JP2004092914A - Cylinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder in which sending-out to three positions with one piston rod can be performed with high precision, and moreover, moving among states of the three positions can be stably performed. <P>SOLUTION: The cylinder is characterized in that a first spring member and a spring receiving member are arranged between a piston and one end face of a piston chamber so that movement is regulated by the one end face, a recessed part and a stopper to limit movement in the direction opposite to the piston of the spring receiving member are provided to the piston rod. A stop pin, which is engaged with the recessed part and energized by a second spring member, is arranged to a cylinder tube, and the sending-out of the piston rod is regulated to the following three positions, that is, a position where the other end face of the piston chamber and the piston are brought into contact with each other, a position where the end part apart from the piston at the recessed part and the stop pin are brought into contact with each other, and a position where the end part on the piston side of the recessed part and the stop pin are brought into contact with each other or movement of the spring receiving member in the piston direction is stopped. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a cylinder, and more particularly, to a cylinder used for a load port compatible with a FOUP (Front Opening Unified Unified Pod) having various latch key receiving shapes.

Conventionally, open cassettes have been widely used as containers for storing a plurality of semiconductor wafers.The mini-environment method has been used as a means for reducing the cost required for clean rooms and making high-performance semiconductor devices at low cost. It has been proposed that SMIF (Standard Mechanical Interface) is widely used for 200 mm wafers and FOUP (Front Opening Unified Unified Pod) is being used for 300 mm wafers.

FOUP is a mini-environment system standardized by SEMI (Semiconductor Equipment and Materials International) organized by semiconductor manufacturing equipment and materials manufacturers from all over the world. We are trying to build a line.
The FOUP method was standardized by technical studies by the SEMI Standards Committee. However, the mechanical interface of the load port for opening and closing the FOUP and the FOUP door requires the accuracy of the load port. While strictly stipulated, the FOUP dares to have a degree of freedom, thereby giving the FOUP manufacturer originality (SEMI Standard E57-0299).

Such a FOUP system is described in detail in, for example, JP-A-8-279546. The structure and the opening / closing mechanism will be described with reference to FIGS.
FIG. 5 shows a load port for opening and closing the FOUP. The load port 30 includes a frame 31 having an opening, a stage 32 having three kinematic pins 34 and capable of moving back and forth in the frame direction, and a port door 33 inserted into and retracted from the opening from a direction opposite to the stage. Consists of The port door 33 is provided with two registration pins 36 arranged diagonally and two latch keys 35 rotatable between an upright state (90 °) and a horizontal state (0 °). Further, a suction pad 37 for suction-fixing the FOUP door 52 is attached so as to surround the registration pin 36.

As shown in FIG. 6, the FOUP 50 is composed of a FOUP box 51 and a FOUP door 52. The FOUP box 51 is provided with a shelf for mounting a wafer 53, a handle 56 for an operator, and the like. . A latch hole 55 and a registration hole 54 are formed in the FOUP door 52 at positions corresponding to the latch key 35 and the registration pin 36 of the port door 33. A latch key receiver that engages with the latch key 35 is provided inside the latch hole 55, and the latch 56 is locked and released by rotating the latch key receiver with the latch key.
Although the SEMI standard stipulates that the FOUP box 51 and the FOUP door 52 are fixed and released by setting the latch key holder to 90 ° and 0 ° positions, the specific fixing method is described by the FOUP manufacturer. It has been left to. A specific example of the FOUP door opening / closing structure is disclosed in, for example, US Pat. No. 5,915,562.

Next, a method of opening and closing the FOUP will be described.
The FOUP is positioned by being placed on three kinematic pins 34 arranged on the stage.
By moving the stage 32 forward in this state, the registration holes 55 of the FOUP 50 fit into the registration pins 36 of the port door, and the position of the FOUP door is corrected. By further moving the stage forward, the latch key 35 of the port door fits into the latch key receiver through the latch hole 55 of the FOUP, and finally the FOUP door and the port door come into close contact with each other. In this state, the suction pad 37 disposed at the root of the registration pin 36 is set to a negative pressure, whereby the FOUP door can be fixed to the port door.

Next, the FOUP box and the FOUP door are unlocked by rotating the latch key 90 ° to the 0 ° position. The port door moves rearward while holding the FOUP door, and further descends, so that the wafer can be taken out through the opening.
In this state, the wafer stored in the FOUP box can be transferred to the substrate processing apparatus by a scalar type robot for transferring a substrate described in Japanese Patent No. 2749314.
To close the FOUP door, the above operation may be performed in reverse.
JP-A-8-279546

This FOUP system was established as a provisional specification of SEMI in 1996, and each company has been developing and manufacturing FOUPs and load ports based on this standard. However, as the verification of operation in the FOUP system is actually advanced, Various problems have become apparent.

