Donor plates, deposition devices, and deposition methods

Abstract

A donor plate (1) for deposition of a deposition material (2) on a target (30) is disclosed herein. The donor plate comprises a flexible substrate (10) having a first main surface (101) followed by an electrode layer (11), a first electrically insulating layer (12), a resistive heater layer (13), a second electrically insulating layer (14) and a patterned layer (15) with one or more recesses (155) for holding a deposition material (2) to be deposited on the target. The electrode layer (11) comprises first and second electrodes (111, 112) of complementary shape and electrically insulated from each other. The resistive heater layer (13) is electrically connected to the contact surface of the first electrode (111) and the contact surface of the second electrode (112) respectively through at least one respective slit (121, 122) in the first electrically insulating layer.

Description

Technical Field

[0001] The present invention relates to a donor plate for depositing a deposition material on a target.

[0002] The present invention further relates to a deposition apparatus comprising a donor plate.

[0003] The present invention still further relates to a deposition method using a donor plate.

[0004] The present invention also relates to a record carrier comprising a computer program that causes a programmable device to execute the foregoing method. Background Art

[0005] A deposition method is known in which a deposition material to be deposited is discharged from a recess in a surface of a donor plate onto a surface of a target. For example, US Patent Application Publication No. 2017 / 0013724 discloses a tracks pattern production apparatus that transfers a filler contained in a groove of a donor substrate to a receptor object. In this document, a scanning laser is proposed to effect thermal transfer of the filler. The lateral position at which the filler to be transferred is deposited on the receptor object depends not only on the lateral position of the groove that is the origin of the filler, but also on the transfer direction in which the filler leaves the groove when discharged. In practice, it may sometimes be difficult to accurately control the transfer direction, which results in a lateral deviation at the deposition position. Accordingly, there is a need to provide a means that enables more accurate control of the deposition position.

[0006] As shown in Figure 1, other deposition methods have been proposed. For example, instead of using a scanning laser to induce heat to cause the release of a filler, such as a functional ink, resistance heating is applied. In the example shown in Figure 1, the anode and cathode are provided as busbars embedded in the wafer, which acts as a carrier, and the resistance heater is provided as a resistance layer having respective resistance layer sections extending between pairs of busbars of opposite polarity. The filler is provided in cavities in the insulating layer deposited on the side of the carrier on which the resistance layer is provided. When electrical energy is supplied, the resistance layer sections [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2017 / 0013724 [Overview of the project] [Means for solving the problem]

[0008] According to the first embodiment, a donor plate for depositing sediment material on a target as described in claim 1 is provided.

[0009] The donor plate comprises a flexible substrate, the flexible substrate having an electrode layer, a first electrical insulating layer, a resistance heater layer, a second electrical insulating layer, and a pattern layer having one or more recesses for holding the deposited material to be deposited on the target, following a first main surface.

[0010] The electrode layer comprises first and second electrodes of complementary shape and electrically insulated from one another, and the resistance heater layer is electrically connected to the contact surfaces of the first electrode and the second electrode, respectively, through at least one slit in each of the first electrical insulating layers.

[0011] When electrical energy is supplied to the resistance heater layer, the heat generated in the resistance heater layer deforms the flexible substrate, causing the pattern layer to move toward the target. As a result, the gap between the pattern layer and the target is reduced, thereby reducing the displacement of the deposition position caused by the misalignment of the transfer direction.

[0012] The deposited material is a viscous material. The viscosity is typically at least 50 Pa.s (to avoid undesirable deformation). In some cases, the viscosity is around 1000 Pa.s. Exemplary deposited materials include conductive materials such as conductive polymers, metallized polymers, solder paste, and conductive adhesives; electrical insulating materials such as electrical insulating polymers; and semiconducting materials such as semiconducting polymers. Alternatively, the deposited material, whether conductive, semiconducting, or insulating, can function as an insulator or, rather, as a thermal conductor.

[0013] Additional elements beyond those described above may exist. For example, a thermal diffusing layer may be provided between the second electrical insulating layer and the pattern layer in the region having a recess to further improve the heat flux toward the deposit material in the recess. In an exemplary embodiment, the pattern layer is made of a thermal insulating material. The recess forms a discontinuity therein to allow for efficient heat flow from the resistance heater layer toward the deposit material.

[0014] In one embodiment, at each position of the resistance heater layer, the minimum distance between at least one slit of the first electrode and at least one slit of the second electrode is at most one-tenth of the square root of the effective surface area of ​​the resistance heater layer. The effective surface area of ​​the resistance heater layer as referred to herein is the area of ​​the resistance heater layer that is electrically connected to both electrodes. This approach achieves that the power for heating the resistance heater layer can be supplied at a relatively low supply voltage. A lower supply voltage allows for the implementation of a thinner first electrical insulation layer. Furthermore, a lower supply voltage allows for a reduction in the electrode spacing. As a result, the electrode layer can function as an efficient and substantially homogeneous heat sink. Thereafter, the donor plate can cool rapidly to restore its original shape. Consequently, the donor plate can retract away from the target surface before the deposited material has a chance to solidify and adhere to the donor plate.

