JP2020126874A - Alignment method - Google Patents

Abstract

To quickly detect an alignment mark.SOLUTION: There is a case where depending on pattern matching with respect to a picked-up image, an alignment mark M cannot be found and a cumulative area of a plurality of picked-up images becomes equal to or larger than an area of a search area SA. In such a case, by combining every picked-up image acquired until then, a combined image GA is displayed on a touch panel 40. Through specification of the alignment mark M by an operator who views the combined image GA, the alignment mark M is identified. This makes it possible to quickly detect the alignment mark M even if the alignment mark M is dirty or unclear and therefore the pattern matching is difficult.SELECTED DRAWING: Figure 11

Description

The present invention relates to an alignment method.

The package substrate in which the device is formed in the region divided by the dividing line is cut by the cutting blade along the dividing line. In order to carry out this cutting process, the processing device specifies the planned dividing line. For this purpose, for example, an alignment mark formed on the surface of the package substrate is used (see Patent Documents 1 and 2).

In the processing apparatus, first, the package substrate held on the chuck table is imaged by a camera to search and detect the alignment mark, and the coordinates thereof are recognized. Then, based on the recognized coordinates, θ alignment is performed to rotate the chuck table so that the planned division line is parallel to the cutting direction of the cutting blade, and the planned division line is specified.

When the package substrate is placed on the chuck table by the transfer means, the actual placement position may slightly deviate from the predetermined placement position. For this reason, the search range of the alignment mark is set wider than the imaging range of the camera so that the alignment mark can be found even when the package substrate is placed with a shift.

JP2012-256793A JP, 2017-050309, A

In the search for the alignment mark, pattern matching is performed in which a predetermined position is imaged and it is confirmed whether or not there is a place that matches the alignment mark in the captured image.
However, if the alignment mark is dirty or unclear, it may be difficult to find the alignment mark by pattern matching, and it may be necessary for the operator to detect the alignment mark. In this case, it takes a lot of time to detect the alignment mark because the alignment mark is visually detected using a narrow imaging area.

An object of the present invention is to quickly detect alignment marks.

According to the alignment method of the present invention, a device is formed in a region defined by a first planned division line set on the surface and a second planned division line that intersects the first planned division line, and A packaged substrate having alignment marks arranged outside the partitioned area is held by a chuck table and captured by an image capturing unit to obtain a captured image, and the alignment mark is detected from the captured image. An alignment method for identifying the first planned division line and the second planned division line based on an alignment mark, the registration step of registering the alignment mark smaller than the imaging area of the imaging means, and the alignment mark. A search area setting step for setting a search area for finding a target area, an imaging step for acquiring the captured image corresponding to the imaging area set on the package substrate by the imaging means, and the alignment mark in the captured image. A pattern matching step of confirming the presence or absence by pattern matching, and an image pickup area changing step of changing the image pickup area of the image pickup means so as to be overlapped by pixels of the alignment mark, the image pickup step, the pattern matching step, and A confirmation step of repeating the imaging step until the alignment mark is detected or the cumulative area of the captured image becomes equal to or larger than the area of the search area; and a case where the alignment mark is not detected in the confirmation step. , A combined image display step of forming a combined image having the same area as the cumulative area by combining the plurality of captured images captured in the confirmation step and displaying the combined image on a screen, and an operator who visually observes the combined image When the alignment mark is designated by, the planned division line specifying step of specifying the first planned division line and the second planned division line based on the designated alignment mark.

With this alignment method, even if the alignment mark is dirty or unclear and it is difficult to detect the alignment mark by pattern matching, the combined image is displayed to allow the operator to specify the alignment mark. It is possible. Therefore, the alignment mark can be detected quickly. As a result, the time required for alignment can be shortened.

It is a perspective view showing composition of a cutting device concerning one embodiment of the present invention. It is a top view which shows the structure of a package substrate. It is a perspective view which shows the package board|substrate supported by the annular frame. It is explanatory drawing which shows the registration process of an alignment mark. It is explanatory drawing which shows the search area|region set to a package board|substrate. It is explanatory drawing which shows the imaging region regarding the 1st imaging in a confirmation process. It is explanatory drawing which shows the imaging region regarding the 2nd imaging in a confirmation process. It is explanatory drawing which shows the imaging region regarding the 3rd imaging in a confirmation process. It is explanatory drawing which shows the imaging region regarding the 4th imaging in a confirmation process. It is explanatory drawing which shows the moving path of the imaging region in a confirmation process. It is explanatory drawing which shows the combined image displayed in a combined image display process.

