JP6879807B2 - Processing equipment - Google Patents

Description

The present invention relates to a processing apparatus for processing a wafer.

A workpiece such as a wafer is fixed to a substrate with an adhesive such as wax in order to increase the rigidity of the wafer during transportation or processing, and the substrate side is held on a holding table of a grinding device, for example, and then the substrate is held. Wafers may be ground and polished. Thereby, the wafer can be processed satisfactorily (see, for example, Patent Document 1 below). After processing the wafer, the substrate is removed from the wafer, for example, the wafer is attached to the tape attached to the ring frame to form a work set, and the work set is conveyed to the holding table of the cutting apparatus. , The wafer is divided into individual chips (see, for example, Patent Document 2 below).

Japanese Unexamined Patent Publication No. 2010-165802 Japanese Unexamined Patent Publication No. 2015-170719

However, in the above process, after grinding the wafer with a substrate with a grinding device, the substrate is removed from the wafer and the tape mount (tape replacement) that allows the ring frame to support the wafer via tape. Since it is necessary to perform the above, the number of steps increases and it takes time. Further, when the wafer is made of a hard material, a large warp may occur in the outer peripheral portion of the wafer, and there is a problem that the wafer cannot be sucked and held by the holding surface of the holding table.

The present invention has been made in view of the above circumstances, and an object of the present invention is to allow a wafer having a warp to be sucked and held on a holding table for processing.

The present invention comprises a holding means for holding a work set that supports a wafer via a tape attached to a ring frame, a processing means for processing the wafer of the work set held by the holding means, and the work set. A processing device including a conveying means for conveying to a holding means and an elevating means for raising and lowering the conveying means. The conveying means is held by a frame holding portion for holding the ring frame and the holding means. The tape provided with a pressing portion for pressing the annular portion between the inner circumference of the ring frame held by the frame holding portion and the outer periphery of the wafer of the tape of the work set, and the annular portion is pressed by the pressing portion. The lower surface of the tape and the holding surface of the holding means are brought into close contact with each other, and the wafer can be sucked and held on the holding surface via the tape. The outer peripheral portion of the wafer of the work set may be warped in the direction of peeling from the tape.

The processing apparatus according to the present invention provides a holding means for holding a work set that supports a wafer via a tape attached to a ring frame, a processing means for processing the wafer of the work set held by the holding means, and a work set. A transport means for transporting to the holding means and an elevating means for raising and lowering the transport means are provided, and the transport means is held by a frame holding portion that holds the ring frame and a frame holding portion of the tape of the work set held by the holding means. It is provided with a pressing portion that presses the annular portion between the inner circumference of the ring frame and the outer circumference of the wafer, and the annular portion is pressed by the pressing portion to bring the lower surface of the tape and the holding surface of the holding means into close contact with each other to suck and hold the wafer. Therefore, the sealing effect between the lower surface of the tape and the holding surface of the holding means can be enhanced, and even when the outer peripheral portion of the wafer of the work set is warped in the direction of peeling from the tape. The warp can be corrected and the wafer can be reliably sucked and held on the holding surface. Further, according to the processing apparatus according to the present invention, since the wafer can be conveyed and processed in the form of a work set, for example, when dividing a wafer with a substrate after grinding or polishing, a sub from the wafer is used. It is not necessary to perform processes such as straight removal and tape mounting, which can save time.

It is a perspective view which shows the structure of an example of a processing apparatus. It is sectional drawing which shows the structure of the work set, the transport means and the holding means. It is sectional drawing which shows the state which puts the work set on the holding means by the transport means. It is sectional drawing which shows the state which transports a work set by a transport means, and holds a work set by a holding means. It is sectional drawing which shows the state which raises the transport means in the direction away from the holding means.

The processing device 1 shown in FIG. 1 is an example of a polishing device that performs polishing processing on a wafer W of a workstation WS. The work set WS is a unit that supports the wafer W via a tape T attached to a ring frame F having an opening in the center. The work set WS has an annular portion Tc of the tape T that is exposed between the inner circumference of the ring frame F and the outer circumference of the wafer W.

