WO2007095916A2

WO2007095916A2 - Device for aligning and machining a wafer

Info

Publication number: WO2007095916A2
Application number: PCT/DE2007/000319
Authority: WO
Inventors: Andreas Behr
Original assignee: Innolas Gmbh
Priority date: 2006-02-24
Filing date: 2007-02-21
Publication date: 2007-08-30
Also published as: WO2007095916A3; DE112007001002A5; DE202006002998U1

Abstract

The invention relates to a device for aligning and/or machining a wafer, especially for marking or inscribing a wafer by means of a laser beam, said wafer (10.7) comprising a circular periphery with a pre-determined deformation section. The inventive device comprises a rotary table (3.7) that can rotate about a rotational axis and on which only the edge or an edge region of a wafer (10.7) to be machined lies tangentially, a clamping device (5.7) for clamping and holding a wafer on the rotary table (3.7), the clamping device engaging in the deformation section (10.17) on the periphery of the wafer in order to align the wafer on the rotary table (3.7), and a position measuring device which is coupled to the clamping device (5.7) in order to determine a clamping position of the wafer, when the wafer (10.7) is clamped to the rotary table (3.7) in the clamping device (5.7).

Description

Device for aligning and processing a wafer

The present invention relates to a device for ^aligning and / or processing a wafer according to the preamble of claim 1.

DE 20 2004 011 907 U9 describes an apparatus for marking or writing a wafer with a laser beam, the wafer having a circular peripheral edge with a predetermined deformation portion, e.g. a notch or notch can be. The known device or Aligner has a turntable, which can rotate about its axis of rotation and rests on a wafer to be processed only with its edge or edge region in the manner of a tangential edge contact. In the case of the known aligner, when the wafer is aligned, it may now happen that the wafer is placed obliquely on the turntable or slips when aligned during rotational alignment, which impedes or even prevents proper alignment or processing of the wafer with the intended high accuracy. A rotational movement performed during the processing of the wafer can lead to an undesired slippage of the wafer on the turntable, so that a regular processing of the wafer may no longer be possible.

The object of the present invention is therefore to provide a device which avoids an unwanted change in position of a wafer when aligning and processing the wafer to achieve a high alignment and processing accuracy.

This object is achieved by the device of claim 1. Accordingly, the apparatus for aligning and / or processing a wafer, in particular for marking or writing a wafer with a laser beam, the wafer having a circular circumference with a predetermined deformation portion, a turntable, which can rotate about a rotation axis and on a wafer to be processed rests only with its edge or edge region, a clamping device for clamping and holding a wafer on the turntable, wherein the clamping device engages in the deformation section on the periphery of the wafer to align the wafer on the turntable, and a position measuring device, the is coupled to the clamping device for determining a clamping position of the wafer, when the wafer is clamped on the turntable in the clamping device.

The device of the invention has the advantage, due to the pinching and the consequent holding of the wafer, of allowing an accurate alignment of the wafer in a processing position and also maintaining a defined position of the wafer when the wafer is rotated during processing , Thus, when processing the wafer, faster rotational movements can be performed on the turntable without the wafer slipping on the turntable, whereby the processing throughput of the wafers can be significantly increased and also the processing accuracy of the wafers, e.g. when laser marking of wafers, can be increased. In addition, the machining accuracy can also be improved by the position measurement of the wafer in the aligned position on the turntable, since the measured position of the wafer in the processing of the wafer, e.g. by laser beam, can be considered. With the device or the method of the invention, therefore, a processing accuracy in the processing of wafers by means of a laser beam of up to + 5 microns and typically ± 20 microns can be achieved.

Preferably, the device of the invention has a diameter measuring device for measuring the diameter of a resting on the turntable wafer when pinched in the clamping device, whereby, for example, a difference in size of the respective wafer to a reference wafer or standard wafer or a given wafer size can be detected.

The position measuring device and / or the diameter measuring device may be coupled to the clamping device and a movement of the clamping device is taken into account in the measurement of the position or the wafer diameter. This has the advantage that a reliable measurement of the position of the wafer on the turntable or its diameter is made possible by the clamping.

Preferably, the clamping device is fixedly mounted on the turntable and rotates with the turntable, whereby a very compact and therefore space-saving construction of the device of the invention can be achieved.

The clamping device may have a first, movable clamping portion and a second, fixed clamping portion opposite to the first clamping portion for clamping a wafer between the two clamping portions, wherein the clamping portions touch the wafer only at its edge periphery when clamping, whereby damage or adverse contamination of Processing surfaces of the wafer can be prevented.

The second, fixed clamping section preferably has a plurality of stop parts or stops which are arranged separately along a circle about an axis of rotation of the turntable in a horizontal plane, in which the wafer rests on the turntable, and against which a wafer abuts with its edge circumference, if he is trapped in the clamping device. At the stops, the wafer can slide along during the clamping process to achieve alignment of the wafer. The first, movable cleram portion may be movable radially and linearly with respect to a rotation axis of the turntable and be supported on the turntable, which means that the clamping device always has a fixed position relative to the turntable.

There may be provided a drive means for the clamping means, which is preferably provided with a fluid, e.g. Compressed air moving clamping device. The use of a pneumatic drive enables a compact and cost-saving construction of the drive, in particular in the turntable, since e.g. only a compressed air line and a compressed air cylinder must be integrated as an actuator in the turntable, which only have a small footprint.

Preferably, the drive means for the clamping device has a pneumatic actuator which is coupled to the first, movable clamping portion of the clamping device to move it radially with respect to the rotational axis of the turntable and relative to the turntable linear or rectilinear. By a corresponding compressed air applied to the clamping device by the pneumatic actuator force transmitted can be adjusted precisely such that the wafer when clamping acts only a force that avoids damage or unwanted bending of the wafer during clamping.

Preferably, the compressed air actuator is arranged in a recess of the turntable, resulting in a compact construction of the device.

A spring device can be coupled to the clamping device for biasing the clamping device in an initial position relative to the turntable or to a wafer, which can be ensured that the clamping device is always in its maximum open position without compressed air. The attached to the turntable air actuator is preferably coupled to a compressed air line extending in a hollow shaft of the turntable, which is symmetrical to the axis of rotation of the turntable, whereby a particularly simple and easy compressed air supply to the built-in turntable compressed air cylinder can be realized. In this context, the compressed air actuator is preferably coupled via a compressed air coupling joint with the compressed air line.

The first, movable clamping portion preferably has at least one clamping pin for contacting the edge periphery of the wafer, wherein a vertical central axis of the clamping pin extends parallel to the axis of rotation of the turntable. The clamping pin allows secure engagement in e.g. a marginal notch or Notch of the wafer and therefore also a regular alignment of the wafer by clamping on the turntable.

Alternatively, the first clamping portion may have at least two clamping pins for contacting the periphery of the wafer, each of the clamping pins having a vertical central axis extending parallel to the axis of rotation of the turntable. With this design, a safe starting and clamping of a wafer with straight flattening or Fiat can be realized at the edge circumference and a correspondingly secure alignment of this wafer.

Preferably, a length measuring device is coupled to the clamping device or the first movable clamping section of the clamping device in order to be able to determine a path length during the movement of the clamping device or of the first clamping section or a clamping position. By means of the path measuring device, the absolute, aligned position of the clamped wafer can be determined on the turntable. The length measuring device may have an optoelectronic linear encoder or an incremental displacement meter, which allow a reliable, practically wear-free and very accurate measurement, since they work optically, so non-contact.

Preferably, the apparatus has an offset detecting means which generates an offset signal or offset information or data indicative of a local offset or alignment error between a target machining position in which a wafer is to be machined and the actually achieved actual machining position of the workpiece Wafers after clamping in the pinching device, the device of the invention can use the offset signal or the offset information or data of the offset detecting means for correcting or compensating for the offset of the wafer when processing the wafer in the achieved actual machining position, which in turn the accuracy of wafer processing can be significantly improved.

