Solid Metal Printing

Abstract

A method and apparatus for printing a metal layer onto a receiver medium in a desired contour shape is provided. [Solution] An apparatus and method for printing metal onto a receiving substrate in a desired contour shape using a foil pre-coated with a layer of metal, wherein the deposition process includes laser ablation to define the desired material contour shape, selective application of adhesive to the deposited material, and selective removal of material from a carrier substrate.

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for printing a metal layer onto a receiver medium in a desired configuration, and in particular to such printing using selective removal of portions of a metal layer coated on a foil to produce a desired pattern on the receiver medium.

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 823,087, filed March 25, 2019. [Background technology]

[0003] There are many challenges involved in depositing precise thin layers of material in a desired pattern onto a substrate, such as a printed circuit board (PCB). Printing metal materials onto a substrate according to conventional methods, such as photolithography, involves three steps: pre-processing, pattern writing, and post-processing. Digital patterning is a method used for direct writing of materials onto a substrate.

[0004] Metal deposition is generally carried out by one of three main methods defined by the phase of the deposited material. In the first such method, atomic deposition, metal layers are grown by thermal or plasma evaporation in vacuum or by electrolytic reduction of ionic metals in solution. Such non-local deposition methods require complex pre- and post-processing steps to define 2D patterns, unlike digital patterning, which is simpler. Furthermore, these steps involve hydrous processing, which requires careful selection of the receiving substrate. In addition, metal atoms are highly reactive to the environment, so this method also poses requirements for specific environmental conditions.

[0005] The second metal deposition method relies on various phases of nano- or micro-particles. These particles are less reactive than metal atoms and therefore can be operated with fewer restrictions regarding the environment. Furthermore, the deposition of nanoparticles can offer more flexibility in the choice of deposition method. Typically, when particles are used for metallization, it involves two successive steps: first the printing / deposition step of the particles, then the sintering step, i.e., a thermal / chemical process that melts the particles together to form a solid metal. The specific printing and sintering method depends on the particle matrix. Usually, the particles are in the form of a liquid, aerosol, or powder. The use of this metal phase allows for the digital definition of the printing pattern. This is done using selective printing and / or selective sintering methods. Most additive manufacturing (AM) methods for metals utilize nanoparticles or particulates. Variations of this method are characterized by the specific choice of printing and sintering techniques used for production.

[0006] In a third method of metal printing, molten metal droplets are transferred from a bulk phase. One such process is the dispenser method, which requires that the dispenser is made of a heat-resistant material selected according to the melting temperature of the metal to be transferred. Thus, this method is favorable for the transfer of metals with low melting temperatures, such as gallium alloys, solder, and aluminum. For metals with higher melting points, these methods become more complicated. Another limiting factor in the dispenser process is the size of the droplets. Molten metals exhibit high viscosity, making it difficult for traditional dispenser techniques to transfer small droplets with volumes below the picoliter range. Another approach to printing metal droplets is the laser-induced forward transfer (LIFT) method. In the LIFT method, a focused laser beam is made incident on a thin layer of printing material, and droplets are ejected away from the original layer by localized heating. Typically, the thickness of the layer is on the order of tens of nanometers. The LIFT method allows metal microdroplets and submicron droplets to be printed directly from a bulk solid phase.

