Heat sink of porous graphite

Abstract

A heat sink using porous graphite having graphite particle-stacked porous graphite is provided. The heat sink may provide good heat conductivity and improve strength of carbon foam.

What is claimed is: 
     
         1 . A porous graphite heat sink having a main body made of graphite stacked with granulated graphite particles, wherein voids are formed among the granulated graphite particles. 
     
     
         2 . The porous graphite heat sink as claimed in  claim 1 , further including a fin structure. 
     
     
         3 . The porous graphite heat sink as claimed in  claim 1 , having a shape of lamp cup. 
     
     
         4 . The porous graphite heat sink as claimed in  claim 1 , further comprising a protecting layer or an insulating layer provided on the surface of the porous graphite being a heat conductor. 
     
     
         5 . The porous graphite heat sink as claimed in  claim 1 , wherein the porous graphite is prepared by following steps:
 a granulation step for granulating graphite powder and a binder to obtain graphite having large particle size;   a molding step for molding the graphite particles into a green body; and   a heat treatment step for heating the green body to a predetermined temperature for a predetermined period and then cooling off to obtain porous graphite heat sink.   
     
     
         6 . The porous graphite heat sink as claimed in  claim 1 , wherein the size of granulated graphite particles ranges from 300 μm˜1000 μm. 
     
     
         7 . The porous graphite heat sink as claimed in  claim 1 , wherein the porous graphite has porosity rate ranging from 5 to 30%.