Abstract
The present invention relates to a substrate carrier for accommodating and transporting a substrate, to a changing station comprising such a substrate carrier as well as to a method for treating a substrate.
Claims
1. A substrate carrier for accommodating and transporting a substrate, wherein the substrate carrier comprises a centering device adapted to center the substrate along a first axis, wherein the centering device comprises two inwardly preloaded springs opposite each other.
2. The substrate carrier according to claim 1, wherein each of the springs comprises a contact area which is provided to come into contact with the substrate, wherein the contact area has a radius of curvature of at least 5 mm.
3. The substrate carrier according to claim 1, wherein each of the springs comprises an accommodating area for a first movement element and wherein the springs can be moved outwards by means of the first movement elements.
4. The substrate carrier according to claim 1, further comprising a substrate that is accommodated in the substrate carrier, wherein each of the springs comprises a contact area provided to come into contact with the substrate, wherein, in the contact area in the direction of the substrate thickness, the spring has an extension that is greater than the thickness of the substrate.
5. The substrate carrier according to claim 4, wherein the substrate is oriented substantially vertically in the substrate carrier and wherein the substrate rests on the substrate carrier at its lower edge extending parallel to the first axis, wherein a static friction force exists between the lower edge of the substrate and the substrate carrier and wherein a decentration of the substrate along the first axis by 2 mm generates a resultant force of the two springs onto the substrate that is greater than the static friction force.
6. The substrate carrier according to claim 1, further comprising a plurality of locking devices adapted to hold the substrate in the substrate carrier in a form-fitting and force-free manner.
7. The substrate carrier according to claim 1, further comprising a further centering device adapted to center the substrate along a second axis, wherein the further centering device comprises two pairs of inwardly preloaded springs opposite each other.
8. The substrate carrier according to claim 5, wherein the coefficient of static friction is less than 0.2
9. A changing station comprising a substrate carrier according to claim 1.
10. The changing station according to claim 9, wherein each of the springs comprises an accommodating area for a first movement element and wherein the changing station comprises two or more first movement elements adapted to move the springs outwards.
11. A method for treating a substrate comprising the following steps: (a) inserting a substrate into a substrate carrier according to claim 1; and (b) treating the substrate.
12. The method according to claim 11, wherein, prior to the insertion of the substrate, the springs of the centering device are moved outwards, wherein the substrate carrier comprises a plurality of locking devices adapted to hold the substrate in the substrate carrier in a form-fitting and force-free manner, and wherein, prior to the insertion of the substrate, the locking devices are opened.
13. The method according to claim 11, wherein, after the insertion of the substrate, the springs of the centering device are moved inwards, wherein the substrate carrier comprises a plurality of locking devices adapted to hold the substrate in the substrate carrier in a form-fitting and force-free manner, and wherein, after the insertion of the substrate, the locking devices are closed.
14. The method according to claim 11, further comprising the step: (c) removing the substrate from the substrate carrier.
15. The method according to claim 14, wherein, prior to the removal of the substrate, the springs of the centering device are moved outwards, wherein the substrate carrier comprises a plurality of locking devices adapted to hold the substrate in the substrate carrier in a form-fitting and force-free manner, and wherein the locking devices are opened prior to the removal of the substrate.
16. The method according to claim 11, wherein the substrate carrier and/or the substrate are heated from a first temperature to a second temperature between steps (a) and (b), wherein the first temperature is in a range below 100° C. and wherein the second temperature is in a range above 120° C.
17. The method according to claim 11, wherein, between steps (a) and (b), the substrate is held in the substrate carrier in a form-fitting and force-free manner by means of a plurality of locking devices.
18. The method according to claim 11, wherein the substrate is oriented substantially vertically in step (b), wherein the centering device is located in the lower half of the substrate.
19. The method according to claim 18, wherein no frictional forces act between the substrate and the substrate carrier during steps (a) and/or (c).
20. The method according to claim 19, wherein in step (a) the substrate is inserted into the substrate carrier in a manner inclined with respect to a plane defined by the substrate carrier such that first the lower edge of the substrate rests on a lower side of the substrate carrier and subsequently the substrate is tilted into the plane of the substrate carrier.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In the following, the present invention is explained in more detail with reference to the Figures, in which
[0028] FIG. 1 shows a top view of a substrate carrier of the invention according to a preferred embodiment;
[0029] FIG. 2 shows the spring of a centering device of the invention according to a preferred embodiment in the open position;
[0030] FIG. 3 shows the spring of FIG. 2 in the closed position;
[0031] FIG. 4 shows a cross-sectional view of a substrate carrier of the invention according to a preferred embodiment;
[0032] FIG. 5 shows a detailed view of FIG. 4;
[0033] FIG. 6 shows a view analogous to FIG. 5, but with the substrate offset;
[0034] FIG. 7 shows a top view of a substrate carrier of the invention according to a further preferred embodiment;
[0035] FIG. 8 shows a perspective view of the movement elements for a centering device of a changing station of the invention according to a preferred embodiment;
[0036] FIG. 9 shows a perspective view of the movement elements for a locking device of a changing station according to a preferred embodiment,
[0037] FIG. 10 shows a vertical cross-section through a substrate in the substrate carrier according to a preferred embodiment; and
[0038] FIG. 11 shows a vertical cross-section through the substrate of FIG. 10 during the removal.
