JP7148373B2 - Wafer delivery device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer transfer device, and more particularly to a wafer transfer device for holding and conveying a disk-shaped semiconductor wafer and transferring the semiconductor wafer to a predetermined table.

In a semiconductor device manufacturing process, a large number of rectangular areas are defined on the surface of a disk-shaped semiconductor wafer (hereinafter simply referred to as "wafer") by grid-like dividing lines, and ICs and LSIs are formed on the surfaces of these rectangular areas. After forming such electronic circuits, all the lines to be divided are cut (diced) to obtain a large number of semiconductor chips from one wafer. The semiconductor chips thus obtained are packaged by resin sealing and are widely used in various electric and electronic devices such as mobile phones and PCs (personal computers).

Also, a wafer such as a thin silicon wafer sliced from a silicon ingot or the like, for example, is finally commercialized through various processing treatments. In the processing of the wafers, it is common to transfer the wafers to various processing steps in sequence.

2. Description of the Related Art When wafers are sequentially transferred to various processing steps, the wafers are sometimes transferred by transfer means having a vacuum suction type wafer holding mechanism. If the transfer means is of the vacuum suction type, the wafer surface is suctioned. Therefore, during repeated production operations, particles adhere to the suction pad and are transferred to the wafer surface, resulting in quality deterioration.

For this reason, today, when a wafer is loaded/unloaded, an edge clamping method, in which the outer peripheral edge (edge portion) of the wafer is held and transported to prevent contamination of the wafer surface, is often adopted. .

However, in the edge clamp method, since the surface of the wafer is not sucked when the wafer is loaded/unloaded, the position of the wafer is shifted when the wafer is unloaded. For this reason, when the wafer is placed on a suction table, it is difficult to position the wafer in an accurate position, resulting in quality deterioration during wafer processing due to misalignment.

Therefore, a method of using a pin for restraining the lateral movement of the wafer when setting the wafer has been proposed (see, for example, Japanese Unexamined Patent Application Publication No. 2002-100003). In the method described in Patent Document 1, a holding member that protrudes downward from the lower surface of the support plate to support the outer peripheral edge of the wafer and spacer pins that keep the support plate horizontal during transfer are positioned on the outer peripheral surface of the wafer. , and three of each are provided at approximately equal intervals.

Japanese Patent No. 5137747

The method using pins for holding the wafer described in Patent Document 1 has the following problems (1) to (3).
(1) Although the lateral movement of the wafer can be restrained to some extent, more accurate positioning transfer cannot be performed.
(2) If the inner diameter of the spacer pins enclosing the wafer is set to the very limit of the outer diameter of the wafer in order to ensure positioning accuracy, the risk of the spacer pins coming into contact with the wafer during the clamping operation increases.
(3) In addition, if the suction porous portion on the chuck table side is made small in order to avoid a vacuum drop due to the positional displacement of the wafer on the chuck table side, fluttering of the outer diameter of the wafer and sludge water during processing may be generated inside the chuck table. easier to get into. As a result, the wear of the rotary joint elements that electrically and mechanically connect the chuck table and the outside becomes severe.

Also, in the case of the edge clamp method, there is a tendency to avoid pressing the edge portion as much as possible, and it is desired that other members do not come into contact with the wafer as much as possible during transfer.

Therefore, there arises a technical problem to be solved in order to provide a wafer transfer device that can transfer a wafer to a predetermined table with high accuracy without shifting the position of the wafer. An object of the present invention is to solve this problem.

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object, and a first aspect of the present invention is a wafer transfer apparatus for holding and transferring a wafer and transferring the wafer to a predetermined table. a holding means having claws for holding the wafer by bringing the outer peripheral edge of the wafer into contact therewith, and releasing the wafer onto the table when the wafer is transported to a predetermined position above the table; and, when the holding means holds the wafer, it is arranged at a position not contacting the wafer, and when the wafer is released from the holding means, the wafer is moved to a position substantially perpendicular to the table, and the and wafer guide means having guide surfaces for guiding wafer delivery.

According to this configuration, when the wafer held by the holding means is transported to a predetermined position above the predetermined table, the guide surface of the wafer guide means is positioned substantially perpendicular to the table. . Then, the wafer released from the holding means is guided by the guide surface of the wafer guide means so as to fall vertically onto the table, and the wafer is guided by the guide surface to a predetermined position on the table. Positioned and placed.