As described above, the SEMI standard strictly regulates the accuracy of the load port, but the FOUP has a degree of freedom. For example, the shape and size of the latch key are strictly defined, including tolerances, but the shape and size of the latch key receiver are not specified. For this reason, the following problems have occurred.
That is, the rotation angle of the latch key has a tolerance of ± 1 ° at each of the 0 ° position and the 90 ° position according to SEMI standard E62-0999. However, since the size of the latch key receiver is not specified, as shown in FIG. 13, when the width W1 of the latch key receiver 57 is larger than the width W2 of the latch key 35 to some extent, the latch key receiver is rotated even if it is rotated by 90 °. Does not rotate to 90 °, and a state not at the 90 ° position (ie, 90-θ °) can occur. Therefore, depending on the width difference (W1-W2), a case may occur in which the latch is not locked. Also, even within the range where the latch is locked, if the stage is advanced to open the FOUP, if the latch key receiver is not at the 90 ° position and is conveyed to the load port of the next substrate processing step, The latch key and the latch key receiver may come into contact with or collide with each other. This contact and the like may cause dust generation and contaminate the wafer transfer space, and the repeated contact and the like may cut and deform the latch key receiver. When the latch key receiver is deformed, for example, even if the latch key is rotated to 0 °, the latch key receiver cannot rotate to the 0 ° position, that is, stops at a position having a tolerance of 1 ° or more (eg, 5 °). The FOUP box and the FOUP door are configured such that the latch key receiver becomes 0 ° ± 1 ° and the fixing is released. However, the latch key receiver cannot be released due to deformation of the latch key receiver. It is a big problem.

To solve the above problems, FOUP manufacturers have been conducting various studies, but due to problems such as cost and reliability, at present no appropriate solution has been obtained.

The inventor of the present invention has studied in detail the method of inserting the latch key into the latch key receiver, the mechanism of the latch, and the like using a cylinder as the drive mechanism of the latch key in order to solve the above problems. It was concluded that correcting the latch key receiver to the 90 ° position after latching was the most reliable. That is, when locking the latch, the latch key is rotated to an angle (90 ° + θ) larger than the 90 ° position so that the latch key receiver is at the 90 ° position, and then the latch key is returned to the 90 ° position.

In order to realize this method, a cylinder capable of accurately feeding the piston rod to at least three positions is indispensable. Then, the present inventor connects the 90 ° rotation cylinder 71 and the minute angle (θ) rotation cylinder 72 to produce a connection type cylinder shown in FIG. 12, and describes a FOUP having latch key receivers of various shapes. , Locking and releasing of the latch were studied. By controlling the pressure of the air supplied to the four fluid ports using this cylinder, it becomes possible to feed the piston rod to the three states shown in FIGS. 12A, 12B and 12C. It was found that the problem could be solved. However, the size of the entire cylinder is too large, and it is practically difficult to install the cylinder on a SEMI standard port door. The present inventor has further studied based on the above findings and studied a cylinder structure that can be reduced in size, and as a result, has completed the cylinder of the present invention.
That is, an object of the present invention is to provide a small-sized three-position cylinder, and in particular, to provide a cylinder suitably used for a highly reliable load port capable of reliably performing a latch operation when opening and closing a FOUP. With the goal.

The cylinder of the present invention is a cylinder in which a piston chamber having two end surfaces is provided in a cylinder tube, and a piston rod is reciprocated by a pressure applied to a piston by fluid supplied to the piston chamber through two fluid ports. ,
A spring receiving member movably disposed coaxially with the piston rod so that movement is defined by the one end surface between the piston and at least one end surface of the piston chamber;
A first spring member arranged to separate the spring receiving member and the piston;
A stopper provided on the piston rod, for limiting movement of the spring receiving member in a direction opposite to the piston with respect to the piston rod;
A recess provided in the piston rod at a position farther from the piston than the stopper,
A stop pin disposed in the cylinder tube so as to engage with the recess, and urged in a direction toward the recess by a second spring member.
A position where the other end surface of the piston chamber is in contact with the piston, a position where the end of the recess away from the piston is in contact with the stop pin, and a position where the end of the recess on the piston side is in contact with the stop pin. The delivery of the piston rod is defined at three positions, that is, a position where the piston rod comes into contact with or where the movement of the spring receiving member in the piston direction is stopped.
Further, a spring guide member is disposed coaxially with the piston rod between the piston and the stopper, and an inner diameter side of the spring member is supported by the spring guide member and the spring receiving member. Are not directly in contact with each other.

こ と With such a configuration, it is possible to send out to three positions with high accuracy with one piston rod, and it is possible to stably shift between the three positions. Further, the number of components such as the switching valve can be greatly reduced as compared with the configuration in which the two cylinders are connected, which is extremely advantageous in terms of cost. As a result, it is possible to realize a small, low-cost, and highly reliable three-position cylinder.

