System and method for printing solder paste and other viscous materials with high resolution

Abstract

A system and method for addressing mis-jetting while avoiding problems caused by the screen printing process is provided. [Solution] A system and method includes printing or otherwise transferring dot-like portions of a material (e.g., a viscous material such as solder paste) onto an intermediate substrate in a first printing unit, moving the intermediate substrate with the printed dot-like portions of the material to a second printing unit, and then transferring the dot-like portions of the material from the intermediate substrate to a final substrate in the second printing unit. Optionally, the first printing unit includes a coating system that produces a uniform layer of material on the donor substrate, and the material is transferred in discrete dot-like portions from the donor substrate onto the intermediate substrate in the first printing unit. Each of the first and second printing units can use different printing or other transfer technologies. The system can also include a material curing unit and an imaging unit to support the overall process.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Patent Application No. 62 / 969,233, filed on February 3, 2020, and U.S. Patent Application No. 16 / 807,489, filed on March 3, 2020.

[0002] (Technical Field) The present invention relates to a system and method for printing viscous materials such as solder paste, which performs an initial printing of the viscous material on a film with appropriate print quality and then, subsequently, transfers the printed viscous material from the film to a substrate by a laser - assisted deposition / laser dispensing system with high resolution and high speed.

Background Art

[0003] Surface Mount Technology (SMT) is a field of electronics assembly used to mount components on the surface of a printed circuit board (PCB), as opposed to inserting electronic components into holes in the PCB as in conventional assembly. SMT was developed to reduce manufacturing costs and use PCB space efficiently. As a result of the introduction of surface mount technology and the continuously improving level of automation, it is now possible to finish very complex electronic circuits into increasingly smaller assemblies with high reproducibility.

[0004] The solder - attaching process for surface mounting involves placing the electrical contacts of an electronic component or substrate, a small amount of solder paste, and solder - wettable pads in close proximity to each other. Then, the materials are heated until the solder reflows to form an electrical connection between the solder - wettable pad and the electrical contact of the electronic component. Once the solder has reflowed, an electrical and mechanical connection is formed between the electronic component and the printed circuit board. This process has many advantages over other interconnection methods because it can interconnect components simultaneously, is reproducible, has low cost, and is easily adaptable to mass production.

[0005] One of the most important parts of the surface mount assembly process is applying solder paste to the printed circuit board. The purpose of this process is to accurately deposit the correct amount of solder onto each pad to be soldered. This is generally done by screen printing the solder paste through a stencil or foil, although it may also be done by jet printing. This part of the process is widely considered to be the cause of most assembly defects if not properly controlled.

[0006] The solder paste itself is a mixture of a flux composition and a powdered solder metal alloy and is widely used in the electronics industry. At room temperature, the solder paste is sufficiently compliant so that it can be adapted to virtually any shape. At the same time, the solder paste is sufficiently "sticky" so that it tends to adhere to any surface it contacts. These properties make the solder paste useful for both surface mount soldering and for forming solder bumps on electronic components such as ball grid array packages or on printed circuit boards.

[0007] The printing of solder paste is a very important step in the current surface mount assembly process. When using a stencil or film for printing, there are several items that can negatively affect the procedure and result in defects in the final product. For example, the stencil itself needs to be very precise: a stencil that is too thick will cause solder bridging shorts, while a stencil that is too thin will result in insufficient solder application. Similarly, if the stencil opening size is too large, solder bridging shorts will occur, but if it is too small, the solder paste will not be applied sufficiently. Generally, it is considered best to use a circular stencil opening that is slightly smaller than the pad size of the PCB to prevent bridging defects during reflow. Still, defects can occur in the production of the stencil.

[0008] The blade used for screen printing also needs to be optimized: The blade angle affects the vertical force applied to the solder paste. If the angle is too small, the solder paste will be pushed into the stencil opening. If the blade pressure is too small, smooth application of the solder paste onto the stencil will be hindered, and if it is too high, it will cause paste leakage.

[0009] Another important point is that the higher the printing speed, the shorter the time spent applying the solder paste through the stencil opening surface, so there is a possibility that the solder application will be insufficient at high printing speeds. In the current process, it is necessary to control the printing speed to approximately 20 - 40 mm / s. Therefore, the maximum speed is currently limited by the printing process.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Summary of the Invention

Problems to be Solved by the Invention

[0011] Solder paste is a high-viscosity thixotropic material, and thus jet printing for use in the printing process is limited because injection becomes very complicated, since most injection heads are designed for low-viscosity materials and are very prone to clogging. However, injection and dispensing are very promising techniques, as can be seen from extensive research in this field. See, for example, International Publication No. 2007 / 084888 (A2), U.S. Published Patent Application No. 2011 / 0017841 (A1), U.S. Patent No. 9808822 (B2), and U.S. Patent No. 8740040 (B2). Although promising, the injection of viscous materials produces defects in the final assembled product, along with some unwanted debris.

Means for Solving the Problems

[0012] The inventors recognize that it is desirable to jet-print solder paste material (or any other viscous material), but it is desirable to do so in a way that does not cause defects in the final assembled product. To that end, the inventors have developed a system and method that separates the injection process from the coating process, thereby addressing injection defects while avoiding problems resulting from the screen printing process. In one embodiment of the present invention, a solder paste printing system includes an initial printing onto an intermediate substrate and a secondary high-precision, debris-free printing onto a final substrate. This system can include one or more imaging devices for monitoring and controlling various processes. Also, a curing device for the intermediate material along with the final product can be included.

[0013] In some embodiments of the present invention, the printing system includes a coating system that generates a uniform layer of printing material on a substrate. When present, the coating system can include a syringe of the printing material and an air or mechanical pump that drives the material onto a donor or carrier substrate. The donor substrate is then moved through and passed between rollers or knives into a precisely defined gap to generate a uniform layer of printing material having a thickness defined by the gap. Alternatively, the coating system can include a screen printing module, in which case the material is coated onto a screen or stencil of a film having precisely defined holes, and a blade or squeegee is used to transfer the material to the donor substrate with a soft or hard engagement. In yet another embodiment of the present invention, the coating system can include a dispenser or inkjet head that prints the material onto the substrate, a gravure or microgravure system, a slot die system, or a roller coating system that coats the substrate with a highly uniform layer of the material to be printed. The coating system can be housed within an enclosed compartment having a controlled environment (low or high temperature) to prevent evaporation of solvents from the printing material or oxidation of the material, thereby extending the pot life of the material. Also, the coating system can include two or more materials, thereby creating the possibility of printing multiple materials onto an intermediate substrate in a controlled order and enabling printing of two or more materials onto the final substrate. Within the coating system, the donor substrate can be translated in both directions or otherwise in a controlled manner, for example while widening the gap between coater rollers, creating the possibility of recoating the same area of the donor substrate with the printing material without contamination of the rollers, reducing or eliminating the amount of substrate consumed during the initial printing process, thereby preventing waste.

[0014] In various embodiments of the present invention, the printing material is a solder paste or other metal paste(s) for printed electronics, a metal paste or a ceramic paste, a high-viscosity material, a wax material, a polymer material or a mixture of a polymer material and a monomer material, a sensitive low-viscosity material, a material curable by ultraviolet (UV) light or visible light or by heating, or a material capable of being dried.

