Folded fin heat sink assembly

Abstract

A folded fin heat sink assembly and a method of fabricating a folded fin heat sink assembly for use as a cooling solution in micro-electronics and/or telecommunication applications. The heat sink assembly is formed by placing a sheet or paste of Sn—Zn solder upon a copper base plate, placing one or more aluminum folded fin assemblies on the solder sheet or paste, heating the base plate, the folded fin assembly and the solder to a temperature exceeding the liquidus temperature of the solder and allowing the solder to flow, and cooling the solder to form a soldered joint between the base plate and the folded fin assembly.

1 . A folded fin heat sink assembly, comprising: 
 a base plate; and    a folded fin structure soldered to said base plate with a lead-free solder comprising Sn and Zn.    
     
     
         2 . The folded fin heat sink assembly of  claim 1  wherein said folded fin structure comprises Al.  
     
     
         3 . The folded fin heat sink assembly of  claim 1  wherein said base plate comprises Cu.  
     
     
         4 . The folded fin heat sink assembly of  claim 1  wherein said folded fin structure comprises Cu.  
     
     
         5 . The folded fin heat sink assembly of  claim 1  wherein said base plate comprises Al.  
     
     
         6 . The folded fin heat sink assembly of  claim 1  wherein said lead-free solder comprises about 91% Sn and about 9% Zn.  
     
     
         7 . The folded fin heat sink assembly of  claim 1  wherein said base plate is unplated.  
     
     
         8 . The folded fin heat sink assembly of  claim 1  wherein said base plate is nickel plated.  
     
     
         9 . A method of constructing a folded fin heat sink assembly, comprising: 
 placing a lead-free solder comprising Sn and Zn on a base plate;    placing a folded fin structure on the lead-free solder on the base plate;    heating said lead-free solder to a temperature exceeding the liquidus temperature of the solder; and    cooling said lead-free solder to form a soldered joint between said base plate and said folded fin structure.    
     
     
         10 . The method of  claim 9  wherein said folded fin structure comprises Al.  
     
     
         11 . The method of  claim 9  wherein said base plate comprises Cu.  
     
     
         12 . The method of  claim 9  wherein said folded fin structure comprises Cu.  
     
     
         13 . The method of  claim 9  wherein said base plate comprises Al.  
     
     
         14 . The method of  claim 9  wherein said lead-free solder comprises about 91% Sn and about 9% Zn.  
     
     
         15 . The method of  claim 9  wherein said base plate is unplated.  
     
     
         16 . The method of  claim 9  wherein said base plate is nickel plated.  
     
     
         17 . The method of  claim 9  wherein heating said lead-free solder comprises heating said lead-free solder to a temperature of about 220 to 260 degrees Celsius.  
     
     
         18 . A heat sink assembly, comprising: 
 a nickel plated base plate; and    a fin structure soldered to said base plate with a lead-free solder comprising Sn and Zn.    
     
     
         19 . The heat sink assembly of  claim 18  wherein said fin structure comprises Al.  
     
     
         20 . The heat sink assembly of  claim 18  wherein said base plate comprises Cu.  
     
     
         21 . The heat sink assembly of  claim 18  wherein said fin structure comprises Cu.  
     
     
         22 . The heat sink assembly of  claim 18  wherein said base plate comprises Al.  
     
     
         23 . The heat sink assembly of  claim 18  wherein said lead-free solder comprises about 91% Sn and about 9% Zn.  
     
     
         24 . A method of constructing a heat sink assembly, comprising: 
 placing a lead-free solder comprising Sn and Zn on a nickel plated base plate;    placing a fin structure on the lead-free solder on the base plate;    heating said lead-free solder to a temperature exceeding the liquidus temperature of the solder; and    cooling said lead-free solder to form a soldered joint between said base plate and said fin structure.    
     
     
         25 . The method of  claim 24  wherein said fin structure comprises Al.  
     
     
         26 . The method of  claim 24  wherein said base plate comprises Cu.  
     
     
         27 . The method of  claim 24  wherein said fin structure comprises Cu.  
     
     
         28 . The method of  claim 24  wherein said base plate comprises Al.  
     
     
         29 . The method of  claim 24  wherein said lead-free solder comprises about 91% Sn and about 9% Zn.  
     
     
         30 . The method of  claim 24  wherein heating said lead-free solder comprises heating said lead-free solder to a temperature of about 220 to 260 degrees Celsius.