[0015] In this embodiment, the first and second electrodes are comb-shaped, each having a set of comb fingers, with the comb fingers of the first and second electrodes arranged alternately. At least one slit in the first electrode provides a corresponding slit for each comb finger of the first electrode, and at least one slit in the second electrode provides a corresponding slit for each comb finger of the second electrode. Each slit in the first electrical insulating layer extends longitudinally over the respective contact surfaces of the comb fingers. Typically, the distance l between the slits is constant and the thickness d of the resistance heater layer is uniform, but this is not essential. Variations in distance l and thickness d are acceptable as long as the product of the square of distance l and the sheet resistance is constant.

[0016] In other examples, the first and second electrodes extend parallel to each other along a helical trajectory. At least one first slit extends longitudinally over the contact surface of the first electrode, and at least one second slit extends longitudinally over the contact surface of the second electrode.

[0017] Some embodiments of the donor plate further include a set of one or more independently controllable resistance heating elements positioned between the second electrical insulating layer and the pattern layer within each zone defined by each of the recesses. The set of one or more independently controllable resistance heating elements allows for independent control of the release of the deposit from the recesses. This allows the timing of the release of the deposit from the recesses to be independently selected from the timing of the activation of each resistance heating layer. This makes it possible to control the rate at which the released deposit reaches the target. In this example, at least one set of one or more independently controllable resistance heating elements comprises at least two independently controllable resistance heating elements. Through the independent control of at least two independently controllable resistance heating elements, the distribution of forces exerted on the deposit released from the recesses can be adapted to the morphology of the target surface. This also allows for further methods of controlling the shape in which the deposit solidifies on the target surface.

[0018] According to a second aspect, a deposition device as described in claim 7 is provided. The deposition device comprises a donor plate according to one of the embodiments or a specific example of the embodiments specified above, and further comprises a plate carrier. The donor plate is mounted laterally to the first plate carrier surface of the plate carrier at a second main surface opposite to its first main surface. The plate carrier functions as a retainer for the donor plate. Since the flexible substrate is mounted to the donor plate carrier only around its periphery, the donor plate can be freely deformed as a result of thermal expansion within the constraints defined by its mounting around its periphery. In one example of a plate carrier, the plate carrier is mounted on a reference frame at a first side and slidably coupled to the reference frame by a linear slide at a second side opposite to the first side to allow the plate carrier to expand in a direction along the axis from the aforementioned first side to the aforementioned second side. The plate carrier is not directly heated but may be subjected to temperature changes due to heat induced in the donor plate. In this way, deformation of the plate carrier due to such temperature changes can be avoided. When extremely high deposition accuracy is required, it may be considered to adapt the pattern design to compensate for the lateral displacement of pattern elements caused by the aforementioned sliding. The expected displacement, along with a suitable adaptation, can be calculated relatively easily, for example, by simulation. Alternatively, it may be considered to measure the position of the deposited material on the target and design an improved pattern for the donor plate from these observations.

[0019] In one embodiment of the deposition device, a donor plate is fixed to a plate carrier along with a round going seal. The plate carrier, in one example, has one or more channels extending through the carrier, which are configured to be coupled to a pressure control unit. The donor plate may be mounted to the plate carrier in a pre-tensioned manner so that the donor plate is held flat against the surface of the plate carrier in the standby mode of the deposition device prior to the deposition mode. However, since the pre-tension must be compensated, this means that a relatively large supply power is required to sufficiently deform the donor plate. In this embodiment, it is not essential that the donor plate is mounted with pre-tension. The pressure control unit is configured to apply a vacuum in the center of the donor plate in the standby mode so that the donor plate is held firmly and flat against the plate carrier. During plate deformation, the vacuum seal should be automatically broken. This can be achieved by the deformation of the plate creating a temporary opening therein that allows air to pass through, thereby releasing the vacuum.

[0020] In one embodiment of the deposition device, one or more spacers are provided on the free surface of the pattern layer. The spacers contribute to maintaining a stable reference distance between the donor plate and the target.

[0021] In one embodiment of a deposition device, the donor plate has, in a radially outward direction, a central section, a resistively heatable intermediate section, and a peripheral section. Wherein the central section comprises a section of a flexible substrate having an electrode layer, a first electrical insulating layer, a resistance heater layer, a second electrical insulating layer, and a pattern layer. The intermediate section surrounds the central section, and the donor plate is attached to a plate carrier by its peripheral section. By resistively heating the intermediate section, the central section of the donor plate can be translated toward the target without substantial deformation. In the example of this embodiment, the intermediate section has a coefficient of thermal expansion greater than that of the central section. This can be achieved in that the substrate is locally modified.

[0022] Thereby, substantial deformation of the intermediate section can be achieved.

[0023] In one example, the intermediate section of the segmented plate as described above can comprise a plurality of heating layers. Thereby, a relatively large heat flux can be induced to achieve considerable deformation of the intermediate section.

[0024] In one example, the central section of the segmented plate as described above comprises an additional resistance heater layer, and the resistance heater layer and the additional resistance heater layer are arranged on both sides of an imaginary central plane of the central section. In this example, one of the resistance heater layers arranged closer to the pattern layer is heated to cause release of the deposition material. The other of the resistance heater layers closer to the plate carrier is heated to minimize a temperature gradient in the thickness direction of the central section, with the result that deformation of the central section is mitigated.

