CN105914164A - Machining apparatus - Google Patents

Abstract

The invention provides a machining apparatus which can reliably hold a wrapped wafer. A position detecting mechanism (124) is provided with a guiding part (124c). The guiding part supports the wafer (W) which exceeds the outer periphery of a central working platform (124a) and corrects the wafer (W) in a projected wrapped shape. Furthermore, on condition that the wafer (W) is corrected to horizontal, the outer peripheral edge (WE) of the wafer (W) is detected through a position detecting sensor (124d), and furthermore the central position of the wafer (W) is calculated according to the detected outer peripheral edge (WE) of the wafer (W) for aligning with the central position of a chuck worktable.

Description

Processing device

technical field

The present invention relates to a processing device, in particular to a processing device for processing warped wafers.

Background technique

In order to respond to demands for thinning/miniaturization of electronic products, semiconductor devices are processed into various shapes. Among them, CSP semiconductor devices of the type WL-CSP (Wafer Level CSP: Wafer Level Package) are covered with a resin film on the entire surface in the state of the wafer, and are connected to the electrodes of the semiconductor device formed on the silicon wafer by soldering. The balls are formed in a state aligned on the upper surface thereof (Patent Document 1). Such a WL-CSP is cut into chips of individual semiconductor devices by a cutting device (Patent Document 2).

Patent Document 1: Japanese Unexamined Patent Publication No. 2001-7135

Patent Document 2: Japanese Unexamined Patent Publication No. 2013-74021

Patent Document 3: Japanese Patent No. 4303041

However, in recent years, the thickness reduction and miniaturization of WL-CSP have further advanced, and the wafer has been formed to be very thin. Therefore, there are many cases where the state of the wafer is greatly warped, and there is a problem that transportation or holding becomes difficult due to the warpage. For example, there is a problem that a warped wafer cannot be held and the position cannot be detected in a position detection mechanism (Patent Document 3) for detecting a wafer taken out of a cassette before it is held by a chuck table. position and position the wafer at the specified position on the chuck table.

Contents of the invention

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a processing apparatus capable of reliably holding a warped wafer.

In order to solve the above-mentioned problems and achieve the object, the processing apparatus of the present invention processes wafers and includes: a cassette mounting table for mounting cassettes containing wafers; the cassette on which the wafer is carried out and the wafer is carried into the cassette; the chuck table holds the wafer carried out by the carry-out unit; and the processing unit processes the wafer held on the chuck table, The processing device is characterized in that the processing device has a position detection mechanism into which the wafers unloaded from the cassette are carried, the position detection mechanism detects the position of the wafer, and the position detection mechanism has: a central table, It attracts and holds the wafer using a holding surface corresponding to a region near the center of the wafer; a position detection unit detects the outer peripheral edge of the wafer held by the central table, and infers the position of the wafer; a rotation unit makes the The central table rotates; and a guide supporting the wafer beyond the outer periphery of the central table around the central table.

According to the processing apparatus of the present invention, since the guide portion supports the wafer extending beyond the outer periphery of the central table around the central table, a warped wafer can be corrected to be horizontal. Accordingly, the wafer can be reliably sucked and held by the center table.

Description of drawings

FIG. 1 is a perspective view showing a configuration example of a processing device.

Fig. 2 is a cross-sectional view showing a structural example of a cartridge mounting mechanism.

Fig. 3 is a plan view showing a configuration example of a position detection mechanism.

FIG. 4 is a flowchart showing an example of the operation of the position detection mechanism.

Fig. 5 is a cross-sectional view showing an operation example (Part 1) of the position detection mechanism.

6 is a sectional view of main parts showing an operation example (Part 2) of the position detection mechanism.

7 is a sectional view of main parts showing an operation example (Part 3) of the position detection mechanism.

Fig. 8 is a plan view showing an operation example (No. 4) of the position detection mechanism.