[0007] The main drawback of the AM method of printing metals can be traced back to the fragmentation of the metal into the building blocks (e.g., atoms, nanoparticles, microparticles, droplets) from which the metal is made, but this fragmentation process is also essential to each AM process. Some examples of undesirable attributes resulting from such fragmentation are surface roughness, material density inhomogeneity (e.g., voids), and boundary formation between building blocks. When the metal is printed to form traces or tracks on a receiving substrate, such fragmentation affects the physical properties of the printed tracks, including the electrical conductivity as well as the electromagnetic reactivity of the tracks. Furthermore, adhesion of the metal to different types of receivers is not guaranteed, so it is usually necessary to carry out pre-treatments. The specification of U.S. Pat. No. 3,006,795, according to its first paragraph, describes an improvement to the type of transfer patterns commonly called decalcomania, which are generally used for advertising or decoration, but which may also have other uses, for example other uses requiring printed electrical circuits or metal foil patterns, and relates to new transfer prints of this character and to a method for their manufacture. Also, in the specification of U.S. Patent Application No. 2003 / 0178227, according to its abstract, a transfer sheet used in forming a conductor circuit is described, the transfer sheet including a base and a metal layer formed in a circuit pattern on the base. The metal layer is transferred to the surface of an insulating layer. At least a part of the circuit pattern of the metal layer is formed by laser processing. Since the metal layer can be removed by irradiating a laser beam with a fine beam diameter to fine parts of the conductor circuit without using an etching process or a plating process, it is possible to form a fine conductor circuit with a width and pitch of 50 micrometers or less, and it is possible to prevent disconnection of the conductor circuit due to excessive etching or poor plating adhesion, and short circuit of the conductor circuit due to etching residue or plating short. According to the abstract of JP 2004-306412 A, a resin layer is formed on a base film, a metal layer is formed on the resin layer in a predetermined pattern by electroplating using a semi-additive method and a subtractive method, and an adhesive layer is formed on the metal layer as needed to obtain a metal pattern transfer sheet. After the metal layer (or the adhesive layer) is bonded to the surface of the adherend, the base film is peeled off from the surface of the resin layer, and the metal layer is transferred onto the adherend in a predetermined pattern. According to this method, the metal layer does not easily peel off from the resin layer before use, but if it peels off at the interface between the resin layer and the base film, the metal layer is easily transferred when the transfer sheet is used. Also, U.S. Patent No. 3,506,507, in its abstract, describes a process for providing a designed pattern in a thin metal foil for application to a background support, the process comprising the steps of (1) temporarily attaching a thin metal foil to a temporary carrier, (2) defining a desired pattern on the metal foil with an etch-resistant adhesive, and (3) removing portions of the metal foil not defining the pattern. This assembly is then attached to the background support to provide a decorative or useful finished product. Summary of the Invention

[0008] The present invention provides an apparatus and a method for printing metal on a receiving substrate in a desired geometry using a foil precoated with a layer of metal. The deposition process consists of three steps: laser ablation to define the geometry of the metal tracks, then selective application of an adhesive to the tracks on the substrate, and finally selective removal of the metal tracks from the foil. To overcome drawbacks such as those mentioned above, the proposed method uses a foil precoated with a metal layer having high electrical conductivity and low roughness. The geometry of the deposited metal is defined using selective ablation of the desired pattern. The metal layer is then coated with a suitable adhesive that ensures adhesion on the receiving substrate. Finally, selective removal of the defined metal pattern, for example by laser irradiation, is carried out.

[0009] One embodiment of the invention begins with a transparent film that is coated or laminated with a desired solid material, such as a metal. To later deposit a desired shape of material onto a substrate, a laser system ablates a narrow strip of material around this shape. This separates the material being deposited from excess material.

[0010] The material is then coated with a layer of UV curable adhesive. In another embodiment of the invention, the adhesive can be applied before the ablation step. In yet another embodiment, excess material is removed from the transparent film before applying the adhesive. The material is then contacted with a receiving substrate and the adhesive is cured using a UV diode or UV laser. Care is taken to ensure that only the adhesive adjacent to the features to be deposited is cured, ensuring that the relevant portions of the material adhere to the substrate.

[0011] In various embodiments of the process, the adhesive can be cured through the transparent substrate. Alternatively, the UV curable adhesive can be replaced with a thermally curable adhesive that is selectively cured using heat from a laser. In yet another embodiment, the UV curable adhesive is replaced with a contact adhesive that is selectively cured by contact pressure. In yet another embodiment, the UV curable adhesive is selectively applied to only the desired areas of the material to be transferred to the receiving substrate, with no subsequent removal of the adhesive required.

[0012] Once the material has been transferred to the receiving substrate, the film is peeled off the substrate. Once the film has been peeled off from the feature to be deposited, a laser is used to selectively apply heat to break the bond between the film itself and the material. In this way, the film is removed with the undesired material still adhering, while the material defining the desired feature for deposition remains adhered to the substrate.

[0013] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. [Brief description of the drawings]

