TW201812881A - Cutting method of workpiece - Google Patents

Abstract

Provides a cutting method for a workpiece that can precisely control the depth of cutting of the workpiece by the cutter in a short time.

A method for cutting a workpiece includes: a step of maintaining surface information memory, which uses a moving unit to move a cutting unit mounted with a height measuring device for measuring height, and moves the disk table relative to each other, and moves the coordinates between a plurality of coordinates (X , Y) measure the height (Z) of the holding surface of the pan table, and memorize the relationship between the coordinates (X, Y) and the height (Z) as the information of the holding surface; the thickness information storage step is to measure the thickness of the workpiece, It is memorized as the thickness information; the holding step is to hold the processed object with the thickness information stored on the pan table; the calculation step is to calculate the thickness information at any coordinates (X, Y) from the holding surface information and thickness information The height above the workpiece held by the disk table; and the cutting step, based on the height of the workpiece calculated in the calculation step, causes the cutter to cut into the workpiece held on the disk table to form a desired depth Groove section.

Description

   Cutting method of workpiece   

This invention relates to the cutting method of the to-be-processed object used when cutting a plate-shaped to-be-processed object.

When a plate-like workpiece representing a semiconductor wafer is divided into a plurality of wafers, a cutting device including, for example, a disk table for holding the workpiece and a ring cutter for cutting the workpiece is used. While rotating the cutting blade into the workpiece held by the disk table, the cutter and the disk table are moved relative to each other, and the workpiece is cut along the path of the movement.

In the above-mentioned cutting device, the height of the holding surface of the pan table that is in contact with the workpiece is usually set as the reference (zero point) of the height of the cutting blade. According to this, the height of the cutter can be aligned with the workpiece on the disk table, and the cutter can be cut to the desired depth of the workpiece.

However, in recent years, there has been an increase in the opportunity to provide an insulating film having a low dielectric constant, such as a Low-k film, on the workpiece. Because the Low-k film is fragile, it may peel off in unexpected areas when cutting the workpiece. Then, a method and the like of removing only the Low-k film superimposed on a predetermined cutting line (cutting line, predetermined dividing line) and the like have been developed (for example, refer to Patent Document 1).

In this method, a cutting blade is cut into a Low-k film having a thickness of about several μm, and only the Low-k film that overlaps the planned cutting line is removed from the workpiece. In addition, the holding surface of the disk table also has a height deviation of, for example, several μm or more. In this case, since the cutting depth of the cutting object with respect to the workpiece also varies by the same degree, the above method cannot be appropriately implemented.

In this regard, a method has been proposed in which a cutter is cut into a plurality of positions of a workpiece, and a depth of a groove (cut, notch) for confirmation is formed as a reference, and a method of confirming a cut depth of the cutter is proposed (for example, refer to Patent Documents) 2). If the cutting depth confirmed by this method is used and the height of the cutter is controlled, even if the holding surface of the pan table has a deviation in height, only the thin Low-k film can be cut and removed.

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2015-18965

[Patent Document 2] Japanese Patent Laid-Open No. 2015-142022

However, in the above-mentioned method, since the length of the workpiece must be measured after the plural grooves are formed, the time required until the cutting is completed is greatly increased.

The present invention has been made in view of such a problem, and an object thereof is to provide a cutting method of a workpiece that can control the depth of cutting of a workpiece with a cutting tool with high accuracy in a short time.

According to one aspect of the present invention, a method for cutting a workpiece is provided, which is a method for cutting a workpiece using a cutting device. The cutting device is provided with: a disc table which is held on a holding surface to maintain a plate shape A workpiece; a cutting unit for machining the workpiece held on the disk table by a cutter; a moving unit for X-axis parallel to the holding surface of the disk table and the cutting unit Relative movement in the direction and Y-axis direction, the cutting method of the workpiece includes: a step of maintaining surface information memory, which uses the moving unit to install the cutting unit mounted with a height measuring device for measuring height, and the pan The table moves relative. Measure the height (Z) of the holding surface of the pan table at plural coordinates (X, Y), and memorize the relationship between each coordinate (X, Y) and height (Z) as the information of the holding surface; The thickness information memorizing step is to measure the thickness of the workpiece and memorize it as thickness information; the holding step is to keep the workpiece with the thickness information memorized on the pan table; the calculation step is to calculate from Keep face info and The thickness information calculates the height above the workpiece held by the pan table at any coordinates (X, Y); and the cutting step is based on the height of the workpiece calculated in the calculation step, so that The cutter cuts into the workpiece held on the pan table to form a groove portion of a desired depth.

