Conveying mechanism

Abstract

[Problem] To prevent individual wafers from drying and reduce film deflection during the transport of multiple wafers. [Solution] A transport mechanism is provided, comprising a transport frame unit, wherein the frame unit is attached to an adhesive film attached to an annular frame in such a way that the central opening of the annular frame is blocked, and workpieces divided into multiple wafers are attached to the area corresponding to the opening, and the annular frame, adhesive film, and multiple wafers are integrated into one unit. The transport mechanism includes: a holding mechanism that holds the frame unit; and a moving mechanism that moves the holding mechanism. The holding mechanism includes: an annular frame holding mechanism having a plurality of holding members that respectively hold the annular frame; and a humidifying gas supply mechanism having a plate-shaped head having one or more openings at the bottom, and suppressing the drying of multiple wafers by supplying humidified gas toward the multiple wafers from one or more openings during the transport of the frame unit.

Description

Technical Field

[0001] The present invention relates to a conveying mechanism, wherein the conveying frame unit is attached to an adhesive film of an annular frame in such a way as to block the opening in the central part of the annular frame, and a workpiece divided into multiple wafers is attached to the area corresponding to the opening, and the annular frame, the adhesive film and the multiple wafers are integrated into one unit. Prior Technology

[0002] When cutting semiconductor wafers and other workpieces, cutting water such as pure water is supplied to the cutting blade for lubrication between the high-speed rotating cutting blade and the workpiece, and cooling water such as pure water is supplied to the processing point where the workpiece contacts the cutting blade for cooling.

[0003] During cutting, the chuck is fed while the high-speed rotating cutting blade cuts into the workpiece held and attracted by the chuck. In this way, the workpiece is divided into multiple wafers (component wafers) along each of the multiple predetermined dividing lines set in a grid pattern on one side of the workpiece.

[0004] During the cutting process, contaminants such as cutting powder are generated, and the wafers can be contaminated by used cutting water and cooling water containing these contaminants. If contaminants adhere to the wafers, they can cause product defects.

[0005] Therefore, the cut workpieces (i.e., multiple wafers) are transported from the chuck table to the rotary cleaning device by the conveying mechanism, and the cut workpieces are cleaned by the rotary cleaning device.

[0006] However, during the period from the completion of cutting to the start of cleaning, if the moisture dries and the contaminants adhere to the wafer, even using a rotary cleaning device cannot completely remove the contaminants from the wafer.

[0007] To prevent the wafers from drying out during transport, a transport mechanism has been proposed that includes a cleaning water retention member having an upper wall and an annular sidewall (see, for example, Patent Document 1). When transporting the cut workpiece, the cleaning water retention member is first positioned on the adhesive film to cover each wafer supported on the annular frame through the adhesive film.

[0008] Next, the cylindrical space (i.e., the cleaning water storage chamber) defined by the cleaning water storage component and the adhesive film is filled with cleaning water. Then, the conveying mechanism, while holding the annular frame in place, transports multiple wafers, adhesive films, and the annular frame together to the rotary cleaning device. [Known Technical Documents] [Patent Literature]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2010-87443 Summary of the Invention

[0010] [The problem that the invention aims to solve] However, the weight of the cleaning water stored in the cleaning water storage chamber can cause the film to flex, thus causing adjacent wafers on the film to come into contact with each other, which may result in cracks or chips on the wafers.

[0011] The present invention was made in view of this problem, and its object is to prevent the individual wafers from drying out and to reduce the deflection of the adhesive film during the transport of multiple wafers.

[0012] [Technical means to solve the problem] According to one aspect of the present invention, a conveying mechanism is provided, which conveys a frame unit. The frame unit is attached to an adhesive film of an annular frame in such a way that it blocks an opening in the central part of the annular frame. A workpiece divided into multiple wafers is attached to an area corresponding to the opening. The annular frame, the adhesive film, and the multiple wafers are integrated into one unit. The conveying mechanism includes: a holding mechanism that holds the frame unit; and a moving mechanism that moves the holding mechanism. The holding mechanism includes: an annular frame holding mechanism having multiple holding members that respectively hold the annular frame; and a humidifying gas supply mechanism having a plate-shaped head with one or more openings at the bottom, and suppressing the drying of the multiple wafers by supplying humidified gas from the one or more openings toward the multiple wafers during the conveying of the frame unit.

