Conveying mechanism

Abstract

To provide a transfer mechanism for preventing drying of each chip and reducing deflection of a tape during transfer of a plurality of chips.SOLUTION: A transfer mechanism for transferring a frame unit 19 in which a workpiece 11 having a plurality of chips 13a divided therein is attached to a tape 15 attached to a ring frame so as to close an opening at a center portion of a ring frame 17 in an area corresponding to the opening, and the ring frame, the tape and the plurality of chips are integrated with one another, includes a holding mechanism for holding the frame unit, and a moving mechanism for moving the holding mechanism. The holding mechanism includes a ring frame holding mechanism 26 having a plurality of holding members 22c each holding the ring frame, and a humidifying gas supply mechanism 42 which has a plate-shaped head portion 28 having one or more openings at the bottom portion thereof, and supplies a humidified gas from the one or more openings to the plurality of chips during transfer of the frame unit, thereby restraining drying of the plurality of chips.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a transport mechanism for transporting a ring frame unit in which a workpiece divided into a plurality of chips is attached in a region corresponding to an opening in a tape attached to a ring frame so as to close the opening in the central portion of the ring frame, and the ring frame, the tape, and the plurality of chips are integrated.

Background Art

[0002] When cutting a workpiece such as a semiconductor wafer, cutting water such as pure water is supplied to a cutting blade for lubrication between the cutting blade rotating at high speed and the workpiece, and cooling water such as pure water is supplied to the machining point where the workpiece and the cutting blade come into contact to cool the machining point.

[0003] During cutting, the chuck table is fed for machining with a cutting blade rotating at high speed being cut into a workpiece sucked and held by the chuck table. Thereby, the workpiece is cut along each of a plurality of division planned lines set in a grid pattern on one surface of the workpiece, and the workpiece is divided into a plurality of chips (device chips).

[0004] During cutting, contamination such as cutting dust is generated, and the chips are contaminated by the used cutting water and cooling water containing the contamination. Adhesion of contamination to the chips causes product defects.

[0005] Therefore, the workpiece after cutting (i.e., a plurality of chips) is transported from the chuck table to a spinner cleaning device by a transport mechanism, and the workpiece after cutting is cleaned by the spinner cleaning device.

[0006] However, if moisture dries and the contamination adheres firmly to the chips between the end of cutting and the start of cleaning, the contamination cannot be completely removed from the chips even by cleaning using a spinner cleaning device.

[0007] Therefore, in order to prevent the chips from drying out during transport, a transport mechanism has been proposed that includes a wash water storage member having an upper wall and an annular side wall (see, for example, Patent Document 1). When transporting the workpiece after cutting, first, the wash water storage member is placed on the tape so as to cover each chip supported by the ring frame via the tape.

[0008] Next, the cylindrical space defined by the cleaning water storage member and the tape (i.e., the cleaning water storage chamber) is filled with cleaning water. After that, the transport mechanism, while holding the ring frame by suction, transports the multiple chips together with the tape and ring frame to the spinner cleaning device. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2010-87443 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] However, the weight of the cleaning water stored in the cleaning water reservoir causes the tape to sag, which can cause adjacent chips on the tape to come into contact with each other, potentially resulting in cracks or chips in the chips.

[0011] This invention has been made in view of the aforementioned problems, and aims to prevent drying of each chip and reduce tape deflection during the transport of multiple chips. [Means for solving the problem]

[0012] According to one aspect of the present invention, a conveying mechanism is provided for conveying a frame unit in which a ring frame, tape, and the plurality of chips are integrated, wherein a workpiece divided into a plurality of chips is attached to a tape attached to a ring frame so as to close an opening in the center of the ring frame, and the chips are attached in the area corresponding to the opening, the conveying mechanism comprising a holding mechanism for holding the frame unit and a moving mechanism for moving the holding mechanism, the holding mechanism comprising a ring frame holding mechanism having a plurality of holding members for each of the ring frame, and a humidifying body supply mechanism having a plate-shaped head portion having one or more openings at the bottom, and which suppresses drying of the plurality of chips by supplying humidified gas from the one or more openings toward the plurality of chips when the frame unit is conveyed. [Effects of the Invention]