Preferably, a device for depositing, lifting and holding the wafer in a position at a distance from the turntable is provided such that the turntable can rotate without a wafer. Among other things, this device enables a coarse alignment of the wafer relative to the turntable.

Preferably, the apparatus of the invention is used as a marking device having laser means for generating a laser beam which is directed to a wafer surface via a laser beam deflecting unit and focusing means for marking or writing a wafer at a designated location, the laser beam deflecting unit detecting one local offset or associated offset coordinates for correcting or compensating for an alignment error of the wafer on the turntable when marking or writing the wafer. When clamping the wafer, the clamping device is preferably moved out of a clamping start position, in which the wafer is not clamped, by moving a distance to a clamping position in which the wafer is clamped on the circumference, wherein the clamping device does not engage in the deformation section of the wafer , and the distance or clamping position is used as a measure of the diameter of the wafer, whereby advantageously the diameter of the respective wafer can be determined.

Preferably, when clamping the wafer, the clamping means will come out of a clamping initial position in which the wafer is not clamped, moving a distance to a clamping position in which the wafer is clamped circumferentially, the clamping means engaging the deformation portion, and the distance becomes is used as a measure of offset of the wafer from a given target processing position of the wafer. As a result of this method step, it is possible to determine both an orientation of the wafer and an actual position of the aligned wafer, and thus also an alignment offset of the wafer.

Preferably, when clamping the wafer, the clamping means will come out of an initial position in which the wafer is not clamped, move a distance to a clamping position in which the wafer is clamped circumferentially, the clamping means engages the deformation portion, and the wafer becomes realigned in its initial position when the measured distance or clamping position is less than a first predetermined value. In this way, in particular the case can be detected that the clamping device is not properly retracted into the notch or the deformation portion and thus the intended orientation of the wafer has failed.

The clamping device may, when clamping the wafer out of its initial position, in which the wafer is not clamped, be moved a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device does not engage in the deformation portion, and the wafer can then be removed from the turntable, when the distance is greater than a second predetermined value. In this way, in particular the case can be detected that the clamping device does not clamp on the edge circumference of the wafer, which is an indication that the wafer rests for example obliquely on the plate and thus has been undermined by the clamping device or that there is no wafer on the turntable is.

When clamping the wafer, the clamping device is preferably moved out of an initial position in which, the wafer is not clamped, by a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device engages in the deformation portion, and the wafer is then removed from the turntable when the distance is greater than a third predetermined value. In this way, it can be found in particular that the clamping device, although obviously retracted correctly into the notch or the deformation section, but the notch depth is too large, so that the wafer is rejects, or that the wafer was obliquely or simply slant was placed on the turntable.

The apparatus of the invention can be used in a method for aligning and / or processing a wafer, in particular for marking or writing a wafer with a laser beam, the wafer having a circular circumference with a predetermined deformation section, the wafer being deposited on a turntable is and the wafer rests on the turntable only with its edge or edge region, wherein the wafer and a clamping device are aligned relative to each other such that the deformation portion is in a predetermined initial position relative to the clamping device, the wafer then at its edge periphery of the clamping is clamped and held when clamping the wafer from the initial position in which the wafer is not clamped, by a distance in a clamping position in which the wafer is clamped by the clamping device on the periphery, and the traversed Distance of the clamping device or reached clamping position of the clamping device is measured.

The clamping device moves when clamping the wafer from a Klemmanfangsstellung in which the wafer is not clamped, preferably by a distance to a clamping position in which the wafer is clamped at the periphery, wherein the clamping device does not interfere with the deformation portion and wherein the measured Distance or measured clamping position is a measure of the diameter of the wafer.

Furthermore, when clamping the wafer, the clamping device can move out of a clamp start position in which the wafer is not clamped by a distance to a clamping position in which the wafer is clamped circumferentially, wherein the clamping device engages in the deformation section and wherein the measured Distance or measured clamping position is a measure of an offset of the wafer from a predetermined target processing position of the wafer.

Preferably, an offset signal or offset information of the offset data is generated by an offset detection device that represents a measure of the offset between a target machining position in which the wafer is to be machined and an actual actual machining position in an alignment device Offset signal or the offset information or data of the offset detection means is usable for correcting or compensating the offset of the aligned wafer in the clamping position in the wafer processing. When clamping the wafer, the clamping device preferably moves out of an initial position in which the wafer is not clamped by a distance to a clamping position in which the wafer is clamped on the circumference, wherein the clamping device engages in the deformation section and wherein the wafer in its initial position is realigned when the measured distance or the measured clamping position is less than a first predetermined value.

The clamping device may, when clamping the wafer out of its initial position, in which the wafer is not clamped, move a distance to a clamping position in which the wafer is clamped circumferentially, wherein the clamping device does not engage in the deformation portion and wherein the wafer is removed from the turntable when the measured distance or the measured clamping position is greater than a second predetermined value.

Further, when clamping the wafer from an initial position in which the wafer is not clamped, the clamping device can move a distance to a clamping position in which the wafer is clamped on the periphery, wherein the clamping device engages the deformation portion of the wafer and the wafer is removed from the turntable when the measured distance or the measured clamping position is greater than a third predetermined value.

The clamping device can also, when clamping a wafer from an initial position in which the wafer is not clamped move by a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device does not engage in the deformation portion and wherein the measured distance or the measured clamping position is used as a measure of the diameter of the wafer. In addition, when clamping a wafer from an initial position in which the wafer is not clamped, the clamping device can move about a clamping travel distance into a clamping position in which the wafer is clamped on the circumference, wherein the clamping device engages in the deformation section and the measured clamping travel distance or the measured clamping position is a measure of an offset of the wafer from a predetermined desired processing position of the wafer.

The determined, measured clamping travel distance or associated clamping position can be compared with the determined, measured distance or associated clamping position, corresponding to the diameter, and the deformation portion of the wafer can be searched again if the clamping distance or the associated clamping position is greater than or equal to the previously determined diameter of the Wafers is.

The clamping operation or the clamping of the wafer can be stopped and the clamping device can be reopened when the clamping travel distance or clamping position is greater than a predetermined maximum clamping distance or clamping position.

Further advantageous developments of the invention can be found in the dependent claims. Further advantages, advantageous developments and possible applications of the invention are to be taken from the following description of exemplary, preferred embodiments of the invention in conjunction with the drawings, which show:

Fig. 1 is a partial side view of a first embodiment of the invention with an applied wafer in the direction of arrow I of Fig. 2 seen, with only one Aligner is shown and a Clamping device can engage in a notch of the wafer shown;

Fig. 2 is a plan view of the embodiment of the invention of Figure 1 in the direction of the arrow II. Seen from Figure 1;

Fig. 3 is a side view of the embodiment of the invention of Fig. 1 in the direction of arrow III. seen from Fig. 1;

Fig. 4 is a perspective view of the embodiment of the invention of Fig. 1;

Fig. 5 is a partial view of Fig. 2 of the first embodiment of the invention, showing primarily a clamp and a drawn wafer;

Fig. 6 is a cut-away plan view of the embodiment of the invention of Figs. 1 and 2 with an associated side elevational view, showing the clamp in its initial position prior to clamping the wafer;

Fig. 7 is a cut-away plan view of the embodiment of the invention of Figs. 1 and 2 with an associated side view similar to Fig. 6, wherein the clamping means engages a notch of the wafer and the wafer is clamped in the clamping means and thus on a turntable is aligned;

8 is a cut-away plan view of the embodiment of the invention of FIG. 1 and FIG. 2 with an associated side view similar to FIG. 6 and FIG. 7, in FIG. 8 the clamping device has moved under the wafer; FIG. 9 is a detail view of FIG. 5, showing the clamping device larger; FIG.

Fig. 10 is a partial plan view of a second embodiment of the invention with an overlaid wafer, showing substantially a turntable and a clamping device of an alignment device of the invention, in which a clamping device may attach to a flattened portion of the wafer;

11 is a perspective view of the embodiment of the invention of FIG. 10 with a wafer resting thereon.