[0013] [Invention Benefits] Compared to methods that prevent wafers from drying by immersing them in cleaning water stored in a cleaning water storage chamber, the conveying mechanism of the present invention reduces film deflection and inhibits wafer drying by supplying humidified gas during the conveying of the frame unit. Simple Explanation of the Diagram

[0014] Figure 1 is a perspective view of the cutting device. Figure 2 is a perspective view of the frame of the upper conveying mechanism. Figure 3 is a bottom view of the frame of the upper conveying mechanism. Figure 4 is a partial cross-sectional side view of the humidifying gas supply source. Figure 5 is a three-dimensional view of the cut frame unit. Figure 6 is a side view showing the state in which the frame unit is attracted, held, and transported. Implementation

[0015] Referring to the accompanying drawings, one embodiment of the present invention will be described. FIG1 is a perspective view of the cutting apparatus 2. Furthermore, in FIG1, a portion of the constituent elements are represented by a functional block diagram. In FIG1, the X-axis direction (machining feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (vertical direction) are mutually perpendicular.

[0016] The cutting device 2 has a base 4 that supports all its components. An opening 4a is provided at the front corner of the base 4. A lifting machine 6a, which is raised and lowered by a lifting mechanism (not shown), is provided in the opening 4a. A cassette 6b for accommodating multiple wafers (workpieces) 11 is placed on the upper surface of the lifting machine 6a.

[0017] The wafer 11 may have, for example, a disk-shaped single-crystal substrate formed of a semiconductor material such as silicon. Furthermore, there are no limitations on the material, shape, structure, or size of the single-crystal substrate. Multiple predetermined dicing lines (cutting tracks) are arranged in a lattice pattern on the front side 11a of the wafer 11.

[0018] Components such as ICs (Integrated Circuits) are formed in rectangular areas divided by multiple predetermined dividing lines. The central portion of a dicing film (film) 15, which has a diameter larger than that of the wafer 11, is attached to the back side 11b of the wafer 11, which is located on the opposite side from the front side 11a.

[0019] The annular frame 17, made of metal, is attached to the outer periphery of the cutting film 15. That is, the cutting film 15 is attached to the annular frame 17 in a manner that blocks the opening 17a formed in the central part of the annular frame 17.

[0020] Before dicing, the wafer 11 is attached to the area corresponding to the opening 17a and supported on the annular frame 17 by the dicing adhesive film 15. The wafer 11 and the annular frame 17 are integrated by the dicing adhesive film 15 to form the frame unit 19.

[0021] The wafer 11 is housed in the cassette 6b in the frame unit 19 state. A rectangular opening 4b with a long side along the X-axis is formed on the side of the elevator 6a. A worktable cover 10 is provided in the opening 4b.

[0022] The worktable cover 10 has serpentine cover members 12 that can extend and retract along the X-axis on both sides. The worktable cover 10 has a disc-shaped chuck platform 14.

[0023] Negative pressure is transferred from the suction source (not shown) of a vacuum pump, ejector, etc., to the upper surface of the chuck stage 14, where it functions as the holding surface 14a of the suction holding frame unit 19. Multiple clamping units 16 are provided on the outer periphery of the chuck stage 14, each capable of clamping the annular frame 17 in the thickness direction.

[0024] The chuck stage 14 is configured to rotate about a rotational axis that is substantially parallel to the Z-axis direction by means of a rotary drive source (not shown) such as a motor. Furthermore, the chuck stage 14 is configured to move along the X-axis direction by means of a ball screw type X-axis direction moving mechanism (machining feed unit) not shown.

[0025] Above the area adjacent to opening 4a in opening 4b, there is a pair of guide rails (not shown) used for moving frame unit 19 into and out of cartridge 6b. The length of each pair of guide rails is arranged along the Y-axis and can move in a way that approaches or moves away along the X-axis.

[0026] A gate-shaped support 4c is provided at the center of the base 4 in the X-axis direction, spanning the opening 4b. On one side of the support 4c, which is approximately parallel to the YZ plane, there are a lower conveying mechanism 18 and an upper conveying mechanism 22 for conveying the frame unit 19.

[0027] The lower conveying mechanism 18 is used when removing the frame unit 19 from the cassette 6b and when moving the cleaned frame unit 19 into the cassette 6b. The lower conveying mechanism 18 has a cylinder 18a, which includes a piston rod that can move along the Z-axis.

