Method and apparatus for producing and sintering fine lines and patterns

Abstract

The present invention aims to provide a non-contact method for producing small conductive tracks on a substrate, to this end, a method for selective material deposition is provided, which method comprises depositing a first material on a substrate, subsequently selectively solidifying the first material in a first solidified pattern by one or more energy beams, and subsequently removing unsolidified material from the substrate by large area photonic exposure controlled in timing, energy and intensity to leave behind the first solidified pattern of the first material. [Selection diagram] None

Description

[Technical field]

[0001] The present invention relates to an enhanced method and apparatus for producing and sintering fine lines and patterns. [Background technology]

[0002] There are several methods for producing fine lines on a substrate. These methods can be further subdivided into two main categories: contact-based and non-contact-based deposition methods. Typically, the printing of a conductive paste is based on a contact method. For example (rotary) screen printing involves the printing of a conductive paste. Although very high resolutions (but still >20 μm) can be achieved, this method requires that the screen be in contact with the surface. However, various device stacks may not allow contact since they include barrier stacks. Therefore, non-contact methods for providing patterned structures are desired. For example, inkjet printing has the advantage of being non-contact. However, the nozzle size limits the usable particle size of the conductive ink, and the maximum resolution is affected by the diffusion (low viscosity) and the droplet size. Improved control over high speed (and non-contact) high-resolution (<10 μm) patterning of large area structures from materials with a wide range of viscosities is still desired.

[0003] In "Three-Dimensional Printing of Interconnects by Laser Direct-Write of Silver Nanopastes" Pique et al, Advanced Materials Volume 22, Issue 40, pages 4462-4466, October 25, 2010, laser direct-write of a solvent-based, dry nanosilver paste that is transferred to a substrate is presented to provide an alternative to electrical wirebond interconnects for bare-die LEDs. This direct-write laser technique is capable of transferring a variety of materials onto a substrate and is also known as Laser-Induced Forward Transfer (LIFT). LIFT uses laser pulses to transfer small volumes of material from a donor film onto an acceptor substrate. The donor substrate is coated with a thin film of material, and a laser beam is directed to the donor substrate / film interface. Over the duration of the pulse, laser energy deposits within the interface at the laser spot, vaporizing a small amount of material, thereby forcing and accelerating the unvaporized portion of the donor film toward the acceptor substrate.

[0004] EP 2883709 describes a method similar to LIFT, but in which the donor material is transferred by a flash, which is selectively directed at the donor material by using a mask to prevent the flash energy from reaching donor material where transfer is not desired. To obtain uniform transfer, the transfer area of ​​the material is further subdivided into individual raster elements.

[0005] The described LIFT method can generate small conductive tracks, but the accuracy of the generation depends on how the material is transferred from the donor surface and how the transferred material impacts the substrate where the conductive tracks will be formed. Possible instabilities during the initial transfer, flight, and impact can change the direction of the donor material and cause the generated tracks to be incomplete. The deposited material is also subjected to strong energy pulses and can potentially be degraded, thereby reducing the performance of the material.

[0006] US2009013042 relates to a patterning method in which a focused laser beam is scanned over a donor substrate covered with a layer of donor material to leave a desired printed structure on said donor substrate formed from the remaining donor material.

[0007] WO2013 / 024280 discloses a LIFT-based patterning method in which ink on a surface is removed to leave a desired printed structure. After forming the printed structure, the ink is transformed to form a metal structure, such as a conductive track. As in US2009013042, the track is defined by a double pass of the laser along both sides of the track, whereby the accuracy of the generated track depends on the alignment of the laser and / or the way material is transferred from the surface, limiting the ability to form fine conductive tracks. The scanning of the focused laser beam further limits the process speed, especially for printing patterns that require the removal of donor material over large areas of the substrate.