Fig. 12 is a plan view of the embodiment of the invention of Fig. 10 with lifting device.

Hereinafter, the first embodiment of the invention of FIGS. 1 to 9 will be described. In the figures, an alignment device of the invention is shown without a processing device. The alignment device or the Aligner of the first embodiment of the invention shown has a housing 1, a lifting device 2, a turntable 3, a clamping device 5 which is attached to the turntable 3 and thus rotates with it, and an optical detector 4 and Sensor, which is aligned with an edge of a wafer 10, which here for example rests on the turntable 3 and at its edge 10.2 or peripheral edge has a notch 10.1, which is also referred to as Notch. However, the wafer 10 is not on the lifting device 2, but between the bottom of the wafer 10 and the lifting device 2 is in the position shown a small distance o- the free space left, which is difficult to see in the drawings due to realistic proportions. As shown in Fig. 5 in more detail, the turntable 3 has an approximately rectangular, horizontal support 30 or base frame, which is centrally mounted on a vertical hollow shaft 60 in which a central axis of rotation of the turntable 3, around which the turntable 3 can rotate. The axis of rotation of the turntable 3 extends in the z-direction or corresponds to a z-axis of a fictitious Cartesian coordinate system. At the corner regions of the carrier 30 is in each case a triangular arm 31, 32, 33 and 34, on the terminal each a support member 39, 38, 35 and 36 is fixed for a wafer 10. The support member 35 on the arm 33 has an inclined support surface which is inclined to the rotational axis of the turntable 3 in the radial direction and on which the wafer 10 rests only with its edge in the manner of a tangential contact. The support member 36 on the arm 34 has an inclined support surface and the same function and the same structure as the support member 35. The support members 35 and 36 opposite to the support 30 arranged support members 40 and 39 each have a radially inclined support surface on the the wafer 10 rests tangentially with its edge 11. The bearing surfaces of the bearing parts 35, 36, AO and 39 are therefore inclined radially so that, as stated, the wafer only rests tangentially on it, in order to avoid the possibility of impairments and contamination of the wafer processing surfaces, ie the underside and the top side of the wafer. to minimize. The resting on the turntable 3 wafer 10 is only on these inclined bearing surfaces with its edge or its peripheral edge.

The clamping device 5 of the invention has a first clamping portion 52 and a second clamping portion 55 facing the first clamping portion 52, and serves to clamp a wafer 10 between the clamping portions 52 and 55 and hold it in processing the wafer.

The first clamping portion 52 is movable radially to the axis of rotation of the turntable 3 and has a movable carriage 67, the ra dial is reciprocable with respect to the axis of rotation and can be extended to the area of the wafer edge 10.2 with a free end. At the free end of the carriage 67 has a bracket at the center of a vertically projecting clamping pin 51 is fixed and extends beyond the top of a wafer 10 also. The carriage 67 has two spaced and parallel to each other and identically constructed linear bearings 56 and 57, with which it is mounted on associated guide rails 59 and 58, which in turn are secured to a bottom of a receptacle 38 of the carrier 30. The carriage 67 has a center axis which extends in the y-direction or on the y-axis of the attached Cartesian coordinate system and perpendicularly intersects the axis of rotation of the turntable 3. The center axis of the clamping pin 51 extends parallel to the z-direction and intersects the center axis of the carriage 67 of the clamping device. 5

The second clamp portion 55 has two fixed stoppers 53 and 54 which project vertically from the support members 39 and 40 and constitute a stopper for the wafer 10 when the wafer 10 is clamped in the clamp 5, that is, between the movable clamp portion 52 and the fixed one Each of the stops 53, 54 has a vertically projecting pin which projects beyond a wafer 10 in the z-direction and is surrounded by a rolling sleeve 55.1 or roller, which rotates about a center axis of the respective Can perform pin so that the wafer edge 10.2 when aligning the wafer 10 by engagement of the clamping pin 51 in a notch 10.1 of the wafer without jerking along can slide along.

In the receptacle 38 of the carrier 30 and a compressed air cylinder / piston unit 70 is arranged as a drive means for the carriage 67 of the movable, first clamping portion 52 of the clamping device 5. As shown in more detail in Fig. 11, the air cylinder / piston unit 70 has a compressed air cylinder 70, a piston 71 which is movably mounted in the air cylinder 70 and having a free piston end to which a follower pin 72 is fixed and protrudes vertically in the z-direction. The driver pin 72 engages in a through hole of a bearing ball 66 a form-fitting, which is arranged in the manner of a ball joint in an inner groove of a circular bearing plate 65 which is fixed to a central extension 68 of the carriage 67. The carriage 67 is thus pivotally coupled to the air cylinder / piston unit 70 to prevent tilting of the carriage 67 on the guide rails 58 and 59 during the movement of the carriage 67 can. A spring 73 engages the carriage 67 to force it into its maximally extended stop position or initial position, which is outwardly spaced from the edge 10.2 of the wafer 10, when the air cylinder / piston unit 70 is not pressurized with compressed air , The spring force of the spring 73 or spring means thus acts opposite to the extension direction of the piston 71 of the compressed air cylinder / piston unit 70th

As a position measuring device or path measuring device, an optoelectronic, incremental odometer 80 is provided which has a straight line ruler 82 and an associated photodetector 81. The bar ruler 82 is fixed to an underside of the carriage 67 and thus moves with the carriage 67, while the photodetector 81 is fixedly attached opposite the bar ruler 82 at the bottom of the receptacle 38 of the carrier and scanning the bar ruler 82 photoelectrically. The bar ruler 82 extends parallel to the two guide rails 58 and 59 and in the direction of movement of the carriage 67. Upon movement of the carriage 67 are generated by the photodetector position signals o- the pulse signals via a signal line 83, which is accommodated in the carrier 30 to a Evaluation circuit 84, which is designed as a microprocessor system and determines a position of the carriage 67 in response to the position signals. The position measuring device can also have a direction discriminator in order to be able to distinguish the directions of movement of the carriage 67. The hollow shaft 60 of the turntable 3 is provided at its lower end with an angle measuring device or encoder (not shown) having an annular angular ruler and an associated optoelectronic photodetector for generating a rotational angular position signal of the hollow shaft 60 and thus of the turntable 3. On the hollow shaft 60 in the lower end region and an angled compressed air hinge joint 90 is arranged, which has a horizontal, fixed leg which is fixed to the housing 1, and a rotatable leg which is rotatable about a vertical center axis on the fixed leg, wherein the center axis and the axis of rotation of the hollow shaft 60 coincide and the rotatable leg complies with the rotational movement of the hollow shaft 60. At the top of the support another, identical compressed air hinge piece (not shown) is housed, the fixed leg is coupled to the carrier 30.

A rotary drive of the turntable 3 has a controlled by a central control unit DC motor, the shaft is coupled via a gear and a belt with the hollow shaft 60 directly drivingly to rotate the hollow shaft 60 and thus also the turntable 3 can.

The compressed air system of the device of the invention has a supply of compressed air, which may be coupled eg to a compressor for generating the compressed air, a compressed air valve for supplying compressed air to a controllable pressure reducer whose output pressure is adjustable, a controllable outlet valve for blowing off the compressed air downstream of the pressure reducer, the compressed air swivel joint 90 after the pressure reducer, the further compressed air swivel joint and corresponding hose connections between these components in order to provide a fluid-tight, dense supply of compressed air to the air cylinder / piston unit 70 in the carrier 30 can. The lifting device 2 has structurally identical, firmly connected lifting arms 2.1 and 2.2, which are arranged opposite to the housing 1 such that they have a lifting movement in the z-direction for lifting a wafer 10 from the turntable 3, for holding the wafer 10 at a distance to the turntable 3, so that the turntable 3 can rotate without wafer 10, and can run back to the turntable 3 to lower the wafer 10 again. On the lifting arm 2.1 a Hebearinbügel 2.3 is mounted centrally, at the boom ends in each case a support part 2.4 or 2.5 is fixed, each in turn have a surface which is inclined to the axis of rotation of the turntable 3 in the radial direction. On these inclined surfaces, a wafer 10 is tangent with its edge alone when the lifting device 2 is operating. As a drive of the lifting device, for example, a controlled DC motor can be used, which is coupled via a transmission with the lifting device. An associated encoder is attached to a motor shaft of the DC motor.