[0014] [Figure 1A] 1A-1C show examples of layers of material (eg, metal) carried on a transparent substrate for use in accordance with embodiments of the present invention. [Figure 1B] 1A-1C show examples of layers of material (eg, metal) carried on a transparent substrate for use in accordance with embodiments of the present invention. [Figure 2A] 1 is a side view of ablation of a desired shape of a metal layer carried on a transparent substrate, according to an embodiment of the present invention. [Figure 2B] 1 is a plan view of ablation of a desired shape of a metal layer carried on a transparent substrate, according to an embodiment of the present invention. [Figure 2C] FIG. 13 illustrates an alternative embodiment in which excess or unwanted material is removed by ablation prior to application of the adhesive layer. [Figure 3A] 11A-11C show further examples of ablation processes that can be used in accordance with embodiments of the present invention. [Figure 3B] 11A-11C show further examples of ablation processes that can be used in accordance with embodiments of the present invention. [Figure 3C] 11A-11C show further examples of ablation processes that can be used in accordance with embodiments of the present invention. [Figure 4A] FIG. 1 illustrates one example of coating a metal layer with an adhesive according to an embodiment of the present invention. [Figure 4B] FIG. 4B illustrates an alternative embodiment in which excess or unwanted material has been removed by ablation, as shown in FIG. 2C, prior to application of the adhesive layer, as shown in FIG. 4B. [Diagram 5] 11A-11C show examples of removal of a portion of the adhesive from areas of the metal layer that are not transferred to the substrate, according to embodiments of the present invention. [Figure 6] 1 illustrates the transfer of a metal layer to a receiving substrate according to an embodiment of the present invention. [Figure 7] 1A-1C show examples of laser-induced delamination of a metal layer transferred to a receiving substrate according to embodiments of the present invention. [Figure 8] 1A-1C show examples of laser-induced delamination of a metal layer transferred to a receiving substrate according to embodiments of the present invention. [Figure 9] FIG. 1 illustrates an example of a system configured to print a metal layer on a receiver medium in a desired contour shape, in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention provides an apparatus and method for printing a material, for example a metal, on a receiving substrate in a desired contour shape using a foil or other carrier pre-coated with a layer of the material to be printed. The deposition process generally involves laser ablation to define the material track contour shape, selective application of adhesive onto the substrate tracks, and finally selective removal of the metal tracks from the foil. To overcome drawbacks such as those mentioned above, an embodiment of the present invention uses a foil pre-coated with a metal layer having high electrical conductivity and low roughness. The contour shape of the deposited metal is defined using selective ablation of the desired pattern. The metal layer is then coated with a suitable adhesive that ensures adhesion on the receiving substrate. Finally, selective removal of the defined metal pattern is carried out, for example, by laser irradiation.

[0016] One embodiment of the invention begins with a transparent film that is coated or laminated with a desired solid material, such as a metal. To later deposit a desired shape of material onto a substrate, a laser system ablates a narrow strip of material around this shape. This separates the material to be deposited from any excess material.

[0017] The material is then coated with a layer of adhesive, for example a UV curable adhesive. In another embodiment of the invention, the adhesive can be applied before the ablation step. The material is then contacted with a receiving substrate and the adhesive is cured using a UV diode or ultraviolet laser. Care is taken to ensure that only the adhesive adjacent to the features to be deposited is cured, ensuring that the relevant parts of the material adhere to the substrate.

[0018] In various embodiments of the process, the adhesive can be cured through the transparent substrate. Alternatively, the UV curable adhesive can be replaced with a thermally curable adhesive that is selectively cured using heat from a laser. In yet another embodiment, the UV curable adhesive is replaced with a contact adhesive that is selectively cured by contact pressure. In yet another embodiment, the UV curable adhesive is selectively applied to only the desired areas of the material to be transferred to the receiving substrate, with no subsequent removal of the adhesive required.

[0019] Once the material has been transferred to the receiving substrate, the film is peeled off from the substrate. When the film is peeled off from the deposited feature, heat is selectively applied using a laser to break the bond between the film itself and the material. Although the film is thus removed, the undesired material still adheres to the film, while the material that defines the desired feature for deposition remains adhered to the substrate.

[0020] Referring now to FIG. 1A, a foil assembly 10 is shown. The foil assembly has a transparent substrate 12, e.g., a rigid material such as glass or a flexible material such as polyethylene terephthalate (PET) / polyethylene naphthalate (PEN) foil / polyimide foil (e.g., sold under the trade name Kapton™), to which a material 14 is laminated. In various embodiments, the material 14 is a metal, e.g., copper, aluminum, silver, or other metal, but may be another material for selective deposition on a receiving substrate. The material layer 14 is adhered to the substrate 12 by an adhesive 16. Although FIG. 1A shows a single material layer 16, the foil assembly 10', as shown in FIG. 1B, can include a stack of n materials 14', 14'', 14''', each of which can be a different material or various materials can be repeated in the stack. Multiple layers of materials in the stack can be adhered to each other, with the material layer 14' adjacent to the substrate 12 adhered to the substrate by the adhesive layer 16. For example, the material stack can include a first layer of copper (e.g., having a thickness of 10 μm to 50 μm, in one embodiment 20 μm) coated with a layer of chromium or nickel (e.g., having a thickness of 0.5 μm to 3 μm, in one embodiment 1 μm) to enhance electrical contact of the material layer on the semiconductor substrate.

