Abstract: There is provided a solder work material for forming solder-coated circuit boards, which is capable of preventing the malfunction of circuit that may be caused to generate by voltage noises that tend to be generated by the volumetrical expansion of the flux residue in a soldered laminated ceramic capacitor, etc. even under the environments where temperatures fluctuate widely (for example, −40° C. to +85° C.), or that may be caused to generate by voltage noises to be generated by the fluctuation of parasitic capacity between circuits which may be caused to generate due to a flux residue. There is also provided a circuit board having a residual film of flux left thereon after the deposition of the solder work material. This solder work material is formed of a solder paste composition or a resin flux-cored solder, both comprising a flux containing, as a resin component, acrylic resin for preventing the generation of voltage noises in electronic devices.

Abstract: Disclosed is a photosensitive resin composition which can be developed using a dilute aqueous alkaline solution after ultraviolet ray exposure, is excellent in pot life, capable of preventing deposits from being generated in a cured coated film, capable of widening heat control tolerance, and is excellent in sensitivity, in heat resistance, in chemical resistance and in electric insulating properties, thereby rendering the composition suitable for use as a solder resist for producing a printed wiring board. This photosensitive resin composition comprises (A) an active energy ray-curable resin having at least two ethylenic unsaturated linkages per molecule thereof, (B) at least one kind material selected from acid salts of N-substituted melamine compound and acid salts of guanamine compound, (C) a photopolymerization initiator, (D) a diluent, and (E) a thermosetting compound. There is also disclosed a printed wiring board where this photosensitive resin composition is employed.

Abstract: There is provided a lead-free solder which makes it possible to reliably and accurately perform the inspection of various kinds of defective soldering in the inspection using an image inspection apparatus after the reflow soldering. According to this lead-free solder, the delustering of the metallic luster of fillet is realized in order to minimize the probability of generating a dark portion at the area where no defective soldering is existed and instead to increase the area of whitish portion which can be generated through the irregular reflection of beam. Specifically, this invention provides a lead-free solder comprising an Sn—Ag—Cu-based lead-free solder containing a small quantity of Bi and Sb as an element which is capable of generating a delustering component for minimizing metallic luster of the fillet.

Abstract: The invention provides a water-soluble preflux that can solve problems with a soldering land array having a narrow spacing in that fused solder is likely to cause soldering bridges with defective soldering, a printed circuit board with its film formed thereon, and a surface treatment process for a metal in that circuit. The water-soluble preflux comprises given two different benzimidazoles compound and an iodine-based compound optionally with an amino acid, etc. The invention provides a printed circuit board with a film of that preflux formed thereon, and a surface treatment process for the metal in that circuit.

Abstract: A package for mounting a semiconductor device has a surface exposed to an atmosphere. The exposed surface is covered with a covering material such as a paint, a tape or a seal.

Abstract: Disclosed are a curable resin composition which is capable of forming a low dielectric interlayer insulating material wherein the attenuation of signals due to an enhancement in frequency of circuit can be hardly attenuated, a multi-layer printed wiring board or a printed wiring board each provided with a cured film thereof, and a dry film provided with a semi-cured filmy coating. This curable resin composition comprises a polyfunctional vinylbenzyl ether and a curing promotor. This curable resin composition may further comprise a photosensitive resin, a photopolymerization initiator and a diluent, thus forming a photosensitive/thermosetting resin composition.

Abstract: The invention provides an industrially efficient, low-cost, mass-production system for the process of producing fine solder powders using an in-oil atomization method wherein solder is melted in a heated dispersion medium for fine granulation. Molten solder melted in a solder melting tank and a mixture of a particle dispersion medium and a particle coalescence-preventing agent, prepared in a dispersion medium heating tank, are fed to a fine-granulation machine, in which dispersion energy is applied to obtain a dispersion of molten solder particles. The dispersion is processed in a solidifier-by-cooling to obtain a dispersion of solid solder particles, which is processed in a solid-liquid separator to separate the solid solder particles. The solid solder particles are washed and dried to obtain fine powders. The respective devices at these steps are connected together by way of piping, so that fine solder powders can continuously be produced.

