WO2008084982A1 - Dispositif de reconnaissance optique de code d'identification de tranche - Google Patents

Dispositif de reconnaissance optique de code d'identification de tranche Download PDF

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Publication number
WO2008084982A1
WO2008084982A1 PCT/KR2008/000135 KR2008000135W WO2008084982A1 WO 2008084982 A1 WO2008084982 A1 WO 2008084982A1 KR 2008000135 W KR2008000135 W KR 2008000135W WO 2008084982 A1 WO2008084982 A1 WO 2008084982A1
Authority
WO
WIPO (PCT)
Prior art keywords
wafer
image
illumination
identification code
unit
Prior art date
Application number
PCT/KR2008/000135
Other languages
English (en)
Inventor
Sang-Yun Byun
Original Assignee
Semics Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020070003032A external-priority patent/KR100789698B1/ko
Application filed by Semics Inc. filed Critical Semics Inc.
Priority claimed from KR1020080002394A external-priority patent/KR100952694B1/ko
Publication of WO2008084982A1 publication Critical patent/WO2008084982A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67242—Apparatus for monitoring, sorting or marking
    • H01L21/67294—Apparatus for monitoring, sorting or marking using identification means, e.g. labels on substrates or labels on containers

Definitions

  • the present invention relates to an apparatus for recognizing a wafer identification code by using a wafer prober, and more particularly, to an apparatus for recognizing a wafer identification code capable of accurately recognizing a wafer identification code from a wafer image by controlling an illumination angle of an illumination unit and capturing a clear image of the wafer.
  • a wafer prober station is one of EDS examination devices used for a process of manufacturing a semiconductor which electrically tests whether dies in a wafer state before packaging a semiconductor chip formed on a semiconductor wafer normally operate by contacting an examination probe to a die in the semiconductor wafer and applying an electrical signal to the probe.
  • the aforementioned wafer prober is a device for reducing a loss of raw-material and time to be used for a subsequent packaging process and a packaging test process and the like by early removing a defective die by directly contacting and testing a pad of a wafer.
  • FIG. 1 is a front view illustrating a wafer prober station. Referring FIG.
  • the wafer prober station is constructed with a wafer loader for conveying a semiconductor wafer from a FOUP or cassette to a position to be tested or onto a chuck, a stage for enabling a wafer to contact a probe card by precisely conveying the wafer so as to test the wafer, and a tester for examining the wafer located on the chuck on the stage.
  • a probe card is mounted on a header of the tester. It is checked whether a chip is defective by applying an electrical signal to the chip on the wafer by using the probe card and measuring the result.
  • the wafer prober station needs to recognize a type, a lot number, and a wafer identification code of the wafer to be tested. For this, a unique identification code is allocated to each wafer. Each identification code is displayed at a predetermined position by using an etching or a printing technique on a flat surface or a predetermined position on the flat surface. A technique of recognizing the wafer identification code by using a camera is referred to as optical character recognition (hereinafter, abbreviated to 'OCR').
  • optical character recognition hereinafter, abbreviated to 'OCR'
  • FIG. 2 illustrates a schematic structure of an OCR apparatus of a wafer prober station according to a conventional technique.
  • the conventional OCR apparatus is combined with a camera module and an illumination module.
  • a procedure of identifying the wafer identification code (ID) by using the OCR apparatus with the aforementioned structure will be briefly described.
  • a flat/notch of the wafer is recognized by using an optical sensor and a centering camera by moving or rotating the wafer located on a wafer seat by controlling a motor and a motor driving unit.
  • a charge coupled device (CCD) camera for identifying a wafer ID captures an area in which the wafer ID is printed and recognizes the wafer ID by processing and analyzing the captured image.
  • CCD charge coupled device
  • a reflection angle of illumination light from the wafer surface or an amount of reflected light are different depending on a method of processing a surface on which the wafer identification code is printed or a method of printing the wafer identification code.
  • the wafer identification code may not be recognized, if a type of a wafer is changed.
  • the present invention provides an apparatus for recognizing a wafer identification code capable of accurately recognizing the wafer identification code by adjusting an angle of an illumination unit and an amount of light provided to a surface of a wafer.