[0028] The lower end of the piston rod is fixed with the base end of an arm arranged along the X-axis. A frame 18b, which is roughly H-shaped in top view, is fixed to the front end of the arm. Suction pads 18c are provided on the bottom sides of the four corners of the frame 18b.

[0029] The negative pressure is transmitted from suction sources (not shown) such as vacuum pumps and ejectors to each suction pad 18c through flexible tubes (not shown). The suction pads 18c hold the frame unit 19 by suction holding the annular frame 17.

[0030] Within the frame 18b, a gripping unit 18d is provided at the front end of the elevator 6a side, capable of gripping the annular frame 17. The lower conveying mechanism 18 includes a moving mechanism 20 disposed below the support body 4c.

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

[0032] A nut portion (not shown) is provided at the upper end of cylinder 18a. A screw shaft (not shown) arranged along the Y-axis direction is rotatably connected to the nut portion through balls (not shown).

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

[0034] The upper conveying mechanism (conveyor) 22 is used to convey the frame unit 19 from the chuck table 14 to the rotary cleaning device 54 described later. The upper conveying mechanism 22 has an arm that is arranged to protrude along the X-axis direction, and a cylinder 22a is provided at the front end of the arm. The cylinder 22a includes a piston rod that can move along the Z-axis direction.

[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 metal such as aluminum alloy or stainless steel, and has a pair of first straight portions 22b 1 arranged along the Y-axis direction (see Figure 2).

[0036] As shown in Figure 2, a pair of first straight sections 22b 1 are connected to each other at the midpoint of their length direction by a second straight section 22b 2 arranged along the X-axis. At the bottom side of the front end of each first straight section 22b 1 (i.e., the four corners of the frame 22b), there are suction pads (holding members) 22c.

[0037] The negative pressure is transmitted from the suction source 24, such as the vacuum pump and ejector, to each suction pad 22c through the flexible tube 22d. Referring to Figures 2 and 3, the upper conveying mechanism 22 will be described in detail. Figure 2 is a perspective view of the frame 22b of the upper conveying mechanism 22, and Figure 3 is a bottom view of the frame 22b of the upper conveying mechanism 22.

[0038] Furthermore, in Figure 2, a portion of the constituent elements is represented by lines and functional block diagrams. The frame 22b and the four suction pads 22c constitute the annular frame holding mechanism 26, which attracts and holds the annular frame 17 by negative pressure.

[0039] Alternatively, clamping units (not shown) that can clamp the annular frame 17 in its thickness direction can be provided to replace the suction pad 22c, thereby forming an annular frame holding mechanism 26 for holding the annular frame 17.

[0040] The lower end of the piston rod of cylinder 22a is fixed to the upper surface of the second straight section 22b 2. A disc-shaped (plate-shaped) head 28 is provided on the lower surface of the second straight section 22b 2.

[0041] At the bottom 28a of the head 28, multiple (more than one) openings 28b are formed in the manner of a shower head. Each opening 28b is arranged in a manner that adjacent openings 28b are approximately equally spaced from each other, forming a generally complete whole of the bottom 28a.

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

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

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

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

[0046] An air supply mechanism 36 is provided in the first space 32a. The air supply mechanism 36 introduces air from an air supply port (not shown) formed in the housing 32 and supplies air 36a from the opening 34a of the partition wall 34 to the second space 32b.

[0047] Although the air supply mechanism 36 in this embodiment has a fan composed of a motor, fan blades, etc., as long as the function of air supply can be realized, the air supply mechanism 36 can have a blower or a compressor to replace the fan.

[0048] Pure water 38 is stored in the second space 32b at a position lower than the opening 34a. An ultrasonic vibrating plate 40 is fixed at the bottom of the second space 32b by immersing it in this pure water. The ultrasonic vibrating plate 40 includes an ultrasonic vibrator formed of lead zirconate titanate (PZT) or the like.

[0049] If an oscillator or similar device connected to a power source is used, and power of a frequency suitable for ultrasonic vibration is supplied to the ultrasonic vibrator, ultrasonic vibration with a predetermined vibration frequency of 20 kHz or higher is transmitted from the ultrasonic vibration plate 40 to the pure water 38.

