JP2021034467A - Cutting blade and processing method - Google Patents

Abstract

To provide a cutting blade that enables easy division of a wafer while avoiding peeling of an insulating film.SOLUTION: A cutting blade that cuts a film layer along a street of a wafer in which a device is formed in a plurality of regions partitioned by a plurality of streets arranged in a grid pattern, and formed with a film layer containing an insulating film on the street includes a fibrous material having hardness higher than the film layer and a bond material that fixes a fibrous material, and includes an annular cutting edge with a thickness less than the width of the street, and the fibrous material protrudes from the bond material.SELECTED DRAWING: Figure 3

Description

The present invention relates to a cutting blade for cutting a wafer and a processing method for processing a wafer using the cutting blade.

In the device chip manufacturing process, for example, a film layer (functional layer) including various films (conductive film, insulating film, etc.) constituting a device made of IC (Integrated Circuit), LSI (Large Scale Integration), etc. is surfaced. A wafer formed on the side is used. The wafer is partitioned by a plurality of streets (scheduled division lines) arranged in a grid pattern so as to intersect each other, and a device is formed in each of the regions.

By splitting the wafer along the street, a plurality of device chips, each with a device, are obtained. For example, a cutting device is used to divide the wafer. The cutting apparatus includes a chuck table for holding the wafer and a spindle on which an annular cutting blade in which abrasive grains such as diamond are fixed by a bonding material is mounted.

When the cutting blade is attached to the spindle and the spindle is rotated, the cutting blade rotates about the axis of the spindle as a rotation axis. By cutting the cutting blade into the wafer in this state, the wafer is cut. Then, when the wafer is cut along all the streets, the wafer is divided into a plurality of device chips.

In recent years, in order to improve the processing capacity of a device, a method of using a low dielectric constant insulating film (Low-k film) as an interlayer insulating film of the device has been put into practical use. In addition, a passivation film may be formed to cover the device for the purpose of protecting the device. When a film layer containing an insulating film such as a low dielectric constant insulating film or a passivation film is formed up to the streets that partition the device, when the wafer is cut along the streets with a cutting blade, the abrasive grains of the cutting blade become a film. Contact the layer.

When the abrasive grains of the cutting blade come into contact with the insulating film contained in the film layer, the insulating film may be pulled by the abrasive grains and peeled off. Then, if this peeling progresses to the formed area of the device, the device may be damaged. Therefore, when a film layer including a low dielectric constant insulating film, a passivation film, or the like is formed on the street, it becomes difficult to properly divide the wafer with a cutting blade.

Therefore, a method using a laser processing device for removing the film layer formed on the street has been proposed. Patent Document 1 discloses a method in which a low dielectric constant insulating film formed on a street is first removed by irradiating the wafer with a laser beam, and then the wafer is cut along the street with a cutting blade. By using this method, contact between the cutting blade and the low dielectric constant insulating film can be avoided, and damage to the device due to peeling of the low dielectric constant insulating film can be prevented.

Japanese Unexamined Patent Publication No. 2005-64231

As described above, when a wafer having a film layer including an insulating film such as a low dielectric constant insulating film or a passivation film formed on a street is cut by a cutting blade, the device may be damaged due to the peeling of the insulating film. Further, when the method of removing the film layer by irradiating the laser beam is used, a laser processing device is required in addition to the cutting device, which increases the cost of the process and equipment required for dividing the wafer.

The present invention has been made in view of such a problem, and provides a cutting blade capable of easily dividing a wafer while avoiding peeling of an insulating film, and processes a wafer using the cutting blade. The subject is to provide a processing method.

According to one aspect of the present invention, a wafer in which a device is formed in a plurality of regions partitioned by a plurality of streets arranged in a grid pattern and a film layer containing an insulating film is formed on the streets. A cutting blade that cuts a film layer along the street, including a fibrous material having a hardness equal to or higher than that of the film layer and a bond material for fixing the fibrous material, and having a thickness less than the width of the street. The fibrous material is provided with a cutting blade that projects from the bond material.

