A flexible printed circuit board includes a base layer and a pattern line. At least one communication hole penetrating opposite surfaces of the base layer. The pattern line includes two conductive circuit layers formed on the opposite surfaces of the base layer. At least one conductive pole are formed in the at least one communication hole and electrically connects the two conductive circuit layers. A gap being is formed between the conductive pole and the base layer.

A novel compound which absorbs long-wavelength active energy rays and generates with high-efficiency radicals and strong bases, and which has excellent reaction efficiency in a base generating chain reaction; a photopolymerization initiator which contains said compound; and a photosensitive resin composition which contains said photopolymerization initiator are provided, where the novel compound is represented by formula (1), where, in formula (1), R.sub.1, R.sub.2, R.sub.3, R.sub.5 and R.sub.6 independently represent a hydroxyl group, an alkoxy group, or an organic group other than those substituents, the R.sub.4's independently represent an organic group including a thioether bond, ‘A’ represents a substituent represented by formula (1-1) or (1-2), where, in formula (1-1), R.sub.7 and R.sub.8 independently represent a hydrogen atom, an alkyl group or a heterocyclic group, and where, in formula (1-2), R.sub.9 and R.sub.10 independently represent an amino group or a substituted amino group.

The invention provides an inkjet method for producing a solder mask in the manufacture of a Printed Circuit Board. By using a solder mask inkjet ink containing at least one photoinitiator, at least one free radical polymerizable compound and at least one mercapto functionalized carboxylic acid as adhesion promoter, a high quality solder mask withstanding the high thermal stress during the soldering process while maintaining excellent physical properties, may be produced.

Provided is a photosensitive element including a support film, and a photosensitive layer provided on the support film and formed from a photosensitive resin composition, in which the surface roughness of the surface of the support film that is in contact with the photosensitive layer is 200 to 4,000 nm.

An inkjet method for producing a solder mask in the manufacture of a Printed Circuit Board uses a solder mask inkjet ink containing a polymerizable adhesion promoter and a phenolic compound including at least two phenolic groups. A high quality solder mask withstanding the high thermal stress during the soldering process while maintaining excellent physical properties is produced.

To provide a negative-type photosensitive resin composition that is highly sensitive and capable of formation of a low-taper pattern shape and that is capable of providing a cured film that is excellent in heat resistance. A negative-type photosensitive resin composition contains an (A) alkali-soluble resin, a (B) radical polymerizable compound, and a (C) photo initiator, the negative-type photosensitive resin composition being characterized in that the (A) alkali-soluble resin contains one or more species of resins selected from a (A-1) polyimide, a (A-2) polybenzoxazole, a (A-3) polyimide precursor, a (A-4) polybenzoxazole precursor, a (A-5) polysiloxane, and a (A-6) cardo based resin, and that the (B) radical polymerizable compound contains a compound having five ethylenic unsaturated bond groups in a (B-1) molecule, in an amount within the range of 51 to 99 mass %.

A bulb-type light source includes a globe transmitting a light and at least one light emitting device filament disposed in the globe. The light emitting device filament includes a substrate including n (n is a natural number equal to or greater than 2) flat portions and n−1 bendable portions disposed between the flat portions, a plurality of light emitting device chips disposed on the flat portions, a fluorescent substance layer covering each light emitting device chip and converting a wavelength of a light from each light emitting device chip, and a connection line disposed on the flat portions and electrically connecting the light emitting device chips adjacent to each other between the adjacent light emitting device chips.

A flexible printed circuit board (PCB) may have one or more coin cell batteries mounted thereto such that the flexibility of the flexible PCB is maintained. The flexible PCB has one or more battery contact pads fabricated thereon. Each battery contact pad includes a pattern of metalized vias each extending from a top surface to a bottom surface of the flexible PCB. A coin cell battery may be positioned over or under the battery contact pad. Conductive light curable epoxy is applied to and in each metalized via to contact and adhere to the coin cell battery to form a conductive path from the battery through the battery contact pad to printed conductors on the flexible PCB. Methods of mounting one or more coin cell batteries to a flexible PCB are also provided, as are other aspects.

A display device and a method of manufacturing a display device are provided. A display device may include: a display panel including a first area, a second area spaced apart from the first area, and a bending area between the first area and the second area; a driving circuit chip on the second area of the display panel; a flexible printed circuit board on the second area of the display panel and spaced apart from the driving circuit chip; and a bending protection layer including a first pre-formed bending protection layer covering a portion of the flexible printed circuit board, and a first post-formed bending protection layer covering the bending area of the display panel.

A machine can include a UV zone that includes LED-based UV radiation sources; and a controller that controls conditions within the machine to regulate temperature of the LED-based UV radiation sources.