  • the present invention also provides an apparatus for recognizing a wafer identification code capable of accurately recognizing the wafer identification code by acquiring a plurality of images by using illumination units with different characteristics, composing the plurality of images acquired by using the different illumination units, and processing the composition image.
  • an apparatus for recognizing a wafer identification code displayed on a surface of a wafer comprising: a camera unit capturing an image of a predetermined position of the wafer; a plurality of illumination units illuminating the surface of the wafer to be examined when the camera unit takes the image; a plurality of motors respectively connected to the plurality of illumination units, the plurality of motors rotating or moving the plurality of illumination units; a plurality of motor driving units respectively connected to the plurality of motors, the plurality of motor driving units respectively driving the motors; and a control unit controlling the motor driving units, the camera unit, and the illumination units and recognizing the wafer identification code by using images provided by the camera unit, wherein the control unit enables an image pickup area of the wafer to be accurately illuminated by controlling illumination angles of the illumination units by transmitting a driving signal for the motors to the motor driving unit.
  • the control unit may recognize the wafer identification code by processing the image provided
  • an apparatus for recognizing a wafer identification code displayed on a surface of a wafer comprising: a camera unit capturing an image of a predetermined position of the wafer; at least one illumination unit illuminating the surface of the wafer to be examined when the camera unit takes the image; a control unit controlling operations of the camera unit and the illumination units and recognizing the wafer identification code by using the images provided by the camera; a diffusion plate of which surface is processed so that light is diffused, the diffusion plate located in front of the illumination unit; and a reflective plate reflecting light of the illumination units to an image pickup area of the wafer provided through the diffusion plate, wherein the light provided by the illumination unit is diffused by the diffusion plate and provided to an image pickup area of the wafer.
  • control unit may acquire a plurality of images of the wafer by controlling the illumination unit and the camera unit, generate a composition image by composing the acquired images, and recognize the wafer identification code by using the composition image, and the plurality of images may be taken in different illumination environments.
  • control unit may compare image data of each pixel of the composition image with a predetermined reference value. If image data of a pixel is greater than the reference value, the image data of the pixel is set to 1 I 1 . If image data of a pixel is less than the reference value, the image data of the pixel is set to 1 O'.
  • the composition image is changed to a binary image represented by binary data. The wafer identification code is recognized by using the changed binary image.
  • FIG. 5 illustrates images captured by adjusting angles of illumination units according to an embodiment by using the apparatus for recognizing the wafer identification code and an image captured without adjusting the angles of the illumination units according to a conventional technique.
  • (a) is an image captured without adjusting an illumination angle of the illumination unit 312 of FIG. 3
  • (b) and (c) are images captured by adjusting the illumination angle of the illumination unit 312.
  • the captured image is clear and it is possible to easily recognize the wafer identification code by adjusting the illumination angle of the illumination unit according to the embodiment of the present invention.
  • FIGS. 6 to 9 illustrate images captured by using conventional basic illumination units and images captured by using a diffusion plate and a reflective plate according to an embodiment of the present invention.
  • (a) isan image according to a conventional technique
  • (b) is an image according to the embodiment of the present invention.
  • an image captured in a state where light of the illumination unit is scattered by using the diffusion plate and the reflective plate according to the embodiment is clear. As a result, it is possible to easily recognize the wafer identification code.
  • (a) is an image obtained by capturing a state in which the wafer identification code is unrecognizable due to damage such as a scratch in the wafer identification code
  • (b) is an image obtained by capturing the wafer identification code by passing through the scratch by using the diffusion plate and the reflective plate.
  • (a) is an image obtained by capturing a state in which the wafer identification code is unrecognizable due to a wafer pattern since the wafer identification code overlaps the wafer pattern
  • (b) is an image obtained by capturing a state in which only the wafer identification code is emphasized without influence of a surrounding pattern by using the diffusion plate and the reflective plate according to the embodiment of the present invention.
