JP7336960B2 - Centering method - Google Patents

Description

The present invention relates to a centering method.

Cutting devices are used to separate workpieces, such as semiconductor wafers, into individual chips (see, for example, US Pat.

Conventionally used cutting devices disclosed in the above-mentioned Patent Documents 1 and 2 are provided with imaging means for capturing an image of a workpiece and detection means for measuring the height of the workpiece. there is In the conventionally used cutting apparatus, the relative positional relationship between the imaging means and the detection means is predetermined as a design value.

JP 2015-112698 A Japanese Patent Application Laid-Open No. 2005-093710

However, the conventionally used cutting apparatus described above has a mounting error in the mounting position of at least one of the imaging means and the detecting means, and the positional relationship determined by design values differs from the actual positional relationship.

For this reason, the conventionally used cutting apparatus described above detects the height of the position recognized from the image obtained by the imaging means by the detection means, even if the height is detected by the detection means. There was a problem that processing according to the height could not be performed accurately.

In order to solve this type of problem, Patent Literature 1 proposes a method of measuring the actual positional relationship between an imaging device and a detection device using a dummy chip. However, the method disclosed in Patent Document 1 requires a dummy chip, which is troublesome.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and its object is to provide a center positioning method that allows an easy grasp of the actual positional relationship between the imaging means and the detecting means.

In order to solve the above-described problems and achieve the object, the centering method of the present invention comprises a circular chuck table for holding a workpiece, X-axis moving means for moving the chuck table in the X-axis direction, imaging means for imaging the workpiece held on the chuck table; first Y-axis moving means for moving the imaging means in the Y-axis direction; and height of the workpiece held on the chuck table. A center positioning method for positioning the detection center of the detection means at the imaging center of the imaging means in an apparatus including detection means for detecting and second Y-axis movement means for moving the detection means in the Y-axis direction. Then, the X-axis moving means and the first Y-axis moving means are operated, and the coordinates (X1, Y1) of the center of the chuck table are obtained based on the image obtained by the imaging means. a central coordinate detecting step of (1), and operating the X-axis moving means and the second Y-axis moving means to obtain the coordinates (X2, Y2) of the center of the chuck table based on the detection result of the detecting means. a second center coordinate detection step, wherein the X coordinate of the center of the chuck table obtained based on the image obtained by the imaging means is defined as X1, and the chuck table obtained based on the detection result of the detection means; The X coordinate of the center is X2, the distance α between the centers is obtained as (X1-X2), and the Y coordinate of the center of the chuck table obtained based on the image obtained by the imaging means is Y1, Y coordinate of the center of the chuck table obtained based on the detection result of the detection means is Y2, and a distance β between the centers is calculated as (Y1-Y2); a center matching step of positioning the detection center of the detection means at the coordinates of X0-α and YO-β when positioned at the coordinates of X0 and Y0, and aligning the imaging center of the imaging means with the detection center of the detection means; , and is characterized by being configured.

In the center positioning method, the first center coordinate detection step includes capturing an image of a feature point on the outer peripheral side of the center of the chuck table with an imaging device to determine the coordinates (X11, Y11) of the feature point, Rotate the chuck table by an arbitrary angle and image the feature point to obtain the coordinates (X12, Y12) of the feature point. Y12), the coordinates of a position that is half the distance between the two coordinates from the center on a linear function orthogonal to the center of the chuck table are obtained as the coordinates (X1, Y1) of the center of the chuck table. In the center coordinate detection step, three or more coordinates of the detection means positioned on the outer circumference of the chuck table where the detection results change suddenly are detected, and the coordinates (X2, Y2) of the center of the chuck table are determined from the three or more detected coordinates. ) may be requested.

In the center positioning method, the first center coordinate detecting step picks up an image of an area including the outer circumference of the chuck table, and detects three or more coordinates of the imaging center of the imaging means positioned on the outer circumference from the picked-up image. , the coordinates (X1, Y1) of the center of the chuck table are determined from the coordinates of the detected three or more points, and the second center coordinate detection step includes the detection means positioned on the outer circumference of the chuck table where the detection result changes suddenly. may be detected at three or more points, and the coordinates (X2, Y2) of the center of the chuck table may be obtained from the detected coordinates at the three or more points.

In the centering method, the imaging means is arranged in a first processing means connected to the first Y-axis movement means, and the detection means is connected to the second Y-axis movement means. It may be arranged in the second processing means.

In the centering method, the first Y-axis moving means and the second Y-axis moving means are one Y-axis moving means, and the imaging means and the detecting means are coupled to the Y-axis moving means. It may be arranged in the processing means.

The present invention produces an effect that the actual positional relationship between the imaging means and the detection means can be easily grasped.