[0015] Either or both of the first and / or second printing process(es) can use a laser-based system that houses a high-frequency laser to enable the injection of material from one substrate to another. For either of the printing processes, a laser-assisted deposition / laser dispensing system can be used that rotates by 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which it is located, enabling a simpler mechanism without degrading the print quality.

[0016] Optionally, the first printing process can use an inkjet head system that enables the injection of material directly onto an intermediate substrate, a dispenser head system that enables the printing of material directly onto an intermediate substrate, or an offset printing press module, a gravure printing module, or another printing press module that enables the printing of material directly onto an intermediate substrate. Alternatively, the first printing process can use a screen printing module, in which case the material is coated onto a screen or stencil of a film with clearly defined holes, and a blade or squeegee is used to transfer the material onto the substrate in a soft or hard engagement to create dots on the substrate. In some embodiments of the present invention, after printing on the intermediate substrate in the first printing unit, the printed intermediate substrate is further cured with UV light or dried with a heater and then returned to the first printing unit for a second (or additional) layer printing.

[0017] In some embodiments of the present invention, the first printing unit includes a gap control unit configured to maintain a very clearly defined gap between the donor substrate and the intermediate substrate. For example, a very clearly defined gap between the coated substrate and the intermediate substrate can be maintained in a plane consisting of three actuators at the corners of a control unit that allows both translation and rotation, as described in U.S. Patent Publication No. 2005 / 109734 (A1), U.S. Patent No. 6122036 (A), International Publication No. 2016 / 198291, and European Patent No. 3219412 (A1). Such actuators can be used at the corners of the control unit for both the coated substrate and the intermediate substrate to allow both translation and rotation in two planes, where the two planes are independent of each other or overlap.

[0018] In another embodiment of the present invention, a very clearly defined gap between the donor substrate and the intermediate substrate is achieved by providing a fixed support below the intermediate substrate, which is part of the coating system configuration. Alternatively, a very clearly defined gap between the coated substrate and the intermediate substrate can be achieved by using a transparent solid substrate instead of a film as the intermediate substrate.

[0019] In some embodiments of the present invention, the intermediate substrate can be a continuous transparent film substrate, a transparent film substrate coated with a metal layer or by a metal layer and a dielectric layer, or a transparent solid substrate.

[0020] In some embodiments of the present invention, after the first printing, the intermediate substrate is moved by a motor from the first printing unit towards the second printing unit. Thus, the intermediate substrate can be a continuous film substrate that can deliver the material printed by the first printing unit to the second printing unit by rolling. Alternatively, the intermediate substrate can be a transparent solid substrate that can deliver the material printed by the first printing unit to the second printing unit with any direction change(s) (plural possible) by a robotic arm.

[0021] In some embodiments of the present invention, during the transfer of the intermediate substrate from the first printing unit to the second printing unit, the printed material is cured with UV light or dried with a heater. Further, the printed image can be processed by an imaging system. Such an imaging system can be a microscope or a charge-coupled device (CCD) that takes a photograph of the material dots printed on the intermediate substrate and measures the dots two-dimensionally, and the measurement data is then transferred to the second printing unit for accurate deposition onto the final substrate. Alternatively, the imaging system can be a three-dimensional (3D) microscope that takes a photograph of the material dots printed on the intermediate substrate and measures the dots three-dimensionally, and the measurement data is then transferred to the second printing unit for accurate deposition onto the final substrate. In yet another embodiment of the present invention, the imaging system includes two microscopes or CCDs arranged such that one images the material dots printed on the intermediate substrate and measures the dots two-dimensionally (e.g., length and width), while the other measures the dots in a third dimension (e.g., height), and all of the measurement data is then transferred to the second printing unit for accurate deposition onto the final substrate. In any case, the imaging system can be included in front of and / or behind the second printing unit and can capture images from the intermediate substrate, the final substrate, or both. In one embodiment of the present invention, the imaging system in the second printing unit can simultaneously image both the dimensions of the dots and the target area of the final substrate using a mirror for obtaining an image from the surface of the intermediate substrate and / or the main laser channel of the second printing unit.

[0022] In some embodiments of the present invention, the second printing unit can be a laser-based system that houses a high-frequency laser enabling dot ejection from the intermediate substrate to the final substrate by laser jet emission, or a laser jet emission system equipped with a one-dimensional or two-dimensional (2D) array scanning laser. Alternatively, in some cases, the second printing unit can include only the deposition position where the intermediate substrate directly engages with the final substrate. In any case, after printing on the final substrate with the second printing unit (or by another method), the printed final substrate can be further cured with UV light or dried with a heater.

[0023] Hereinafter, these and further embodiments of the present invention will be described in detail.

Brief Description of the Drawings

[0024] The present invention is shown, by way of example and not limitation, in the figures of the accompanying drawings.

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Embodiments for Carrying Out the Invention

[0025] Before explaining the present invention in detail, it is useful to refer to FIG. 1, which gives a conceptual overall view of a system 10 that uses a narrow-gap or contact-gap printing system (or even a non-digital printing system) 12, pre-print processing and / or inspection 14a, 14b, and digital high-gap printing 16 to provide high-resolution and high-speed printing of viscous materials such as solder paste, in accordance with embodiments of the present invention. As will be further explained below, the narrow-gap or contact-gap printing system 12 performs an initial printing of the viscous material onto an intermediate substrate. As part of the pre-print processing and / or inspection 14a, 14b, the intermediate substrate can be observed with one or more imaging devices to monitor and control the initial and subsequent printing processes. Next, the intermediate substrate can be used as part of a second high-gap printing 16 of the viscous material onto the final substrate. This second printing procedure can also be observed with one or more imaging devices and is highly accurate and forms little, if any, debris. In one embodiment of this two-step printing procedure, the viscous material is dispensed as dots (e.g., small, generally round spots or droplets) onto the intermediate substrate by a first printing process and then moved through an imaging system to a second printing process where the dots (or at least a portion thereof) are deposited onto the final substrate.

[0026] The first printing process can be laser-assisted deposition or other laser dispensing printing, in which case the dots of the viscous material are ejected onto (or into) the intermediate substrate from its uniform layer on the coated substrate (e.g., donor substrate) using a high-frequency laser. The ejection of the material is preferably performed in a well-defined and robust manner to minimize dot size variation. To ensure a uniform coating of the viscous material on the donor substrate, after coating the donor substrate using any coating system 18, it can be supplied to a first printing unit where laser-assisted deposition or other laser dispensing printing is performed. This coating system can be a conventional coating system, such as a coating system based on microgravure or slot die coater or roller coating system. Alternatively, the coating system can be a coating system based on screen printing, dispenser, or inkjet system. In yet another embodiment, the coating system can be based on a syringe and gap system, in which case the viscous material is dispensed from the syringe onto the donor substrate, and then the substrate passes through a well-defined gap formed, for example, by a blade of another kind of barrier, or a pair of rollers or cylinders. After passing through the gap, a uniform layer of the viscous material will be present on the donor substrate, and the laser-assisted deposition / laser dispensing system can eject dots of the material from the coated donor substrate onto the intermediate substrate. After supplying a uniform layer of the viscous material for printing in the first printing process, the donor substrate can be returned (e.g., in a loop or by linear translational movement) to the coating system to create a new uniform coating layer on the donor substrate for the next printing by the first printing process. The donor substrate can be a transparent film or other substrate, with or without a metal (or other) film.

