KR20110001446U - The development equipment of auto Markingsurface defect machine vision and using methods of semiconductor IC - Google Patents

Abstract

 As information and communication develops, communication systems must develop accordingly, and the trend toward miniaturization and lightening of the system is increasing. The present invention is a device that automatically inspects the state of the mark on the surface of the semiconductor and automatically detects the defect in Machine Vision to check and classify the defect. Mark inspection items are Chipping, ScratchSurface, Blemish Surface, Missing Reference, MissingMark, Reverse Mark, Tilted Mark, WrongPosition Mark, PoorContrast, Missing Char, Broken Char, Splash Char, Wrong Size Char, Wrong Char (OCV). The Mark inspection result window was invented to display the number of errors for Mark inspection items and to display the total number of good and defective items, the total number of inspection and the number of satisfaction of the good. The present invention aims to increase the productivity by contributing to the identification of the cause of the defective rate and improvement of quality by automatically inspecting the quality of the marked letters, the Seral No. and the surface of the semiconductor IC and the quality in the manufacturing line in real time. The system consists of machine vision system, inspection method, inspection algorithm and system to classify defects. This system consists of one line scan CCD camera for inspection of marked letters and Seral No. of semiconductor IC, surface grabber, computer for lighting, computer for lighting, and Riview inspection. It consists of hardware and software such as 1 area scan CCD camera, frame grabber, computer for image processing, and lighting equipment. First of all, it is a device that captures the image of the object, and the image data is transferred to the computer's memory through the image frame grabber. CCD camera consists of camera body, signal cable and lens. It is a device that receives the image data stored in the CCD camera, and is in charge of driving and interface of the CCD camera. The frame grabber used in this system consists of three parts: camera interface, image memory and PCI bus interface. The instrument part consists of a transport mechanism to smooth the part and transport it onto the correct inspection system, an optical mechanism for the optimal inspection environment, and a housing for light control. And an optical filter. The control panel is a PLC and other electrical and electronic systems that provide outputs to the motion controller, proximity sensor, lighting controller, host computer and peripheral equipment for driving inspection programs, and reports on defective parts. The inspection software runs on Windows XP's O / S on the main computer, controls peripheral devices, performs inspections, sets inspection items and parameters, as well as marked letters and seral numbers and surfaces of ICs in semiconductors. It plays a key role in storing images about the state of.

 Marked letters and Seral No. and surface condition inspection system of semiconductor IC, semiconductor component inspection equipment, LCD component inspection equipment, electrical component inspection equipment, electronic component inspection equipment, mechanical component inspection equipment.

Description

 The development equipment of auto marking, surface defect machine vision and using methods of semiconductor IC

 This inspection technology field is a semiconductor component element that is essential for home appliances and communication equipments, and it cannot be identified by the naked eye during production, and it must be expanded by 10 times or more through a microscope and perform automatic inspection as it flows in the process. This inspection device is an important device that automatically checks the quality of the marked letters, the seral number and the surface appearance of semiconductor ICs. It requires accurate defect inspection and needs to be processed quickly and accurately. In addition, the configuration of the inspection equipment of the present invention is largely divided as shown in the [representative diagram], the feeder part, the escape part and the transfer part, the instrument part, the inspection part and the lighting, the optical part, the control panel and the inspection software part, the driving unit to put the product into the vision part by alignment. It consists of a motor part. The mechanism part is a housing for the transport mechanism, the optical mechanism for the optimal inspection environment, and the light control to facilitate the movement and alignment of the marked letters and the Seral No. and the surface state of the semiconductor IC, and to move them over the correct inspection system. The optics consists of camera and lens, high brightness LED special lighting and optical filter to get clear images. In addition, the inspection unit should use 1 set of line scan cameras, and in case of defects, 1 set area camera is used to enlarge the review and defective parts for the purpose of reproducing the marked letters of the IC, the serial number and the surface state of the semiconductor. do. Inspection conditions were developed for full inspection. And the method of automatic inspection of the marked letters, Seral No. and surface condition of semiconductor IC is as follows.