FIG. 1 is a perspective view showing a configuration example of a processing apparatus that implements a centering method according to Embodiment 1. FIG. 2 is a plan view schematically showing the imaging center of the imaging unit of the processing apparatus shown in FIG. 1. FIG. 3 is a plan view schematically showing the detection center of the detection unit of the processing apparatus shown in FIG. 1. FIG. 4 is a plan view showing a coordinate system of an imaging position of an imaging unit and a detection position of a detection unit of the processing apparatus shown in FIG. 1. FIG. FIG. 5 is a flow chart showing the flow of the centering method according to the first embodiment. FIG. 6 is a plan view showing a state in which the image pickup unit picks up an image of a feature point on the holding surface of the chuck table in the first central coordinate detection step shown in FIG. FIG. 7 is a plan view showing a state in which the image pickup unit picks up an image of a characteristic point on the holding surface of the chuck table rotated by a predetermined angle from the state shown in FIG. 6 in the first central coordinate detection step shown in FIG. 8 is a side view schematically showing a state in which the detection unit is moved along the holding surface of the chuck table in the second central coordinate detection step of the positioning method shown in FIG. 5. FIG. 9 is a diagram showing detection results of the detection unit shown in FIG. 8. FIG. 10 is a plan view showing three points on the outer periphery of the chuck table specified by the detection result of the detection unit shown in FIG. 9. FIG. FIG. 11 is a plan view schematically showing a state in which the image capturing unit captures images of three points on the outer periphery of the chuck table in the first center coordinate detection step of the center positioning method according to the second embodiment. FIG. 12 is a perspective view showing a configuration example of a processing apparatus that implements the centering method according to Embodiments 1 and 2. FIG.

A form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. In addition, various omissions, substitutions, or changes in configuration can be made without departing from the gist of the present invention.

[Embodiment 1]
A centering method according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration example of a processing apparatus that implements a centering method according to Embodiment 1. FIG. 2 is a plan view schematically showing the imaging center of the imaging unit of the processing apparatus shown in FIG. 1. FIG. 3 is a plan view schematically showing the detection center of the detection unit of the processing apparatus shown in FIG. 1. FIG. 4 is a plan view showing a coordinate system of an imaging position of an imaging unit and a detection position of a detection unit of the processing apparatus shown in FIG. 1. FIG. FIG. 5 is a flow chart showing the flow of the centering method according to the first embodiment.

(processing equipment)
The centering method according to the first embodiment is performed by a processing apparatus 1 shown in FIG. 1, which is an apparatus. The processing device 1 is a cutting device that cuts a workpiece 200 shown in FIG. In the first embodiment, the workpiece 200 is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer whose base material is silicon, sapphire, gallium, or the like. A workpiece 200 has devices 203 formed in regions partitioned in a grid pattern by a plurality of division lines 202 formed in a grid pattern on a surface 201 .

In addition, the workpiece 200 of the present invention may be a so-called TAIKO (registered trademark) wafer having a thin central portion and a thick outer peripheral portion. A rectangular package substrate having a plurality of elements, a ceramic substrate, a ferrite substrate, or a substrate containing at least one of nickel and iron may be used. In Embodiment 1, the back surface 204 of the workpiece 200 is adhered to an adhesive tape 206 having an annular frame 205 attached to the outer peripheral edge thereof, and is supported by the annular frame 205 .

The processing apparatus 1 shown in FIG. 1 is a cutting apparatus that holds a workpiece 200 on a chuck table 10 and performs cutting (corresponding to machining) with a cutting blade 23 along a dividing line 202 . As shown in FIG. 1 , the processing apparatus 1 includes a chuck table 10 having a circular planar shape that sucks and holds a workpiece 200 on a holding surface 11 , and a cutting blade 23 that cuts the workpiece 200 held by the chuck table 10 . a first cutting unit 21 as a first processing means for cutting, a second cutting unit 22 as a second processing means for cutting the workpiece 200 held by the chuck table 10 with a cutting blade 23, and a chuck table An imaging unit 30 as imaging means for imaging the workpiece 200 held by the chuck table 10, a detection unit 40 as detection means for measuring the height of the workpiece 200 held by the chuck table 10, and a control unit 100. and

The processing apparatus 1 also includes a moving unit 50 that relatively moves the chuck table 10 and the cutting unit 20, as shown in FIG. The movement unit 50 includes an X-axis movement unit 51 that feeds the chuck table 10 in the X-axis direction parallel to the horizontal direction, and a first cutting unit 21 and imaging unit 30 that are parallel to the horizontal direction and orthogonal to the X-axis direction. A first Y-axis moving unit 52 for indexing and feeding in the Y-axis direction, a second Y-axis moving unit 53 for indexing and feeding the first cutting unit 21 and the detection unit 40 in the Y-axis direction, and a first cutting A first Z-axis moving unit 54 for cutting and feeding the unit 21 in the Z-axis direction parallel to the vertical direction perpendicular to both the X-axis direction and the Y-axis direction, and a second cutting unit 22 for cutting in the Z-axis direction. A second Z-axis movement unit 55 for feeding and a rotation movement unit 56 for rotating the chuck table 10 around an axis parallel to the Z-axis direction are provided. As shown in FIG. 1, the processing apparatus 1 is a two-spindle dicer, a so-called facing dual type cutting apparatus, which includes a first cutting unit 21 and a second cutting unit 22 .

The X-axis movement unit 51 moves the chuck table 10 in the X-axis direction, which is the processing feed direction, to thereby relatively feed the chuck table 10 and the cutting unit 20 along the X-axis direction. is. The first Y-axis moving unit 52 moves the first cutting unit 21 and the imaging unit 30 in the Y-axis direction, which is the index feed direction, so that the chuck table 10, the first cutting unit 21, and the imaging unit 30 move. are relatively indexed along the Y-axis direction. The second Y-axis movement unit 53 moves the second cutting unit 22 and the detection unit 40 in the Y-axis direction, which is the index feed direction, so that the chuck table 10, the second cutting unit 22 and the detection unit 40 are moved. is a second Y-axis moving means for relatively indexing and feeding along the Y-axis direction.

