DE102010060517A1 - Method for handling flat object e.g. semiconductor wafer, involves fixing object placed in receiving unit by negative pressure while rotating receiving unit - Google Patents

Abstract

The radially extending receiving units (36,38) are rotatable about an axis by a turning device (14). The object (10) placed in the receiving unit is fixed by negative pressure while rotating the receiving unit. The object is fed and taken away through the belt-shaped conveying elements (16,18) of the receiving units. The longitudinal edge portions of the object are made to rest on the conveying elements. The receptacle is made of plastic such as polyaryletherketone. An independent claim is included for arrangement for handling flat object.

Description

The invention relates to a method for handling flat objects, such as wafers or plates, wherein the object is taken up by a radially extending receptacle of a turning device rotatable about an axis and turned by turning the turning device. Furthermore, the invention relates to an arrangement for handling an object, such as wafer or plate, comprising a turning device rotatable about an axis with at least one radially extending receptacle and a transport device for feeding and removing the object to or from the receptacle.

When processing z. B. Wafers for the production of solar cells, it is necessary that the front and back are provided with contacts. For this purpose, the wafers are rotated by 180 °. So z. B. applied to the back of the wafer, a solderable contact layer, the wafer then turned by 180 °, to then apply fingers or busbars on the front of the wafer.

Known devices that allow the turning, use so-called turning wheels, spaced from each other, having an axis rotatable discs with radially extending slots into which the wafers are introduced with their edge regions.

Also vacuum turning units are known, by means of which the wafers are fixed by negative pressure and then turned.

For treating thin objects sees the EP-B-0 970 899 two spaced apart from a wave outgoing disc-shaped cheeks, which have radially open towards the periphery slots as receptacles for the objects. As the cheeks rotate, the slots are closed by a flexible element.

Of the EP-A-0 637 561 For example, a method and an arrangement for converting printed circuit boards from a first transport plane to a second one with approximately the same level can be seen. For this purpose, a rotary wheel is provided in the form of a fan storage, the objects are supplied translationally or led away from this. During turning, the objects are in pockets of the individual compartments.

A disadvantage of the known arrangements is that the objects in the receptacles are mechanically stressed, since the width of the slots is greater than the thickness of the wafers to be received, so that during turning the wafers are moved back and forth between the boundaries. Also, the wafers are basically supported in their outer longitudinal edge areas, so that a breaking of the edges can take place. A mechanical loading of the edge region also takes place in that, when the wafers are fed to the turning device, the wafers are guided laterally.

The present invention is based on the object, a method and an arrangement of the type mentioned in such a way that the mechanical stress on the objects is reduced.

In another aspect, the stress on the edges in the region of the longitudinal edges is to be reduced. It should also be avoided in one aspect that the wafers are contaminated by the material of the recordings.

According to the invention, it is proposed in terms of method to solve for at least one of the aspects that the article is fixed during the turning within the recording by means of negative pressure.

According to the invention an uncontrolled movement of the object is avoided within the slot, since a fixing takes place at one of the limits of the recording by means of negative pressure. The suction by means of negative pressure is then interrupted when the object is turned and oriented basically horizontally, to then be led away with the transport device from the receptacle.

In an embodiment of the invention it is provided that the object with a blow-off pulse in the position in which the object is to be transferred to the transport device, is acted upon. Thus, a targeted placement is ensured on the transport device, so that the object is not exposed to uncontrolled mechanical stress.

In a further development of the invention it is provided that the object is fed by means of two mutually parallel belt or belt-shaped conveying elements of the recording and led away from the turn after turning, wherein the article during conveying with one of its extending in the conveying direction longitudinal edges on one of the conveying elements rests, the turning device or the receptacle extends between the conveying elements and is adjustably designed such that the receptacle extends outside the conveying path of the conveying element or is aligned therewith.

Through the measures in this regard, a mode "run" is possible in which the Turning device is lowered from the conveyor. For this purpose, the turning device z. B. moved by means of pneumatic cylinders, lifting spindles or other suitable adjusting mechanisms in the required extent in the conveying path or be removed from this.

In a further development of the invention it is provided that the object is received at a distance from its respective longitudinal edge of a respective receptacle formed by a slot, wherein a boundary of the respective slot has a plurality of openings through which the object is sucked by means of the negative pressure.

