Gas sensor apparatus for automotive exhaust gas applications

Abstract

A gas sensor apparatus and method of forming the same generally includes a gas sensor element comprising a heater and a plurality of electrodes. A ceramic substrate can be provided for supporting the electrodes on one side of the ceramic substrate and the heater on the opposite side of the ceramic substrate. The gas sensor element is preferably embedded in the ceramic substrate. The ceramic substrate also possesses a substantially circular shape in order to prevent a breakage of the gas sensor element, avoid thermal loss, and permit the gas sensor apparatus to withstand mechanical shock and high vibrations while occupying a minimal package space.

1 . A gas sensor apparatus, comprising;
 a gas sensor element comprising a heater and a plurality of electrodes; and   a ceramic substrate for supporting said plurality of electrodes on one side of said ceramic substrate and said heater on an opposite side of said ceramic substrate, wherein said gas sensor element is embedded in said ceramic substrate, said ceramic substrate having a substantially circular shape in order to prevent a breakage of said gas sensor element, avoid thermal loss, and permit said gas sensor apparatus to withstand mechanical shock and high vibrations while occupying a minimal package space.   
     
     
         2 . The apparatus of  claim 1  further comprising:
 a plurality of contact terminals connected to said ceramic substrate in order to provide at least one electrical connection to said gas sensor apparatus; and   a metallic housing, which surrounds and protects said gas sensor element, said heater element and said ceramic substrate.   
     
     
         3 . The apparatus of  claim 2  wherein said gas sensor element comprises a holding end portion located and secured in said metallic housing and a sensing end portion exposed to exhaust gases thereof. 
     
     
         4 . The apparatus of  claim 1  wherein said heater comprises a plurality of platinum heater elements and said plurality of electrodes comprises platinum. 
     
     
         5 . The apparatus of  claim 1  wherein said plurality of electrodes is coated with a sensing material. 
     
     
         6 . The apparatus of  claim 2  wherein said gas sensor element comprises at least one platinum conductive pad and wherein said plurality of contact terminals are resistance-welded to said ceramic substrate. 
     
     
         7 . The apparatus of  claim 1  wherein said heater maintains a temperature of said gas sensor element. 
     
     
         8 . The apparatus of  claim 2  wherein said metallic housing comprises an outer baffle and an inner baffle configured in said metallic housing, thereby covering a gas exposed portion of said gas sensor element. 
     
     
         9 . The apparatus of  claim 8  wherein said inner baffle forms a cup-like groove towards said gas sensor element. 
     
     
         10 . The apparatus of  claim 8  further comprising an embossed element that assists a flow of gas flow near said gas sensor element. 
     
     
         11 . A gas sensor apparatus, comprising;
 a gas sensor element comprising a heater and a plurality of electrodes;   a ceramic substrate for supporting said plurality of electrodes on one side of said ceramic substrate and said heater on an opposite side of said ceramic substrate, wherein said gas sensor element is embedded in said ceramic substrate, said ceramic substrate having a substantially circular shape in order to prevent a breakage of said gas sensor element, avoid thermal loss, and permit said gas sensor apparatus to withstand mechanical shock and high vibrations while occupying a minimal package space;   a plurality of contact terminals connected to said ceramic substrate in order to provide at least one electrical connection to said gas sensor apparatus; and   a metallic housing, which surrounds and protects said gas sensor element, said heater element and said ceramic substrate.   
     
     
         12 . The apparatus of  claim 11  wherein gas said sensor element comprises a holding end portion located and secured in said metallic housing and a sensing end portion exposed to exhaust gases thereof. 
     
     
         13 . The apparatus of  claim 11  wherein:
 said heater comprises a plurality of platinum heater elements and said plurality of electrodes comprises platinum; and   wherein said plurality of electrodes is coated with a sensing material.   
     
     
         14 . The apparatus of  claim 11  wherein said gas sensor element comprises at least one platinum conductive pad and wherein said plurality of contact terminals are resistance-welded to said ceramic substrate. 
     
     
         15 . The apparatus of  claim 11  wherein said heater maintains a temperature of said gas sensor element and said metallic housing comprises an outer baffle and an inner baffle configured in said metallic housing, thereby covering a gas exposed portion of said gas sensor element. 
     
     
         16 . A method of forming a gas sensor apparatus, comprising;
 configuring a gas sensor element to comprise a heater and a plurality of electrodes, wherein said heater maintains a temperature of said gas sensor element;   providing a ceramic substrate for supporting said plurality of electrodes on one side of said ceramic substrate and said heater on an opposite side of said ceramic substrate;   embedding said gas sensor element in said ceramic substrate; and   configuring said ceramic substrate to comprise a substantially circular shape in order to prevent a breakage of said gas sensor element, avoid thermal loss, and permit said gas sensor apparatus to withstand mechanical shock and high vibrations while occupying a minimal package space.   
     
     
         17 . The method of  claim 15  further comprising:
 connecting a plurality of contact terminals to said ceramic substrate in order to provide at least one electrical connection to said gas sensor apparatus; and   surrounding and protecting said gas sensor element, said heater element and said ceramic substrate with a metallic housing.   
     
     
         18 . The method of  claim 16  further comprising:
 configuring said gas sensor element to comprise a holding end portion located and secured in said metallic housing and a sensing end portion exposed to exhaust gases thereof.   
     
     
         19 . The method of  claim 15  further comprising:
 configuring said heater to comprise: a plurality of platinum heater elements and said plurality of electrodes comprises platinum; and   coating said plurality of electrodes with a sensing material.   
     
     
         20 . The method of  claim 16  further comprising:
 configuring said gas sensor element to comprise at least one platinum conductive pad;   resistance-welding said plurality of contact terminals to said ceramic substrate;   configuring said metallic housing to comprise an outer baffle and an inner baffle configured in said metallic housing, thereby covering a gas exposed portion of said gas sensor element;   configuring said inner baffle to form a cup-like groove towards said gas sensor element; and   providing an embossed element that assists a flow of gas flow near said gas sensor element.