The fibrous material is preferably carbon nanotubes, boron nitride nanotubes, or silicon nanotubes. Further, preferably, the cutting blade cuts the film layer including a low dielectric constant insulating film or a passivation film as the insulating film.

Further, according to one aspect of the present invention, it is a processing method for processing the wafer by using the cutting blade, the step of holding the wafer by the chuck table, the chuck table holding the wafer, and the cutting. Provided is a processing method comprising a step of removing the film layer along the street by relatively moving the blade and bringing the fibrous material protruding from the bond material into contact with the film layer. ..

The cutting blade according to one aspect of the present invention includes a cutting edge in which a fibrous material is fixed by a bonding material. Then, when the cutting blade is cut into the wafer along the street, the insulating film contained in the film layer is cut and removed by the fibrous substance. As described above, when a cutting blade containing a fibrous substance is used for removing the film layer, peeling of the insulating film contained in the film layer is suppressed, and damage to the device is prevented.

Further, by using the cutting blade according to the present embodiment, the film layer can be removed by the cutting device. Therefore, it is not necessary to prepare a laser processing apparatus or the like for removing the film layer, and it is possible to simplify the wafer dividing process and reduce the cost of the apparatus.

FIG. 1A is a perspective view showing a wafer, and FIG. 1B is a cross-sectional view showing a wafer. FIG. 2A is a perspective view showing a cutting blade made of a cutting edge, and FIG. 2B is a perspective view showing a cutting blade provided with a base and a cutting edge. FIG. 3A is a front view showing the cutting blade, and FIG. 3B is an enlarged front view showing the tip end portion of the cutting edge of the cutting blade. It is a perspective view which shows the cutting apparatus. It is a perspective view which shows the cutting unit. FIG. 6A is a cross-sectional view showing how a wafer is machined by a cutting device, and FIG. 6B is an enlarged cross-sectional view showing how a film layer is cut by a cutting blade. It is sectional drawing which shows the manufacturing apparatus. FIG. 8A is a cross-sectional view showing a base on which an electroformed layer is formed, FIG. 8B is an enlarged cross-sectional view showing an electroformed layer, and FIG. 8C is an electroformed layer as a base. It is sectional drawing which shows the state of being peeled off from a table.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, a configuration example of a wafer that can be machined by the cutting blade according to the present embodiment will be described. FIG. 1A is a perspective view showing the wafer 11, and FIG. 1B is a cross-sectional view showing the wafer 11.

The wafer 11 includes a disk-shaped substrate 13 made of a material such as silicon and having a front surface 13a and a back surface 13b. On the surface 13a side of the substrate 13, a film layer (functional layer) 15 including various films (conductive film, insulating film, etc.) constituting the device 17 made of IC (Integrated Circuit), LSI (Large Scale Integration), etc. is formed. It is formed. Further, the wafer 11 is divided into a plurality of regions by a plurality of streets (scheduled division lines) 19 arranged in a grid pattern so as to intersect each other, and a device 17 is formed in each region.

There are no restrictions on the material, shape, structure, size, etc. of the substrate 13. For example, as the substrate 13, a substrate made of a semiconductor other than silicon (SiC, GaAs, InP, GaN, etc.), sapphire, ceramics, resin, metal, or the like can be used. Further, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the device 17.

The film layer 15 includes a conductive film (electrode, etc.) constituting the device 17, a low dielectric constant insulating film (Low-k film) used as an interlayer insulating film of the device 17, a passivation film for protecting the device 17, and the like. Insulating film is included. The low dielectric constant insulating film is an insulating film made of a material such as an inorganic substance such as SiOF, SiOC, BSG (SiOB), or an organic substance made of a polyimide-based polymer or a parylene-based polymer. The passivation film is made of a silicon nitride film, a silicon oxide film, or the like, and is, for example, an insulating film formed so as to cover a plurality of devices 17.

