Flexible electrical devices comprising electrode layers on softening polymers and methods of manufacturing such devices, including lift-off processes for forming electrodes on softening polymers, processes for forming devices with a patterned double softening polymer layer, and solder reflow processes for forming electrical contacts on softening polymers.

A method of fabricating a transparent conductor includes the following steps. The first step is drawing a substrate from a first reel to a second reel along a travelling path, and along the travelling path. Next step is forming a metal nanowire dispersion layer on the substrate and then drying the metal nanowire dispersion layer to form a metal nanowire network layer. Next step is forming a matrix layer on the metal nanowire network layer so as to form a conductive layer of the metal nanowire network layer embedded in the matrix layer.

There is provided a copper foil provided with a carrier exhibiting a high peeling resistance against the developer in the photoresist developing process and achieving high stability of mechanical peel strength of the carrier. The copper foil provided with a carrier comprises a carrier; an interlayer disposed on the carrier, the interlayer having a first surface adjacent to the carrier and containing 1.0 atom % or more of at least one metal selected from the group consisting of Ti, Cr, Mo, Mn, W and Ni and a second surface remote from the carrier and containing 30 atom % or more of Cu; a release layer disposed on the interlayer; and an extremely-thin copper layer disposed on the release layer.

Multilayer articles that include electrical circuits are prepared by the adhesive transfer of electrical circuit elements to the surface of an adhesive. A number of different methodologies are used, with all of the methodologies including the use of simple layers of circuit-forming material on a releasing substrate and structuring to generate circuit elements which can be transferred to an adhesive surface. In some methodologies, a structured releasing substrate is used to selectively transfer circuit-forming material, either from protrusions on the releasing substrate or from depressions on the releasing substrate. In other methodologies, an unstructured releasing substrate is used and either embossed to form a structured releasing substrate or contacted with a structured adhesive layer to selectively transfer circuit-forming material.

Disclosed is a cavity forming method for a printed circuit board. The method includes: stacking a plurality of substrates to form a stacked structure, each substrate including a prepreg and a copper clad circuit formed on a surface of the prepreg; attaching a release film to an outer surface of the stacked structure; demarcating a cavity region by forming a cutting line in the release film and the underlying prepreg; and removing the released film and the underlying prepreg inside the demarcated cavity region, thereby forming a cavity. The method is advantageous in terms of easy processing, mass production, and low manufacturing cost for printed circuit boards. Further, a cavity having an exactly same size as an actually required size can be designed for a printed circuit board, and it is possible to prevent an adhesive component from seeping out into a cavity from prepregs during formation of the cavity.

Electrically conductive patterns formed on a substrate are provided with a reduced visibility. A region of a major surface of the substrate is selectively roughened to form a roughened pattern on the major surface of the substrate. Electrically conductive traces are directly formed on the roughened region and are conformal with the roughened pattern on the major surface of the substrate.

A circuit component decal comprising a transparent sheet and an opaque circuit pattern. The transparent sheet includes opposing top and bottom surfaces and a number of edges. The opaque circuit pattern includes an electronic component footprint and a number of circuit lead paths. The electronic component footprint includes a number of contact points representing the location of leads of the electronic component. The circuit lead paths extend from the contact points to the edges of the transparent sheet. The opaque circuit pattern corresponds to only a section of a complete circuit pattern and is configured to block energy from reaching a first portion of the intermediate substrate when the transparent sheet is positioned on the intermediate substrate so as to form the section of the complete circuit pattern.

A multi-layer circuit board, successively constituted by surface sticking layer, single-layer circuit board, middle sticking layer, single-layer circuit board, surface sticking layer, said multi-layer circuit board is provided with a hole, a hole wall of said hole is formed with conductive seed layer, and partial outer surface of said surface sticking layer is formed with a circuit pattern layer of conductive seed layer, wherein said conductive seed layer comprises a ion implantation layer implanting below the hole wall of said hole and below partial outer surface of said surface sticking layer.

Methods of making metal patterns on flexible substrates are provided. Releasable solid layer is selectively formed on a patterned surface of the flexible substrate by applying a liquid solution thereon. Metal patterns on the flexible substrate can be formed by removing the releasable solid layer after metallization. In some cases, the releasable solid layer can be transferred from the patterned surface to a transfer layer where the metal patterns are formed.

There is provided a copper foil provided with a carrier exhibiting a high peeling resistance against the developer in the photoresist developing process and achieving high stability of mechanical peel strength of the carrier. The copper foil provided with a carrier comprises a carrier; an interlayer disposed on the carrier, the interlayer having a first surface adjacent to the carrier and containing 1.0 atom % or more of at least one metal selected from the group consisting of Ti, Cr, Mo, Mn, W and Ni and a second surface remote from the carrier and containing 30 atom % or more of Cu; a release layer disposed on the interlayer; and an extremely-thin copper layer disposed on the release layer.