Cutting device

Abstract

To prevent adhering of sawdust to a workpiece after cutting during a time period when the workpiece after the cutting is carried into a cleaning unit.SOLUTION: A cutting device includes: a holding table which holds a frame unit including a frame, a sheet, and a workpiece; a cutting unit which cuts the workpiece held by the holding table; a first transfer unit which has a first frame holding part and a workpiece cover part and is used to transfer the frame unit; a dome which is disposed at a moving path of the workpiece cover part, has a protruding curved surface, and is used to cause the workpiece formed with cut grooves to protrude upward through the sheet. The workpiece cover part includes: a housing which may cover the workpiece; a liquid supply part which supplies a liquid to a space of the housing; and an ultrasonic vibration application unit. In a state that the workpiece formed with the cut grooves is immersed in the liquid stored in the space of the housing, the ultrasonic vibration application unit applies ultrasonic vibration to the liquid in the space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cutting device equipped with a cutting unit that cuts a workpiece held by a holding table. [Background technology]

[0002] A cutting device is known that forms a frame unit in which a workpiece such as a disk-shaped semiconductor wafer or a rectangular package device substrate is supported by an annular frame via adhesive tape, and then divides the workpiece into device units while the frame unit is held on a holding table.

[0003] The cutting device includes a cutting unit having a spindle, and a cutting blade having an annular cutting edge is attached to the tip of the spindle. When cutting a workpiece with the cutting blade, cutting is performed while supplying a cutting fluid such as pure water to the workpiece for the purpose of cooling the cutting blade and discharging cutting chips from the processing point.

[0004] Cutting debris is carried by the used cutting fluid and adheres to the workpiece after cutting. Therefore, in order to reduce the amount of adhering cutting debris, a cutting device has been proposed in which the workpiece is submerged in a water tank and ultrasonic vibrations are applied to the workpiece while cutting the workpiece, thereby reducing the amount of adhering cutting debris (see, for example, Patent Document 1).

[0005] Since the workpiece after cutting usually has used cutting fluid and cutting chips attached to it, the workpiece after cutting is transported to a cleaning unit where it is washed with pure water or the like and dried.

[0006] However, it may take some time for the workpiece to be transported to the cleaning unit after cutting due to reasons such as waiting for the completion of cleaning and drying of other workpieces that were previously brought into the cleaning unit, or waiting for the cutting device to resume operation due to an error.

[0007] If it takes a long time to transport the workpiece to the cleaning unit, the cutting fluid on the workpiece may dry out, causing the cutting chips contained in the cutting fluid to adhere to the workpiece. If the cutting chips adhere to the workpiece, it becomes difficult to remove them even if the workpiece is cleaned in the cleaning unit.

[0008] Since a workpiece with a certain amount of remaining cutting debris is treated as a defective product, the adhesion of cutting debris causes a decrease in the productivity of device chips and packaged devices. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-344630 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in view of the above problems, and has as its object to prevent cutting chips from adhering to a workpiece after cutting while the workpiece is being transported to a cleaning unit. [Means for solving the problem]

[0011] According to one aspect of the present invention, a cutting device includes a holding table for holding a frame unit including an annular frame having an opening in the center, a sheet attached to one surface of the frame so as to close the opening, and a workpiece supported by the frame via the sheet at the opening; a cutting unit having a spindle and cutting the workpiece of the frame unit held by the holding table with a cutting blade attached to the tip of the spindle; a first frame holding section for holding the frame of the frame unit; and a workpiece covering section for covering the workpiece of the frame unit, the first conveying unit for holding the frame with the first frame holding section and for conveying the frame unit with the workpiece covered by the workpiece covering section; and a convex curved surface disposed on a movement path of the workpiece covering section. and a dome having a bottom opening for projecting the workpiece, on which the cutting groove has been formed, upward through the sheet, wherein the workpiece covering section of the first conveying unit includes a housing having an opening at the bottom and capable of covering the workpiece, a liquid supply section having a conduit fixed to the housing and supplying liquid to a space in the housing, and an ultrasonic vibration imparting unit having an ultrasonic vibrator fixed to the housing and imparting ultrasonic vibrations to the liquid in the space, wherein the frame is held by the first frame holding section, and the workpiece, on which the cutting groove has been formed, is supported by the dome, and the ultrasonic vibration imparting unit imparts ultrasonic vibrations to the liquid in the space when the workpiece, on which the cutting groove has been formed, is immersed in the liquid contained in the space in the housing, with the opening at the bottom of the housing closed by the sheet and the frame.

[0012] Preferably, the cutting device further includes a second conveying unit having a second frame holding portion that holds the frame of the frame unit, the dome is fixed to the upper part of the second frame holding portion, and the first conveying unit and the second conveying unit move so that the dome and the housing overlap, thereby positioning the dome on the movement path of the workpiece covering portion.

[0013] Preferably, the first frame holding portion has an annular suction holding member formed of an elastic material, the suction holding member including an annular opening and capable of sucking the frame by negative pressure generated in the annular opening, and the second frame holding portion has a pair of plate members and suction pads provided on the underside of each plate member and capable of sucking the frame by negative pressure generated in the suction pads.