-. Introduce the marked letters, Seral No. and surface of the IC of the semiconductor discharged from the conveyor at the end of the process into the tester.

-. Marked letters, Seral No. and surface condition of the inserted IC's IC are inspected by taking a picture of the IC's top as it progresses.

-. Each inspection determines whether the IC's marked letters, the serial number, and the surface are defective or not.

-. In the case of good products, make sure to load them into good cassete.

-. In case of defective product, load it into defective product cassette.

-. It displays the inspection results and statistics. Therefore, this device is an inspection equipment using robot technology as part of the field that adopts the automation technology in the production process, and the field that requires image recognition processing technology, precision control technology, precision optical technology, and mechanical design technology. to be.

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[Image 3] Image processing, Craig A.Lindly

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[5] Laser Focus World, A PennWell Publication

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[7] Rfael. C conzalez and Richard E. Woods, Digital Image

        Processingrentic Hall 2001.

[8] Simon Haykim, Adaptive Filter Wedge Bridge Prence Hall 2002.

9 Tannas. L> E.Jr, "Evolution of flat-panel display," proceedings of

 the IEEE, vol82, no.4, pp 499-509, Apr. 1994

This inspection technology field is a semiconductor component element, which is essentially installed in home appliances and communication devices, and cannot be identified by the naked eye at the time of production, and is only a field that can be inspected by expanding more than 10 times through a microscope. Therefore, it is a field that needs image recognition processing technology, precision control technology, precision optical technology, and mechanical design technology as inspection equipment using robot technology. The inspection equipment of the present invention has been developed by using a new algorithm in a field that is difficult to inspect in the past, and has developed the inspection speed and precision to suit the wheel scene working environment. The developed test items and their solutions are as follows. The types of inspection items are Chipping, ScratchSurface, Blemish Surface, Missing Reference, MissingMark, Reverse Mark, Tilted Mark, WrongPosition Mark, PoorContrast, Missing Char, Broken Char, Splash Char, Wrong Size Char, Wrong Char (OCV). . The inspection algorithm that effectively detects such inspection items is as follows.

-Create and modify Reference Model

The purpose of creating the reference model is to check the mark of the mark by compensating the movement and rotation amount even if the package is moved or rotated based on the set reference model.

Click the Reference Model button in the Tools box and set two Reference Model ROIs on the left edge of the package as shown above. To delete a badly created reference model, delete it by pressing the Delete button when the reference model becomes available for deletion with the Select button selected. To adjust the size of the Reference Model ROI, first select the Select button.

-Create and modify surface area

The purpose of creating the surface area is to check whether the chipping or scratch surface errors have occurred on the mold surface of the processed package. Press the Surface Area button in the Tools box and set it to the center of the white outline frame as shown above. To delete a badly created surface area, press the Delete button when the surface area becomes available for deletion with the Select button selected. Resizing the Surface Area ROI is done by first selecting the Select button box, and then using the mouse or keyboard navigation keys while the Surface Area ROI is editable. In Mark inspection, it is recommended to set the Surface Area in the middle between the Picker's outer frame and the package.

After creating and modifying the Surface Area ROI, click the Next button to execute the next step.

When the Reference Model ROI is modifiable, use the mouse or keyboard navigation keys to modify it. This system is a feeder part, transfer part, instrument part, inspection part and lighting part and optical part, control panel and inspection that align the marked letters and seral No. of the IC of the semiconductor and the state of the surface to the vision part as alignment It consists of software part and driving motor part. First of all, the feeder unit arranges the marked letters, the seral number, and the surface state of the loaded semiconductor IC to more than 100PPM and supplies it to Escape. Then, Transfer serves to put the marked letters and Seral No. of the IC of the semiconductor arranged on the escape and the state of the surface on the stage of the vision part, and the mechanical part is the marked letters and Seral No. of the IC of the semiconductor and It consists of a transport mechanism to smooth the flow of the surface condition and transfer it onto the correct inspection system, an optical mechanism for the optimal inspection environment, and a housing for lighting control. It is composed of 1 set of line scan camera and lens, high brightness LED special lighting and optical filter to obtain the image of Seral No. and surface condition. The control part was developed as a PLC and other electrical and electronic systems that output power to the host computer and peripheral equipment for driving the motion control unit, proximity sensor, lighting control unit, inspection program, and report the defective parts. The board block diagram and the flow chart are shown to illustrate the function.