[0025] In an example of the above-segmented plate, the thickness of the central section increases in a radially outward direction. As a result, the thermal equilibrium time also increases in the radially outward direction. Therefore, thermal expansion is relatively higher at radially outer positions of the donor plate compared to more radially inner positions. Thereby, bending of the donor plate is compensated, and the donor plate can be kept flat in the printing area. The thickness that increases radially outward can be provided, for example, in that the thickness of the flexible substrate increases in said direction, or in that the flexible substrate is provided with a coating having such a thickness profile on the side facing the plate carrier.

[0026] According to a third aspect, the deposition method according to claim 16 is provided. The deposition method specified herein uses a donor plate comprising a flexible substrate, wherein the flexible substrate successively has, on a first main surface, an electrode layer, a first electrically insulating layer, a resistance heater layer, a second electrically insulating layer, and a pattern layer provided with one or more recesses for holding deposition material to be deposited onto a target, the electrode layer comprises first and second electrodes of complementary shapes that are electrically insulated from each other, and the resistance heater layer is electrically connected to each of the first electrode and the second electrode via at least one respective slit in the first electrically insulating layer.

[0027] The method according to the third aspect of claim 16 positioning the donor plate in front of the target in a manner where the pattern layer of the donor plate does not contact the target; heating the donor plate substantially uniformly by the resistance heater layer, so as to deform the donor plate as a result of thermal expansion and move the pattern layer toward the target; releasing the deposition material to be deposited from the recesses onto the target; cooling the donor plate to remove the pattern layer from the target; comprising the above steps.

[0028] When heated, the donor plate moves towards the target and, in some cases, comes into contact with the target, reducing the printing gap. This improves printing accuracy.

[0029] It should be noted that the step of uniformly heating the donor plate may simultaneously heat the sediment sufficiently, leading to its release.

[0030] In one embodiment of the method according to a third aspect, the donor plate has a set of one or more independently controllable resistive heating elements positioned between the second electrically insulating layer and the pattern layer in each zone defined by each of the recesses, and the method further includes independently controlling the step of release by supplying electrical energy to the aforementioned set of one or more independently controllable resistive heating elements. In this embodiment, the release of the sediment can be controlled so as to allow control of the rate at which the sediment is propelled toward the target by being carried out in a particular state of the donor plate.

[0031] The steps of the method may be performed by a programmable processor, for example, to control the supply of electrical energy to a resistance heater layer and / or a set of one or more independently controllable resistance heating elements. For this purpose, a computer program product may be provided that includes a computer program that causes the programmable processor to perform such steps of the method when executed by the programmable processor.

[0032] Other embodiments described above will be explained in more detail with reference to the drawings. [Brief explanation of the drawing]

[0033] [Figure 1A] This figure schematically shows one embodiment of a donor plate according to the present invention for the deposition of sedimentary material on a target. [Figure 1B] This figure shows the heat flux measured as a function of position. [Figure 1C] This figure shows another embodiment of the donor plate according to the present invention. [Figure 2] Figure 1A is a top view of the donor plate. [Figure 3A] This figure schematically illustrates one of the three operating stages of a deposition device comprising one embodiment of the donor plate according to the present invention. [Figure 3B] This figure schematically illustrates one of the three operating stages of a deposition device comprising one embodiment of the donor plate according to the present invention. [Figure 3C] This figure schematically illustrates one of the three operating stages of a deposition device comprising one embodiment of the donor plate according to the present invention. [Figure 4A] This figure shows one operation step in one embodiment of a deposition device not according to the present invention. [Figure 4B] This figure shows one operation step in one embodiment of the deposition device according to the present invention. [Figure 5] This figure shows an alternative embodiment of the donor plate according to the present invention. [Figure 6] This figure shows a further embodiment of the deposition device according to the present invention. [Figure 7A] This figure shows a further embodiment of the deposition device according to the present invention. [Figure 7B] This figure shows a further embodiment of the deposition device according to the present invention. [Figure 8] This diagram schematically shows the donor plate model used in the simulation. [Figure 9A] This diagram shows the transformed forms of this model. [Figure 9B] This diagram shows the transformed forms of this model. [Figure 9C] This diagram shows the transformed forms of this model. [Figure 10A] This figure shows the simulation results. [Figure 10B] This figure shows the simulation results. [Modes for carrying out the invention]

[0034] Similar reference symbols in various drawings indicate the same element unless otherwise indicated.

[0035] Figure 1A schematically shows one embodiment of a donor plate 1 for the deposition of a deposit material 2 on a target 30. The donor plate comprises a flexible substrate 10, which is, for example, a silicon substrate, and the flexible substrate 10 has, following a first main surface 101, an electrode layer 11, a first electrical insulation layer 12, a resistance heater layer 13, a second electrical insulation layer 14, and a pattern layer 15 having one or more recesses 155 for holding the deposit material 2 to be deposited on the target. The pattern layer 15 may include an insulating layer 21 to reduce the heat flux outside the area defined by the recesses. The electrode layer 11 comprises a first electrode 111 and a second electrode 112, which are complementary in shape and electrically insulated from each other by a gap 113. The gap may be provided as a free space or may be filled with an insulating material, for example, a carrier material. In one example, the gap width Wg is less than 10 microns, for example, less than 3 microns. The resistance heater layer 13 is electrically connected to the contact surfaces of the first electrode 111 and the second electrode 112, respectively, through at least one slit 121, 122 in the first electrical insulation layer. In the example shown, the slit has a width Ws of less than 3 microns.