In one aspect of the present invention, a position information memory step is further provided, which is before the calculating step. In order to image the workpiece, an imaging unit or the height measuring device mounted on the cutting unit is used to detect The coordinates of the outer periphery of the workpiece held by the pan table and the marks formed on the outer periphery or the workpiece are used to memorize position information. In the thickness information memorization step, the plural coordinates (x, y) Measure the thickness (t) of the workpiece, and memorize the relationship between the coordinates (x, y) and thickness (t) as the thickness information. In the calculation step, from the position information and the holding surface information and the For the thickness information, it is better to calculate the height of the upper surface of the workpiece at any coordinates (x, y).

Furthermore, in one aspect of the present invention, the workpiece includes a device including a functional layer laminated on one surface side, and in the cutting step, the cutting is performed along a plurality of cutting lanes that partition the device. It is preferable that the groove is formed by a knife.

In the cutting method of a workpiece related to one aspect of the present invention, the holding surface information obtained by measuring the height (Z) of the holding surface of the pan table at a plurality of coordinates (X, Y), and the measurement is performed. The thickness information obtained from the thickness of the workpiece is calculated at any coordinates (X, Y) to the height above the workpiece to be held on the table, so the cutting depth of the workpiece by the cutter can be controlled with high precision .

Furthermore, in the method for cutting a workpiece related to one aspect of the present invention, since it is not necessary to form a groove portion for confirmation in the workpiece, it can be shortened to a conventional method of forming a groove portion for confirmation. Time required for cutting to complete. In this way, if the cutting method of the workpiece related to one aspect of the present invention is adopted, the cutting depth of the workpiece by the cutting blade can be controlled with high accuracy in a short time.

11‧‧‧Processed

11a‧‧‧ surface (one side, top)

11b‧‧‧Back (the other side, below)

11c‧‧‧Groove

13‧‧‧cut plan line (cut line, split plan line)

15‧‧‧ device

21‧‧‧Protective member

21a‧‧‧ surface

21b‧‧‧Back

31, 33‧‧‧ measuring line

35‧‧‧Horizon

37‧‧‧ area (coordinates)

2‧‧‧ cutting device

4‧‧‧ abutment

4a, 4b, 4c‧‧‧ opening

6‧‧‧ Cassette support

8‧‧‧ Cassette

10‧‧‧X-Axis Mobile Stage

12‧‧‧Dustproof and drip-proof cover

14‧‧‧ 挟 台

16‧‧‧ keep face

18‧‧‧ cutting unit

20‧‧‧ supporting structure

22‧‧‧ cutting unit moving mechanism

24‧‧‧Y-axis guide

26‧‧‧Y-axis moving plate

28‧‧‧Y-axis ball screw

30‧‧‧Y-axis pulse motor

32‧‧‧Z-axis guide

34‧‧‧Z axis moving plate

36‧‧‧Z-axis ball screw

38‧‧‧Z-axis pulse motor

40‧‧‧ Spindle

42‧‧‧Cutter

44‧‧‧ composite measuring unit (height measuring device, camera unit)

46‧‧‧washing unit

48‧‧‧Control unit

48a‧‧‧Memory Department

52‧‧‧Thickness measuring device

54‧‧‧holding table

56‧‧‧ keep face

58‧‧‧Measurer

FIG. 1 (A) is a perspective view schematically showing a configuration example of an object to be processed, and FIG. 1 (B) is a perspective view schematically showing a state where a protective member is adhered to the object to be processed.

FIG. 2 is a diagram schematically showing a configuration example of a cutting device.

FIG. 3 (A) is a side view for explaining a step of holding the surface information, and FIG. 3 (B) is a plan view schematically showing a setting example of a measurement line.

FIG. 4 (A) is a side view for explaining a thickness information memorizing step, and FIG. 4 (B) is a plan view schematically showing a setting example of a measurement line.

FIG. 5 (A) is a side view for explaining the holding step, and FIG. 5 (B) is a top view for explaining the position information storing step.

