JP2006313865A - Substrate holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate holder preventing a substrate mount position from shifting when holding a substrate, improving processing accuracy of the substrate, also improving processing speed by simultaneously carrying a plurality of substrates while preventing a shift in the mount position, improving the processing accuracy, and preventing contamination by particles or the like by holding an edge or its vicinity of the substrate. <P>SOLUTION: The substrate holder includes claws 21A-21C provided on each of five end effectors 21 for holding an edge of the substrate P by reciprocating to come into contact with and farther away from the edge of the substrate P, steel tapes 221A-221C having one end connected respectively to the claws 21A-21C and the other end connected respectively to supports 222A-222C, and driving cylinders 224A and 224C for reciprocating the supports 222A-222C. The driving cylinders 224A and 224C are driven to reciprocate the steel tapes 221A-221C, thereby synchronously reciprocating the claws 21A-21C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate holding apparatus that holds a circular thin substrate such as a silicon wafer.

  A circular thin substrate (hereinafter simply referred to as a substrate) such as a silicon wafer used for manufacturing a semiconductor is taken out from a cassette case in which a plurality of substrates are stored by a robot arm and transported to a predetermined place.

At this time, the substrate is transported in a state where the edge is gripped by a plurality of claws provided in the robot arm. The gripping of the edge of the substrate is performed by the whole of the plurality of claws as one of the plurality of claws moves in a direction from the edge of the substrate toward the central axis and comes into contact with the edge of the substrate (for example, , See Patent Document 1). In the configuration of Patent Document 1, the piston rod that constitutes one of the plurality of claw portions moves to contact the edge of the substrate.
US Pat. No. 6,618,645

  However, in the configuration of Patent Document 1 described above, when the substrate is gripped, only a single claw portion of the plurality of claw portions is moved to come into contact with the substrate. The position has shifted. Conventionally, this displacement of the mounting position has not been a problem because it is within the error range. However, in recent years, since the accuracy of the mounting position has been demanded from the viewpoint of improving the processing accuracy for the substrate, this nail The displacement of the mounting position due to the contact of the parts is a problem.

  The object of the present invention is to prevent the placement position of the substrate from shifting during gripping, to improve the processing accuracy for the substrate, while preventing the displacement of the placement position and improving the processing accuracy, It is an object of the present invention to provide a substrate gripping device that can simultaneously transport a plurality of substrates and improve the processing speed, and can grip the edge portion of the substrate or the vicinity of the edge portion to prevent contamination by particles or the like.

(1) a substrate holding portion having three or more claw portions for gripping the edge of the substrate;
And a moving means for reciprocally moving each of the three or more claw portions in a moving direction from the edge of the substrate toward the center portion.

  In this configuration, when gripping and releasing the substrate, the three or more claw portions provided in the substrate holding portion reciprocate in the movement direction in synchronization. Therefore, three or more claw portions simultaneously contact and separate from the edge of the substrate.

  (2) The substrate holding portion includes three or more convex portions that support the back surface of the substrate facing the substrate holding portion on an apex portion or an inclined surface closer to the center portion of the substrate than the apex portion. It is characterized by.

  In this configuration, the apex portions of the three or more convex portions provided in the substrate holding portion or the inclined surface closer to the center portion of the substrate than the apex portions support the back surface of the substrate. Therefore, when supporting the back surface of the substrate at the apex portion, there is a force that the substrate is pulled in the direction in which each nail portion is separated from the edge of the substrate due to friction at the contact point with each nail portion when releasing the gripping state. Although generated, a frictional force is generated at the contact point with the three or more convex portions, so that the placement position of the substrate is prevented from being moved by the pulled force.

  On the other hand, when the inclined surface closer to the center portion of the substrate than the vertex portion supports the back surface of the substrate, the back surface of the edge portion of the substrate is supported, and the vertex portion is open without facing the back surface of the substrate. Therefore, the height position is higher than the back surface of the substrate. Therefore, even if the substrate is pulled in a direction in which each claw portion is separated from the edge of the substrate, the movement of the substrate in the separating direction is restricted by the apex portion of each convex portion. Is prevented.