[0008] In an alternative method, WO 2013 / 024280 discloses the use of a wide beam in combination with a mask to define the printed structures, which introduces alignment issues and additional process steps, slowing down the manufacturing process. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to provide a non-contact method for producing small conductive tracks on a substrate. For this purpose, a method for selective material deposition is provided, which comprises depositing a first material on a substrate, followed by selectively solidifying the first material in a first solidified pattern by one or more energy beams, followed by removing unsolidified material from the substrate by a large area photonic exposure controlled in timing, energy and intensity to leave the first solidified pattern of the first material. [Means for solving the problem]

[0010] In the proposed method, a first material is solidified, for example sintered into a track, without first transferring the material. The position of the track on the substrate is thereby only dependent on the point at which the energy beam is focused on the substrate. Subsequently, the unsolidified material is removed by a large area flash photonic exposure. In contrast to EP 2883709 and WO 2013 / 024280, after the formation of the track, a high energy flash exposure is used to move the undesired material from the substrate. In contrast, EP 2883709 forms the track by transferring a material to the substrate for adhesion thereto. Moreover, EP 2883709 and WO 2013 / 024280 can only transfer the desired material by using an additional mask or a scanning laser beam to protect the track from the transfer energy. In contrast, the proposed method does not require an additional mask. The present invention relies on the adhesion of the desired solidified pattern to the substrate to prevent it from being transferred away from the substrate. For example, a first material is deposited on the substrate and selectively solidified into a solidified pattern by one or more energy beams that scribe fine lines, e.g., less than 5 micrometers. Unsolidified material is transferred away from the substrate by large-area (bulk) photonic exposure controlled in energy, timing, and intensity to leave the desired solidified pattern of the first material.

[0011] Whether the desired solidified pattern remains on the substrate during the transfer of the flash of unsolidified material can be controlled by the amount of energy distributed to the desired pattern, depending on how dense the already sintered pattern is. It can also depend on the amount of adhesive force that the unsolidified material exerts on the desired solidified pattern during transfer. The density of the sintered pattern can be increased by increasing the energy level of the sintering step, either by increasing the laser power or by slowing down the moving speed of the laser spot, thereby increasing the time that the laser spot is directed at a specific point on the pattern to be sintered. An option to minimize the time required to pre-sinter the desired pattern is to pre-sinter the edges of the tracks of the desired pattern more significantly than the center of the tracks of the pattern. This allows the desired tracks to be most effectively protected at the edges of the tracks from the peeling forces of the transferred unsolidified material.

[0012] During the transfer of the unsolidified material from the substrate, a force is applied to the solidified pattern. This force is caused by the fragmentation effect of the unsolidified material being transferred away from the substrate. Optionally, this force can be reduced by directing the unsolidified material to fragment into smaller pieces, thereby reducing the force applied by the momentum of the moving away material contacting the edge of the desired solidification track. This can be achieved by adding a second solidification pattern, e.g. partially contoured, surrounding the pattern, causing the unsolidified material to fragment as it is transferred. The second pattern can be, for example, a conformal line, dashed line, or dotted line, or any shape that can fragment a large surface transferred near the desired first solidification pattern into smaller areas.

[0013] Optionally, it is also possible to reduce the force that the displaced unsolidified material exerts on the desired solidified pattern by designing the edges of the track in such a way that the amount of edge area perpendicular to the main orientation of the desired track is minimized, thereby providing an averaged force over time. This can be obtained, for example, by giving the track a notched design, and several alternatives are available, for example, sawtooth, dentil, sawtooth, or tooth-shaped designs.

[0014] Additionally or alternatively, it is also possible to choose how to deposit the initial first material. This can be done in bulk, for example by curtain coating or any other suitable bulk deposition means. Alternatively, the first material can be selectively deposited by a droplet deposition technique, for example by an inkjet printer, whereby the amount of unsolidified material that has to be transferred away from the substrate is already minimized. [Brief description of the drawings]