FIG. 6 (A) is a diagram showing the height (Z) of the holding surface shown in the holding surface information, and FIG. 6 (B) is a diagram showing the thickness (t) of the workpiece shown in the thickness information. FIG. 6 (C) is a diagram showing the height of the surface (upper surface) of the workpiece visually.

Fig. 7 is a plan view schematically showing a cutting step.

With reference to the attached drawings, an embodiment related to one aspect of the present invention will be described. The cutting method of the workpiece related to the present embodiment includes a step of storing surface information storage (refer to FIG. 3 (A) and FIG. 3 (B)), and a step of memory of thickness information (refer to FIG. 4 (A) and FIG. 4 (B). )), Holding step (refer to FIG. 5 (A)), position information storage step (refer to FIG. 5 (B)), calculation step (refer to FIG. 6 (A), FIG. 6 (B), and FIG. 6 (C)) and Cutting step (see Fig. 7).

In the step of memorizing the information of the holding surface, the height (Z) of the holding surface provided on the cutting table of the cutting device is measured at a plurality of coordinates (X, Y), and the relationship between the coordinates (X, Y) and the height (Z) is memorized. As holding information. In the thickness information storing step, the thickness (t) of the workpiece is measured at a plurality of coordinates (x, y), and the relationship between each coordinate (x, y) and the thickness (t) is memorized as thickness information.

In the holding step, the workpiece to be memorized thickness information is held on the pan table. In the position information storage step, the coordinates of the outer periphery of the workpiece held on the pan table and the marks (or marks formed on the workpiece) formed on the outer periphery are detected, Remember location information. In the calculation step, the height above the workpiece is calculated from the position information, the holding surface information, and the thickness information at arbitrary coordinates (X, Y).

In the cutting step, based on the height of the upper surface of the workpiece calculated in the calculation step, the cutting blade is cut into and a groove portion having a desired depth is formed in the workpiece. Hereinafter, the cutting method of the workpiece related to this embodiment will be described in detail.

FIG. 1 (A) is a perspective view schematically showing a configuration example of a workpiece to be cut in this embodiment, and FIG. 1 (B) is a perspective view schematically showing a state where a protective member is adhered to the workpiece. . As shown in FIG. 1 (A), the processed object 11 in this embodiment is a disc-shaped wafer formed using, for example, a semiconductor material such as silicon, and on the surface (one side, upper surface) 11a side, A functional layer (not shown) such as a metal film for wiring or an insulating film (including a low-k film) between insulating wirings is provided.

On the surface 11a side of the workpiece 11 on which the functional layer is provided, predetermined cutting lines (cutting lines, dividing lines) 13 arranged in a grid pattern are divided into a plurality of areas, and devices such as ICs and LSIs are formed in each area 15 . Each device 15 includes the above-mentioned functional layer as a constituent element. That is, the function layer becomes a part of the device 15. Furthermore, a groove 11c (or an orientation plane) is provided on the outer periphery of the workpiece 11 to mark the direction (for example, the crystal orientation) of the workpiece 11 when it is determined.

In addition, in this embodiment, although a disc-shaped wafer made of a semiconductor material such as silicon is used as the processed object 11, the material, shape, structure, and the like of the processed object 11 are not limited. For example, a substrate made of a material such as ceramic, metal, or resin may be used as the workpiece 11. Similarly, the type, number, arrangement, etc. of the devices 15 are not limited.

In addition, the pattern of the device 15 formed on the surface 11a side of the workpiece 11 may be used together with or instead of the groove 11c and the like as the time for determining the direction of the workpiece 11 mark. In this case, it is not always necessary to provide the groove 11c or the like at the outer periphery of the workpiece 11.

As shown in FIG. 1 (B), a protective member 21 is adhered to the back surface (the other surface, the lower surface) 11b side of the workpiece 11. The protective member 21 is a circular thin film (tape) having the same diameter as that of the workpiece 11, and a paste layer having an adhesive force is provided on the surface 21a side. When the protection member 21 is adhered to the workpiece 11, the surface 21a side is brought into close contact with the back surface 11b side of the workpiece 11.

