Hitherto, various resin compositions have been used for forming insulation layers in electronic components such as laminated plates and printed wiring boards. For example, in multilayer printed wiring boards, resin compositions are used for forming insulation layers to insulate interlayers located internally, and for forming insulation layers located on surface layer portions. The insulation layers generally have circuit patterns, which are metal layers, formed on the surface thereof.
In addition, for circuit formation in manufacture of a semiconductor package, it is important how to accurately form circuit (Cu plating, etc.) patterns. As one method for forming a circuit pattern, there is a method in which a patterned groove is formed on an insulation layer and a metal is loaded into the groove to form a circuit pattern within the groove. This method is called a trenching process. A method for forming a groove by the trenching process is disclosed, for example, in Patent Literature 1 below.