[0015] [Figure 1A] 1A illustrates the solidification of a layer of unsolidified material by an energy beam, where the material was deposited in bulk. [Figure 1B] FIG IB illustrates the solidification of a layer of unsolidified material using an energy beam, where the material was deposited in bulk. [Figure 1C] 1C illustrates the solidification of a layer of unsolidified material using an energy beam, where the material was deposited in bulk. [Figure 2A] 2A illustrates the solidification by an energy beam of a track of unsolidified material, where the material has been selectively deposited only where desired in the solidification pattern. [Figure 2B] 2B illustrates solidification by an energy beam at a track of unsolidified material, where the material has been selectively deposited only where desired in the solidification pattern. [Figure 2C] 2C illustrates solidification by an energy beam at a track of unsolidified material, where the material has been selectively deposited only where desired in the solidification pattern. [Figure 3A] FIG. 3A is a diagram showing an example of a first solidification pattern. [Figure 3B] FIG. 3B is a diagram showing an example of a first solidified pattern and a complementary second solidified pattern in the form of lines surrounding the first solidified pattern. [Figure 3C] FIG. 3C illustrates an example of a first solidified pattern and a complementary second solidified pattern in the form of a dotted line surrounding the first solidified pattern. [Figure 4A] FIG. 4A is a diagram showing an example of a first solidification pattern having parts that are relatively close and parts that are relatively far from each other. [Figure 4B] FIG. 4B is a diagram showing an example of a first solidified pattern having portions that are relatively close and far from each other, and a complementary second solidified pattern in the form of a line surrounding the first solidified pattern. [Figure 4C] FIG. 4C illustrates an example of a first solidified pattern having portions that are relatively close and far from one another, and a complementary second solidified pattern in the form of a dotted line surrounding the first solidified pattern. [Figure 5A] FIG. 5A illustrates a more complex example solidification pattern with multiple details. [Figure 5B] FIG. 5B illustrates a more complex example solidified pattern having multiple details and a complementary second solidified pattern in the form of lines surrounding the first solidified pattern. [Figure 5C] FIG. 5C illustrates a more complex example solidified pattern having multiple details and a complementary second solidified pattern in the form of a dotted line surrounding the first solidified pattern. [Figure 6] 6 is an example of a first solidified pattern, with the enlarged portion detailing the edge structure of the first solidified pattern, showing a sharp, sawtooth profile. [Figure 7]7 is an example of a first solidified pattern, with the enlarged portion detailing the edge structure of the first solidified pattern, showing a more rounded edge profile. [Figure 8] FIG. 8 shows another example of the substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The following detailed description of certain exemplary embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or uses in any way. Therefore, this description should not be taken in a limiting sense, and the scope of the system is defined only by the appended claims. In the detailed description of the invention, reference is made to the accompanying drawings, which form a part hereof, in which specific embodiments in which the described devices and methods may be practiced are shown by way of illustration. These embodiments have been described in sufficient detail to enable those skilled in the art to practice the disclosed systems and methods, and it should be understood that other embodiments may be utilized and structural and logical changes may be made without departing from the spirit and scope of the system. Moreover, for the purposes of clarity, detailed descriptions of well-known devices and methods have been omitted so as not to obscure the description of the system.

[0017] Figure 1 shows a schematic overview of some of the process steps involved. In Figure 1A, a first material 1002 is deposited on a substrate 1001, which can be done in bulk, for example by a curtain coater over the entire surface of the substrate, or using intermittent coating techniques, for example for sub-portions of the substrate where the desired first pattern is to be generated. Subsequently, an energy beam 1003 is directed at the first material and selectively solidifies the desired first pattern. The movement of the energy beam is depicted here by an arrow 1005, generating a first solidified pattern 1004. Figure 1B shows the situation when the energy beam has solidified the entire first pattern, which in this case is represented diagrammatically by a simple solidified track 1004. Unsolidified material 1006 is still present on the substrate. FIG. 1C shows the same substrate 1001, this time in a slightly different orientation, where a large area photonic exposure 1007 has been created such that unsolidified material 1006 is moved away from the substrate 1001, leaving a first solidified pattern 1004 on the substrate 1001.

[0018] The use of large-area photonic exposure allows for efficient removal of unsolidified material, since all of the unsolidified material in the area exposed by the large-area photonic exposure will be transferred at once. Since it is desired to maintain the first solidified pattern on the substrate, the large-area photonic exposure needs to be uniform enough to allow the entire unsolidified material to be transferred away from the surface, but not so strong that it peels off the first solidified pattern. There are several types of large-area photonic exposure systems, such as flash systems using xenon lamps, or LED-based systems. Depending on the size of the structures to be patterned and the uniformity required, a single flash unit may be able to cover the substrate, or multiple flash units may be required to cover the substrate. In order to be able to cover the desired portion of the substrate from which unsolidified material needs to be removed, the large-area photonic exposure is not limited to a single light source, but can be a combination of multiple light sources that generate a large-area photonic exposure. In some embodiments, the substrate to be processed is limited in size and can be photonically exposed in its entirety using the large-area photonic exposure. In some embodiments, it is conceivable that the substrate may be very large, for example when using roll-to-roll processes, in which case the photonic exposure is directed to areas of the substrate being processed that require removal of unsolidified material. In this regard, a "large area photonic exposure" is an exposure to electromagnetic radiation of visible and near-visible wavelengths that does not have a specific patterning to provide an imaged pattern. In contrast, the electromagnetic radiation provides an area exposure of the substrate with a typical area that is approximately the typical length or area amount of the first solidified pattern, or an area larger than that. For example, the large area photonic exposure can expose an area that is at least 2-10 times the line width of the line pattern of the first solidified pattern, or much larger than that.