A part of the film layer 15 is also formed on the street 19 adjacent to the device 17. The film layer (functional layer) 15a shown in FIG. 1B corresponds to a region of the film layer 15 formed on the street 19. The film layer 15a includes an insulating film such as a low dielectric constant insulating film or a passivation film.

By cutting the substrate 13 and the film layer 15a along the street 19, the wafer 11 is divided into a plurality of device chips each including a device 17. For example, for dividing the wafer 11, a cutting device including a chuck table for holding the wafer 11 and a spindle on which a cutting blade for cutting the wafer 11 is mounted is used.

The cutting blade is configured by fixing abrasive grains made of, for example, diamond or the like with a bond material. The wafer 11 is cut by mounting the cutting blade on the spindle and cutting the wafer 11 while rotating the cutting blade.

When the cutting blade is cut into the wafer 11, the insulating film (low dielectric constant insulating film, passivation film, etc.) contained in the film layer 15a comes into contact with the abrasive grains of the cutting blade. At this time, the abrasive grains may cut deeply into the insulating film, and the insulating film may be pulled by the abrasive grains and peeled off. Then, if this peeling proceeds to the formed region of the device 17, the device 17 may be damaged.

Therefore, in the present embodiment, the film layer 15a formed on the street 19 is cut by using a cutting blade provided with a cutting edge in which the fibrous material is fixed by the bonding material. When this cutting blade is used, the film layer 15a is cut by contacting the fibrous substance with the film layer 15a.

The fibrous material is more flexible and easily deformed than the above-mentioned abrasive grains, and it is difficult to cut deeply into the insulating film contained in the film layer 15a. Therefore, even if the film layer 15a is cut by the fibrous material, the insulating film contained in the film layer 15a is not easily pulled by the fibrous material, and the insulating film is not easily peeled off. As a result, damage to the device 17 due to peeling of the insulating film is suppressed.

Hereinafter, a configuration example of the cutting blade according to the present embodiment will be described. FIG. 2 shows a configuration example of the cutting blade according to the present embodiment.

FIG. 2A is a perspective view showing a cutting blade 21 composed of a cutting edge 23. The cutting blade 21 is composed of an annular cutting edge 23 having a circular opening 23a in the center. The cutting blade 21 composed of the annular cutting edge 23 is called a washer type (washer blade).

FIG. 2B is a perspective view showing a cutting blade 25 including a base 27 and a cutting edge 29. The cutting blade 25 is composed of an annular base 27 having a circular opening 27a in the center and an annular cutting edge 29 formed on the outer edge of the base 27. The cutting blade 25 having the cutting edge 29 formed on the outer edge of the base 27 is called a hub type (hub blade).

Further, the base 27 has an annular grip portion 27b protruding in the width direction of the cutting blade 25. When machining an workpiece using a cutting device, the user (operator) of the cutting device can attach the cutting blade 25 to the cutting device by holding the grip portion 27b.

FIG. 3A is a front view showing the cutting blade 21, and FIG. 3B is an enlarged front view showing the tip end portion of the cutting edge 23 of the cutting blade 21. In FIG. 3B, the tip portion 23b of the cutting edge 23 is enlarged and shown.

The cutting edge 23 is configured by fixing a plurality of fibrous materials 33 with a bond material 31. As the bond material 31, a metal bond, a resin bond, a vitrified bond, or the like can be used.

The fibrous substance 33 is a fibrous substance composed of a filamentous or tubular substance whose hardness is equal to or higher than the hardness of the film layer 15a. The fibrous material 33 is fixed by the bond material 31, and as shown in FIG. 3B, a part of the fibrous material 33 projects from the surface of the outer peripheral portion of the bond material 31. The material of the fibrous substance 33 is appropriately selected according to the material of the film layer 15a (hardness of the film layer 15a) and the like.