In addition, in this embodiment, although the protective member 21 is stuck on the back surface 11b side of the workpiece 11 to expose the surface 11a side, even when the workpiece 11 is cut from the back surface 11b, etc., it is on the surface 11a side. The protective member 21 may be adhered to expose the back surface 11b side. That is, in this case, the back surface 11b of the workpiece 11 becomes the upper surface, and the front surface 11a becomes the lower surface. In addition, as long as the damage or the like of the workpiece 11 is not a problem, the protection member 21 may not necessarily be adhered to the back surface 11b (or the front surface 11a) of the workpiece 11.

Further, as described above, by cutting the workpiece 11 from the back surface 11b side, the functional layer on the surface 11a side can be left while a groove portion can be formed on the back surface 11b side of the workpiece 11. Accordingly, the method for cutting a workpiece related to the present invention is also effective in a case where the functional layer is to be surely left while other parts of the workpiece 11 are removed.

FIG. 2 is a diagram schematically showing a configuration example of a cutting device 2 used in the embodiment. As shown in FIG. 2, the cutting device 2 includes a base 4 that supports each structure. A rectangular opening 4a is formed at a corner in front of the base table 4, and a raised and lowered cassette support table 6 is provided in the opening 4a. On the cassette support base 6, a cassette 8 capable of accommodating a plurality of workpieces 11 is loaded. In addition, in FIG. 1, for convenience of explanation, only the outline of the cassette 8 is shown.

A rectangular opening 4b having a long X-axis direction (front-rear direction, processing feed direction) is formed on the side of the cassette support base 6. In the opening 4b, an X-axis moving table 10, an X-axis moving mechanism (moving unit) (not shown) for moving the X-axis moving table 10 in the X-axis direction, and a dust-proof and drip-proof cover 12 covering the X-axis moving mechanism are provided. .

The X-axis moving mechanism includes a pair of X-axis guides (not shown) parallel to the X-axis direction, and the X-axis moving table 10 is mounted on the X-axis guide so as to be slidable. A nut portion (not shown) is provided on the lower side of the X-axis moving table 10, and the nut portion is screwed to an X-axis ball screw (not shown) parallel to the X-axis guide.

An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. When the X-axis ball screw is rotated by the X-axis pulse motor, the X-axis moving table 10 moves along the X-axis guide in the X-axis direction.

A disk table 14 is provided above the X-axis moving table 10 to hold the workpiece 11. The disk table 14 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis substantially parallel to the Z-axis direction (vertical direction). The disk table 14 is processed and fed in the X-axis direction together with the X-axis moving table 10 by the X-axis moving mechanism.

The upper surface of the pan table 14 is a holding surface 16 that attracts and holds the workpiece 11. The holding surface 16 is connected to a suction source (not shown) through a suction path or the like formed inside the pan table 14.

A transport unit (not shown) for transporting the workpiece 11 to the disk table 14 is provided at a position close to the opening 4b. The workpiece 11 to be transported by the transport unit is placed on the holding surface 16 of the disk table 14 such that the surface 11 a side is exposed above.

A gate-shaped support structure 20 for supporting two sets of cutting units 18 is disposed on the base 4 so as to span the opening 4b. Two sets of cutting unit moving mechanisms (moving units) 22 that move each cutting unit 18 in the Y-axis direction (left-right direction, indexing feed direction) and the Z-axis direction are provided on the front surface of the support structure 20.

Each of the cutting unit moving mechanisms 22 includes a pair of Y-axis guide rails 24 arranged in front of the support structure 20 and parallel to the Y-axis direction. On the Y-axis guide 24, a Y-axis moving plate 26 constituting each cutting unit moving mechanism 22 is mounted so as to be slidable.

A nut portion (not shown) is provided on the back side (rear side) of each Y-axis moving plate 26, and the nut portion is screwed with a Y-axis ball screw 28 parallel to the Y-axis guide 24. A Y-axis pulse motor 30 is connected to one end of each Y-axis ball screw 28. When the Y-axis ball screw 28 is rotated by the Y-axis pulse motor 30, the Y-axis moving plate 26 moves along the Y-axis guide 24 and moves in the Y-axis direction.

A pair of Z-axis guide rails 32 are provided on the surface (front surface) of each Y-axis moving plate 24 in parallel with the Z-axis direction. On the Z-axis guide rail 32, the Z-axis moving plate 34 is mounted so as to be slidable.

