Semiconductor device

• Main Author: SHIMOKAWA HANAE,OKUDAIRA HIROAKI,NAKATSUKA TETSUYA,INABA YOSHIHARU,NISHIMURA ASAO,SOGA TASAO,ISHIDATOSHIHARU
• Format: Patent
• Language: English
• Published: 31.01.2007
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CABLES; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CONDUCTORS; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INSULATORS; MACHINE TOOLS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; PRINTED CIRCUITS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; SEMICONDUCTOR DEVICES; SOLDERING OR UNSOLDERING; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WELDING; WORKING BY LASER BEAM

Provided are a bonded structure by a lead-free solder and an electronic article comprising the bonded structure. The bonded structure has a stable bonding interface with respect to a change in process of time, an enough strength and resistance to occurrence of whiskers while keeping good wettability of the solder. In the bonded structure, a lead-free Sn-Ag-Bi alloy solder is applied to an electrode through an Sn-Bi alloy layer. The Sn-Bi alloy, preferably, comprises 1 to 20 wt% Bi in order to obtain good wettability of the solder. In order to obtain desirable bonding characteristics having higher reliability in the invention, a copper layer is provided under the Sn-Bi alloy layer thereby obtaining an enough bonding strength.