METHOD TO REDUCE DIE EDGE SHORTING ON PRESSURE SENSORS USING CONDUCTIVE ELASTOMERIC SEALS

摘要

A pressure sensor includes a sensing element fabricated on an N-type epitaxial layer (110) grown on a P-type substrate (120), a P-type isolation region (130) located around the edge of the sensing element die (100) and in contact with the P-type substrate (120), and a conductive elastomeric seal engaging the P-type isolation region (130) prevents shorting of the conductive elastomeric seal with the N-type epitaxial layer (110) of the sensing element die. A method of making a pressure sensor comprises growing an n-type epitaxy layer (110) on a p-type substrate wafer (120), resulting in a pressure sensor die (100) and substrate having an edge, obtaining a mask adapted for fabricating an isolation diffusion layer (130) around the edge using P-type material, and creating an isolation layer diffusion using P-type doping material around the edge using the mask. A conductive elastomeric seal can then be placed over the sensor die (100) to make electrical contact to the package.