[0027] Using a system configured in accordance with an embodiment of the present invention, a wide variety of liquid and / or paste materials can be printed. However, the present invention particularly provides advantages for printing highly viscous materials that cannot be well printed at high resolution by other methods. For example, a system configured in accordance with an embodiment of the present invention finds particular use in printing highly viscous polymers such as acrylic, epoxy, and urethane-based adhesives, pastes or waxes, along with solder paste and other metal pastes. The present invention can also maintain the coated donor substrate in a controlled environment prior to the first printing process to avoid solvent evaporation or oxidation of the material to be printed, and thus can be used for printing sensitive materials. Such a space can also provide a controlled area for temperature-sensitive materials.

[0028] The first printing process does not necessarily need to use a laser-assisted deposition / laser dispensing system. In some embodiments, the first printing process can use a dispenser or an inkjet head, or can use conventional 2D printing techniques such as offset printing, gravure printing, or other printing techniques. The first printing process can also be performed using screen printing or a combination of these techniques.

[0029] A second printing process for transferring the viscous material from the intermediate substrate to the final substrate can utilize a laser jet ejection system. For example, if the viscous material exists in the form of dots on the intermediate substrate, a printing head in the form of a laser jet ejection system can be used to selectively transfer some or all of the dots of the viscous material from the intermediate substrate to the final substrate. The laser jet ejection system can include a high-frequency laser arranged to scan the intermediate substrate two-dimensionally to eject dots from the intermediate substrate to the final substrate. Alternatively, a direct transfer system can be used in which the intermediate substrate directly engages the final substrate and transfers dots of the viscous material therebetween. After printing onto the final substrate, the viscous material can be cured with ultraviolet or infrared light, or dried with a heater.

[0030] Figures 2a and 2b schematically show aspects of systems 20a, 20b configured according to the conceptual overview presented in Figure 1. Each of these systems separates the injection process of the viscous material from the coating process, thereby addressing injection defects while avoiding problems resulting from conventional printing processes. Each system includes one or more imaging devices for monitoring and controlling the injection and coating processes. In Figure 2b, printing system 20b includes a coating system 22 that forms a uniform layer 26 of material to be printed (e.g., a highly viscous material such as solder paste or other metal paste(s) for printed electronics, ceramic paste, wax material, polymer material, or a mixture of a polymer material and a monomer material, or a sensitive low-viscosity material) on a donor substrate 28.

[0031] In one embodiment of the present invention, coating system 22 includes a syringe of the material to be printed and an air or mechanical pump that drives the material onto donor substrate 28. Next, a motor is used to move donor substrate 28 towards a clearly defined gap between rollers or knives, creating a uniform layer 26 of the material to be printed having a thickness defined by the gap. In some embodiments of the present invention, donor substrate 28 translates in both directions in a controlled manner while widening the gap between the coater rollers, creating the possibility of re-coating the same area of the donor substrate with the material to be printed without contamination of the rollers, reducing or eliminating the amount of substrate consumed during the initial printing process, thereby preventing waste.

[0032] In another embodiment, the coating system 22 can include a screen printing module, in which case the donor substrate 28 is coated using a screen or stencil with defined holes, a viscous material is applied thereto using a blade or squeegee, and the viscous material is later transferred to the donor substrate 28 with a soft or hard engagement. Alternatively, the coating system 22 can include a dispenser or an inkjet head for printing the viscous material onto the donor substrate 28. Or, the coating system 22 can be a gravure or microgravure system that coats the donor substrate 28 with a highly uniform layer 26 of the material to be printed. In one embodiment of the present invention, the coating system 22 is a slot die system that coats the donor substrate 28 with a highly uniform layer 26 of the material to be printed. In another embodiment of the present invention, the coating system 22 is a roller coating system that coats the donor substrate 28 with a highly uniform layer 26 of the material to be printed. Although not shown in detail, the printing system 20a of FIG. 2a can also include a coating system as part of the narrow gap / contact printing process 30 that forms the first printing process described above.

[0033] As shown in FIG. 2a, in one embodiment of the present invention, the narrow gap / contact printing process 30, which can include a first printing unit 32 and optionally a coating system 22, is housed within a closed compartment with a controlled environment 34 (low or high temperature) to prevent evaporation of the solvent from the material to be printed or to prevent oxidation of the material, thereby extending the pot life of the material. In some embodiments of the present invention, the coating system 22 houses two or more materials, thereby creating the possibility of printing multiple materials onto the intermediate substrate 36 in a controlled order and enabling printing of two or more materials onto the final substrate 38.

[0034] The first printing unit 32 creates an area 24 of the material to be printed on the intermediate substrate 36. In one embodiment of the present invention, a continuous transparent film substrate is used as the intermediate substrate 36 of the system. Alternatively, a transparent film substrate coated with a metal layer or a metal layer and a dielectric layer can be used as the intermediate substrate 36 for the present system.

[0035] The first printing unit 32 used in the narrow gap / contact printing process 30 can include a laser-based system that houses a high-frequency laser configured to eject a portion of the layer of the coating material 26 from the donor substrate 28 onto the intermediate substrate 36 by a laser-assisted deposition / laser dispensing system. The laser-assisted deposition / laser dispensing system can be rotated 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which it is located, enabling a simpler mechanism without degrading the print quality.

[0036] Alternatively, if no coating system is used, the first (e.g., narrow gap / contact) printing process 30 can use an inkjet head system that enables direct injection of the material to be printed onto the intermediate substrate 36. Alternatively, the first printing process can use a dispenser head system that enables direct printing of the material onto the intermediate substrate 36. Or, the first printing process can directly print the material onto the intermediate substrate 36 using an offset printing press module, a gravure printing module, or any conventional printing technique. For example, the first printing process can use a screen printing module, in which case the material to be printed is coated onto a film screen or stencil with clearly defined holes, and a blade or squeegee is used to transfer the material onto the intermediate substrate 36 with a soft or hard engagement to create a dot array 40 of the material to be printed on the intermediate substrate 36.

[0037] In some embodiments of the present invention, the first printing unit 32 used in the narrow gap printing process 30 includes a gap control unit that is very clearly defined between the donor substrate 28 and the intermediate substrate 36. In one example, the very clearly defined gap between the donor substrate 28 and the intermediate substrate 36 is maintained using a set of three actuators at the corners of a control unit that allows for both translation and rotation, as described in U.S. Patent Publication No. 2005 / 109734(A1), U.S. Patent No. 6122036(A), International Publication No. 2016 / 198291, and European Patent No. 3219412(A1), which are incorporated herein by reference. A set of three actuator units is used at the corners of the control unit for both the donor substrate and the intermediate substrate to allow for both translation and rotation in both planes, where the two planes are independent of each other or overlap. Alternatively, the very clearly defined gap between the donor substrate 28 and the intermediate substrate 36 can be maintained by providing a fixed support below the donor substrate and / or the intermediate substrate. Or, by using a transparent solid substrate instead of a film as the intermediate substrate 36, a very clearly defined gap between the donor substrate 28 and the intermediate substrate 36 can be maintained.

