JP6259630B2 - Tape application method - Google Patents

Description

  The present invention relates to a tape attaching method for attaching a tape to a surface of a workpiece having irregularities formed on the surface.

  As a method of dividing a workpiece into individual chips, there are cutting and laser processing. As a method of division by cutting, after sticking a tape on the surface of a workpiece, the surface side on which the tape is stuck is held by a holding table, and a cutting blade is cut from the back side opposite to the surface. There is a method of forming a cutting groove by providing a slight uncut portion along the planned dividing line, and dividing the workpiece into individual chips from the cutting groove as a starting point (for example, see Patent Document 1 below) ).

  Further, as a method of division by laser processing, after a tape is attached to the surface of the workpiece, the surface side to which the tape is attached is held by a holding table, and is permeable to the workpiece. There is a method in which a modified layer is formed inside a workpiece by irradiating a laser beam toward the back side of the workpiece, and the workpiece is divided into individual chips starting from the modified layer ( For example, see Patent Document 2 below).

JP 2001-319899 A JP 2005-2222988 A

  However, when unevenness is formed on the surface of the workpiece, if the tape is attached to the surface, the tape enters the recess and is attached to the bottom of the recess. If the surface side of the work piece to which the tape is stuck is sucked and held in this state with a holding table, the tape tends to become flat, so that the concave portion is pulled and a uniform height position with respect to the work piece. In addition, there is a possibility that cutting or laser processing cannot be applied to the workpiece, and the workpiece may be pulled locally and the workpiece itself may be damaged.

  The present invention has been made in view of the above circumstances, and reduces the possibility that the workpiece cannot be processed at a uniform height position, and prevents the workpiece itself from being damaged. Objective.

  The present invention is a tape adhering method for adhering a tape to a surface of a workpiece having irregularities formed on the surface, wherein the back surface side of the workpiece is sucked and held by a holding table to expose the surface. A holding step, a tape adhering step for adhering a tape to the convex portion of the surface of the workpiece sucked and held by the holding table, and a workpiece on the holding table after performing the tape adhering step. A peeling step of sucking the tape with a suction means and peeling the tape stuck to the concave portion from the concave portion while keeping the back surface side of the vacuum suctioned.

Additional workpiece, when a plurality of chips on the upper surface of the substrate in which are disposed, in the tape applying step, and attaching a tape on surfaces of the chips of the workpiece, said In the peeling step, the tape attached to the upper surface of the substrate is peeled off from the upper surface of the substrate.

In the tape attaching method according to the present invention, after the tape attaching step is performed and the tape is attached to the surface of the workpiece, the workpiece is sucked by the suction means while the back side of the workpiece is sucked and held. In order to perform the peeling step of sucking the tape attached to the surface of the workpiece and peeling the tape from the recess, even if the tape enters and adheres to the bottom of the recess formed on the surface of the workpiece, the recess The tape can be peeled off to flatten the tape.
Therefore, even if the surface side of the work piece to which the tape is attached is sucked and held when the back surface of the work piece is processed, the concave portion is not pulled, so the uniform height position with respect to the work piece The possibility that the material cannot be processed can be reduced. Moreover, even if the surface side of the workpiece is sucked and held, the workpiece is not locally pulled, and therefore the possibility of damaging the workpiece itself can be reduced.

It is a perspective view which shows the structure of a wafer. It is sectional drawing which shows the structure of a wafer. It is sectional drawing which shows a holding | maintenance step. It is sectional drawing which shows a tape sticking step. It is sectional drawing which shows a peeling step. It is sectional drawing which shows a process step.

  A wafer 1 shown in FIG. 1 is an example of a workpiece, and is a COW (Chip on Wafer) in which a plurality of chips are arranged on a circular substrate. On the surface 2 of the wafer 1, chips 5 are arranged in the respective areas partitioned by the grid-like division planned lines 4. On the other hand, nothing is formed on the back surface 3 which is the surface opposite to the front surface 2 of the wafer 1, and the back surface 3 is a surface to be processed.

