JP5011003B2 - Alignment method - Google Patents

Description

  The present invention relates to an alignment method that is performed prior to processing a workpiece held by a holding unit with the processing unit.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially disc-shaped semiconductor wafer, and circuits such as IC and LSI are divided into the partitioned regions. Form. Then, the semiconductor wafer is cut along a line to be divided by a dicing apparatus or the like to divide the region where the circuit is formed, thereby manufacturing individual semiconductor chips.

  Here, in dicing by a dicing apparatus, prior to dicing, it is necessary to perform alignment processing for precisely aligning a cutting line (street) of a semiconductor wafer and a cutting blade for cutting along the cutting line. In this alignment, pattern matching is performed at two locations (alignment strokes) at a certain distance on the semiconductor wafer, and the positional deviation and inclination angle of the street to be cut in the XY axis are detected, and the positional deviation and inclination are detected. By performing alignment so as to eliminate the above, dicing can be automatically performed.

  In addition, when the shape is indefinite, the alignment stroke distance is determined by recognizing the shape based on image processing (see, for example, Patent Document 4), or a fail mark on the upper surface of the wafer even if the shape is circular. In the case of a wafer where the pattern is hidden in some places, alignment is performed by identifying chip coordinates without a fail pattern from the map coordinates of the entire wafer (for example, (See Patent Document 6).

JP 2003-151920 A Japanese Patent No. 2617870 JP 2004-241686 A Japanese Patent No. 3173552 Japanese Patent Laid-Open No. 4-109965 Japanese Patent No. 3223411

  However, there are wafers in which the alignment target is not regularly clear or missing depending on the defects in the previous process and the workpiece surface condition (dirt, scratch, fail mark, etc.). Even with such wafers, in order to make effective use of normal device parts, alignment processing is required to enable accurate cutting along the street, but alignment targets exist only at indefinite positions. In this case, in the conventional method, the alignment that automatically performs the θ adjustment is impossible, and the alignment must be performed manually, which is not efficient.

  The present invention has been made in view of the above, and a pattern serving as an alignment target is missing in some places, and even a wafer having an alignment target in an indefinite position can be automatically and accurately aligned. An object of the present invention is to provide an alignment method capable of efficiently processing a workpiece.

  In order to solve the above-described problems and achieve the object, an alignment method according to the present invention includes a holding unit that holds a workpiece, a rotating unit that rotates the holding unit, and a holding unit that holds the workpiece. A processing means for processing a workpiece, a processing feed means for processing and feeding the holding means and the processing means in the X-axis direction, and a holding means and the processing means in the Y-axis direction. Using a processing apparatus comprising: indexing and feeding means for indexing and feeding; imaging means for imaging the surface of the workpiece held by the holding means by relative movement in the X-axis direction and the Y-axis direction; The holding means is provided with a workpiece in which a plurality of rectangular regions having the same pattern as the key pattern are defined in the same position partitioned by streets arranged in a lattice pattern on the surface, and the pattern is missing in some places Prior to processing the workpiece along the street by holding the workpiece, the position of the workpiece held on the holding means is aligned relative to the processing means. A matching method, in which a pattern in a predetermined search area set in advance of a workpiece is sequentially searched by the imaging unit, and a pattern that matches the key pattern is counted for each line in the search area. An alignment line selection step for selecting a line having the largest number of patterns as an alignment execution line, and a direction in which the pattern on the selected alignment execution line is sequentially separated toward the outside of the search area in the X-axis direction. Search, and set the two patterns searched at the most distant positions as the θ alignment reference pattern. Detecting a position of the set θ alignment reference pattern on the X-axis and the Y-axis, calculating a street inclination angle θ with respect to the X-axis and the Y-axis based on the detected position, and the holding means by the rotating means And a θ adjustment step of rotating the lens by the inclination angle θ.