[0038] In some embodiments of the present invention, after printing on the intermediate substrate 36 with the first printing unit 32, the printed intermediate substrate is returned to the first printing unit 32 for printing a second (or additional) layer of the adhesive material. In any case, after printing with the adhesive material (in the form of dots 40 or other regions 24), the intermediate substrate 36 moves from the first printing unit 32 towards the second printing unit 44. Optionally, the second printing unit can be a selective release system 46 (e.g., a laser-based system) equipped with an in-line inspection unit 48. The intermediate substrate can be moved by a motor, for example, when the intermediate system is a film or a similar substrate, or can be moved by rolling to deliver the material printed by the first printing unit to the second printing unit when the intermediate substrate is a continuous film substrate. In one embodiment of the present invention, the intermediate substrate 36 is a transparent solid substrate that can use a robotic arm to deliver the material printed by the first printing unit to the second printing unit with any possible direction change(s) in between.

[0039] In some embodiments of the present invention, during the movement of the intermediate substrate 36 from the first printing unit 32 to the second printing unit 44, the material printed on the intermediate substrate (which can be a material cured by ultraviolet (UV) light or by heating) can be cured with ultraviolet light or dried with a heater. Further, while the intermediate substrate 36 moves from the first printing unit 32 to the second printing unit 44, the material printed on the intermediate substrate can be processed by an imaging system 50.

[0040] Such an imaging system 50 can include one or more microscopes, charge-coupled devices (CCDs), and / or other imaging components that photograph dots 40 of the material printed on the intermediate substrate 36 and measure the dots two-dimensionally or three-dimensionally. For example, the imaging system 50 can include two microscopes or CCDs arranged such that one images the dots printed on the intermediate substrate and measures the dots two-dimensionally (e.g., length and width), while the other measures the dots in a third dimension (e.g., height). This measurement data can then be transferred to the second printing unit 44 to ensure accurate deposition of the adhesive material onto the final substrate 38. For example, and as also shown in FIG. 2A, it may be revealed by optical or other imaging inspection that many of the dots 40 are suitable for transfer to the final substrate 38 (e.g., indicated by check marks in the figure), while some of the dots 40 are defective in shape or otherwise unsuitable for transfer to the final substrate 38 (e.g., indicated by "X" in the figure). In that case, a controller (not shown) that has access to this data can operate the second printing unit to omit the transfer of the unsuitable dots 40 to the final substrate. The imaging system can be included in front of and / or behind the material transfer area of the second printing unit 44 and can capture an image from the intermediate substrate 36, the final substrate 38, or both. In one embodiment of the present invention, the imaging system is positioned at the second printing unit 44 and uses a mirror or other optical element and / or the laser channel 52 of the second printing unit 44 used to obtain an image from the surface of the intermediate substrate 36 to image both the dimensions of the dots and the printing area of the final substrate while simultaneously using the in-line inspection system 48.

[0041] As described above, the second printing unit 44 can be a laser-based system that houses a high-frequency laser configured to eject suitable dots 40 of material from the intermediate substrate 36 to the final substrate 38 (under the control of a controller), for example, by laser jet ejection. In some embodiments of the present invention, the second printing unit can be a laser jet ejection system comprising a two-dimensional (2D) array scanning laser configured to scan a laser beam in a raster pattern above the intermediate substrate 36 when passing through the target area to eject suitable dots 40 of material onto the final substrate 38. Such a laser jet ejection system can be rotated by 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which it is located, enabling a simpler mechanism without degrading print quality.

[0042] In some embodiments of the present invention, the second printing unit itself does not exist, but the intermediate substrate 36 directly engages with the final substrate 38, and there is only a deposition position where dots 40 of material are transferred between the intermediate substrate 36 and the final substrate 38 through such contact. In either example (laser transfer or direct contact transfer), after printing on the final substrate, the printed material can be further cured with UV light or dried with a heater.

[0043] FIG. 3A shows an example of a system 60 configured according to the present invention. The system 60 exemplifies the aspects of the systems 20a and 20b described above. In particular, the system 60 includes a coating system 22 that uses air or a mechanical pump (not shown) to create a uniform layer 26 of the material to be printed on the donor substrate 28 in order to drive the material 62 from a reservoir, such as a syringe 64, onto the donor substrate 28. Then, the donor substrate 28 is moved towards a clearly defined gap 70 between a roller or a knife 72 using a roller or a gear 66 to create a uniform layer 26 of the material to be printed with a thickness defined by the gap 70 on the donor substrate 28.

[0044] System 60 also includes a first printing unit 32 configured to generate dots 40 of material 62 on an intermediate substrate 36. In this example, the donor substrate 28 can be a transparent film, and the first printing unit 32 includes a first laser module 74 that houses a high-frequency laser arranged to form dots 40 on the intermediate substrate 36 by ejecting a portion of the coating material layer 26 from the donor substrate 28 and focusing a laser beam at the interface between the material layer 26 and the intermediate substrate 36. The incident laser beam causes local heating with a phase change and high local pressure, thereby driving the ejection of the printing material onto the intermediate substrate 36. After printing on the intermediate substrate 36 in the first printing unit 32, the printed intermediate substrate can be returned for second (or additional) layer printing of material 62 by reversing the direction of the roller or gear 66 or by continuing the movement of the intermediate substrate 36 through the coating system 22 in a loop process.

[0045] Alternatively, the donor substrate 26 can be a screen or grid into which the material 62 is introduced through the holes of the screen by a coater 72, and the coater 72 can be a roller or a blade. In such a case, the incident laser beam from the laser module 74 transfers the printing material from the holes of the screen onto the intermediate substrate 36.

[0046] Once the dots 40 are printed on the intermediate substrate 36, the dots move towards the second printing unit 44, for example, by moving the intermediate substrate 36 using a roller or gear 78. Although not shown in this drawing, the intermediate substrate can be a film substrate that moves in a continuous loop fashion, so that dots of material are printed thereon by the first printing unit 32 and subsequently transferred to the final substrate 38 by the second printing unit 44, and now the bare intermediate substrate can be returned to the transfer area of the first printing unit 32 to receive new dots 40 of material.

[0047] During the transfer of the intermediate substrate 36 from the first printing unit 32 to the second printing unit 44, the dots 40 of the material can be cured with UV light or dried with a heater. Further, while the intermediate substrate 36 is moving from the first printing unit 32 to the second printing unit 44, the dots of the material printed on the intermediate substrate can be processed by an imaging system 50. It includes one or more 3D (80) and / or 2D (82) imaging components that take pictures of the printed dots 40 of the material and measure the dots in two or three dimensions. This measurement data can be used in the second printing unit 44 to ensure the accurate deposition of the viscous material onto the final substrate 38.

