JP2018194378A - Wafer abnormality location detection apparatus and wafer abnormality location identification method - Google Patents

Abstract

[Problem] The present invention aims to provide a wafer abnormality detection device and a wafer abnormality identification method capable of identifying with high accuracy, with a simple configuration, which location on the other main surface of the wafer corresponds to when an abnormality detected on one main surface of the wafer. [Solution] The wafer abnormality detection device 100 includes a stage 1 for placing a wafer 5, a camera 2 for capturing an image of one main surface 51 of the wafer 5 placed on the stage 1, an image processing unit 3 for acquiring the position of the abnormality of the wafer 5 in the image of one main surface captured by the camera 2 and applying a mark indicating the abnormality on the image of one main surface, and a projector 4 for projecting the image of one main surface processed by the image processing unit 3 onto the other main surface 52 of the wafer 5 placed on the stage 1 so that the positional relationship between the image of one main surface processed by the image processing unit 3 and the one main surface 51 of the wafer 5 coincides in a plan view. [Selected Figure] Figure 1

Description

  The present invention relates to an apparatus for detecting an abnormal position of a wafer and a method for identifying an abnormal position of a wafer.

  As a method for detecting an abnormal portion of a wafer having a plurality of chips formed on the front surface, for example, the appearance abnormality on the back surface of the wafer is confirmed using a microscope or the like, and the wafer is removed using tweezers having a needle-like tip. There is known a method for identifying which chip formed on the front surface of the wafer corresponds to an abnormal portion on the back surface of the wafer by scratching both sides of the wafer.

  As another method for inspecting the appearance abnormality of the wafer, there is a method in which two cameras for imaging the front surface and the back surface of the wafer are provided, and images on both surfaces of the wafer are superposed on the image processing apparatus to inspect the abnormal portion. It is known (see, for example, Patent Document 1).

JP 2008-261667 A

  In the method described above, since the abnormal part on the backside of the wafer is marked by pinching the wafer with tweezers, the position accuracy is low and the abnormal part on the wafer surface is accurately identified. It was difficult to do.

  In Patent Document 1, defects on the appearance are analyzed by combining images on the front and back surfaces of a wafer on an image processing apparatus. In this case, it is necessary to synthesize the images of the front and back surfaces of the wafer with high accuracy, and the inspection is performed while moving the stage holding the wafer, which causes a problem that the configuration of the apparatus becomes complicated.

  The present invention has been made to solve the above-described problems, and it is possible to accurately determine which portion of the other main surface of the wafer corresponds to the abnormal portion detected on the one main surface of the wafer with a simple configuration. An object of the present invention is to provide an apparatus for detecting an abnormal part of a wafer and a method for identifying an abnormal part of a wafer that can be specified well.

  An apparatus for detecting an abnormal position of a wafer according to the present invention includes a stage for placing a wafer, a camera for imaging one main surface of the wafer placed on the stage, and an abnormality of the wafer in the one main surface image captured by the camera. The positional relationship between the image processing unit that acquires the position of the part and marks the one main surface image indicating the abnormal part, the one main surface image processed by the image processing unit, and the one main surface of the wafer is a plan view. And a projector that projects the one main surface image processed by the image processing unit onto the other main surface of the wafer placed on the stage.

  A method for identifying an abnormal position of a wafer according to the present invention is a method for identifying an abnormal position of a wafer using an apparatus for detecting an abnormal position of a wafer, wherein the apparatus for detecting an abnormal position of a wafer is placed on a stage on which the wafer is placed. A camera that images one main surface of the wafer, an image processing unit that acquires a position of the abnormal portion of the wafer in the one main surface image captured by the camera, and applies a mark indicating the abnormal portion to the one main surface image; And a projector for projecting the one main surface image processed by the image processing unit onto the other main surface of the wafer placed on the stage. A method for identifying an abnormal wafer location includes: (a) a camera mounted on the stage; A step of imaging one main surface of the placed wafer, and (b) the image processing unit acquires the position of the abnormal portion of the wafer in the one main surface image captured by the camera, and the one main surface image includes the abnormal portion. A step of applying a mark indicating c) The image is projected onto the other main surface of the wafer placed on the stage so that the positional relationship between the one main surface image processed by the image processing unit and the one main surface of the wafer matches in plan view. Projecting the one principal surface image processed by the processing unit.