  The alignment method according to the present invention includes a holding unit that holds a workpiece, a rotating unit that rotates the holding unit, a processing unit that processes the workpiece held by the holding unit, and the holding unit. Machining feed means for machining and feeding the means and machining means relatively in the X-axis direction, index feeding means for indexing and feeding the holding means and the machining means relative to the Y-axis direction, and the X-axis direction And a processing device provided with an image pickup means for picking up an image of the surface of the workpiece held by the holding means by relative movement in the Y-axis direction, and a control device, and is partitioned by streets arranged in a lattice pattern on the surface. A plurality of rectangular areas having the same pattern as the key pattern are defined in the same position, and a workpiece having a pattern missing in some places is held on the holding means, and the workpiece is moved to the street. Prior to processing along the alignment means, the alignment method of aligning the street of the workpiece held on the holding means relative to the processing means, Patterns in a predetermined search area that has been set are sequentially searched by the imaging means, the position of the pattern that matches the key pattern is recognized for each line in the search area, and the pattern is located at the most separated position in the X-axis direction. The alignment line selection step for selecting a line having a position as an alignment execution line, and the pattern on the selected alignment execution line is sequentially searched in the direction away from the search area in the X-axis direction. A θ alignment reference pattern setting step for setting the two patterns searched at the most distant positions as a θ alignment reference pattern; Further, the position of the θ alignment reference pattern on the X axis and the Y axis is detected, the street inclination angle θ with respect to the X axis and the Y axis is calculated based on the detected position, and the rotation means rotates the holding means to the inclination angle θ. And a θ adjustment step in which the rotation is only performed.

  In the alignment method according to the present invention, a pattern within a predetermined search area set in advance of a workpiece is sequentially searched by an imaging means and pattern matching with a predetermined key pattern is performed to perform a count result for each line or a maximum. The alignment execution line is selected according to the separation position, and for the selected alignment execution line, the pattern is further searched in the direction away from the search area in the X-axis direction, and the search is performed at the most separated position. The two patterns are set as the θ alignment reference pattern, and the street inclination angle θ with respect to the X and Y axes is calculated by detecting the position of the set θ alignment reference pattern on the X axis and the Y axis. Since the holding means is rotated by the inclination angle θ by the means to eliminate the street inclination, the alignment target Even with wafers where the target pattern is missing and the target for alignment is in an indefinite position, it is possible to automatically find an appropriate θ alignment reference pattern that can secure the longest alignment stroke. It is possible to detect the angle with high accuracy and automatically perform alignment so that the inclination is eliminated, and it is possible to efficiently perform pre-processing before processing.

  Hereinafter, an alignment method in a processing apparatus which is the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view showing an example of a processing apparatus to which the alignment method according to the embodiment of the present invention is applied, and FIG. 2 is a perspective view showing an extracted configuration around the processing means. The processing apparatus 10 according to the present embodiment is applied to a cutting apparatus that cuts a workpiece 11 along a planned division line. As shown in FIG. 1, a holding means 12 and an imaging means 13 are schematically shown. , Processing means 20, and control means 30.

  The processing means 20 includes a spindle 22 on which a cutting blade 21 is detachably mounted, and a cylindrical housing 23 including a drive source (not shown) that rotatably supports the spindle 22 and rotationally drives the holding means 12. The cutting blade 21 acts on the workpiece 11 held on the workpiece 11 to perform cutting.

  The image pickup means 13 is a microscope equipped with a CCD camera or the like for picking up an image of the surface of the workpiece 11 held by the holding means 12, and is used for alignment of the cutting blade 21 with respect to a division planned line (street) to be cut. It is. As shown in FIG. 2, the imaging unit 13 is provided on a side portion of the housing 23 and can be moved integrally with the processing unit 20.

  The workpiece 11 is composed of a wafer W that is integrated with the frame F via a holding tape T. As shown in FIG. 2, the holding means 12 that holds the workpiece 11 is connected to a rotating means 14 and is rotatable in a horizontal plane. The rotating means 14 is fixed to the moving base 15. Here, the cutting device 10 includes a processing feed means 50, a cutting feed means 60, and an index feed means 70 for performing a feed operation necessary for the cutting operation.

  The processing feed means 50 is for processing and feeding the holding means 12 relative to the processing means 20 in the X-axis direction by moving the movable base 15 in the X-axis direction. The processing feed means 50 includes a ball screw 51 disposed in the X-axis direction, a pulse motor 52 connected to one end of the ball screw 51, and a pair of guide rails 53 arranged in parallel with the ball screw 51. The ball screw 51 is screwed with a nut (not shown) provided at the lower portion of the moving base 15. The ball screw 51 is driven and rotated by a pulse motor 52, and accordingly, the moving base 15 is guided by a guide rail 53 and moves in the X-axis direction.