An arrangement of the type mentioned above is characterized in that an object-limiting boundary of the receptacle has at least one acted upon with negative pressure opening for sucking the object, in particular, the recording is a boundary as web-like abutment surface having slot and the boundary more along a straight line having extending connected via a channel with negative pressure acted upon openings.

In order to ensure safe picking and turning of the object, it is provided in particular that the turning device has a pair of pairs each extending in a common radially extending plane spaced receptacles and that the transport device has two belt or belt-shaped transport elements, one of which adjacent to one of the paired receptacle and extends along the respective outer side. Furthermore, the turning device to the transport element is preferably adjustable such that the turning device, if desired, runs outside the conveying path of the article.

Due to the solution according to the invention a safe turning of the article is ensured with structurally simple measures, the mechanical stress during turning is reduced so that in principle a risk of breakage is excluded.

The fact that the object is fixed in slot-shaped recordings by means of negative pressure, a relative movement between the object and the recording during turning can not be done.

As a device for generating the negative pressure in particular a Venturi nozzle is provided. A vacuum generation according to the Bernoulli principle is also possible.

Preferably, the receptacle consists of two bar or rod-shaped elements delimiting the slot. In one of the elements, the channel runs with the openings. Furthermore, a Venturi nozzle should be integrated in the corresponding element to generate the negative pressure. All of the venturi nozzles integrated in the receptacles of the turning device can furthermore be connected to a common compressed air source.

In order to ensure a safe depositing on the surface of the receptacle, which runs when moving the object in alignment with the transport device, provides an emphasized development that the channel connected to the openings is directly connected to the compressed air source or via the venturi with this. In a direct connection between the compressed air source and the channel and thus the openings, a blow-off pulse can be applied in the storage position on the object, so that a secure release of the object takes place from the previously acted upon with negative pressure openings.

The pairwise, each extending in a common radial plane of the turning device recordings capture the object spaced from the respective longitudinal edge, being given as the preferred distance between 10 mm and 20 mm. Immediately adjacent to the recordings run the belt or belt-shaped transport means to introduce the objects into the receptacle or lead away after turning away from the recording. Lateral guides of the object are not required, whereby a sparing of the longitudinal edges takes place in comparison to known arrangements.

To rotate the recordings, a direct drive such as a torque motor can be used so that slip-free turning is possible, an advantage over toothed belts or gearboxes.

The turning device, which can preferably be raised or lowered via pneumatic cylinders, lifting spindle drives or equivalent elements, represents a modular unit, so that several turning devices can be arranged in a multi-track production line. Consequently, one of the turning devices, irrespective of other units z. B. replaced or repaired.

The fact that in each recording, the vacuum source in the form z. B. the venturi or an equivalent element is integrated, short evacuation times can be achieved, so that as a result, a secure detection of the object takes place without the risk that the article is conveyed so in the recording that this with the reason of the recording like that Slot collides. If the object is properly received by a receptacle, this can be detected by a sensor to activate the turning device.

In order to avoid contamination of the objects by contacting with the receptacles, it is further provided that at least the object-side surfaces of the receptacles are made of plastic or coated with plastic, wherein the plastic is preferably a polyaryletherketone.

For more details, advantages and features of the invention will become apparent not only from the claims, the features to be taken these features - alone and / or in combination, but also from the following description of the drawing to be taken preferred embodiments.

Show it:

1 a turning device arranged in a production line,

2 the arrangement according to 1 in side view,

3 the arrangement according to 1 and 2 in plan view,

4 the turning device in a position removed from the production line,

5 a turning wheel in front view,

6 the turning wheel according to 5 in side view,

7 the turning wheel according to 5 and 6 in rear view,

8th the turning wheel of the 5 to 7 in perspective, viewed from behind,

9 a finger of the turning wheel according to the 5 to 8th .

10 a section along the line AA in 9 .

11 according to the finger 9 and 10 in perspective,

12 a detail of the turning device and

13 a section of a multi-lane production line.

With reference to the figures, in which like elements are given the same reference numerals, a method and an arrangement are described, with the flat objects 10 can be turned. At the flat objects 10 In particular, these may be semiconductor substrates, such as wafers, which are processed to produce solar cells. Turning through 180 ° creates the possibility of processing the front and rear in different process stages, providing them with contacts. By a related application example, however, the teaching of the invention is not limited.