  According to the apparatus for detecting an abnormal position of a wafer and the method for identifying an abnormal position of a wafer according to the present invention, the position of the abnormal position in the one main surface image of the wafer imaged by the camera is acquired and the mark is applied to the one main surface image. Then, the projector is provided with a mark on the other principal surface of the wafer placed on the stage so that the positional relationship between the one principal surface image and the one principal surface of the wafer coincides in plan view. Project an image. Therefore, it is possible to specify with high accuracy with a simple configuration, which part of the other main surface of the wafer corresponds to the abnormal portion detected on the one main surface of the wafer.

1 is a schematic cross-sectional view of an apparatus for detecting an abnormal wafer location according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating a hardware configuration of a control unit including an image processing unit of the apparatus for detecting an abnormal position of a wafer according to the first embodiment. 5 is a flowchart showing the operation of the wafer abnormal point detection apparatus according to the first embodiment. 3 is a flowchart illustrating an operation of the image processing unit according to the first embodiment. FIG. 6 is a plan view of a stage of an apparatus for detecting an abnormal wafer location according to a second embodiment. 10 is a flowchart illustrating an operation of an image processing unit according to the second embodiment. 10 is a diagram for explaining an operation of an image processing unit according to Embodiment 2. FIG. FIG. 10 is a schematic perspective view of an apparatus for detecting an abnormal wafer location according to a third embodiment. 10 is a flowchart showing the operation of the wafer abnormal point detection apparatus according to the third embodiment. It is a figure explaining the method of marking the abnormal location of a wafer with tweezers.

<Embodiment 1>
<Configuration>
FIG. 1 is a schematic cross-sectional view of an apparatus 100 for detecting an abnormal wafer location according to the first embodiment. The apparatus 100 for detecting an abnormal wafer location includes a stage 1, a camera 2, an image processing unit 3, and a projector 4. The wafer 5 is placed on the stage 1. As shown in FIG. 1, the wafer 5 placed on the stage 1 has the one main surface 51 of the wafer 5 facing the lower side of the stage 1 and the other main surface 52 of the wafer 5 facing the upper side of the stage 1. The camera 2 picks up an image of at least one main surface 51 of the wafer 5 from below the stage 1 and generates image data (that is, an image signal). In the following description, moving image data (that is, a video signal) by a video camera is targeted as image data, but the present invention is not limited to this, and a still image by a still camera, for example, may be used. The image processing unit 3 acquires the position of the abnormal portion of the wafer 5 in the one main surface image captured by the camera 2 and puts a mark indicating the abnormal portion on the one main surface image. The image processing unit 3 performs various processes such as mirror image conversion, alignment adjustment, and the like, which will be described later, as generation of image data to be output to the projector 4. The image processing unit 3 is included in the control unit 30. A display device 21 and an input device 22 are connected to the control unit 30. The display device 21 displays the image data output from the image processing unit 3 and the processing content processed by the image processing unit 3. The input device 22 performs, for example, input and selection of commands necessary for operating the wafer abnormal part detection apparatus 100, and input of positional information indicating the abnormal part of the wafer. The control unit 30 controls the camera 3, the projector 4, and the like.

  The projector 4 projects the one main surface image processed by the image processing unit 3 onto the other main surface 52 of the wafer 5 placed on the stage 1. At this time, the projector 4 projects so that the positional relationship between the one main surface image processed by the image processing unit 3 and the one main surface 51 of the wafer 5 coincides in plan view.

  The position of the camera 2 with respect to the stage 1 is fixed. The camera 2 includes, for example, an imaging device such as a CCD and a CMOS, a lens, and an interface for outputting image data to the outside. If the wafer 5 is 8 inches (diameter 20 cm) or less, for example, the number of pixels of the camera 2 is preferably 2 million pixels or more in order to obtain a clear image over the entire main surface 51. Hereinafter, an image acquired by the camera 2 is referred to as a one-side main image. Therefore, the one main surface image includes the entire image of the one main surface 51 of the wafer 5.

  Note that a light source may be disposed below the stage 1 in order to clearly image the one main surface 51 of the wafer 5 with the camera 2. The light source is, for example, a ring light that surrounds the camera 2.

  The position of the projector 4 with respect to the stage 1 is fixed. The projector 4 projects an image using, for example, a liquid crystal panel, a digital micromirror device (DMD), or the like. In order to project a clear image on the entire other main surface 52 of the wafer 5, the number of pixels of the projector 4 is preferably equal to or greater than the number of pixels of the camera 2 and at least 2 million pixels. In addition to this, the projector 4 includes a projection lens and an interface for inputting image data from the outside. In order to project an image on the entire other main surface 52 of the wafer 5, the distance from the projector 4 to the other main surface 52 of the wafer 5 is preferably 50 cm or more.