[0036] Figure 2 shows a top view of the plate as seen in the direction away from the target surface 30.

[0037] In the embodiment shown in Figure 2, the first electrode 111 and the second electrode 112 are comb-shaped. Each electrode has its own set of comb teeth 1111, 1121. As can be seen in Figure 2, the comb teeth 1111 of the first electrode 111 and the comb teeth 1121 of the second electrode 112 are arranged alternately. At least one slit 121 of the first electrode 111 provides a slit for each comb tooth 1111 of the first electrode 111, and at least one slit 122 of the second electrode 112 provides a slit for each comb tooth 1121 of the second electrode 112. The slits in the first electrical insulating layer 12 extend longitudinally over the respective contact surfaces 1112, 1122 of the comb teeth. In the example shown in Figure 2, the distance De between the slits is less than about 2 mm.

[0038] In the examples shown in Figures 1A and 2, the minimum distance De between at least one slit 121 of the first electrode 111 and at least one slit 122 of the second electrode 112 at each position of the resistance heater layer 13 is at most equal to the effective surface area A of the resistance heater layer 13. eff It is one-tenth of the square root of . The effective surface area A of the resistance heater layer 13 referred to herein. eff A is the area of ​​the resistance heater layer that is electrically connected to both electrodes. In the example shown, the effective surface area is A. eff This is equal to the product of the length L and width W of the resistance heater layer 13 that is in electrical contact with electrodes 111 and 112.

[0039] For example, the values ​​for length L and width W may both be 3 cm, thereby the distance De between the slits is equal to the effective surface area A of the resistance heater layer. eff It is less than one-tenth of the square root of .

[0040] During operation, a voltage is applied between electrodes 111 and 112 to resistively heat the deposited material 2 provided in the recesses 155 of the pattern layer 15. Figure 1B shows the heat flux measured as a function of position in the direction from left to right along the surface of the resistance heater layer 13 facing the pattern layer 15. As shown in Figure 1B, the configuration of the resistance heater layer in Figures 1A and 2 provides a very homogeneous heat flow so that the deposited material is released at a uniform release rate within the recesses 155. Only slight deviations occur. That is, at the location of the slit 122, there is a slight drop in the heat flux toward the pattern layer. This is due to the fact that an electrical connection is formed between the electrodes and the resistance heater layer 13, which also provides a thermal connection, so some of the heat flows toward electrodes 111 and 112. However, as can be seen in Figure 1B, this effect is minimal due to the small width of the slit. Local spikes in the heat flux toward the pattern layer may also be observed, but this is due to a lower heat sink effect in the gaps between adjacent electrodes. In other words, electrodes 111 and 112 are typically made of metals that generally have relatively high conductivity, while electrical insulating materials, such as SiO2 or SiN, generally have lower thermal conductivity. Also, as can be seen in Figure 1B, the spikes are modest due to the relatively small width Wg of the gap between the electrodes. As a further measure, a thermal diffusing layer 20 made of a material with high thermal conductivity is provided at the bottom of the recess 155, and this thermal diffusing layer 20 contributes to the uniform distribution of the heat flux toward the pattern layer 15. Figure 1B shows that the magnitude of the heat flux slightly exceeds the threshold heat flux The required to release the deposited material 2 out of the recess.

[0041] Referring to Figure 1C, it should be noted that the distance between consecutive slits is not necessarily the same across the entire plate. For example,

[0042]

number

[0043] Thus, the first pair of consecutive slits may have a distance l1, and the second pair of consecutive slits may have different distances l2.

[0044] During the ceremony,

[0045]

number

[0046] and

[0047]

number

[0048] These are the sheet resistances of the portions of the resistance heater layer 13 between the first pair of consecutive slits and between the second pair of consecutive slits, respectively. These portions may have different sheet resistances from each other by appropriate selection of the resistive material for the portions of the resistance heater layer or by appropriate selection of their thickness.

[0049] Figures 3A, 3B, and 3C schematically illustrate the three operating stages of the deposition device. Referring, for example, to Figure 3A, which shows the deposition device in the initial operating stage, the deposition device comprises a donor plate 1 and a plate carrier 16. The donor plate 1 is attached laterally to the first plate carrier surface 161 of the plate carrier 16 at a second main surface 102 opposite to its first main surface 101.

[0050] The plate carrier 16 is attached to the reference frame REF at the first side surface 163. The plate carrier 16 is slidably coupled to the reference frame at the second side surface 164 opposite to the first side surface, in order to allow the plate carrier 16 to expand in a direction along the axis from the first side surface to the second side surface.

[0051] As further shown in Figure 3A, the donor plate 1 is fixed to a plate carrier 16 together with a round-going seal 165, the plate carrier having one or more channels 166 extending through the plate itself, the channels 166 being configured to be coupled to a pressure control unit.

