Method of making an electronic package

Abstract

An electronic package and method of making the electronic package is provided. A layer of dielectric material is positioned on a first surface of a substrate which includes a plurality of conductive contacts. At least one through hole is formed in the layer of dielectric material in alignment with at least one of the plurality of conductive contacts. A conductive material is positioned in the at least one through hole substantially filling the through hole. At least one conductive member is positioned on the conductive material in the through hole and in electrical contact with the conductive material. The electronic package improves field operating life of an assembly which includes a semiconductor chip attached to a second surface of the substrate and a printed wiring board attached to the conductive members.

1 . An electronic package comprising: 
 a substrate having a first surface, said first surface having a plurality of conductive contacts thereon;    a layer of dielectric material having a first and second surface, said first surface of said dielectric material positioned substantially on said first surface of said substrate;    at least one through hole positioned in said layer of dielectric material substantially aligned with at least one of said plurality of said conductive contacts, said at least one through hole having a side wall;    a conductive material positioned in said at least one through hole, said conductive material substantially filling said through hole and being in electrical contact with said at least one of said plurality of conductive contacts; and    at least one conductive member positioned on said conductive material in said at least one through hole and in electrical contact with said conductive material.    
   
   
       2 . The electronic package of  claim 1  wherein said substrate is comprised of a ceramic material.  
   
   
       3 . The electronic package of  claim 2  wherein said ceramic material includes at least one layer of glass.  
   
   
       4 . The electronic package of  claim 1  wherein said layer of dielectric material has an elastic modulus of from about 50,000 psi. to about 300,000 psi.  
   
   
       5 . The electronic package of  claim 1  wherein said layer of dielectric material is comprised of a material selected from the group of organic polymers consisting of fluoropolymers, allyated polyphenyl ethers, and cyanate ester epoxies.  
   
   
       6 . The electronic package of  claim 1  wherein said layer of dielectric material includes a plurality of said through holes therein.  
   
   
       7 . The electronic package of  claim 1  wherein said at least one through hole includes a layer of plated material on said side wall.  
   
   
       8 . The electronic package of  claim 7  wherein said layer of plated material is selected from the group consisting of copper, nickel, gold, palladium, tin, and lead.  
   
   
       9 . The electronic package of  claim 1  wherein said conductive material is selected from the group consisting of eutectic solder, high melt solder, lead free solders, and conductive inks.  
   
   
       10 . The electronic package of  claim 1  wherein said conductive member comprises a solder ball.  
   
   
       11 . The electronic package of  claim 10  wherein said solder ball comprises high melt solder and lead free solder.  
   
   
       12 . The electronic package of  claim 1  further including at least one conductive pad positioned on said second surface of said dielectric material, said conductive pad in electrical contact with both said conductive material and said at least one conductive member.  
   
   
       13 . A method of making an electronic package comprising the steps of: 
 providing a substrate having a first surface, said first surface having a plurality of conductive contacts thereon;    positioning a layer of dielectric material having a first and second surface substantially on said first surface of said substrate;    forming at least one through hole in said layer of dielectric material in alignment with said at least one of said plurality of said conductive contacts, said at least one through hole having a side wall;    positioning a conductive material in said at least one through hole so as to substantially fill said through hole and to be in electrical contact with said at least one of said plurality of conductive contacts; and    positioning at least one conductive member on said conductive material in said at least one through hole and in electrical contact with said conductive material.    
   
   
       14 . The method of making the electronic package of  claim 13  wherein said layer of dielectric material is positioned by laminating a layer of an organic polymeric material onto a first metal layer, said first metal layer including at least one clearance hole therein, and positioning a second layer of metal having a preselected thickness on one surface of said layer of organic polymeric material, said second layer of metal and said first metal layer being separated by said layer of organic polymeric material.  
   
   
       15 . The method of making the electronic package of  claim 14  wherein said at least one clearance hole is formed by etching prior to said laminating of said layer of organic polymeric material onto said first metal layer.  
   
   
       16 . The method of making the electronic package of  claim 14  wherein said step of positioning said second layer of metal having a preselected thickness on one of said surfaces of said layer of organic polymeric material further includes removing a portion of said second layer of metal to reduce said preselected thickness after said positioning of said second layer of metal on one of said surfaces of said layer of organic polymeric material.  
   
   
       17 . The method of making the electronic package of  claim 16  wherein the step of removing a portion of said second layer of metal comprises etching said second layer of metal to a thickness of about 3 microns.  
   
   
       18 . The method of making the electronic package of  claim 16  wherein said step of forming said at least one through hole in said layer of dielectric material is accomplished by laser drilling.  
   
   
       19 . The method of making the electronic package of  claim 16  wherein said step of positioning said conductive material in said at least one through hole comprises screening.  
   
   
       20 . The method of making the electronic package of  claim 19  further including the step of removing said second layer of metal from said one surface of said organic polymeric material prior to said screening.  
   
   
       21 . The method of making the electronic package of  claim 20  further including the step of plating a layer of copper on said side wall of said at least one through hole prior to removing said second layer of metal from said one surface of said organic polymeric material.  
   
   
       22 . The method of making the electronic package of  claim 13  wherein the step of positioning said at least one conductive member on said conductive material comprises placing a high melt solder ball on said conductive material.