Benchmarking of 96 Alumina Substrates for Thick Film Hybrids

摘要

Alumina substrates have been the foundation of hybrid circuitry for over fifty years. Presently, there are multiple substrate suppliers supporting hybrid technology. Each supplier has proprietary methods for manufacturing their products that result in differences in the fired microstructure of the substrates. 96% alumina is the most commonly used substrate, and this particular composition leaves a 4% margin of variation in the chemical make up from each supplier. Data presented in this paper reflect possible differences between suppliers that affect thick film properties when applied to the substrate. Demands from customers may require the use of more than one substrate vendor, and caution must be taken that fired film properties on different substrates may not be identical. The focus of this evaluation is the variation of substrates; no optimization of paste formulations or processing conditions was included in this study. This paper will focus on the affects of the fired properties of precious metal conductors, such as adhesion, solder ability, and conductivity values. Additionally, a comparison of commonly recognized properties of substrates, surface roughness and porosity, is presented. Although this paper will primarily focus on the values and characteristics previously listed, other fired film properties may be affected.