JPH0625013Y2 - Wafer positioning device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to various inspections of a disc-shaped substrate (hereinafter referred to as a "wafer"), which is a material, in a semiconductor manufacturing process, such as a film thickness meter. The present invention relates to a positioning device such as a device for aligning with a predetermined mounting position.

[Conventional technology]

In order to position a wafer in a semiconductor manufacturing process, a means for bringing the outer peripheral portion of the wafer into contact with a hitting means arranged at a required position is generally applied.

The hitting means may be, for example, a member having an arcuate abutting edge adapted to the shape of the target wafer installed at a predetermined position, or a plurality of hitting members having a circumference adapted to the outer diameter of the wafer. There is known a means of arranging the wafer along a line or a wafer conveyed by an appropriate conveyor device is stopped by a hitting member installed at a required position and positioned at the stop position.

[Problems to be solved by the device]

In each of the conventional means described above, the size of the wafer to be positioned is
If it is limited to a certain standard, it may be fixedly installed at the required position, but when handling various wafers with different dimensions, it is necessary to replace the contact member and adjust the installation position. Becomes

With the contact member having the arc-shaped contact edge, the contact member itself must be replaced each time the wafer standard changes.
Further, the means for arranging a plurality of hitting members on the circumference corresponding to the outer diameter of the wafer and the means for stopping the hitting member at a desired position by the hitting member attached to the conveyor device are installed in accordance with the size of the wafer. You have to change the position.

Since these contact members must be replaced or the positions must be changed each time the standard size of the target wafer changes, it is extremely complicated and efficient when sequentially handling various wafers with different standards. Is bad.

The present invention relates to a wafer positioning device that solves these problems.

[Means for Solving the Problems]

A plurality of sliders are movably mounted along respective guide rails installed radially from the central axis, and positioning pins are provided upright on the upper ends of the respective sliders. On the other hand, the ends of a plurality of rods of equal length, each of which has one end pivotally attached to the peripheral edge of the rotary plate that rotates around the central axis, are pivotally engaged with a connecting shaft vertically extending to the lower surface side of each slider. As the rotary plate rotates, each slider (and the positioning pin erected on it) is synchronously moved.

A fork having a guide groove in the radial direction is projected on the rotary plate, and a tip roller of a crank which is rotationally driven by a pulse motor is fitted in the guide groove of the fork, and the crank is rotated to move through the fork. The rotating plate is rotated to move each slider synchronously. The pulse motor uses the position where each slider has moved to the outermost position as a reference starting position, inputs the required number of control pulses, and drives it to rotate by an angle corresponding to the number of input pulses, and the rotation amount of the rotary plate and each slide. It is controlled by the drive control means for controlling the moving amount of the pendulum.

Further, at least 5 or more sets of guide rails, sliders and rods are radially arranged.

[Action]

When the rotating plate is rotationally driven by the rotation of the pulse motor through the crank and the fork, the sliders connected to the peripheral edge of the rotating plate by rods move forward and backward toward the center synchronously. .

By arranging each set of sliders, rods, and pivot positions of rods on the rotary plate in the same phase, each slider (and the positioning pin standing on them) is always a distance from the center. Move in an equal relationship with each other.

When the pulse motor is driven with the position where each slider moves to the outermost position as the reference starting position, each slider moves inward, and the positioning pins push the peripheral edge of the wafer toward the center. Move and position. By selecting the number of pulses to be input to the pulse motor based on the outer diameter of the target wafer in advance, the position where the positioning pin erected on each slider contacts the outer edge of the target wafer. Stop the pulse motor and align the wafer to the desired position.

Further, by setting the number of positioning pins to 5 or more, the positioning can be performed without being affected by the orientation of the orientation flat formed on the wafer.

〔Example〕

FIG. 1 is a perspective view showing the configuration of a first embodiment device of the present invention.

An appropriate number of columns that are erected on a base (not shown) (1) (1)
・ ・ Supports the base plate (2) horizontally by
The wafer mounting portion is pivotally supported by the bearing (3) mounted in the center of the wafer. In FIG. 1, the wafer mounting portion has a structure in which a rotary shaft having a vacuum suction chuck (4) at the upper end is rotationally driven by a motor (5) at the lower end, but it is not necessary to rotate it. However, the present invention is not limited to the illustrated configuration.

