LAMINATED WIRING BOARD, ELECTRIC APPARATUS, AND ITS MOUNTING STRUCTURE

PROBLEM TO BE SOLVED: To provide a laminated wiring board that can obtain high mounting reliability even when the wiring board is interposed between an electric element composed of Si etc., having a small coefficient of thermal expansion and an external circuit board, such as the printed board etc., having a large coefficient of thermal expansion, and to provide an electric apparatus using the wiring board and the mounting structure of the apparatus. SOLUTION: The laminated wiring board A is composed of a first and second wiring boards 1 and 2 respectively provided with a first and second insulating substrates 1b and 2b and wiring layers 1a and 2a on at least the front and rear surfaces of the substrates 1b and 2b. The wiring layer 1a on the rear surface of the first wiring board 1 and the wiring layer 2a on the front surface of the second wiring board 2 are connected to each other through connecting electrodes 5. The coefficient of thermal expansion of the first wiring board 1 at 0-150°C is smaller than that of the second wiring board 2 at 0-150°C and the ratio (S1/S2) of the surface area (S1) of the first wiring board 1 to that (S2) of the second wiring board 2 is adjusted to ≤0.3. COPYRIGHT: (C)2005,JPO&NCIPI