In addition, since an edge clamping method is employed in which the outer peripheral edge (edge portion) of the wafer is held and transferred, contact with the wafer surface can be eliminated when the wafer is loaded/unloaded. As a result, the wafer surface can be prevented from being contaminated and the quality of the wafer can be prevented from deteriorating.

Further, the guide surface of the wafer guide means is arranged at a position that does not contact the wafer when the holding means holds the wafer, and moves to a position perpendicular to the table when the wafer is released from the holding means. , guide the delivery of the wafer, so that the contact between the guide surface of the wafer guide means and the wafer can be minimized. Therefore, contamination of the wafer due to contact between the guide surface and the wafer can be suppressed, and deterioration of the quality of the wafer can be further prevented.

According to a second aspect of the invention, in the configuration according to the first aspect, the wafer guide means has the guide surface and is configured to be rotatable in a substantially vertical direction with respect to the table, a rotating member capable of switching between a wafer guide position in which the guide surface is substantially perpendicular to the table and a retracted position in which the guide surface does not contact the outer peripheral side surface of the wafer; and a stopper for restricting the rotation of the rotating member, which is biased to rotate by the biasing means, at the retracted position. The rotating member is disposed at a position capable of coming into contact with a member, and the rotating member rotates from the retracted position to the wafer guide position against the biasing force of the biasing means in accordance with the amount of contact with the table. A wafer transfer apparatus is provided.

According to this configuration, the guide surface is provided on the rotating member. The rotatable member provided with the guide surface is arranged at a retracted position where it does not come into contact with the wafer when the holding means holds the wafer. Upon contact, the rotating member is rotated from the retracted position toward the wafer guide position according to the contact amount of the rotating member with the table and against the biasing force of the biasing means. When the wafer reaches a predetermined position above the table, the rotating member is moved to the wafer guide position where the guide surface is substantially perpendicular to the table. Further, when the wafer is released from the holding means in this state, the released wafer is guided by the guide surface and falls substantially vertically, and is placed at a predetermined position on the table. As a result, the wafer can be accurately positioned and placed at a predetermined position on the table.

A third aspect of the present invention provides the wafer transfer apparatus according to the first or second aspect, wherein three or more wafer guide means are provided at approximately equal intervals.

According to this configuration, since three or more wafer guide means are provided at approximately equal intervals, the wafer can be guided stably and accurately positioned.

The invention according to claim 4 is the structure according to claim 1, 2 or 3, characterized in that the wafer guide means is made of a resin material. wafer delivery device.

According to this configuration, since the wafer guide means is made of a resin material, damage to the wafer when it comes into contact with the wafer can be suppressed. It should be noted that if a resin material having wear resistance, water resistance, and high strength is used, the durability and the like can be improved.

According to a fifth aspect of the present invention, in the configuration according to the first, second, third or fourth aspect, the wafer guide means is formed continuously with the guide surface, and guides the released wafer to the guide surface side. To provide a wafer transfer device having a guide surface for guiding toward.

According to this configuration, even if there is a slight deviation in the position between the guide surface of the wafer guide means and the released wafer, the released wafer is received by the guide surface and guided to the guide surface. , is dropped almost vertically onto the table. As a result, even if the dimensional accuracy of the wafer guide means is somewhat rough, the wafer can be reliably guided, and the cost can be reduced.

According to a sixth aspect of the present invention, in the configuration of the first, second, third, fourth or fifth aspect, when the wafer guide means tilts and abuts against the table, the wafer guide means is held substantially horizontally. Provided is a wafer transfer apparatus having an attitude control adjustment mechanism for controlling attitude.

According to this configuration, when there is variation in the inclination of the guide surface with respect to the table (perpendicularity with respect to the table) among the wafer guide means, the attitude control adjustment mechanism adjusts the guide surface simultaneously with the inclination of each wafer guide means. Tilt can be adjusted. By adjusting all the guide surfaces so that they are perpendicular to the table, delivery accuracy can be improved.

