Substrate assembly provided with capacitive interconnections, and manufacturing method thereof

An assembly comprising:

• a first substrate, having a first surface, housing a first electrical-interconnection element and a second electrical-interconnection element at the first surface;
• a second semiconductor substrate, having a second surface, housing a third electrical-interconnection element and a fourth electrical-interconnection element at the second surface, and provided with a dielectric layer extending across a region of the second surface and covering the third electrical-interconnection element, wherein the dielectric layer is spaced apart from the first substrate by air;
• an opening in the dielectric layer formed at the fourth electrical-interconnection element;
• a first coupling element comprising conductive solder, extending between the first electrical-interconnection element and the third electrical-interconnection element and at least partially aligned to the first electrical-interconnection element and to the third electrical-interconnection element;
• and
• a second coupling element of conductive material, extending between the second electrical-interconnection element and the fourth electrical-interconnection element, at least partially aligned to the second and to the fourth electrical-interconnection elements,
• the first coupling element being ohmically coupled to the first electrical-interconnection element and capacitively coupled to the third electrical-interconnection element, and the second coupling element being ohmically coupled to the second electrical-interconnection element and to the fourth electrical-interconnection element.