Cutting blade manufacturing method

Abstract

To provide a desired cutting blade that can cut an insulating film while suppressing the insulating film that easily peels when cutting a Low-k film or the like.SOLUTION: Provided is a cutting blade comprising a bonding material and abrasive grain, in which the abrasive grain is fixed with the bonding material at least a portion of which is made of glassy carbon. Preferably an average particle diameter of the abrasive grain of the cutting blade is 12 μm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cutting blade having abrasive grains fixed by a binder, a method for manufacturing the cutting blade, and a method for cutting a wafer by using the cutting blade to cut an insulating film provided on one side of the wafer. [Background technology]

[0002] A method is known in which a wafer, on which devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrations) are formed in each area defined by a plurality of planned dividing lines set on the front surface, is divided along each planned dividing line.

[0003] A multilayer wiring layer is formed on the front surface of the wafer, with insulating films and metal layers alternately stacked. To improve the processing capacity of circuits such as ICs and LSIs, the insulating films are sometimes made of low-dielectric-constant insulating materials (i.e., low-k materials). Low-k materials include inorganic materials such as SiO2, SiOF, and SiOB, and organic materials such as polyimides and parylenes.

[0004] When an insulating film made of a low-k material (i.e., a low-k film) is stacked in a multilayer wiring layer, cutting the multilayer wiring layer along the planned dividing line with a cutting blade can cause cracks or breaks in the low-k film, resulting in the low-k film peeling off from the wafer.

[0005] Therefore, generally, a laser beam is irradiated onto the front surface of the wafer along the planned dividing lines to form laser grooves in which the multilayer wiring layer is partially removed (see, for example, Patent Documents 1 and 2). After the laser grooves are formed, the bottoms of the laser grooves are cut using a cutting blade or a laser beam to cut the wafer into a plurality of device chips. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-188475 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-64230 Summary of the Invention [Problem to be solved by the invention]

[0007] However, since laser processing equipment is expensive, if it were possible to remove the multilayer wiring layer along the planned division lines without using a laser beam, the cost required for dividing the wafer could be reduced.Therefore, there is a need for a cutting blade that can cut insulating films such as low-k films, which are prone to peeling during cutting, while suppressing peeling of these insulating films.

[0008] The present invention has been made in consideration of the above problems, and aims to provide a cutting blade that can cut an insulating film while suppressing peeling of the insulating film, which is prone to peeling during cutting. [Means for solving the problem]

[0011] According to one aspect of the present invention, a method for manufacturing a cutting blade in which abrasive grains are fixed by a binder includes the following steps: a molding step in which a mixture containing a thermosetting resin and the abrasive grains is hot-compressed at a temperature of 100°C or higher and 200°C or lower to form a molded body of a predetermined shape from the mixture; a firing step in which the molded body is fired at a temperature of 100°C or higher and 300°C or lower to form a fired body; and a heat treatment step in which the fired body is heat-treated at a temperature of 500°C or higher and 1500°C or lower in an inert gas atmosphere or a vacuum atmosphere after the firing step. a dressing step of dressing the cutting blade manufactured by the heat treatment step; Equipped with The average particle size of the abrasive grains is 12 μm or less, In the heat treatment step, at least a portion of the thermosetting resin becomes the binder of the glassy carbon. In the dressing process, the outer circumferential thickness of the cutting blade is made thinner than the inner circumferential thickness, and the outer circumferential thickness is set to 20 μm to 30 μm. A method for manufacturing a cutting blade is provided. Preferably, in the dressing step, the cutting blade after the heat treatment step is dressed using a dressing board including linear grooves having a width corresponding to the outer circumferential thickness. Also, preferably, the inner circumferential thickness of the cutting blade after the dressing step is 100 μm to 300 μm.

[0012] According to still another aspect of the present invention, an insulating film is provided on the front surface side of a wafer on which devices are formed in each of a plurality of regions divided by dividing lines set in a grid pattern. A cutting blade manufactured by the above manufacturing method A wafer cutting method, comprising: a holding step of holding the wafer in a state where the front surface side of the wafer is exposed by suctioning a back surface side of the wafer opposite to the front surface side of the wafer with a chuck table; Applicable and a cutting step of cutting the insulating film located on the front surface side along the planned dividing lines using a cutting blade. [Effects of the Invention]

[0014] In one embodiment of the cutting blade, abrasive grains are fixed by a binder at least partly made of glassy carbon. The hardness of a cutting blade containing glassy carbon as a binder is higher than that of a typical resin-bonded blade, allowing for a thinner blade thickness compared to a typical resin-bonded blade. This allows for a narrower kerf width compared to a typical resin-bonded blade.