According to the invention, the wafer released from the holding means is guided by the guide surface of the wafer guide means so as to fall substantially vertically onto the predetermined table, thereby accurately positioning the wafer at a predetermined position on the table. can be placed This improves the delivery accuracy of the wafer and contributes to the improvement of processing accuracy.

1 is a cross-sectional side view schematically showing part of a wafer transfer device according to one embodiment of the present invention; FIG. FIG. 4A is a partial cross-sectional side view schematically showing the process of receiving a wafer from a predetermined chuck table in a previous process, in which (a) shows a wafer transfer mechanism arranged on a predetermined chuck table in a previous process and a wafer FIG. 4B is a diagram showing a state in which the conveying mechanism is lowered to a position where the claw portion faces a predetermined side surface of the chuck table in the previous process, and FIG. Fig. (c) A state in which the arm portion is moved inward and the claw portion enters below the outer circumference of the wafer during vacuum operation, (d) A state in which the wafer is placed on the chuck table during blow operation. (e) is a diagram showing a state in which the claw catches the wafer and rises, and the wafer is started to be conveyed to a post-process. FIG. 4A is a partial cross-sectional side view schematically showing the process of transferring a wafer to a predetermined chuck table in a post-process, FIG. (b) is a diagram showing a state in which the wafer transport mechanism is moved upward and then lowered to a position where the wafer faces the chuck table of the chuck table in the post-process. The wafer transfer mechanism is further lowered, and the rotating member is in contact with the upper surface of the chuck table in the post-process. A diagram showing a state in which the wafer is placed at the wafer guide position, (d) shows that the chuck table in the post-process is in vacuum operation, the claw portion is moved outward, the claw portion releases the wafer, and the wafer is on the chuck table. (e) is a diagram showing a state in which the chuck table in the post-process is in vacuum operation and the wafer transfer mechanism is lifted away from the chuck table in the post-process. It is the perspective view which looked at the wafer conveyance mechanism from the upper surface side. It is the top view which looked at the wafer conveyance mechanism from the upper surface side. FIG. 6 is a partially enlarged cross-sectional side view of the wafer guide means viewed along line CC of FIG. 5; FIG. 6 is a partially enlarged cross-sectional side view of the pawl viewed along line DD in FIG. 5; 8 is an enlarged perspective view showing a partial configuration of FIG. 7; FIG. FIG. 4 is a cross-sectional side view schematically showing the schematic structure of the balancer mechanism, where (a) is a diagram showing a state in which the wafer transfer mechanism is not leveled with respect to the chuck table, and (b) is a chuck table of the wafer transfer mechanism; is adjusted by the balancer mechanism.

SUMMARY OF THE INVENTION In order to achieve the object of the present invention, which is to provide a wafer transfer apparatus capable of accurately transferring a wafer to a predetermined table without shifting the position of the wafer, the wafer is held and transferred. and a wafer transfer device for transferring the wafer to a predetermined table, wherein the outer peripheral edge of the wafer is held in contact with the table, and when the wafer is transferred to a predetermined position above the table, a holding means having claws for releasing the wafer onto the table; and a holding means arranged at a position not contacting the wafer when the holding means holds the wafer, so that the wafer is released from the holding means. wafer guide means having a guide surface for guiding the transfer of the wafer by moving to a position substantially perpendicular to the table when the wafer is transferred.

An example according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the following examples, when referring to the number, numerical value, amount, range, etc. of constituent elements, unless otherwise specified or clearly limited to a specific number in principle, the specific number It is not limited, and may be more than or less than a specific number.

In addition, when referring to the shape or positional relationship of components, etc., unless otherwise specified or in principle clearly considered otherwise, etc. include.

In addition, the drawings may exaggerate characteristic parts by enlarging them in order to make the characteristics easier to understand. In addition, in cross-sectional views, hatching of some components may be omitted in order to facilitate understanding of the cross-sectional structure of the components.

Further, in the following description, expressions indicating directions such as up and down, left and right, etc. are not absolute, and are appropriate when each part of the wafer transfer apparatus of the present invention is depicted in the posture. If there is a change in the position, it should be interpreted according to the change in posture. Also, the same reference numerals are given to the same elements throughout the description of the embodiments.