A plurality of (5 in the illustrated embodiment) through grooves (6) are formed in the base plate (2).
(6) ... are engraved radially from the center at equal angular intervals, and a pair of guide rails (7) (7) ...
Are installed along the direction of each through groove (6).

One slider (8) is slidably attached to each guide rail (7). The slider (8) has a shape projecting from the through groove (6) of the base plate (2) to the upper surface as shown in the second illustration, and the positioning pin (9) is erected on the upper end of the slider (8) and on the lower surface side. Has a connecting shaft (10) vertically provided at a position aligned with the axis of the positioning pin (9). The height of the slider (8) is set so that the positioning pin (9) can be brought into contact with the outer edge of the wafer when the wafer to be processed is mounted on the central mounting portion. deep.

On the other hand, below the base plate (2), the rotary plate (11) is arranged so as to be rotatable around the central axis. The rotary plate (11) is loosely fitted so that it can rotate independently of the rotary shaft of the wafer mounting portion, and the same number of shafts (12) as the sliders (8) are provided on the periphery thereof.
Are erected at equal angular intervals on the same circumference, and one end of each rod (13) is pivotally attached thereto.

Each rod (13) is made equal in length, and at the tip end side thereof, a connecting shaft (1
The lower end of (0) is pivotally attached, and the rotation of the rotary plate (11) is transmitted to the slider (8) via the rod (13) and moved along the guide rail (7).

In addition, on the lower surface of the base plate (2), each spring groove (6) and the guide rail (7) are erected in a fixed positional relationship with respect to the lower part of one spring hanging shaft (14). A spring (16) is installed between this and the spring hook shaft (15) installed at a proper position of each rod (13).

With the above configuration, when the rotating plate (11) rotates, the rod (13)
The slider (8) is driven along the guide rail (7) via the, while the rods (13) are all of equal length, and the pivotal portion to the rotating plate (11) is Since they are arranged at equal angular intervals on a common circumference, it is possible to hold each slider (8) at the same distance from the center of the rotating plate (11) and move them synchronously. it can.

On the other hand, a fork (17) protruding in the radial direction is attached at an appropriate position on the periphery of the rotary plate (11), and a roller (19) axially supported by a driving crank (18) is engaged with the fork (17). . Crank (1
8) is driven to rotate by a pulse motor (20), and by inputting a required control pulse to the pulse motor (20), the crank (18) is rotated by a required angle in a desired direction, and the circle of the roller (19) is accompanied by it. By the movement, the rotary plate (11) is rotated via the forks (17), and the respective sliders (8) are synchronously moved.

The shaft of the pulse motor (20) is provided with a sector plate (21) having a notch (22) formed in a part of its peripheral edge, and the sector plate (21) is rotated integrally with the crank (18) so that the notch (22) A lamp (23) and a photoelectric element (24) are placed opposite to each other across the passage, and when the notch (22) is at that position, a light beam is incident on the photoelectric element (24) to output a signal. It is configured to output. This signal output position is the position where each slider (8) has moved to the outermost position, that is,
As shown in FIG. 3, a signal is output when the crank (18) moves to a position where the fork (17) moves to the start end of its swing stroke.

Next, the operation of the wafer positioning apparatus having the above structure will be described according to the operation procedure.

First, rotate the pulse motor (20) in the clockwise direction (the direction of arrow A in the first drawing), and at the position where the notch (22) of the sector (21) is aligned with the light incident light path to the photoelectric element (24). , Photoelectric device
Stop by the output from (24). At this time, each slider
(8) is in a standby state in which it takes the starting position shown in FIG. 3 moved to the outside of the movement stroke as described above.

Therefore, the wafer to be processed is transferred and placed on the vacuum suction chuck (4) by an appropriate transfer means or manual operation. The mounting position at this time is usually deviated from the correct position because no positioning means is applied.

Then, the pulse motor (20) is started, and the crank (18) is rotated in the direction opposite to the arrow A shown in FIGS. 1 and 3, which is determined in advance in accordance with the outer diameter of the target wafer. A number of control pulses are applied to the pulse motor (20), and the crank (18) is rotated by an angle amount determined by the number of applied pulses.

