Tape casting of high dielectric ceramic composite substrates for microelectronics application

The current device of miniaturization and higher device counts in IC (integ rated circuit) packages has significantly increased the use of both multila yer ceramic packages (MLCP) and multilayer capacitors (MLC). Crucial to the production of these ceramic substrates is the use of a tape cater with pre cise control of tape thickness, uniformity and surface finishes. The contro l of green tape thickness is crucial in governing the properties of tape ca st products. Currently, the production and accurate reproduction of smaller and thinner substrates are limited by several factors, one of which is the precise control of the green tape thickness. This is in turn influenced by the various processing parameters and formulation of the materials used. T ape casting was performed on a batch process type easter, and the tapes wer e cast using varying blade gaps and casting speeds. It can be concluded tha t a higher degree of accuracy in tape thickness can be obtained when castin g at lower casting speeds. However, this accuracy decreases when thinner ta pes are required, and the optimized use of an increasing casting speed woul d be needed to maintain this accuracy. An optimal setting between the casti ng speed and the blade gap setting is, therefore, needed in order to achiev e accurate and reproducible results when performing tape casting. Determina tion of this optimum combination would depend on the required thickness of the final product. (C) 1999 Published by Elsevier Science S.A. All rights r eserved.