Abstract
An assembly includes a master for imprinting of micro-structures and nano-structures. The master has on its upper surface an active area with relief structure for imprinting of the micro-structures and nano-structures, and the master has a thickness d.sub.master. The assembly includes frame pieces arranged around and flushing along the outer circumference of the master, with the frame pieces having a thickness d.sub.frame. The thickness d.sub.frame of the frame pieces deviates from the thickness d.sub.master of the master by at most 250 .Math.m. A a flexible stamp has improved alignment.
Claims
1. An assembly comprising: a master for imprinting of micro-structures and nano-structures, the master being arranged on a substrate carrier and having on an upper surface an active area with relief structure for imprinting of the micro-structures and nano-structures, the master having a thickness d.sub.master: a set of frame pieces mounted on the substrate carrier and arranged around and flushing along the an outer circumference of the master, the frame pieces having a thickness d.sub.frame, wherein the thickness d.sub.frame of the frame pieces deviates from the thickness d.sub.master of the master by at most 250 .Math.m.
2. The assembly according to claim 1, wherein the master is a scaled-up master, the scaled-up master being made-up from a multitude of tiled master units having on upper surfaces active areas with relief structure for imprinting of the micro-structures and nano-structures, the upper surfaces of the tiled master units forming in total the upper surface of the scaled-up master.
3. The assembly according to claim 2, wherein the set of frame pieces further comprises intermediate frame pieces which are mounted on the substrate carrier and are arranged between tiled master units and flush along side edges of the tiled master units adjoining the intermediate frame pieces.
4. The assembly according to claim 1, wherein the thickness d.sub.frame of the frame pieces differs from the thickness d.sub.master of the master.
5. The assembly according to claim 1, wherein the frame pieces have a width of at least 5 mm.
6. The assembly according to claim 1, wherein the frame pieces have an optically detectable relief structure on a surface being directed in the a same direction as the upper surface of the master.
7. The assembly according to claim 1 wherein the frame pieces arranged around the outer circumference of the master are shaped and oriented such that two neighboring edges per frame piece form an extrapolation of two neighboring edges of the master.
8. The assembly according to claim 1 wherein the outer circumference of the master has a non-quadratic and non-rectangular contour and the frame pieces arranged around the outer circumference of the master are shaped and arranged such that edges adjoining the master are adapted in shape and size to follow the contour of the circumference of the master while the frame pieces with the outer edges form a square or rectangle.
9. The assembly according to claim 2, the scaled-up master being made-up from tile-shaped master units, wherein adjoining edges of neighboring master units are parallel with each other and wherein the master units forming the master are arranged such that splice lines between the master units only have junctions between master units where at most three corners of neighboring master units are brought together.
10. A method of using frame pieces in an imprint process for manufacturing of a flexible stamp, comprising replicating the flexible stamp from a master having on an upper surface an active area with relief structure for imprinting of micro-structures and nano-structures, wherein the master has a thickness d.sub.master, arranging the frame pieces are around and flushing along an outer circumference of the master, wherein the frame pieces have a thickness d.sub.frame, wherein the thickness d.sub.frame of the frame pieces deviates from the thickness d.sub.master of the master by at most 250 .Math.m and wherein master and frame pieces are mounted on a substrate carrier and are distinct from the substrate carrier.
11. The method according to claim 10 wherein the master is a scaled-up master comprising a multitude of tiled master units having on an upper surface, active areas with relief structure for imprinting of micro-structures and nano-structures, the upper surfaces of the tiled master units forming in total the upper surface of the scaled-up master and the frame pieces being arranged at least around and flushing along the outer circumference of the scaled-up master.
12. The method according to claim 10 wherein, the thickness d.sub.frame of the frame pieces is larger than the thickness d.sub.master of the master by at most 250 .Math.m.
13. The method according to claim 10, wherein the frame pieces have a relief structure on the upper surface to facilitate control of resin flow during an imprint process.
14. The method according to claim 11, wherein the scaled-up master comprises tile-shaped tiled master units, wherein adjoining edges of neighboring tiled master units are parallel with each other and wherein the tiled master units are arranged in the flexible stamp such that splice lines between the sub-units only have junctions between sub-units wherein at most three corners of neighboring sub-units are brought together.
