Myong-Jae Yoo

Fabrication of multilayer interconnection materials and bonding film for high integration applications

To meet the demands for increased integration and multi functions for multilayer electronic components the related materials and process technique for layer-to-layer interconnection have to be developed together. Using nano-, micro-sized metal powders and epoxy resins conductive via pastes have been formulated. Via conductance was measured before and after solder floating(288 °C) to observe the change rate after thermal shock. Thermal conductivity of fabricated paste was evaluated by making disk-type pressed specimens. As the results, the electrical conductivities of tested pastes showed the values of about 10−5 Ωcm. Trimodal pastes showed better solder shock resistance thanbimodal pastes. Thermal conductivities over 15 W/mK were obtained from several paste compositions. Also regarding higher integration demands bonding film was developed. Composite material composed of epoxy based resin with inorganic fillers was used due to low process cost, good processability, and low temperature curability. As a result bonding film with glass transition temperature over 170 °C, peel strength above 7N/cm and fine patterning of line space width of 15 μm was fabricated.

Effect of Solvent Mixture Ratio on Rheology Property of Slurry and Thickness Control of Ceramic Green Sheets

The effect of organic solvent mixture ratio on the rheology property of slurry and thickness control of ceramic green sheet was investigated. For selecting a suitable dispersant multiple light scattering method was used to evaluate the particle migration velocity and variation of clarification layer thickness. Using the selected dispersant the dispersion property of solution according to solvent mixture ratio was investigated. Binder and plasticizers were added to formulate slurries and their viscosity was evaluated according to solvent mixture ratio. Ceramic green sheets with average thickness of 30, 50 urn were fabricated via tape casting and their thickness tolerances measured. As a result according to solvent mixture ratio the solution and slurry properties varied and for the mixture ratio of ethanol/toluene of 80/20 the ceramic green sheet with the lowest thickness tolerance was obtained.