[0013] A transport mechanism according to one aspect of the present invention reduces tape deflection and suppresses chip drying compared to the case where chips are immersed in washing water stored in a washing water storage chamber to prevent chip drying, by supplying humidified gas when transporting the frame unit. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view of a cutting machine. [Figure 2] This is a perspective view showing the frame and other components of the upper transport mechanism. [Figure 3] This is a bottom view showing the frame and other components of the upper transport mechanism. [Figure 4] This is a partial cross-sectional side view of a humidifier supply source. [Figure 5] This is a perspective view of the frame unit after machining. [Figure 6] This is a side view showing how the frame unit is held and transported by suction. [Modes for carrying out the invention]

[0015] Referring to the accompanying drawings, an embodiment according to one aspect of the present invention will be described. FIG. 1 is a perspective view of a cutting device 2. In FIG. 1, a part of the components is shown as a functional block diagram. Also, the X-axis direction (machining feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (vertical direction) in FIG. 1 are directions perpendicular to each other.

[0016] The cutting device 2 includes a base 4 that supports each component. An opening 4a is provided at the front corner of the base 4. Inside the opening 4a, an elevator 6a that moves up and down by an elevating mechanism (not shown) is provided. On the upper surface of the elevator 6a, a cassette 6b for accommodating a plurality of wafers (workpieces) 11 is placed.

[0017] The wafer 11 has, for example, a disk-shaped single crystal substrate formed of a semiconductor material such as silicon. Note that there are no restrictions on the material, shape, structure, size, etc. of the single crystal substrate. A plurality of division planned lines (streets) are set in a grid pattern on the surface 11a of the wafer 11.

[0018] Devices 13 such as ICs (Integrated Circuits) are formed in each rectangular region partitioned by the plurality of division planned lines. At the back surface 11b of the wafer 11 located on the side opposite to the surface 11a, the central portion of a dicing tape (tape) 15 having a diameter larger than that of the wafer 11 is attached.

[0019] A ring frame 17 formed of metal is attached to the outer peripheral portion of the dicing tape 15. That is, the dicing tape 15 is attached to the ring frame 17 so as to close an opening 17a formed in the central portion of the ring frame 17.

[0020] The wafer 11 before division is attached to the region corresponding to the opening 17a and is supported by the ring frame 17 via the dicing tape 15. The wafer 11 and the ring frame 17 are integrated via the dicing tape 15 to form a frame unit 19.

[0021] The wafer 11 is accommodated in the cassette 6b in the state of the frame unit 19. On the side of the elevator 6a, a rectangular opening 4b having a long side along the X-axis direction is formed. A table cover 10 is provided in the opening 4b.

[0022] On both sides of the table cover 10 in the X-axis direction, bellows-shaped cover members 12 that can be expanded and contracted along the X-axis direction are provided. On the table cover 10, a disk-shaped chuck table 14 is provided.

[0023] On the upper surface of the chuck table 14, negative pressure is transmitted from a suction source (not shown) such as a vacuum pump and an ejector, and it functions as a holding surface 14a that sucks and holds the frame unit 19. On the outer peripheral portion of the chuck table 14, a plurality of clamp units 16 that can sandwich the ring frame 17 in the thickness direction are provided.

[0024] The chuck table 14 is configured to be rotatable around a rotation axis substantially parallel to the Z-axis direction by a rotation drive source (not shown) such as a motor. Further, the chuck table 14 is configured to be movable along the X-axis direction by a ball screw type X-axis direction movement mechanism (machining feed unit) not shown.

[0025] Above the region of the opening 4b adjacent to the opening 4a, a pair of guide rails (not shown) used when loading and unloading the frame unit 19 with respect to the cassette 6b are provided. The pair of guide rails are arranged such that each long hand portion is along the Y-axis direction and is movable so as to approach and separate along the X-axis direction.

