BST DIELECTRIC LAYER, CAPACITOR LAYER-FORMING MATERIAL COMPRISING THE BST DIELECTRIC LAYER, CAPACITOR LAYER-FORMING MEMBER WITH ELECTRODE CIRCUIT, AND PRINTED WIRING BOARD HAVING BUILT-IN CAPACITOR CIRCUIT

摘要

Disclosed is a dielectric layer or the like which is small in capacitance density change even when the temperature is changed due to heat generation. Specifically disclosed is a BST dielectric layer to be used for capacitor circuit production, which is characterized by having a composition balance between barium and strontium satisfying the following relation: Ba<SUB>X</SUB>Sr<SUB>1-X</SUB>TiO<SUB>3</SUB> (0.8 = X < 1). This BST dielectric layer is also characterized by having a thickness of 0.3-0.7 µm. Also specifically disclosed is a capacitor layer-forming material for printed wiring boards, which comprises a lower electrode-forming layer on one side of the BST dielectric layer and an upper electrode-forming layer on the other side of the BST dielectric layer.