Transfer mechanism

Abstract

(Task) During the transport of multiple chips, prevent drying of each chip and reduce tape warping. (Solution) A conveying mechanism for conveying a frame unit in which a ring frame, a tape, and a plurality of chips are integrated, wherein a workpiece divided into a plurality of chips is attached to a tape attached to a ring frame to block an opening in the central part of the ring frame, and the conveying mechanism comprises a holding mechanism for holding the frame unit and a moving mechanism for moving the holding mechanism, wherein the holding mechanism comprises a ring frame holding mechanism having a plurality of holding members for holding each ring frame, and a humidifying gas supply mechanism having a plate-shaped head part having one or more openings at the bottom, and suppressing drying of the plurality of chips by supplying humidified gas from one or more openings toward the plurality of chips when conveying the frame unit.

Description

Technology Field

[0001] The present invention relates to a conveying mechanism for conveying a ring frame unit in which a ring frame, a tape, and a plurality of chips are integrated, wherein a workpiece divided into a plurality of chips is attached to a tape attached to a ring frame to block an opening in the central part of the ring frame. Background Technology

[0002] When cutting a workpiece such as a semiconductor wafer, cutting water, such as pure water, is supplied to the cutting blade to lubricate the high-speed rotating cutting blade and the workpiece, and cooling water, such as pure water, is supplied to the processing point to cool the processing point where the workpiece and the cutting blade come into contact.

[0003] When cutting, the cutting blade rotating at high speed is fed into the workpiece held by the chuck table, and the chuck table is moved to process. By doing so, the workpiece is cut along each of the multiple division lines set in a grid pattern on one side of the workpiece, thereby dividing the workpiece into multiple chips (device chips).

[0004] During cutting, contamination such as cutting debris occurs, and the chips become contaminated by used cutting fluid and cooling water containing this contamination. If contamination adheres to the chips, it causes product defects.

[0005] Therefore, the workpiece after cutting (i.e., multiple chips) is conveyed from the chuck table to the spinner cleaning device by the conveying mechanism, and the workpiece after cutting is cleaned by the spinner cleaning device.

[0006] However, if moisture dries out and contamination adheres to the chip between the end of cutting and the start of cleaning, the contamination cannot be completely removed from the chip even if a spinner cleaning device is used.

[0007] Therefore, in order to prevent the drying of chips during transport, a transport mechanism is proposed that includes a cleaning water reservoir member having an upper wall and an annular side wall (see, for example, Patent Document 1). When transporting a workpiece after cutting, the cleaning water reservoir member is first placed on the tape to cover each chip supported on the ring frame through 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. Then, the conveying mechanism conveys a plurality of chips, together with the tape and the ring frame, to the spinner cleaning device while holding the ring frame in suction. Prior art literature

[0009] Japanese Patent Publication No. 2010-87443 The problem to be solved

[0010] However, as the tape bends due to the weight of the cleaning water stored in the cleaning water storage chamber, chips placed adjacent to each other on the tape come into contact, and cracks or defects may occur in the chips.

[0011] The present invention was made in consideration of these problems and aims to prevent drying of each chip and reduce bending of the tape during the transport of a plurality of chips. means of solving the problem

[0012] According to one embodiment of the present invention, a conveying mechanism is provided for conveying a frame unit in which a workpiece divided into a plurality of chips is attached to a tape attached to a ring frame to block an opening in the central part of the ring frame, and the ring frame, the tape, and the plurality of chips are integrated. The conveying mechanism comprises a holding mechanism for holding the frame unit and a moving mechanism for moving the holding mechanism. The holding mechanism comprises a ring frame holding mechanism having a plurality of holding members for holding each of the ring frames, and a humidifying gas supply mechanism having a plate-shaped head portion having one or more openings at the bottom, which suppresses drying of the plurality of chips by supplying humidified gas from the one or more openings toward the plurality of chips during conveying of the frame unit. Effects of the invention

[0013] A conveying mechanism related to one embodiment of the present invention can reduce tape bending and also suppress chip drying by supplying humidified gas during conveying of the frame unit, compared to the case where the chip is immersed in cleaning water stored in the cleaning water storage chamber to prevent drying of the chip. Brief explanation of the drawing

[0014] Figure 1 is a perspective view of a cutting device. FIG. 2 is a perspective view showing the frame, etc. of an upper conveying mechanism. Figure 3 is a lower view showing the frame, etc. of an upper conveying mechanism. Figure 4 is a partial cross-sectional side view of a humidifying gas supply source. Fig. 5 is a perspective view of the frame unit after cutting. FIG. 6 is a side view showing the frame unit being sucked in and maintained for transport. Specific details for implementing the invention

[0015] With reference to the attached drawings, an embodiment related 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 in a functional block diagram. In FIG. 1, the X-axis direction (processing feed direction), the Y-axis direction (output feed direction), and the Z-axis direction (up and down direction) are directions that are orthogonal to each other.

