Direction adjustment method

Abstract

To adjust a direction of a workpiece without depending on two key patterns that are separated so that it is not housed at the same time within a visual field range of an imaging unit.SOLUTION: The present invention provides a direction adjustment method comprising: a step of displaying a first image obtained by imaging a front surface of a workpiece held by a holding table with an imaging unit to a display device; a step of designating a start position by an operator after a center point of the first image or a designation point optionally designated by the operator is set as a rotational center; a step of designating a termination position by the operator; a step of rotating the first image at a circumference of the rotational center in a direction where it is progressed from the start position to the termination position by an image processing by a rotational angle regulated by the start position, the termination position, and the rotational center of the first image; and a step of matching a direction of a second image obtained by imaging the workpiece with an imaging unit to a direction of the first image after the rotation by adjusting a direction of the holding table on the basis of the rotational angle, and displaying the second image to the display device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an orientation adjusting method for adjusting the orientation of a workpiece held on a holding table of a processing device when the workpiece has a plurality of planned dividing lines set in a lattice pattern on its surface. [Background technology]

[0002] Semiconductor device chips are manufactured by dividing a semiconductor wafer (workpiece) using a processing device. A number of division lines are set in a grid pattern on the surface of the workpiece, and devices such as ICs (Integrated Circuits) are formed in each rectangular area defined by the division lines.

[0003] For example, when a cutting device is used as the processing device, the workpiece is held by suction on the chuck table, and the lower end of the cutting blade rotating at high speed around the spindle as the rotation axis is positioned at a height between the workpiece and the holding surface of the chuck table, and the chuck table is moved along the processing feed direction (e.g., the X-axis direction).

[0004] At this time, in order to cut the workpiece along the planned dividing line within the width of the planned dividing line, it is necessary to perform an alignment process before actually cutting the workpiece, in which the cutting device is made to recognize the position of the planned dividing line and the planned dividing line is made approximately parallel to the processing feed direction of the chuck table.

[0005] Before carrying out this alignment process, typically, a key pattern (also called an alignment mark, target pattern, etc.) having a specific regular pattern that is provided at the same position on each device is first stored in the cutting device, and the distance from this key pattern to the nearest planned division line is also stored in the cutting device (teach process).

[0006] Then, in the alignment process after the teach process, when the planned division line is made approximately parallel to the processing feed direction, first, pattern matching is performed between the key pattern in the image obtained by capturing an image of the key pattern with an imaging unit and the key pattern stored in the teach process, and the key pattern that is the same as the key pattern stored in the teach process is identified.

[0007] In the alignment process, the chuck table is then moved a predetermined amount along the processing feed direction, and an image of an area different from that of the previous image is then captured to obtain an image including the key pattern, and pattern matching is performed in the same manner.

[0008] When the coordinates of the two key patterns obtained by imaging are misaligned in the indexing feed direction (e.g., the Y-axis direction) perpendicular to the processing feed direction, the planned division line is disposed obliquely with respect to the processing feed direction. Therefore, the orientation of the chuck table is adjusted so that the coordinates of the two key patterns approximately match in the indexing feed direction (see, for example, Patent Document 1).

[0009] When adjusting the orientation of the chuck table, in order to detect minute differences in the coordinates of two key patterns in the indexing feed direction, two key patterns that are sufficiently separated in the processing feed direction (i.e., so far apart that they cannot be contained within the field of view of the imaging unit at the same time) are used, rather than two key patterns that are simultaneously located within the field of view of the imaging unit.

[0010] However, because the operator specifies which part of the workpiece to image on the touch panel of the cutting device, for example, if the device size is small, the operator may mistakenly select two key patterns that are located near different planned division lines rather than the same planned division line.

[0011] The alignment process is also performed when cutting another workpiece having the same specifications. If the worker mistakenly selects two key patterns that are located near different planned division lines, the cutting blade will pass through the device during the cutting process, destroying the device.

[0012] The division line must be substantially parallel to the processing feed direction of the chuck table not only in the alignment step described above but also in the teaching step. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] JP 2004-241686 A Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been made in consideration of such problems, and aims to adjust the orientation of the workpiece without relying on two key patterns that are so far apart that they cannot be simultaneously captured within the field of view of the imaging unit. [Means for solving the problem]

[0015] According to one aspect of the present invention, there is provided an orientation adjustment method for adjusting an orientation of a workpiece held on a holding table of a processing device when the workpiece has a plurality of planned division lines set in a grid pattern on its surface, the method comprising the steps of: holding the workpiece on a holding surface of the holding table; a first image displaying step of displaying on a display device a first image obtained by imaging the surface of the workpiece held on the holding surface with an imaging unit; a start point position designating step of the operator designating a start point position that is a start point for rotation of the first image, with the center point of the first image displayed on the display device or a designated point of the first image arbitrarily designated by an operator being set as the center of rotation of the first image; and a rotation adjustment step of adjusting the orientation of the workpiece held on a holding table of the processing device when the workpiece has a plurality of planned division lines set in a grid pattern on its surface. an image rotation step of calculating a rotation angle defined by the start point position and the end point position around the rotation center of the first image and the rotation center of the first image, and rotating the first image by the rotation angle around the rotation center in a direction proceeding from the start point position to the end point position by image processing; and a second image display step of adjusting, after the image rotation step, an orientation of the holding table around a rotation axis of the holding table perpendicular to the holding surface based on the rotation angle, thereby making an orientation of a second image obtained by imaging the workpiece with the imaging unit the same as that of the first image after the image rotation step, and displaying the second image on the display device.

[0016] Preferably, in the first image display step, a predetermined identification mark is displayed on the display device as the center of rotation.

[0017] Also, preferably, in the second image display step, an imaged area of ​​the workpiece when obtaining the second image is made the same as an imaged area corresponding to the first image rotated by the rotation angle.

[0018] In addition, preferably, the orientation adjustment method further includes a misalignment correction step of, after the second image display step, moving the imaging unit and the workpiece relatively along a predetermined direction that is parallel to the holding surface while displaying a reference line on the display device, and then rotating the holding table so that the orientations of the reference line and the planned division line coincide with each other.

