JP2001291762A - Method and apparatus for peeling protective sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely peel a protective sheet so as not to leave its adhesive on a semiconductor wafer. SOLUTION: When circuit patterns 51 of semiconductor chips are formed on a semiconductor wafer W as shown in Fig. 5, if a protective sheet is peeled from the portion of a side 51a of each circuit pattern 51 as shown by an arrow 52, then there is the possibility of leaving the adhesive of the protective sheet in the portion of the side 51a of each circuit pattern 51. Therefore, the peeling direction of the protective sheet is so set as to peel it from a corner portion 51b of each circuit pattern 51 as shown by an arrow 55. As a result, the protective sheet can be completely peeled without leaving its adhesive in the portion of the side 51a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for peeling a protective sheet attached to a semiconductor wafer.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, there is a process of polishing a back surface of a semiconductor wafer (hereinafter, simply referred to as a wafer) to make a semiconductor chip thinner. Surface) is protected by attaching a protective sheet made of an adhesive film or the like having an adhesive layer provided on one side of a film substrate. After polishing, the protective sheet is peeled off from the wafer.

[0003] As a method of peeling the protective sheet from the wafer, for example, the protective sheet adhered to the wafer is adhered to an end of the protective sheet using an adhesive tape of a predetermined length. A method of pulling an adhesive tape to peel off the protective sheet is known (see Japanese Patent Application Laid-Open No. H11-16862).

[0004]

In the conventional peeling method, when the protective sheet is peeled off, the adhesive attached to the protective sheet sometimes remains on the wafer. Therefore,
An object of the present invention is to prevent an adhesive from remaining on a wafer even when a protective sheet is peeled off.

[0005]

Means for Solving the Problems In order to solve the above problems,
The present inventors have conducted extensive research and experiments and found that changing the direction in which the protective sheet was peeled changed the remaining amount of the adhesive on the wafer. And as a result of earnest research,
It was found that when the protective sheet was peeled off from the corners of the circuit pattern formed on the wafer, the adhesive hardly remained on the wafer.

For example, as shown in FIG. 5, when a circuit pattern 51 of a semiconductor chip is formed on a wafer W, a side 5 of the circuit pattern 51 is
When peeled from the portion 1a, the side 5 of the circuit pattern 51
The pressure-sensitive adhesive of the protective sheet may remain on the portion 1a. On the other hand, as shown by the arrow 55, the corner 5 of the circuit pattern 51
When the protective sheet is peeled from 1b, the pressure-sensitive adhesive hardly remains on the side 51a, and the protective sheet can be peeled cleanly.

That is, in the present invention, the protective sheet is peeled off so as to be peeled off from the corner of the circuit pattern.

Further, in the protective sheet peeling apparatus of the present invention, a rotatable table on which a semiconductor wafer is placed is provided, and the rotational position of the table is controlled so that the protective sheet is peeled from the corner of the circuit pattern. Configured.

[0009]

FIG. 1 shows a protective sheet peeling apparatus 1 for carrying out a protective sheet peeling method according to the present invention. The protective sheet peeling apparatus 1 can be moved in a direction of an arrow 4 with a base 3. The wafer holding / rotating mechanism 5 includes a table 23 on which a wafer W is placed. The wafer holding / rotating mechanism 5 includes a tape feeding unit 7, a peeling head unit 9, and a heater cutter unit 11.

First, an outline of the apparatus 1 will be described. A wafer W to which a protection sheet S is attached is placed on a table 2.
3 and transported to the right in FIG. On the other hand, the adhesive tape T is fed out of the tape feeding section 7 and shown in FIG.
It is pulled out by the peeling head 9 as shown in FIG. The adhesive tape T is thermocompression-bonded to the end of the protective sheet S by the heater cutter 11 as shown in FIG. 2B, and cut into a predetermined short length. Next, the peeling head unit 9 holds and pulls the adhesive tape T to peel off the protective sheet S from the wafer W as shown in FIG. 2C (the tape feeding unit 7 and the heater cutter unit 11 are retracted upward). . At this time, the table 23 moves to the left in FIG. 2, the peeling head 9 moves to the right in FIG. 2, and the peeled protection sheet S is discarded into the waste box 12. The details of this device 1 are described in the above-mentioned gazette (JP-A-11-16682).
It is described in.

As shown in FIG. 3, the wafer holding and rotating mechanism 5 includes a table 23 on which a wafer W is placed and a table 23.
And a rail 27 for guiding the movable plate 25 in the direction of transport of the wafer W (the direction of the arrow 4 in FIG. 1). The moving plate 25 is moved by a motor 26.

