JP2024035879A - Workpiece cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a workpiece cutting method capable of improving processing efficiency.

SOLUTION: A workpiece cutting method for cutting a workpiece by a cutting blade comprises: a first fixing step of fitting the cutting blade to a first blade mount mounted to a tip of a first spindle; a correction step of correcting a shape of the cutting blade so as to keep variations in a distance from a rotary shaft of the first spindle to an outer peripheral edge of the cutting blade within a permissible range by dressing the cutting blade fixed to the first blade mount; a removing step of removing the cutting blade from the first blade mount; a second fixing step of fixing the cutting blade to a second blade mount mounted to a tip of a second spindle so as to match a positional relationship between the cutting blade and the second blade mount with that between the cutting blade and the first blade mount in the first fixing step; and a cutting step of cutting the workpiece by the cutting blade fixed to the second blade mount.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a method for cutting a workpiece by cutting the workpiece with a cutting blade.

By dividing a wafer on which a plurality of devices are formed into individual pieces, device chips including devices are manufactured. Furthermore, a package substrate is formed by covering and sealing a plurality of device chips mounted on a mounting substrate with a resin layer (molding resin). By dividing this package substrate into individual pieces, a package device including a plurality of packaged device chips is manufactured. Device chips and package devices are incorporated into various electronic devices such as mobile phones and personal computers.

A cutting device is used to divide workpieces such as wafers and package substrates. The cutting device includes a chuck table that holds a workpiece, and a cutting unit that performs cutting on the workpiece. The cutting unit has a built-in spindle, and a blade mount is attached to the tip of the spindle. The workpiece is cut and divided by fixing an annular cutting blade to the blade mount and cutting into the workpiece while rotating the cutting blade.

The blade mount includes a disc-shaped flange portion that supports the cutting blade, and a cylindrical support shaft (boss portion) that protrudes from the flange portion. The cutting blade is mounted so that the support shaft is inserted into an opening (through hole) provided in the center of the cutting blade, and is fixed to the blade mount with a fixing nut. At that time, a method of positioning the cutting blade concentrically with the blade mount by injecting gas such as air from the support shaft (see Patent Document 1) or applying ultrasonic vibration to the support shaft (see Patent Document 2) is sometimes used.

When machining a workpiece with a cutting blade, dressing is performed to intentionally wear the tip of the cutting blade for the purpose of modifying the shape of the cutting blade and ensuring its sharpness. For example, dressing is performed by cutting a dressing board with a cutting blade (see Patent Document 3).

The cutting blade includes abrasive grains and a binding material that fixes the abrasive grains. When dressing is performed, the binding material at the tip of the cutting blade comes into contact with the dressing board and wears out. As a result, the abrasive grains are appropriately exposed from the bonding material (sharpening), and the shape of the cutting blade is adjusted so that the distance from the rotation axis of the spindle to the outer periphery of the cutting blade is constant (truing).

Japanese Patent Application Publication No. 9-314465 Japanese Patent Application Publication No. 2010-253600 Japanese Patent Application Publication No. 2006-218571

When the cutting blade continues cutting the workpiece, the cutting blade gradually wears out. Therefore, used cutting blades are replaced with new cutting blades at a predetermined frequency. After the cutting blade is replaced, dressing is performed prior to cutting the workpiece, and the new cutting blade is sharpened and trued.

If dressing is performed every time the cutting blade is replaced as described above, processing of the workpiece will be frequently interrupted and processing efficiency will decrease. Therefore, a method is being considered in which a large number of cutting blades are dressed and stored in advance, and when the cutting blades are replaced, the dressed cutting blades are attached to the blade mount as new cutting blades. By adopting this method, it is expected that machining of a workpiece can be started immediately after a new cutting blade is attached to the blade mount.

However, in order to smoothly attach the cutting blade to the blade mount, the diameter of the opening provided in the cutting blade is set to be slightly larger than the diameter of the support shaft of the blade mount (for example, approximately 5 μm or more and 10 μm or less). Therefore, when the cutting blade is attached to the blade mount for dressing, the position of the cutting blade relative to the blade mount varies, and the rotational axis of the spindle and the center position of the cutting blade often do not perfectly match. . If you continue dressing in this state, the distance from the spindle rotation axis to the outer periphery of the cutting blade will be constant, but the distance from the center of the opening of the cutting blade to the outer periphery of the cutting blade will vary, and after dressing. The cutting blade becomes eccentric.

When a new cutting blade is mounted on a blade mount in an eccentric state when processing a workpiece, the distance from the rotation axis of the spindle to the outer periphery of the cutting blade is not necessarily constant. That is, when a new cutting blade is installed, sharpening has been completed, but truing is incomplete. Therefore, after installing the cutting blade, it is necessary to perform dressing for truing again. As a result, even if the dressing is performed in advance, cutting of the workpiece cannot be started promptly, and a decrease in processing efficiency cannot be effectively suppressed.

The present invention has been made in view of this problem, and an object of the present invention is to provide a method for cutting a workpiece that can improve processing efficiency.

