Removal of Pores and Fissures in Thick Ceramic Films
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Ceramic dielectrics and glasses sometimes require heavy slurries in thickness of 12 to 30 microns. Elimination of porosity, fissures and craters in such thicknesses is difficult. The use of high temperatures is often restrictive. To eliminate these flaws and to lower the densification temperature, hot isostatic pressing (HIP) with an interposed thin metal membrane is employed in the following steps, as shown in the figure. 1. First, the thick film slurry is applied and baked to remove organic vehicles and to establish desired oxygen content. 2. Second, the part is placed in a metal envelope. The top is a thin metal membrane of Cu, Au, Ag, Ni, Fe, INVAR* which is opposed to the slurry surface. The envelope is welded closed. 3.