  Furthermore, in any case, since the convex portion makes point contact or line contact with the back surface of the substrate, the contact area with the back surface of the substrate can be minimized. Therefore, contamination due to transfer of contaminants such as particles adhering to the convex portion to the back surface of the substrate is minimized.

(3) having a plurality of the substrate holding portions each holding a single substrate;
The plurality of substrate holders are supported so that the central axes of the plurality of gripped substrates are coaxially positioned, and the intervals in the central axis direction between the plurality of substrates are all the same. A pitch conversion mechanism, wherein each of the plurality of substrate holders is moved in the direction of the central axis to change the interval; and
And a reversing mechanism for rotating the pitch conversion mechanism around an axis orthogonal to the central axis and stopping at a predetermined angular position.

  In this configuration, the plurality of substrates are supported by the pitch conversion mechanism unit via the plurality of substrate holding units so that the central axes are coaxially positioned and the distance between them in the central axis direction is the same. . In addition, the plurality of substrate holders move in the direction of the central axis by driving the pitch conversion mechanism, and the interval changes. Further, the pitch conversion mechanism rotates to rotate the plurality of substrates around an axis orthogonal to the central axis.

  Thereby, the angle of the direction orthogonal to the center axis | shaft of a board | substrate is arrange | positioned in a mutually different angle position, and a board | substrate is transferred between cassette cases from which the arrangement | positioning space | interval of a board | substrate differs. Therefore, a plurality of processes are performed on the substrate, such as changing the interval and transferring, while preventing the displacement of the substrate placement position. In addition, since a plurality of substrates are held at a time, the substrate transport speed is improved.

  (4) Three or more guides for restricting movement of each of the three or more claw portions in the plurality of substrate holding portions in the central axis direction are provided.

  In this configuration, the movement of the three or more claw portions in the central axis direction of the substrate is regulated by the three or more guides. Therefore, when the substrate holding part is rotated by driving the reversing mechanism part, it is possible to prevent the claw parts from dropping off due to their own weight, the displacement of the arrangement position, and the like.

  (5) The moving means is connected to each of three or more tension members connected at one end to the three or more claw portions in the plurality of substrate holding portions and the other end of the three or more tension members. Driving means for reciprocating the three or more tension members in the moving direction.

  In this configuration, one end of each of the three or more tension members is connected to three or more claw portions of the plurality of substrate holding portions, and the other end is connected to the driving means. By driving the driving means, the tension member reciprocates and the claw portion reciprocates in the moving direction. Therefore, since the tension member is used, the three or more claw portions provided in the plurality of substrate holding portions are reciprocally moved synchronously by driving of a single driving means.

  (6) Each of the three or more tension members includes an elastic portion in part or in whole.

  In this configuration, an elastic portion is provided in a part or all of each of the three or more tension members. Further, when changing the interval in the central axis direction of the plurality of substrates, the plurality of substrate holding portions are moved in the central axis direction of the substrate, but one end and the other end of the tensile member are fixed. The one end of the tension member moves in the direction of the central axis, and the distance between the one end and the other end of the tension member changes. When this distance is shortened, the tension member bends. However, since part or all of the tension member has an elastic portion, this bend is absorbed.

  (7) Each of the three or more tension members is characterized in that the other end is located in the middle of a reciprocating range of the one end in the central axis direction.

  In this configuration, each of the other ends of the tension member is located in the middle of the reciprocation range in the central axis direction of the substrate at each end of the tension member. The amount of change in the distance between the one end and the other end of the tension member due to the movement of the one end of the tension member in the central axis direction of the substrate is minimized.

  (1) Since the three or more claw portions provided in the substrate holding portion are synchronously reciprocated in the movement direction, the edge of the substrate of the three or more claw portions can be brought into contact with and separated from each other at the same time. In addition, it is possible to prevent the mounting position of the substrate from shifting when the claw portion is in contact, and to improve the processing accuracy for the substrate.

