KR20040044473A - Method and device for contactless handling or fixing of a glass object - Google Patents

Abstract

The present invention relates to an apparatus for non-contact handling or fixing of an object, in particular a glass panel. The device comprises at least one first partial surface for which traction is applied to the object, and at least one agent for surrounding the first partial surface and optionally having a repulsive force applied to the object by a gas cushion on the porous gas exit surface. And two adjoining partial surfaces, wherein the traction and repelling forces are optionally selected and adjusted to balance the weight of the object to maintain the object in a non-contact stable position. The present invention is characterized in that a traction force that can be generated and adjusted for an object is applied to the object by magnetic force or by one or more low pressure regions, irrespective of the repulsive force. The invention is also characterized in that the traction and repulsive forces act simultaneously on the same side and the same area of the object. The present invention is also characterized in that the direction of action and mass of the repulsive force are independent of the traction force.

Description

METHOD AND DEVICE FOR CONTACTLESS HANDLING OR FIXING OF A GLASS OBJECT}

In the processing of glass or glass ceramics, it is often necessary to handle or transport bodies with very sensitive surfaces.

Conventional devices for movement, in particular ascent, transfer the force required to move the object by direct contact with the object, for example by a grappler or finger. Numerous embodiments are known and possible here. However, in common, contact with the surface is inevitable. Often, the surface is in a state where the contact or the contact portion of the device is damaged by the contact.

In other devices, the moving object is contacted through the inhaler. Here, it is important that a sufficiently good sealing of the inhaler to the object allows for a low pressure build up inside the inhaler to allow non-positive coupling. For the sealing, a flexible material such as plastic or a fine metal structure is used. However, the seal is only effective when the seal is placed close to the surface of the object or compressed. Again, such contact may result in damage to the surface of the object and / or damage to the inhaler.

Particularly critical are objects having a surface that has just been treated, for example with an uncured coating, or a surface prepared for subsequent processing. Since all contacts of the object are sources for surface damage, high requirements are placed on the device to be in contact with the object. In particular, contaminants due to wear of the mobile device should not be transferred to the object.

In other cases, the surface of the object to be manufactured is in a state where no contact is allowed because it does not have a suitable contact material. For example, there is little material in the vacuum inhaler for high temperature glass parts because all flexible plastic materials are destroyed in the shortest time at temperatures above 450 ° C. Other materials that withstand the temperature leave traces on the glass part surface.

The present invention relates to the field of handling of a body, in particular of a body made of glass or glass ceramics. However, the present invention also relates to all other objects having surfaces that are sensitive to contact.

1 is a schematic representation of an object and a device acting on the object.

2 a plan view of the device according to FIG. 1;

It is an object of the present invention to provide a method and apparatus capable of handling, moving or transporting a sensitive body made of glass or glass ceramic without damaging the surface or deforming the body.

This object is achieved by the features of the independent claims.

The present invention makes it possible to move an object by applying force to the object without making direct contact between the part of the device and the object. In particular, it is possible to raise and hold the object against gravity without having a portion of the device in contact with the object.

The invention can be applied to any object having a surface that is sensitive to contact. For example, the object is a semiconductor wafer during chip manufacturing.

The invention is based on the fact that, with a suitable combination of the traction and repulsive forces generated independently of one another, the object can be held at small intervals from the device according to the invention. When traction, repulsive force, and lift of the object are handled, the interaction of gravity can set the state in which force can be transmitted to the object without making direct contact between the device and the object.

When the object is placed at a constant equilibrium distance (H _o ) from the device, the traction force (F _A ), repulsive force (F _R ) and gravity (G) against the object are in equilibrium. In other words, the resulting force F becomes zero:

F (H ₀ ) = G + F _R (H ₀ )-F _A (H ₀ ) = 0

In this case, for example, corresponding to the elevation of the object, gravity G and repulsive force F _R are negative and traction force F _A is positive. For the resulting force F, the negative sign indicates the repulsion of the device and the positive sign indicates the traction of the device.

