JP2007141980A - Bonding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bonding apparatus, having a chip automatic binarization recognizing function capable of preventing misrecognition. <P>SOLUTION: If the proportion of the area occupied by black data in the area of entire chip image is, e.g. less than 20%, a chip is treated as a conforming product (S5), and if it is not less than 20%, it is decided as to whether the proportion of the area occupied by the black data exceeds, e.g. 50% (S6). If it exceeds 50%, it is decided that chip does not exist (S7); and if it does not exceed 50%, it can be decided that the proportion of the area occupied by the black data (dark data) is 20%-50% and that an ink dot is applied to a chip or the chip has cracks. Furthermore, if the black data are not included in white data, it is decided that the black data are an ink dot (S9). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bonding apparatus that recognizes a chip.

  Conventionally, when bonding a chip such as a semiconductor to a lead frame or the like, a bonding apparatus has been used.

  This bonding apparatus is configured to bond a chip picked up from a wafer to a lead frame or the like. The bonding apparatus is configured to set a wafer ring, and a wafer sheet is stretched on the wafer ring. A wafer is stuck on the wafer sheet, and the wafer is diced. Thus, dicing streets are formed vertically and horizontally on the wafer, and a chip is formed by each street.

  In the bonding apparatus in which the wafer ring is set, an image of the wafer is acquired and image processing is performed on the wafer image to determine the presence / absence of a chip and pass / fail.

  FIG. 5 is a diagram showing a wafer image 801 acquired by a camera and a binarized image 802 obtained by binarizing the wafer image 801. In the binarized image 802, chip images 803,. .. Are displayed in white (light color), and the part 804 without the chip and the part indicating the street 805 are displayed in black (dark color).

  In addition, ink is applied to the chips 812 that have been inspected by the probe on the wafer 811, and these chips 812 are provided with ink dots 813,... That are not used during bonding. Yes. The ink dot image 814 indicating the ink dot 813 is configured to be displayed as a black dot in the binarized image 802, and the chip 812 to which the ink dot 813 is attached is recognized from the binarized image 802. Thus, bonding of the chip 812 can be avoided.

  That is, in order to recognize the chip 812 to which the ink dot 813 is attached, in the chip image 803 displayed in the binarized image 802, the absolute position of the ink dot image 814 with respect to the chip image 803 is set to a rectangular search area 821. The operator teaches and stores it in the apparatus.

  Thus, when bonding is performed, whether or not the chip 812 is used for bonding is determined based on whether or not the black (dark) ink dot image 814 exists in the search area 821 set at the stored absolute position. It is comprised so that determination of can be performed.

  Some chips 812 of the wafer 811 have chipped 815, and a chipped image 816 indicating the chipped 815 is configured to be displayed in black in the binarized image 802. Thus, by recognizing the chip 812 in which the chip 815 has occurred from the binarized image 802, bonding of the chip 812 can be avoided.

  That is, in order to recognize the chip 812 in which the chipping 815 has occurred, in the chip image 803 displayed in the binarized image 802, the absolute position of the chipping image 816 with respect to the chip image 803 is used as a rectangular search area 825. Teaches and stores it in the device.

  Thus, when bonding is performed, whether or not the chip 812 is used for bonding is determined based on whether or not there is a black (dark) missing image 816 in the search area 825 set at the stored absolute position. It is comprised so that determination of can be performed.

  However, in such a bonding apparatus, since the search area 821 is stored as an absolute position, as shown in FIG. 6, when an ink dot image 814 exists in the center of the search area 821, this is detected. However, if the ink dot image 814 is present at a location off the center of the search area 821, this may not be detected.

  As a result, there is a risk of erroneous recognition.

  The present invention has been made in view of such a conventional problem, and eliminates the need for teaching work in a search area for searching for NG portions such as ink dots attached to a chip and chipping generated in the chip, It is an object of the present invention to provide a bonding apparatus that can prevent erroneous recognition while eliminating problems caused by the set position of a search area.