A nut portion (not shown) is provided on the back side (rear side) of each Z-axis moving plate 34, and the nut portion is screwed with a Z-axis ball screw 36 parallel to the Z-axis guide rail 32. A Z-axis pulse motor 38 is connected to one end of each Z-axis ball screw 36. When the Z-axis ball screw 36 is rotated by the Z-axis pulse motor 38, the Z-axis moving plate 34 moves in the Z-axis direction along the Z-axis guide rail 32.

A cutting unit 18 is provided below the respective Z-axis moving plates 34. This cutting unit 18 includes an annular cutting plate 42 attached to one end side of a main shaft 40 (see FIG. 7) serving as a rotation axis. Furthermore, a height measuring device (height measuring unit) for measuring the height of the holding surface 16 and the like of the disk table 14 is mounted on the cutting unit 18, and a camera (imaging unit) for imaging the workpiece 11 and the like is integrated. Composite measuring unit (height measuring unit (height measuring unit), camera (camera unit)) 44.

When the Y-axis moving plate 26 is moved in the Y-axis direction by each cutting unit moving mechanism 22, the cutting unit 18 and the composite measurement unit 44 are indexed and fed in the Y-axis direction together. When the Z-axis moving plate 34 is moved in the Z-axis direction by each cutting unit moving mechanism 22, the cutting unit 18 and the composite measuring unit 44 are raised and lowered together.

A circular opening 4c is formed with respect to the opening 4b at a position opposite to the opening 4a. A cleaning unit 46 is provided in the opening 4c for cleaning the processed object 11 and the like after cutting. The control unit 48 is connected to constituent elements such as the X-axis moving mechanism, the disk table 14, the cutting unit 18, the cutting unit moving mechanism 22, the composite measurement unit 42, and the washing unit 46. Each component is controlled by the control unit 48.

In the method for cutting a workpiece related to this embodiment, first, the height (Z) of the holding surface 16 of the disk table 14 is measured at a plurality of coordinates (X, Y), and each coordinate (X, The relationship between Y) and height (Z) is used as a step of memorizing the retained surface information. FIG. 3 (A) is a side view for explaining a step of storing the face information.

As shown in FIG. 3 (A), the holding surface information storing step is performed using a height measuring device of the composite measuring unit 44 mounted on the cutting unit 18. The height measuring device is, for example, a laser displacement meter that measures the position (height) of the object using the laser beam L1, and can measure the height (Z) of the holding surface 16 of the disk table 14 without contact.

In the step of memorizing the holding surface information, first, the pan table 14 and the composite measurement unit 44 are moved relative to each other, so that the composite measurement unit 44 is moved to the measurement line 31 of the holding surface 16 set in advance (see FIG. 3 (B)) Above. Moreover, as shown in FIG. 3 (A), while the laser beam L1 for measurement is irradiated with the composite measurement unit 44, the pan table 14 and the composite measurement unit 44 are relatively moved along the measurement line 31.

Accordingly, the height (Z) of the holding surface 16 of the disk table 14 can be measured at a plurality of coordinates (X, Y) on the measurement line 31. The relationship between the height (Z) and the coordinates (X, Y) measured by the complex measurement unit 44 is stored in the storage unit 48a of the control unit 48 as the holding surface information. When the height (Z) of the holding surface 16 is measured along all the set measurement lines 31, and the corresponding holding surface information is stored in the storage portion 48a, the holding surface information storing step ends.

FIG. 3 (B) is a plan view schematically showing a setting example of the measurement line 31. In the setting example of FIG. 3 (B), linear measurement lines 31 perpendicular to the X-axis direction (parallel to the Y-axis direction) are respectively set at positions where the X coordinates are X ₁ , X ₂ , and X ₃ . Further, at the positions where the Y coordinates are Y ₁ , Y ₂ , and Y ₃ , linear measurement lines 31 that are perpendicular to the Y-axis direction (parallel to the X-axis direction) are respectively set.

So, for example, if the X coordinate holding surface 16 of the height (Z) measured along the 31 measuring ₁ X line, may be made with respect to a plurality of coordinates (X _1, the Y) 31 on the measurement line height (Z) Information . In addition, in this embodiment, although a total of six measurement lines 31 are set on the holding surface 16, the number, arrangement, and the like of the measurement lines 31 to be set are not limited. The measurement line 31 can be freely set in accordance with the required cutting accuracy and the like.

