicon wafer sorting device provided by the present invention;

FIG. 3 is an enlarged schematic view of the structure at A in FIG. 2 according to the present invention;

FIG. 4 is a schematic flow chart illustrating the screening process of the single crystal silicon wafer by the dimension detecting unit according to the present invention;

FIG. 5 is a schematic diagram of an ultrasonic generator of the present invention transmitting ultrasonic waves counterclockwise in real time to a monocrystalline silicon wafer to be tested;

FIG. 6 is a schematic diagram of an ultrasonic generator of the present invention transmitting ultrasonic waves clockwise in real time to a monocrystalline silicon wafer to be tested;

FIG. 7 is a schematic diagram of a single crystal silicon wafer with a main positioning edge A in a P-type <111> crystal orientation, which is obtained by the size detection unit according to the present invention;

FIG. 8 is a schematic diagram of a single crystal silicon wafer with a primary positioning edge A and a secondary positioning edge B in a P-type <100> crystal orientation identified and screened by a dimension detecting unit according to the present invention;

FIG. 9 is a schematic diagram of a single crystal silicon wafer with a primary positioning edge A and a secondary positioning edge B in an N-type <111> crystal orientation identified and screened by a dimension detecting unit according to the present invention;

FIG. 10 is a schematic diagram of a single crystal silicon wafer with a primary positioning edge A and a secondary positioning edge B of an N-type <100> crystal orientation obtained by size detection unit identification screening according to the present invention;

FIG. 11 is a view showing a size detecting unit identifying and screening a complete single crystal silicon wafer having neither a primary positioning edge nor a secondary positioning edge according to the present invention;

FIG. 12 is a schematic diagram of two sets of time change points occurring at the edge of a monocrystalline silicon wafer for constructing a positioning edge recognition computation model when an ultrasonic wave is transmitted clockwise in real time according to the present invention;

FIG. 13 is a schematic diagram of two sets of time change points occurring at the edge of a monocrystalline silicon wafer for constructing a positioning edge recognition computation model when ultrasonic waves are transmitted counterclockwise in real time according to the present invention;

FIG. 14 is a schematic perspective view of a second push plate of the device according to the present invention;

fig. 15 is a schematic view of an enlarged structure of the support plate and the second baffle of the device of the present invention.

In the figure: 1. a first stage; 2. a second stage; 3. a third stage; 4. a first support frame; 5. a second support frame; 6. a size detection unit; 7. a sorting mechanical arm; 8. a first stopper; 9. a first electric push rod; 10. a first push plate; 11. a turntable; 12. a first baffle; 13. a support plate; 14. a second baffle; 15. an empty flower basket pushing mechanism; 16. a servo motor; 17. a second electric push rod; 18. a second push plate; 19. a first fixed angle iron; 20. an arc-shaped section; 21. a first reinforcing rib; 22. a first fabrication hole; 23. a second fixed angle iron; 24. a third fixed angle iron; 25. a support bar; 26. a third baffle plate; 27. a fourth baffle; 28. a second reinforcing rib; 29. a second fabrication hole; 30. a connecting plate; 31. a third support frame; 32. a control panel; 33. an ultrasonic generator; 34. an ultrasonic receiver.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-3, the single crystal silicon wafer sorting apparatus provided by the present invention includes a first stage 1, a second stage 2, and a third stage 3, where the third stage 3 is configured to continuously convey a single crystal silicon wafer obtained after cutting to the second stage 2, the second stage 2 is configured to screen a single crystal silicon wafer, and the first stage 1 is configured to sort single crystal silicon wafers of different wafer types and crystal orientations obtained after screening into different empty single crystal silicon wafer output baskets;

a second support frame 5 is fixedly arranged on the second carrying platform 2, a size detection unit 6 for detecting the size of the wafer is fixedly arranged on the second support frame 5, and the size detection unit 6 comprises a main control module, an ultrasonic generator and an ultrasonic receiver; a sorting mechanical arm 7 for moving the monocrystalline silicon wafers and a plurality of groups of first limiting blocks 8 are fixedly arranged on the first carrying platform 1 and the third carrying platform 3, a rotating disc 11 for conveying the monocrystalline silicon wafer output baskets to one side of the first carrying platform 1 is rotatably sleeved on the first carrying platform 1, and a plurality of first electric push rods 9 for pushing the monocrystalline silicon wafer output baskets to the rotating disc 11 and an empty basket pushing mechanism 15 for pushing the empty baskets to the inner side of the rotating disc 11 to abut against any one group of the plurality of groups of first limiting blocks 8 on the first carrying platform 1 for limiting are fixedly arranged on the first carrying platform 1;

the sorting mechanical arm 7 arranged on the third carrying platform 3 moves the monocrystalline silicon wafers in the basket limited to the first limiting block 8 to the second carrying platform 2, after the detection of the size detection unit 6, the control panel 32 sends an instruction to the sorting mechanical arm 7 on the first carrying platform 1, and the sorting mechanical arm 7 on the first carrying platform 1 is controlled to place the identified monocrystalline silicon wafers in the monocrystalline silicon wafer output baskets belonging to the same class; the third carrying platform 3 and the first electric push rod 9 are fixedly provided with monitoring modules for detecting the number of monocrystalline silicon wafers stored in the flower basket in real time, the second carrying platform 2 is fixedly provided with a third support frame 31, one side of the third support frame 31 is rotatably connected with a control panel 32, and the control panel 32 is in wireless communication connection with the size detection unit 6, the first electric push rod 9, the monitoring modules on the third carrying platform 3 and the first electric push rod 9, the turntable 11 and the vacant flower basket pushing mechanism 15.