[0050] By means of ultrasonic vibration from the ultrasonic vibrating plate 40, pure water 38 mist 38a (ultrasonic atomization) is generated in the second space 32b. Alternatively, an immersion-type ultrasonic vibrator can be installed at the bottom of the second space 32b to replace the ultrasonic vibrating plate 40.

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

[0052] The mist 38a generated by ultrasonic vibration will be supplied to the head 28 from the second space 32b through the tube 34b and the flexible tube 28c, carried by the flow of air 36a.

[0053] The openings 28b of the head 28 supply humidified air 36b, which is mist 38a of pure water 38. For example, humidified air 36b with a temperature of room temperature ±2°C and a relative humidity of 50% to 60% is supplied from the openings 28b.

[0054] Thus, humidified air 36b with 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 installed is supplied from the opening 28b of the head 28.

[0055] When the frame unit 19 is transported from the chuck table 14 to the rotary cleaning device 54 by the upper side conveying mechanism 22, the drying can be suppressed by humidifying the diced wafer 11 (i.e., multiple component chips 13a (see Figure 5)) with humidified air 36b.

[0056] In this embodiment, the head 28, the flexible tube 28c, and the humidifying gas supply source 30 constitute the humidifying gas supply mechanism 42. Furthermore, the aforementioned annular frame holding mechanism 26 and the humidifying gas supply mechanism 42 constitute the holding mechanism 44 of the holding frame unit 19.

[0057] Here, referring back to Figure 1, other components of the cutting device 2 will be described. The upper conveying mechanism 22 includes an upper moving mechanism (moving mechanism) 46 disposed on the support body 4c. The upper moving mechanism 46 is, for example, a ball screw type moving mechanism. The upper moving mechanism 46 has a track 46a arranged along the Y-axis direction.

[0058] The base end of the arm of the upper conveying mechanism 22 is slidably mounted on the track 46a. A nut (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 via balls (not shown).

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

[0060] On one side of the support 4d, which is approximately parallel to the YZ plane, there is a pair of cutting unit moving mechanisms (indexing feed unit and infeed feed unit) 48. 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. A portion of a cylindrical spindle (not shown) arranged substantially parallel to the Y-axis direction is rotatably housed in the spindle housing.

[0062] A rotation drive source such as a motor (not shown) is provided at one end of the spindle, and a cutting blade with a circular cutting edge is mounted at the other end of the spindle. Furthermore, a camera unit 52 is provided in the cutting unit 50, which is arranged to face the holding surface 14a.

[0063] During the dicing of wafer 11, firstly, the lower transport mechanism 18 uses a pair of guide rails (not shown) to transport a frame unit 19 from the cassette 6b to the chuck stage 14.

[0064] The frame unit 19, held by the holding surface 14a and four clamping units 16, is cut along predetermined dividing lines by one or two cutting units 50 and divided into multiple component wafers (wafers) 13a (see Figure 5).

[0065] Figure 5 is a perspective view of the cut frame unit 19. The wafer 11 is divided into multiple component wafers 13a by dicing grooves 13b formed along the predetermined dicing lines. In addition, the multiple component wafers 13a are attached to the dicing film 15 in the area corresponding to the opening 17a of the annular frame 17.

[0066] After dicing, multiple component wafers 13a, dicing film 15, and annular frame 17 form frame unit 19. As described above, dicing powder and other contaminants are generated during dicing, and the component wafers 13a are contaminated by used dicing water and cooling water containing contaminants.

[0067] After cutting, in order to clean the individual component wafers 13a, the upper conveying mechanism 22 attracts and holds the frame unit 19 and transfers it from the chuck stage 14 to the rotary cleaning device 54. Figure 6 is a side view showing the state in which the upper conveying mechanism 22 attracts, holds, and transfers the cut frame unit 19. In addition, in Figure 6, some of the constituent elements are represented by lines and functional block diagrams.

[0068] In this embodiment, after the cutting is completed, the arm of the upper conveying mechanism 22 is moved above the chuck table 14, and the four places of the ring frame 17 are attracted and held by the ring frame holding mechanism 26. Humidifying air 36b is supplied to each component wafer 13a by the humidifying gas supply mechanism 42.

