TWI773933B - Inspection method for adherend and packaging method for semiconductor wafer - Google Patents

Abstract

Proposed are an inspection method for adherend and a packaging method for semiconductor wafers, whereby it can be more correctly than before to determine if adherend adhered to a wafer carrying container containing semiconductor wafers is adhered to a surface to be adhered to. A method for inspecting if adherend to a transparent wafer carrying container for containing and carrying a plurality of wafers is adhered to a surface to be adhered to, characterized by including a imaging step(step S11) of imaging at least the surface to be adhered to of the wafer carrying container under low illumination, a image processing step(step S12) of executing at least a binarization processing to obtained images, and a determining step(step S13) of determining if the adherend is adhered to the surface to be adhered to according to the images which at least the binarization processing is executed to.

Description

Inspection method of attached object and packaging method of semiconductor wafer

The present invention relates to a method for inspecting an attached object and a method for packaging a semiconductor wafer.

When semiconductor wafers such as silicon wafers manufactured are shipped and transported, a FOSB (Front Opening Shipping Box) is known as a wafer transfer container for accommodating these semiconductor wafers (for example, refer to Patent Document 1). ~3). FOSB is standardized according to SEMI (Semiconductor Industry Association International) specification M31.

Figure 1 shows an exemplary exploded perspective view of a general FOSB. The FOSB 100 shown in the figure is a transparent container made of resin, and includes a container body 10 capable of accommodating a plurality of semiconductor wafers W in parallel with each other, a lid 20 detachably fitted to the opening of the container body 10 , and a door closing buffer. device 30.

Inside the container body 10 , a plurality of pairs of left and right support pieces 12 are arranged vertically at predetermined intervals, and a plurality of semiconductor wafers W are accommodated between the support pieces 12 in parallel with each other. In addition, the door closing buffer 30 (also referred to as a “front baffle”) has a frame body 32 , an elastic piece 34 and a plurality of pairs of grooved blocks 36 , and can be detachably attached to the inside of the cover 20 .

Then, when the lid portion 20 is fitted to the container body 10, the end portions of the semiconductor wafer W are inserted into the groove portions of the pair of grooved blocks 36, and the elastic force of the elastic sheet 34 is used to press and fix the grooved blocks 36 to the container. body 10 . In this way, the FOSB 100 containing the semiconductor wafer W is transported by all routes such as land, air, and sea. [Prior Technology Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2005-353898 [Patent Document 2] Japanese Patent Publication No. 2005-518318 [Patent Document 3] Japanese Patent Publication No. 2014-527721

FIG. 2 shows the flow of the conventional packaging method of semiconductor wafers W performed until the wafer transfer container 100 containing a plurality of semiconductor wafers W is shipped as described above. First, in step S1, as described above, the wafer transfer container (product) 100 in which a plurality of semiconductor wafers W are accommodated is received. Next, in step S2, the wafer transfer container 100 is affixed with a label showing product information, information of laser marks, and the like.

Next, in step S3, it is visually confirmed whether the label is attached to the surface to be attached, and when the label is not attached to the surface to be attached, the label is peeled off and reattached to the surface to be attached. On the other hand, when the label is attached to the surface to be attached, in step S4, the wafer transfer container 100 is packaged in a transparent bag, and a desiccant is attached to the wafer transfer container 100 through the transparent bag.

Next, in step S5, visually confirm whether the desiccant is attached to the surface that should be attached. When the desiccant is not attached to the surface that should be attached, peel off the desiccant and re-attach it to the surface that should be attached. Check again if necessary. On the other hand, when the desiccant is attached to the surface to be attached, in step S6, the wafer transfer container 100 is packaged in a bag such as an aluminum bag. After the packaging operation is completed in this way, the semiconductor wafer W is shipped.

[Problems to be solved by the invention]

As described above, in the flow of the conventional packaging method for semiconductor wafers W shown in FIG. 2 , the determination of whether or not to attach stickers such as labels and desiccants to the surfaces to be stuck is performed by the operator's eyesight. Therefore, it is possible to overlook the wafer transfer container 100 on which the sticker is attached to the wrong side.