[0014] Preferably, the housing of the workpiece covering portion of the first conveying unit is provided with a cover portion of the housing. It also functions as an escape route for gas. Includes a through hole. [Effects of the Invention]

[0015] In a cutting device according to one aspect of the present invention, a frame is held by a first frame holding part, a workpiece on which a cutting groove has been formed is supported by a dome, and the workpiece on which the cutting groove has been formed is immersed in a liquid contained in a space within a housing whose bottom opening is closed by a sheet and a frame. The ultrasonic vibration imparting unit imparts ultrasonic vibrations to the liquid. This prevents cutting chips from adhering to the cut workpiece while the cut workpiece is being transported to the cleaning unit. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 4(A) is a partially cross-sectional side view of the upper transport unit, and FIG. 4(B) is a bottom view of the upper transport unit. [Figure 5] FIG. 10 is a diagram showing how a workpiece is cut. [Figure 6] FIG. 10 is a partial cross-sectional side view of an upper transport unit and the like in which liquid is accommodated in the space of a housing. [Figure 7] FIG. 10 is a partial cross-sectional side view showing how the dome and the housing overlap. [Figure 8]FIG. 10 is a partial cross-sectional side view showing the workpiece after cutting during standby. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a cutting device 2. Note that the X-axis direction (processing feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (up-down direction, cutting feed direction) shown in Fig. 1 are perpendicular to one another.

[0018] The cutting device 2 includes a base 4 that supports each of the components. The base 4 is rectangular when viewed from above, and a recess 4a that is also rectangular when viewed from above is formed at one corner of the base 4. A lifting platform 6 that moves up and down by a lifting mechanism (not shown) is provided in this recess 4a.

[0019] A cassette 8 containing a plurality of workpieces 11 is placed on the upper surface of the lifting platform 6. Each workpiece 11 is contained in the cassette 8 in the form of a frame unit 17 supported by a metal annular frame 15 via a resin sheet 13.

[0020] The workpiece 11 is, for example, a wafer having a disk-shaped single crystal silicon substrate. However, there are no limitations on the material, shape, structure, size, etc. of the workpiece 11. The workpiece 11 may also have a substrate made of other materials such as semiconductors, ceramics, resins, metals, etc.

[0021] In this embodiment, the surface 11a of the workpiece 11 is divided into a plurality of rectangular small regions by a plurality of mutually orthogonal dividing lines (streets), and devices such as ICs (Integrated Circuits) and MEMS (Micro Electro Mechanical Systems) are formed in each small region.

[0022] However, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of the devices. No devices may be formed on the workpiece 11. The frame 15 has a circular opening 15a formed in the center in the radial direction.

[0023] The frame 15 has one surface 15b and another surface 15c, each of which is substantially flat. The above-described sheet 13 is attached to the workpiece 11 and the frame 15. The sheet 13 in this embodiment is an adhesive tape (dicing tape) having a laminated structure of a base layer and an adhesive layer (glue layer).

[0024] The base layer is made of, for example, polyethylene, polypropylene, or polystyrene, and the adhesive layer is made of, for example, an epoxy-based, acrylic-based, or rubber-based adhesive.

[0025] For example, the sheet 13 is attached to one side 15b and the back side 11b of the workpiece 11 so as to cover the opening 15a, with the frame 15 and the workpiece 11 placed on a predetermined table (not shown) so that one side 15b of the frame 15 is exposed and the back side 11b of the workpiece 11 is exposed in the opening 15a of the frame 15.

[0026] In this manner, a frame unit 17 is formed, which includes the workpiece 11, the sheet 13, and the frame 15. The sheet 13 may have only a base layer without an adhesive layer. When the sheet 13 does not have an adhesive layer, the sheet 13 is attached to the workpiece 11 and the frame 15 by, for example, thermocompression bonding.

[0027] A recess 4b having a rectangular shape in top view and with its long side aligned along the X-axis direction is formed adjacent to the recess 4a in the Y-axis direction in the base 4. A ball screw type X-axis direction movement mechanism (processing feed unit) 10 is provided inside the recess 4b.

[0028] The X-axis direction moving mechanism 10 includes an X-axis direction moving table (not shown). The X-axis direction moving table is slidably supported on a pair of guide rails (not shown) arranged along the X-axis direction. A nut portion (not shown) is provided on the underside of the X-axis direction moving table.

[0029] A screw shaft (not shown) arranged along the X-axis direction is rotatably connected to the nut portion via a ball (not shown). A drive source (not shown), such as a motor, is connected to one end of the screw shaft. When the drive source rotates the screw shaft, the X-axis direction moving table moves along the X-axis direction.

[0030] A table cover 10a is disposed above the X-axis direction moving table. Stretchable accordion-shaped covers 10b are provided on both sides of the table cover 10a in the X-axis direction. A disk-shaped chuck table (holding table) 12 that holds a frame unit 17 is provided above the table cover 10a.

[0031] The chuck table 12 can be rotated around a rotation axis that is approximately parallel to the Z-axis direction by a drive source (not shown), such as a motor, provided on the X-axis direction moving table. Also, the chuck table 12 can be moved along the X-axis direction together with the X-axis direction moving table.

[0032] The chuck table 12 is positioned in the loading / unloading area A1 and the cutting area A2 by moving along the X-axis direction. The frame unit 17 is loaded into or unloaded from the chuck table 12 placed in the loading / unloading area A1.

[0033] Furthermore, after the workpiece 11 is held by suction on the chuck table 12 arranged in the loading / unloading area A1, the chuck table 12 moves to the cutting area A2, where the workpiece 11 is cut by the cutting units 84a and 84b described later.