By using the cylinder of the present invention, it is possible to obtain a highly reliable load port capable of reliably performing the latch operation when opening and closing the FOUP. Such a load port includes a frame having an opening, a stage on which a substrate storage container holding a front door fixed by a latch and holding a sealed state inside is mounted, and which is movable in the direction of the frame; A port door inserted into the opening from the opposite side to lock and release the latch of the front door, and moving the stage to the frame side to tightly fix the front door to the port door. In the load port for locking and releasing the latch of the front door in a state where the front door is locked, the port door is a latch key for locking and releasing the latch of the front door, and is rotated to a vertical position to lock the latch. A latch key for releasing the lock in a horizontal position, and a cylinder for rotating the latch key. When performing the locking of the latch is rotated to a straight position, it is rotated to an angle greater than 90 ° the latch keys from the horizontal position, then characterized by being configured to return to 90 ° position.
That is, since the latch key is rotated by 90 ° or more to lock the latch, even if the FOUP has various shapes, the door can be securely fixed to the FOUP box and the inside can be sealed. Further, since the latch key receiver after the latch is locked is always at the 90 ° position, it is possible to avoid a problem such as a collision between the latch key and the latch key receiver at the time of unlocking the latch at the load port in the next process. By using such a load port, the latch can be locked and released with high reliability.

The cylinder of the present invention is used for driving the latch key.
A position where the other end surface of the piston chamber is in contact with the piston, a position where the end of the recess away from the piston is in contact with the stop pin, and a position where the end of the recess on the piston side is in contact with the stop pin. By associating the three positions of contacting or stopping the movement of the spring receiving member in the piston direction with the horizontal position, the vertical position, and the angle greater than 90 ° of the latch key, a highly reliable latching operation is achieved. Can be performed. Furthermore, since the small cylinder of the present invention is used, the cylinder can be attached to the port door with a margin, and can sufficiently comply with the SEMI standard.

When releasing the latch by rotating the latch key to a horizontal position, the latch key is further rotated by a predetermined angle beyond the horizontal position. Thereby, the reliability of the release of the latch can be further enhanced.
Further, it is preferable that the two latch keys are connected to each other so that one cylinder rotates the two latch keys simultaneously. As a result, the number of cylinders and valves can be reduced to half, and the cost of the load port can be further reduced.
Further, it is possible to construct a production system capable of mass-producing, for example, a semiconductor integrated circuit using the load port.

As described above, according to the present invention, it is possible to provide a cylinder that can be sent to three positions and that can stably transition between the three positions. In addition, the number of fluid ports can be halved to two as compared with the case where two cylinders are connected, so that the number of fluid ports can be halved, miniaturization can be achieved, and cost can be reduced.
In addition, by configuring the load port using such a cylinder, it is possible to provide a highly reliable load port that can reliably perform the latch operation when opening and closing the FOUP. Further, by connecting two latch keys, it is possible to fix and release the two latches with one cylinder, so that the cost of the port door and further the load port can be reduced.
Furthermore, the semiconductor production system using such a load port enables a wafer to be transported between processing apparatuses in a tightly sealed and clean state, and wafer processing in each processing chamber to be performed stably. It becomes. Mass production of semiconductor integrated circuits and the like becomes possible while reducing the cost of the clean room.

The present invention will be described in detail below with reference to examples.

(Cylinder)
The cylinder of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic sectional view showing an example of the three-point positioning cylinder of the present invention.
In the figure, 2 is a cylinder tube, 3 is a piston rod, 4 is a piston, and 5, 6 are fluid ports. A piston chamber (I-II) having an inner diameter substantially equal to the outer diameter of the piston 4 is formed between the cylinder covers 7 and 19 in the cylinder tube 2.

ス リ ー ブ A sleeve 8 is fixed to one end of the piston rod 3, a groove (recess) 9 is formed on an outer peripheral surface thereof, and a taper 10 is formed at a distal end thereof. Between the piston 4 and the sleeve 8, a spring receiving member 14 formed of a cylindrical member having a flange attached to one end surface is disposed coaxially with the piston rod 3 so as to be movable in the axial direction independently of the piston rod 3. I have. A spring (first spring member) 15 is disposed between the spring receiving member 14 and the piston 4 so as to urge the spring receiving member 14 to the right. The rightward movement of the spring receiving member 14 is suppressed by the cylinder cover 19 and the sleeve 8. That is, the sleeve 8 also functions as a stopper that suppresses the rightward movement of the spring receiving member 14. In the figure, a spring guide member 16 for smoothly performing the action of the spring 15 is fixedly arranged on the piston rod 3 and the piston 4.