The cutting device 1 shown in FIG. 1 is a device that performs cutting by cutting a rotating cutting blade 63 on a package substrate W, which is a plate-shaped workpiece held on a chuck table 30.

First, the configuration of the package substrate W will be described.
As shown in FIG. 2, a package substrate W, which is an example of a workpiece, is a substrate having a rectangular outer shape made of, for example, a predetermined alloy, PCB (polychlorinated biphenyl), or the like. A plurality of (three in the illustrated example) device regions W1 are formed on the front surface Wa of the package substrate W. Each device area W1 is surrounded by a surplus area W2.

The device region W1 is further divided into a plurality of rectangular regions by the first planned dividing line S1 and the second planned dividing line S2 which are orthogonal to each other on the front surface Wa. A device D is arranged in each rectangular area. By cutting the package substrate W along the planned dividing lines S1 and S2, each rectangular region becomes a chip including the device D. In the device region W1, for example, packaging with an epoxy resin (not shown) is performed so as to cover the planned dividing lines S1 and S2 and the device D.

Further, alignment marks M are provided at the four corners of the package substrate W. The alignment mark M is used in alignment performed before cutting the package substrate W. As shown in FIG. 1, the alignment mark M is arranged outside the area defined by the planned dividing lines S1 and S2, that is, outside the device area W1.
The alignment mark M may be formed for each planned dividing line.

When the package substrate W is processed, a dicing tape T larger than the package substrate W is attached to Wb of the package substrate W, as shown in FIG. An annular frame F having a circular opening is attached to the outer peripheral area of the adhesive surface of the dicing tape T. In this way, the package substrate W is supported by the annular frame F via the dicing tape T. Thereby, the package substrate W can be handled via the annular frame F.

Next, the configuration of the cutting device 1 will be described. As shown in FIG. 1, the cutting device 1 includes a base 10, a gate type column 14 erected on the base 10, a casing 15 that covers the base 10 and the gate type column 14, and each of the cutting devices 1. The control means 9 which controls a member is provided.

Cutting feed means 11 is arranged on the base 10. The cutting feed means 11 moves the chuck table 30 along the cutting feed direction (X-axis direction). The cutting feed means 11 includes a pair of guide rails 111 extending in the X-axis direction, an X-axis table 113 mounted on the guide rails 111, a ball screw 110 extending parallel to the guide rails 111, and a motor 112 for rotating the ball screw 110. Contains.

The pair of guide rails 111 are arranged on the upper surface of the base 10 parallel to the X-axis direction. The X-axis table 113 is installed on the pair of guide rails 111 so as to be slidable along the guide rails 111. The holding unit 3 is placed on the X-axis table 113.

The ball screw 110 is screwed into a nut portion (not shown) provided on the lower surface side of the X-axis table 113. The motor 112 is connected to one end of the ball screw 110 and drives the ball screw 110 to rotate. When the ball screw 110 is rotationally driven, the X-axis table 113 and the holding unit 3 move along the guide rail 111 along the X-axis direction that is the cutting feed direction.

The holding unit 3 includes a chuck table 30 that holds the package substrate W, a rotating unit 31 that is a rotating shaft that supports and rotates the chuck table 30, and a plurality of clamps 32 that sandwich and fix the annular frame F of the package substrate W. Have The clamps 32 are arranged around the chuck table 30 at equal intervals in the circumferential direction.

The chuck table 30 is a member for sucking and holding the package substrate W shown in FIGS. 2 and 3, and is formed in a disc shape. The chuck table 30 has a holding surface 30a that is an exposed surface. The holding surface 30a includes a porous material and is in communication with a suction source (not shown). The chuck table 30 sucks and holds the package substrate W by the holding surface 30a.

