| 摘要 |
PROBLEM TO BE SOLVED: To enhance adhesion between an insulation film or a wiring circuit film formed by build-up method and a wiring board forming a core by admixing the insulation layer of the wiring board forming a core with a resin having a significant difference in the molecular weight and/or the curing point. SOLUTION: A wiring board comprising an insulation layer 2 composed of at least two kinds of resin having a significant difference in the molecular weight and/or the curing point, and a wiring circuit layer 3 forms a core 4 onto which an insulation film 5 and a wiring circuit film 6 are formed sequentially by build-up method thus producing a multilayer wiring board 1. The resin having a significant difference in the molecular weight and/or the curing point includes thermosetting resins, e.g. polyphenylene ether or bismaleimide triazine, epoxy resin, polyimide resin, fluororesin or phenol resin, and thermoplastic resins and imide based resins excellent in heat resistance moisture absorbance and electric characteristics in high frequency region is most suitable. |