15. A flexible stamp from a master having on an upper surface an active area with relief structure for imprinting of micro-structures and nano-structures, rendered to the flexible stamp by the assembly according to claim 2 .
Description
[0039] The invention is explained now in more detail with reference to the following figures, wherein the scope of the invention is not limited by the figures:
[0040] FIG. 1: Assembly of tiled master units with four corner junctions (prior art).
[0041] FIG. 2: Assembly of tiled master units of FIG. 1 with four corner junctions after being moved together when being conveyed to an imprinting station (prior art).
[0042] FIG. 3: Cross-section along line A-A though the assembly of FIG. 1 being placed on a substrate carrier (prior art).
[0043] FIG. 4: Assembly according to the invention comprising a scaled-up master made-up from four tiled master units, and in addition comprising outer frame pieces.
[0044] FIG. 5: Cross-section along line B-B through the assembly of FIG. 4 being placed on a substrate carrier with frame pieces having of the same thickness as the master units.
[0045] FIG. 6: Cross-section along line B-B through the assembly of FIG. 4 being placed on a substrate carrier with frame pieces, the thickness of which is larger than the thickness of the master units.
[0046] FIG. 7: Cross-section along line B-B through the assembly of FIG. 4 being placed on a substrate carrier with frame pieces, the thickness of which is less than the thickness of the master units.
[0047] FIG. 8: Assembly according to the invention comprising a scaled-up master made-up from four master units, further comprising outer frame pieces and in addition intermediate frame pieces between the master units.
[0048] FIG. 9: Assembly according to the invention comprising a scaled-up master made-up from four master units, comprising in addition outer frame pieces shaped and oriented such that two neighboring edges of a frame piece form an extrapolation of two neighboring edges of the master.
[0049] FIG. 10: Assembly according to the invention comprising a triangular scaled-up master, comprising in addition outer frame pieces shaped and arranged such that they form with their inner edges a triangle adapted to the scaled-up master and with their outer edges a rectangle.
[0050] FIG. 1 shows a prior art assembly 1 comprising a scaled-up master 2 being made-up from four master units 3, 4, 5, 6. In this example, the four master units 3, 4, 5, 6 having a rectangular shape are arranged such that they meet with their corners at a center point thus forming a cross joint or cross junction 7. The master units 3, 4, 5, 6 may have active areas 8 with relief structure, which in the present case cover part of the surface of the master units 3, 4, 5, 6. Initially, the four master units 3, 4, 5, 6 are arranged with adjoining edges of neighboring master units being parallel with each other and the splice lines (also called stitch lines or seams) formed between adjoining edges of the master units 3, 4, 5, 6 are uniform and well controlled.
[0051] When the master units 3, 4, 5, 6 of the prior art assembly 1 of FIG. 1 are pushed or moved together when being conveyed to an imprinting station for transferring, i.e. imprinting the relief structure of the multitude of master units 3, 4, 5, 6 and the scaled-up master, respectively, to replicate a flexible stamp, the last master units 5 and 6 may push the other master units 3, 4 aside, resulting in a misaligned and rotated tiling. It should be mentioned that for such an assembly of master units forming a scaled-up master as shown in FIG. 2, misaligned and rotated tiling may already be created during the tiling process itself, i.e. when the master units 3, 4, 5, 6 are arranged next to each other. This leads to non-uniform gaps 9, 10 between the master units 3, 4, 5, 6 and high strain levels at the corners at cross junction 7, as shown in FIG. 2. When manufacturing of a large-area flexible stamp from this assembly 1 of master units 3, 4, 5, 6 having misaligned and rotated tiling and non-uniform gaps, also the flexible stamp will show the same deficiencies.
[0052] FIG. 3 shows a cross-section of the assembly 1 of FIG. 1 along line A-A with master units 5, 6 being mounted and arranged side-by-side on a substrate carrier 12, each master unit 5, 6 having an active area 8 with relief structure. Master units 5, 6 have thickness d.sub.master, leading to height step 13 between upper surface 14 of the master units 5, 6 and upper surface 15 of substrate carrier 12, which height step is equal to the thickness d.sub.master.
