Sintered Ceramic Substrate Surface Treatment for Electrochemical Robustness

The patent extracts and removes sintering aids and impurities from the ceramic surface through chemical etching processes. The etching solution selectively removes the glassy additive phase and accumulated sintering aids from the surface while preserving the ceramic bulk material, thereby eliminating the source of electrochemical migration without affecting the sintering performance already achieved.

The patent applies local quality by creating a surface treatment that differs from the bulk material. The chemical etching process modifies only the surface region, removing sintering aids from the surface while leaving the interior structure intact. This results in a surface with different composition and properties than the bulk, specifically reducing electrochemical activity at the surface where it is most problematic.

The patent uses an intermediary approach by employing a chemical etching solution that selectively targets the glassy additive phase and sintering aids rather than the ceramic bulk material. The etching chemistry is chosen to preferentially react with and remove the unwanted surface components while being less aggressive toward the stable ceramic matrix, thus acting as a selective mediator in the removal process.

The patent controls the etching process by adjusting parameters such as etching solution composition, temperature, and exposure time to achieve selective removal. By optimizing these parameters, the process removes sintering aids effectively while minimizing ceramic bulk material loss. The parameter control ensures that the etching stops at the desired depth, preserving the structural integrity of the ceramic substrate.