Method and apparatus for reducing thermal resistance in a vertical heat sink assembly

Abstract

A method and apparatus for an electronic package includes a substrate; a heat source component operably coupled to the substrate, and in direct contact with and electrically connected to a top surface of the substrate; a heat sink assembly in thermal communication with the substrate. The heat sink assembly includes a plurality of distinct vapor chambers, each containing a heat transfer fluid configured to evaporate on a wall in thermal contact with a back surface of the heat source component and condense on an opposing wall defining an exterior wall defining the vapor chambers. Each of the plurality of distinct vapor chambers are serially aligned having facing sidewalls defining each relative to contiguous vapor chambers and at least one of the plurality of distinct vapor chambers includes a lower sidewall defining one distinct vapor chamber substantially aligned with a bottom defining the heat source component such that a bottom portion defining the one distinct vapor chamber is substantially aligned with a bottom portion of the heat source component.

1 . An electronic package comprising: 
 a substrate;    a heat source component operably coupled to said substrate, said component in direct contact with and electrically connected to a first surface of said substrate;    a heat sink assembly in thermal communication with an opposite second surface of said substrate, said heat sink assembly including a plurality of discrete vapor chambers vertically aligned with respect to each other, each of said plurality of discrete vapor chambers containing a heat transfer fluid in thermal contact with a back surface of said heat source component, said heat transfer fluid configured to evaporate from a bottom portion defining each of said plurality of discrete vapor chambers and condense on an upper surface defining an top portion of each of said vapor chambers of said heat sink assembly; and    wherein said each of said plurality of discrete vapor chambers are serially aligned having facing lower and upper surfaces defined by at least one wall therebetween corresponding to contiguous vapor chambers, a lower surface defining one of said plurality of discrete vapor chambers being substantially aligned with a bottom defining said heat source component such that the lower surface defining said one of said plurality of discrete vapor chambers is substantially aligned with a bottom portion of said heat source component.    
   
   
       2 . The electronic package of  claim 1 , wherein said heat sink assembly includes a heat sink in thermal communication with an outer surface defining a lid attached to said substrate.  
   
   
       3 . The electronic package of  claim 2 , wherein said heat sink is integrally formed with said lid.  
   
   
       4 . The electronic package of  claim 2 , wherein said plurality of discrete vapor champers are separated by a horizontal barrier extending from said lower surface to said upper surface and defining contiguous vapor chambers.  
   
   
       5 . The electronic package of  claim 1 , wherein said plurality of vapor chambers includes an upper vapor chamber and a lower vapor chamber.  
   
   
       6 . The electronic package of  claim 5 , wherein when said heat source component is substantially centrally located relative to a length defining said heat sink assembly, said upper vapor chamber is longer than said lower vapor chamber.  
   
   
       7 . The electronic package of  claim 5 , wherein when said heat source component is located substantially above a central location relative to a length defining said heat sink assembly, said lower vapor chamber is longer than said upper vapor chamber.  
   
   
       8 . The electronic package of  claim 1 , wherein said package is selected from the group consisting of ball grid array modules, pin grid array modules, land grid array modules and HyperBGA® modules.  
   
   
       9 . The electronic package of  claim 2 , wherein said lid is formed from material selected from the group consisting of aluminum, copper, Invar, gold, silver, nickel, aluminum-silicon carbide, plastics, ceramics and composites.  
   
   
       10 . The electronic package of  claim 1 , wherein said substrate includes material selected from the group consisting of ceramics, fiberglass, polytetraflouroethylene, and polymers.  
   
   
       11 . The electronic package of  claim 1 , wherein a solid thermal transfer medium is in direct contact with a back surface of each heat source component and an outer surface of a lower wall of said heat sink assembly.  
   
   
       12 . The electronic package of  claim 1 , wherein said heat source component is one of a DCM and a MCM.  
   
   
       13 . A method for lowering a thermal resistance of a vertically oriented heat sink assembly to dissipate heat from a heat source component, the method comprising: 
 configuring a heat sink assembly with a plurality of discrete vapor chambers, each of said plurality of discrete vapor chambers containing a heat transfer fluid in thermal contact with a back surface of the heat source-component, said heat transfer fluid configured to evaporate from a bottom portion defining, each of said plurality of discrete vapor chambers and condense on an upper surface a top portion of each of said vapor chambers of said heat sink assembly; and    configuring said each of said plurality of discrete vapor chambers to be serially, vertically aligned having facing lower and upper surfaces defined by at least one wall therebetween corresponding to contiguous vapor chambers, a lower surface defining one of said plurality of discrete vapor chambers being substantially aligned with a bottom defining the heat source component such that the lower surface defining said one discrete vapor chamber is substantially aligned with a bottom portion of the heat source component.    
   
   
       14 . The method of  claim 13 , further comprising: 
 disposing a heat sink in thermal communication with an outer surface defining lid attached to said substrate.    
   
   
       15 . The method of  claim 14 , further comprising: 
 integrally forming said heat sink with said lid.    
   
   
       16 . The method of  claim 14 , further comprising: 
 separating said plurality of discrete vapor champers with a horizontal barrier extending from said lower surface to said upper surface defining contiguous vapor chambers.    
   
   
       17 . The method of  claim 13 , wherein said plurality of vapor chambers includes an upper vapor chamber and a lower vapor chamber.  
   
   
       18 . The method of  claim 17 , further comprising: 
 locating the heat source component in a central location relative to a length defining said heat sink assembly, wherein said upper vapor chamber is longer than said lower vapor chamber.    
   
   
       19 . The method of  claim 17 , further comprising: 
 locating the heat source component substantially above a central location relative to a length defining said heat sink assembly, wherein said lower vapor chamber is longer than said upper vapor chamber.    
   
   
       20 . The method of  claim 13 , further comprising: 
 disposing a solid thermal transfer medium in direct contact with a back surface of each heat source component and an outer surface defining said heat sink assembly.    
   
   
       21 . The method of  claim 13 , wherein the heat source component is one of a DCM and a MCM.