Characterization ofWireBondability onOverhang Structured ChipinMultiChipPackage

Characteristics of wirebondingon theoverhang structured chipwereinvestigated inthisstudy. During the wirebonding process, chipcrack andbondability weresevere factors forthin waferbonding. Chipcrack wasinvestigated bychipstrength test andparametric study wasperformed by changing bonding parameters, constant velocity, force, and power. Bondability wasmeasured for500,700,and1000pim overhang length. Bonding strength wastested byball shear testmethod. 700ptmoverhang showedbetter performance than500ptm.1000ptm overhang showedverylow bondability. Bondingcharacteristics wereobserved by numerical FEM method. Nonlinear dynamic analysis was performed. Unstable contact pressure andshear stress were observed between ball andmetal pad. Noiseofreaction force wasincreased withoverhang length.