[0048] The second printing unit 44 can include a laser module 84 with an in-line inspection unit 48. When the intermediate substrate 36 is moved to the target area 86 of the second printing unit 44, the laser module 84 is activated to emit a laser beam incident on the intermediate substrate 36 in order to deliver the material printed in the first printing unit to the final substrate 38. The in-line inspection unit 48 positioned in the second printing unit 44 acquires an image from the surface of the intermediate substrate 36 and helps align the final substrate located below the target area 86 via a configured stage 90 that moves in two or three dimensions, and is used to assist in synchronizing the pulsed operation of the laser module 84 t times when the dots 40 of the material on the intermediate substrate 36 are in the target area 86, and includes a mirror 88 or other optical element. In some embodiments of the present invention, the laser module 84 of the second printing unit 44 can be configured to scan the laser beam above the intermediate substrate 36 in a raster pattern as the intermediate substrate passes through the target area 86 and release suitable ones of the dots 40 of the material onto the final substrate 38. The material can pass through a UV curing system and / or a drying system on the way to the second printing unit 44, and / or UV curing and / or drying can be used after the material is printed on the final substrate 38.

[0049] An alternative arrangement of the first printing unit 32 is shown in FIG. 3b. In this example, a system 92 configured in accordance with the present invention includes a coating system 22 where material 62 is driven from a reservoir, such as a syringe 64, onto roller 94 using an air or mechanical pump (not shown). Roller 94 is recessed or otherwise formed with a recess to accommodate a predetermined amount of the material to be printed, and this amount is transferred to printing roller 96 when the two rollers contact each other in material transfer region 100. Alternatively, roller 94 can have a screen or grid-like surface with holes through which material 62 is introduced. Roller 96 can contact the screen to achieve transfer of the material thereto. Roller 96 transfers the material in the form of dots 40 onto intermediate substrate 36 upon completion of its rotation through printing region 102. After the material is transferred from roller 94, that roller passes through inspection region 104 and any remaining material can be removed using a knife 106 or other instrument before applying a new layer of material. The remaining elements of system 92 are as described above with respect to system 60 shown in FIG. 3a.

[0050] FIG. 3c shows yet another embodiment of the present invention. In this system 110, a coating system 22 creates a uniform layer of the material to be printed on donor substrate 28 using, for example, one of the techniques described above. The first printing unit 32 then prints the material from the uniform layer on the donor substrate 28 onto the intermediate substrate 36. In this example, a fixed support 114 located beneath the intermediate substrate 36 in the vicinity of the first printing unit 32 is used to maintain a very well-defined gap 112 between the coated donor substrate 28 and the intermediate substrate 36. The remaining elements of system 110 are as described above, and in this example, the positioning of an ultraviolet curing system and / or drying system 116 for curing the material on the intermediate substrate on its way towards the second printing unit 44 is shown. Also shown is a post-first-print imaging system 118 for the intermediate substrate 36, which can be used to ensure proper transfer of the material from the intermediate substrate to the final substrate 38 by the second printing unit 44.

[0051] Figure 3d shows a system 120 that is configured substantially the same as the system 110 shown in Figure 3c, except that in this configuration, the first printing is performed by the printing unit 32 at 90 degrees (or any other orientation) with respect to the gravitational field in which the first printing unit is located. As an example, in this explanatory drawing, the gravitational field is assumed to be from the top to the bottom of the page, and the first printing unit is configured to print the material from the donor substrate 28 to the intermediate substrate 36 at an angle orthogonal to the gravitational field. This arrangement provides a smaller and simpler configuration than possible configurations using some of the other printing systems described above, together with the print head of the laser-assisted deposition / laser dispensing system.

[0052] As described above, the intermediate substrate 36 can be a film, but in other embodiments, it can be a transparent solid substrate 124 to ensure better alignment and synchronization between the first and second printing units. Figure 3e shows the process of printing from the coated donor substrate 28 onto the transparent solid substrate 124 (left figure), and then turning it over to create a target for the second printing unit 44 used for printing onto the final substrate (right figure).

[0053] Figures 4a and 4b further show the generation of a uniform layer 26 of material on the donor substrate 28 by placing an amount of material 62 with a syringe 64 on the film substrate 28 (Figure 4a) and creating a uniform layer of the material through the material in a clearly defined gap (Figure 4b). The clearly defined gap 126 is created by bringing a pair of rollers 128a, 128b or a knife closer to each other using a suitable control unit (e.g., a stepper motor or a piezo transducer).

[0054] Figures 5a and 5b show an example of screen printing directly onto a film substrate (such as the intermediate substrate 36) according to some embodiments of the present invention. In this technique, droplets 132 of a high-viscosity material are printed from a screen or grid 130 to form 2D and / or 3D structures on a receiving substrate such as film 134. First, a substantially uniform layer of the viscous material is coated onto the mesh-like transport screen 130 and held within its voids 140 by adhesion to the mesh surface and surface tension. Next, the mesh 130 coated with the material is brought into the working area and contacted with a blade 136 that passes above the holes of the mesh, ejecting droplets 132 onto the film substrate 134 across a small gap 142. Alternatively, the droplets 140 can be printed directly onto the substrate 134 by contacting them with the mesh-like transport screen 130. In either printing technique, the printing can be done one droplet at a time, or one layer at a time.

[0055] The opening 140 of the screen 130 is preferably of uniform size (or substantially uniform) and can be of regular (e.g., circular, square, rectangular, oval, triangular, etc.) or irregular shape. The screen 130 is generally made of metal (e.g., metal foil), but can also be made from other materials including, without limitation, plastic, nylon, glass, quartz, etc. In some embodiments, the screen can be made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polyimide (e.g., plastic foil such as Kapton (trademark)). The mesh structure of the screen can be shaped by laser drilling, by which the thickness of the screen and the opening dimensions of the screen can be controlled independently of each other. Preferably, the screen 130 is made of a flexible material so as to be accommodated on a loop conveyor, but in other embodiments, a more rigid screen can be used and a conveying mechanism for accommodating the screen can be used (e.g., an actuator that moves the entire screen in one or two dimensions in a plane at once). Accordingly, the screen 130 is a regular arrangement of the openings 140 in each of the two planar dimensions and is maintained in a tensioned state via a suitable actuator 138 to assist in the release of the viscous material in accordance with the shape and volume of the openings and the viscosity and composition of the material filling the openings.

[0056] Figure 6 shows an example of printing material from a lattice or mesh substrate 152 using a laser assist deposition / laser dispensing system 150, according to some embodiments of the present invention. In this embodiment, a laser 152 is used to create droplets 154 of a high viscosity material, which, when solidified into aggregates, form 2D and / or 3D structures on a receiving substrate (not shown in this figure). In this technique, a substantially uniform layer of the viscous material is coated onto a mesh-like carrier screen 156 and held within its voids by adhesion to the mesh surface and surface tension. Next, the mesh coated with the material is brought into the working area, and the laser 152 is used to heat the material within the holes of the mesh and eject droplets. More specifically, a focused laser beam is incident on a thin layer of the viscous material in a small working area, and this thin layer of the material is transported into the working area using a mesh-like screen 156 having small holes or other openings periodically arranged therein. As described above, the openings of the screen can be of a desired size depending on the application and can be regular (e.g., circular, square, rectangular, oval, triangular, etc.) or irregular in shape. The screen can be made of other materials, including, but not limited to, metal (e.g., metal foil), or plastic, nylon, glass, quartz, etc. Preferably, the screen is made of a flexible material, but in other embodiments, a more rigid screen can be used and a transport mechanism for accommodating the screen can be employed (e.g., an actuator that moves the entire screen in one or two dimensions in a plane at once). When the laser focuses through a transparent (at least at the target laser wavelength(s)) substrate 158 onto the opening (or the region adjacent to the opening) of the screen 156, the material within the opening is heated and droplets 154 are ejected towards the substrate (not shown in this figure). The droplets 154 are approximately the same size as the openings of the screen 156 and have a volume approximately equal to the volume of the material contained within the openings. The mesh screen 156 is held under tension (e.g., a lateral tension with respect to the plane of the screen) 160 when being transported through the working area by one or more actuators. In some embodiments, the screen transport and tensioning mechanism can be configured to operate in both forward and reverse directions.

