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Embroidered Circuit Board Disclosure Number: IPCOM000248121D
Publication Date: 2016-Oct-27
Document File: 2 page(s) / 145K

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The Prior Art Database


Described is a process for using embroidery techniques to weave conductive fibers into a fiberglass cloth during the manufacturing process for printed circuit boards. By placing the wires in this manner, the process avoids the subtractive etching of copper layers and all of the chemical waste and environmental impacts that come along with it.

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Embroidered Circuit Board

Traditional PCBs are fabricated using a sequential subtractive build process. That is, cores consisting of copper and glass-impregnated resin are circuitized, then laminated together using prepreg (glass fabric impregnated with a B-staged resin) to create a multilayer board. Electrical connections between the layers are accomplished by means of plated through holes and/or vias. Cores are circuitized via a subtractive process wherein copper is etched off of the core to create individual lines/spaces. This circuitization process results in large amounts of chemical waste as well as being subject to yield detractors (i.e., misalignment of the photomask, over/under etching, etc.). Consequently, a novel approach to the manufacture of multilayer PCBs that mitigates many of these detractors is warranted.

    Glass fabric is used as the non-conductive filament and the Ag-coated copper thread is used as the conductive filament. Circuit traces are 'embroidered' into the glass fabric using a computerized knitting machine [1]. The individual, circuitized cloth is then impregnated with a traditional PCB resin and subsequently B-staged. These sheets are then assembled into a layered stack using the standard lamination processes and cured. Interconnection between the circuit traces is accomplished via standard through hole processes.

    Information on threads: "Previously, the researchers had used silver-coated polymer thread with a 0.5-mm diameter, each thread made up of 600 even finer filaments twisted together. The new threads have a 0.1-mm diameter, made with only seven filaments. Each filament is copper at the center, enameled with pure silv...