A reel-to-reel method of creating pads on a layer of metal sheet or circuitry pattern on the fly. The method includes placing a sintering paste in the intended spots for pads followed by irradiation of the sintering paste by a laser.

A method of layering a layer of circuitry pattern to another layer of circuitry pattern during the manufacturing of a multilayer flexible printed circuit in a reel-to-reel machine. The method includes feeding both layers of circuitry pattern reel-to-reel into the machine, placing a layer of dielectric sheet material on the fly between the two layers of circuitry patterns reel-to-reel, followed by simultaneously passing the two layers of circuitry pattern and the dielectric sheet material under a laser scanner in the reel-to-reel machine to irradiate a laser beam on a layer of circuitry pattern to weld the two layers of circuitry patterns together.

The head (1) for the three-dimensional printing of molten metal comprises a hollow body (2) comprising: a first chamber (3) adapted to contain a molten metal (4) in which a dispensing opening (5) is formed for the dispensing of the molten metal (4); a second chamber (9) adapted to contain an operating fluid (10) and connected to pressure variation means (11) adapted to define a pressure difference between the first chamber (3) and the second chamber (9); and a dispensing assembly (12, 13) comprising a flexible laminar element (12) separating the first chamber (3) and the second chamber (9), the laminar element (12) being deformable by means of a pressure variation in the second chamber (9) and the deformation of the laminar element (12) determining the outflow of the molten metal (4) from the dispensing opening (5).

A reel-to-reel method to laser-ablate a circuitry pattern on the fly in a reel-to-reel machine as part of a process to fabricate a printed flexible circuit. The laser ablation method includes using an appropriate laser to irradiate a metal sheet thus ablating the edges of an intended circuitry pattern. Slugs can be removed by using an optional sacrificial liner, and the slugs can be optionally ablated into smaller parts first. The laser ablation can also include an optional method of creating tie bars to provide structural support to the web of circuitry patterns.

A reel-to-reel machine to fabricate a printed flexible circuit on the fly, the machine has a plurality of reels, a laser scanner to ablate a metal foil, a source of UV light or heat to curing an adhesive in a coverlay, another source of UV light or heat to debond a sacrificial liner on the fly. There is a depositor to deposit a sintering paste on the fly onto a predetermined spot for a pad on the metal foil. Removal of slugs are also possible on the fly.

A reel-to-reel method of creating pads on a layer of metal sheet or circuitry pattern on the fly. The method includes placing a sintering paste in the intended spots for pads followed by irradiation of the sintering paste by a laser.

A reel-to-reel lamination method to laminate a metal foil or circuitry pattern on the fly. The method includes applying a UV laminate or thermoset laminate to the metal foil or the circuitry pattern reel to reel, and then apply a UV radiation or heat to the laminate. There can be an optional enclosure connected to a suction source. The enclosure can have a flexible bladder that physically compresses the laminate.

A method of layering a layer of circuitry pattern to another layer of circuitry pattern during the manufacturing of a multilayer flexible printed circuit in a reel-to-reel machine. The method includes feeding both layers of circuitry pattern reel-to-reel into the machine, placing a layer of dielectric sheet material on the fly between the two layers of circuitry patterns reel-to-reel, followed by simultaneously passing the two layers of circuitry pattern and the dielectric sheet material under a laser scanner in the reel-to-reel machine to irradiate a laser beam on a layer of circuitry pattern to weld the two layers of circuitry patterns together.

Manufacturing technology to fabricate liquid metal-based soft and flexible electronics (sensors, antennas, etc.) in a high-throughput fashion, with fabrication rates that may approach that of the traditional integrated circuit components and circuits, are described. The technique allows creation of liquid-metal-only circuits, as well as seamless integration of solid IC chips into the circuits, in which liquid metal traces are used as flexible interconnects and/or as other circuit elements. The process may be applied at the wafer scale and may be integrated into the traditional microelectronics fabrication processes. Many sensors, antennas, and other circuit elements may be directly created using liquid metal, and when combined with the IC chips, a broad range of electronic functionality may be provided in a flexible, soft circuit that can be conformable, wearable.

A method of direct printing or writing of a metallic material involves depositing, with a printing device or writing device, an ink comprising of at least undercooled liquid metallic particles dispersed in a carrier fluid. The ink is deposited on any substrate surface to deposit the undercooled liquid metal particles thereon as one or more layers that can form a desired pattern or layered structure.