Of the 1 is a section of a production line refer to the subject 10 on a transport device 12 a turning device 14 supplied or led away after turning it. The transport device 12 consists in the embodiment of two mutually parallel conveyor belts or belts 16 . 18 on which the object 10 in the transport direction with its longitudinal edge sections 20 . 22 comes to rest.

The turning device 14 has in the exemplary embodiment two mutually spaced turning wheels 24 . 26 on, paired by fingers 28 . 30 . 32 . 34 limited recording slots 36 . 38 have, in a common with respect to the axis of rotation of the turning device 14 extending radially extending plane. In the embodiment, a total of six pairs 40 . 42 . 44 . 46 . 48 . 50 from corresponding paired fingers 28 . 30 . 32 . 34 and with it slits 36 . 38 provided, which extend radially at the same distance from each other.

The pairs of paired and the slots 36 . 38 limiting finger 28 . 30 respectively. 32 . 34 go from hubs 70 . 71 out, over a wave 52 are connected. The wave 52 is from a housing 53 surrounded by a carrier 54 or from this outgoing flat element-like supports 56 . 58 is stored. The carrier 54 is in turn via a pneumatic cylinder 60 , a spindle drive or an equivalent element to the conveyor 12 adjustable, like a comparison of 1 and 4 clarified. This gives the possibility that the turning device 14 with her the slots 36 . 38 limiting fingers 28 . 30 respectively. 32 . 34 outside the conveying path of the conveyor 12 can run (s. 4 ), so that of the conveyor, so of the conveyor belts or belts 16 . 18 recorded objects 10 over the turning device 14 can be transported away.

To ensure safe guiding of the turning device 14 ensure leadership posts go 62 . 64 of the support structure of the conveyor belts 16 . 18 from, as this results in principle from the figures. The guide columns 62 . 64 enforce the carrier 54 the turning device 14 ,

In the 5 to 8th is that in 1 illustrated front turning wheel 26 the turning device 14 shown enlarged. You can see it from the hub 70 the wave 52 outgoing paired fingers 32 . 34 that the slot 38 limit, in which the object to be turned 10 is introduced. It is according to the representation according to the 9 to 11 in the feed direction of the article 10 each lower finger 34 designed such that it fixes the object to be turned by means of negative pressure. This is indicated by the finger 34 , which may have a rectangular profile, in its the object 10 supporting surface 72 preferably along a straight line extending openings 74 . 76 on, over a common channel 78 connected to each other and the one in the finger 34 existing venturi 80 leads to over the channel 78 and thus the holes 74 . 76 to generate a negative pressure in the desired extent. The Venturi nozzle 80 that in the finger 34 is integrated, is in the manner described below via a line 81 connected to an air pressure source, not shown, which also with the fingers in the other pairs 40 . 42 . 44 . 46 . 48 . 50 integrated Venturi nozzles is connected.

When applying the respective Venturi nozzle 80 with compressed air is consequently in the openings 74 . 76 creates a vacuum, leaving one on the surface 72 lying object 10 is sucked.

There is also the option of the channel 78 bypassing the Venturi nozzle 80 Apply directly to vacuum air, so that when the object 10 on the conveyor belts or belts 16 . 18 should be handed over after his turn (representation in 1 ), a compressed air pulse over the holes or openings 74 . 76 on the object 10 is discharged with the result that a safe release of the surface 72 and thus an undisturbed further transport over the conveyor belts or belts 16 . 18 can be done.

The switching of suction, so applying the Venturi nozzle 80 with compressed air and dispensing the release pulse is done automatically. These are in the front of the finger 34 two openings 90 . 92 present, one of which to the venturi 80 and the other, bypassing the functions of the Venturi nozzle 80 to the channel 78 leads. The compressed air supply is designed such that in the receiving position of the turning wheel 26 and while turning to the dispensing position with the Venturi nozzle 80 related opening 90 Compressed air is applied. Is that the object 10 receiving slot 38 in the transfer position, it becomes the venturi nozzle 80 leading opening 92 closed and at the same time over the opening 90 the channel 78 supplied the required Druckluftabblasimpuls.

The leadership of the compressed air and the basic structure of the fingers are also evident from the representations of 5 to 12 , which are self-explanatory.