[0057] Figure 7 shows an example of printing a punctiform material from a film substrate using a laser jet ejection system 170, according to some embodiments of the present invention. In this embodiment, a laser 172 is used to create droplets 174 of a high-viscosity material, which, when solidified into aggregates, form a 2D and / or 3D structure on a receiving substrate (not shown in this figure). In this technique, a substantially regular pattern (e.g., dots 176) of a viscous material is printed or otherwise applied onto a transparent substrate 178 (e.g., intermediate substrate 36 from above), and then brought into the working area. A laser 172 is used to heat the interface between the transparent substrate 178 and the material 176 to eject the droplets 174. The substrate 178 is transparent at least at the target laser wavelength(s), and the heating by the laser 172 causes the droplets 174 to be ejected towards a receiving material (not shown in this figure). The substrate 178 is held under a tension (e.g., a lateral tension with respect to the plane of the screen) 180 when being conveyed through the working area by one or more actuators. Optionally, the tensioning mechanism can be configured to operate in both the forward and reverse directions. The material can be considered to be printed or applied to the substrate 178 as dots 176 or as a layer of any other shape or form.

[0058] Figure 8 shows an aspect of imaging dots on a solid or film substrate using a main laser channel, according to some embodiments of the present invention. In this example, dots 192 of a material are printed on a solid substrate 194 (e.g., final substrate 38 such as a printed circuit board), and a camera 196 is used to image the dots via the main laser channel. Alternatively, the camera 196 can be offset from the main laser channel and a semi-transparent mirror 198 can be inserted therein to reflect the image of the dots 192 towards the camera. This kind of imaging can be used to ensure an optimal placement of the material dots on the final substrate. The same imaging system can be used to monitor the material on the final substrate from above and / or from the side.

[0059] The above discussion has mainly related to systems and methods for printing high-viscosity materials onto a substrate at high resolution and at high speed. However, the same systems and methods can be used for stamp production or for printing multiple materials onto the same layer. For example, FIG. 9 shows an aspect of stamp manufacturing by such a system. In a first step 200, a shaped layer 202 of a UV-curable material (not necessarily a dot matrix) is printed onto an intermediate substrate 204. Next, this layer is exposed to light from a UV light source and cured to form a cured layer 206. Thereafter, the intermediate substrate with the cured layer of the material is returned to the first printing unit, and a second (or additional) layer 208 of the material is dispensed onto the coated substrate and printed by the first printing unit. Next, this second / additional layer is exposed to the UV light source to create a second / additional cured layer 210 of the material. In this way, multiple layers of the same or different materials can be printed onto the intermediate substrate.

[0060] FIG. 10 shows an aspect of printing multiple materials onto the same layer. One or more sections of a first material 212 are printed onto a film substrate 214 in the manner described above, but then the intermediate substrate is returned to the first printing unit, and a second (or third or more) section(s) 216 of a different material are dispensed onto the coated substrate to form a uniform layer. Using this technique, multiple materials can be printed simultaneously onto the final substrate.

[0061] One example of printing multiple materials from an intermediate substrate to a final substrate is adhesive printing. In such cases, the reaction between materials can be initiated by mixing two materials (e.g., in the case of epoxy-amine or silanol-platinum catalyst). Instead of mixing the materials on the intermediate substrate, they are printed only once on the final substrate. By doing so, clogging or other undesirable side effects are avoided, and the mixing occurs only at the desired location.

[0062] Thus, a system and method for printing a viscous material such as solder paste have been developed. In various embodiments, these systems and methods employ a multi-step procedure in which the viscous material is dispensed onto a donor substrate and then printed onto an intermediate substrate before finally being transferred either in a second printing process or a direct coating process onto the final substrate. The material may pass through one or more stages within a curing system, a drying system, and / or an imaging system as it progresses through the various stages of the printing process. In order to achieve a very narrow dot size distribution in printing onto the intermediate substrate, it is important to perform very precisely defined distance control between the coated donor substrate and the intermediate substrate. For this purpose, any of several mechanical solutions can be used. For example, the distance between the coated donor substrate (which can be a film or foil) and the intermediate film can be deterministically defined by placing both on the same machine part. Alternatively, the distance can be controlled by using a mechanical, precisely defined foil or two rollers adjacent to each other. Furthermore, the distance can be controlled by coupling both together in one unit using a plane consisting of three actuators at the corners of a support unit that allows both translational and rotational movement for each substrate.

[0063] To increase the jetting arrangement and resolution during printing, an imaging system can be added to monitor the dimensions and placement of the dots printed on the intermediate substrate and on the final substrate. For this purpose, one or more imaging systems can be added to monitor the intermediate substrate as well as the final substrate. The imaging system for the intermediate substrate can monitor the dot size on the intermediate substrate plane and / or the dot height at an angle perpendicular to the intermediate substrate plane using a CCD, a microscope, or a 3D microscope and computer software. This monitoring can also be performed in front of and / or behind the second printing unit that serves to transfer the material to the final substrate. The same imaging system can be used to monitor the material on the final substrate from above and / or from the side. Various image processing solutions are aimed at increasing the success rate of placement, reducing the need for reprocessing, and resulting in highly reliable and reproducible results.

[0064] Although not shown in detail, it should be understood that the various components of the printing system described herein operate under the control of one or more controllers, which are preferably processor-based controllers that operate in accordance with instructions of machine-executable instructions stored on a tangible machine-readable medium. Such a controller can include a microprocessor and a memory communicatively connected to each other by a bus or other communication mechanism for transmitting information. The memory can include a dynamic memory such as a random access memory (RAM) or other dynamic storage device, as well as a program storage memory such as a read-only memory (ROM) or other static storage device, each connected to the bus to provide and store information and instructions executed by the microprocessor. Also, the dynamic memory can be used to store temporary variables or other intermediate information during the execution of instructions by the microprocessor. Alternatively, or in addition to this, a storage device such as a solid-state memory, magnetic disk, or optical disk can be provided and connected to the bus to store information and instructions. The controller can also include various input devices, including a display for displaying information to the user as part of the user interface for the printing system, as well as a cursor control device such as an alphanumeric keyboard, a mouse, and / or a trackpad. Further, one or more communication interfaces can be included to provide two-way data communication with the printing system. For example, such communication can be provided using a network interface including a wired and / or wireless modem.

[0065] Next, in various embodiments, the present invention provides the following:

[0066] 1. A system and method for enabling high-resolution and high-speed printing of a viscous material, the system and method including two printing units and an intermediate substrate for transferring the viscous material between the two printing units.

