JP5304566B2 - Substrate transport device with fail-safe mechanism - Google Patents

Description

  The present invention provides a substrate transport apparatus having a positioning table mechanism that floats air by a hydrostatic bearing to perform substrate transport, when the control means such as the power supply being cut off while the positioning table is waiting at a predetermined position is stopped. In addition, the positioning table is prevented from entering the entry prohibition area due to inertia by the spring reaction force of the leaf spring provided at the tip of the stopper shaft, and when an excessive load due to runaway occurs in the table traveling direction It is related with the fail safe mechanism which has the stopper function of the progress prevention of 2 steps | paragraphs which interrupts | blocks the air supply to a static pressure bearing by turning ON, and suppresses progress of a positioning table.

The conventional fail-safe mechanism for preventing the advancement in the substrate conveying apparatus using the static pressure bearing is provided with a separate air control means for controlling the air supplied to the static pressure bearing. When the drive control means is stopped, the air to the static pressure bearing is provided. Is stopped and the static pressure bearing is grounded to suppress the progress of the positioning table (see, for example, Patent Document 1).
In addition, there is a configuration in which a fixing device capable of elastically constraining the movable portion and the fixed portion of the positioning table is provided and the constrained state and the non-constrained state are switched according to the state (see, for example, Patent Document 2).
FIG. 2 and FIG. 3 show a configuration of a conventional travel-preventing fail-safe mechanism of the substrate transfer device using a static pressure bearing.
In FIG. 2, the main body base 1 and the positioning table 2 are supported by being floated by a static pressure bearing 3. The movement of the positioning table 2 is controlled by the drive control means 14, and the air supply of the static pressure bearing is performed by the air control means 15 provided separately. At this time, when the drive control means 14 stops due to power interruption or the like, the air control means 15 automatically stops the air supply to the static pressure bearing and grounds the static pressure bearing to suppress the progress due to inertia of the positioning table.
Further, in FIG. 3, the positioning table 2 that floats on the body base 1 by the hydrostatic bearing 3 has an elastic body between the body base and the positioning table without giving an impact to the apparatus when a large vibration or the like is applied to the apparatus. It is fixed by a fixing device 17 provided with 16 to avoid damage to the device.
Thus, the conventional advance prevention fail-safe mechanism of the substrate conveying device using the hydrostatic bearing suppresses the advancing force of the positioning table due to inertia when the control means is stopped by grounding the air bearing with the friction force due to its own weight, or The advancing force of the positioning table is suppressed by sandwiching and fixing the movable part by the fixing device.

JP 2000-176762

JP 2005-166996 A

The conventional fail-safe mechanism for preventing the advancement of the substrate conveying apparatus by the static pressure bearing is provided with an air control means separately from the drive control means, so that when the control means stops, the air supply to the static pressure bearing is stopped, The structure is such that the static pressure bearing is grounded and the traveling force is suppressed by the frictional force due to its own weight.
However, depending on the grounding brake that shuts off the air supply to the hydrostatic bearing each time the progress of the equipment is suppressed, the restart procedure of the equipment, including the release of the air supply shutoff, becomes complicated and the air supply shuts off. Since the ground contact brake of the static pressure bearing is used regularly, there is a problem that the possibility of inducing serious problems such as chipping of the gap surface of the static pressure bearing and seizure of the gap surface is increased. For this reason, it is desirable to employ a brake by grounding the hydrostatic bearing, specially for emergency.
Also, in the case of unexpected trouble, when the movable part is sandwiched and stopped by a fixing device equipped with an elastic body, if the device runs out of control and an excessive load is generated, only the impact absorption by the elastic body There was also a risk that the main parts of the device could be damaged due to unacceptableness.
The present invention has been made to solve such a problem, and effectively suppresses the progress of the positioning table due to inertia when the control means stops in the substrate transport apparatus, and excessively increases the positioning table due to unforeseen circumstances. It is configured to suppress the progress of the positioning table with a two-stage mechanism so as to stop the positioning table by grounding the hydrostatic bearing by shutting off the air supply to the hydrostatic bearing only when a strong thrust is generated An object of the present invention is to provide a simple and effective fail-safe mechanism for preventing the advancement of a substrate transport apparatus.

