A power semiconductor device comprising: - a first die and a second die; and - a package of the surface mount type, housing the first and second dice; and wherein the package comprises: - a first bottom insulation multilayer and a second bottom insulation multilayer, which carry, respectively, the first and second dice and each include a respective top metal layer (26a, 126a), a respective bottom metal layer (26b, 126b) and a respective intermediate insulating layer (26c, 126c), interposed between the corresponding top metal layer (26a, 126a) and the corresponding bottom metal layer (26b, 126b); and - a covering metal layer, arranged on top of the first and second dice; characterized in that each of the first and second dice comprises a plurality of conductive contact regions (12, 112) and a passivation region (13, 113), which includes a number of projecting dielectric regions (10', 110') and a number of windows (18, 118), adjacent windows (18,118) being separated by a corresponding projecting dielectric region (10', 110'), each conductive contact region being arranged within a corresponding window (18,118); and wherein said covering metal layer comprises projecting metal regions (36, 136), which extend into the windows (18,118) so as to couple electrically with corresponding conductive contact regions (12, 112), said covering metal layer moreover forming a number of cavities (40, 140), interposed between the projecting metal regions (36, 136) so as to overlie corresponding projecting dielectric regions (10', 110'). - a first die and a second die; and - a package of the surface mount type, housing the first and second dice; and wherein the package comprises: - a first bottom insulation multilayer and a second bottom insulation multilayer, which carry, respectively, the first and second dice and each include a respective top metal layer (26a, 126a), a respective bottom metal layer (26b, 126b) and a respective intermediate insulating layer (26c, 126c), interposed between the corresponding top metal layer (26a, 126a) and the corresponding bottom metal layer (26b, 126b); and - a covering metal layer, arranged on top of the first and second dice; - a first bottom insulation multilayer and a second bottom insulation multilayer, which carry, respectively, the first and second dice and each include a respective top metal layer (26a, 126a), a respective bottom metal layer (26b, 126b) and a respective intermediate insulating layer (26c, 126c), interposed between the corresponding top metal layer (26a, 126a) and the corresponding bottom metal layer (26b, 126b); and - a covering metal layer, arranged on top of the first and second dice; characterized in that each of the first and second dice comprises a plurality of conductive contact regions (12, 112) and a passivation region (13, 113), which includes a number of projecting dielectric regions (10', 110') and a number of windows (18, 118), adjacent windows (18,118) being separated by a corresponding projecting dielectric region (10', 110'), each conductive contact region being arranged within a corresponding window (18,118); and wherein said covering metal layer comprises projecting metal regions (36, 136), which extend into the windows (18,118) so as to couple electrically with corresponding conductive contact regions (12, 112), said covering metal layer moreover forming a number of cavities (40, 140), interposed between the projecting metal regions (36, 136) so as to overlie corresponding projecting dielectric regions (10', 110').