Heat sink and method of removing heat from power electronics components

Abstract

A heat sink 28 is provided for removing heat from a component 30 on a circuit board 22. The heat sink 28 includes a base 12 having a top 14, a bottom 16, and opposing sides 18 and 20. The top is generally planar for being adhered to a circuit board. Each of the opposing sides has a cutout defining a stepped shoulder 26. The heat sink also includes a plurality of fins 24 extending from the bottom of the base. Locating structure 50 is provided on the top of the heat sink for locating the heat sink with respect to the circuit board 22. Since the heat sink can be glued to the circuit board, a common heat sink can be used for any power electronics component.

What is claimed is:  
     
         1 . A heat sink for removing heat from a component on a substrate, the heat sink comprising: 
 a base having a top, a bottom and opposing sides, the top being generally planar for being adhered to a substrate, each of the opposing sides having a cutout defining a stepped shoulder, and    a plurality of fins extending from the bottom of the base.    
     
     
         2 . The heat sink of  claim 1 , wherein the base and fins are formed integrally.  
     
     
         3 . The heat sink of  claim 2 , wherein the base and fins are an extrusion.  
     
     
         4 . The heat sink of  claim 2 , wherein the base and fins are composed of one of aluminum and magnesium.  
     
     
         5 . The heat sink of  claim 1 , further comprising locating structure on the top of the base for locating the heat sink with respect to a substrate.  
     
     
         6 . The heat sink of  claim 5 , wherein the locating structure includes a plurality of members of generally rectangular cross-section extending from the top of the base.  
     
     
         7 . A heat sink for removing heat from a component on a substrate, the heat sink comprising: 
 a base having a top, a bottom and opposing sides, the top being generally planar for being adhered to a substrate, the base including locating structure on the top thereof for locating the heat sink with respect to a substrate, and    a plurality of fins extending from the bottom of the base.    
     
     
         8 . The heat sink of  claim 7 , wherein the locating structure includes a plurality of members of generally rectangular cross-section extending from the top of the base.  
     
     
         9 . A method of removing heat from a component mounted on a substrate, the method including: 
 providing a heat-generating component on a top side of a substrate,    providing a heat sink having a base including a top, a bottom and opposing sides, the top being generally planar for mounting to a circuit board, the heat sink also including a plurality of fins extending from the bottom of the base, and    applying thermal adhesive to the bottom of the substrate or at least a portion of the top of the heat sink and securing the top of the heat sink to the bottom side of the substrate so as to remove heat from the component.    
     
     
         10 . The method of  claim 9 , wherein each of the opposing sides of the heat sink has a cutout defining a stepped shoulder, the method further comprising: 
 providing a cover member having a top surface and a bottom surface, and a bore there-through, at least the top surface being generally planar,    inserting the fins through the bore with sealant, provided between the top surface of the cover member and the shoulders, sealing the bore.    
     
     
         11 . The method of  claim 9 , wherein the component provided is a power electronics component.  
     
     
         12 . The method of  claim 11 , wherein the power electronics component is a MOSFET.  
     
     
         13 . The method of  claim 10 , wherein the cover member is composed of one of plastic and aluminum and is configured to protect the bottom side of the substrate without contacting any portions of electrical components on the bottom side of the substrate.  
     
     
         14 . The method of  claim 9 , wherein the sealant is silicone.  
     
     
         15 . The method of  claim 9 , wherein the heat sink is composed of one of aluminum and magnesium.  
     
     
         16 . The method of  claim 9 , wherein the top of the base includes locating structure and the substrate includes locating holes therein, the securing step including placing the locating structure in the locating holes.  
     
     
         17 . The method of  claim 9 , wherein the adhesive applied to the portion of the top of the base.  
     
     
         18 . A method of making a heat sink comprising: 
 extruding material to form a heat sink extrusion of a certain length, the heat sink extrusion having a base including a top, a bottom and opposing sides, the top being generally planar for mounting to a circuit board, the heat sink extrusion also including a plurality of fins extending from the bottom of the base,    machining, at each of the opposing sides, a cutout defining a stepped shoulder, and    cutting the extrusion across the certain length at various locations to provide a plurality of heat sinks from the extrusion.    
     
     
         19 . The method of  claim 18 , wherein the extrusion further includes at least one rib on the top of the base extending the certain length, after the cutting step, the method including removing a central portion of the rib to define locating structure.  
     
     
         20 . The method of  claim 19 , wherein the locating structure comprises at least one pair of locators, each locator having a generally rectangular cross-section.