JP6009238B2 - Cutting blade and cutting method - Google Patents

Description

  The present invention relates to a cutting blade mounted on a rotary shaft and used for cutting various workpieces and a cutting method.

  Semiconductor wafers formed on the surface by dividing devices such as ICs and LSIs by dividing lines are divided into individual devices by cutting the dividing lines by a cutting machine equipped with a rotatable cutting blade. Etc. are used. A package device configured by dividing a substrate on which a plurality of devices are packaged for each device is also divided by a cutting apparatus including a rotatable cutting blade and used for various electronic devices.

  For cutting blades, electroformed hub blades composed of diamond abrasive grains solidified by nickel plating, resin bond blades composed of diamond abrasive grains solidified by resin bonds, diamond abrasive grains solidified by metal bonds, etc. There are metal bond blades configured, vitrified bond blades configured by solidifying diamond abrasive grains etc. with vitrified bond, etc., and select the appropriate one from these blades according to the characteristics of the work piece (For example, refer to Patent Document 1).

JP 2010-36291 A

  However, when cutting a hard material such as sapphire or silicon carbide (SiC), cutting is performed while supplying a cutting fluid to the cutting blade, but the frictional heat between the cutting blade and the hard material cannot be removed, There is a problem that sparks are generated and processing quality is deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting blade and a cutting method capable of reducing frictional heat generated at the processing points of the cutting blade and the hard material.

The cutting blade of the present invention is a cutting blade formed into a disk shape by cutting abrasives at a high speed while cutting the workpieces held at a holding table and bonding abrasive grains with a binder to cut the workpieces. The both surfaces of the binder are coated with a material having a thermal conductivity of 200 W / m · K or more at least as wide as the depth to be cut into the workpiece , and the coated film of the material The thickness is smaller than the protruding amount of the abrasive grains from both side surfaces of the binder, and the both side surfaces are flat outer peripheral blades .

The cutting method of the present invention is a cutting method for cutting a workpiece made of a hard material, which is held on a holding table, and is formed by combining abrasive grains with a binder to form a disk shape. A material having a thermal conductivity of 200 W / m · K or more is coated on both surfaces of the material at least to a width greater than the depth of cutting into the workpiece , and the thickness of the coated material is the binding material And a step of cutting into the work piece while rotating at high speed a cutting blade which is a peripheral blade having a flat surface on both side surfaces .

  The cutting blade according to the present invention coats the side of the cutting blade where the friction between the cutting blade and the hard material increases when cutting the hard material with a material having a high thermal conductivity (200 W / m · K or more). The frictional heat is removed smoothly, the generation of sparks is prevented as much as possible, and the processing quality can be improved.

Drawing 1 is a figure showing the example of composition of the cutting device concerning an embodiment. FIG. 2 is a view showing a processing means having a hub blade. FIG. 3 is a cross-sectional view of the main part of the processing means. FIG. 4 is an enlarged cross-sectional view of the outer peripheral portion of the cutting blade. FIG. 5 is a diagram illustrating a processing unit according to a first modification of the embodiment.

  Hereinafter, a cutting blade and a cutting method according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 to 4. The present embodiment relates to a cutting blade and a cutting method. 1 is a diagram illustrating a configuration example of a cutting device according to an embodiment, FIG. 2 is a diagram illustrating a processing unit having a hub blade, FIG. 3 is a cross-sectional view of a main part of the processing unit, and FIG. It is an expanded sectional view of an outer peripheral part.

  The cutting device 1 performs a cutting process on the workpiece W. As shown in FIG. 1, the chuck table 10, a processing unit 20, an X-axis moving unit (not shown), a Y-axis moving unit 30, The Z-axis moving means 40 and the control device 50 are included.

  The chuck table 10 is a holding table that holds the workpiece W. The chuck table 10 holds the workpiece W in an exposed state by sucking the workpiece W placed on the surface. The chuck table 10 is detachably fixed to the table moving base 2. In addition, a clamp portion 11 is provided around the chuck table 10, and the clamp portion 11 is driven by an air actuator so that the frame F holding the workpiece W is held via the dicing tape T. To do.

  Here, the workpiece W is a workpiece to be processed by the cutting apparatus 1, and in this embodiment, the workpiece W is made of a semiconductor wafer having a base material such as silicon, sapphire, SiC, gallium, CSP substrate, glass, resin, or the like. It is a plate-shaped member. The workpiece W has, for example, a device-side surface on which a plurality of devices are formed and a back surface opposite to the device-side surface attached to the dicing tape T, and the dicing tape T attached to the workpiece W is attached to the frame F. By being worn, it is fixed to the frame F.

  The processing means 20 performs cutting on the workpiece W held on the chuck table 10. The processing means 20 includes a cutting blade 21, a rotary spindle 22, a blade cover device 23, a housing 24, and a nozzle 25.