The chuck table 30 is supported by rotation means 31 arranged on the bottom surface side of the chuck table 30. The rotating means 31 is provided on the upper surface of the X-axis table 113 so as to be rotatable in the XY plane. Therefore, the rotating means 31 can support the chuck table 30 and rotate the chuck table 30 in the XY plane.

On the rear side (−X direction side) on the base 10, a gate-shaped column 14 is erected so as to straddle the cutting feed means 11. A cutting means moving mechanism 13 that moves the cutting means 6 is provided on the front surface (the surface on the +X direction side) of the gate column 14. The cutting means moving mechanism 13 index-feeds the cutting means 6 in the Y-axis direction and feeds the cutting means 6 in the Z-axis direction by cutting. The cutting means moving mechanism 13 includes an index feeding means 12 for moving the cutting means 6 in the index feeding direction (Y-axis direction) and a cutting feeding means 16 for moving the cutting means 6 in the cutting feeding direction (Z-axis direction). ing.

The index feeding means 12 is arranged on the front surface of the gate column 14. The index feeding means 12 reciprocates the cutting feeding means 16 and the cutting means 6 along the Y-axis direction. The Y-axis direction is a direction orthogonal to the direction (horizontal direction) of the holding surface 30a with respect to the X-axis direction.

The index feeding means 12 includes a pair of guide rails 121 extending in the Y-axis direction, a Y-axis table 123 mounted on the guide rails 121, a ball screw 120 extending in parallel with the guide rails 121, and a motor 122 for rotating the ball screw 120. Contains.

The pair of guide rails 121 are arranged in parallel to the Y-axis direction on the front surface of the gate column 14. The Y-axis table 123 is installed on the pair of guide rails 121 so as to be slidable along the guide rails 121. The cutting feed means 16 and the cutting means 6 are placed on the Y-axis table 123.

The ball screw 120 is screwed into a nut portion (not shown) provided on the back side of the Y-axis table 123. The motor 122 is connected to one end of the ball screw 120 and drives the ball screw 120 to rotate. When the ball screw 120 is rotationally driven, the Y-axis table 123, the cutting feed means 16 and the cutting means 6 move along the guide rail 121 in the Y-axis direction which is the index feed direction.

The cutting feed means 16 reciprocates the cutting means 6 along the Z-axis direction (vertical direction). The Z-axis direction is a direction that is orthogonal to the X-axis direction and the Y-axis direction and is orthogonal to the holding surface 30a of the chuck table 30.

The cutting feed means 16 includes a pair of guide rails 161 extending in the Z-axis direction, a support member 163 placed on the guide rail 161, a ball screw 160 extending parallel to the guide rail 161, and a motor 162 for rotating the ball screw 160. I'm out.

The pair of guide rails 161 are arranged on the Y-axis table 123 in parallel with the Z-axis direction. The support member 163 is installed on the pair of guide rails 161 so as to be slidable along the guide rails 161. The cutting means 6 is attached to the lower end of the support member 163.

The ball screw 120 is screwed into a nut portion (not shown) provided on the back side of the support member 163. The motor 162 is connected to one end of the ball screw 160 and drives the ball screw 160 to rotate. When the ball screw 160 is rotationally driven, the support member 163 and the cutting means 6 move along the guide rail 161 in the Z-axis direction which is the cutting feed direction.

The cutting means 6 includes a housing 61 provided at the lower end of the support member 163, a rotary shaft 60 extending in the Y-axis direction, a cutting blade 63 attached to the rotary shaft 60, and a motor (not shown) that drives the rotary shaft 60. ) Is provided.
The rotating shaft 60 is rotatably supported by the housing 61. The cutting blade 63 rotates at high speed by the motor driving the rotary shaft 60.

Further, the cutting means 6 includes, on the front surface of the housing 61, a macro imaging means 51 for imaging the package substrate W at a low magnification and a micro imaging means 52 for imaging the package substrate W at a high magnification. The macro image pickup means 51 corresponds to an example of an image pickup means. The macro imaging unit 51, the micro imaging unit 52, and the cutting unit 6 are interlocked and move in the Y-axis direction and the Z-axis direction.