The drives of the lifting device 2 and the turntable 3 and also the compressed air system with the pneumatic cylinder / piston unit are controlled by a central control unit, e.g. a software-controlled microcontroller or microprocessor system controlled, in turn receives encoder signals from the encoder on the hollow shaft 60 and the encoder of the drive of the lifting device 2 and a position indication of the carriage 67 of the evaluation circuit 84 in order to control the device of the invention.

For aligning and processing a wafer 10 with a notch 10.1 as a deformation section on the wafer edge 10.2, the method is carried out as follows under the control of the central control unit.

The wafer 10 is removed by means of a known handling robot from a cassette and placed on the inclined bearing surfaces of the support members 35, 36, 53 and 54 of the turntable 3. The turntable 3 is located in its defined and predefines start position or zero position with a rotation angle of 0 °. In this starting position, the lifting device 2 is in its lowered rest position and the first, movable clamping portion 52 of the clamping device 5 is forced to stop by the spring force of the spring 73 in its outboard initial position in which the clamping device 5 is opened to the maximum. The Anafangsstellung the clamping device 5 is shown for clarity in Fig. 6, in which the clamping pin 51 is significantly removed from the edge of the wafer 10. The clamping pin 51 is arranged in a rotational angle position of the turntable of 0 °. In the initial position, the compressed air cylinder / piston unit 70 is not pressurized with compressed air.

The turntable 3 is now rotated by the turntable drive in rotation about the axis of rotation of the hollow shaft 60 and performs at least a complete rotation of 360 °. During the rotation, the edge of the wafer 10 is scanned by the optical detector 4 and a detection signal is generated when the optical detector 4 detects the notch 10. 1 of the wafer 10. The detection signal of the optical detector 4 corresponds to a rotational angle value of the angle encoder or incremental protractor on the hollow shaft 60, which measures the angle of rotation of the turntable 3 starting from the starting position. The control unit has thus recognized where the notch 10.1 of the wafer 10 is relative to the predetermined start position or zero position of the turntable and the turntable 3 is then again in the start position or zero position corresponding to a rotation angle of 0 °.

The control unit then examines whether the notch 10.1 of the wafer 10 coincides with the zero position of the turntable 3, which would mean that the notch 10.1 of the wafer 10 is aligned with the clamping pin 51 of the clamping device 5, or if the notch 10.1 to the clamping pin 51 angularly already staggered. If the notch 10.1 here already aligned with the clamping pin 51, ie that the notch 10.1 coincidentally already the position of the rotary If 0 ° corresponds to 0 °, the lifting device 2 is raised, as a result of which the wafer 10 is lifted vertically from the turntable 3 in the z direction and is held in a raised position above the turntable 3. The turntable 3 is then rotated in a defined manner, for example by 30 °, so that the notch 10.1 of the wafer 10 is securely offset from the zero position of the turntable 3, or in other words, the pin 51 is offset relative to the notch 10.1 of the wafer 10. The lifting device 2 is then lowered vertically again under the control of the control unit and the wafer 10 is thus again placed on the turntable 3.

If notch 10.1 and clamping pin 51 offset, now the compressed air cylinder / piston unit 70 is pressurized with compressed air, whereby the carriage 67 and thus the clamping pin 51 of the clamping device 5 is moved against the force of the spring 73 radially towards the axis of rotation and the clamping device 5 is closed, the wafer 10 is clamped between the movable clamping portion 52 and the fixed clamping portion 55 with the stops 54 and 53 in order to determine the diameter of the wafer can. Specifically, the carriage 67 or clamping pin 51 travels a certain distance in the clamping process, which is measured by the linear incremental displacement meter 80 as a position measuring device and diameter measuring device and corresponds to a first clamping position, which in turn is assigned to a diameter value by the controller 84th eg is determined or calculated from an allocation table between the first clamping position and wafer diameter and the central control unit is supplied for further processing.

It is then checked by the control unit, whether the determined diameter value of the wafer 10 is within a predetermined tolerance range for wafer diameter, eg ± 100 microns. If this is not the case, for example, the wafer 10 can rest on the turntable 3 obliquely, so that the clamping pin 51 is retracted under the wafer 10 in its maximum clamping position. The clamping Direction 5 is then opened and the wafer 10 is then removed from the turntable 3 with the lifting device 2 or the handling robot and then placed again on the turntable 3 to perform the measurement of the diameter of the wafer 10 by means of the clamping device 5 and the incremental odometer 80 again ,

Has the clamp pin 51 does not move during the clamping operation up to its end stop and it was found that the ge ^¬ metered diameter is according to the first clamping position outside the predetermined diameter tolerance range, the clamp 5 is opened and the wafer 10 is removed from the turntable 3, since he is probably committee.

If the determined diameter of the wafer 10 according to the first clamping position, however, in the predetermined tolerance range to continue the alignment of the wafer 10, the clamping device 5 is opened again, the compressed air is discharged via the blow-off from the air cylinder / piston unit 70 and the Spring 73 biases the carriage 67 with clamping pin 51 back to its initial position. Then, the lifting device 2 is raised and the wafer 10 is lifted off the turntable 3 and held at a distance from the turntable 3. The turntable 3 is then rotated until the notch 10.1 of the wafer 10 is relatively aligned with the clamping pin 51 of the clamping device 5 in the zero position at a rotational angle of 0 °. The lifting device 2 is then lowered again and the wafer 10 is deposited on the turntable 3 again.

The clamping device 5 is then pressurized again to clamp the wafer 10 in the clamping device 5. In this case, the clamping pin 51 engages in the notch 10.1 of the wafer 10 and thereby slides along an edge or both edges of the V-shaped notch 10.1 until it abuts a bottom or the tip of the notch 10.1, and takes the wafer 10th with, until this abuts opposite to the stops 54 and 53 of the second clamping portion 55 and thus aligned against these stops 53 and 54. The clamping pin 51 is then in a second clamping position. Since the incremental odometer 80 has constantly detected the movement of the carriage 67, it can now generate a position signal and output to the evaluation device, which indicates a value for the reached second clamping position or the distance traveled by the clamping device 5 when clamping the wafer 10 , This actual value for the achieved second clamping position is then transmitted by the evaluation device to the control unit.

It is then checked by the control unit whether the determined actual value of the second clamping position of the wafer 10 is within a predetermined tolerance range of e.g. ± 50 μm for the second clamping position. If this is not the case, e.g. the wafer 10 rest on the turntable 3 obliquely, so that the clamping pin 51 is retracted under the wafer 10 in its maximum clamping position to stop. The clamping device 5 is then opened again and the wafer 10 can then be removed from the turntable 3 with the lifting device 2 or the handling robot and then placed again on the turntable 3 to repeat the measurement of the second clamping position of the wafer 10 or the wafer 10th is finally removed from the device. To clarify this case, reference is made to FIG. 8, in which the clamping pin 51 is shown in an inadmissible position or clamping position under the wafer 10.

