E.i. Dupont De Nemours and Company

Samuel Jacob Horowitz

Lewis Charles Hoffman

Thick film conductors for hybrid microelectronic applications, having improved aged adhesion on various substrates such as 96% Al.sub.2 O.sub.3 and BeO, are provided. The improved aged adhesion at the solder joints is a result of the incorporation of cobalt-based additives into the inorganic binder.

Thick film conductors having improved aged adhesion

Thick film resistors, based on pyrochlore conductive phase, glass, and refractory fillers having a thermal expansion coefficient range of 40.times.10.sup.-7 -60.times.10.sup.-7 /.degree. C. and low solubility in the glass, are provided. Such thick film resistor pastes afford resistors having excellent stability to mechanical or thermal stresses.

Stable pyrochlore resistor compositions

Compositions useful for making electrical conductor patterns on a nonconductive substrate, the compositions comprising finely divided Pd/Ag and inorganic binder. The binder is free of bismuth oxide to reduce staining at conductor/resistor interfaces, and comprises certain proportions of glass, copper oxide, and pyrochlore-related oxide (lead ruthenate and/or copper bismuth ruthenate); lead oxide is optional. Despite the absence of bismuth oxide, aged adhesion is good, as is solder acceptance.

Novel silver compositions

Compositions useful for making electrical conductor patterns on a nonconductive substrate, the compositions comprising metal powder and 1-5% glass-free inorganic binder. The binder consists essentially of certain amounts of bismuth oxide and oxides of copper and/or lead, and optionally MnB.sub.2 and/or MnO.sub.2. The metal powder is either silver or a mixture of silver with a second metal powder; the second metal powder is Pt, Pd, Au, or an alloy of Cu with one or more of Pt, Pd, Au, and Ag. The weight ratio of Ag to other metals is at least 17/1. These compositions are useful for making conductor patterns on substrates, which patterns have good adhesion to the substrate, both initially and after thermal aging (e.g., 150.degree. C. for 48 hours).

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Snyder, NY, United States of America

Samuel Jacob Horowitz