JPH04327441A - Non-contact handling device - Google Patents

Abstract

PURPOSE:To provide a non-contact handling device formed in such a way as to detect the position shift of a semiconductor wafer held in the non-contact state to the holding face of a holding body. CONSTITUTION:A non-contact handling device is provided with a holding body 1 with a holding face 1a, an exhaust nozzle 4 provided at the holding body 1 so as to jet out a fluid for holding a plate like semiconductor wafer 5 to the holding face 1a in the non-contact state, a movable body 7 movable from the opposed position to the holding face 1a of the holding body 1 into the non- opposed position, a driving motor 11 for driving this movable body 7, a light emitting element 12 provided at either one of mutualy opposed parts of the holding face 1a and movable body 7, and a line sensor 6 provided at the other opposed part so as to receive the light from the light emitting element 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact handling device for holding and transporting plate-shaped workpieces such as semiconductor wafers in a non-contact manner.

0002

[Prior Art] For example, in the manufacturing process of semiconductor devices,
There are many processes in which a semiconductor wafer housed in a recess such as a tray or placed on a platform must be taken out and transferred to a predetermined location. One example is the atmospheric pressure CVD equipment.
There is an operation in which semiconductor wafers are transported on a flat plate and transferred to another station.

In such cases, a method is generally used in which the edge of the semiconductor wafer is gripped with a hand having three claws. Retaining the periphery of the semiconductor wafer reduces the problems described above. However, the semiconductor wafer may be chipped due to impact upon contact.

[0004] Therefore, a handling device for holding and transporting semiconductor wafers in a non-contact manner has been developed. This handling device consists of a holder having a lower surface as a holding surface and a spout formed in the center. When the holding surface of the holder is brought close to the semiconductor wafer and fluid such as compressed air is ejected from the spout, negative pressure is generated between the holding surface and the semiconductor wafer due to the Bernoulli effect. The negative pressure allows the semiconductor wafer to be held on the holding surface in a non-contact manner.

By the way, in such a handling device, since the semiconductor wafer is held on the holding surface in a non-contact state, there is no frictional force between them. Therefore, when a force is applied to the semiconductor wafer in a direction parallel to the holding surface, the semiconductor wafer easily shifts in the lateral direction. In other words, unless the holding surface is always perpendicular to the direction of gravity, a force will be applied to the semiconductor wafer in a direction parallel to the holding surface, causing the semiconductor wafer to become misaligned. . Furthermore, even if the holding surface is maintained perpendicular to the direction of gravity, if the holding body is moved at a speed that applies acceleration to the semiconductor wafer in order to transport the semiconductor wafer in that state, the semiconductor wafer will be Since no force is applied in the moving direction, the semiconductor wafer is largely displaced from the predetermined position on the holding surface.

In order to prevent such misalignment of the semiconductor wafer, guide pins are provided protruding from the periphery of the holding surface, and the semiconductor wafer is placed in contact with the guide pins to prevent the semiconductor wafer from misaligning by more than a predetermined amount. things are being done.

However, when the semiconductor wafer is brought into contact with the guide pins, problems arise in that the semiconductor wafer is chipped due to the impact upon contact, and that the chips generate dust.

Therefore, in order to prevent such misalignment of the semiconductor wafer, it has been considered to detect the amount of misalignment of the semiconductor wafer with respect to the holding surface and control the inclination angle of the holder based on the detected signal. . In other words, if the holder is tilted, the semiconductor wafer will slide downward in the direction of inclination of the holding surface, so by tilting the holder according to the amount of deviation of the semiconductor wafer, the deviation with respect to the holding surface is corrected. can do.

When correcting the deviation of the semiconductor wafer with respect to the holding surface in this manner, it is required to accurately detect the amount of deviation of the semiconductor wafer with respect to the holding surface.

0010

[Problem to be Solved by the Invention] In this way, when correcting the displacement of the workpiece relative to the holding surface of the holding body by controlling the inclination angle of the holding body, it is necessary to accurately position the workpiece relative to the holding surface. It becomes necessary to detect the

The present invention has been made based on the above circumstances, and its object is to provide a non-contact handling device that can accurately detect the position of a workpiece relative to the holding surface of a holding body. It's about doing.

0012

[Means for Solving the Problems] In order to solve the above problems, a first means of the present invention is to provide a holding body having a holding surface;
A spouting part provided on the holding body and ejecting fluid for holding a plate-shaped workpiece on the holding surface without contact; A movable body movable to a position where It is characterized by comprising a light receiving means for receiving light from the light projecting means.