  The notch feeding means 60 moves the supporting means 16 that supports the housing 23 of the processing means 20 in the Z-axis direction relative to the wall portion 17, thereby moving the processing means 20 up and down to make an incision into the workpiece 11. It is for controlling the amount. The cutting feed means 60 includes a ball screw 61 disposed in the Z-axis direction on one surface of the wall portion 17, a pulse motor 62 that rotates the ball screw 61, and a pair arranged in parallel to the ball screw 61. The guide rail 63 and a nut (not shown) inside the support portion 16 are screwed into the ball screw 61. The support portion 16 is driven by the pulse motor 62 and is guided by the guide rail 63 as the ball screw 61 rotates to move up and down in the Z-axis direction, and the cutting blade of the processing means 20 supported by the support portion 16. 21 is also configured to move up and down in the Z-axis direction.

  The index feeding means 70 moves the wall portion 17 that supports the housing 23 of the processing means 20 via the support portion 16 in the Y-axis direction, thereby moving the processing means 20 relative to the holding means 12 in the Y-axis direction. It is for indexing and feeding. The index feeding means 70 includes a ball screw 71 disposed in the Y-axis direction, a pulse motor 72 connected to one end of the ball screw 71, and a pair of guide rails 73 arranged in parallel with the ball screw 71. A nut (not shown) provided inside the moving base 18 formed integrally with the wall portion 17 is screwed to the ball screw 71. The ball screw 71 is rotated by being driven by a pulse motor 72, and accordingly, the moving base 18 is guided by the guide rail 73 and moves in the Y-axis direction.

  Prior to the cutting of the workpiece 11 by the cutting blade 21, the control means 30 positions the division line (street) of the workpiece 12 held on the holding means 12 relative to the processing means 20. In order to perform the alignment, it is in charge of processing for controlling each means such as the rotation means 14 so as to automatically automatically execute an alignment line selection process, a θ alignment reference pattern setting process, and a θ alignment process, which will be described later.

  Here, the workpiece 11 to be processed in the present embodiment will be described with reference to FIGS. 3 and 4. The wafer W in the workpiece 11 has a plurality of rectangular regions 83 having the same pattern 82 as a predetermined key pattern set in advance in the same position partitioned by streets 81 arranged in a lattice pattern on the surface. Although defined, the pattern 82 is missing in some places. In particular, in the present embodiment, due to various factors such as defects in the previous process and manufacturing technology, the peripheral portion of the wafer W becomes defective as illustrated in FIG. 3, and only a normal pass near the central portion of the wafer W is passed. A workpiece 11 in which product parts are concentrated is targeted. For example, if there are no defective parts, there are about 900 chips, but in reality, there are about hundreds of acceptable chips. In addition, on the wafer W, there may be irregularly and irregularly concealed portions 84 due to dirt and scratches or fail marks that hinder recognition of the pattern 82 in each rectangular area 83.

  After such a workpiece 11 is held on the holding means 12, the workpiece 11 held on the holding means 12 is cut prior to cutting the workpiece 11 along the street 81 with the cutting blade 21. An alignment process (alignment process) for aligning the street 81 relative to the cutting blade 21 of the processing means 20 is performed. Prior to this alignment process, a pre-alignment process is performed so that one of the grid-like streets 81 is substantially aligned with the workpiece 11 held on the holding unit 12 in the X-axis direction. That is, the surface of the wafer W is imaged and recognized extensively using a relatively low-magnification imaging means (not shown) (positioned in the vicinity of the imaging means 13) for recognizing the surface of the wafer W relatively widely. Is extracted, the inclination with respect to the X axis is calculated based on the extraction result, and the holding means 12 is rotated in a horizontal plane by the rotating means 14 so as to eliminate this inclination (for example, see JP-A-6-69319). . Thereby, the inclination of the street 81 with respect to the X axis is set to be within about ± 3 °. FIG. 3 shows an example of the workpiece 11 after being held by the holding means 12 and subjected to the pre-alignment process.

  As a first step of such alignment processing for the workpiece 11, an alignment line selection step is executed by the control means 30. In this step, as shown in FIGS. 3 and 4, a pattern 82 in a predetermined search area 85 preset around the center of the wafer W is sequentially searched by pattern matching on the imaging result by the imaging means 13. Is executed. Here, the search area 85 is set to an appropriate size according to the workpiece 11 and the like, and the position is defined by XY coordinates. However, as illustrated in FIG. 3, the search area 85 is in the wafer W to be processed. It is set to be sufficiently smaller than the size of a normal acceptable product part (for example, several hundred chips). The search area 85 includes a plurality of lines, and is set to a size that can include a plurality of rectangular regions 83 to such an extent that a minimum alignment stroke can be secured in the line direction. As a result, the search area 85 is, for example, several lines, and each line has a size that can include about 20 chips. Such a search area 85 is defined in order to shorten the time required for the pattern matching process in the alignment process as much as possible.