The macro image pickup means 51 is composed of, for example, an image pickup element, a low-magnification objective lens, illumination, and the like (all not shown). In the macro image pickup means 51, for example, one pixel is 10 μm.
The micro image pickup means 52 is composed of, for example, an image pickup device (not shown), a high-magnification objective lens, and illumination (all are not shown). In the micro image pickup means 52, for example, the magnification is 10 times that of the macro image pickup means 51, and one pixel is 1 μm.

The control unit 9 includes a storage unit 91 that stores various data and programs. The control means 9 executes various processes to centrally control each component of the cutting device 1.
For example, the detection results from various detectors (not shown) are input to the control means 9. Further, the control unit 9 controls the cutting feed amount of the chuck table 30 by the cutting feed unit 11, the index feed amount and the cutting feed amount of the cutting unit 6 by the cutting unit moving mechanism 13, and the chuck table by the rotating unit 31. The rotation amount (angular position) of 30 is controlled (θ adjustment).
Further, the control unit 9 controls the motor of the cutting unit 6 to perform the cutting process on the package substrate W, and also controls the macro image pickup unit 51 and the micro image pickup unit 52 to perform the image pickup on those image pickup regions. ..

A touch panel 40 is installed on the front surface of the housing 15. The touch panel 40 displays various information such as the processing status of the cutting device 1 and the processing conditions regarding the processing of the package substrate W by the cutting device 1. The touch panel 40 is also used to input various information such as processing conditions. As described above, the touch panel 40 functions as an input unit for inputting information and also as a display unit for displaying the input information.

Next, in order to identify the alignment method performed before cutting the package substrate, that is, the first planned dividing line S1 and the second planned dividing line S2 of the package substrate W held on the chuck table 30. The method will be described.

In the alignment method according to the present embodiment, the control unit 9 images the package substrate W held by the chuck table 30 with the macro image pickup unit 51. The imaging area of the macro imaging unit 51 is smaller than the area (that is, the size of the device D) divided by the first planned dividing line S1 and the second planned dividing line S2. The control means 9 acquires a picked-up image corresponding to this picked-up area. Further, the control means 9 detects the alignment mark M from the captured image and specifies the first planned division line S1 and the second planned division line S2 based on the alignment mark M.

Below, each process of this alignment method is demonstrated.
(1) Registration Step In this step, the control means 9 registers (stores) the alignment mark M of the package substrate W shown in FIG.
The registration of the alignment mark M is performed as follows, for example.

First, the chuck table 30 shown in FIG. 1 sucks and holds the package substrate W with the front surface Wa thereof facing upward. Then, the chuck table 30 holding the package substrate W by suction is moved in the X-axis direction by the cutting feed means 11. Further, the macro imaging unit 51 is moved in the Y-axis direction by the index feeding unit 12. As a result, one corner of the package substrate W is arranged immediately below the objective lens of the macro imaging unit 51.

Then, as shown in FIG. 4, the imaging region 510 of the macro imaging unit 51 is set on the front surface Wa of the package substrate W, the front surface Wa of the package substrate W is captured, and a captured image is formed.

The alignment mark M is smaller than the imaging area 510 in the macro imaging unit 51. Then, in the present embodiment, the alignment mark M is registered as an image of a rectangular area that is smaller than the imaging area 510 and is indicated by a chain double-dashed line. That is, the target image GT including the entire alignment mark M is stored in the storage unit 91.

Further, the control unit 9 stores the distance Lx from the alignment mark M to the center line passing through the center of the width of the second planned dividing line S2 in the storage unit 91. Further, the control unit 9 stores the distance Ly from the alignment mark M to the center line passing through the center of the width of the first planned dividing line S1 in the storage unit 91.

In many cases, in the cutting device 1, a plurality of package substrates W of the same type are continuously cut. The registration process is a pre-process (preparation process) of cutting work, and is performed using the first package substrate W before cutting the first package substrate W, for example. The registration process does not need to be performed again when cutting the second and subsequent package substrates W.

(2) Search Area Setting Step This step is performed when the package substrate W is held on the chuck table 30 for each package substrate W that is actually cut.