[0052] The deposition device shown in this example includes one or more spacers 151 on the free surface 17 of the pattern layer 15.

[0053] Next, a deposition method using a deposition device will be described for the three operational stages shown in Figures 3A, 3B, and 3C. In the first stage S1 shown in Figure 3A, the donor plate 1 is positioned in front of the target 30 in such a manner that its pattern layer 15 does not come into contact with it. This ensures that the spacer 151 maintains a predetermined distance of the pattern layer 15 to the target surface. Alternatively, a servo system may be used to achieve proper positioning. In the first stage, the donor plate typically has a temperature equal to room temperature, which is, for example, about 20°C.

[0054] As shown in Figure 3B, in the next step S2, a voltage is applied to the resistance heater layer 13 of the donor plate in order to heat the donor plate in a substantially uniform manner. As a result, the first main surface 101, which is closer to the pattern layer, heats up more rapidly than the second main surface 102, which faces the plate carrier 16, creating a substantial temperature difference. For example, while the second main surface 102 is still at a temperature close to room temperature, the first main surface 101 can rapidly reach a considerably high temperature of several hundred degrees, for example, 500°C, within, for example, 5 to 15 microseconds. As a result, the donor plate is deformed over a width Wd until the pattern layer 15 contacts the target. At that point, the deposit material deposited on the target from the recess 151 is released in step S3. Since the pattern layer 15 is in contact with the target at this stage, the distance traveled for the deposit material is substantially zero, and as a result, lateral displacement at the deposition location is minimized.

[0055] As shown in Figure 3C, in step S4, the donor plate is cooled so that the pattern layer 15 retracts away from the target. The retraction may also be done rapidly, for example within 20 to 40 microseconds, and the plate is cooled to a uniform temperature of several tens of degrees, for example 40°C, within a time frame of, for example 30 microseconds, and is completely retracted to the plate carrier 16.

[0056] In the embodiment described above, the release of the sedimentary material 2 is initiated by a step of resistance heating.

[0057] As shown in Figures 4A and 4B, rapid retreat of the donor plate 1 contributes to better release of the deposit 2. In the example shown, the donor plate 1 retreats away from the target 30 over a distance PG. The distance PG may also be a function of the printing thickness PT, i.e., the depth of the recess in the pattern layer of the plate, for example, PG is about 1 / 3 to 1 / 2 of the printing thickness PT. In the example shown in Figure 4A, the retreat is relatively slow, taking, for example, a few milliseconds, for example, 10 milliseconds. Within this time frame, the deposit 2a may come into contact with the edge of the recess from which it was released by flowing out, and may adhere to that edge after solidification.

[0058] Figure 4B shows a scenario where retreat occurred within a few to tens of microseconds, for example, within 10 microseconds. Within this timeframe, the sediment 2b does not have enough time to flow out, thus preventing the sediment 2b from adhering to the donor plate after release.

[0059] In an alternative embodiment, a donor plate such as the one shown in Figure 5 is used, having a set of one or more independently controllable resistance heating elements positioned between the second electrical insulating layer 14 and the pattern layer 15 within each zone defined by each of the recesses. In operation, the donor plate is heated in step S2 to a temperature high enough to deform the plate, and in step S3, the release of the deposited material 2 can be precisely controlled by selectively supplying electrical energy to specific selected control electrodes 212a, 212b, ... 212n of one or more dedicated resistance heating elements. The resistance heating elements may share a common second electrode 211, thereby allowing the timing of the release to be controlled independently of the timing of the plate deformation.

[0060] In this embodiment, the release of sediment 2 can be controlled to occur in a specific state of the donor plate 1.

[0061] For example, the rate at which the deposit material 2 is released in step S3 can be increased by timing the release to coincide with the movement of the donor plate 1 toward the target 30. For instance, assuming that the velocity of the donor plate 1 toward the target 30, resulting from thermal expansion of the donor plate 1 in step S2, is 10 m / s, and that the deposit material 2 is released from the donor plate 1 at a rate of 10 m / s by supplying energy to one or more of the dedicated resistance heating elements, the deposit material 2 will be transferred toward the target 30 at a rate of 20 m / s.

[0062] The opposite can also occur. If the deposit material 2 is released at 10 m / s while the donor plate 1 is receding at 10 m / s, the resulting velocity is 0 m / s, thereby causing gravity to drop the deposit material onto the target 30. This reduced impact velocity may be advantageous in preventing lower viscosity deposit material from splashing or in allowing the surface to be coated with ink without fracture due to strong shear forces.

[0063] Figure 6 shows an example of a deposition device in which the donor plate 1 has a central section 1C, a resistance-heatable intermediate section 1I, and a peripheral section 1P in a radially outward direction. The central section 1C comprises a section of a flexible substrate 10 having an electrode layer 11, a first electrical insulation layer 12, a resistance heater layer 13, a second electrical insulation layer 14, and a pattern layer 15. The intermediate section 1I surrounds the central section 1C, and the donor plate 1 is attached to the plate carrier 16 by its peripheral section 1P. In the example shown, the central section 1C has a bottom resistance heater layer 13CB and a top resistance heater layer 13CT arranged on mutually opposing sides of the neutral plane defined by the flexible substrate 10. The intermediate section 1I is also resistance-heatable in that it has a bottom resistance heater layer 13IB and a top resistance heater layer 13IT.