Initiation of the inspection system of the semiconductor device's semiconductor IC's marked letters, Seral No. and surface condition is started by the inspection software. The user adjusts the inspection object and inspection parameters to set the degree of judgment and the inspection. To start. The transfer mechanism automatically detects and operates the flow of the marked letters and seral numbers and surface states of the IC of the semiconductor component element semiconductor. It operates and gets the image of the IC's marked letter, the image of Seral No. and the state of the surface, and it is transmitted from the main computer to check and determine whether it is defective or normal. Frame Grabber is a plug-n-play board for acquiring images in Machine Vision application program. It can easily interface the camera connected with Frame Grabber with various trigger, strobe and asynchronous reset options, and control and monitor external events. There is an I / O function. Frame Grabber consists of three main parts: Camera Interface, Image Memory and PCI-bus Interface. Connector Pin-Out consists of two 15-pin / 26-pin video connectors and digital I / O ports. . Power terminal, 2. camera pulse terminal, 3. lighting pulse terminal 4. motor driver terminal, 5. limit sensor terminal

The following briefly summarizes the function of each terminal.

 1) MCU: A medium that executes commands received through serial communication with a PC.

 2) Power supply unit: Circuit that applies voltage and current required for electronic parts.

 3) Motor drive part and lighting: pulse and driving direction signal for driving motor

    Make circuit and lighting signal applied.

 4) Pulse generator: The camera can be used to take a test object while the X-Y Stage is moving.

    Circuit giving a pulse.

 5) Sensor drive unit: Circuit to determine the presence or absence of the inspection object.

When a defect is detected, the main computer sends a defective output signal to the PLC to send out an output signal to the user so that the user can recognize the defect, and at the same time, sends a signal to the ejecting mechanism to eject the defective product. It is designed to allow the user to monitor the signal from the external outputs and perform additional tasks such as changing parameters or adjusting the test settings as required.

1. Marking letters and Seral No. and surface condition inspection part of IC of semiconductor

(1) Line scan CCD camera, 8K ---------- 1 set

(2) magnification lens ----------------- 1 set

(3) Front Ring LED light -------------- 1 unit

(4) frame grabber board --------------- 1 set

(5) fixtures for camera and light ------ 1 unit

2. Marked letters and Seral No. of semiconductor IC and surface re-inspection part

(1) Area scan CCD camera, 1K ---------- 1 set

(2) magnification lens (x30) ------------ 1 set

(3) light ----------------------------- 1 unit

(4) frame grabber board --------------- 1 set

(5) fixtures for camera and light ------ 1 unit

3. System control unit

(1) MCU Part

(2) Control from PC with RS-232C serial communication

(3) Camera Trigger Signal Generation

(4) Deliver Image to PC

(5) Integrate vision system, logistic system, sensor, etc. in PC

    Control

4. Personal Computer

(1) PC for IC Marking inspection & Review --------- 2 set

   master PC and Sleeve PC

(2) PC for Reinspection ------------ 1 set

5. Logistic System

(1) frame -------------------------- 1 unit

(2) aligning unit ------------------ 1 unit

(3) Defective main detection conveyor ------ 1 unit

(4) Extra conveyor ----------------- 1 unit

(5) defective product separation device ------------ 1

(6) other defective products separation device ------- 1

(7) sensors ------------------------ 1 unit

6. Image processing software

(1) image processing algorithm ----- 2 units

(2) GUI ----------------- 1 unit

7. General

1.Descriptions of Objects to Be Inspected

(1) Objects: Marked letters, Seral No. and surface state of IC of Defect for semiconductor.

