CONTROLLED DEPOSITION METHOD OF A DONOR MATERIAL ONTO A TARGET SURFACE AND PLATE THEREFOR

Abstract

A method of depositing a donor material onto a target surface is provided herein, in which a first main side of a substrate is covered with a stretchable layer that is attaching thereto with a sealing around an enclosed area at the first main side, therewith defining an enclosure. The stretchable layer has an outer surface that faces away from the substrate, and that is patterned with one or more recessed areas filled with the donor material to be deposited. A relatively high pressure is provided in an interior of the enclosure so that its volume is increased and the patterned surface of the stretchable layer is pressed against the target surface. In that state of the stretchable layer the substrate is irradiated at a second main side opposite its first main side with photon radiation that has an intensity and a duration that causes a transfer of donor material from the one or more recessed areas to the target surface. Also a plate and a deposition device are provided.

Claims

1. A method of depositing a donor material onto a target surface comprising the steps of: covering a first main side of a substrate with a stretchable layer, by attaching the stretchable layer to the first main side with a sealing around an enclosed area at the first main side, there with defining an enclosure, wherein the stretchable layer has an outer surface facing away from the substrate, and wherein the outer surface is patterned with one or more recessed areas ; filling the one or more recessed areas with the donor material to be deposited; providing for a relatively high pressure in an interior of the enclosure, as compared to a pressure in an exterior of the enclosure, by supplying a gas to the interior through an opening in the substrate, the providing a relatively high pressure increasing a volume of the interior, and the increasing the volume pressing the patterned surface of the stretchable layer against the target surface; and irradiating the substrate at a second main side, opposite its first main side, with photon radiation, wherein the irradiating with photon radiation is carried out with photon radiation having an intensity and for a duration sufficient to cause a transfer of donor material from the one or more recessed areas to the target surface.

2. The method according to claim 1, comprising using, during the filling, a doctor blade to fill the one or more recessed areas with the donor material.

3. The method according to claim 1, further comprising evacuating the interior of the enclosure before the filling the one or more recessed areas.

4. The method according to claim 1, wherein the providing for a relatively high pressure is achieved by performing at least one of the group consisting of: supplying a gas into the interior, and reducing a pressure in the exterior.

5. The method according to claim 1, wherein the intensity and the duration of the irradiating with photon radiation is selected to evaporate a portion of the donor material present at an interface with the outer surface of the stretchable layer.

6. The method according claim 1, wherein the intensity and the duration of the irradiating with photon radiation is selected to at least partially cure the donor material.

7. The method according to claim 1, further comprising, after the providing for a relatively high pressure, causing a releasing of the stretchable layer from the target surface by providing for a relatively low pressure in the interior as compared to a pressure in the exterior.

8. The method according to claim 1, further comprising cleaning, subsequent to said transferring, the patterned surface.

9. A plate for deposition of a donor material onto a target surface, the plate comprising: a substrate including: a first main side; and a second main side that is opposite the first main side, wherein the first main side is covered with a patterned layer having a patterned surface configured to be directed towards the target surface, and the patterned surface is patterned with one or more recessed areas configured to be filled with the donor material, wherein the second main side is configured to receive photon radiation suitable to be transmitted through the substrate so as to enable a transfer of donor material from the one or more recessed areas to the target surface by providing the photon radiation to the second main side at an intensity and for a duration that is sufficient to cause the transfer, wherein the patterned layer is made of a stretchable material that is attached to the first main side with a sealing around an enclosed area at said first main side, therewith defining an enclosure having an interior and an exterior, wherein the interior of the enclosure has a volumethat is dependent on a difference in a pressure in the interior relative to a pressure in the exterior, and wherein an opening extends through the substrate towards the interior of the enclosure.

10. The plate according to claim 9, wherein the stretchable layer is reinforced with one or more relatively rigid elements.