1 to 3 are diagrams schematically showing an example of a wafer transfer device 10 according to one embodiment of the present invention, and FIG. 1 is a cross-sectional side view schematically showing a part of the wafer transfer device 10. FIG. 2 is a partial cross-sectional side view showing the process of receiving the wafer W from the predetermined chuck table A11 in the previous process, and FIG. 3 is a partial cross-sectional side view showing the process of transferring the wafer W to the predetermined chuck table B11 in the subsequent process. It is a diagram.

1 to 3, the wafer transfer device 10 transfers the wafer W placed on the chuck table A11 arranged in the pre-process shown in FIG. 2 to the chuck table arranged in the post-process shown in FIG. A wafer transport mechanism 12 for transporting the wafer W is provided for transporting the wafer W above the B11 and placing the transported wafer W on a predetermined chuck table B11.

The chuck table A11 and the chuck table B11 have a suction portion 14 formed of a porous material fitted to the upper surface 13a of the frame 13. When vacuum operation is performed, air is sucked from the upper side of the suction portion 14, and suction is performed. A horizontal upper surface (mounting surface) 14a of the portion 14 can absorb and hold the wafer W. As shown in FIG. Contrary to the vacuum operation, the suction unit 14 is supplied with air from the lower side (inside), and blows the air upward to separate the wafer W from the upper surface 14 a of the suction unit 14 . Driving is also possible.

Further, the outer diameter D2 of the suction portion 14 of the chuck table A11 is formed smaller than the outer diameter of the wafer W as shown in FIG. 2(a). On the chuck table B11 side, on the other hand, as shown in FIG. formed.

The detailed configuration of the wafer transfer mechanism 12 is shown in FIGS. 4 to 7. FIG. 4 is a perspective view of the wafer transfer mechanism 12 viewed from above, FIG. 5 is a plan view of the wafer transfer mechanism 12 similarly viewed from above, and FIG. 6 is a view taken along line CC of FIG. FIG. 7 is a partially enlarged cross-sectional side view of the wafer guide means, FIG. 7 is a partially enlarged cross-sectional side view of the claw portion as seen along line DD in FIG. 5, and FIG. 8 is an enlarged partial configuration of FIG. It is a perspective view.

4 to 8 are added to FIGS. 1 to 3 to further describe the configuration of the wafer transfer mechanism 12. FIG. As shown in detail in FIGS. 4 and 5, the wafer transfer mechanism 12 includes a main body 16, holding means 17 and wafer guide means 18 attached to the main body 16, and wafer detection means 19. there is

The main body 16 is attached to a robot arm (not shown) via a pivot 15 . Between the main body 16 and the pivot 15, a balance mechanism (not shown) is provided as an attitude control mechanism for controlling the attitude of the wafer guide means 18 substantially horizontally by tilting the main body 16 in the vertical direction with respect to the pivot 15. A child mechanism (also called a “gimbal mechanism”) 30 is provided. As shown in FIG. 9, the balancer mechanism 30 is arranged in a state in which the attitude (parallelism) level of the main body 16 with respect to the upper surface 13a of the chuck table B11 is not matched, for example, as shown in FIG. When the wafer transfer mechanism 12 is lowered and the lower surface of the wafer guide means 18 (the lower surface 18g of a stopper, which will be described later) is brought into contact with the upper surface 13a of the chuck table B11, the main body 16 is vertically moved around the pivot 15 as a fulcrum. By freely swinging, the parallelism between the body portion 16 and the upper surface 13a of the chuck table B11 is automatically obtained as shown in FIG.

As shown in FIGS. 4 and 5, the holding means 17 is a pair of arms that are horizontally movably attached to the main body 16 while extending in two directions from the outer peripheral side surface of the main body 16. 17a and 17b. The pair of arm portions 17a and 17b are slidable in the Xa-Xb direction (the inner Xa direction and the outer Xb direction) in FIG. . The switching by the cylinder can be alternatively switched between two movements: a release movement in which the pair of arm portions 17a and 17b move in the outward Xb direction, and a clamping movement in which the pair of arm portions 17a and 17b move in the inward Xa direction.

Further, the distal ends of the respective arm portions 17a and 17b are branched into two arms 17a1, 17a2, 17b1 and 17b2. A claw portion 20 is attached so as to protrude substantially vertically toward the side.