  As shown in FIG. 2, the plurality of chips 5 arranged on the surface 2 of the wafer 1 have a predetermined height. Irregularities corresponding to the thickness of the chip 5 are formed on the surface 2 of the wafer 1 on which the chip 5 is disposed. That is, the gap formed between the adjacent chips 5 is a concave portion 6a, and the chip 5 is a convex portion 6b. Below, the method of sticking the tape which protects the surface 2 of the wafer 1 is demonstrated, referring an accompanying drawing.

(1) Holding Step First, as shown in FIG. 3, the wafer 1 is transferred to a holding table 7 that holds a workpiece. The holding table 7 has a suction holding surface 8 that supports a workpiece from below, and a suction source 9 is connected to the suction holding surface 8. After the back surface 3 side of the wafer 1 is placed on the suction holding surface 8 of the holding table 7 to expose the front surface 2 of the wafer 1 upward, the suction source 9 is activated and the suction holding surface 8 of the holding table 7 activates the wafer. 1 is held by suction.

(2) Tape Adhering Step After performing the holding step, as shown in FIG. 4, the adhesive surface protective tape 10 is pressed against the surface 2 side of the wafer 1 and pasted using, for example, a roll-shaped pressing roller 12. To wear. Specifically, the outer peripheral edge of the surface protection tape 10 is attached to the annular frame 11, and the surface protection tape 10 is attached to the convex portions 6 b of the plurality of chips 5 disposed on the surface 2 of the wafer 1. At this time, the pressing roller 12 rolls, for example, in the direction of the arrow X1 while pressing the upper portion of the surface protection tape 10, thereby protecting the convex portions 6b of all the chips 5 disposed on the surface 2 of the wafer 1 with surface protection. The tape 10 is stuck. The surface protective tape 10 is not particularly limited as long as the surface on the side in contact with the surface 2 has adhesiveness.

(3) Peeling step By performing the sticking step, as shown in FIG. 5A, the surface protection tape 10 enters the concave portion 6a on the surface 2 of the wafer 1 and is stuck to the bottom of the concave portion 6a. Therefore, using the suction pad 13, the sinking portion 10a of the surface protection tape 10 that has entered the recess 6a is peeled off. The suction pad 13 has a porous member 14, and the lower surface of the porous member 14 is a suction holding surface 15 for sucking an object to be sucked. The suction holding surface 15 communicates with the suction hole 16 via the porous member 14, and the suction hole 16 is connected to the suction source 17. The bottom of the recess 6 a is on the same plane as the surface 2 of the wafer 1.

  As shown in FIG. 5 (b), the suction holding surface 15 of the suction pad 13 faces downward and faces the surface protection tape 10 and is lowered to bring the suction holding surface 15 of the suction pad 13 into contact with the surface protection tape 10. At this time, as shown in FIG. 5C, the suction source 9 is continuously operated, and the suction source 17 is operated while the back surface 3 of the wafer 1 is sucked and held by the holding table 7, and the suction pad 13 is operated. The surface protection tape 10 is sucked at the suction holding surface 15.

  The suction pad 13 sucks not only the portion attached to the convex portion 6b but also the submerged portion 10a of the surface protective tape 10 that has entered and stuck into the concave portion 6a, and the submerged portion 10a is sucked into the bottom portion of the concave portion 6a. Peel upward from. As a result, as shown in FIG. 5D, the entire surface of the surface protection tape 10 becomes flat along with the suction holding surface 15. When the sinking portion 10a of the surface protection tape 10 is peeled off from the bottom of all the recesses 6a, the operation of the suction source 17 is stopped and the suction pad 13 is separated from the surface protection tape 10 to complete the peeling step.

(4) Processing Step After performing the peeling step, as shown in FIG. 6, the wafer 1 is held by the holding means 30, and a modified layer serving as a division starting point is formed inside the wafer 1 by the laser beam irradiation head 20. Form. The holding unit 30 includes a holding unit 31 that holds the wafer 1, a frame mounting unit 32 that is connected to the outer peripheral side of the holding unit 31 and on which the frame 11 is mounted, and a shaft that is disposed on the frame mounting unit 32. And at least a clamp portion 34 that rotates about the shaft portion 33 as a fulcrum and clamps the frame 11 placed on the frame placement portion 32.

