A surface mounting device (50) has one body (6) of semiconductor material such as an ASIC, and a package surrounding the body. The package has a base region (15) carrying the body, a cap (20) and contact terminals (3). The base region (15) has a Young's modulus lower than 5 MPa. For forming the device, the body (6) is attached to a supporting frame (1) including contact terminals (3) and a die pad (2), separated by cavities; bonding wires (14) are soldered to the body (6) and to the contact terminals (3); an elastic material is molded so as to surround at least in part lateral sides of the body (6), fill the cavities of the supporting frame (1) and cover the ends of the bonding wires (14) on the contact terminals; and a cap (20) is fixed to the base region (15). The die pad (2) is then etched away.