  • (a) is an image obtained by capturing a state in which a belt on the surface of the wafer overlaps the wafer identification code, and letters of the wafer identification code are confused as other letters
  • (b) is an image obtained by capturing a state in which only the wafer identification code is emphasized by reducing the influence of the belt on the surface by using the diffusion plate and the reflective plate according to the embodiment of the present invention.
  • FIG. 9 (a) is an image obtained by capturing a state in which the wafer identification code is unrecognizable due to fingerprints when there are the fingerprints on the wafer identification code, and (b) is an image obtained by capturing the wafer identification code by passing through the fingerprints on the wafer identification code by using the diffusion plate and the reflective plate according to the embodiment of the present invention.
  • FIG. 1 illustrates an entire structure of a general wafer prober station.
  • FIG. 2 illustrates a schematic structure of an apparatus for recognizing a wafer identification code according to a conventional technique.
  • FIG. 3 illustrates a schematic structure of an apparatus for recognizing a wafer identification code according to a first embodiment of the present invention.
  • FIG. 4 is a schematic block diagram illustrating the apparatus for recognizing a wafer identification code according to the first embodiment of the present invention.
  • FIG. 5 illustrates images captured by adjusting angles of illumination units according to an embodiment of the present invention and an image captured without adjusting the angles of the illumination units according to a conventional technique.
  • FIGS. 6 to 9 illustrate images captured by using a diffusion plate and a reflective plate according to an embodiment of the present invention and images captured according to a conventional technique.
  • FIG. 10 illustrates images taken in environments in which angles and positions of illumination units with respect to the same wafer by using an apparatus for recognizing a wafer identification code according to an embodiment.
  • FIG. 11 illustrates an example of an image obtained by changing a black and white image to a new binary image represented by black and white colors by using the control unit of the apparatus for recognizing the wafer identification code according to the second embodiment of the present invention.
  • FIG. 3 illustrates a schematic structure of an apparatus 30 for recognizing a wafer identification code according to a first embodiment of the present invention.
  • FIG. 4 is a schematic block diagram illustrating only essential elements of the apparatus 30 for recognizing the wafer identification code according to the first embodiment of the present invention. Now, a structure and an operation of the apparatus 30 for recognizing a wafer identification code according to the first embodiment will be described in detail with reference to FIG. 3 and 4.
  • the apparatus 30 for recognizing a wafer identification code serves to recognize a wafer identification code displayed at a predetermined position on a surface of the wafer.
  • the apparatus 30 for recognizing the wafer identification code includes a camera unit 300, at least one illumination unit 310 or 312, motor 320 or 324, a motor driving unit 330, a control unit 340 for controlling an entire operation, a reflective plate 350, and a diffusion plate 360.
  • the camera unit 300 captures an image of a predetermined position of the wafer and provides the captured image to the control unit 340.
  • the illumination unit 310 or 312 is illumination lamp for illuminating the surface of the wafer to be examined when the camera unit takes an image.
  • the apparatus for recognizing a wafer identification code includes a plurality of illumination units.
  • the motor 320 or 324 connected to the illumination unit 310 or 312 rotates or moves the illumination unit.
  • the motor 320 or 324 are driven by the motor driving unit 330.
  • the motors 320 and 324 according to the first embodiment may employ step motors.
  • the motor driving unit 330 drives the motors 320 and 324 according to a driving signal transmitted from the control unit 340. Accordingly, the illumination unit 310 or 312 rotated or moved by the motor that is driven according to the driving signal provided by the control unit 340. An illumination angle and position are adjusted by the control unit.
  • the control unit 340 entirely controls operations of modules of the apparatus for recognizing the wafer identification code.
  • the control unit 340 controls operations of the motor driving unit, the camera unit, and the illumination unit.
  • the control unit 340 recognizes the wafer identification code by processing images of the wafer provided by the camera unit and analyzing the processed images.
  • control unit 340 enables an image pickup area of the wafer that is to be photographed by the camera unit to be accurately illuminated by controlling angles and positions of the illumination units by transmitting signals for driving the motors to the motor driving unit.