According to one aspect of the present invention, there is provided a method for cutting a workpiece by cutting the workpiece with a cutting blade, the cutting blade being fixed to a first blade mount attached to the tip of a first spindle. 1 fixing step and, after the first fixing step, dressing the cutting blade fixed to the first blade mount, thereby reducing the variation in the distance from the rotation axis of the first spindle to the outer periphery of the cutting blade. a modification step of modifying the shape of the cutting blade so that the shape of the cutting blade falls within an acceptable range; a removal step of removing the cutting blade from the first blade mount after the modification step; and a removal step of removing the cutting blade from the first blade mount after the modification step; The cutting blade is mounted on a second blade mount attached to the tip of the cutting blade, and the positional relationship between the cutting blade and the second blade mount is the positional relationship between the cutting blade and the first blade mount in the first fixing step. and a cutting step of cutting the workpiece with the cutting blade fixed to the second blade mount after the second fixing step. A cutting method is provided.

Note that the first spindle and the second spindle may be mounted on different cutting devices. Further, in the first fixing step and the second fixing step, the cutting blade may be fixed in a predetermined direction based on a mark attached to the cutting blade.

Further, the first blade mount and the second blade mount may include a support shaft that supports the inner peripheral edge of the cutting blade, and in the first fixing step and the second fixing step, the support shaft is The cutting blade may be fixed while injecting gas toward the inner peripheral edge of the cutting blade. Further, the first blade mount and the second blade mount may include a support shaft that supports the inner peripheral edge of the cutting blade, and in the first fixing step and the second fixing step, the support shaft is attached to the support shaft. The cutting blade may be fixed while applying ultrasonic vibration.

In the method for cutting a workpiece according to one aspect of the present invention, the positional relationship between the cutting blade and the first blade mount when dressing the workpiece, and the positional relationship between the cutting blade and the second blade mount when cutting the workpiece are determined. Match the positional relationship. As a result, the state of the cutting unit immediately after truing is performed on the cutting blade is reproduced in the cutting unit that cuts the workpiece. As a result, it becomes possible to immediately start cutting the workpiece after the cutting blade is attached, improving processing efficiency.

It is a perspective view showing a cutting device. FIG. 2(A) is a perspective view showing the cutting unit, and FIG. 2(B) is a side view showing the cutting unit. It is a flowchart which shows the cutting method of a workpiece. FIG. 4(A) is a perspective view showing the first cutting unit with the cutting blade attached to the first blade mount, and FIG. 4(B) is a perspective view of the first cutting unit with the cutting blade attached to the first blade mount. FIG. 4C is a side view showing the first cutting unit, and FIG. 4C is a front view showing the first cutting unit with the cutting blade attached to the first blade mount. FIG. 5(A) is a perspective view showing the first cutting unit with the cutting blade fixed to the first blade mount, and FIG. 5(B) is a perspective view of the first cutting unit with the cutting blade fixed to the first blade mount. FIG. 1 is a side view showing one cutting unit. FIG. 6(A) is a perspective view showing the first cutting unit in the correction step, and FIG. 6(B) is a side view showing the first cutting unit in the correction step. FIG. 7(A) is a perspective view showing the first cutting unit in the removing step, and FIG. 7(B) is a side view showing the first cutting unit in the removing step. FIG. 8(A) is a perspective view showing the second cutting unit with the cutting blade attached to the second blade mount, and FIG. 8(B) is a perspective view of the second cutting unit with the cutting blade attached to the second blade mount. FIG. 8(C) is a side view showing the second cutting unit, and FIG. 8(C) is a front view showing the second cutting unit with the cutting blade attached to the second blade mount. FIG. 9(A) is a perspective view showing the second cutting unit with the cutting blade fixed to the second blade mount, and FIG. 9(B) is a perspective view of the second cutting unit with the cutting blade fixed to the second blade mount. FIG. 2 is a side view showing two cutting units. FIG. 10(A) is a perspective view showing the second cutting unit in the cutting step, and FIG. 10(B) is a side view showing the second cutting unit in the cutting step. FIG. 11(A) is a perspective view showing a cutting unit that injects gas from the blade mount toward the inner periphery of the cutting blade, and FIG. 11(B) shows injecting gas from the blade mount toward the inner periphery of the cutting blade. It is a front view showing a cutting unit. FIG. 12(A) is a perspective view of a cutting unit that applies ultrasonic vibration to the blade mount, and FIG. 12(B) is a front view of the cutting unit that applies ultrasonic vibration to the blade mount.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a configuration example of a cutting device that can be used to implement the method for cutting a workpiece according to the present embodiment will be described. FIG. 1 is a perspective view showing a cutting device 2 that cuts a workpiece 11. As shown in FIG. In FIG. 1, the X-axis direction (processing feed direction, first horizontal direction, left-right direction) and the Y-axis direction (indexing feed direction, second horizontal direction, front-rear direction) are directions perpendicular to each other. Further, the Z-axis direction (height direction, vertical direction, up-down direction) is a direction perpendicular to the X-axis direction and the Y-axis direction.

The cutting device 2 includes a base 4 that supports or accommodates each component that constitutes the cutting device 2. A cover 6 is provided above the base 4 to cover the upper surface side of the base 4. A space (processing chamber) in which the workpiece 11 is cut is provided inside the cover 6 .

A cutting unit 8 is provided in the processing chamber inside the cover 6. A cutting blade 10, which is an annular processing tool for cutting a workpiece 11, is attached to the cutting unit 8. Further, a moving unit (not shown) is connected to the cutting unit 8. The moving unit is configured by, for example, a ball screw type moving mechanism, and moves the cutting unit 8 along the Y-axis direction and the Z-axis direction.