  First, the processing feed means 50 is driven to move the holding means 12 and the index feed means 70 is driven to cause the image pickup means 13 to have the first rectangular area 83 in the search area 85 as a guide based on the XY coordinates of the search area 85. An imaging operation is performed by positioning to an existing line, and a rectangular area 83 in which the same pattern 82 exists is searched by pattern matching with a predetermined key pattern. When a matching pattern 82 is searched, the positions (coordinates) on the X axis and Y axis are recognized and stored in a memory (not shown), and the holding means 12 (workpiece 11) is moved in the X axis direction by the processing feed means 50. The image is moved by a predetermined distance, and a part of the image of the next rectangular area 83 on the same line around the pattern 82 is captured by the imaging unit 13, and the same pattern 82 exists by pattern matching with the predetermined key pattern for the imaging result. Search whether or not to do. When the matching pattern 82 is searched, the positions (coordinates) on the X axis and the Y axis are recognized and stored in a memory (not shown). Here, the pattern 82 is not searched in the rectangular area 83 where the concealing portion 84 exists. After such processing is similarly performed for other rectangular regions 83 on the same line in the search area 85, the image pickup means 13 is divided and sent in one line in the Y-axis direction. Repeat for other lines.

  Then, for each line in the search area 85, the number of patterns 82 searched for in agreement with the key pattern is counted. In the example of FIG. 4 showing the search area 85 in FIG. 3 in an enlarged manner, the count results of 6, 5, 4, 3, and 3 in order from the top for each line in the search area 85. It becomes. Therefore, in this alignment line selection step, the first line having the largest number of counted patterns 82 is selected as the alignment line.

  As a second process following the alignment line selection process, the θ alignment reference pattern setting process is executed by the control means 30. In this step, as indicated by an arc-shaped arrow in FIG. 5, the pattern 82 on the alignment execution line selected in the alignment line selection step described above is sequentially separated toward the outside of the search area 85 in the X-axis direction. The image is picked up by the image pickup means 13 in the direction and searched. This search process extended outside the search area 85 is executed within the range L. The range L is sufficiently longer than the length of the search area 85, but in order to avoid useless search processing, the range L is set with reference to a range in which a normal acceptable product portion in the workpiece 11 to be processed can exist. . It suffices for the range L to be a length corresponding to a general alignment stroke in a normal wafer having almost no defective products. Further, the length of the range L is set in consideration of the alignment time. Then, as a result of the search, the two patterns 82M and 82N searched at the most distant positions in the X-axis direction are set as the θ alignment reference pattern.

  As a third process following the θ alignment reference pattern setting process, the θ alignment process is executed by the control means 30. In this step, the positions (coordinates) of the set θ alignment reference patterns 82M and 82N on the X axis and the Y axis are detected as (Xm, Ym) and (Xn, Yn), respectively, and the detected positions (coordinates) are detected. Based on the above, the inclination angle θ of the street 81 with respect to the X axis and the Y axis is calculated by θ = (Yn−Ym) / (Xn−Xm). Then, under the control of the control means 30, the holding means 12 holding the workpiece 11 is rotated in the horizontal plane by an inclination angle θ by the rotating means 14, so that the street 81 is inclined with respect to the X axis and the Y axis. Let go.

  As described above, according to the alignment method of the present embodiment, the pattern 82 within the predetermined search area 85 set in advance of the workpiece 11 is sequentially searched by the imaging means 13 and the pattern with the predetermined key pattern. As a result of the matching, the line having the largest number of patterns 82 is selected as the alignment execution line as the count result for each line, and the pattern 82 is sequentially moved out of the search area 85 in the X-axis direction for the selected alignment execution line. The extended search is performed in the direction away from each other, the two patterns 82M and 82N searched at the most distant positions are set as the θ alignment reference patterns, and the X and Y axes of the set θ alignment reference patterns 82M and 82N are set. The inclination angle θ of the street 81 with respect to the X axis and the Y axis is calculated by detecting the position at Since the inclination of the street 81 is eliminated by rotating the means 12 by the inclination angle θ, the alignment target pattern is lost in some places, and even the wafer W having the alignment target at an indefinite position is as long as possible. Appropriate θ alignment reference patterns 82M and 82N that can ensure a stroke can be automatically searched. Therefore, the inclination angle θ of the street 81 can be detected with high accuracy, and the alignment can be automatically performed so that the inclination is eliminated, and the pretreatment before cutting can be efficiently processed. In addition, the search processing by the image pickup means 13 for securing an alignment stroke that is as long as possible is within the search area 85 set to be small and within the range L for one line that is the alignment execution line selected within the search area 85. It is only necessary to perform the process in, and it is possible to search efficiently in a short time.