[0015] Furthermore, cutting blades containing glassy carbon as a binder are relatively hard but brittle, making them more susceptible to self-sharpening than electroformed bond blades or metal bond blades. Therefore, compared to cutting with electroformed bond blades or metal bond blades, they are less likely to impact the insulating film, which is prone to peeling, and therefore less likely to break or crack. Therefore, peeling of the insulating film, which is prone to peeling during cutting, can be suppressed. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. [Figure 2] FIG. 2 is a flow chart showing a method for manufacturing a cutting blade. [Figure 3] FIG. 2 is a schematic diagram showing a blending step. [Figure 4]FIG. 4(A) is an exploded perspective view of a mold used in the molding process, and FIG. 4(B) is a perspective view of the mold into which the mixture is supplied. [Figure 5] Figure 5(A) is a cross-sectional view showing the mixture supplied to the mold, Figure 5(B) is a cross-sectional view showing the process of leveling the mixture supplied to the mold, Figure 5(C) is a cross-sectional view showing the process of inserting the through hole of the upper punch into the middle punch, and Figure 5(D) is a cross-sectional view showing the process of molding the mixture to form a molded body. [Figure 6] FIG. 6(A) is a perspective view of a wafer unit, and FIG. 6(B) is a cross-sectional view of a wafer and the like. [Figure 7] FIG. 7(A) is a perspective view of a wafer unit and the like in a cutting process, and FIG. 7(B) is a cross-sectional view of a wafer in the cutting process. [Figure 8] FIG. 1 is a flow chart showing a cutting method. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a cutting blade 2. The cutting blade 2 is a washer-type (also called a hubless-type) blade that is entirely composed of abrasive grains 2a and a bonding material 2b (bond).

[0018] The abrasive grains 2a are made of diamond, but the material for forming the abrasive grains 2a is not limited to diamond. The abrasive grains 2a may be made of cBN (cubic boron nitride), white alundum (WA), green carbon (GC), etc.

[0019] The particle diameter of the abrasive grains 2a is very small, with an average particle diameter of 12 μm or less. The average particle diameter is determined based on the frequency distribution of a particle group expressed using a specific particle diameter (i.e., length), for example, when the size of a single particle is expressed by this particle diameter. There are known methods for expressing particle diameter, such as geometric diameter and equivalent diameter.

[0020] Geometric diameters include Feret diameter, maximum diameter in a certain direction (i.e., Krummbein diameter), Martin diameter, sieve diameter, etc., and equivalent diameters include diameter equivalent to a circle with a projected area (i.e., Heywood diameter), diameter equivalent to a sphere with an equal surface area, diameter equivalent to a sphere with an equal volume, Stokes diameter, light scattering diameter, etc. When a frequency distribution is created for a particle group with particle diameter (μm) on the horizontal axis and frequency on the vertical axis, the average particle diameter is, for example, the average diameter of the weight-based distribution or volume-based distribution.

[0021] The particle size of the abrasive grains 2a may be determined not by the average particle size but by the particle size (#) specified in JIS R6001-2 of the Japanese Industrial Standards (JIS). For example, the particle size (#) determined by the particle size distribution of the fine powder for precision polishing measured by a sedimentation test method or an electrical resistance test method is used.

[0022] Specifically, fine powder having a grain size of #1000 or more (i.e., #1000, #1200, #1500, #2000, #2500, #3000, etc.) is used as the abrasive grains 2a. The larger the number shown to the right of #, the greater the particle diameter (i.e., median diameter) D at which the cumulative frequency reaches 50%. 50 becomes smaller.

[0023] In the case of #1000, the particle diameter D measured by the sedimentation test method 50 The particle diameter D measured by the electrical resistance test method ranges from 14.5 μm to 16.4 μm. 50 The particle diameter D of #1200 or larger is in the range of 10.5 μm to 12.5 μm. 50 is 14.0 μm or less by the sedimentation test method and 10.3 μm or less by the electrical resistance test method.

[0024] The multiple abrasive grains 2a are fixed to one another by a binder 2b. Thermosetting resins such as phenolic resin, epoxy resin, polyimide resin, and melamine resin are used as raw materials for the binder 2b. After the thermosetting resin and the abrasive grains 2a are mixed, the mixture is baked and then heat-treated to form the binder 2b. After the heat treatment, part or all of the binder 2b is made of glass-like carbon.