As an embodiment of this embodiment, the sorting mechanical arm 7 may be a lifting four-axis mechanical arm in the prior art, and an output end of the four-axis mechanical arm is fixedly connected with a fork, the four-axis mechanical arm conveys monocrystalline silicon wafers to be detected in a feeding basket on the third carrier 3 through the fork, a plurality of sets of first stoppers 8 are fixedly mounted on the first carrier 1 and the second carrier 2, as an embodiment of this embodiment, two to ten sets of first stoppers 8 are fixedly mounted on the first carrier 1 for limiting two to ten sets of baskets, so as to cooperate with the sorting mechanical arm 7 to sort the detected monocrystalline silicon wafers, two sets of first stoppers 8 are fixedly mounted on the third carrier 3 for limiting two baskets, after the screening of the monocrystalline wafers in one basket is completed, the sorting mechanical arm 7 can screen the wafers in the other basket, at this time, after the staff or the control panel 32 collects the information that the number of the monocrystalline silicon wafers in the feeding basket is 0 from the monitoring module on the third carrying platform 3, the control panel 32 controls the mechanical arm of the feeding device to take down the empty basket and place the feeding basket containing the cut monocrystalline silicon wafers to be detected in a group of first limiting blocks 8, and the feeding basket is limited by the group of first limiting blocks 8, so that the sorting mechanical arm 7 on the third carrying platform 3 can work continuously, the sorting efficiency of the monocrystalline wafers is improved, a rotating disc 11 for conveying the basket to one side of the first carrying platform 1 is rotatably sleeved on the first carrying platform 1, as an implementation mode of the embodiment, the rotating disc 11 can be formed by assembling a hollow rotating disc and a driving motor in the prior art, a transmission bracket can be arranged at the bottom of the hollow rotating disc, and the output end of the driving motor is fixedly sleeved on the transmission bracket, so that the driving motor drives the hollow turntable to rotate, a plurality of first electric push rods 9 used for pushing the monocrystalline silicon wafer output basket to the turntable 11 are fixedly installed on the first carrying platform 1, monitoring units which are not shown in the drawing and used for detecting the monocrystalline silicon wafer output basket in real time and storing the monocrystalline silicon wafers are fixedly installed on the first electric push rods 9, the monitoring data are transmitted to the control panel 32 in real time, and the control panel 32 controls the whole device to carry out the sorting step of the monocrystalline silicon wafers.

As a preferred embodiment of the present invention, as shown in fig. 3, each set of first stoppers 8 includes two first stoppers 8 that are symmetrical to each other, and one end of each first stopper 8 extends obliquely outward, so that when the second pushing plate 18 pushes an empty basket, the empty basket is guided, and the empty basket is accurately positioned at the empty collecting position.

Further preferably, the equal fixed mounting in one end of first electric putter 9 has first push pedal 10, first electric putter 9 becomes the arc all with arrange on first microscope carrier 1, improve the area of contact of first electric putter 9 output and basket of flowers through first push pedal 10, improve the stability of propelling movement basket of flowers, arrange the design through the arc structure, improved the quantity that can place the basket of flowers on the 1 mesa of first microscope carrier, and make a plurality of baskets of flowers on the 1 first microscope carrier equal with the interval of sorting arm 7, the debugging degree of difficulty of this device has been reduced.

Further preferably, the top of the turntable 11 is flush with the top of the first carrying platform 1, the first carrying platform 1 is fixedly provided with a first baffle 12 matched with the turntable 11, jolting during movement of the flower basket is avoided, the flower basket on the turntable 11 is limited through the first baffle 12, and the flower basket is prevented from sliding under the action of centrifugal force and being separated from the turntable 11, so that the use stability of the device is influenced.

As a preferred embodiment of the present invention, as shown in fig. 4, the method for screening the single crystal silicon wafer obtained after the cutting by the size detection unit 6 includes the following steps:

s1: as shown in fig. 5-6, the ultrasonic generator 33 and the ultrasonic receiver 34 of the size detection unit 6 in the second carrier 2 are disposed directly above the detected monocrystalline silicon wafer, both the ultrasonic generator 33 and the ultrasonic receiver 34 are in wireless communication with the main control module, the control panel 32 sends an instruction to the main control module, the main control module controls the ultrasonic generator to sequentially send ultrasonic waves in real time from a point directly above the center of the monocrystalline silicon wafer to the edge of the monocrystalline silicon wafer clockwise or counterclockwise, the ultrasonic waves are counterclockwise in fig. 5 and clockwise in fig. 6, and the ultrasonic receiver in the same horizontal plane as the ultrasonic generator receives the ultrasonic waves reflected in real time;

s2: judging whether the detected monocrystalline silicon wafer has a main positioning edge or not according to the change condition of an included angle theta (t) between the axis of the wafer circle center O of the monocrystalline silicon wafer where the ultrasonic generator 1 is located and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point M, which is obtained by real-time detection of the ultrasonic receiver in the step S1, and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point M, if the included angle theta (t) between the axis of the wafer circle center O of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point M is within the time t of one cycle of real-time transmission of the ultrasonic waves along the edge of the monocrystalline silicon wafer _s If the silicon wafer is changed, the detected monocrystalline silicon wafer has a main positioning edge, and the step S3 is carried out; otherwise, judging that the detected monocrystalline silicon wafer has no positioning edge, and entering the step S4;

s3: according to the judgment result of the step S2, if the wafer has the main positioning edge, a positioning edge recognition calculation model is constructed to determine the main positioning edge and the secondary positioning edge and determine the wafer type and the crystal orientation of the monocrystalline silicon wafer;

in the prior art semiconductor silicon wafer, there are two types of conductivity: the crystal orientations of P-type monocrystalline silicon wafers and N-type monocrystalline silicon wafers, which are commonly used in chip fabrication of integrated circuits or solar cell fabrication, are the <111> crystal orientation and the <110> crystal orientation.

The P-type monocrystalline silicon wafer and the N-type monocrystalline silicon wafer are distinguished as follows:

n-type is electron conducting and P-type is hole conducting. The P-type monocrystalline silicon wafer is usually made of boron as a doping element, and the more boron is doped, the more holes generated by silicon can be replaced, the stronger the conductivity is, and the lower the resistivity is. The material for manufacturing the N-type monocrystalline silicon wafer generally uses phosphorus or arsenic as a doping element, and the more phosphorus is doped, the more free electrons are, the stronger the conductivity is, and the lower the resistivity is.

Thus, the alignment edge facilitates the orientation of the wafer and its positioning in the cassette or processing equipment (large major flat edge) and also facilitates the differentiation between crystal orientation and conductivity type (smaller minor flat edge)

S4: and according to the judgment result in the step S2, if the main positioning edge does not exist, whether the single crystal silicon wafer fragments exist is determined, if the single crystal silicon wafer fragments do not exist, the main control module sends an instruction to the control panel 32, and the control panel 32 controls the sorting mechanical arm 7 on the first carrying platform (1) to throw the fragments into the single crystal silicon wafer output basket for collecting the fragments.

