Circuit board and process for producing the same

摘要

In the case of using a photosensitive insulating resin for a surface protective layer of a circuit wiring pattern, or for an insulating layer between circuit wiring conductor layers in a circuit board, Na ions adsorbed on the photosensitive insulating resin are replaced with a polyvalent metal through a treatment step containing Na ions which is executed after a heat curing step of the photosensitive insulating resin. For the polyvalent metal, a II group including Mg or Ca can be selected.