[0019] More specifically, the energy beam for solidifying the first solidified pattern typically has a spot size of 1-250 microns, preferably 2-100 microns, and even more preferably 2-25 microns, to solidify highly defined pattern features. The large area photonic exposure can remove unsolidified material from the surface. The surface area photonically exposed by the large area photonic exposure is typically at least 100 times larger, preferably even 1000 times larger, than the surface area photonically exposed by a single energy beam for solidifying the first solidified pattern.

[0020] FIG. 2, like FIG. 1, provides a schematic overview of some of the process steps involved. However, in this case, the deposition of the first material is not done by simply coating the entire area where the desired pattern should be generated, but by a more selective material deposition technique, for example by using a droplet deposition technique, such as inkjet printing, dispensing, or LIFT. The deposition of the first material can be done in such a way that it is already close to the desired pattern. Since current selective deposition techniques are not able to generate features with the desired resolution, the first material 2002 that has been selectively deposited on the substrate 2001 is then solidified by an energy beam 2003 to form a first solidified pattern. In this document, the movement of the energy beam is depicted by an arrow 2005. As shown in FIG. 2B, the remaining, unsolidified material 2006 is significantly reduced by using a selective deposition technique. FIG. 2C shows the same substrate 2001, now in a slightly different orientation, where a large area photonic exposure 2007 has been created such that unsolidified material 2006 is moved away from the substrate 2001, leaving a first solidified pattern 2004 on the substrate 2001.

[0021] Although it may be preferable to minimize the amount of unsolidified material, this is not always possible using inkjet or other selective deposition systems, such as microdosing, spray deposition, dispensing, or LIFT. These selective deposition systems often impose limitations on the materials they can process, such as the maximum allowable viscosity they can process. Therefore, depending on the material required to generate the first pattern, bulk deposition or selective deposition can be selected.

[0022] FIG. 3A shows an example of a first solidified pattern 3003 on a substrate 3001 covered by a first material 3002. As described above, the first material can also be selectively deposited, resulting in covering the substrate with the first material more in line with the pattern to be generated. When removing the unsolidified material from the substrate, the circled region 3004 will initially move in its entirety from the substrate, resulting in increased peel forces on the first solidified pattern 3003. Depending on the adhesion of the first solidified pattern to the substrate, these forces may be tolerable, and as shown in FIG. 3A, the first solidified pattern may be sufficient to prevent the desired first solidified pattern 3003 from peeling from the substrate 3001, resulting in the desired small tracks.

[0023] FIG. 3B provides a solution for cases where the adhesion between the first solidified pattern 3003 and the substrate 3001 is insufficient. By adding a complementary second solidified pattern 3004 to the first solidified pattern 3003, the large area that initially moves from the surface 3005 is broken up from the now smaller surface area 3006 by the second solidified pattern 3004. Hence, the unsolidified material will be moved from the surface in sub-areas. The smaller sub-areas 3006 connected to the first solidified pattern exert a significantly reduced peeling force on the first solidified pattern 3003. This allows fine tracks to be created in the substrate when material is not sufficiently inherently connected to the substrate. Or, this allows even finer tracks to be created that would not provide sufficient adhesion to the substrate to resist the movement of the unsolidified material.

[0024] The second solidified pattern shown in FIG. 3B shows that it is a continuous conformal track surrounding the first solidified pattern. However, this is not necessary as shown in FIG. 3C and the desired protection can also be provided by a non-continuous structure such as dashed or dotted lines 3007. Any structure that prevents the area 3004 from reaching the edge of the first solidified pattern is sufficient. The distance 3008 from the first solidified pattern to the second pattern, measured perpendicular to the main edge of the solidified pattern, is preferably 0.1 to 500 microns, more preferably 3 to 200 microns, and even more preferably 5 to 100 microns.

