A method of producing a wired circuit board including an insulating layer and a conductive pattern, including: (1), an insulating layer having an inclination face, (2), a metal thin film provided at least on the inclination face, (3), a photoresist provided on the surface of the metal thin film, (4), a light shield portion of a photomask disposed so that a first portion, where the conductive pattern is to be provided in the photoresist, is shielded from light, and the photoresist is exposed to light through the photomask, (5), the first portion of the photoresist is removed to expose the metal thin film corresponding to the first portion, and (6), the conductive pattern is provided on the surface of the metal thin film exposed from the photoresist.

Techniques for low- or zero-misaligned vias are disclosed. In one embodiment, a high-photosensitivity, medium-photosensitivity, and low-photosensitivity layer are applied to a substrate and exposed at the same time with use of a multi-tone mask. After being developed, one layer forms a mold for a first via, one layer forms a mold for a conductive trace and a second via, and one layer forms an overhang over the position for the second via. The molds formed by the photosensitive layers are filled with copper and then etched. The overhang prevents the top of the copper infill below the overhang region from being etched. As such, the region under the overhang forms a pillar or column after etching, which can be used as a via. Other embodiments are disclosed.

A non-reactive photosensitive resin composition storable at room temperature comprises a carboxylic acid-modified bisphenol epoxy (meth)acrylate, a photosensitive monomer, a photosensitive prepolymer, a photo-initiator, and a coloring agent. Each of the carboxylic acid-modified bisphenol epoxy (meth)acrylate, photosensitive monomer, and photosensitive prepolymer has a plurality of carbon-carbon double bonds, so that the carboxylic acid-modified bisphenol epoxy (meth)acrylate, photosensitive monomer and photosensitive prepolymer may be polymerized to form a dense cross-linking network structure when the photosensitive resin composition is exposed to ultraviolet radiation. A film and a printed circuit board using the photosensitive resin composition are also provided.

A method for forming a structure for a radio frequency identification device includes dispensing a photosensitive compound onto a substrate. Subsequently, first portions of the photosensitive compound are exposed to a light pattern from a light source, while second portions of the photosensitive compound remain unexposed to the light source. Exposing the photosensitive compound to light reduces the photosensitive compound to a metal layer. The unexposed second portions of the photosensitive compound may be rinsed away to leave the metal layer. Processing may continue to form an RFID circuit from the metal layer, and a completed RFID transponder comprising the RFID circuit.

A method of producing a wired circuit board including an insulating layer and a conductive pattern, including: (1), an insulating layer having an inclination face, (2), a metal thin film provided at least on the inclination face, (3), a photoresist provided on the surface of the metal thin film, (4), a light shield portion of a photomask disposed so that a first portion, where the conductive pattern is to be provided in the photoresist, is shielded from light, and the photoresist is exposed to light through the photomask, (5), the first portion of the photoresist is removed to expose the metal thin film corresponding to the first portion, and (6), the conductive pattern is provided on the surface of the metal thin film exposed from the photoresist.

A photosensitive element comprising a support film, a barrier layer, and a photosensitive layer in this order, wherein the barrier layer contains a water-soluble resin and an ultraviolet absorber.

A thermally expandable material includes microcapsules and a binder having a conducting property, each microcapsule including a shell having an insulating property, and a thermally expandable component contained in the shell and having a property of expanding by heating, the shell deforming due to expansion of the thermally expandable component to come in contact with another capsule and have an insulating state with the other capsule.

A microcapsule includes a shell including a conducting component, and a thermally expandable component contained in the shell and having a property of expanding by heating. The shell is deformable in accordance with expansion of the thermally expandable component when the thermally expandable component is heated.

The present disclosure relates to an apparatus for manufacturing flexible printed circuit board (FPCB) and method for manufacturing the FPCB, having no limitations of length of a circuit pattern being formed on a base film.

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.