  Further, as shown in FIG. 2, the processing means 20 includes a fixing flange 26, a fixing nut 27, and a fixing bolt 28. The cutting blade 21 is used to cut the workpiece W while rotating it at a high speed on the workpiece W held on the chuck table 10, and is formed in a disk shape by bonding abrasive grains with a binder. ing. The cutting blade 21 of this embodiment is a so-called hub blade, and the cutting blade 21 is integrally fixed to the outer periphery of the hub 29. The cutting blade 21 is formed in an annular shape for cutting the workpiece W, and is configured in a state in which an abrasive made of abrasive grains is held in a binding material.

  By inserting the boss portion 26 a of the fixing flange 26 into the through hole 29 a of the hub 29 and screwing the fixing nut 27 into the male screw portion 26 b of the fixing flange 26, the fixing flange 26, the cutting blade 21, and the fixing nut 27 are connected. It is fixed integrally. Also, the fixing flange 26 is fixed to the rotating spindle 22 by inserting the fixing bolt 28 into the through hole 26 c of the fixing flange 26 and screwing it into the female screw portion 22 a of the rotating spindle 22. Thus, the cutting blade 21 is detachably fixed to the rotary spindle 22.

  The rotary spindle 22 is rotatably supported by a cylindrical housing 24 and is connected to a rotation drive source (not shown) connected to the housing 24. The cutting blade 21 rotates at a high speed (several thousand to several tens of thousands rpm) by the rotational force generated by the rotational drive source.

  The blade cover device 23 in FIG. 1 covers the cutting blade 21 attached to the tip of the rotary spindle 22. Two nozzles 25, 25 are arranged in the blade cover device 23. The nozzles 25 are opposed to each other in the axial direction of the rotary spindle 22 with the cutting blade 21 interposed therebetween. Each nozzle 25 supplies cutting fluid supplied from a cutting fluid supply source (not shown) to the cutting blade 21 and the workpiece W. The supply of the cutting fluid through the nozzle 25 is controlled by the control device 50. Further, the blade cover device 23 is provided with a nozzle (not shown) opposed to the outer periphery of the cutting blade 21 in the radial direction, and the cutting fluid is also supplied from the nozzle to the cutting blade 21 and the workpiece W. .

  The X-axis moving means moves the workpiece W held on the chuck table 10 relative to the cutting blade 21 in the X-axis direction in the cutting apparatus 1. The X-axis moving means moves the table main body 2 in the X-axis direction while guiding the table moving base 2 with an X-axis guide rail (not shown) by a rotational force generated by an X-axis pulse motor (not shown). Here, the table moving base 2 is supported so as to be rotatable in the θ direction in the cutting apparatus 1 around the central axis of the table moving base 2. The table moving base 2 is connected to a rotational drive source (not shown), and can rotate at an arbitrary angle, for example, 90 degrees or continuous rotation in the θ direction by the rotational force generated by the rotational drive source. The control device 50 can cause the workpiece W held on the chuck table 10 to be driven to rotate at an arbitrary angular rotation or continuous rotation around the central axis of the table moving base 2 with respect to the cutting blade 21. .

  As shown in FIG. 1, the Y-axis moving unit 30 moves the cutting blade 21 relative to the workpiece W held on the chuck table 10 in the Y-axis direction of the cutting apparatus 1. The Y-axis moving means 30 moves the processing means 20 in the Y-axis direction while guiding the processing means 20 by a Y-axis guide rail (not shown) by a rotational force generated by a Y-axis pulse motor (not shown).

  The Z-axis moving unit 40 moves the cutting blade 21 relative to the workpiece W held on the chuck table 10 in the Z-axis direction in the cutting apparatus 1. The Z-axis moving means 40 moves the machining means 20 in the Z-axis direction while guiding the machining means 20 by a Z-axis guide rail (not shown) by a rotational force generated by a Z-axis pulse motor (not shown).

  The control device 50 is a control means, and controls each of the above-described components constituting the cutting device 1. The control device 50 rotates the cutting blade 21 at a high speed and cuts the workpiece W by relatively moving the chuck table 10 and the cutting blade 21 in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ direction. Processing is performed by the processing means 20. The cutting method executed by the control device 50 includes a step of cutting the workpiece W into the workpiece W by relatively moving the chuck table 10 and the cutting blade 21 while rotating the cutting blade 21 at a high speed. Note that the control device 50 is mainly configured by an arithmetic processing device configured by a CPU or the like, or a microprocessor (not shown) provided with a ROM, a RAM, or the like.

  Here, at the time of cutting, the cutting fluid is supplied to the cutting blade 21 and the workpiece W for cooling, but the frictional heat between the cutting blade 21 and the workpiece W cannot be sufficiently removed, and a spark is generated. Occurs, and the processing quality deteriorates. Such a problem is likely to occur when a workpiece W made of a hard material such as sapphire or SiC is cut.

