JP2004304133A - Wafer treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer treatment device capable of peeling a film from a wafer, where a circuit is formed on the surface, protected by the film, and of newly sticking another adhesive tape on the same surface. <P>SOLUTION: In an alignment unit 80, a wafer W, to which a protection tape P positioned at a prescribed reference position is stuck, is placed on a movable dicing tape mounting table 142. A protective tape peeling unit 90 is arranged at a lower part and a dicing tape delivery unit 180 is arranged at an upper part. Thereby, the protective tape is peeled from the upper part by a peeling tape S, and then the dicing tape T is stuck to a wafer 2 from above by the dicing tape delivery unit 180. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wafer processing apparatus, and more particularly, to a wafer processing apparatus in which a film attached to one surface of a wafer is peeled off from that surface, a dicing tape is attached to the same surface, and the wafer is sent to the next step.
[0002]
[Prior art]
In the manufacturing process of the semiconductor device, the protective tape P is adhered to the circuit surface 2a of the wafer 2, and after cutting the back surface, the dicing tape T is adhered. At this time, the dicing tape T is generally attached to the back surface of the cut wafer. When transferring from one adhesive tape 2a attached to the circuit surface of a wafer to another adhesive tape, a wafer transfer device that attaches another adhesive tape T to the back surface side is conventionally known (for example, Patent Document 1).
[0003]
FIGS. 7 and 8 show simple processing steps of such a wafer transfer device.
However, in recent years, attempts have been made to improve the function of a semiconductor device by providing an adhesive tape having various functionalities to a cut surface of a cut wafer to provide functional performance. The adhesive surface of such an adhesive tape is usually protected by a release film laminated thereon. Then, in order to perform the next dicing step, the release film is peeled off, and a dicing tape is stuck on the adhesive surface to fix the wafer. That is, a process is performed in which the film on the surface attached to the wafer is peeled off, and an adhesive tape, which is an adhesive film having another functionality, is attached on the same surface. There has been no single wafer processing apparatus for the purpose of replacing the adhesive tape on the same surface of such a wafer.
[0004]
In recent years, a silicon wafer dicing apparatus has been developed which has a function of detecting a dicing street from a cut surface (back surface) of a wafer by using an infrared camera and performing positioning of a dicing blade according to the detected dicing street. . When this function is used, the dicing tape is stuck on the circuit surface side, and therefore, both the replacement of the protective tape and the dicing tape during grinding of the back surface is performed on the circuit surface. Again, no device exists for such a purpose.
[0005]
[Patent Document 1]
JP-A-2000-68293
[0006]
[Problems to be solved by the invention]
In the present invention, there is provided a removable wafer processing apparatus in which a film attached to one side of a wafer is peeled off as in the above process, and then another adhesive tape is attached to the same side. It is an object.
[0007]
[Means for Solving the Problems]
A wafer processing apparatus according to the present invention for achieving the above object,
A wafer processing apparatus for peeling the film from a wafer body having a film adhered to one surface of a wafer in advance and newly attaching a dicing tape to the same surface from which the film has been peeled,
A wafer delivery unit containing the wafer body,
A film peeling unit that sticks a peeling tape to the film side of the wafer body and peels the film,
An alignment unit that is disposed between the wafer transfer unit and the film peeling unit and controls the wafer body in a correct posture.
A ring frame is transferred one by one from a ring frame stocker in which the ring frame is stored, and a dicing tape mount table configured to be movable with respect to the film peeling unit,
A dicing tape feeding unit arranged in the moving area of the dicing tape mount table,
One wafer body sucked from the wafer transfer unit is transported to the alignment unit by the transport unit, and the wafer body controlled to a correct posture by the alignment unit is placed near the film peeling unit in advance. A ring frame is placed, transferred onto the dicing tape mount table that is being moved, and thereafter, the film of the wafer body is peeled by the film peeling unit. On the other hand, a dicing tape is stuck by the upper dicing tape feeding unit.
[0008]
According to the present invention having such a configuration, after the protective tape is peeled off from the surface of the wafer, the dicing tape can be adhered to the circuit surface side of the wafer in the posture as it is.
Therefore, in a single wafer processing apparatus, it is possible to peel off the film stuck on one side of the wafer and then stick another adhesive tape on the same side.
