TWM599025U - Wafer position determination system - Google Patents

Abstract

A wafer position judgment system includes a storage device, a photographing device, an image pre-processing device and a processing device. The imaging device shoots the wafer basket and the wafers to be tested placed in the wafer basket to generate the initial image to be tested. The image pre-processing device pre-processes the initial image to be tested according to the data stored in the storage device to obtain the processed image. For measuring the image, the final processing device determines the position of the wafer to be tested in the wafer basket according to the positions and slopes of a plurality of judgment reference lines extending substantially along a specific direction in the processed image.

Description

Wafer position judgment system

The present invention relates to an automation system for semiconductor manufacturing process, in particular to a wafer position judgment system.

The existing wafer position judgment system uses the upper and lower edges of the wafer basket and the number of wafer placement columns to estimate the position of the wafer in the wafer basket. For example, when there are 25 wafer placement fields in the wafer basket, and the height of the wafer basket is 25 cm, it can be estimated that a wafer can be placed about every 1 cm apart.

However, such a wafer position judgment system cannot overcome the possible frame deformation of the wafer basket, and it cannot overcome the possibility of wafer displacement in the wafer basket due to various external forces (such as electrostatic forces). Sex. In addition, if the shooting angle of the wafer basket and wafers to be tested is deviated, it is likely to affect the accuracy of the wafer position determination system.

In order to solve the above problems, the present invention proposes a wafer position judging system. The wafer position judging system can organize the shot images and convert them into images shot at a preset angle, and can overcome problems such as wafer baskets. Problems such as frame deformation or wafer position deviation.

From one aspect, the present invention proposes a wafer position judgment system, which is suitable for judging the position of a wafer to be tested in a wafer basket including a plurality of wafer placement fields. The wafer position determination system includes a storage device, a photographing device, an image pre-processing device and a processing device. The storage device is used to store a preset data group. The preset data group includes a standard image feature group corresponding to a standard image obtained by shooting a wafer basket placed in a preset state, and a plurality of specific parts related to the standard image The default size information group. The photographing device is suitable for photographing the wafer basket to be tested and the wafers to be tested placed in the wafer basket to generate an initial image to be tested. The image pre-processing device is electrically coupled to the photographing device and the storage device, which obtains the initial image to be measured and the preset size information group, and pre-processes the initial image to be measured according to the preset size information group to rotate the initial image to be measured. Obtain the processed image to be tested. The processing device is electrically coupled to the image pre-processing device and the storage device, which obtains the processed image to be tested and the standard image feature set, analyzes the image features of the processed image to be tested to obtain the corresponding feature set of the image to be tested, and matches The standard image feature group and the image feature group to be tested are used to determine the position of the wafer to be tested in the wafer basket. The wafer basket placed in the preset state includes a plurality of standard wafers placed in the wafer basket.

In one embodiment, when the aforementioned image pre-processing device performs pre-processing on the initial image to be tested according to the preset size information group to rotate the initial image to be tested to obtain the processed image to be tested, it includes: analyzing the initial image to be tested to Find the image area corresponding to the wafer basket in the initial image to be tested; find the coordinate information group in the image corresponding to the above-mentioned specific part from the aforementioned image area; compare the preset size information group with the coordinates in the image Information group, and determine the rotation angle according to the comparison result, where the wafer basket shown in the initial image to be tested is formed by rotating the wafer basket represented by the preset data group by this rotation angle; and the image area is rotated in the reverse direction This rotation angle is used to generate the processed image to be measured.

In one embodiment, the above-mentioned specific part includes the edge or corner of the wafer basket.

In one embodiment, the above-mentioned standard image feature group includes the appearance features of the standard wafer basket obtained from the wafer basket in the standard image, and the above-mentioned image feature group to be tested includes the appearance features of the standard wafer basket in the image to be tested. The appearance characteristics of the wafer basket to be tested obtained and the appearance characteristics of the wafer to be tested obtained according to the wafer to be tested.

In one embodiment, when the processing device analyzes and processes the image features of the image to be tested to obtain the corresponding feature group of the image to be tested, it includes: analyzing the processed image to obtain the appearance feature of the wafer basket to be tested; The position and number of multiple judgment reference lines extending substantially along a specific direction in the post-test image; and the area between two adjacent judgment reference lines with a slope within the preset slope range as a hypothetical wafer The appearance characteristics of the wafer under test are taken as the appearance characteristics of the assumed wafer appearance.

In one embodiment, when the processing device matches the standard image feature group and the image feature group to be tested to determine the position of the wafer to be tested in the wafer basket, it includes: according to the appearance features of the wafer to be tested and the wafer to be tested. The appearance characteristics of the round basket are obtained, and the relative position parameters of the hypothetical wafers and the wafer basket in the image to be tested after processing are obtained; and the primary wafers are obtained according to the relative position parameters to be tested and the appearance characteristics of the standard wafer basket Placement field, where the preliminary selection wafer placement field is the wafer placement field in the standard image corresponding to the relative position parameter to be measured.