However, if the clamping pin 51 has not moved to its limit stop during the clamping process for determining the second clamping position in the maximum retracted position and it was found that the measured actual value of the clamping position is outside the predetermined tolerance range for the second clamping position, the clamping device 5 is opened and the Wafer 10 finally removed from the turntable 3, as it is obviously committee. However, if the value in the measurement of the second clamping position lies within the specified tolerance range, the clamping position achieved can be maintained for the actual subsequent processing of the wafer. FIG. 7 shows the case when the clamping pin 51 has reached an approved second clamping position in the notch 10. 1 of the wafer 10. The control unit then compares the actual value of the second clamping position with a predetermined desired value for the second clamping position, which is stored in the control unit. The setpoint value of the second clamping position can previously be determined, for example, once with a standard wafer or reference wafer by clamping in the clamping device 5, similar to just described with reference to the wafer to be processed 10 and stored in the control unit or simply as a setpoint in the control unit will be entered. More specifically, the actual value of the second clamping position of the clamper 5 or the wafer 10 in the notch 10.1 generally corresponds to a location coordinate or a y-coordinate on the y-axis or a corresponding distance between the bottom and the top of the notch 10.1 of the wafer 10 and the opposite edge perimeter on the y-axis.

It is generally advantageous that the central control unit, if a processing of the wafer 10 is to succeed, can calculate an offset value or offset information from the difference between the predetermined desired value and the determined actual value in accordance with the second clamping position. The offset value may then be used in the actual wafer processing to compensate or correct for the remaining positional offset in the orientation of the wafer 10. In other words, a determined machining value indicating a location on the wafer 10 where the wafer 10 is to be processed may be corrected by directionally adding the offset value to the machining value or subtracting the offset value from the machining value to compensate or correct of the lasting one To obtain offset in aligning the wafer, which is performed directly in the processing of the wafer 10.

The device of the invention may, for example, be designed as a marking device for marking or writing on wafers by means of a laser beam. A typical marking device is more accurate e.g. in EP 1231627 A2, the contents of which are fully incorporated herein by reference.

The marking device essentially has a laser device which generates a laser beam which is directed onto the wafer surface via a laser beam deflection unit and a focusing device in order to mark or describe a wafer at a designated location. As the laser beam deflecting unit, e.g. an electromotively driven galvanometer mirror device can be used. In the position adjustment of the laser beam deflection unit, the position offset value determined in the control unit or the associated offset coordinates can now be taken into account in order to be able to compensate for a permanent alignment error of the wafer 10 on the turntable 3, thereby enabling a highly accurate processing or marking of the wafer 10.

Hereinafter, a second embodiment of the invention according to FIG. 10 to FIG. 12 will be described. Also in these figures, an alignment device of the invention is shown without a processing device. The alignment device of the second embodiment of the invention has a housing 1.7, a lifting device 2.7, a turntable 3.7, a clamping device 5.7, which is mounted on the turntable 3.7 and thus rotates with it, and an optical detector 4.7 or sensor, the on a Aligned edge of a wafer 10.7, which rests here by way of example on the turntable 3.7 and at its circular border or peripheral edge 10.27 has a flattened portion 10.17, which is also referred to as Fiat. However, the wafer 10.7 is not on the lifting device 2.7, but between the underside of the wafer 10.7 and the lifting device 2.7 is left in the position shown in FIG. 10, a small distance or clearance as in the first embodiment of the invention.

As shown in Fig. 10 and Fig. 12 shows in more detail, the turntable 3.7 has an approximately circular, horizontally arranged plate 30.7, which is centrally mounted on a vertical hollow shaft 60.7, in which a central axis of rotation of the turntable 3.7 runs around which the turntable 3.7 can turn. The axis of rotation of the turntable 3.7 extends in the z-direction or corresponds to a z-axis of a fictitious Cartesian coordinate system. At one edge of the plate 30.7 are several equally structured support part 39.7, 38.7, 35.7 and 36.7 attached to a wafer 10.7. The support parts 39.7, 38.7, 35.7 and 36.7 each have an inclined support surface, which is inclined towards the axis of rotation of the turntable 3.7 in the radial direction and rests on the wafer 10.7 only with its edge in the manner of a tangential contact. Furthermore, identical support members 91, 92, 93 and 94 are attached to the plate 30.7, each having a radially inclined support surface on which the wafer 10.7 rests tangentially with its edge 10.27. It should be noted that the wafer 10.7 rests only on the inclined bearing surfaces of the support parts and is supported and otherwise comes in no other place with the turntable 3.7 in touch.

The clamping device 5.7 of the second embodiment of the invention has a first, movable clamping portion 52.7 and a second, fixed clamping portion 55.7, which is opposite to the first clamping portion 52.7 on the turntable 3.7, and serves to clamp a wafer 10.7 between the clamping portions 52.7 and 55.7 and in the Processing of the wafer 10.7, as has already been explained in detail in connection with the first embodiment of the invention. Here, too, the first clamping section 52.7 is movable radially with respect to the axis of rotation of the turntable 3.7 and has a movable carriage 61.1, which is movable back and forth and rectilinearly radially with respect to the axis of rotation and is extended to the region of the wafer rim with a free end can. At the free end of the car has 67.7 two identical bracket, each with a free bracket end, wherein at each of the free bracket ends a vertically projecting flat clamping pin 51.7 is attached and extends beyond the top of a wafer 10.7 addition. The two flat clamping pins 51.7 are at a distance from each other. The carriage 67.7 has a linear bearing 56.7, with which it is guided and supported in a straight line on an associated guide rails 59.7, which in turn is fixed to a bottom of a receptacle 38.7 of the plate 30.7. The carriage 67.7 has a center axis which extends in the y-direction or on the y-axis of the attached Cartesian coordinate system and the axis of rotation of the turntable 3.7 perpendicularly intersects. The center axes of the two flat clamping pins 51.7 extend parallel to the z-direction and intersect the center axis of the carriage 67.7 of the clamping device 5.7.

The second clamping portion 55.7 has four fixed stops 95, 96, 97 and 98 which project vertically from the support members 91, 92, 93 and 9A and constitute a stop for the wafer 10.7 when the wafer 10.7 is clamped in the clamping device 5.7, ie between the movable clamping portion 52.7 and the fixed clamping portion 55.7 with the stops 95, 96, 97 and 98 is clamped. Each of the stoppers 95, 96, 97 and 98 has a vertically projecting pin that projects beyond a wafer 10.7 in the z-direction and is surrounded by a rolling sleeve 55.71 or roller that can make a rotational movement about a center axis of the respective pin the wafer edge 10.27 when aligning the wafer 10.7 by engagement or abutment of the flat-clamping pins 51.7 on the Fiat 10.17 or on the regular wafer edge 10.27 of the wafer 10.7 slide along without jerking along can. The flat-clamping pins 51.7 also each have a central pin which is surrounded by a roller sleeve and in this respect the same structure as the stops 95, 96, 97 and 98th

In the receptacle 38.7 of the plate 30.7 as in the first embodiment of the invention, a compressed air cylinder / piston unit 70.7 is arranged as a drive means for the carriage 67.7 of the movable first clamping portion 52.7 of the clamping device 5.7. As shown in more detail in Fig. 10, the air cylinder / piston unit 70.7 has the same structure, as already explained with respect to the first embodiment, with a compressed air cylinder, an associated piston which is movably mounted in the air cylinder and which has a free piston end to which a driver pin is attached and projects vertically in the z direction. The driver pin engages here in a through hole of a ball bearing a form-fitting, which is arranged in the manner of a ball joint in an inner groove of a circular bearing plate which is fixed to the carriage 67.7. Also, the carriage 67.7 is thus pivotally coupled to the air cylinder / piston unit 70.7 in order to prevent tilting of the carriage 67.7 on the guide rail 59.7 during the movement of the carriage 67.7 can. A spring 73 engages the carriage 67.7 to force it into its maximum extended stop position or initial position when the compressed air cylinder / piston unit 70.7 is not acted upon by compressed air. The spring force of the spring 73.7 thus acts opposite to the extension direction of the piston of the compressed air cylinder / piston unit 70.7.