  FIG. 2 is a diagram illustrating a hardware configuration of the control unit 30 including the image processing unit 3. The control unit 30 and the image processing unit 3 are realized by an input / output interface HW1, a processing circuit HW2, and a memory HW3. The input / output interface HW1, the processing circuit HW2, and the memory HW3 are mutually connected by a bus. The input / output interface HW1 inputs an image signal SG1 output from the camera 2 and outputs an image signal SG2 output from the processing circuit HW2. In addition, a general input such as a display device 21 such as a liquid crystal display and an input device 22 such as a mouse is input. This is an interface for exchanging signals with output devices.

  The processing circuit HW2 may be dedicated hardware. The processing circuit HW2 may be a CPU (Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, DSP) that executes a program stored in the memory HW3.

  When the processing circuit HW2 is dedicated hardware, the processing circuit HW2 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. . The functions of the control unit 30 and the image processing unit 3 may be realized by one processing circuit HW2, or may be realized by a plurality of processing circuits.

  When the processing circuit HW2 is a CPU, the functions of the control unit 30 and the image processing unit 3 are realized by software, firmware, or a combination of software and firmware. Software and firmware are described as programs and stored in the memory HW3. The processing circuit HW2 implements the functions of the control unit 30 and the image processing unit 3 by reading and executing the program stored in the memory HW3. These programs can also be said to cause a computer to execute the procedures and methods of the control unit 30 and the image processing unit 3. Here, the memory HW3 is, for example, a nonvolatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, EEPROM, magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD, etc. Applicable.

  Note that part of the functions of the control unit 30 and the image processing unit 3 may be realized by dedicated hardware, and part of the functions may be realized by software or firmware. As described above, the processing circuit can realize the functions described above by hardware, software, firmware, or a combination thereof.

  The display device 21 and the input device 22 may be separately prepared as a display and a mouse, or may be an integrated form such as a display with a touch panel.

<Operation>
FIG. 3 is a flowchart showing the operation of the wafer abnormal point detection apparatus 100. FIG. 4 is a flowchart showing the operation of the image processing unit 3, that is, the details of step S102 in FIG.

  First, the camera 2 captures an image of the entire main surface 51 of the wafer 5 placed on the stage 2 and acquires a main surface image (step S101). Next, the image processing unit 3 performs processing on the one main surface image (step S102). Step S102 will be described later with reference to FIG. Next, the projector 4 projects the processed one main surface image onto the other main surface 52 of the wafer 5. At this time, the projector 4 projects so that the positional relationship between the one main surface image processed by the image processing unit 3 and the one main surface 51 of the wafer 5 coincides in plan view. The projected main surface image is marked with an abnormal location. Accordingly, a mark is projected on a portion of the other main surface 52 of the wafer 5 corresponding to the abnormal portion of the one main surface 51 of the wafer 5.

  Then, ink is spotted on the other main surface 52 of the wafer 5 where the mark is projected, for example, with a pen. This makes it possible to identify from the other main surface 52 of the wafer 5 which part of the wafer 5 is abnormal. Further, as described in the third embodiment, ink dots may be automatically performed.

  The operation (step S102) of the image processing unit 3 will be described with reference to FIG. First, the image processing unit 3 acquires the one main surface image captured by the camera 2 and displays it on the display device 21 (step S1021). In this state, the worker who performs the inspection visually observes the image displayed on the display device 21. In the image of the one main surface of the wafer 5 displayed on the display device 21, when the operator finds an abnormal part, the operator operates the input device 22 to identify the abnormal part. When the input device 22 is a mouse, an operation for specifying an abnormal location is performed by, for example, clicking the cursor linked to the mouse on the abnormal location in the image of the one main surface of the wafer 5 displayed on the display device 21. To be implemented. Further, when the display device 21 and the input device 22 are displays with a touch panel, an operation for specifying an abnormal location is performed by, for example, touching the abnormal location in the image of one main surface of the wafer 5 displayed on the display. Is done.

