Heat sink and a method of manufacturing the heat sink

Abstract

A heat sink includes a base plate and a plurality of thin-sheet fins. The base plate has a plurality of recesses and protruding ribs formed between every two recesses. The protruding ribs are spaced by the respective recesses with an equal space. Each thin-sheet fin comprises a folded engaging portion and a dissipating portion connecting with the engaging portion. The engaging portion has a first extending portion and a second extending portion parallel to the first extending portion and connecting with the first extending portion. The engaging portions are inserted into the recesses of the base plate and abut against a bottom of the recesses.

1 . A heat sink comprising:
 a base plate having a plurality of recesses and protruding ribs formed between every two adjacent recesses; and   a plurality of thin-sheet fins comprising a folded engaging portion and a dissipating portion connecting with the engaging portion, the engaging portion having a first extending portion and a second extending portion parallel to the first extending portion and connecting with the first extending portion, the engaging portion being inserted into the recesses of the base plate and abutting against a bottom of the recesses.   
   
   
       2 . The heat sink as described in  claim 1 , wherein each second extending portion has a free end, the free end abuts against corresponding protruding rib of the base plate. 
   
   
       3 . The heat sink as described in  claim 1 , wherein the first and second extending portions of each thin-sheet fin are curved to have portions thereof inclined to the dissipating portion of each thin-sheet fin. 
   
   
       4 . The heat sink as described in  claim 1 , wherein the first and second extending portions of the engaging portion of each thin-sheet fin are continuously curved and have wavy configurations. 
   
   
       5 . The heat sink as described in  claim 1 , wherein each recess has a configuration corresponding to that of the engaging portion of each thin-sheet fin. 
   
   
       6 . The heat sink as described in  claim 1 , wherein the base plate is made of aluminum extrusion. 
   
   
       7 . The heat sink as described in  claim 1 , wherein each of the protruding ribs has a dent on a center of a top surface thereof. 
   
   
       8 . A method of manufacturing a heat sink, the method comprising the steps of:
 a) forming a plurality of recesses at a surface of a base plate and protruding ribs respectively spaced by the recesses, each recess having two side faces;   b) folding an end of each thin-sheet fin to form an engaging portion having a first extending portion and a second extending portion;   c) inserting the engaging portions of the thin-sheet fins in the recesses; and   d) punching the protruding ribs by plastic deformations of protruding ribs, the side faces of the recesses crimping the thin-sheet fins in the recesses.   
   
   
       9 . The method as described in  claim 8 , wherein the base plate is made by aluminum extrusion. 
   
   
       10 . The method as described in  claim 8 , wherein the second extending portion is parallel and close to the first extending portion. 
   
   
       11 . The method as described in  claim 8 , wherein the step b) further comprises curving the first and second extending portion so that a lower portion of each engaging portion is inclined to the other portion of each thin-sheet fin. 
   
   
       12 . The method as described in  claim 8 , wherein the step b) further comprises curving the first and second extending portion into wavy configurations. 
   
   
       13 . The method as described in  claim 8 , wherein each of the protruding ribs has a dent on a center of a top surface thereof. 
   
   
       14 . The method as described in  claim 8 , wherein the thin-sheet fins are inserted from a side of the base plate along extending directions of the recesses in the step c). 
   
   
       15 . A heat sink comprising:
 a base plate defining a plurality of first recesses and a plurality of second recesses communicating with the first recesses, each first recess inclined relative to each second recess; and   a plurality of fins inserted into the first and second recesses, each fin comprising a folded first portion received in corresponding first recess and a second portion vertically extending from the first portion and partially received in corresponding second recess;   wherein a step portion is formed at a joint of the each first and second recess, and a free end of the first portion abuts against the step portion.   
   
   
       16 . The heat sink as described in  claim 15 , wherein the first portion of each fin is inclined relative to the second portion. 
   
   
       17 . The heat sink as described in  claim 15 , wherein the first portion of each fin has a substantially U-shaped configuration. 
   
   
       18 . The heat sink as described in  claim 17 , wherein a bottom of the first portion abuts against a bottom of the first recess of the base plate.