[0009]
In addition, since there is no need to change the wafer and no need to turn the wafer, there is no need for a reversing device, which can simplify the process.
Here, a second transfer unit may be provided in the vicinity of the transfer unit, and an ultraviolet irradiation device for irradiating the wafer with ultraviolet light may be provided in a rotation radius region of the second transfer unit.
[0010]
With such a configuration, when an ultraviolet-curable film is used, the pressure-sensitive adhesive layer can be cured and the film can be easily peeled off.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment relates to a process of transferring the protective tape P from the state in which the protective tape P is applied to the circuit surface of the wafer B to the dicing tape T on the same circuit surface side.
FIG. 1 is a top view of a wafer processing apparatus 20 according to one embodiment of the present invention. FIG. 2A is a schematic sectional view of a wafer W supplied to the wafer processing apparatus 20 of the present embodiment, and FIG. 2B is a view of the wafer W after being processed by the processing apparatus of FIG. It is a schematic sectional drawing of B.
[0012]
In addition, as shown in FIG. 2A, the wafer body W used in the processing apparatus of this embodiment has a film (hereinafter, referred to as a protective tape P) attached to the circuit surface 2a of the wafer 2. It is formed in a substantially disk shape.
In the processing apparatus 20 of the present embodiment, the protective tape P is peeled off from the wafer body W shown in FIG. 2A, and a dicing tape T is adhered to the same surface where the protective tape P has been peeled off. It is formed.
[0013]
In the wafer processing apparatus 20 illustrated in FIG. 1, for example, a protective tape P is attached to a circuit surface of the wafer 2, and a circuit of the wafer 2 is formed by a wafer body W having a back surface ground by a back surface grinding device or a pre-dicing method. Dicing the wafer surface to a predetermined depth in the thickness direction of the wafer, forming a groove with a bottom in a dice pattern, attaching a protective tape P to the wafer surface, grinding the back surface of the wafer, and then handling the wafer body. Has become.
[0014]
Then, a large number of wafer bodies W are accommodated in the wafer transfer unit 60 provided on the base 14 of the wafer processing apparatus 20. At this time, the protective tape P side may be either upper or lower, and it is preferable that the judgment can be made by a machine or a sensor.
The wafer delivery unit 60 has a delivery table 61 for accommodating the wafer bodies W, and places a cassette on which a large number of cassettes are housed on the table 61 in a state of being separated by a predetermined distance so that the wafer bodies W do not overlap. It is supposed to. The transfer table 61 is configured such that the wafer storage unit can be moved up and down by the rotational driving force of a motor (not shown). Further, instead of providing a wafer transfer table 61 on which a cassette accommodating a large number of wafers W is placed in the wafer storage section, the wafers W processed in the previous process are stored in a storage container 70, and this storage container 70 is used to take out the wafer body W for each batch.
[0015]
On the other hand, in the processing apparatus 20 of the present embodiment, the wafer body W is sucked from below and conveyed to a predetermined position in the depth direction of the base 14, that is, the substantially central portion in the YY direction shown in FIG. A transfer unit 40 is provided.
As shown in FIG. 3, the transport unit 40 has, for example, three arms 45, 46, 47 and three joints 45a, 46a, 47a, and these joints 45a, 46a, 47a are motor-driven. By driving, the wafer holder 43 can be arbitrarily moved in the up, down, left and right directions within the movement area, and the wafer holder 43 provided separately at the tip of the arm 47 is moved by the motor 50. It can be rotated by driving. A suction mechanism is provided at a distal end portion 43a of the wafer holding unit 43 so as to be able to suck the wafer, and is configured to be able to suck and hold the wafer.
[0016]
An alignment unit 80 is provided in the operation area of the transfer unit 40 and near the downstream side (counterclockwise) of the wafer transfer unit 60.
In the alignment unit 80, the wafer W placed on the table is suction-held by an internal suction member. In this state, the position is adjusted in the vertical and horizontal directions (XY directions) and the rotation direction (θ direction) along the wafer dividing line of the wafer body W using, for example, an image recognition camera (not shown) arranged above, and the reference position is set. The wafer body W can be positioned at the same time. In addition, as this position adjustment method, it is also possible to perform position adjustment by recognizing the position of the wafer W such as an orientation flat or a notch.
