JP2008311430A - Semiconductor chip detection device, and semiconductor chip detection method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily detect the presence of a semiconductor chip on a wafer without erroneous recognition. <P>SOLUTION: This semiconductor chip detection device detects individual separated semiconductor chips 12 on a wafer. The semiconductor chip detection device includes: a light source 10; a camera 16 facing the light source 10 by interposing a dicing sheet 14 with the semiconductor chips 12 stuck thereto, and acquiring image data by imaging the semiconductor chips 12 irradiated with light by the light source 10; a processing part 18 subjecting the image data to a binarization process; and a recognition part 20 recognizing presence of the semiconductor chip from the image data subjected to the binarization process by the processing part 18. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor chip detection apparatus and a semiconductor chip detection method for detecting individual semiconductor chips separated on a wafer.

  Conventionally, in the mounting process of a semiconductor chip (hereinafter also referred to as a chip), in order to mount a non-defective semiconductor chip, a technique for performing mounting after recognizing the position of the non-defective semiconductor chip in advance is used.

  For example, Patent Document 1 describes a semiconductor chip detection device that detects the presence / absence of a semiconductor chip and a defective mark, and performs position correction for mounting if it is a non-defective product. In this semiconductor chip detection device, a reference line for detecting a position of a semiconductor chip is provided on a sheet, a camera is provided on the upper surface of the chip, a sensor is provided on the lower surface, and the chip arrangement is addressed to prevent erroneous recognition. . This eliminates recognition of a semiconductor chip other than the designated semiconductor chip, improves the mounting throughput, and enables mounting even a discontinuous semiconductor chip or a semiconductor chip in a tooth-missed state.

  Further, Patent Document 2 describes a bonding apparatus that prevents problems during pickup. The bonding apparatus sets a first reference point and a second reference point where different chips located in the same row and spaced apart in the X direction from the chips aligned on the wafer, and in the same direction as the first reference point chip in the Y direction. A reference point for setting a fourth reference point where a chip located in the same row as the chip of the second reference point is located, and a third reference point where the chip spaced apart from the third reference point is located The position of the chip arranged between each reference point is calculated according to the point setting means and the expansion rate in the X direction and Y direction between the reference points before and after the wafer sheet expansion, and the wafer map data Means for correcting the position information.

FIG. 4 is a diagram illustrating the semiconductor chip detection device described in Non-Patent Document 1. In FIG. 4, the semiconductor chip 82 is stuck on the sheet 84 stuck on the wafer ring 92. The semiconductor chip detection device includes a light source 80 and a camera 86 with respect to the vertical direction of the semiconductor chip 82. The light source 80 irradiates the semiconductor chip 82 with light, and the camera 86 images the semiconductor chip 82. The recognizing unit 90 performs binarization and multi-value processing from the obtained image data, and the pattern or configuration of a chip group including a non-defective product or a target chip registered in advance by a pattern matching method or a periphery thereof (defective appearance ( The position of the semiconductor chip 82 is recognized by comparing the structure of the non-molded) good appearance product) with a chip that may be the reference chip on the wafer or a chip group including the periphery thereof.
JP-A-11-040634 JP 2006-013012 A Wafer Chip Sorter WC-SM-7000R Instruction Manual (M-Tech Co., Ltd.) Third Edition 2003.05

However, the prior art described in the above literature has room for improvement in the following points.
In the semiconductor chip detection device described in Patent Document 1, a reference line for chip position detection is provided on a sheet, and the array is addressed by a line sensor. This apparatus is based on the premise that a reference line is provided on the sheet, and requires time and effort.

  Further, the bonding apparatus described in Patent Document 2 is premised on recognizing four reference points on the wafer. Therefore, if the four points cannot be recognized reliably, the chip position is erroneously recognized.

Further, in the semiconductor chip detection device described in Non-Patent Document 1, pattern matching recognition is easily affected by lot variation and wafer in-plane variation, and the matching rate (threshold value) must be lowered to avoid it. If the threshold value is lowered, the possibility of erroneous recognition increases. In addition, as the number of chips per wafer increases as the size of a small chip (for example, about 1 mm square) or a wafer increases, it becomes more difficult to find a pre-registered chip (target chip). Even if the position of is shifted by several lines, it is recognized, and there is a high possibility of erroneous recognition of the chip position. As a means for preventing such misrecognition, confirmation by an operator is indispensable, and it is extremely difficult for small chips and large-diameter products.
The above is also recognized in chip position recognition by pattern matching in a chip sorter for 300 mm diameter wafers.

  The present invention has been made in view of the above circumstances, and easily detects the presence or absence of a semiconductor chip on a wafer without erroneous recognition.

According to the present invention,
A semiconductor chip detection device for detecting individual semiconductor chips separated on a wafer,
A light source;
A camera that opposes the light source across the sheet on which the semiconductor chip is attached, captures the semiconductor chip irradiated with light from the light source from a surface opposite to the light irradiation surface, and acquires image data;
A processing unit for binarizing image data;
A recognition unit that recognizes the presence or absence of a semiconductor chip from the image data binarized by the processing unit;
There is provided a semiconductor chip detection device characterized by comprising:

Moreover, according to the present invention,
A method of detecting a semiconductor chip using the semiconductor chip detection device described above,
Irradiating the semiconductor chip with light; and
Imaging a semiconductor chip irradiated with light to obtain image data;
A step of binarizing the image data;
Recognizing the presence or absence of a semiconductor chip from the binarized image data;
A method for detecting a semiconductor chip is provided.