A chuck table (holding table) 12 that holds a workpiece 11 is provided below the cutting unit 8 . The upper surface of the chuck table 12 is a flat surface that is generally parallel to a horizontal plane (XY plane), and constitutes a holding surface 12a that holds the workpiece 11. The holding surface 12a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), etc. formed inside the chuck table 12. When the workpiece 11 is placed on the holding surface 12a and a suction force (negative pressure) from a suction source is applied to the holding surface 12a, the workpiece 11 is suctioned and held by the chuck table 12.

A moving unit (not shown) and a rotational drive source (not shown) are connected to the chuck table 12. The moving unit is constituted by, for example, a ball screw type moving mechanism, and moves the chuck table 12 along the X-axis direction. Also. The rotational drive source is constituted by a motor or the like, and rotates the chuck table 12 around a rotation axis that is generally parallel to the Z-axis direction. Further, a plurality of clamps 14 for fixing the workpiece 11 are provided around the chuck table 12.

A cassette elevator 16 is installed at the front corner of the base 4. A cassette 18 that can accommodate a plurality of workpieces 11 is arranged on the cassette elevator 16 . The cassette elevator 16 adjusts the height of the cassette 18 so that the workpiece 11 can be carried out from the cassette 18 or loaded into the cassette 18 appropriately.

A display unit (display section, display device) 20 that displays various information regarding the cutting device 2 is provided on the front surface 6a side of the cover 6. For example, a touch panel display is used as the display unit 20. In this case, the display unit 20 also functions as an input unit (input unit, input device) for inputting various information to the cutting device 2, and the operator can input information such as processing conditions to the cutting device 2 by touching the display unit 20. Can enter information. That is, the display unit 20 functions as a user interface.

Each component (cutting unit 8, chuck table 12, cassette elevator 16, display unit 20, etc.) constituting the cutting device 2 is connected to a controller (control unit, control section, control device) 22. The controller 22 controls the operation of the cutting device 2 by outputting control signals to each component of the cutting device 2.

For example, the controller 22 is configured by a computer and includes a calculation section that performs calculations necessary for the operation of the cutting device 2 and a storage section that stores various information (data, programs, etc.) used for the operation of the cutting device 2. . The arithmetic unit includes a processor such as a CPU (Central Processing Unit). Further, the storage unit is configured to include memories such as ROM (Read Only Memory) and RAM (Random Access Memory).

When cutting the workpieces 11 with the cutting device 2, first, the plurality of workpieces 11 are housed in a cassette 18, and the cassette 18 is set on a cassette elevator. Then, the workpiece 11 is transported from the cassette 18 to the chuck table 12 by a transport mechanism (not shown), and is held by the chuck table 12. Thereafter, the workpiece 11 is cut by the cutting blade 10 attached to the cutting unit 8. The workpiece 11 after cutting is transported again by the transport mechanism and is housed in the cassette 18 .

FIG. 2(A) is a perspective view showing the cutting unit 8, and FIG. 2(B) is a side view showing the cutting unit 8. An annular cutting blade 10 is attached to the cutting unit 8 . A circular opening (through hole) 10a that penetrates the cutting blade 10 in the thickness direction is provided in the center of the cutting blade 10. Inside the opening 10a, an inner peripheral edge (inner wall) 10b of the cutting blade 10 is exposed.

For example, as the cutting blade 10, a hub-type cutting blade (hub blade) is used. The hub blade includes an annular hub base made of metal or the like, and an annular cutting blade formed along the outer periphery of the hub base, and an opening 10a is provided in the hub base. The cutting edge of the hub blade is composed of an electroformed grindstone that includes abrasive grains made of diamond or the like and a binding material such as a nickel plating layer that fixes the abrasive grains. However, there are no restrictions on the materials of the abrasive grains and binding material.

Moreover, a washer type cutting blade (washer blade) can also be used as the cutting blade 10. The washer blade is composed only of an annular cutting edge in which abrasive grains made of diamond or the like are fixed by a binding material made of metal, ceramics, resin, or the like.

As shown in FIG. 2(A), a mark 10c indicating the direction (angle) of the cutting blade 10 is attached to the cutting blade 10. For example, the mark 10c is printed, pasted, or coated on the surface side of the hub base of the cutting blade 10. However, as long as it is possible to indicate the direction of the cutting blade 10, there is no limit to the form of the mark 10c. For example, although FIG. 2A shows an example in which a polygonal (triangular) mark 10c is attached to the cutting blade 10, the mark 10c may be a circular or oval mark, or an arrow or It may be a scale.

The cutting unit 8 includes a cylindrical housing 30, and the housing 30 accommodates a cylindrical spindle 32 (see FIG. 2(B)) arranged along the Y-axis direction. The tip (one end) of the spindle 32 is exposed outside the housing 30, and the base end (other end) of the spindle 32 is connected to a rotational drive source (not shown) such as a motor. When the rotational drive source is driven, the spindle 32 rotates around a rotation axis 32a that is generally parallel to the Y-axis direction.

A blade mount 34 is attached to the tip of the spindle 32. For example, the blade mount 34 is fixed to the tip of the spindle 32 with a fastening bolt or the like, and is integrated with the spindle 32.

The blade mount 34 includes a disk-shaped flange portion 36 and a cylindrical support shaft (boss portion) 38 protruding from the center of the surface 36a of the flange portion 36. The outer peripheral part of the flange part 36 supports the back side of the cutting blade 10, and the support shaft 38 supports the inner peripheral edge 10b of the cutting blade 10. Further, a male threaded portion (thread groove, not shown) is formed on the outer circumferential surface of the tip end of the support shaft 38.