[0026] At the central portion of the base 4 in the X-axis direction, a gantry-shaped support 4c is provided so as to straddle the opening 4b. On one side of the support 4c substantially parallel to the Y-Z plane, a lower transfer mechanism 18 and an upper transfer mechanism 22 for respectively transferring the frame unit 19 are provided.

[0027] The lower transport mechanism 18 is used when unloading the frame unit 19 from the cassette 6b and when loading the cleaned frame unit 19 into the cassette 6b. The lower transport mechanism 18 has an air cylinder 18a that includes a piston rod that is movable along the Z-axis.

[0028] The base end of an arm section, which is positioned along the X-axis, is fixed to the lower end of the piston rod. A frame 18b, which is roughly H-shaped when viewed from above, is fixed to the tip of the arm section. Suction pads 18c are provided on the bottom sides of the four corners of the frame 18b.

[0029] Negative pressure is transmitted to each suction pad 18c from a suction source (not shown), such as a vacuum pump or ejector, via a flexible tube (not shown). The suction pads 18c can hold the frame unit 19 by suction-holding the ring frame 17.

[0030] A gripping unit 18d capable of gripping the ring frame 17 is provided at the tip of the frame 18b on the elevator 6a side. The lower transport mechanism 18 includes a lower moving mechanism 20 provided on the support 4c.

[0031] The lower moving mechanism 20 in this embodiment is a ball screw type moving mechanism and has a rail 20a arranged along the Y-axis direction. The upper end of the air cylinder 18a is slidably attached to the rail 20a.

[0032] A nut portion (not shown) is provided at the upper end of the air cylinder 18a. A screw shaft (not shown), which is arranged along the Y-axis, is rotatably connected to the nut portion via a ball (not shown).

[0033] A drive source (not shown), such as a motor, is connected to one end of the screw shaft. By operating the drive source, the lower transport mechanism 18 moves along the Y-axis. Next, the upper transport mechanism 22 will be described.

[0034] The upper transport mechanism (transport mechanism) 22 is used to transport the frame unit 19 from the chuck table 14 to the spinner cleaning device 54, which will be described later. The upper transport mechanism 22 has an arm that protrudes along the X-axis, and an air cylinder 22a including a piston rod that is movable along the Z-axis is provided at the tip of the arm.

[0035] A frame 22b, which is roughly H-shaped in top view, is fixed to the lower end of the piston rod. The frame 22b is made of a metal such as aluminum alloy or stainless steel and has a pair of first straight sections 22b1 arranged along the Y-axis (see Figure 2).

[0036] As shown in Figure 2, a pair of first linear sections 22b1 are connected to each other by a second linear section 22b2 positioned along the X-axis at their midpoint in the longitudinal direction. Suction pads (holding members) 22c are provided on the bottom side of the tip of each first linear section 22b1 (i.e., the four corners of the frame 22b).

[0037] Negative pressure is transmitted to each suction pad 22c from a suction source 24 such as a vacuum pump or ejector via a flexible tube 22d. The upper transport mechanism 22 will be described in detail with reference to Figures 2 and 3. Figure 2 is a perspective view showing the frame 22b etc. of the upper transport mechanism 22, and Figure 3 is a bottom view showing the frame 22b etc. of the upper transport mechanism.

[0038] In Figure 2, some of the components are shown using lines and functional block diagrams. The frame 22b and the four suction pads 22c constitute the ring frame holding mechanism 26, which holds the ring frame 17 by suction using negative pressure.

[0039] Alternatively, instead of the suction pad 22c, a ring frame holding mechanism 26 may be configured to hold the ring frame 17 by providing clamp units (not shown) capable of clamping the ring frame 17 in its thickness direction.

[0040] The lower end of the piston rod of the air cylinder 22a is fixed to the upper surface of the second linear section 22b2. A disc-shaped (plate-shaped) head section 28 is provided on the lower surface of the second linear section 22b2.

[0041] The bottom 28a of the head portion 28 has multiple (one or more) openings 28b, similar to a shower head. Each opening 28b is arranged across approximately the entire bottom 28a such that adjacent openings 28b are spaced approximately equally apart.