[0025] If the distance from the edge of the first pattern to the edge between the unsolidified and uncoated areas is short enough, such as would preferably be the desired distance from the second solidified pattern, these areas may not even need a second protective pattern in those areas. Therefore, the second solidified pattern does not need to surround the entire first solidified pattern, but is only needed if there is an excess of unsolidified material connected to the first solidified material.

[0026] FIG. 4 provides another example of a substrate 4001 provided with a first material 4002, where a first solidification pattern 4003 is depicted. Here, an example of a first solidification pattern with three parallel tracks 401, 402, and 403 is shown. These tracks are parallel at a certain distance, but the distance between the edges of tracks 401 and 402 is relatively short, and the distance between tracks 402 and 403 is designed to be longer. This provides an example of the need for the second solidification pattern depending on the amount of unsolidified material to be transferred adjacent to the first solidification pattern. Between tracks 402 and 403, it may be necessary to provide a second solidification pattern as shown in FIG. 4B and FIG. 4C. There is no need to provide a second solidification pattern between tracks 401 and 402 because the amount of unsolidified material between both tracks is limited. The allowable distance between tracks in a first solidified pattern without the need for an intermediate second solidified pattern varies depending on the adhesion of the solidified pattern to the substrate as well as the width of the tracks in the desired solidified pattern: the narrower the track width, the weaker the adhesion across the tracks, and therefore the shorter the distance between tracks in the first solidified pattern, the less a second solidified pattern may be required.

[0027] If the distance 40 between two tracks in the first solidified pattern is less than 200 microns, more preferably less than 50 microns, and even more preferably less than 20 microns, there is no need to add a second solidified pattern between them.

[0028] As previously mentioned, if the adhesion of the first solidification pattern to the substrate is strong enough to prevent the first solidification material from peeling off from the substrate during the transfer of the unsolidified material, a second solidification pattern may not be needed at all. It can be understood that if the first solidification pattern has relatively rough features and some delicate features, a second solidification pattern is likely only needed near the delicate features, since the rough features do not require additional protection to leave the rough features on the substrate during the transfer of the unsolidified material.

[0029] 4B and 4C also distinguish between continuous patterns, i.e., lines to form second solidified pattern 4004, and interrupted patterns, i.e., dashed or dotted lines 4005. The advantage of the disconnected dashed or dotted line variants 4005 is that these structures are not connected and therefore cannot conduct current if they remain on the substrate.

[0030] It is noted that the dashed or dotted line examples mentioned above may be any suitable shape that will cause the unsolidified material to break apart during transfer. The same applies to the continuous second solidification pattern. It may be a line only a few microns wide, which breaks apart the unsolidified material during transfer, but does not adhere to the surface enough to remain on the substrate, and is therefore transferred away with the broken apart unsolidified material. Therefore, the design of the secondary solidification material can be optimized either to remain on the substrate during the transfer of the unsolidified material, or to be peeled off during this transfer step, still separating the unsolidified material, but not remaining on the surface. This balance can be reached by changing the surface area of ​​the second solidification pattern, or alternatively by changing the adhesion of the second solidification pattern to the substrate, for example by changing the cure strength of the second solidification pattern. Alternatively, if it is desired that the second solidified pattern remain on the substrate, the edges of the second solidified pattern can be made more strongly hardened or designed in a way to average out the forces applied to the pattern, as shown in Figures 6 and 7 for the first solidified pattern.

[0031] Figure 5 shows a more complex example. Figure 5A shows an example of a first solidified pattern 5003 on a substrate 5001 covered by a first material 5002. This can be a functional pattern if the adhesion between the first solidified pattern and the substrate 4001 is strong enough to prevent the first solidified material from peeling off the substrate during the transfer of the unsolidified material. However, if this is not fully the case, Figures 5B and 5C show a second solidified pattern added in a critical location. The relatively robust main portion 500 of the first solidified pattern 5003 has enough adhesive surface to remain on the substrate during the transfer of the unsolidified material, and therefore no specific second solidified pattern is needed to protect it. The smaller tracks 501 may need additional protection, but are connected to the main portion 500 on one side, and on two sides there is almost no unsolidified material adjacent to it. Therefore, on these sides no second solidified pattern is needed. However, there is a large area of ​​unsolidified material underneath that may result in excessive removal forces and a second solidified pattern 504 is desired.

[0032] On the other side of the main portion 500 there is a delicate track 502 which can be protected by a second solidified pattern 506 .