  (2) When the substrate held by the substrate holding part is released by bringing the apex portion of the three or more convex portions provided in the substrate holding portion or a portion other than the apex portion into contact with the back surface of the substrate, Deviation can be prevented, and the processing accuracy for the substrate can be improved.

  In addition, since the convex portion is in point contact or line contact with the back surface of the substrate, the contact area with the back surface of the substrate can be minimized and the contaminants such as particles adhering to the convex portion can be transferred to the back surface of the substrate. Contamination due to the transfer of can be minimized.

  (3) By providing the plurality of substrate holding units, the pitch changing mechanism unit, and the reversing mechanism unit, it is possible to accurately perform a plurality of processes on the substrate while preventing the substrate mounting position from being shifted. In addition, since a plurality of substrates can be held at a time, the substrate transport speed can be improved.

  (4) By restricting the movement of the three or more claw portions in the central axis direction of the substrate by three or more guides, each claw portion is dropped and arranged when the substrate holding portion is rotated by driving the reversing mechanism portion. Since it is possible to prevent the occurrence of a positional shift or the like, it is possible to maintain a gripping force with respect to the substrate. Thereby, even if it is the structure which rotates a board | substrate, it can continue holding | grip a board | substrate.

  (5) By connecting one end of each of the three or more tension members to three or more claw portions of the plurality of substrate holding portions and connecting the other end to the driving means, the plurality of substrate holding portions can be obtained by a single driving means. The substrates can be gripped in synchronization with each other. Thereby, space saving can be achieved.

  (6) Since some or all of the three or more tension members are provided with an elastic portion, it is possible to absorb the bending of the tension member that occurs when changing the interval between the plurality of substrates, so that the holding force to the substrate is constant. It is possible to prevent the substrate mounting position from shifting.

  (7) The amount of change in the distance between the positions of one end of the tension member and the other end by disposing each of the other ends of the tension member in the middle of the movement range in the central axis direction of the substrate at each end of the tension member Therefore, the holding force of the substrate can be kept constant.

  FIG. 1 is a perspective view showing a partial configuration of a robot arm according to an embodiment of the present invention. The robot arm 1 which is a substrate holding apparatus of the present invention conveys a substrate stored in one cassette case with the same interval to the other cassette case having a different interval from one cassette case, or a substrate In such a state that it is reversed, it is transported to the other cassette case. The robot arm 1 includes a hand edge clip finger part 2, a pitch conversion mechanism part 3, a reversing mechanism part 4 and the like.

  As shown in FIGS. 1 and 2, the hand edge clip finger portion 2 is composed of five end effectors 21, moving means 22 and the like, and can simultaneously hold five substrates P. The end effector 21 which is a substrate holding part of the present invention has three claw parts 21A to 21C, and one end is supported by the pitch conversion mechanism part 3 via an end effector mounting plate.

  Each of the claw portions 21A to 21C can reciprocate in the direction of the arrow shown in FIG. 2 from the edge of the substrate P toward the center, and the substrate P placed on the end effector 21 by movement as shown in FIG. To hold the substrate P as a whole. Each of the claw portions 21A to 21C is guided by guides 23A to 23C and reciprocates in the moving direction as shown in FIG. The guides 23A to 23C also restrict movement of the three claw portions 21A to 21C in the direction of the central axis of the substrate P.

  As shown in FIG. 2, the moving means 22 includes steel tapes 221A to 221C, support members 222A to 222C, guides 223A to 223C, drive cylinders 224A and 224C, a connecting member 225, and the like located in the pitch conversion mechanism section 3. Then, the claw portions 21A to 21C are reciprocated in the moving direction.

  The steel tape 221 which is a tension member of the present invention is provided in each of the five end effectors 21 by the number of the claw portions 21A to 21C of each end effector 21, and one end of each is connected to the claw portions 21A to 21C. The other end is connected to the support members 222A to 222C. The steel tape 221 is reciprocated by the reciprocating movement of the support members 222A to 222C to reciprocate the claw portions 21A to 21C.