An annular fixing nut 40 is fastened to the support shaft 38 . A circular opening (through hole) 40a passing through the fixing nut 40 in the thickness direction is provided in the center of the fixing nut 40. The opening 40a is formed to have approximately the same diameter as the support shaft 38. Furthermore, a female threaded portion (thread groove, not shown) corresponding to the male threaded portion of the support shaft 38 is formed on the inner peripheral edge of the fixing nut 40 exposed through the opening 40a.

When the cutting blade 10 is positioned so that the support shaft 38 is inserted into the opening 10a of the cutting blade 10, the cutting blade 10 is mounted on the blade mount 34. When the fixing nut 40 is fastened to the support shaft 38 in this state, the cutting blade 10 is held between the flange portion 36 and the fixing nut 40. Thereby, the cutting blade 10 is fixed to the blade mount 34.

The cutting blade 10 rotates around the rotation axis 32a of the spindle 32 by power transmitted from a rotational drive source via the spindle 32 and the blade mount 34. Then, while rotating the cutting blade 10, the tip of the cutting blade 10 is cut into the workpiece 11 (see FIG. 1) held by the chuck table 12 (see FIG. 1), thereby cutting the workpiece 11. Be cut.

Next, a specific example of a method of cutting the workpiece 11 using the cutting device 2 will be described. FIG. 3 is a flowchart showing a method for cutting a workpiece. In the method for cutting a workpiece according to the present embodiment, the cutting blade 10 is dressed, and then the workpiece 11 is cut with the cutting blade 10. As an example, a case will be described below in which dressing the cutting blade 10 and cutting the workpiece 11 are performed using different cutting devices 2.

In addition, in FIGS. 4(A) to 7(B), the cutting unit 8 (first cutting unit) mounted on the cutting device 2 (first cutting device) that performs dressing of the cutting blade 10, the spindle 32 (first spindle), blade mount 34 (first blade mount), flange portion 36 (first flange portion), and support shaft 38 (first support shaft) are designated by symbols 8A, 32A, 34A, 36A, and 38A, respectively. are doing. In addition, in FIGS. 8(A) to 10(B), a cutting unit 8 (second cutting unit) mounted on a cutting device 2 (second cutting device) that performs cutting on a workpiece 11, The spindle 32 (second spindle), blade mount 34 (second blade mount), flange portion 36 (second flange portion), and support shaft 38 (second support shaft) have symbols 8B, 32B, 34B, 36B, and 38B, respectively. is attached.

In this embodiment, first, a blade mount 34A (first blade) is attached to the tip of a spindle 32A (first spindle) mounted on a cutting device 2 (first cutting device) that performs dressing of the cutting blade 10. The cutting blade 10 is fixed to the mount (first fixing step S1). In the first fixing step S1, the cutting blade 10 is attached to the blade mount 34A, and then the cutting blade 10 is fixed to the blade mount 34A with the fixing nut 40.

FIG. 4(A) is a perspective view showing the cutting unit 8A with the cutting blade 10 mounted on the blade mount 34A. FIG. 4(B) is a side view showing the cutting unit 8A with the cutting blade 10 attached to the blade mount 34A. FIG. 4(C) is a front view showing the cutting unit 8A with the cutting blade 10 attached to the blade mount 34A.

In the first fixing step S1, first, the cutting blade 10 is positioned so that the support shaft 38A of the blade mount 34A is inserted into the opening 10a of the cutting blade 10 (see FIG. 2(A)). Thereby, the inner peripheral edge 10b of the cutting blade 10 is supported by the support shaft 38A, and the cutting blade 10 is mounted on the blade mount 34A.

Note that the diameter of the inner circumferential edge 10b of the cutting blade 10 is set to be slightly larger than the diameter of the support shaft 38A so that the cutting blade 10 is smoothly mounted on the blade mount 34A. The difference between the diameter of the inner peripheral edge 10b of the cutting blade 10 and the diameter of the support shaft 38A is, for example, 5 μm or more and 10 μm or less.

When the cutting blade 10 is attached to the blade mount 34A, the upper end of the inner peripheral edge 10b is supported by the support shaft 38A, and the lower end of the inner peripheral edge 10b is slightly separated from the support shaft 38A, as shown in FIG. 4(C). state. This causes a misalignment between the rotational axis 32a of the spindle 32A and the center of the cutting blade 10 (the center of the inner peripheral edge 10b), resulting in variations in the distance from the rotational axis 32a of the spindle 32A to the outer peripheral edge of the cutting blade 10. .

Note that in the first fixing step S1, the cutting blade 10 is mounted so that the mark 10c is positioned at a predetermined position. For example, as shown in FIG. 4C, the direction (angle) of the cutting blade 10 is adjusted so that the mark 10c is positioned directly above the upper end of the support shaft 38A. Thereby, the cutting blade 10 and the blade mount 34A are arranged in a predetermined positional relationship.

Next, the cutting blade 10 is fixed to the blade mount 34A with the fixing nut 40. FIG. 5(A) is a perspective view showing the cutting unit 8A with the cutting blade 10 fixed to the blade mount 34A, and FIG. 5(B) is a perspective view of the cutting unit 8A with the cutting blade 10 fixed to the blade mount 34A. It is a side view which shows 8A.

After the cutting blade 10 is mounted on the blade mount 34A, the fixing nut 40 is fastened to the support shaft 38A. As a result, the cutting blade 10 is held between the flange portion 36A and the fixing nut 40, and is fixed to the blade mount 34A.