[0033] Moreover, there is a combination of two tracks 503 shown. These tracks are placed close to each other, therefore no second solidification pattern is needed between them, but due to their size, it may be necessary to add a surrounding second solidification pattern 507. It can be noted that the distance between the track to be protected and the second solidification pattern may be different depending on the width of the track to be protected, and the thinner and more delicate the track that needs protection, the closer the second solidification pattern is placed near the track to be protected to minimize the amount of unsolidified material adjacent to it. Figure 5C shows a structure similar to that shown in Figure 5B, but now using an alternative second solidification pattern in the form of a dotted line. As stated, any shape suitable for isolating a large area of ​​unsolidified material is useful, such as dots, circles, tracks of lines, diamonds, triangles, octagons, polygons, any random shape.

[0034] Figures 6 and 7 show another example of a substrate 6001, 7001 provided with a first material 6002, 7002, where a first solidified pattern 6003, 7003 is depicted. Here, an enlarged portion 60, 70 is given to show in more detail the edge of the first solidified pattern 6003, 7003. In Figure 6, the edge is not a straight line, but has a notch, in this example a sawtooth profile 601. As shown in Figure 7, also different profiles can be applied, for example a more rounded edge 701.

[0035] In FIG. 6, dashed line 61 is shown, which would logically be the edge of the track, without the sawtooth profile. Arrows 62, 63 and 64 indicate the main direction in which the shock wave resulting from the movement of unsolidified material approaches the first solidified pattern. Without the profile at the edge, the shock wave traveling with arrow 62 would strike the straight edge almost simultaneously over the entire width of the edge, resulting in a high peak force applied to the track. The same is true for shock waves traveling in the direction of arrows 63 and 64. By adjusting the profile using notches, e.g. sawtooth, rounded or spiked structures, as shown in FIG. 6 and FIG. 7, the shock wave will first strike the tops of these structures and then proceed further towards the more concave solidified pattern, thereby increasing the contact time of the shock wave with the edge, thereby averaging the force applied to the track. This results in a longer but significantly lower force being applied to the track. If the applied force is kept below the threshold holding force of the track against the surface, the first solidified pattern will not peel off from the surface and will remain on the substrate as desired. While the examples here show sawtooth and rounded edge profiles, it can be understood that any edge profile that provides an outer edge that runs in a direction perpendicular to the major edge line 61 can achieve this protection. Edge profiles designed with sharp notches, rounded notches, or a combination of both will provide the desired results.

[0036] The above example shows a first solidified pattern with a notched edge, and the second solidified pattern can be designed to have a similar notched edge, for example to control the moment the pattern is released during transfer of the unsolidified material, or to leave elements or the entire second pattern on the surface.

[0037] 8 shows another example of a substrate 8001 provided with a first material 8002, in which a first solidified pattern 8003 is depicted. An enlarged portion 80 is now provided, showing a portion of the first solidified pattern in more detail.

[0038] Instead of an edge profile, one can choose to sinter the edge portion 801 more harshly than the core 802 of the track, again protecting the track from peeling off during the transfer of the unsolidified material. If the edge portion 801 of the track does not peel off, the remaining part of the solidified track will also remain on the substrate. The width 811 of the edge portion to be cured or sintered more harshly is typically 1-30 microns, more preferably 2-25 microns, even more preferably 2-10 microns. Even when producing narrow tracks, e.g. 8 microns wide, a 2 micron edge portion can still provide a significant process speed optimization, because only 1 / 2 of the track needs to be cured more harshly while still creating enough adhesion strength at the edge of the pattern to prevent the first solidified pattern from peeling off during the transfer of the unsolidified material.

[0039] This technique can be applied to the first solidification pattern as well as the second solidification pattern, if desired.

[0040] The large area photonic exposure used can also be adjusted to minimize the effect on the first solidified pattern during the transfer of the unsolidified material. For example, multiple flashes can also be used to average the force on the first solidified pattern, for example using a double flash or multiple flashes of lower intensity to achieve the same transfer result, but with a lower intensity of peak force applied to the first solidified pattern. Typical types of flashes that can be used are 3-59 kW / cm. 2 and pulse widths from 1 μs to 10 ms. Typical wavelengths present in these flashes are between 300 and 1200 nm.

[0041] A moving mirror may be suitable for directing the energy beam to the substrate; alternatively, a prism, polygon, or transmitting polygon can be used to direct the energy beam to the substrate.