[0021] Typically, the material layer 14 (or stack of material layers) can have a thickness in the range of 2 μm to 100 μm. Material layers 14 (or stacks of material layers) having a thickness less than 2 μm can be used, but care must be taken when removing such layers (as described below) to do so without damaging very thin layers. Similarly, material layers 14 (or stacks of material layers) thicker than 100 μm can be used, but the ablation process (see below) may become slower and the edge quality of the removed material may begin to deteriorate. As a result, it may be necessary to change the irradiation time and / or conditions. In general, the ablation time and energy (of the laser) will vary as a function of material properties and / or laser light properties. For convenience in the following description, the description will assume the deposition of a single layer of material 14, but the process and apparatus described are equally applicable to the deposition of a stack of material layers.

[0022] 2A-2B and 3A-3C illustrate aspects of an ablation process that defines a desired pattern of material for deposition on a receiving substrate. As shown in FIG. 2B, the desired pattern of material 14 to be deposited has an associated shape 26. This may be the shape of a printed pattern for a metal layer of a printed circuit board, a patch antenna, a semiconductor device, or the like. Through laser ablation of material layer 14, the desired shape is delineated or outlined in the material layer, such that excess material 22 within the material layer is separated from the desired shape of material 26 by ablated regions 24. FIG. 2B illustrates, in a plan view, how the desired shape of material 26 is defined throughout material layer 14, while FIG. 2A illustrates, in a side view, such separation of the desired portion of material 14 from excess material 22.

[0023] As shown, ablation is performed using a laser system 20. In one embodiment, a pulsed laser is used. As shown in Figures 3A-3C, laser light energy absorbed in material layer 14 (Figure 3A) heats the material until a portion of the material vaporizes (Figure 3B). By repeating the process multiple times, it is possible to ablate through the entire thickness of the material layer (Figure 3C).

[0024] In different variations of the ablation process, the pulse times of a given laser can be shortened or lengthened relative to each other. As the pulse time is shortened, the contouring process becomes slower, but more precise. As the pulse time is lengthened, the process becomes less precise, but the ablation becomes faster. For most applications, the preferred pulse duration will vary between 0.1 ns and 2 ns. However, the thicker the layer, the longer the pulse can be used, from 2 ns to 100 ns. For high resolution patterns less than 10 μm wide, and / or special materials such as silicone, plastic, or heat-sensitive materials, short pulses of picosecond or femtosecond duration can be used.

[0025] Scanning the laser over the desired shape can be performed with an optical scanning system such as a galvanometer, polygon mirror, resonant mirror, MEMS mirror, or other system. During the ablation process, it is desirable (even necessary) to use an exhaust to evacuate the ablated gases. Such exhaust reduces debris on the remaining metal layer 14, improving the speed and quality of the ablation process.

[0026] 4A, once the desired pattern of material to be deposited has been defined, the remaining portions of the metal layer 14 are coated with a thin layer 38 of adhesive (e.g., approximately 1 μm). During this process, care is taken not to deposit adhesive on any of the ablated regions 24. As illustrated, one method of applying the adhesive coating is to translate the foil assembly 10 relative to an applicator 28. As the foil assembly 10 passes the applicator, liquid or paste adhesive 32 from an associated reservoir 34 is applied by brushes 36 or other fixtures mounted on the outer periphery of the rotating disk. Gravure coating is preferred because it allows for the deposition of a thin layer 38 of adhesive only on the metal portions that contact the applicator 28, allowing for a roll-to-roll process. Nevertheless, other coating methods such as slot-die deposition, rod coating, offset printing, flexography, micro-spraying, and other coating methods can be used. Also, digital printing techniques, such as inkjet printing or laser deposition, can be used to print onto the desired areas, avoiding the need for subsequent ablation of adhesive layer 38, as described further below.

[0027] In embodiments of the present invention, different adhesives 32 can be used. In many cases, the adhesive selected will depend on the receiving substrate, and the adhesive will be compatible with the particular receiving substrate. For example, for solar cell metallization, the adhesive 32 may be a thin, non-sticky adhesive that can be bonded to a dielectric layer (e.g., S) with appropriate post-printing heat treatment to improve contact resistance. i O2 / SiN x The optical filter may contain glass frit to etch the anti-reflective / passivation coating.