The processing apparatus 1 has an apparatus base 2 extending in the Y-axis direction. Stages 3a and 3b are arranged adjacent to each other in the front portion of the device base 2 in the Y-axis direction. A cassette 4a for accommodating the work set WS before processing is arranged on the stage 3a, and a cassette 4b for accommodating the work set WS after processing is arranged on the stage 3b. In the vicinity of the cassettes 4a and 4b, a carry-in / out means 5 for carrying out the work set WS from the cassette 4a and carrying in the work set WS into the cassette 4b is arranged.

In the movable range of the loading / unloading means 5, a temporary setting table 6 for temporarily placing the work set WS before processing and a cleaning means 7 for cleaning the wafer W of the work set WS after processing are arranged. .. A turntable 8 that can rotate around the center is arranged in the center of the upper surface of the device base 2, and a holding means 10 for holding the work set WS is provided on the turntable 8. In the vicinity of the temporary placement table 6, a transport means 40 for transporting the work set WS before processing from the temporary placement table 6 to the holding means 10 and an elevating means 43 for raising and lowering the transport means 40 in the Z-axis direction are provided. .. In the vicinity of the cleaning means 7, a second transport means 50 for transporting the processed work set WS from the holding means 10 to the cleaning means 7 is provided.

A column 9 extending in the Z-axis direction is erected at the rear portion of the device base 2 in the Y-axis direction. In front of the column 9, the processing means 20 for polishing the wafer W of the work set WS held by the holding means 10 and the processing feed direction (Z-axis direction) in which the processing means 20 approaches and separates from the holding means 10. The processing means 20 is provided with a processing feed means 30 for raising and lowering the processing means 20.

The processing means 20 includes a spindle 21 having an axial center in the Z-axis direction, a spindle housing 22 surrounding the outer periphery of the spindle 21, a holder 23 for holding the spindle housing 22, and a motor 24 attached to one end of the spindle 21. A polishing wheel 25 fixed to the tip of the spindle 21 and a polishing pad 26 detachably attached to the lower portion of the polishing wheel 25 are provided. The processing means 20 can rotate the polishing pad 26 together with the polishing wheel 25 at a predetermined rotation speed by being driven by the motor 24.

The machining feed means 30 includes a ball screw 31 extending in the Z-axis direction, a motor 32 connected to one end of the ball screw 31, a pair of guide rails 33 extending in parallel with the ball screw 31, and a holder 23 on one surface. It is provided with an elevating plate 34 connected to the above. A pair of guide rails 33 are slidably contacted with the other surface of the elevating plate 34, and a ball screw 31 is screwed into a nut formed at the center of the elevating plate 34. When the ball screw 31 is driven by the motor 32 and rotates, the elevating plate 34 can be moved up and down in the Z-axis direction along the pair of guide rails 33, and the processing means 20 can be moved up and down in the Z-axis direction.

Two holding means 10 shown in this embodiment are arranged on the turntable 8, but the number is not limited to this. The periphery of the holding means 10 is covered with a concave case 19 that receives the polishing liquid used during processing. A drain port 190 for draining the polishing liquid to the outside of the apparatus is formed on the bottom surface of the case 19. The rotation of the turntable 8 causes the holding means 10 to revolve, and the position where the wafer W of the work set WS is processed by the processing means 20 and the work set WS by the transport means 40 and the second transport means 50. The holding means 10 can be moved to a position where loading and unloading are performed.

As shown in FIG. 2, the holding means 10 includes a holding portion 11 having a holding surface 11a for sucking and holding the wafer W via the tape T, a frame body 12 for accommodating the holding portion 11, and a holding surface 11a. It includes a table frame holding portion 13 that sucks and holds the lower surface of the ring frame F by lowering the upper surface of the ring frame F from the height position, and a rotating means 16 that rotates the holding means 10. The holding portion 11 is formed of, for example, porous ceramics. The table frame holding portion 13 is formed at a height position lower than the holding surface 11a. A recess 14 is formed between the outer peripheral side surface of the frame body 12 and the inner peripheral side surface of the table frame holding portion 13. When the work set WS is held by the holding means 10, the annular portion Tc of the tape T is positioned directly above the recess 14.

