Solder attach apparatus and method

Abstract

An electronic device including a solder structure and methods of forming an electrical interconnection are shown. Solder structures are shown including a solder ball formed from a first solder having a first melting temperature, and a connecting structure coupling the solder ball to one or more electrical connection pads, the connecting structure formed from a second solder having a second melting temperature lower than the first melting temperature. Electronic devices are shown including a polymer mold material formed over the solder structures.

1 . A method, comprising:
 coupling a solder ball to an electrical connection pad using a second solder with a second melting temperature lower than a first melting temperature of the solder ball;   forming a mold material over the solder ball at a temperature lower than the second melting temperature; and   opening a via into the mold material to expose the solder ball.   
     
     
         2 . The method of  claim 1 , wherein forming the mold material includes extruding under pressure and curing the mold material over the solder ball. 
     
     
         3 . The method of  claim 1 , wherein opening a via into the mold material includes laser drilling. 
     
     
         4 . The method of  claim 1 , wherein opening a via into the mold material includes etching. 
     
     
         5 . The method of  claim 1 , wherein coupling the solder ball to an electrical connection pad includes coupling a solder ball to an electrical connection pad on a topside of a first semiconductor chip package substrate. 
     
     
         6 . The method of  claim 5 , further including bonding a second semiconductor chip package to the topside of the first semiconductor chip package, and electrically connecting the first semiconductor chip package to the second semiconductor chip package by reflowing the solder ball and the second solder. 
     
     
         7 . A method of forming an electronic device, comprising:
 coupling a solder ball to a connection pad on a first package substrate using a second solder with a second melting temperature lower than a first melting temperature of the solder ball;   forming a mold material over the solder ball at a temperature lower than the second melting temperature; and   opening a via into the mold material to expose the solder ball; and   coupling a second package substrate to the solder ball, over the mold material.   
     
     
         8 . The method of  claim 7 , wherein coupling a solder ball includes using a solder having a melting temperature greater than approximately 210° C. 
     
     
         9 . The method of  claim 7 , wherein coupling a solder ball includes using a solder having a melting temperature between approximately 246° C. and 252° C. 
     
     
         10 . The method of  claim 7 , wherein coupling a solder ball includes using a solder having a melting temperature between approximately 215° C. and 220° C. 
     
     
         11 . The method of  claim 7 , wherein coupling a solder ball includes coupling a tin based solder ball. 
     
     
         12 . The method of  claim 7 , wherein the coupling a solder ball includes coupling a tin antimony based solder ball. 
     
     
         13 . A method, comprising:
 coupling a solder ball to an electrical connection pad using a second connecting structure with a second melting temperature lower than a first melting temperature of the solder ball;   forming a mold material over the solder ball at a temperature lower than the second melting temperature; and   opening a via into the mold material to expose the solder.   
     
     
         14 . The method of  claim 13 , wherein the connecting structure includes mixed flux and solder particles. 
     
     
         15 . The method of  claim 13 , wherein the connecting structure is formed from a solder having a melting temperature between approximately 180° C. and 210° C. 
     
     
         16 . The method of  claim 15 , wherein the connecting structure is formed from a tin silver copper based solder. 
     
     
         17 . The method of  claim 16 , wherein the tin silver copper based solder further includes indium and zinc. 
     
     
         18 . The method of  claim 16 , wherein the tin silver copper based solder further includes indium and bismuth. 
     
     
         19 . The method of  claim 15 , wherein the connecting structure is formed from a solder including tin, silver, indium and zinc.