The first Z-axis moving unit 54 moves the first cutting unit 21 and the imaging unit 30 in the Z-axis direction, which is the cutting feed direction, so that the chuck table 10, the first cutting unit 21, and the imaging unit 30 move. is a first Z-axis moving means for relatively cutting and feeding along the Z-axis direction. The second Z-axis moving unit 55 moves the second cutting unit 22 and the detection unit 40 in the Z-axis direction, which is the feed direction for cutting, so that the chuck table 10, the second cutting unit 22 and the detection unit 40 move. is a second Z-axis moving means for relatively cutting and feeding along the Z-axis direction.

The X-axis moving unit 51, the Y-axis moving units 52 and 53, and the Z-axis moving units 54 and 55 are a well-known ball screw provided rotatably around the axis, and a known motor for rotating the ball screw around the axis. and known guide rails for supporting the chuck table 10 or the cutting unit 20 so as to be movable in the X-axis direction, the Y-axis direction, or the Z-axis direction.

The chuck table 10 has a disk shape, and a holding surface 11 for holding the workpiece 200 is formed of porous ceramic or the like. In addition, the chuck table 10 is moved in the X-axis direction by the X-axis movement unit 51 over a machining area below the cutting unit 20 and a loading/unloading area separated from the bottom of the cutting unit 20 and where the workpiece 200 is loaded/unloaded. , and is rotatable about an axis parallel to the Z-axis direction by a rotary movement unit 56 . The chuck table 10 is connected to a vacuum suction source (not shown) and is sucked by the vacuum suction source to suck and hold the workpiece 200 placed on the holding surface 11 . In Embodiment 1, the chuck table 10 sucks and holds the back surface 204 side of the workpiece 200 via the adhesive tape 206 .

The first cutting unit 21 and the second cutting unit 22 are cutting means to which a cutting blade 23 for cutting the workpiece 200 held on the chuck table 10 is detachably mounted. The first cutting unit 21 is connected to the first Y-axis movement unit 52 and is movable in the Y-axis direction by the first Y-axis movement unit 52 with respect to the workpiece 200 held on the chuck table 10 . and is movably provided in the Z-axis direction by the first Z-axis moving unit 54 . The first cutting unit 21 is provided on one of the pillars of the gate-shaped support frame 3 erected from the apparatus main body 2 via a first Y-axis movement unit 52, a first Z-axis movement unit 54, and the like. It is

The second cutting unit 22 is connected to the second Y-axis movement unit 53 and is movable in the Y-axis direction by the second Y-axis movement unit 53 with respect to the workpiece 200 held on the chuck table 10 . and is movably provided in the Z-axis direction by the second Z-axis moving unit 55 . The second cutting unit 22 is provided on the other column portion of the support frame 3 via a second Y-axis movement unit 53, a second Z-axis movement unit 55, and the like. Note that the support frame 3 connects the upper ends of the pillars with horizontal beams. The first cutting unit 21 and the second cutting unit 22 can position the cutting blade 23 at any position on the holding surface 11 of the chuck table 10 by Y-axis moving units 52, 53 and Z-axis moving units 54, 55. It has become.

Each cutting unit 21, 22 is moved in the Y-axis direction and the Z-axis direction by a cutting blade 23, which is an ultra-thin cutting wheel having a substantially ring shape, Y-axis movement units 52, 53, and Z-axis movement units 54, 55. A freely provided spindle housing 24 and a spindle which is provided rotatably around an axis in the spindle housing 24 and which serves as a rotating shaft to which a cutting blade 23 is attached at the tip thereof are provided.

The imaging unit 30 is arranged in the first cutting unit 21 . In Embodiment 1, the imaging unit 30 is fixed to the first cutting unit 21 so as to move together with the first cutting unit 21 . The image pickup unit 30 includes a plurality of image pickup elements that pick up images of areas to be divided of the workpiece 200 before cutting held on the chuck table 10 . The imaging device is, for example, a CCD (Charge-Coupled Device) imaging device or a CMOS (Complementary MOS) imaging device. The image pickup unit 30 picks up an image of the workpiece 200 held on the chuck table 10 and produces an image 31 shown in FIG. and outputs the obtained image 31 to the control unit 100 .

In the first embodiment, the image 31 captured by the imaging unit 30 has a rectangular shape whose longitudinal direction is parallel to the Y-axis direction and whose lateral direction is parallel to the X-axis direction, as shown in FIG. The imaging center 32 of the imaging unit 30 is the center of the image 31 in the X-axis direction and the Y-axis direction. The imaging unit 30 faces the position indicating the center of the image 31, which is the imaging center 32, along the Z-axis direction.

The detection unit 40 is arranged in the second cutting unit 22 . In Embodiment 1, the imaging unit 30 is fixed to the second cutting unit 22 so as to move together with the second cutting unit 22 . In the first embodiment, the detection unit 40 is a back pressure sensor that detects the position in the Z-axis direction, which is the height of the workpiece 200 held on the chuck table 10. However, the present invention is limited to the back pressure sensor. A laser displacement meter or a contact sensor may be used instead. The detection unit 40 detects the position in the Z-axis direction, which is the height of the detection center 42 within the detection range 41 shown in FIG. 3, and outputs the detection result to the control unit 100 .

In addition, in Embodiment 1, the detection range 41 of the detection unit 40 is circular as shown in FIG. Further, the detection center 42 of the detection unit 40 is the center of the detection range 41 in the X-axis direction and the Y-axis direction. The detection unit 40 faces the position indicating the detection center 42 along the Z-axis direction.

