Abstract: A method for forming a photosensitive, heat-resistant resin composition film including the step of coating a base material with a varnish made up of a polyimide precursor having no photosensitivity, a photopolymerizable monomer or oligomer capable of providing a high-heat-resistant polymer upon being polymerized, and a polymerization initiator for the monomer or oligomer. The coating is exposed to a light pattern to polymerize the monomer or oligomer in a pattern. The remaining coating is selectively removed from the non-patterned areas. The patterned coating is heat treated to cure the polyimide precursor, thereby forming the film.

Abstract: A visible radiation-curable solder resist composition which comprises a resin component, a component for promoting photo-polymerization or -crosslinking, and optionally a diluent and any other additives, the resion componebt comprising a novolak resin skeleton and a polyfunctional acrylic monomer and the component for promoting photo-polymerization or -crosslinking comprising a photo-reaction initiator, a sensitizing dye and a heterocyclic compound having at least two endocyclic nitrogen atoms.

Abstract: A circuit board comprising a core material made from magnesium, a magnesium alloy, or a magnesium-based composite material, and an electric circuit formed on the core material. A process for producing the circuit board comprises the steps of (1) forming an electrodeposition-painted coating on such a core material, (2) forming a polyimide resin coating on the electrodeposition-painted coating, (3) forming a via hole extending through the resin coating to the underlying electrodeposition-painted coating, (4) etching and removing the electrodeposition-painted coating in the region exposed in the bottom of the via hole while masking the other region with the resin coating thereby extending the via hole to the core material, (5) forming a metal film on at least a free surface of the resin coating and an inner surface of the extended via hole, and (6) etching the metal film by using a photoresist mask to form a conductor layer having a predetermined pattern.

Abstract: A via hole structure for interlayer connection formed in an insulating film and a process for the formation of the same. Via holes are formed in an insulating film of a multilayer interconnected board or the like so as to have a shape such that when a metallic film for wiring is formed on the insulating film, the metal film can completely fill up the via holes. The via holes are formed by gradually increasing from the bottom toward the top of an insulating layer 8 the apertures of the via holes 7 formed in the insulating layer 8, comprised of a plurality of insulating resin film or photosensitive insulating resin film layers 2, 5, in a multilayer interconnected board comprising the insulating layer 8 laminated alternately with a wiring layer 13 comprised of an electric conductor.

Abstract: A circuit board comprising: a core material made from magnesium, a magnesium alloy, or a magnesium-based composite material, and an electric circuit formed on the core material. A process for producing the circuit board comprises the steps of (1) forming an electrodeposition-painted coating on such a core material, (2) forming a polyimide resin coating on the electrodeposition-painted coating, (3) forming a via hole extending through the resin coating to the underlying electrodeposition-painted coating, (4) etching and removing the electrodeposition-painted coating in the region exposed in the bottom of the via hole while masking the other region with the resin coating thereby extending the via hole to the core material, (5) forming a metal film on at least a free surface of the resin coating and an inner surface of the extended via hole, and (6) etching the metal film by using a photoresist mask to form a conductor layer having a predetermined pattern.

Abstract: A method of and apparatus for forming a volume type phase hologram comprising the steps of, after exposure of a holographic material comprising a polymeric matrix having a radiation active substance associated therewith to an interference pattern of radiation, dipping the pattern-wise exposed holographic material in a swelling solution consisting of a first solvent which can act as a good solvent for the polymer of the matrix and a second solvent which can act as a poor solvent for the polymer and has a higher boiling point than that of the first solvent, and then pulling the swollen holographic material up from the swelling solution, whereby uniformly developed holograms having a large size and high qualities can be easily produced by a simple production process.

Abstract: A method of and apparatus for forming a volume type phase hologram comprising the steps of, after exposure of a holographic material comprising a polymeric matrix having a radiation active substance associated therewith to an interference pattern of radiation, dipping the pattern-wise exposed holographic material in a swelling solution consisting of a first solvent which can act as a good solvent for the polymer of the matrix and a second solvent which can act as a poor solvent for the polymer and has a higher boiling point than that of the first solvent, and then pulling the swollen holographic material up from the swelling solution, whereby uniformly developed holograms having a large size and high qualities can be easily produced by a simple production process.