Therefore, an object of the present invention is to propose an inspection method and a semiconductor wafer which can more accurately determine whether or not an attachment attached to a wafer transfer container for accommodating a semiconductor wafer is attached to the surface to which it should be attached. Round packaging method. [means to solve the problem]

The gist configuration of the present invention for solving the above-mentioned problems is as follows.

[1] A method for inspecting an attached object, which is a method of inspecting whether or not an attached object of a transparent wafer transfer container for accommodating and transporting a plurality of semiconductor wafers is attached to the surface to be attached, characterized by comprising: The photographing step is to photograph at least the above-mentioned surface to be attached to the above-mentioned wafer transfer container under low illumination; an image processing step, at least performing a binarization process on the obtained image; and In the determination step, it is determined whether or not the attachment is attached to the surface to be attached based on the image at least subjected to the binarization process.

[2] The method for inspecting an attached object according to the above [1], wherein the photographing step is performed under an illumination intensity of 50 Lux or more and 30 Lux or less.

[3] The method for inspecting an attached object according to the above [1] or [2], wherein the determination step includes a position determination step of determining whether or not the attached object is arranged in a predetermined area on the surface to be attached. Inside.

[4] The method for inspecting an attached object according to any one of the above [1] to [3], wherein the determination step includes an orientation determination step for determining whether or not the attached object is attached in a predetermined direction. .

[5] The method for inspecting an attached object according to any one of the above [1] to [4], wherein the attached object is a label.

[6] The method for inspecting an attached object according to any one of the above [1] to [4], wherein the attached object is a desiccant, the wafer transfer container is accommodated in a transparent bag, and the desiccant is passed through the The above-mentioned transparent bag is attached to the above-mentioned wafer transfer container.

[7] A packaging method for semiconductor wafers, characterized in that: Attaching a label to a wafer transfer container for accommodating a plurality of semiconductor wafers, according to the method described in any one of the above [1] to [6], determining whether the label is attached to the surface to be attached; When it is determined that the label is attached to the surface to be attached, after the wafer transfer container is packaged in a transparent bag, a desiccant is attached to the wafer transfer container through the transparent bag, according to the above [1] to [6 ] The method described in any one of ], determine whether the above-mentioned desiccant is attached to the surface it should be attached to; When it is determined that the desiccant is attached to the surface to which it should be attached, the wafer transfer container is packaged in a predetermined bag. [Inventive effect]

According to the present invention, it is possible to more accurately determine whether or not the sticker attached to the wafer transfer container for accommodating the semiconductor wafer is attached to the surface to which it should be attached.

(Inspection method for attached objects) Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 3 is a flowchart showing the inspection method of the sticker of the present invention. The inspection method of the attached object of the present invention is a method of inspecting whether the attached object is attached to the surface to be attached to the transparent wafer transfer container 100 for accommodating a plurality of semiconductor wafers W, and is characterized by having: The photographing step (step S11 ) is to photograph at least the surface to be attached to the wafer transfer container 100 under low illumination; the image processing step (step S12 ) is to perform at least a binarization process on the obtained image; and the determination step (step S12 ) S13), according to at least the binarized image, it is determined whether the sticker is sticking to the surface to be sticked.

As described above, with regard to the conventional inspection method of the attached object which relies on the visual confirmation of the operator, there is a risk of being overlooked even when the attached object is attached to the wrong side due to human error. Therefore, the inventors of the present invention have studied a method for inspection without relying on the operator, and as a result, they have conceived of using a photographing device to photograph the surface to which the attachment of the wafer transfer container 100 should be attached, and analyze the obtained image for inspection.

However, it has been found that the label and the desiccant are sometimes difficult to recognize even when the label-attached surface of the wafer transfer container 100 is photographed. As a result of studies conducted by the present inventors, it is understood that this is because the surface of the semiconductor wafer W is mirror-polished, and when photographing is performed in a bright environment where lighting is illuminated, the surface of the semiconductor wafer W is reflected on the surface of the semiconductor wafer W by the background, the operator, or by light from the lighting. light reflection, etc.