[0042] Depending on the intensity and wavelength required to solidify the first solidified pattern, different types of energy sources can be used, for example, conventional laser sources, diode lasers, LEDs, electron beams, xenon lamps.

[0043] It is also possible to only partially solidify the first solidified pattern enough that it remains on the substrate during the transfer of the unsolidified material, and then using other sintering or hardening means, the first solidified pattern can be further solidified into its final structure by heating the entire pattern in an oven, or alternatively, by using a large area photonic exposure system, but now using different pulse and intensity settings, where no transfer is achieved, but the track is still exposed to a high enough energy level to be fully solidified as desired.

[0044] If some parts of the structure are too delicate to remove the unsolidified material using bulk photonic exposure, it is also possible to remove the unsolidified material from these areas by using an energy source that uses a pulse width that is used to solidify the desired solidified pattern, but where the unsolidified material is either removed from the substrate, removed from the surface, or moved away from the surface.

[0045] This can optionally be performed prior to large area photonic exposure to remove less significant portions of the unsolidified material.

[0046] 1 and 2, the energy beam and bulk photonic exposure are shown as being directed from different sides of the substrate, this is not required and the energy beam 1003, 2003 could also be directed through the substrate to solidify the pattern from the other side.

[0047] The solidification of the material can be a sintering consolidation, in which the solvent is evaporated and the particles that may be present in the material are sintered together to obtain conductive tracks, but also different types of solidification can be envisaged, for example UV-curable or photocurable compositions that polymerize during exposure to certain wavelengths, or compositions sensitive to other energy beams.

[0048] In these cases, it is also possible to add specific spectral filters to the flash unit so that the flash does not solidify the unsolidified material that is to be dislodged from the substrate. The flash will remove the material instantly, so that it does not have time to adhere, but the removed material can be reused without significant degradation.

[0049] The unsolidified material that is moved away can be collected on surfaces or grooves arranged in the direction of movement, so that the collected material can be reused.

[0050] The second solidification pattern is designed to break up large areas of the unsolidified material during the transfer of the unsolidified material on the substrate. Depending on the dimensions and solidification state of the second solidification pattern, the pattern will remain on the substrate, but the second solidification pattern can also be designed as a sacrificial pattern, which will be lifted off by the moving unsolidified material during the transfer of the unsolidified material, thus causing the transferred unsolidified material to break up, but will not remain on the substrate.

[0051] In the latter case, the unsolidified material that is moved away can still be recovered for reuse, but filtration may be required to remove the solidified material portions from the second solidified pattern.

[0052] Finally, the above discussion is intended to be merely illustrative of the present system, and should not be construed as limiting the appended claims to any particular embodiment or group of embodiments. Accordingly, while the present system has been described in particular detail with reference to specific exemplary embodiments thereof, it should also be understood that numerous modifications and alternative embodiments may be contemplated by those skilled in the art without departing from the broad intended spirit and scope of the present system as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative manner, and not as limiting the scope of the appended claims.

[0053] In interpreting the appended claims, it is to be understood that the word "comprising" does not exclude the presence of other elements or acts than those recited in a given claim, the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements, any reference signs in the claims do not limit their scope, several "means" may be represented by the same or different items or implemented structures or functions, any of the disclosed devices or parts thereof may be combined with each other or divided into further parts unless expressly stated otherwise, and no specific order of acts or steps is intended to be essential unless expressly indicated, and no specific ordering of elements is intended to be essential unless expressly indicated.

Claims

1. 1. A method for selective material deposition comprising: Depositing a first material onto a deposition surface on a substrate, followed by selectively solidifying the first material in a first solidification pattern with one or more energy beams; and subsequently removing unsolidified first material from the substrate as exfoliated regions by moving the unsolidified material away from the substrate via large area photonic exposure controlled in timing, energy and intensity, leaving behind the first solidified pattern of the first material. Including, The large area photonic exposure is directed at the first material from an exposed surface of the substrate opposite the deposition surface. The method.

2. 10. The method of claim 1, comprising selectively solidifying the first material with one or more energy beams in a second solidification pattern prior to removing the unsolidified first material from the substrate with large area photonic exposure, the second solidification pattern being complementary to the first solidification pattern and constructed to fragment the unsolidified first material when removed.