[0042] A tubular section (not shown) is formed inside the head section 28. One end of this tubular section branches into multiple sections connected to each opening 28b, and the other end of this tubular section is connected to the humidifier supply source 30 via a flexible tube 28c.

[0043] Figure 4 is a partial cross-sectional side view of the humidifier supply source 30. The humidifier supply source 30 is located, for example, in the cleanroom where the cutting device 2 is installed. Note that one humidifier supply source 30 may be provided for each cutting device 2, or one may be provided for each building.

[0044] The humidifier supply source 30 has a rectangular parallelepiped housing 32 made of metal. A cavity is formed inside the housing 32. The cavity inside the housing 32 is divided into two spaces, a first space 32a and a second space 32b, by a partition wall 34.

[0045] An opening 34a is formed in a portion of the partition wall 34 to connect the first space 32a and the second space 32b. The opening 34a is formed, for example, above the Z-axis half of the partition wall 34.

[0046] A blower mechanism 36 is located in the first space 32a. The blower mechanism 36 takes in air from an air supply port (not shown) formed in the housing 32 and blows the air 36a into the second space 32b through the opening 34a of the partition wall 34.

[0047] The blower mechanism 36 of this embodiment has a fan composed of a motor, blades, etc., but the blower mechanism 36 may have a blower or a compressor instead of a fan, as long as it can achieve the function of blowing air.

[0048] Below the opening 34a of the second space 32b, pure water 38 is stored. At the bottom of the second space 32b, an ultrasonic vibrating plate 40 containing an ultrasonic transducer made of lead zirconate titanate (PZT) or the like is fixed so as to be submerged in this pure water.

[0049] By supplying power with a frequency suitable for ultrasonic vibration to the ultrasonic transducer using an oscillator connected to a power supply, ultrasonic vibrations having a predetermined frequency of 20 kHz or higher are transmitted from the ultrasonic vibrating plate 40 to the pure water 38.

[0050] Ultrasonic vibrations from the ultrasonic vibrating plate 40 generate a mist 38a of pure water 38 in the second space 32b (ultrasonic atomization). Alternatively, instead of the ultrasonic vibrating plate 40, an immersion-type ultrasonic transducer may be placed at the bottom of the second space 32b.

[0051] A cylindrical tube section 34b is provided at the top of the second space 32b. The lower end of the tube section 34b protrudes into the second space 32b, and a flexible tube 28c is connected to the upper end of the tube section 34b.

[0052] The mist 38a generated by ultrasonic vibration is supplied to the head unit 28 from the first space 32a via the pipe section 34b and the flexible tube 28c, carried by the flow of air 36a.

[0053] From each opening 28b of the head unit 28, a gas humidified with mist 38a of pure water 38, i.e., humidified air 36b, is supplied. For example, humidified air 36b with a temperature of ±2°C of the cleanroom room temperature and a relative humidity of 50% to 60% is supplied from the opening 28b.

[0054] In this manner, humidified air 36b, which has a higher humidity than the air in the internal space of the cutting device 2 or the air in the cleanroom where the cutting device 2 is located, is supplied from the opening 28b of the head unit 28.

[0055] When the frame unit 19 is transported from the chuck table 14 to the spinner cleaning device 54 by the upper transport mechanism 22, drying can be suppressed by moistening the wafer 11 (i.e., multiple device chips 13a (see Figure 5)) that has been divided after cutting with humidified air 36b.

[0056] In this embodiment, the head portion 28, the flexible tube 28c, the humidifier supply source 30, etc. constitute the humidifier supply mechanism 42. Furthermore, the ring frame holding mechanism 26 and the humidifier supply mechanism 42 together constitute a holding mechanism 44 that holds the frame unit 19.

[0057] Now, returning to Figure 1, we will describe the other components of the cutting apparatus 2. The upper transport mechanism 22 includes an upper moving mechanism (moving mechanism) 46 provided on the support 4c. The upper moving mechanism 46 is, for example, a ball screw type moving mechanism. The upper moving mechanism 46 has rails 46a arranged along the Y-axis.

