Heat sink and method for manufacturing a heat sink

Abstract

A heat sink of a composite material having a first material and a second material is described, the first material including an electrical insulator, and the second material including an electrical conductor, the heat sink having a first side parallel to a main plane of extent of the heat sink, and the heat sink having a second side essentially parallel to the first side and opposite the first side perpendicularly to the main direction of extent, and furthermore the proportion of the first material in the area of the first side being greater than the proportion of the first material in the area of the second side.

1 - 17 . (canceled) 
     
     
         18 . A heat sink made of a composite material, the composite material having a first material and a second material, the first material including an electrical insulator, and the second material including an electrical conductor, the heat sink having a first side parallel to a main plane of extent of the heat sink, and the heat sink having a second side, which is parallel to the first side and is opposite the first side perpendicularly to the main plane of extent, wherein a proportion of the first material in an area of the first side is greater than a proportion of the first material in an area of the second side. 
     
     
         19 . The heat sink as recited in  claim 18 , wherein a proportion of the second material in the composite material in the area of the second side is greater than a proportion of the second material in the area of the first side, the first side having only the first material. 
     
     
         20 . The heat sink as recited in  claim 18 , wherein a proportion of the second material in the composite material in the area of the second side is greater than a proportion of the second material in the area of the first side, the second side having only the second material. 
     
     
         21 . The heat sink as recited in  claim 18 , wherein the proportion of the first material in the composite material decreases from the first side to the second side perpendicularly to the main direction of extent while the proportion of the second material in the composite material increases from the first side to the second side perpendicularly to the main direction of extent. 
     
     
         22 . The heat sink as recited in  claim 21 , wherein the composite material decreases one of continuously, monotonously, and in stages from the first side to the second side perpendicularly to the main direction of extent. 
     
     
         23 . The heat sink as recited in  claim 21 , wherein the proportion of the second material in the composite material increases one of continuously, monotonously, and in stages from the first side to the second side perpendicularly to the main direction of extent. 
     
     
         24 . The heat sink as recited in  claim 18 , wherein the first material has an open porosity, the porosity increasing from the first side to the second side perpendicularly to the main direction of extent, at least one of the pore size and pore density of the first material increasing on an average from the first side to the second side perpendicularly to the main direction of extent, the pores being filled with the second material. 
     
     
         25 . The heat sink as recited in  claim 18 , wherein the composite material has a plurality of composite material layers perpendicularly to the main direction of extent, a ratio of the first material to the second material being different from one composite material layer to another composite material layer. 
     
     
         26 . The heat sink as recited in  claim 18 , wherein the first material is joined to the second material by at least one of a form-fit and a force-fit connection. 
     
     
         27 . The heat sink as recited in  claim 18 , wherein the first material together with the second material forms interpenetrating networks. 
     
     
         28 . The heat sink as recited in  claim 18 , wherein the first material has a profile of a degree of porosity of from 0 vol % to  95  vol % perpendicularly to the main plane of extent, the first side having a composite material layer completely of the first material at least 50 μm thick perpendicularly to the main plane of extent. 
     
     
         29 . The heat sink as recited in  claim 28 , wherein the profile of a degree of porosity is from 0 vol % to  65  vol % perpendicularly to the main plane of extent. 
     
     
         30 . The heat sink as recited in  claim 18 , wherein the first material includes a ceramic material, and the second material includes a metallic material. 
     
     
         31 . The heat sink as recited in  claim 30 , wherein the first material includes at least one of oxides, nitrides and carbides. 
     
     
         32 . The heat sink as recited in  claim 30 , wherein the first material includes at least one of Al 2 O 3 , AlN, Si 3 N 4  and SiC. 
     
     
         33 . The heat sink as recited in  claim 30 , wherein the first material includes Al 2 O 3 . 
     
     
         34 . The heat sink as recited in  claim 30 , wherein the metallic material includes at least one of copper, copper alloys, aluminum and aluminum alloys. 
     
     
         35 . An assembly having a heat sink, the heat sink made of a composite material, the composite material having a first material and a second material, the first material including an electrical insulator, and the second material including an electrical conductor, the heat sink having a first side parallel to a main plane of extent of the heat sink, and the heat sink having a second side, which is parallel to the first side and is opposite the first side perpendicularly to the main plane of extent, wherein a proportion of the first material in an area of the first side is greater than a proportion of the first material in an area of the second side, wherein at least one of an electrical component, electronic component, micromechanical component, a printed conductor and a joining layer is situated on the first side of the heat sink, the first side being covered at least partially with a metal layer. 
     
     
         36 . The assembly, as recited in  claim 35 , wherein the metal layer includes at least one of aluminum and copper. 
     
     
         37 . A method for manufacturing a heat sink, the heat sink made of a composite material, the composite material having a first material and a second material, the first material including an electrical insulator, and the second material including an electrical conductor, the heat sink having a first side parallel to a main plane of extent of the heat sink, and the heat sink having a second side, which is parallel to the first side and is opposite the first side perpendicularly to the main plane of extent, wherein a proportion of the first material in an area of the first side is greater than a proportion of the first material in an area of the second side, the method comprising:
 manufacturing from the first material a preform having a porosity gradient perpendicularly to the main plane of extent; and   filling pores of the preform with the second material.   
     
     
         38 . The method as recited in  claim 37 , wherein the preform is manufactured via negative molding of polyurethane foams pressed together by using slips. 
     
     
         39 . The method as recited in  claim 38 , wherein the preform is manufactured via pressure filtration of a slip and subsequent sintering, at least one slip mold being filled with two slips of different compositions, a ratio between the two slips being varied continuously and then the preform being manufactured via pressure filtration and a sintering method. 
     
     
         40 . The method as recited in  claim 37 , wherein the preform is manufactured via powder pressing, powders of different compositions being layered on top of each other in a female mold and subsequently pressed. 
     
     
         41 . The method as recited in  claim 37 , wherein the preform is manufactured by stacking and sintering a plurality of greenware plates, the greenware plates being stacked on top of each other and yielding different porosities during sintering. 
     
     
         42 . The method as recited in  claim 37 , wherein the preform is manufactured by stacking and joining plates of different porosities, ceramic plates being stacked on top of each other and subsequently sintered to join them together. 
     
     
         43 . The method as recited in  claim 37 , wherein the preform is manufactured via a film-casting method, in which slips of different compositions are cast one over the other by using the film-casting technique, and are subsequently sintered. 
     
     
         44 . The method as recited in  claim 37 , wherein the filling step includes a melt infiltration method in which the preform is infiltrated with the second material in a pressure-assisted procedure and the second material is converted into a liquid aggregate state before the filling step.