As the fibrous substance 33, a fibrous nanomaterial (nanofiber) having a diameter on the order of nm (for example, 1 nm or more and 100 nm or less) can be used. For example, hollow fiber-like nanomaterials (nanotubes), solid fiber-like nanomaterials (nanowires, nanorods), and the like can be used. Specific examples of the fibrous material 33 include carbon nanotubes (CNTs), boron nitride nanotubes (BNNTs), and silicon nanotubes.

However, the size of the fibrous substance 33 is not limited to the above. For example, as the fibrous substance 33, a fibrous substance having a diameter on the order of μm (for example, 1 μm or more and 10 μm or less) may be used. This material may be in the form of hollow fibers (microtubes) or in the form of solid fibers (microwires, microrods).

Although the cutting edge 23 of the cutting blade 21 has been described with reference to FIG. 3, the cutting edge 29 of the cutting blade 25 shown in FIG. 2B can also be configured in the same manner.

The cutting blade 21 is attached to the tip of a spindle provided in the cutting device and is supported by the spindle in a rotatable manner. When the spindle is rotated while the cutting blade 21 is mounted on the spindle, the cutting blade 21 rotates with the axis of the spindle as the rotation axis. Then, the film layer 15a is cut by cutting the rotating cutting blade 21 into the wafer 11 along the street 19.

Next, a configuration example of a cutting device to which the cutting blade 21 is mounted will be described. FIG. 4 is a perspective view showing the cutting device 2.

The cutting device 2 includes a base 4 that supports each component constituting the cutting device 2. An opening 4a is formed in the front corner of the base 4, and a cassette support 6 that moves in the vertical direction (Z-axis direction) by an elevating mechanism (not shown) is provided in the opening 4a. .. A cassette 8 accommodating a plurality of wafers 11 is mounted on the upper surface of the cassette support base 6. In FIG. 4, the outline of the cassette 8 is shown by a chain double-dashed line.

The wafer 11 is housed in the cassette 8 in a state of being supported by an annular frame 43 having a circular opening in the center. Specifically, the back surface side of the wafer 11 (the back surface 13b side of the substrate 13, see FIG. 1) is made of a material such as resin and is attached to the central portion of a circular tape 41 having a diameter larger than that of the wafer 11. Further, the outer peripheral portion of the tape 41 is attached to the annular frame 43. As a result, the wafer 11 is supported by the annular frame 43 via the tape 41.

An operation panel 10 for an operator to input machining conditions and the like is provided on the front side of the base 4. Further, behind the opening 4a, a transfer mechanism 12 for carrying out the wafer 11 from the cassette 8 and carrying in the wafer 11 into the cassette 8 is provided.

Between the cassette 8 and the transfer mechanism 12, a temporary placement area 14 is provided, which is a region in which the wafer 11 carried out from the cassette 8 or the wafer 11 carried into the cassette 8 is temporarily placed. The temporary placement region 14 is provided with an alignment mechanism 16 for aligning the wafer 11.

A transport mechanism 18 provided with a swivel arm that attracts the annular frame 43 and transports the wafer 11 is provided in the vicinity of the temporary placement region 14. A chuck table 20 for holding the wafer 11 is provided on the side of the opening 4a. The upper surface of the chuck table 20 constitutes a holding surface 20a for holding the wafer 11. Further, around the chuck table 20, four clamps 22 for fixing the annular frame 43 from all sides are provided.

The chuck table 20 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis substantially parallel to the vertical direction. Further, a moving mechanism (not shown) is provided below the chuck table 20, and this moving mechanism moves the chuck table 20 in the machining feed direction (X-axis direction). Further, the holding surface 20a of the chuck table 20 is connected to a suction source (not shown) such as an ejector via a suction path (not shown) formed inside the chuck table 20.