[0034] The chuck table 12 has a disk-shaped frame made of metal. A disk-shaped recess is formed on the upper surface of the frame, concentric with the outer diameter of the frame, and a porous plate made of porous ceramics is fixed in this recess.

[0035] The frame has grooves, through-holes, etc. formed therein for transmitting negative pressure to the porous plate. When negative pressure is transmitted to the porous plate from a suction source (not shown), such as a vacuum pump, negative pressure is generated on the upper surface of the porous plate.

[0036] The upper surfaces of the frame body and the porous plate are formed to be substantially flush with each other and function as a holding surface 12a that suction-holds the frame unit 17. Four clamps 12b are provided around the frame body of the chuck table 12 to clamp the four sides of the frame 15 of the frame unit 17.

[0037] Above the loading / unloading area A1, a pair of guide rails 14 are provided, with their longitudinal directions aligned along the Y-axis direction. The pair of guide rails 14 can move towards or away from each other while maintaining a generally parallel state.

[0038] The pair of guide rails 14 sandwiches the frame unit 17, which is pulled out from the cassette 8 to above the loading / unloading area A1, in the X-axis direction and aligns it to a predetermined position.

[0039] Above the cutting area A2, a gate-shaped first support structure 16 is provided so as to straddle the recess 4b. A lower guide rail 18 is provided on one surface of the first support structure 16 (the surface on the guide rail 14 side) along the Y-axis direction.

[0040] A lower moving block 20 is connected to the lower guide rail 18 so as to be movable in the Y-axis direction. The lower moving block 20 has a nut portion (not shown), and a screw shaft (not shown) arranged along the Y-axis direction is rotatably connected to this nut portion via a ball (not shown).

[0041] A drive source (not shown) such as a motor for rotating the screw shaft is connected to one end of the screw shaft. When the screw shaft is rotated by the drive source, the lower moving block 20 moves along the Y-axis direction.

[0042] A lower transfer unit (second transfer unit) 22 is connected to the lower moving block 20. Fig. 2 is a perspective view of the lower transfer unit 22. The lower transfer unit 22 has an air cylinder 24.

[0043] The air cylinder 24 includes a rod 24a that is movable along the Z-axis direction. The upper surface side of one end of a first support member 26a, whose longitudinal portion is disposed along the X-axis direction, is fixed to the lower end of the rod 24a.

[0044] In this embodiment, the first support member 26a is moved along the Z-axis direction by the air cylinder 24. However, the first support member 26a may also be moved along the Z-axis direction by a ball screw type Z-axis direction movement mechanism driven by a motor (for example, a servo motor).

[0045] The base ends of second support members 26b, each having a longitudinal portion disposed along the Y-axis direction, are fixed to one side and the other side of the other end of the first support member 26a in the Y-axis direction. A third support member (plate member) 26c is fixed to the tip end of each second support member 26b.

[0046] The pair of third support members 26c are arranged with their longitudinal portions aligned along the X-axis direction. A plurality of suction pads 28 are provided on the lower surface 26c1 side of each of the pair of third support members 26c, which suction-hold the other surface 15c of the frame 15 of the frame unit 17 with negative pressure.

[0047] In this embodiment, a negative pressure is transmitted to each suction pad 28 from a suction source (not shown) such as a vacuum pump. The lower frame holding portion 30 uses this negative pressure to suction and hold the frame 15. The first support member 26a, the second support member 26b, the third support member 26c and the plurality of suction pads 28 constitute the lower frame holding portion (second frame holding portion) 30.

[0048] Each suction pad 28 may be a Bernoulli pad (also called a Bernoulli chuck). In this case, air supplied from a compressed air supply source (not shown) is jetted radially or spirally from each suction pad 28, thereby generating negative pressure directly below each suction pad 28 in accordance with Bernoulli's principle.

[0049] A gripping mechanism 32 is provided on the side of the third support member 26c located on the recess 4a side of the lower frame holding portion 30. The gripping mechanism 32 is used when transporting the frame unit 17 between the cassette 8 and the pair of guide rails 14.

[0050] A metal base plate 34a that is circular in top view is fixed to the upper part of the lower frame holding part 30. A solid dome 34b made of diatomaceous earth is fixed to the upper part of the base plate 34a. Note that the dome 34b may be made of a material other than diatomaceous earth, and may be hollow.

[0051] The bottom surface of the dome 34b is circular, and its diameter is approximately the same as the diameter of the base plate 34a. For example, the diameter of the bottom surface of the dome 34b is approximately 350 mm. The dome 34b has a convex curved surface 34b1 that protrudes upward from the bottom surface. For example, the protrusion amount from the bottom surface to the top of the dome 34b is a predetermined value between 10 mm and 50 mm.

[0052] However, the numerical values ​​are merely examples and can be changed as appropriate depending on the size, shape, etc. of the workpiece 11. As will be described later, the dome 34b is used when the workpiece 11, in which the cutting groove 11c is formed, is protruded above the height of the frame 15 via the sheet 13.

[0053] 1, an upper guide rail 38 is provided along the Y-axis direction on one surface of the first support structure 16. An upper moving block 40 is connected to the upper guide rail 38 so as to be movable in the Y-axis direction.

[0054] The upper moving block 40 has a nut portion (not shown), and a screw shaft (not shown) arranged along the Y-axis direction is rotatably connected to this nut portion via a ball (not shown).