[0025] The cutting blade 2 is an annular blade having a through hole 4 at approximately the center of one surface. For example, the diameter of the through hole 4 is 35 mm to 45 mm, and the outer diameter of the cutting blade 2 is 50 mm to 90 mm.

[0026] The thickness of the inner peripheral portion of the cutting blade 2 (i.e., the length from one surface of the annulus to the other surface located opposite the one surface) is, for example, 0.1 mm to 0.3 mm. However, the thickness of the outer peripheral portion of the cutting blade 2 is thinner than that of the inner peripheral portion.

[0027] For example, the outer periphery of the cutting blade 2 has a thickness of 20 μm to 30 μm. To make the outer periphery thinner than the inner periphery of the cutting blade 2, for example, a dresser board is used. The dresser board includes linear grooves having a horizontal width of 20 μm to 30 μm and a vertical width that is sufficiently longer than the horizontal width.

[0028] When using a dresser board to modify the shape of the outer periphery of the cutting blade 2, for example, the cutting blade 2 is cut into the groove of the dresser board while rotating the cutting blade 2 in the circumferential direction while aligning the center of the width of the groove with the center of the thickness of the cutting blade 2.

[0029] As a result, one side and the other side of the outer periphery of the cutting blade 2 are thinned approximately evenly. In the cross section when the cutting blade 2 is cut so as to pass through the center of the ring of the cutting blade 2, the outer periphery of the cutting blade 2 has a convex shape.

[0030] The width of the top of the convex shape (i.e., the thickness of the outer periphery) is a length corresponding to the width of the groove (in this example, 20 μm to 30 μm). The outer periphery blade thickness of 20 μm to 30 μm is, for example, 1 / 10 to 1 / 5 of the thickness of a typical resin-bonded blade formed by baking a resin or the like as a binder.

[0031] In the cutting blade 2 of this embodiment, glassy carbon is used for at least a part of the binder 2b, so the hardness of the cutting blade 2 is higher than that of a general resin-bonded blade. Therefore, the blade thickness can be made thinner than that of a general resin-bonded blade, and a narrower kerf width can be achieved than that of a general resin-bonded blade.

[0032] In addition, when glassy carbon is used for at least a part of the binder 2b, the binder 2b becomes more brittle than electroformed bond or metal bond blades, which makes the cutting blade 2 more susceptible to self-sharpening.

[0033] Therefore, compared to cutting with an electroformed bond or metal bond blade, the cutting blade 2 is less likely to impact an insulating film such as a low-k film, which is prone to peeling during cutting. As a result, the insulating film is less likely to break or crack, and peeling of the insulating film can be suppressed.

[0034] Furthermore, even if at least a portion of the binder 2b is glassy carbon, if the abrasive grains 2a are larger than the blade thickness of the cutting blade 2, the effect of the abrasive grains 2a on the workpiece will be dominant compared to the effect of the binder 2b on the workpiece.

[0035] Therefore, it is preferable to make the average particle size of the abrasive grains 2a smaller than the blade thickness of the outer periphery of the cutting blade 2. For example, if the blade thickness of the outer periphery of the cutting blade 2 is 20 μm to 30 μm, the average particle size of the abrasive grains 2a is set to 12 μm or less. This reduces the effect of the abrasive grains 2a on the workpiece, and therefore prevents peeling of the insulating film, which is prone to peeling during cutting, compared to when the average particle size of the abrasive grains 2a is equal to or greater than the blade thickness of the cutting blade 2.

[0036] Next, a method for manufacturing the cutting blade 2 will be described. Fig. 2 is a flow diagram showing the method for manufacturing the cutting blade 2. First, the above-mentioned abrasive grains 2a and a thermosetting resin 2c (e.g., phenolic resin) which is a raw material for the binder 2b are blended to form a mixture 3 (blending step (S10)). Fig. 3 is a schematic diagram showing the blending step (S10).

[0037] In the blending step (S10), a plurality of abrasive grains 2a and a thermosetting resin 2c are mixed to form a mixture 3. The thermosetting resin 2c is a raw material for the binder 2b. In the blending step (S10), for example, a mixer 6 shown in FIG. 3 is used.