Furthermore, in this embodiment, the height (Z) of the holding surface 16 is continuously measured along a measurement line 31 set in advance, but even if a plurality of measurement points are set in advance, the height of the holding surface 16 is measured at the measurement point. (Z) Yes. Even in this case, the measurement point can be freely set in accordance with the required cutting accuracy and the like.

After the step of maintaining the surface information, the thickness information storage step of measuring the thickness (t) of the workpiece at a plurality of coordinates (x, y), and memorizing the relationship between each coordinate (x, y) and the thickness (t) as the thickness information is performed. . FIG. 4 (A) is a side view for explaining a step of storing thickness information.

As shown in FIG. 4 (A), the thickness information storage step is performed by using an arbitrary thickness measuring device 52 provided inside or outside the cutting device 2. The thickness measuring device 52 includes a holding table 54 for holding the workpiece 11. The upper surface of the holding table 54 is a holding surface 56 for holding the workpiece 11. The holding surface 56 is flat so that the thickness of the workpiece 11 can be measured with high accuracy.

A measuring device 58 is disposed above the holding table 54. The measuring device 58 is, for example, a laser displacement meter that measures the position (height) of the object using the laser beam L2, and can measure the height of the surface 11a of the workpiece 11 to the holding surface 56 of the holding table 54 (that is, Thickness of workpiece 11 including protective member 21). The measuring device 58 is configured to be able to move relative to the holding table 54. The measuring device 58 may be a contact type micrometer or the like.

In the thickness information memorizing step, the processed object 11 is first placed on the holding table 54 such that the holding surface 56 of the holding table 54 is in contact with the back surface 21 b of the protective member 21 adhered to the processed object 11. As a result, the workpiece 11 is held on the holding table 54 in a state where the workpiece 11 is exposed above on the surface 11 a side.

After the workpiece 11 is held by the holding table 54, the holding table 54 and the measuring device 58 are moved relative to each other, and the measuring device 58 is moved to the measurement line 33 of the workpiece 11 set in advance (see FIG. 4 (B)). Above. As shown in FIG. 4 (A), the laser beam L2 for measurement is irradiated with the measuring device 58, and the disk table 14 and the measuring device 58 are moved relative to each other along the measuring line 33.

Accordingly, the thickness (t) of the workpiece 11 can be measured at a plurality of coordinates (x, y) on the measurement line 33. The relationship between the thickness (t) and the coordinates (x, y) measured by the measuring device 58 is sent to the cutting device 2 in an arbitrary manner, and is stored in the memory portion 48a of the control unit 46 as thickness information. When the thickness (t) of the workpiece 11 is measured along all the set measurement lines 33, and the corresponding thickness information is stored in the storage section 48a, the thickness information storage step ends.

FIG. 4 (B) is a plan view schematically showing a setting example of the measurement line 33. In addition, in FIG. 4 (B), the workpiece 11 uses a unique coordinate system (x-coordinate and y-coordinate). In the setting example of FIG. 4 (B), linear measurement lines 33 that are perpendicular to the x-axis direction (parallel to the y-axis direction) are set at positions where the x coordinates are x ₁ , x ₂ , and x ₃ , for example. Further, at positions where the y coordinates are y ₁ , y ₂ , and y ₃ , linear measurement lines 33 that are perpendicular to the y-axis direction (parallel to the x-axis direction) are respectively set.

So, e.g., when measured along the x coordinate x ₁ of the line 33 is measured when the thickness (t) of the workpiece 11, the thickness can be obtained with respect to a plurality of coordinates (x _1, Y) on the measurement line 33 (t) Information. In addition, in this embodiment, the measurement line 31 set on the holding surface 16 is aligned in the above-mentioned holding surface information storage step, and a total of six measurement lines 33 are set on the surface 11a of the workpiece 11. However, The number and arrangement of the measurement lines 33 to be set are not limited. The measurement line 33 can be freely set in accordance with the required cutting accuracy and the like.

Furthermore, in this embodiment, although the thickness (t) of the workpiece 11 is continuously measured along a measurement line 33 set in advance, even if a plurality of measurement points are set in advance, the workpiece 11 is measured at the measurement point. The thickness (t) is also acceptable. Even in this case, the measurement point can be freely set in accordance with the required cutting accuracy and the like.