[0019] In addition, preferably, the orientation adjustment method further includes a registration step of, after the second image display step, registering in the processing device a predetermined area of ​​the workpiece obtained by imaging the workpiece with the imaging unit as a mark to serve as a guide when processing the workpiece with the processing device. Effect of the Invention

[0020] In an orientation adjustment method according to one embodiment of the present invention, the first image is rotated by image processing by an angle determined by the rotation center of the first image and the start and end positions specified by an operator in the first image (image rotation process).

[0021] After the image rotation process, the orientation of the holding table is adjusted based on this rotation angle, so that the orientation of the second image obtained by imaging the workpiece with the imaging unit is made the same as the orientation of the first image after the image rotation process (second image display process).

[0022] In this way, the worker can intuitively specify the rotation angle of the first image to adjust the orientation of the workpiece, without relying on two key patterns that are too far apart to be simultaneously captured within the field of view of the imaging unit. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a flow diagram of an orientation adjustment method. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a diagram showing how the surface of a workpiece is imaged; [Figure 4] 4(A) and 4(B) are diagrams showing the positional relationship between the center of the holding surface of the chuck table and the center of the first image captured by the macro camera. [Diagram 5] FIG. [Figure 6] FIG. 11 is a diagram showing a first image display step. [Figure 7] FIG. 13 is a diagram showing a start point position designation process. [Figure 8] FIG. 13 is a diagram showing an end point position designation step. [Figure 9] FIG. 2 shows a first image that has undergone an image rotation process. [Figure 10] FIG. 11 is a diagram showing a second image display process. [Figure 11] Figure 11(A) is an example of a second image with guide lines displayed, and Figure 11(B) is an example of an image when the chuck table is moved a predetermined amount with the guide lines displayed in the second image. [Figure 12] FIG. [Figure 13] FIG. 13 is a diagram showing a modified example of a start point position designation step. [Figure 14] FIG. 13 is a diagram showing a modified example of an end point position designation step. [Figure 15] FIG. 2 is a perspective view of the laser processing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] (First embodiment) An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a flow diagram of an orientation adjustment method for adjusting the orientation of a workpiece 11 (see Fig. 2 for both) held by suction on a disk-shaped chuck table (holding table) 14 provided in a cutting device (processing device) 2.

[0025] In this embodiment, as shown in FIG. 1, the steps are performed in the following order: a reference coordinate storage step S10, a retention step S20, a first image display step S30, a start point position designation step S40, an end point position designation step S50, an image rotation step S60, a second image display step S70, a misalignment correction step S80, and a registration step S90.

[0026] A series of steps from the reference coordinate storage step S10 to the registration step S90 is a teach step, which is performed before the alignment step performed when cutting the workpiece 11. In the teach step, the position, shape, etc. of the key pattern 15a (see FIG. 3) are stored (i.e., registered) in the cutting device 2.

[0027] First, the cutting device 2 in which each process is performed will be described with reference to Fig. 2. Fig. 2 is a perspective view of the cutting device 2. Note that Fig. 2 shows some of the components of the cutting device 2 in functional blocks. The X-axis direction, Y-axis direction, and Z-axis direction shown in Fig. 2 are mutually orthogonal.

[0028] The X-axis direction is approximately parallel to the processing feed direction, the Y-axis direction is approximately parallel to the indexing feed direction, and the Z-axis direction is approximately parallel to the gravity direction. The cutting device 2 includes a base 4 that supports each of the components.

[0029] A rectangular opening 4a is provided at the front corner (one side in the Y-axis direction) of the base 4. A space exists below the opening 4a, and an elevator 6 capable of ascending and descending along the Z-axis direction is provided in this space. A cassette 8 containing a plurality of workpieces 11 is placed on the upper surface of the elevator 6.

[0030] The workpiece 11 in this embodiment is a semiconductor wafer formed of a single crystal of a semiconductor material such as silicon and having a disk shape. There are no limitations on the material, shape, structure, size, etc. of the semiconductor wafer. For example, the workpiece 11 may be a wafer formed of a semiconductor material other than silicon, or a substrate formed of a material such as ceramics, resin, or metal.

[0031] 3, a plurality of planned dividing lines 13 are set in a lattice pattern on the surface 11a of the workpiece 11. The plurality of planned dividing lines 13 include a plurality of planned dividing lines 13a extending along a first direction and a plurality of planned dividing lines 13b extending along a second direction.

[0032] The division lines 13a and 13b are perpendicular to each other, and devices 15 such as ICs are provided in each rectangular area defined by the division lines 13. However, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of the devices 15.

[0033] As shown enlarged on the right side of Fig. 3, a plurality of key patterns are formed on the outer periphery of the device 15. The plurality of key patterns include various shapes such as horizontal bars, vertical bars, circles, convex shapes, etc. In this embodiment, a convex key pattern 15a is used in the registration step S90 described later, but key patterns of other shapes may also be used.

[0034] A substantially circular dicing tape 17 having an area larger than that of the workpiece 11 is attached to the back surface 11b side of the workpiece 11. The outer periphery of the dicing tape 17 is attached to one surface of the annular frame 19 so that the dicing tape 17 covers the opening of the annular frame 19.

[0035] In this manner, the workpiece 11 is supported by the annular frame 19 via the dicing tape 17 to form a workpiece unit 21. The workpiece 11 is accommodated in the cassette 8 in the state of this workpiece unit 21.

[0036] Returning to Fig. 2, an opening 4b is formed with its longitudinal portion disposed along the X-axis direction at the rear (the other side in the Y-axis direction) of the elevator 6. A rectangular plate-shaped table cover 10 and two bellows-shaped cover members 12, each of which is extendable and contractible and disposed on both sides of the table cover 10 in the X-axis direction, are provided within the opening 4b.

[0037] A ball screw type X-axis direction moving mechanism (not shown) is provided below the table cover 10 and the cover member 12. The X-axis direction moving mechanism has an X-axis direction moving plate (not shown) that is movable along the X-axis direction.

[0038] The X-axis direction moving mechanism includes a first position sensor (not shown). This first position sensor acquires the X-axis direction position of the X-axis direction moving plate. For example, the first position sensor has an optical or magnetic linear encoder including a reader head provided on the lower surface of the X-axis direction moving plate and a scale provided near a pair of X-axis guide rails (not shown) that support the X-axis direction moving plate.