[0064] By resistance heating the intermediate section 1I, the central section 1C of the donor plate can be translated toward the target without substantial deformation. The deformation of the central section 1C is further mitigated in that the bottom resistance heater layer 13CB and the top resistance heater layer 13CT are controlled to avoid a substantial temperature gradient of the central section 1C in the direction of the surface normal to the central section 1C. Alternatively, the intermediate section 1I can have a larger coefficient of thermal expansion than the central section 1C, for example, by local modification of the substrate. This can result in substantial deformation of the intermediate section 1I. In one example, electrodes for supplying power to the resistance heaters 13CB, 13CT, 13IB, and 13IT may be made of copper and embedded in a silicon substrate. Copper has a coefficient of thermal expansion of about 17 ppm / K, while silicon has a coefficient of thermal expansion of about 3.3 ppm / K. Furthermore, copper has very high thermal conductivity. This has the advantage that the heating / cooling of the plate, as well as the resulting expansion and contraction, can be achieved more rapidly.

[0065] Figures 7A and 7B show two further embodiments of the deposition device. In the deposition device of Figure 7A, the donor plate 1 has a central section 1C with a thickness that increases in the radially outward direction. This thickness is achieved in that the flexible substrate 10 of the plate has a thickness that increases in the radial direction.

[0066] In the embodiment shown in Figure 7B, the central section 1C also has a thickness that increases in the radially outward direction. However, in this embodiment, this thickness is achieved by applying a coating 117 with low thermal conductivity and a suitable thickness profile onto the second main surface 102 of the flexible substrate 10. In this case, a suitable flexible substrate 10 is of uniform thickness.

[0067] The thermal equilibrium time is relatively shorter in the center of the plate compared to the more radially outward direction. As a result, greater thermal expansion occurs at the periphery of the plate while the plate remains substantially flat in the printing area.

[0068] It should be noted that, in order to reduce the heat flux into the substrate, one or more thermal buffer layers made of a ceramic material such as SiO2 may be provided between the flexible substrate 10 and the resistance heater layer 13.

[0069] The simulation described below was performed with reference to Figures 8, 9A, 9B, 9C, 10A, and 10B.

[0070] Figure 8 schematically shows a simulated donor plate 1 for the deposition of substance 2, which is ink in this example. The donor plate comprises a silicon substrate 10 having a thickness of 300 microns. The substrate 10 has a copper electrode layer 11 on its first main surface 101 (shown by a dashed line). The electrode layer comprises a first electrode 111 and a second electrode 112 of complementary shape having a thickness of 50 microns, and the first electrode 111 and the second electrode 112 are embedded in the silicon substrate on the first main surface 101 of the silicon substrate and are electrically insulated from each other by the substrate material. Note that not all elements in the drawing are shown at the same scale. For example, for clarity, only the upper portion of the substrate 10 is shown. Further details on the dimensions and material properties used for the simulation are provided in the table below. Following the electrode layer 11, the simulated donor plate 1 comprises a first electrical insulating layer 12 of SiO2, a molybdenum resistance heater layer 13, a second electrical insulating layer 14 of Si3N4, and a pattern layer having one or more recesses 155 for holding the deposited material 2. Note that Figure 8 shows only the portion of the simulated donor plate that forms the recesses 155 in the pattern layer.

[0071] As shown in Figure 8, the resistance heater layer 13 is electrically connected to the contact surfaces of the first electrode 111 and the second electrode 112, respectively, through the slits 121 and 122 in the first electrical insulating layer.

[0072] Figure 8 further shows the thermal diffusion layer 20 at the bottom of the recess 155. The thermal diffusion layer 20 is made of tungsten and has a thickness of 1 micron.

[0073] Further details are shown in the table below.

[0074] [Table 1]

[0075] The simulation was performed at 150 kW / cm². 2 This was performed using a fixed setting for the heat flux generated in the Mo layer. The thickness of the second insulating layer 14 and the dimensions of the slits 121 and 122 were variable.

[0076] Figures 9A, 9B, and 9C show three exemplary simulation settings, labeled Stack 1, Stack 2, and Stack 3, respectively.

[0077] In Figure 9A, the slit tapers outward away from the first electrode 111, from a minimum width of 1 micron to a maximum width of 2 microns, and the second insulating layer 14 has a thickness of 500 nm.

[0078] In Figure 9B, the slit tapers outward away from the first electrode 111, from a minimum width of 0.5 microns to a maximum width of 1.5 microns, and the second insulating layer 14 has a thickness of 200 nm.

[0079] In Figure 9C, the slit tapers outward away from the first electrode 111 from a minimum width of 1 micron to a maximum width of 2 microns, and the second insulating layer 14 has a thickness of 200 nm. In both cases, the molybdenum layer 13 is in electrical contact with the first electrode 111 in the narrow portion of the slit 121. The same applies to the electrical contact between the molybdenum layer 13 and the second electrode 112 in the slit 122. Since the electrical connection with the first electrode and the electrical connection with the second electrode are the same, only the electrical connection with the first electrode is shown.

