DIELECTRIC FILLER CONTAINING RESIN FOR USE IN FORMATION OF BUILT-IN CAPACITOR LAYER OF PRINTED WIRING BOARD AND DOUBLE-SIDED COPPER CLAD LAMINATE WITH DIELECTRIC LAYER FORMED USING THE SAME DIELECTRIC FILLER CONTAINING RESIN, AND PRODUCTION METHOD OF DOUBLE-SIDED COPPER CLAD LAMINATE

摘要

An object is to provide a dielectric layer of a double-sided copper clad laminate, for use in formation of a built-in capacitor layer, which can be formed in an optional thickness without using a skeletal material and is provided with a high strength. For the purpose of achieving the object, "a dielectric filler containing resin for use in formation of the built-in capacitor layer of a printed wiring board obtained by mixing a binder resin comprising 20 to 80 parts by weight of epoxy resin (inclusive of a curing agent), 20 to 80 parts by weight of a solvent soluble aromatic polyamide resin polymer, and a curing accelerator added in an appropriate amount according to need; and a dielectric filler which is a nearly spherical dielectric powder having perovskite structure which is 0.1 to 1.0 mum in the average particle size D_IA, 0.2 to 2.0 mum in the weight cumulative particle size D₅₀ based on the laser diffraction scattering particle size distribution measurement method, and 4.5 or less in the coagulation degree represented by D₅₀/D_IA where the weight cumulative particle size D₅₀ and the average particle size D_IA obtained by the image analysis"; and the like are used.