Therefore, the inventors of the present invention have devoted themselves to studying a method for suppressing the above-mentioned background reflection and light reflection from illumination during shooting. As a result, the inventors found that it is extremely effective to photograph the wafer transfer container 100 under low illumination, and the present invention has been completed. Hereinafter, each step will be described.

First, in step S11, at least the surface to which the attachment object of the wafer transfer container 100 should be attached is photographed under low illumination (photographing step).

In the present invention, the attached object to be inspected is attached to the wafer transfer container 100 at the time of packaging the semiconductor wafer W, such as a label, a desiccant, or the like. Labels include product labels that display product information such as product numbers and shipment batch numbers, laser marking sheets that display information on laser markings, and barcode labels that display product information. Depending on the specifications, the types of labels attached vary. In addition, depending on the specification, which label is attached to which surface may be specified up to the position (area) on the surface. In this way, the combination of the types and arrangements of the attached labels is various, and this variety is a great cause of human error by the operator.

In addition, the desiccant is attached to protect the semiconductor wafer W due to moisture damage caused by moisture in the air when the semiconductor wafer W is transported. As described above, after the wafer transport container 100 is packaged in the transparent bag , and attached to the wafer transfer container 100 .

In the present invention, it is critical to perform the above-mentioned photographing steps under low illumination. Thereby, the background reflection and reflection as described above can be greatly suppressed. Specifically, the photographing step is ideally performed under an illuminance of 50 Lux or more and 300 Lux or less. Thereby, the reflection and reflection of the background are further suppressed, and the detection of the sticker can be performed more easily. The above photographing steps are ideally carried out under the illumination of 120Lux.

The illuminance adjustment in the above-mentioned photographing step, for example, as an illuminating device, can be performed using a illuminating device whose brightness can be finely adjusted. In addition, when the brightness of the illumination device cannot be adjusted, it can be performed by adjusting the light incident from the illumination device to the wafer transfer container 100 to be photographed using, for example, a shading curtain.

The photographing step, when the attached object is a label, can be performed on the upstream line from the packaging wafer transfer container 100 to the transparent bag by disposing a photographing device such as a CCD camera. In addition, when the sticker is a desiccant, it can be performed by arranging a photographing device between the line for packaging the wafer transfer container 100 into the transparent bag and the downstream line for packaging the wafer transfer container 100 into the aluminum bag.

Next, in step S12, at least a binarization process is performed on the image obtained in step S11 (image processing step). For the threshold value used in the binarization process, for example, the luminance value information of each pixel in the image is obtained, and an appropriate threshold value can be determined according to the obtained luminance value distribution. In addition, binarization processing is performed on a plurality of images in advance, and the threshold value at which the label and the desiccant can be detected is obtained empirically, and the binarization processing can be performed using the obtained threshold value. In addition, according to a discriminant analysis method or the like, binarization processing can be performed using a critical value with the largest degree of separation.

FIG. 4 is an example of a label image, and (a) is an image before binarization processing, and (b) is an image after binarization processing, respectively. Because the label is often based on white, as shown in Figure 4, the area around the display label is black compared to the surrounding white display of the label.

In addition, Fig. 5 is an example of a desiccant image, and (a) is an image before binarization processing, and (b) is an image after binarization processing, respectively. Because the desiccant is often based on white, the area around the desiccant is displayed in black compared to the whiteness around the desiccant. In addition, in Fig. 5, there is a white area other than the area of the desiccant, but the presence or absence of the desiccant can be determined in step S13 described later based on information such as the size and shape of the label.

In addition to the above-described binarization processing, other appropriate processing such as differential processing may be performed to facilitate the detection of labels in the video.