[0039] A rotation drive mechanism (not shown) is provided on the X-axis direction moving plate. The rotation drive mechanism has a motor and the like that rotates the above-mentioned chuck table 14 provided on the table cover 10 around a predetermined rotation axis 14b.

[0040] The rotation axis 14b of the chuck table 14 passes through a radial center point 14c of the chuck table 14 and is disposed approximately parallel to the Z-axis direction. In other words, the rotation axis 14b is perpendicular to the holding surface 14a located on the uppermost surface of the chuck table 14.

[0041] When the X-axis direction moving plate is moved along the X-axis direction, the table cover 10, the chuck table 14, the rotary drive mechanism, etc. move integrally along the X-axis direction. The position of the chuck table 14 in the X-axis direction is identified by the first position sensor described above.

[0042] The chuck table 14 includes a disk-shaped frame made of metal. A recess having a smaller diameter than the frame is formed in the center of the upper surface of the frame in the radial direction of the frame, and a disk-shaped porous plate made of porous ceramics is fixed in this recess (see FIG. 5).

[0043] A negative pressure is transmitted to the porous plate from a suction source (not shown) such as a vacuum pump through a flow path formed in the frame. The upper surfaces of the frame and the porous plate form a substantially flat holding surface 14a. The holding surface 14a is disposed substantially parallel to the XY plane.

[0044] A plurality of clamp units 16 are provided at approximately equal intervals around the periphery of the chuck table 14 on the outer side of the chuck table 14. Each clamp unit 16 clamps an annular frame 19 of a workpiece unit 21.

[0045] A cantilever-shaped support structure 18 is disposed at a position adjacent to the opening 4b. A Y-axis / Z-axis movement mechanism 20 is provided on the front surface side of the support structure 18. The Y-axis / Z-axis movement mechanism 20 includes a pair of Y-axis guide rails 22 disposed substantially parallel to the Y-axis direction.

[0046] A Y-axis direction moving plate 24 is attached to be slidable along the Y-axis direction to the Y-axis guide rail 22. A nut portion (not shown) is provided on the back side of the Y-axis direction moving plate 24 (i.e., the support structure 18 side).

[0047] A screw shaft 26 arranged substantially parallel to the Y-axis direction is rotatably connected to this nut portion via a ball (not shown). A stepping motor (not shown) is connected to one end of the screw shaft 26. When the screw shaft 26 is rotated by the stepping motor, the Y-axis direction moving plate 24 moves along the Y-axis direction.

[0048] The Y-axis / Z-axis direction moving mechanism 20 includes a second position sensor (not shown). The second position sensor acquires position information in the Y-axis direction of the Y-axis direction moving plate 24. For example, the second position sensor has an optical or magnetic linear encoder including a reader head provided on the rear surface of the Y-axis direction moving plate 24 and a scale provided in the vicinity of one of the Y-axis guide rails 22.

[0049] A pair of Z-axis guide rails 28 arranged substantially parallel to the Z-axis direction are provided on the front surface side of the Y-axis direction moving plate 24. A Z-axis direction moving plate 30 is attached to the pair of Z-axis guide rails 28 so as to be slidable along the Z-axis direction.

[0050] A nut portion (not shown) is provided on the back side of the Z-axis direction moving plate 30, and a screw shaft 32 arranged approximately parallel to the Z-axis direction is rotatably connected to this nut portion via balls (not shown). A stepping motor 34 is connected to the upper end portion of the screw shaft 32.

[0051] When the screw shaft 32 is rotated by the stepping motor 34, the Z-axis direction moving plate 30 moves along the Z-axis direction. The Y-axis / Z-axis direction moving mechanism 20 includes a third position sensor (not shown). The third position sensor acquires position information of the Z-axis direction moving plate 30.

[0052] For example, the third position sensor has an optical or magnetic linear encoder including a reader head provided on the rear surface of the Z-axis moving plate 30 and a scale provided near one of the Z-axis guide rails 28.

[0053] A cutting unit 36 ​​that cuts the workpiece 11 is provided at the lower end of the Z-axis direction moving plate 30. The cutting unit 36 ​​has a spindle housing 38 whose longitudinal portion is disposed along the Y-axis direction. A cylindrical spindle 40 is partly housed in the spindle housing 38 so as to be rotatable by an air bearing (see FIG. 5).

[0054] The spindle 40 is arranged such that its longitudinal direction runs along the Y-axis direction, and a servo motor (not shown) is provided at the base end of the spindle 40 (note that the base end side of the spindle 40 is omitted in FIG. 5).

[0055] A cutting blade 42 having an annular cutting edge 42a on its outer periphery is attached to the tip of the spindle 40 (see FIG. 5). When the spindle 40 rotates, the cutting blade 42 also rotates with the spindle 40 as the rotation axis.

[0056] A microscope camera unit (imaging unit) 44 for imaging the workpiece 11 held by suction on the chuck table 14 is provided at a position adjacent to the spindle housing 38.

[0057] 3, the microscope camera unit 44 includes a macro camera 46 and a micro camera 48. The positions of the cutting blade 42a, the macro camera 46, and the micro camera 48 in the Y-axis direction and the Z-axis direction are identified by the second and third position sensors described above.

[0058] Fig. 3 is a diagram showing how the surface 11a of the workpiece 11 is imaged. In Fig. 3, some of the components of the cutting device 2 are shown in functional blocks. The macro camera 46 has a lens (not shown), an image sensor 46a, etc. The micro camera 48 similarly has a lens (not shown), an image sensor 48a, etc.

[0059] The imaging elements 46a and 48a are solid-state imaging elements such as a complementary metal-oxide-semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor.

[0060] The macro camera 46 is used when capturing an image at a relatively low magnification of the workpiece 11. The macro camera 46 is used, for example, when performing the above-mentioned reference coordinate storage step S10 to the deviation correction step S80.

[0061] The micro camera 48 is used when capturing an image at a relatively high magnification of the workpiece 11. The micro camera 48 is used, for example, when performing the deviation correction step S80 and the registration step S90.