[0016] The cutting device (2) is provided with a base (4) that supports each component. An opening (4a) is formed at the front corner of the base (4). An elevator (6a) that moves up and down by a lifting mechanism (not shown) is formed inside the opening (4a). A cassette (6b) for accommodating a plurality of wafers (workpieces) (11) is mounted on the upper surface of the elevator (6a).

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

[0018] In each rectangular area partitioned by multiple planned division lines, a device (13), such as an IC (Integrated Circuit), is formed. On the back surface (11b) of the wafer (11) located opposite to the surface (11a), a 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 circumference of the dicing tape (15). That is, the dicing tape (15) is attached to the ring frame (17) to block the opening (17a) formed in the center of the ring frame (17).

[0020] The wafer (11) before splitting is attached to an area corresponding to the opening (17a) and supported by a ring frame (17) through a dicing tape (15). The wafer (11) and the ring frame (17) are integrated through the dicing tape (15) to form a frame unit (19).

[0021] The wafer (11) is housed 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 formed inside the opening (4b).

[0022] On both sides of the table cover (10) in the X-axis direction, bellows-shaped cover members (12) that are extendable along the X-axis direction are formed. On the table cover (10), a disc-shaped chuck table (14) is formed.

[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 or an ejector, and functions as a holding surface (14a) that holds the frame unit (19) in place. On the outer periphery of the chuck table (14), a plurality of clamp units (16) are formed, which can support the ring frame (17) by fitting it between them in the thickness direction.

[0024] The chuck table (14) is configured to rotate around a rotation axis approximately parallel to the Z-axis direction by means of a rotational driving source such as a motor (not shown). Additionally, the chuck table (14) is configured to move along the X-axis direction by means of a ball screw type X-axis movement mechanism (processing feed unit) not shown.

[0025] Above the area adjacent to the opening (4a) in the opening (4b), a pair of guide rails (not shown) are formed for use when bringing in and taking out the frame unit (19) with respect to the cassette (6b). Each of the pair of guide rails is arranged along the Y-axis direction and is movable so as to be spaced apart along the X-axis direction.

[0026] In the central part of the X-axis direction of the support (4), a gate-shaped support (4c) is formed across the opening (4b). On one side of the support (4c) which is approximately parallel to the YZ plane, a lower conveying mechanism (18) and an upper conveying mechanism (22) are formed to convey the frame unit (19) respectively.

[0027] The lower conveying mechanism (18) is used when taking out the frame unit (19) from the cassette (6b) and when bringing the frame unit (19) back into the cassette (6b) after cleaning. The lower conveying mechanism (18) has an air cylinder (18a) including a piston rod movable along the Z-axis direction.

[0028] The base of the arm portion, which is positioned along the X-axis direction, is fixed to the lower end of the piston rod. A frame (18b) that is approximately H-shaped when viewed from the top surface is fixed to the front end of the arm portion. Suction pads (18c) are formed on the lower 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 an ejector, through a flexible tube (not shown). The suction pad (18c) can hold the frame unit (19) by holding the ring frame (17) in suction.

[0030] At the leading end of the frame (18b) on the elevator (6a) side, a gripping unit (18d) capable of gripping the ring frame (17) is formed. The lower conveying mechanism (18) includes a lower moving mechanism (20) formed on the support (4c).

[0031] The lower moving mechanism (20) of the present embodiment is a ball screw type moving mechanism and has a rail (20a) arranged along the Y-axis direction. The upper end of an air cylinder (18a) is slidably mounted on the rail (20a).

[0032] A nut portion (not shown) is formed on the upper part of the air cylinder (18a). A screw shaft (not shown) arranged along the Y-axis direction is rotatably connected to the nut portion through a ball (not shown).

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

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

[0035] At the lower end of the piston rod, a frame (22b) that is approximately H-shaped when viewed from the top surface is fixed. The frame (22b) is formed of a metal such as aluminum alloy or stainless steel and has a pair of first straight sections (22b1) arranged along the Y-axis direction (see FIG. 2).

[0036] As shown in FIG. 2, a pair of first straight sections (22b1) are connected to each other by a second straight section (22b2) arranged along the X-axis direction at an intermediate position along the length direction. A suction pad (retaining member) (22c) is formed on the lower side of the leading edge (i.e., the four corners of the frame (22b)) of each first straight section (22b1).