Next, in step S13, based on the image obtained in step S12 and subjected to at least the binarization process, it is determined whether or not the object to be attached is attached to the surface to be attached (determination step). In the image obtained in the above step S12, the brightness value of the image changes sharply in the vicinity of the outline of the sticker, such as a label and a desiccant. Therefore, the adhering object region in the image can be detected by using such a change in luminance value.

Specifically, the luminance value information of each pixel in the image after the binarization process is acquired, and the pixel whose luminance value difference from the adjacent pixel exceeds a predetermined threshold value is detected, and the area estimated to be the sticker is obtained. Area. Then, a database is prepared in advance for the type of label, display content, size, shape, surface to be attached, and position on the surface, etc., and it is determined whether or not the attachment is attached based on the size of the attachment area estimated as described above, etc. to the surface of the wafer transfer container 100 to be attached.

Also, when the position (area) of the surface to which the sticker should be stuck is determined in advance, by specifying the position of the sticker on the surface clearly, it is possible to determine whether or not the sticker is placed in the position (area) (position determination step) . If it is determined that the position of the sticker is wrong, peel off the sticker and stick it again in the above-mentioned area. If necessary, re-inspection can be carried out.

In addition, when the orientation of the attached object to be attached is determined in advance, the shape of the attached object or the information (for example, characters and numbers) of the attached object region in the image after the binarization process is obtained, and the orientation is determined according to the direction of the attached object. , it can be determined whether or not the attachment is attached in a predetermined direction (orientation determination step). If it is determined that the orientation of the sticker is wrong, peel off the sticker and re-stick it in the correct direction, and re-check if necessary.

(Packaging method for semiconductor wafers) Next, the packaging method of the semiconductor wafer concerning this invention is demonstrated. FIG. 6 shows the flow of the packaging method of the semiconductor wafer of the present invention. In the packaging method for semiconductor wafers of the present invention, a label is attached to a wafer transfer container for accommodating a plurality of semiconductor wafers (step S22 ), and it is determined whether the label is attached to its intended attached surface (steps S23 to S25). Then, when it is determined that the label is attached to the surface to be attached, after packaging the wafer transport container in the transparent bag, the desiccant is attached to the wafer transport container through the transparent bag (step S26), according to the above-mentioned method. In the inspection method of the attached object of the invention, it is determined whether or not the desiccant is attached to the surface to which it should be attached (steps S27 to S29). inside the bag (step S30). Hereinafter, each step will be described.

First, in step S21, the wafer transfer container 100 in which a plurality of semiconductor wafers are accommodated is received.

Next, in step S22 , a label describing product information, laser mark information, and the like is attached to the wafer transfer container 100 . The sticking of the label may be performed mechanically, or may be performed by an operator.

Subsequent steps S23 to S25 correspond to steps S11 to S13 of the above-mentioned method for inspecting an attached object of the present invention, and the description thereof is omitted. According to these steps S23 to S25, it can be determined whether the label is attached to the surface to which it should be attached. When it is judged that the label is not attached to the side where it should be attached, peel off the label, reattach it to the side where it should be attached, and re-inspect it if necessary.

On the other hand, when it is determined that the label is attached to the surface to be attached, the process proceeds to step S26, the wafer transport container 100 is packaged in a transparent bag, and the desiccant is attached to the wafer transport container 100 through the transparent bag. The sticking of the desiccant may be performed mechanically, or may be performed by an operator.

Subsequent steps S27 to S29 correspond to steps S11 to S13 of the above-described method for inspecting an attached object of the present invention, and the description thereof is omitted. According to these steps S27 to S59, it can be determined whether or not the desiccant is attached to the surface to which it should be attached. When it is determined that the desiccant is not attached to the surface to be attached, peel off the desiccant and reattach it to the surface to be attached, and re-inspect it if necessary.

