Adapter which emulates ball grid array packages

Abstract

An adapter for emulating a ball grid array type package includes a dielectric substrate having an array of holes formed therein. A layer of conductive material is deposited on a bottom surface of the substrate and onto the inner walls of the holes. The bottom surface of the substrate is then selectively etched to form separate conductive traces extending from each of said holes and terminating in a pad proximate to each hole. A conductive pin is inserted into each of the holes and soldered in place. The pads are then provided with a small ball of solder, using well known techniques, so that the bottom surface of the substrate now appears virtually identical to a bottom surface of a conventional ball grid array type package. The adapter is then mounted to an array of contact pads on a printed circuit board by fusing the solder balls to corresponding contact pads on the board. The pins are now electrically connected to the contact pads on the circuit board and may be connected to a tester.

What is claimed is: 
     
       1. An adapter for emulating a ball grid array type package comprising: a dielectric substrate, said substrate having an array of holes formed therein, each of said holes having walls at least partially plated with a conductive material, each of said holes having an opening in a top surface of said substrate;   conductive traces formed on a bottom surface of said substrate, each of said traces extending from said conductive material plating a wall of an associated one of said holes and terminating at a first end;   a plurality of conductive pins, each of said pins being inserted into a respective one of said holes and projecting through said top surface, each of said pins making electrical contact with a respective one of said traces through said conductive material plating said walls; and   conductive balls adhered to said traces proximate to said first end, each of said conductive pins being in electrical contact with a respective one of said conductive balls via one of said conductive traces, said conductive balls being formed in a pattern to correspond with a matching pattern of pads on a circuit board, said conductive balls being formed of a material which, when melted, fuse to said pads.   
     
     
       2. The adapter of claim 1 further comprising a restraining means for holding each of said conductive pins in a position substantially orthogonal to said top surface of said substrate to prevent said pins from bending under normal use. 
     
     
       3. The adapter of claim 1 further comprising a dielectric layer formed on said bottom surface of said substrate for exposing said conductive balls but not exposing said holes. 
     
     
       4. The adapter of claim 1 wherein said conductive pins are female connectors. 
     
     
       5. The adapter of claim 1 wherein said conductive balls comprise solder. 
     
     
       6. An adapter for emulating a ball grid array type package comprising: a dielectric substrate, said substrate having an array of holes formed therein, each of said holes having walls at least partially plated with a conductive material, each of said holes having an opening in a top surface of said substrate;   a plurality of conductive pins, each of said pins being inserted into a respective one of said holes and projecting through said top surface, each of said pins making electrical contact with said conductive material plating said walls; and   conductive balls formed on a bottom surface of said substrate, said conductive balls being in electrical contact with said conductive material plating said walls of respective ones of said holes and being in electrical contact with a respective one of said pins, said conductive balls being formed in a pattern to correspond with a matching pattern of pads on a circuit board, said conductive balls being formed of a material which, when melted, fuse to said pads.   
     
     
       7. The adapter of claim 6 further comprising conductive traces formed on said bottom surface of said substrate, each of said traces extending between a wall of a respective one of said holes and one of said conductive balls. 
     
     
       8. The adapter of claim 6 further comprising conductive traces electrically interconnecting said conductive balls with respective ones of said pins. 
     
     
       9. The adapter of claim 8 further comprising a dielectric layer formed on said bottom surface of said substrate for exposing said conductive balls but not exposing said holes. 
     
     
       10. The adapter of claim 6 further comprising a restraining means for holding each of said conductive pins in a position substantially orthogonal to said top surface of said substrate to prevent said pins from bending under normal use. 
     
     
       11. The adapter of claim 6 wherein said conductive pins are female connectors. 
     
     
       12. The adapter of claim 6 wherein said conductive balls comprise solder. 
     
     
       13. A method of fabricating an adapter for emulating a ball grid array type package, said method comprising the steps of: forming a plurality of holes in a dielectric substrate, said holes having openings in a top surface of said substrate;   coating a bottom surface of said substrate and portions of walls of said holes with a conductive coating;   etching said conductive coating to form traces, each of said traces extending from said conductive coating on an associated one of said walls and terminating in a pad proximate to said associated one of said walls;   inserting conductive pins into said holes, said conductive pins being electrically connected to a respective pad via said conductive traces; and   depositing a solder ball on each pad.   
     
     
       14. The method of claim 13 further comprising the step of forming a dielectric layer on said bottom surface of said substrate for exposing said pads and covering openings of said holes in said bottom surface. 
     
     
       15. The method of claim 13 further comprising the step of soldering said pins to said conductive coating after said pins are inserted into said holes. .Iadd. 
     
     
       16.  An adapter for emulating a ball grid array type package comprising: a dielectric substrate, said substrate having an array of holes formed therein, each of said holes having an inner boundary defined by walls of each of said holes, each of said holes having within its inner boundary a conductive material, each of said holes having an opening in a top surface of said substrate;   a plurality of conductive pins, each of said pins being inserted into a respective one of said holes and protecting through said top surface, each of said pins making electrical contact with said conductive material within said inner boundary of a respective one of said holes; and   conductive balls formed on a bottom surface of said substrate, each of said conductive balls being in electrical contact with said conductive material within said inner boundary of a respective one of said holes and being in electrical contact with a respective one of said pins, said conductive balls being formed in a pattern to correspond with a matching pattern of pads on a circuit board, said conductive balls being formed of a material which, when melted, fuse to said pads. .Iaddend..Iadd.   
     
     
       17.  The adapter of claim 16 further comprising conductive traces formed on said bottom surface of said substrate, each of said traces electrically connecting said conductive material within said inner boundary of a respective one of said holes and one of said conductive balls. .Iaddend..Iadd.18. The adapter of claim 16 further comprising conductive traces electrically interconnecting said conductive balls with respective ones of said pins. .Iaddend..Iadd.19. The adapter of claim 16 further comprising a dielectric layer formed on said bottom surface of said substrate for exposing said conductive balls. .Iaddend..Iadd.20. The adapter of claim 16 further comprising a second substrate for holding each of said conductive sins in a position substantially orthogonal to said top surface of said dielectric substrate to help prevent said pins from 
     
     
        bending under normal use. .Iaddend..Iadd.21.  The adapter of claim 16 wherein said conductive pins are female connectors. .Iaddend..Iadd.22. The adapter of claim 16 wherein said conductive balls comprise solder. .Iaddend..Iadd.23. A method of fabricating an adapter for emulating a ball grid array type package, said method comprising the steps of: forming a plurality of holes in a dielectric substrate, said holes having openings in a top surface of said substrate;   providing a conductive material on a bottom surface of said substrate and over at least a portion of said holes;   etching said conductive material on said bottom surface to form traces, each of said traces being electrically connected to said conductive material over said at least a portion of said holes and terminating in a pad associated with one of said holes;   inserting conductive pins into said holes, said conductive pins being electrically connected to a respective pad via said conductive traces; and   
     
     
       depositing a solder ball on each pad. .Iaddend..Iadd.24.  The method of claim 23 further comprising the step of forming a dielectric layer on said bottom surface of said substrate for exposing said pads. .Iaddend..Iadd.25. The method of claim 23 further comprising the step of providing a dielectric layer overlying said dielectric substrate for holding each of said conductive pins in a position substantially orthogonal to said top surface of said dielectric substrate to help prevent said pins from bending under normal use. .Iaddend.