JPS62188642A - Wafer positioning device - Google Patents

Abstract

PURPOSE:To obtain high positioning accuracy, by equipping a circumferential positioning mechanism with stoppers, which are adapted to two places in the flat part of a wafer, and clamping arms which hold the vicinity of said flat part to adapt it to the stoppers. CONSTITUTION:A vertically separated pair of clamping arm holders 23 are rotatably supported through axes 24. Clamping rollers 26 opposing their end faces to each other are rotatably supported to point end parts of these clamping arm holders 23 through two clamping arms 25. A wafer 3 is clamped by these clamping rollers 26. While supporting fixtures 28 are arranged in both right and left sides in point end parts of the clamping arms 25, and fixing rollers (stoppers) 29 are rotatably supported to bottom end parts of these supporting fixtures 28. High accurate positioning in the circumferential direction can be performed by adapting both ends in a flat part of the wafer to these fixing rollers 29.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a positioning device for determining the position of a semiconductor wafer having a flat portion (orienting flat) formed on a part of its side surface.

[Prior Art] Generally, a semiconductor wafer has a flat portion formed in accordance with its crystal orientation. In order to automatically feed such semiconductor wafers to automatic processing machines such as peripheral polishing equipment for polishing, it is necessary not only to center the semiconductor wafers but also to position them in the circumferential direction with high accuracy. must be done.

Conventionally, therefore, the semiconductor wafer is positioned in the circumferential direction in advance using the flat portion as a reference, and centering is performed using positioning devices as shown in FIGS. 5 to 7, respectively.

The positioning device shown in FIG.
are arranged so as to be movable toward and away from each other, and centering is performed by sandwiching the semiconductor wafer (wafer) 3 from the sides by the concave curved surface portions 1 and 1. Further, the positioning device shown in FIG. 6 has a rotatable roller 4 attached to the edge of the concave curved surface portion l of the arm 2 shown in FIG.
...is established. Further, the positioning device shown in FIG. 7 has four rollers 5 arranged on the same circumference and configured to be movable in the radial direction. Centering is performed by pinching the semiconductor wafer 3 placed inside from four directions.

However, each of the above positioning devices has a problem in that the movement of the semiconductor wafer 3 during centering causes the semiconductor wafer 3 to also move in the circumferential direction, resulting in poor positioning accuracy in the circumferential direction.

Therefore, as shown in FIG. 8, the present applicant has developed a pair of fixed rollers 6, 6 (stoppers) spaced apart from each other, and a movable roller that can be freely moved along a perpendicular bisector of a line connecting these fixed rollers 6, 6. We have considered a positioning device equipped with a circumferential positioning mechanism consisting of a moving roller 7.

Here, the circumferential positioning mechanism uses the moving roller 7 to
By moving the semiconductor wafer 3 toward the fixed rollers 6 and 6 and bringing both sides of the flat portion 8 into contact with the fixed rollers 6 and 6, the semiconductor wafer 3 can be positioned in the circumferential direction. ing. That is, when one side of the flat portion 8 comes into contact with one of the fixed rollers 6, a component force T1 acts to rotate the semiconductor wafer 3 toward the other fixed roller 6 using the point of contact with the fixed roller 6 as a fulcrum. The semiconductor wafer 3 rotates. Then, the other side of the flat portion 8 comes into contact with the other fixed roller 6, and the position of the semiconductor wafer 3 in the circumferential direction is determined.

[Problems to be Solved by the Invention] However, in the positioning device described above, since the moving roller 7 is configured to push the side surface of the semiconductor wafer 3 and move it, the moving roller 7 and the fixed roller 6 are separated by a large distance. There is. Therefore, the angle θ between the line connecting the point of force application and the fulcrum on the semiconductor wafer 3 and the direction of force application by the moving roller 7 becomes smaller, and the component force T that attempts to rotate the semiconductor wafer 3 becomes A force T that acts on the moving roller 7 in the moving direction. It is considerably smaller than . As a result, the semiconductor wafer 3 does not rotate sufficiently, making it impossible to obtain high positioning accuracy.

