JP4541791B2 - Manufacturing method of cutting wheel - Google Patents

Description

  The present invention relates to a method for manufacturing a cutting grindstone provided with an electroformed blade.

  When a workpiece such as a semiconductor wafer is cut and divided into individual devices or the like, a cutting apparatus configured to cut a cutting grindstone mounted on a spindle into the workpiece while rotating at high speed is usually used. As a cutting grindstone, a hub blade having a configuration in which an electroformed blade is fixed to one surface of a base and the outer peripheral portion of the electroformed blade protrudes from the outer peripheral side of the base because it can be easily attached to and detached from the spindle. (See, for example, Patent Document 1 and Patent Document 2).

JP 09-314465 A JP 05-345281 A

  However, as described above, the hub blade has a structure in which the electroformed blade is fixed to one side of the base. Therefore, when the blade is rotated at a high speed of, for example, 20000 rpm to 40000 rpm during cutting, the electroformed blade is There is a problem that the electroformed blade is obliquely cut into the workpiece due to the inclination to the side, and high-precision cutting cannot be performed.

  In addition, an ultrasonic vibrator is mounted on the spindle on which the cutting wheel is mounted, and the vibration is transmitted to the diameter direction of the electroformed blade by applying ultrasonic vibration to the spindle and changing the direction of vibration by the ultrasonic wave at the base. Therefore, when using the technology to cut the work efficiently, the ultrasonic vibration is sufficiently transmitted to the electroforming blade because the conversion point of the ultrasonic transmission direction does not match the rotation center of the electroforming blade. There is a problem that it is not.

  Therefore, the problem to be solved by the present invention is to prevent the electroforming blade from tilting during high-speed rotation in the cutting grindstone, and to perform ultrasonic vibration when performing cutting using ultrasonic vibration. It is to be able to fully communicate to the blade.

The method for producing a cutting grindstone according to the present invention is a method for producing a cutting grindstone in which an electrodeposition blade is fixed to a base to form a cutting grindstone, wherein two frustoconical bottoms having different bottom diameters face each other. The masking step of masking the surface other than the ring surface of the base having at least the shape in which the bottom surface with the larger outer diameter protrudes from the facing part to the outer peripheral side and the ring surface is formed, and the base after the masking step was immersed in a plating solution tank, two frustoconical and electrodeposition step of forming the electroformed blade by electrodepositing abrasive grains to the ring plane, the base to remove the ring face removed base from the plating bath is isomorphic And a ring surface removing step of exposing the electrodeposition blade so as to have at least a shape in which a protruding outer peripheral portion is formed on the outer peripheral portion of the facing portion .

In the method for manufacturing a cutting grindstone according to the present invention, two frustoconical bottom surfaces having different bottom surface diameters face each other, and a bottom surface having a larger outer diameter projects from the facing part to the outer peripheral side to form a ring surface. In order to expose the electroformed blade after fixing the electroformed blade to the ring surface of the base having at least the shape, the two bottom surfaces of the same truncated cone face each other, and a protruding outer peripheral portion is formed on the outer peripheral portion of the facing portion. shape having at least a good balance of the centrifugal force during rotation, Ru preferably der for the manufacture of the cutting grindstone is not inclined even during high-speed rotation.

  In the base 1 shown in FIGS. 1 and 2, two frustoconical bottoms having different bottom surface diameters face each other, and a ring surface is formed at a portion where the bottom surface having a larger outer diameter projects from the facing part to the outer peripheral side. 10 is formed. The term “bottom surface” as used herein means a surface having a larger outer diameter among the upper surface and the lower surface, which are two planes constituting a truncated cone. The two frustoconical shapes preferably have the same height (thickness), but even if the heights are different, the heights may be finally made equal by etching or the like.

  In the base 1, two cylindrical portions 11 and 12 having the same outer diameter are formed by extending cylindrically in directions away from each other from the upper surfaces of the two truncated cones, and the inner periphery and the cylindrical portion of the ring surface 10. 11 is connected by a first taper surface 13, and the outer periphery of the ring surface 10 and the outer periphery of the cylindrical portion 12 are connected by a second taper surface 14. Further, the base 1 is formed with a mounting hole 15 that passes through the inside of the cylindrical portions 11 and 12 and the two truncated cones and is mounted on a spindle described later, and is integrally formed as a whole. . The cylindrical portions 11 and 12 are not necessarily essential to the present invention.