[0017]
Thus, the wafer body W adjusted to the correct posture by the alignment unit 80 is sucked again by the wafer holding unit 43 of the transport unit 40 and further transported to the downstream side of the alignment unit 80.
Downstream of the alignment unit 80, a unit (hereinafter, referred to as a protective tape peeling unit 90) for peeling a film attached to a circuit surface of the wafer is provided as described later. Further, a dicing tape feeding unit 180 is provided downstream of the protective tape peeling unit 90. The dicing tape feeding unit 180 is provided at a position where the dicing tape mount table 142 can pass below.
[0018]
On the left side of the left moving end of the dicing tape mount table 142, there is provided a ring frame stocker 144 in which a large number of ring frames R are loaded and accommodated. R is supplied one by one.
The ring frame stocker 144 is provided with a guide frame (not shown) in the up-down direction, and is configured to be able to move up and down along the guide frame. On the other hand, above the ring frame stocker 144, a guide rail 143 is provided between the dicing tape mount table 142 and the ring frame stocker 144. Along this guide rail 143, a ring frame transfer arm 145 for holding the ring frame R by suction is configured to be movable in the left-right direction in FIG. Note that a vacuum suction unit having a vacuum pad is provided at the tip of the ring transfer arm 145.
[0019]
Therefore, the ring frame transfer arm 145 is disposed directly above the ring frame stocker 144 along the guide rail 143 extending in the left-right direction, and then the ring frame stocker 144 is moved upward along the above-described guide rail (not shown). Thus, the ring frame R located at the uppermost portion of the ring frame stocker 144 is suction-held on the ring frame transfer arm 145, and then the ring transfer arm 145 is moved along the guide rail 143 in the left-right direction on the dicing tape mount table 142. Move to Thus, the ring frame R is transferred to a predetermined position on the dicing tape mount table 142.
[0020]
On the other hand, the dicing tape mount table 142 on which the ring frame R is transferred from the ring frame stocker 144 is guided by the guide rail 690 via the guide member 688 provided at the bottom thereof, and moves from the solid line position shown in FIG. It is configured to be able to reciprocate to a position below the right protective tape peeling unit 90 (a position indicated by a two-dot chain line).
[0021]
Note that a suction mechanism capable of sucking the entire wafer W is also provided inside the dicing tape mount table 142, and the suction mechanism can suck and hold the ring frame R and the wafer placed thereon. It is configured.
Then, in this embodiment, after one ring frame R is mounted at a predetermined position on the dicing tape mount table 142 from the ring frame stocker 144, the dicing tape mount table 142 moves along the track of the guide rail 690. Is transported in advance to a position below the protective tape peeling unit 90 (a position indicated by a two-dot chain line), and waits at this position.
[0022]
As described above, while the dicing tape mount table 142 is waiting at a position below the protective tape peeling unit 90, in the present embodiment, the wafer body W adjusted in the correct direction by the alignment unit 80 is transferred to the transport unit 40. From the alignment unit 80 in the counterclockwise direction. Then, the wafer body W is disposed at a predetermined position on the dicing tape mount table 142 at the standby position, and from this position, the wafer body W is sucked downward from inside the dicing tape mount table 142 by the suction mechanism, and is conveyed. When the suction of the wafer W by the unit 40 is released, the wafer body W is disposed inside the ring frame R. This prevents the movement of the wafer body W and the ring frame R on the dicing tape mount table 142. Thereafter, the protective tape P is peeled from the wafer body W on the dicing tape mount table 142 by a protective tape peeling unit 90 described in detail below. Note that, on the dicing tape mount table 142, the protective tapes P are all in the upward orientation. Even if the protective tape P with the downward facing tape is accommodated in the cassette, even if it is set, it is determined whether the protective tape P is up or down by a sensor (not shown). 50 is driven to be inverted.
[0023]
Hereinafter, the protective tape peeling unit 90 for peeling the protective tape P from the wafer body W with the protective tape P facing upward on the dicing tape mount table 142 will be described.
FIG. 4 shows the protective tape peeling unit 90.