  The surface protection tape 10 attached to the wafer 1 is placed on the upper surface of the holding unit 31 and the frame 11 is placed on the frame placement unit 32. Further, the clamp portion 34 rotates with the shaft portion 33 as a fulcrum, and the upper portion of the frame 11 is pressed and fixed.

  The laser beam irradiation head 20 positions the condensing point of the laser beam 21 having a wavelength transmissive to the wafer 1 inside the wafer 1, and the holding means 30 moves the wafer 1 horizontally, for example, in the direction of the arrow X2, while moving the laser. The beam irradiation head 20 irradiates the laser beam 21 toward the back surface 3 of the wafer 1 along the scheduled division line 4 shown in FIG. 1 to form a modified layer 22 inside the wafer 1. And after irradiating the laser beam 21 along all the division | segmentation scheduled lines 4 and forming the modified layer 22 in the inside of the wafer 1, the surface protection tape 10 is peeled and external force is applied to the wafer 1 and the modified layer 22 Is divided into individual chips.

  By performing the peeling step before the processing step, the portion of the surface protective tape 10 that has been stuck to the recess 6a is peeled off and the surface protective tape 10 is flattened. Accordingly, since the wafer 1 is also held flat along the upper surface of the holding unit 31, the laser beam 21 can be condensed at a uniform height position of the wafer 1. The processing step can also be performed by cutting with a cutting blade. In this case as well, the cutting depth of the cutting blade with respect to the wafer can be made uniform.

As described above, in the tape adhering method shown in the present embodiment, after the tape adhering step is performed and the surface protection tape 10 is adhered to the convex portion 6b formed on the surface 2 side of the wafer 1, the wafer 1 In order to carry out a peeling step in which the sinking portion 10a of the surface protection tape 10 is sucked by the suction pad 13 while the back surface 3 is sucked and held by the holding table 7, and the sinking portion 10a is peeled off from the recess 6a. Even if the surface protection tape 10 enters the bottom of the recess 6a formed on the surface 2 of the surface 1, the surface protection tape 10 can be flattened.
Therefore, even when the front surface 3 side of the wafer to which the surface protective tape 10 is adhered is sucked and held when the back surface 3 of the wafer 1 is processed, the concave portion 6a is not pulled and the uniform height with respect to the wafer 1 is obtained. The possibility that cutting or laser processing cannot be performed on the position can be reduced. Moreover, since the surface 2 side of the wafer 1 is not pulled locally, the possibility that the wafer 1 itself is damaged can be reduced.

  In the present embodiment, COW has been described as an example of the workpiece. However, the present invention is not limited to COW and may be any workpiece that has irregularities formed on the surface.

1: Wafer 2: Front surface 3: Back surface 4: Line to be divided 5: Chip 6a: Concave portion 6b: Convex portion 7: Holding table 8: Holding surface 9: Suction source 10: Surface protection tape 10a: Sinking portion 11: Frame 12 : Pressing roller 13: Suction pad 14: Porous member 15: Suction holding surface 16: Suction hole 17: Suction source 20: Laser beam irradiation head 21: Laser beam 22: Modified layer 30: Holding means 31: Holding part 32: Frame placement part 33: Shaft part 34: Clamp part

Claims (2)

A tape adhering method for adhering a tape to the surface of a workpiece having irregularities formed on the surface,
A holding step of sucking and holding the back side of the workpiece by a holding table and exposing the surface;
A tape adhering step of adhering a tape to the convex portion of the surface of the workpiece sucked and held by the holding table;
After performing the tape adhering step, the tape adhered to the recess by sucking the tape with the suction means while the back side of the workpiece is sucked and held on the holding table is removed from the recess. A tape sticking method comprising: a peeling step for peeling. The workpiece is provided with a plurality of chips on the upper surface of the substrate,
The tape sticking step, adhered to the tape on surfaces of the chips of the workpiece,
The tape sticking method according to claim 1, wherein in the peeling step, the tape stuck on the upper surface of the substrate is peeled off from the upper surface of the substrate.

Images