A rotating shaft 15 to which the rotating means 16 is connected is connected to the lower end of the holding means 10. Inside the frame body 12 and the rotating shaft 15, a suction path 120 communicating with the holding portion 11 and a suction path 121 communicating with the table frame holding portion 13 are formed. The suction paths 120 and 121 communicate with the suction source 17 via the valve 18. Then, by opening the valve 18, the suction source 17 and the holding portion 11 are communicated with each other via the suction passage 120, and the suction source 17 and the table frame holding portion 13 are communicated with each other via the suction passage 121, so that the holding portion is connected. A suction force can be applied to the 11 and the table frame holding portion 13.

The rotating means 16 is composed of a drive pulley 161 connected to the motor 160, a driven pulley 162 attached to the rotating shaft 15, and a belt 163 wound around the drive pulley 161 and the driven pulley 162. By driving the drive pulley 161 and causing the belt 163 to drive the driven pulley 162, the rotating shaft 15 can be rotated and the holding means 10 can be rotated.

The transport means 40 includes a disk-shaped plate 41, an arm 42 that supports the plate 41, a frame holding portion 44 that holds the ring frame F, and a ring frame F that is held by the frame holding portion 44 of the tape T. It is provided with a pressing portion 46 that presses the annular portion Tc between the circumference and the outer periphery of the wafer W. An elevating means 43 is connected to the arm 42. The elevating means 43 is at least composed of a shaft member 430 extending in the Z-axis direction, a lifting mechanism (not shown) for raising and lowering the shaft member 430, and a motor (not shown) connected to the shaft member 430. When the shaft member 430 is moved up and down in the vertical direction (Z-axis direction) by the elevating mechanism, the arm 42 is moved up and down, and the plate 41 can be moved up and down. Further, the shaft member 430 is rotatable by a motor, and when the shaft member 430 is rotated, the arm 42 is swiveled in the horizontal direction, and the plate 41 can be swiveled in the horizontal direction.

The pressing portion 46 is a member for applying an external force to the annular portion Tc of the tape T to press it downward. The pressing portion 46 shown in the present embodiment has a chamfered tip surface 46a. A plurality of pressing portions 46 may be provided on the lower surface of the plate 41 at positions inside the frame holding portion 44 so as to form a ring as a whole, or may be composed of a series of ring-shaped members as a whole. .. The material, shape and size of the holding portion 46 are not particularly limited.

For example, four frame holding portions 44 are arranged on the outer peripheral side of the plate 41. The frame holding portion 44 is connected to the suction source 47 via the valve 49a and is connected to the air supply source 48 via the valve 49b. By closing the valve 49b and opening the valve 49a, the suction source 47 and the frame holding portion 44 can communicate with each other, and a suction force is applied to the frame holding portion 44 to suck and hold the ring frame F.

Further, a stretchable spring 45 arranged inside the plate 41 is connected to the frame holding portion 44. By compressing the spring 45, the frame holding portion 44 and the pressing portion 46 can be relatively moved in the vertical direction. That is, when the work set WS is conveyed to the holding means 10 by the conveying means 40, the air supply source 48 and the spring 45 are communicated with each other by closing the valve 49a and opening the valve 49b, and the spring 45 is compressed by the air pressure. The pressing portion 46 can be pushed down. As a result, the annular portion Tc of the tape T can be pressed downward by the tip surface 46a of the pressing portion 46. The pressing portion 46 shown in the present embodiment is configured to be pushed downward by compression of the spring 45, but the pressing portion 46 may be provided with an elevating mechanism.

Next, an operation example of the processing apparatus 1 will be described. The wafer W of the workstation WS is an example of a work piece, and has a circular plate-shaped substrate made of, for example, sapphire or silicon. As shown in FIG. 2, the upper surface Wa of the wafer W is a surface to be polished by the polishing pad 26. On the other hand, a device chip or the like is formed on the lower surface Wb on the opposite side of the upper surface Wa, and the tape T is attached.

Further, in the wafer W shown in the present embodiment, the upper surface Wa is ground and thinned by another grinding device, and the wafer W is curved and warped in the direction of peeling from the tape T (upward) on the outer peripheral portion Wc of the wafer W. Is occurring. This warp is caused by the grinding marks formed on the upper surface Wa of the wafer W. Therefore, it is easy to correct the warp if the wafer is transported in the form of a work set WS, but when the wafer W is made of a hard material such as sapphire, the warp of the outer peripheral portion Wc is as shown in FIG. The force becomes large, and even if the wafer W is supported by the ring frame F via the tape T, the warp cannot be completely corrected, and the tape T attached to the lower surface Wb on the outer peripheral portion Wc side of the wafer W. The portion follows the warp of the outer peripheral portion Wc.