  • the diffusion plate 350 has a surface treatment so that light incident onto the surface is diffused.
  • the diffusion plate 350 is located in front of the illumination unit. Accordingly, light provided by the illumination unit is diffused by the diffusion plate 350.
  • the reflective plate 360 reflects light of the illumination unit which is provided through the diffusion plate 350 to the image pickup area of the wafer.
  • the reflective plate has a curved surface with a predetermined curvature.
  • the light provided by the illumination unit is scattered by the diffusion plate 350 and the reflective plate 360. Accordingly, it is possible to remove noise such as scratches or fingerprints that may be included in the image captured by the camera unit.
  • the apparatus for recognizing the wafer identification code according to the second embodiment can accurately recognize a wafer identification code by acquiring a plurality of images in illumination environments with different features, composing the plurality of images, and analyzing the composition image.
  • a structure of the apparatus for recognizing the wafer identification code according to the second embodiment is the same as that of the first embodiment except an operation of a control unit. Accordingly, only the control unit of the apparatus for recognizing the wafer identification code according to the second embodiment will be described. Since the other elements are the same as those of the first embodiment, description on the other elements wi 11 be omitted.
  • FIG. 10 illustrates images taken by the apparatus for recognizing a wafer identification code according to the second embodiment of the present invention in different environments in which angles and positions of illumination units are different with respect to the same wafer.
  • states of the wafer identification code in the image are different depending on positions and angles of the illumination units.
  • (a) is an image with a vertical scratch in the wafer identification code
  • (b) is an image with a horizontal scratch in the wafer identification code
  • (c) is an image with minute vertical and horizontal scratches.
  • the control unit of the apparatus for recognizing the wafer identification code according to the second embodiment provides a first driving signal for adjusting angles and positions of the illumination units to the motor driving unit.
  • the motor driving unit drives the motors connected to the illumination units according to the first driving signal.
  • the camera unit takes a first image of the wafer and transmits the first image to the control unit.
  • the control unit provides a second driving signal for changing the angles and positions of the illumination units to the motor driving unit.
  • the motor driving unit drives the motors connected to the illumination units according to the second driving signal and adjusts the positions and angles of the illumination units, again.
  • the camera unit takes a second image of the wafer and transmits the second image to the control unit.
  • the control unit acquires a plurality of images of the wafer by repeatedly performing the aforementioned procedure and generates a composition image by composing the acquired images.
  • the method of composing the acquired plurality of images adds image datum of pixels corresponding all the images and obtains a mean value of the image datum.
  • another method of composing a plurality of images which is widely used in the art may be used.
  • the control unit removes noise from the composition image by applying a predetermined algorithm and generates a new image in which only the wafer identification code is clearly displayed.
  • a reference value is set. Image data of each pixel of the composition image is compared with the reference value. If the image data of the corresponding pixel is greater than the reference value, the image data of the pixel is changed to 1 I'. If the image data of the corresponding pixel is less than the reference value, the image data of the pixel is changed to 1 O'.
  • the composition image is changed to a binary image represented by binary data by performing the aforementioned procedure with respect to all the pixels. If it is difficult to accurately recognize the wafer identification code from the binary image, the reference value is modified, a binary image is generated from the composition image by using the modified reference value, and the wafer identification code is recognized from the binary image.
  • FIG. 11 illustrate an example of an image obtained by changing a black and white image to a new binary image represented by black and white colors by using the control unit of the apparatus for recognizing the wafer identification code according to the second embodiment of the present invention.
  • the control unit recognizes the wafer identification code by analyzing the newly generated binary image.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
  • Testing Or Measuring Of Semiconductors Or The Like (AREA)