In order to solve the above problem, the present invention is configured as follows.
The invention according to claim 1 includes a main body base and a positioning table mechanism that is air-lifted by a hydrostatic bearing on the main body base, moves in a Y direction by a linear motor, and conveys a held base or the like to a predetermined position. A leaf spring that is installed on the main body base, protrudes by an expansion and contraction operation, and is configured to suppress the progress in the Y direction by contacting with the table mechanism; and the leaf spring has a certain amount A base conveyance device characterized by comprising a limit switch that is pressed when displaced as described above.
According to a second aspect of the present invention, the leaf spring is elastically deformed in the Y direction upon contact with the table mechanism, thereby generating a spring reaction force, and having a reaction force opposite to the Y direction. The base conveying apparatus according to claim 1, wherein the base transporting device exhibits an effect of pushing back the table mechanism.
According to a third aspect of the present invention, when the leaf spring contacts the table mechanism, the leaf spring is displaced more than the predetermined amount to depress the limit switch and cancel the progress suppression of the table mechanism. The substrate transport apparatus according to claim 1, wherein the table mechanism is caused to pass through in the Y direction.
According to a fourth aspect of the present invention, the leaf spring is configured by overlapping and fastening a thin plate spring on a stopper bar, and the spring reaction force can be adjusted by increasing or decreasing the number of the stacked thin plate springs. It is comprised, The board | substrate conveyance apparatus of Claim 2 characterized by the above-mentioned.
The invention according to claim 5 is characterized in that, when the limit switch is turned on by the leaf spring, the air supply to the static pressure bearing is cut off by this signal. It is a device.
According to a sixth aspect of the present invention, an air cylinder that causes the leaf spring to extend and contract, a sensor that detects expansion or contraction of the air cylinder, and the limit switch are unitized on the same base. The substrate transport apparatus according to claim 1, wherein

According to the first aspect of the present invention, the progress of the positioning table is suppressed by the contact of the leaf spring, and the progress of the positioning table due to inertia when the control means is stopped in the substrate transport apparatus is effectively suppressed, and the unexpected situation The two-stage mechanism suppresses the progress of the positioning table by stopping the positioning table by grounding the static pressure bearing by shutting off the air supply to the hydrostatic bearing only when excessive thrust is generated on the table. Can be configured to do.
According to the second aspect of the present invention, the traveling force due to the inertia of the positioning table is received by the elastic force of the spring, absorbs the impact force, and converts the force as a reaction force action to push the positioning table back to the safety region. The effect can be exerted.
According to the invention described in claim 3, when the leaf spring is in the elastic region, it can be elastically deformed by the generation of force, so that a certain amount of traveling force is received and the traveling force becomes excessive. The table can be passed through by displacing.
According to the fourth aspect of the present invention, since the leaf spring is configured by overlapping and fastening the thin plate spring on the stopper bar, the spring reaction force can be easily set in accordance with the progress suppressing force, and the positioning table Even if a weight change occurs, it can be dealt with by simply increasing or decreasing the number of springs.
According to the fifth aspect of the present invention, the limit switch is turned on and the air supply to the hydrostatic bearing is stopped only when an excessive advance force is generated in the leaf spring and the spring displacement exceeds a certain amount. Since it is a mechanism, it is possible to appropriately determine the means for suppressing table progression due to inertia and the means for suppressing emergency progression according to the situation.
Further, according to the invention described in claim 6, since the expansion / contraction state of the air cylinder can be set according to the stand-by position of the table, a complicated circuit configuration is not required, and a fail-safe for easily and effectively preventing progress. The mechanism can be realized. Further, since this mechanism can be removed as a unit, it is possible to remove the unit as a whole even in an intricate device environment, and perform maintenance such as adjustment / replacement in a wide environment, thereby improving workability.

FIG. 1 is a block diagram of a fail-safe mechanism for preventing the advancement of a substrate transfer device using a hydrostatic bearing according to a first embodiment of the present invention. Fig. 1 is a block diagram of a conventional mechanism for preventing the advancement of a substrate transfer device using a hydrostatic bearing. Fig. 2 is a block diagram of a conventional mechanism for preventing the advancement of a substrate transfer device using a hydrostatic bearing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1A and 1B are diagrams showing a configuration of a fail-safe mechanism for preventing advancing of a substrate conveying apparatus using a hydrostatic bearing according to the present invention, wherein FIG. 1A is a perspective view of the whole, and FIG. 1B is a detailed view of a stopper mechanism.
In the figure, 1 is a main body base, and 2 is a static pressure bearing fixing shaft installed on the main body base. Reference numeral 3 denotes a static pressure bearing movable portion. A linear table 4 is arranged on each movable portion, and a positioning table 5 is mounted that bridges the movable portion and holds and conveys the base.
There is a loading point 6 for transferring the base held on the positioning table 5 to a loader mechanism (not shown) at the tip of the Y traveling direction. In front of the loading point 6, a stopper mechanism 7 is installed perpendicular to the traveling direction in order to suppress the entry of the positioning table 5 when the loader mechanism is entering the loading point 6. The stopper mechanism 7 includes a stopper shaft 9 mounted on the air cylinder 8, a leaf spring 10 provided at the tip of the stopper shaft 7, a limit switch 11 that is turned on when the leaf spring is displaced by a predetermined amount or more, and a sensor 12 that monitors a cylinder expansion / contraction state. It consists of a unit formed on the stopper base 13.