In one embodiment, after obtaining the preliminary selection wafer placement field, the processing device further obtains the first distance between the hypothetical wafer and the preset point, and the preliminary selection wafer placement field and the preset The second distance between the points; use the difference between the first distance and the second distance as the displacement compensation value; and when the displacement compensation value is within the preset distance range, set the initial wafer placement field to occupied Place the field, and relatively, when the displacement compensation value exceeds the preset distance range, select another wafer placement field as the primary wafer placement field and recalculate the displacement compensation value until the displacement compensation value reaches the preset Within the distance range, and set the final initial selection wafer placement field as an occupied placement field.

In another embodiment, the standard image feature group includes a standard wafer position feature obtained according to the relative position of the standard wafer and the wafer basket in the standard image, and the image feature group to be tested includes The position feature of the wafer to be tested based on the relative position of the wafer to be tested and the wafer basket. Further, when the processing device analyzes the image features of the image to be tested after processing to obtain the corresponding feature group of the image to be tested, it includes: determining the position of the judging reference line extending substantially along a specific direction in the processed image to be tested And quantity; and the area between two adjacent judgment reference lines with a slope within the preset slope range is used as a hypothetical wafer, and the relative position of the hypothetical wafer and the wafer basket is the aforementioned wafer to be tested Location characteristics of wafers. Further, when the processing device matches the standard image feature group and the image feature group to be tested to determine the position of the wafer to be tested in the wafer basket, it includes: acquiring the first distance between the hypothetical wafer and the predetermined point ; According to the second distance between each wafer placement field and the preset point, select the wafer placement field closest to the hypothetical wafer as the primary wafer placement field; and The selected preliminary wafer placement field is set as the occupied placement field.

In one embodiment, when the processing device sets the occupied placement field, it also records the control compensation value corresponding to the hypothetical wafer placed in the occupied placement field, where the control compensation value may be a preset Value, the aforementioned displacement compensation value, or the standard average value of multiple aforementioned displacement compensation values corresponding to multiple wafers placed in different places.

In one embodiment, the processing procedure executed by the processing device further includes: obtaining an isolated reference line from the judgment reference line that cannot be paired with other judgment reference lines into a hypothetical wafer; and comparing the position of the isolated reference line with the wafer The difference value between the positions of the boundaries of each unoccupied person in the placement field is set, and the unoccupied wafer placement field with the smallest difference value is set as occupied.

In one embodiment, the wafer position determination system further includes a warning device electrically coupled to the processing device, and the processing device further includes: determining whether there is an oblique insertion reference line, wherein the oblique insertion reference line is the judgment reference line The intermediate slope exceeds the preset slope range; judge whether the wafer containing the diagonal insertion reference line occupies more than two wafer placements according to the slope of the diagonal insertion reference line and the size of the wafer to be tested and the wafer basket Field; and when a wafer containing an oblique insertion reference line occupies more than two wafer placement fields, the processing device controls the warning device to issue a warning.

In one embodiment, the processing device also calculates the wafer access position corresponding to each unoccupied wafer placement field according to the recorded control compensation value, and controls the robotic arm to place the wafer when needed. The other wafers in the round basket are placed in this wafer access position.

Based on the above, the wafer position determination system provided by the present invention can determine the rotation angle between the captured image and the image used for comparison, so the original captured image can be converted into an image captured at a preset angle. It is convenient for subsequent analysis and judgment, and it can be found whether the wafer basket has frame deformation. In addition, the wafer position judging system can also find out the possible edge positions of the wafers, and determine the best wafer position based on the found edge positions of the wafers and the position of the wafer placement field. Potentially occupied wafer placement field, and determine whether the wafer position shifts according to the slope of the edge position of the wafer. In addition, the amount of movement that should be adjusted when the robotic arm accesses the wafer can also be controlled according to the difference between the edge position of the wafer and the position of the occupied wafer placement field.

Please refer to FIGS. 1 and 2 together. Among them, FIG. 1 is a circuit block diagram of a wafer position determination system according to an embodiment of the present invention, and FIG. 2 is an appearance of a wafer basket used in an embodiment of the present invention Schematic. As shown in FIG. 1, the wafer position determination system 10 is suitable for performing image shooting and analysis related operations on the wafer basket 15 to determine the position of the wafer in the wafer basket 15. Among them, the wafer position determination system 10 includes a processing device 100, an image pre-processing device 110, a photographing device 120, and a storage device 130. The processing device 100 is electrically coupled to the image pre-processing device 110 and the storage device 130, respectively. In addition to being electrically coupled to the processing device 100, the image pre-processing device 110 is also electrically coupled to the photographing device 120 and the storage device 130, respectively .

