Hermatic Semiconductor

The present invention is directed to several embodiments of a hermetically sealed semiconductor package. One embodiment is constructed from a substrate of a first copper alloy, a cover member of a second copper alloy and a lead frame of a third copper alloy. A low melting point sealing glass composite is disposed between the cover member and the substrate for sealing the lead frame therebetween. The third copper alloy is precipitation hardenable and has excellent softening resistance at glass sealing temperatures as compared with other conventionally used alloys. In another embodiment, a clad composite having a core of the third copper alloy and cladding layer of a copper alloy having a low oxidation rate may be advantageously used for the lead frame