3. The method of claim 2 , wherein the second solidified pattern comprises solidified portions formed by continuous lines, dashed lines, or dotted lines.

4. The method according to claim 2 or 3, wherein the minimum distance between the first solidified pattern and the second solidified pattern is between 5 and 250 microns.

5. 5. The method of claim 2, wherein the second solidified pattern only includes solidified portions facing unsolidified material over at least 50 microns in a direction away from the first solidified pattern.

6. 6. The method of claim 1, wherein the first solidified pattern has an edge with a notch for averaging forces applied to the edge during removal of unsolidified first material from the substrate.

7. 7. The method of claim 1, wherein the first solidified pattern comprises an edge portion and a core portion, and the edge portion is exposed to the one or more energy beams longer than the core portion of a desired solidified pattern, such that the first solidified pattern is strengthened at the edge portion.

8. The method of any one of claims 1 to 7, further comprising sintering the consolidated pattern of the first material after removing the unconsolidated material.

9. The method of any one of claims 1 to 8, wherein the large area photonic exposure is performed by a plurality of short energy pulses.

10. The large area photonic exposure is between 3 and 50 kW / cm ２ The method according to any one of claims 1 to 9, wherein the photoelectric conversion element is generated by a flash system having an energy density of

11. The method of any one of claims 1 to 10, wherein the first material is deposited in bulk.

12. The method of any one of claims 1 to 11, wherein the first material is selectively deposited using a non-contact deposition technique.

13. The method according to any one of claims 1 to 12, wherein the deposition technique is a droplet deposition technique.

14. 14. The method of any one of claims 1 to 13, wherein the one or more energy beams are generated by a laser having a wavelength of 300 to 1200 nanometers directed towards the first material from the deposition surface and / or the exposure surface.

15. The method of any one of the preceding claims, wherein the one or more energy beams are directed to the substrate by one or more moveable mirrors.

16. 1. A method for selective material deposition comprising: Depositing a first material onto a deposition surface on a substrate, followed by selectively sintering the first material in a first solidification pattern with one or more energy beams; and subsequently removing unsolidified first material from the substrate by moving the unsolidified material away from the substrate with large area photonic exposure controlled in timing, energy and intensity to leave behind the first solidified pattern of the first material. Including, the large area photonic exposure is directed at the first material from an exposed side of the substrate opposite the deposition side; The method.

17. 17. The method of claim 16, comprising selectively solidifying the first material with one or more energy beams in a second solidification pattern prior to removing the unsolidified first material from the substrate with large area photonic exposure, the second solidification pattern being complementary to the first solidification pattern and constructed to fragment the unsolidified first material when removed.

18. The method of claim 17 , wherein the second solidified pattern comprises solidified portions formed by continuous lines, dashed lines, or dotted lines.

19. The method according to claim 17 or 18, wherein the minimum distance between the first solidified pattern and the second solidified pattern is between 5 and 250 microns.

20. 20. The method of any one of claims 17 to 19, wherein the second solidified pattern only comprises solidified portions facing unsolidified material over at least 50 microns in a direction away from the first solidified pattern.

21. 21. The method of any one of claims 17 to 20, wherein the first solidified pattern comprises an edge having a notch for averaging forces applied to the edge during removal of unsolidified first material from the substrate.

22. 22. The method of any one of claims 17 to 21, wherein the first solidified pattern comprises an edge portion and a core portion, and the edge portion is exposed to the one or more energy beams longer than the core portion of a desired solidified pattern, thereby strengthening the first solidified pattern at the edge portion.

23. The method of any one of claims 17 to 22, wherein the large area photonic exposure is performed by a plurality of short energy pulses.

24. The large area photonic exposure is between 3 and 50 kW / cm ２ The method according to any one of claims 17 to 23, wherein the photoelectric conversion element is generated by a flash system having an energy density of

25. The method of any one of claims 17 to 24, wherein the first material is deposited in bulk.

26. The method of any one of claims 17 to 25, wherein the first material is selectively deposited using a non-contact deposition technique.

27. The method according to any one of claims 17 to 26, wherein the deposition technique is a droplet deposition technique.

28. A method according to any one of claims 17 to 27, wherein the energy beam is generated by a laser having a wavelength of 300 to 1200 nanometers.

29. The method of any one of claims 17 to 28, wherein the one or more energy beams are directed to the substrate by one or more moveable mirrors.

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