The processing apparatus 1 also includes an X-axis direction position detection unit 61 for detecting the position of the chuck table 10 in the X-axis direction, and an X-axis direction position detection unit 61 for detecting the positions of the first cutting unit 21 and the imaging unit 30 in the Y-axis direction. A first Y-axis direction position detection unit 62, a second Y-axis direction position detection unit 63 for detecting the positions of the second cutting unit 22 and the detection unit 40 in the Y-axis direction, and a first cutting A first Z-axis direction position detection unit 64 for detecting the Z-axis direction positions of the unit 21 and the imaging unit 30, and a second Z-axis direction position detection unit 64 for detecting the Z-axis direction positions of the cutting unit 22 and the detection unit 40. and a second Z-axis direction position detection unit 65 .

The X-axis direction position detection unit 61 and Y-axis direction position detection units 62 and 63 can be composed of a linear scale parallel to the X-axis direction or the Y-axis direction and a reading head. The Z-axis direction position detection units 64 and 65 detect the Z-axis direction positions of the cutting units 21 and 22 by the pulses of the motors of the Z-axis movement units 54 and 55 . The X-axis direction position detection unit 61, the Y-axis direction position detection units 62 and 63, and the Z-axis direction position detection units 64 and 65 detect the X-axis direction of the chuck table 10, the Y direction of the cutting unit 20, the imaging unit 30, and the detection unit 40. The axial or Z-axis position is output to the control unit 100 .

In the first embodiment, the position in the Z-axis direction is determined by the height from the holding surface 11 of the chuck table 10 with the holding surface 11 as the reference position. Further, in the first embodiment, a coordinate system 301 (hereinafter referred to as a first coordinate system) defined by the X-axis direction and the Y-axis direction of the first cutting unit 21 and the imaging unit 30, and the second cutting unit 22 and the coordinate system 302 in the X-axis direction and the Y-axis direction of the detection unit 40 (hereinafter referred to as a second coordinate system), as shown in FIG. .

In Embodiment 1, the positions of the first cutting unit 21 and the imaging unit 30 in the X-axis direction and the Y-axis direction are defined in advance in the first coordinate system 301 at a reference position 301-1 (an example is shown in FIG. , hereinafter referred to as a first reference position) in parallel with the horizontal directions of the X-axis direction and the Y-axis direction. In addition, the positions of the second cutting unit 22 and the detection unit 40 in the X-axis direction and the Y-axis direction are predetermined reference positions 302-1 in the second coordinate system 302 (an example is shown in FIG. 4, hereinafter referred to as It is determined by the distance parallel to the horizontal direction of the X-axis direction and the Y-axis direction from the second reference position).

The control unit 100 also controls each component of the processing apparatus 1 to cause the processing apparatus 1 to perform processing operations on the workpiece 200 . Note that the control unit 100 includes an arithmetic processing unit having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as ROM (read only memory) or RAM (random access memory), and an input/output unit. A computer having an interface device. The arithmetic processing device of the control unit 100 performs arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the processing device 1 to each of the processing devices 1 through the input/output interface device. Output to a component.

The control unit 100 is connected to a display unit (not shown) composed of a liquid crystal display device for displaying the state of the machining operation, images, etc., and an input unit (not shown) used by the operator to register machining content information. there is The input unit is composed of at least one of a touch panel provided on the display unit and an external input device such as a keyboard.

Further, the control unit 100 includes a central coordinate detection section 101, a coordinate system matching section 102, and a processing control section 103, as shown in FIG. The central coordinate detection unit 101 and the coordinate system matching unit 102 determine the relative relationship between the first coordinate system 301 and the second coordinate system 302 .

The center coordinate detection unit 101 obtains the coordinates (X1, Y1) of the center 12 (shown in FIG. 4) of the chuck table 10 using the image 31 captured by the imaging unit 30 in the first coordinate system 301. is. The center coordinate detection unit 101 uses the detection result of the detection unit 40 in the second coordinate system 302 to locate the chuck positioned at the position where the coordinates (X1, Y1) of the center 12 in the first coordinate system 301 are obtained. The coordinates (X2, Y2) of the center 12 of the table 10 are obtained.

The coordinate system matching unit 102 combines the coordinates (X1, Y1) of the center 12 of the chuck table 10 obtained in the first coordinate system 301 with the coordinates of the center 12 of the chuck table 10 obtained in the second coordinate system 302. The relationship between the first coordinate system 301 and the second coordinate system 302 is obtained from (X2, Y2).

The processing control unit 103 controls the relative position between the imaging center 32 and the lower end of the cutting edge of the cutting blade 23 of the first cutting unit 21, the detection center 42 and the cutting edge of the cutting blade 23 of the second cutting unit 22. A position relative to the bottom edge is stored. The processing control unit 103 uses the relationship between the first coordinate system 301 and the second coordinate system 302 obtained by the coordinate system matching unit 102 and the relative positions stored in advance to obtain images captured by the imaging unit 30. Based on the detected image 31, the detection result of the detection unit 40, and the detection results of the X-axis direction position detection unit 61 and the Y-axis direction position detection units 62 and 63, the imaging center 32 and the detection center 42 are aligned, that is, , each component is controlled so that the position imaged by the imaging unit 30 and the position detected by the detection unit 40 match, and the processing operation of the processing apparatus 1 is controlled.

The functions of the center coordinate detection unit 101, the coordinate system matching unit 102, and the processing control unit 103 are realized by executing a computer program stored in a storage device by an arithmetic processing unit.