(2) Conveyor Line Speed: 60meter / min

(3) Inspection Tact time and speed:

Inspection time: 20 ~ 40 ms

-Inspection accuracy: 0.2 ~ 03Mil

(4). Inspection item of the inspection subject:

-Package Surface: Reject Mark

-Package Dimension: 12um (0.5Mil)

-Miss Align: 12um (0.5Mil)

Chipping, ScratchSurface, Blemish Surface,

Missing Reference, MissingMark, Reverse Mark,

Tilted Mark, WrongPosition Mark,

Poor Contrast, Missing Char, Broken Char,

Splash Char, Wrong Size Char, Wrong Char (OCV), etc.

(5) Rosolution: 5um

(6) Detection Capability: 5um defects or larger

This development system examines the marking characters, the serial number, and the surface parts of the semiconductor ICs of semiconductor components, reports the test results to the user, and configures and inspects the machine vision system to isolate defective products. It consists of an optical mechanism for the optimal inspection environment and a housing for lighting control, and the lighting and the camera are operated to obtain the image of the printed letters and the Seral No. of the IC of the semiconductor component device semiconductor and the state of the surface. When the defect is detected, the main computer sends a bad output signal to the PLC so that the user can recognize the fault. Monitor the signal from the external outputs and change the parameters of the test setup if necessary. Or you can perform additional operations to adjust the degree of inspection. At the same time, it sends out a signal to the ejecting mechanism to eject the defective product. Therefore, the present invention automatically inspects the status of the printed letters, the Seral No. and the surface of the IC of the semiconductor semiconductor, and inspects the quality in the manufacturing line in real time to determine the defective rate. It contributes to the cause identification and quality improvement and increases productivity.In case of a defect, the main computer sends a bad output signal to the PLC and sends an output signal to the outside so that the user can recognize the failure. It has the effect of automatically injecting defective items by sending a signal. In addition, the user can change the parameters related to the inspection setting or adjust the inspection degree if necessary, and is designed to be more flexible and convenient than the conventional simple function, and ultimately reduce the defective rate to contribute to the improvement of quality and productivity. It became.

The present invention is designed to prevent contamination during the alignment and inspection process, which is a conventional problem, and the inspection speed is reduced by about two times or more compared to the conventional method, and the inspection accuracy, that is, the inspection yield is improved by three times compared with the conventional method. Developed together.

The present invention relates to the construction, inspection method, and specification of a machine vision system for inspecting the status of marked letters, seral numbers, and surfaces of ICs of semiconductor semiconductors, reporting inspection results to users, and isolating defective products. This vision system is used for hardware, software, and review inspection of one line scan CCD camera, frame grabber, image processing computer, lighting device, etc. It consists of hardware and software such as an area scan CCD camera, a frame grabber, a computer for image processing, a lighting device, etc. The user of this system is operated using a monitor, a mouse, and a keyboard. It adopts a button menu and a wizard method. The system was developed with a camera unit, a frame grabber unit, an optics unit, a control panel, and four modules and instrumentation units.

- a digital CCD camera is an apparatus for recording an image of the object, image data is transferred to the memory of the computer via the Image Frame Grabber. CCD camera consists of camera body, signal cable and lens.

- Frame Grabber is a device subject to transmit image data stored in the CCD Camera, is also in charge of driving and interface of the CCD camera. The frame grabber used in this system consists of three parts: camera interface, image memory and PCI bus interface.

- lighting devices Appropriate lighting equipment is used according to the inspection object and item, and the lighting equipment of this system is composed of red LED light, source and bracket as top lighting. The review lighting device is a top light and consists of a red LED light and a half mirror light.