11. The plate according to claim 10, wherein the one or more relatively rigid elements locally prevent stretching, but preserve flexibility, and wherein the one or more relatively rigid elements are provided at a side facing away from the substrate with a dielectric coating that provides for an at least substantially uniform heatflux within the recessed portions, in that the dielectric coating has a higher reflectivity for monochromatic photon radiation with a predetermined wavelength incident on a bottom wall of a recessed portion than a reflectivity for said monochromatic radiation incident on a side wall of the recessed portion.

12. The plate according to claim 9, wherein the stretchable layer is attached to the first main side of the substrate at further positions within the enclosed area.

13. The plate according to 9, wherein a plurality of enclosures is formed on the substrate, each one of the plurality of enclosures having a respective stretchable layer or portion attached to the substrate with a respective enclosing sealing.

14. A deposition device for depositing a donor material onto a target surface of a target, the deposition device comprising: a plate comprising: a substrate including: a first main side; and a second main side that is opposite the first main side, wherein the first main side is covered with a patterned layer having a patterned surface configured to be directed towards the target surface, and the patterned surface is patterned with one or more recessed areas configured to be filled with the donor material, wherein the second main side is configured to receive photon radiation suitable to be transmitted through the substrate so as to enable a transfer of donor material from the one or more recessed areas to the target surface by providing the photon radiation to the second main side at an intensity and for a duration that is sufficient to cause the transfer, wherein the patterned layer is made of a stretchable material that is attached to the first main side with a sealing around an enclosed area at said first main side, therewith defining an enclosure having an interior and an exterior, wherein the interior of the enclosure has a volume that is dependent on a difference in a pressure in the interior relative to a pressure in the exterior, and wherein an opening extends through the substrate towards the interior of the enclosure; a holder to hold the target with a target surface of the target facing the first surface of the plate; a photon radiation source to render the photon radiation to be directed towards the second side of the plate; a pressure regulation facility to controllably induce a pressure difference between said interior relative to said exterior; a controller configured to control the pressure regulation facility and the photon radiation source, wherein the controller has a first operational mode wherein the controller: controls the pressure regulation facility to maintain a pressure inside the interior that is lower than the external pressure, and maintains the photon radiation source in a deactivated state, wherein the controller has a second operational mode wherein the controller: controls the pressure regulation facility to maintain a pressure inside the interior that is higher than said external pressure therewith pressing the patterned layer towards the target surface, and causes the radiation source to render the photon radiation to cause irradiating the second main side with photon radiation with an intensity and a duration sufficient to cause a transfer of donor material from the one or more recessed areas to the target surface.

15. The deposition device according to claim 14, wherein the stretchable layer is reinforced with one or more relatively rigid elements.

16. The deposition device according to claim 15, wherein the one or more relatively rigid elements locally prevent stretching, but preserve flexibility, and wherein the one or more relatively rigid elements are provided at a side facing away from the substrate with a dielectric coating that provides for an at least substantially uniform heatflux within the recessed portions, in that the dielectric coating has a higher reflectivity for monochromatic photon radiation with a predetermined wavelength incident on a bottom wall of a recessed portion than a reflectivity for said monochromatic radiation incident on a side wall of said recessed portion.

17. The deposition device according to claim 14, wherein the stretchable layer is attached to the first main side of the substrate at further positions within the enclosed area.

18. The deposition device according to claim 14, wherein a plurality of enclosures is formed on the substrate, each one of the plurality of enclosures having a respective stretchable layer or portion attached to the substrate with a respective enclosing sealing.

19. The deposition device according to claim 15, wherein the stretchable layer is attached to the first main side of the substrate at further positions within the enclosed area.