(Center positioning method)
The center positioning method is performed when at least one of the chuck table 10, imaging unit 30, and detection unit 40 is newly installed, or when it is replaced due to wear or malfunction. The center positioning method is also a method of positioning the detection center 42 of the detection unit 40 at the imaging center 32 of the imaging unit 30, that is, a method of obtaining the relationship between the first coordinate system 301 and the second coordinate system 302. 30 and the position detected by the detection unit 40 are matched. The centering method is started by the processing apparatus 1 when the control unit 100 receives an instruction to start the centering method from the operator. The center positioning method includes, as shown in FIG. 5, a first center coordinate detection step ST1, a second center coordinate detection step ST2, a distance calculation step ST3 between coordinates, and a center matching step ST4. .

(First central coordinate detection step)
FIG. 6 is a plan view showing a state in which the image pickup unit picks up an image of a feature point on the holding surface of the chuck table in the first central coordinate detection step shown in FIG. FIG. 7 is a plan view showing a state in which the image pickup unit picks up an image of a characteristic point on the holding surface of the chuck table rotated by a predetermined angle from the state shown in FIG. 6 in the first central coordinate detection step shown in FIG.

In the first central coordinate detection step ST1, the X-axis moving unit 51 and the first Y-axis moving unit 52 are operated, and based on the image 31 obtained by the imaging unit 30, This is a step of obtaining the coordinates (X1, Y1) of the center 12 of the chuck table 10. FIG. In the first central coordinate detection step ST1, the operator operates the input unit to operate the X-axis moving unit 51 and the first Y-axis moving unit 52 so that the holding surface 11 can be distinguished from other parts and The feature points 13 on the outer peripheral side of the center 12 are made to face the imaging unit 30 in the Z-axis direction.

In the first central coordinate detection step ST1, the operator operates the input unit to image the characteristic point 13 with the imaging unit 30 as shown in FIG. Then, in the first central coordinate detection step ST1, the central coordinate detection section 101 of the control unit 100 detects the first Coordinates (X11, Y11) of the feature point 13 in the coordinate system 301 of .

In the first central coordinate detection step ST1, the operator operates the input unit to operate the rotary movement unit 56 to rotate the chuck table 10 by an arbitrary predetermined angle θ around the axis as shown in FIG. . Although the predetermined angle θ is 90 degrees in the first embodiment, it is not limited to 90 degrees in the present invention.

In the first central coordinate detection step ST1, the operator operates the input unit to operate the X-axis movement unit 51 and the first Y-axis movement unit 52 to move the feature point 13 on the holding surface 11 to the imaging unit 30. Face each other in the Z-axis direction. In the first central coordinate detection step ST1, the operator operates the input unit to image the characteristic point 13 with the imaging unit 30. FIG. Then, in the first central coordinate detection step ST1, the central coordinate detection section 101 of the control unit 100 detects the first Coordinates (X12, Y12) of the feature point 13 in the coordinate system 301 of .

In the first central coordinate detection step ST1, the central coordinate detection section 101 of the control unit 100 calculates the distance d between the two coordinates (X11, Y11) and the coordinates (X12, Y12) of the feature point 13 using the following equation 1. Use

In the first center coordinate detection step ST1, the center coordinate detection section 101 of the control unit 100 calculates the distance r between the position defined by the coordinates (X11, Y11) and the center 12 of the chuck table 10 using Equation 2 below. ask for

In the first center coordinate detection step ST1, the center coordinate detection section 101 of the control unit 100 uses Equations 3 and 4 below to determine the coordinates (X1, Y1) is obtained.

As described above, the first center coordinate detection step ST1 of the center positioning method according to the first embodiment is performed by determining the center 16 between the obtained coordinates (X11, Y11) of the feature point 13 and the coordinates (X12, Y12) of the feature point 13. and passing through the center 12 and each coordinate (X11, Y11) and coordinate (X12, Y12) The coordinates (X1, Y1) of the center 12 of the chuck table 10 are obtained as the coordinates of the position where the angle between the straight lines 17 and 18 is θ. Thus, in the first center coordinate detection step ST1 of the center positioning method according to the first embodiment, the obtained coordinates (X11, Y11) of the feature point 13 and the coordinates (X12, Y12) of the feature point 13 are orthogonal to each other. 1/2 of the distance d between the two coordinates (X11, Y11) and (X12, Y12) from the center on the linear function to obtain the coordinates (X1, Y1) of the center 12 of the chuck table 10 .

(Second central coordinate detection step)
8 is a side view schematically showing a state in which the detection unit is moved along the holding surface of the chuck table in the second central coordinate detection step of the positioning method shown in FIG. 5. FIG. 9 is a diagram showing detection results of the detection unit shown in FIG. 8. FIG. 10 is a plan view showing three points on the outer periphery of the chuck table specified by the detection result of the detection unit shown in FIG. 9. FIG.

In the second center coordinate detection step ST2, the X-axis movement unit 51 and the second Y-axis movement unit 53 are operated, and based on the detection result of the detection unit 40, the center 12 of the chuck table 10 in the second coordinate system 302 is detected. This is a step of obtaining the coordinates (X2, Y2) of . In the second central coordinate detection step ST2, the operator operates the input unit to operate the X-axis movement unit 51 and the second Y-axis movement unit 53, and holds the detection unit 40 as shown in FIG. While moving along the surface 11, the detection unit 40 detects the position of the holding surface 11 in the Z-axis direction.