[0058] The base end of the arm of the upper transport mechanism 22 is slidably attached to the rail 46a. A nut portion (not shown) is provided at the base end of this arm. A screw shaft (not shown), arranged along the Y-axis, is rotatably connected to the nut portion via a ball (not shown).

[0059] A drive source (not shown), such as a motor, is connected to one end of the screw shaft. By operating the drive source, the holding mechanism 44 moves along the Y-axis. On the opposite side of the support 4c from the lower transport mechanism 18 and the upper transport mechanism 22, a gate-shaped support 4d is provided so as to straddle the opening 4b.

[0060] A pair of cutting unit moving mechanisms (indexing feed unit and depth feed unit) 48 are provided on one side of the support 4d, which is substantially parallel to the Y-Z plane. Each cutting unit moving mechanism 48 has a ball screw type Y-axis movement mechanism and a Z-axis movement mechanism, respectively.

[0061] Each cutting unit moving mechanism 48 moves the cutting unit 50 along the Y-axis and Z-axis directions. The cutting unit 50 has a spindle housing. A portion of a cylindrical spindle (not shown), which is arranged substantially parallel to the Y-axis direction, is rotatably housed in the spindle housing.

[0062] A rotational drive source (not shown), such as a motor, is provided at one end of the spindle, and a cutting blade having an annular cutting edge is attached to the other end of the spindle. The cutting unit 50 is also provided with a camera unit 52 positioned to face the holding surface 14a.

[0063] When cutting the wafer 11, the lower transport mechanism 18 first uses a pair of guide rails (not shown) to transport one frame unit 19 from the cassette 6b to the chuck table 14.

[0064] The frame unit 19, held by suction on the holding surface 14a and four clamping units 16, is cut along each planned division line by one or two cutting units 50, dividing it into multiple device chips (chips) 13a (see Figure 4).

[0065] Figure 5 is a perspective view of the frame unit 19 after cutting. The wafer 11 is divided into multiple device chips 13a by cutting grooves 13b formed along each planned division line. The multiple device chips 13a are attached to the dicing tape 15 in the area corresponding to the opening 17a of the ring frame 17.

[0066] After cutting, multiple device chips 13a, dicing tape 15, and ring frame 17 form a frame unit 19. As described above, contamination such as chips is generated during cutting, and the device chips 13a are contaminated by used cutting water and cooling water containing the contamination.

[0067] After cutting, the upper transport mechanism 22 suction-holds the frame unit 19 and transports it from the chuck table 14 to the spinner cleaning device 54 for cleaning each device chip 13a. Figure 6 is a side view showing the upper transport mechanism 22 suction-holding and transporting the frame unit 19 after cutting is complete. Note that in Figure 6, some of the components are shown by lines and functional block diagrams.

[0068] In this embodiment, after cutting is completed, the arm of the upper transport mechanism 22 is moved above the chuck table 14, the ring frame holding mechanism 26 holds the ring frame 17 at four points by suction, and the humidifying element supply mechanism 42 supplies humidified air 36b to each device chip 13a.

[0069] In this embodiment, by supplying humidified air 36b when the frame unit 19 is transported, the deflection of the dicing tape 15 is reduced and drying of the device chip 13a can be suppressed compared to the case where the device chip 13a is immersed in the washing water stored in the washing water storage chamber to prevent drying of the device chip 13a.

[0070] Now, let's return to Figure 1. In the Y-axis direction, a circular opening 4e is formed on the opposite side of opening 4a from opening 4b. A spinner cleaning device 54 is provided in opening 4e.

[0071] The spinner cleaning device 54 has a spinner table 56 that can rotate at high speed while holding the frame unit 19 by suction. A swinging arm 58 is provided near the spinner table 56. A nozzle (not shown) is provided at the tip of the swinging arm 58.