In this step, first, the chuck table 30 shown in FIG. 1 sucks and holds the newly cut package substrate W with the front surface Wa facing upward. The chuck table 30 is moved in the X-axis direction by the cutting feed means 11. Further, the macro imaging unit 51 is moved in the Y axis direction by the index feeding unit 12, and one corner portion of the package substrate W is arranged immediately below the objective lens of the macro imaging unit 51.

Then, as shown in FIG. 5, a search area SA is set at a corner of the front surface Wa of the package substrate W. The search area SA is, for example, an area in which the alignment mark M is likely to be found, and has a predetermined area. This search area SA is larger than the imaging area 510 of the macro imaging means 51 shown in FIG.

(3) Confirmation Step In the steps after the confirmation step, the first planned division line S1 and the second planned division line S2 in the package substrate W are specified using the alignment marks M and the like registered in the registration step.
Then, the confirmation process includes an imaging process, a pattern matching process, and an imaging region changing process.

In the confirmation step, first, as shown in FIG. 6, the control means 9 sets an image pickup area 510 of the macro image pickup means 51 smaller than the search area SA in the search area SA set on the front surface Wa of the package substrate W. .. The control unit 9 captures the captured image G1 by capturing an image of the image capturing area 510. The size of the captured image G1 is the same as the size of the imaging region 510. The control unit 9 stores the captured image G1 in the storage unit 91 (imaging step).

After that, pattern matching is performed on the captured image G1. That is, the control unit 9 includes the pattern matching unit 93 (see FIG. 1). The pattern matching unit 93 performs pattern matching regarding the alignment mark M on the captured image G1. That is, the pattern matching unit 93 confirms the presence or absence of the alignment mark M in the captured image G1, that is, the presence or absence of the target image GT (see FIG. 4) in the captured image G1 by pattern matching.

For example, the pattern matching unit 93 superimposes the target image GT on the captured image G1 shown in FIG. 6 displayed on the virtual screen having a predetermined resolution. Then, the pattern matching unit 93 has the highest correlation with the target image GT in the captured image G1 while moving the target image GT on the captured image G1 by, for example, one pixel in the X-axis direction or the Y-axis direction. The area is detected as an area that matches the target image GT (pattern matching step).

In the example illustrated in FIG. 6, the captured image G1 does not include the target image GT (the entire target image GT). Therefore, the pattern matching unit 93 does not detect an area in the captured image G1 that matches the target image GT. In this case, the control unit 9 changes the image capturing area 510 of the macro image capturing unit 51 and re-images the front surface Wa of the package substrate W.

That is, the control means 9 moves the chuck table 30 holding the package substrate W relative to the macro imaging means 51 by a predetermined distance in the −X direction by the cutting feed means 11 shown in FIG. The moving distance of the chuck table 30 is a value that is shorter than the length of the imaging region 510 of the macro imaging unit 51 in the X-axis direction by the number of pixels of the alignment mark M in the X-axis direction. That is, the control unit 9 changes the image pickup area 510 of the macro image pickup unit 51 so as to overlap the pixels of the alignment mark M (image pickup area changing step).

By moving the chuck table 30 as described above, the imaging region 510 of the macro imaging unit 51 is displaced in the +X direction from the imaging region when the captured image G1 was captured, as shown in FIG. Will be distributed.

Then, the control unit 9 takes an image of the newly set image pickup area 510 on the front surface Wa of the package substrate W by the macro image pickup unit 51 to obtain the picked-up image G2 shown in FIG. Second imaging step). After that, the pattern matching unit 93 of the control unit 9 performs the pattern matching regarding the alignment mark M with respect to the captured image G2, similarly to the above-described captured image G1 (second pattern matching step).

Since the entire target image GT is not included in the captured image G2 shown in FIG. 7, the pattern matching unit 93 does not detect a region that matches the target image GT in the captured image G2. In this case, the control unit 9 re-changes the image pickup area 510 of the macro image pickup unit 51 to re-image the front surface Wa of the package substrate W again.

That is, the control means 9 moves the macro imaging means 51 relative to the chuck table 30 by a predetermined distance in the −Y direction by the index feeding means 12 shown in FIG. The moving distance of the macro imaging unit 51 is, for example, a value shorter than the length of the imaging region 510 of the macro imaging unit 51 in the Y-axis direction by the number of pixels in the Y-axis direction of the alignment mark M. That is, the control unit 9 changes the image pickup area 510 of the macro image pickup unit 51 so as to overlap the pixels of the alignment mark M (second image pickup area changing step).