The ultrasonic wave transmitting point M in the step S2 is an ultrasonic wave transmitting point of the ultrasonic wave generator 33 and a receiving point of the ultrasonic wave receiver 34 for the ultrasonic wave, is actually a point, and is only named differently, namely, the points of the ultrasonic wave transmitted by the ultrasonic wave generator 33 and the ultrasonic wave received by the ultrasonic wave receiver 34 are both the ultrasonic wave transmitting point M which is positioned above the axis of the center O of the wafer of the monocrystalline silicon wafer and is at the position of high H from the plane where the monocrystalline silicon wafer is positioned; meanwhile, the detected monocrystalline silicon wafer in the steps S1-S2 is necessarily a wafer with a fixed radius and a center O of the wafer as a center, and may be a fragment, such as a monocrystalline silicon wafer with a main positioning edge a in a P-type <111> crystal orientation shown in fig. 7, a monocrystalline silicon wafer with a main positioning edge a and a sub positioning edge B in a P-type <100> crystal orientation shown in fig. 8, a monocrystalline silicon wafer with a main positioning edge a and a sub positioning edge B in an N-type <111> crystal orientation shown in fig. 9, or a monocrystalline silicon wafer with a main positioning edge a and a sub positioning edge B in an N-type <100> crystal orientation shown in fig. 10, so that the center O of the monocrystalline silicon wafer is a center of the wafer when the detected monocrystalline silicon wafer is a complete fixed-radius wafer, to determine the position of the ultrasonic wave receiving and sending point M and further determine the positions of the ultrasonic wave generator 1 and the ultrasonic wave receiver 2, and also determine the definition of the included angle θ (t);

after the step S3, the main control module can control the monocrystalline silicon piece collecting baskets with different types and crystal orientations to reach the feeding opening, and then the monocrystalline silicon pieces with different types obtained by identification are classified and delivered to the monocrystalline silicon piece discharging collecting baskets, and then the discharging is classified and delivered after the effective types are distinguished.

As a preferred embodiment of the present invention, the rule of the step S2 for determining whether the detected monocrystalline silicon wafer has the main positioning edge is:

if detected in real timeThe included angle theta (t) between the axis of the center O of the wafer of the monocrystalline silicon piece and the connecting line between the edge point of the monocrystalline silicon piece receiving the ultrasonic wave and the ultrasonic wave transmitting point is within the time t of one cycle of transmitting the ultrasonic wave in real time along one circle of the edge of the monocrystalline silicon piece _s The included angle theta (t) between the axis of the center O of the monocrystalline silicon wafer and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point is theta _max The detected monocrystalline silicon wafer is a complete wafer with radius r as shown in fig. 11, and has neither primary nor secondary positioning edge;

if the included angle theta (t) between the wafer center O axis of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one cycle of transmitting the ultrasonic waves in real time along one circle of the edge of the monocrystalline silicon wafer _s The internal variation is irregular and does not conform to the time t of one period of real-time ultrasonic wave emission along the edge of the monocrystalline silicon wafer as shown in FIG. 11 _s If the situation of the complete monocrystalline silicon wafer without change in the situation is not consistent with the situation with the main positioning edge A as shown in the figures 7-10, the monocrystalline silicon wafer is judged to be the monocrystalline silicon wafer fragment.

As another preferred embodiment of the present invention, the step S3 of constructing a positioning edge recognition computation model includes the following steps:

s301: according to the step S1, the included angle theta (t) between the wafer center O axis of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point M is within the time t of one period of transmitting the ultrasonic waves in real time along one circle of the edge of the monocrystalline silicon wafer _s Judging the condition that the detected monocrystalline silicon wafer has a main positioning edge A and a secondary positioning edge B at the time of the internal change time point; if the variation time points are only three, the detected monocrystalline silicon wafer is the monocrystalline silicon wafer with only the main positioning edge A as shown in FIG. 7, and the monocrystalline silicon wafer is P-type<111>A crystal orientation monocrystalline silicon wafer; if the change time points are six, the six change time points are two groups, each group has three change time points, the detected monocrystalline silicon wafer is the monocrystalline silicon wafer with a main positioning edge A and a secondary positioning edge B, and the main positioning edge A corresponds to one group of change time pointsPoint, the secondary positioning edge B corresponds to another group of change time points;

s302: when the change time points are six, a positioning edge recognition calculation model is constructed, and a first angle alpha corresponding to the ultrasonic wave in the horizontal plane of the monocrystalline silicon piece along the path of the monocrystalline silicon piece edge in the first group of change time points is calculated ₁ And a second angle alpha corresponding to the path in the horizontal plane of the monocrystalline silicon wafer in the second set of change time points ₂ ：

Wherein the first group of change time points is

And

to be at

And

the time in between; | is calculated as an absolute value;

to detect a first minimum angle

At the time of the day,

The initial moment of time of the decrease is,

for detecting included angle theta (t) from a first minimum angle

Gradually increases to a fixed value theta _max At the final moment (i.e. at

To

Within the time range of the included angle theta (t) from the first minimum angle

Gradually increases to a fixed value theta _max In the time range of

The moment of time reaches a fixed value theta _max )，t _s The time is the time of one period of real-time emission of ultrasonic waves along one circle of the edge of the monocrystalline silicon piece (namely, the ultrasonic waves are emitted in real time along one circle of the edge of the monocrystalline silicon piece, the starting point of the ultrasonic waves reaching the edge of the monocrystalline silicon piece is taken as the terminal point, namely, the completion of one period, and the period of time is t _s ) And theta is detected at the rest time _max ；

Wherein the second group of change time points is

And

to be at

And

the time in between;

to detect a second minimum angle

At the time of the day,

The initial moment of time of the decrease is,

for detecting angle theta (t) from a second minimum angle

Gradually increases to a fixed value theta _max The final time of (2); namely that

To

Within the time range of the included angle theta (t) from the second minimum angle

Gradually increases to a fixed value theta _max In the time range of

S303: according to the result obtained by the calculation in the step S32, the corresponding first angle alpha in the horizontal plane of the monocrystalline silicon piece is judged ₁ The path of the corresponding ultrasonic wave in the first group of change time points along the edge of the monocrystalline silicon piece is a main positioning edge or a secondary positioning edge: if α is ₁ >α ₂ Then is from

To

Straight edge at the edge of monocrystalline silicon detected within a time instant (i.e. first angle alpha) ₁ The path of the corresponding ultrasonic wave in the first group of change time points along the edge of the monocrystalline silicon piece) as a main positioning edge if alpha is ₁ <α ₂ Then is from

To

The linear edge at the edge of the monocrystalline silicon detected within the moment is a secondary positioning edge.