Label description

1: processing device; 10: chuck table; 20: processing unit; 40: processing feeding unit; 50: indexing feeding unit; 60: cutting feeding unit; 70: 1st conveying unit; 90: 2nd Transfer unit; 100: loading/unloading unit; 110: box; 120: box loading mechanism; 123: driving unit; 124: position detection mechanism; 124a: central table; 124b: rotating unit; 124c: guide; 124d: position Detecting sensor; 124e: holding surface; 124f: guiding surface; 130: cleaning unit; N: notch; W: wafer; WS: front; WR: back; WE: outer peripheral edge.

detailed description

Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the constituent elements described below include elements that can be easily conceived by those skilled in the art or elements that are substantially the same. In addition, the structures described below can be combined suitably. In addition, various omissions, substitutions, or changes in the structure can be made without departing from the gist of the present invention.

【Implementation】

The processing apparatus of the embodiment will be described. FIG. 1 is a perspective view showing a configuration example of a processing device. Fig. 2 is a cross-sectional view showing a structural example of a cartridge mounting mechanism. Fig. 3 is a plan view showing a configuration example of a position detection mechanism.

The processing device 1 is a facing dual dicer, and cuts a wafer W. As shown in FIG. The machining device 1 has a chuck table 10 , a machining unit 20 , a first gate frame 30 , a machining feed unit 40 , an index feed unit 50 , and a cutting feed unit 60 .

The wafer W is a semiconductor wafer or an optical device wafer on which a semiconductor device or an optical device is formed, an inorganic material substrate, a ductile resin material substrate, a ceramic substrate, a glass plate, or other processed materials. The wafer W is formed in a disc shape, and devices such as ICs and LSIs are formed in a plurality of regions arranged in a grid on the front surface WS. Wafer W is warped due to thinning or the like. On the outer periphery of the wafer W, notches N indicating crystal orientations are provided. In addition, instead of the notch N, an alignment flat that notches the outer peripheral edge WE of the wafer W into a linear shape may be used.

Here, the X-axis direction is a direction in which processing and feeding of the wafer W held on the chuck table 10 is performed. The Y-axis direction is perpendicular to the X-axis direction on the same horizontal plane and is a direction in which the index-feed unit 50 index-feeds the wafer W held on the chuck table 10 . The Z-axis direction is a direction perpendicular to the X-axis direction and the Y-axis direction, that is, a vertical direction.

The chuck table 10 is disposed on the upper surface of the apparatus main body 2 so as to be movable along the opening 2 a provided in the X-axis direction. The chuck table 10 is formed in a disc shape and has a holding surface 11 . The holding surface 11 holds the wafer W. The holding surface 11 is an upper end surface in the vertical direction of the chuck table 10 and is formed flat with respect to the horizontal plane. The holding surface 11 is made of, for example, porous ceramics, etc., and holds the wafer W by suction by negative pressure from a vacuum suction source (not shown).

The processing unit 20 processes the wafer W held on the chuck table 10 . Two processing units 20 are arranged facing each other in the Y-axis direction. The processing unit 20 is fixed to the first gantry frame 30 via the index feeding unit 50 and the cutting feed unit 60, and the first gantry frame 30 straddles the opening provided on the upper surface of the device main body 2 in the Y-axis direction. The device body 2 is erected in the form of the part 2a. The machining unit 20 has a cutting tool 21 , a spindle 22 and a housing 23 . The cutting insert 21 is an annular cutting grinder formed in an extremely thin disk shape. The main shaft 22 is detachably attached to the cutting tool 21 at the front end thereof. The casing 23 has a driving source such as a motor (not shown), and supports the main shaft 22 so as to be rotatable around a rotation axis in the Y-axis direction. The spindle 22 is rotated at high speed, and the wafer W is cut by the cutting blade 21 .

The machining feed unit 40 relatively moves the chuck table 10 and the machining unit 20 in the X-axis direction. For example, the machining feed unit 40 has a drive source such as a ball screw (not shown) or a pulse motor extending in the X-axis direction, and moves an X-axis moving base supporting the chuck table 10 in the X-axis direction.