[0067] 2. A system or method including a first printing unit that optionally incorporates a coating unit and prints a material onto an intermediate substrate, and a second printing unit that receives the intermediate substrate and prints a material onto a final substrate therefrom.

[0068] 3. The system or method according to embodiment 2, wherein the first printing unit includes any coating system configured to produce a uniform layer of material on a donor substrate.

[0069] 4. The system or method according to any one of embodiments 2 or 3, wherein the donor substrate is a flexible substrate.

[0070] 5. The coating system is (a) a syringe of material and an air or mechanical pump that drives the material onto the donor substrate, after which the material is conveyed towards a clearly defined gap between rollers or a knife and a uniform layer of material with a thickness defined by the gap is produced; (b) a screen printing module that coats the material onto a film screen or stencil with clearly defined holes and uses a blade or squeegee to transfer the material to the donor substrate in a soft or hard engagement; (c) a dispenser or inkjet head that prints the material onto the donor substrate; (d) a gravure or microgravure system that coats the donor substrate with a highly uniform layer of material; (e) a slot die system that coats the donor substrate with a highly uniform layer; or (f) a roller coating system that coats the donor substrate with a highly uniform layer, the system or method according to any one of embodiments 2 to 4.

[0071] 6. The system or method according to any one of embodiments 2 to 5, including a coating system within a closed compartment with a controlled environment to extend the pot life of the material.

[0072] 7. The coating system according to any one of embodiments 2-6, which accommodates two or more materials, creates the possibility of printing a plurality of materials on an intermediate substrate in a controlled order, and enables printing of two or more materials on a final substrate.

[0073] 8. The intermediate substrate is translatable in both directions through the coating system in a controlled manner, for example by widening the gap between coater rollers, thereby enabling recoating the same area of the intermediate substrate with material without contamination of the rollers and realizing waste reduction. The system or method according to any one of embodiments 2-7.

[0074] 9. The material is (a) solder paste or other metal paste used in printed electronics, (b) metal paste or ceramic paste, (c) high-viscosity material, (d) wax material, (e) polymer material or a mixture of polymer material and monomer material, (f) sensitive low-viscosity material, (g) curable by UV light or heating, and / or (h) capable of drying. The system or method according to any one of embodiments 2-8.

[0075] 10. The first printing unit includes (a) a laser-based system that houses a high-frequency laser enabling ejection of material from a donor substrate to an intermediate substrate, (b) an inkjet head system configured to eject material directly onto the intermediate substrate, (c) a dispenser head system that prints material directly onto the intermediate substrate, (d) an offset printing press module, a gravure printing module, or other printing module that prints material directly onto the intermediate substrate, or (e) a screen printing module that coats material on a film screen or stencil with clearly defined holes and transfers it to the intermediate substrate. The system or method according to any one of embodiments 2-9.

[0076] 11. The first printing unit is a laser-assisted deposition / laser dispensing system rotated 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which it is located. The system or method according to any one of embodiments 2-10.

[0077] 12. A system or method according to any of embodiments 2-11, wherein a blade or squeegee is used to transfer material to an intermediate substrate in a soft or hard engagement to directly produce an array of dots on the intermediate substrate.

[0078] 13. A system or method according to any of embodiments 2-11, including a gap control unit configured to maintain a clearly defined gap between the donor substrate and the intermediate substrate.

[0079] 14. A system or method according to any of embodiments 2-13, wherein the gap control unit comprises: (a) a plane consisting of three actuators enabling both translation and rotation; (b) a plane consisting of three actuators at the corners of both the donor substrate and the intermediate substrate enabling both translation and rotation of both the donor substrate and the intermediate substrate; (c) a fixed support below the intermediate substrate; or (d) a transparent solid substrate as the intermediate substrate.

[0080] 15. A system or method according to any of embodiments 2-14, wherein the planes of the donor substrate and the intermediate substrate are independent of or overlapping with each other.

[0081] 16. A system or method according to any of embodiments 2-15, wherein the intermediate substrate is: (a) a continuous transparent film substrate; (b) a transparent film substrate coated by a metal layer or by metal and dielectric layers; (c) a transparent solid substrate; (e) a continuous film substrate capable of delivering the material printed by the first printing unit to the second printing unit by rolling; or (f) a transparent solid substrate capable of delivering the material printed by the first printing unit to the second printing unit by a robot arm with optional direction changes.

[0082] 17. A system or method according to any of embodiments 2-16, wherein the intermediate substrate after printing by the first printing unit is moved towards the second printing unit by a motor.

[0083] 18. The system or method according to any one of Embodiments 2 to 17, wherein while the intermediate substrate moves from the first printing unit to the second printing unit, the material is cured with UV light or dried with a heater and / or processed by an imaging system.

[0084] 18. The system or method according to any one of Embodiments 2 to 17, wherein the imaging system includes (a) a microscope or CCD that photographs the printed dots of the material on the intermediate substrate and measures the dots two-dimensionally, (b) a 3D microscope that photographs the printed dots of the material on the intermediate substrate and measures the dots three-dimensionally, or (c) two microscopes or CCDs arranged such that one photographs the printed dots of the material on the intermediate substrate and measures them two-dimensionally, and the other measures the dots in a direction orthogonal to the two-dimension.

[0085] 19. The system or method according to any one of Embodiments 2 to 18, wherein the data collected by the imaging system is transferred to the second printing unit so as to accurately deposit the dots of the material on the final substrate.

[0086] 20. The system or method according to any one of Embodiments 2 to 19, wherein the imaging system includes components positioned in front of and / or behind the second printing unit along the movement path of the material on the intermediate substrate.

[0087] 21. The system or method according to any one of Embodiments 2 to 20, wherein the imaging system is configured to image the intermediate substrate, the final substrate, or both.

[0088] 22. The system or method according to any one of Embodiments 2 to 21, wherein at least a part of the imaging system located in the second printing unit includes a mirror arranged to enable imaging of the surface of the intermediate substrate or simultaneous imaging of the dot dimensions of the material and the target area of the final substrate by using the main laser channel of the second printing unit.

[0089] 23. The system or method according to any one of Embodiments 2 to 22, wherein the second printing unit includes: (a) a laser-based system that houses a high-frequency laser capable of ejecting material dots from an intermediate substrate to a final substrate; (b) a laser jet ejection system; (c) a laser jet ejection system equipped with a 2D array scanning laser; (d) a laser jet ejection system rotated 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which it is located; and / or (e) a deposition position where the intermediate substrate directly engages with the final substrate.

[0090] 24. The system or method according to any one of Embodiments 2 to 23, wherein after printing the material on the final substrate with the second printing unit, the printed final substrate is cured with UV light or dried with a heater.

[0091] 25. After printing the material on the intermediate substrate with the first printing unit, the printed intermediate substrate is cured with UV light or dried with a heater and returned to the first printing unit, and a second (or additional) layer of a second material, which may be different from the material, is printed. The system or method according to any one of Embodiments 2 to 23 is used.