In addition, in order to rotate the semiconductor wafer 3 sufficiently, the force T exerted by the moving roller 7 is applied. If the diameter of the semiconductor wafer 3 is increased, there is a problem in that the outer peripheral portion of the semiconductor wafer 3 is damaged by the moving roller 7 and the fixed roller 6.

[Purpose of the Invention] This invention was made to solve the above problem, and it is possible to reliably bring the flat part of the semiconductor wafer into contact with the fixed roller without damaging the outer peripheral part of the semiconductor wafer, and to An object of the present invention is to provide a wafer positioning device that can position a wafer with high precision.

[Means for Solving the Problems] The wafer positioning device of the present invention includes a centering mechanism that moves the wafer in a direction perpendicular to its axis to determine the left and right positions of the wafer in the radial direction, and a circumferential positioning mechanism that determines a position relative to the wafer and a radial left and right position, and the circumferential positioning mechanism is configured to include a stopper that abuts at least two locations spaced apart from each other on a flat part of the wafer, and a stopper that grips the vicinity of the flat part. The clamp arm draws the wafer toward the stopper and brings the flat part into contact with the stopper.

[Function] In the wafer positioning device configured as described above, the clamp arm is configured to grip the vicinity of the flat part of the semiconductor wafer, so that the point of force application on the semiconductor wafer, the flat part, and one end of the stopper are The angle between the line connecting the contact point (fulcrum) of the clamp arm and the direction in which the force is applied by the clamp arm increases, and as a result, the component force that tries to rotate the semiconductor wafer toward the other end of the stopper increases. growing. Thereby, both ends of the flat portion can be reliably brought into contact with the stopper.

Embodiment FIGS. 1 to 4 are diagrams showing an embodiment of the present invention. The wafer positioning apparatus shown in these figures is roughly composed of a centering mechanism 9 and a circumferential positioning mechanism 10.

First, the centering mechanism 9 will be explained. In FIG. 1, reference numeral 11 is a frame. The frame 11 includes a frame body 11a serving as a framework, and a machine stand 11b provided at the center of the frame body 11a. The frame body 11a is provided with two shafts 12 with their axes oriented in the left-right direction and spaced apart from each other in the front-rear direction. A pair of arm holders are positioned on these shafts 12, 12 so as to sandwich the machine base 11b! 3 and 13 are supported slidably in the axial direction. A side clamp arm I4 whose longitudinal direction is oriented in the front-rear direction and whose one end protrudes forward is fixed to the side of each arm holder I3.

Furthermore, on the lower surface of the tip of the side clamp arm 14,
The axis in the vertical direction (direction perpendicular to the paper surface in Figure 1)
A side clamp roller 15 is rotatably supported.

Next, to explain the configuration for moving the arm holders 13 in the left-right direction, pulleys 16 and I6, whose axes are directed in the front-back direction, are rotatably supported on both sides of the rear end of the frame 11a. A wire 17 is wound around these pulleys 16. And wire 1
The rear end portion of one arm holder 13 is fixed to the upper portion located between the pulleys 16 .

Further, the rear end portion of the other arm holder 13 is fixed to the lower portion of the wire 17. Moreover, a piston cylinder 18 whose longitudinal direction is oriented in the left-right direction is arranged on the upper surface of the machine base zb. The piston rod 19 of this piston cylinder I8 is attached to one arm holder 13.
is fixed to the side of the

In the centering mechanism 9 having such a configuration, the piston rod ■
9 in the left-right direction, the side clamp arms 14 can be moved toward and away from each other in the left-right direction, and each side clamp arm I4.! 4 can be moved by the same dimension.

Next, to explain the circumferential positioning mechanism IO, the first
In the figure, reference numeral 20 is a slide frame. The slide frame 20 is supported by the frame 11a so as to be slidable in the front and rear directions. A piston cylinder 21 whose longitudinal direction is oriented in the front-rear direction is attached to the slide frame 20, with the tip of a piston rod 22 fixed to the frame 11a. This piston cylinder 21 is for moving the slide frame 20 in the front-back direction.