The protective tape peeling unit 90 attaches a heat-fusible peeling tape S separately prepared for peeling to one end of the protective tape P from above, and applies the adhesive force of the peeling tape S to the protective tape P. From the wafer 2.
[0024]
That is, as shown in FIG. 4, the protective tape peeling unit 90 is composed of a tape feeding section 92, a peeling head section 93 as moving means, and a heater cutter section 94 as bonding / cutting means.
When the dicing tape mount table 142 drives the motor 97, the dicing tape mount table 142 is connected to the pulley 98 of the driving shaft of the motor 97 and a pulley (not shown) on the driven side via the connecting tool 101 connected to the belt 100. The dicing tape mount table 142 moves in the left-right direction (X-axis direction) in FIG. 4 on the rail 690 via the guide member 688 provided at the bottom. As described above, the suction mechanism capable of sucking the wafer W is provided on the upper surface of the dicing table 142 so that the entire surface of the upper ring frame R and the wafer body W can be suction-held by negative pressure. Has become.
[0025]
The tape feeding section 92 includes a pinch roller 103 and a tension roller 104 that are in pressure contact with each other, and a guide roller 105 and a pinch roller 106.
The peeling tape S is unwound from the reel 111 shown in FIG. 4, is pinched between the pinch roller 106 and the guide roller 105, is changed in direction by the guide roller 105, and is further rotated by the pinch roller 103 and the tension roller. 104 and is sent to the standby position 119.
[0026]
The tape feeding section 92 is movable in the vertical direction (the Z-axis direction shown in the figure). That is, the tape feeding unit 92 is moved in the Z-axis direction by the cylinder 120.
The release tape S may be a heat-resistant film such as a polyethylene terephthalate film provided with a heat-sensitive adhesive layer, or a release tape itself having a heat-sensitive release tape.
[0027]
The peeling head 93 is movable in the left-right direction in FIG. 4 by the guide 123 by the driving of the peeling head 121 and the arm motor 125 supporting the peeling head 121. The peeling head 93 can hold the peeling tape S by a chuck mechanism.
The heater cutter unit 94 of the protective tape peeling unit 90 is provided with a heater block 134 that can move up and down via a cylinder 133, and a heater is embedded therein.
[0028]
The protection tape peeling unit 90 thus configured is provided with a heater block 134 on the upper surface of the wafer body W, which has been transported with the protection tape P upward on the dicing tape mount table 142 with the ring frame R and the wafer body W. Then, the peeling tape S is adhered to the protective tape P on the wafer surface by heat fusion, and the peeling tape S cut short by the cutter blade 141 is peeled and held by the head 121, and the peeling head 121 is moved rightward in FIG. Simultaneously with the movement, the dicing mount table 142 moves to the left along the rail 690, whereby the protective tape P is peeled off.
[0029]
Thus, the protective tape P is peeled off by the protective tape peeling unit 90. After that, the dicing tape T is stuck on the same surface of the wafer 2 from which the protective tape P has been peeled off by the dicing tape feeding unit 180.
The dicing tape feed-out unit 180 is arranged so that the dicing tape mount table 142 can pass below, similarly to the protective tape peeling unit 90. Then, in the dicing tape feeding unit 180, as shown in FIG. 5, the dicing tape T, which has been precut on the mount D in advance and adhered to the mount at regular intervals, is driven by the dicing tape supply motor 652. From the unwinder 654, the dicing from the mount D is performed by sharply and sharply turning at the tip end of the peel plate 676 through the guide roller 656, the dancer roller 658, the tension roller 672 and the pinch roller 660, and the guide roller 674. The tape T is peeled off. Thereafter, the mount D is wound up by the winder 686 via the dancer roller 682 and the guide roller 684 between the take-up roller 678 and the pinch roller 680.
[0030]
Although not shown, a tape detection mechanism is provided between the tension roller 672 and the pinch roller 660 in the dicing tape passage path of the guide roller 674, and the tape is stopped at a predetermined position by the feeding motor 692.
In this way, the dicing tape T peeled off from the mount D is attached to the ring frame R and the wafer 2 by the press roller 691.
[0031]
Further, the dancer rollers 658 and 682 operate in the vertical direction to respond to the change in the outer diameter of the dicing tape T, and detect the vertical position to drive the dicing tape supply motor 652 and the winder 686. Controlling.