The wafer 11 housed in the cassette 8 is conveyed to the temporary storage area 14 by the transfer mechanism 12. Then, the wafer 11 arranged in the temporary placement region 14 is conveyed onto the chuck table 20 by the conveying mechanism 18, and is supported by the holding surface 20a via the tape 41. Further, the annular frame 43 is fixed by the clamp 22. By applying the negative pressure of the suction source to the holding surface 20a in this state, the wafer 11 is sucked and held by the chuck table 20 in a state where the surface 13a side (film layer 15 side, see FIG. 1) of the substrate 13 is exposed upward. Will be done.

Above the chuck table 20, a cutting unit 24 for cutting the wafer 11 held by the chuck table 20 is provided. For example, a cutting blade 21 (see FIG. 2A) is mounted on the cutting unit 24. The cutting unit 24 is connected to a moving mechanism (not shown), and this moving mechanism moves the cutting unit 24 along the indexing feed direction (Y-axis direction) and the vertical direction (Z-axis direction).

FIG. 5 is a perspective view showing the cutting unit 24. The cutting unit 24 includes a tubular spindle housing 26. In the spindle housing 26, a spindle 28 having a rotation axis in a direction substantially perpendicular to the machining feed direction (X-axis direction) is housed in a rotatable state, and the spindle 28 is a rotation drive source such as a motor (a motor or the like). It is connected with (not shown). The tip of the spindle 28 is exposed to the outside of the spindle housing 26, and the mount flange 30 is fixed to the tip of the spindle 28.

The mount flange 30 includes a fixed flange 30a and a boss portion 30b connected to the fixed flange 30a, and a male screw portion 30c is formed on the boss portion 30b. The mount flange 30 is fixed to the tip of the spindle 28 by a fixing nut 32.

With the boss portion 30b of the mount flange 30 inserted into the opening 23a of the cutting edge 23 of the cutting blade 21 and the opening 34a of the detachable flange 34, the fixing nut 36 is tightened to the male thread portion 30c to allow the cutting blade 21 to spindle. It is attached to the tip of 28. By rotating the spindle 28 by the rotation drive source in this state, the cutting blade 21 rotates.

Although an example in which the washer-type cutting blade 21 shown in FIG. 2 (A) is mounted on the spindle 28 has been described here, the hub-type cutting blade 25 shown in FIG. 2 (B) is mounted on the spindle 28. You may.

A detection mechanism 38 for detecting the position of the street 19 of the wafer 11 is provided above the movement path of the chuck table 20 shown in FIG. 4 in the X-axis direction. The detection mechanism 38 includes an imaging unit 40 including a camera or the like that images the surface side of the wafer 11 (the film layer 15 side, see FIGS. 1A and 1B). Based on the image acquired by the imaging unit 40, the street 19 to be cut by the cutting blade 21 is selected.

A cleaning unit 42 for cleaning the wafer 11 is provided behind the chuck table 20. Further, above the cleaning unit 42, a transfer mechanism 44 for transporting the wafer 11 from the chuck table 20 to the cleaning unit 42 is provided.

When the processing of the wafer 11 by the cutting unit 24 is completed, the wafer 11 is conveyed from the chuck table 20 to the cleaning unit 42 by the transfer mechanism 44, and the wafer 11 is cleaned and dried by the cleaning unit 42. After that, the wafer 11 is conveyed to the temporary storage area 14 by the transfer mechanism 18, and is accommodated in the cassette 8 by the transfer mechanism 12.

Further, the cutting device 2 is provided with a display unit 46 on the upper portion thereof, which displays an image captured by the imaging unit 40, information referred to by the operator, and the like.

FIG. 6A is a cross-sectional view showing how the wafer 11 is processed by the cutting device 2. When processing the wafer 11, first, the wafer 11 is supported by the holding surface 20a of the chuck table 20 via the tape 41, and the annular frame 43 is fixed by the clamp 22. In this state, by applying the negative pressure of the suction source to the holding surface 20a, the wafer 11 is sucked and held by the chuck table 20 with the surface side (film layer 15 side) exposed upward.