Next, by dressing the cutting blade 10 fixed to the blade mount 34A, the cutting blade 10 is dressed so that the variation in the distance from the rotation axis 32a of the spindle 32A to the outer peripheral edge of the cutting blade 10 falls within an allowable range. The shape is corrected (correction step S2). FIG. 6(A) is a perspective view showing the cutting unit 8A in the correction step S2, and FIG. 6(B) is a side view showing the cutting unit 8A in the correction step S2.

In the modification step S2, the cutting blade 10 is dressed by cutting the cutting blade 10 into the dressing board 21. For example, the dressing board 21 is a plate-like member formed into a rectangular shape in plan view, and includes a surface (first surface) 21a and a back surface (second surface) 21b that are generally parallel to each other. Further, the dressing board 21 includes abrasive grains made of green carborundum (GC), white arundum (WA), or the like, and a binding material such as resin bond or vitrified bond that fixes the abrasive grains. However, there are no restrictions on the shape, material, etc. of the dressing board 21.

The dressing board 21 is held by a chuck table (holding table) 24 mounted on the cutting device 2 (see FIG. 1). The upper surface of the chuck table 24 is a flat surface that is generally parallel to the horizontal plane (XY plane), and constitutes a rectangular holding surface 24a that holds the dressing board 21. The holding surface 24a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), etc. formed inside the chuck table 24. Furthermore, a moving unit (not shown) that moves the chuck table 24 along the X-axis direction is connected to the chuck table 24.

For example, the dressing board 21 is placed on the chuck table 24 so that the front surface 21a side is exposed upward and the back surface 21b side faces the holding surface 24a. At this time, the orientation (angle) of the dressing board 21 is adjusted so that two side surfaces are along the X-axis direction and the other two sides are along the Y-axis direction. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 24a, the dressing board 21 is suctioned and held by the chuck table 24. However, the dressing board 21 may be held by the chuck table 12 (see FIG. 1).

Next, the cutting unit 8A is moved along the Y-axis direction to align the positions of the dressing board 21 and the cutting blade 10 in the Y-axis direction. Further, the cutting unit 8A is moved along the Z-axis direction, and the lower end of the cutting blade 10 is positioned below the surface 21a of the dressing board 21. Then, while rotating the cutting blade 10, the chuck table 24 is moved along the X-axis direction. As a result, the dressing board 21 and the cutting blade 10 move relatively along the X-axis direction, and the tip of the cutting blade 10 cuts into the surface 21a of the dressing board 21.

When the tip of the cutting blade 10 comes into contact with the dressing board 21, the binding material of the cutting blade 10 is worn away, and the abrasive grains embedded in the binding material are appropriately exposed (sharpening). Further, the shape of the cutting blade 10 is corrected (truing) so that variations in the distance from the rotation axis 32a of the spindle 32A to the outer peripheral edge of the cutting blade 10 fall within an allowable range. The above tolerance range is appropriately set depending on the material of the workpiece 11, processing conditions, etc.

Note that there is no limit to the number of times the cutting blade 10 cuts into the dressing board 21 in the modification step S2. That is, depending on the material and condition of the cutting blade 10, the cutting blade 10 may be cut into the dressing board 21 multiple times.

Here, as mentioned above, the diameter of the inner peripheral edge 10b of the cutting blade 10 is set slightly larger than the diameter of the support shaft 38A (see FIG. 4(C)), and the diameter of the inner peripheral edge 10b of the cutting blade 10 is set to be slightly larger than the diameter of the support shaft 38A (see FIG. 4(C)). The center of the cutting blade 10 does not match. When the cutting blade 10 is cut into the dressing board 21 in this state, the portion of the outer peripheral edge of the cutting blade 10 that is farther from the rotating shaft 32a wears out preferentially. As a result, the distance from the rotating shaft 32a to the outer peripheral edge of the cutting blade 10 is approximately constant.

On the other hand, when dressing is performed, the distance from the center of the inner peripheral edge 10b of the cutting blade 10 to the outer peripheral edge of the cutting blade 10 varies. Therefore, the cutting blade 10 after dressing is in an eccentric state in which the center position of the outer peripheral edge of the cutting blade 10 and the center position of the inner peripheral edge 10b do not match.

Next, the cutting blade 10 is removed from the blade mount 34A (removal step S3). FIG. 7(A) is a perspective view showing the cutting unit 8A in the removal step S3, and FIG. 7(B) is a side view showing the cutting unit 8A in the removal step S3.

In the removal step S3, first, the fixing nut 40 is loosened and removed from the support shaft 38A of the blade mount 34A. Thereafter, the dressed cutting blade 10 is removed from the blade mount 34A. The fixing nut 40 and the cutting blade 10 may be removed automatically using a dedicated replacement device, or may be removed manually by an operator. The dressed cutting blade 10 is then stored at a predetermined location as a replacement cutting blade.

By sequentially repeating the first fixing step S1, modification step S2, and removal step S3 described above, dressing of a plurality of cutting blades 10 is performed continuously. Thereby, the dressed cutting blades 10 can be efficiently stocked.

The dressed cutting blade 10 is used to process a workpiece 11. When cutting the workpiece 11 with the cutting blade 10, first, the tip of the spindle 32B (second spindle) mounted on the cutting device 2 (second cutting device) that cuts the workpiece 11 is cut. The cutting blade 10 is fixed to the blade mount 34B (second blade mount) attached to the section (second fixing step S4). In the second fixing step S4, after the cutting blade 10 is mounted on the blade mount 34B, the cutting blade 10 is fixed on the blade mount 34B with the fixing nut 40.

