New method for adjustment of elevation of the ceramic flatness for direct deposition

This paper deals with dispensing technology process, some times known “writing”, regarding high resolution deposition of thixotropic materials including standard conductor, resistor and dielectric thick film pastes with common viscosity values. The aim of this work is to achieve in the reproducible process the resolution below 100 µm. In this case, it is necessary to use a higher level of the optimization in comparison with standard conditions. Dispensing system for high resolution printing as a whole is to be divided into several categories. It is necessary to start from the preparation of the substrate and his elevation fixation with dispensing head. Due to the fact that the commercial supplied ceramic substrate for hybrid integrated circuits (usually alumina) does not meet the required geometric parameters for high precision printing inevitable to make a correction for curvature of the surface. While during the printing with common resolution 500 µm is not affected by the flatness of the ceramic surface, in the case of resolutions better than 200 µm (< 100 µm) are subtle motifs practically impossible to print. To assure constant distance between ceramic surface and the dispensing unit is necessary to control Z axis level of the dispensing unit in conformity with corresponding actual value. This fact results from thixotropic materials physical behavior during the dispensing process, where distance fluctuation has to be smaller than 10 µm [1,2,3].