[0062] The images obtained by the macro camera 46 and the micro camera 48 are stored in a controller 56 described later and are used for registering the key pattern 15a in the teaching process, the alignment process, kerf check after cutting, and the like.

[0063] Returning to Fig. 2, behind the opening 4b, there is provided a spinner cleaning unit 52. After cutting, the workpiece 11 is cleaned and dried in the spinner cleaning unit 52, and then returned to the cassette 8. An exterior panel (not shown) is provided above the base 4, and a touch panel 54 is provided on the front surface of the exterior panel.

[0064] The touch panel 54 functions as a display device that displays images acquired by the microscope camera unit 44, a GUI (graphical user interface), and the like, and also functions as an input device through which an operator inputs instructions to the cutting device 2.

[0065] In this manner, in this embodiment, the touch panel 54, which allows the operator to input instructions using his / her hand, a dedicated input pen, or the like, functions as both a display device and an input device. However, instead of the touch panel 54, a liquid crystal display, an OELD (Organic Electro Luminescence Diode) display, or the like, which has a display device function but no input function, may be used.

[0066] When using such a display dedicated to display, input devices such as a mouse, trackball, touchpad, trackpad, digitizer, etc. are used to move the pointer or cursor displayed on the screen, determine a position on the screen, select a GUI, etc.

[0067] The operations of the elevator 6, X-axis direction moving mechanism, rotation drive mechanism, suction source, clamp unit 16, Y-axis direction Z-axis direction moving mechanism 20, cutting unit 36, microscope camera unit 44, spinner cleaning unit 52, touch panel 54, etc. are controlled by a controller 56.

[0068] The controller 56 is configured by a computer including, for example, a processor 58 represented by a CPU (Central Processing Unit) and a memory 60. The memory 60 includes a main storage device such as a DRAM (Dynamic Random Access Memory) and an auxiliary storage device such as a flash memory, a hard disk drive, or a solid state drive.

[0069] The auxiliary storage device stores software including a predetermined program. The functions of the controller 56 are realized by operating the processor 58 and other components in accordance with this software. The auxiliary storage device also stores coordinates, which will be described later, and also stores programs necessary for image processing.

[0070] Next, with reference to FIG. 1 and FIG. 4(A) to FIG. 12, an adjustment method for adjusting the orientation of the workpiece 11, which is performed in a teaching step before the cutting device 2 cuts the workpiece 11, will be described.

[0071] Typically, before the cutting device 2 is shipped from the factory to the user, the X coordinate of the chuck table 14 and the Y coordinate of the macro camera 46 when the center point 14c of the holding surface 14a coincides with the center point of the image obtained by the macro camera 46 (i.e., the geometric center position of the two-dimensional image) are registered in advance.

[0072] That is, the reference coordinates (X0, Y0) are registered in advance, and if the position of the chuck table 14 in the X-axis direction is X0 and the position of the macro camera 46 in the Y-axis direction is Y0, then the center point 14c of the holding surface 14a and the center point 46c of the first image 46b obtained by capturing an image with the macro camera 46 coincide on the XY plane (see FIG. 4(B)).

[0073] However, due to an accidental event such as an operator touching the microscope camera unit 44 during maintenance of the cutting device 2, the relative positional relationship between the chuck table 14 and the microscope camera unit 44 may change.

[0074] FIG. 4(A) shows that the center point 14c of the holding surface 14a and the center point 46c of the first image 46b are misaligned even though the chuck table 14 and the macro camera 46 are each positioned at pre-registered reference coordinates (X0, Y0).

[0075] 4(A), it is necessary to correct the reference coordinates (X0, Y0) in the reference coordinate storage step S10. To explain a specific example of the correction work, first, attention is paid to an arbitrary point A1 (not shown) on the holding surface 14a.

[0076] Point A1 is, for example, a point in a two-dimensional area consisting of a predetermined figure, pattern, color, letter or number, or a combination of these, intentionally formed on the holding surface 14a, but it may also be a point in a two-dimensional area formed unintentionally, such as the shape of a pore exposed on the holding surface 14a.

[0077] Then, the center point 46c of the first image 46b obtained by the macro camera 46 is placed at point A1, and the X coordinate (X1) of the chuck table 14 and the Y coordinate (Y1) of the microscope camera unit 44 at this time are obtained (first alignment step). Next, the chuck table 14 is rotated by 90 degrees (rotation step). With the rotation, point A1 moves.

[0078] Next, the chuck table 14 is moved along the X-axis direction and the microscope camera unit 44 is moved along the Y-axis direction to position the center point 46c of the first image 46b at the moved point A1 (second alignment process).

[0079] Furthermore, in the second alignment step, the X coordinate (X2) of the chuck table 14 and the Y coordinate (Y2) of the microscope camera unit 44 when the center point 46c and the point A1 coincide with each other are obtained.

[0080] Using the coordinates (X1, Y1) obtained in the first alignment process and the coordinates (X2, Y2) obtained in the second alignment process, the corrected reference coordinates (X C ,YC ) can be calculated using the following formula:

[0081] X C =X1+(dX-dY) / 2,Y C =Y1+(dX+dY) / 2 However, dX = X1-X0, dY = Y1-Y0

[0082] Corrected reference coordinate (X C ,Y C ) is stored in the controller 56. After obtaining the corrected reference position in the above manner, the X-coordinate of the chuck table 14 is C The Y coordinate of the macro camera 46 is Y C In this case, as shown in FIG. 4B, the center point 14c of the holding surface 14a and the center point 46c of the first image 46b coincide on the XY plane.

[0083] 4(B) is a diagram showing a case where the center point 14c of the holding surface 14a and the center point 46c of the first image 46b coincide with each other. Note that the reference coordinate storage step S10 may be completed at the factory before shipping, and the relative positional relationship between the chuck table 14 and the microscope camera unit 44 may not change. In this case, the reference coordinate storage step S10 may be omitted.

[0084] In this embodiment, the holding step S20 is performed after the reference coordinate storage step S10. Fig. 5 is a diagram showing the holding step S20 in which the workpiece 11 is suction-held by the holding surface 14a. In the holding step S20, a transport mechanism (not shown) provided in the cutting device 2 transports the workpiece unit 21 from the cassette 8 to the chuck table 14.