ス ト ッ プ Further, the cylinder tube 2 is provided with a stop pin 11 which can be engaged with the recess 9 formed in the sleeve 8. The stop pin 11 is urged in the central axis direction of the piston rod 3 by a spring 12 (second spring member) and a cover 13. The engagement of the stop pin 11 and the concave portion 9 limits the axial movement of the piston rod 3. The stop pin 11 is pushed back by the pressurized fluid introduced into the fluid port 6, and the engagement with the recess 9 is released.

Next, a method of sending the piston rod to three different positions together with the operation of the cylinder will be described with reference to FIG. 2A, 2B, and 2C show states in which the feed amounts are different, and the feed amounts increase in the order of (A), (B), and (C) (that is, L ₃ > L ₂ >). L ₁ ).

First, as shown in FIG. 2A, when the fluid port 5 is set to a high pressure (H) and the fluid port 6 is set to a low pressure (L), the piston rod 3 is pushed rightward in the drawing, and the delivery amount is set to a minimum value L. It becomes ₁ . This position, spring receiving member 14 and the spring guide member 16 and abuts a position where both distance L ₀ becomes zero. That is, the minimum amount of feeding is determined by the position where the spring receiving member 14 and the spring guide member 16 contact. The minimum feed amount may be determined at a position where the left end of the concave portion 9 contacts the stop pin 11 in addition to the position at which the interval L ₀ becomes zero.

Next, as shown in FIG. 2B, when the fluid port 5 is set at a low pressure from the state shown in FIG. 2A, the piston 4 is pushed leftward by the force of the spring 15, and the piston rod 3 moves leftward. Then, it stops at a position where the right end of the concave portion 9 contacts the stop pin 11. This position is the second feed amount L _2. The feed amount L ₂ is determined by the position of the right end of the recess 9, this time, the spring 15 is sufficient spring constant and length to stop pin 11 moves the piston rod 3 until it abuts against the right end of the recess It goes without saying that a spring having

Finally, FIG. 2 (C) showing the state in which the delivery amount is the maximum, the left pressure is applied to the piston 4 by setting the fluid port 5 to a low pressure and the fluid port 6 to a high pressure, and the piston rod 3 is delivered. However, when the pressure of the fluid port 6 is set to a high pressure in the state of FIG. 2B, a leftward force is applied to the piston rod 3 and the friction between the stop pin 11 and the end face of the recess 9 causes the engagement between the stop pin 11 and the recess 9. Since the combination may not be released, for example, it is preferable to shift to the state shown in FIG. 2C via the state shown in FIG. That is, if the fluid port 5 is set at a high pressure and the fluid port 6 is also set at a high pressure, a pressure that pushes back the stop pin 11 can be applied without applying a force between the right end of the recess 9 and the stop pin 11. The engagement between the recess 11 and the recess 9 can be stably released. Subsequently, by setting the fluid port 5 to a low pressure state, the piston rod 3 moves to the left, and stops at a position where the piston 4 contacts the cylinder cover 7. This state corresponds to the maximum delivery position L _3.

さ せ る When shifting from the state of FIG. 2C to the state of FIGS. 2A and 2B, the fluid port 5 is set at a high pressure and the fluid port 6 is set at a low pressure. Since the pressure of the fluid port 6 is low, the stop pin 11 is protruded by the force of the spring 12, but the piston rod 3 moves rightward because the tapered portion 10 is formed on the end surface of the sleeve 8. In this case, the tapered portion 10 moves while pushing the stop pin 11 back, so that reliable operation can be ensured.

As described above, by using the cylinder shown in FIG. 1, by appropriately selecting the position and length of the recess 9, the distance L ₀ between the spring receiving member 14 and the spring guide member 16, and the cylinder cover 7, The feed amount of the piston rod 3 at the stage can be changed to various values, and each position can be accurately defined.

The cylinder shown in FIG. 1 has a configuration in which a stop pin, a concave portion, a spring receiving member, and the like are provided on the side opposite to the piston rod delivery direction of the piston, but a stop pin and the like are provided on the piston rod delivery direction side. A configuration is also possible. FIG. 3 shows a cylinder having such a configuration.
In the example of FIG. 3, the sleeve 8 having the tapered portion 10 as shown in FIG. 1 is not provided, and a part 17 of the piston rod acts as a stopper for restricting the movement of the spring receiving member 14 to the left. A groove (recess) 9 is formed on the outer periphery of the rod 3. The spring guide member 16 has the same shape as the spring receiving member 14. Here, both members 14 and 16 in FIG. 3 are not fixed to the piston rod 3 and can move independently in the axial direction. In the cylinder of FIG. 3, the states shown in (A), (B), and (C) correspond to the three feeding positions of the piston rod 3. In the case of FIG. 3, the piston chamber is a chamber having the piston stopper 18 and the cylinder cover 19 as end faces.