First, the work set WS before processing is taken out from the cassette 4a by the loading / unloading means 5 shown in FIG. 1 and temporarily placed on the temporary storage table 6. At this time, the turntable 8 rotates and the holding means 10 is positioned within the movable range of the conveying means 40. The transport means 40 sucks and holds the ring frame F of the work set WS temporarily placed on the temporary placement table 6 by the frame holding portion 44, and raises the plate 41 together with the arm 42 by the elevating means 43 and rotates it in the horizontal direction. As a result, as shown in FIG. 2, the work set WS is moved above the holding means 10.

Next, as shown in FIG. 3, the plate 41 is lowered by the elevating means 43 in a direction approaching the holding surface 11a of the holding portion 11, the tape T on the wafer W side is placed on the holding surface 11a, and the frame holding portion is placed. At 44, the ring frame F is pressed toward the table frame holding portion 13. When the work set WS is conveyed to the holding means 10 in this way, the annular portion Tc of the tape T is positioned directly above the recess 14, and the pressing portion 46 is positioned directly above the annular portion Tc of the tape T. At this time, a gap 100 is formed between the lower surface of the tape T on the outer peripheral portion Wc side and the holding surface 11a of the holding portion 11. The holding surface 11a of the holding portion 11 is a conical surface that is inclined downward from the central portion to the outer peripheral side, but is actually slightly inclined so that it cannot be recognized by the naked eye.

With the ring frame F pressed against the table frame holding portion 13 by the frame holding portion 44, the air supply source 48 and the spring 45 communicate with each other by closing the valve 49a and opening the valve 49b as shown in FIG. .. When the spring 45 is compressed by the pressure of the air of the air supply source 48, the pressing portion 46 is lowered, and the annular portion Tc is pressed downward toward the recess 14 by the tip surface 46a thereof, and the lower surface of the tape T is pressed by the holding portion 11. The gap 100 shown in FIG. 3 can be sealed by being brought into close contact with the entire surface of the holding surface 11a. Along with this, the outer peripheral portion Wc of the wafer W is pulled downward to correct the warp. In this state, by opening the valve 18, a suction force is applied to the holding portion 11 and the table frame holding portion 13, and the wafer W is sucked and held by the holding surface 11a of the holding portion 11 via the tape T, and the table frame is held. The holding portion 13 sucks and holds the ring frame F.

After the work set WS is held by the holding means 10, the transporting means 40 is raised in the direction of separating from the holding means 10 by the elevating means 43 as shown in FIG. Subsequently, the turntable 8 shown in FIG. 1 rotates to move the holding means 10 below the processing means 20. The holding means 10 holding the work set WS is rotated by the rotating means 16 at a predetermined rotation speed. The processing means 20 drives the motor 24 and rotates the spindle 21 to rotate the polishing pad 26 at a predetermined rotation speed, while the processing feeding means 30 processes the polishing pad 26 in a direction approaching the wafer W. To do. The polishing surface of the polishing pad 26 that rotates while descending is brought into contact with the wafer W, and the polishing pad 26 and the wafer W are relatively slid. At this time, the suction force does not leak from the holding surface 11a on the outer peripheral portion Wc side of the wafer W, and the state in which the work set WS is held by the holding means 10 can be stably maintained.

During the processing of the wafer W, the polishing liquid is supplied between the polishing pad 26 and the wafer W from a polishing liquid supply source (not shown). The used polishing liquid is scattered around the polishing pad 26 or dropped into the case 19 and is drained from the drain port 190 to the outside of the apparatus. In this way, when the wafer W reaches the desired finish thickness, the processing means 20 is raised by the processing feed means 30 to complete the processing.

