Metallized Ceramic Cermet Substrate Topseal Process
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
A method of protecting thin film cermet (Cr3Si/SiO2) resistors from contamination and moisture encountered during processing is accomplished by the application of a blanket layer of silicon dioxide over an entire substrate at a point during the manufacturing process shortly after the cermet material is exposed to the environment. The method is described below. The cermet-covered substrate is sputtered with successive layers of chromium (Cr), copper (Cu), and chromium (Cr). Photoresist is applied, exposed, and developed to enable the Cr/Cu/Cr and cermet layers to be etched to personalize circuit lines. The resist is then stripped. Another layer of photoresist is applied, exposed, and developed. The Cr/Cu/Cr layers are etched. The resist is then stripped, and the substrate is cleaned.