Then, in the detection result of the detection unit 40, as shown in FIG. 9, there is a position 19 where the position in the Z-axis direction changes suddenly. The horizontal axis in FIG. 9 indicates the distance in the direction parallel to the holding surface 11 from a predetermined position, and the vertical axis in FIG. 9 indicates the position detected by the detection unit 40 in the Z-axis direction. Also, the vertical axis in FIG. 9 indicates the position upward as it goes upward in FIG. 9 . Note that the position 19 of the detection unit 40 when the detection result suddenly changes corresponds to a position positioned outside the outer edge of the chuck table 10 .

In the second central coordinate detection step ST2, the central coordinate detection section 101 of the control unit 100 determines the positions 19-1 and 19-2 of the detection unit 40 based on the detection result of the detection unit 40 when the detection result suddenly changes. , 19-3 at least three points. In the first embodiment, in the second central coordinate detection step ST2, the central coordinate detection section 101 of the control unit 100, as shown in FIG. -2 and 19-3 are specified at three points, but in the present invention, the specified positions 19-1, 19-2 and 19-3 are not limited to three points.

In the second center coordinate detection step ST2, the center coordinate detection section 101 of the control unit 100 detects the specified three points based on the detection results of the X-axis direction position detection unit 61 and the second Y-axis direction position detection unit 63. The coordinates (X21, Y21) of the position 19-1 in the second coordinate system 302, the coordinates (X22, Y22) of the position 19-2, and the coordinates (X22, Y22) of the position 19-3 are obtained.

Here, let the coordinates (X2, Y2) of the center 12 of the chuck table 10 in the second coordinate system 302 and let R be the radius of a circle passing through the three points 19-1, 19-2, and 19-3. Equation 5 below holds.

In the second central coordinate detection step ST2, the central coordinate detection section 101 of the control unit 100 substitutes coordinates (X21, Y21), (X22, Y22) and (X22, Y22) for X and Y in Equation 5. Then, the coordinates (X2, Y2) of the center 12 of the chuck table 10 in the second coordinate system 302 are obtained.

As described above, the second center coordinate detection step ST2 of the center positioning method according to the first embodiment is performed at the positions 19-1, 19-2, and 19-1, 19-2, and 19-2 of the detection unit 40 positioned on the outer circumference of the chuck table 10 where the detection result changes abruptly. Three or more coordinates (X21, Y21), (X22, Y22) and (X22, Y22) of 19-3 are detected, and coordinates of three or more detected positions 19-1, 19-2, 19-3 ( The coordinates (X2, Y2) of the center 12 of the chuck table 10 in the second coordinate system 302 are obtained from (X21, Y21), (X22, Y22) and (X22, Y22).

(Inter-coordinate distance calculation process)
In the inter-coordinate distance calculation step ST3, the X coordinate of the center 12 of the chuck table 10 in the first coordinate system 301 obtained based on the image 31 captured by the imaging unit 30 is defined as X1, and the detection result of the detection unit 40 is The X coordinate of the center 12 of the chuck table 10 in the second coordinate system 302 obtained based on is determined as X2, and the distance α between the centers 12 is determined as (X1-X2). Y1 is the Y coordinate of the center 12 of the chuck table 10 in the first coordinate system 301 obtained based on the image 31, and the center of the chuck table 10 in the second coordinate system 302 obtained based on the detection result of the detection unit 40. Y2 is the Y coordinate of , and the distance β between the centers 12 is determined as (Y1-Y2). In the inter-coordinate distance calculation step ST3, the coordinate system matching section 102 of the control unit 100 calculates X1-X2 to calculate the distance α, and Y1-Y2 to calculate the distance β.

(Center match process)
In the center matching step ST4, when the imaging center 32 of the imaging unit 30 is positioned at the coordinates of X0 and Y0, the detection center 42 of the detection unit 40 is positioned at the coordinates of X0-α and YO-β, and the imaging of the imaging unit 30 is performed. This is a step of aligning the center 32 with the detection center 42 of the detection unit 40 . In the center matching step ST4, the coordinate system matching section 102 of the control unit 100 sets the coordinates of the imaging center 32 of the imaging unit 30 in the first coordinate system 301 to (X0, Y0), and sets the detection center 42 of the detection unit 40 to the 2 coordinate system is (X02, Y02), the coordinate system of the detection center 42 of the detection unit 40 is changed from the second coordinate system 302 to the first coordinate system using the following formulas 6 and 7: 301.

X02=X0-α (Formula 6)
Y02=Y0-β (Formula 7)

Thus, in the center matching step ST4, the coordinate system matching section 102 of the control unit 100 converts the coordinate system of the detection center 42 of the detection unit 40 from the second coordinate system 302 to the first coordinate system 301, and the imaging unit 30 is positioned at the position of coordinates (X0, Y0), the detection center 42 of the detection unit 40 is positioned at the position of coordinates (X0-α, YO-β). The imaging center 32 of the imaging unit 30 in the coordinate system 301 and the detection center 42 of the detection unit 40 in the second coordinate system 302 are matched. Further, in the center matching step ST4, the coordinate system matching section 102 of the control unit 100 uses Equations 6 and 7 to set either the coordinates (X0, Y0) or the coordinates (X02, Y02) to arbitrary coordinates. Thus, the relationship between arbitrary coordinates (X0, Y0) of the first coordinate system 301 and arbitrary coordinates (X02, Y02) of the second coordinate system 302 is obtained as shown in formulas 6 and 7, End the positioning method.