DETAILED DESCRIPTION
[0039] FIG. 1 shows a preferred embodiment of a substrate carrier 1 according to the invention in a top view. A substrate 2 is already accommodated in the substrate carrier 1, said substrate 2 being held in the substrate carrier 1 in a form-fitting and force-free manner by means of a plurality of locking devices 4. Although ten locking devices 4 are depicted in the illustrated embodiment, it should be appreciated that fewer or more locking devices can also be provided in other symmetrical or asymmetrical arrangements. The substrate carrier 1 further comprises a centering device adapted to center the substrate along a first axis, wherein the centering device comprises two inwardly preloaded springs 3 opposite each other.
[0040] In the illustrated preferred embodiment, the substrate 2 is oriented substantially vertically in the substrate carrier 1 so that the substrate 2 rests on the substrate carrier 1 at its lower edge, which extends parallel to the first axis between the two springs 3. In such an arrangement, the vertical orientation of the substrate 2 with respect to the substrate carrier 1 is actually defined by the fact that the substrate 2 rests on the substrate carrier at its lower edge. A centration takes place only in the horizontal direction, i.e., along the first axis extending between the two springs 3. For this purpose, at least two springs 3 opposite each other are required at the respective vertical side edges of the substrate 2, which are preferably each arranged at the same height with respect to the lower edge of the substrate 2. Preferably, the springs 3 of the centering device are located in the vicinity of the lower edge, as shown in FIG. 1. This enables the forces to act in the lower region of the substrate 2 for its centration. However, the springs can also be provided further up. Furthermore, two or more pairs of springs opposite each other can also be provided.
[0041] In FIGS. 2 and 3, the right one of the two centering springs 3 of FIG. 1 is shown in detail, once in the open position (cf. FIG. 2) and once in the closed position (cf. FIG. 3). The spring 3 comprises a curved spring element 6 which is mounted on two mountings 7. Said spring element 6 comprises a contact area 6a which is provided to come into contact with the substrate 2 at its side edge. As can be seen in FIG. 2, said contact area has a curvature whose radius of curvature is preferably at least 5 mm. In the depicted preferred embodiment, the movable end of the spring element 6 ends in the region of the contact area 6a in a loop or hook which comprises or forms an accommodating area for a first movement element 9a. Said first movement element 9a can be part of a changing station, which will be explained in the following. In the depicted embodiment, the first movement element 9a is essentially a pin that can plunge into the loop or curve or hook of the spring element 6. In the open spring position shown in FIG. 2, the spring element 6 is held in the outwards or rightwards deflected position against its preload by means of said pin 9a so that the contact area 6a does not contact the side edge of the substrate 2. In this position of the spring 3, the substrate 2 can be easily inserted into or removed from the substrate carrier without interaction with the spring 3.
[0042] As soon as the substrate 2 has been inserted into the substrate carrier 1, the pin 9a is moved to the left along the elongated hole 8 on a circular path (cf. FIG. 3) so that the spring element 6 springs inwards or leftwards due to its preload and the contact area 6a comes into contact with a side edge of the substrate 2. In order to ensure that the spring element 6 does not get jammed or twisted, a second movement element 9b can be provided which is moved along the curved elongated hole 8 together with the first movement element 9a and, in the depicted preferred embodiment, presses onto the loop or hook of the spring element 6 from the outside to move the spring element 6 into the position shown in FIG. 3. Subsequently, the two pins 9a and 9b can be removed from the corresponding accommodating areas of the spring 3, since the spring element 6 now acts on the side edge of the substrate 2 solely due to its preload.