[0080] Figures 10A and 10B show the temperature distribution of the materials in each of these cases as a function of their position from left to right in the diagram. For comparison, the positions of slits 121 and 122 are shown. Figure 10A shows the absolute value of the temperature, while Figure 10B shows the temperature deviation from the mean temperature. To account for the different thicknesses of the second insulating layer 14 in stack 1 and in stacks 2 and 3, the temperature distribution of stack 1 was measured after 6 microseconds, and the temperature distributions of stacks 2 and 3 were determined after 5 microseconds. As is best seen in Figure 10B, the temperature distributions of stacks 1 and 3 are very similar to each other. The temperature distribution of stack 2 is more uniform than that of stacks 1 and 3. This is explained by the fact that the contact area between the resistive layer 13, which does not generate heat, and the electrode 111 is substantially smaller in stack 2 than in stacks 1 and 3, respectively.

[0081] As can be further observed in Figures 10A and 10B, it is achieved that the temperature above slits 121 and 122 reaches a maximum value approximately equal to the average temperature. This can be explained by the following: Firstly, the fact that the slits have inclined sidewalls provides a relatively large surface area with respect to the projection of this surface in the recess 155. Thereafter, the heat flux in the projection of the sidewall surface, i.e., the output per unit area, is higher than the heat flux generated at the sidewall. Secondly, depending on the deposition technique used for the resistance layer, it can be achieved that the heat flux generated at the sidewall of the resistance layer is greater than the heat flux generated in the region of the resistance layer between the slits. For example, if the resistance layer 13 is deposited by sputtering, the material for deposition is distributed on the sidewall over a larger area than in the region of the resistance layer between the slits. Thereafter, the thickness of the resistance layer at the sidewall is less than the thickness of the resistance layer between the slits. The relatively high resistance of the resistance layer present on the sidewall generates a relatively high heat flux therein. By appropriately selecting the thickness of the first insulating layer 12, and the dimensions of the tapered slits 121 and 122, i.e., the width of the slits in the contact area with the electrode 111 and the width of the slits on the main surface of the resistive layer, it is possible to achieve that the average heat flux in the projected area of ​​the slits 121 and 122 is approximately equal to the heat flux in the region between the slits. Note that the heat flux in the recess can be further homogenized by the heat distribution layer 20, as shown in Figures 8, and 9A, 9B, and 9C. This allows those skilled in the art to make a trade-off between the desired degree of homogeneity and the efficiency of the device. If a high degree of homogeneity is desired, a relatively thick heat distribution layer 20 may be selected, at the cost of some loss of efficiency, in that longer heating times and more energy are required to obtain the desired average temperature. Therefore, if efficiency is more important, a thinner heat distribution layer 20 may be selected.

[0082] The technical terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit the invention. In this specification, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. Where the terms “comprises” and / or “comprising” are used herein, they specify the presence of an expressed feature, complete, step, action, element, and / or component, but do not preclude the presence or addition of one or more other features, complete, step, action, element, component, and / or group thereof. Furthermore, unless explicitly stated otherwise, “or” means inclusive or not, not exclusive or. For example, situation A or B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist). [Explanation of symbols]

[0083] 1. Donor plate 1C Central Section 1I Intermediate Section 1P Surrounding Section 2 Deposited material 2a Deposited material 2b Deposited material 10 Flexible substrate 11 Electrode layer 12. First electrical insulating layer 13. Resistance heater layer, molybdenum layer, resistance layer 13CB Bottom Resistance Heater Layer 13CT Top Resistance Heater Layer 13IB Bottom Resistance Heater Layer 13IT Top Resistance Heater Layer 14. Second electrical insulating layer 15 pattern layers 16 Plate carrier 17 Free surface 18 Further resistance heating layer 19 Virtual Central Plane 20. Thermal diffusion layer, thermal distribution layer 21 Insulation layer 30 targets, target surface 101 First main surface 102 Second main surface 111 First electrode 112 Second electrode 113 Gap 117 Covering 121 Slit 122 slits 151 Spacer 155 recess 161 First plate support surface 163 First Aspect 164 Second Aspect 165 Round Going Seal 166 channels 211 Second electrode 212a Control electrode 212b Control electrode 212n control electrode 1111 Comb fingers 1121 Comb fingers A eff Effective surface area of ​​the resistance heater layer 13 Distance between slits L is the length of the resistance heater layer 13. l1 distance l2 distance PG distance PT print thickness REF Reference Frame S1 First Stage S2 Step S3 Step S4 Step The threshold heat flux W width of resistance heater layer 13 Wd width Wg Gap width Ws Slit width

Claims

1. A donor plate (1) for depositing a deposit material (2) on a target (30), wherein the donor plate comprises a flexible substrate (10), the flexible substrate (10) having, following a first main surface (101), an electrode layer (11), a first electrical insulating layer (12), a resistance heater layer (13), a second electrical insulating layer (14), and a pattern layer (15) having one or more recesses (155) for holding the deposit material (2) to be deposited on the target, the electrode layer (11) comprising first and second electrodes (111, 112) of complementary shape and electrically insulated from each other, and the resistance heater layer (13) being electrically connected to the contact surface of the first electrode (111) and the contact surface of the second electrode (112) via at least one respective slit (121, 122) in the first electrical insulating layer.

