Abstract: There is provided a laser drilling method that prevents hanging, expansion, or crinkles of copper foil caused when an ultraviolet laser beam that requires no surface roughening is used for a thin double-sided copper-clad film. The drilling method of the copper-clad film comprises the steps of: using an ultraviolet laser as a laser beam; drilling after bonding a resin film to the backside of the film which is the opposite side to the laser-beam-incidence; and delaminating the resin film on the backside after drilling. The resin film bonded to the backside prevents the copper foil from hanging, thus allowing the laser beam to be efficiently applied to the copper foil, and allowing the copper foil to be completely removed by ablation. In the case of a blind hole, the resin film bonded to the backside prevents expansion of the copper foil. Crinkles can be also prevented.

Abstract: The principal surface of a substrate made of group III-V compound semiconductor is about (100) plane. A light emitting lamination structure is disposed on the principal surface. The light emitting lamination structure includes a quantum well layer made of group III-V mixed crystal semiconductor containing In, a pair of carrier confinement layers made of semiconductor material having a band gap wider than the quantum well layer and sandwiching the quantum well layer, and a pair of clad layers made of semiconductor material having a band gap wider than the carrier confinement layers and sandwiching the quantum well layer and the carrier confinement layers. A difference of 100 meV or larger exists between an energy level of the carrier confinement layers at a conduction band lower end and a ground level of an electron in the quantum well layer.

Abstract: A positive type photosensitive resin composition which can be developed by an aqueous alkaline solution and which is excellent in the developability and the adhesion to a substrate, is presented.

Abstract: An improved method and apparatus for drilling blind via holes to connect between upper conductive layers and lower conductive layers of printed wiring boards with laser lights. The resin layer contacting the targeted conductive layer is drilled to remain the residual layer with laser lights, and the residual layer is removed with a UV laser beam whose energy density is lower than the decomposition energy threshold of the conductive layer and higher than that of the resin layer. The apparatus for this drilling has at least two laser paths. The spatial energy distributions are made top-hat-shaped with beam homogenizer units in the paths, and the diameters and the energy densities are adjusted independently.

Abstract: A light diffusion sheet receives light fluxes radiated from a light radiating element at a first plane of the light diffusion sheet and scatters or diffracts the received light fluxes, and radiates the scattered or diffracted light from an opposite second plane. A light distributing member distributes the light radiated from the second plane of the light diffusion sheet along some direction. A light radiating device is provided which has a relatively large light beam spot.

Abstract: A polyimide precursor having a repeating unit represented by the following general formula (1), wherein R1 contains a bivalent organic group constituting a diamine having a hexafluoropropylidene group in its molecule represented by the following general formula (2), and the reduced viscosity is from 0.05 to 5.0 dl/g (in N-methylpyrrolidone at a temperature of 30° C., concentration: 0.5 g/dl), and a polyimide obtained by imidizing said precursor: (wherein R1 is a bivalent organic group constituting a diamine, A is a hydrogen atom, a linear alkyl group including a methyl group, or a trifluoromethyl group, and n is the number of a substituent on an aromatic ring and an integer of from 1 to 4).

Abstract: A snowmobile comprises a seat having a soft cushion layer, a more firm boundary layer, and a rigid support structure. Passages are provided between the soft cushion layer and a chamber such that air can be exchanged from within the seat and the chamber depending upon whether the operator is seated on the seat or standing above the seat. When an operator sits on the seat, air is forced out of the seat cushion material and into the chamber. When the operator stands and the seat cushion rebounds, air is provided to the seat from the chamber. The snowmobile also includes a lit trunk. The trunk is lit by a light bulb used for a rear tail light assembly. The light bulb is secured in a mounting plate that is formed of a translucent material that provides a window into the trunk. The light bulb can have an integrally formed socket, which can be translucent as well, to increase the amount of light transmitted into the trunk. The trunk preferably is not the chamber that communicates with the seat.

Abstract: The present invention is an improved method and apparatus for drilling blind via holes to connect between upper conductive layers and lower conductive layers of printed wiring boards with laser lights. The resin layer contacting the targeted conductive layer is dilled to remain the residual layer with laser lights, and the residual layer is removed with a UV laser beam whose energy density is lower than the decomposition energy threshold of the conductive layer and higher than that of the resin layer. The apparatus for this drilling has at least two laser paths. The spatial energy distributions are made top-hat-shaped with beam homogenizer units in the paths, and the diameters and the energy densities are adjusted independently. Moreover, the paths are aligned to a common axis near the surface of a substrate for shortening the processing time.

Abstract: A light diffusion sheet receives light fluxes radiated from a light radiating element at a first plane of the light diffusion sheet and scatters or diffracts the received light fluxes, and radiates the scattered or diffracted light from an opposite second plane. A light distributing member distributes the light radiated from the second plane of the light diffusion sheet along some direction. A light radiating device is provided which has a relatively large light beam spot.

Abstract: A snowmobile comprises a seat having a soft cushion layer, a more firm boundary layer, and a rigid support structure. Passages are provided between the soft cushion layer and a chamber such that air can be exchanged from within the seat and the chamber depending upon whether the operator is seated on the seat or standing above the seat. When an operator sits on the seat, air is forced out of the seat cushion material and into the chamber. When the operator stands and the seat cushion rebounds, air is provided to the seat from the chamber. The snowmobile also includes a lit trunk. The trunk is lit by a light bulb used for a rear tail light assembly. The light bulb is secured in a mounting plate that is formed of a translucent material that provides a window into the trunk. The light bulb can have an integrally formed socket, which can be translucent as well, to increase the amount of light transmitted into the trunk. The trunk preferably is not the chamber that communicates with the seat.

Abstract: Objects of the present invention are to provide colored coating compositions which can form easily a colored glass gel coating film being excellent in water resistance, boiling water resistance, alkali resistance, weather resistance, etc. at low temperatures on the outer surface of glass products, metal products, etc. and to provide colored coating compositions with which colored bottles having no haze can be obtained even if the bottles are coated in a high-humidity environment. The colored coating compositions according to the present invention comprise a sol-gel liquid obtained by polycondensation of phenyltrialkoxysilane or an oligomer thereof, acryl polyol, polyester polyol, polyether polyol and/or lower alkyl polyol (or the acryl polyol, the polyester polyol and/or the polyether polyol and a polyisocyanate resin), and an organic coloring agent.