Uop Lcc

Daniel S Janikowski

Steven A Bradley

Ming S Shum

Conductive pigment-coated surfaces which are resistant to the effect of moisture may be prepared by admixing an alloy consisting of a conductive nonnoble metal such as copper and preferentially oxidizable material such as boron with a lead-containing compound such as lead oxide. The resulting composite may be further mixed with an organic vehicle to form a conductive ink which, after being painted on a substrate such as alumina and subsequently fired, will provide a conductive pigment-coated surface which is moisture-resistant and which will possess excellent conductive characteristics.

Conductive pigment-coated surfaces

Conductive thick film pigment-coated surfaces which possess desirable conductivity and solderability characteristics are formed from an alloy comprising a mixture of a nonnoble conductive metal, a noble metal and at least one oxidizable material. The oxidizable material is present in the alloy in an amount in the range of from about 5% to about 25% by weight, the nonnoble metal in an amount in the range of from about 94% to about 60% by weight and the noble metal in an amount in the range of from about 1% to about 15% by weight of the alloy. The desired product is prepared by admixing a nonnoble metal, an oxidizable material and a noble metal, arc-melting the mixture to form an alloy, grinding the arc-melted alloy to a powdered form, admixing the powder with the carrier binder, depositing said admixture on an inert surface, firing the admixture and surface in an oxygen-containing atmosphere at a temperature in the range of from about 500.degree. to about 950.degree. C. and fluxing the resultant conductive thick film pigment-coated surface with a zinc-chloride based flux to provide the desired product.

Conductive pigment-coated surfaces may be prepared by alloying a nonnoble conductive metal with an oxidizable material, admixing the alloy with an organic vehicle and a binder to form an ink followed by firing the ink in an oxidizing atmosphere containing about 20% by volume of oxygen at a temperature in excess of 1000.degree. F. If so desired, a vitreous frit may also be present in the mixture. The resulting ink will possess desirable characteristics such as increased resistivity to oxidation, and increased firing strength when the oxidizable material such as boron is present in the alloy in an amount in the range of from about 12% to about 25% by weight.

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Lake Geneva, WI, United States of America

Daniel S Janikowski