Generally speaking, the wafer basket 15 may include a plurality of wafer placement fields 150, and each wafer placement field 150 is suitable for placing a wafer, wherein each wafer placement field The position of 150 is defined by the inner wall of the wafer basket and the support frame. For example, the position of the wafer placement field 150 shown in FIG. 1 is defined by the left and right side walls of the wafer basket 15 and the support frames 160a, 160b, 170a, and 170b; the upper edge of the wafer placement field 150 is The upper edge 152 of the fence shown in the figure (corresponding to the lower side of the support frames 170a and 170b), and the lower edge position is the lower edge 154 of the fence shown in the figure (equivalent to the upper edges of the support frames 160a and 160b). side). Under normal circumstances, the operator would expect the left and right sides of the wafer to be supported by the support frames 160a and 160b respectively and to be completely stored in a wafer placement field 150 (the wafer as shown in Figure 1 The wafer 180 is completely stored in a wafer placement field). However, sometimes due to mechanical errors, the wafers may be placed into the wafer basket 15 at an angle, causing the wafers to occupy more than two wafer placement fields 150 at the same time (as shown in Figure 1 The shown wafer 190 occupies two wafer placement fields). The wafer position determination system 10 proposed in the description document of the present invention can determine whether the wafer is properly placed, and reduce the problems caused by mechanical operation errors.

In order to solve the problems existing in the prior art, the aforementioned photographing device 120 is installed in a position where the wafer basket 15 can be photographed, and the photographing device 120 can photograph the wafer basket 15 and the wafers placed in the wafer basket 15 The current status of the slices 180, 190 (hereinafter also referred to as wafers to be tested), etc., to obtain a corresponding initial test image. This initial image to be tested is sent from the camera 120 to the image pre-processing device 110, and the image pre-processing device 110 performs image pre-processing operations based on the relevant information it obtains from the storage device 130 to rotate the initial image to be tested into The result of shooting from a preset angle of view to facilitate subsequent image analysis.

In this embodiment, the storage device 130 pre-stores a preset data group. In order to generate this default data set, the user can first take an image of the wafer basket 15 in a certain preset state to obtain the corresponding standard image, and then generate the default data set based on this standard image . In this embodiment, it is selected to shoot a wafer basket 15 full of standard wafers to obtain a corresponding standard image, but this is not a limitation of the present invention.

The aforementioned preset data group includes a standard image feature group corresponding to the standard image, and a preset size information group related to the wafer basket 15 and a plurality of specific parts of the standard wafer in the standard image. Among them, the standard image feature group includes various image features (Image Feature) obtained from the standard image, and the preset size information group may include the coordinate value of each corner of the wafer basket 15, the length or extension direction of each edge, The length, edge coordinates and center coordinates of the standard wafers, and the relative distance between the wafer basket 15 or the standard wafers, etc. Further, the preset size information group may also include values such as the coordinates, length, or distance between this part with shape characteristics and certain preset points. The method of obtaining image features and the method of comparing image features between different images can be performed using the processing methods of the prior art, which will not be described here; the following will describe an implementation of generating a preset size information group in conjunction with Figure 2 example.

Please refer to Figure 2. In order to be able to clarify the position of all the wafers as much as possible, a corresponding standard wafer 200-218 is placed in all the wafer placement fields of the wafer basket 15. The round basket 15 is in a fully loaded state (that is, the preset state adopted in this embodiment is a fully loaded state). When the preset data set is to be generated, the wafer basket 15 in this state and the standard wafers 200-218 placed therein can be photographed first to generate corresponding standard images. Next, one of the corners of the wafer basket 15 in the standard image (assumed to be the corner P1) can be used as the origin of the coordinate axis, and then the standard can be set with a preset ratio according to the distance between the corners P1~P7. The coordinates of the other corners P2, P3, P4, P5, P6, and P7 of the wafer basket 15 in the image relative to the corner P1. These coordinates can be stored as part of the aforementioned preset size information group. At the same time, the coordinates of the end or center of the standard wafer 200-218 in the standard image relative to the corner P1 can also be stored as part of the aforementioned preset size information group. Further, when the distance between the corners, the distance between each standard wafer 200-218 and the wafer basket 15 or the size of the standard wafer 200-218 is required, the above coordinates can also be used to determine Perform backward calculations.

Since the purpose of the default data set is only to establish a reference point for comparison, any method that can create a default data set that meets the needs can be applied here. For example, in another embodiment, the deviation angle and extension distance of each edge of the wafer basket and wafers relative to a certain reference line (such as a specific edge) can be recorded as one of the preset data sets. Part. A person skilled in the art can set a default data set suitable for the working environment according to the content stated in the specification of the present invention. The foregoing embodiment of generating the default data set is not intended to limit the implementation of the present invention.

The above technical content can be systematically organized into the operation flowchart of the wafer position determination system shown in FIG. 3. As shown in FIG. 3, after the photographing device 120 generates the initial image to be measured by photographing the wafer basket 15 in FIG. 1 (step S302), the photographed initial image to be measured is transferred to the image preprocessing device 110 To perform image pre-processing operations (step S304). In order to perform the image pre-processing operation smoothly, the image pre-processing device 110 first obtains part of the content in the aforementioned preset data set that can be used in the image pre-processing operation before performing the image pre-processing operation (step S306). After obtaining the initial image to be tested and the content that must be used in the preset data group, that is, the aforementioned preset size information group, the image pre-processing device 110 can use the obtained content to perform image pre-image processing on the initial image to be tested. The processing operation (step S308) enables the processed image to be tested generated by the image preprocessing device 110 to have the same shooting angle as the standard image used when generating the preset data set.