With the rotation of the crank (18), the roller (19) vertically supported by the crank (18) moves in an arc, so that the rotary plate (11) moves to the third position via the fork (17) holding the roller (19). It is driven to rotate in the direction of arrow B shown in the figure.

With the rotation of the rotary plate (11), the pivotal attachment portion (12) of the rod (13) at the peripheral edge of the rotary plate (11) moves in the direction of arrow B, and
Through the rod (13), move the slider (8) toward the center along the guide rail (7) (the guide rail (7) is not shown in FIGS. 3 and 4). Pull and move.

The movement of the slider (8) is performed by moving a plurality of pairs of sliders (8) and rods.
Since the (13) and the like are arranged in the same relative positional relationship, all the sliders (8) are synchronized and always move at the same distance from the center of the device. Therefore, a plurality of positioning pins (9) standing on the upper end of each slider (8)
Is always moved while maintaining the positional relationship arranged on the circumference centered on the vacuum suction chuck (4) installed in the center of the apparatus, on the periphery of the wafer placed on the vacuum suction chuck (4),
It abuts one after another and pushes it toward the center to displace it.

Depending on the size of the wafer to be processed, a preset number of pulses are input to the pulse motor (20) and the crank (18)
Is rotated by an angle corresponding to the number of input pulses, the plurality of positioning pins (9) evenly contact the outer edge of the wafer,
The center of the circular wafer is aligned with the center of the vacuum suction chuck (4) for accurate positioning. The pulse motor (20) stops at the position where the set number of pulses have been input.

Then, the vacuum pump connected to the vacuum suction chuck (4) is activated to suck and hold the wafer.

Then, the pulse motor (20) is started in the reverse direction to rotate the crank (18) in the direction of arrow A, and the rotary plate (18) is rotated through the roller (19) and fork (17) in the direction of arrow B. By rotating in the opposite direction, each slider (8) is moved to the outside, and each positioning pin (9) erected on it is separated from the peripheral edge of the wafer after positioning. At this time, the spring (1
Since each rod (13) is urged outward by (6), the roller (19) and the forks are separated between the shaft (12) and the rod (13).
The gaps generated between (17), between the slider (8) and the guide rail (7), and between the connecting shaft (10) and the rod (13) are absorbed by one contact. As a result, smooth driving is ensured.

At the position where each slider (8) has moved outward,
The notch (22) of the sector (21) attached to the shaft of (0)
The optical element (24) is aligned with the optical axis, the photoelectric element (24) outputs a signal, the pulse motor (20) is stopped, and the first standby state is restored.

After the required measurement or processing is completed for the positioned wafer and it is sent to the discharge side, the next wafer is positioned by the same procedure and mounted on the vacuum suction chuck (4), and the measurement or processing is performed sequentially. Do. Subsequent wafers
If the outer diameter differs from the preceding one, use the pulse motor (2
This is dealt with by adjusting the number of control pulses to be applied to 0) according to the size of the wafer.

That is, depending on the size of the wafer to be applied in advance, the rotation angle amount of the crank (18) corresponding to the distance to move each slider (8) from the standby position toward the center and the crank (18 ) To obtain the number of control pulses to be applied to the pulse motor (20) to rotate that angle, various wafer dimensions can be obtained by inputting the required number of control pulses based on the individual wafer dimensions. Can be swiftly dealt with, and reliable positioning can be performed for wafers of any standard.

Although the above description is based on the illustrated embodiment, the present invention is not limited to the above contents. For example, in the above-mentioned embodiment, the positioning pin (9), the slider (8), the rod (13)
Etc. are provided in five sets, but a larger number of six sets or more may be provided.

If the wafer to be positioned is a perfect circle, the number of positioning pins and the like can be reduced to perform positioning with 4 or 3 sets. Since an orientation flat is formed by cutting off a part of the above into a straight line, positioning may be inaccurate when the number of positioning pins is four or less.

FIG. 5 is a schematic diagram showing that state. FIG. 5 (B) shows the case where there are four positioning pins, and (C) shows the case where there are three positioning pins. F)
If the positioning pin (9) has four or three when placed in a position facing one of the positioning pins (9), the wafer (W)
Indicates that the position of is displaced from the correct alignment position shown by the chain line. Therefore, in these cases, when mounting the wafer (W), it is necessary to take care so that the orientation flat (F) does not face the positioning pins, which is a disadvantage for automation of the apparatus.