FIG. 8(A) is a perspective view showing the cutting unit 8B with the cutting blade 10 mounted on the blade mount 34B. FIG. 8(B) is a side view showing the cutting unit 8B with the cutting blade 10 attached to the blade mount 34B. FIG. 8(C) is a front view showing the cutting unit 8B with the cutting blade 10 attached to the blade mount 34B.

The procedure of the second fixing step S4 is similar to the first fixing step S1 (see FIGS. 4(A) to 5(B)). However, the cutting blade 10 is fixed to the blade mount 34B such that the positional relationship between the cutting blade 10 and the blade mount 34B matches the positional relationship between the cutting blade 10 and the blade mount 34A in the first fixing step S1. .

Specifically, the position of the mark 10c on the cutting blade 10 with respect to the support shaft 38B is made to be the same as the position of the mark 10c with respect to the support shaft 38A in the first fixing step S1 (see FIG. 4(C)). , the direction (angle) of the cutting blade 10 is adjusted. For example, if the cutting blade 10 is mounted so that the mark 10c is positioned directly above the upper end of the support shaft 38A in the first fixing step S1 (see FIG. 4(C)), also in the second fixing step S4, The cutting blade 10 is mounted so that the mark 10c is positioned directly above the upper end of the support shaft 38B (see FIG. 8(C)).

Next, the cutting blade 10 is fixed to the blade mount 34B with the fixing nut 40. FIG. 9(A) is a perspective view showing the cutting unit 8B with the cutting blade 10 fixed to the blade mount 34B, and FIG. 9(B) is a perspective view of the cutting unit 8B with the cutting blade 10 fixed to the blade mount 34B. It is a side view which shows 8B.

After the cutting blade 10 is mounted on the blade mount 34B, the fixing nut 40 is fastened to the support shaft 38B. As a result, the cutting blade 10 is held between the flange portion 36B and the fixing nut 40 and fixed to the blade mount 34B.

As described above, in this embodiment, the orientation of the cutting blade 10 is aligned in the first fixing step S1 and the second fixing step S4 with reference to the mark 10c attached to the cutting blade 10. As a result, the state of the cutting unit 8A immediately after the cutting blade 10 is trued in the correction step S2 (see FIGS. 6(A) and 6(B)) is changed to the state of the cutting unit 8B that cuts the workpiece 11. Reproduced. As a result, the cutting blade 10 is fixed to the blade mount 34B such that variations in the distance from the rotation axis 32a of the spindle 32B to the outer peripheral edge of the cutting blade 10 are within an allowable range.

Next, the workpiece 11 is cut with the cutting blade 10 fixed to the blade mount 34B (cutting step S5). FIG. 10(A) is a perspective view showing the cutting unit 8B in cutting step S5, and FIG. 10(B) is a side view showing the cutting unit 8B in cutting step S5.

For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as single crystal silicon, and has a front surface (first surface) 11a and a back surface (second surface) 11b that are substantially parallel to each other. The workpiece 11 is divided into a plurality of rectangular regions by a plurality of streets (dividing lines) 13 arranged in a grid pattern so as to intersect with each other.

Devices 15 such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices are installed on the surfaces 11a of the plurality of areas divided by the streets 13, respectively. It is formed. By cutting and dividing the workpiece 11 along the streets 13 with the cutting blade 10, a plurality of device chips each including a device 15 are manufactured.

However, there are no restrictions on the type, material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 may be a substrate (wafer) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramics, resin, metal, or the like. Furthermore, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of the devices 15, and the device 15 does not need to be formed on the workpiece 11.

Further, the workpiece 11 may be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate. For example, a package substrate is formed by sealing a plurality of device chips mounted on a mounting substrate with a resin layer (molding resin). By dividing the package substrate into individual pieces using the cutting blade 10, a plurality of packaged devices each including a plurality of packaged device chips are manufactured.

When cutting the workpiece 11 with the cutting device 2, the workpiece 11 is supported by an annular frame 17 for convenience in handling (transportation, holding, etc.) the workpiece 11. The frame 17 is a plate-shaped member made of metal such as SUS (stainless steel) or aluminum, hard resin, or the like. A circular opening 17a is provided in the center of the frame 17, passing through the frame 17 in the thickness direction. Note that the diameter of the opening 17a is larger than the diameter of the workpiece 11.

A sheet 19 that supports the workpiece 11 is fixed to the workpiece 11 and the frame 17 . For example, as the sheet 19, a circular tape (dicing tape) including a film-like base material and an adhesive (glue) provided on the base material is used. The base material is made of resin such as polyolefin, polyvinyl chloride, polyethylene terephthalate, or the like. Further, the adhesive may be an epoxy-based, acrylic-based, or rubber-based adhesive. Note that the adhesive may be an ultraviolet curable resin.

With the workpiece 11 placed inside the opening 17a of the frame 17, the center part of the sheet 19 is attached to the back surface 11b of the workpiece 11, and the outer peripheral part of the sheet 19 is attached to the frame 17. Ru. Thereby, the workpiece 11 is supported by the frame 17 via the sheet 19.

