A substrate for an electronic unit and methods for their preparation, electronic unit and methods for their preparation

A substrate for an electrical unit having a core substrate (101), in the form of a thin plate, a metal electrode (110) disposed on the core substrate (101) and electrically connected to an electrode of an electronic component (201) with which the core substrate is is to be fitted (101), respectively; and an electrically insulating layer (102) which is provided to surround the metallic electrode (110).