As shown in FIG. 6, each claw portion 20 has an engaging claw 21 protruding toward the main body portion 16 on the side facing the outer peripheral surface of the wafer W. As shown in FIG. The locking claw 21 has a lower surface 21a side formed by a flat surface substantially parallel to the lower surfaces of the arms 17a1 and 17b1, and an upper surface side formed by a tapered surface 21b that slopes upward from the tip toward the root side.

By sliding the arm portions 17a and 17b in the Xa-Xb direction by means of cylinders, the claw portions 20 move from the outside to the inside of the arrangement area S of the wafer W, as shown in FIG. and a release position 23 (position indicated by a solid line in FIG. 6) where the locking claw 21 has moved from the inner side (clamping position 22) of the arrangement region S of the wafer W to the outer region (the position indicated by the solid line in FIG. 6). 6) and the position indicated by the one-dot chain line).

In addition, when the locking claw 21 is moved to the clamping position 22, the vertical inner surface 21c of the claw portion 20 is arranged outside the arrangement area S of the wafer W, and the outer periphery of the wafer W arranged in the arrangement area S It is adjusted so that a gap m is formed between the side surfaces. This is because, as shown in FIG. 6, when the wafer W is clamped by the locking claws 21 and transferred, the substantially right-angled lower outer peripheral edge of the wafer W is in substantially linear contact with the tapered surface 21b. This is to prevent the wafer W from becoming dirty by minimizing the contact between the wafer W and the claw portion 20 . In this embodiment, for example, when the outer diameter WD of the wafer W is 300 mm, the outer diameter of the inner region surrounded by the vertical inner surfaces 21c of the four claw portions 20 is adjusted and set to 302 mm.

The position of the lower surface 21a (see FIG. 6) of the locking claw 21 is higher than the lower surface 18g of the stopper 18f provided on the mounting bracket 18b of the wafer guide means 18, which will be described later with reference to FIGS. set. Even if the lower surface 18g of the stopper 18f comes into contact with the upper surface 13a of the frame 13 in the chuck table B11 in the post-process, the lower surface 21a of the locking claw 21 does not contact the upper surface 13a of the frame 13. The clamping position 22 and the release position 23 can be switched to eliminate friction between the lower surface 21a of the locking claw 21 and the upper surface 13a of the frame body 13 so that the opening/closing operation of the claw portion 20 is smooth. there is

As shown in FIGS. 4 and 5, the wafer guide means 18 are spaced around the main body 16 at approximately equal intervals around the main body 16 and are arranged so as not to overlap the claws 20 of the wafer transfer mechanism 12. As shown in FIGS. , there are provided three pieces which are shifted by a predetermined angle in the circumferential direction with respect to the claw portion 20 . Each wafer guide means 18 includes an arm portion 18a that extends radially outward from the main body portion 16 and extends substantially horizontally, and as shown in FIG. The mounting bracket 18b is arranged to protrude vertically, and one side surface 18b1 of the left and right side surfaces of the mounting bracket 18b is mounted vertically (perpendicular to the upper surface of the chuck table B11) via the mounting shaft 18c. ), and a coil spring 18e mounted on the mounting shaft 18c and acting as biasing means for biasing the rotating member 18d downward. ing.

Mounting bracket 18b is a block-shaped piece, as shown in detail in FIG. 7 and as shown in perspective in FIG. At the lower end of the mounting bracket 18b, there are formed a turning member housing recess 18h in which the turning member 18d is housed, and a stopper 18p which is inclined on the lower surface side of the turning member housing recess 18h. ing. The stopper 18p abuts against the back surface 18d1 of the rotating member 18d to restrict the amount of downward rotation of the rotating member 18d.

As shown in FIGS. 7 and 8, one end of the rotating member 18d is mounted in the rotating member housing recess 18h by means of a mounting shaft 18c. arranged as possible. A coil spring 18e as a biasing means is attached to the mounting shaft 18c. One coil end of the coil spring 18e is hooked and fixed to the mounting bracket 18b, and the other coil end is hooked and fixed to the rotating member 18d to urge the rotating member 18d to rotate toward the stopper 18p. It is installed in the upright position. As a result, the rotating member 18d is biased by the biasing force of the coil spring 18e in a direction in which the rear surface 18d1 on the other end side of the rotating member 18d comes into contact with the stopper 18p. Therefore, when the rotating member 18d is free, the rotating member 18d is arranged at the retracted position O in contact with the stopper 18p, as indicated by the solid line in FIG. 7(a). In addition, FIG. 8 also shows a state in which it is arranged at the retracted position O. As shown in FIG. Note that the rotating member 18d arranged at the retracted position O rotates upward when the rear surface 18d1 side is pushed upward against the biasing force of the coil spring 18e, and the one-dot chain line in FIG. can move to a wafer guide position G indicated by .

