Tamurakaken Corporation

Other

Takao Ono

Yoshiyuki Takahashi

Masahiro Nomura

Toshiyuki Oga

Ichiro Miura

Takanobu Gido

Hiroaki Koyahara

Kenji Fujimori

Kazutaka Nakanami

Rika Sasaki

Shinichi Akaike

Mitsuru Iwabuchi

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, &minus;40&deg; C. to &plus;85&deg; 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. The circuit board is accompanied with a residual film of such a flux.

Solder work material for forming solder-coated circuit board and circuit board

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.

Photosensitive resin composition and printed wiring board

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&mdash;Ag&mdash;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.

Lead-free solder, and paste solder composition

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.

Water-soluble preflux, printed circuit board, and process for treating the surface of a metal in a printed circuit board

Growing community of inventors

Saitama, Japan

Takao Ono