  Next, the image processing unit 3 acquires the position of the abnormal portion of the wafer 5 in the one main surface image based on the input from the input device 22, and marks the abnormal portion of the one main surface image (step S1022). ). It is preferable that the mark has a color and shape that can be easily identified when the mark is projected onto the other main surface 52 of the wafer 5. Note that the accuracy of detecting an abnormal location is not as high as that currently performed by an operator, but the image processor 3 may automatically detect an abnormal location by analyzing the one-side image. good. In this case, the analysis of the one main surface image and the detection of the abnormal part are performed, for example, by comparing the acquired one main surface image with an ideal one main surface image without defects prepared in advance. On the other hand, the method of analyzing the main surface image and detecting the abnormal part is not limited to this, and any method for specifying the abnormal part based on the appearance of the wafer is applicable.

  Next, the image processing unit 3 reverses the left and right of the one main surface image to which the mark is applied (step S1023). Here, inverting the left and right of the one main surface image means performing mirror image conversion on the one main surface image. Then, the image processing unit 3 outputs the processed one main surface image, that is, the one main surface image to which the mark is applied and the left and right are inverted to the projector 4 (step S1024).

<Effect>
An apparatus 100 for detecting an abnormal wafer location according to the first embodiment includes a stage 1 on which a wafer 5 is placed, a camera 2 that takes an image of one main surface 51 of the wafer 5 placed on the stage 1, and an image taken by the camera 2. The image processing unit 3 that obtains the position of the abnormal portion of the wafer 5 in the one main surface image and applies a mark indicating the abnormal portion to the one main surface image, and the one main surface image processed by the image processing unit 3 The one main surface image processed by the image processing unit 3 is projected onto the other main surface 52 of the wafer 5 placed on the stage 1 so that the positional relationship with the one main surface 51 of the wafer 5 matches in plan view. And a projector 4 for performing.

  According to wafer abnormal part detection apparatus 100 in the first embodiment, the position of the abnormal part in the one main surface image of wafer 5 imaged by camera 2 is acquired and the one main surface image is marked. Then, the projector 4 places a mark on the other main surface 52 of the wafer 5 placed on the stage 1 so that the positional relationship between the one main surface image and the one main surface 51 of the wafer 5 matches in plan view. The given one-side image is projected. Therefore, it is possible to specify with high accuracy with a simple configuration which part of the other main surface 52 of the wafer 5 corresponds to the abnormal part detected on the one main surface 51 of the wafer 5.

  In the wafer abnormal point detection apparatus 100 according to the first embodiment, one main surface 51 of the wafer 5 is a surface facing the lower side of the stage 1, and the other main surface 52 of the wafer 5 is above the stage 1. The camera 2 images one main surface 51 of the wafer 5 from below the stage 1. Accordingly, the other main surface 52 of the wafer 5 onto which the image is projected is a surface facing upward of the stage 1, so that a mark indicating an abnormal location projected on the other main surface 52 of the wafer 5 is placed above the stage 1. It is visible from.

  Further, in the wafer abnormal point detection apparatus 100 according to the first embodiment, the position of the camera 2 is fixed with respect to the stage 1, and the camera 2 can image the entire one main surface 51 of the wafer 5. The position of the projector 4 is fixed with respect to the stage 1, and the projector 4 can project the one main surface image processed by the image processing unit 3 onto the entire other main surface 52 of the wafer.

  Therefore, a mechanism for relatively moving the positions of the stage 1, the camera 2, and the projector 4 is not required, and the positions of the camera 2 and the projector 4 can be fixed with respect to the stage 1. Thereby, the positional accuracy of the camera 2 and the projector 4 with respect to the stage 1 can be improved.

  Further, in the wafer abnormality point detection apparatus 100 according to the first embodiment, the camera 2 has 2 million pixels or more, the projector 4 has 2 million pixels or more, and the projector 4 to the wafer 5. The distance to the other main surface 52 is 50 cm or more. Although the number of pixels of the projector 4 is 2 million pixels or more, it is desirable that the number of pixels be equal to or more than the number of pixels of the camera 2.

  By setting the number of pixels of the camera 2 to 2 million pixels or more, it is possible to clearly image the entire one main surface 51 of the wafer 5 having a large diameter of 20 cm, for example. Further, the number of pixels of the projector 4 is set to 2 million pixels or more, and the distance from the projector 4 to the other main surface 52 of the wafer 5 is set to 50 cm or more, so that the entire other main surface 52 of the large-diameter wafer 5 is formed. An image can be projected clearly.