Explanation of Signs

[0092] 22 Coating System 26 Uniform Layer of Material to be Printed 28 Donor Substrate 32 First Printing Unit 36 Intermediate Substrate 38 PCB Substrate 40 Dot Array of Material to be Printed 44 Second Printing Unit 48 In-line Inspection Unit (Inspection 2) 50 Imaging System 60 System Configured According to the Present Invention 62 Material 64 Syringe 66 Roller or Gear 70 Clearly Defined Gap 72 Coater (Roller or Knife) 74 Laser Module 1 76 Laser beam 78 Roller or gear 80 3D imaging component (3D inspection) 82 2D imaging component (Inspection 1) 84 Laser module 2 86 Target area 88 Mirror 90 2D stage

Claims

1. A system (20a, 20b, 60, 92, 110, 120), comprising: A first printing unit (32) configured to print individual dot-shaped portions (40) of a material (62) on an intermediate substrate (36); A second printing unit (44) configured to receive the intermediate substrate (36) on which the dot-shaped portions (40) of the material (62) have been printed and transfer the dot-shaped portions (40) of the material (62) from the intermediate substrate (36) to a final substrate (38); Comprising: The first printing unit (32) includes a coating system (22) configured to generate a uniform layer (26) of the material (62) on a donor substrate (28); The coating system (22) is: (a) A syringe (64) of the material (62) and an air or mechanical pump arranged to drive the material onto the donor substrate (28), the coating system (22) further transporting and passing a donor substrate (28) with the material (62) through a first gap (70) between rollers or a knife (72) to form a uniform layer (26) of the material (62) having a thickness defined by the first gap (70) on the donor substrate (28), the syringe (64) and the air or mechanical pump; (b) A gravure or microgravure system configured to coat the donor substrate (28) with the uniform layer (26) of the material (62); (c) A slot die system configured to coat the donor substrate (28) with the uniform layer (26) of the material (62); Or (d) A roller coating system configured to coat the donor substrate (28) with the uniform layer (26) of the material (62); Including: The first printing unit (32) is further configured to transfer the material (62) of the individual dot-shaped portions (40) from the donor substrate (28) onto the intermediate substrate (36); Either or both of the first printing unit (32) and / or the second printing unit (44) is a laser-assisted deposition / laser dispensing system rotated 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which the first printing unit (32) and / or the second printing unit (44) is located; A system (20a, 20b, 60, 92, 110, 120), characterized in that.

2. The coating system (22) is the system (20a, 20b, 60, 92, 110, 120) according to claim 1, which is confined in a controlled environment (34).

3. The coating system (22) is the system (20a, 20b, 60, 92, 110, 120) according to claim 1 or 2, which is configured to apply two or more materials to the intermediate substrate (36) in a plurality of printing procedures.

4. The material (62) includes solder paste or other metal paste used in printed electronics, metal paste, ceramic paste, high-viscosity material, wax material, polymer material or a mixture of polymer and monomer materials, sensitive low-viscosity material, ultraviolet (UV) light or a material curable by heating, or a dryable material. The system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 3.

5. Either or both of the first printing unit (32) and / or the second printing unit (44) includes a laser-based system including a high-frequency laser configured to eject dot-shaped portions (40) of the material (62) from one substrate to another substrate. The system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 4.

6. The first printing unit (32) is the system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 5, which is configured to maintain a second gap (112) between the donor substrate (28) and the intermediate substrate (36).

7. The intermediate substrate (36) is a continuous film substrate, and the system (20a, 20b, 60, 92, 110, 120) includes a roller that delivers dot-shaped portions (40) of the material (62) printed on the intermediate substrate (36) by the first printing unit (32) to the second printing unit (44). The system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 6.

8. The intermediate substrate (36) is a transparent solid substrate (124), and the system (20a, 20b, 60, 92, 110, 120) includes a robotic arm for delivering the dot-shaped portions (40) of the material (62) printed on the intermediate substrate (36) by the first printing unit (32) to the second printing unit (44), the system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 6.

9. The system (20a, 20b, 60, 92, 110, 120) further comprises ultraviolet (UV) light (116) and / or a heater (116) arranged to (i) cure the dot-shaped portions (40) of the material (62) printed on the intermediate substrate (36) during movement of the intermediate substrate (36) from the first printing unit (32) to the second printing unit (44), (ii) cure the final substrate (38) after transferring the dot-shaped portions (40) of the material (62) to the final substrate (38), or (iii) do both, the system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 8.

10. The system (20a, 20b, 60, 92, 110, 120) further comprises one or more imaging systems (50) arranged to image (i) the dot-shaped portions (40) of the material (62) printed on the intermediate substrate (36) during movement of the intermediate substrate (36) from the first printing unit (32) to the second printing unit (44), (ii) the dot-shaped portions (40) of the material (62) after the dot-shaped portions (40) of the material (62) have been transferred to the final substrate (38), or (iii) both, the system (20a, 20b, 60, 92, 110, 120) according to any one of claims 1 to 9.

11. At least one of the imaging systems (50) is configured to (i) measure, in two or three dimensions, the dot-like portions (40) of the material (62) printed on the intermediate substrate (36) while the intermediate substrate (36) moves from the first printing unit (32) to the second printing unit (44), and (ii) transfer data collected by the measurement to the second printing unit (44) for use when transferring the dot-like portions (40) of the material (62) onto the final substrate (38), the system (20a, 20b, 60, 92, 110, 120) according to claim 10.

12. Printing, by the first printing unit (32), individual dot-like portions (40) of the material (62) onto the intermediate substrate (36); Transferring, by the second printing unit (44) configured to receive the intermediate substrate (36) having the dot-like portions (40) of the material (62) printed thereon, the dot-like portions (40) of the material (62) onto the final substrate (38); A method comprising: The first printing unit (32) includes a coating system (22) that generates a uniform layer (26) of the material (62) on a donor substrate (28); The coating system (22) (a) a syringe (64) for the material (62) and an air or mechanical pump arranged to drive the material onto the donor substrate (28), the coating system (22) further conveying the donor substrate (28) provided with the material (62) past a first gap (70) between rollers or a knife (72) and generating a uniform layer (26) of the material (62) having a thickness defined by the first gap (70) on the donor substrate (28), the syringe (64) and the air or mechanical pump; (b) a gravure or microgravure system configured to coat the donor substrate (28) with the uniform layer (26) of the material (62); (c) a slot die system configured to coat the donor substrate (28) with the uniform layer (26) of the material (62); or (d) a roller coating system configured to coat the donor substrate (28) with the uniform layer (26) of the material (62); comprising The first printing unit (32) transfers the material (62) of the individual dot-shaped portions (40) from the donor substrate (28) onto the intermediate substrate (36), The method, wherein either or both of the first printing unit (32) and / or the second printing unit (44) is a laser-assisted deposition / laser dispensing system rotated 0 to 90 degrees or 90 to 180 degrees from the main axis of the gravitational field in which the first printing unit (32) and / or the second printing unit (44) is located.

13. The method according to claim 12, wherein the coating system (22) applies two or more materials onto the intermediate substrate (36) in a plurality of printing steps.

14. The dot-shaped portion (40) of the material (62) printed on the intermediate substrate (36), the final substrate (38) after the dot-shaped portion (40) of the material (62) has been transferred, or both thereof, are (i) cured using ultraviolet (UV) light and / or heat, (ii) imaged using one or more imaging systems (50), or (iii) both of these are carried out, according to the method of claim 12 or 13.

Images