The index feed unit 50 relatively moves the chuck table 10 and the machining unit 20 in the Y-axis direction. For example, the index feed unit 50 has a driving source such as a ball screw 51 and a pulse motor 52 extending in the Y-axis direction, and moves the machining unit 20 in the Y-axis direction.

The plunge feed unit 60 moves the machining unit 20 in the Z-axis direction perpendicular to the holding surface 11 of the chuck table 10 . For example, the plunging feed unit 60 has a drive source such as a ball screw 61 and a pulse motor 62 extending in the Z-axis direction, and moves the machining unit 20 in the Z-axis direction.

The processing apparatus 1 further includes a first conveying unit 70 , a second gate frame 80 , a second conveying unit 90 , a loading/unloading unit 100 , a cassette 110 , a cassette loading mechanism 120 , a cleaning unit 130 , and a control unit 140 .

The first transfer unit 70 receives the wafer W from the carry-out unit 100 , and transfers the wafer W to the chuck table 10 . The carry-out unit 100 carries the wafer W into and out of the cassette 110 . The first transport unit 70 is disposed on a second gate frame 80 erected on the apparatus main body 2 so as to straddle the opening 2 a of the apparatus main body 2 in the Y-axis direction. The first transport unit 70 has a linear motion mechanism 71 , a support portion 72 , a telescopic mechanism 73 , and an adsorption portion 74 . The linear motion mechanism 71 drives the slider by, for example, a ball screw or a rotating belt, and is arranged from one end of the second gate frame 80 in the Y-axis direction to the center. The support portion 72 is formed in an L-shape, one end of which is fixed to the slider 71 a of the linear motion mechanism 71 , and the telescopic mechanism 73 is disposed at the other end. The telescopic mechanism 73 fixes the suction part 74 at its front end, and moves the suction part 74 in the Z-axis direction. The expansion and contraction mechanism 73 is, for example, an air actuator that expands and contracts in the Z-axis direction, and moves the suction unit 74 from the position of the front surface WS of the wafer W held on the chuck table 10 to a predetermined height. The suction unit 74 holds the wafer W by suctioning the front surface WS of the wafer W via a suction pad (not shown).

The second transfer unit 90 transfers the processed wafer W placed on the chuck table 10 to the cleaning unit 130 . Then, the second transfer unit 90 transfers the wafer W cleaned by the cleaning unit 130 to the cassette 110 . The second transport unit 90 is disposed on the second door frame 80 and has a linear motion mechanism 91 , a support portion 92 , a telescopic mechanism 93 , and an adsorption portion 94 . The linear motion mechanism 91 drives the slider by, for example, a ball screw or a rotating belt, and is arranged from one end to the other end of the second gate frame 80 in the Y-axis direction. The support portion 92 is formed in an L-shape, one end of which is fixed to a slider (not shown) of the linear motion mechanism 91 , and the telescopic mechanism 93 is disposed at the other end. The retractable mechanism 93 has a suction part 94 fixed at its front end, and moves the suction part 94 in the Z-axis direction. The telescopic mechanism 93 is, for example, an air actuator that expands and contracts in the Z-axis direction, and moves the suction unit 94 from the position of the front surface WS of the wafer W placed on the chuck table 10 to a predetermined height. The suction unit 94 holds the wafer W by suctioning the front surface WS of the wafer W via a suction pad (not shown).

The carry-out unit 100 carries out the wafer W from the cassette 110 and carries the wafer W into the cassette 110 . For example, the loading/unloading unit 100 is formed in a bifurcated shape, has a holding hand 101 holding the wafer W, and a drive source such as a ball screw and a pulse motor (not shown) extending in the Y-axis direction, so that the holding hand 101 moves in the Y-axis direction. move up.