Next, the position of the cutting unit 24 is arranged so that the cutting blade 21 is arranged on the extension line of the street 19 and the lower end of the cutting blade 21 is arranged below the surface of the film layer 15a formed on the street 19. To adjust. Further, the angle of the chuck table 20 is adjusted so that the street 19 is substantially parallel to the machining feed direction (X-axis direction).

Then, the chuck table 20 is moved in the machining feed direction (X-axis direction) while rotating the cutting blade 21. As a result, the cutting blade 21 and the chuck table 20 move relatively, the cutting blade 21 cuts into the film layer 15a, and the film layer 15a is cut along the street 19.

FIG. 6B is an enlarged cross-sectional view showing how the film layer 15a is cut by the cutting blade 21. The cutting edge 23 of the cutting blade 21 is formed so that its thickness (width) is less than the width of the street 19 (distance between two adjacent devices 17). Then, when cutting the wafer 11, the position of the cutting unit 24 in the indexing feed direction (Y-axis direction) is adjusted so that the cutting edge 23 cuts along the street 19 without contacting the device 17.

Further, as shown in FIG. 6B, the fibrous material 33 protrudes from the bond material 31 at the tip of the cutting blade 21. The position (height) of the cutting blade 21 in the vertical direction (Z-axis direction) is adjusted so that the bond material 31 does not come into contact with the film layer 15a and the fibrous material 33 comes into contact with the film layer 15a. ing. Therefore, when the cutting blade 21 is cut into the wafer 11, the fibrous material 33 comes into contact with the film layer 15a, and the film layer 15a is cut.

The fibrous material 33 cuts the film layer 15a so that a cutting groove 15b (see FIG. 6A) reaching the surface 13a of the substrate 13 is formed in the film layer 15a. As a result, a part of the film layer 15a formed on the street 19 is removed.

When the film layer 15a is cut by the fibrous material 33 without bringing the bond material 31 into contact with the film layer 15a, the film layer 15a may not be removed by one cutting depending on the thickness of the film layer 15a. In this case, the film layer 15a is removed by cutting the cutting blade 21 a plurality of times along one street 19 while changing the height of the cutting blade 21.

When the film layer 15a is cut by the fibrous material 33 in this way, it is included in the film layer 15a as compared with the case where a cutting blade containing abrasive grains made of diamond is brought into contact with the film layer 15a for cutting. The insulating film (low dielectric constant insulating film, passivation film, etc.) is less likely to peel off. It is presumed that this is because the fibrous substance 33 is more flexible and easily deformed than the abrasive grains, and it is difficult to cut deeply into the insulating film contained in the film layer 15a.

After that, the same processing is repeated for the film layer 15a formed on the other streets 19, and the cutting grooves 15b are formed along all the streets 19. As a result, the film layer 15a is removed along all the streets 19.

After forming the cutting groove 15b, the substrate 13 is cut along the street 19 to divide the wafer 11 into a plurality of device chips each including a device 17. For the division of the wafer 11, for example, a cutting blade for dividing the wafer in which abrasive grains made of diamond or the like are fixed by a bonding material can be used.

Specifically, first, the cutting blade 21 mounted on the cutting unit 24 (see FIG. 4) is removed, and the above-mentioned cutting blade for wafer division is mounted on the cutting unit 24. However, as the cutting blade for division, a cutting blade having a thickness (width) smaller than that of the cutting blade 21 is used.

Next, the cutting unit 24 is arranged so that the lower end of the cutting blade for division is positioned below the back surface 13b of the substrate 13. Then, the chuck table 20 is moved in the machining feed direction (X-axis direction) while rotating the cutting blade for division. As a result, the substrate 13 is cut along the cutting groove 15b.

