50 μm fine pitch ball bonding technology

Importance of fine pitch bonding technology for high-density assembly of semi-conductor devices is increasing in the background of rapidly advancing downsizing and performance enhancement of the devices. Presently, the wire bonding method is dominant as a method of electric interconnection between pad electrodes on Si chip and external electrodes, wherein demands are increasing for connection in narrower pitches between adjacent wires. 70 μm-pitch bonding has been applied to mass-produced devices and 40 μm-pitch bonding is expected to come to commercial use by 2005. This paper describes technology developments of 50 μm-pitch bonding involving high strength thin bonding wire, optimum relationship between the capillary shape and ball diameter, optimization of bonding conditions, etc.