[0055] A drive source (not shown), such as a motor, for rotating the screw shaft is connected to one end of the screw shaft. When the screw shaft is rotated by the drive source, the upper moving block 40 moves along the Y-axis direction.

[0056] An upper transport unit (first transport unit) 42 is connected to the upper moving block 40. Fig. 3 is a perspective view of the upper transport unit 42. Fig. 4(A) is a partially cross-sectional side view of the upper transport unit 42, and Fig. 4(B) is a bottom view of the upper transport unit 42.

[0057] The upper conveying unit 42 has an air cylinder 44. The air cylinder 44 includes a rod 44a that is movable along the Z-axis direction. A central portion of a fourth support member 46a, whose longitudinal portion is disposed along the X-axis direction, is fixed to the lower end of the rod 44a.

[0058] Fifth support members 46b, each with its longitudinal portion aligned along the Y-axis direction, are fixed to both ends of the fourth support member 46a. A cylindrical housing 50 is fixed to the lower portions of the pair of fifth support members 46b via connecting members 48.

[0059] The housing 50 of this embodiment moves along the Z-axis direction by the air cylinder 44. However, instead of the air cylinder 24, the housing 50 may be moved along the Z-axis direction by a ball screw type Z-axis movement mechanism driven by a motor (for example, a servo motor).

[0060] The housing 50 has a disk-shaped lid 50a fixed to the connecting member 48. The top of a hollow tubular portion 50b is connected to the outer periphery of the lid 50a. A circular opening 50c having approximately the same diameter as the inner diameter of the tubular portion 50b is formed at the bottom of the tubular portion 50b.

[0061] Furthermore, a suction-holding member 52 is provided at the bottom of the cylindrical portion 50b in an annular shape along the circumferential direction of the cylindrical portion 50b. The suction-holding member 52 is made of an elastic material, and when suction-holding the other surface 15c of the frame 15, it can flexibly deform to come into close contact with the other surface 15c.

[0062] The suction and retention member 52 includes a small diameter ring 52a and a large diameter ring 52b arranged substantially concentrically. The small diameter ring 52a and the large diameter ring 52b are made of an elastic material such as resin, rubber, or elastomer.

[0063] The lower end of the small diameter ring 52a is thinner than the upper end thereof, and the lower end of the large diameter ring 52b is also thinner than the upper end thereof. An annular opening 52c is formed between the small diameter ring 52a and the large diameter ring 52b.

[0064] A flow path 50d formed in the lid portion 50a and the cylindrical portion 50b is connected to the annular opening 52c, and negative pressure is transmitted from a suction source 54 such as a vacuum pump via a flexible tube 56 and the flow path 50d.

[0065] The negative pressure generated in the annular opening 52c suction-holds the other surface 15c of the frame 15. The suction-holding member 52, the suction source 54, the flexible tube 56, etc. constitute an upper frame holding portion (first frame holding portion) 58 that suction-holds the frame 15 of the frame unit 17.

[0066] The upper frame holding portion 58 may have a plurality of support claws (not shown) that respectively support the one surface 15b side of the frame 15. The plurality of support claws are provided on the outside of the cylindrical portion 50b of the housing 50, for example.

[0067] By supporting one surface 15b of frame 15 with each support claw, frame 15 can be held without generating negative pressure in annular opening 52c. Therefore, by omitting flow path 50d, the structure of housing 50 can be simplified, and flexible tube 56 can also be omitted.

[0068] However, even in this case, the suction and hold member 52 is not omitted. The suction and hold member 52 flexibly deforms so as to come into close contact with the other surface 15c of the frame 15 when each support claw presses the frame 15 against the bottom of the cylindrical portion 50b, thereby functioning as a sealing material.

[0069] In this embodiment, when the frame 15 is held by suction, first, the housing 50 is placed on the frame 15 of the frame unit 17 so that the suction holding member 52 comes into contact with the other surface 15c. At this time, the workpiece 11 after cutting is covered with the housing 50.

[0070] Next, negative pressure is generated in the annular opening 52c, and the suction and holding member 52 adheres to the other surface 15c to hold the frame 15 by suction. When the opening 50c is closed by the sheet 13 and the frame 15, the workpiece 11 after cutting is accommodated in a space 50e (see FIG. 6) inside the housing 50 defined by the housing 50, the sheet 13, and the frame 15.

[0071] In this manner, the upper transport unit 42 transports the frame unit 17 with the cut workpiece 11 accommodated in the space 50e. The lid 50a of the housing 50 is provided with a nozzle 60 (see FIG. 4(B)) for supplying a liquid 60a (see FIG. 6) such as pure water into the space 50e inside the housing 50.

[0072] A flexible tube (conduit) 62 is connected to the nozzle 60. The flexible tube 62 is fixed to the lid portion 50a of the housing 50. A liquid 60a is supplied from a liquid supply source 64 to a space 50e within the housing 50 via the nozzle 60 and the flexible tube 62.

[0073] The liquid supply source 64 includes, for example, a tank in which the liquid 60a is stored, a temperature adjustment mechanism that adjusts the temperature of the liquid 60a in the tank to a predetermined temperature, and a pump (none of which are shown) that supplies the liquid 60a in the tank to the nozzle 60. However, the liquid supply source 64 is not limited to this configuration.

