Patent ID: 6598483
Filing Date: 2003-07-29
Classification: G01L

Abstract:
A capacitive vacuum sensor for providing electrical information to an electrical circuit in response to pressure exerted by a gas, said capacitive vacuum sensor comprising:a rigid structure comprising a diaphragm electrode portion having a plurality of elastic portions and a rigid portion for supporting said plurality of elastic portions, each of said plurality of elastic portions having an area that is different than the remaining elastic portions, each of said elastic portions arranged so as to contact the gas, each of said elastic portions being capable of deforming a deformation amount that is proportional to its area in response to a pressure exerted by the gas, each area of said elastic portions differs from the remaining areas of said elastic portions such that each respective deformation amount differs successively; a non-conducting substrate arranged to oppose said rigid structure such that a space is disposed between said non-conducting substrate and said rigid structure; a plurality of fixed electrodes disposed on a side of said non-conducting substrate, the number of fixed electrodes in said plurality of fixed electrodes is equal to the number of elastic portions in said plurality of elastic portions, each of said fixed electrodes is disposed so as to oppose a respective one of said elastic portions, each of said fixed electrodes having an area equal to the area of said respective one of said elastic portions, whereby a change in capacitance between each fixed electrode and respective elastic portion in response to a deformation of said respective elastic portion in accordance with the pressure exerted by the gas provides electrical information to an electrical circuit such that the pressure of the gas is determined from the electrical information; and a plurality of compensating electrodes disposed on said non-conducting substrate, each of said compensating electrodes being disposed adjacent a respective one of said fixed electrodes so as to oppose said rigid portion, each of said compensating electrodes having an area equal to the area of said respective one of said fixed electrodes.