Abstract: Contact ring, which is brought into contact with a probe card having tungsten needles, has a multiplicity of POGO pins on its one surface facing the probe card. The contact ring has, on another surface opposite to the one surface, press-fitting sockets electrically connected with the POGO pins. Motherboard has sockets similar in construction to the press-fitting sockets of the contact ring. Coaxial cables each have press-fit terminals that are press-fittable in one of the sockets of the contact ring and in one of the sockets of the motherboard, and thereby these coaxial cables electrically connect the contact ring with the motherboard. Because the contact ring and the motherboard are electrically connected with each other by the press-fit engagement alone, there are encountered no inconveniences due to the conventional soldering-based connection.

Abstract: For instance, when a washing-free yet low-residue type of flux is coated on a solder resist film, soldering can be carried out while no solder balls remain on a circuit substrate.A photosensitive resin composition comprises a photopolymerizable and photosensitive resin having at least one of a carboxyl group and an onium group, a photopolymerizable reactive diluent, a photopolymerization initiator, a thermosetting component, and an inorganic powder having an average particle size of 2 .mu.m to 20 .mu.m. A cured film thereof is used as a solder resist film for circuit substrate fabrication.A washing-free yet low-residue type of flux is so uniformly coated on the solder resist film that soldering can be carried out in the absence of any solder ball.

Abstract: To enable accurate yarn tension measurement by the elastic substrate in a yarn tension detecting apparatus including an elastic substrate 3, a yarn guide support 4 attached to the elastic substrate 3 approximately perpendicularly, a yarn guide 7 fixed at a free end of the yarn guide support 4, a strain measuring member 8 for measuring strain in the elastic substrate 3, and a resistor 9 that corrects effect of the temperature of the elastic substrate 3 from having a biased temperature distribution, a synthetic resin spacer 5 is interposed between the yarn guide 7 and the yarn guide support 4 and fixed thereto by a synthetic resin fixing member.

Abstract: For instance, when a washing-free yet low-residue type of flux is coated on a solder resist film, soldering can be carried out while no solder balls remain on a circuit substrate.A photosensitive resin composition comprises a photopolymerizable and photosensitive resin having at least one of a carboxyl group and an onium group, a photopolymerizable reactive diluent, a photopolymerization initiator, a thermosetting component, and an inorganic powder having an average particle size of 2 .mu.m to 20 .mu.m. A cured film thereof is used as a solder resist film for circuit substrate fabrication.A washing-free yet low-residue type of flux is so uniformly coated on the solder resist film that soldering can be carried out in the absence of any solder ball.

Abstract: The present invention relates to a photopolymerizable composition; more specifically, the present invention relates to a photopolymerizable composition useful as photoimageable solder mask of one component type, which can form image by ultraviolet exposure and development in an aqueous solution of dilute alkali after film formation and which has excellent ultraviolet curability and heat resistance of solder. The composition contains a reaction product, a diluent and a sensitizer, the reaction product being produced by adding epoxy group-containing acrylic acid ester or epoxy group-containing methacrylic acid ester to a part of the carboxyl group of the copolymer of acrylic acid ester or methacrylic acid ester with acrylic acid or methacrylic acid.

Abstract: Disclosed is a photopolymerizable resin composition suitable for forming a solder mask layer, for example, on a printed circuit board. The photopolymerizable resin composition of the invention can be prepared in the form of an aqueous solution and is developable with water as the developer liquid so that the problems and disadvantages inherent in the use of organic solvents can be completely solved. The composition comprises, in addition to a photopolymerization initiator and a polyenic compound as a reactive diluent, a unique prepolymer as a resinous ingredient which is a copolymer of, for example, an alkyl (meth)acrylate and glycidyl (meth)acrylate modified at the epoxy groups in the copolymer partly by the reaction with (meth)acrylic acid and partly by the reaction with an onium group-containing compound, e.g. a quaternary ammonium compound, to impart solubility in water.

Abstract: The present invention provides a photopolymerizable composition useful as a liquid photoimageable solder mask comprising (a) a reaction product obtained by reacting epoxy resin A containing at least two terminated epoxy groups with 0.8 to 1.2 mol, per 1 epoxy equivalent of epoxy resin A, of an .alpha.,.beta.-unsaturated carboxylic acid and then reacting same with 0.2 to 1.0 mol, per 1 epoxy equivalent of epoxy resin A, of polybasic acid anhydride, (b) diluent, (c) sensitizer, (d) epoxy resin B consisting of tris (2,3-epoxypropyl) isocyanurate whose melting point is 130.degree. C. or less, and (e) an epoxy resin curing agent represented by the general formula [I:] ##STR1## wherein R is --H, halogen, --NH.sub.2, --SH, aromatic hydrocarbon, a C.sub.1 -C.sub.4 alkyl group or NHR' (R' is a C.sub.1 -C.sub.4 alkyl group having --CN or NH.sub.2 C.dbd.NH).

Abstract: A photopolymerizable composition used suitably as a solder resist for a printed circuit board which comprises:(a) 0.1 to 5.0 wt. % of a s-triazine compound represented by the general formula I: ##STR1## [wherein R.sup.1 stands for ##STR2## (wherein R.sup.2 stands for a hydrogen atom, an alkyl group or a phenyl group and R.sup.3 stands for a hydrogen atom or a lower alkyl group)];(b) 5 to 50 wt. % of a photopolymerizable oligomer which has an average molecular weight in the range of 200 to 4000 and has 2 or more of acryloyl groups or methacryloyl groups in a molecule;(c) 5 to 50 wt. % of vinyl monomer having 1 or more of acryloyl groups or methacryloyl groups which are liquid at 50.degree. C.;(d) 0.5 to 5 wt. % of a photo-initiator which acts to initiate a cross-linking reaction between said photopolymerizable oligomer and said vinyl monomer when subjected to activated radiation; and(e) 5 to 60 wt. % of an inorganic filler.