Minimum feed amount L _1, as shown in FIG. 3 (A), is achieved by the high pressure fluid port 5, the fluid port 6 and the low pressure. The piston rod 3 moves rightward and stops at a position where the piston 4 contacts the cylinder cover 19. That is, feeding amount L ₁ is determined by the position of the cylinder cover 19. In this state, the stop pin 11 has been pushed back by the piston rod 3.
The second feeding amount L _2, as shown in FIG. 3 (B), the fluid port 5 and the low pressure, and a fluid port 6 to the high pressure, the piston rod 3 is moved to the left, the stop pin 11 and the recess 9 Is achieved by lowering any of the fluid ports to a low pressure. When the pressure difference on both sides of the piston is eliminated, the piston rod 3 moves rightward by the force of the spring 15, and stops at the position where the stop pin 11 contacts the left end of the concave portion 9. This state corresponds to the second feed amount, feed amount L ₂ is determined by the position of the stop pin 11 and the recess 9 left end abuts.

Next, when the fluid port 6 is set to a high pressure in the state of FIG. 3B, the piston rod 3 is fed out until it comes into contact with the right end face of the stop pin 11 (FIG. 3C). That is, the maximum feed quantity L ₃ would right end of the stop pin 11 and the recess 9 is determined by the position abutting. Note that, similarly to FIG. 1, a position where the spring receiving member 14 and the spring guide member 16 abut (that is, L ₀ = 0) may be set as the maximum feeding amount.

In order to shift from the state of FIG. 3 (B) or (C) to the state of FIG. 3 (A), as shown in FIG. 2, as shown in FIG. Is set to a high pressure, the fluid port 5 is set to a high pressure, and then the fluid port 6 is set to a low pressure. By doing so, the stop pin 11 is easily pushed back, and the transition to the state (A) is smoothly performed.

Further, as shown in FIG. 4, for example, as shown in FIG. 4, the cylinder according to the present invention is configured such that a concave portion, a spring receiving member, a stop pin, and the like are arranged at predetermined positions on both sides of the piston, so that the delivery amount is increased to four or more. It is also possible to realize a cylinder structure defined by position.

As described above, the configuration examples of the cylinder of the present invention are shown in FIGS. 1 to 4, but the present invention is not limited to these, and various design changes may be made based on these. For example, the concave portion 9 formed on the sleeve 8 or the piston rod 3 does not necessarily need to be formed over the entire outer peripheral surface, but may be formed only on a portion that engages with the stop pin 11. Further, the spring guide member 16 is not limited to the structure shown in FIGS. 1 and 3, but may be any structure as long as it can secure the expansion and contraction of the spring stably. You don't have to. Further, the spring guide member 16 can be omitted. If omitted, the spacing L ₀ is a distance between the piston 4 and the spring receiving member 14.
The spring receiving member 14 may have any structure as long as it is locked by the stopper 17 such as the cylinder cover 19 (or the piston stopper 18) or the sleeve 8, as shown in FIGS. It is not limited to things.
Further, the spring member of the present invention may be of any structure and material as long as it presses the spring receiving member 14 and the stop pin 11, such as a coil spring, a disc spring, a sponge, and rubber. It is a meaning including.

(Load port)
Next, a load port using the cylinder of the present invention will be described.
FIG. 5 is a schematic perspective view showing a configuration example of the load port. As shown in the figure, the load port 30 is provided with a FOUP 50 shown in FIG. 6, a frame 31 having an opening for transferring a substrate, a FOUP mounting stage 32 movable in the direction of the frame 31, A port door 33 which can be inserted into the opening and which retreats and retreats downward when transferring the substrate in the FOUP. The FOUP mounting stage 32 has three kinematic pins for positioning the FOUP. On the other hand, as described later, the port door is provided with two sets of the latch key 35 and the cylinder 1 for driving the latch key 35, and latches the FOUP door 52 and releases the latch. After releasing the latch of the FOUP door 52, the port door 33 moves further backward and downward together with the FOUP door, and retreats to a position where the transfer of the substrate by the robot is not hindered.

FIG. 7A is a schematic view of a state where the front cover of the port door is removed, as viewed from the stage 32 side. Two latch keys 35 and two registration pins 36 are attached to the FOUP door 51 at positions corresponding to the latch holes 55 and the registration holes 54, respectively. The latch key 35 is connected to a connecting member 38, and the connecting member 38 is rotatably connected to the knuckle 21 at the tip of the piston rod of the air cylinder. As a result, the latch key can rotate with the reciprocating movement of the piston rod 3 of the air cylinder. The other end of the air cylinder 1 forms a clevis-type support structure 20 and is rotatably fixed to a support member 42 attached to the rear cover 41 of the port door. The ports 5 and 6 of the cylinder are connected to a switching valve via an air pipe 40, and further to a compressed air source.
Further, a suction pad 37 is attached so as to surround the registration pin 36 so that when the FOUP door and the port door are in close contact with each other, the space between the suction pad 37 and the FOUP door 52 can be evacuated. The suction pad is connected to a vacuum device (not shown) via a vacuum pipe 39.