Abstract: There is provided a lead-free solder which makes it possible to reliably and accurately perform the inspection of various kinds of defective soldering in the inspection using an image inspection apparatus after the reflow soldering. According to this lead-free solder, the delustering of the metallic luster of fillet is realized in order to minimize the probability of generating a dark portion at the area where no defective soldering is existed and instead to increase the area of whitish portion which can be generated through the irregular reflection of beam. Specifically, this invention provides a lead-free solder comprising an Sn—Ag—Cu-based lead-free solder containing a small quantity of Bi and Sb as an element which is capable of generating a delustering component for minimizing metallic luster of the fillet.

Abstract: The invention provides a water-soluble prefluxe that can solve problems with a soldering land array having a narrow spacing in that fused solder is likely to cause soldering bridges with defective soldering, a printed circuit board with its film formed thereon, and a surface treatment process for a metal in that circuit. The water-soluble preflus comprises given two different benzimidazoles compound and an iodine-based compound optionally with an amino acid, etc. The invention provides a printed circuit board with a film of that preflux formed thereon, and a surface treatment process for the metal in that circuit.

Abstract: Disclosed is a photosensitive resin composition which can be developed using a dilute aqueous alkaline solution after ultraviolet ray exposure, is excellent in pot life, capable of preventing deposits from being generated in a cured coated film, capable of widening heat control tolerance, and is excellent in sensitivity, in heat resistance, in chemical resistance and in electric insulating properties, thereby rendering the composition suitable for use as a solder resist for producing a printed wiring board. This photosensitive resin composition comprises (A) an active energy ray-curable resin having at least two ethylenic unsaturated linkages per molecule thereof, (B) at least one kind material selected from acid salts of N-substituted melamine compound and acid salts of guanamine compound, (C) a photopolymerization initiator, (D) a diluent, and (E) a thermosetting compound. There is also disclosed a printed wiring board where this photosensitive resin composition is employed.

Abstract: Disclosed is a photosensitive resin composition for use as a solder resist, which is free from anti-tackiness and excellent in flexibility, adhesiveness and heat resistance without other film properties being sacrificed, and can be easily designed so as to obtain properties in conformity with the end use thereof. This photosensitive resin composition comprising (A) an active energy ray-curable resin having at least two ethylenic unsaturated linkages per molecule, (B) a photopolymerization initiator, (C) a reactive diluent, and (D) a thermosetting compound; wherein said (A) comprises a resin which is obtained by a process wherein an epoxy compound is successively reacted with a unsaturated monocarboxylic acid and with a polybasic acid to form a compound, which is then allowed to react with a novolac epoxy resin to obtain the resin. There is also disclosed a printed wiring board formed using the aforementioned photosensitive resin composition.

Abstract: Disclosed is a photosensitive resin composition for use as a solder resist, which is free from anti-tackiness and excellent in flexibility, adhesiveness and heat resistance without other film properties being sacrificed, and can be easily designed so as to obtain properties in conformity with the end use thereof.

Abstract: There is provided an in-oil atomization method wherein a solder is fused and dispersed in a heated particle dispersion medium, the method being featured in that even if the quantity of the particle dispersion medium to be employed is relatively small, fine solder particles can be effectively obtained. Namely, this invention provides a method of manufacturing fine particles, wherein solder is fused in the heated particle dispersion medium to obtain a molten solder, which is then dispersed by means of an agitator to obtain molten solder particles which are subsequently cooled and solidify, the method being characterized in that the above dispersing step is performed in the presence of a particle coalescence-preventing agent. This invention also provides a fine metal particles-containing substance and a paste solder composition.