  As shown in FIGS. 3 and 4, masking 16 is applied to a surface other than the ring surface 10 of the base 1 (masking process). It should be noted that it is desirable to provide a region where no masking is performed on the upper end of the first tapered surface 13 as in the illustrated example.

  Next, as shown in FIG. 5, the base 1 to which the masking 16 is applied is immersed in the plating solution tank 20 with the ring surface 10 facing upward. A plating solution 21 such as nickel sulfate is accommodated in the plating solution tank 20, and diamond abrasive grains 22 are mixed in the plating solution 21, for example.

  A plating metal such as a nickel rod 23 is immersed in the plating solution 21. A positive electrode of a DC power supply 24 is connected to the nickel rod 23, and a negative electrode of the DC power supply 24 is connected to the base 1 immersed in the plating solution 21 through a switch 25. The plating solution tank 20 is provided with a stirrer 26 for stirring the plating solution 21.

  The base 1 is immersed with the ring surface 10 facing upward, and the plating solution 21 is stirred by the stirrer 26 with the switch 25 turned off. Then, the stirring is stopped and the diamond abrasive grains 22 are allowed to settle, and the switch 25 is turned on. Then, the settled diamond abrasive grains 22 are received and deposited on the ring surface 10, and the deposited diamond abrasive grains 22 are electrodeposited and fixed by the nickel plating layer grown by the voltage supplied from the DC power source 24. FIG. As shown in FIG. 2, an electroformed blade 17 having a predetermined thickness is formed (electrodeposition process).

  Next, as shown in FIG. 7, the masking 16 is removed, and the second taper surface 14 is etched away to the third taper surface 18 shown by a two-dot chain line in FIG. The electroformed blade 17 is exposed. The state where the electroformed blade 17 is exposed in this manner is shown in FIGS. The ring surface 10 is removed by etching to the third taper surface 18, and both surfaces of the electrodeposition blade 17 are exposed (ring surface removal step).

  As shown in FIG. 9, by etching the second tapered surface 14 up to the third tapered surface 18, the first tapered surface 13 and the third tapered surface 18 have the same inclination angle, A protruding outer peripheral portion 19 is formed at a portion where the tapered surface 13 and the third tapered surface 18 are connected. The shape of the base 1 is symmetric with respect to the projecting outer peripheral portion 19, and the base 1 and the electroformed blade 17 constitute a cutting grindstone 30. That is, this cutting grindstone 30 has two bases of the same truncated cone shape facing each other and a base 1 having a shape in which a protruding outer peripheral portion 19 is formed on the outer peripheral portion of the facing portion, and the protruding outer peripheral portion 19 toward the outer peripheral side. And an electroformed blade 17 fixedly protruding.

  Thus, the cutting grindstone 30 having the configuration in which the electroformed blade 17 is fixed to the base 1 is mounted on, for example, the spindle 41 shown in FIG. The spindle 41 is rotatably supported by a housing 42, and a mount wall 43 that receives the cutting grindstone 30 is formed on the spindle 41. When the mounting hole 15 of the cutting grindstone 30 is inserted into the spindle 41 and brought into contact with the mount wall 43, and the flange 44 is screwed and fixed to the tip of the spindle 41, the cutting tool 40 is obtained.

  And this cutting tool 40 is mounted in the cutting apparatus 50 shown, for example in FIG. The cutting device 50 includes a loading / unloading means 53 having a role of carrying the plate-like object accommodated in the cassette 51 into the temporary placement area 52 and accommodating the plate-like object placed in the temporary placement area 52 in the cassette 51. , A chuck table 54 that holds a plate-like object to be cut, a conveying means 55 that conveys the plate-like object carried to the temporary placement region 52 to the chuck table 54, and an alignment that detects a position of the plate-like object to be cut. It comprises means 56 and a cutting tool 40 for cutting the position. In addition, in the cutting tool 40 in FIG. 11, the cutting grindstone 30 etc. are covered with the cover member.