[0028] Referring to FIG. 5, once the adhesive layer 38 has been applied, a second ablation process is performed to remove adhesive from portions of the metal layer 14 that are not part of the desired pattern to be deposited on the receiving substrate. In some cases, this can be done by returning the foil assembly 10 to an ablation station that includes the same laser system 20 that was used to outline the desired shape of material in the layer 14. This may involve unwinding the foil ribbon to reposition the area to be ablated or translating the foil assembly 10, such as by an actuator. In other cases, a separate ablation station can be used. As shown in FIG. 5, ablation of portions of the adhesive layer 38 leaves voids 40 where no adhesive is present. These voids correspond to sections of the metal layer 14 with excess material 22.

[0029] An alternative procedure is shown in Figures 2C and 4B. In Figure 2C, prior to application of the adhesive layer, portions of excess or unwanted material 22 in material layer 14 are ablated away to a desired depth "d" using laser system 20. Thereafter, adhesive is applied only to portions of material layer 14 that make up the desired pattern 26 to be deposited, as shown in Figure 4B.

[0030] In some embodiments, a UV curable adhesive 32 may be used for adhesive layer 38. In such cases, adhesive layer 38 may be selectively cured using, for example, a UV laser or a digital UV light projector (e.g., a DLP digital projector) such that areas of unwanted adhesive are cured. Adhesive layer 38 may also be pre-coated onto the material layer prior to ablation of the selected pattern and selectively removed afterwards.

[0031] The adhesive 32 is applied to ensure good adhesion between the material layer 14 (i.e., portions thereof related to the desired pattern) and the receiving substrate. In the above example, the adhesive was applied as a layer 38 to the foil assembly 10, but in other cases the adhesive 32 can be applied to the receiving substrate rather than to the metal layer 14. Alternatively, the adhesive can be associated with the tape which can be applied to the metal layer 14 or receiving substrate, e.g., a pre-applied layer of adhesive which can be exposed after the tape is secured to the metal layer 14 or receiving substrate, or the adhesive can be applied to the tape after it is so secured.

[0032] 6, once the adhesive layer 38 has been patterned to match the portions 26 of the metal layer 14 that define the desired shape of the material to be deposited on the receiving substrate, the foil assembly 10 is brought into contact with the receiving substrate 50 and bonded thereto by the adhesive layer 38. This is necessary to avoid displacement of the material pattern during the laser release process described below.

[0033] The type of adhesive used depends on the receiving substrate properties, the required bond strength and application. As non-limiting examples, the adhesive can be a pressure sensitive adhesive (PSA, with or without liner, one coat, two coat, transfer type or other type PSA configuration), a heat activated adhesive, a water activated adhesive, or another type of adhesive. Depending on the adhesive type, high pressure can be applied during application, or less pressure for longer periods, or high temperatures can be used to achieve good bond strength. If the receiving substrate 50 is transparent, the adhesive can be a UV activated adhesive that can be activated by a UV light source during application of the foil assembly 10 to the receiving substrate 50.

[0034] The adhesive can be, for example, any known chemical property acrylic adhesive, silicone adhesive, epoxy adhesive, polyurethane, natural adhesive, etc. If the adhesive is applied directly to the receiving substrate or tape, the adhesive can have any of the above mentioned chemical properties and can be applied in any known manner, for example, as a spray coat, roll coat, spin coat, etc.

[0035] Although the illustrated embodiment shows a planar surface, the receiving substrate 50 may have a non-planar surface to which the foil assembly is bonded. In such cases, ablation must take into account the topology of the receiving substrate, and bonding of the metal layer 14 may need to be performed incrementally across the length and / or width of the foil assembly 10 to avoid air bubbles being trapped between the metal layer 14 and the surface of the receiving substrate 50.

[0036] 7 and 8, once the foil assembly 10 is bonded to the receiving substrate 50 by the adhesive layer 38, the laser system 30 can be used to remove the material layer 14 from the substrate 12. If the substrate 12 is transparent, at least at the wavelength of the laser system 30, the laser beam can irradiate the adhesive layer 16 that bonds the material layer 14 to the substrate 12 through the substrate 12 itself. This irradiation is selective in that it is performed only on the portions 26 of the material layer 14 that represent the desired shape of the material to be deposited on the receiving substrate 50. The excess material 22 is not removed from the substrate 12 when the foil assembly 10 is separated from the receiving substrate 50, for example by peeling the substrate 12 from the receiving substrate 50, as shown in FIG. 8, so that the portions of the excess material 22 are also removed. Of course, this step is not taken until all of the adhesive layer 16 that bonds the portions 26 of the metal layer 12 that represent the desired shape of the material to be deposited on the receiving substrate 50 have been removed. Removal of portions of adhesive layer 16 in this manner results in small amounts of adhesive layer 16 associated with portions 26 of material layer 14 that represent the desired shape of the material to be deposited on receiving substrate 50. 42 This may be due to evaporation of the layer of material 14.

