A Study for the Effectiveness of Wire Bond Process Parameters on AI-Cu Intermetallic Compound Distributions and the Correlation between Bonded Ball Adhesions and IMC Coverage

摘要

This study try to conduct the major factors of IMC coverage and the correlation between ball shear and IMC coverage. Based on our analysis, the major factor of IMC distribution is USG Pre-bleed. And USG Pre-bleed is also the key factor of IMC distribution type. Follow this resu few test units bonded by different level of USG Pre-bleed showed that with the increasing of USG Pre-bleed, IMC coverage percentage was significant improved and the distribution was changed from ring type to center type. And the further finding from this experiment indicated that center type of IMC distribution is mostly with better IMC coverage percentage and ball shear reading than ring type IMC distribution. It concluded that good distribution of IMC might need to input proper level of USG Pre-bleed. However, increased of USG Pre-bleed will also induce under layer damage if the setup is improper. And the correlation between ball shear and IMC coverage percentage is with moderate positive correlation. This result is a reference data to improve bondability by checking both IMC coverage percentage and distribution type instead of only rely on ball shear reading as before.