Prepreg epoxy resin composition and a prepreg, a multilayer printed circuit board

A without generating harmful substances upon combustion, excellent flame retardancy, solder heat resistance after moisture absorption, and used in the manufacture of printed circuit boards particularly multilayer printed wiring board hot rigidity is excellent prepreg epoxy resin composition, to provide a prepreg, and a multilayer printed wiring board. A phosphorus compound having a phenolic hydroxyl group of less than three average 1.8 or more in a molecule and an average 0.8 or more phosphorus atoms and specific (biphenyl type, naphthalene type, a dicyclopentadiene type chosen) bifunctional epoxy resin and 20 mass% or more of prereacted epoxy resin obtained by previously reacting at an equivalent ratio of 1.2 or more less than 3/1 epoxy group / phenolic hydroxyl group relative to the total epoxy resin 55 contained such that less mass%, polyfunctional epoxy resins containing epoxy groups average 2.8 or more in one molecule, the curing agent consisting of dicyandiamide and / or polyfunctional phenolic compound, and the thermal decomposition temperature 400 ° C. or higher epoxy resin composition containing an inorganic filler is used as Puripuragu for printed wiring board manufacturing. .BACKGROUND