Cassette 110 accommodates a plurality of wafers W. As shown in FIG. 2 , the cassette 110 has an opening 111 for carrying in and out and a storage shelf 112 . In the storage rack 112, a plurality of support plates 112a for supporting the wafer W are formed protruding from opposite side walls in the X-axis direction, and the support plates 112a are arranged at equal intervals in the Z-axis direction. The distance between the support plates 112a in the Z-axis direction is larger than the thickness of the wafer W. As shown in FIG. A pair of support plates 112a facing each other in the X-axis direction support the wafer W horizontally.

The cartridge loading mechanism 120 is arranged on the front surface of the second door frame 80 and places the cartridge 110 thereon. The cassette loading mechanism 120 moves the cassette 110 up and down in the Z-axis direction, and determines the position of the cassette 110 in the Z-axis direction with respect to the loading/unloading unit 100 . The cartridge placement mechanism 120 has a housing 121 , a support member 122 , and a drive unit 123 . The upper surface of the housing 121 forms a cartridge mounting table 121 a on which the cartridge 110 is placed. The cassette mounting table 121 a is formed larger than the bottom surface of the cassette 110 , and mounts the cassette 110 storing wafers W thereon. The support member 122 supports the frame body 121 and has a support base 122 a that supports the frame body 121 and an arm 122 b that extends from the support base 122 a toward the drive unit 123 and engages with the drive unit 123 . The drive unit 123 raises and lowers the housing 121 supported by the supporting member 122 in the Z-axis direction. The drive unit 123 has an unillustrated guide rail extending in the Z-axis direction, a ball screw 123 a arranged parallel to the guide rail, and an unillustrated arm 122 b screwed to the ball screw 123 a and fixed to the support member 122 . nut and a pulse motor (not shown) that rotates the ball screw 123a. The drive unit 123 moves the support member 122 fixed to the nut in the Z-axis direction by rotating the ball screw 123a with a pulse motor.

The cassette loading mechanism 120 further includes a position detection mechanism 124 that detects the position of the wafer W unloaded from the cassette 110 by the unloading/unloading unit 100 and the notch N of the wafer W. The position detection mechanism 124 is arranged in the housing 121 of the cassette loading mechanism 120, and has a central table 124a, a rotation unit 124b, a guide 124c, and a position detection sensor 124d.

The central table 124a is formed in a disc shape, and its diameter is formed to be smaller than that of the wafer W. As shown in FIG. The central table 124a is disposed near the center of the bottom surface 121b of the housing 121 with its holding surface 124e being horizontal. The center table 124a is rotated by a rotation unit 124b composed of a pulse motor or the like. The holding surface 124e is made of, for example, porous ceramics, and holds a region near the center of the wafer W by suction from a vacuum suction source (not shown).

The guide part 124c supports the wafer W protruding from the outer periphery of the center table 124a around the center table 124a. As shown in FIG. 3 , the guide part 124c is formed in the shape of a letter "U" when viewed from the Z-axis direction, and is disposed so as to surround the central table 124a except the path R along which the loading/unloading unit 100 moves. The guide surface 124f of the guide portion 124c that guides the wafer W is set at the same height as the holding surface 124e of the center table 124a. The guide surface 124f is coated with a material having a low coefficient of friction such as fluororesin so as not to suppress the sliding of the wafer W rotating by the center table 124a. In addition, there is a possibility that static electricity may be generated due to the slide of the wafer W on the guide surface 124f. In this case, static electricity is preferably neutralized by a static eliminator not shown.

The position detection sensor 124d detects the outer peripheral edge WE of the wafer W held by the center table 124a. The position detection sensor 124d is arranged at a position capable of detecting the outer peripheral edge WE of the wafer W held by the center table 124a. For example, the position detection sensor 124d is located in the vicinity of the side surface 121c in the depth direction of the housing 121, and is arranged in the recessed part 124i formed by partially removing the rear end of the guide part 124c. The position detection sensor 124d is, for example, an optical sensor, and has a light emitting unit 124g and a light receiving unit 124h. The light emitting unit 124g and the light receiving unit 124h are arranged to face each other in the Z-axis direction with a certain interval therebetween. The light emitting unit 124g emits light toward the light receiving unit 124h. The light receiving part 124h receives the light irradiated from the light emitting part 124g, converts the received light amount into a voltage, and outputs it. The position detection sensor 124d positions the wafer W between the light emitting unit 124g and the light receiving unit 124h, and detects a voltage that changes when the light irradiated from the light emitting unit 124g is blocked by the outer peripheral edge WE of the wafer W. Furthermore, the position detection sensor 124d detects the notch N formed on the outer peripheral edge WE of the wafer W. As shown in FIG.