[0037] In some cases, this laser-induced release (LIR) process can be performed simultaneously with the physical separation of the foil assembly 10 from the receiving substrate 50. For example, as the successive portions 26 of the material layer 14 are removed from the substrate 12 via the action of the laser system 30, the corresponding portions of the foil assembly 10 can be physically separated from the receiving substrate 50. In one inventive embodiment, this is accomplished using a roll-to-roll process in which the foil assembly is transferred from one spool to another spool via the LIR station. As the foil assembly passes through the LIR station and the successive portions 26 of the material layer 14 are liberated from the substrate 12, the removed foil assembly continues on the take-up spool, while the now-separated portion of the receiving substrate with the material portions 26 is redirected to a different path.

[0038] 7 can be different from the laser system 20 described above in connection with the ablation process. Alternatively, in some embodiments, the laser system 30 can be the same laser system used for the ablation process, in which case the foil assembly 10 and the receiving substrate may need to be transferred to the working area of ​​the laser system 20, or the laser system 20, or at least the laser beam, may need to be redirected to the working area associated with irradiating the adhesive layer 16.

[0039] 9, one embodiment of a system 100 for printing material onto a receiving substrate in a desired configuration using an assembly, such as a foil 102 pre-coated with a layer of material (such as metal). The system 100 is configured as a roll-to-roll system, where the foil 102 pre-coated with a layer of material advances from a material supply section 104 through an ablation channel 106, an adhesive coating stage 108, and an LIR and printing stage 110. After printing of the material on the receiving substrate, the foil 102 with any remaining excess material attached is captured on a take-up spool 112.

[0040] The system 100 operates based on instructions from the controller 114. In one embodiment, the controller 114 includes a processor that executes computer-readable instructions (i.e., computer programs or routines) that define the methods described herein, which are instantiated and executed on a non-transitory computer-readable medium. Such processes can be rendered in any computer language and executed on any suitable programmable logic hardware. A processor-based controller 114 capable of implementing the methods of the present invention will typically include a bus or other communication mechanism for communicating information, a main memory, such as a RAM or other dynamic storage device coupled to the bus, for storing information and instructions executed by the processor and for storing temporary variables or other intermediate information during execution of instructions executed by the processor, and a ROM or other static storage device coupled to the bus for storing static information and instructions for the processor. Storage devices, such as a hard disk or solid state drive, may also be included and coupled to the bus for storing information and instructions. The subject controller may, in some cases, include a display coupled to the bus for displaying information to a user. In such cases, input devices, including alphanumeric and / or other keys, may also be coupled to the bus for communicating information and command selections to the processor. Other types of user input devices, such as cursor control devices, may also be coupled to the bus for communicating directional information and command selections to the processor and for controlling cursor movement on the display.

[0041] The controller 114 may also include a communications interface coupled to the processor that provides bidirectional, wired and / or wireless data communications to and from the controller, for example, over a local area network (LAN). The communications interface sends and receives electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information. For example, the controller 114 may be networked with a remote unit (not shown) to provide data communications to a host computer or other equipment operated by a user. Thus, the controller may exchange messages and data, including diagnostic information, with the remote unit to aid in troubleshooting errors, if necessary.

[0042] In operation, the system 100 can be used to print a material, such as a metal, onto a receiving substrate and in a desired profile shape in the manner described above. For example, using a foil 102 that is pre-coated with a layer of material, the controller 114 operates the material supply spool 116 and take-up spool 118 to advance the foil through various stages of the deposition process. First, in the laser ablation channel 106, the laser system 20 is used to define the desired material pattern profile shape as described above in connection with Figures 2A-2B and 3A-3C. Through laser ablation of the material layer on the foil 102, the desired shape for deposition is written out or outlined. The laser used for the ablation process can be a pulsed laser, where the laser light energy absorbed in the material layer of the foil heats the material until a portion of it vaporizes. The laser system 20 ablates a narrow strip of the material layer around the desired shape to be deposited, and the deposited material is separated from any excess material.

[0043] As shown, the ablation process can be observed using an inspection system 118, such as one or more cameras. The cameras can image the ablation process in the visible and / or infrared spectrum, and the imaging data can be provided as feedback to a controller 114 that operates the laser system 20 accordingly. For example, the controller 114 can use the imaging data to adjust the pulse duration and / or frequency of the laser system 20 to selectively control the ablation of the material layer on the foil 102. As discussed above, proper air flow and exhaust in the ablation channel 106 can be provided. 120 is maintained to evacuate the material vapor.