Abstract: There is provided a solder work material for forming solder-coated circuit boards, which is capable of preventing the malfunction of circuit that may be caused to generate by voltage noises that tend to be generated by the volumetrical expansion of the flux residue in a soldered laminated ceramic capacitor, etc. even under the environments where temperatures fluctuate widely (for example, −40° C. to +85° C.), or that may be caused to generate by voltage noises to be generated by the fluctuation of parasitic capacity between circuits which may be caused to generate due to a flux residue. There is also provided a circuit board having a residual film of flux left thereon after the deposition of the solder work material. This solder work material is formed of a solder paste composition or a resin flux-cored solder, both comprising a flux containing, as a resin component, acrylic resin for preventing the generation of voltage noises in electronic devices.

Abstract: The present invention provides a wireless device including: at least an antenna; and at least a conductive ground serving as a ground, through which a high frequency current flows, and the conductive ground having at least a side which is approximately one quarter wavelength of a radio wave transmitted from the antenna, the at least side of the conductive ground having a feeding point, at which the antenna is electrically connected to the conductive ground, wherein the feeding point on the side is positioned closer to one end of the side than a center position, so that the feeding point is positioned asymmetrical to the conductive ground in any directions included in a plane parallel to the conductive ground, whereby the high frequency current flowing, through the conductive ground has an asymmetrical distribution of current over the conductive ground.

Abstract: The invention provides a memory system that allows connection of a memory controller to each of plural memory modules in an equal distance. The memory system includes a memory controller, three memory modules, a single socket which the three memory modules can be inserted into and pulled out from, and a mother board on which the memory controller and the socket are mounted, etc. And, the memory controller and each of the memory modules are connected in an equal distance through the socket pins of the socket that are branched from bus wirings on the mother board. The socket is furnished with three sets of the plural socket pins in a radial form, in correspondence with each of the memory modules. The socket has two types of structures: one has three module-board contacts for one board-bus connection, and the other has one module-board contact for one board-bus connection.

Abstract: The present invention provides a bicycle equipped with an antitheft device of the type which suspends the function of the bicycle as by locking the saddle in unridable form and which requires a fewer number of operating steps for parking the bicycle. The bicycle is characterized in that it is provided with a key device for locking the saddle in the parked state, a stand locking device for locking the stand in the erected state, and a connecting rod which is adapted to be pulled up in operative connection with the turning movement of the saddle from the in-service state to the parked state and whose lower end is connected to the stand locking device. When the saddle is turned to the parked state, the connecting rod is pulled and the stand is locked by the stand locking device. When the saddle is turned to the in-service state, the connecting rod is depressed to cancel the locked state.

Abstract: The antenna for a radio equipment includes a base portion boot made of a flexible material and secured to an edge of an opening of a support hole in a radio equipment body such that it partially extends outwardly over a predetermined length from the radio equipment body. A flexible pipe is integrally coated on an outer periphery of a portion of a linear antenna element which is positioned in a through-hole of the base portion boot when the linear antenna element is at its retracted position in the radio equipment body.

Abstract: In order to achieve two-way communications at two different frequencies, an impedance matching circuit is coupled to an antenna. The circuit includes a first inductor which is directly coupled to the antenna. The first inductor induces antenna input impedance to be capacitive at a first resonant frequency and induces the antenna input impedance to be inductive at a second resonant frequency. The first resonant frequency is lower than the second resonant frequency. Further, a first capacitor is coupled to the first inductor. By providing the first capacitor, a reactance component at the first resonant frequency is rendered substantially equal to a reactance component at the second resonant frequency. Further, the circuit includes a second inductor and a second capacitor which are coupled between the second means and a feeder.

Abstract: A miniature and high performance antenna applicable to a radio communication apparatus and made up of a straight antenna rod and a loading coil. The tip of the straight antenna rod is received in the coil such that capacity coupling is set up between them. An antenna configuration is provided for setting up capacity coupling between the antenna rod and a feed portion.