The cleaning unit 130 cleans and dries the wafer W processed by the processing unit 20 . Cleaning unit 130 has rotary table 131 holding wafer W. As shown in FIG. The cleaning unit 130 holds the wafer W on the rotary table 131 and rotates it at high speed, sprays a cleaning solution such as pure water toward the wafer W to perform cleaning, and sprays clean air (compressed air) or the like toward the wafer W to perform cleaning. dry.

The control unit 140 controls each component of the processing apparatus 1 . For example, the control unit 140 is connected to a drive circuit (not shown) that drives the pulse motors of the machining feed unit 40, the index feed unit 50, and the cutting feed unit 60, and controls the drive circuit to determine the X-axis of the chuck table 10. The position in the direction and the position of the machining unit 20 in the Y-axis direction and the Z-axis direction.

In addition, the control unit 140 is connected to the position detection mechanism 124, estimates the position of the wafer W based on the outer peripheral edge WE of the wafer W detected by the position detection mechanism 124, and controls the first transfer unit 70 and the process feeding unit 40 so that the wafer The center position of W is aligned with the center position of the chuck table 10 . Then, the control unit 140 controls the rotation unit 124b of the center table 124a based on the notch N detected by the position detection mechanism 124, and aligns the orientation of the crystal orientation of the wafer W in a predetermined direction. In addition, the control unit 140 and the position detection sensor 124d function as a position detection unit.

Next, an example of the operation of the processing device 1 will be described. FIG. 4 is a flowchart showing an example of the operation of the position detection mechanism. Fig. 5 is a cross-sectional view showing an operation example (Part 1) of the position detection mechanism. 6 is a sectional view of main parts showing an operation example (Part 2) of the position detection mechanism. 7 is a sectional view of main parts showing an operation example (Part 3) of the position detection mechanism. Fig. 8 is a plan view showing an operation example (No. 4) of the position detection mechanism.

First, the wafer W is unloaded from the cassette 110 (step S1 shown in FIG. 4 ). For example, the control unit 140 controls the drive unit 123 of the cartridge placement mechanism 120 to set the cartridge 110 at a predetermined position in the Z-axis direction. For example, the control unit 140 positions the cassette 110 at a position where the holding hand 101 of the carry-out unit 100 can carry out the wafer W to be processed. The control unit 140 controls the loading/unloading unit 100 to move the holding hand 101 in a direction (Y-axis direction) approaching the cassette 110 to position the holding hand 101 on the rear surface WR of the wafer W to be processed. At this time, there is a slight gap between the holding hand 101 and the back surface WR of the wafer W, and the holding hand 101 and the wafer W are in a non-contact state. Then, the control unit 140 controls the driving unit 123 of the cassette loading mechanism 120 to lower the cassette 110 slightly, and holds the wafer W by suctioning the back surface WR of the wafer W by the suction pad 101a (see FIG. The wafer W moves away from the storage rack 112 in the Z-axis direction. Then, the control unit 140 controls the loading/unloading unit 100 to move the holding hand 101 in a direction away from the cassette 110 (Y-axis direction) to unload the wafer W from the cassette 110 .