Further, as shown in FIGS. 7 and 8, a guide surface 18d2 and a guide surface 18d3 are formed on the other end side of the rotating member 18d. The guide surface 18d2 is substantially parallel (perpendicular) to the outer peripheral side surface Wa of the wafer W, that is, substantially perpendicular to the upper surface 14a of the chuck table B11 when the rotating member 18d is switched to the wafer guide position G. is formed in On the other hand, the guide surface 18d3 is formed continuously with the upper end side of the guide surface 18d2, and as indicated by the one-dot chain line in FIG. , the guide surface 18d2 is slanted so as to gradually approach one end side (mounting shaft 18c side) of the rotating member 18d as it goes upward from the upper end of the guide surface 18d2. Even if there is some positional deviation in the horizontal direction between the guide surface 18d2 and the outer peripheral side surface Wa of the wafer W, the guide surface 18d3 is inclined so that the wafer W is positioned toward the center. so that the wafer W can be dropped and delivered from the vertical direction at all times. Note that the guide surface 18d3 does not necessarily have to be provided.

In this embodiment, a wafer W having an outer diameter of 300 mm is used. In this case, the outer diameter of the inner region surrounded by the guide surfaces 18d2 of the three rotating members 18d is 300.4 mm. adjusted and set as follows.

Further, the rotating member 18d is made of a resin material so as not to damage the wafer W when it comes into contact with the wafer W. As shown in FIG. The resin material here is preferably a wear-resistant, water-resistant, and high-strength resin.

The wafer detection means 19 is a sensor that detects whether or not the wafer W is present on the predetermined chuck table A11 in the previous process. The sensor used in the wafer detection means 19 is, for example, a capacitance type sensor, a photoelectric sensor, or a photoelectric sensor based on the position of the cylinder.

Next, the wafer W placed on the predetermined chuck table A11 in the pre-process shown in FIG. 2 is transferred above the predetermined chuck table B11 in the post-process shown in FIG. The operation of the wafer transfer apparatus 10 according to the present invention will be described by taking as an example a case where the wafer is placed on the B11 and transferred.

FIG. 2 shows the process of the wafer transfer mechanism 12 receiving the wafer W from the chuck table A11 in the previous process.

As shown in FIG. 2(a), when the wafer W is placed on the chuck table A11 of the preceding process during vacuum operation, the pair of arms 17a and 17b of the wafer transfer mechanism 12 move the cylinders. 5, and the claw portion 20 of the holding means 17 is also positioned outside the wafer placement area S (see FIG. 6), that is, at the release position 23 . Then, in this state, the wafer transfer mechanism 12 is lowered to a predetermined position where the claw portion 20 of the holding means 17 faces the side surface of the chuck table A11. The presence or absence of the wafer W on the chuck table A11 is detected by a pressure state by a pressure sensor (not shown) on the chuck table A11 side and a signal from the wafer detection means 19. FIG. 2(b) and FIG. 7(a). 2, the position is restricted by the stopper 18p and arranged at the retracted position O, as indicated by the solid line.

After the wafer transfer mechanism 12 is lowered to a predetermined position, the pair of arms 17a and 17b are moved inward (Xa direction) shown in FIG. A portion of the locking claw 21 is positioned inside the wafer placement area S, that is, at the clamping position 22, as shown by solid lines in FIGS.

When the claw portion 20 of the holding means 17 is arranged at the clamping position 22, the chuck table A11 is switched to the blowing operation, and as shown in FIG. It is released from the chuck of the chuck table A11.

