Power diode for use in rectifier bridge of rotary electric machine such as alternator for automobile vehicles

The power diode comprises a base (1) with a massive main part (10) extended axially into a socket (2) having on its free upper extremity a fastening plane (3) for a semiconductor element (101) placed below a connection element (100) and encapsulated by an electrically insulating resin (103) making it joined with the base. The periphery (20) of the socket (2) has a groove (4) made radially below the fastening plane and filled with the resin in the process of encapsulation. The fastening plane (3) is extended axially on its periphery to form a sleeve (8) demarcating a cavity where the semiconductor element is placed and surrounded with a ring layer (102) of electrically insulating material, e.g. synthetic material such as polyimide, which is more flexible than the surrounding resin, e.g. epoxy resin. The sleeve (8) is of ring form, and the layer (102) is globally a ring surrounded with the sleeve. In variants of the service, the groove (4) is of cross-section in the form of letter U, or of semicircular form. The semiconductor element is fastened by a solder layer on the lower face (104) of the head of connection element, and the encapsulation with the resin makes it watertight. The ring layer (102) serves as a buffer against the thermal expansion of the resin (103). Diodo de potencia destinado especialmente a equipar el puente rectificador de una máquina eléctrica giratoria, del tipo de un alternador para vehículo automóvil. El diodo de potencia comprende un apoyo (1) dotado de una parte principal (10) maciza prolongada axialmente por medio de un zócalo (2) que presenta en su extremo libre superior una cara de fijación (3) para un elemento semiconductor (101) cubierto por una resina (103) aislante eléctricamente solidaria con el apoyo (1), y está caracterizado por el hecho de que la periferia externa (20) del zócalo (2) presenta una ranura (4) implantada axialmente por debajo de la cara de fijación (3). Aplicación: puente rectificador de una máquina eléctrica giratoria.