In detail, when performing the image pre-processing operation in step S308, the image pre-processing device 110 first analyzes the initial image to be tested to find the position of the wafer basket 15 in the image (hereinafter referred to as the image area). Next, the image pre-processing device 110 finds out the coordinate information related to the specific part of the wafer basket 15 in the initial image to be tested according to the image area of the wafer basket 15 (hereinafter referred to as the intra-image coordinate information group). The specific part of the wafer basket 15 mentioned here is related to the part of the wafer basket used in the previous generation of the preset data set. For example, it was previously generated based on the specific corner of the wafer basket (for example, the corner P1) When the data set is preset, the specific part that needs to be searched at this time is the corner of the wafer basket in the initial image to be tested; on the other hand, if the preset data set was generated based on a specific edge previously, then this The specific part that needs to be searched is the edge of the wafer basket in the initial image to be tested. After finding the corresponding specific part, the image pre-processing device 110 compares the found coordinate information group in the image with the preset size information group stored in the preset data group, and obtains the information according to the comparison result The wafer basket in the initial image to be tested is the result of the rotation of the wafer basket represented by the preset data set (the angle of rotation is referred to as the rotation angle hereinafter).

In one embodiment, the aforementioned rotation angle is calculated from the displacement of the coordinate information representing the same specific part in the initial image to be measured and the preset data set. For example, the coordinate axis of a certain corner of the wafer basket in the initial image to be measured is (X1, Y1, Z1), and the coordinate axis in the preset size information group is (X2, Y2, Z2), then this corner is in X The displacements of X1-X2, Y1-Y2, and Z1-Z2 appear on the axis, Y-axis, and Z-axis, respectively; the same method can also be used to calculate the displacement of other rotation angles. After the displacement status is calculated, the image pre-processing device 110 can use a specific rotation angle (for example, rotation angle P1) as the origin, and calculate the initial measured image in accordance with the displacement status of this specific rotation angle and the displacement status of other rotation angles. The rotation angle of each rotation angle relative to each rotation angle in the preset data group.

Next, the image pre-processing device 110 performs a reverse rotation operation of a reverse rotation angle on the entire initial image to be measured according to the calculated rotation angle. In other words, assuming that the calculated rotation angle is 30 degrees clockwise on the X axis, 25 degrees clockwise on the Y axis, and no rotation on the Z axis, the reverse rotation operation performed by the image preprocessing device 110 is to change the initial waiting The measurement image is rotated with the X axis rotated 30 degrees counterclockwise, the Y axis rotated 25 degrees counterclockwise, and the Z axis does not rotate. After performing a reverse rotation operation on the initial image to be measured, the image pre-processing device 110 can generate a corresponding processed image to be measured, and the obtained processed image to be measured will be transmitted to the processing device 100. The processing device 100 obtains a preset data set (step S310), and determines the position of the wafer according to the content of the preset data set and the obtained processed image to be tested (step S312).

There are many possible methods for the processing device 100 to determine the location of a wafer. One of them is to combine the image features (hereinafter referred to as the wafer basket image) corresponding to the processed wafer basket in the image to be tested ( Later referred to as the appearance characteristics of the wafer basket to be tested), the image features corresponding to the wafer under test in the processed image to be tested (hereinafter referred to as the image of the wafer under test) (hereinafter referred to as the appearance feature of the wafer under test) And compare the image features (hereinafter referred to as the appearance features of the standard wafer basket) corresponding to the wafer basket in the standard image (including standard wafers), and obtain the location of the wafer to be tested based on this. Regarding the method of obtaining image features and the method of comparing image features of different images, the processing methods provided by the prior art can be used, and no further description is given here.

Please also refer to FIG. 4, which is an operation flowchart performed by the processing device according to an embodiment of the present invention when analyzing and processing the image features of the image to be tested to obtain the corresponding feature group of the image to be tested. In this embodiment, the processing device 100 analyzes the previously obtained processed image to be tested to obtain the appearance characteristics of the wafer basket to be tested (step S400). Specifically, the processing device 100 may use the image of the wafer basket that was previously found in the image pre-processing process and obtained after reverse rotation to capture image features, and use the captured image features as the wafer basket to be tested Appearance characteristics. Since the analysis is the entire reverse-rotated wafer basket image, the appearance characteristics of the wafer basket to be tested also include the image features of the wafers 180 and 190 to be tested. Therefore, the processing device 100 searches for the position and number of multiple lines (hereinafter referred to as the judgment reference line) extending substantially along a specific direction in the appearance characteristics of the wafer basket to be tested (step S402). The aforementioned specific direction can be changed with the placement of the wafers. When the wafers are placed horizontally and arranged vertically, the specific direction is the horizontal direction; on the contrary, when the wafers are placed vertically and arranged horizontally When, the specific direction is the vertical direction. In order to reduce the tilt that may occur when storing the wafers, the wafers are generally stored in a horizontal and vertical arrangement as shown in FIG. 1 or FIG. 2. Therefore, in this embodiment, the horizontal direction is used as the specific direction, and the processing device 100 will look for the judgment reference line extending substantially along the horizontal direction in the appearance characteristics of the wafer basket to be tested.