By moving the macro image pickup means 51 as described above, the image pickup area 510 of the macro image pickup means 51 is displaced in the −Y direction from the image pickup area when the picked-up image G2 is picked up, as shown in FIG. Placed in a position.

Then, the control unit 9 captures the newly set image capturing area 510 by the macro image capturing unit 51, acquires the captured image G3 illustrated in FIG. 8, and stores the captured image G3 in the storage unit 91 (third capturing step). After that, the pattern matching unit 93 of the control unit 9 performs the pattern matching regarding the alignment mark M with respect to the captured image G3, similarly to the captured images G1 and G2 described above (the third pattern matching step).

Since the captured image G3 shown in FIG. 8 does not include the entire target image GT, a region matching the target image GT is not detected, and the control unit 9 further changes the captured region 510 of the macro imaging unit 51. Then, the front surface Wa of the package substrate W is further imaged.

That is, the control means 9 moves the chuck table 30 by a predetermined distance in the −X direction relative to the macro imaging means 51 by the cutting feed means 11 shown in FIG. 1. At this time, similarly to the first image pickup area changing step, the control unit 9 changes the image pickup area 510 of the macro image pickup unit 51 so as to overlap by the pixels of the alignment mark M (third image pickup area changing step). ).

As the chuck table 30 is moved as described above, the image pickup area 510 of the macro image pickup unit 51 is displaced in the −X direction from the image pickup area when the picked-up image G3 is picked up, as shown in FIG. Will be distributed to

Then, the control unit 9 captures the newly set image capturing area 510 on the front surface Wa of the package substrate W by the macro image capturing unit 51, acquires the captured image G4 illustrated in FIG. 9, and stores the captured image G4 in the storage unit 91 ( Fourth imaging step). After that, the pattern matching unit 93 of the control unit 9 performs the pattern matching regarding the alignment mark M with respect to the captured image G4, similarly to the above-described captured image G1 and the like (fourth pattern matching step).

The entire target image GT is included in the captured image G4 shown in FIG. Therefore, the control unit 9 can normally detect the target image GT, that is, the alignment mark M by pattern matching. However, if the alignment mark M is dirty or unclear, it is difficult to detect the target image GT by pattern matching.
Therefore, in this case, the control unit 9 determines that the target image GT is not detected by the pattern matching, similarly to the pattern matching of the first to third times.

In this way, the control unit 9 acquires a picked-up image while changing the image pickup area 510 of the macro image pickup unit 51, and carries out pattern matching. At this time, as shown in FIG. 10, the imaging region 510 is changed such that the movement path R of the imaging region 510 draws a spiral trajectory in the clockwise direction on the package substrate W when viewed from above ( Spiral search).

Then, the control unit 9 finds the alignment mark M in the picked-up image by performing pattern matching by the pattern matching unit 93 in the picking-up step, the pattern matching step, and the picked-up area changing step in the confirmation step, or acquires the picked-up image. This is repeated until the cumulative area becomes equal to or larger than the area of the search area SA.

In the confirmation step, when the pattern matching unit 93 detects the area matching the target image GT in the captured image by pattern matching and finds the alignment mark M, the control unit 9 causes the control unit 9 to determine the X-axis coordinate of the alignment mark M. The position and the Y-axis coordinate position are acquired and stored in the storage unit 91.

On the other hand, when the alignment mark M cannot be found by pattern matching with respect to the captured images and the cumulative area of the plurality of captured images is equal to or larger than the threshold area, the control unit 9 ends the confirmation step and executes the combined image display step. ..

It should be noted that the control unit 9 is configured to avoid overlapping and accumulating overlapping portions of the images when calculating the cumulative area of the captured images. That is, the control unit 9 calculates the cumulative area of the captured image by accumulating the portions of the captured image that are not included in the previous captured image.