When cutting the workpiece 11, the workpiece 11 is first held by the chuck table 12 (see FIG. 10(B)). For example, the workpiece 11 is placed on the chuck table 12 so that the front surface 11a side faces upward and the back surface 11b side (sheet 19 side) faces the holding surface 12a. Further, the frame 17 is held and fixed by the plurality of clamps 14. When the suction force (negative pressure) of the suction source is applied to the holding surface 12a in this state, the workpiece 11 is suction-held by the chuck table 12 via the sheet 19.

Next, the workpiece 11 is cut along the streets 13 with the cutting blade 10 . Specifically, first, the chuck table 12 is rotated to align the length direction of a predetermined street 13 with the X-axis direction. Further, the position of the cutting unit 8 in the Y-axis direction is adjusted so that the cutting blade 10 overlaps the extension line of the predetermined street 13. Furthermore, the height of the cutting unit 8 is adjusted so that the lower end of the cutting blade 10 is positioned below the back surface 11b of the workpiece 11.

Then, while rotating the cutting blade 10, the chuck table 12 is moved along the X-axis direction. As a result, the chuck table 12 and the cutting blade 10 move relatively along the X-axis direction (processing feed), and the cutting blade 10 cuts into the workpiece 11 along a predetermined street 13. As a result, a cut (kerf) extending from the front surface 11a to the back surface 11b of the workpiece 11 is formed along the street 13, and the workpiece 11 is divided.

Thereafter, the workpiece 11 is cut along all the streets 13 by repeating the same procedure. As a result, the workpiece 11 is divided into a plurality of chips (device chips) each including a device 15. However, there is no limit to the content of the cutting process in the cutting step S5.

Here, as described above, when the second fixing step S4 (see FIGS. 8(A) to 9(B)) is completed, the cutting blade 10 is fixed from the rotation axis 32a of the spindle 32B to the outer peripheral edge of the cutting blade 10. It is fixed to the blade mount 34B so that variations in distance fall within an allowable range. Therefore, in the subsequent cutting step S5, cutting of the workpiece 11 by the cutting blade 10 can be immediately started without performing dressing for truing.

Note that in the above, the dressing of the cutting blade 10 (see FIGS. 4(A) to 7(B)) and the cutting of the workpiece 11 (see FIGS. 8(A) to 10(B)) are different from each other in the cutting device 2. Although the case has been described in which these processes are performed in the same cutting device 2, these processes may be performed in the same cutting device 2. In this case, the cutting units 8A, 8B, spindles 32A, 32B, blade mounts 34A, 34B, flanges 36A, 36B, and support shafts 38A, 38B are the same components.

As described above, in the method for cutting a workpiece according to the present embodiment, the positional relationship between the cutting blade 10 and the blade mount 34A when performing dressing, and the cutting blade 10 and the blade when cutting the workpiece 11 are explained. Match the positional relationship with the mount 34B. As a result, the state of the cutting unit 8A immediately after the cutting blade 10 is trued is reproduced in the cutting unit 8B that cuts the workpiece 11. As a result, it becomes possible to start cutting the workpiece 11 immediately after the cutting blade 10 is attached, and processing efficiency is improved.

In the above embodiment, an example has been described in which the positional relationship between the cutting blade 10 and the blade mount 34 is matched in the first fixing step S1 and the second fixing step S4 using the mark 10c attached to the cutting blade 10 as a reference. However, there is no limit to the method of adjusting the positional relationship between the cutting blade 10 and the blade mount 34.

11(A) is a perspective view showing the cutting unit 8 that injects gas from the blade mount 34 toward the inner peripheral edge 10b of the cutting blade 10, and FIG. 11(B) is a perspective view showing the cutting unit 8 from the blade mount 34 toward the inner peripheral edge 10b of the cutting blade It is a front view which shows the cutting unit 8 which injects gas toward 10b. As shown in FIG. 11(A), the support shaft 38 of the blade mount 34 may be provided with a plurality of injection ports 38a that eject gas such as air.

The injection port 38a is formed to open at the outer peripheral surface of the support shaft 38. For example, three or more injection ports 38a are arranged at approximately equal intervals along the circumferential direction of the support shaft 38. Each of the plurality of injection ports 38a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), etc. provided inside the blade mount 34. However, there are no restrictions on the shape or number of the injection ports 38a, and for example, the annular injection ports 38a may be continuously formed along the outer peripheral surface of the support shaft 38.

In the first fixing step S1 (see FIGS. 4(A) to 5(B)) and the second fixing step S4 (see FIGS. 8(A) to 9(B)), the inner part of the cutting blade 10 is The cutting blade 10 is fixed while injecting gas toward the peripheral edge 10b. Specifically, the support shaft 38 is inserted into the opening 10a of the cutting blade 10 with gas such as air being injected radially outward of the support shaft 38 from the plurality of injection ports 38a. As a result, a uniform annular gap (gas layer) 42 is formed between the inner peripheral edge 10b of the cutting blade 10 and the support shaft 38, and the cutting blade 10 is aligned between the center position of the inner peripheral edge 10b and the center position of the support shaft 38. are maintained in a consistent state.

Then, the fixing nut 40 is fastened to the support shaft 38 while maintaining the state in which gas is injected from the plurality of injection ports 38a. As a result, the cutting blade 10 is fixed concentrically with the support shaft 38 such that the center position of the inner peripheral edge 10b and the center position of the support shaft 38 coincide.