With the P-type as shown in FIG. 8<100>Taking a monocrystalline silicon wafer with a main positioning edge A and a secondary positioning edge B in a crystal orientation as an example, the steps from S302 to S303 are specifically explained, and the monocrystalline silicon wafer of the type has two positioning edges: the main positioning edge a and the sub positioning edge B, so that six change time points can be obtained after the ultrasonic wave emitted from the ultrasonic generator 1 is received by the ultrasonic receiver 2, as shown in fig. 12, when the ultrasonic generator sequentially emits the ultrasonic wave from a point right above the center of the monocrystalline silicon wafer to a point clockwise above the edge of the monocrystalline silicon wafer in real time, the first group of change time points

And

on the single crystal silicon wafer are respectively C point, D point and E point, so that the connecting line OC of the wafer center O and C point and the wafer center O and E pointThe included angle between the connecting lines OE of the points E is a first angle alpha ₁ Second group of change time points

And

on the single crystal silicon wafer are respectively F point, G point and K point, and the included angle between the connection OF OF the circle center O and the F point OF the wafer and the connection OK OF the circle center O and the K point OF the wafer is a second angle alpha ₂ Thus, for P type<100>For a monocrystalline silicon wafer with a crystal orientation having a main positioning edge A and a sub-positioning edge B, when ultrasonic waves are emitted clockwise along the edge of the monocrystalline silicon wafer, a first angle alpha is formed ₁ To a second angle alpha ₂ Is in a relation of ₁ >α ₂ From

At time (point C) to

A linear edge CE at the edge of the single crystal silicon detected at the time (point E) is a main positioning edge a;

as shown in FIG. 13, when the ultrasonic generator sequentially emits the ultrasonic waves in real time from a point right above the center of the single crystal silicon wafer to a point counterclockwise on the edge of the single crystal silicon wafer, the first group of the change time points

And

on the single crystal silicon wafer, there are K point and G point and F point, so that the included angle between the line OK between the circle center O and K point OF the wafer and the line OF between the circle center O and F point OF the wafer is the first angle alpha ₁ Second set of time points of change

And

the point C, the point D and the point E are respectively arranged on the monocrystalline silicon piece, and the included angle between the connecting line OE of the circle center O and the point E of the wafer and the connecting line OC of the circle center O and the point C of the wafer is a second angle alpha ₂ Thus, for P type<100>For a monocrystalline silicon wafer with a crystal orientation having a main positioning edge A and a sub-positioning edge B, when ultrasonic waves are emitted counterclockwise along the edge of the monocrystalline silicon wafer, a first angle alpha is formed ₁ At a second angle alpha ₂ Is in a relation of ₁ <α ₂ At this time from

At time (K point) to

The straight edge KF at the edge of the single-crystal silicon detected at the time (point F) is the secondary positioning edge B.

Therefore, by the method for constructing the positioning edge identification calculation model, which comprises the steps of S301-S303, whether the ultrasonic generator sequentially emits ultrasonic waves to points on the edge of the monocrystalline silicon wafer anticlockwise or clockwise from right above the center of the monocrystalline silicon wafer, the obtained result is that the length of the edge straight line CE (the length corresponding to the primary positioning edge A) is greater than the length of the edge straight line FK (the length corresponding to the secondary positioning edge B), namely the specific positions of the primary positioning edge A and the secondary positioning edge B can be determined.

The other three types and crystal orientations of the monocrystalline silicon wafer can achieve the same technical effect, so that the positioning edge identification calculation model provided by the invention is not limited to the direction of the ultrasonic wave emitted by the ultrasonic generator along the edge of the detected monocrystalline silicon wafer, and can accurately identify and position the main positioning edge and the secondary positioning edge.

When the ultrasonic wave emitted by the ultrasonic generator is sequentially emitted along the edges of six points which are not the main positioning edge or the secondary positioning edge, because the edges which do not comprise the six points are wafers with fixed radiuses and the center O of the wafer, the included angle theta (t) between the axis of the center O of the wafer of the monocrystalline silicon wafer to be detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point M is always maintained to be a fixed value and is continuous, and when the ultrasonic wave is emitted along the main positioning edgeOr when the secondary positioning sides transmit in sequence, from the time point

(point C) to time point

In the process of point D, the distance H from the ultrasonic wave transmitting point M to the horizontal plane of the monocrystalline silicon wafer is constant, but the distance between the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the center O of the wafer is continuously reduced from point C to point D (i.e. the distance is gradually reduced from the radius of the wafer to OD), so that the line connecting the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point M is also continuously reduced according to the Pythagorean theorem, as shown in FIG. 1-2, therefore, the included angle theta (t) is continuously reduced until the point D reaches the minimum value, therefore, the fixed value of the included angle theta (t) between the axis of the center O of the wafer center of the monocrystalline silicon wafer, the edge of which is detected in real time and the line connecting the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point M is the maximum value theta (t) _max When the distance from the point D to the point E is larger, the distance between the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the center O of the wafer is gradually increased from the point C to the point D (i.e. the distance value from the point D is gradually increased to the radius of the wafer), so that the included angle theta (t) is gradually increased to the maximum value theta (t) _max And maintaining the fixed value, and generating the same change principle and rule on the secondary positioning edge B; the same situation occurs when ultrasonic waves emitted from an ultrasonic generator are sequentially emitted counterclockwise along the edge of the single crystal silicon wafer. Therefore, the midpoint of the main positioning side a is point D, and the midpoint of the sub positioning side is point G.