A recess 23a is formed in the center of the table 23, and a porous plate 29 is fitted in the recess 23a. A cylindrical shaft 31 is attached to the table 23, and the cylindrical shaft 31 is rotatably attached to a cylindrical bearing 33 fixed to the moving plate 25. The moving plate 25 has a motor 3
5, a pulley 37 attached to a motor 35 and a pulley 39 attached to a cylindrical shaft 31 are connected by a timing belt 41, and the motor 35 drives the table 23 to rotate.

The hollow portion of the cylindrical bearing 33 has a joint shaft 4
3 are arranged, and a pipe 45 is
A negative pressure is applied to the table recess 23 a through the vent 47, and the back surface of the wafer W placed on the porous plate 29 is sucked and fixed on the table 23 by suction.

On the wafer W, an orientation flat 53 (orientation flat) or V
A reference portion such as a notch is formed. To detect this reference portion, the optical sensors 4
9, 49 are arranged.

Next, the operation of the above device will be described. First, the wafer W to which the protection sheet S has been attached is placed on the table 23 by a manual or automatic transfer device. Next, when a start switch (not shown) is turned on, the wafer W is suction-fixed to the table 23, the motor 35 is driven to rotate the table 23, and the orientation sensor 53 of the wafer W is detected by the optical sensor 49. When the orientation flat portion 53 is detected, the table 23 is rotated so that the protection sheet S is peeled off from the corner portion 51b of the circuit pattern 53 formed on the wafer W based on the position thereof, and the rotation angle of the wafer W is determined.

For example, as shown in FIG. 5, a circuit pattern 51 of a semiconductor chip generally formed on a wafer W
The orientation flat 53 of the wafer W and the side 51 of the circuit pattern 51
a are arranged in parallel. Now, assuming that the peeling direction of the protective sheet is the direction indicated by the arrow 55 in FIG. This rotation angle is
Can be appropriately changed and set according to the shape of the circuit pattern 51 to be formed.

Next, the moving plate 25 is moved to move the wafer W
Is transported under the heater cutter unit 11 and
The adhesive tape T is pulled out by the peeling head 9, is thermocompression-bonded to the end of the protective sheet S by the heater cutter 11, and is cut into a predetermined short length. Then, the peeling head 9 holds the adhesive tape T and
And the protective sheet S is peeled off from the wafer W by pulling to the right. At this time, the table 23 moves in a direction opposite to the peeling direction of the protection sheet S (to the left in FIG. 1).

As described above, since the protective sheet S is peeled off from the corners 51b of the circuit pattern 51, the adhesive of the protective sheet rarely remains on the wafer. Can be.

The above is an example in which the present invention is applied to a method of peeling a protective sheet using an adhesive tape having a predetermined length.
The present invention is not limited to this, and the present invention can be applied to a method in which an adhesive tape is pressure-bonded to a protective sheet over the entire length, and the protective sheet is peeled off by peeling the adhesive tape. Further, in the above embodiment, the wafer is rotated using the wafer holding and rotating mechanism to position the protective sheet in the peeling direction.
The wafer may be placed on an apparatus for peeling the protection sheet, and the protection sheet may be peeled from the corner of the circuit pattern.

[0020]

As described above, according to the present invention,
Since the protective sheet is peeled off from the corners of the circuit pattern formed on the semiconductor wafer, the protective sheet can be peeled cleanly without the adhesive remaining on the circuit pattern.

[Brief description of the drawings]

FIG. 1 is a side view of an example of a protective sheet peeling device to which the present invention is applied.

FIG. 2 is a view showing a peeling operation of a protective sheet peeling device.

FIG. 3 is a sectional view of a table rotating mechanism.

FIG. 4 is a plan view of a table rotation mechanism.

FIG. 5 is a plan view illustrating a peeling direction of a protective sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective sheet peeling apparatus 5 Wafer holding and rotating mechanism 23 Table 35 Motor 51 Circuit pattern 51a Side 51b Corner 52, 55 Protective sheet peeling direction W Semiconductor wafer S Protective sheet

Claims (2)

[Claims] 1. A method for peeling a protective sheet attached to a semiconductor wafer having a circuit pattern formed thereon, wherein the protective sheet is peeled from a corner of the circuit pattern. 2. An apparatus for peeling a protective sheet attached to a semiconductor wafer on which a circuit pattern is formed, wherein a rotatable table on which the semiconductor wafer is mounted is provided, and the protective sheet is removed from a corner of the circuit pattern. A protective sheet peeling device, wherein the rotation position of the table is controlled so that the table is peeled off.