20. The deposition device according to claim 15, wherein a plurality of enclosures is formed on the substrate, each having a respective stretchable layer or portion attached to the substrate with a respective enclosing sealing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIGS. 1A, 1B schematically show an embodiment of the plate as claimed herein. Therein FIG. 1A is a plane view of the plate and FIG. 1B is a cross-section according to IB-IB in FIG. 1A;

[0037] FIGS. 2A-2D illustrate steps of an embodiment of the method as claimed, FIG. 2E illustrates an alternative application of the method;

[0038] FIG. 3 shows an alternative embodiment of the plate as claimed;

[0039] FIG. 4 shows another alternative embodiment of the plate as claimed;

[0040] FIG. 5 shows an embodiment of a deposition device as claimed.

DETAILED DESCRIPTION OF EMBODIMENTS

[0041] FIGS. 1A, 1B schematically shows a plate 1 that comprises a donor material 2 to be deposited onto a target surface 51 (See FIG. 2B) of a target 5 (FIG. 2B). Therein FIG. 1B shows a cross-section according to IB-IB in FIG. 1A. The plate comprises a substrate 10 with a first main side 11 and a second main sides opposite thereto. The first main side 11 of the substrate 10 is covered with a patterned layer 4 that has a patterned surface 41 that is to be directed towards the target surface. The patterned surface 41 is patterned with one or more recessed areas. In the example of FIGS. 1A, 1B these comprise a first and a second trench 42a, 42e that are each filled with a proper portion 2a, 2b of the donor material 2. In this example, the one or more recessed areas also comprise wells 42c, 42d, and 42e that are also filled with a proper portion 2c, 2d, 2e of the donor material 2.

[0042] In use, the second main side 12 of the plate 1 is to receive photon radiation to be transmitted through the substrate 10 towards the donor material. The photon radiation applied in said use has an intensity and a duration that causes a transfer of the donor material 2a,...,2e from the one or more recessed areas 42a,...,42e to the target surface 51 of the target (also denoted as acceptor) 5. The patterned layer 4 is of a stretchable material and it is attached to the first main side 11 with a sealing 43 around an enclosed area 13 at the first main side 11. Therewith the substrate 10, the sealing 43 and the layer of a stretchable material 4 define an enclosure 6 with an interior 61 and an exterior 62 (See FIG. 5). The interior has a volume V.sub.61 dependent on a difference between a pressure P.sub.int in the interior 61 and the pressure P.sub.ext in the exterior 62.

[0043] An embodiment of a method using the plate 1 is described with reference to FIGS. 2A-2E.

[0044] In a manufacturing step, not shown here, a first main side 11 of a substrate 10 is covered with a stretchable layer 4. The stretchable layer 4 is attached to the first main side 11 with a sealing 43 that is provided around an enclosed area 13 at the first main side 11. In some embodiments, the sealing is provided as an epoxy-based adhesive. In other embodiments, the material of the stretchable layer 4 forms itself a sealing. This is possible if the surface at the first main side 11 of the substrate 10 is locally roughened where the sealing is to be formed and the stretchable layer is mechanically adhered to the locally roughened surface. The substrate 10, the stretchable layer 4 and the sealing 43, either formed by the material of the stretchable layer itself or formed by a separate material, forms an enclosure 6 with an interior 61 and an exterior 62. The stretchable layer 4 has an outer surface 41, facing away from the substrate 10, that is patterned with one or more recessed areas. In FIG. 2A, by way of example the recessed areas 42a, 42b area shown.

[0045] In a subsequent step the one or more recessed areas are filled with the donor material 2 to be deposited. In the example shown the recessed area 42a is already filled with a portion 2a of the donor material, and the recessed area 42b is being filled with another portion 2b of the donor material, here using a doctor blade 20. Exemplary donor materials for deposition are copper, aluminum, tungsten, chromium, polysilicon provided as particles in a suspension medium, which may further comprise a solvent and a binder. Other materials than metals are also suitable for use as a donor material. The donor material may for example be provided as an ink wherein conductive particles are suspended. Rheological properties of the donor material may be modified by additives or solvent, for example to obtain a shear-thickening, a shear-thinning, a thixotropic, a rheopectic or a Bingham plastic behavior. By way of example, the donor material is a viscous silver nanoparticle ink with a high metal load. In some embodiments the viscosity of the donor material is in a range of 100 - 1000 Pa.s.