So runs along the flat element-like support 56 the compressed air line or compressed air hose 81 , which has an elbow fitting 85 with an opening 83 in an annular section 87 the prop 56 connected is. In the annular section 87 run channels to a 180 ° peripheral opening slot 89 and a hole 91 , The peripheral slot 89 is when turning the turning wheel with the openings 90 the finger 34 connected, via an angle of rotation between the receiving position of an object 10 and the delivery position. As a result, the respective opening 90 of the respective finger 34 pressurized with the result that one at the Venturi nozzle 80 Passed channel 93 can be acted upon with compressed air. By the at the venturi 80 As a result, passing compressed air is in the channel 78 generates the required negative pressure. The finger 34 furthermore has an outlet opening 95 on, out of the in the channel 93 at the Venturi nozzle 80 passing compressed air flows out.

The in the annular approach 87 existing hole 91 is in the transfer position of the item 10 located finger 34 with the hole 92 in conjunction with the consequence that omitting the function of the Venturi nozzle 80 the channel 78 With compressed air is applied, so that over the openings 74 . 76 on the one in the slot 38 existing object 10 a blow-off pulse is emitted, allowing a release from the surface 72 takes place and the object on the surface 72 opposite and the slot 38 limiting area 82 comes to rest. Is the connection with the hole 92 made, is the connection with the slot at the same time 89 interrupted.

So that the objects 10 when contacting the fingers 28 . 30 respectively. 32 . 34 can not be contaminated, at least that with the object 10 contacting area 82 coated with plastic or the finger 32 . 34 itself is made of plastic, with the preferred material is polyaryletherketone, in particular PEEK.

The turning device according to the invention 14 has radially extending pairwise associated with each other as a gripper finger fingers to be designated 28 . 30 . 32 . 34 on that the slots 36 . 38 limit, in turn, as recordings for the flat object 10 serve. In each case two pairs of finger pairs are arranged in a common radially extending plane such that the object 10 is received at a distance from its longitudinal edge, wherein the distance between the respective pair of fingers 28 . 30 respectively. 32 . 34 and the longitudinal edge of the object 10 should be between 10 mm and 20 mm.

In each case in the transport feed direction lying down fingers 30 . 34 are openings or holes 74 . 76 present, which are subjected to negative pressure. This is in the respective fingers 30 . 34 a venturi integrated, wherein preferably all Venturi nozzles and the corresponding fingers are connected to a common air pressure source. Is there an item in a slot? 36 . 38 , this is detected by a sensor to turn the turning wheel. During this time, the object to the openings 74 . 76 having surface of the respective finger 30 . 34 sucked.

Of course, the invention is not abandoned when the openings or holes 74 . 76 are provided in the finger in the transport feed direction when depositing the object 10 above the object 10 runs, so in the finger 28 . 32 ,

After 180 ° rotation of the wheel becomes the object 10 solved by a blow-off and in the outlet region of the turning device 14 on the conveyor 12 or the conveyor belts or belts 16 . 18 stored. Vacuum and blow-off impulse are generated during the rotation of the reversing wheel 24 . 26 automatically generated or switched off by a corresponding arrangement of the air ducts. It is thus only a compressed air connection 81 necessary for both functions. The transmission of compressed air takes place via a rotary feedthrough in the support 56 . 58 or their from the wave 52 interspersed annular section 84 , the form-fitting in the hub 70 is used. The holding force of the vacuum becomes the object 10 during rotation, no mechanical stress is exposed by the rotation itself, so that a breakage reduction is given. The turning device 14 and thus the gripper fingers 28 . 30 . 32 . 34 are located in the middle of the conveyor line, ie between the conveyor belts or belt 16 . 18 , Because of the gripper fingers 28 . 30 . 32 . 34 the object 10 do not engage at the outer edges, the object runs 10 no danger of getting stuck on otherwise usual guide rails and thus causing a disturbance. The object 10 becomes free in the discharge area on the conveyor belts or belts 16 . 18 laid down and not affected by mechanical limitations during further transport. The drive of the turning wheels 24 . 26 is preferably via a direct drive, which excludes a slip.