  In order to solve the above problems, in the bonding apparatus according to claim 1 of the present invention, a chip image indicating a chip and an NG portion indicating an NG portion such as an ink dot attached to the chip or a chip generated on the chip. In the bonding apparatus for determining the presence or absence of the NG portion using a binarized image binarized as data different from the partial image, the NG partial image with respect to a range indicating the chip image in the chip image When the proportion of the range indicating is larger than a predetermined value, there is provided a determination means for determining that the chip indicated by the chip image has the NG portion.

  That is, when discriminating a chip with ink dots or a chip with a chip using a binarized image, the range of the range indicating the NG portion image with respect to the range indicating the chip image in the chip image. It is determined whether or not the occupying ratio is larger than a predetermined value. When the occupying ratio of the range indicating the NG portion image is large, it is determined that the chip indicated by the chip image has the NG portion.

  For this reason, compared with the conventional method in which it is determined whether or not there is an NG portion image indicating an NG portion such as an ink dot or a chip in the search area set at the absolute position, the ink dot is positioned at a fixed position of the chip. Even when no mark is attached or no chip occurs at a fixed position of the chip, the chip having the NG portion can be detected based on the ratio of the range indicating the NG portion image. .

  And since it discriminate | determines based on the ratio of the said NG part image, the teaching operation | work which memorize | stores a search area becomes unnecessary.

  In the bonding apparatus according to claim 2, the binarized image shows the chip image in a light color and the NG portion image in a dark color, while the determination means has an area of the entire chip image. On the other hand, when the proportion of the area of the dark color portion is larger than a preset value, it is determined that the NG portion is present in the chip indicated by the chip image.

  That is, in the binarized image, the chip image indicating the chip is displayed in a light color, while the NG portion image indicating the NG portion is displayed in a dark color.

  Then, the ratio of the area of the dark color portion to the entire area of the chip image is compared with a predetermined set value, and when the ratio of the area of the dark color portion is larger than the set value, the chip It is determined that the chip indicated by the image has the NG portion.

  As described above, in the bonding apparatus according to the first aspect of the present invention, in the chip image, the ratio of the range indicating the NG portion image to the range indicating the chip image is larger than a predetermined value. Whether or not there is an NG portion such as an ink dot attached to a chip indicated by the chip image or a chipped portion can be accurately determined.

  For this reason, when there is no NG portion at the fixed position of the chip as compared with the conventional case where it is determined whether or not there is an NG portion image indicating ink dots or missing in the search area set at the absolute position. Even so, it is possible to accurately detect the chip in which the NG portion exists based on the ratio of the range indicating the NG portion image. Thereby, misrecognition can be prevented.

  Then, since the NG chip is determined based on the ratio of the NG portion image, teaching work for storing the search area becomes unnecessary. Thereby, the operativity can be improved.

  In addition, it is determined whether or not the NG portion image is included in the chip image, and when the NG portion image is included in the chip image, the NG portion image is an ink dot attached to the chip. It can be judged that there is. Further, when the NG portion image is not included in the chip image, it can be determined that the NG portion image is a chipped chip.

  In the bonding apparatus according to the second aspect, in the binarized image, the chip image indicating the chip can be displayed in a light color, while the NG portion image indicating the NG portion can be displayed in a dark color. The partial image can be clearly divided.

  Then, it is possible to accurately determine whether or not the NG portion is present in the chip indicated by the chip image by comparing the ratio of the area of the dark color portion with respect to the entire area of the chip image with a set value. it can.

  It is determined whether or not the dark color portion is contained in the light color portion. If the dark color portion is contained in the light color portion, the dark color portion is an ink dot attached to a chip. It can be judged. In addition, when the dark color portion is not included in the light color portion, it can be determined that the dark color portion is a chipped chip.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a bonding apparatus 1 according to the present embodiment. The bonding apparatus 1 picks up a chip 4 on a wafer sheet 3 stretched on a wafer ring 2 and leads a lead frame (not shown). It is a device that moves up and bonds.

  A wafer 5 is stuck on the wafer sheet 3 and the wafer 5 is diced. As a result, streets 6,... Formed by dicing are formed vertically and horizontally on the wafer 5, and the chips 4,.