Further, on the upper surface of the slide frame 20, as shown in FIG.
3 and 23 are rotatably supported via shafts 24 and 24. At the tips of these clamp arm holders 23, 23, clamp rollers 26, whose ends face each other, are rotatably supported via two clamp arms 25, 25, respectively. Here, the clamp arm 25 is made of elastically deformable steel wire,
By folding this in the left-right direction, the clamp roller 26 can be moved slightly in the left-right direction. Further, the clamp roller 26 is for gripping the semiconductor wafer 3, and O-rings 27 made of rubber are fixed to the mutually facing end surfaces thereof, as shown in FIG. It is designed so that it can be held securely without any problems.

Furthermore, supports 28 are arranged on both left and right sides of the tip of the clamp arm 25.

A fixed roller (stopper) 29 whose axis is vertically oriented is rotatably supported at the lower ends of these supports 28. The fixed roller 29 positions the semiconductor wafer 3 in the circumferential direction by abutting both ends of the flat portion 8 of the semiconductor wafer 3 .

Next, the configuration for driving the clamp arm holder 23 will be described. A piston cylinder 30 is fixed to the side of the slide frame 20. On the other hand, a link arm 31 having one end projecting downward is fixed to the rear end of the upper clamp arm holder 23. The tip of the link arm 3I and the piston rod 32 of the piston cylinder 3° are connected to be movable in the vertical direction. Furthermore, the upper and lower clamp arm holders 23 are provided with a transmission mechanism (not shown), and when the upper clamp arm holder 23 rotates around the shaft 24, the lower clamp arm holder 23 also rotates, and the clamp The rollers 26 and 26 move in the direction of approaching and separating.

Further, the circumferential positioning mechanism IO having such a configuration is provided with a detection mechanism for confirming the position of the semiconductor wafer 3 in the circumferential direction. That is, in FIGS. 3 and 4, the reference numeral 33 is a swing arm. The swing arm 33 is
It is supported by the machine stand 11b so as to be rotatable in the front and back directions with its longitudinal direction facing up and down, and a tentacle 34 that projects downward is fixed to the lower end thereof. On the other hand, the support 28 has a sensor 3 with its tip facing the swing arm 33 side.
5 are arranged. The sensor 35 measures the distance from its tip surface to the side surface of the swing arm 33.

When the flat part 8 of the semiconductor wafer 3 comes into contact with the tip of the tentacle 34 and the tentacle 34 moves toward the fixed roller 29, the swinging arm 33 rotates toward the sensor 35, thereby causing the semiconductor wafer to It is now possible to check whether the flat portion 8 of No. 3 has come into contact with the fixed rollers 29, 29.

In addition, what is indicated by the reference numeral 36 in the figure is a feeder,
The semiconductor wafer positioned by the wafer positioning device configured as described above is fixed to the surface of the semiconductor wafer by vacuum suction, and can be transported to a subsequent process.

Next, the operation of positioning the semiconductor wafer 3 using the wafer positioning apparatus having the above configuration will be described. First, the clamp rollers 26, 26 are moved back to leave the side clamp rollers 15, 15 open, and the semiconductor wafer 3, which has been roughly positioned in advance, is positioned so that its flat part 8 is in the direction of the number mrRffJ of the fixed rollers 29, 29. Place it on the feeder 36 so that it does. Next, the clamp roller 26
- 26 is advanced and the vicinity of the flat portion 8 of the semiconductor wafer 3 is gripped. Next, the clamp rollers 26, 26 are moved back,
Pull the flat portion 8 toward the fixed rollers 29. Then, one side of the flat portion 8 comes into contact with one of the fixed rollers 29,
A component force is generated that attempts to rotate the semiconductor wafer 8 toward the other fixed roller 29 using the contact point as a fulcrum, and the semiconductor wafer 8 rotates. Then, the other side of the flat portion 8 comes into contact with the other fixed roller 29, and the position of the semiconductor wafer 3 in the circumferential direction and the rear position in the radial direction are determined.