[0053] FIG. 4 shows an assembly 101 according to the invention with a scaled-up master 102 being made-up from four master units 103, 104, 105, 106 having active areas 108 with relief structure. In addition to the prior art assembly 1 shown in FIG. 1, the assembly 101 of FIG. 3 comprises frame pieces 116, 117, 118, 119 being arranged around and flushing along the outer circumference of the master 102. With the frame pieces 116, 117, 118, 119 being arranged around and flushing along the outer circumference of scaled-up master 102 misaligning and rotating of the master units 103, 104, 105, 106 during processing for replicating a flexible stamp can at least be reduced. Instead, accurate alignment of the tiled master units 103, 104, 105, 106 in a process for replicating a flexible stamp from the scaled-up master 102 being made-up from the tiled master units 103, 104, 105, 106 can be facilitated.
[0054] FIG. 5 is a cross-section of the assembly 101′ of FIG. 4 along line B-B with master units 105, 106 shown in FIG. 5 lying and being arranged side-by-side on a substrate carrier 112, each master unit 105, 106 having an active area 108 with relief structure. At the outer edges 120, 121 of master units 105, 106 frame pieces 117′,119′ are mounted as discrete pieces on the substrate carrier and are arranged around the master units. Preferably, frame pieces 117′,119′ are removably mounted on the substrate carrier, but can also be fixed to the substrate carrier e.g. by a glue. In the embodiment shown in FIG. 5 frame pieces 117′, 119′ have the same thickness as master units 105, 106.
[0055] With an assembly 101′ as shown in the cross section in FIG. 5 resin overflow will be transferred into the region of the frame pieces 117′, 119′ when a flexible stamp is replicated from the scaled-up master 102 shown in FIG. 4, wherein the resin flowing into the frame area has a controlled thickness which is the same as the thickness of the replicated flexible stamp. Formation of uncontrolled height steps and/or bumps at the edges of the scaled-up master unit 102 can be avoided and height step 113′ between upper surface 114 of the master units 105, 106 and upper surface 123 of frame pieces 117′,119′, respectively, and upper surface 115 of substrate carrier 112 is far from master units 105, 106.
[0056] In FIG. 6 a further embodiment 101″ of the cross-section of the assembly of FIG. 4 along line B-B with master units 105, 106 is shown. At the outer edges 120, 121 of master units 105, 106 frame pieces 117″, 119″ are mounted on the substrate carrier and are arranged around the master units, which frame pieces having a thickness which is larger than the thickness of master units 105, 106. In this case, a defined height step 122″ is created between upper surface 114 of master units 105, 106 and upper surface 123″ of frame pieces 117″,119″, by which defined height step 122″ the thickness of the active area of the flexible stamp is predetermined which is replicated from the assembly 101″ shown in FIG. 6. Due to the frame pieces 117″, 119″, height step 113″ to upper surface 115 of substrate carrier 112 is far from master units 105, 106. As in FIG. 4, frame pieces 117″,119″ in FIG. 6 are distinct pieces separate from the support carrier.
[0057] A further embodiment 101‴ of a cross-section of the assembly of FIG. 4 along line B-B is shown in FIG. 7. In this embodiment, an assembly with master units 105, 106 is shown. At the outer edges 120, 121 of master units 105, 106 frame pieces 117′″,119′″ are mounted on a substrate carrier and are arranged around the master units, which frame pieces having a thickness which is less than the thickness of master units 105, 106 and of the scaled-up master 102, respectively. In this case, a defined height step 122‴ is created between upper surface 114 of master units 105, 106 and upper surface 123‴ of frame pieces 117′″,119′″, which is lower. By adjusting the amount of resin used for replication of a flexible stamp from the assembly shown in FIG. 7, overflow of resin into the frame area can be controlled such that a defined height step is produced in the outer area of the flexible stamp which was allocated in the frame area during replication. This step increase in thickness of the flexible stamp at the sides of a master unit may later on serve as a vertical spacer that provides imprint thickness control of the final imprint product in a process for replicating the final imprint product from the flexible stamp.
[0058] Also, for the embodiment shown in FIG. 7, due to the frame pieces 117‴, 119‴ height step 113‴ to upper surface 115 of substrate carrier 112 is far from master units 105, 106.
