Electrical Feedthrough Assembly

Abstract

A device includes a hermetically sealed case with electronic circuitry housed within. One surface of the hermetically sealed case includes a metallic plate and a co-fired ceramic electrical feedthrough with a number of vias. The co-fired ceramic electrical feedthrough is hermetically joined to the metallic plate and a hybrid circuit is connected to the feedthrough.

What is claimed is: 
     
         1 . A feedthrough comprising:
 a body having a first side and a second side separated by a thickness;   a first conductive pad on the first side;   a second conductive pad on the second side; and   a plurality of conductive vias electrically connecting the first conductive pad and the second conductive pad.   
     
     
         2 . The feedthrough of  claim 1 , wherein the first conductive pad and second conductive pad comprise different materials. 
     
     
         3 . The feedthrough of  claim 1 , wherein the first conductive pad and the second conductive pad have a common geometry. 
     
     
         4 . The feed through of  claim 3 , wherein a center point of the first conductive pad and a center point of the second conductive pad could be connected by a straight line perpendicular to the first and second conductive pads. 
     
     
         5 . The feedthrough of  claim 1 , wherein the vias have a common geometry. 
     
     
         6 . The feedthrough of  claim 1 , wherein the vias are equidistant from each other. 
     
     
         7 . The feedthrough of  claim 1 , wherein a center of a cross-section of each via is equidistant from a center-point of the first conductive pad. 
     
     
         8 . The feedthrough of  claim 1 , wherein the plurality of vias comprises three vias. 
     
     
         9 . The feedthrough of  claim 1 , wherein each via has a separate contact with the first conductive pad. 
     
     
         10 . The feedthrough of  claim 1 , wherein each via does not electrically communicate with any other via except through the first and second conductive pads. 
     
     
         11 . The feedthrough of  claim 1 , wherein a projection of each via onto the first side remains within a perimeter of the first conductive pad. 
     
     
         12 . The feedthrough of  claim 1 , wherein each via is straight and extends perpendicular to the first and second conductive pads. 
     
     
         13 . The feedthrough of  claim 1 , further comprising an array of vies, each via in the array of vias extending between a unique conductive pad on the first surface and a unique conductive pad on the second surface. 
     
     
         14 . The feedthrough of  claim 1 , further comprising a third conductive pad on the first side and a fourth conductive pad on the second side, where the third and fourth conductive pads are connected by a second plurality of vies. 
     
     
         15 . The feedthrough of  claim 14 , wherein:
 the first and second conductive pads and the plurality of vias form a first structure,   the third and fourth conductive pads and the second plurality of vias form a second structure, and   the first and second structure have a common geometry.   
     
     
         16 . The feedthrough of  claim 15 , further comprising an array of vies, each via in the array of vies extending between a unique conductive pad on the first surface and a unique conductive pad on the second surface 
     
     
         17 . A method of forming a ceramic feedthrough for a hermetically sealed case, the method comprising:
 forming multiple stacked layers comprising green sheet material and metal, wherein the metal forms a plurality of vias through the stacked layers;   co-firing the multiple stacked layers; and   forming a first conductive pad on a top surface of the feedthrough, wherein the first conductive pad is in electrical communication with a second conductive pad on a bottom surface of the feedthrough, the first and second conductive pads electrically connected by the plurality of vias.   
     
     
         18 . The method of  claim 17 , further comprising: brazing the ceramic feedthrough using a braze material containing ceramic particulate. 
     
     
         19 . A device comprising:
 a hermetically sealed case with electronic circuitry housed therein, wherein one surface of the hermetically sealed case comprises:   a metallic plate,   a co-fired ceramic electrical feedthrough hermetically joined to the metallic plate, the feedthrough comprising:
 a conductive via passing from a first conductive pad on a first side of the feedthrough to a second conductive pad on a second side of the feedthrough; and 
 a shield of conductive material shielding the via, the shield not in electrical contact with the via; and 
   a circuit electrically coupled to the via of the feedthrough.   
     
     
         20 . The device of  claim 19 , wherein the shield comprises an electrical contact on the first side of the feedthrough.