  The bonding apparatus 1 includes a camera 12 that acquires an image of the wafer 5 on the wafer sheet 3 set on the wafer table 11. The camera 12 is configured to acquire a wafer image 13 (see FIG. 2) obtained by photographing the wafer 5 on the wafer sheet 3. The wafer image 13 acquired by the camera 12 is an image processing unit. 14 is configured so as to be output to 14.

  The image processing unit 14 is configured around a microcomputer, and processes a wafer image 13 from the camera 12 to generate a binarized image 21 composed of data obtained by binarizing each pixel based on a gray value. (See FIG. 2). The image processing unit 14 is configured to inspect the state of the chip such as the presence or absence of the chip 4 by performing image processing on the wafer image 13.

  The image processing unit 14 is configured to output a signal to the wafer table control unit 31, and the wafer table control unit 31 controls the wafer table 11 based on the signal from the image processing unit 14. By moving, for example, by skipping at the position of the chip 4 to which the ink dot is attached, the pickup of the chip 4 can be prevented.

  The operation of the bonding apparatus 1 according to the present embodiment having the above configuration will be described with reference to the flowchart shown in FIG.

  That is, the image processing unit 14 that has acquired the wafer image 13 from the camera 12 calculates an optimum threshold used when forming the binarized image 21 from the wafer image 13 (S1), Each pixel of the wafer image 13 is binarized into either white data (bright color data) or black data (dark color data) using the optimum threshold value to form the binarized image 21 (S2).

  At this time, as shown in FIG. 2, a pattern 41,... Is formed on the chip 4, and the ink dots that are not used at the time of bonding are applied to the chip 4 to which the probe is applied in the inspection process. 42 is attached. For this reason, in the binarized image 21b binarized with the non-optimal threshold, the pattern image 46 indicating the pattern 41 appears on the chip image 45, and the pattern image 46 and the ink dot indicating the ink dot 42 are displayed. The image 47 cannot be distinguished.

  In order to prevent this, in the step S1, the pixels of the part indicating the chip 4 and the pixels of the part indicating the pattern 41 are white data (light color data), the pixels of the part indicating the ink dots 42 and the chip. It is assumed that the optimum threshold is set so that the pixels in the part 48 having no 4 are converted into black data (dark color data).

  Then, at the chip position where the chip 4 is arranged, white data (bright color data) is detected (S3), and in the single chip image 45 indicated by the white data (bright color data), the chip image 45 is detected. It is determined whether or not the ratio of the area occupied by black data (dark color data) to the entire area is a predetermined value, for example, less than 20% (S4).

  At this time, when the ratio of the area occupied by the black data (dark color data) is less than 20%, it can be determined that the chip 4 indicated by the chip image 45 does not have the NG portion such as the ink dot 42 or the chip 71, and therefore the chip. 4 is set as a non-defective chip (S5), and is transferred to the main routine, and a pickup process for bonding is executed in the main routine.

  Further, when the ratio of the area occupied by the black data (dark color data) is 20% or more in the determination of step S4, the black image is compared with the entire area of the chip image 45 in the chip image 45. It is determined whether the ratio of the area occupied by the data (dark color data) exceeds a predetermined value, for example, 50% (S6).

  At this time, if the ratio of the area occupied by the black data (dark color data) exceeds 50%, it can be determined that the chip 4 is not disposed in this area, so that it is transferred to the main routine as a no-chip (S7). The pickup at this position is skipped in the main routine.

  If it is determined in step S6 that the ratio of the area occupied by the black data (dark color data) does not exceed 50%, the area of the entire chip image 45 in the chip image 45 is determined. The ratio of the area occupied by the black data (dark color data) is 20% or more and 50% or less which is a predetermined set value, and the chip 4 exists but the ink dot 42 is attached to the chip 4. It can be determined that the chip 4 is missing or the chip 71 is present.

  Therefore, it is determined whether or not the black data (dark color data) is included in white data (bright color data) indicating the chip image 45 (S8).

