Locally embedded phase change material for heat sinks

Abstract

A PCM heat sink comprises a thermally conductive body member having a plurality of PCM-receiving bores defined therein from at last one surface thereof. A plurality of pre-cast PCM rods are disposed in respective bores have a phase change temperature from solid to liquid at or just below a specified maximum operating temperature. A plurality of sealing members is disposed in respective bores to seal the rods in the bores. The sealing members may be plugs or thin disc-like lids that are brazed, welded or otherwise secured to the body member at the bore openings.

What is claimed is: 
     
         1 . A PCM heat sink for use in thermally managing components of a system having a maximum permissible operating temperature significantly higher than ambient temperature, said heat sink comprising;
 a thermally conductive body member having a plurality of PCM-receiving blind holes defined therein from at least one surface thereof, wherein said one surface is configured and located to be disposed proximate or adjacent a system component to be thermally managed during use of the heat sink;   PCM material disposed in said blind holes, wherein said PCM material is in solid phase at ambient temperature and has a phase change temperature from solid to liquid at or just below said maximum permissible operating temperature; and   a plurality of sealing members configured to be disposed in respective ones of said blind holes at said one surface to seal said PCM material in said blind holes.   
     
     
         2 . The PCM heat sink of  claim 1 , wherein said PCM material comprises a plurality of PCM rods disposed in respective ones of said blind holes. 
     
     
         3 . The PCM heat sink of  claim 2 , wherein said sealing members are expandable plugs inserted into said blind holes at said one surface, or thin lids brazed or welded to said body member at open ends of said blind holes at said one surface. 
     
     
         4 . The PCM heat sink of  claim 2 , wherein said body member has axial and transverse dimensions, and wherein at least some of said blind holes extend axially into said body member, and others of said blind holes extend transversely into said body member. 
     
     
         5 . The PCB heat sink of  claim 2 , wherein said body member has axial and transverse dimensions, wherein said body member has multiple through-holes defined axially therethrough, and wherein said blind holes are interspersed between and extend parallel to said through-holes. 
     
     
         6 . The PCB heat sink of  claim 2 , wherein the thermally conductive body member is made of aluminum or copper. 
     
     
         7 . The PCB heat sink of  claim 2 , wherein said body member has axial and transverse dimensions, and wherein the axial dimension is substantially shorter than said transverse dimension. 
     
     
         8 . The PCB heat sink of  claim 7 , wherein body member has multiple through-holes defined axially therethrough, and wherein said blind holes are interspersed between and extend parallel to said through-holes. 
     
     
         9 . The PCB heat sink of  claim 2 , wherein said body member has axial and transverse dimensions, wherein the axial dimension is substantially shorter than said transverse dimension, wherein body member has multiple through-holes defined axially therethrough, and wherein said blind holes are interspersed between and extend parallel to said through-holes. 
     
     
         10 . A method for providing a PCM heat sink for use in thermally managing components of a system having a maximum permissible operating temperature significantly higher than ambient temperature, said method comprising;
 providing a thermally conductive body member having mutually perpendicular axial and transverse dimensions, wherein the axial dimension is substantially shorter than the transverse dimension;   forming a plurality of PCM-receiving blind holes extending axially in said body member from one surface thereof;   disposing a plurality of PCM rods in respective ones of said blind holes, wherein said rods are in solid phase at ambient temperature and have a phase change temperature from solid to liquid at or just below said maximum permissible operating temperature; and   sealing said rods in said blind holes at said one surface.   
     
     
         11 . The method of  claim 10  wherein sealing said rods in said blind holes comprises inserting Lee plugs plugs in said blind holes at said one surface. 
     
     
         12 . The method of  claim 10  wherein sealing said rods in said blind holes comprises brazing or welding disc-like lids to said body member at open ends of said blind holes at said one surface. 
     
     
         13 . The method of  claim 10  wherein forming said blind holes comprises machining blind holes axially into said body member from said one surface. 
     
     
         14 . The method of  claim 10  wherein forming said blind holes comprises machining blind holes transversely into said body member from the body member periphery. 
     
     
         15 . The method of  claim 10  wherein said body member has multiple through-holes defined axially therethrough, and wherein forming said blind holes comprises machining said blind holes into said body member from said one surface at locations interspersed between said through-holes.