[0044] After the ablation process, the foil 102 is 1 or 2 or more The foil 102 is advanced to the adhesive coating stage 108 via rollers 122 and spools 116, 118. As previously described with reference to Figure 4, selective application of a UV curable adhesive onto the material layer of the foil 102 is performed at this stage. As mentioned above, in some embodiments of the invention, the adhesive may be applied prior to the ablation step.

[0045] From the adhesive coating stage 108, the foil is advanced to the LIR and printing stage 110, where selective removal of the defined material pattern is performed, for example, by laser irradiation. During the LIR process, the material of the foil 102 is brought into contact with a receiving substrate on a receiving carrier 126, and the adhesive applied to the adhesive coating stage 108 can be cured using one or more UV diodes, UV lasers, or other UV sources 124, or other means, as described above. The controller 114 is programmed to cause the laser system 30 to emit pulses, so that desired portions of the material layer of the foil 102 are removed. Excess material of the foil 102 is not deposited, so that when the foil 102 is separated from the receiving substrate, for example by peeling the foil, and taken up on a spool 118, portions of the excess material are also removed. The material-coated receiving substrate can be removed from the receiving carrier 126, and a new receiving substrate can be introduced for printing. Although not shown, as with the ablation channel 106, one or more inspection cameras can be used to monitor the deposition process and provide feedback to the controller 114 in the form of imaging data that refines the operation of the LIR and print stages.

[0046] Although the system 100 is described using a roll-to-roll process for material foils, other forms of material transport can be used, for example, a robotic handover system, if a rigid substrate coated with a layer of material is used. For example, the material-coated substrate can be moved between the ablation channel 106, the adhesive coating station 108, the LIR and the printing stage 110 using a robotic arm having an end effector to properly position the substrate. After material printing on the receiving substrate, the carrier substrate, which remains coated with excess material, can be removed from the LIR and printing stage, again by the robotic arm, and reused by removal of excess material and recoating a layer of material.

[0047] Thus, a method and apparatus for printing a layer of material onto a receiving medium in a desired configuration has been described, and in particular, printing that utilizes selective removal of portions of a metal layer coated on a foil to generate a desired pattern on the receiving medium. In one embodiment of the invention, a material (e.g., metal) is printed onto a receiving substrate in a desired configuration by laser ablating an assembly that has been precoated with a layer of material to define the desired material configuration. An adhesive is selectively applied onto the desired material. The desired material is then applied to the receiving substrate by laser ablating the assembly. Adhesion The desired material can be selectively removed from the assembly onto the receiving substrate by laser ablating the desired material and removing excess material from the receiving substrate. In some cases, the assembly includes a transparent substrate (e.g., a transparent film), in which case excess material can be removed from the receiving substrate by removing the transparent substrate to which the excess material was adhered. In the above examples, the adhesive is selectively applied onto the desired material after laser ablating the assembly, but in some cases, the adhesive is selectively applied onto the desired material before the assembly is laser ablated. In various embodiments, bonding the desired material to the receiving substrate generally includes contacting the desired material with the receiving substrate. If the adhesive is a UV-curable adhesive, bonding further includes UV-curing the adhesive before laser irradiating the desired material. Alternatively, if the adhesive is a contact adhesive or a heat-curable adhesive, curing can be by contact pressure or heat, respectively.

[0048] In a further embodiment of the invention, an apparatus for printing a material (e.g., metal) onto a receiving substrate in a desired contour shape includes a laser ablation stage for ablating a layer of material coated on a carrier substrate (e.g., a transparent substrate such as a transparent film) to define the desired material contour shape, an adhesive application stage for applying an adhesive onto the desired material, and a laser ablation stage for applying the desired material to the receiving substrate. Adhesionand a printing stage that selectively removes the desired material from the assembly onto the receiving substrate by laser ablating the desired material and laser irradiating the desired material to remove excess material from the receiving substrate. The printing stage can be configured to remove excess material from the receiving substrate by peeling away the transparent substrate to which the excess material is adhered. In various embodiments, an adhesive application stage passes a layer of adhesive through the apparatus such that selective application of adhesive on the desired material occurs after laser ablation of the layer of material. Career The adhesive application stage can be positioned after the laser ablation stage in the direction of travel of the substrate, or the adhesive application stage can be moved through the apparatus such that selective application of adhesive on the desired material occurs prior to laser ablation of the layer of material. Career The printing stage may be positioned prior to the laser ablation stage in the direction of substrate travel. The printing stage may also be configured to bond the desired material to the receiving substrate by contacting the desired material with the receiving substrate. If the adhesive is a UV curable adhesive, the printing stage may be further configured to UV cure the adhesive with one or more UV sources prior to lasing the desired material. If the adhesive is a contact adhesive or a heat curable adhesive, curing may be by contact pressure or heat, respectively.