Therefore, as another preferred real-time mode of the present invention, in the step S3, specific positions of the primary positioning edge a and the secondary positioning edge B on the single crystal silicon wafer can be determined according to an included angle between the midpoint D of the primary positioning edge a and the midpoint G of the secondary positioning edge, that is, the type and the crystal orientation of the single crystal silicon wafer can be determined according to an included angle β between a connection line OD of the circle center O and the point D of the wafer and a connection line OG of the circle center O and the point G of the wafer, which specifically includes the following steps:

wherein i =1,2,j =1,2,i ≠ j, i.e. if

Is composed of

Then

Is composed of

If it is

Is composed of

Then

Is composed of

And

if the beta is 90 degrees or 270 degrees, judging that the detected monocrystalline silicon piece is a P-type <100> crystal orientation monocrystalline silicon piece as shown in figure 8; beta in fig. 8 is a case where the calculation result is 90 °, and beta in fig. 8 is labeled as a position at a mutual circumferential angle with beta in fig. 8 when the calculation result is 270 °;

if the beta is 45 degrees or 315 degrees, the detected monocrystalline silicon piece is judged to be an N-type <111> crystal orientation monocrystalline silicon piece as shown in FIG. 9; in fig. 9, β is 45 °, and in the case of 315 °, β in fig. 9 is labeled as a position at a mutual circumferential angle with β in fig. 9;

when β is 180 °, it is determined that the detected single crystal silicon wafer is an N-type <100> crystal orientation single crystal silicon wafer as shown in fig. 10.

As shown in fig. 8-9, in a P-type<100>For the crystal orientation monocrystalline silicon wafer as an example, if the included angle between OD and OG is calculated clockwise, point D is

At time, point G is

The time can be calculated according to the formula in step S311

Can also be

Due to the calculation of absolute values, therefore

Is composed of

Or also

The same, but even if the ultrasonic waves are sequentially emitted clockwise along the single crystal silicon wafer,

and with

The final β value is also different due to the calculation of (b), and thus the β value is 90 ° when calculated for the formula (1), but 270 ° when calculated for the formula (2).

When the ultrasonic waves emitted by the ultrasonic generator are sequentially emitted along the edge of the monocrystalline silicon wafer clockwise or anticlockwise, the result of the beta value is also 90 degrees or 270 degrees; meanwhile, the other three types and crystal orientations of the monocrystalline silicon wafer are based on the same principle, so that when the type and the crystal orientation of the monocrystalline silicon wafer are determined, the clockwise or anticlockwise ultrasonic generator does not need to be used for sequentially emitting along the edge of the monocrystalline silicon wafer, the sequence substituted into the step S311 does not need to be considered, the type and the crystal orientation of the monocrystalline silicon wafer can be judged according to the calculation result of the step S312, and the detected monocrystalline silicon wafer can be effectively identified and subjected to classified delivery blanking in the next step.

As another preferred embodiment of the present invention, as shown in fig. 1-3, a first support frame (4) is further fixedly mounted on the first carrying platform (1), and the vacant basket pushing mechanism (15) is fixedly mounted on the first support frame (4); the vacant basket pushing mechanism (15) comprises a servo motor (16) fixedly arranged on the first support frame (4), a second electric push rod (17) arranged at the output end of the servo motor (16), and a second push plate (18) fixedly arranged at the output end of the second electric push rod (17); as shown in fig. 14, both sides of the second pushing plate (18) are fixedly connected with fourth baffles (27), the positions of both sides of the basket are limited by the fourth baffles (27), it is avoided that the basket slides due to the influence of the turntable 11 in the pushing process, so that the basket cannot accurately move to the position of the basket output by any one group of the first limiting blocks 8 on the first carrying platform 1, a plurality of second reinforcing ribs (28) are fixedly mounted on the second pushing plate (18), the supporting strength of the second pushing plate 18 is improved by the second reinforcing ribs 28, the basket pushing process of the second pushing plate 18 is prevented from being greatly bent, the pushing stability of the second pushing plate 18 is improved, a second process hole (29) is formed in one side of the second pushing plate (18), the lightweight design of the second pushing plate 18 is realized through the second process hole 29, the manufacturing cost of the second pushing plate 18 is reduced, a plurality of connecting plates (30) are fixedly mounted on the inner walls of both sides of the second process hole (29), the supporting strength of both sides of the second process hole 29 is improved through the connecting plates (30), and the pushing stability of the second pushing plate 18 is further ensured.

Further preferably, as shown in fig. 2 and fig. 15, two second baffle plates 14 are fixedly mounted on the first carrying platform 1, one end of each second baffle plate 14 extends obliquely onto the rotating disk 11, and one end of each second baffle plate 14 extending onto the rotating disk 11 bends inward, so as to improve the limiting effect on the flower basket on the rotating disk 11; a first fixing angle iron 19 is fixedly installed on one side of the second baffle plate 14, the second baffle plate 14 is fixedly connected with the first carrying platform 1 through the first fixing angle iron 19, as an implementation manner of the embodiment, the first fixing angle iron 19 is welded with the second baffle plate 14 to ensure that one side of the second baffle plate 14 is smooth, abrasion generated in the guiding process of the flower basket is reduced, the service life of the flower basket is prolonged, an arc section 20 is arranged on the second baffle plate 14, the guiding of the second baffle plate 14 during guiding of the flower basket is improved through the arc section 20 to be smoother, severe impact generated in the guiding process of the flower basket by the second baffle plate 14 is avoided, further damage to wafers in the flower basket is avoided, a plurality of first reinforcing ribs 21 are fixedly installed on one side of the second baffle plate 14, the supporting strength of the second baffle plate 14 is improved through the first reinforcing ribs 21, further the guiding stability of the second baffle plate 14 is ensured, a plurality of first process holes 22 are formed in one side of the second baffle plate 14, the lightweight design of the second baffle plate 14 is realized through the first process holes 22, and the manufacturing cost of the second baffle plate 14 is reduced; a plurality of third fixed angle irons 24 are fixedly installed on one side of the first carrying platform 1, a same supporting plate 13 is fixedly installed on the plurality of third fixed angle irons 24, the supporting plate 13 is welded with the third fixed angle irons 24 to guarantee the smoothness of the top of the supporting plate 13, the abrasion generated in the guiding process of the flower basket is reduced, the service life of the flower basket is prolonged, a third baffle plate 26 is fixedly installed on one side of the supporting plate 13 far away from the first carrying platform 1, as an implementation mode of the embodiment, the third baffle plate 26 is welded with the supporting plate 13 to guarantee the smoothness of the top of the supporting plate 13, the abrasion generated in the guiding process of the flower basket is reduced, the service life of the flower basket is prolonged, meanwhile, the flower basket on the supporting plate 13 is limited through the third baffle plate 26, the flower basket on the supporting plate 13 is prevented from falling to the ground, and the safety in the sorting process of the wafer is guaranteed, one side fixedly connected with bracing piece 25 of third fixed angle bar 24, bracing piece 25 keeps away from the one end and the third baffle 26 fixed mounting of third fixed angle bar 24, improve backup pad 13's support intensity through bracing piece 25, avoid backup pad 13 long-time back atress to take place the bending, prolong backup pad 13's life, one side fixed mounting of backup pad 13 has second fixed angle bar 23, second fixed angle bar 23 and second baffle 14 fixed mounting, in order to further improve backup pad 13 and second baffle 14's support intensity, improve the stability in use of this device, as an implementation of this embodiment, one side of second baffle 14 and third baffle 26 all can be provided with the foam-rubber cushion, further reduce the impact that produces between basket of flowers and second baffle 14 and third baffle 26.

