Abstract: An object of the present invention is to provide a printed wiring board which does not require arranging signal lines oblique to the warp or weft threads constituting a substrate and is capable of reducing a difference in transmission rates between the signal lines. The present invention relates to a printed wiring board including: an insulating layer; and a signal layer including a set of at least two signal lines and disposed on one side of the insulating layer. A substrate is embedded inside the insulating layer in such a manner to be further from the signal layer than a center of the insulating layer in a thickness direction of the insulating layer is. The insulating layer has a laminated structure of a thick layer, the substrate, and a thin layer. A ratio of a thickness of the thick layer to a thickness of the thin layer is greater than five.

Abstract: Provided is a thermosetting resin composition that contains 40 to 80 parts by volume of an inorganic filler with respect to 100 parts by volume of thermosetting resin solids and the inorganic filler. The inorganic filler contains (A) at least one type of particles selected from among gibbsite-type aluminum hydroxide particles and magnesium hydroxide particles having an average particle size (D50) of 1 to 15 ?m; (B) aluminum oxide particles having an average particle size (D50) of 1.5 ?m or less; and (C) a molybdenum compound, and the blending ratios (by volume) of the component (A), the component (B) and the component (C) with respect to 100% as the total amount of inorganic filler are component (A): 30 to 70%, component (B): 1 to 40%, and component (C): 1 to 10%.

Abstract: Disclosed is a prepreg obtained by impregnating a woven fabric base with a thermosetting resin composition, wherein the thermosetting resin composition contains 80 to 200 volume parts of an inorganic filler per 100 volume parts of a thermosetting resin, and the inorganic filler contains (A) gibbsite aluminum hydroxide particles having an average particle diameter (D50) of 2 to 15 ?m, (B) at least one inorganic component selected from the group consisting of boehmite particles having an average particle diameter (D50) of 2 to 15 ?m and inorganic particles that have an average particle diameter (D50) of 2 to 15 ?m and that contain crystal water having a release initiation temperature of 400° C. or higher or contain no crystal water, and (C) aluminum oxide particles having an average particle diameter (D50) of 1.

Abstract: A laminate with superior thermal conductivity, heat resistance, drill workability, and fire retardancy is provided. In a prepreg obtained by impregnating a woven or nonwoven fabric base with a thermosetting resin composition, the thermosetting resin composition contains 80 to 200 parts by volume of an inorganic filler per 100 parts by volume of a thermosetting resin, the inorganic filler contains (A) gibbsite type aluminum hydroxide particles having an average particle diameter (D50) of 2 to 15 ?m and (B) magnesium oxide having an average particle diameter (D50) of 0.5 to 15 ?m, and a compounding ratio (volume ratio) of the gibbsite type aluminum hydroxide particles (A) to the magnesium oxide (B) is 1:0.3 to 3.

Abstract: Disclosed is a prepreg obtained by impregnating a woven fabric base with a thermosetting resin composition, wherein the thermosetting resin composition contains 80 to 200 volume parts of an inorganic filler per 100 volume parts of a thermosetting resin, and the inorganic filler contains (A) gibbsite aluminum hydroxide particles having an average particle diameter (D50) of 2 to 15 ?m, (B) at least one inorganic component selected from the group consisting of boehmite particles having an average particle diameter (D50) of 2 to 15 ?m and inorganic particles that have an average particle diameter (D50) of 2 to 15 ?m and that contain crystal water having a release initiation temperature of 400° C. or higher or contain no crystal water, and (C) aluminum oxide particles having an average particle diameter (D50) of 1.

Abstract: The poly(phenylene oxide) resin composition of the invention is a poly(phenylene oxide) resin composition containing poly(phenylene oxide) and triallyl isocyanurate, wherein the poly(phenylene oxide) has a number average molecular weight in a range from 2,000 to 12,000 and the IPN structure can be formed in a cured product of the poly(phenylene oxide) and triallyl isocyanurate to provide a high heat resistance, and at the same time by using a poly(phenylene oxide) with a relatively low molecular weight, the fluidity of the melt resin can be made desirable at the time of molding to result in high molding properties.

Abstract: The poly(phenylene oxide) resin composition of the invention is a poly(phenylene oxide) resin composition containing poly(phenylene oxide) and triallyl isocyanurate, wherein the poly(phenylene oxide) has a number average molecular weight in a range from 2,000 to 12,000 and the IPN structure can be formed in a cured product of the poly(phenylene oxide) and triallyl isocyanurate to provide a high heat resistance, and at the same time by using a poly(phenylene oxide) with a relatively low molecular weight, the fluidity of the melt resin can be made desirable at the time of molding to result in high molding properties.

