Interlayer member used for producing multilayer wiring board and method of producing the same

摘要

To increase the dimensional accuracy of an interlayer member used for producing a multilayer wiring board which is inserted between two wiring layers to establish interlayer insulation and interlayer electrical connection between the wiring layers, to thereby increase a layout density. A mask film is formed on a main surface of a sheet-like carrier layer. A metal column for interlayer connection is formed on the main surface of the carrier layer by plating a copper using the mask film as a mask. The mask film is removed. An interlayer insulating layer and a protective sheet are laminated on the main surface of the carrier layer in such a manner that the metal column for interlayer connection penetrates them. The interlayer insulating layer and the protective sheet are polished until the upper surface of the metal column for interlayer connection is exposed. Then, the carrier layer is removed. Furthermore, the protective sheet is removed.