Method for manufacturing circuit devices

A method for manufacturing circuit devices comprising:

• preparing a laminated plate by laminating a first conductive film and a second conductive film via a third conductive film;
• forming a first conductive wiring layer by etching said first conductive film into a desirable pattern;
• selectively removing said third conductive film by use of said first conductive wiring layer as a mask;
• laminating an insulating sheet where a first insulating layer has been fitted to a fourth conductive film so that said first insulating layer covers front-surface portions of the second conductive film exposed by removing said third conductive film, said first conductive wiring layer, and end faces of the third conductive film;
• forming a second conductive wiring layer by etching said fourth conductive film into a desirable pattern;
• forming multilayer connecting means and thus electrically connecting said first conductive wiring layer with said second conductive wiring layer;
• covering said second conductive wiring layer with a second insulating layer;
• forming exposed portions by selectively exposing said second conductive wiring layer by partially removing said second insulating layer;
• fixedly fitting semiconductor elements onto said second insulating layer to electrically connect said semiconductor elements with said second conductive wiring layer;
• covering said semiconductor elements with a sealing resin layer;
• removing said second conductive film to expose said third conductive film on the rear surface.