CN104362111B - Silicon wafer edge breakage automatic detection method - Google Patents

Abstract

The invention relates to a silicon wafer edge breakage automatic detection method and belongs to the field of silicon wafer production. The method includes the steps that firstly, a silicon wafer is drawn out from a basket and horizontally placed on a moving conveyor belt, the conveyor belt drives to the silicon wafer to move until the silicon wafer is conveyed to a silicon wafer stopping position opposite to a camera, a conveying device stops, the camera is automatically focused, the focal distance is automatically adjusted, a picture is shot, a control unit calculates an RGBdiff numerical value of the side face of the whole silicon wafer according to the acquired picture, if the RGBdiff numerical value of a measurement unit exceeds a set threshold value, it is judged that edge breakage is likely to happen in the position, if the RGBdiff numerical value of the measurement unit does not exceed the set threshold value, it is judged that edge breakage is not likely to happen in the position, the control unit controls the conveying device to operate, and a detection system enters a next detection period. The detection system is high in work efficiency, a short pause exists in the working process, the camera is automatically focused, the picture with the high definition is obtained, and detection accuracy is greatly improved.

Description

A kind of automatic testing method of silicon chip chipping

Technical field

The invention belongs to field of silicon chip production, particularly to a kind of method of automatic detection silicon chip chipping.

Background technology

With the fast development of quasiconductor and photovoltaic industry, the prescription more and more higher to silicon chip for the equipment, and chipping is then It is one of topmost mass defect of silicon chip.

Traditional chipping detection method adopts artificial naked eyes recognition detection, and the go-on-go for chipping has sentencing of perception Disconnected.Due to the quantity of silicon chip product in actual production very huge (quantity is up to hundreds thousand of tablet per day), to each silicon Piece carries out manual measurement sorting, then the labor intensity bringing is excessive, and operating cost also can be too high.

Engendered Automatic Measurement Technique later, principle is using fixed-focus camera, the silicon chip being in travel position to be carried out Take pictures, and carry out the analysis of primaries value rgb.

The problem so brought is, in conventional detecting system, using belt conveyance silicon chip, to be in dynamic environment Silicon chip is unstable to be had tiny vibrations, rocks, image blur when causing to find a view；

Using fixed-focus camera, the silicon chip being in travel position is taken pictures, focus image camera to image position, focal length and thing Reason position etc. requires extremely harshness, and the tiny mechanical shock of detecting system also can aggravate image blur, and the rotation of silicon chip also can be led Cause local tomography distortion, lead to flase drop.

Content of the invention

Technical problem to be solved

In order to solve in existing silicon chip detection method, easy flase drop, missing inspection and a kind of automatic detection silicon chip chipping is proposed Method, with realize detecting system high accuracy, closed loop system high-intelligentization.

The technical scheme providing for solving the above problems is:

A kind of method of automatic detection silicon chip chipping it is characterised in that: be by mean of silicon chip transportation and detection apparatus to realize , described silicon chip transportation and detection apparatus include conveyer belt, for driving the motor of conveyer belt operating, sensor, automatically Zoom camera and computer control system, are provided with autozoom camera, in autozoom above the side of the outfan of conveyer belt It is provided with for detecting the sensor that silicon chip passes through at the picture-taking position of camera, described motor, sensor, autozoom Camera is all connected with computer control system；Specifically include following steps:

Step one: silicon wafer horizontal to be detected is placed on the conveyer belt being kept in motion, conveyer belt drives silicon chip to enter Row moves, and when silicon chip passes through sensing station, the silicon chip detecting is sent to computer controls system by sensor by information System；(purpose of this step one is, level is taken out to avoid secondary damage during silicon chip extracting and to ensure that detecting system can be efficient Work, silicon chip is delivered to the precise degrees that fixed position ensures detection, and unconventional " sweep and cross ")

Step 2: computer control system controls motor to stop operating and photographing instruction is sent to autozoom phase Machine, autozoom camera automatic focus adjustable is simultaneously taken pictures, and sends the pictures to computer control system (this step 2 afterwards Purpose is to hold transport ring, opens lower calculating ring, automatic focusing camera automatic focus adjustable be aligned silicon chip side is to ensure static Under state, accessed silicon chip image can have resolution as big as possible it is ensured that follow-up accurate calculation)

Step 3: on the one hand computer control system controls motor to restart, on the other hand to autozoom phase Machine is taken a picture and is calculated and detect:

Photo detection according to obtaining calculates Red Green Blue value rgb of whole silicon chip side, and is designated as rgbavg；Again silicon chip side is divided into several measuring units, and detects the rgb value calculating each detector unit, and remember For rgbs；The misalignment rate value of each detector unit is；