As position measuring device or path measuring device, an optoelectronic, incremental odometer 80.7 is provided, which has a straight line ruler and an associated photodetector. The bar ruler is also fixed in the second embodiment of the invention to an underside of the carriage 67.7 and thus moves with the carriage 67.7, while the photodetector opposite to the bar ruler at the bottom of the recording 38.7 of the plate 30.7 is fixed in place and scans the bar ruler photoelectronically. The dash ruler extends parallel to the two guide rail 59.7 or in the direction of movement of the carriage 67.7. Upon movement of the carriage 67.7, position signals or pulse signals generated by the photodetector are transmitted via a signal line housed in the plate 30.7 to an evaluation circuit 84.7, which is designed as a microprocessor system and determines a position of the carriage 67.7 in response to the position signals. The position measuring device can also have a direction discriminator in order to distinguish the directions of movement of the carriage 67.7.

The hollow shaft 60.7 of the turntable 3.7 is provided at its lower end with an angle measuring device or encoder, which has an annular straight line and an associated optoelectronic photodetector for generating a rotational angular position signal of the hollow shaft 60.7 and thus of the turntable 3.7. Also disposed on the hollow shaft 60.7 in the lower end region is an angled pneumatic swivel joint having a horizontal, fixed leg internally secured to the housing 1.7 and a rotatable leg rotatable about a vertical center axis on the stationary leg. wherein the center axis and the axis of rotation of the hollow shaft 60.7 coincide and the rotatable leg complies with the rotational movement of the hollow shaft 60.7. At the top of the carrier is another, identical compressed air joint piece is provided, whose fixed leg is coupled to the plate 30.7.

A rotary drive of the turntable 3.7 has a DC motor controlled by a central control unit, the shaft of which is coupled via a gear and a belt to the hollow shaft 60.7 in order to be able to rotate the hollow shaft 60.7 and thus also the turntable 3.7. The compressed air system of the device of the invention has a supply of compressed air, which may be coupled eg to a compressor for generating the compressed air, a compressed air valve for supplying compressed air to a controllable pressure reducer whose output pressure is adjustable, a controllable outlet valve for blowing off the compressed air downstream of the pressure reducer, the compressed air joint piece 90 after the pressure reducer, the other compressed air joint piece and corresponding hose connections between these components in order to provide a fluid-continuous supply of compressed air to the air cylinder / piston unit 70.7 at the port 70.71 in the plate 30.7.

The lifting device 2.7 has structurally identical, firmly connected lifting arms 2.17 and 2.27, which are arranged opposite to the housing 1.7 such that they move in the z-direction to lift a wafer 10.7 of the turntable 3.7, for holding the wafer 10.7 at a distance from the turntable 3.7, so that the turntable 3.7 can rotate without wafer 10.7, and to lower the wafer 10.7 back to the turntable 3.7 can run back. On the lifting arm 2.17 a Hebearmbügel 2.37 is mounted centrally, at the boom ends in each case a support part is attached 2.47 or 2.57, each in turn have a surface which is inclined to the axis of rotation of the turntable 3.7 in the radial direction. On these inclined surfaces, a wafer 10.7 lies tangentially with its edge alone when the lifting device 2.7 is working. As the drive of the lifting device, e.g. a controlled DC motor can be used, which is coupled via a gear with the lifting device 2.7. An associated encoder is attached to a motor shaft of the DC motor.

The drives of the lifting device 2.7 and the turntable 3.7 and also the compressed air system with the compressed air cylinder / piston unit 70.7 are controlled by a central control unit, for example a software-controlled microcontroller, which in turn en- encoder signals from the encoder to the hollow shaft 60.7 and the encoder of the drive of the lifting device 2.7 and a position indication of the carriage 67.7 of the evaluation circuit 84.7 receives to control the device of the invention according to the second embodiment.

For aligning and processing a wafer 10.7 with a Fiat 10.17 as a deformation section on the wafer edge 10.27, the control of the central control unit is performed as follows.

The wafer 10.7 is removed by means of a known handling robot from a cassette and placed on the inclined bearing surfaces of the support members 35.7, 36.7, 38.7, 39.7, 91, 92, 93 and 94 of the turntable 3.7. The turntable 3.7 is located in its defined and predetermined starting position or zero position with a rotation angle of 0 °. In this starting position, the lifting device 2.7 is in its lowered rest position and the first, relative to the rotational axis of the turntable 3.7 movable clamping portion 52.7 of the clamping device 5.7 is forced to stop by the spring force of the spring 73.7 in its initial position in which the clamping device is 5.7 open maximum. The two flat-clamping pins 51.7 are arranged in a rotational angle position of the turntable of 0 ° such that centrally between them the stationary optical detector 4.7 is arranged in the rotational angle position 0 ° of the turntable 3.7. In the initial position, the compressed air cylinder / piston unit 70.7 is not pressurized with compressed air.

The turntable 3.7 is now offset by the turntable drive in rotation about the axis of rotation of the hollow shaft 60.7 and performs at least a complete rotation of 360 °. During the rotation, the edge of the wafer 10.7 is scanned by the optical detector 4.7. The detector 4.7 generates an initial signal when the optical detector 4.7 detects the beginning of the fiat 10.17 of the Wafers 10 detected. The initial signal of the optical detector 4.7 corresponds to an initial rotational angle value of the encoder on the hollow shaft 60.7, which measures the angle of rotation of the turntable 3.7 starting from the start position. The detector 4.7 generates an end signal when the optical detector 4.7 detects the end of the wafer 10.17 of the wafer 10. The end signal of the optical detector 4.7 then corresponds to a final rotational angle value of the encoder on the hollow shaft 60.7. The angle portion between the initial rotation angle and the end rotation angle is a flat angle range. The control unit recognizes, due to constant angular velocity of the turntable 3.7, where a center angle of the Fiat 10.17 or the flattened edge location of the wafer 10.7 is located, namely exactly in the middle between the Anfangsdrehwinkelwert and the Enddrehwinkelwert relative to the predetermined starting position or zero position of the turntable 3.7 , After a complete rotation, the turntable 3.7 is then again in the start position or zero position, which corresponds to a rotation angle of 0 °.

Subsequently, the lifting device 2.7 is raised, whereby the wafer is raised 10.7 from the turntable 3 from perpendicular in the z-direction and held in a raised position on the turntable 3.7. The turntable 3.7 is then defined rotated such that the two flat-clamping pins 51.7 are safe outside the Fiatwinkelbereichs. Preferably, however, the turntable 3.7 is rotated so that the central angle or the center of the Fiat 10.17 are aligned exactly 90 ° relative to the y-axis of the carriage 67.7 of the movable clamping portion 52.7. The Fiat 10.17 of the wafer 10.7 is then safely offset outside the range of flat clamping pins 51.7. The lifting device 3.7 is then lowered vertically again under the control of the control unit and the wafer 10.7 is thus deposited again on the turntable 3.7.

Now, the compressed air cylinder / piston unit 70.7 is acted upon with compressed air, whereby the carriage 67.7 and thus the Flat- Clamping pins 51.7 of the clamping device 5.7 is closed against the force of the spring 73.7 to the wafer 10.7 between the movable clamping portion 52.7 and the fixed clamping portion 55.7 with the stops 95, 96, 97, 98 is clamped to determine the diameter of the wafer can be 10.7 , More precisely, the carriage 67.7 with its flat clamping pins 51.7 during the clamping process travels a certain distance, which is measured by the linear, incremental displacement meter 80 and corresponds to a first clamping position, which in turn is assigned to a diameter value determined by the evaluation circuit 84.7 with controller or is calculated and the control unit is supplied for further processing. When measuring the diameter, the flat clamping pins 51.7 and also the opposing stops touch the regular, circular-arc-shaped edge of the wafer 10.7 outside the Fiat 10.17 in order to be able to determine the regular diameter of the wafer 10.7.