On the other hand, if the number of positioning pins (9) is set to 5, even if the orientation flat (F) faces one of the positioning pins (9) as shown in FIG. A required alignment state can be obtained by the positioning pins of, and the positioning can be performed without being influenced by the orientation of the wafer (W).

In the above-mentioned embodiment, the through groove (6) (6), the guide rail
(7) (7) ... are arranged radially at equal angular intervals, and each rod (1
The positions of the shafts (12) that pivotally attach (3) to the rotary plate (11) are also equiangular intervals corresponding thereto, but these may not necessarily be equiangular intervals. However, even if these arrangements are not arranged at equal angular intervals, the positioning pins (9) should be arranged so that the positional relationship between the through groove and the guide rail and the pivot shaft in each set is in the same phase. However, it goes without saying that the vacuum suction chuck (4) should always be positioned and moved on the circumference of the circle.

[Effect of device]

(1) The center of the wafer is aligned with the center of the required mounting portion by synchronously moving the plurality of positioning pins from the outside toward a position on the circumference that matches the outer diameter of the wafer. As described above, the positioning can be accurately performed.

(2) When sequentially processing wafers with different standard dimensions, by selecting the number of control pulses to be input to the pulse motor, the movement amount of each positioning pin can be easily and quickly adapted to the wafer size. Therefore, it is not necessary to adjust the position of the hitting member unlike the conventional means.

(3) Since the positioning pins having a small diameter are in contact with the peripheral edges of a plurality of places on the wafer, contamination is small.

(4) In the unlikely event that the pulse motor of the drive source does not stop at the specified position due to a failure of the drive control device, or if the drive motor continues to run uncontrollably, the rotating plate, slider, etc. on the driven side will remain constant. It only reciprocates within the stroke range, and damage to the mechanical device itself can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a device of one embodiment of the present invention, FIG. 2 is an elevation view of a slider, and FIGS. 3 and 4 are plan views for explaining a moving mechanism of the slider. FIG. 5 (A) is a plan view showing the positioning of the wafer by the five positioning pins of the present invention, and FIGS. 5 (B) and (C) are plan views showing the error when there are four or three positioning pins. is there. (2) …… base plate, (4) …… vacuum suction chuck, (5) …… motor, (6) …… through groove, (7) …… guide rail, (8) …… slider, ( 9) …… Positioning pin, (10) …… Connecting shaft, (11) …… Rotating plate, (12) …… Axis, (13) …… Rod, (14) (15) …… Spring shaft, ( 16) …… Spring, (17) …… Fork, (18) …… Crank, (19) …… Roller, (20) …… Pulse motor, (21) …… Sector plate, (23) …… Lamp, (24) …… Photoelectric element, (W) …… Wafer, (F) …… Orientation flat.

Claims (1)

[Scope of utility model registration request] 1. A base plate which is held horizontally and has a wafer supporting means mounted in the center thereof, and a plurality of sets of guide rails which are installed radially along the base plate with the wafer supporting means mounting position as the center. A plurality of sliders, each of which is slidably mounted on the guide rail, has a positioning pin erected on the upper end side protruding from the upper surface of the base plate, and has a connecting shaft vertically hung on the lower surface side; A rotary plate that is installed below the base plate so as to be rotatable around the center position, and has a peripheral edge of the rotary plate at an angular interval equal to the arrangement of the guide rails and at a position equidistant from the center. , One end of which is pivotally attached, and the other end of which is engaged with a connecting shaft that is vertically provided on the lower surface of the slider, so that the plurality of sliders are respectively guided by the rotation of the rotating plate. Along with the A number of rods of equal length, a fork for rotation that radially protrudes from the peripheral edge of the rotating plate, a crank whose tip is slidably fitted in the fork, and which rotates, A pulse motor for rotationally driving, and each of the sliders causes the pulse motor to input a required number of control pulses on the basis of the position moved outward, and the rotary plate is rotated at an angle corresponding to the number of input pulses. A wafer positioning device provided with a drive control unit that rotates and synchronously moves a positioning pin erected on each of the sliders to a position corresponding to a size of a target wafer.