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

[0038] In addition, in FIG. 2, parts of the components are shown as lines or functional blocks. The frame (22b) and four suction pads (22c) form a ring frame holding mechanism (26) that holds the ring frame (17) by suction under negative pressure.

[0039] In addition, instead of the suction pad (22c), a ring frame holding mechanism (26) that holds the ring frame (17) may be constructed by forming a clamp unit (not shown) that can support the ring frame (17) by inserting it between each other in the thickness direction.

[0040] On the upper side of the second straight section (22b2), the lower end of the piston rod of the air cylinder (22a) is fixed. On the lower side of the second straight section (22b2), a disc-shaped (plate-shaped) head section (28) is formed.

[0041] In the bottom portion (28a) of the head portion (28), a plurality (1 or more) of openings (28b) are formed, such as in a shower head. Each opening (28b) is arranged approximately over the entire bottom portion (28a) so that adjacent openings (28b) are approximately equally spaced.

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

[0043] FIG. 4 is a partial cross-sectional side view of a humidifying gas source (30). The humidifying gas source (30) is, for example, placed in a clean room where a cutting device (2) is placed. Additionally, one humidifying gas source (30) may be formed for one cutting device (2) or one may be formed for one building.

[0044] The humidifying gas supply source (30) has a rectangular housing (32) formed 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] In a part of the partition wall (34), an opening (34a) is formed to connect the first space (32a) and the second space (32b). The opening (34a) is formed, for example, above half of the partition wall (34) in the Z-axis direction.

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

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

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

[0049] When power of a frequency suitable for ultrasonic vibration is supplied to an ultrasonic vibrator using an oscillator connected to a power source, ultrasonic vibration having a predetermined frequency of 20 kHz or higher is transmitted from the ultrasonic vibrator (40) to the pure water (38).

[0050] By ultrasonic vibration from the ultrasonic vibrator (40), a mist (38a) of pure water (38) is generated in the second space (32b) (ultrasonic atomization). Additionally, instead of the ultrasonic vibrator (40), an injectable ultrasonic vibrator may be placed at the bottom of the second space (32b).

[0051] A cylindrical tube portion (34b) is formed in the upper part of the second space (32b). The lower end of the tube portion (34b) protrudes into the second space (32b), and a flexible tube (28c) is connected to the upper end of the tube portion (34b).

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

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

[0054] In this way, 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 clean room where the cutting device (2) is placed, is supplied from the opening (28b) of the head part (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 wetting the wafer (11) (i.e., a plurality of device chips (13a) (see FIG. 5)) that has been cut and divided with humidified air (36b).

[0056] In this embodiment, the head portion (28), flexible tube (28c), humidifying gas supply source (30), etc. constitute a humidifying gas supply mechanism (42). Additionally, the ring frame holding mechanism (26) described above and the humidifying gas supply mechanism (42) constitute a holding mechanism (44) that holds the frame unit (19).

[0057] Here, returning to FIG. 1, another configuration of the cutting device (2) is described. The upper conveying mechanism (22) includes an upper moving mechanism (moving mechanism) (46) formed in the support (4c). The upper moving mechanism (46) is, for example, a ball screw type moving mechanism. The upper moving mechanism (46) has a rail (46a) arranged along the Y-axis direction.

[0058] On the rail (46a), the base portion of the arm of the upper conveying mechanism (22) is slidably mounted. A nut portion (not shown) is formed on the base portion of the arm. A screw shaft (not shown) arranged along the Y-axis direction is rotatably connected to the nut portion through a ball (not shown).

[0059] A driving source (not shown), such as a motor, is connected to one end of the screw shaft. By operating the driving source, the holding mechanism (44) moves along the Y-axis direction. On the opposite side of the lower conveying mechanism (18) and the upper conveying mechanism (22) relative to the support body (4c), a gate-shaped support body (4d) is formed across the opening (4b).

[0060] On one side of a support (4d) approximately parallel to the YZ plane, a pair of cutting unit moving mechanisms (output feed unit, cut feed unit) (48) are formed. Each cutting unit moving mechanism (48) has a ball screw type Y-axis moving mechanism and a Z-axis moving mechanism.

[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. The spindle housing rotatably accommodates a portion of a cylindrical spindle (not shown) positioned approximately parallel to the Y-axis direction.

[0062] At one end of the spindle, a rotational driving source (not shown), such as a motor, is formed, and at the other end of the spindle, a cutting blade having an annular cutting edge is mounted. Additionally, a camera unit (52) is formed in the cutting unit (50) so as to face the retaining surface (14a).

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

[0064] The frame unit (19), which is held in place by suction by the retaining surface (14a) and four clamp units (16), is cut along each planned division line by one or two cutting units (50) to divide into a plurality of device chips (chips) (13a) (see FIG. 4).