Abstract

dispositif de reconnaissance de code d'identification de tranche, comprenant une unité de prise de vues saisissant une image de zone préétablie de tranche sur laquelle est imprimé ledit code, des unités d'éclairage de tranche lorsque l'unité de prise de vues prend l'image, des moteurs reliés aux unités d'éclairage, tournant et déplaçant ces unités d'éclairage, une unité d'entraînement de moteur, une unité de contrôle des opérations, une plaque de diffusion dont la surface est traitée de manière à diffuser la lumière incidente, cette plaque étant située devant l'unité d'éclairage, et une plaque réfléchissante réfléchissant la lumière de l'unité d'éclairage et la fournissant à la zone de saisie d'image de la tranche. On peut obtenir une image claire en contrôlant les angles d'éclairage des unités d'éclairage et en éclairant de façon uniforme la zone de saisie d'image, par le biais de la plaque de diffusion et de la plaque réfléchissante. Il est donc possible de reconnaître avec précision le code d'identification de tranche.
PCT/KR2008/000135 2007-01-10 2008-01-09 Dispositif de reconnaissance optique de code d'identification de tranche WO2008084982A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR1020070003032A KR100789698B1 (ko) 2007-01-10 2007-01-10 웨이퍼 식별 코드 인식 장치
KR10-2007-0003032 2007-01-10
KR10-2008-0002394 2008-01-09
KR1020080002394A KR100952694B1 (ko) 2008-01-09 2008-01-09 웨이퍼 식별 코드 인식 장치

Publications (1)

Publication Number Publication Date
WO2008084982A1 true WO2008084982A1 (fr) 2008-07-17

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103778421B (zh) * 2012-10-18 2018-01-12 中芯国际集成电路制造(上海)有限公司 读取晶圆标识的方法及晶圆标识读取装置
WO2018111227A1 (fr) * 2016-12-12 2018-06-21 Intel Corporation Systèmes, appareils, et procédés d'inspections de réticules
CN110390325A (zh) * 2019-07-30 2019-10-29 深圳市技美智能自动化有限公司 一种网络集中式ocr识别系统及方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05133726A (ja) * 1991-11-13 1993-05-28 Hitachi Ltd パターン読取方法および装置
WO1995019012A1 (fr) * 1994-01-11 1995-07-13 Hine Design Incorporated Appareil et procedes permettant d'inspecter des marques d'identification sur des tranches de semiconducteur
JP2000205823A (ja) * 1999-01-11 2000-07-28 Tokyo Electron Ltd 被処理体の識別方法並びに被処理体の位置決め方法及び被処理体の位置決め装置
US20040206819A1 (en) * 2002-10-01 2004-10-21 Aisin Engineering Co., Ltd. Code reader

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05133726A (ja) * 1991-11-13 1993-05-28 Hitachi Ltd パターン読取方法および装置
WO1995019012A1 (fr) * 1994-01-11 1995-07-13 Hine Design Incorporated Appareil et procedes permettant d'inspecter des marques d'identification sur des tranches de semiconducteur
JP2000205823A (ja) * 1999-01-11 2000-07-28 Tokyo Electron Ltd 被処理体の識別方法並びに被処理体の位置決め方法及び被処理体の位置決め装置
US20040206819A1 (en) * 2002-10-01 2004-10-21 Aisin Engineering Co., Ltd. Code reader

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103778421B (zh) * 2012-10-18 2018-01-12 中芯国际集成电路制造(上海)有限公司 读取晶圆标识的方法及晶圆标识读取装置
WO2018111227A1 (fr) * 2016-12-12 2018-06-21 Intel Corporation Systèmes, appareils, et procédés d'inspections de réticules
CN110390325A (zh) * 2019-07-30 2019-10-29 深圳市技美智能自动化有限公司 一种网络集中式ocr识别系统及方法
CN110390325B (zh) * 2019-07-30 2021-07-02 深圳市静尚云科技有限公司 一种网络集中式ocr识别系统及方法

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