On the other hand, as described above, the dicing tape mount table 142 is moved along the guide rail 690 in the left-right direction via the guide member 688 provided at the bottom thereof, as shown in FIG. It is configured to be movable in a direction approaching and moving away from the camera.
[0032]
Accordingly, as shown in FIG. 6A, the dicing tape mount table 142 on which the wafer 2 and the ring frame R on which the protective tape P has been peeled is placed in the dicing tape mount table 142 in the protective tape peeling unit. It is moved along the guide rail 690 in the direction approaching the peel plate 676 (to the left in FIG. 1) so that one end of the ring frame R is positioned near the tip of the peel plate 676 and stopped.
[0033]
Then, the dicing tape T is peeled off from the backing paper D by sharply and sharply turning back at the tip of the peel plate 676. At this time, the tip of the dicing tape T is auxiliaryly separated by air blow or the like. Prevents entanglement in backing paper.
Thereafter, as shown in FIG. 6B, the dicing tape mount table 142 is raised by a vertical cylinder (not shown), and the tip of the dicing tape T is pressed against the ring frame R by the press roller 691.
[0034]
Further, as shown in FIG. 6C, the dicing tape mount table 142 is moved along the guide rail 690 in a direction away from the peel plate 676 (left direction in FIG. 6), and the dicing is performed by the press roller 691. The tape T is attached to the wafer 2 and the ring frame R, and the wafer 2 and the ring frame R are integrated.
[0035]
Thus, a wafer body B in which the dicing tape T is stuck on the wafer 2 shown in FIG. 2B is configured.
Thereafter, the processed wafer body B is sucked by the tip of the ring transfer arm 145 that has moved rightward in FIG. 1 by the guide rail 143, and then the trajectory of the guide rail 143 moves leftward again in FIG. Returning this time, the wafer body B is transferred to the discharge push unit 900, and is pushed and conveyed on the roller 902 by the push mechanism 170, and is stored in the storage cassette of the unloader 1100.
[0036]
Thus, the operation by the wafer processing apparatus 20 ends.
In this embodiment, when a tape having an ultraviolet curable adhesive is used as the protective tape P, the transport unit 40 is moved upstream from the wafer transfer unit 60, that is, from the position of the wafer transfer unit 60. It is preferable that a known ultraviolet irradiation device 300 is provided at a position rotated clockwise, and a second transfer unit 200 that suctions and transfers the wafer W is provided near the ultraviolet irradiation device 300. By doing so, the wafer body W to which the ultraviolet-curable adhesive tape has been adhered is taken out of the wafer delivery table 61 by the transport unit 40 and delivered to the suction surface of the second transport unit, and is cured by the ultraviolet irradiation device 300. If the surface of the mold adhesive tape is irradiated with ultraviolet rays, the protective tape P can be easily separated.
[0037]
Further, in the above embodiment, the protective tape P is adhered on the wafer 2, and after the protective tape P is peeled off, the dicing tape T is adhered on the same surface, but a circuit is formed. A dicing tape T is adhered to the opposite surface where no circuit is formed, and the protective tape P is adhered to the opposite surface where no circuit is formed. In the case where the apparatus is also used as a conventional step of peeling P, an alignment unit 1300 is provided on the front side of the dicing tape mount table 142 shown in FIG. 1, and the alignment unit detects the attitude of the wafer 2 and In addition to controlling the posture to be correct, the protective tape peeling unit 1400 is placed on the side of the dicing tape mount table 142 opposite to the alignment unit 1300. Only it is sufficient.
[0038]
In this case, the transfer direction of the wafer W is determined in the order of the delivery table 61, the transfer unit 40, the ultraviolet irradiation device 300 via the second transfer unit 200, the alignment unit 1300, and the dicing tape mount unit 142 in this order. At this position, the dicing tape T is adhered by the dicing tape feeding unit 180, and then, after the wafer is turned over, the protective tape P may be peeled by the protective tape peeling unit 1400. Subsequent movement is the same as in the above-described embodiment.
[0039]
As described above, although not used in this embodiment, if the alignment unit 1300 and the protective tape peeling unit 1400 are provided at the position shown in FIG. This can be done. This example is described in detail in JP-A-2000-68293.