A second means of the present invention is a holder having a holding surface, and a spouting section provided on the holder for spouting a fluid for holding a plate-shaped workpiece without contacting the holding surface. and a light projecting means provided on the conveyance path of the workpiece held and transported by the holding body, and a light receiving means provided on the holding surface of the holding body and receiving light from the light projecting means. It is characterized by

[0014]

[Operation] According to the first means, the light emitting means and the light receiving means can be opposed to each other via the workpiece held on the holding surface of the holder, so that the light from the light emitting means can be directed to the workpiece. - Displacement of the workpiece with respect to the holding surface can be detected by determining the state in which the workpiece is blocked by the workpiece using the light receiving means. According to the second means, it is possible to detect the displacement of the workpiece during the process of holding and conveying the workpiece from the state of light reception by the light receiving means provided on the holder.

[0015]

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

FIGS. 1 to 4 show an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a disc-shaped holder. A shaft body 2 is provided protruding from the center portion of the upper surface of the holder 1 . This shaft body 2 is attached to an arm of a robot (not shown) that is driven in the X, Y, Z, and θ directions.

A compressed air supply path 3 is bored in the shaft body 2 . One end of this supply path 3 communicates with a supply source of compressed air (not shown), and the other end communicates with a spout 4 as a spout section formed in the thickness direction of the holder 1.

The lower surface of the holding body 1 serves as a holding surface 1a that holds a semiconductor wafer 5 as a workpiece in a non-contact state by blowing out compressed air from the blowing port 4 using the Bernoulli effect. . A pair of line sensors 6 serving as light receiving means are provided on this holding surface 1a and are spaced apart from each other at a predetermined interval in the radial direction. The line sensor 6 is formed by arranging a large number of light receiving elements 6a to 6n in a line, as shown in FIG.

A pair of band-shaped movable bodies 7 are provided on the lower surface side of the holder 1. That is, one end of each movable body 7 is provided with a support shaft 8 connected to the other end. Each support shaft 8 is rotatably supported at one end in the radial direction of the holding body 1 corresponding to one end in the longitudinal direction of the line sensor 6 . The other ends of these support shafts 8 protrude toward the upper surface of the holder 1 . The other end of each support shaft 8 is connected to a drive motor.
The rotary shaft 11 is connected to a rotating shaft (not shown) of the rotor 11.

Each movable body 7 is driven by the drive motor 11 from the parallel closed state shown in FIG. 2 in the open direction shown by the arrow. On the upper surface of the movable body 7 facing the holding surface 1a, a light-emitting element 12 consisting of a light-emitting diode, an electroluminescent device, etc. is provided as a light projecting means.
It is provided in a straight line corresponding to the In other words, the line sensor 6 and the light emitting element 12 constitute a transmission type optical sensor. Note that if electroluminescence is used for the light emitting element 12, the thickness of the movable body 7 can be made sufficiently thin.

Next, the operation of the above configuration will be explained. When holding the semiconductor wafer 5 on the holding surface 1a of the holding body 1, the pair of movable bodies 7 are driven in the opening direction as shown by chain lines in FIG. In this state, the holding surface 1a of the holding body 1 is brought close to the semiconductor wafer 5 placed in an appropriate position. Then, when compressed air is jetted out from the jet nozzle 4, a negative pressure is created between the holding surface 1a and the semiconductor wafer 5 due to the Bernoulli effect, and this negative pressure causes the semiconductor wafer 5 to be held against the holding surface 1a. Can be held in contact.

Once the semiconductor wafer 5 is held on the holding surface 1a, the pair of drive motors 11 are operated to drive the pair of movable bodies 7, which are in the open state, to the closed state, and in this state, the line sensor 6 is opened. and the light emitting element 12 are activated. That is, each light emitting element 12 provided on the upper surface of the pair of movable bodies 7 is opposed to the pair of line sensors 6 provided on the holding surface 1a.

A semiconductor wafer 5 is interposed between the line sensor 6 and the light emitting element 12 which face each other. Therefore, the light receiving elements 6a to 6n of the line sensor 6 that detect light from the light emitting element 12 differ depending on the position of the semiconductor wafer 5 held on the holding surface 1a. For example, in the state shown in FIG. 4, light receiving elements 6a to 6d receive light. Therefore, by detecting which light receiving element among the many light receiving elements of the line sensor 6 is receiving light from the light emitting element 12, the position of the semiconductor wafer 5 with respect to the holding surface 1a can be determined. .

The semiconductor wafer 5 thus detected
If the holding position relative to the holding surface 1a is shifted,
The inclination of the holder 1 is controlled by the signal from the line sensor 6. That is, since the semiconductor wafer 5 slides downward in the direction of inclination by inclining the holding surface 1a, the deviation can be eliminated by controlling the inclination of the holder 1 in the direction of the deviation.