The control unit was developed as a PLC and other electrical and electronic systems that provide output to the host computer and peripheral equipment for driving motion control, proximity sensors, lighting controls, inspection programs and reports on defective parts.

-The software sector has a user interface with hardware interface modules such as frame grabbers to obtain the marked letters and seral numbers of the ICs of the inspection program's semiconductors and the status images of the surfaces, and digital I / Os that send the test result signals to the PLC. It is developed as a UI module for displaying interface and inspection status, inspection setting module for selecting inspection items and inspection environment setting, and kernel module for analyzing, processing, and measuring images. The developed test items and their solutions are as follows. First of all, the inspection items are Chipping, Scratch Surface, Missing Reference, Missing Mark, Tilted Mark, Wrong Position Mark.

1) Create and modify Reference Model

The purpose of creating the reference model is to check the mark of the mark by compensating the movement and rotation amount even if the package is moved or rotated based on the set reference model.

2) Create and modify Mark Model

The purpose of creating the Mark Model is error such as Chipping, ScratchSurface, Blemish Surface, Missing Reference, MissingMark, Reverse Mark, Tilted Mark, WrongPosition Mark, PoorContrast, Missing Char, Broken Char, Splash Char, Wrong Size Char, Wrong Char (OCV) To check.

Click the Mark Model button in the Tools box to find and set the appropriate letter position to be examined. To adjust the size of the ROI of the Mark Model, first select three Mark Model ROIs by holding down the Select button, and then modify them using the mouse or the keyboard movement keys in the editable state. After creating and modifying the Mark Model ROI, click the Next button to execute the next step. The purpose of the chipping test is to determine whether the molded surface in the package is broken as shown in the chipping parameter box.

Input value of Chipping Area: It shows the minimum size of the area that can be seen by Chipping. In the figure above, it can be seen that the Chipping Area is set to 60 Pixel, which means that if it is over 60 Pixel, it detects as an error.

3) Input value of Reduce Area: The actual package is regarded as reducing the package size by the input value from the package size obtained after package binarization. The reason for this process is that in the surface area between the package and the white outer frame, even if the package area obtained after the binarization process is not chipping, there is a possibility of error processing by chipping.

4) Min / Max input value: Input value for binarization process to obtain package area.

To set the optimal inspection conditions, it is recommended to set the chip area to 60 pixels, reduce area to 2 pixels, and package surface gray to 50 or less to catch the package area after binarization. Since the chipping may occur if the gray value of the buried package surface is more than 50, see if the 3rd Mark lighting is appropriate, adjust the lighting voltage or adjust the brightness with the camera Irish.

5) Scratch Surface Parameter Box

It is a box that modifies the parameter for checking the scratch of the processed package. If the scratch length is more than the input pixel value, it is determined as an error. If the lighting is bright or this material is on the gray surface of the package over 50, the scratch surface error may occur. See if the 3rd Mark lighting is appropriate, adjust the lighting voltage or adjust the brightness with the camera Irish.

6) Missing Reference Parameter Box

The purpose of the Missing Reference check is to determine whether a package exists in the package picker. Missing Reference performs pattern check with trained information. If it is less than Accept Score input value, it is judged as an error, and pattern check searches within angle tolerance.

7) Gray Search: To search the pattern test with the change value of Gray value 0 ~ 255. (Scan speed is slower than Binary Search, but scan is more accurate than Binary Search)

8) Binary Search: To search the pattern test by changing the gray values 0 and 1. (The scan speed is faster than Gray Search, but the scan is less accurate than Binary Search.)

9) Missing Mark Parameter Box

-The purpose of the Missing Mark test is to determine whether there is a Mark on the package mold surface.If it is less than the Accept Score input value compared to the trained data, it is judged as an error and the Missing Mark Test is also a pattern test (Gray / Binary). Search).

10) Tilted Mark parameter box: The purpose of the Tilted Mark inspection is to determine if the print status of the Mark is out of tolerance based on the trained data.

