SUBSTRATE FOR PRINTED WIRING BOARDS, PRINTED WIRING BOARD AND METHOD FOR PRODUCING SUBSTRATE FOR PRINTED WIRING BOARDS

摘要

The present invention provides a substrate for printed wiring boards, wherein an opening of a base film is densely filled with a conductor, and which achieves excellent electrical conductivity. A substrate for printed wiring boards according to the present invention is provided with: a base film (1) which has insulation properties and has one or more openings (4); first conductive layers (2) that are respectively laminated on both surfaces of the base film (1) and filled into the openings (4) by means of application and heat treatment of a conductive ink containing metal particles; and second conductive layers (3) that are respectively laminated on at least one surface of each first conductive layer (2) by plating. The metal particles preferably have an average particle diameter of from 1 nm to 500 nm (inclusive). It is preferable that the both surfaces of the base film (1) are subjected to a hydrophilizing treatment. The metal particles are preferably formed of copper. It is preferable that a region of each first conductive layer (2) within 500 nm from the interface with one surface or the other surface of the base film (1) and the regions within the openings have a porosity of from 1% to 50% (inclusive).