[0074] The liquid supply source 64 may be a pure water recycling device (not shown) that performs impurity removal processes such as filtration and ion exchange on the cutting fluid used in the cutting device 2. The nozzle 60, the flexible tube 62, and the liquid supply source 64 function as a liquid supply unit 66 that supplies the liquid 60a to the space 50e of the housing 50.

[0075] A through-hole 68 that penetrates the lid portion 50a of the housing 50 is formed in a position different from the nozzle 60. The through-hole 68 is circular in top view, and functions as an escape route for gas (e.g., air) when the liquid 60a is poured into the space 50e of the housing 50.

[0076] Although the through-hole 68 in this embodiment is a single circular hole, there is no limitation on its shape as long as it can function as an escape route for gas, and it may be triangular or rectangular, or may be made up of multiple small holes.

[0077] In the space 50e of the housing 50, a plurality of ultrasonic vibrators 70 are provided at positions different from the nozzles 60 and the through-holes 68 (see FIG. 4(B)). The ultrasonic vibrators 70 of this embodiment are of a so-called throw-in type, and are fixed to the lid portion 50a in a manner that they are suspended from the underside of the lid portion 50a.

[0078] The ultrasonic vibrator 70 is disposed at a predetermined distance from the lid 50a to the opening 50c so as to be immersed in the liquid 60a contained in the space 50e. In this embodiment, the distance from the lid 50a to the ultrasonic vibrator 70 is fixed.

[0079] However, a wire (not shown) may be connected to the ultrasonic vibrator 70 and configured to be able to be wound up and fed out by a motor or the like, thereby making the distance from the lid portion 50a to the ultrasonic vibrator 70 adjustable.

[0080] The ultrasonic vibrators 70 are arranged so as to hang down from between the center and the outer periphery of the bottom surface of the lid 50a, but the arrangement position can be changed as appropriate. The number of ultrasonic vibrators 70 is not limited to two, and may be one, or three or more.

[0081] An oscillator 74 is connected to the ultrasonic vibrator 70 via a cable 72. The oscillator 74 receives power from a power source (not shown) and generates a high-frequency electrical signal for vibrating the ultrasonic vibrator 70.

[0082] The ultrasonic vibrator 70 vibrates at a predetermined frequency of, for example, 20 kHz or more and 5 MHz or less while immersed in the liquid 60a contained in the space 50e, thereby applying ultrasonic vibrations to the liquid 60a.

[0083] The ultrasonic vibrator 70, the cable 72, and the oscillator 74 constitute an ultrasonic vibration imparting unit 76. In this embodiment, the housing 50, the liquid supply unit 66, and the ultrasonic vibration imparting unit 76 constitute a workpiece coating unit 78 in the upper conveying unit 42.

[0084] Returning to Figure 1, we will now explain other components of the cutting device 2. A gate-shaped second support structure 80 is disposed on the other side of the first support structure 16. Two ball screw-type Y-axis and Z-axis movement mechanisms (indexing feed unit and cutting feed unit) 82a and 82b are provided on one side of the second support structure 80 (the side facing the first support structure 16).

[0085] One cutting unit 84a is connected to the Y-axis / Z-axis movement mechanism 82a, and one cutting unit 84b is also provided to the Y-axis / Z-axis movement mechanism 82b. The cutting units 84a and 84b have approximately the same structure.

[0086] Each of the Y-axis / Z-axis movement mechanisms 82a, 82b includes a Y-axis drive source (not shown) such as a motor (stepping motor) connected to a screw shaft (not shown) for driving in the Y-axis direction. Each of the cutting units 84a, 84b is moved along the Y-axis direction by the Y-axis drive source (indexing feed).

[0087] Each of the Y-axis and Z-axis movement mechanisms 82a and 82b includes a Z-axis direction drive source such as a motor (stepping motor) connected to a screw shaft (not shown) for driving in the Z-axis direction. Each of the cutting units 84a and 84b is moved along the Z-axis direction by the Z-axis direction drive source (cutting feed).

[0088] The cutting unit 84a has a spindle 86 whose longitudinal portion is arranged substantially parallel to the Y-axis direction (see FIG. 5). A portion of the spindle 86 is rotatably housed in a spindle housing. A drive source (not shown), such as a motor, is provided at the base end of the spindle 86.

[0089] A cutting blade 88 having an annular cutting edge is attached to a tip 86a of the spindle 86. The cutting unit 84b has the spindle 86 and the like, similar to the cutting unit 84a, but is disposed in approximate mirror symmetry with respect to the cutting unit 84a with respect to a predetermined plane parallel to the XZ plane.

[0090] A nozzle (not shown) is provided near the tip 86a of each spindle 86 to supply cutting fluid such as pure water to the workpiece 11 and cutting blade 88. Also, as shown in Fig. 1, a microscope camera unit 90 capable of capturing an image of the workpiece 11 held by the chuck table 12 is provided near the cutting units 84a and 84b.

[0091] A spinner cleaning unit 92 is provided on the opposite side of the recess 4b from the lifting table 6 in the Y-axis direction. The spinner cleaning unit 92 has a disk-shaped spinner table 94 that holds the frame unit 17 in a cleaning space.

[0092] The spinner table 94 holds the cut workpiece 11 by applying negative pressure via the seat 13. A plurality of pendulum-type clamps are provided on the outer periphery of the spinner table 94 along the circumferential direction of the spinner table 94.