In addition, as shown in FIG. 2E, the wafer transfer mechanism 12 moves upward with the locking claw 21 of the claw portion 20 catching the wafer W, and moves above the chuck table B11 in the subsequent process. As shown in FIG. 6, the chucking of the wafer W by the locking claws 21 is such that a gap m is formed between the vertical inner surface 21c of the claw portion 20 and the outer peripheral side surface of the wafer W, and the wafer W is held at a substantially right angle. The lower end side of the outer peripheral edge is placed on the tapered surface 21b only by approximately linear contact.

FIG. 3 shows a process in which the wafer transfer mechanism 12 delivers the wafer W to the chuck table B11 in the post-process.

As shown in (a) of FIG. 3, the wafer transfer mechanism 12 that has captured the wafer W and has been moved from the previous process is placed above the chuck table B11 in the subsequent process. In this state, the rotating member 18d of the wafer guide means 18, which is urged to rotate by the coil spring 18e, is positionally regulated by the stopper 18p as shown by solid lines in FIGS. 2(b) and 7(a). and is rotated to the retracted position O.

Then, the wafer transfer mechanism 12 descends. When the wafer transfer mechanism 12 descends to a predetermined position, the rear surface 18d1 of the rotating member 18d of the wafer guide means 18 contacts the upper surface 13a of the frame 13 on the chuck table B11. Further, when the wafer transfer mechanism 12 descends further, the rotating member 18d resists the biasing force of the coil spring 18e and moves by an amount corresponding to the amount of descent of the wafer transfer mechanism 12, indicated by the dashed line in FIG. 7(a). It rotates toward the wafer guide position G shown. When the lower surface 18g of the stopper 18f of the wafer guide means 18 is lowered until it contacts the upper surface 13a of the frame 13, the rotating member 18d reaches the wafer guide position G indicated by the solid line in FIG. 7B. Since the lower surface 21a of the locking claw 21 is set higher than the lower surface 18g of the stopper 18f of the wafer guide means 18, the lower surface 18g of the stopper 18f contacts the upper surface 13a of the frame 13. Also, the lower surface 21a of the locking claw 21 is arranged at the clamping position 22 indicated by the solid line in FIG.

When the wafer transfer mechanism 12 is lowered until the lower surface 18g of the stopper 18f contacts the upper surface 13a of the frame 13 of the chuck table B11, the chuck table B11 is vacuum-operated as shown in FIG. 3(d). Then, the locking claw 21 of the claw portion 20 in the holding means 17 is arranged outside the wafer arrangement area S, that is, at the release position 23 . At the same time, the wafer W released from the locking claws 21 is dropped onto the upper surface 14a of the suction portion 14 of the chuck table 11B that is in vacuum operation and held under vacuum. That is, it is transferred to a predetermined position (the upper surface 14a of the adsorption section 14) of the chuck table 11B.

Since the lower surface 21a of the locking claw 21 and the upper surface 13a of the frame 13 are not in contact with each other, frictional resistance is generated between the lower surface 21a and the upper surface 13a. It opens smoothly. Further, since the guide surface 18d2 of the rotating member 48d is arranged at substantially equal intervals on the outer periphery of the arrangement area S of the wafer W, the wafer W released from the locking claw 21 is guided by the guide surface 18d2. It is guided and falls vertically, and is held by suction on the upper surface 14a of the suction portion 14 of the chuck table B11. If the released wafer W is slightly displaced, it abuts against the guide surface 18d3, is guided by the guide surface 18d3 toward the guide surface 18d2, passes through the guide surface 18d2, and reaches the upper surface 14a of the suction unit 14. Fall.

After the wafer W is released, the wafer transfer mechanism 12 starts to rise and returns to a predetermined position as shown in FIG. 3(e). Further, when the wafer transfer mechanism 12 rises, the lower surface 18g of the stopper 18f of the wafer guide means 18 separates from the upper surface 13a of the frame 13 as it rises. At the same time, the rotating member 18d starts rotating toward the retracted position O indicated by solid lines in FIGS. 2(b) and 7(a) by the spring force of the coil spring 18e. When the rear surface 18d1 of the rotating member 18d hits the stopper 18p, the rotating member 18d is rotated back to the retracted position O, which is indicated by the solid line in FIG. This operation is repeated.