In order to prevent various problems associated with the shape of the latch key receiver 57 and to perform stable locking and release of the latch, the latch key receiver 57 after locking the latch is required for any latch-shaped FOUP. It is important to always keep the piston at the 90 ° position. For this purpose, the cylinder of the present invention, which can control the amount of feed of the piston rod in three stages, is preferably used. That is, by using the cylinder of the present invention, regardless of the shape of the latch key receiver 57, the latch key receiver 57 after the completion of the latching operation can always be kept at the 90 ° position, and the reliability of the latch can be improved and the latch release can be performed. Therefore, when the latch key 35 is inserted into the latch key receiver 57, collision between the two can be prevented.

The opening / closing operation of the FOUP door when the port door is configured using the air cylinder having the structure shown in FIG. 1 will be described with reference to FIGS. FIG. 8 is a schematic sectional view showing a state of a cylinder corresponding to each operation, and FIG. 9 is a schematic view showing an operation of a switching electromagnetic valve connected to an air port and a latch key position. FIG. 8 shows specific numerical values of the piston rod position in each operation.
The FOUP 50 is mounted on the stage 32 of the load port 30 with the kinematic pins 34 aligned. Here, the FOUP box 51 and the door 52 are fixed by a latch, and the inside is completely shut off from the outside and is in a sealed state. Further, the two latch key receivers 57 are at positions rotated by 90 ° from the horizontal direction. On the other hand, the two latch keys 35 of the port door are also at the 90 ° position.

When the stage 32 is moved in the direction of the port door 33 by a drive mechanism (not shown), the registration pins 36 are inserted into the registration holes 54 of the FOUP door 52 to position the two. It is inserted into the latch key receiver 57. While the port door 33 and the FOUP door 52 are in close contact with each other, the inside of the suction pad 37 is evacuated by a vacuum device (not shown), and the FOUP door 52 is fixed to the port door 33 by suction.
In this state, the operation of unlocking the latch and opening the FOUP door 52 is performed. The relationship between the movement of the piston rod and the supply of air to the ports 5 and 6 will be described with reference to FIGS. Note that the two cylinders perform exactly the same operation.

The two cylinders in the state where the latch key 35 is inserted into the latch key receiver 57 are in the state shown in FIG. 8A, and the valves A and B connected to the ports 5 and 6 are both switched to the atmospheric pressure side. (FIG. 9A). The piston rod 3 is pushed leftward by a spring, and the right end of the recess 9 is locked by a stop pin 11. At this time, the latch key is at the 90 ° position.

Next, when the valve A is first switched to the compressed air side and then the valve B is switched to the compressed air side (FIG. 9B), the piston 4 is slightly shifted rightward and both sides of the piston are in the pressurized state. Therefore, the stop pin 11 is pushed back by this pressure against the force of the spring 12, and the engagement between the stop pin and the recess is released (FIG. 8B).

When the valve A is switched to the atmospheric pressure side in this state (FIG. 9 (C)), a leftward force is applied to the piston 4, the piston rod 3 is pushed out, and the piston 4 stops at a position where the piston 4 comes into contact with the cylinder cover 7. In response, the latch key 35 rotates to the 0 ° position. With the rotation of the latch key 35, the latch key receiver 57 also rotates, and the latch of the FOUP door is released (FIG. 8C).

(4) Here, the port door 33 is retracted and retracted from the opening by a driving mechanism (not shown), so that a substrate transfer operation by a robot (not shown) is possible. The substrate is transferred between the FOUP and the substrate processing apparatus, the substrate stored in the FOUP is processed, and the substrate after the processing is transferred again into the FOUP.

After all the substrates have been processed, an operation of fixing the FOUP door 52 to the FOUP box 51 is performed. With the port door 33 retracted, the port door is raised, further advanced and inserted into the opening by a drive mechanism (not shown), and the FOUP door 52 is pressed against the FOUP box 51. In this state, the valves A and B are switched to the compressed air side and the atmospheric pressure side, respectively (FIG. 9D). The piston rod 3 moves to the right, the stop pin 11 engages with the concave portion 9, advances further than the position where the stop pin contacts the right end of the concave portion, and stops at the position where the interval L ₀ becomes zero. Correspondingly, the latch key 35 stops at the 90 ° + θ position beyond the 90 ° position (FIGS. 8D and 9D), while the latch key receiver 57 is at the 90 ° position.