(4) Combined image display step In this step, as shown in FIG. 11, the control unit 9 combines all the captured images acquired up to that point to form a combined image having the same area as the accumulated area of the captured images. GA is formed, and this combined image GA is displayed on the touch panel 40 which is a screen. In response to this, the operator visually recognizes the combined image GA, detects the alignment mark M inside the combined image GA, and specifies the display portion of the alignment mark M on the touch panel 40. For example, the operator touches the display portion of the alignment mark M on the touch panel 40 with a finger.

In response to this, the control unit 9 specifies the position of the alignment mark M based on the portion of the touch panel 40 designated by the operator, acquires the X-axis coordinate position and the Y-axis coordinate position, and stores the storage unit. Store in 91.

In this way, the control means 9 specifies and stores the X-axis coordinate position and the Y-axis coordinate position of the alignment mark M based on pattern matching or designation by the operator.

(5) Scheduled division line specifying step The control means 9 specifies the first scheduled division line S1 and the second scheduled division line S2 based on the X-axis coordinate position and the Y-axis coordinate position of the alignment mark M.

That is, the control unit 9 performs the detection of the alignment mark M performed in each of the above steps for the plurality of alignment marks M located at positions distant from each other in the X-axis direction.

Then, the control means 9 performs the θ adjustment for aligning the first planned dividing line S1 of the package substrate W substantially in parallel with the X-axis direction based on the positions of the plurality of alignment marks M. In the θ adjustment, the control unit 9 adjusts the angular position of the chuck table 30 holding the package substrate W by suction with the rotating unit 31 so that the Y-axis coordinate positions of the plurality of alignment marks M are substantially aligned. In this way, the θ alignment for making the first planned dividing line S1 substantially parallel to the X-axis direction is completed.

Further, the control means 9 uses the cutting feed means 11 and the index feed means 12 to position the center of the front surface Wa of the package substrate W in the image pickup area of the micro image pickup means 52 and obtain a picked-up image including the alignment mark M. .. The control means 9 uses the index feeding means 12 to make the deviation of the Y-axis coordinate position of the alignment mark M within the picked-up image from the reference line (hairline) of the micro-imaging means 52 within an allowable value. 52 is moved in the Y-axis direction.

After that, the control unit 9 causes the index feeding unit 12 to move the micro imaging unit 52 in the Y-axis direction by the distance Ly from the alignment mark M to the center line in the width direction of the first planned dividing line S1. As a result, the hairline of the micro-imaging unit 52 is superimposed on the first planned dividing line S1. The control unit 9 stores the coordinate position of the hairline in the Y-axis direction at this time in the storage unit 91 as the position of the first planned dividing line S1.
The alignment mark M imaged by the macro imaging unit 51 and the alignment mark M imaged by the micro imaging unit 52 may be the same or different.

After that, the control means 9 rotates the chuck table 30 by 90 degrees, similarly, superimposes the hairline of the micro imaging means 52 on the second planned division line S2, and stores the position of the second planned division line S2 in the storage section. Store in 91.

In this way, the control means 9 identifies the first planned division line S1 and the second planned division line S2 of the package substrate W. This completes the alignment.

After the completion of the alignment, the control unit 9 arranges the cutting blade 63 of the cutting unit 6 at the Y-axis coordinate position of the first planned dividing line S1 stored in the storage unit 91. The control means 9 causes the cutting feed means 16 to lower the cutting means 6 in the −Z direction to dispose the cutting means 6 at a predetermined cutting feed position and rotate the cutting blade 63. Then, the control means 9 causes the cutting feed means 11 to feed the chuck table 30 holding the package substrate W toward the cutting means 6 at a predetermined cutting feed speed.

In this way, the cutting blade 63 cuts the first planned dividing line S1. The control unit 9 cuts all the first planned dividing lines S1 while changing the first planned dividing lines S1 that are cut by using the index feeding unit 12.

Further, the control means 9 rotates the chuck table 30 by 90 degrees and similarly cuts the second planned dividing line S2. Thereby, the control means 9 can cut all the planned dividing lines S1 and S2 of the package substrate W.