Specifically, since the normally placed wafer will be in a horizontal state, the upper and lower edges of the wafer to be tested should also be roughly horizontal. Therefore, the processing device 100 first finds two judgment reference lines that are adjacent and whose slopes are within a certain range among these judgment reference lines, and use these two judgment reference lines as the upper and lower sides of a hypothetical wafer. The edge, that is, the hypothetical wafer occupies the area between the two judgment reference lines (step S404). After the hypothetical wafer is set, the processing apparatus 100 can use the appearance feature obtained according to the appearance of the hypothetical wafer as the aforementioned appearance feature of the wafer to be tested (step S406).

After obtaining the image feature group to be tested, the processing device 100 can determine the location of the wafer to be tested by comparing the image features. Please refer to FIG. 5, which is a flowchart of operations performed by the processing device according to an embodiment of the present invention when determining the location of the wafer to be tested by comparing image features. In this embodiment, the processing device 100 first obtains the relative position parameters between the hypothetical wafer and the image of the wafer basket to be tested according to the appearance characteristics of the wafer to be tested and the appearance features of the wafer basket to be tested (step S500). For example, in step S500, the processing device 100 can obtain corresponding hypothetical wafers and specific locations of the images of the wafer basket to be tested by comparing the appearance characteristics of the wafer to be tested and the appearance features of the wafer basket to be tested ( For example, the distance of the upper edge), or confirm the image characteristics of the support frame that carries the hypothetical wafer in the image of the wafer basket to be tested. The distance or image feature found in the foregoing processing can be used as the relative position parameter between the hypothetical wafer and the image of the wafer basket under test (hereinafter referred to as the relative position parameter under test).

After obtaining the relative position parameters to be measured between the hypothetical wafer and the image of the wafer basket to be tested, the processing device 100 further compares the relative position parameters to be measured and the appearance characteristics of the standard wafer basket, and uses the previously obtained Find the corresponding wafer placement column in the standard image relative to the position parameters (step S502). For example, when the relative position parameter to be measured is assumed to be the distance between the wafer and the upper edge of the wafer basket image to be measured, the processing device 100 can find out the same distance as the upper edge of the wafer basket of the standard image The wafer placement field (hereinafter referred to as the primary wafer placement field), and this primary wafer placement field is the storage location of the hypothetical wafer currently being processed. In another example, when the relative position parameter to be measured is the image feature of the support frame that carries the hypothetical wafer in the image of the wafer basket to be tested, the processing device 100 may compare the image feature of the support frame that carries the hypothetical wafer with The appearance features of the standard wafer basket are compared and the corresponding primary wafer placement column is found in the wafer basket of the standard image.

After locating the preliminary wafer placement column, it is assumed that the wafer position determination procedure is basically completed. However, because there may still be misjudgments in the process of position judgment based on image features, the aforementioned position judgment results can be further enhanced.

For example, referring to FIG. 6, after obtaining the preliminary selection wafer placement column, the processing device 100 may obtain the first distance between the hypothetical wafer and a predetermined point on the physical wafer basket ( Step S600), and obtain a second distance between the primary wafer placement field and the same preset point on the physical wafer basket (Step S602). Next, the processing device 100 calculates the difference between the first distance and the second distance, and uses the calculated difference as the displacement compensation value (step S604). When the displacement compensation value is within the preset distance range, it means that it is assumed that the location of the wafer should not be far from the result determined by using the image feature, so the processing device 100 determines that there is no need to update the primary wafer placement column (Step S606), and set the existing preliminary wafer placement field as an occupied placement field (Step S608). In contrast, when the displacement compensation value is outside the preset distance range, it means that there may be some factors that may cause the misjudgment of the wafer position. Therefore, the processing device 100 will determine that it is necessary to update the preliminary wafer placement column at this time. (Step S606), and then select one of the unoccupied wafer placement columns as the primary wafer placement column (Step S608) and enter steps S602 to S606 to repeat the process of calculation and determination. The above occupied placement field is used to indicate that wafers have been stored in this wafer placement field. All the wafers can be determined when the wafer position is judged at the beginning of each image to be tested. The placement fields are all set to an unoccupied state, and then as the position of each wafer is determined, the wafer placement fields occupied by these wafers can also be marked together, so in In step S608, when selecting other wafer placement fields, the number of selectable objects will be reduced and therefore the speed of obtaining correct results will be increased.

Because image processing sometimes causes errors in judgment due to changes in light and shadow during shooting, it cannot be ruled out that sometimes only the upper or lower edge of the wafer can be identified. Therefore, please refer to FIG. 7. After the above-mentioned processing, the processing device can further search from the previously obtained judgment reference line to find whether there is a single judgment reference line that cannot be matched with any other judgment reference line and becomes a hypothetical wafer. Line (hereinafter referred to as isolated baseline) (step S700).