It is now checked by the control unit, whether the determined diameter value of the wafer 10.7 is within a predetermined tolerance range for wafer diameter. If this is not the case, e.g. the wafer 10.7 rest on the turntable obliquely, so that at least one of the flat clamping pins 51.7 is retracted under the wafer 10.7 in its maximum clamping position. The clamping device 5.7 is then opened and the wafer 10.7 is then removed from the turntable 3.7 with the lifting device 2.7 or the handling robot and then placed again on the turntable 3.7 to the measurement of the diameter of the wafer 10.7 by means of the clamping device 5.7 and the incremental odometer 80.7 again perform.

However, if the flat clamping pins 51.7 have not moved to their end stop during the clamping process and it has been determined that the measured diameter corresponding to the first clamping position is outside a predetermined diameter tolerance range for the wafer 10.7, the clamping device 5.7 is opened and the wafer 10.7 is removed from the turntable 3.7, as it is probably broke.

However, if the determined diameter of the wafer 10.7 according to the first clamping position in the predetermined tolerance range to continue the alignment of the wafer 10.7, the clamping device 5.7 is opened again, the compressed air is discharged through the blow-off from the air cylinder / piston unit 70.7 and the spring 73.7 the carriage 67.7 with the flat clamping pins 51.7 biases back to its initial position radially out of ^¬ half of the wafer 10.7. Then, the lifting device 2.7 is raised again and the wafer 10.7 lifted off the turntable 3.7 and held at a distance from the turntable 3.7. The turntable 3.7 is then rotated until the center angle of the Fiat 10.17 of the wafer 10.7 coincides relatively with the y-axis of the carriage 67.7 and thus coincides with the zero position at a rotation angle of 0 °. The lifting device 2.7 is then lowered again and the wafer 10.7 stored on the turntable 3.7 again.

The clamping device 5.7 is then pressurized again to clamp the wafer 10.7 in the clamping device 5.7. The flat clamping pin 51.7 strike the Fiat 10.17 of the wafer 10.7 and push the wafer 10.17 until it abuts against the stops 95, 96, 97, 98 of the second clamping section 55.7 and is thus aligned against these stops. The flat clamping pins 51.7 and the carriage 67.7 are then in a second clamping position. Since the incremental displacement meter 80.7 has constantly detected the movement of the carriage 67.7, it can now generate a position signal and output it to the evaluation circuit 84.7 which has a value for the second clamping position reached or that of the clamping device 5.7 when the wafer 10.7 is clamped indicates distance traveled. This actual value for the reached, second clamping position is then transmitted by the evaluation circuit 84.7 to the control unit. It is then checked by the control unit, whether the determined actual value of the second clamping position of the wafer 10.7 is within a predetermined tolerance range for the second clamping position. If this is not the case, for example, the wafer 10.7 can rest on the turntable 3.7 obliquely, so that at least one of the flat clamping pin 51.7 is retracted under the wafer 10.7 to its maximum clamping position to stop. The clamping device 5.7 is then opened again and the wafer 10.7 can then be removed from the turntable 3.7 with the lifting device 2.7 or the handling robot and then placed again on the turntable 3.7 to repeat the measurement of the second clamping position of the wafer 10.7, or the wafer 10.7 is finally removed from the device according to the second embodiment of the invention.

However, the flat clamping pins 51.7 have not moved to a predetermined end stop in the maximum retracted position during the clamping operation for determining the second clamping position and it has been determined that the measured actual value of the clamping position is outside a predetermined plus-minus tolerance range for the second clamping position , the clamping device 5.7 is opened and the wafer 10.7 finally removed from the turntable 3.7, as it is obviously Committee.

However, if the value in the measurement of the second clamping position is within the specified tolerance range, the clamping position achieved can be retained for the actual, subsequent processing of the wafer 10.7.

The control unit then compares the actual value of the second clamping position with a predetermined desired value for the second clamping position, which is stored in the control unit. The desired value of the second clamping position can be determined beforehand, for example, once with a standard wafer or reference wafer by clamping in the clamping insert. direction 5.7, as has just been explained with reference to the wafer 10.7 to be processed, determined and stored in the control unit or simply entered as a setpoint in the control unit. More precisely, the actual value of the second clamping position of the clamping device 5.7 or of the wafer 10.7 when engaged in the Fiat 10.17 generally corresponds to a location coordinate or a y-coordinate on the y-axis or a corresponding distance between the Fiat 10.17 of the wafer 10.7 and the opposite edge circumference of the Wafer 10.7 on the y-axis.

The controller may, if processing of the wafer 10.7 is to succeed, calculate an offset value or offset information from the difference between the preset target value and the measured actual value. The offset value may then be used in the actual wafer processing to compensate for or correct for the remaining positional offset in the alignment of the wafer 10.7. In other words, a determined machining value indicating a location on the wafer 10.7 at which the processing of the wafer 10.7 is to be performed may be corrected by directionally adding the offset value to the machining value or subtracting the offset value from the machining value of the permanent offset when aligning the wafer with the correction being made directly during processing.

The device of the invention according to the second embodiment, like the first embodiment, may, for example, be designed as a marking device for marking or writing on wafers by means of a laser beam.

The marking device essentially has a laser device which generates a laser beam which is directed onto the wafer surface via a laser beam deflection unit and a focusing device in order to mark or describe a wafer at a designated location. As a laser beam deflection unit, for example, an electromotively driven galvanic Mirror device can be used. In the position adjustment of the laser beam deflection unit, the position offset value determined in the control unit or the associated offset coordinates can now be taken into account in order to be able to compensate for a permanent alignment error of the wafer 10.7 on the turntable 3.7, whereby highly precise processing or marking of the wafer 10.7 with Fiat 10.17 is enabled.

Claims

claims

Device for aligning and / or processing a wafer, in particular for marking or writing a wafer with a laser beam, the wafer (10, 10.7) having a circular circumference with a predetermined deformation section, the device having a turntable (3.7), which can rotate about an axis of rotation and on which a wafer (10, 10.7) to be processed rests tangentially only with its edge or edge region, characterized by a clamping device (5, 5.7) for clamping and holding a wafer on the turntable (3, 3.7 ), wherein the clamping device engages in the deformation section (10.1, 10.17) on the circumference of the wafer in order to align the wafer on the turntable (3, 3.7), and a position measuring device with the clamping device (5, 5.7) for determining a clamping position of the Wafer is coupled when the wafer (10, 10.7) on the turntable (3, 3.7) in the clamping device (5, 5.7) is clamped.

2. Device according to claim 1, characterized by a diameter measuring device for measuring the diameter of a on the turntable (3, 3.7) resting wafer when pinched in the clamping device (5, 5.7).

3. Apparatus according to claim 1 or claim 2, characterized in that the position measuring device and / or the diameter measuring device with the clamping device (5, 5.7) is coupled and a movement of the clamping device (5, 5.7) taken into account in the measurement of the clamping position or the wafer diameter ,

4. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) on the rotary plate (3, 3.7) is mounted and moves with the turntable.

5. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) has a first, movable clamping portion (52, 52.7) and a second clamping portion opposite the first second clamping portion (55, 55.7) for clamping a wafer (10, 10.7) between the two clamping portions, wherein the clamping portions touch the wafer only at its periphery or edge (10.2, 10.27) when pinched.

6. The device according to claim 5, characterized in that the second, fixed clamping portion (55, 55.7) a plurality of stop members (91, 92, 93, 94) which along a circle about an axis of rotation of the turntable (3, 3.7) around in a horizontal plane are arranged and against which a wafer strikes with its edge circumference when it is clamped in the clamping device (5, 5.7).

7. The device according to claim 6, characterized in that the first, movable clamping portion radially with respect to the axis of rotation of the turntable (3, 3.7) is linearly movable and is mounted on the turntable.

8. Device according to one of the preceding claims, characterized by a drive device which is coupled to the clamping device (5, 5.7) for carrying out a clamping movement of the clamping device for clamping a wafer (10, 10.7).

9. Apparatus according to claim 8, characterized in that the drive means by means of a fluid, the clamping device (5, 5.7) moves.