Depending on the difference between the latch key receiving width W1 and the latch key width W2, the latch key receiving 57 does not reach 90 ° even when the latch key 35 is at the 90 ° position (for example, when W1 = 6 mm and W2 = 5 mm, the latch key receiving angle = 86 °), in this state, the latch key 35 and the periphery of the latch key receiver 57 come into contact with each other at the time of releasing the latch in the next step, and the latch is insufficiently locked and the airtightness is insufficient, so that the inside is contaminated during FOUP conveyance. There is a problem that can be done. However, since the latch key 35 rotates to the 90 ° + θ position by the cylinder shown in FIG. 1, the latch key receiver 57 can always be at the 90 ° position, and the above problem can be prevented.

Here, when the valve A of the port 5 is switched to the atmospheric pressure side, the force of the spring 15 causes the piston rod 3 to move leftward until the stop pin 11 contacts the right end of the concave portion. Correspondingly, the latch key 35 also returns to the 90 ° position, and both the latch key receiver 57 and the latch key 35 return to the 90 ° position. As a result, the load port is in a state where the latch release operation of the next FOUP can be performed, and the FOUP can also release the door without any trouble by the load port of the next process.
Since the cylinder receives a force perpendicular to the axis by the reciprocating motion of the piston rod, both ends 21 and 20 of the cylinder are rotatably connected to the connecting member 38 and the supporting member 42, respectively. Accordingly, in the series of operations described above, the cylinder moves as shown in FIG.

When the latch is released, the latch key is rotated to the horizontal position as described above. However, when the latch key receiving width W1 becomes a large FOUP, even if the latch key 35 is returned to 0 [deg.], The latch key receiving 57 remains at the latch release angle ( 0 ° ± 1 °) and the latch cannot be released. Thus, in order to stably release the latch, the latch key 35 may be further rotated beyond 0 °. That is, the latch key 35 may be rotated to (−θ) to increase the reliability of the latch release. This angle (−θ) can be determined by the position where the piston 4 contacts the cylinder cover 7.

Although the load port using the cylinder of FIG. 1 has been described above, the same applies to the case where the cylinder having the configuration shown in FIG. 3 is used. In this case, the cylinder position shown in FIG.
Further, although two cylinders corresponding to two latch keys are attached to the port door of FIG. 5, it is also possible to realize a similar latch operation with one cylinder. FIG. 7B shows an example of a port door configuration in this case.
In the example shown in the figure, a connection member 38 of two latches and a knuckle 21 of a cylinder are connected using a T-shaped connection member 43. Due to the reciprocating motion of the cylinder, the two latch keys rotate in phase, and the locking and release of the latch can be performed by one cylinder.

(Production method)
Next, a semiconductor production system using the above-described cylinder and load port will be described with reference to FIG. In the semiconductor factory, the wafer 53 that undergoes various processes moves between the processing apparatuses 61 while being stored in the FOUP 50. Since the FOUP 50 storing the 300 mm diameter wafer 53 weighs 8 kg or more, it is difficult to consider manual transfer by safety, and an automatic transfer device such as an OHT (Overhead Hoist Transfer) 60 is used.

In the example of FIG. 11, the FOUP 50 storing the wafer 53 to be processed is transferred from the stocker installed in the process to the processing device 61 (for example, an etching device) by the OHT unit 60.

Next, the FOUP 50 is lowered onto the load port 30 of the processing device 61 using the hoist mechanism 62 and set at a predetermined position (transfer position). Next, the V-groove provided on the lower surface of the FOUP 50 is guided onto the kinematic pin 34 on the load port 30 and fixed at a predetermined position.

Next, the hoist mechanism 62 is removed from the FOUP 50, and the FOUP 50 is placed on the load port 30. Thereafter, the FOUP 50 is moved forward to be fixed to the port door 33 in close contact. Next, the latch of the FOUP door 52 is released by rotating the latch key 35.

Next, the FOUP door 52 is removed from the FOUP box 51 by driving the port door opening / closing mechanism, and the FOUP door 52 is moved to a lower portion inside the processing device 61. With the FOUP door 52 removed, the wafer 53 is taken out from the front of the FOUP 50, and the wafer 53 is transferred to a processing unit (not shown) in the processing device 61 by a wafer transfer robot (not shown) in the processing device 61. Perform processing. Until a semiconductor chip is formed, the opening and closing operation of the FOUP door 52 is performed from 500 times to about 1000 times in many cases.

Next, after the processing is completed, the processed wafer 53 is returned to the FOUP 50 using the wafer transfer robot. After the required processing is performed on each of the wafers 53 stored in the FOUP 50 in this way, the boat door opening / closing mechanism is driven to insert the FOUP door 52 into the FOUP box 51, and the latch key 35 using the cylinder of the present invention. Is temporarily rotated to the position of 90 ° + θ, and the latch is locked by returning the latch key 35 to the 90 ° position, and the FOUP door 52 is fixed to the FOUP box 51.