  According to the present invention, the semiconductor chip is imaged by the camera facing the light source across the semiconductor chip and binarized. As a result, the portion with the semiconductor chip can be displayed in black, and the portion without the semiconductor chip can be displayed in white, and the presence or absence of the semiconductor chip can be easily grasped.

  According to the present invention, it is possible to easily detect the presence or absence of a semiconductor chip on a wafer without erroneous recognition.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate. Furthermore, in the present invention, the front / rear, left / right, and upper / lower directions are defined, but this is defined for convenience in order to briefly explain the relative relationship of the components of the present invention. The direction at the time of manufacture and use is not limited.

FIG. 1 is a schematic diagram showing the semiconductor chip detection device of the present embodiment. This semiconductor chip detection device detects individual semiconductor chips 12 separated on a wafer. The semiconductor chip 12 facing the light source 10 with the light source 10 and the dicing sheet 14 to which the semiconductor chip 12 is attached being sandwiched and irradiated with light from the light source 10 taken from a surface opposite to the light irradiation surface is imaged. A processing unit 18 that binarizes image data, and a recognition unit 20 that recognizes the presence or absence of a semiconductor chip from the image data binarized by the processing unit 18.
The wafer ring 22 is a jig used in the process of dicing the wafer. The wafer ring 22 holds the wafer 15 via the dicing sheet 14.

  The apparatus according to the present embodiment makes it possible to check wafer pickup data including position information of semiconductor chips and good / bad information and binarized image data and confirm pickup of good semiconductor chips. .

  Specifically, the apparatus according to the present embodiment includes a light source 10, a camera 16, a processing unit 18, a recognition unit 20, an output unit 24, and a reading unit 23.

  The camera 16 images the semiconductor chip 12 irradiated with light from the light source 10.

  The processing unit 18 binarizes the entire image of the wafer imaged by the camera 16 to generate image data.

  The reading unit 23 reads wafer mapping data. The wafer mapping data may be read from a storage unit (not shown) provided in the external apparatus by connecting to the external apparatus. Further, it may be read from a storage disk such as a flexible disk.

  The recognition unit 20 recognizes the position of the semiconductor chip 12 from the image data binarized by the processing unit 18. Also, the wafer mapping data read by the reading unit 23 is received, and the wafer mapping data and the image data are collated.

  The output unit 24 outputs information on the position and number of semiconductor chips recognized by the recognition unit 20. Further, the recognition unit 20 outputs a result of collating the wafer mapping data and the image data.

  The wafer 15 is manufactured through a pre-process of a known semiconductor chip manufacturing process. This wafer 15 is attached on a dicing sheet 14 attached to a wafer ring 22 as a preparation for dicing, and then cut by a dicing saw, and the dicing sheet 14 is expanded, whereby individual semiconductor chips 12 are obtained. Separated.

  The wafer mapping data includes position information indicating the position of the semiconductor chip 12 provided on the wafer ring 22 in coordinates, and good / defective information indicating whether the semiconductor chip 12 provided in each position information is a non-defective product or a defective product. Are stored in association with each other. By reading this wafer mapping data, it is configured so that the position of the semiconductor chip 12 can be grasped. FIG. 2 is a diagram for explaining wafer mapping data. FIG. 2 (a) is an enlarged view of FIG. 2 (b). FIG. 2B shows the entire wafer. The semiconductor chips 12 are arranged on the wafer 15, and the individual semiconductor chips 12 are distinguished from good and defective. In FIG. 2A, for the sake of explanation, it is indicated that the semiconductor chip 12 indicating NG is a defective product, and the semiconductor chip 12 indicating OK is a non-defective product.

FIG. 3 is a diagram illustrating an example of image data generated by the processing unit 18. FIG. 3 shows an overall image of the wafer 15. A light source 10 is applied from the surface of a diced wafer 15 on a wafer mount (not shown), and the wafer is mounted by a camera 16 placed on the opposite side of the light source 10 with the dicing sheet 14 (in other words, on the back side of the wafer 15). 15 whole images are taken and binarized by the processing unit 18 to obtain image data (FIG. 3A).
Further, the entire image of the wafer 15 is picked up by the camera 16 after pick-up, and binarization processing is performed by the processing unit 18 to obtain image data (FIG. 3B). In this image, the part where the semiconductor chip 12 is actually displayed is black and the part where the semiconductor chip 12 is not is displayed white. The processing unit 18 sends the obtained image data to the recognition unit 20.

  The recognition unit 20 stores reference chip size information in advance. The recognition unit 20 recognizes the rectangular semiconductor chip 12 that is a molded chip from the image data received from the processing unit 18 based on the chip size information. Therefore, this makes it possible to distinguish between molded chips and non-molded chips, and to recognize the position and number of molded chips. (FIG. 3A).