(Processing operation of processing device)
In the processing apparatus 1 , an operator registers processing content information in the control unit 100 and places the workpiece 200 before cutting processing on the holding surface 11 of the chuck table 10 . After that, the processing apparatus 1 starts the processing operation when the operator gives an instruction to start the processing operation. When starting the processing operation, the processing apparatus 1 suction-holds the rear surface 204 side on the holding surface 11 of the chuck table 10 via the adhesive tape 206 .

In the machining operation, the X-axis movement unit 51 moves the chuck table 10 toward the machining area, the imaging unit 30 images the workpiece 200, and the imaging unit 30 images the image. Alignment is performed based on the image 31 . Also, the detection unit 40 detects the position of the workpiece 200 in the Z-axis direction.

The processing apparatus 1 moves the workpiece 200 and the cutting unit 20 relatively along the dividing lines 202, and causes the cutting blade 23 to cut into each dividing line 202 to cut the workpiece 200 into individual pieces. Divide into devices 203 . When the processing apparatus 1 cuts the workpiece 200 along the dividing line 202, the processing control unit 103 of the control unit 100 uses the above-described Equations 6 and 7 to determine the position and the image captured by the imaging unit 30. The machining operation of the machining device 1 is controlled by controlling each component so that the positions detected by the detection unit 40 match. The processing apparatus 1 cuts all the dividing lines 202 to divide the workpiece 200 into the individual devices 203, and ends the processing operation.

As described above, the center positioning method according to the first embodiment is based on the image 31 captured by the imaging unit 30, the detection result of the detection unit 40, and the detection results of the position detection units 61, 62, and 63. , the relationship between the coordinates (X0, Y0) of the imaging center 32 of the imaging unit 30 and the coordinates (X02, Y02) of the detection center 42 of the detection unit 40 in the first coordinate system 301 can be obtained. The positional relationship between the imaging unit 30 and the detection unit 40 can be grasped in a state in which nothing is placed on the surface. As a result, the center positioning method according to the first embodiment produces an effect that the actual positional relationship between the imaging unit 30 and the detection unit 40 can be easily grasped.

[Embodiment 2]
A centering method according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 11 is a plan view schematically showing a state in which the image capturing unit captures images of three points on the outer periphery of the chuck table in the first center coordinate detection step of the center positioning method according to the second embodiment. In addition, FIG. 11 attaches|subjects the same code|symbol to the same part as Embodiment 1, and abbreviate|omits description. The center positioning method according to the second embodiment is the same as that of the first embodiment except that the first center coordinate detection step ST1 is different from that of the first embodiment.

In the first center coordinate detection step ST1 according to the second embodiment, the operator operates the input unit to operate the X-axis movement unit 51 and the first Y-axis movement unit 52, and the outer circumference of the chuck table 10 is imaged. It faces the unit 30 in the Z-axis direction. In the first central coordinate detection step ST1 according to the second embodiment, the operator operates the input unit to intermittently rotate the chuck table 10 by a predetermined angle using the rotational movement unit 56, and while the chuck table 10 is stopped, the imaging unit At 30, an area 33 including the outer circumference of the chuck table 10 is imaged at three or more locations. In the second embodiment, the imaging unit 30 captures images of the region 33 at three locations, but the present invention is not limited to three locations.

In the first central coordinate detection step ST1 according to the second embodiment, the central coordinate detection section 101 of the control unit 100 performs detection based on the detection results of the X-axis direction position detection unit 61 and the first Y-axis direction position detection unit 62. , the coordinates (X13, Y13) of the position 32-1 of the imaging center 32, the coordinates (X14, Y14) of the position 32-2, and the coordinates (X15, Y15) is obtained.

In the first central coordinate detection step ST1 according to the second embodiment, the central coordinate detection unit 101 of the control unit 100 assigns coordinates (X13, Y13), (X14, Y14) and (X15, Y15), the coordinates (X1, Y1) of the center 12 of the chuck table 10 in the first coordinate system 301 are obtained.

As described above, the first center coordinate detection step ST1 of the center positioning method according to the second embodiment picks up an image of the area including the outer circumference of the chuck table 10, and picks up the image of the imaging unit 30 positioned on the outer circumference from the picked up image 31. Three or more coordinates (X13, Y13), (X14, Y14) and (X15, Y15) of the center 32 are detected, and coordinates of the detected three or more points (X13, Y13), (X14, Y14) and (X15, Y15), the coordinates (X1, Y1) of the center 12 of the chuck table 10 are obtained.

In the center positioning method according to the second embodiment, the imaging unit 30 and The positional relationship of the detection units 40 can be grasped. As a result, the center positioning method according to the first embodiment has the effect that the actual positional relationship between the imaging unit 30 and the detection unit 40 can be easily grasped, as in the first embodiment.

[Modification]
A centering method according to modifications of Embodiments 1 and 2 of the present invention will be described with reference to the drawings. FIG. 12 is a perspective view showing a configuration example of a processing apparatus that implements the centering method according to Embodiments 1 and 2. FIG. In addition, FIG. 12 attaches|subjects the same code|symbol to the same part as Embodiment 1, and abbreviate|omits description.

As shown in FIG. 12, the center positioning method according to the modification includes a cutting unit 21-1, a Y-axis moving unit 52-1, a Z-axis moving unit 54-1, a Y-axis direction position detection unit 62-1, a Z-axis It is the same as Embodiment 1 except that the processing device 1-1, which is a device having only one direction position detection unit 64-1 and the detection unit 40 is arranged in the cutting unit 21-1, performs .