2. The donor plate (1) according to claim 1, wherein at each position of the resistance heater layer (13), the minimum distance between the at least one slit (121) of the first electrode (111) and the at least one slit (122) of the second electrode (112) is at most one-tenth of the square root of the effective surface area of ​​the resistance heater layer (13).

3. The donor plate (1) according to claim 2, wherein the first electrode (111) and the second electrode (112) are comb-shaped, each having a set of comb fingers (1111, 1121), the comb fingers (1111) of the first electrode (111) and the comb fingers (1121) of the second electrode (112) are arranged alternately, the at least one slit (121) of the first electrode (111) comprises a slit for each comb finger (1111) of the first electrode (111), the at least one slit (122) of the second electrode (112) comprises a slit for each comb finger (1121) of the second electrode (112), and each slit in the first electrical insulating layer (12) extends longitudinally over the respective contact surfaces (1112, 1122) of the comb fingers.

4. The donor plate (1) according to claim 2, wherein the first electrode (111) and the second electrode (112) extend side by side with respect to a helical trajectory, the at least one slit (121) of the first electrode (111) extends longitudinally over the contact surface of the first electrode (111), and the at least one slit (122) of the second electrode (112) extends longitudinally over the contact surface of the second electrode (112).

5. The donor plate (1) according to claim 1, further comprising a set of one or more independently controllable resistive heating elements positioned between the second electrical insulating layer (14) and the pattern layer (15) within each zone defined by each of the recesses (155).

6. The donor plate (1) according to claim 5, wherein the set of at least one independently controllable resistive heating element comprises at least two independently controllable resistive heating elements.

7. A deposition device comprising a donor plate (1) according to any one of claims 1 to 6 and a plate carrier (16), wherein the donor plate (1) is attached laterally to the first plate carrier surface (161) of the plate carrier (16) on a second main surface (102) opposite to its first main surface (101).

8. The deposition device according to claim 7, wherein the plate carrier (16) is attached to a reference frame (REF) at a first side surface (163), and at a second side surface (164) opposite to the first side surface, is slidably coupled to the reference frame to allow the plate carrier (16) to expand in a direction along the axis from the first side surface to the second side surface.

9. The deposition device according to claim 7 or 8, wherein the donor plate (1) is fixed to the plate carrier (16) together with a round-going seal (165), the plate carrier having one or more channels (166) extending through the plate carrier, and the channels (166) are configured to be coupled to a pressure control unit.

10. The deposition device according to claim 7, 8, or 9, wherein the free surface (17) of the pattern layer (15) is provided with one or more spacers (151).

11. The deposition device according to any one of claims 7 to 10, wherein the donor plate (1) has a central section (1C), a resistance-heatable intermediate section (1I), and a peripheral section (1P) in a radially outward direction, the central section comprises a section of the flexible substrate (10) having the electrode layer (11), the first electrical insulating layer (12), the resistance heater layer (13), the second electrical insulating layer (14), and the pattern layer (15), the intermediate section (1I) surrounds the central section (1C), and the donor plate is attached to the plate carrier (16) by its peripheral section (1P).

12. The deposition device according to claim 11, wherein the intermediate section (1I) has a thermal expansion coefficient greater than that of the central section (1C).

13. The deposition device according to claim 11 or 12, wherein the intermediate section (1I) comprises a plurality of heating layers.

14. The deposition device according to claim 11, 12, or 13, wherein the central section (1C) comprises a further resistance heater layer (18), and the resistance heater layer (13) and the further resistance heater layer (18) are arranged on both sides of the virtual central plane (19) of the central section (1C).

15. The deposition device according to claim 11, 12, or 13, wherein the thickness of the central section (1C) increases in the radially outward direction.

16. A deposition method using a donor plate (1) comprising a flexible substrate (10), wherein the flexible substrate (10) has, following a first main surface (101), an electrode layer (11), a first electrical insulating layer (12), a resistance heater layer (13), a second electrical insulating layer (14), and a pattern layer (15) having one or more recesses (151) for holding a deposit material (2) to be deposited on a target (30), wherein the electrode layer (11) comprises first and second electrodes (111, 112) of complementary shape and electrically insulated from each other, and the resistance heater layer (13) is electrically connected to the first electrode (111) and the second electrode (112) respectively through at least one slit (121, 122) in the first electrical insulating layer, and the method is, Step (S1) involves positioning the donor plate in front of the target (30) in such a manner that its pattern layer (15) does not come into contact with it. Step (S2) involves substantially uniformly heating the donor plate with the resistance heater layer (13) to deform the donor plate and move the pattern layer (15) toward the target, Step (S3) of releasing the deposited material from the recess (151) onto the target, Step (S4) involves cooling the donor plate to remove the pattern layer (15) from the target, Methods that include...

17. The method according to claim 16, wherein the donor plate has a set of one or more independently controllable resistive heating elements positioned between the second electrical insulating layer (14) and the pattern layer (15) in each zone defined by each of the recesses, and the method further comprises independently controlling the discharge step (S3) by supplying electrical energy to the set of one or more independently controllable resistive heating elements.

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