[0069] In this embodiment, humidified air 36b is supplied during the transport of frame unit 19. This reduces the deflection of cutting film 15 and suppresses the drying of component wafer 13a compared to preventing the component wafer 13a from drying by immersing it in cleaning water stored in cleaning water storage chamber.

[0070] Here, we return to Figure 1 again. A circular opening 4e is formed in the Y-axis direction relative to opening 4b and opposite to opening 4a. A rotating cleaning device 54 is provided in opening 4e.

[0071] The rotary cleaning device 54 has a rotary table 56 that can rotate at high speed when the retaining frame unit 19 is attracted. A swing arm 58 is provided near the rotary table 56. A nozzle (not shown) is provided at the front end of the swing arm 58.

[0072] During cleaning, the rotating stage 56 of the retaining frame unit 19 is rotated at high speed, and the swing arm 58 is swung while spraying a mixture of pure water and air downwards to clean the component chip 13a.

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

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

[0075] The main memory devices include DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), and ROM (Read Only Memory), while the auxiliary memory devices include flash memory, hard disk drives, and solid-state drives.

[0076] The auxiliary memory device stores software containing a predetermined program. By following this software, the processing device and other components are operated, thereby realizing the function of the control unit 60.

[0077] In this embodiment, humidified air 36b is supplied during the transport of frame unit 19. This reduces the deflection of cutting film 15 and suppresses the drying of component wafer 13a compared to preventing the component wafer 13a from drying by immersing it in cleaning water stored in cleaning water storage chamber.

[0078] In this way, during the transport of frame unit 19, the drying of component wafer 13a can be suppressed and the occurrence rate of defects caused by contact between adjacent component wafers 13a can be reduced.

[0079] Furthermore, the structure and method of the above embodiments can be appropriately modified and implemented as long as they do not depart from the scope of the present invention. For example, at the bottom 28a of the head 28, only one opening with a diameter larger than one opening 28b can be provided instead of multiple openings 28b.

[0080] 2: Cutting device 4:Abutment 4a, 4b: Opening 4c, 4d: Support 4e: Opening 6a: Elevator 6b: Cartridge 10: Workbench cover 12: Cover components 11: Wafer (workpiece) 11a: Front 11b: Back 13: Components 13a: Component wafer (chip) 13b: Cutting groove 14: Chuck Table 14a: Maintain surface 16: Fixture Unit 15: Cutting the adhesive film (adhesive film) 17: Ring-shaped frame 17a: Opening 18: Lower conveying mechanism 18a: Cylinder 18b: Frame 18c: Attraction Pad 18d: Grip unit 19: Frame Unit 20: Lower moving mechanism 20a: Track 22: Upper conveying mechanism (conveyor mechanism) 22a: Cylinder 22b: Frame 22b 1: First straight section 22b 2: Second straight section 22c: Suction pad (retention component) 22d: Flexible tube 24: Source of Attraction 26: Ring-shaped frame retaining mechanism 28: Head 28a: Bottom 28b: Open 28c: Flexible tube 30: Humidifying gas supply source 32: Shell 32a: First Space 32b: Second Space 34: Partition wall 34a: Opening 34b: Management Department 36: Air supply mechanism 36a: Air 36b: Humidified air (gas that has been humidified) 38: Pure water 38a: Fog 40: Ultrasonic Vibrating Plate 42: Humidifying gas supply mechanism 44: Maintaining the organization 46: Upper moving mechanism (moving mechanism) 46a: Track 48: Cutting Unit Moving Mechanism 50: Cutting Unit 52: Camera Unit 54: Rotary cleaning device 56: Rotary table 58: Swing arm 60: Control Unit

Claims

1. A conveying mechanism comprising a conveying frame unit, the frame unit being attached to an adhesive film of an annular frame in such a way as to block an opening in the central portion of the annular frame, wherein a workpiece divided into multiple wafers is attached to an area corresponding to the opening, and the annular frame, the adhesive film, and the multiple wafers are integrally formed, characterized in that the conveying mechanism comprises: a holding mechanism for holding the frame unit; and a moving mechanism for moving the holding mechanism; the holding mechanism comprising: an annular frame holding mechanism having a plurality of holding members for holding the annular frame respectively; and a humidifying gas supply mechanism having a plate-shaped head having one or more openings at the bottom, and suppressing the drying of the multiple wafers by supplying humidified gas from the one or more openings toward the multiple wafers during the conveying of the frame unit.

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