  At this time, when the black data (dark color data) is included in white data (light color data) indicating the chip image 45, the black data (dark color data) is an ink dot image 47. Since the determination can be made, the ink dot chip to which the ink dot 42 is attached is transferred to the main routine (S9), and the pickup of the ink dot chip is skipped in the main routine.

  On the other hand, if the black data (dark color data) is not included in the white data (light color data) indicating the chip image 45 in step S8, the black data (dark color data) Since it can be determined that the chipped image 81 indicates the chipped 71, the break chip in which the chipped 71 has occurred (S10) is transferred to the main routine, and the pickup of the break chip is skipped in the main routine.

  Thus, in the chip image 45, the ratio of the area occupied by the black data (dark color data) indicating the NG portion image composed of the ink dot image 47 and the missing image 81 to the area indicating the chip image 45 However, it is possible to accurately determine whether or not the ink dot 42 is attached to the chip 4 indicated by the chip image 45 or the chip 71 is generated depending on whether or not the predetermined value is larger than a predetermined set value.

  For this reason, the ink at a fixed position of the chip 4 is compared with the conventional case where it is determined whether or not there is an ink dot image 47 indicating the ink dot 42 in the search area for ink dot search set at the absolute position. Even when the dot 42 is not attached, the chip to which the ink dot 42 is attached is based on the proportion of the area of the dark color portion showing the ink dot image 47 and the positional relationship between the dark color portion and the light color portion. 4 can be accurately detected. Thereby, misrecognition can be prevented.

  Similarly, the chip 4 in which the chipped portion 71 is generated can be accurately detected based on the ratio of the area of the dark color portion shown as the chipped image 81 and the positional relationship between the dark color portion and the light color portion. , Can prevent misrecognition.

  FIG. 4 shows the relationship between a single chip image 45 indicated by white data (bright color data) detected in the search area and the black data (dark color data) 61 detected in the chip image 45, and In the chip image 45, the black image (dark color data) 61 having a predetermined area is the area indicating the chip image 45 regardless of the location other than the center. On the other hand, when the proportion of the area occupied by the black data (dark color data) 61 is within 20% to 50%, this can be recognized as the ink dot chip 62.

  When the black data (dark color data) 61 is not included in the white data (light color data) 45, the black data (dark color data) 61 is missing from the chip 4, and the break chip 63 is used. It can be judged that there is.

  Furthermore, when the ratio of the area occupied by the black data (dark color data) 61 to the area showing the chip image 45 is less than 20%, the non-defective chip 64 having no ink dots 42 and chip defects is obtained. Can be recognized. At this time, even when the black data (dark color data) 61 of less than 20% is detected due to noise mixing, this can be canceled.

  Further, since the ink dot chip 62 is determined based on the ratio and the positional relationship of the ink dot image 47, teaching work for storing the search area becomes unnecessary. Thereby, the operativity can be improved.

It is a block diagram which shows one embodiment of this invention. It is explanatory drawing which shows the wafer image and binarized image of the embodiment. It is a flowchart which shows the operation | movement of the embodiment. It is explanatory drawing which shows the recognition result of the embodiment. It is explanatory drawing which shows the conventional wafer image and a binarized image. It is explanatory drawing which shows the recognition result in the conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bonding device 4 Chip 5 Wafer 13 Wafer image 21 Binary image 41 Pattern 42 Ink dot 45 Chip image 47 Ink dot image

Claims (2)

Using the binarized image obtained by binarizing the chip image indicating the chip and the NG portion image indicating the NG portion such as an ink dot attached to the chip or a chip generated on the chip as a different data, the NG In a bonding device that determines the presence or absence of a part,
If the ratio of the range indicating the NG portion image to the range indicating the chip image in the chip image is larger than a predetermined value, it is determined that the chip indicated by the chip image has the NG portion. A bonding apparatus comprising a judging means. While the binarized image shows the chip image in a light color and the NG portion image in a dark color,
The determination means determines that the chip indicated by the chip image has the NG portion when the ratio of the area of the dark color portion to the total area of the chip image is larger than a predetermined set value. The bonding apparatus according to claim 1, wherein the bonding apparatus is characterized in that:

Images