Next, the wafer W is carried into the position detection mechanism 124 (step S2). For example, the control unit 140 controls the drive unit 123 of the cassette placement mechanism 120 to raise the position detection mechanism 124 to set it at a predetermined position in the Z-axis direction. For example, the control unit 140 positions the position detection mechanism 124 at the front position of the holding hand 101 holding the wafer W as shown in FIG. 5 . The control unit 140 controls the loading/unloading unit 100 to move the holding hand 101 holding the wafer W in a direction (Y-axis direction) approaching the position detection mechanism 124, and as shown in FIG. Above the central table 124a. Furthermore, the control unit 140 controls the drive unit 123 of the cassette loading mechanism 120 to raise the position detection mechanism 124 to a predetermined position. For example, as shown in FIG. 7 , control unit 140 raises position detection mechanism 124 to the same height as the position of holding surface 124e of center table 124a and the position of rear surface WR of wafer W. At this time, in the state where the wafer W is held by the holding hand 101, the back surface WR near the outer peripheral edge WE of the wafer W comes into contact with the guide surface 124f of the position detection mechanism 124, and is pushed up by the guide surface 124f as the position detection mechanism 124 rises. The outer peripheral edge WE of the wafer W is raised. Thereby, the warp of the wafer W is corrected by the guide surface 124f, and the wafer W becomes flat. In a flat state of wafer W, center stage 124a sucks and holds a region near the center of wafer W. At this time, as shown in FIG. 8 , the outer peripheral edge WE of the wafer W is located between the light emitting portion 124 g and the light receiving portion 124 h of the position detection sensor 124 d. The control unit 140 controls the drive unit 123 of the cassette placement mechanism 120 to slightly raise the position detection mechanism 124 to release the suction and holding of the wafer W by the suction pad 101 a of the holding hand 101 .

Next, the position of the wafer W and the notch N are detected (step S3). For example, the control unit 140 controls the rotation unit 124b of the center table 124a to detect the positions of the outer peripheral edge WE of the wafer W at three or more locations. For example, the position detection sensor 124d detects a voltage that changes when light irradiated from the light emitting unit 124g is blocked by the outer peripheral edge WE of the wafer W, and outputs it to the control unit 140 as a detected voltage. The control unit 140 detects three or more positions of the outer peripheral edge WE of the wafer W based on the detection voltage output from the position detection sensor 124d. Then, the control unit 140 obtains each coordinate of the detected position of the outer peripheral edge WE by a trigonometric function, and estimates the center position of the wafer W from the coordinates.

Next, the orientation of the crystal orientation of the wafer W is set (step S4). For example, the position detection sensor 124 d detects the notch N formed on the outer peripheral edge WE of the wafer W and outputs a detection signal to the control unit 140 . The control unit 140 rotates the center table 124a based on the detection signal to align the orientation of the crystal orientation of the wafer W in a predetermined direction. For example, the orientation of the crystallographic orientation of the wafer W held on the center stage 124a and the orientation of the crystallographic orientation of the wafer W held on the chuck table 10 are made to be the same direction.

Next, the wafer W is transferred to the chuck table 10 (step S5). For example, the control unit 140 controls the drive unit 123 of the cassette loading mechanism 120 to lower the position detection mechanism 124 holding the wafer W, and the suction pad 101a of the holding hand 101 sucks and holds the back surface WR of the wafer W. Then, the control unit 140 cancels the suction of the center table 124a, controls the unloading and loading unit 100, and moves the holding hand 101 in a direction away from the position detection mechanism 124 (Y-axis direction) to carry out the wafer W from the housing 121. . The control unit 140 controls the first transfer unit 70 to suction and hold the front WS of the wafer W held by the holding hand 101 by the suction unit 74 to move the wafer W in the Y-axis direction to the movement path of the chuck table 10 . At this time, the wafer W is moved in the Y-axis direction based on the difference between the center position of the wafer W calculated in the above-mentioned step S3 and the center position of the center table 124a. Then, the control unit 140 controls the processing feed unit 40 to move the chuck table 10 in the X-axis direction to the lower side of the wafer W held on the suction portion 74 of the first transport member 70 . At this time, the chuck table 10 is moved in the X-axis direction based on the difference between the center position of the wafer W calculated in the above-mentioned step S3 and the center position of the center table so that the center position of the wafer W and the center table are aligned with each other. The center positions of the chuck table 10 are consistent. Then, the control unit 140 controls the first transfer unit 70 to extend the telescopic mechanism 73 to lower the wafer W and hold the wafer W on the chuck table 10 .