[0046] When filling the recessed areas with the donor material, the interior 61 of the enclosure is typically held at a relatively low pressure P.sub.int, i.e. lower than the pressure P.sub.ext prevailing in the exterior. This can be achieved by evacuating the interior 61, and/or by pressurizing the exterior.

[0047] FIG. 2B shows the plate 1 having the recessed areas filled with the donor material 2a, 2b and with the interior 61 of the enclosure still held at a relatively low pressure. FIG. 2B further shows the target (acceptor) 5. As shown in FIG. 2B. the target 5 has an uneven surface 51.

[0048] FIG. 2C shows a next step, wherein a pressure P.sub.int is provided in the interior 61 of the enclosure 6 that is higher than a pressure P.sub.ext in the exterior of the enclosure. Therewith a volume V.sub.61 of the interior 61 is increased and the patterned surface 41 of the stretchable layer 4 is pressed against the target surface 51, so that its shape becomes compliant with that of the target surface.

[0049] FIG. 2C also shows that in this state the second main side 12 of the substrate 10 is irradiated with photon radiation having an intensity and a duration that causes a transfer of donor material 2a, 2b from the recessed areas 42a, 42b to the target surface 51. The transferred donor material 2a, 2b therewith forms elements 2aa, 2bb on the target surface. Due to the fact that the stretchable layer 4 in this state conforms to the target surface 51., the donor material can be very accurately deposited thereon.

[0050] FIG. 2D shows how the stretchable layer 4 is released from the target surface 51 by providing for a pressure P.sub.int in the interior 61 of the enclosure 6 that is lower than a pressure P.sub.ext in the exterior. Therewith the elements 2aa, 2bb formed by the deposited donor material remain at the target surface 51. In the example shown the target surface is uneven, for example in that the target 5 comprises a plurality of layers 55, 56. The elements 2aa, 2bb are for example electrical connections between these layers 55, 56.

[0051] FIG. 2E shows another example, wherein a component 52 is mounted on a component carrier 5, and wherein the method was used to apply electrical connections 2aa, 2bb between the component carrier 5 and contacts at a component surface 53 elevated above the carrier 5.

[0052] FIG. 3 shows an alternative embodiment of the improved plate 1, as seen at the first side 11 of the substrate 10. Parts therein corresponding to those in the preceding figures have the same reference in the drawing. In the embodiment shown in FIG. 3, the stretchable layer 4 is reinforced with relatively rigid elements 45a, 45b, 45c, 45d. The recessed areas 42a,..., 43d are provided in the reinforced portions of the stretchable layer. Therewith a deformation of the stretchable layer 4 to comply with a target surface is still possible, but local deformations in the neighborhood of the recessed areas are mitigated. In exemplary embodiments the reinforcement locally prevents stretching, but preserves flexibility. This is for example the case in an embodiment wherein the reinforced portions with the recessed areas are provided of a relative thin glass layer, e.g. a SiO2 layer, for example having a thickness in the range of 5-10 micron. These locally flexible, but non-stretchable portions may be provided at a side facing away from the substrate with a dielectric coating that provides for a uniform heatflux within the recessed portions as specified in more detail in European patent application 20167549.3 filed by the same applicant. Alternatively, or additionally, the stretchable layer 4 may be reinforced in regions outside the recessed areas. Alternatively, or additionally the stretchable layer 4 may be attached to the first main side 11 of the substrate 10 at further positions within the enclosed area to control the way in which it can be deformed by pressure differences.