[0072] During cleaning, the device chip 13a is cleaned by rapidly rotating the spinner table 56, which holds the frame unit 19 by suction, and by spraying a mixed fluid of pure water and air downwards while oscillating the oscillating arm 58.

[0073] After cleaning, the frame unit 19 is transported from the spinner cleaning device 54 to the cassette 6b via a pair of guide rails by the lower transport mechanism 18. The operation of each component of the cutting device 2 is controlled by the control unit 60.

[0074] The control unit 60 is composed of a computer that includes, for example, a processing unit such as a processor represented by a CPU (Central Processing Unit), a main memory, and an auxiliary memory.

[0075] Main memory includes DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), ROM (Read Only Memory), etc., while auxiliary memory includes flash memory, hard disk drives, solid state drives, etc.

[0076] The auxiliary storage device stores software, including a predetermined program. The functions of the control unit 60 are realized by operating the processing unit and other components according to this software.

[0077] In this embodiment, by supplying humidified air 36b when the frame unit 19 is transported, the deflection of the dicing tape 15 is reduced and drying of the device chip 13a can be suppressed compared to the case where the device chip 13a is immersed in the washing water stored in the washing water storage chamber to prevent drying of the device chip 13a.

[0078] In this way, during the transport of the frame unit 19, it is possible to suppress drying of the device chips 13a and reduce the occurrence rate of chipping and other damage caused by contact between adjacent device chips 13a.

[0079] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the object of the present invention. For example, instead of multiple openings 28b, the bottom portion 28a of the head portion 28 may be provided with only one opening that is larger in diameter than one of the openings 28b. [Explanation of Symbols]

[0080] 2:Cutting device 4: Base, 4a, 4b: Opening, 4c, 4d: Support, 4e: Opening 6a: Elevator, 6b: Cassette 10: Table cover, 12: Cover component 11: Wafer (workpiece), 11a: Front side, 11b: Back side 13: Device, 13a: Device chip (chip), 13b: Cutting groove 14: Chuck table, 14a: Holding surface, 16: Clamp unit 15: Dicing tape (tape), 17: Ring frame, 17a: Opening 18: Lower transport mechanism 18a: Air cylinder, 18b: Frame, 18c: Suction pad, 18d: Gripping unit 19: Frame Unit 20: Lower moving mechanism, 20a: Rail 22: Upper conveying mechanism (conveying mechanism), 22a: Air cylinder 22b: Frame, 22b1: First straight section, 22b2: Second straight section 22c: Suction pad (holding member), 22d: Flexible tube 24: Suction source, 26: Ring frame holding mechanism 28: Head section, 28a: Bottom section, 28b: Opening, 28c: Flexible tube 30: Humidifier supply source, 32: Enclosure, 32a: First space, 32b: Second space 34: Partition wall, 34a: Opening, 34b: Pipe section 36: Blower mechanism, 36a: Air, 36b: Humidified air (humidified gas) 38: Pure water, 38a: Mist, 40: Ultrasonic vibrator 42: Humidifier supply mechanism, 44: Holding mechanism 46: Upper moving mechanism (moving mechanism), 46a: Rail 48: Cutting unit movement mechanism, 50: Cutting unit, 52: Camera unit 54: Spinner cleaning device, 56: Spinner table, 58: Oscillating arm 60: Control Unit

Claims

[Claim 1] A transport mechanism for transporting a frame unit in which the ring frame, tape, and multiple chips are integrated, wherein a tape is attached to the ring frame so as to close an opening in the center of the ring frame, and a workpiece divided into multiple chips is attached to the area corresponding to the opening. The transport mechanism is, A retaining mechanism for holding the frame unit, A moving mechanism for moving the holding mechanism, Equipped with, The holding mechanism is, A ring frame holding mechanism having a plurality of holding members that each hold the ring frame, A humidifier supply mechanism having a plate-shaped head portion with one or more openings at its bottom, which supplies humidified gas from the one or more openings toward the plurality of chips during transport of the frame unit, thereby suppressing the drying of the plurality of chips, A transport mechanism characterized by including the following.

Images