Next, the clamp rollers 26 and 26 are temporarily released, and the semiconductor wafer 3 is sandwiched from the sides by the side clamp rollers I5 and 15, and the semiconductor wafer 3 is positioned laterally in the radial direction. Next, side clamp roller 15!
5 is opened, and while the semiconductor wafer 3 is being pulled by the clamp rollers 26, 26, the side clamp rollers 15, 15 are closed again, and the semiconductor wafer 3 is finally positioned. At this time, the clamp roller 26
26 moves slightly in the left and right direction as the semiconductor wafer 3 moves.

Next, the semiconductor wafer 3 is finned by vacuum suction.

- After fixing to the feeder 36, open the clamp rollers 26, 26 and side clamp rollers 15, 15, and
6 is moved and the semiconductor wafer 3 is carried out to a subsequent process.

In the above wafer positioning device, the semiconductor wafer 3 is clamped from the left and right by the side clamp rollers 15, so that the semiconductor wafer 3 can be positioned in the radial direction left and right with high accuracy.

Further, the vicinity of the flat portion 8 of the semiconductor wafer 3 is gripped by the clamp rollers 26 and fixed rollers 29 and
29 side, the straight line connecting the point of application of the force acting on the semiconductor wafer 3 and the point of contact (fulcrum) between one side of the flat portion 8 and one of the fixed rollers 29 and the clamp roller 26・The angle formed by the direction of force exerted by 26 is large. As a result, the component force that tries to rotate the semiconductor wafer 3 toward the other fixed roller 29 increases, making it possible to bring both sides of the flat portion 8 into contact with the fixed rollers 29 with a small force and reliably. can. Therefore, high positioning accuracy can be achieved not only in the radial direction of the wafer 3 but also in its circumferential direction without damaging the outer peripheral portion of the semiconductor wafer 3.

Further, in the above embodiment, since a detection mechanism for confirming the position of the semiconductor wafer 3 in the circumferential direction is provided, high reliability regarding the quality of the semiconductor wafer 3 can be obtained.

In the above embodiment, the flat portion 8 is configured to be in contact with the two fixed rollers 29, 29, but the configuration is not limited to this. A stopper or two spaced stoppers may be arranged.

[Effects of the Invention] As explained above, the wafer positioning device of the present invention includes a centering mechanism that moves the wafer in a direction perpendicular to its axis to determine the left and right positions of the wafer in the radial direction, and a centering mechanism that moves the wafer in a direction perpendicular to its axis and a centering mechanism that a circumferential positioning mechanism that determines the position and the radial front and rear positions; It has a structure that includes a clamp arm that pulls it toward the stopper and brings the flat part into contact with the stopper.
The flat part of the semiconductor wafer can be brought into contact with the stopper reliably with a small force. Therefore, not only can positioning in the left and right radial directions be performed with high precision, but also high positioning precision can be obtained in the radial direction forward and backward and circumferential directions without damaging the outer periphery of the semiconductor wafer. is obtained.

[Brief explanation of drawings]

1 to 4 are views showing one embodiment of the present invention, in which FIG. 1 is a plan view showing a wafer positioning device, and FIG. 2 is a plan view showing a wafer positioning device.
Figure 3 is a cross-sectional view taken along the line ■-■ in Figure 1; Figure 4 is a cross-sectional view taken along the line IV--IV in Figure 3. Figures 5 through 8 are 2A and 2B are plan views showing examples of conventional wafer positioning devices, respectively. 3... Semiconductor wafer (wafer), 6...
...Fixed roller (stopper), 8...Flat portion, 9...Centering mechanism, lO...Circumferential positioning mechanism, 25... clamp arm,

Claims (1)

[Claims] A positioning device that positions a circular wafer with a flat portion formed on a part of its side surface, the centering mechanism moving the wafer in a direction perpendicular to its axis to determine the radial left and right positions of the wafer. and a circumferential positioning mechanism that determines the position in the circumferential direction and the front and rear positions in the radial direction of the wafer, and the circumferential positioning mechanism includes a stopper that abuts on at least two locations spaced apart from each other on the flat portion; A wafer positioning device comprising: a clamp arm that grips the vicinity of the flat portion, draws the wafer toward the stopper, and brings the flat portion into contact with the stopper.