After the thickness information storing step, a step of holding the workpiece 11 holding the stored thickness information on the pan table is performed. Fig. 5 (A) is a side view for explaining a holding step. In this holding step, the processing object 11 is placed on the disk table 14 such that the holding surface 16 of the disk table 14 is in contact with the back surface 21 b of the protective member 21 adhered to the processing object 11. Thereafter, the negative pressure of the suction source is applied to the holding surface 16, and the workpiece 11 is sucked and held on the disk table 14 with the surface 11a side exposed above.

After the holding step, the coordinates for detecting the outer periphery of the workpiece 11 held by the disk table 14 and the groove 11c (or, formed on the surface of the workpiece 11) formed on the outer periphery are performed. 11a device 15 pattern, etc.), a location information storage step for storing location information. FIG. 5 (B) is a plan view for explaining a step of memorizing position information.

In the position information storage step, first, the field of view 35 of the camera provided in the composite measurement unit 44 is aligned with an area including the outer periphery of the processed object 11, and the area is imaged by the camera. For example, the imaging performed by a camera is performed at different plural positions while the pan table 14 is rotated. The data of the image formed by the camera is sent to the control unit 48.

The control unit 48 performs edge detection processing on the image sent from the camera, and obtains a curve representing the outer periphery of the object 11 to be processed. After that, the control unit 48 extracts the coordinates of any three points A, B, and C on the curve. The coordinates of three points A, B, and C may be extracted from one image data obtained by one imaging, and even if plural image data obtained from multiple imaging are extracted.

Next, the control unit 48 calculates the coordinates of the intersection of the bisector perpendicular to the line segment connecting the points A and B and the bisector perpendicular to the line segment connecting the points B and C. The coordinates of the intersection point correspond to the coordinates of the center O of the workpiece 11. After calculating the coordinates of the center O (coordinates of the intersection point), the coordinates of the groove 11c are extracted, and a straight line connecting the center O and the groove 11c is calculated, and the angle formed by the center O to an arbitrary reference line parallel to the surface 11a is calculated. θ (not shown).

After calculating the coordinates of the center O (the coordinates of the intersection point) and the angle θ, these are stored in the storage unit 48 a of the control unit 48 as the position information of the processed object 11 on the disk table 14. By using this position information, it is possible to convert the thickness information indicated by the inherent coordinate system (x coordinate and y coordinate) on the workpiece 11 into the coordinate system (X coordinate and Y coordinate).

After the position information storage step, a calculation step of calculating the height of the surface 11a of the workpiece 11 from the position information, the holding surface information, and the thickness information is performed at arbitrary coordinates (X, Y). FIG. 6 (A) is a diagram showing the height (Z) of the holding surface 16 shown in the holding surface information, and FIG. 6 (B) is a diagram showing the thickness of the workpiece 11 shown in the thickness information ( t), and FIG. 6 (C) is a view showing the height of the surface 11a of the workpiece 11 visually.

In addition, FIG. 6 (B) shows the thickness (t) after conversion to the coordinate system of the disk table 14. In addition, in FIG. 6 (A), FIG. 6 (B), and FIG. 6 (C), a reference value of height or thickness is represented by "0", and a numerical value such as "+1", "-1", etc. The amount by which the reference value is offset.

For example, as shown in FIGS. 6 (A) and 6 (B), in the area (coordinates) 37 on the pan table 14, the height of the holding surface 16 is "0", and the thickness of the workpiece 11 is "+" 1". Accordingly, in this region 37, as shown in FIG. 6 (C), the height (t + Z) of the surface 11a of the workpiece 11 is calculated to be "+1" (that is, only higher than the reference value "0" Higher than "1").

In addition, it is also conceivable that the coordinates of the surface information and the coordinates of the thickness information do not correspond. In this case, for example, if the holding surface information (height (Z)) relative to an arbitrary coordinate and the thickness information (thickness (t)) of the nearest coordinate are used, the height of the surface 11a of the workpiece 11 may be calculated. In addition, if the measurement lines 31 and 33 (or measurement points) are set appropriately, the coordinates of the surface information can also be maintained when the workpiece 11 is rotated on the disk table 14 according to the angle θ calculated in the position information storage step. Coordinate with thickness information.