  Further, in the wafer abnormal point detection apparatus 100 according to the first embodiment, a plurality of semiconductor chips are formed on the other main surface 52 of the wafer 5. Therefore, it is possible to identify which semiconductor chip formed on the other main surface 52 of the wafer 5 corresponds to the abnormal portion detected on the one main surface 51 of the wafer 5.

<Embodiment 2>
<Configuration>
FIG. 5 is a plan view of the stage 1 of the wafer abnormality point detection apparatus 200 according to the second embodiment as viewed from below. Four alignment marks 11 are arranged at equal intervals on the lower surface of the stage 1. The four alignment marks are arranged so that the center of gravity of the four alignment marks 11 coincides with the center of the wafer 5 placed on the stage 1.

  Since the configuration other than the alignment mark 11 disposed on the lower surface of the stage 1 is the same as that of the first embodiment (FIG. 1), the description thereof is omitted.

<Operation>
FIG. 6 is a flowchart showing the operation of the image processing unit 3 in the second embodiment. FIG. 7 is a diagram for explaining the operation of the image processing unit 3. In each of the one main surface images IMG1, IMG2, and IMG3 shown in FIG. 7, one main surface 51 of the wafer 5 is shown, but this is not the one main surface 51 of the wafer 5, but one of the wafers 5 itself. It is an image of the main surface 51. The same applies to the stage 1 and the alignment mark 11.

  The operation of the image processing unit 3 will be described with reference to FIGS. Since the second embodiment is the same as the first embodiment except for the operation of the image processing unit 3, the description of the operation is omitted.

  First, the image processing unit 3 acquires the one main surface image IMG1 captured by the camera 2 (step S2021). The one main surface image IMG1 captured by the camera 2 includes four alignment marks 11 arranged on the stage 1 together with the one main surface 51 of the wafer 5.

  Next, the image processing unit 3 adjusts the alignment of the one main surface image IMG1 based on the four alignment marks 11 in the one main surface image IMG1, and obtains the one main surface image IMG2 (step S2022). The alignment adjustment is, for example, correction of distortion, inclination, etc. of the one principal surface image IMG1.

  Next, the image processing unit 3 analyzes the one main surface image IMG2 to detect an abnormal portion, and applies the mark 6 to the abnormal portion of the one main surface image IMG2 (step S2023). Then, the image processing unit 3 obtains the one main surface image IMG3 by inverting the left and right of the one main surface image IMG2 on which the mark 6 is applied, with the center of gravity of the four alignment marks 11 as a reference (step S2024). In step S2024, the image processing unit 3 obtains the centroids 7 of the four alignment marks 11 by drawing diagonal lines so as to connect the alignment marks 11 facing each other in the one principal surface image IMG2, as shown in FIG. Then, the left and right sides of the one principal surface image IMG2 are reversed with the centroid 7 as a reference. That is, the image processing unit 3 does not invert the left and right sides of the one main surface image IMG with the center of the one main surface image IMG2 itself as an axis, but the one main surface image IMG2 with the center of gravity 7 of the four alignment marks 11 as an axis. Invert the left and right of.

<Effect>
In the wafer abnormal point detection apparatus 200 according to the second embodiment, four or more alignment marks 11 are provided on the surface facing the lower side of the stage 1 so as to surround the wafer 5 placed on the stage 1. The center of gravity of the plurality of alignment marks 11 coincides with the center of the wafer 5 placed on the stage 1, and the one principal surface image of the wafer 5 is shown in the one principal surface image captured by the camera 2. And a plurality of alignment marks 11 are included. Therefore, the alignment of the one main surface image can be adjusted using the alignment mark included in the one main surface image.

  Further, in the wafer abnormal portion detection apparatus 200 according to the second embodiment, the image processing unit 3 inverts the left and right sides of the one main surface image with reference to the plurality of alignment marks 11 in the one main surface image. Accordingly, it is possible to invert the left and right sides of the one main surface image with reference to the center of the one main surface 51 of the wafer 5 in the one main surface image. Thereby, even if the center of the one main surface 51 of the wafer 5 is deviated from the center of the one main surface image in the one main surface image, the left and right sides of the image of the one main surface 51 of the wafer 5 are increased. It is possible to invert with accuracy.