  The support members 222A to 222C are supported by the movement guides 223A to 223C so as to be reciprocally movable in the movement directions of the claw portions 21A to 21C. The support members 222A and 222B are connected to the drive cylinder 224A via the connecting member 225, and reciprocate by the drive of the drive cylinder 224A. Further, the support member 222C is connected to the drive cylinder 224C, and reciprocates as the drive cylinder 224C is driven. The drive cylinders 224A and 224C are driven by pneumatic pressure.

  Each of the end effectors 21 includes convex portions 226A to 226C as shown in FIG. The convex portions 226A to 226C are located on the moving direction of the claw portions 21A to 21C, and support the back surface of the substrate P with an inclined surface that is not the apex portion. Further, the convex portions 226A to 226C prevent the placement position of the substrate P from shifting when the claw portions 21A to 21C are separated from the edge of the substrate P.

  For example, in the cassette case, in order to grip and take out a plurality of substrates P stored at a predetermined interval in the central axis direction in a state where two points of the edge are supported by the support portion, first, the end effector 21 is taken out. The hand edge clip finger portion 2 is moved into the cassette case so that each of the two is positioned below the five substrates P to be taken out. Next, the hand edge clip finger part 2 is raised to a position where the end effector 21 supports each substrate P.

  Thereafter, the drive cylinders 224A and 224C are driven to move the claw portions 21A to 21C to a position where they are in contact with the edge of the substrate P in synchronization. Thereby, the five board | substrates P can be hold | gripped. Next, the five board | substrates P can be taken out by moving the edge clip finger part 2 to the exterior from the inside of a cassette case.

  On the other hand, in order to store the extracted five substrates P in another cassette case, first, the edge clip finger portion is arranged so that each substrate P is positioned above the arrangement position of the support portion to be placed in the cassette case. 2 is moved into the cassette case.

  Next, the drive cylinders 224 </ b> A and 224 </ b> C are driven, and the claw portions 21 </ b> A to 21 </ b> C are synchronously separated from the edge of the substrate P. At this time, a force that is pulled in the moving direction of the claw portions 21A to 21C (a direction away from the edge of the substrate P) due to friction at the contact portions with the claw portions 21A to 21C is generated on the substrate P. Due to the relationship of the moving directions of 21A to 21C, a force is generated that pulls the substrate P in the direction from the pitch conversion mechanism 3 toward the substrate P, but the movement of the substrate P is restricted by the inclined surfaces of the convex portions 226A to 226C. Therefore, it is possible to prevent the placement position from shifting. Moreover, since the convex portions 226A to 226C are in line contact with the back surface of the substrate P, the contact area with the back surface of the substrate P can be minimized. Therefore, contamination due to transfer of contaminants such as particles adhering to the protrusions 226A to 226C to the back surface of the substrate P is minimized.

  In addition, the force by which the substrate P is pulled in the direction from the pitch conversion mechanism unit 3 toward the substrate P is the resultant force of the force pulled by the claw portions 21A and 21B in the direction from the pitch conversion mechanism unit 3 toward the substrate P. This occurs because it is stronger than the force pulled by the claw portion 21 </ b> C in the direction from P to the pitch conversion mechanism portion 3. Further, the arrangement positions of the convex portions 226A to 226C are not particularly limited to this, and may be any edge of the substrate P.

  Thereafter, the edge clip finger part 2 is lowered and moved from the inside of the cassette case to the outside. As a result, the five substrates P are stored in the cassette case in a state of being supported by the support portion.

  In the present embodiment, the convex portions 226A to 226C are arranged so that the inclined surface supports the back surface of the substrate P, but the back surface of the substrate P may be supported by the apex portion of the convex portion. Thereby, it is prevented that the mounting position of the board | substrate P moves according to the frictional force which generate | occur | produced in the contact location with the vertex part of a convex part similarly to the above. In addition, since the apex portion of the convex portion makes point contact with the back surface of the substrate P, the contact area with the back surface of the substrate P can be minimized, and contamination due to transfer of contaminants to the back surface of the substrate P as described above. Is minimized.