[0085] Thereafter, the workpiece 11 placed on the holding surface 14a is suction-held on the holding surface 14a via the dicing tape 17, and the annular frame 19 is clamped by the multiple clamp units 16. After the holding step S20, the macro camera 46 captures an image of the surface 11a of the workpiece 11.

[0086] The controller 56 displays the first image 46b captured by the macro camera 46 on the touch panel 54 (first image display step S30). Fig. 6 is a diagram showing the first image display step S30, which shows an example of the first image 46b on the touch panel 54.

[0087] 6, for convenience of explanation, the X-axis direction and the Y-axis direction are shown outside the image display area of ​​the touch panel 54, but the X-axis direction and the Y-axis direction may be displayed inside the image display area. The same applies to Figs. 7 to 14 described later.

[0088] The center point 46c of the first image 46b displayed on the touch panel 54 becomes the rotation center 62 of the first image 46b. Note that in the first image 46b shown in Fig. 6, a crosshair (wavy line) and a circle (i.e., a predetermined identification mark) as the rotation center 62 are displayed at the center position of the image.

[0089] However, the rotation center 62 may be displayed with characters such as "center" in addition to a circle. The rotation center 62 may be displayed with a figure, a pattern, a color, a letter or a number, or a combination of these. Also, displaying one or both of the crosshairs and the rotation center 62 is not essential and may be omitted.

[0090] 6, the planned division line 13a is inclined with respect to the X-axis direction, and the planned division line 13b is also inclined with respect to the Y-axis direction. If the workpiece 11 is inclined in the XY plane in this manner when the key pattern 15a is registered in the controller 56 in the registration step S90, the key pattern 15a having an inclined shape is registered in the controller 56.

[0091] When cutting the workpiece 11, alignment (i.e., the task of determining the position of the planned division line 13) is performed by pattern matching between the key pattern 15a registered in the teaching process and the key pattern 15a provided on the workpiece 11 to be cut. Therefore, if a key pattern 15a with an inclined shape is registered, pattern matching will not work well, resulting in problems such as matching errors.

[0092] Therefore, in this embodiment, the orientation in the XY plane of the workpiece 11 suction-held by the holding surface 14a (i.e., the orientation in the XY plane of the chuck table 14) is adjusted so that the planned division line 13a of the first image 46b becomes approximately parallel to the X-axis direction. This allows more accurate pattern matching to be performed.

[0093] In this embodiment, in order to adjust the orientation of the workpiece 11 within the XY plane, the center point 46c of the first image 46b displayed on the touch panel 54 is set as the rotation center 62 of the first image 46b, and the worker specifies a starting point position 66 that serves as the starting point for the rotation of the first image 46b (starting point position specification process S40).

[0094] Fig. 7 is a diagram showing the start point position designation step S40. Note that Fig. 7 shows a simplified view of the worker's hand 64, and the hand 64 is not displayed in the first image 46b. The coordinates of a point designated by the fingertip of the hand 64 are stored in the controller 56 as the start point position 66.

[0095] After the start point position designation step S40, in order to designate the rotation of the first image 46b so that the planned division line 13a becomes parallel to the X-axis direction, the worker designates an end point position 68, which is a position different from the start point position 66 and serves as an end point of the rotation around the rotation center 62 of the above-mentioned start point (end point position designation step S50). Fig. 8 is a diagram showing the end point position designation step S50.

[0096] 8, in the end position designation step S50, the fingertip is slid in a straight line (i.e., a drag operation is performed) while maintaining the fingertip in contact with the touch panel 54. The position where the fingertip stops is stored in the controller 56 as the end position 68.

[0097] Alternatively, after the fingertip is slid while keeping the fingertip in contact with the touch panel 54 , the position at which the fingertip is released from the touch panel 54 may be stored in the controller 56 as the end position 68 .

[0098] The controller 56 calculates a rotation angle α defined by the start position 66 and the end position 68 around the rotation center 62 of the first image 46b and the rotation center 62 of the first image 46b, and then, through image processing, rotates the first image 46b by the rotation angle α around the rotation center 62 in the direction from the start position 66 to the end position 68 (image rotation process S60).

[0099] 9 is a diagram showing a first image 46b that has been subjected to the image rotation step S60. In this embodiment, the rotation angle α satisfies 0 degrees<α≦90 degrees (degrees: arc degree). For example, an affine transformation is used as the image processing algorithm.

[0100] In the image rotation step S60, the first image 46b may be rotated after the end point position designation step S50 is completed, or the first image 46b may be rotated together with the movement of the fingertip (that is, in parallel with the end point position designation step S50).

[0101] Furthermore, in order to compensate for missing pixels due to the affine transformation, a nearest neighbor method, a bilinear method, a bicubic method, a Lanczos method, or the like may be applied to the affine transformation, which allows the first image 46b to be displayed more clearly after rotation or during rotation.

[0102] After the image rotation step S60, the controller 56 controls the operation of the rotation drive mechanism based on the rotation angle α to adjust the orientation of the chuck table 14 around the rotation axis 14b (that is, so-called θ-axis adjustment is performed).

[0103] In the image rotating step S60 of this embodiment, since the first image 46b is rotated clockwise by the rotation angle α when the holding surface 14a is viewed in a plan view, the chuck table 14 is rotated counterclockwise by the rotation angle α.

[0104] As a result, the orientation of the second image 46d obtained by actually capturing an image of the workpiece 11 with the microscope camera unit 44 is made the same as the orientation of the first image 46b after the image rotation step S60 (see Figure 10), and the controller 56 displays this second image 46d on the touch panel 54 (second image display step S70).

[0105] 10 is a diagram showing a second image display step S70. In particular, in this embodiment, in addition to the orientation being the same, the imaged area of ​​the surface 11a when obtaining the second image 46d (see FIG. 10) is made the same as the imaged area corresponding to the first image 46b (see FIG. 9) rotated by the above-mentioned rotation angle α.

