Method of protecting aluminum nitride circuit substrates during electroless plating using sol-gel oxide films and article made therefrom
AssigneeGTE Laboratories Incorporated
InventorsSandra L. Smith, Brian J. Hazen
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Abstract
The present invention describes a process for protecting aluminum nitride circuit substrates during electroless plating using a sol-gel technique. The aluminum nitride substrate is coated with a metal. The coated substrate is etched to form a circuit pattern thereby exposing the aluminum nitride. The etched substrate is placed in a solution of tetraethylorthosilicate and withdrawn. The substrate is dried in air and then baked in an oven to remove all of the organic solvents leaving a stoichio metric film of silica on the exposed substrate. The substrate is then placed in an electroless plating solution and the circuit pattern is plated to a predetermined thickness.
Claims4
A method for forming a microwave circuit on an aluminum nitride substrate comprising the steps of:
- coating said substrate with a metal stack to form a coated substrate;
- etching said coated substrate to form a pattern of said metal stack and exposed surfaces of said coated substrate;
- covering said exposed surfaces of said coated substrate with a dielectric coating;
- and
- electrolessly gold plating said metal stack pattern by dipping said coated substrate into an alkaline electroless gold plating bath.
A method for forming a microwave circuit on an aluminum nitride substrate comprising the steps of:
- coating said substrate with a metal stack to form a coated substrate;
- etching said coated substrate to form a pattern of said metal stack and exposed surfaces of said coated substrate;
- covering said exposed surfaces of said coated substrate with a dielectric coating by dipping said coated substrate into a solution selected from the group consisting of tetraethylorthosilicate and tetraethylorthotitanate;
- electrolessly gold plating said metal stack pattern by dipping said coated substrate into an alkaline electroless gold plating bath;
- removing said coated substrate from said solution and drying in air;
- and
- heating said coated substrate for 10 minutes at 100.degree. C. and then for 10 minutes at 600.degree. C.
Dependencies are inferred from the claim text.