  The support members 222A to 222C, the guides 223A to 223C, the drive cylinders 224A and 224C, and the connecting member 225 correspond to the drive means of this invention.

  As shown in FIGS. 5A and 5B, the pitch conversion mechanism unit 3 includes an end effector mounting plate 31, a pitch conversion guide 32, a pitch conversion cylinder 33, and the like. The axial interval W is changed. Each of the end effector mounting plates 31 supports one end of the end effector 21. Each of the end effector mounting plates 31 is supported by the pitch converting cylinder 33 and guided by the pitch converting guide 32 to reciprocate in the central axis direction of the substrate P. The pitch converting cylinder 33 is driven by air pressure to reciprocate the end effector mounting plate 31.

  The pitch conversion mechanism unit 3 according to the present embodiment can change the interval W in the central axis direction of the five substrates P in two steps in the wide pitch mode and the narrow pitch mode. The state shown in FIG. 5A is the wide pitch mode, and the interval W between the five substrates P is larger than that in the narrow pitch mode. The state shown in FIG. 5B is a narrow pitch mode.

  6A and 6B are side cross-sectional views showing changes in the other ends of the steel tapes 221A to 221C in the wide pitch mode and the narrow pitch mode. 6A and 6B show only the steel tape 221B, the other steel tapes 221A and 221C have the same configuration. The steel tape 221B forms an elastic part T on the other end side as shown in FIGS. The elastic part T is a part where a part of the steel tape 221B is refracted. The elastic part T generates an elastic force in the moving direction of the steel tape 221B. Therefore, when the distance W between the five substrates P changes, the distance between the positions of the steel tape 221B and the other end of the steel tape 221B changes, and the steel tape 221B bends. Is absorbed. Therefore, even when the interval W changes in a state where the five substrates P are gripped, the gripping force of each substrate P can be held constant.

  In the present embodiment, the elastic portion T is provided in a part of the steel tapes 221A to 221C. However, the present invention is not particularly limited thereto, and the elastic portion T may be formed as a whole.

  Further, the other end of the steel tape 221B is located in the middle of the reciprocating movement range Q of one end in the central axis direction of the substrate P. This is because, as described above, when the distance W between the five substrates P changes, the distance between the arrangement positions of the one end and the other end of the steel tape 221B changes, so that the amount of change is minimized. . As a result, the gripping force of each substrate P can be kept constant as described above.

  The end effector 21 located at the lowest position shown in FIGS. 6A and 6B does not move even when the pitch mode changes, so the elastic portion T is provided as described above, and the other end is not fixed. Also good.

  By providing the above configuration, for example, the single robot arm 1 can perform conveyance between cassette cases having different arrangement intervals in the central axis direction of the plurality of substrates P placed thereon.

  The reversing mechanism unit 4 is composed of a motor or the like (not shown), and rotatably supports one end of the pitch conversion mechanism unit 3. The pitch conversion mechanism 3 rotates in the direction of the arrow shown in FIG. 1 around the axis orthogonal to the central axis of the substrate P by driving the motor, and the five held substrates P also rotate. The reversing mechanism unit 4 in the present embodiment can rotate the five substrates P to an arbitrary angle. Thereby, the angle of the direction orthogonal to the center axis | shaft of the board | substrate P is arrange | positioned in an mutually different angle position, and the board | substrate P can be transferred between cassette cases from which the arrangement | positioning space | interval of the board | substrate P differs.

  Even when the five substrates P are reversed, the movement of the claw portions 21A to 21C in the central axis direction of the substrate P is restricted by the guides 23A to 23C. Generation | occurrence | production of 21A-21C drop-off | omission, the shift | offset | difference of an arrangement position, etc. can be prevented, and the holding | grip force with respect to the board | substrate P can be maintained. Therefore, the front and back surfaces can be reversed and transported without dropping the five substrates P.