[0053] As shown in FIG. 4, a plurality of enclosures is formed on the substrate 10. Each enclosure has a proper stretchable layer portion 4_1, 4_2,...,4_9 of a stretchable layer 4 that is attached to the substrate with a proper enclosing sealing 43_1, 43_2,...,43_9. The internal pressure in these enclosures can be independently controlled via respective channels 14_1, 14_2,...,14_9. In the example shown, the stretchable layer portions are locally reinforced in the same way as shown in FIG. 3. In other embodiments, a reinforcement may be absent. Whereas in the example of FIG. 4 a single stretchable layer 4 is used, alternative embodiments exist wherein one or more enclosures have a proper stretchable layer. It may be contemplated to use different stretchable materials for different enclosures dependent on their position on the plate 1.

[0054] FIG. 5 schematically shows a deposition device 100 comprising an improved plate 1, for example as shown in and described with reference to one of the preceding figures.

[0055] The deposition device 100 further comprises a holder 9 to hold a target 5 with a target surface 51 facing the first surface 11 of the plate 1. The deposition device 100 further comprises a photon radiation source 3 to render the photon radiation that is to be directed towards the second side 12 of the plate 1, as shown in FIG. 2C.

[0056] The deposition device 100 also comprises a pressure regulation facility 7 to controllably induce a pressure difference between said interior 61 relative to the exterior 62. In the embodiment shown, the pressure regulation facility 7 is coupled via a first conduct 71 and an opening 14 in the plate 1 to the interior 61 of the enclosure 6. The components of the deposition device 100 are arranged in a closed housing 110, that confines the exterior 62 of the enclosure 6. The pressure regulation facility 7 has a second conduct 72 with an opening in the exterior 62. Therewith, the pressure regulation facility 7 can both control a pressure inside the interior as well as a pressure inside the exterior 62. In other embodiments the pressure regulation facility 7 controls one of the pressures. For example an embodiment of the device 100 not having a closed housing, the pressure regulation facility 7 is used to control the pressure in the interior 61 of the enclosure 6 only.

[0057] The deposition device 100 comprises a controller 8 to control the pressure regulation facility 7 and the photon radiation source 3, in FIG. 5 with a control signal C3 and a control signal C7 respectively.

[0058] The controller 8 has a first operational mode wherein it controls the pressure regulation facility 7 to maintain a pressure inside the interior 61 that is lower than the pressure in the exterior 62, and wherein in maintains the photon radiation source 3 in a deactivated state. The controller has a second operational mode wherein it controls the pressure regulation facility 7 to maintain a pressure inside the interior 61 that is higher than the pressure in the exterior 62. Therewith the stretchable patterned layer 4 is pressed towards the target surface 51. With the stretchable patterned layer 4 pressed against the target surface 51 as shown in FIG. 2C, it causes the radiation source 3 to render photon radiation R3 with the proper intensity and duration that causes a transfer of donor material 2a, 2b from the one or more recessed areas 42a,...,42e to the target surface 51. Various options are available. In one option a large area of the second side 12 of the plate is irradiated with the proper intensity and duration that causes a simultaneous transfer of donor material in the recessed areas of the plate. By way of example, in that case an excimer laser is used as the photon radiation source 3. Alternatively, a scanning laser is used that generates a laser beam that is scanned over the area with the donor material to be transferred as is schematically shown in FIG. 2C. Also in this case the laser can be a pulsed laser, but that is not necessary. In this case the duration with which the area is locally exposed to the radiation can alternatively (or additionally) be controlled with the speed with which the laser beam is scanned. Therewith the exposure duration is inversely proportional to the scanning speed.

[0059] Typically the controller 8 has a transient operational mode in which the photon radiation source 3 is kept in a deactivated state as long as the state wherein the stretchable patterned layer 4 is compliant with the target surface 51 is not yet achieved. Typically the controller 8 also has a release operational mode in which the stretchable patterned layer 4 is released from the target surface 51, by reducing the relative pressure (relative to the external pressure) prevailing in the interior 61 as shown in FIGS. 2D and 2E.

[0060] Further embodiments of the deposition device are provided with transport facilities to automatically replace the plate 1 by a fresh plate and to replace the target 5 by a new target once it has received the donor material. The controller 8 can therewith control such transport facilities.