| abstract |
A semiconductor package comprises an aluminum nitride substrate having a semiconductor element mounted thereon, a lead frame junctioned to the side of the aluminum nitride substrate directly contacting the mounted semiconductor element, and a ceramic sealing member junctioned to the aluminum nitride substrate so as to seal the semiconductor element. The lead frame has a coating layer of a nonmagnetic metallic material formed in a thickness of not more than 20 μm on only one of the opposite surfaces of a lead frame matrix made of a ferromagnetic metal to which a bonding wire is to be junctioned. The layer of the nonmagnetic metallic material is formed by any of such thin film forming technique as the vacuum deposition technique, the spattering technique, and the plating technique. The coating layer formed on only one of the opposite surfaces of the lead frame matrix is capable of amply curbing the resistance and the dependency of inductance on frequency. The aluminum nitride substrate is capable of imparting an ideal ability to radiate heat. The semiconductor package enables a high-speed quality semiconductor element having such a high system clock frequency as is not less than 50 MHz to be operated stably. |