Pre-curved spring bolster plate

Abstract

A method and apparatus to mount a pre-curved bolster plate to a substrate. One embodiment of the invention involves a method to assemble a pre-curved bolster plate on a substrate. A second embodiment of the invention involves a method to fabricate a pre-curved bolster plate. A third embodiment of the invention involves an assembled substrate with a pre-curved bolster plate on the opposite side of the assembled substrate, under an electrical contact area of a component on the assembled substrate.

What is claimed is:  
     
         1 . A method to assemble a pre-curved bolster plate to one side of a substrate having a first side and a second side, comprising: 
 attaching a component to an electrical contact area on said first side of said substrate; and    attaching said pre-curved bolster plate on said second side of said substrate, wherein said pre-curved bolster plate is attached to said second side opposite said electrical contact area on said first side of said substrate.    
     
     
         2 . The method of  claim 1 , wherein said component is a land grid array (LGA) component.  
     
     
         3 . The method of  claim 1 , wherein said substrate is selected from a group of substrates consisting of: a printed circuit board (PCB), a multi-chip module (MCM), and a flexible substrate.  
     
     
         4 . The method of  claim 1 , wherein said pre-curved bolster plate includes a material selected from the group consisting of: a stainless steel alloy, a powder-coated spring steel alloy, a plated spring steel alloy, a painted spring steel alloy, a titanium steel alloy, a carbon steel alloy, a magnesium alloy, and an aluminum alloy.  
     
     
         5 . The method of  claim 1 , wherein said pre-curved bolster plate has a spherical curvature.  
     
     
         6 . The method of  claim 1 , wherein said pre-curved bolster plate has a cylindrical curvature.  
     
     
         7 . The method of  claim 1 , wherein said pre-curved bolster plate has a radius of curvature in excess of 100 inches (254 centimeters).  
     
     
         8 . A method to fabricate a pre-curved bolster plate, comprising: 
 selecting a set of physical dimensions of said pre-curved bolster plate;    estimating an initial radius of curvature for said pre-curved bolster plate;    modeling said pre-curved bolster plate after assembly on a substrate;    estimating a more precise radius of curvature for said pre-curved bolster plate after modeling said pre-curved bolster plate after assembly on said substrate;    cutting said pre-curved bolster plate according to said set of physical dimensions; and    stamping said pre-curved bolster plate to achieve said more precise radius of curvature.    
     
     
         9 . The method of  claim 9 , wherein said pre-curved bolster plate is fabricated from a material selected from the group of materials consisting of: a stainless steel alloy, a powder-coated spring steel alloy, a plated spring steel alloy, a painted spring steel alloy, a titanium steel alloy, a carbon steel alloy, a magnesium alloy, and an aluminum alloy.  
     
     
         10 . The method of  claim 9 , wherein said pre-curved bolster plate is stamped to achieve a spherical curvature.  
     
     
         11 . The method of  claim 9 , wherein said radius of curvature is greater than 100 inches (254 centimeters).  
     
     
         12 . The method of  claim 9 , wherein said pre-curved bolster plate is stamped to achieve a cylindrical curvature.  
     
     
         13 . An assembled substrate, comprising 
 a substrate having a first and a second side, and an electrical contact area on said first side;    an electrical component having a plurality of leads attached to said electrical contact area of said substrate; and    a pre-curved bolster plate attached to said second side of said substrate opposite said electrical contact area of said substrate.    
     
     
         14 . The assembled substrate of  claim 13 , wherein said substrate is selected from the group of substrates consisting of: a printed circuit board (PCB), a multi-chip module (MCM), and a flexible substrate.  
     
     
         15 . The assembled substrate of  claim 13 , wherein said component is a land grid array (LGA) component.  
     
     
         16 . The assembled substrate of  claim 13 , wherein said pre-curved bolster plate is fabricated from a material selected from the group of materials consisting of: a stainless steel alloy, a powder-coated spring steel alloy, a plated spring steel alloy, a painted spring steel alloy, a titanium steel alloy, a magnesium alloy, and an aluminum alloy.  
     
     
         17 . The assembled substrate of  claim 13 , wherein said pre-curved bolster plate has a spherical curvature.  
     
     
         18 . The assembled substrate of  claim 13 , wherein said pre-curved bolster plate has a cylindrical curvature.  
     
     
         19 . The assembled substrate of  claim 13 , wherein said pre-curved bolster plate has a radius of curvature in excess of 100 inches (254 centimeters).  
     
     
         20 . The assembled substrate of  claim 13 , wherein said pre curved bolster plate has a radius of curvature less than 100 inches (254 centimeters).