[0049] Yet another embodiment of the invention involves laser ablating an assembly (which may include a transparent substrate, such as a transparent film) that has been pre-coated with a layer of material to define a desired material profile, removing excess material from the assembly, selectively applying an adhesive onto the desired material, and attaching the desired material to a receiving substrate. Adhesion and selectively removing the desired material from the assembly onto the receiving substrate by laser irradiating the desired material from the assembly to print a material (e.g., metal) in a desired contour shape onto the receiving substrate. Generally, bonding the desired material to the receiving substrate includes contacting the desired material with the receiving substrate and, if the adhesive is a UV curable adhesive, UV curing the adhesive prior to laser irradiating the desired material. Alternatively, if the adhesive is a contact adhesive or a heat curable adhesive, curing can be by contact pressure or heat, respectively. [Explanation of symbols]

[0050] 20 Laser System 104 Material supply department 112 Receiving spool 118 Inspection 120 Air Flow and Exhaust 106 Ablation Channel 108 Adhesive Coating

Claims

1. 1. A method of printing a material onto a receiving substrate in a desired contour shape, comprising: laser ablating a layer of material of an assembly precoated with a layer of material to define a desired portion of the layer of material, the layer of material being formed of a metal, the desired portion being traced or outlined within the layer of material by separating excess material within the layer of material from the desired portion by an ablated region; applying adhesive onto the desired portion and onto the excess material; laser ablating to remove the adhesive from the excess material; selectively removing the desired portion from the assembly onto the receiving substrate by bonding the desired portion to the receiving substrate and irradiating the desired portion with a laser to remove the assembly together with the excess material from the receiving substrate; Including, The method, wherein an exhaust system evacuates ablated gases during the step of laser ablating the layer of material.

2. The method of claim 1 , wherein the assembly includes a transparent substrate, and removing the excess material from the receiving substrate includes peeling the transparent substrate to which the excess material is adhered from the receiving substrate.

3. The method of claim 1 , wherein bonding the desired portion to the receiving substrate comprises contacting the desired portion with a receiving substrate and UV curing the adhesive prior to irradiating the desired portion with a laser.

4. The method of claim 3 , wherein the transparent substrate comprises a transparent film.

5. The method of claim 1 , wherein bonding the desired portion to the receiving substrate comprises contacting the desired portion with a receiving substrate, the adhesive comprising one of a contact adhesive or a thermal cure adhesive.

6. 1. An apparatus for printing a material onto a receiving substrate in a desired contour shape, comprising: a laser ablation stage for ablating a layer of material formed of a metal coated on a carrier substrate to define a desired portion of the layer of material, the desired portion being traced or outlined within the layer of material by separating excess material within the layer of material from the desired portion by an ablated region, the laser ablation stage including an exhaust system for exhausting ablated gases; an adhesive application stage for applying adhesive onto the desired portion and excess material; means for returning the carrier substrate to the laser ablation stage for laser ablation to remove the adhesive from the excess material; a printing stage for selectively removing the desired portion from the carrier substrate onto the receiving substrate by bonding the desired portion to the receiving substrate and irradiating the desired portion with a laser to remove the assembly from the receiving substrate together with the excess material; 13. An apparatus comprising:

7. 7. The apparatus of claim 6, wherein the carrier substrate comprises a transparent substrate, and the printing stage is configured to remove the assembly together with the excess material from the receiving substrate by peeling the transparent substrate to which the excess material is adhered from the receiving substrate.

8. 7. The apparatus of claim 6, wherein the printing stage is configured to bond the desired portion to the receiving substrate by contacting the desired portion with the receiving substrate and UV curing the adhesive with one or more UV sources prior to laser irradiating the desired portion.

9. The apparatus of claim 6 , wherein the carrier substrate comprises a transparent film.

10. 7. The apparatus of claim 6, wherein the print stage is configured to bond the desired portion to the receiving substrate by contacting the desired portion with the receiving substrate, and the adhesive comprises one of a contact adhesive or a thermal curing adhesive.

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