[0040]
As described above, the protection tape P is firstly peeled off from the wafer body W on which the protection tape P is pasted on the circuit surface 2a by the single wafer processing apparatus 20 according to the embodiment of the present invention. The dicing tape T can be replaced on the same surface from which the protective tape has been peeled off. In addition, since it can be attached without being inverted, there is no need to change the wafer body B.
[0041]
In the present embodiment, the existing processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-68293 only needs to be provided with the alignment unit 80 and the protective tape peeling unit 90 on the downstream side. You can do it without change.
As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example at all.
[0042]
For example, in the above embodiment, the wafer body W which is not diced in a dice pattern is used. However, instead of this, the wafer body W which has been diced in a dice pattern in advance and which is prevented from falling apart by the protective tape P is used. Can be similarly processed.
Further, in the above-described embodiment, the example in which the dicing tape is adhered after the peeling tape P is peeled off is shown, but the processing apparatus of the present invention is not limited to this, and the transfer device or the pickup tape is adhered. In some cases, it can be applied.
[0043]
【The invention's effect】
As described above, according to the wafer processing apparatus of the present invention, the film stuck on the circuit surface of the wafer is peeled off from the wafer, and then a new dicing tape is stuck on the surface where the film has been peeled off. The attachment can be performed with the same device. In addition, there is no need to change the wafer, and no need to turn over the wafer body.
[Brief description of the drawings]
FIG. 1 is a top view of a wafer processing apparatus according to one embodiment of the present invention.
FIG. 2A is a schematic sectional view of a wafer body before being processed by the processing apparatus of the present embodiment,
FIG. 2B is a schematic sectional view of the wafer body after being processed by the same apparatus.
FIG. 3 is a perspective view of the transport unit shown in FIG. 1;
FIG. 4 is a front view of the protective tape peeling unit of the present invention.
FIG. 5 is a front view of a dicing tape feeding unit.
FIGS. 6A, 6B, and 6C are schematic views illustrating the operation of a dicing tape mount unit of the wafer processing apparatus according to the present invention.
FIG. 7 is a schematic diagram showing the steps of processing until both the protective tape and the dicing tape are attached and the protective tape is removed thereafter.
FIG. 8 is a schematic diagram showing a processing step from peeling of a protective tape to pasting of a dicing tape and before dicing.
[Explanation of symbols]
2a ... Circuit surface
2 .... wafer
20 ... Wafer processing equipment
40 ··· Transport unit
60 Wafer transfer unit
80 ... Alignment unit
90 ... Protective tape peeling unit
140 ... Dicing tape mount unit
142 ... Dicing tape mount table
144 ... Ring frame stocker
180 ・ ・ ・ ・ Dicing tape feeding unit
P ... Protective tape (film)
R ... Ring frame
S ... peeling tape
T ... Dicing tape
W: Wafer body

Claims (2)

A wafer processing apparatus for peeling the film from a wafer body having a film adhered to one surface of a wafer in advance and newly attaching a dicing tape to the same surface from which the film has been peeled,
A wafer delivery unit containing the wafer body,
A film peeling unit that sticks a peeling tape to the film side of the wafer body and peels the film,
An alignment unit that is disposed between the wafer transfer unit and the film peeling unit and controls the wafer body in a correct posture.
A ring frame is transferred one by one from a ring frame stocker in which the ring frame is stored, and a dicing tape mount table configured to be movable with respect to the film peeling unit,
A dicing tape feeding unit arranged in the moving area of the dicing tape mount table,
By the transfer unit, one wafer body sucked from the wafer transfer unit is transferred to the alignment unit, and the wafer body controlled to a predetermined posture by the alignment unit is located near the film peeling unit. A ring frame is mounted in advance, transferred onto the moving dicing tape mount table, and thereafter, the film of the wafer body is peeled by the film peeling unit, and thereafter, the wafer from which the film is peeled A dicing tape is attached by the upper dicing tape feeding unit. 2. The apparatus according to claim 1, wherein a second transfer unit is provided in the vicinity of the transfer unit, and an ultraviolet irradiation device for irradiating the wafer with ultraviolet light is provided within a rotation radius region of the second transfer unit. 3. The wafer processing apparatus according to claim 1.

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