[0065] FIG. 5 is a perspective view of the frame unit (19) after cutting. By cutting grooves (13b) formed along each planned division line, the wafer (11) is divided into a plurality of device chips (13a). Additionally, the plurality of device chips (13a) are attached to a dicing tape (15) in an area corresponding to the opening (17a) of the ring frame (17).

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

[0067] After cutting, in order to clean each device chip (13a), the upper conveying mechanism (22) sucks up and holds the frame unit (19) and conveys it from the chuck table (14) to the spinner cleaning device (54). FIG. 6 is a side view showing the frame unit (19) sucked up and held and conveyed by the upper conveying mechanism (22) after the cutting is finished. Also, in FIG. 6, parts of the components are shown as lines or functional block diagrams.

[0068] In this embodiment, after the cutting is finished, the arm of the upper conveying mechanism (22) is moved upward on the chuck table (14), and while the ring frame holding mechanism (26) sucks and holds the four parts of the ring frame (17), humidifying air (36b) is supplied toward each device chip (13a) by the humidifying gas supply mechanism (42).

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

[0070] Here, we return to Fig. 1. On the side opposite to the opening (4a) with respect to the opening (4b) in the Y-axis direction, a circular opening (4e) is formed. A spinner cleaning device (54) is formed in the 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) in suction. A oscillating arm (58) is formed near the spinner table (56). A nozzle (not shown) is formed at the tip of the oscillating arm (58).

[0072] During cleaning, the device chip (13a) is cleaned by spraying a mixed fluid of pure water and air downward while simultaneously rotating the spinner table (56), which holds the frame unit (19) in place, at high speed and shaking the shaking arm (58).

[0073] After cleaning, the frame unit (19) is returned from the spinner cleaning device (54) to the cassette (6b) via a pair of guide rails by the lower return 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 including a processing unit such as a processor, represented by, for example, a CPU (Central Processing Unit), a main memory, and an auxiliary memory.

[0075] Main memory devices include DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), ROM (Read Only Memory), etc., and secondary memory devices include flash memory, hard disk drives, solid-state drives, etc.

[0076] Software containing a predetermined program is stored in the auxiliary storage device. By operating the processing unit, etc. according to this software, the function of the control unit (60) is realized.

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

[0078] In this way, when transporting the frame unit (19), it is possible to achieve both suppression of drying of the device chip (13a) and reduction of the occurrence rate of defects caused by contact between adjacent device chips (13a).

[0079] Furthermore, the structure, method, etc. related to the above-described embodiment may be appropriately modified and implemented as long as it does not deviate from the scope of the purpose of the present invention. For example, in the bottom portion (28a) of the head portion (28), instead of a plurality of openings (28b), only one opening with a larger diameter than one opening (28b) may be formed. Explanation of the symbols

[0080] 2 : Cutting device 4: Expector, 4a, 4b: Opening, 4c, 4d: Support, 4e: Opening 6a : Elevator, 6b : Cassette 10: Table cover, 12: Cover part 11: Wafer (workpiece), 11a: Surface, 11b: Back side 13: Device, 13a: Device chip (chip), 13b: Cutting groove 14: Chuck table, 14a: Retaining surface, 16: Clamp unit 15: Dicing tape (tape), 17: Ring frame, 17a: Opening 18: Lower return mechanism 18a: Air cylinder, 18b: Frame, 18c: Suction pad, 18d: Grasp 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 (retention member), 22d: Flexible tube 24: Suction source, 26: Ring frame retaining mechanism 28: Head section, 28a: Bottom section, 28b: Opening, 28c: Flexible tube 30: Humidifying gas source, 32: Housing, 32a: First space, 32b: Second space 34: Partition wall, 34a: Opening, 34b: Pipe 36: Blower, 36a: Air, 36b: Humidified air (humidified gas) 38: Pure, 38a: Mist, 40: Ultrasonic vibrator 42: Humidifying gas supply device, 44: Maintenance device 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 conveying mechanism for conveying a frame unit in which a workpiece divided into multiple chips is attached to a tape attached to a ring frame to block an opening in the central part of the ring frame, and the ring frame, the tape, and the multiple chips are integrated, wherein the conveying mechanism comprises a holding mechanism for holding the frame unit and a moving mechanism for moving the holding mechanism, and wherein the holding mechanism comprises a ring frame holding mechanism having a plurality of holding members for holding each of the ring frames, and a humidifying gas supply mechanism having a plate-shaped head portion having one or more openings at the bottom portion and supplying humidified gas toward the multiple chips from the one or more openings during the conveying of the frame unit.

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