[0038] The agitator 6 has, for example, a substantially cylindrical housing 8. An opening 8a is provided in the housing 8. Furthermore, on the opposite side of the opening 8a in the height direction of the housing 8, there is a bottom surface 8b of the housing 8.

[0039] One end of the shaft 10 is connected to the bottom surface 8b. The other end of the shaft 10 is connected to a rotary drive source (not shown) that rotates the shaft 10. When the rotary drive source is operated, the housing 8 rotates around the shaft 10 as a rotation axis 10a.

[0040] The rotation shaft 10a is tilted at a predetermined angle from the vertical direction (i.e., the direction of gravity) as shown in Fig. 3. By tilting the rotation shaft 10a, stirring is performed efficiently when the housing 8 is rotated, so that the plurality of abrasive grains 2a and the thermosetting resin 2c are mixed approximately uniformly.

[0041] A lid (not shown) may be provided on the opening 8a. A stirring rod (not shown) may be provided inside the housing 8. Furthermore, a stirring blade that comes into contact with the material may be attached to the tip of the stirring rod.

[0042] In the mixing step (S10), a plurality of abrasive grains 2a and thermosetting resin 2c, each weighed in a predetermined amount, are supplied into housing 8 through opening 8a.

[0043] Then, when the rotary drive source is operated to rotate the housing 8, the materials are mixed approximately uniformly to form the mixture 3. After the blending step (S10), a molded body having a predetermined shape is formed from the mixture 3 using a mold 12 (see FIGS. 4(A) and 4(B)) (molding step (S20)).

[0044] Fig. 4(A) is an exploded perspective view of the mold 12 used in the molding step (S20), and Fig. 4(B) is a perspective view of the mold 12 into which the mixture 3 is supplied. The mold 12 has a disk-shaped bottom plate 14. The upper and lower surfaces of the bottom plate 14 have diameters larger than the diameter of the cutting blade 2 to be manufactured.

[0045] An outer cylinder 16 is provided on the bottom plate 14. The outer cylinder 16 is a cylindrical body formed with a side wall of a predetermined thickness and has a through hole 16a. The outer diameter of the outer cylinder 16 corresponds to the outer diameter of the bottom plate 14, and the inner diameter of the outer cylinder 16 corresponds to the outer diameter of the cutting blade 2 to be manufactured. In addition, the height of the outer cylinder 16 is greater than the thickness of the cutting blade 2.

[0046] An annular lower punch 18 is provided on the bottom plate 14 and inside the outer cylinder 16. The outer diameter of the lower punch 18 is approximately equal to the inner diameter of the outer cylinder 16, and the thickness of the lower punch 18 is smaller than the thickness of the outer cylinder 16. The lower punch 18 has a through hole 18a.

[0047] A cylindrical middle punch 20 is provided in the through hole 18a of the lower punch 18. The diameter of the through hole 18a is approximately equal to the diameter of the middle punch 20. The middle punch 20 has a thickness approximately equal to that of the outer cylinder 16.

[0048] An annular upper punch 22 is provided above the lower punch 18. The upper punch 22 has a through hole 22a into which the middle punch 20 is inserted. The outer diameter of the upper punch 22 is approximately equal to the inner diameter of the outer cylinder 16.

[0049] Before the molding step (S20) is performed, the outer cylinder 16 is placed on the bottom plate 14, and the lower punch 18 is placed in the through hole 16a of the outer cylinder 16. Then, the middle punch 20 is inserted into the through hole 18a of the lower punch 18. At this time, the lower punch 18 and the middle punch 20 are supported by the bottom plate 14.

[0050] In this way, an annular space is formed by the inner surface of the outer cylinder 16, the upper surface 18b of the lower punch 18, and the outer peripheral surface of the middle punch 20. Thereafter, by inserting the middle punch 20 into the through-hole 22a of the upper punch 22, the lower surface 22b of the upper punch 22 can press this annular space.

[0051] Next, the molding step (S20) using the mold 12 will be described with reference to Figures 5(A) to 5(D). In the molding step (S20), first, the mixture 3 is supplied to the annular space formed by the outer cylinder 16, the lower punch 18, and the middle punch 20. Figure 5(A) is a cross-sectional view showing the mixture 3 supplied to the mold 12.

[0052] Next, the mixture 3 supplied to the annular space is pressed into the bottom of the annular space while being made substantially flat using a leveling jig 24. Fig. 5(B) is a cross-sectional view showing how the mixture 3 supplied to the mold 12 is leveled.