If an isolated reference line is found in step S700, the processing device 100 will confirm the position of the isolated reference line in a suitable manner (step S702). Among them, the position determination of the isolated reference line can be performed in many ways. For example, but not limited to, the wafer to be tested in FIG. 5 can be changed to an isolated reference line and suitable image characteristic parameters can be used for position confirmation. Since the isolated datum line may be the edge of a wafer, the processing device 100 can compare and calculate the position of the isolated datum line with the position of the boundary (upper and lower edge) of the wafer placement field that has not yet been occupied The difference between the two (step S704). Finally, the processing device 100 can determine the wafer placement field with the smallest difference value as being occupied by the wafer represented by the isolated reference line, and set the wafer placement field as an occupied place. Place the column (step S706). In another embodiment, if the difference between the isolated reference line and the unoccupied wafer placement field is too large, the wafer represented by the isolated reference line may be discarded or controlled by the processing device 100 The warning device 140 sends a warning to notify the user for confirmation.

In contrast, if it is found in step S700 that there is no isolated reference line, the process can be directly ended and other required processing can be performed.

Further, in this embodiment, since the normally placed wafer will be in a horizontal state (the wafer 180 shown in FIG. 1), the processing device 100 will use a slope when looking for a hypothetical wafer The upper and lower edges of the hypothetical wafer are formed based on the judgment baseline within a certain range. However, occasionally, incorrectly placed wafers may exist in the wafer basket. For example, the wafer 190 shown in FIG. 1 occupies two wafer placement fields at the same time. In order to find these misplaced wafers, when setting the specific range of the slope, it must be adjusted according to the size of the wafer and the wafer basket.

Please refer to FIG. 8, which is an operation flowchart of the processing device according to an embodiment of the present invention when performing enhanced processing on the wafer position determination result. This embodiment is mainly performed on the judgment reference line with an excessively large tilt angle. First, in step S800, the processing device 100 first confirms whether there is a judgment reference line with a slope exceeding the aforementioned preset slope range (hereinafter referred to as the oblique interpolation reference line). If there is an oblique insertion reference line, the processing device 100 will further determine the wafer to be tested corresponding to the oblique insertion reference line according to the slope of the oblique insertion reference line, the size of the wafer to be tested, and the size of the wafer basket 15 Whether more than two wafer placement fields are occupied at the same time (step S802). If the wafer to be tested corresponding to the oblique insertion reference line may occupy more than two wafer placement fields, the processing device 100 will control the warning device 140 to issue a warning.

After processing through the above-disclosed technology, the wafer position determination system 10 can determine the position of the wafer and whether there is an oblique insertion error. Further, the occupied placement field set during the position determination process can also be used as a basis for selecting the field when the robot arm is subsequently controlled to place other wafers. Moreover, if the position error between the wafer and the field where the wafer is placed (hereinafter referred to as the control compensation value) can be recorded while setting the occupied placement field, then the subsequent control of the robot arm to take out or place It can also reach a more precise wafer access position when entering the wafer.

It is worth mentioning that the aforementioned control compensation value can be a preset value, or the displacement compensation value between the previously calculated wafer and the wafer placement field where the wafer is placed, or also It can be a standard average value derived from the displacement compensation values between multiple wafers and their respective wafer placement fields.

In another embodiment, the processing device 100 directly uses the position relationship as the image feature. In other words, the previously mentioned standard image feature group includes the standard wafer position feature obtained based on the relative position of the standard wafer and the wafer basket in the standard image, while the to-be-detected image feature group includes The position feature of the wafer to be tested is obtained according to the relative position of the wafer to be tested and the wafer basket in the image to be tested.

In this embodiment, when the processing device 100 analyzes and processes the image to be tested to obtain the corresponding feature group of the image to be tested, it is mainly necessary to perform steps S402 to S406 to find a suitable judgment baseline and hypothetical wafer; When matching the standard image feature group and the image feature group to be tested to determine the position of the wafer to be tested in the wafer basket, you can skip the process in Figure 5 and directly use the method shown in Figure 6 to obtain the occupied Place relevant information such as the field and the corresponding displacement compensation value. Moreover, since the matching of the wafer and the wafer placement field is directly based on the relative position, the wafer placement field with the smallest displacement compensation value can be directly used as the placement of the wafer. The operations of updating the preliminary selection wafer placement column performed in steps S606 and S610 can be omitted.

Other related technologies as shown in FIGS. 7 and 8 or other related technologies can also be used in the embodiment where the position relationship is used as the image feature. The specific operation process is roughly the same as that described in the previous embodiment, so I will not add more here. description.

Based on the above, the wafer position determination system provided by the present invention can determine the rotation angle between the captured image and the image used for comparison, so the original captured image can be converted into an image captured at a preset angle. It is convenient for subsequent analysis and judgment, and it can be found whether the wafer basket has frame deformation. In addition, the wafer position judging system can also find out the possible edge positions of the wafers, and determine the best wafer position based on the found edge positions of the wafers and the position of the wafer placement field. Potentially occupied wafer placement field, and determine whether the wafer position shifts according to the slope of the edge position of the wafer. In addition, the amount of movement that should be adjusted when the robotic arm accesses the wafer can also be controlled according to the difference between the edge position of the wafer and the position of the occupied wafer placement field.