<Embodiment 3>
<Configuration>
FIG. 8 is a schematic perspective view of an apparatus 300 for detecting an abnormal wafer location according to the third embodiment. The apparatus 300 for detecting an abnormal wafer location further includes an ink hitting portion 8 as compared with the apparatus 100 for detecting an abnormal wafer location (FIG. 1) according to the first embodiment. The ink hitting part 8 includes a pen 81. The pen 81 is movable in the horizontal direction (that is, the xy direction) and the vertical direction (that is, the z direction) with respect to the other main surface 52 of the wafer 5 placed on the stage 1, and is, for example, a moving mechanism (used for an XY plotter ( (Not shown). The movement mechanism is controlled by the control unit 30.

  Since the configuration other than the ink spot portion 8 in the wafer abnormal part detection apparatus 300 is the same as that of the wafer abnormal part detection apparatus 100 (FIG. 1), description thereof is omitted.

<Operation>
FIG. 9 is a flowchart showing the operation of the wafer abnormal point detection apparatus 300. Steps S201 to S203 in FIG. 9 are the same as steps S101 to S103 in FIG.

  In step S <b> 204 of FIG. 9, the ink hitting unit 8 receives a control signal from the control unit 30 and automatically hits ink with a pen 81 at a position where the mark 6 on the other main surface 52 of the wafer 5 is projected. . For example, the ink hitting portion 8 hits ink with a pen 81 at a location where the mark 6 on the other main surface 52 of the wafer 5 is projected. Further, when a semiconductor chip is formed on the other main surface 52 of the wafer 5 and the mark 6 is projected onto the semiconductor chip, the ink hitting portion 8 is used to apply ink with a pen 81 at the center of the upper surface of the semiconductor chip. May be.

  The function of automatically depositing ink at a location where the mark 6 on the other main surface 52 of the wafer 5 is projected is not limited to the above-described function. This function may be realized by, for example, a camera, a processing circuit, and a memory mounted on the ink spotting unit 8 without using a control signal from the control unit 30. The processing circuit is a CPU that executes a program stored in a memory.

  In order to correspond to a hitting point on a semiconductor chip having a side length of about 1 mm, the hitting point of ink hitting by the pen 81 is preferably 0.5 mm or more and 1 mm or less in diameter.

  The ink spot 8 described above may be applied to the wafer abnormal point detection apparatus 200 in the second embodiment.

<Effect>
The apparatus 300 for detecting an abnormal wafer location according to the third embodiment includes an ink hitting portion 8 including a pen 81 that is movable in the horizontal and vertical directions with respect to the other main surface 52 of the wafer 5 placed on the stage 1. Further, the ink hitting part 8 automatically hits ink with the pen 81 on the other main surface 52 of the wafer 5 based on the location where the mark 6 on the other main surface 52 of the wafer 5 is projected.

  As shown in FIG. 10, there is known a method of marking an abnormal part by pinching the wafer 5 with tweezers 9 having needles 91 at both ends and scratching the abnormal part. In this method, there is a possibility that a portion having no abnormality of the wafer 5 is erroneously damaged. Further, when the thickness of the wafer 5 is as small as 100 μm or less, if the force for pinching the wafer 5 with the tweezers 9 is strong, the wafer 5 itself may be damaged. On the other hand, in the third embodiment, ink is hit with the pen 81 on the other main surface 52 of the wafer 5 based on the location where the mark 6 on the other main surface 52 of the wafer 5 is projected. That is, since the mark for identifying the abnormal portion is marked by hitting ink, damage to the wafer 5 can be reduced. Further, since the ink is automatically spotted by the ink spotting unit 8, it is possible to spot the ink with higher accuracy than in the case where the ink is spotted manually.

  Further, in the wafer abnormal point detection apparatus 300 according to the third embodiment, the ink hitting point that the pen 81 hits has a diameter of 0.5 mm or more and 1 mm or less. Accordingly, ink can be spotted even on a semiconductor chip having a side length of about 1 mm.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  1 stage, 2 cameras, 3 image processing units, 4 projectors, 5 wafers, 6 marks, 7 center of gravity, 8 ink hitting points, 9 tweezers, 91 needles, 11 alignment marks, 51 one main surface, 52 other main surface, 100 , 200, 300 Wafer abnormal part detection device, HW1 input / output interface, HW2 processing circuit, HW3 memory.

