Precise alignment technique for TAB inner-lead bonding

A precise alignment technique for inner-lead bonding of TAB (tape automated bonding), called direct alignment, is described. In this technique, inner leads on a tape and bumps on a LSI (large-scale integration) chip are detected at the bonding station. The position of leads is detected from the projection waveform of a dark-field illuminated image, where complicated background information of LSI patterns is eliminated. The position of bumps, which are partially concealed by the leads, is detected from the projection waveform of a bright-field illuminated image by utilizing the lead position information detected before. This technique has been applied to an automatic TAB inner-lead bonder, and alignment accuracy after bonding of less than +5 μm is achieved