$rgbdiff=\frac{\left(\right|rgbs-rgbavg\left|\right)}{rgbavg}\×100$

Wherein, rgbdiff is the misalignment rate value of each detector unit；

(this step 3 purpose is, try to achieve each unit color value and deviation and try to achieve several deviation ratio magnitude, The position deviation value that thus can more be tended to damage trend is bigger, and it is less to tend to full location deviation, has due to point Some units it is hereby achieved that with chipping position, if cooperation corresponding instrument also can direct measurement go out the degree that crumbles)

Step 4: the misalignment rate of each detector unit that step 3 is obtained and the silicon chip misalignment rate setting Value is compared one by one, and the misalignment rate value if there are some detector unit is more than the silicon chip misalignment rate value setting, Then think that this silicon chip to be detected has chipping；Otherwise, there is not chipping in this silicon chip to be detected；

Complete the automatic detection of silicon chip chipping.

(this step 4 purpose is that the outside corresponding warning facility of cooperation warns this block silicon chip to there is chipping probability, to enter Row sorting or other process, computer survey calculation is concluded numerical value and can be immediately entered next detection cycle for several milliseconds, efficiently transports Turn the detection efficiency improving detecting system)

Compared with prior art, acquired has the beneficial effect that the present invention

(1) sensor fixing duration different from the past stops dynamic formula equipment, and the discrimination capabilities of sensor precisely, sense silicon chip Arrive at signal back computer control system, silicon chip transportation and detection apparatus stop each silicon chip stop position all with auto-focusing Camera is just right, and resting state ensures to find a view validity, improves accuracy of detection.

(2) conveyer belt continuative transport different from the past, the streamline that camera is continuously taken pictures is galloped along on horseback and is seen lamp-based detection mode, Because automatic focusing camera focusing needs necessarily not often, but the photo shooting is with respect to solid Jiao's formula camera, advantage be find a view clear, The distortion factor is little, improves accuracy of detection further.

(3) the above-mentioned automatic focusing camera referring to, sensor, silicon chip transportation and detection apparatus and computer control system are formed One closed loop detecting system, and unconventional open loop detection means, sensor detects no silicon chip in a long time and arrives at, entirely System meeting autostop, could open after ensureing safety by testing staff's detection fault, therefore safety coefficient is higher.

(4) after using this detection means, tristimulus values rgb detection method resolution is higher, and before being not in, photo is no The phenomenon of method identification, is not in more flase drop, detection leakage phenomenon, if making field silicon chip missing inspection, silicon inferior in high precision silicon slice After piece is applied to electronic instrument and equipment or large-sized solar panel devices, once breaking down, whole electronics can be led to Instrument is paralysed, if occurring catastrophe failure also can explode, induce fire and can cause hardly imaginable serious consequence, therefore in high precision silicon Piece makes field, and Si wafer quality is the most important thing.

Brief description

Fig. 1 is conveying arrangement structural representation

Fig. 2 is rgbdiff bit map/bitmap

Fig. 3 is the silicon chip side view that there is chipping defect

Specific embodiment

Described conveying arrangement includes sensor 1, autozoom camera 2 and computer control system 3.

Below, in conjunction with Fig. 1 to Fig. 3 and specific embodiment, the present invention will be further described.

A kind of method of automatic detection silicon chip chipping, is by mean of silicon chip transportation and detection apparatus to realize, described silicon Piece transportation and detection apparatus include conveyer belt, for drive conveyer belt operating motor, sensor 1, autozoom camera and Computer control system 3, is provided with autozoom camera above the side of the outfan of conveyer belt, and autozoom camera can be carried out Auto-focusing, is provided with for detecting the sensor 1 that silicon chip passes through at the picture-taking position of autozoom camera, described driving Motor, sensor 1, autozoom camera 2 are all connected with computer control system 3；

Described autozoom camera 2 also can carry out the angle change of 10-60 degree.

Specifically include following steps:

Step one: silicon wafer horizontal to be detected is placed on the conveyer belt being kept in motion, conveyer belt drives silicon chip to enter Row moves, and when silicon chip passes through sensor 1 position, the silicon chip detecting is arrived at information and sends to computer controls by sensor 1 System 3；

Described motor is connected with conveyer belt, when silicon chip to be detected is extracted out from the gaily decorated basket and is horizontally placed at conveying When on band, computer control system 3 controls motor to rotate, and conveyer belt carries silicon chip and moves, when silicon chip reaches sensing just During device 1 present position, sensor 1 senses that silicon chip arrives at, and will arrive at feedback of the information and return computer control system 3.

Step 2: computer control system controls motor to stop operating and photographing instruction is sent to autozoom phase Machine, autozoom camera automatic focus adjustable is simultaneously taken pictures, and sends the pictures to computer control system afterwards；

Photographing instruction is sent to autozoom camera 2 by computer control system 3, and autozoom camera 2 adjust automatically is burnt Away from, the timer countdown that simultaneous computer control system 3 comprises 1 second, auto-focusing while timing finished timer in 1 second Camera 2 is taken pictures and is completed, and by photo feedback back to computer control system 3.