  The cutting blade 21 according to the present embodiment is coated with a material having high thermal conductivity on both surfaces of the binder. Thereby, the frictional heat generated at the processing point between the cutting blade 21 and the workpiece W can be reduced. In order to reduce the frictional heat generated at the machining point, the temperature rise at the machining point between the cutting blade 21 and the workpiece W is suppressed by releasing the generated frictional heat by heat transfer or heat dissipation. included.

  FIG. 4 shows an enlarged cross-sectional view of the main part C1 of FIG. The cutting blade 21 of the present embodiment is formed by combining diamond abrasive grains 4 with a binding material 5 into a disk shape. The binding material 5 of this embodiment is a resin bond. A part of the diamond abrasive grains 4 protrudes from the surfaces (side surfaces) 5 a and 5 b of the binding material 5.

  A coating film 6 is formed on both surfaces 5 a and 5 b of the binding material 5. The coating film 6 of this embodiment has a disk shape. The coating film 6 is coated to a width of at least the depth D1 cut into the workpiece W. The coating film 6 is formed with a predetermined width W1 from the outermost periphery of the cutting blade 21 toward the radially inner side with respect to both surfaces 5a and 5b. The predetermined width W1 is not less than the depth D1 at which the cutting blade 21 cuts into the workpiece W, and is preferably larger than the depth D1. The predetermined width W1 is determined to be equal to or greater than the depth D1 to be cut into the workpiece W even when the wear amount of the cutting blade 21 is maximized within the allowable range. In other words, the predetermined width W1 when not in use is equal to or greater than the sum of the depth D1 cut into the workpiece W and the allowable maximum wear width of the cutting blade 21 in the radial direction.

  The material of the coating film 6 is a material having a thermal conductivity of 200 W / m · K or more. The material of the coating film 6 is, for example, aluminum, gold, silver or the like, but is not limited thereto. The coating film 6 having a high thermal conductivity is formed on the surfaces 5a and 5b of the binding material 5, thereby reducing the frictional heat generated at the processing point of the workpiece W made of the cutting blade 21 and the hard material. be able to. The coating film 6 can suppress the accumulation of heat in the cutting blade 21 by, for example, promoting the release of heat to the cutting fluid or air that comes into contact with the coating film 6. Further, the coating film 6 can release the heat generated at the processing point to the inside in the radial direction, and can suppress the temperature rise of the outer peripheral portion of the cutting blade 21, that is, the portion in contact with the workpiece W.

  Table 1 shows the thermal conductivity of various materials and the occurrence of sparks during cutting when the coating film 6 is formed of the materials. A nickel film, an aluminum film (deposition only), a gold film, and a silver film are formed on the side surfaces of the cutting blade 21 that is a resin blade by plating or vapor deposition, respectively. The film thickness of the coating film 6 is 0.1 to 2 μm. This film thickness is thinner than the protrusion amount P1 of the diamond abrasive grains 4 from the surfaces 5a and 5b of the binder 5 (see FIG. 4). In addition, the protrusion amount P1 can be an average protrusion amount of the diamond abrasive grains 4, for example. Since the film thickness of the coating film 6 is determined so that the diamond abrasive grains 4 protrude, the self-generated blade is smoothly performed and occurrence of clogging of the side surfaces is suppressed.

  In the experiment in which the results shown in Table 1 were obtained, the abrasive particle size of the cutting blade 21 was 2 to 6 μm. A covering film 6 was formed. The workpiece W to be cut was a 2 inch × 100 μm sapphire substrate, and the workpiece W was cut by cutting about 30 μm to confirm the occurrence of sparks. The machining conditions were a spindle rotation speed of 15,000 rpm, a feed rate (C / T) of 10 mm / s, and a 10 μm cut was made three times to create a groove with a depth of 30 μm on the workpiece W.

  There are four types of materials for the coating film 6 in the experiment: nickel, aluminum, gold, and silver. As shown in Table 1, sparks were generated in the cutting blade 21 on which the nickel coating film 6 was formed, but sparks were generated on the cutting blade 21 in which the aluminum, gold, and silver coating film 6 was formed. Was not seen. That is, when the cutting blade 21 is coated with a material having a thermal conductivity of 200 W / m · K or more, frictional heat generated at a processing point when cutting a hard material is reduced, and generation of sparks is suppressed. . The material of the coating film 6 may have, for example, a thermal conductivity equal to or higher than that of aluminum. The cutting blade 21 of this embodiment has high strength because the coating film 6 is formed.