Abstract: An epoxy resin composition of the invention comprises: an epoxy resin; a hardening agent; and a phenol-modified polyphenylene oxide having a number average molecular weight of 1000 to 4000, which is prepared by carried out a redistribution reaction between a polyphenylene oxide and a phenol compound in the presence of a reaction initiator which can be decomposed to generate an alcohol, a prepreg and a metal-clad laminate of the invention contain the epoxy resin composition.

Abstract: A halogen-free flame retardant resin composition comprising a radically polymerizable resin which is modified with a phosphorus-containing compound of the formula (1): in which R is a hydrogen atom or a group of the formula: —(CH2)n—R1 in that R1 is a group derived from a compound having at least two phenolic hydroxyl groups or epoxy groups, and n is an integer of 0 to 3.

Abstract: An epoxy resin composition of the invention comprises: an epoxy resin; a hardening agent; and a phenol-modified polyphenylene oxide having a number average molecular weight of 1000 to 4000, which is prepared by carried out a redistribution reaction between a polyphenylene oxide and a phenol compound in the presence of a reaction initiator which can be decomposed to generate an alcohol, a prepreg and a metal-clad laminate of the invention contain the epoxy resin composition.

Abstract: A glass fiber forming composition exhibits a remarkably high dielectric constant .epsilon..sub..GAMMA. as well as superior chemical resistance, yet it is readily spun into glass fibers. The composition is characterized to show a devitrification temperature which is lower than a spinning temperature at which the glass composition exhibits a viscosity of 10.sup.2.5 poise, so as to be readily spun into corresponding glass fibers. The composition consists essentially of 40 to 65 mol % of SiO.sub.2 ; 20 to 45 mol % of at least one component selected from the group consisting of MgO, CaO, SrO and BaO; 5 to 25 mol % of at least one component selected from the group consisting of TiO.sub.2 and ZrO.sub.2 ; and 0.5 to 15 mol % of NbO.sub.5/2 as calculated from an incorporated amount of Nb.sub.2 O.sub.5. Alternately, the composition consist essentially of 40 to 65 mol % of SiO.sub.

Abstract: A glass fiber forming composition exhibits a remarkably high dielectric constant .epsilon..sub.r as well as superior chemical resistance, yet it is readily spun into glass fibers. The composition is characterized to show a devitrification temperature which is lower than a spinning temperature at which the glass composition exhibits a viscosity of 10.sup.2.5 poise, so as to be readily spun into corresponding glass fibers. The composition consists essentially of 40 to 65 mol % of SiO.sub.2 ; 20 to 45 mol % of at least one component selected from the group consisting of MgO, CaO, SrO and BaO; 5 to 25 mol % of at least one component selected from the group consisting of TiO.sub.2 and ZrO.sub.2 ; and 0.5 to 15 mol % of NbO.sub.5/2 as calculated from an incorporated amount of Nb.sub.2 O.sub.5. Alternately, the composition consist essentially of 40 to 65 mol % of SiO.sub.

Abstract: A glass fiber forming composition exhibits a remarkably high dielectric constant .epsilon..sub.r as well as superior chemical resistance, yet it is readily spun into glass fibers. The composition is characterized to show a devitrification temperature which is lower than a spinning temperature at which the glass composition exhibits a viscosity of 10.sup.2.5 poise, so as to be readily spun into corresponding glass fibers. The composition consists essentially of 40 to 65 mol % of SiO.sub.2 ; 20 to 45 mol % of at least one component selected from the group consisting of MgO, CaO, SrO and BaO; 5 to 25 mol % of at least one component selected from the group consisting of TiO.sub.2 and ZrO.sub.2 ; and 0.5 to 15 mol % of NbO.sub.5/2 as calculated from an incorporated amount of Nb.sub.2 O.sub.5. Alternately, the composition consist essentially of 40 to 65 mol % of SiO.sub.

Abstract: A composite dielectric is formed with a matrix synthetic resin and particulate porous, inorganic dielectric dispersed in the matrix synthetic resin. The dielectric constant of this composite dielectric can be thereby elevated effectively without enlarging the dissipation factor (tan .delta.) of the composite dielectric.