  With the above configuration, the edges of the substrate P of the three claw portions 21A to 21C can be brought into contact with and separated from each other at the same time, so that the placement position of the substrate P is shifted when the claw portions 21A to 21C are brought into contact with each other. This can be prevented, and the processing accuracy for the substrate P can be improved. In addition, since a plurality of substrates P can be held at a time, the conveyance speed of the substrates P can also be improved.

  Furthermore, since the plurality of end effectors 21, the pitch conversion mechanism unit 3, and the reversing mechanism unit 4 are provided, a plurality of the substrate P such as a change in the interval and transfer of the substrate P can be prevented while preventing the placement position of the substrate P from shifting. This process can be executed with high accuracy.

  In addition, one end of each of the steel tapes 221A to 221C is connected to the claw portions 21A to 21C, and the other end is connected to the support members 222A to 222C included in the driving means, so that a plurality of ends can be obtained by a single driving means. The holding of the substrate P in each of the effectors 21 can be performed synchronously. Thereby, space saving can be achieved.

  In the present embodiment, the configuration is such that the five substrates P are gripped. However, the present invention is not particularly limited to this, and a configuration that grips a single substrate P or a configuration that grips a plurality of substrates P may be used. . In addition, the pitch conversion mechanism 3 and the reversing mechanism 4 may not be provided.

  Furthermore, although the robot arm 1 has been described in the present embodiment, the present invention can be applied to all apparatuses as long as the apparatus includes a mechanism for gripping a substrate.

It is a perspective view which shows the structure of a part of robot arm which concerns on embodiment of this invention. It is a top sectional view showing the composition of a part of the robot arm. It is side surface sectional drawing which shows the structure of the end effector with which the robot arm was equipped. It is explanatory drawing which shows the structure of the periphery of the nail | claw part with which the robot arm was equipped. It is side surface sectional drawing of the pitch conversion mechanism part with which the robot arm was equipped. It is side surface sectional drawing which shows the change of the other end of the steel tape at the time of the narrow pitch mode and wide pitch mode in the robot arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Robot arm 2 Hand edge clip finger part 3 Pitch conversion mechanism part 4 Inversion mechanism part 21 End effector 21A-21C Claw part 22 Movement means 23A-23C Guide 221A-221C Steel tape 222A-222C Support member 223A-222C Movement guide 224A, 224C Drive cylinder T Elastic part P Substrate Q Reciprocating range W Interval

Claims (7)

A substrate holding part having three or more claw parts for holding an edge of the circular thin substrate;
And a moving means for reciprocally moving each of the three or more claw portions in a moving direction from the edge of the circular thin substrate toward the center portion.   The substrate holding portion includes three or more convex portions that support the back surface of the circular thin substrate facing the substrate holding portion on an apex portion or an inclined surface closer to the center portion of the substrate than the apex portion. The substrate holding apparatus according to claim 1, wherein A plurality of the substrate holding portions each holding the single circular thin substrate;
Holding the plurality of substrates so that the center axes of the plurality of circular thin substrates gripped are coaxially positioned and the intervals in the central axis direction between the plurality of circular thin substrates are all the same. A pitch conversion mechanism unit for supporting the unit, wherein each of the plurality of substrate holding units is moved in the central axis direction to change the interval, and
The reversing mechanism part which rotates the said pitch conversion mechanism part centering | focusing on the axis | shaft orthogonal to the said central axis, and stops at a predetermined | prescribed angular position is provided. Substrate holding device.   The substrate holding mechanism according to claim 3, further comprising three or more guides for restricting movement of each of the three or more claw portions in the plurality of substrate holding portions in the central axis direction.   The moving means has one end connected to each of three or more tension members connected to the three or more claw portions in the plurality of substrate holding portions, and each of the other ends of the three or more tension members. The substrate holding apparatus according to claim 3, further comprising a driving unit that reciprocates the tension member in the moving direction.   6. The substrate holding apparatus according to claim 5, wherein each of the three or more tension members includes an elastic part in part or in whole.   6. The substrate holding apparatus according to claim 5, wherein each of the three or more tension members has the other end positioned in the middle of a reciprocating range of the one end in the central axis direction.

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