On the other hand, when it is determined that the desiccant is attached to the surface to be attached, the process proceeds to step S30, and the wafer transfer container 100 is packaged in a predetermined bag, and as a predetermined bag, moisture is isolated so as not to affect the wafer quality. , you can use aluminum bags, transparent moisture-proof bags, etc. In this way, the packaging operation is completed. The packaged semiconductor wafer W is shipped and transported to a predetermined destination. [Industrial availability]

The present invention is useful in the semiconductor wafer manufacturing industry because it is possible to more accurately determine whether or not an object attached to a wafer transfer container for accommodating semiconductor wafers is attached to the surface to be attached.

10: Container body 12: Support sheet 20: Cover 30: Door closing buffer 32: Frame 34: elastic sheet 36: Attached groove block 100: FOSB (wafer transfer container) W: semiconductor wafer

[Figure 1] is an example exploded perspective view of a general FOSB; [Fig. 2] is a flow chart of a conventional packaging method for semiconductor wafers; [Fig. 3] is a flowchart of the inspection method of the attached object of the present invention; [Fig. 4] is an example of a label image, respectively showing that (a) is the image before binarization, and (b) is the image after binarization; [Fig. 5] An example of an image of a desiccant, showing that (a) is an image before binarization, and (b) is an image after binarization; and [FIG. 6] It is the flow of the packaging method of the semiconductor wafer of this invention.

S11: Photograph the surface on which the attachment of the wafer transfer container should be attached under low illumination

S12: Perform at least a binarization process on the obtained image

S13: Whether the attachment is attached to the surface that should be attached

Claims (12)

A method for inspecting an attached object, which is a method of inspecting whether an attached object of a transparent wafer transfer container used for accommodating and transporting a plurality of semiconductor wafers is attached to the surface to be attached, characterized by comprising: a photographing step, photographing at least the surface to be attached to the wafer transfer container under low illumination; an image processing step of performing at least a binarization process on the obtained image; and a determination step of determining the above image based on at least the binarized image. Whether the attached object is attached to the above-mentioned surface to be attached, wherein, the above-mentioned photographing step is performed under the illumination intensity of 50Lux or more and 300Lux or less. The method for inspecting an attached object according to claim 1, wherein the determination step includes a position determination step of determining whether or not the attached object is arranged in a predetermined area of the surface to be attached. The method for inspecting an attached object according to claim 1, wherein the determination step includes an orientation determination step for determining whether or not the attached object is attached in a predetermined direction. The method for inspecting an attached object according to claim 2, wherein the determination step includes an orientation determination step for determining whether or not the attached object is attached in a predetermined direction. The inspection method of an attached object according to claim 1, wherein the attached object is a label. The inspection method of an attached object according to claim 2, wherein the attached object is a label. The inspection method of an attached object according to claim 3, wherein the attached object is a label. The method for inspecting an attached object according to claim 1, wherein the attached object is a desiccant, the wafer transfer container is accommodated in a transparent bag, and the desiccant is attached to the wafer through the transparent bag. Round transport container. The method for inspecting an attached object according to claim 2, wherein the attached object is a desiccant, the wafer transfer container is accommodated in a transparent bag, and the desiccant is attached to the wafer through the transparent bag. Round transport container. The method for inspecting an attached object according to claim 3, wherein the attached object is a desiccant, the wafer transfer container is accommodated in a transparent bag, and the desiccant is attached to the wafer through the transparent bag. Round transport container. The method for inspecting an attached object according to claim 4, wherein the attached object is a desiccant, the wafer transfer container is accommodated in a transparent bag, and the desiccant is attached to the wafer through the transparent bag. Round transport container. A method for packaging semiconductor wafers, characterized in that: a label is attached to a wafer transport container for accommodating a plurality of semiconductor wafers; Attached to the surface that should be attached; when it is determined that the label is attached to the surface that should be attached, after packaging the wafer transport container in a transparent bag, attach a desiccant to the wafer transport through the transparent bag The container, according to the method described in any one of the claims 1 to 11 of the scope of the application, to determine whether the above-mentioned desiccant is attached to the surface to be attached; when it is determined that the desiccant is attached to the surface to be attached The above-mentioned wafer transfer container is packaged in a predetermined bag.

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