[0106] In order to make the imaged areas of the second image 46d and the first image 46b the same, the counterclockwise direction when the holding surface 14a is viewed in plan is set as the positive direction of rotation, and the corrected reference coordinates (X C ,Y C ) is the origin of the coordinate system, and the coordinates of the rotation center 62 before the second image display step S70 relative to this reference coordinate are (X A ,Y A ), for example, the rotation center 62 (X B ,Y B ) can be calculated using the following formula:

[0107] X B =(X A 2 +Y A 2 ) 1 / 2 cos(atan2(Y A ,X A )-α) Y B =(X A 2 +Y A 2 ) 1 / 2 sin(atan2(Y A ,X A )-α)

[0108] In the second image display step S70, the rotation center 62 is set to (X A ,YA ) to (X B ,Y B ), in addition to rotating the chuck table 14 around the rotation axis 14b, the position of the macro camera 46 in the Y-axis direction and the position of the chuck table 14 in the X-axis direction may be adjusted.

[0109] In this embodiment, the worker intuitively specifies the rotation angle α of the first image 46b, thereby adjusting the orientation of the workpiece 11. In other words, the orientation of the workpiece 11 can be adjusted without relying on the two key patterns 15a that are too far apart to be simultaneously included within the field of view of the microscope camera unit 44.

[0110] In addition, in this embodiment, the imaged area is substantially the same in the image rotation step S60 and the second image display step S70, thereby improving the operability of the cutting device 2 by the operator. After the second image display step S70, a deviation correction step S80 is performed.

[0111] In the previous image rotation step S60, the rotation angle α is specified by the amount of movement of the fingertip of the operator's hand 64, so if an image with a higher resolution is used for inspection, there is a possibility that the division line 13a crosses the X-axis direction. In other words, there is a possibility that the division line 13a is not completely parallel to the X-axis direction and forms a small angle.

[0112] Therefore, in the deviation correction step S80, the deviation of the planned division line 13a from a state in which it is parallel to the X-axis direction (i.e., the deviation of the planned division line 13a from the X-axis direction in the circumferential direction around the center point 14c of the holding surface 14a) is corrected.

[0113] In the misalignment correction step S80, as shown in FIG. 11(A), the controller 56 causes the touch panel 54 to display a guide line 70 arranged parallel to the X-axis direction (that is, a predetermined direction parallel to the holding surface 14a).

[0114] Fig. 11(A) is an example of the second image 46d on which the reference lines 70 are displayed. In Fig. 11(A), the end of one of the planned division lines 13a in the Y-axis direction and the reference line 70 overlap with each other.

[0115] With the reference line 70 displayed on the touch panel 54, the macro camera 46 and the workpiece 11 are moved relatively a predetermined amount along the X-axis direction. Specifically, the position of the microscope camera unit 44 is fixed, and the chuck table 14 is moved a predetermined amount in the X-axis direction. The predetermined amount is sufficiently larger than the width of the imaging area of ​​the macro camera 46 in the X-axis direction (e.g., 640 μm), and is 100 mm in one example.

[0116] Fig. 11(B) is an example of an image when the chuck table 14 is moved by a predetermined amount with the reference line 70 displayed on the second image 46d. In the example shown in Fig. 11(B), the reference line 70 and the planned division line 13a are misaligned by an angle β.

[0117] In this case, the worker operates the rotation drive mechanism on the touch panel 54 to rotate the chuck table 14. As a result, the chuck table 14 is rotated around the rotation axis 14b so that the orientations of the guide line 70 and the planned division line 13a on the touch panel 54 coincide with each other in the XY plane.

[0118] In the deviation correction step S80, as described above, after the reference line 70 and the intended division line 13a are arranged approximately parallel to each other by the macro camera 46, the macro camera 46 is then switched to the micro camera 48, and deviation correction is performed in the same manner.

[0119] That is, the deviation correction step S80 includes a rough deviation correction using the macro camera 46 and a fine deviation correction using the micro camera 48. By performing the deviation correction step S80, the orientation of the workpiece 11 can be adjusted so as to complement the rotation angle α intuitively indicated by the operator on the touch panel 54.

[0120] Of course, it is not always possible to make the tangible division line 13a parallel to the X-axis direction in a mathematical sense, but it is possible to align the division line 13a in the X-axis direction to an extent that can reduce the frequency of matching errors in pattern matching (for example, to approximately zero frequency) and prevent cutting across the device 15.

[0121] After the deviation correction step S80, the worker operates the touch panel 54 to store (i.e., register) in the controller 56 an area (a specified area) of the surface 11a of the workpiece 11 obtained by imaging the surface 11a of the workpiece 11 with the micro camera 48 as a mark 15b (see FIG. 12) that will serve as a guide when cutting (processing) the workpiece 11 with the cutting device 2 (registration step S90).

[0122] The mark 15b is a rectangular area of ​​a predetermined size wider than the key pattern 15a, and includes the key pattern 15a and its surrounding area. The mark 15b is used in the alignment process.

[0123] Fig. 12 is a diagram showing an image 46e displayed on the touch panel 54 in the registration step S90. For ease of explanation, in Fig. 12, the mark 15b is surrounded by a dashed rectangular line, and the area surrounded by the dashed rectangular line is shown enlarged outside the image 46e.

[0124] As described above, by going through the first image display process S30 to the deviation correction process S80 and then registering the mark 15b including the key pattern 15a in the controller 56, the degree of inclination of the key pattern 15a in the X-axis direction (or Y-axis direction) can be reduced, thereby reducing the frequency of matching errors in pattern matching in the alignment process.

[0125] In the registration step S90, in addition to registering the mark 15b, the distance in the Y-axis direction from a predetermined position (for example, a point that is a corner) of the key pattern 15a to the planned division line 13a is also stored (ie, registered) in the controller 56.

[0126] The distance in the Y-axis direction from a predetermined position of the key pattern 15a to the intended division line 13a is measured, for example, by moving the microscope camera unit 44 in the Y-axis direction while the guide line 70 is displayed on the touch panel 54.

[0127] After the registration step S90 is completed, the controller 56 rotates the chuck table 14 by 90 degrees. Then, the deviation correction step S80 is similarly performed for the intended division line 13b, and then the registration step S90 is performed.

