Heat sink and process and molding tool for production of same

Abstract

A heat sink of metal material, in particular a light metal alloy, for semi-conductor elements or similar components, has plate-like cooling ribs projecting from a base plate at intervals (f) and approximately parallel to each other, protrude with a connection strip into the base plate in which they are cast. A molding tool designed for production of the heat sink includes a casting mold with a mold chamber for the base plate. The mold chamber contains an area to receive the connection strips of the cooling ribs. Two parallel side walls of the casting mold and intermediate layers arranged parallel between them, each defining a receiver gap, are arranged displaceably on at least one shaft passing through them. The walls can be moved to produce the compact casting mold after insertion of the cooling ribs in the receiver gaps.

1 . A heat sink having a base plate; a plurality of cooling ribs extending from the base plate, the cooling ribs being spaced from each other a distance f and each cooling rib having a connection strip which protrudes into the base plate, the improvement which comprises: 
 the base plate and cooling ribs are a cast structure wherein the base plate is cast onto the connection strips of the cooling ribs.    
     
     
         2 . A heat sink according to  claim 1 , wherein the base plate is provided with at least one insert of highly heat-conductive material.  
     
     
         3 . A heat sink according to  claim 2 , wherein the insert is a heat pipe.  
     
     
         4 . A heat sink according to  claim 3 , wherein a plurality of heat pipes are provided which run substantially parallel to each other and to end faces of the base plate.  
     
     
         5 . A heat sink according to  claim 2  including a plurality of inserts wherein the inserts extend between parallel sides of the base plate.  
     
     
         6 . A process for the production of a heat sink comprising the steps of: 
 providing a mold having a plurality of space apart intermediate layers which define therebetween a plurality of receiver gaps of width f, the mold having a chill mold chamber and the receiver gaps opening into the mold cavity;    positioning cooling ribs into the plurality of receiver gaps wherein a portion of each cooling rib extends into the chill mold chamber a distance n to form connection strips; and    casting molten metal into the chill mold chamber around the connection strips and cooling the metal to form a base plate cast to the cooling ribs.    
     
     
         7 . A process according to  claim 6 , wherein the mold includes two face walls parallel to the intermediate layers and the process includes moving the two face walls toward each other after the positioning and prior to the casting.  
     
     
         8 . A process according to  claim 6 , wherein prior to casting, inserts of heat conductive material are located in the chill mold chamber.  
     
     
         9 . A molding tool for the production of a heat sink having a base plate and cooling ribs projecting approximately parallel from the base plate comprising a casting mold having a chill mold chamber for forming the base plate and this chill mold chamber includes means to receive connection strips of height (n) of the cooling ribs, wherein (n) is less than a height (e) of the chill mold chamber.  
     
     
         10 . A molding tool according to  claim 9 , wherein the casting mold further includes two parallel side walls and intermediate layers arranged parallel between the side wall wherein the side walls and intermediate layers are arranged displaceably on at least one shaft passing through them.  
     
     
         11 . A molding tool according to  claim 10 , wherein the chill mold chamber has a bore which is substantially formed by edges of the intermediate layers.  
     
     
         12 . A molding tool according to  claim 10 , wherein the shaft form a stop for the cooling ribs inserted in the receiver gaps an insertion depth (t) is less than the height (h 1 ) of the cooling ribs.