10: Wafer position judgment system 15: Wafer Basket 100: processing device 110: Image pre-processing device 120: Photography device 130: storage device 140: warning device 150: Wafer placement field 152: Top Edge of Column 154: bottom edge of field 160a, 160b, 170a, 170b: support frame 180, 190: Wafer 200～218: Standard wafer P1～P7: corner S302~S312: Steps during operation of an embodiment of the present invention S400～S406: Steps during operation of an embodiment of the present invention S500～S502: Steps during operation of an embodiment of the present invention S600～S610: Steps during operation of an embodiment of the present invention S700～S706: Steps during operation of an embodiment of the present invention S800～S804: Steps during operation of an embodiment of the present invention

FIG. 1 is a circuit block diagram of a wafer position determination system according to an embodiment of the present invention. 2 is a schematic diagram of the appearance of a wafer basket used in an embodiment of the new type. FIG. 3 is an operation flowchart of the wafer position determination system according to an embodiment of the present invention. 4 is a flowchart of operations performed by the processing device according to an embodiment of the present invention when analyzing and processing the image features of the image to be tested to obtain a corresponding feature group of the image to be tested. FIG. 5 is a flowchart of operations performed by the processing device according to an embodiment of the present invention to determine the location of the wafer to be tested by comparing image features. 6 is an operation flowchart of the processing device according to an embodiment of the present invention when performing enhanced processing on the wafer position determination result. FIG. 7 is an operation flow chart of the processing device according to an embodiment of the present invention when performing enhanced processing on the wafer position determination result. FIG. 8 is an operation flowchart of the processing device according to an embodiment of the present invention when performing enhanced processing on the wafer position determination result.

10: Wafer position judgment system

15: Wafer Basket

100: processing device

110: Image pre-processing device

120: Photography device

130: storage device

140: warning device

150: Wafer placement field

152: Top Edge of Column

154: bottom edge of field

160a, 160b, 170a, 170b: support frame

180, 190: Wafer

Claims (17)