The position of the cutting unit 24 in the Y-axis direction is adjusted so that the cutting blade for division cuts inside the cutting groove 15b. Therefore, the cutting blade for division does not come into contact with the insulating film contained in the film layer 15 when cutting the substrate 13. Therefore, peeling of the insulating film due to contact between the abrasive grains contained in the cutting blade for division and the film layer 15 is avoided.

Then, when the above steps are repeated and the substrate 13 is cut along all the cutting grooves 15b, the wafer 11 is divided into a plurality of device chips.

As described above, the cutting blade 21 according to the present embodiment includes a cutting blade 23 in which the fibrous material 33 is fixed by the bonding material 31. Then, when the fibrous material 33 is cut into the wafer 11 along the street 19, the insulating film contained in the film layer 15a is cut and removed by the fibrous material 33. By removing the film layer 15a with the fibrous substance 33 in this way, peeling of the insulating film contained in the film layer 15a is suppressed, and damage to the device 17 is prevented.

Further, by using the cutting blade according to the present embodiment, the film layer 15a can be removed by the cutting device 2. Therefore, it is not necessary to prepare a laser processing apparatus or the like for removing the film layer 15a, and it is possible to simplify the partitioning process of the wafer 11 and reduce the cost of the apparatus.

In the present embodiment, an example in which the lower end of the bond material 31 is positioned above the upper surface of the film layer 15a has been described (see FIG. 6B), but the tip of the bond material 31 is formed by the fibrous material 33. When properly covered, the lower end of the bond material 31 may be positioned slightly below the upper surface of the film layer 15a. In this case, since the fibrous material 33 covering the tip of the bond material 31 prevents the bond material 31 from coming into contact with the film layer 15a, the insulating film contained in the film layer 15a is unlikely to peel off.

Further, in the present embodiment, an example in which the film layer 15a is removed mainly by using the washer type cutting blade 21 has been described, but the hub type cutting blade 25 shown in FIG. 2B is used to remove the film layer 15a. It can also be used.

Next, an example of a method for manufacturing a cutting blade made of a cutting edge including a bond material and a fibrous material will be described. The cutting blade can be manufactured by a method such as electroforming.

FIG. 7 is a cross-sectional view showing a manufacturing apparatus 50 used for manufacturing a cutting blade. When manufacturing a cutting blade, first, a bathtub 52 containing an electrolytic solution 54 is prepared. The material of the electrolytic solution 54 can be arbitrarily selected, and for example, an electrolytic solution containing nickel such as nickel sulfate or nickel nitrate can be used.

The electrolytic solution 54 is mixed with the fibrous substance 56 contained in the cutting edge of the cutting blade. The fibrous substance 56 is solubilized by modifying its surface, and then added to the electrolytic solution 54. Further, a dispersant (surfactant or the like) for dispersing the fibrous substance 56 in the electrolytic solution 54 substantially evenly is added to the electrolytic solution 54 together with the fibrous substance 56.

Next, the disk-shaped base 58 made of a metal material such as stainless steel or aluminum and the electrode 60 made of nickel or the like are immersed in the electrolytic solution 54 in the bathtub 52. A mask 62 corresponding to the shape of the cutting edge of the cutting blade is formed on the surface of the base 58. When forming an annular cutting edge as shown in FIG. 2A, a mask 62 having an annular opening 62a is formed in a plan view.

Further, the base 58 is connected to the negative terminal (negative electrode) of the DC power supply 66 via the switch 64, and the electrode 60 is connected to the positive terminal (positive electrode) of the DC power supply 66. The switch 64 may be arranged between the electrode 60 and the DC power supply 66.

Next, the fan 70 is rotated by the rotary drive source 68 composed of a motor or the like to stir the electrolytic solution 54, and the switch 64 is short-circuited. As a result, a direct current flows through the electrolytic solution 54 with the base 58 as the cathode and the electrode 60 as the anode, and the electroplated layer is electrodeposited on the surface of the base 58.