  The cutting method according to the present embodiment is a cutting method for cutting a workpiece W made of a hard material, which is held on a chuck table 10, and is formed into a disk shape by bonding abrasive grains with a bonding material 5. The cutting blade 21 coated with a material having a thermal conductivity of 200 W / m · K or more on at least the width D1 of the depth D1 or more cut into the workpiece W on both surfaces of the binder 5 is rotated at high speed. A step of cutting into the workpiece W is included. The hard material includes, for example, at least one of sapphire and SiC. The workpiece W is, for example, a sapphire substrate or a SiC substrate.

  By the cutting method of cutting with the cutting blade 21 coated with a material having a thermal conductivity of 200 W / m · K or more, the frictional heat when cutting the workpiece W made of a hard material is reduced, and the spark Occurrence is suppressed.

  In this embodiment, the bonding material 5 is a resin bond, but is not limited to this. The binding material 5 may be a metal bond, a vitrified bond, nickel, or the like. Moreover, the material of the coating film 6 is not limited to what was illustrated. The surface of the cutting blade 21 may be coated with another material having the above-described thermal conductivity. Further, the abrasive grains are not limited to diamond.

[First Modification of Embodiment]
A first modification of the embodiment will be described. FIG. 5 is a diagram illustrating a processing unit according to a first modification of the embodiment. The cutting blade 21 of the processing means 20 may be a washer blade as shown in FIG. The machining means 20 of this modification includes a rotary spindle 22, a fixing flange 26, a cutting blade 21, a flange 31, a fixing nut 27 and a fixing bolt 28. The cutting blade 21 is formed in an annular shape for cutting the workpiece W, and is configured in a state in which an abrasive made of abrasive grains is held in a binding material.

  The boss portion 26a of the fixing flange 26 is inserted into the hole portion of the cutting blade 21 and the annular flange 31, and the fixing nut 27 is screwed into the male screw portion 26b of the fixing flange 26, thereby cutting the fixing flange 26 and the cutting flange 21. The blade 21, the flange 31, and the fixing nut 27 are fixed integrally. Also, the fixing flange 26 is fixed to the rotating spindle 22 by inserting the fixing bolt 28 into the through hole 26 c of the fixing flange 26 and screwing it into the female screw portion 22 a of the rotating spindle 22.

  Also for such a washer blade type cutting blade 21, the coating film 6 is formed of a material having a high thermal conductivity (for example, 200 W / m · K or more) as in the above-described embodiment, whereby the cutting blade 21 is formed. And the frictional heat generated at the processing point of the hard material can be reduced. Further, the frictional heat generated at the processing point in the cutting of the workpiece made of the hard material by the cutting method of cutting into the workpiece W while rotating the cutting blade 21 having the coating film 6 formed on both surfaces at high speed. Can be reduced.

[Second Modification of Embodiment]
In the above embodiment and the first modification, the coating film 6 having the predetermined width W1 is formed on both surfaces of the cutting blade 21, but the coating film 6 is formed on the entire surface of both surfaces of the cutting blade 21, for example. Also good. Further, the coating film 6 may be formed so as to come into contact with members such as the fixed flange 26, the hub 29, and the flange 31, that is, an attachment member that attaches the cutting blade 21 to the rotary spindle 22. On the contrary, the coating film 6 may be formed so as not to come into contact with an attachment member for attaching the cutting blade 21 to the rotary spindle 22.

  Further, the coating film 6 may be divided into a plurality of regions in the circumferential direction and the radial direction. For example, the coating film 6 may have a plurality of disk-shaped regions arranged at different positions in the radial direction. Moreover, the coating film 6 may have a plurality of fan-shaped regions arranged at different positions in the circumferential direction.

  The contents disclosed in the above embodiments and modifications can be executed in appropriate combination.

DESCRIPTION OF SYMBOLS 1 Cutting device 4 Diamond abrasive grain 5 Binding material 5a, 5b Surface 6 Coating film 10 Chuck table (holding table)
20 Processing means 21 Cutting blade 22 Rotating spindle 50 Controller D1 Depth of cut P1 Projection amount W Workpiece W1 Predetermined width

Claims (2)

A cutting blade that is formed into a disk shape by combining abrasive grains with a binder to cut and cut the workpiece while rotating the workpiece held on the holding table at high speed,
Both surfaces of the binder are coated with a material having a thermal conductivity of 200 W / m · K or more at least as wide as the depth to be cut into the workpiece , and the film thickness of the coated material is A cutting blade characterized in that it is thinner than the protruding amount of the abrasive grains from both side surfaces of the binding material and is a peripheral blade having a flat side surface . A cutting method for cutting a workpiece made of a hard material held by a holding table,
A material having a thermal conductivity of 200 W / m · K or more at a width greater than the depth of cutting into the workpiece on both surfaces of the binding material by bonding abrasive grains with a binding material. And the coating blade is thinner than the protruding amount of the abrasive grains from both sides of the binder, and the cutting blade which is a flat outer peripheral blade on both sides is rotated at high speed. A cutting method comprising a step of cutting into the workpiece while performing the cutting.

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