[0128] After the registration step S90 is completed for both of the planned division lines 13a, 13b (i.e., the teaching step is completed), an alignment step is followed by a cutting step in which the workpiece 11 is actually cut. That is, the orientation adjustment method described in this embodiment is a method for adjusting the orientation of the workpiece 11 that is performed when the workpiece 11 is cut using the cutting device 2.

[0129] (Modification) Next, a modification will be described with reference to Fig. 13 and Fig. 14. Fig. 13 is a diagram showing a modification of the start point position designation process S40. Note that, in Fig. 13 as well, the worker's hand 64 is simplified. Moreover, the hand 64 is not displayed in the first image 46b.

[0130] In the start point position designation process S40 of the modified example, a designated point on the first image 46b arbitrarily designated by the worker (in the example shown in Figure 13, the coordinates of a point designated by the thumb tip of the hand 64) is set as the rotation center 62 of the first image 46b, and the worker then designates a start point position 66 that serves as the starting point for the rotation of the first image 46b.

[0131] 13, the start position 66 is the coordinates of a point specified by the tip of the index finger of the hand 64. The rotation center 62 and the start position 66 that are specified are stored in the controller 56.

[0132] After the rotation center 62 and the start position 66 are specified, an end position specification step S50 is performed. Fig. 14 is a diagram showing a modified example of the end position specification step S50. Specifically, the fingertip of the finger that specified the start position 66 is rotated around the rotation center 62 while being kept in contact with the touch panel 54.

[0133] The position where the fingertip stops is stored in the controller 56 as the end position 68. In this way, the operator specifies the end position 68, which is a position different from the start position 66 and serves as the end point of the rotation around the above-mentioned starting point of rotation center 62. Note that, instead of this, the position where the fingertip leaves the touch panel 54 after rotating around the rotation center 62 may be stored in the controller 56 as the end position 68.

[0134] Second Embodiment Next, a second embodiment will be described with reference to Fig. 15. Fig. 15 is a perspective view of a laser processing device (processing device) 72. In the second embodiment, the laser processing device 72 is used instead of the cutting device 2.

[0135] However, components of the laser processing device 72 that are common to the cutting device 2 are given the same reference numerals as those of the cutting device 2, and descriptions of those components are omitted. Specifically, descriptions of the chuck table 14, microscope camera unit 44, touch panel 54, controller 56, etc. are omitted.

[0136] The laser processing device 72 includes a base 74 that supports each component. An X-axis / Y-axis direction movement mechanism 76 is provided on the upper surface of the base 74. The X-axis / Y-axis direction movement mechanism 76 includes a pair of Y-axis guide rails 78.

[0137] A Y-axis direction moving plate 80 is slidably attached to the upper surface side of the pair of Y-axis guide rails 78. A nut portion (not shown) is provided on the lower surface side of the Y-axis direction moving plate 80, and a screw shaft 82 is rotatably connected to this nut portion via a ball (not shown).

[0138] A driving source 84 such as a pulse motor is connected to one end of the screw shaft 82. When the driving source 84 is operated, the Y-axis direction moving plate 80 moves along the Y-axis direction. The above-mentioned second position sensor (not shown) is provided below the Y-axis direction moving plate 80, and the second position sensor acquires position information of the Y-axis direction moving plate 80.

[0139] A pair of X-axis guide rails 86 are fixed to the upper surface of the Y-axis direction moving plate 80. An X-axis direction moving plate 88 is slidably attached to the upper surface side of the pair of X-axis guide rails 86. A nut portion (not shown) is provided on the lower surface side of the X-axis direction moving plate 88, and a screw shaft 90 is rotatably connected to this nut portion via a ball (not shown).

[0140] A driving source 92 such as a pulse motor is connected to one end of the screw shaft 90. When the driving source 92 is operated, the X-axis direction moving plate 88 moves along the X-axis direction. The above-mentioned first position sensor (not shown) is provided below the X-axis direction moving plate 88, and the first position sensor acquires position information of the X-axis direction moving plate 88.

[0141] A cylindrical table base 94 is provided on the upper surface side of the X-axis direction moving plate 88. The above-mentioned chuck table 14 is provided on the top of the table base 94, and a rotation drive mechanism including a motor and the like that rotates the above-mentioned chuck table 14 about a predetermined rotation axis 14b is provided inside the table base 94.

[0142] A support structure 96 is provided in a predetermined area of ​​the base 4 located behind the X-axis and Y-axis direction movement mechanism 76. The support structure 96 is provided with a Z-axis direction movement mechanism 98. The Z-axis direction movement mechanism 98 has a pair of Z-axis guide rails 100.

[0143] 15 shows only one of the pair of Z-axis guide rails 100. A Z-axis direction moving plate 102 is slidably attached to the pair of Z-axis guide rails 100.

[0144] A nut portion (not shown) is provided on the back side of the Z-axis direction moving plate 102. A screw shaft (not shown) is rotatably connected to the nut portion via a ball (not shown). A driving source 104 such as a pulse motor is connected to the upper end of the screw shaft.

[0145] When the driving source 104 is operated, the Z-axis direction moving plate 102 moves along the Z-axis direction. A support 106 is fixed to the Z-axis direction moving plate 102. The support 106 supports a laser beam irradiation unit 108.

[0146] The laser beam irradiation unit 108 has a laser oscillator (not shown). The laser oscillator has a Nd:YVO4 crystal, a Nd:YAG crystal, or the like as a laser medium. The laser beam irradiation unit 108 has a cylindrical housing 110 whose longitudinal portion is arranged along the Y-axis direction.

[0147] An irradiation head 112 is fixed to the tip of the housing 110. A condenser lens (not shown) and the like are housed in the irradiation head 112. The irradiation head 112 irradiates a pulsed laser beam having a wavelength that is transmitted through the workpiece 11 or absorbed by the workpiece 11 toward the holding surface 14a.

[0148] The above-mentioned microscope camera unit 44 is fixed to a side surface of the housing 110 located near the irradiation head 112 in a manner that allows it to face the holding surface 14a. The housing 110, the irradiation head 112, the microscope camera unit 44, etc. can be moved integrally along the Z-axis direction by a Z-axis direction moving mechanism 98.

