Removal of Carbonaceous Residue with Wet Hydrogen in Greensheet Processing for Multilayer Ceramic Module: II, Reaction in Large Modules Influenced by Pore Diffusion and Mass Transfer

An experimental and mathematical investigation of the removal of carbonaceous residue deposited on the ceramic substrate in the fabrication of multilayer ceramic modules has been conducted. Such carbonaceous residue is formed when the organic binder is pyrolyzed during the firing of greensheets. This paper is the second of a two‐part series that reports on and discusses the principal findings of the investigation. In this paper we describe the removal of carbonaceous residue from large blocks of the multilayer ceramic module in which the diffusion of gaseous species may play a role. A mathematical model is developed using the Law of Additive Reaction Times for fluid‐solid reactions, which incroporates the effects of intrinsic chemical kinetics, pore diffusion, and external mass transfer. This law gives an approximate solution to the governing equations which describe the removal of carbonaceous residue from the MLC module during firing.