The work set WS is transported from the holding means 10 to the cleaning means 7 by the second transport means 50. After cleaning the wafer W by the cleaning means 7, the cleaned work set WS is taken out from the cleaning means 7 by the loading / unloading means 5 and stored in the cassette 4b. In this way, when the machining of the workpiece WS is completed in the machining apparatus 1, the work set WS is conveyed in the form of the workpiece WS to, for example, a cutting apparatus or a laser processing apparatus. When the wafer W is made of sapphire, since the wafer W is a transparent body, it is possible to easily perform alignment for detecting the planned division line from the work surface side of the wafer W, and the wafer W can be smoothly attached to each device chip. Can be divided into.

As described above, in the processing apparatus 1 according to the present invention, the holding means 10 for holding the work set WS for supporting the wafer W via the tape T attached to the ring frame F and the work set WS held by the holding means 10 The processing means 20 for processing the wafer W, the transport means 40 for transporting the work set WS to the holding means 10, and the elevating means 43 for raising and lowering the transport means 40 are provided, and the transport means 40 holds the ring frame F. A holding portion that holds the annular portion Tc between the inner circumference of the ring frame F held by the frame holding portion 44 and the outer circumference of the wafer W of the tape T of the workpiece WS held by the holding means 44 and the frame holding portion 44. 46 is provided, and the annular portion Tc is pressed by the pressing portion 46 so that the lower surface of the tape T and the holding surface 11a of the holding means 10 are brought into close contact with each other, and the wafer W is sucked and held by the holding surface 11a. The sealing effect between the lower surface and the holding surface 11a can be enhanced, and even if the outer peripheral portion Wc of the wafer W is warped, the warp can be corrected and the wafer W can be reliably sucked and held by the holding surface 11a. it can.
Further, according to the processing apparatus 1 according to the present invention, since the wafer W can be conveyed and processed in the form of the work set WS, for example, the wafer W (including the wafer with a substrate) after grinding and polishing is divided. When doing so, steps such as tape mounting can be omitted, and time can be shortened. Since the tape mount can be omitted, the amount of tape T used can be reduced.

Although the processing device 1 shown in the above embodiment has been described as a polishing device, the processing device 1 is not limited to this configuration, and may be any processing device capable of mounting the transport means 40, for example, a grinding device, a cutting device, and laser machining. The present invention can also be applied to the device. In the grinding apparatus, the wafer W is once ground to be thinned, and then the outer peripheral portion Wc is likely to be warped even when re-grinding, which is particularly useful when re-grinding is expected.

1: Processing equipment 2: Equipment bases 3a, 3b: Stages 4a, 4b: Cassette 5: Loading / unloading means 6: Temporary storage table 7: Cleaning means 8: Turntable 9: Column 10: Holding means 11: Holding part 11a: Holding Surface 12: Frame 120, 121: Suction path 13: Table frame holding part 14: Recess 15: Rotating shaft 16: Rotating means 160: Motor 161: Drive pulley 162: Driven pulley 163: Belt 17: Suction source 18: Valve 19 : Case 190: Drain port 20: Machining means 21: Spindle 22: Spindle housing 23: Holder 24: Motor 25: Polishing wheel 26: Polishing pad 30: Machining feed means 31: Ball screw 32: Motor 33: Guide rail 34: Lifting plate 40: Conveying means 41: Plate 42: Arm 43: Elevating means 430: Shaft member 44: Frame holding part 45: Spring 46: Holding part 47: Suction source 48: Air supply source 49a, 49b: Valve 50: Second transport Means W: Waha Wa: Front surface Wb: Back surface Wc: Outer peripheral portion T: Tape Tc: Circular portion F: Frame WS: Work set

Claims (2)

A holding means for holding a work set that supports a wafer via a tape attached to a ring frame, a processing means for processing the wafer of the work set held by the holding means, and a work set being conveyed to the holding means. A processing device provided with a transporting means for raising and lowering the transporting means
The transport means includes a frame holding portion for holding the ring frame and a frame holding portion.
Of the tape of the work set held by the holding means, a holding portion for holding an annular portion between the inner circumference of the ring frame held by the frame holding portion and the outer circumference of the wafer is provided.
A processing device that presses the annular portion by the pressing portion so that the lower surface of the tape and the holding surface of the holding means are brought into close contact with each other, and the wafer is sucked and held on the holding surface via the tape. The processing apparatus according to claim 1, wherein a warp is formed on the outer peripheral portion of the wafer of the work set in a direction in which the tape is peeled off.

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