[0093] When spinner table 94 rotates at a rotational speed equal to or greater than a predetermined value, centrifugal force causes the claws of each clamp to press down on the other surface 15c of frame 15. In this way, frame 15 is sandwiched between the multiple clamps and the outer periphery of spinner table 94.

[0094] A drive source (not shown) that rotates the spinner table 94 at high speed is connected to the lower part of the spinner table 94. Above the spinner table 94, a nozzle-equipped arm 96 is provided, which includes a nozzle that sprays cleaning fluid (for example, a mixed fluid of water and air) toward the frame unit 17 held by the spinner table 94.

[0095] The workpiece 11 can be cleaned by rotating the spinner table 94 holding the frame unit 17 and by swinging the nozzle-equipped arm 96 so that the nozzle crosses directly above the spinner table 94, while spraying cleaning fluid from the nozzle.

[0096] Each component of the cutting device 2 is controlled by a control unit 98. The control unit 98 is configured by a computer including, for example, a processing device such as a CPU (Central Processing Unit), a main storage device such as a DRAM (Dynamic Random Access Memory), and an auxiliary storage device such as a flash memory.

[0097] The functions of the control unit 98 are realized by operating the processing device in accordance with the software stored in the auxiliary storage device. Next, a series of processing steps for processing the workpiece 11 by the cutting device 2 will be described.

[0098] First, the lower transport unit 22 grips the frame 15 with the gripping mechanism 32 and pulls out one frame unit 17 onto the pair of guide rails 14. Next, the pair of guide rails 14 aligns the one frame unit 17 in the X-axis direction.

[0099] Thereafter, when the lower transport unit 22 suction-holds the other surface 15c of the frame 15 with a plurality of suction pads 28, the pair of guide rails 14 separate and the frame unit 17 is handed over to the chuck table 12 arranged in the loading / unloading area A1.

[0100] When the chuck table 12 holds the frame unit 17 by suction with the holding surface 12a and the multiple clamps 12b and moves to the cutting area A2, the cutting process of the workpiece 11 begins. Figure 5 is a diagram showing how the workpiece 11 is cut by the cutting unit 84a.

[0101] In the cutting process, first, the microscope camera unit 90 captures an image of the surface 11a, and the orientation of the chuck table 12 is adjusted so that the planned dividing line set on the surface 11a is approximately parallel to the X-axis direction.

[0102] Next, the position of the chuck table 12 is adjusted so that the cutting unit 84a is positioned outside the holding surface 12a in the XY plane direction, and the cutting blade 88 is positioned on an extension of one of the planned division lines.

[0103] Then, the spindle 86 starts to rotate, and the lower end of the cutting blade 88 is positioned at a height between the rear surface 11b of the workpiece 11 and the holding surface 12a.

[0104] In this state, by feeding the chuck table 12 along the X-axis while supplying cutting fluid, a cutting groove 11c is formed along the intended dividing line, and the workpiece 11 is cut at the cutting groove 11c.

[0105] Next, the workpiece 11 is similarly cut along the division lines adjacent to the formed cutting grooves 11c in the Y-axis direction. After the workpiece 11 has been cut along all of the division lines along the X-axis direction, the chuck table 12 is rotated approximately 90 degrees.

[0106] Then, similarly, the workpiece 11 is cut along all of the planned division lines along the X-axis direction. In this way, the workpiece 11 of this embodiment is divided into a plurality of device chips 11d (see FIG. 6) along the cutting grooves 11c.

[0107] It is also possible to use both cutting units 84a and 84b to cut the workpiece 11. For example, a cutting blade 88 having a thinner cutting edge than that of cutting unit 84a is attached to cutting unit 84b, and the workpiece 11 is cut by step cutting.

[0108] More specifically, after the cutting unit 84a forms half-cut grooves along each planned dividing line of the workpiece 11, the cutting unit 84b further cuts each half-cut groove to cut the workpiece 11. Note that the workpiece 11 does not necessarily have to be cut, and the cutting process may be completed when half-cut grooves are formed to a predetermined depth along each planned dividing line.

[0109] Since the workpiece 11 after cutting has used cutting fluid and cutting chips attached to it, the workpiece 11 after cutting is transported by the upper transport unit 42 to the spinner cleaning unit 92, where it is cleaned and dried.

[0110] However, it may take some time for the workpiece 11 after cutting to be transported to the spinner cleaning unit 92 due to reasons such as waiting for the completion of cleaning and drying of other workpieces 11 that were previously brought into the spinner cleaning unit 92, or waiting for the cutting device 2 to resume operation due to an error.

[0111] If the transport takes a long time, cutting chips will adhere to the workpiece 11, which will be a problem. Therefore, in this embodiment, after cutting and before cleaning in the spinner cleaning unit 92, the workpiece 11 after cutting is cleaned using the upper transport unit 42 or the like.

[0112] Specifically, first, the chuck table 12 is moved from the cutting area A2 to the carry-in / carry-out area A1, and then the upper frame holding portion 58 of the upper transport unit 42 holds the frame 15 by suction (holding step).

[0113] As a result, the opening 50c of the housing 50 is closed by the sheet 13 and the frame 15, and the workpiece 11 after cutting is accommodated in a space 50e within the housing 50. Then, a liquid 60a is supplied into the space 50e from the nozzle 60 (see FIG. 6).