A wafer position judging system is suitable for judging the position of a wafer to be tested in a wafer basket including a plurality of wafer placement columns. The wafer position judging system is characterized by including: A storage device for storing a preset data set, the preset data set including a standard image feature set corresponding to a standard image obtained by shooting the wafer basket in a preset state, and the standard image A set of preset size information related to multiple specific parts; A photographing device adapted to photograph the wafer basket to be tested and the wafer to be tested placed in the wafer basket to generate an initial image to be tested; An image pre-processing device is electrically coupled to the photographing device and the storage device. The image pre-processing device obtains the initial image to be tested and the preset size information group, and performs the initial waiting according to the preset size information group. Pre-processing the test image to rotate the initial test image to obtain a processed image to be tested; and A processing device is electrically coupled to the image pre-processing device and the storage device. The processing device obtains the processed image to be tested and the standard image feature set, and analyzes the image features of the processed image to be tested to obtain a corresponding And match the standard image feature set and the image feature set to be tested to determine the position of the wafer to be tested in the wafer basket, Wherein, the wafer basket placed in the preset state includes a plurality of standard wafers placed in the wafer basket. The wafer position determination system according to claim 1, wherein the image pre-processing device performs pre-processing on the initial image to be tested according to the preset size information group to rotate the initial image to be tested to obtain the processed image The image measurement process includes: analyzing the initial image to be measured to find an image area corresponding to the wafer basket in the initial image to be measured; Find out an in-image coordinate information group corresponding to the specific parts from the image area; Compare the preset size information group with the coordinate information group in the image, and determine a rotation angle according to the comparison result, wherein the wafer basket presented in the initial image to be tested is represented by the preset data group The wafer basket is rotated by the rotation angle; and The image area is reversely rotated by the rotation angle to generate the processed image to be measured. The wafer position determination system according to claim 1, wherein the specific parts include edges or corners of the wafer basket. The wafer position judgment system according to claim 1, wherein the standard image feature group includes a standard wafer basket appearance feature obtained from the wafer basket in the standard image, and the image feature group to be tested includes The appearance feature of a wafer basket under test obtained according to the wafer basket in the image to be tested and an appearance feature of a wafer under test obtained according to the wafer under test. The wafer position determination system according to claim 4, wherein when the processing device analyzes the image features of the processed image to be tested to obtain the corresponding feature set of the image to be tested, it includes: Analyze the processed image to be tested to obtain the appearance characteristics of the wafer basket to be tested; Determine the position and number of multiple determination reference lines that extend substantially along a specific direction in the image to be tested after the processing; and The area between the two adjacent judgment reference lines with a slope within a preset slope range is taken as a hypothetical wafer, and the appearance feature obtained according to the appearance of the hypothetical wafer is taken as the to-be-tested Wafer appearance characteristics. The wafer position determination system according to claim 5, wherein when the processing device matches the standard image feature set and the image feature set to be tested to determine the location of the wafer to be tested in the wafer basket, include: According to the appearance feature of the wafer to be tested and the appearance feature of the wafer basket to be tested, a relative position parameter to be tested between the hypothetical wafer and the wafer basket in the processed image to be tested is obtained; and According to the relative position parameters to be tested and the appearance characteristics of the standard wafer basket, a preliminary selection wafer placement field is obtained, and the preliminary selection wafer placement field is the wafer placement fields in the standard image Which corresponds to the relative position parameter to be measured. The wafer position judging system according to claim 6, wherein the processing device after obtaining the preliminary selection wafer placement field further includes: Acquiring a first distance between the hypothetical wafer and a predetermined point; Acquiring a second distance between the preliminary selection wafer placement field and the preset point; Taking the difference between the first distance and the second distance as a displacement compensation value; When the displacement compensation value is within a preset distance range, set the preliminary selection wafer placement field as an occupied placement field; and When the displacement compensation value exceeds the preset distance range, select another of the wafer placement fields as the primary wafer placement field and recalculate the displacement compensation value until the displacement compensation value reaches Within the preset distance range, and set the finally obtained preliminary selection wafer placement field as the occupied placement field. The wafer position judgment system according to claim 7, wherein the processing device also records a control corresponding to the hypothetical wafer placed in the occupied placement field when setting the occupied placement field The compensation value, wherein the control compensation value is a preset value, the displacement compensation value, or a standard average value of a plurality of displacement compensation values corresponding to a plurality of wafers placed in different places. The wafer position determination system according to claim 8, wherein the processing device calculates a wafer storage corresponding to the unoccupied person in each of the wafer placement fields according to the recorded control compensation value. Take the position, and when necessary, control a robotic arm to place another wafer to be put into the wafer basket to the wafer access position. The wafer position determination system according to claim 7, wherein the processing device further includes: Obtain from the judgment reference lines an isolated reference line that cannot be paired with any of the judgment reference lines to form the hypothetical wafer; and Compare the position of the isolated reference line with a difference value between the position of each unoccupied boundary in the wafer placement columns, and compare the unoccupied wafer with the smallest difference value. The circle placement field is set to be occupied. The wafer position judging system according to claim 5, further including a warning device electrically coupled to the processing device, wherein the processing device further includes: Judging whether there is an oblique insertion reference line, where the oblique insertion reference line is the judgment reference line whose slope exceeds the preset slope range; According to the slope of the diagonal insertion reference line and the size of the wafer to be tested and the wafer basket, determine whether the wafer containing the diagonal insertion reference line occupies more than two of the wafer placement columns; and When the wafer containing the oblique insertion reference line occupies more than two of the wafer placement columns, the processing device controls the warning device to issue a warning. The wafer position determination system according to claim 1, wherein the standard image feature group includes a standard wafer position obtained according to the relative positions of the standard wafers and the wafer basket in the standard image Features, and the image feature group to be tested includes a wafer position feature to be tested obtained according to the relative position of the wafer to be tested and the wafer basket in the image to be tested. The wafer position determination system according to claim 12, wherein when the processing device analyzes the image features of the processed image to be tested to obtain the corresponding feature group of the image to be tested, it includes: Determine the position and number of multiple determination reference lines that extend substantially along a specific direction in the image to be tested after the processing; and The area between the two adjacent judgment reference lines with a slope within a preset slope range is taken as a hypothetical wafer, and the relative position of the hypothetical wafer and the wafer basket is taken as the test wafer Wafer location characteristics. The wafer position determination system according to claim 13, wherein when the processing device matches the standard image feature set and the image feature set to be tested to determine the position of the wafer to be tested in the wafer basket, include: Acquiring a first distance between the hypothetical wafer and a predetermined point; According to a second distance between each of the wafer placement fields and the predetermined point, the one closest to the hypothetical wafer among the wafer placement fields is selected as a primary wafer placement Place fields; and Set the preliminary selection wafer placement field as an occupied placement field. The wafer position judgment system according to claim 14, wherein when the processing device sets the occupied placement field, it also records a control corresponding to the hypothetical wafer placed in the occupied placement field Compensation value, wherein the control compensation value is a preset value, a displacement compensation value, or a standard average value of a plurality of displacement compensation values corresponding to a plurality of wafers placed in different places, and the displacement compensation value Is the distance between the hypothetical wafer and the occupied placement field. The wafer position determination system according to claim 15, wherein the processing device calculates a wafer storage corresponding to the unoccupied person in each of the wafer placement fields according to the recorded control compensation value. Take the position, and when necessary, control a robotic arm to place another wafer to be put into the wafer basket to the wafer access position. The wafer position determining system according to claim 14, wherein the processing device further includes: Obtain from the judgment reference lines an isolated reference line that cannot be paired with any of the judgment reference lines to form the hypothetical wafer; and Compare the position of the isolated reference line with a difference value between the position of each unoccupied boundary in the wafer placement columns, and compare the unoccupied wafer with the smallest difference value. The circle placement field is set to be occupied.

Images