The recognizing unit 20 compares the position information of the wafer mapping data with the position information recognized from the image data, and determines whether the position information of the wafer mapping data matches the position information recognized from the image data. . This makes it possible to recognize the position and quantity of the formed chips even in the case of a tooth missing wafer that has already been picked up (FIG. 3B).
Further, the position of the wafer map and the actual wafer can be surely recognized by comparing the image data and the wafer mapping data. For example, comparing with FIG. 2 and FIG. 3B, it can be confirmed that a good semiconductor chip has been picked up.

Hereinafter, a method of using the apparatus of this embodiment will be described.
The wafer 15 affixed to the dicing sheet 14 is cut into chips by a dicing saw, set in the apparatus of this embodiment, and separated into individual semiconductor chips. Image data indicating the semiconductor chip 14 after separation is acquired, and another device is used to determine whether each semiconductor chip 14 is good or bad, and wafer mapping data is created. The created wafer mapping data is read into the apparatus of the present embodiment, and a non-defective semiconductor chip 14 is picked up using a vacuum chuck or the like with reference to the wafer mapping data. After picking up, using the apparatus of this embodiment, the semiconductor chip is irradiated with light, the semiconductor chip irradiated with the light is imaged to obtain image data, and this is binarized. The apparatus according to the present embodiment recognizes that the portion projected in black in the image data before pick-up is projected in white in the image data after pick-up, and collates with the wafer mapping data. By outputting this verification result, it is confirmed that a good product has been picked up.

Next, the effect of this embodiment will be described.
In the conventional technique for collating wafers after dicing and wafer map data, it is very difficult to accurately recognize chips that employ pattern matching or the like. In particular, the larger the number of chips per wafer due to the smaller size of the chip or the larger diameter of the wafer, the higher the possibility of erroneous recognition.
In this embodiment, a dicing wafer consisting of the shape and configuration of individual chips of a diced wafer by applying light from the front side of the wafer, recognizing with a camera from the back side of the wafer, and performing binarization processing Can capture the whole picture. Further, by comparing the binarized image data with the wafer mapping data, it is possible to confirm that a non-defective product (or defective product) is picked up according to the wafer map data. In addition, it is possible to prevent a defective product from being erroneously mounted by comparing it with map data for each good pickup.

  Further, according to this apparatus, it is possible to reliably check the actual wafer and the wafer map, and the processing capability and the yield of the semiconductor chips are improved. Further, since there is no erroneous recognition due to pattern matching, the processing capability and the semiconductor chip yield are improved. In addition, since it is not affected by variations between wafer lots and variations in the wafer surface, the processing capability and yield are improved. Furthermore, since there is no pattern recognition (registration work) of the semiconductor chip, it is possible to eliminate the superiority or inferiority of the recognition result due to the skill level of the operator and to eliminate human error.

As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.
For example, when the camera cannot be installed on the back surface of the wafer due to the apparatus configuration, the restriction can be avoided by setting the camera position on the wafer surface. In this case, the obtained image data is projected black where the semiconductor chip is, and white where there is no semiconductor chip.

It is a schematic diagram which shows the semiconductor chip detection apparatus of this embodiment. It is a figure explaining wafer mapping data. FIG. 2 (a) is an enlarged view of FIG. 2 (b). FIG. 2B shows the entire wafer. It is a figure which shows an example of the image data which the semiconductor chip detection apparatus of this embodiment produces | generates. FIG. 3A shows the entire wafer after dicing. FIG. 2B shows the entire wafer after picking up. It is a figure explaining the semiconductor chip detection apparatus of a prior art.

Explanation of symbols

10 Light source 12 Semiconductor chip
14 Dicing sheet 15 Wafer 16 Camera 18 Processing unit 20 Recognition unit 22 Wafer ring 23 Reading unit 24 Output unit

Claims (5)

A semiconductor chip detection device for detecting individual semiconductor chips separated on a wafer,
A light source;
A camera that captures image data from a surface opposite to the light irradiation surface by capturing the semiconductor chip irradiated with light from the light source, facing the light source across a sheet on which a semiconductor chip is attached,
A processing unit for binarizing the image data;
A recognition unit for recognizing the presence or absence of a semiconductor chip from the image data binarized by the processing unit;
A semiconductor chip detection device comprising:   2. The semiconductor according to claim 1, wherein wafer mapping data including position information and good / bad information of the semiconductor chip and the binarized image data are collated to confirm pickup of a good semiconductor chip. Chip detection device.   3. The semiconductor chip detection apparatus according to claim 1, wherein the recognition unit recognizes a rectangular semiconductor chip from the binarized image data.   3. The semiconductor chip detection device according to claim 1, wherein the recognition unit grasps the number of rectangular semiconductor chips from the binarized image data. A method for detecting a semiconductor chip using the semiconductor chip detection device according to claim 1,
Irradiating the semiconductor chip with light; and
Imaging the semiconductor chip irradiated with light to obtain image data;
Binarizing the image data; and
Recognizing the presence or absence of a semiconductor chip from the binarized image data;
A method for detecting a semiconductor chip, comprising:

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