According to one aspect of the present disclosure, a cover film for a flexible printed circuit board includes: an adhesive layer; and a protective layer that is layered on a surface of the adhesive layer, wherein a lamination temperature range in which a ratio of a viscosity of the protective layer to a viscosity of the adhesive layer is five times or more is present within a temperature range of 50° C. or more and 150° C. or less.

Provided is a laminate having a good whiteness and a high infrared-shielding property. Provided are also a kit forming the above-mentioned laminate, a method for producing a laminate, and an optical sensor. The laminate includes an infrared-shielding layer and a white layer, in which the infrared-shielding layer is a layer that shields at least a part of a wavelength range at 800 to 1,500 nm, and the white layer has a value of L* of 35 to 100, a value of a* of −20 to 20, and a value of b* of −40 to 30 in a L*a*b* color coordinate system of CIE 1976.

A lighting device includes a substrate having a plurality of flat portions and a non-flat portion disposed between the flat portions, a plurality of light emitting sources disposed on the substrate, a fluorescent substrate layer covering one or more light emitting sources and converting a wavelength of a light from the light emitting source, and a connection line disposed on the substrate and electrically connecting the light emitting sources adjacent to each other between the adjacent light emitting sources. The substrate has a first end and a second end are arranged at different distance from a central axis.

Provided is a resin composition which has good solubility and photocurability, further has good alkaline-developability when containing a photo initiator and a compound containing one or more carboxyl groups, and in addition, is capable of providing a resin sheet having suppressed tackiness; and a resin sheet, multilayer printed wiring board, and semiconductor device using the same. The resin composition of the present invention contains a particular bismaleimide compound (A), and at least two maleimide compounds (B) selected from the group consisting of six kinds of particular compounds which are different from this bismaleimide compound (A).

A circuit board includes a circuit substrate, at least one metal pad, and a tin bar corresponding to each of the at least one metal pad. Each of the at least one metal pad is formed on a side of the circuit substrate and is electrically connected to the circuit substrate. A surface of the metal pad facing away from the circuit substrate is recessed toward the circuit substrate to from a recess. The tin bar is received in the recess. A method for manufacturing a circuit board is also provided.

Provided is a resin composition which has good solubility and photocurability, further has good alkaline-developability when containing a photo initiator and a compound containing one or more carboxyl groups, and in addition, is capable of providing a resin sheet having suppressed tackiness; and a resin sheet, multilayer printed wiring board, and semiconductor device using the same. The resin composition of the present invention contains a particular bismaleimide compound (A), and at least two maleimide compounds (B) selected from the group consisting of six kinds of particular compounds which are different from this bismaleimide compound (A).

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.

In order to provide (A) a photosensitive resin composition which (i) obtains an excellent tack-free property after being applied and dried, (ii) can be subjected to fine processing so as to have photosensitivity, (iii) prepares a cured film having excellent flexibility, flame retardancy, and electrical insulation reliability, and (iv) has small warpage after being cured, (B) a resin film, (C) an insulating film, and (D) an printed wiring board provided with an insulating film, the photosensitive resin composition containing at least (A) binder polymer; (B) cross-linked polymer particles, whose polymer has a urethane bond in its molecule; (C) thermosetting resin; and (D) photo-polymerization initiator is used.

A method of forming a flexible circuit, including providing a flexible flat cable with a first surface and a second surface. The first surface of the flexible flat cable is diametrically opposed to the second surface. A dispensing apparatus including a nozzle is further provided, and an extruded material is dispensed through the nozzle onto the first surface of the flexible flat cable. The extruded material is shaped into a pattern and cured onto the first surface of the flexible flat cable.

A circuit board includes an insulating layer having a protrusion on a surface, and a connection pad formed on an upper surface of the protrusion. A peripheral portion of a lower surface of the connection pad is exposed from the protrusion.