[0053] Next, the through hole 22a of the upper punch 22 is inserted into the middle punch 20, and the mixture 3 is pressed and molded with the lower surface 22b of the upper punch 22. Fig. 5(C) is a cross-sectional view showing the insertion of the through hole 22a of the upper punch 22 into the middle punch 20, and Fig. 5(D) is a cross-sectional view showing the molding of the mixture 3 to form a molded body 5.

[0054] For example, by pressing the upper punch 22 against the lower punch 18, the pressure is increased to 200 kgf / cm 2 More than 1000kgf / cm 2 The mixture 3 is pressed with a pressure below 100°C, and the mold 12 is heated so that the temperature of the mixture 3 is 100°C or higher and 200°C or lower. That is, in the molding step (S20), the mixture 3 is molded by hot compression molding to form a circular ring-shaped molded body 5.

[0055] Next, the compact 5 is fired in a firing furnace (not shown) (firing step (S30)). The firing furnace is, for example, an electric furnace. By firing the compact 5 at a temperature of 100°C or higher and 300°C or lower (for example, 180°C) for 30 to 40 hours (for example, 36 hours), a fired body is formed in which the abrasive grains 2a are fixed by the fired thermosetting resin 2c.

[0056] After the firing step (S30), the fired body is removed from the firing furnace and transferred to a heat treatment furnace (not shown). The fired body is then heat-treated in the heat treatment furnace (heat treatment step (S40)). The heat treatment furnace is, for example, an electric furnace.

[0057] The heat treatment furnace is provided with a gas inlet (not shown) and a suction port (not shown), and the atmosphere during heat treatment can be an inert gas atmosphere such as nitrogen or argon, or a vacuum atmosphere (for example, 100 Pa or less).

[0058] In the heat treatment step (S40), first, the fired body is placed in a heat treatment furnace, and then the heat treatment furnace is made into an airtight space and nitrogen gas is supplied into the furnace to create a nitrogen atmosphere (inert gas atmosphere) inside the furnace.

[0059] Next, the heat treatment furnace is heated, and the sintered body is heat-treated in a nitrogen atmosphere at a temperature of 500°C to 1500°C (e.g., 800°C) for 30 minutes to 2 hours (e.g., 1 hour). Note that instead of the nitrogen atmosphere, the sintered body may be heat-treated in a vacuum atmosphere at a temperature of 500°C to 1500°C for 30 minutes to 2 hours.

[0060] In the heat treatment step (S40), a part or all of the thermosetting resin 2c is transformed into glassy carbon, thereby producing the above-mentioned cutting blade 2. After the heat treatment step (S40), the cutting blade 2 is shaped into a desired shape by truing, dressing, etc.

[0061] In the above manufacturing method, the firing furnace and the heat treatment furnace are described as being different furnaces, but the firing furnace and the heat treatment furnace may be the same furnace. For example, an electric furnace whose interior can be set to either an air atmosphere or an inert gas atmosphere may be used, and the firing step (S30) may be performed in an air atmosphere, and then the heat treatment step (S40) may be performed in an inert gas atmosphere.

[0062] Next, a method for cutting the wafer 11 using the cutting blade 2 will be described. First, the configuration of the wafer 11 will be described with reference to Figures 6(A) and 6(B). The wafer 11 has a disk-shaped substrate 23 made mainly of silicon, for example. However, there is no limitation on the material of the substrate 23. The substrate 23 may be made of gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC), etc.

[0063] A multilayer wiring layer 25 is provided on one surface side of the substrate 23 (i.e., the front surface 11a side of the wafer 11). The multilayer wiring layer 25 is a laminate in which insulating films (not shown) made of low-dielectric-constant insulating materials (so-called low-k materials) and metal layers (not shown) are alternately stacked. That is, in the multilayer wiring layer 25, insulating films (i.e., low-k films) made of low-k materials and the like are stacked.

[0064] A plurality of dividing lines 13 are set in a grid pattern on the front surface 11a of the wafer 11. A device 15 is formed in each of a plurality of regions separated by the dividing lines 13.

[0065] Each device 15 is formed of a functional region formed from one surface of the substrate 23 to a predetermined depth inside the substrate 23, and a wiring region located above the functional region in the multilayer wiring layer 25. This wiring region is a convex portion that protrudes above the region of the multilayer wiring layer 25 where the planned division lines 13 are set.

