TAPE CASTING OF HIGH DIELECTRIC CERAMICS COMPOSITE/HYBRID SUBSTRATES FOR MICROELECTRONICS APPLICATION

摘要

The concept of tape casting was first introduced during the 1940s as a method of forming thin sheets of piezoelectric materials and capacitors. Since then, the production of thin layers of ceramic-loaded polymers which can be stacked and laminated into multilayered structures, form the backbone of two, multi-billion-dollar industries: multilayered capacitors (MLC) and multilayered ceramic packages (MLCP). Tape Casting (or Doctor Blading) is an economical method of producing large surface areas of thin ceramic sheets with controlled thickness, high uniformity and excellent surface finishes. In this process, a homogeneous, well-dispersed concentrated slurry comprising ceramic particles and organic/polymer additives were passed under a doctor blade onto a temporary carrier. The solvents were evaporated, leaving the remaining slurry to density and form a leather-like flexible green sheet. This paper outlines the various parameters relating to proper formulation and processing for the production of good quality green tapes. It was found that proper control of both the formulation as well as the processing parameters were critical to the quality and reproducibility of the green tapes. This include the optimal formulation of powders, solvents, deflocculants, plasticizers and binders, as well as the exposure environment after tape casting.