In order to remain in this position by itself, even when slightly deflected from the equilibrium due to the process, the traction and repulsive forces must be selected and adjusted so that the traction force prevails when the object is slightly deflected from the equilibrium in the direction away from the device. When the object is deflected from equilibrium towards the device, the repulsive force must prevail.

The resulting force F depends on the distance H between the object and the device. The following formula applies:

dF (H)

… <0 H H ₀

dH

If H decreases to a value smaller than H ₀ , the repulsion becomes large. If H increases to a value _greater than H ₀ , traction is caused. If the forces match each other in the above manner, the objects remain at a small distance H ₀ from the device in a metastable equilibrium because the traction and repulsive forces themselves are adjusted to the equilibrium interval H ₀ . If the object deflects very much in the direction away from the device, the traction and thus the holding action will someday stop.

In embodiments the traction may be provided in different ways.

When the object is moved by magnetic force, a magnet can be used. Through the strength of the magnet and its spacing to the object surface, the magnitude of the traction can be adjusted. Preferably electromagnets with variable intensities are used.

In the case of nonmagnetic objects, the traction is provided by one or more low pressure regions. The magnitude of the traction force can be varied by the size of the low pressure region, the suction force of the connected pump, and the gap width H _k between the low pressure region and the moving object.

Repulsive forces are generated, for example, by gas cushions formed in one or more areas on the device surface towards the moving object. The region of the device is formed of a gas permeable material, preferably a porous material, and a gas overpressure is applied to the back side of the material. The overpressure causes gas to flow through the material. The repulsive force can be controlled by the size of the region and the amount of gas passing through, which is formed upon a lack of constant access to the device. Preferably the gas amount of 0.1-30 l / (min * cm <2>) is used. If the device according to the invention is large, preferably a small amount of gas per unit area is used.

The device surface facing the moving object includes one or more regions in which traction is generated, and one or more regions in which repulsive force is generated. Preferably the regions are arranged to surround each other to prevent the object from tilting against the device, for example in the form of concentric rings or regions.

When a low pressure zone is used to generate traction, a zone is provided between the zone and the gas cushion zone, through which air can flow into the low pressure zone without degrading the effectiveness of the rebound gas cushion zone. It is preferable. The area where the traction force is generated by the low pressure should preferably have a distance larger than the area where the gas cushion acts on the moving object by an amount H _K. H _K is preferably moved from 0.1 to 1 mm.

The equilibrium spacing (H _o ) where the repulsive and traction forces are in equilibrium with gravity in general is 1 mm. Therefore, the surfaces facing each other of the object and the device should be well matched. If the surfaces are well matched, the arbitrarily formed object can be moved or held by the corresponding device.

In particular, it is possible to move objects with spherical, non-spherical and otherwise curved surfaces. Here, by the shape of the front face, inherent stabilization of the lateral movement of the object is achieved.

If the object is flat, the device has a flat front face. In this case, a restriction suitable for the side is mounted to prevent the object from slipping to the side from the device. If side contact of the object is allowed (such as in a surface coated disc), the contact may be made by a simple retaining strip. If side contact is not allowed, stabilization can be effected by means of side mounted devices or by gas nozzles, likewise with a repellent gas film.

Although the device has been considered to elevate an object with a sensitive surface, the principles can be applied to other devices where force must be transmitted in a non-contact manner to hold, guide, attract or move the object. The principle can also be applied to coupling of two surfaces. For example, it is possible to contactlessly fix an object to a frictionless support such as an air bearing table.

The present invention can be used in many ways. The present invention is intended for use in areas where objects with contact sensitive surfaces are handled, for example in optical lenses, or in semifinished products with fire polished surfaces, in flat glass panels or flat glass discs, in filter discs or in semiconductor substrates in chip manufacturing. Can be. The invention is particularly important in the coating process.

Hereinafter, with reference to the accompanying drawings of the present invention will be described in detail.

