In recent years, from the demands for faster operation and miniaturization of semiconductor devices, a wiring referred to as a redistribution layer formed on a first pad electrode which is a part of an uppermost layer wiring of a multilayer wiring layer on a semiconductor substrate has been used. The redistribution layer is mainly composed of a thick copper film formed by, for example, the plating method in order to reduce the wiring resistance. Apart of an upper surface of the redistribution layer is a region to be connected to an external connection terminal formed of a bump electrode, a bonding wire, or the like, and constitutes a second pad electrode. Then, the second pad electrode is electrically connected to a printed circuit board or the like.
For example, Patent Document 1 (Japanese Patent Application Laid-Open Publication No. 2009-194144) describes a technique for forming a redistribution layer on a multilayer wiring layer.