[0066] Before cutting the wafer 11, a circular dicing tape 17 having a diameter larger than that of the wafer 11 is attached to the back surface 11b (i.e., the other surface of the substrate 23) opposite the front surface 11a of the wafer 11. Furthermore, one surface of a metal ring-shaped frame 19 is attached to the outer periphery of the dicing tape 17.

[0067] In this manner, a wafer unit 21 is formed in which the wafer 11 is supported on the frame 19 via the dicing tape 17. Fig. 6(A) is a perspective view of the wafer unit 21, and Fig. 6(B) is a cross-sectional view of the wafer 11 and the like.

[0068] The wafer 11 is cut using, for example, a cutting device 30. The cutting device 30 will now be described with reference to Fig. 7(A). The cutting device 30 has a chuck table 32 that holds the back surface 11b side of the wafer 11 by suction.

[0069] The chuck table 32 has a substantially disk-shaped porous plate (not shown). A flow path (not shown) is connected to the back surface (lower surface) of the porous plate, and this flow path is connected to a suction source such as an ejector. When the suction source is operated, negative pressure is generated on the front surface (upper surface) of the porous plate.

[0070] A θ table (not shown) that rotates the chuck table 32 is connected below the chuck table 32. An X-axis direction moving unit (not shown) is provided below the θ table. The X-axis direction moving unit moves the θ table, chuck table 32, etc. along the X-axis direction.

[0071] A cutting unit 34 is provided above the chuck table 32. The cutting unit 34 has a spindle housing 36, and a cylindrical spindle (not shown) is rotatably housed within the spindle housing 36. A screw hole (not shown) is formed at the tip of the spindle, into which a fixing member such as a bolt is fastened.

[0072] A substantially disk-shaped rear flange (not shown) is disposed at the tip of the spindle. A predetermined hole (not shown) substantially equivalent to the screw hole of the spindle is formed in the center of the rear flange. When a bolt is fastened to the screw hole with the hole of the rear flange aligned with the screw hole of the spindle, the annular portion around the hole of the rear flange is clamped and fixed between the head of the bolt and the tip of the spindle.

[0073] A cylindrical boss (not shown) is formed on the rear flange on the side opposite to the side that contacts the spindle. The outer diameter of the boss is smaller than the through-hole 4 of the cutting blade 2, and a male thread is formed on the outer periphery of the tip of the boss. The cutting blade 2 is fixed in position by being sandwiched between the rear flange and the annular front flange 38.

[0074] Specifically, first, the through hole 4 of the cutting blade 2 is inserted into the boss portion, and then the through hole (not shown) of the front flange 38 is inserted into the boss portion. Then, an annular press nut 40 with a thread formed on the inner periphery is fastened to the male thread of the boss portion. As a result, the cutting blade 2 is clamped between the rear flange and the front flange 38.

[0075] A camera unit 42 for photographing an object such as the wafer 11 arranged below is provided on the side of the spindle housing 36. The camera unit 42 is used for detecting (aligning) the planned dividing line 13, checking the kerf width, etc.

[0076] Next, a description will be given of a method for cutting the wafer 11 using the cutting device 30. Fig. 8 is a flow chart showing the cutting method. First, the wafer unit 21 is placed on the chuck table 32, and the suction source is operated.

[0077] The wafer 11 is held by suction on the back surface 11b side of the wafer 11 to the chuck table 32 with the multilayer wiring layer 25 exposed (holding step (S100)). After the holding step (S100), the planned dividing lines 13 of the wafer 11 are detected using the camera unit 42.

[0078] Then, the chuck table 32 is rotated so that one of the planned dividing lines 13 is approximately parallel to the X-axis direction, and the cutting blade 2 is positioned at one of the planned dividing lines 13. At the same time, the lower end of the cutting blade 2, which rotates around the spindle as its rotation axis, is positioned at the height of the boundary between the substrate 23 and the multilayer wiring layer 25 (i.e., one surface of the substrate 23).

[0079] Then, the X-axis direction moving unit is used to relatively move the cutting blade 2 and the chuck table 32 along the X-axis direction. As a result, the multilayer wiring layer 25 is cut along one of the planned division lines 13, and the insulating film of the multilayer wiring layer 25 is cut by the cutting blade 2 (cutting step (S110)).

[0080] 7(A) is a perspective view of the wafer unit 21 etc. in the cutting step (S110), and FIG. 7(B) is a cross-sectional view of the wafer 11 in the cutting step (S110). As described above, the cutting blade 2 uses glassy carbon for at least a part of the binder 2b.