1 shows the following in detail. The plate is placed in the horizontal plane. All materials, such as glass, are used for the plates. On the plate is arranged an apparatus 2 according to the invention. The device comprises a disc 2.1 and a circular ring 2.2. The disc 2.1 and the circular ring 2.2 are arranged concentrically with each other. Disc 2.1 has a radius R ₀ . Circular ring 2.2 has an inner radius R ₁ and an outer radius R ₂ .

The spacing between the circular ring 2.2 and the plate 1 is H. The gap between the plate 1 and the disc 2.1 is H + H _k .

The plate 1 is not shown in FIG. 2 for the purpose of clarity.

Device 2 acts as follows:

A negative pressure is applied on the plate 1 by the disc 2.1, and a positive pressure is applied by the circular ring 2.1. This can be implemented as follows:

The disc 2.1 may have a hole. The holes penetrate the disc 2.1 and are evenly distributed over the entire surface. The hole is connected to the low pressure device.

Instead, the disc may have a single center through hole.

In each case, the chamber between disc 2.1 and plate 1 is somewhat strongly evacuated. As an alternative, magnets, preferably magnets of variable strength, can be used in this area.

Alternatively, the compressed gas is guided through the circular ring 2.2. For this purpose, the circular ring 2.2 can also have a through hole. When the overpressure device is connected to the hole, the gas emerges from the side of the circular ring 2.2 towards the plate 1 and exerts a corresponding pressure on the plate.

Instead of the through holes, the disc 2.1 and / or the circular ring 2.2 may be embodied in an open porous material. This is preferable because a planar action can be obtained.

In each case, the corresponding parameters are set such that the interaction of the traction and repulsive forces is achieved and the plate 1 remains suspended. In this case, a constant distance H between the plate 1 and the circular ring 2.2 and a constant distance H + H _K between the plate 1 and the disc 2.1 must be obtained.

It is also possible that the intervals are maintained by a control device comprising a sensor for detecting the actual interval and a CPU for setting the set interval.

Thus, it is possible for the plate 1 to be handled in any manner, in particular to be raised or held in position, or moved from one place to another, in particular without contact between the plate 1 and the device 2.

The apparatus may have a different shape than shown here. For example, the disc 2.1 and / or the circular ring 2.2 can be divided. The device need not be circular. The device may be square or rectangular or have another shape. The device preferably has a contour identical or similar to that of the object to be handled when viewed in plan view.

The object to be moved does not have to be flat and flat. If the front side of the device matches the surface of the body, a body with an arbitrarily formed surface can be treated as a corresponding device.

Claims (5)

At least one first partial surface for which a traction force is applied to the object, At least one second adjacent partial surface that surrounds the first partial surface and optionally causes a repelling force to be applied to the object by a gas cushion on the porous gas discharge surface, In the device for non-contact handling or fixing of an object, in particular a glass panel, said traction or repulsion force is selected and adjusted to balance the weight of the object with the object in some cases so as to maintain the object in a non-contact stable position. A traction force that can be generated and adjusted for the object is applied to the object by magnetic force or by one or more low pressure regions, irrespective of the repulsive force, The traction and repulsive forces act simultaneously on the same side and the same area of the object, Apparatus for non-contact handling or fixing the object, characterized in that the direction of action and mass of the repulsive force is independent of the traction force. The method of claim 1, Said traction forces act on the object by at least one low pressure region, Between the gas cushion or all gas cushions and the adjacent low pressure region, there is an ambient pressure region separating the overpressure region and the low pressure region so that the gas cushion is not affected by the low pressure region. Device for fixing. The method of claim 2, Non-contact handling of an object, characterized in that the device side facing the object is further away from the surface of the object in the region between the at least one peripheral pressure region and the adjacent low pressure region by a distance difference H _K than in the at least one gas cushion region. Or a device for fixing. The method according to any one of claims 1 to 3, Apparatus for non-contact handling or securing an object, characterized in that the surface of the device facing the object is substantially flat. The method according to any one of claims 1 to 3, And the device surface facing the object has any shape suitable for the object surface facing the device.