Surface mount heat sink apparatus

Abstract

A surface mountable heat sink apparatus for use with surface mount electronic components comprises a heat dissipating body and a plurality of solderable feet complying with Surface Mounting Technology (SMT). The heat dissipating body and the solderable feet are made of different materials and of unitary construction. The solderable feet project partially beyond one edge of the heat dissipating body. The surface mount heat sink apparatus and surface mount electronic component are touchlessly sandwiched and simultaneously soldered onto the solder drain pads on the printed circuit board. Heat dissipated from the surface mount electronic component is conductively transferred to the heat sink body through the solder drain pad, printed circuit board and solderable feet, and finally rejected to surroundings thereafter. Like all the SMT electronic components, the surface mount heat sink apparatus can be placed onto the printed circuit board manually or automatically by a pick-&-place automation equipment.

1 . A surface mount heat sink apparatus for use with at least one SMT electronic component; the apparatus comprising:
 (a) a heat dissipating body; and   (b) a plurality of solderable feet;   said heat dissipating body and said solderable feet being made of different materials and of unitary construction; said solderable feet configured having fixed and tight connection with said heat dissipating body;   
     
     
         2 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 1  wherein said heat dissipating body configured being a U-shaped member having two side walls or legs with continuous interior and exterior surfaces. 
     
     
         3 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 2  wherein said continuous exterior surfaces of said U-shaped member usually having fins attached or born thereto, and said continuous interior surfaces maybe having fins attached or born thereto; 
     
     
         4 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 2  wherein said the two side walls or legs, each having a circular aperture close to its free end; 
     
     
         5 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 4  wherein said circular aperture having a length “l”, an internal diameter of “d” and an arc “α” defined to be 180°<α<360°, preferred to be 270°. 
     
     
         6 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 1  wherein said solderable feet configured being a solid rod or wire having a length “L” and a diameter of “D”; 
     
     
         7 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 6  wherein said diameter (D) of said rod is slighter smaller than said internal diameter (d) of said circular aperture on said side wall or leg, expressed as D<d; 
     
     
         8 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 6  wherein said length (L) of said rod may be slighter longer than said length (l) of said circular aperture on said side wall or leg, expressed as L>l; 
     
     
         9 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 1  wherein said unitary construction being that said solderable feet configured to cooperatively engage a corresponding said circular aperture in said heat dissipating body fixedly and tightly; 
     
     
         10 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 9  wherein said solderable feet configured to cooperatively engage a corresponding said circular aperture in said heat dissipating body including partial body of each said foot projects beyond the boundary of said heat dissipating body; 
     
     
         11 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 1  wherein said fixed and tight connection configured to minimize the thermal resistance of the interfaces between said solderable feet and said heat dissipating body; 
     
     
         12 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 1  wherein said different materials referring to said heat dissipating body being made of conductive material, like aluminum, and said solderable feet being made of solderable material, like copper; 
     
     
         13 . A surface mount heat sink apparatus for use with at least one SMT electronic component; the apparatus comprising:
 (a) a heat dissipating body;   (b) a plurality of solderable feet; and   (c) means for joining said solderable feet inside;   said heat dissipating body and said solderable feet being made of different materials and of unitary construction; said solderable feet configured having fixed and tight interface connection with said heat dissipating body; said means for said unitary construction or joining of said heat dissipating body and said solderable feet together being very economical;   
     
     
         14 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 13  wherein said economical means of joining ensuring tight contact and minimizing the thermal resistance at the interface; 
     
     
         15 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 13  wherein said economical means including machiningless, weldingless and fixtureless assembly operations; 
     
     
         16 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 15  wherein said assembly operations including deforming, pressing and swaging, etc. simple mechanical work; 
     
     
         17 . A surface mount heat sink apparatus for use with at least one SMT electronic component as recited in  claim 15  wherein said assembly operations including taking the advantage of TEC (thermal expansion coefficient) of material properties of the two parts, and using temperature differentials in the assembly operation.