By using a transmission type optical sensor consisting of a line sensor 6 and a light emitting element 12 to detect the position of the semiconductor wafer 5, the detection accuracy due to ambient light can be improved compared to the case where a reflective type optical sensor is used. Can be done.

That is, in the case of a reflective optical sensor, since the horizontal positions of the light emitting element and the light receiving element are shifted, the light receiving element may be directly blocked by the semiconductor wafer 5. In such a case, disturbance light may enter the light receiving element, making it impossible to accurately detect the position of the semiconductor wafer 5.

On the other hand, in the case of a transmission type optical sensor, the line sensor 6 and the light emitting element 12 are vertically opposed to each other, and the semiconductor wafer 5 is inserted between them to directly block the light from the light emitting element 12. Therefore, the disturbance light hardly enters the light receiving elements 6a of the line sensor 6 that are blocked by the semiconductor wafer 5. Therefore, the transmission type sensor provides higher detection accuracy than the reflection type.

Furthermore, in the case of a reflective optical sensor, if the surface of the workpiece is not a mirror surface, reflected light cannot be reliably detected. On the other hand, a transmission type optical sensor is not affected by the surface condition of the workpiece. Therefore, even if the workpiece is a semiconductor wafer 5 which has been subjected to various surface treatments and whose surface is not in a mirror-like state, the position can be reliably detected.

FIG. 5 shows another embodiment of the invention. In this embodiment, a pair of line sensors 6 are provided on the holding surface 1a of the holding body 1.
This embodiment is the same as the above embodiment in that it is provided with
The light emitting element 12 is not provided on the holder 1 but on the semiconductor wafer 5.
The semiconductor wafer 5 is placed near a platform 21 provided on a conveyance path along which the semiconductor wafer 5 is conveyed for delivery.

According to this configuration, the semiconductor wafer 5 placed on the platform 21 is held on the holding surface 1 of the holding body 1.
It is possible to detect whether the holding state is shifted when the holding state is held by a. In other words, a shift in the holding state of the semiconductor wafer 5 can be detected during transportation.

Although not shown, if the light emitting elements 12 are provided along the entire length of the conveyance path along which the semiconductor wafer 5 is conveyed, it is possible to constantly detect the positional deviation of the semiconductor wafer 5 during the conveyance. .

Although a pair of drive motors are used to rotationally drive a pair of movable bodies, gears that mesh with each other are provided on the pair of movable bodies, and one movable body is rotated by the drive motor. By doing so, the other movable body may be linked,
The driving means is not limited in any way.

[0033]

As described above, according to the first means of the present invention, either the light emitting means or the light receiving means is provided on the holding surface of the holder that holds the workpiece in a non-contact state, The other is provided on a movable body that is driven between a facing state and a non-facing state with respect to the holding surface. Therefore, the positional deviation of the workpiece held on the holding surface can be reliably detected by the light projecting means and the light receiving means.

According to the second aspect of the invention, since the light receiving means is provided on the holding surface of the holding body and the light projecting means is provided on the workpiece conveyance path, the workpiece can be held easily. During the transportation process, the positional deviation can be reliably detected.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a bottom view showing the holding surface side of the holding body.

FIG. 3 is a top view showing the top side.

FIG. 4 is an explanatory diagram of the position detection state of the semiconductor wafer.

FIG. 5 is a schematic diagram showing another embodiment of the invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Holding body, 1a... Holding surface, 4... Spout (spouting part), 5
...Semiconductor wafer (work), 6...Line sensor (light receiving means), 7...Movable body, 11...Drive motor (drive means), 1
2...Light emitting element (light projecting means), 21...Platform (transport path).

Claims (2)

[Claims] Claim 1: A holder having a holding surface; a spout section provided on the holder for ejecting a fluid for holding a plate-shaped workpiece in a non-contact manner on the holding surface; a movable body that is movable from a position facing the holding surface to a position not facing the holding surface, a driving means for driving the movable body, and a portion of the holding surface and the movable body that face each other; A non-contact handling device comprising a light projecting means provided on one side and a light receiving means provided on the other side for receiving light from the light projecting means. 2. A holder having a holding surface, a spouting section provided on the holder for ejecting a fluid for holding a plate-shaped workpiece in a non-contact manner on the holding surface, and a workpiece held by the holder. A non-contact device characterized by comprising a light projecting means provided on the conveyance path of the work to be transported, and a light receiving means provided on the holding surface of the holder for receiving light from the light projecting means. handling equipment.