Therefore, according to the wafer transfer apparatus 10 described in this embodiment, the wafer W held by the holding means 17 is placed at a predetermined position above the chuck table B11 (at the upper surface 13a of the frame 13 and the stopper of the rotating member 18d). 18f abutted), the guide surface 18d2 of the wafer guide means 18 is placed at a position substantially parallel to the outer peripheral side surface of the wafer W, that is, at a wafer guide position substantially perpendicular to the chuck table B11. be done. Then, the wafer W released from the holding means 17 is guided by the guide surface 18d2 of the wafer guide means 18 so as to fall vertically onto a predetermined chuck table B11. As a result, the wafer W can be accurately positioned and disposed on the predetermined position of the chuck table B11, that is, on the upper surface 14a of the suction unit 14, thereby improving the transfer accuracy of the wafer W and contributing to the improvement of processing accuracy. do.

In addition, since an edge clamping method is employed in which the outer peripheral edge (edge portion) of the wafer W is held and conveyed, contact of the claw portion 20 with the wafer surface is eliminated when the wafer W is loaded/unloaded. This can prevent contamination on the wafer surface and prevent deterioration of quality.

In the above-described embodiment, the locking claw 21 of the claw portion 20 in the holding means 17 is structured to open and close by linearly moving the pair of arm portions 17a and 17b in the Xa-Xb direction in FIG. disclosed, the opening and closing action may be pivotal.

In addition, the present invention can be modified in various ways without departing from the spirit of the invention, and the present invention naturally extends to such modifications.

10 Wafer transfer device A11 Pre-process chuck table B11 Post-process chuck table 12 Wafer transfer mechanism 13 Frame 13a Upper surface 14 Adsorption unit 14a Upper surface (mounting surface)
15 pivot 16 main body 17 holding means 17a, 17b arm 18 wafer guide means 18a arm 18b mounting bracket 18b1 side surface 18c mounting shaft 18d rotating member 18d1 rear surface 18d2 guide surface 18d3 guide surface 18e coil spring (biasing means)
18f Stopper 18g Lower surface of stopper 18h Rotating member storage recess 18p Stopper 19 Wafer detection means 20 Claw portion 21 Locking claw 21a Lower surface 21b Tapered surface 21c Vertical inner surface 22 Clamp position 23 Release position 30 Balance mechanism (attitude control mechanism)
D1 Outer diameter of frame
D2 Outer diameter O of suction unit Retreat position G Wafer guide position S Wafer placement area m Gap W Wafer Wa Outer peripheral side surface WD of wafer Outer diameter Xa-Xb of wafer Movement direction of pair of arm portions

Claims (6)

A wafer transfer device for holding and transferring a wafer and transferring the wafer to a predetermined table,
holding means having claws for holding an outer peripheral edge of the wafer in contact with the wafer and releasing the wafer onto the table when the wafer is transported to a predetermined position above the table;
When the holding means holds the wafer, it is arranged at a position where it does not come into contact with the wafer, and when the wafer is released from the holding means, it rotates to a position substantially perpendicular to the table, and the wafer guide means having a guide surface for guiding the transfer of the wafer;
A wafer transfer device comprising: The wafer guide means
a wafer guide position having the guide surface and being rotatable in a substantially vertical direction with respect to the table, and a wafer guide position where the guide surface is substantially vertical to the table; a retracted position that does not contact the rotating member that can be switched to;
biasing means for biasing the rotating member toward the retracted position;
a stopper that restricts rotation of the rotating member that is biased to rotate by the biasing means at the retracted position;
with
the table is disposed at a position capable of coming into contact with the rotating member;
2. The apparatus according to claim 1, wherein said rotating member is rotated from said retracted position to said wafer guide position against the biasing force of said biasing means according to the amount of contact with said table. Wafer transfer apparatus as described. 3. The wafer transfer device according to claim 1, wherein three or more of said wafer guide means are provided at approximately equal intervals. 4. A wafer transfer apparatus according to claim 1, wherein said wafer guide means is made of a resin material. 2, wherein said wafer guide means has a guide surface formed continuously with said guide surface for guiding said released wafer toward said guide surface. 5. The wafer transfer device according to 3 or 4. 6. An apparatus according to claim 1, further comprising an attitude control mechanism for controlling the attitude of the wafer guide means to be substantially horizontal when the wafer guide means inclines and abuts against the table. The wafer transfer device according to 1.

Images