The turning device 14 with the required components is modular as a unit. Will the turning device 14 not needed, so this can be between the conveyor belts or belt 16 . 18 be lowered down. The raising or lowering of the turning device 14 Can be realized via pneumatic cylinders, actuator or spindle drives. The modular unit allows trouble-free maintenance or removal. So z. B. several turning devices according to the invention are arranged side by side in a multi-lane production line, as the 8th clarified. For maintenance or removal of a turning device 14 the remaining ones can remain in operation.

By a suitable material selection of the gripper fingers or a coating of this can be prevented from any contamination or contamination. The preferred material is PEEK.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0970899 B [0005]
• EP 0637561 A [0006]

Claims (14)

Method for handling flat objects ( 10 ), such as wafers or plates, the article being supported by a radially extending receptacle ( 36 . 18 ) a turning device rotatable about an axis ( 14 ) and turned by turning the turning device, characterized in that the object ( 10 ) while turning within the receptacle ( 36 . 38 ) is fixed by means of negative pressure. Method according to claim 1, characterized in that the article ( 10 ) by means of two mutually parallel belt or belt-shaped conveying elements ( 16 . 18 ) of the recording ( 36 . 38 ) is fed and led away from the turning after the turning, wherein the article rests on one of the conveying elements during conveying, each with one of its longitudinal edge regions extending in the conveying direction. A method according to claim 1 or 2, characterized in that the turning device or the receptacles extends or extend between the conveying elements. Method according to at least one of the preceding claims, characterized in that the turning device ( 14 ) is designed so adjustable that the recordings ( 36 . 38 ) from the conveying path of the conveying elements ( 16 . 18 ) for the object ( 10 ) are removable. Method according to at least one of the preceding claims, characterized in that the object ( 10 ) spaced from its respective longitudinal edge by one each through a slot ( 36 . 38 ), whereby a limitation ( 72 ) of a respective slot has a plurality of openings ( 74 . 76 ), over which the object is sucked by means of the negative pressure. Method according to at least one of the preceding claims, characterized in that the object ( 10 ) is applied after turning with a compressed air pulse. Arrangement for handling a flat object ( 10 ), like wafers or. Plate comprising a turning device rotatable about an axis ( 14 ) with at least one radially extending receptacle ( 36 . 38 ) and a transport device ( 12 ) for bringing and removing the object to or from the receptacle, characterized in that an object-side boundary ( 72 ) of the recording ( 36 . 38 ) at least one vacuum acted upon opening for sucking the object ( 10 ) having. Arrangement according to claim 7, characterized in that the receptacle ( 36 . 38 ) the boundary such as web-shaped bearing surface ( 72 ) and that the boundary has a plurality of preferably along a straight line over a channel ( 78 ) and can be acted upon with negative pressure ( 74 . 76 ) having. Arrangement according to claim 7 or 8, characterized in that the turning device ( 14 ) a plurality of pairs each extending in a common radially extending plane and spaced apart recordings ( 36 . 38 ), that the transport device ( 12 ) two belt or belt-shaped transport elements ( 16 . 18 ), one of which is adjacent to one of the paired receptacles and along their outer sides, and that preferably the turning device is adjustable to the transport elements such that the turning device, if desired, outside the conveying path of the object ( 10 ) runs. Arrangement according to at least one of claims 7 to 9, characterized in that the receptacle of two web or rod-shaped slot ( 36 . 38 ) limiting elements ( 28 . 30 . 32 . 34 ), wherein in one of the elements the channel ( 78 ) with the openings ( 74 . 76 ) runs. Arrangement according to at least one of claims 7 to 10, characterized in that in which the channel ( 78 ) having a Venturi nozzle ( 80 ) is integrated to generate the negative pressure. Arrangement according to at least one of claims 7 to 11, characterized in that in the recordings or these limiting elements ( 28 . 30 . 32 . 34 ) integrated venturi nozzles ( 80 ) are connected to a common compressed air source. Arrangement according to at least one of claims 7 to 12, characterized in that the with the openings ( 74 . 76 ) connected channel ( 78 ) directly with the compressed air source or via the Venturi nozzles ( 80 ) is connected to this. Arrangement according to at least one of claims 7 to 13, characterized in that at least the object-side extending surface ( 72 ) of the recording ( 36 . 38 ) is made of plastic or coated with plastic, wherein the plastic preferably consists of a polyaryletherketone or contains.

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