  Here, if a new pattern 82 is not searched outside the search area 85 on the alignment execution line in the θ alignment reference pattern setting process, the alignment searched in the search area 85 in the alignment line selection process. Two patterns at the most distant positions among the patterns 82 on the execution line are set as the θ alignment reference patterns. At this time, as the alignment execution line, the line having the largest count result of the searched pattern 82 is selected. Therefore, even in the search area 85, the alignment stroke can be as long as possible. A minimum accuracy can be ensured in calculating the angle θ.

  On the other hand, in the alignment line selection process, when no pattern 82 is searched in the search area 85, this is a situation caused by the reason that the range of the concealing portion 84 is extremely wide due to the contamination being serious, The alignment process for the workpiece 11 is interrupted and a warning is issued by an error display or the like. Thereby, it is possible to deal with such a workpiece 11 such as entrusting it to manual processing.

  Further, in the alignment line selection step, the pattern 82 search processing is performed for all the lines in the search area 85. However, the maximum condition (as shown in FIG. In the example, when the line that satisfies 6) appears, the search process is stopped, the alignment execution line is selected, and the processing time is shortened by moving to the next θ alignment reference pattern setting process. Also good. Further, in the alignment line selection step, when there are a plurality of lines having the largest pattern 82 as a counting result, any line may be selected.

In the present embodiment, the holding means 12 is rotated by the rotating means 14 only in the final θ alignment process. However, for each pattern 82 searched by pattern matching during the alignment line selection process. The position (coordinates) on the X axis and the Y axis are sequentially calculated, the inclination angle θ of the line (street 81) with respect to the X axis and the Y axis is calculated, and the holding means 12 is rotated by the inclination angle θ by the rotation means 14 to obtain the line. You may make it search the pattern 82 on the same line, eliminating the inclination of (street 81). For example, referring to FIG. 4, the inclination angle θ of the line is calculated from the coordinates (X ₁ , Y ₁ ) of the pattern 82 searched _first and the coordinates (X ₂ , Y ₂ ) of the pattern 82 searched next. It is calculated as θ = (Y ₂ −Y ₁ ) / (X ₂ −X ₁ ), and the inclination angle θ is sequentially eliminated. The same applies to the θ alignment reference pattern selection step. Finally, the inclination of the street 81 is eliminated in the θ adjustment process described above. According to such processing, the search processing of the pattern 82 existing at a specific position in the rectangular area 83 proceeds with the inclination of the line (street 81) as small as possible, so that the pattern 82 can be easily searched by pattern matching. Thus, the processing speed can be increased.

  In the present embodiment, the line with the largest count result of the pattern 82 is selected as the alignment execution line in the alignment line selection step. However, a predetermined search area 85 set in advance for the workpiece 11 is selected. The pattern 82 is sequentially searched by the imaging means 13, the position (coordinates) of the pattern 82 that matches a predetermined key pattern set in advance for each line in the search area is recognized, and the position most distant in the X-axis direction The line in which the searched pattern exists may be selected as the alignment execution line.

For example, in the example shown in FIG. 6, as the search result in the search area 85, the coordinates of the two patterns 82 at positions separated in the X-axis direction in the first line are (X ₂₁ , Y ₂₁ ), (X ₆₁ , Y ₆₁ ), on the fifth line, the coordinates of the two patterns 82 at positions separated in the X-axis direction are (X ₁₅ , Y ₁₅ ), (X ₆₅ , Y ₆₅ ). Therefore, in the search area 85, the two patterns 82 indicated by (X ₁₅ , Y ₁₅ ) and (X ₆₅ , Y ₆₅ ) are the patterns searched at the most separated positions in the X-axis direction. Therefore, in the alignment line selection step, the fifth line is selected as the alignment execution line. In the example shown in FIG. 6, in the case of the above-described counting result, the first line is selected as the alignment execution line. Here, however, there is a pattern having a searched pattern at the most distant position in the X-axis direction. By selecting the line as the alignment execution line, it is possible to make the alignment stroke as long as possible in the search area 85. Therefore, if a new pattern is not searched in the subsequent θ alignment reference pattern setting step, it is possible to ensure accuracy in calculating the inclination angle θ of the street 81.