The basket of flowers is stopped through two second baffles 14, and the basket of flowers produces with sorting mechanical arm 7 when avoiding the basket of flowers motion and interferes, and then influences the work precision of this device, and the basket of flowers of accomplishing the collection on carousel 11 through the one end that second baffle 14 leaned on the carousel 11 and extended guides to backup pad 13 on, supports temporarily and deposits the basket of flowers of accomplishing the collection through backup pad 13, and the staff of being convenient for picks up at any time, reduces staff's work load.

1) The control panel 32 controls a mechanical arm of the feeding device to place a feeding basket provided with cut monocrystalline silicon wafers which are not classified and screened at the first limiting block 8 of the third carrying platform 3 for limiting, and the control panel 32 controls a sorting mechanical arm 7 on the third carrying platform 3 to sequentially move the monocrystalline silicon wafers in the feeding basket to the second carrying platform 2;

2) The control panel 32 controls the size detection unit 6 in the second carrying platform 2 to be started, sequentially identifies whether the monocrystalline silicon wafer moved to the second carrying platform 2 is a fragment or not, identifies the wafer type and the crystal orientation of the monocrystalline silicon wafer, and transmits the identified result to the control panel 32;

3) After receiving the recognition result, the control panel 32 sends an instruction to the sorting mechanical arm 7 on the first carrier 1, controls the sorting mechanical arm 7 on the first carrier 1 to put the detected monocrystalline silicon wafer into the corresponding monocrystalline silicon wafer output basket arranged on the inner side of the turntable 11 according to the wafer type and the crystal orientation of the monocrystalline silicon wafer obtained by recognition, and puts the fragments into the monocrystalline silicon wafer output basket which is used for separately containing the fragments;

4) When a monitoring unit in a first electric push rod 9 monitors that one or more monocrystalline silicon wafer output baskets on a turntable 11 are full of monocrystalline silicon wafers in real time, a signal is sent to a control panel 32, the control panel 32 controls the first electric push rod 9 to push the monocrystalline silicon wafer output baskets full of monocrystalline silicon wafers to the first turntable 11, then the turntable 11 is controlled to rotate to the discharging side of the monocrystalline silicon wafer output baskets, the control panel 32 continuously controls a mechanical arm of a discharging device to move the classified monocrystalline silicon wafer output baskets out of a first carrying platform 3, and controls an empty basket pushing mechanism 15 to push the empty monocrystalline silicon wafer output baskets to the inner side of the turntable 11, so that each empty monocrystalline silicon wafer output basket abuts against any one group of two first limiting blocks 8 on the first carrying platform 1 for limiting and waiting for delivery of the screened monocrystalline silicon wafers;

5) After the monitoring module in the third loading platform 3 monitors the empty basket in the feeding flower basket filled with the cut monocrystalline silicon wafers, the control panel 32 receives the signal, and the control panel 32 continuously controls the mechanical arm of the feeding device to move the feeding flower basket filled with the monocrystalline silicon wafers which are not classified and screened after being cut into the third loading platform 3, so that the continuous screening and fragment removal in the preparation process of the monocrystalline silicon wafers are completed.

Further preferably, the size detection unit 6 in step 2) sequentially identifies the wafer type and the crystal orientation of the single crystal silicon wafer moved onto the second stage 2, and includes the following steps:

2.1 A main control module of the size detection unit 6 controls an ultrasonic generator to sequentially send ultrasonic waves clockwise or anticlockwise to a point on the edge of the monocrystalline silicon wafer right above the center of the monocrystalline silicon wafer in real time, and controls an ultrasonic receiver to receive ultrasonic signals reflected by the monocrystalline silicon wafer;

2.2 The main control module of the size detection unit 6 judges whether the detected monocrystalline silicon piece has a main positioning edge or not according to the data acquired in the step 2.1), and further judges whether the detected monocrystalline silicon piece is a complete wafer without a main positioning edge or a secondary positioning edge or a fragment of the monocrystalline silicon piece;

2.3 According to the judgment result of the step 2.2), under the condition that the detected monocrystalline silicon wafer is confirmed to have a main positioning edge, determining the main positioning edge and the secondary positioning edge of the detected monocrystalline silicon wafer and determining the type and the crystal orientation of the monocrystalline silicon wafer;

2.4 Then the main control module of the size detection unit 6 sends an instruction to the control panel 32, and the control panel 32 controls the sorting mechanical arm on the first stage 7 to sort and deliver the monocrystalline silicon fragments and the different types of monocrystalline silicon pieces obtained by identification to different monocrystalline silicon piece output baskets.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. The monocrystalline silicon piece sorting device comprises a first carrying platform (1), a second carrying platform (2) and a third carrying platform (3), wherein the third carrying platform (3) is used for continuously conveying monocrystalline silicon pieces obtained after cutting to the second carrying platform (2), the second carrying platform (2) is used for screening the monocrystalline silicon pieces, and the first carrying platform (1) is used for classifying the monocrystalline silicon pieces of different wafer types and crystal orientations obtained after screening into different vacant monocrystalline silicon piece output baskets;