[0059] FIG. 8 shows an embodiment of an assembly 201 according to the invention with a scaled-up master 202 being built-up from four master units 203, 204, 205, 206 having active areas 208 like the assembly shown in FIG. 4. In contrast to the assembly of FIG. 4, the present assembly 201 has intermediate frame pieces 231, 232, 233 in addition to outer frame pieces 216, 217, 218, 219 being arranged around and flushing along the outer circumference of the master 202. By using such an assembly having also intermediate frame pieces 231, 232, 233, it is possible to control resin overflow at the outer circumference of the scaled-up master 202 as well as local resin flow in the inner area of the scaled-up master 202. In FIG. 8, an example of resin flow during replication of a flexible stamps from the four master units 203, 204, 205, 206 is indicated by the dark-grey areas 243, 244, 245, 246. As can be seen in this example, resin covers all active areas 208 and may also cover the areas of the master units 203, 204, 205, 206 surrounding the active areas 208. In addition, resin may flow into the frame areas of outer and intermediated frame pieces 216, 217, 218, 219, 231, 232, 233, whereby the thickness of the resin areas in the frame areas is controlled by the thickness of the frame pieces 216, 217, 218, 219, 231, 232, 233 in relation to the thickness of the master units 203, 204, 205, 206. Thus, master units 203, 204, 205, 206 e.g. may have different textures or structures in their active areas 208 on their upper surfaces which finally will lead to different imprint products. With the intermediate frame pieces 223, 224, 225 being arranged between the master units 203, 204, 205, 206 a clear distinction between the active areas 208 of the master units 203, 204, 205, 206 and thus between the different imprint products is possible. As described in previous embodiment, a step height at the intermediate frame pieces can function as a vertical spacer in the product replication process.
[0060] In FIG. 9 an assembly 301 according to the invention comprising frame pieces is shown, which is similar to the assembly 101 of FIG. 4. In contrast to the assembly 101 of FIG. 4, the present assembly 301 has frame pieces 316, 317, 318, 319 being arranged around and flushing along the outer circumference of the master 302 being made-up from master units 303, 304, 305, 306, which frame pieces are shaped and oriented such that two neighboring edges of a frame piece form an extrapolation of two neighboring edges of master 302. For example, edges 331 and 332 of frame piece 316 form an extrapolation of edges 341 and 342 of master 302.
[0061] By this design of the frame pieces 316, 317, 318, 319 the length of the frame pieces does not have to be adapted exactly to the length of the edge of the master 302 the frame piece adjoins, but the length the frame pieces may be longer, as is shown in FIG. 9. In this way mismatch of the length of the frame pieces to the length of the edges of the master can be avoided.
[0062] FIG. 10 represents an assembly 401 according to the invention comprising a master 402 having a triangular shape. Master 402 is made-up from four triangular master units 403, 404, 405, 406 having active areas 408 with relief structure on their upper surface. The assembly 401 of FIG. 10 further comprises frame pieces 412, 413, 414 being arranged around and flushing along the outer circumference of the master 402. Shape, orientation and arrangement of frame pieces 412, 413, 414 is such that they form with their inner edges adjoining master 402 a triangle adapted in shape and size to master 402. The outer circumference of the arrangement of frame pieces 412, 413, 414 has the contour of a rectangle. The rectangular outer contour of the assembly 401 of FIG. 10 allows for an easy handling of the assembly in an imprint process for replicating a flexible stamp from triangular master 402, even though master 402 is built-up from a multitude of tiled master units 403, 404, 405, 406, which in the present case also have a triangular form. In addition, frame pieces 412, 413, 414 also facilitate alignment of triangular master units 403, 404, 405, 406 during a process to replicate a flexible stamp from scaled-up master 402.
[0063] It should be noted that also for the assembly shown in FIG. 10 frame pieces 412, 413, 414 are shaped and oriented such that two neighboring edges of a frame piece form an extrapolation of two neighboring edges of master 402. Like for the assembly shown in FIG. 9, by this problem resulting from a mismatch of the length of the frame pieces to the length of the edges of the master can be reduced. However, for the example shown in FIG. 10 the length of frame piece 414 still has to be adapted exactly to the length of the edge of master 402 it adjoins as well as to the width of frame piece 412.
