Patent ID: 7279724

Claim:
A device comprising: a ceramic substrate having atop surface and a bottom surface, the top surface having at least one metal electrode Mr electrical connection to an electrode of an overlying semiconductor device, the ceramic substrate comprising a first area containing a first metal oxide, the first area forming a metal oxide varistor that provides electrostatic discharge (ESD) protection of a semiconductor device mounted over a top surface of the ceramic substrate, the ceramic substrate also comprising a second area containing a ceramic second material that does not contain any first metal oxide, the second area not forming a varistor. wherein the first metal oxide comprises zinc oxide, and wherein the-zinc oxide is located only around at least a portion of a periphery of the ceramic substrate, and the second area is located at a central portion of the ceramic substrate; metal pads on a top surface of the ceramic substrate for connection to the semiconductor device; metal electrodes for electrical connection to a printed circuit board; metal vias through the ceramic substrate for electrically connecting the metal pads to the metal electrodes; and the second material comprises one of aluminum oxide, aluminum nitride, silicon carbide, or boron nitride, and the first metal oxide comprises zinc oxide.