Next, wafer W is cut (step S6). For example, the control unit 140 controls the processing feeding unit 40 to move the chuck table 10 to the cutting processing position, and controls the processing unit 20 and the like to perform cutting processing on the wafer W.

Next, the wafer W is cleaned and dried (step S7). When the cutting process of the wafer W is completed, the control unit 140 controls the second transfer unit 90 to transfer the wafer W held on the chuck table 10 to the cleaning unit 130 . The cleaning unit 130 holds the wafer W on the rotary table 131 and rotates it at high speed, cleans the wafer W with a cleaning liquid, and dries the wafer W after cleaning.

Next, the wafer W is accommodated in the cassette 110 (step S8). The control unit 140 controls the second transfer unit 90 to transfer the wafer W held on the rotary table 131 to the transfer unit 100 . The carry-out unit 100 holds the wafer W by the holding hand 101 and stores the wafer W in the cassette 110 .

As described above, according to the processing apparatus 1 of the embodiment, the guide part 124c supports the wafer W protruding from the outer periphery of the center table 124a of the position detection mechanism 124, and straightens the convexly warped wafer W horizontally. Thus, since the wafer W is horizontal when the wafer W is sucked and held by the central table 124a, the holding surface 124e of the central table 124a is in surface contact with the back surface WR of the wafer W, so that the wafer W can be reliably sucked and held by the holding surface 124e. Wafer W.

In addition, although the position of the outer peripheral edge WE of the warped wafer W differs from the position of the actual outer peripheral edge WE of the wafer W in a plan view, in the present invention, since the wafer W is straightened to be horizontal, the position of the outer peripheral edge WE in a plan view is different from that of the actual wafer W. This is the same as the actual position of the outer peripheral edge WE of the wafer W, and the center position of the wafer W can be accurately detected. Furthermore, since the wafer W is straightened to be horizontal, the position of the notch N can also be reliably detected.

【Modification】

The guide portion 124c is in the shape of a letter "U", but any shape may be used as long as it can support the wafer W protruding from the outer periphery of the center table 124a. For example, the guide part 124c may be in the shape of a character "U" or "C", and a plurality of guide parts may be arranged so as to support the wafer W at a plurality of points.

Furthermore, an example in which an optical sensor is used as the position detection sensor 124d has been described, but the outer peripheral edge WE of the wafer W may be imaged by, for example, an imaging device. In this case, the eccentricity of the wafer W is estimated from the captured image.

Furthermore, although the center position of the wafer W is estimated first and then the position of the notch N is detected, the center position of the wafer W may be estimated after the position of the notch N is detected. Thereby, it is possible to avoid erroneous detection of the notch N as the outer peripheral edge WE.

Claims (1)

1. a processing unit (plant), wafer is processed by it, and this processing unit (plant) has: box mounting table, it is to storage The box of wafer loads；Taking out of and move into unit, wafer is taken out of also by it from this box being positioned in this box mounting table And wafer is moved into this box；Chuck table, its holding takes out of, by this, the wafer moving into unit and take out of；And add Work order is first, and the wafer being maintained on this chuck table is processed by it, and described processing unit (plant) is characterised by,

This processing unit (plant) has position detecting mechanism, and the wafer taken out of from this box is moved to this position detecting mechanism, should The position of wafer is detected by position detecting mechanism,

This position detecting mechanism has:

Central authorities' workbench, it utilizes the holding face attracting holding wafer corresponding with the region of the immediate vicinity of wafer；

Position detection unit, the outer peripheral edge of its wafer to keeping by this central authorities' workbench is detected, and is pushed away Break and the position of wafer；

Rotating unit, it makes this central authorities' workbench rotate；And

Guide portion, the wafer of the periphery beyond this central authorities' workbench is supported around this central authorities' workbench by it.