As described above, in the alignment method of the cutting device 1, when the alignment mark M cannot be found by the pattern matching with the captured image and the cumulative area of the plurality of captured images acquired is equal to or larger than the area of the search area SA, control is performed. The means 9 carries out the combined image display step. Then, in the combined image display step, the control unit 9 forms a combined image GA (see FIG. 11) by combining all the captured images acquired so far, and displays the combined image GA on the touch panel 40. When the operator who visually checks the combined image GA detects and designates the alignment mark M, the control means 9 specifies and stores the position of the alignment mark M designated by the worker. Then, the control means 9 specifies the first planned division line S1 and the second planned division line S2 based on the alignment mark M through position adjustment (θ adjustment and the like) using the alignment mark M.
It should be noted that it is possible to prevent the captured images from being accumulated and pressure on the memory by stopping the acquisition of the captured images when the area becomes equal to or larger than the area of the search area SA.

As described above, according to this alignment method, even if the alignment mark M is dirty or unclear and it is difficult to detect the alignment mark M by pattern matching, the operator can display the combined image. Can specify the alignment mark M. Therefore, the alignment mark M can be detected quickly. As a result, the time required for alignment can be shortened.

The alignment method of the present embodiment may be carried out in a laser processing apparatus that performs desired processing on the package substrate W by laser irradiation.

Further, the registration process described above is not limited to the method shown in this embodiment. For example, the storage unit 91 may store in advance device data in which a plurality of processing conditions corresponding to the types of package substrates to be processed are listed. The processing conditions are data including various settings for performing an appropriate cutting process on the package substrate, and the various settings include the cutting feed speed of the chuck table 30 by the cutting feed means 11 shown in FIG. 1 and the index feed means. It includes information on the index feed amount of the cutting means 6 by 12 and the alignment mark.

In this case, in response to the operator selecting an appropriate processing condition for the package substrate W shown in FIG. 1 from the device data, the control means 9 sets the alignment mark recorded in the device data as the alignment mark M. You may register. In this case, the image pickup by the macro image pickup unit 51 for registering the alignment mark M is unnecessary.

Further, in the planned split line specifying step, after performing macro alignment using the macro image pickup means 51, a more accurate θ alignment step using the micro image pickup means 52 may be performed. This step can be performed based on a captured image obtained by capturing a part of the alignment mark M as a micro alignment mark by the micro image capturing means 52.

1: Cutting device,
3: holding part, 30: chuck table, 31: rotating means,
9: control means, 91: storage unit, 93: pattern matching unit,
11: cutting feed means, 12: index feed means, 16: cutting feed means,
6: cutting means, 63: cutting blade,
51: macro imaging means, 52: micro imaging means, 510: imaging area,
40: Touch panel,
W: package substrate, S1: first planned dividing line, S2: second planned dividing line,
M: alignment mark, GT: target image,
SA: search area, G1 to G4: captured image, GA: combined image

Claims (1)

A device is formed in a region partitioned by a first planned dividing line set on the surface and a second planned dividing line intersecting the first planned dividing line, and outside the partitioned region. The package substrate on which the alignment mark is arranged is held by the chuck table and is imaged by the image pickup means to obtain a picked-up image, the alignment mark is detected from the picked-up image, and the first mark is detected based on the alignment mark. An alignment method for identifying a first planned division line and the second planned division line,
A registration step of registering the alignment mark smaller than the imaging area of the imaging means;
A search area setting step of setting a search area for finding the alignment mark;
An image pickup step of obtaining the picked-up image corresponding to the image pickup area set on the package substrate by the image pickup means, a pattern matching step of confirming the presence or absence of the alignment mark in the picked-up image by pattern matching, and the alignment An image pickup area changing step of changing the image pickup area of the image pickup means so as to overlap only pixels of the mark, and the image pickup step, the pattern matching step and the image pickup step are performed by detecting the alignment mark, or A confirmation step repeated until the cumulative area of the captured image becomes equal to or larger than the area of the search area;
When the alignment mark is not detected in the confirmation step, a plurality of the captured images captured in the confirmation step are combined to form a combined image having the same area as the cumulative area and displayed on the screen. Combined image display process,
When the alignment mark is designated by the operator who visually inspected the combined image, the planned division line specifying the first planned division line and the second planned division line based on the designated alignment mark. Process,
An alignment method including.

Images