Semiconductor device and method for manufacturing semiconductor device

A method for manufacturing a semiconductor device comprising:

• mounting a semiconductor element, with a surface for forming an electrode terminal(s) facing up on a first surface of a core substrate, in which core wirings are disposed on a surface of the first surface and a surface of a second surface opposite to said first surface, and a penetrating via(s) connecting the core wirings of said first surface and said second surface is further disposed;
• forming a first insulating layer, covering said semiconductor element, on said first surface;
• forming a first wiring that forms a first wiring layer on a surface of said first insulating layer, and forms a wiring connected to an electrode terminal(s) of said semiconductor element through a connecting portion(s) and a wiring(s) connected to said core wiring disposed on said first surface through a via(s) on said first wiring layer;
• forming a second insulating layer on said second surface;
• and
• forming a second wiring that forms a second wiring layer on a surface of said second insulating layer, and forms a wiring(s) connected to said core wiring disposed on said second surface through a via(s) on said second wiring layer,
• wherein a set of said forming said first insulating layer and said first wiring forming is carried out in a different step from a set of said forming said second insulating layer and said second wiring forming.