the wafer size detection device is characterized in that a second support frame (5) is fixedly mounted on the second carrying platform (2), a size detection unit (6) for detecting the size of a wafer is fixedly mounted on the second support frame (5), and the size detection unit (6) comprises a main control module, an ultrasonic generator and an ultrasonic receiver; a sorting mechanical arm (7) used for moving the monocrystalline silicon wafers and a plurality of groups of first limiting blocks (8) are fixedly mounted on the first carrying platform (1) and the third carrying platform (3), a rotating disc (11) used for conveying the monocrystalline silicon wafer output baskets to one side of the first carrying platform (1) is rotatably sleeved on the first carrying platform (1), a plurality of first electric push rods (9) used for pushing the monocrystalline silicon wafer output baskets to the rotating disc (11) and an empty basket pushing mechanism (15) used for pushing empty baskets to the inner side of the rotating disc (11) and abutting any one of the plurality of groups of first limiting blocks (8) on the first carrying platform (1) for limiting pushing are fixedly mounted on the first carrying platform (1);

the device is characterized in that monitoring modules for detecting the number of monocrystalline silicon wafers stored in the flower basket in real time are fixedly mounted on the third carrying platform (3) and the first electric push rod (9), a third supporting frame (31) is fixedly mounted on the second carrying platform (2), one side of the third supporting frame (31) is rotatably connected with a control panel (32), and the control panel (32) is in wireless communication connection with the size detection unit (6), the first electric push rod (9), the monitoring modules on the third carrying platform (3) and the first electric push rod (9), the turntable (11) and the vacant flower basket pushing mechanism (15).

2. The single crystal silicon wafer sorting apparatus according to claim 1, wherein the size detecting unit (6) screens the single crystal silicon wafer obtained after the slicing, comprising the steps of:

s1: the control panel (32) sends an instruction to the main control module, the main control module controls the ultrasonic generator to sequentially send out ultrasonic waves in real time from a point right above the center of the detected monocrystalline silicon piece to the edge of the monocrystalline silicon piece, and an ultrasonic receiver which is positioned on the same horizontal plane with the ultrasonic generator receives the ultrasonic waves reflected in real time;

s2: according to the change condition of the included angle theta (t) between the axis of the center of the wafer circle O of the monocrystalline silicon wafer detected by the ultrasonic receiver in real time in the step S1 and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point, judgingIf the detected monocrystalline silicon piece has a main positioning edge, if the included angle theta (t) between the axis of the center of the wafer circle O of the monocrystalline silicon piece detected in real time and the connecting line between the edge point of the monocrystalline silicon piece receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one period of transmitting the ultrasonic waves in real time along one circle of the edge of the monocrystalline silicon piece _s If the silicon single crystal wafer is changed, the detected silicon single crystal wafer has a main positioning edge, and the step S3 is carried out; otherwise, judging that the detected monocrystalline silicon wafer has no positioning edge, and entering the step S4;

s3: according to the judgment result of the step S2, if the wafer has a main positioning edge, a positioning edge recognition calculation model is constructed so as to determine the main positioning edge and the secondary positioning edge and determine the type and the crystal orientation of the monocrystalline silicon wafer;

s4: and according to the judgment result of the step S2, if no main positioning edge exists, whether the single crystal silicon wafer fragments exist is determined, if yes, the main control module sends an instruction to the control panel (32), and the control panel (32) controls the sorting mechanical arm (7) on the first carrying platform (1) to throw the fragments into a single crystal silicon wafer output basket for collecting the fragments.

3. The single crystal silicon wafer sorting apparatus according to claim 2, wherein the rule of the step S2 of determining whether the detected single crystal silicon wafer has a main positioning edge is:

if the included angle theta (t) between the wafer center O axis of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one cycle of transmitting the ultrasonic waves in real time along one circle of the edge of the monocrystalline silicon wafer _s The included angle theta (t) between the axis of the center O of the wafer of the monocrystalline silicon wafer and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point is theta _max The detected monocrystalline silicon wafer is a complete wafer with the radius of r and has no main positioning edge or secondary positioning edge;

if the line between the axis of the center O of the wafer of the monocrystalline silicon wafer detected in real time and the edge point of the monocrystalline silicon wafer receiving the ultrasonic wave and the ultrasonic wave transmitting point is connectedThe included angle theta (t) between the two is within the time t of one cycle of real-time ultrasonic wave emission along one circle of the edge of the monocrystalline silicon piece _s The internal change is irregular, and the time t of one period of real-time ultrasonic wave emission in one circle along the edge of the monocrystalline silicon wafer is not met _s And judging that the monocrystalline silicon wafer is a fragment of the monocrystalline silicon wafer if the condition of no change in the monocrystalline silicon wafer does not meet the condition of having a main positioning edge.

4. The single crystal silicon wafer sorting device according to claim 3, wherein the S3 step of constructing a positioning edge recognition calculation model comprises the steps of:

s301: according to the step S1, the included angle theta (t) between the wafer center O axis of the monocrystalline silicon wafer detected in real time and the connecting line between the edge point of the monocrystalline silicon wafer receiving the ultrasonic waves and the ultrasonic wave transmitting point is within the time t of one period of real-time transmission of the ultrasonic waves along one circle of the edge of the monocrystalline silicon wafer _s Judging the condition that the detected monocrystalline silicon wafer has a main positioning edge and a secondary positioning edge at the moment of the internal change time point; if the change time points are only three, the detected monocrystalline silicon wafer is the monocrystalline silicon wafer only with the main positioning edge, and the monocrystalline silicon wafer is the P type monocrystalline silicon wafer<111>A crystal orientation monocrystalline silicon wafer; if the change time points are six, the detected monocrystalline silicon piece is a monocrystalline silicon piece which is provided with a main positioning edge and a secondary positioning edge, the main positioning edge corresponds to one group of change time points, and the secondary positioning edge corresponds to the other group of change time points;

Wherein the first group of change time points is

And

to be at

And

the time in between; | is calculated as an absolute value;

to detect a first minimum angle

At the time of the day,

The initial moment of time of the decrease is,

for detecting included angle theta (t) from a first minimum angle

Gradually increases to a fixed value theta _max The final time of (d);

wherein the second group of change time points is

And

to be at

And

the time in between;

to detect a second minimum angle

At the time of the day,

The initial moment of time of the decrease is,

for detecting angle theta (t) from a second minimum angle

Gradually increases to a fixed value theta _max The final time of (d);

To

To

5. The single crystal silicon wafer sorting device according to claim 4, wherein the determination of the wafer type and the crystal orientation of the single crystal silicon wafer in the step S3 comprises the steps of:

wherein i =1,2,j =1,2,i ≠ j, i.e. if

Is composed of

Then

Is composed of

If it is

Is composed of

Then the

Is composed of

And

6. The single crystal silicon wafer sorting device according to claim 1, wherein a first support frame (4) is further fixedly mounted on the first carrying platform (1), and the vacant basket pushing mechanism (15) is fixedly mounted on the first support frame (4); the vacant basket pushing mechanism (15) comprises a servo motor (16) fixedly mounted on the first support frame (4), a second electric push rod (17) mounted at the output end of the servo motor (16), and a second push plate (18) fixedly mounted at the output end of the second electric push rod (17); the equal fixedly connected with fourth baffle (27) in second push pedal (18) both sides, fixed mounting has a plurality of second strengthening ribs (28) on second push pedal (18), second fabrication hole (29) have been seted up to one side of second push pedal (18), the both sides inner wall fixed mounting of second fabrication hole (29) has a plurality of connecting plates (30).