[0114] The amount of liquid 60a to be supplied is determined in advance according to the volume of the housing 50. The liquid 60a is supplied in an amount corresponding to, for example, approximately half the volume of the housing 50 so that the cut workpiece 11 supported by the dome 34b is immersed in the liquid 60a and so that the liquid 60a does not overflow from the through-hole 68 of the lid portion 50a.

[0115] In this way, the workpiece 11 with the cut groove 11c formed therein is immersed in the liquid 60a contained in the space 50e (immersion process). Figure 6 is a partial cross-sectional side view of the upper conveying unit 42 and the frame unit 17 with the liquid 60a contained in the space 50e of the housing 50.

[0116] In this embodiment, during the cutting process and the holding and immersion processes performed by the upper transport unit 42, the lower transport unit 22 is operated (moving process) so that the dome 34b completes its movement to directly above the spinner cleaning unit 92. In this way, the dome 34b is positioned on the movement path of the housing 50.

[0117] Then, when the housing 50, frame unit 17, etc. move to directly above the dome 34b, the upper transport unit 42 then lowers the housing 50, etc. toward the dome 34b (see FIG. 7). FIG. 7 is a partial cross-sectional side view showing the upper transport unit 42 moving so that the dome 34b and the housing 50 overlap.

[0118] For example, the upper conveying unit 42 lowers the housing 50 until the sheet 13 of the frame unit 17 contacts the first support member 26a of the lower conveying unit 22. Note that if the dome 34b and the housing 50 can be overlapped, the dome 34b may be raised and the housing 50 may be lowered, or only the dome 34b may be raised.

[0119] When the workpiece 11 with the cutting grooves 11c formed therein is supported by the dome 34b, the sheet 13 expands to conform to the curved surface 34b1 of the dome 34b, thereby widening the spacing between the device chips 11d (i.e., the workpiece 11 after cutting) (see Figure 8).

[0120] At this time, the dome 34b protrudes above the opening 50c, so that the liquid 60a is pushed upward and the ultrasonic vibrator 70 is immersed in the liquid 60a. Then, the ultrasonic vibration imparting unit 76 is operated to impart ultrasonic vibration to the liquid 60a (see FIG. 8).

[0121] The ultrasonic vibration imparting unit 76 imparts ultrasonic vibration to the liquid 60a to clean the workpiece 11 after cutting while the upper transport unit 42 and the lower transport unit 22 are waiting directly above the spinner cleaning unit 92 (waiting / cleaning process).

[0122] 8 is a partial cross-sectional side view showing the workpiece 11 after cutting while the upper transport unit 42 and the lower transport unit 22 are on standby. Note that the standby / cleaning step aims to prevent the workpiece 11 from drying out after cutting, and cleaning does not necessarily remove all cutting debris.

[0123] After the standby and cleaning process, the lower transport unit 22 retreats from directly above the spinner cleaning unit 92, and the upper transport unit 42 descends to the spinner table 94. Then, the suction hold of the frame unit 17 by the upper frame holding portion 58 is released, and the housing 50 is raised, thereby transferring the frame unit 17 to the spinner table 94.

[0124] When the housing 50 is raised, the liquid 60a contained in the space 50e flows out into a waste liquid chamber (not shown) of the spinner cleaning unit 92. Next, the spinner table 94 holds the frame unit 17 by suction, and the workpiece 11 after cutting is cleaned and dried (cleaning and drying process).

[0125] After the cleaning and drying process, the lower transport unit 22 transports the cleaned and dried frame unit 17 from the spinner cleaning unit 92 to the cassette 8 via the pair of guide rails 14 .

[0126] In this embodiment, the frame 15 is held by the upper frame holding portion 58, the workpiece 11 on which the cutting groove 11c is formed is supported by the dome 34b, and the workpiece 11 on which the cutting groove 11c is formed is immersed in the liquid 60a contained in the space 50e within the housing 50, and the ultrasonic vibration imparting unit 76 imparts ultrasonic vibrations to the liquid 60a.

[0127] Therefore, it is possible to prevent cutting chips from adhering to the cut workpiece 11 while the cut workpiece 11 is being transported to the spinner cleaning unit 92. Furthermore, in this embodiment, by supporting the cut workpiece 11 with the dome 34b via the sheet 13, it is possible to increase the spacing between the device chips 11d.

[0128] This prevents the corners at the upper ends of adjacent device chips 11d across the cut groove 11c from colliding with each other due to ultrasonic vibrations and being damaged, thereby preventing a deterioration in the quality of the device chips 11d.

[0129] The dome 34b may be provided on the movement path of the housing 50 as a top plate of the spinner cleaning unit 92.

[0130] In this case, the dome 34b is composed of, for example, two bodies with its bottom surface divided into two semicircular halves, and the two bodies are configured to be movable in a manner that allows them to move closer to and away from each other by a driving source (not shown) such as an actuator or motor.

[0131] Specifically, when supporting the workpiece 11 after cutting, the two bodies come close to each other to form a single dome 34b. On the other hand, when transporting the frame unit 17 between the spinner table 94, the dome 34b separates into two bodies to form a space through which the frame unit 17 can pass.

[0132] Furthermore, in the above-described embodiment, the case of a cutting groove 11c (i.e., a full-cut groove) that cuts the workpiece 11 has been described, but a cutting groove 11c (i.e., a half-cut groove) that does not completely cut the workpiece 11 in the thickness direction of the workpiece 11 may also be formed in the workpiece 11.