Step 3: computer control system 3 one aspect controls motor to restart, on the other hand to autozoom phase Machine is taken a picture and is calculated and detect:

Photo detection according to obtaining calculates Red Green Blue value rgb of whole silicon chip side, and is designated as rgbavg；Again silicon chip side is divided into several measuring units, and detects the rgb value calculating each detector unit, and remember For rgbs；The misalignment rate value of each detector unit is；

$rgbdiff=\frac{\left(\right|rgbs-rgbavg\left|\right)}{rgbavg}\×100$

Wherein, rgbdiff is the misalignment rate value of each detector unit；

Computer control system 3 controls motor to start, and simultaneous computer is by the computational methods pair of above-mentioned rgbdiff Silicon chip is detected, electric motor starting just detects simultaneously and completes.

Step 4: the misalignment rate of each detector unit that step 3 is obtained and the silicon chip misalignment rate setting Value is compared one by one, and the misalignment rate value if there are some detector unit is more than the silicon chip misalignment rate value setting, Then think that this silicon chip to be detected has chipping；Otherwise, there is not chipping in this silicon chip to be detected；

As reservation threshold, rgbs is compared external staff's input certain numerical value by computer with rgbavg, if this survey Amount cell colors deviation ratio has exceeded given threshold, then judge that this position has and there is a possibility that chipping, this measuring unit face Colo(u)r bias ratio no exceedes given threshold, then judge that the probability of chipping is excluded in this position, enters next inspection after judging to finish In the survey cycle, prepare to detect next silicon chip, by accordingly outside alarming device testing result fed back to after judging to finish simultaneously External environment condition, operator obtains warning and does respective record and obtain and be judged as existing the silicon chip of chipping and carry out respective handling,

Described sensor 1 may also be disposed in the middle part of conveyer belt, when sensor 1 is arranged in the middle part of conveyer belt, silicon chip quilt Conveying is detected in way, and silicon chip is fed back meeting computer control system 3, computer control system 3 by signal by sensor 1 Control timer 0.5 second reciprocal, on a timeline multiple silicon chip stop positions are set with 0.5 second for spacing, 0.5 reciprocal sec finishes Control unit controls silicon chip transportation and detection apparatus to stop, and now silicon chip, just at silicon chip stop position, then executes above-mentioned successively Step 2, three, four steps.

In conjunction with Fig. 2,3 illustrate, the wherein concrete numerical value of Fig. 2 is as shown in the table:

By can show in above-mentioned table that a little 1～7rgbdiff (misalignment ratio) value is less, then represent herein with everywhere Rgb value is equal, and exclusion where there is the probability of chipping, and 8-14 point position rgbdiff (misalignment ratio) value is larger, corresponding With the presence of several unit shades in Fig. 3, then represent the probability that where there is chipping.

Claims (1)

1. a kind of method of automatic detection silicon chip chipping it is characterised in that: this method is come real by means of silicon chip transportation and detection apparatus Existing, described silicon chip transportation and detection apparatus include conveyer belt, for driving the motor of conveyer belt operating, sensor, automatically Zoom camera and computer control system, are provided with autozoom camera, in autozoom above the side of the outfan of conveyer belt It is provided with the sensor for detecting silicon chip, described motor, sensor, autozoom camera at the picture-taking position of camera All it is connected with computer control system；Specifically include following steps:

Step one: silicon wafer horizontal to be detected is placed on the conveyer belt being kept in motion, conveyer belt drives silicon chip to be moved Dynamic, when silicon chip passes through sensing station, the silicon chip detecting is arrived at information and sends to computer control system by sensor；

Step 2: computer control system controls motor to stop operating and photographing instruction is sent to autozoom camera, Autozoom camera automatic focus adjustable is simultaneously taken pictures, and sends the pictures to computer control system afterwards；

Step 3: on the one hand computer control system controls motor to restart, on the other hand to autozoom camera institute Take a picture and calculated and detect:

Photo detection according to obtaining calculates the tristimulus values rgb of whole silicon chip side, and is designated as rgbavg；Again by silicon chip side Face is divided into several measuring units, and detects the rgb value calculating each detector unit, and is designated as rgbs；Each detection The misalignment rate value of unit is；

$rgbdiff=\frac{\left(\right|rgbs-rgbavg\left|\right)}{rgbavg}\×100$

Wherein, rgbdiff is the misalignment rate value of each detector unit；

Step 4: the misalignment rate of each detector unit that step 3 is obtained with set silicon chip misalignment rate value by One is compared, and the misalignment rate value if there are some detector unit is more than the silicon chip misalignment rate value setting, then recognize There is chipping for this silicon chip to be detected；Otherwise, there is not chipping in this silicon chip to be detected；

Complete the automatic detection of silicon chip chipping.