7. The single crystal silicon wafer sorting device according to claim 1, wherein two second baffles (14) are fixedly mounted on the first carrying platform (1), one end of each second baffle (14) obliquely extends onto the rotating disc (11), and one end of each second baffle (14) extending onto the rotating disc (11) is bent inwards to be close to the circle center of the rotating disc (11); one side of the second baffle (14) is fixedly provided with a first fixed angle iron (19), the second baffle (14) is fixedly connected with the first carrying platform (1) through the first fixed angle iron (19), an arc-shaped section (20) is arranged on the second baffle (14), one side of the second baffle (14) provided with the first fixed angle iron (19) is fixedly provided with a plurality of first reinforcing ribs (21), and a plurality of first process holes (22) are formed in the gap between the plurality of first reinforcing ribs (21) of the second baffle (14).

8. The monocrystalline silicon piece sorting device according to claim 7, wherein a plurality of third fixed angle irons (24) are fixedly installed on one side of the first carrying platform (1), the same supporting plate (13) is fixedly installed on the plurality of third fixed angle irons (24), a third baffle plate (26) is fixedly installed on one side of the supporting plate (13) far away from the first carrying platform (1), a supporting rod (25) is fixedly connected to one side of the third fixed angle irons (24) far away from the first carrying platform (1), one end of the supporting rod (25) far away from the third fixed angle irons (24) is fixedly installed with the third baffle plate (26), a second fixed angle iron (23) is fixedly installed on one side of the supporting plate (13), and the second fixed angle iron (23) is fixedly installed with the second baffle plate (14).

9. A method for sorting a single crystal silicon wafer by using the apparatus according to any one of claims 1 to 8, comprising the steps of;

1) the control panel (32) controls a mechanical arm of the feeding device to place a feeding basket provided with cut monocrystalline silicon wafers which are not classified and screened on the first limiting block (8) of the third carrying platform (3) for limiting, and the control panel (32) controls a sorting mechanical arm (7) on the third carrying platform (3) to sequentially move the monocrystalline silicon wafers in the feeding basket to the second carrying platform (2);

2) The control panel (32) controls a size detection unit (6) in the second carrying platform (2) to be started, whether the monocrystalline silicon wafers moved to the second carrying platform (2) are fragments or not is sequentially identified, the wafer types and the wafer orientations of the monocrystalline silicon wafers are identified, and the identified results are transmitted to the control panel (32);

3) After receiving the recognition result, the control panel (32) sends an instruction to a sorting mechanical arm (7) on the first carrying platform (1), controls the sorting mechanical arm (7) on the first carrying platform (1) to throw the detected monocrystalline silicon wafers into corresponding monocrystalline silicon wafer output baskets placed on the inner side of the turntable (11) according to the wafer types and crystal orientations of the monocrystalline silicon wafers recognized by the detected monocrystalline silicon wafers, and throws the fragments into the monocrystalline silicon wafer output baskets containing the fragments separately;

4) When monitoring that one or more monocrystalline silicon wafer output baskets on the turntable (11) are full of monocrystalline silicon wafers in real time, a monitoring unit in the first electric push rod (9) sends a signal to the control panel (32), the control panel (32) controls the first electric push rod (9) to push the monocrystalline silicon wafer output baskets full of monocrystalline silicon wafers to the first turntable (11), then controls the turntable (11) to rotate to the blanking side of the monocrystalline silicon wafer output baskets, the control panel (32) continuously controls a mechanical arm of a blanking device to move the classified monocrystalline silicon wafer output baskets out of the first carrying platform (3) and controls the empty basket pushing mechanism (15) to push the empty monocrystalline silicon wafer output baskets to the inner side of the turntable (11), so that each empty monocrystalline silicon wafer output basket and any two first limiting blocks (8) on the first carrying platform (1) abut against limiting blocks to wait for the screened monocrystalline silicon wafers to enter into delivery;

5) After the monitoring module in the third carrying platform (3) monitors an empty basket in the feeding flower basket filled with cut monocrystalline silicon wafers, the control panel (32) receives the signal, and the control panel (32) continuously controls the mechanical arm of the feeding device to move the feeding flower basket filled with the monocrystalline silicon wafers which are not classified and screened after being cut into the third carrying platform (3) so as to complete screening and fragment removal in the continuous monocrystalline silicon wafer preparation process.

10. The method for sorting single crystal silicon wafers according to claim 9, wherein the size detection unit (6) in the step 2) sequentially identifies the wafer type and the crystal orientation of the single crystal silicon wafer moved onto the second stage (2), comprising the steps of:

2.1 A main control module of the size detection unit (6) controls an ultrasonic generator to sequentially send ultrasonic waves to points on the edge of the monocrystalline silicon wafer right above the center of the monocrystalline silicon wafer in real time, and controls an ultrasonic receiver to receive ultrasonic signals reflected by the monocrystalline silicon wafer;

2.2 A main control module of the size detection unit (6) judges whether the detected monocrystalline silicon wafer has a main positioning edge or not according to the data acquired in the step 2.1), and further judges whether the detected monocrystalline silicon wafer is a complete wafer without a main positioning edge or a secondary positioning edge or a fragment of the monocrystalline silicon wafer;

2.4 Then a main control module of the size detection unit (6) sends an instruction to a control panel (32), and the control panel (32) controls a sorting mechanical arm on the first carrying platform (7) to sort and deliver the monocrystalline silicon fragments and the different types of monocrystalline silicon pieces obtained by identification to different monocrystalline silicon piece output baskets.