[0043] In FIG. 3, a situation is illustrated in which the contact area 6a of the spring element 6 of the spring 3 just comes into contact with a side edge of the substrate 2 without exerting a substantial force on the substrate 2, since the movable end of the spring element 6 rests against the stop 14 in the position depicted in FIG. 3. If, however, starting from the position depicted in FIG. 3, the substrate 2 were now to expand along the first axis, i.e. here in the horizontal direction (or the substrate carrier 1 were to contract accordingly), the right-hand side edge of the substrate 2 would push the contact area 6a of the spring element 6 outwards or rightwards so that the spring element 6 no longer rests against the stop 14. The spring force then exerted by the spring element 6 onto the side edge of the substrate 2 (as well as the corresponding force of the opposite spring element) would then ensure a symmetrical or centered arrangement of the substrate 2 in the substrate carrier 1.
[0044] In FIG. 8, a corresponding actuator 11 of a changing station for opening and closing the springs is illustrated a perspective view, said changing station being not further illustrated and being known per se. The actuator 11 is provided with two movement elements, of which the first movement element 10a is clearly visible. Said first movement element 10a projects through the curved elongated hole 8 into the loop formed by the spring element 6 in the region of the contact area 6a, as previously discussed with reference to FIGS. 2 and 3. The actuator 11 causes the two movement elements or pins to move along the elongated hole 8, as described above. A further actuator, not shown, can retract the two movement elements from the corresponding accommodating areas 9a and 9b of the spring.
[0045] A corresponding actuator 13 and corresponding engagement elements or pins 12a and 12b can be provided for opening and closing the locking devices 4 (cf. FIG. 9). For opening and closing by means of the pins 12a and 12b, the actuator 13 moves the locking loop 4a shown in FIG. 9, which secures the substrate, for example, against tipping out of the substrate carrier.
[0046] FIG. 4 shows a sectional view of the substrate carrier according to FIG. 1 along the first axis. As can be clearly seen there, the substrate 2 rests against the substrate carrier 1 at its side edges and the two opposite (here vertical) side edges of the substrate 2 are in contact with the contact areas 6a of the spring element 6 of the two springs 3.
[0047] FIG. 5 shows an enlarged detail for the left spring 3, where it can be clearly seen that the left side edge of the substrate 2 directly rests against the contact area 6a of the spring 3. It is preferred that, in the contact area 6a perpendicular to the substrate surface, the extension or thickness D1 of the spring 3 is significantly greater than the thickness D2 of the substrate.
[0048] As already explained, the ratio between D1 and D2 is preferably at least 1.5 and particularly preferably at least 2.
[0049] The advantage of this feature can be seen in FIG. 6, which is analogous to FIG. 5, wherein, however, the substrate 2 is here offset downwards by an offset V, which can be caused, for example, by a curvature of the substrate. Since the thickness D1 is greater than the thickness D2, the outer edge of the substrate 2 still rests against the contact area 6a of the spring 3 in this situation, so that a centration by the spring 3 can still be ensured.
[0050] The substrate carrier according to the invention enables, i.a., a frictionless removal of a substrate from the substrate carrier, which will be explained with reference to the schematic cross-sectional views of FIGS. 10 and 11. FIG. 10 shows a vertical cross-section through a substrate 2 in the substrate carrier 1 according to a preferred embodiment, wherein the substrate 2 rests on the substrate carrier 1 at its lower edge 2a. In the illustrated preferred embodiment, the substrate carrier comprises, in the region of the contact surface, a strip 15 made of a material with a low coefficient of static friction in order to minimize the static friction force between the substrate and the substrate carrier. In the situation illustrated in FIG. 10, the substrate is secured against tipping out of the substrate carrier by means of the locking loop 4a (cf. also FIG. 9) of the locking device 4. The actuator 13 shown in FIG. 9 now moves the locking loop 4a downwards to open the locking device 4 (cf. FIG. 11). In this state, the substrate can now first be tilted out of the (here: vertical) plane defined by the substrate carrier, preferably by means of a robot, so that only the lower edge 2a of the substrate 2 rests on a lower side 15 of the substrate carrier, as shown in FIG. 11. Subsequently, the substrate can be removed in the tilted state, preferably without friction. In an analogous manner, the substrate can be inserted into the substrate carrier without friction.
[0051] Instead of a vertical orientation of the substrate, the substrate can also be oriented substantially horizontally in the substrate carrier, as exemplarily shown in FIG. 7. In this case, however, it is preferred that, in addition to the two springs 3 of the first centering device, a further centering device with two pairs of inwardly preloaded springs 23 opposite each other is provided which is adapted to center the substrate along a second axis which is perpendicular to the first axis. The arrangement of the springs 3 and 23 in FIG. 7 is exemplary, wherein, however, the symmetrical arrangement is preferred.
[0052] In the preferred embodiments shown, the springs are configured as leaf springs. However, other types of springs can also be used in the context of the present invention. However, it is preferred that the spring can be easily assembled and disassembled by simply clipping it on.