Thereafter, the FOUP 50 is retracted and stored in the transfer position. In response to the transfer request, the empty OHT unit 60 is stopped on the load port 30, that is, the load port 30 where the FOUP 50 that is the target of the transfer request is placed, and the robot hand (not shown) of the hoist mechanism 62 is moved. Use and pull up.

Next, the FOUP 50 is transported to the stocker by the OHT unit 60 and temporarily stored, and then transported to the next processing step (for example, an ashing step). A desired circuit is formed on the wafer 53 by repeating such a flow (substrate storage jig conveying method).

In the above description, an example in which the OHT unit 60 is used for automatic conveyance has been described. However, the present invention is not limited thereto, and an AGV (Automated Guided Vehicle) or an RGV (Rail Guided Vehicle) may be used. Obviously, manual conveyance using (Person Guided Vehicle) may be used.
In the above-described production system, it is desirable to attach the above-described load ports 30 to all the processing devices 61. However, even in a configuration in which a part of the conventional load port is replaced with the above-described load port, compared to the conventional production system, More stable production can be performed. For example, even when the load port 30 is attached to one of the load ports of the five or six processing units 61 and the conventional load port is attached to the other processing units, the FOUP is connected to the load port. When it is transported, the displacement of the latch key receiver caused by the conventional load port is corrected, and the position can be accurately set to 90 °. As a result, the occurrence of problems such as contact and collision between the latch key and the latch key receiver when releasing the latch key is reduced, and more stable production can be performed.

FIG. 2 is a schematic sectional view illustrating a configuration of a cylinder according to the first embodiment. FIG. 4 is a schematic cross-sectional view illustrating the operation principle of the cylinder according to the first embodiment. FIG. 7 is a schematic sectional view illustrating a cylinder according to a second embodiment. FIG. 9 is a schematic sectional view illustrating a cylinder according to a third embodiment. FIG. 2 is a schematic perspective view illustrating a configuration of a load port. It is a schematic perspective view which shows FOUP. FIG. 2 is a configuration diagram of a port door incorporating the cylinder of the present invention. FIG. 5 is a schematic sectional view illustrating the operation principle of a cylinder of a load port. It is a schematic diagram which shows (a) latch key operation of a load port, and (b) the solenoid valve circuit of a cylinder. It is a top view explaining rocking of a cylinder accompanying reciprocation of a piston rod. It is a conceptual diagram showing the semiconductor production system of the present invention. It is the schematic sectional drawing which shows the cylinder which connected two cylinders of the conventional structure, and made it possible to send out the piston rod to three positions. FIG. 4 is a schematic diagram showing a relationship between a latch key and a latch key receiver.

Explanation of reference numerals

1 cylinder,
2 cylinder tube,
3 piston rod,
4 pistons,
5, 6 fluid ports,
7, 19 cylinder cover,
8 sleeves,
9 groove (recess),
10 Taper,
11 stop pins,
12 spring (second spring member),
13 cover,
14 spring receiving member,
15 spring (first spring member),
16 spring guide member,
17 Stopper part,
18 Piston stop,
21 Knuckles,
30 load ports,
31 frames,
32 stages,
33 port doors,
34 kinematic pins,
35 latch key,
36 registration pins,
37 suction pads,
50 FOUP,
51 FOUP box,
52 FOUP door,
54 registration holes,
55 latch holes,
56 latches,
57 Latch key holder 60 OHT section,
61 processing equipment,
62 hoist mechanism,
71, 72 cylinders.

Claims (2)

A cylinder in which a piston chamber having two end faces is provided in a cylinder tube and a piston rod is reciprocated by a pressure applied to a piston by fluid supplied to the piston chamber through two fluid ports,
A spring receiving member movably disposed coaxially with the piston rod so that movement is defined by the one end surface between the piston and at least one end surface of the piston chamber;
A first spring member arranged to separate the spring receiving member and the piston;
A stopper provided on the piston rod, for limiting movement of the spring receiving member in a direction opposite to the piston with respect to the piston rod;
A recess provided in the piston rod at a position farther from the piston than the stopper,
A stop pin disposed in the cylinder tube so as to engage with the recess, and urged in a direction toward the recess by a second spring member.
A position where the other end surface of the piston chamber is in contact with the piston, a position where the end of the recess away from the piston is in contact with the stop pin, and a position where the end of the recess on the piston side is in contact with the stop pin. A cylinder, wherein the delivery of the piston rod is defined at three positions, which are in contact with or at which the movement of the spring receiving member in the piston direction is stopped. A spring guide member is arranged coaxially with the piston rod between the piston and the stopper, and an inner diameter side of the spring member is supported by the spring guide member and the spring receiving member, so that the spring member directly contacts the piston rod. The cylinder according to claim 1, wherein the cylinder is not configured.

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