Claims (12)

A stage on which the wafer is placed;
A camera for imaging one main surface of the wafer placed on the stage;
An image processing unit that acquires a position of the abnormal portion of the wafer in the one main surface image captured by the camera and applies a mark indicating the abnormal portion to the one main surface image;
The one main surface image processed by the image processing unit and the one main surface of the wafer are aligned with the other main surface of the wafer placed on the stage so that the positional relationship between the one main surface and the wafer matches in plan view. A projector for projecting the one principal surface image processed by the image processing unit;
Comprising
Wafer abnormal point detection device. The one main surface of the wafer is a surface facing downward of the stage;
The other main surface of the wafer is a surface facing upward of the stage;
The camera images the one main surface of the wafer from below the stage;
The apparatus for detecting an abnormal position of a wafer according to claim 1. The position of the camera is fixed with respect to the stage,
The camera is capable of imaging the entire one main surface of the wafer;
The position of the projector is fixed with respect to the stage;
The projector is capable of projecting the one main surface image processed by the image processing unit onto the entire other main surface of the wafer.
The apparatus for detecting an abnormal position of a wafer according to claim 1 or 2. The camera has 2 million pixels or more,
The projector has 2 million pixels or more,
The distance from the projector to the other main surface of the wafer is 50 cm or more,
The apparatus for detecting an abnormal position of a wafer according to any one of claims 1 to 3. On the surface facing the lower side of the stage, a plurality of alignment marks of four or more are arranged at equal intervals so as to surround the wafer placed on the stage,
The center of gravity of the plurality of alignment marks coincides with the center of the wafer placed on the stage,
The one main surface image captured by the camera includes the one main surface of the wafer and the plurality of alignment marks.
The apparatus for detecting an abnormal position of a wafer according to any one of claims 1 to 4. The image processing unit reverses the left and right of the one main surface image with reference to the center of gravity of the plurality of alignment marks in the one main surface image.
The apparatus for detecting an abnormal portion of a wafer according to claim 5. An ink hitting portion comprising a pen that is movable in a horizontal direction and a vertical direction with respect to the other main surface of the wafer placed on the stage;
The ink hitting part automatically hits ink with the pen on the other main surface of the wafer based on a position where the mark on the other main surface of the wafer is projected.
The apparatus for detecting an abnormal position of a wafer according to any one of claims 1 to 6. The ink hitting point that the pen hits is 0.5 mm to 1 mm in diameter,
The apparatus for detecting an abnormal position of a wafer according to claim 7. A plurality of semiconductor chips are formed on the other main surface of the wafer.
The apparatus for detecting an abnormal position of a wafer according to any one of claims 1 to 8. A method for identifying an abnormal wafer location using an apparatus for detecting an abnormal wafer location,
The apparatus for detecting an abnormal portion of a wafer is
A stage on which the wafer is placed;
A camera for imaging one main surface of the wafer placed on the stage;
An image processing unit that acquires a position of the abnormal portion of the wafer in the one main surface image captured by the camera and applies a mark indicating the abnormal portion to the one main surface image;
A projector that projects the one main surface image processed by the image processing unit onto the other main surface of the wafer placed on the stage;
With
The method for identifying an abnormal portion of the wafer is:
(A) the camera imaging the one main surface of the wafer placed on the stage;
(B) The image processing unit acquires a position of the abnormal portion of the wafer in the one main surface image captured by the camera, and applies a mark indicating the abnormal portion to the one main surface image;
(C) The projector is placed on the stage so that the positional relationship between the one main surface image processed by the image processing unit and the one main surface of the wafer coincides in plan view. Projecting the one principal surface image processed by the image processing unit onto the other principal surface of the wafer;
Comprising
Wafer abnormality location identification method. On the surface facing the lower side of the stage, a plurality of alignment marks of four or more are arranged at equal intervals so as to surround the wafer placed on the stage,
The center of gravity of the plurality of alignment marks coincides with the center of the wafer placed on the stage,
In the step (a), the one main surface image captured by the camera includes the one main surface of the wafer and the plurality of alignment marks,
(D) the image processing unit inverting the left and right of the one main surface image with reference to the center of gravity of the plurality of alignment marks in the one main surface image;
Further comprising
The method for identifying an abnormal portion of a wafer according to claim 10. The apparatus for detecting an abnormal portion of a wafer is
An ink hitting portion comprising a pen that is movable in a horizontal direction and a vertical direction with respect to the other main surface of the wafer placed on the stage;
In the step (c), the ink hitting portion automatically hits ink with the pen on the other main surface of the wafer based on a position where the mark on the other main surface of the wafer is projected. ,
The method for identifying an abnormal position of a wafer according to claim 10 or 11.

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