The operation of the above configuration will be described below. The positioning table 5 that holds and conveys the base and the like is floated on the main body base 1 by the static pressure bearing fixed shaft 2 and the movable portion 3, and is driven by the linear motor 4. The positioning table 5 delivers the loader mechanism and the substrate at a predetermined loading point 6 and waits at a predetermined position to avoid a collision with the loader mechanism when the loader mechanism enters the loading point 6. It is controlled as follows.
However, when the control means is stopped due to power interruption or the like, the positioning table 5 that floats in a non-contact manner by the air bearing does not have a holding force to stop at that position, so that it may enter the loading point 6 due to inertia. For this reason, in the state where the positioning table 5 is waiting at a predetermined position, the air cylinder 8 constituting the stopper mechanism 7 extends the stopper shaft 9, thereby closing the traveling route by the leaf spring 10 provided at the tip, and loading. The position table 5 is prevented from entering the point 6. Further, the leaf spring 10 provided at the tip of the stopper shaft 9 can be elastically deformed in the traveling direction of the positioning table 5, and even if the positioning table 5 travels due to inertia and contacts the leaf spring 10, its advancing force Is elastically deformed and is converted into a spring reaction force to exert an effect of pushing the positioning table 5 back toward the standby position. The leaf spring 10 is configured by overlapping and fastening a thin plate spring on a stopper bar, and is configured so that the spring reaction force can be easily and effectively adjusted by increasing or decreasing the number of stacked springs.
Furthermore, when an excessive load due to runaway or the like occurs due to an unexpected situation of the positioning table 5, it is difficult to cope with only the effect of suppressing the advancement by the spring reaction force of the leaf spring 10. Driving stop means is required. However, shutting off the air supply and grounding the hydrostatic bearing is effective as a drive stop means, but using it as a regular means increases the risk of chipping and seizing on the gap surface of the air bearing. Appropriate measures such as specializing in emergency must be determined. For this reason, only when the leaf spring 10 receives an excessive load and is displaced by a certain amount, the leaf spring 10 pushes the limit switch 11 provided in the traveling direction to turn on the switch signal of the limit switch, and air to the hydrostatic bearing Configure to cut off supply. Further, the leaf spring 10 is displaced by a predetermined amount or more, thereby canceling the progress of the positioning table 5 and causing the leaf spring 10 to pass through. Accordingly, when the control means is stopped, the progress suppression due to inertia uses the spring reaction force of the leaf spring 10 and the progress suppression of emergency or the like in which an excessive load is generated is appropriate depending on the situation where the air supply is shut off. A two-stage fail-safe mechanism is configured.
Since the stopper mechanism 7 is unitized on the stopper base 13 together with the air cylinder 8 and the stopper shaft 9, the leaf spring 10 and the sensor 12 for monitoring the expansion / contraction state of the cylinder and the limit switch 11 for shutting off the air supply, it is complicated. However, it is possible to remove and adjust / replace the entire unit even in a device environment, contributing to improved workability.

  The difference between the present invention and the prior art is that the stopper shaft expands and contracts according to the position of the positioning table, and the progress of the table is blocked by a leaf spring provided at the tip of the stopper shaft, thereby suppressing the progress of the spring reaction force. In the margin where an excessive load is generated, there is a two-stage fail-safe mechanism that can switch the progress suppressing means to the grounding of the air bearing before damaging the equipment, and a stopper mechanism. By making the unit, it is possible to make adjustment / replacement by removing the unit and improve workability.

  Since the present invention has a two-stage fail-safe mechanism corresponding to the failure status of the apparatus, it can secure higher reliability and has an effective maintainability. Therefore, the semiconductor manufacturing stage such as wafer transfer and reticle transfer is particularly preferred. Useful as a mechanism for the device.

DESCRIPTION OF SYMBOLS 1 Main body base 2 Static pressure bearing fixed shaft 3 Static pressure bearing movable part 4 Linear motor 5 Positioning table 6 Loading point 7 Stopper mechanism 8 Air cylinder 9 Stopper shaft 10 Leaf spring 11 Limit switch 12 Monitoring sensor 13 Stopper base 14 Drive control means 15 Air control means 16 Elastic body 17 Fixing device

Claims (6)

In a substrate transport apparatus comprising a main body base and a positioning table mechanism that floats on the main body base by a hydrostatic bearing, moves in the Y direction by a linear motor, and transports the held substrate to a predetermined position.
A leaf spring installed on the main body base, protruding by an expansion / contraction operation and configured to suppress the progress in the Y direction by contacting the table mechanism, and pressed when the leaf spring is displaced by a predetermined amount or more. And a limit transfer switch.   The leaf spring is elastically deformed in the Y direction upon contact with the table mechanism to generate a spring reaction force, and exerts an effect of pushing back the table mechanism by generating a reaction force action opposite to the Y direction. The substrate carrying device according to claim 1.   When the leaf spring contacts the table mechanism, the leaf spring is displaced more than the predetermined amount to press the limit switch, and the progress of the table mechanism is released to let the table mechanism pass through in the Y direction. The board | substrate conveyance apparatus of Claim 1 characterized by these.   The leaf spring is configured by overlapping and fastening a thin plate spring on a stopper bar, and is configured to adjust the spring reaction force by increasing or decreasing the number of stacked thin plate springs. 2. The substrate transfer device according to 2.   4. The substrate transfer apparatus according to claim 3, wherein when the limit switch is turned on by the leaf spring, the air supply to the static pressure bearing is cut off by this signal.   2. The air cylinder that causes the leaf spring to extend and contract, a sensor that detects expansion or contraction of the air cylinder, and the limit switch are configured as a unit on the same base. Base transport device.

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