Printed wiring board, method for manufacturing same, and circuit device

摘要

The printed wiring board comprises, on at least one surface of an insulating film, a base metal layer and a conductive metal layer formed on the base metal layer, and is characterized in that in a section of the wiring board the bottom width of the conductive metal layer is smaller than the top width of the base metal layer. The circuit device comprises the printed wiring board and an electronic part mounted thereon. The process for producing a printed wiring board comprises bringing a base metal layer and a conductive metal layer into contact with an etching solution capable of dissolving the conductive metal to form a wiring pattern and then sequentially bringing the resultant into contact with a first treating solution capable of dissolving the metal for forming the base metal layer, a microetching solution capable of selectively dissolving the conductive metal and a second treating solution having a different chemical composition from the first treating solution in this order.