[0081] In this case, the bonding material 2b is more brittle than with electroformed bond or metal bond blades, making it easier for the cutting blade 2 to self-sharpen. Therefore, compared to cutting with an electroformed bond or metal bond blade, the cutting blade 2 is less likely to impact the insulating film, which is prone to peeling. Therefore, the insulating film is less likely to break or crack, making it possible to suppress peeling of the insulating film, which is prone to peeling during cutting.

[0082] Furthermore, since the average particle diameter of the abrasive grains 2a is smaller than the blade thickness of the outer periphery of the cutting blade 2 (for example, if the blade thickness of the outer periphery of the cutting blade 2 is 20 μm to 30 μm, the average particle diameter of the abrasive grains 2a is 12 μm or less), the effect of the abrasive grains 2a on the workpiece is reduced, and peeling of the insulating film, which is prone to peeling during cutting, can be suppressed.

[0083] By cutting the multilayer wiring layer 25, cutting grooves 13a are formed in the substrate 23, exposing the substrate 23 along the division lines 13. After the cutting grooves 13a are formed along all of the division lines 13, the bottoms of the cutting grooves 13a are cut using another cutting blade (cutting step (S110)). In this way, the wafer 11 is cut along all of the division lines 13, thereby producing a plurality of chips (not shown).

[0084] After manufacturing the plurality of chips, the wafer 11 is transported to a cleaning unit (not shown) and cleaned (cleaning step (S120)). After the cleaning step (S120), the plurality of chips are each removed from the dicing tape 17 (removal step (S130)).

[0085] In the above example, after forming the cutting groove 13a in the multilayer wiring layer 25 with the cutting blade 2, the substrate 23 is cut with another cutting blade, but it is also possible to cut both the multilayer wiring layer 25 and the substrate 23 using only the cutting blade 2.

[0086] Additionally, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. For example, the object to be cut by the cutting blade 2 is not limited to the low-k film of the multilayer wiring layer 25. The cutting blade 2 may also be used to cut a passivation film (insulating film) that is prone to peeling during cutting. In this case, too, the insulating film can be cut while preventing peeling of the insulating film that is prone to peeling during cutting. [Explanation of symbols]

[0087] 3 mixture 5 Molded body 11 wafers 11a surface 11b Back side 13 Planned division line 13a Cutting groove 15 devices 17 Dicing tape 19 frames 21 Wafer Unit 23 Circuit Board 25 Multilayer wiring layer 2 cutting blades 2a Abrasive grain 2b Binding material 2c thermosetting resin 4 through holes 6 Stirrer 8. Housing 8a aperture 8b Bottom 10 Shaft 10a Rotation axis 12 Mold 14 Bottom plate 16 Outer cylinder 16a,18a,22a through hole 18 Lower Punch 18b Top side 20 Medium Punch 22 Upper Punch 22b Bottom surface 24 Leveling jig 30 Cutting equipment 32 Chuck table 34 Cutting unit 36 Spindle housing 38 Front flange 40 retaining nut 42 Camera Unit

Claims

1. A method for manufacturing a cutting blade in which abrasive grains are fixed by a binder, comprising the steps of: a molding step of hot compression molding a mixture containing a thermosetting resin and the abrasive grains at a temperature of 100°C or higher and 200°C or lower to form a molded body of a predetermined shape from the mixture; a firing step of firing the compact at a temperature of 100°C or higher and 300°C or lower to form a fired body after the molding step; a heat treatment step of heat treating the fired body at a temperature of 500°C or higher and 1500°C or lower in an inert gas atmosphere or a vacuum atmosphere after the firing step; a dressing step of dressing the cutting blade manufactured by the heat treatment step; Equipped with The average particle size of the abrasive grains is 12 μm or less, In the heat treatment step, at least a portion of the thermosetting resin becomes the binder of the glassy carbon; In the dressing step, the outer peripheral thickness of the cutting blade is made thinner than the inner peripheral thickness, and the outer peripheral thickness is set to 20 μm to 30 μm.

2. A method for manufacturing a cutting blade as described in claim 1, characterized in that in the dressing process, the cutting blade after the heat treatment process is dressed using a dressing board including linear grooves having a width corresponding to the outer peripheral thickness.

3. A method for manufacturing a cutting blade as described in claim 1 or 2, characterized in that the inner peripheral thickness of the cutting blade after the dressing process is 100 μm to 300 μm.

Images