12(A) is a perspective view showing the cutting unit 8 that applies ultrasonic vibration to the blade mount 34, and FIG. 12(B) is a front view showing the cutting unit 8 that applies ultrasonic vibration to the blade mount 34. be. As shown in FIG. 12(A), an ultrasonic vibration applying unit 44 that applies ultrasonic vibration (vibration at a frequency belonging to the ultrasonic band) to the blade mount 34 is connected to the blade mount 34. good.

For example, the ultrasonic vibration imparting unit 44 is housed in the housing 30 and includes a piezoelectric body (piezoelectric ceramics) made of barium titanate, lead zirconate titanate, lithium tantalate, etc., and an electrode for applying voltage to the piezoelectric body. Ru. When ultrasonic vibration is applied to the blade mount 34 by the ultrasonic vibration applying unit 44, the diameter of the support shaft 38 expands and contracts at a period corresponding to the ultrasonic vibration. Note that the amount of variation in the diameter of the support shaft 38 (the difference between the maximum value and the minimum value of the diameter of the support shaft 38) is, for example, 5 μm or more and 10 μm or less.

In the first fixing step S1 (see FIGS. 4(A) to 5(B)) and the second fixing step S4 (see FIGS. 8(A) to 9(B)), ultrasonic vibration is applied to the support shaft 38. While doing so, the cutting blade 10 is fixed. Specifically, the support shaft 38 is inserted into the opening 10a of the cutting blade 10 while the diameter of the support shaft 38 is periodically expanded and contracted by ultrasonic vibration. Thereby, the support shaft 38 comes into contact with the inner peripheral edge 10b of the cutting blade 10 in a short period, and the entire inner peripheral edge 10b of the cutting blade 10 is supported by the support shaft 38. As a result, the cutting blade 10 is maintained such that the center position of the inner peripheral edge 10b and the center position of the support shaft 38 are aligned.

Then, the fixing nut 40 is fastened to the support shaft 38 while maintaining the ultrasonic vibration of the support shaft 38. As a result, the cutting blade 10 is fixed concentrically with the support shaft 38 such that the center position of the inner peripheral edge 10b and the center position of the support shaft 38 coincide.

As described above, in the first fixing step S1 and the second fixing step S4, the cutting blade 10 is fixed to the support shaft 38 by injecting gas from the support shaft 38 or applying ultrasonic vibration to the support shaft 38. They may be fixed concentrically. Thereby, the positional relationship between the cutting blade 10 and the blade mount 34 in the first fixing step S1 can be matched with the positional relationship between the cutting blade 10 and the blade mount 34 in the second fixing step S4.

In addition, the structure, method, etc. according to the above embodiments can be modified and implemented as appropriate without departing from the scope of the objective of the present invention.

11 Workpiece 11a Surface (first surface)
11b Back side (second side)
13 Street (planned dividing line)
15 Device 17 Frame 17a Opening 19 Sheet 21 Dressing board 21a Surface (first surface)
21b Back side (second side)
2 Cutting device 4 Base 6 Cover 6a Front 8, 8A, 8B Cutting unit 10 Cutting blade 10a Opening (through hole)
10b Inner peripheral edge (inner wall)
10c Marker 12 Chuck table (holding table)
12a Holding surface 14 Clamp 16 Cassette elevator 18 Cassette 20 Display unit (display section, display device)
22 Controller (control unit, control section, control device)
24 Chuck table (holding table)
24a Holding surface 30 Housing 32, 32A, 32B Spindle 32a Rotating shaft 34, 34A, 34B Blade mount 36, 36A, 36B Flange portion 36a Surface 38, 38A, 38B Support shaft (boss portion)
38a injection port 40 fixing nut 40a opening (through hole)
42 Gap (gas layer)
44 Ultrasonic vibration imparting unit

Claims (5)

A method for cutting a workpiece by cutting the workpiece with a cutting blade, the method comprising:
a first fixing step of fixing the cutting blade to a first blade mount attached to the tip of the first spindle;
After the first fixing step, by dressing the cutting blade fixed to the first blade mount, variations in the distance from the rotation axis of the first spindle to the outer peripheral edge of the cutting blade are brought within an acceptable range. a modification step of modifying the shape of the cutting blade to fit;
a removal step of removing the cutting blade from the first blade mount after the modification step;
After the removing step, the cutting blade is mounted on a second blade mount attached to the tip of the second spindle, and the positional relationship between the cutting blade and the second blade mount is that of the cutting blade in the first fixing step. a second fixing step of fixing to match the positional relationship with the first blade mount;
A method for cutting a workpiece, comprising, after the second fixing step, a cutting step of cutting the workpiece with the cutting blade fixed to the second blade mount. 2. The method for cutting a workpiece according to claim 1, wherein the first spindle and the second spindle are mounted on different cutting devices. The workpiece according to claim 1 or 2, wherein in the first fixing step and the second fixing step, the cutting blade is fixed in a predetermined direction with reference to a mark attached to the cutting blade. cutting method. The first blade mount and the second blade mount include a support shaft that supports an inner peripheral edge of the cutting blade,
3. The cutting blade according to claim 1, wherein in the first fixing step and the second fixing step, the cutting blade is fixed while injecting gas from the support shaft toward the inner peripheral edge of the cutting blade. How to cut the workpiece. The first blade mount and the second blade mount include a support shaft that supports an inner peripheral edge of the cutting blade,
3. The method for cutting a workpiece according to claim 1, wherein in the first fixing step and the second fixing step, the cutting blade is fixed while applying ultrasonic vibration to the support shaft.

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