FIG. 8A is a cross-sectional view showing the base 58 on which the electroformed layer 72 is formed, and FIG. 8B is an enlarged cross-sectional view showing the electroformed layer 72. An annular electroformed layer 72 is formed in a region (inside the opening 62a) of the surface of the base 58 that is not covered by the mask 62. As shown in FIG. 8B, the electroformed layer 72 formed on the surface of the base 58 contains the fibrous substance 56 added to the electrolytic solution 54.

After that, the base 58 is taken out from the bathtub 52, and the electroformed layer 72 formed on the surface of the base 58 is peeled off from the base 58. As a result, the annular electroformed layer 72 having a circular opening 72a in the center is separated from the base 58. FIG. 8C is a cross-sectional view showing how the electroformed layer 72 is peeled off from the base 58.

Then, if necessary, the surface of the electroformed layer 72 is etched to project the fibrous material 56 from the surface of the electroformed layer 72. As a result, as shown in FIG. 3B, a cutting blade 21 composed of a cutting edge 23 in which the fibrous material 33 protrudes from the bond material 31 is obtained.

Although the method for manufacturing the washer-type cutting blade has been described here as an example, the hub-type cutting blade 25 (see FIG. 2B) can also be manufactured by the same method. In this case, instead of the base 58, the base 27 is immersed in the electrolytic solution 54 in the bathtub 52. Further, the mask 62 is formed so as to cover a region other than the outer peripheral portion of the base 27.

In addition, the structure, method, etc. according to the above-described embodiment can be appropriately modified and implemented as long as the scope of the object of the present invention is not deviated.

11 Wafer 13 Substrate 13a Front surface 13b Back surface 15, 15a Film layer (functional layer)
15b Cutting groove 17 device 19 Street (planned division line)
21 Cutting blade 23 Cutting blade 23a Opening 23b Tip 25 Cutting blade 27 Base 27a Opening 27b Gripping part 29 Cutting blade 31 Bonding material 33 Fibrous material 41 Tape 43 Circular frame 2 Cutting device 4 Base 4a Opening 6 Cassette support 8 Cassette 10 Operation panel 12 Conveyance mechanism 14 Temporary placement area 16 Alignment mechanism 18 Conveyance mechanism 20 Chuck table 20a Holding surface 22 Clamp 24 Cutting unit 26 Spindle housing 28 Spindle 30 Mount flange 30a Fixed flange 30b Boss part 30c Male thread part 32 Fixing nut 34 Detachable flange 34a Opening 36 Fixing nut 38 Detection mechanism 40 Imaging unit 42 Cleaning unit 44 Conveyance mechanism 46 Display 50 Manufacturing equipment 52 Bathtub 54 Electrolyte 56 Fibrous material 58 Base 60 Electrode 62 Mask 62a Opening 64 Switch 66 DC power supply 68 rotations Drive source 70 Fan 72 Electrocast layer 72a Opening

Claims (4)

A device is formed in a plurality of regions partitioned by a plurality of streets arranged in a grid pattern, and the film layer of a wafer having a film layer containing an insulating film formed on the street is cut along the street. It is a cutting blade that
An annular cutting edge comprising a fibrous material having a hardness equal to or higher than that of the film layer and a bonding material for fixing the fibrous material and having a thickness less than the width of the street.
A cutting blade characterized in that the fibrous material protrudes from the bond material. The cutting blade according to claim 1, wherein the fibrous material is a carbon nanotube, a boron nitride nanotube, or a silicon nanotube. The cutting blade according to claim 1 or 2, wherein the film layer including a low dielectric constant insulating film or a passivation film is cut as the insulating film. A processing method for processing the wafer using the cutting blade according to any one of claims 1 to 3.
The step of holding the wafer by the chuck table and
The film layer is removed along the street by relatively moving the chuck table holding the wafer and the cutting blade and bringing the fibrous material protruding from the bond material into contact with the film layer. A processing method characterized by including steps to be performed.