Inner lead bonding techniques for 500 lead dies having a 90 μm lead pitch

A study of tape automated bonding (TAB) undertaken in order to investigate the application of 500-lead bonding in mass production is discussed. The Toshiba TT1-700, the automatic inner lead bonder used, has a maximum applied pressure of 30 kgf, an alignment accuracy of 10 μm, and an index time of 3.9 s, including a 1-s bonding time. The machine´s alignment and bonding accuracy, the determination of acceptable bonding conditions, the effects of tool planarity an parallelism on bond strength and bump deformation, and the effects of bonding conditions on the rate of bond strength degradation during continuous bonding, using 12.7-mm² and 504-lead test dies with a lead pitch of 90 μm, are discussed. Employment of the TTI-700 resulted in highly accurate inner lead bonding for finely pitched leads with high lead counts