Patent ID: 7262467

Claim:
An over-voltage protection device, comprising: a substrate including an upper surface and a lower surface; a first electrode provided on the upper surface of the substrate; a second electrode provided on the lower surface on the substrate; a first conductive layer overlying the lower surface of the substrate, the first conductive layer being a conductive layer of a first type; a second conductive layer provided over the first conductive layer, the second conductive layer having a higher resistivity than the first conductive layer; a plurality of first conductive regions provided proximate the upper surface of the substrate, the plurality of first conductive regions being conductive regions of the first type; and a plurality of second conductive regions provided proximate the upper surface of the substrate, the plurality of second conductive regions being conductive regions of a second type, the second conductive regions being configured to provide a forward bias with the second conductive layer, wherein the plurality of the first conductive regions are provided in an alternating manner with the plurality of second conductive regions, wherein the first electrode is contacting the plurality of the first and second conductive regions, wherein the over-voltage protection device is configured to act as a resistor when the first electrode is applied with a voltage that is less than a snapback voltage and as a forward-biased diode if the voltage applied exceeds the snapback voltage, wherein the first electrode is provided a distance w from an edge of the substrate, the distance w being larger than a diffusion length of holes in the second conductive layer.