Tool wear investigation on the precision progressive die for the IC dam-bar cutting process

摘要

The IC dam-bar cutting process is conducted with the precision progressive shearing die, while the cutting quality of the sheared product is subject to the wear status of the punch. The main objective of this study was to explore the relationship between the burnished band of the sheared surface and the wear of the shearing punch in the thin sheet cutting process. Firstly, the Taguchi method was applied to scheme the dam-bar cutting experiments. Two different HSS punches, ASP60 and SKH9, were used to punch the simulated leads made of the phosphor bronze C5191R-H. The variance analysis and confirmation experiments were also executed to verify the analytical results. The experimental data was collected to establish the punch wear estimated model. Secondly, a concept of an equivalent wear length of the punch flank was introduced to examine the wear of the punch flank, and the gravimetric wear rate was also calculated to examine the amount of the punch wear due to weight loss. Finally, the estimated model of the gravimetric wear rate through the burnished area of the dam-bar sheared surface was constructed. One can directly determine the status of the cutting punch depending on the size of the burnished band, as a basis for tool changing or regrinding.