It is an external appearance perspective view which shows an example of the processing apparatus with which the positioning method of embodiment of this invention is applied. It is a perspective view which extracts and shows the structure around the process means of FIG. It is a perspective view which shows an example of the workpiece made into the object of this Embodiment. It is explanatory drawing which expands the search area part in FIG. 3, and shows the process of an alignment line selection process. It is explanatory drawing which expands a part in FIG. 3 and shows the process of a θ alignment reference pattern setting process. It is explanatory drawing which expands a search area part and shows the process of the alignment line selection process of a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Workpiece 12 Holding means 13 Imaging means 14 Rotating means 20 Processing means 30 Control means 50 Process feed means 70 Index feed means 81 Street 82 Pattern 83 Rectangular area 85 Search area

Claims (2)

A holding means for holding the workpiece, a rotating means for rotating the holding means, a processing means for processing the workpiece held by the holding means, and the holding means and the processing means are relatively A machining feed means for machining and feeding in the axial direction, an index feeding means for relatively indexing and feeding the holding means and the machining means in the Y-axis direction, and a relative movement in the X-axis direction and the Y-axis direction for the holding. The same pattern as the key pattern in the same position defined by the streets arranged in a lattice pattern on the surface using a processing device comprising an image pickup means for picking up the surface of the workpiece held by the means and a control means Prior to processing the workpiece along the street by holding the workpiece on which the plurality of rectangular regions having a defined area and the pattern missing in some places are held on the holding means, the holding hand A positioning method of the street workpiece held on the so registering relative position with respect to the processing means,
A pattern in a predetermined search area set in advance of the workpiece is sequentially searched by the imaging means, and a pattern matching the key pattern is counted for each line in the search area, and the number of the counted patterns is the largest. An alignment line selection process for selecting existing lines as alignment execution lines;
The pattern on the selected alignment execution line is searched in the direction away from the search area sequentially in the X-axis direction, and the two patterns searched at the most distant positions are used as θ alignment reference patterns. A θ alignment reference pattern setting step to be set;
The position of the set θ alignment reference pattern on the X axis and the Y axis is detected, the street inclination angle θ with respect to the X axis and the Y axis is calculated based on the detected position, and the holding means is tilted by the rotating means. A θ alignment step of rotating by an angle θ;
A registration method characterized by comprising: A holding means for holding the workpiece, a rotating means for rotating the holding means, a processing means for processing the workpiece held by the holding means, and the holding means and the processing means are relatively A machining feed means for machining and feeding in the axial direction, an index feeding means for relatively indexing and feeding the holding means and the machining means in the Y-axis direction, and a relative movement in the X-axis direction and the Y-axis direction for the holding. The same pattern as the key pattern in the same position defined by the streets arranged in a lattice pattern on the surface using a processing device comprising an image pickup means for picking up the surface of the workpiece held by the means and a control means Prior to processing the workpiece along the street by holding the workpiece on which the plurality of rectangular regions having a defined area and the pattern missing in some places are held on the holding means, the holding hand A positioning method of the street workpiece held on the so registering relative position with respect to the processing means,
A pattern in a predetermined search area set in advance of the workpiece is sequentially searched by the imaging means, and the position of the pattern that matches the key pattern is recognized for each line in the search area, and the pattern in the X-axis direction is the highest. An alignment line selection step of selecting a line having a pattern at a separated position as an alignment execution line;
The pattern on the selected alignment execution line is searched in the direction away from the search area sequentially in the X-axis direction, and the two patterns searched at the most distant positions are used as θ alignment reference patterns. A θ alignment reference pattern setting step to be set;
The position of the set θ alignment reference pattern on the X axis and the Y axis is detected, the street inclination angle θ with respect to the X axis and the Y axis is calculated based on the detected position, and the holding means is tilted by the rotating means. A θ alignment step of rotating by an angle θ;
A registration method characterized by comprising:

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