11) Wrong Position Mark parameter box: The purpose of the Wrong Position Mark inspection is to determine the error from the X and Y axis by the pixel value based on the trained data of the Mark. Inspection tact time of this development system is 20 ~ 40 ms and Inspection accuracy is 0.2 ~ 03Mil. As shown in [Fig. 1], the software part is a frame grabber for obtaining the marked character and Seral No. of the IC of the inspection program and the state image of the surface, and a digital I / O that sends the test result signal to the PLC. It was developed as a UI module for displaying the interface between the hardware interface module and the user and the test status, a test setting module for selecting the test items and setting the test environment, and a kernel module for analyzing, processing, and measuring the images. The following is about each drawing, etc. First, [FIG. 3] shows that the inspection is performed by adjusting the X-Y precision stage by the concept of the present development equipment. 4 is a UI showing the display data and control of the equipment as shown in the entire screen, [FIG. 5] is a calibration complete screen of a camera, lighting, and an optical system of a vision system, and [FIG. 6] is an IC of a semiconductor. Marked letter and Seral No. and the appearance of the state inspection equipment appearance of the surface, [FIG. 7] shows the control board flow chart, [FIG. 8] shows the inspection method in a flow chart. 9 is a view showing the angle adjustment position of the measuring device, etc. [10] is a picture of the entire equipment and each part. FIG. 11 is a self-developed Auto X-Y-Z motorized stage part, and FIG. 12 is a front view and a side view of a self-developed Auto X-Y-Z motorized stage part. FIG. 13 is a plan view of a self-developed Auto X-Y-Z motorized stage unit, and FIG. 14 shows the entire equipment drawing and front view, top view, side view, and elevation view.

1 is a software internal structure diagram such as image acquisition and image processing.

2 is a diagram illustrating a process such as the operation flow of the entire equipment and the alignment of parts, and the control process of each part is also included to make it easy to understand.

3 is an overall equipment structure diagram and configuration diagram.

4 is an inspection screen GUI.

5 is a calibration complete screen of a camera, lighting, an optical system, and the like of a vision system.

6 is an overall appearance of the equipment.

7 shows a control board flowchart.

8 shows the inspection method in a flow chart.

Figure 9 shows the angle adjustment position of the measuring instrument and the like.

Figure 10 shows the appearance of the overall equipment.

11 is an auto-developed Auto X-Y-Z motorized stage.

12 is a plan view of a self-developed Auto X-Y-Z motorized stage.

13 is a front view and a side view of a self-developed Auto X-Y-Z motorized stage.

Figure 14 shows the external equipment and front view, side view, elevation view of the overall equipment.

Claims (17)

Invention of Marked Letters and Seral No. and Surface Condition Automatic Inspection Equipment of Semiconductor IC  [Figure 1] and internal structure diagram of Software such as image acquisition and image processing  2 is a schematic diagram illustrating a process such as an operation flow and alignment of an entire apparatus.  Control process diagram of each unit Instrument design and structure diagram of image acquisition unit  3 and the mechanical design, structure, function, etc. of the entire semiconductor IC Marking inspection equipment  [Figure 4] and screen configuration, structure  5 and the overall appearance of the equipment, appearance.  6 and the principle of aligning the photographic and camera, lighting, optical system, etc. of the semiconductor IC marking vision system.  7 and control board flow chart, control mechanism design, control structure, function  8 and system operation principle and method  9 and the angle adjusting position of the measuring instrument  [Figure 10] and the overall equipment, such as each part and configuration design  Motorized X-Y-Z Stage Blueprint and Stage Adjustment Method  FIG. 11 and an auto-developed Auto X-Y-Z motorized stage unit.  12 is a front view, side view of the self-developed Auto X-Y-Z motorized Stage.  Figure 13 and a plan view of a self-developed Auto X-Y-Z motorized Stage.  [Fig. 10] and the overall equipment picture and each configuration and design.  [Figure 14] and the external equipment and front view, side view, elevation view of the entire equipment

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