10. The device according to claim 9, characterized in that the drive means by means of compressed air Kleinmeinrichtung

(5, 5.7) drives.

11. The device according to claim 10, characterized in that the drive means for the clamping device has a pneumatic actuator which is coupled to a first, movable clamping portion of the clamping device (5, 5.7) to radially with respect to the axis of rotation of the turntable (3, 3.7) and to move linearly relative to the turntable.

12. The apparatus according to claim 11, characterized in that the compressed air actuator is attached to the turntable (3, 3.7).

13. The apparatus according to claim 12, characterized in that the compressed air actuator (70, 70.7) has a compressed air cylinder and a piston which is pneumatically supported in the compressed air cylinder is mounted.

14. The apparatus according to claim 13, characterized in that the compressed air cylinder on the turntable (3, 3.7) is fixed and that a free piston end of the movable piston with the clamping device (5, 5.7) or the first, movable clamping portion (52, 52.7) the clamping device is coupled.

15. The apparatus of claim 13 or claim 14, characterized in that the compressed air actuator in a recess (38, 38.7) of the turntable (3, 3.7) is arranged.

16. Device according to one of the preceding claims, characterized by a spring means (73, 73.7) which is coupled to the clamping device for biasing the clamping device in an initial position relative to the turntable (3, 3.7) or to a wafer.

17. The apparatus according to claim 16, characterized in that the spring means (73, 73.7) biases the clamping device in an initial position in which the clamping device (5, 5.7) is open to the maximum.

18. The apparatus according to claim 16, characterized in that the spring device biases the clamping device in an initial position in which the clamping device is closed at maximum.

19. The apparatus according to claim 17, characterized in that the spring means (73, 73.7) counteracts a pressurized air compressed air actuator for moving the clamping device or a movable clamping portion of the clamping device acts.

20. Device according to one of the preceding claims, characterized in that the fixed to the turntable compressed air actuator is coupled to a compressed air line extending in a hollow shaft (60, 60.7) of the turntable, which is symmetrical to the axis of rotation of the turntable.

21. The apparatus according to claim 20, characterized in that the compressed air actuator is coupled via a Druckluftkoppelgelenk with the compressed air line

22. Device according to one of the preceding claims, characterized in that the first, movable clamping portion has at least one clamping pin (51, 51.7) for contacting the periphery of the wafer, wherein a vertical central axis of the clamping pin parallel to the axis of rotation of the turntable ( 3, 3.7).

23. Device according to claim 22, characterized in that the clamping pin (51, 51.7) of the first, movable clamping section is designed to engage in a deformation section of a wafer (10, 10.7).

24. The device according to claim 22, characterized in that the first movable clamping portion has at least two clamping pins (51.7) for contacting the periphery of the wafer (10.7), each of the clamping pins having a vertical central axis extending parallel to the axis of rotation of the turntable extends.

25. The apparatus according to claim 24, characterized in that the first, movable clamping portion has two clamping pins (51.fk) which are arranged at a distance from one another such that they form a rectilinear flattening or a fiat (10.17) as a deformation section on the circumference a wafer (10.7) can touch to align the wafer.

26. The device according to claim 3, characterized in that the position measuring device has a distance measuring device which is coupled to the clamping device (5, 5.7) or the first, movable clamping portion of the clamping device to determine a distance during the movement of the clamping device or the first clamping portion to be able to.

27. The device according to claim 26, characterized in that the distance measuring device has an optoelectronic linear encoder or an incremental displacement meter (80, 80.7).

28. An apparatus according to any one of the preceding claims, characterized by an offset detection means which generates an offset signal or offset information or data indicative of an offset or alignment error between a target machining position in which a wafer (10, 10.7) is to be machined , and the actually achieved Are processing position of the wafer after being pinched in the pinching device, and that the device uses the offset signal or the offset information or data of the offset detecting means for correcting or compensating for the offset of the wafer when the wafer is processed in the achieved actual machining position.

29. The device according to claim 28, characterized in that the offset detecting means detects the movement of the clamping device (5, 5.7) between an initial position of the clamping device, in which the clamping device does not touch a wafer on the turntable, and the clamping position, in which the wafer in the clamping device is clamped.

30. The device according to claim 29, characterized in that a first clamping position of the clamping device (5, 5.7) is associated with a predetermined actual diameter of a wafer to be processed (10, 10.7).

31. The device according to claim 30, characterized in that a control unit checks whether the actual diameter of the wafer to be processed (10, 10.7) is within a predetermined tolerance range of the diameter of the wafer to be processed.

32. Device according to one of claims 29 to 31, characterized in that a second clamping position of the clamping device (5, 5.7) is associated with an aligned position or actual position of the wafer (10, 10.7) on the turntable (3, 3.7), wherein the Clamping device engages in the deformation section on the circumference of the wafer.

33. The apparatus of claim 32, characterized in that the second clamping position of a .vorgegebenen desired position of the wafer is assigned, which corresponds to a predetermined target orientation of the wafer on the turntable (3, 3.7) for processing.

34. Apparatus according to claim 32 and claim 33, characterized in that the position measuring device determines an actual position value of the wafer in the second clamping position and that the difference between a predetermined desired position value in the desired position and the measured actual position value is a measure of an offset of the aligned wafer.

35. Device according to one of the preceding claims, characterized by means for holding the wafer (10,10.7) in a position at a distance from the turntable (3, 3.7) such that the turntable can rotate without a wafer.

36. Device according to one of the preceding claims, characterized in that the marking device has a laser device which generates a laser beam, which is directed via a laser beam deflection unit and a focusing on the wafer surface to mark or describe the wafer in a designated location, and that the laser beam deflection unit takes into account a determined offset or associated offset coordinates for correcting or compensating for an alignment error of the wafer (10, 10.7) on the turntable (3, 3.7) when marking or writing the wafer.

37. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) when clamping the wafer out of a clamp start position in which the wafer is not clamped moves by a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device does not engage in the deformation portion, and that the measured distance or measured clamping position is a measure of the diameter of the wafer.

38. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) during Clamping the wafer out of a clamp start position where the wafer is not clamped, moving a distance to a clamped position in which the wafer is clamped circumferentially, the clamp engaging the deformation portion, and the measured distance or measured clamp Position is a measure of an offset of the wafer from a predetermined target processing position of the wafer.

An apparatus according to any one of the preceding claims, characterized in that an offset detecting means generates an offset signal or offset information or data indicative of the offset between a target machining position in which the wafer is to be machined and an actual actual machining position in an alignment apparatus, wherein the offset signal or the offset information or data of the offset detection means is usable for correcting or compensating for the offset of the aligned wafer in the clamping position in the wafer processing.

40. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) when clamping the wafer out of an initial position in which the wafer is not clamped moves by a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device engages in the deformation portion, and that the wafer is realigned in its initial position when the measured distance or the measured clamping position is smaller than a first predetermined value.

41. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) when clamping the wafer from its initial position in which the wafer is not clamped moves by a distance in a clamping position in which the wafer is clamped at the circumference, where- wherein the clamping device does not engage in the deformation section, and that the wafer is removed from the turntable when the measured distance or the measured clamping position is greater than a second predetermined value.

42. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) when clamping the wafer out of an initial position in which the wafer is not clamped moves by a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device engages in the deformation portion, and that the wafer is removed from the turntable when the measured distance or the measured clamping position is greater than a third predetermined value.

43. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) when clamping a wafer out of an initial position in which the wafer is not clamped moves by a distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device does not engage in the deformation portion, and that the measured distance or the measured clamping position is a measure of the diameter of the wafer.

44. Device according to one of the preceding claims, characterized in that the clamping device (5, 5.7) when clamping a wafer out of an initial position in which the wafer is not clamped moves to a clamping distance in a clamping position in which the wafer is clamped at the periphery, wherein the clamping device engages in the deformation portion, and that the measured Klemmverfahrstrecke or the measured clamping position is a measure of an offset of the wafer from a predetermined desired processing position of the wafer.