After the calculation step, the height (t + Z) of the surface 11a of the workpiece 11 calculated in the calculation step is performed, and the rotating cutting blade 42 is cut into the workpiece 11 to form a desired depth in the workpiece 11 Cutting step of groove. Fig. 7 is a plan view schematically showing a cutting step.

In this embodiment, the height (t + Z) of the surface 11a of the workpiece 11 is accurately calculated, so that the cutting blade 42 can be cut with high accuracy based on the height (t + Z) of the surface 11a. Accordingly, a groove portion having a desired depth can be formed from the surface 11 a of the workpiece 11 along the planned cutting line 13.

As described above, in the cutting method of the workpiece related to the present embodiment, the holding surface information obtained by measuring the height (Z) of the holding surface 16 of the disk table 14 at a plurality of coordinates (X, Y) , And the thickness information obtained by measuring the thickness (t) of the processed object 11, calculate the height of the surface (upper surface) 11a of the processed object 11 held on the pan table 14 at an arbitrary coordinate (X, Y), Therefore, the cutting depth of the cutting tool 42 into the workpiece 11 can be controlled with high accuracy.

Furthermore, in the method for cutting a workpiece related to this embodiment, since it is not necessary to form a groove portion for confirmation in the workpiece 11, it can be shortened to cutting compared with the conventional method of forming a groove portion for confirmation. The time needed to complete.

In addition, the present invention is not limited to the description of the above-mentioned embodiments, and can be implemented with various changes. For example, in the thickness information memorizing step of the above implementation mode, although the plurality of coordinates (x, y) on the measurement line 33 measures the thickness (t) of the workpiece 11, the thickness deviation of the workpiece 11 is very small. For example, the thickness (t) of one point of the workpiece 11 can be used as the thickness information. In this case, the position information storage step may be omitted.

Furthermore, in the position information storing step of the above embodiment, a camera (imaging unit) provided with the composite measurement unit 44 is used to detect the outer periphery of the workpiece 11 or the groove 11c, etc., but a composite measurement unit may be used. The height measuring device (height measuring unit) included in 44 detects the outer periphery of the workpiece 11 or the groove 11c.

In addition, the structures, methods, and the like related to the above-mentioned embodiments can be appropriately modified and implemented as long as they do not depart from the purpose of the present invention.

Claims (3)

    A cutting method of a workpiece, which is a cutting method of a workpiece using a cutting device, the cutting device includes: a pan table that holds a plate-shaped workpiece on a holding surface; and a cutting unit that performs cutting Knife processing is held on the workpiece of the reel table; a moving unit is a relative movement of the reel table and the cutting unit in X-axis direction and Y-axis direction parallel to the holding surface, the The cutting method of the workpiece includes: a step of maintaining surface information memory, which uses the moving unit to relatively move the cutting unit mounted with a height measuring device for measuring height and the pan table to move relative to the plurality of coordinates ( X, Y) measure the height (Z) of the holding surface of the pan table, memorize the relationship between each coordinate (X, Y) and height (Z) as the holding surface information; the thickness information memory step is to measure the processed The thickness of the object is memorized as the thickness information; the holding step is to keep the workpiece to be memorized with the thickness information on the pan table; the calculation step is to use the holding surface information and the thickness information in any Coordinates (X, Y) The height above the workpiece held by the disk table; and a cutting step based on the height of the workpiece calculated in the calculation step, causing the cutter to cut into the workpiece held on the disk table The object to be processed forms a groove with a desired depth.         The method for cutting a workpiece as described in claim 1 further includes a position information storage step, which is performed before the calculating step. In order to image the workpiece, a camera unit or a height mounted on the cutting unit is used. The measuring device detects the coordinates of the outer periphery of the workpiece held on the pan table, and marks formed on the outer periphery or the upper surface of the workpiece, memorizing position information, and in the thickness information memorizing step, The thickness (t) of the workpiece is measured at a plurality of coordinates (x, y), and the relationship between each coordinate (x, y) and the thickness (t) is memorized as the thickness information. In the calculation step, from the position information and The holding surface information and the thickness information are calculated at any coordinates (X, Y) on the upper surface of the workpiece.         The method for cutting a workpiece according to claim 1 or 2, wherein the workpiece has a device including a functional layer laminated on one surface side, and in the cutting step, a plurality of the devices are divided along the zone. The cutting path forms the groove portion with the cutting blade.