[0149] An exterior panel (not shown) is provided above the base 74, and the above-mentioned touch panel 54 is provided on the front surface of the exterior panel. The operations of the chuck table 14, the microscope camera unit 44, the touch panel 54, the X-axis and Y-axis direction moving mechanism 76, the Z-axis direction moving mechanism 98, the laser beam irradiation unit 108, etc. are controlled by a controller 56.

[0150] The auxiliary storage device of the controller 56 in the laser processing device 72 stores a program different from the program required to operate the cutting device 2. However, the program for executing each step described in FIG.

[0151] The direction adjustment method using the laser processing device 72 is also performed according to the procedure shown in Fig. 1. That is, the contents of the first embodiment and its modified examples described above are also applicable to the laser processing device 72.

[0152] Therefore, the worker can intuitively specify the rotation angle α of the first image 46b to adjust the orientation of the workpiece 11. In other words, the orientation of the workpiece 11 can be adjusted without relying on the two key patterns 15a that are too far apart to be simultaneously included within the field of view of the microscope camera unit 44.

[0153] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. For example, the first image display process S30 to the deviation correction process S80 can be applied not only to the teaching process but also to the alignment process.

[0154] In the above embodiment, it is assumed that the microscope camera unit 44 captures an image of the surface 11a of the workpiece 11 exposed upward with visible light. However, when the back surface 11b is exposed upward, the microscope camera unit 44 has a light source capable of irradiating light having a wavelength that transmits the workpiece 11 and a solid-state image sensor capable of photoelectrically converting the light of this wavelength, and captures an image of the surface 11a through the workpiece 11.

[0155] In addition, when the back surface 11b is exposed upward, a holding plate (not shown) formed of substantially transparent glass or the like that transmits visible light may be used instead of the porous plate that constitutes the chuck table 14, and the microscope camera unit 44 may image the front surface 11a from below the holding plate through the holding plate. [Explanation of symbols]

[0156] 2: Cutting equipment (processing equipment), 4: Base, 4a, 4b: Opening 6: Elevator, 8: Cassette 10: table cover, 12: cover member 11: Workpiece, 11a: Front surface, 11b: Back surface 13, 13a, 13b: Planned division lines 14: Chuck table (holding table) 14a: holding surface, 14b: rotation axis, 14c: center point 15: device, 15a: key pattern, 15b: mark 16: clamp unit, 18: support structure 17: dicing tape, 19: annular frame, 21: workpiece unit 20: Y-axis and Z-axis direction movement mechanism 22: Y-axis guide rail, 24: Y-axis direction moving plate, 26: screw shaft 28: Z-axis guide rail, 30: Z-axis direction moving plate, 32: screw shaft 34: Stepping motor, 36: Cutting unit 38: spindle housing, 40: spindle 42: cutting blade, 42a: cutting edge 44: Microscope camera unit (imaging unit) 46: macro camera, 46a: image sensor 46b: first image, 46c: center point, 46d: second image, 46e: image 48: micro camera, 48a: image sensor 52: Spinner cleaning unit 54: touch panel, 56: controller, 58: processor, 60: memory 62: Rotation center, 64: Hand, 66: Start position, 68: End position, 70: Guide line 72: Laser processing device (processing device), 74: Base, 76: X-axis and Y-axis movement mechanism 78: Y-axis guide rail, 80: Y-axis direction moving plate, 82: screw shaft, 84: driving source 86: X-axis guide rail, 88: X-axis direction moving plate, 90: screw shaft, 92: driving source 94: table base, 96: support structure, 98: Z-axis direction movement mechanism 100: Z-axis guide rail, 102: Z-axis direction moving plate, 104: driving source 106: Support, 108: Laser beam irradiation unit 110: housing, 112: irradiation head S10: Reference coordinate storage process, S20: Holding process, S30: First image display process S40: start point position designation step, S50: end point position designation step, S60: image rotation step S70: second image display step, S80: deviation correction step, S90: registration step α: rotation angle, β: angle

Claims

1. 1. An orientation adjustment method for adjusting an orientation of a workpiece held by a holding table of a processing device when a workpiece having a plurality of planned dividing lines set in a lattice pattern on a surface thereof is processed by the processing device, comprising: a holding step of holding the workpiece on a holding surface of the holding table; a first image display step of displaying a first image obtained by imaging the surface of the workpiece held on the holding surface with an imaging unit on a display device; a start point position designation step in which the operator designates a start point position that is a start point for rotation of the first image, with a center point of the first image displayed on the display device or a designated point of the first image arbitrarily designated by an operator as a rotation center of the first image; an end point position designation step in which an operator designates an end point position that is a position different from the start point position and that is an end point of the rotation around the rotation center of the start point; an image rotation step of calculating a rotation angle defined by the start point position and the end point position around the rotation center of the first image and the rotation center of the first image, and rotating the first image by the rotation angle around the rotation center in a direction proceeding from the start point position to the end point position by image processing; a second image display step of adjusting, after the image rotation step, an orientation of the holding table around a rotation axis of the holding table perpendicular to the holding surface based on the rotation angle, so that an orientation of a second image obtained by imaging the workpiece with the imaging unit is made the same as an orientation of the first image after the image rotation step, and displaying the second image on the display device; An orientation adjustment method comprising:

2. 2. The method according to claim 1, wherein in the first image display step, a predetermined identification mark is displayed on the display device as the center of rotation.

3. The orientation adjustment method according to claim 1, characterized in that in the second image display process, the imaged area of ​​the workpiece when obtaining the second image is made the same as the imaged area corresponding to the first image rotated by the rotation angle.

4. The orientation adjustment method according to claim 1, further comprising a misalignment correction process, after the second image display process, moving the imaging unit and the workpiece relatively along a predetermined direction that is parallel to the holding surface while displaying a reference line on the display device, and then rotating the holding table so that the orientations of the reference line and the planned division line coincide with each other.

5. The orientation adjustment method according to any one of claims 1 to 4, further comprising a registration step of registering, in the processing device, a predetermined area of ​​the workpiece obtained by imaging the workpiece with the imaging unit after the second image display step, as a mark that serves as a guide when processing the workpiece with the processing device.

Images