Patent Number: 6,761,790

Title: Wiring board and method of manufacturing the same

Abstract: The present invention provides a method of manufacturing a wiring board, including the steps of forming a through hole on a prepreg having a releasing resin film on at least one of its surfaces, the prepreg being obtained by impregnating a porous film having a thickness of 5 to 90 .mu.m and a porosity of 30 to 98% with a half cured thermosetting resin, filling the through hole with a conductive paste containing a conductive filler, peeling the resin film, laminating a metal foil on a surface from which the resin film is peeled, and heating and pressurizing the laminated product. Moreover, the present invention provides a wiring board including an insulating layer obtained by impregnating a porous film having a thickness of 5 to 90 .mu.m and a porosity of 30 to 98% with a thermosetting resin and curing them, and a conductive connection structure between wiring layers in which a through hole provided on the insulating layer is filled with a conductive paste, wherein the conductive connection structure has the conductive filler at only a boundary surface with the porous film and in an inner part thereof.

Inventors: Kawashima; Toshiyuki (Ibaraki, JP), Tahara; Nobuharu (Ibaraki, JP), Ikeda; Kenichi (Ibaraki, JP)

Assignee: Nitto Denko Corporation

International Classification: H05K 3/40 (20060101); H05K 3/46 (20060101); H05K 001/03 ()

Expiration Date: 07/13/2021