  For example, when the wafer W integrated with the frame F is held on the chuck table 54 via the adhesive tape T, the chuck table 54 moves in the + X direction and is positioned immediately below the alignment means 56, so that the surface of the wafer W is After the image is picked up and the position to be cut is detected, the chuck table 54 is further moved in the + X direction, and cutting is performed under the action of the cutting grindstone 30 as shown in FIG. At the time of cutting, cutting water 45 a is ejected from the nozzle 45.

  As shown in FIG. 13, in the cutting tool 40, an ultrasonic transducer 46 may be attached to the spindle 41. In this case, the ultrasonic wave 47 transmitted from the ultrasonic transducer 46 in the axial direction of the spindle 41 is transmitted to the base 1 constituting the cutting grindstone 30, and the transmission direction is vertical at the central portion 1 a of the base 1. The direction is converted and transmitted to the electroformed blade 17. That is, the base 1 functions as a vibration conversion unit that converts the vibration direction of the ultrasonic waves. Then, the cutting grindstone 30 is cut into the wafer W while rotating at a high speed, and the cutting is also performed by ultrasonic vibration by ultrasonic waves transmitted to the electroformed blade 17.

  When cutting is performed in this manner, since the base 1 is formed symmetrically in the spindle direction with respect to the protruding outer peripheral portion 19, the balance of centrifugal force when the cutting grindstone 30 rotates at high speed is good. The electroformed blade 17 does not tilt. Therefore, since the electroformed blade 17 does not cut obliquely with respect to the wafer W, cutting can be performed with high accuracy.

  In addition, since the base 1 is formed symmetrically, when ultrasonic vibration is applied to the spindle and the transmission direction of the ultrasonic wave is converted in the base, the central portion 1a serving as a conversion point is electroformed. It coincides with the rotation center of the blade 17 and the ultrasonic wave is sufficiently transmitted to the electroformed blade 17, so that the plate-like object can be cut more efficiently.

It is a perspective view which shows the base of the shape where the bottom surfaces of two truncated cone shapes from which the outer diameter of a bottom face differs faced each other. It is a side view which shows the base. It is a perspective view which shows the state which masked the base. It is sectional drawing which shows the state which masked the base. It is a schematic sectional drawing which shows an example of an electrodeposition process. It is sectional drawing which shows the state by which the electrocasting blade was electrodeposited to the base. It is sectional drawing which shows the state which removed the masking from the base. It is a perspective view which shows the state which removed some bases and was made into the left-right symmetry. It is sectional drawing which shows the state which removed the base and made it left-right symmetric. It is a perspective view which shows an example of a structure of a cutting tool. It is a perspective view which shows an example of a cutting device. It is a perspective view which shows a mode that a wafer is cut using a cutting tool. It is explanatory drawing which shows a mode that an ultrasonic wave is transmitted in a cutting tool.

1: base 10: base 11, 12: cylindrical portion 13: first tapered surface 14: second tapered surface 15: mounting hole 16: masking 17: electroformed blade 18: third tapered surface 19: Protruding outer peripheral portion 20: Plating bath 21: Plating solution 22: Diamond abrasive grains 23: Nickel rod 24: DC power supply 25: Switch 26: Stirrer 30: Cutting grindstone 40: Cutting tool 41: Spindle 42: Housing 43: Mount wall 44 : Flange 45: Nozzle 46: Ultrasonic vibrator 47: Ultrasonic 50: Cutting device 51: Cassette 52: Temporary placement area 53: Carrying in / out means 54: Chuck table 55: Carrying means 56: Alignment means

Claims (1)

A method for manufacturing a cutting grindstone, in which an electrodeposition blade is fixed to a base and used as a cutting grindstone,
The ring surface of the base having at least a shape in which two frustoconical bottom surfaces with different outer diameters of the bottom surfaces face each other, and a bottom surface with a larger outer diameter protrudes from the facing portion to the outer peripheral side. A masking process for masking other surfaces,
An electrodeposition step of immersing the base after the masking step in a plating solution tank, and electrodepositing abrasive grains on the ring surface to form an electroformed blade;
The base is removed from the plating bath, and the ring surface is removed so that the bottoms of the two truncated cones of the same type face each other, and the outer peripheral part of the facing part has a protruding outer peripheral part. A method for producing a cutting grindstone comprising at least a ring surface removing step of exposing the electrodeposition blade.

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