[0133] When a half-cut groove is formed, in the waiting and cleaning process, the dome 34b can be pressed against the workpiece 11 after cutting and ultrasonic vibration can be applied to extend a crack from the half-cut groove, thereby splitting the workpiece 11.

[0134] For example, a half-cut groove is formed on the front surface 11a of the workpiece 11, and during the waiting and cleaning process, a crack is extended from the bottom of the half-cut groove to the back surface 11b, thereby splitting the workpiece 11.

[0135] By splitting the workpiece 11 by extending the crack, the cutting allowance on the surface where the crack reaches can be reduced (for example, to approximately 0 μm) compared to the kerf width of the cut groove 11c (for example, approximately 50 μm).

[0136] When cutting the workpiece 11 by extending the crack, it is easier to apply vibrations to the workpiece 11 by using a relatively low ultrasonic frequency in the waiting and cleaning process. For example, a relatively low frequency band of 20 kHz or more and 100 kHz or less is selected. [Explanation of symbols]

[0137] 2: cutting device, 4: base, 4a, 4b: recess, 6: lifting table, 8: cassette 10: X-axis direction movement mechanism, 10a: table cover, 10b: accordion-shaped cover 11: Workpiece, 11a: Front surface, 11b: Back surface 11c: cutting groove, 11d: device chip 12: chuck table (holding table), 12a: holding surface, 12b: clamp 13: seat, 15: frame, 15a: opening, 15b: one surface, 15c: other surface 14: Guide rail 16: First support structure, 18: Lower guide rail, 20: Lower moving block 17: Frame unit 22: Lower conveying unit (second conveying unit), 24: Air cylinder, 24a: Rod 26a: first support member, 26b: second support member, 26c: third support member (plate member) 28: suction pad, 30: lower frame holding portion (second frame holding portion), 32: gripping mechanism 34a: base plate, 34b: dome, 34b1: curved surface 38: Upper guide rail, 40: Upper moving block 42: Upper conveying unit (first conveying unit), 44: Air cylinder, 44a: Rod 46a: fourth support member, 46b: fifth support member, 48: connecting member 50: housing, 50a: lid, 50b: tube, 50c: opening 50d: flow path, 50e: space 52: suction holding member, 52a: small diameter ring, 52b: large diameter ring, 52c: annular opening 54: suction source, 56: flexible tube 58: Upper frame holding part (first frame holding part) 60: nozzle, 60a: liquid, 62: flexible tube (conduit) 64:Liquid supply source, 66:Liquid supply part, 68:Through hole 70: ultrasonic vibrator, 72: cable, 74: oscillator, 76: ultrasonic vibration imparting unit 78: Workpiece covering part 80: Second support structure, 82a, 82b: Y-axis and Z-axis movement mechanism 84a, 84b: Cutting unit 86: spindle, 86a: tip, 88: cutting blade, 90: microscope camera unit 92: Spinner cleaning unit, 94: Spinner table, 96: Arm with nozzle 98: Control unit A1: Loading / unloading area, A2: Cutting area

Claims

1. A cutting device, a holding table that holds a frame unit including an annular frame having an opening in the center, a sheet attached to one surface of the frame so as to close the opening, and a workpiece supported by the frame via the sheet at the opening; a cutting unit having a spindle for cutting the workpiece of the frame unit held by the holding table with a cutting blade attached to a tip of the spindle; a first transport unit having a first frame holding portion that holds the frame of the frame unit and a workpiece covering portion that covers the workpiece of the frame unit, for transporting the frame unit in a state in which the frame is held by the first frame holding portion and the workpiece is covered by the workpiece covering portion; a dome having a convex curved surface disposed on a moving path of the workpiece covering unit, the dome causing the workpiece having the cutting groove formed therein to protrude upward through the sheet; Equipped with The workpiece covering portion of the first conveying unit includes: a housing having an opening at a bottom and capable of covering the workpiece; a liquid supply unit having a conduit fixed to the housing and supplying liquid to the space in the housing; an ultrasonic vibration imparting unit having an ultrasonic vibrator fixed to the housing and imparting ultrasonic vibration to the liquid in the space; Including, A cutting device characterized in that the frame is held by the first frame holding portion, the workpiece on which the cutting groove is formed is supported by the dome, and the ultrasonic vibration imparting unit imparts ultrasonic vibrations to the liquid in the space while the workpiece on which the cutting groove is formed is immersed in the liquid contained in the space within the housing, the opening at the bottom of the housing being closed by the sheet and the frame.

2. a second transport unit having a second frame holding portion that holds the frame of the frame unit; The dome is fixed to an upper portion of the second frame holding portion, The cutting device according to claim 1, characterized in that the dome is positioned on the movement path of the workpiece covering portion by moving the first conveying unit and the second conveying unit so that the dome and the housing overlap.

3. the first frame holding portion has an annular suction holding member formed of an elastic material, the suction holding member including an annular opening, and the frame can be sucked by negative pressure generated in the annular opening; The cutting device according to claim 2, characterized in that the second frame holding portion has a pair of plate members and suction pads provided on the underside of each plate member, and is capable of sucking the frame by negative pressure generated on the suction pads.

4. 4. The cutting device according to claim 1, wherein the housing of the workpiece covering portion of the first transport unit includes a through-hole provided in a cover portion of the housing and functioning as an escape route for gas.

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