The cutting unit 21-1 of the processing apparatus 1-1 shown in FIG. 12 has the same configuration as the first cutting unit 21 of the first embodiment, etc. The configuration is the same as the one Y-axis movement unit 52, the Z-axis movement unit 54-1 has the same configuration as the first Z-axis movement unit 54 of the first embodiment, etc., and the Y-axis direction position detection unit 62 -1 has the same configuration as the first Y-axis direction position detection unit 62 of the first embodiment, etc., and the Z-axis direction position detection unit 64-1 is the first Z-axis direction position detection unit of the first embodiment, etc. It has the same configuration as unit 64 .

Thus, in the modified example, the first Y-axis moving unit 52 and the second Y-axis moving unit 53 are a Y-axis moving unit 52-1 that is one Y-axis moving means, and the imaging unit 30 and the detection unit 40 are , the cutting unit 21-1, which is a processing means connected to the Y-axis moving unit 52-1.

The center positioning method according to the modification is based on the image 31 captured by the imaging unit 30, the detection result of the detection unit 40, and the detection results of the position detection units 61, 62, and 63. The positional relationship of the units 40 can be grasped. As a result, the center positioning method according to the first embodiment has the effect that the actual positional relationship between the imaging unit 30 and the detection unit 40 can be easily grasped, as in the first embodiment.

In addition, this invention is not limited to the said embodiment. That is, various modifications can be made without departing from the gist of the present invention.

1, 1-1 processing equipment (equipment)
10 chuck table 12 center 13 characteristic point 21 first cutting unit (first processing means)
21-1 Cutting unit (processing means)
22 second cutting unit (second processing means)
30 imaging unit (imaging means)
31 image 32 imaging center 40 detection unit (detection means)
42 detection center 51 X-axis movement unit (X-axis movement means)
52 first Y-axis movement unit (first Y-axis movement means)
52-1 Y-axis movement unit (Y-axis movement means)
53 Second Y-axis movement unit (second Y-axis movement means)
200 work piece ST1 first central coordinate detection step ST2 second central coordinate detection step ST3 inter-coordinate distance calculation step ST4 center matching step

Claims (5)

a circular chuck table that holds the workpiece;
X-axis moving means for moving the chuck table in the X-axis direction;
imaging means for imaging the workpiece held on the chuck table;
a first Y-axis moving means for moving the imaging means in the Y-axis direction;
detection means for detecting the height of the workpiece held on the chuck table;
a second Y-axis movement means for moving the detection means in the Y-axis direction,
A center positioning method for positioning the detection center of the detection means at the imaging center of the imaging means,
A first center for obtaining the coordinates (X1, Y1) of the center of the chuck table based on the image obtained by operating the X-axis moving means and the first Y-axis moving means and imaging by the imaging means. a coordinate detection step;
a second center coordinate detecting step of operating the X-axis moving means and the second Y-axis moving means to obtain coordinates (X2, Y2) of the center of the chuck table based on the detection result of the detecting means; ,
Let X1 be the X coordinate of the center of the chuck table obtained based on the image obtained by the imaging means, and X2 be the X coordinate of the center of the chuck table obtained based on the detection result of the detection means, While obtaining the distance α between the centers as (X1-X2),
Y1 is the Y coordinate of the center of the chuck table obtained based on the image obtained by the imaging means, and Y2 is the Y coordinate of the center of the chuck table obtained based on the detection result of the detection means, A coordinate distance calculation step of obtaining the distance β between the centers as (Y1-Y2);
When the imaging center of the imaging means is positioned at the coordinates of X0 and Y0, the detection center of the detection means is positioned at the coordinates of X0-α and YO-β, and the imaging center of the imaging means and the detection center of the detection means are positioned. a center matching step of matching with
A centering method comprising: The first central coordinate detection step includes:
capturing an image of a feature point on the outer peripheral side of the center of the chuck table with an image capturing means to obtain the coordinates (X11, Y11) of the feature point;
Rotating the chuck table by an arbitrary angle and imaging the feature point to determine the coordinates (X12, Y12) of the feature point,
The coordinates of a position that is half the distance between the coordinates (X11, Y11) of the feature point and the coordinates (X12, Y12) of the feature point obtained from the center on the linear function orthogonal to the center of the coordinates of the feature point (X11, Y11) and the coordinates of the feature point (X12, Y12) Obtained as coordinates (X1, Y1) of the center of the chuck table,
The second central coordinate detection step includes:
Detecting coordinates of three or more points of the detecting means positioned on the outer circumference of the chuck table where the detection result changes suddenly,
2. A center positioning method according to claim 1, wherein the coordinates (X2, Y2) of the center of said chuck table are determined from the detected coordinates of three or more points. The first central coordinate detection step includes:
capturing an image of an area including the outer circumference of the chuck table, detecting three or more coordinates of the imaging center of the imaging means positioned on the outer circumference from the captured image;
obtaining the coordinates (X1, Y1) of the center of the chuck table from the detected coordinates of the three or more points;
The second central coordinate detection step includes:
Detecting coordinates of three or more points of the detecting means positioned on the outer circumference of the chuck table where the detection result changes suddenly,
2. A center positioning method according to claim 1, wherein the coordinates (X2, Y2) of the center of said chuck table are determined from the detected coordinates of three or more points. The imaging means is arranged in a first processing means connected to the first Y-axis moving means,
2. The centering method according to claim 1, wherein said detecting means is arranged in a second processing means connected to said second Y-axis moving means. The first Y-axis moving means and the second Y-axis moving means are one Y-axis moving means,
2. The centering method according to claim 1, wherein said imaging means and said detecting means are disposed in processing means coupled to said Y-axis moving means.

Images