Heat sink and electronic device employing the same

Abstract

A fan-motor-incorporated heat sink effectively supplies cooling air flow in a thin electronic device having limited space above the heat sink. The heat sink enables air intake above the heat sink by positioning a fan, the fins of a heat sink substrate and the side wall of the substrate lower than the fan driving unit. The heat sink substrate and the fins are formed such that air is exhausted only in one direction. A cover is provided on the side of the heat sink substrate on which the fan driving unit is mounted and to which air is taken in to prevent exhausted air from being taken in. The structure of the electronic device is positioned close to the upper surface of the fan driving unit on the heat sink. Thus, the heat sink can be installed on a thin electronic device while improving the cooling of a heat emitting element.

What is claimed is:  
     
       1. A heat sink comprising: 
       a substrate having a floor and a vertical side wall open in one direction;  
       a plurality of fins vertically projecting from said floor of said substrate;  
       driving means at least a part of which is supported by said floor of said substrate; and  
       a fan rotated by said driving means wherein:  
       a height of an upper surface of said side wall is lower than that of an upper surface of said driving means relative to said floor of said substrate.  
     
     
       2. A heat sink according to  claim 1 , characterized in that the fan has a shape of an axial fan. 
     
     
       3. A heat sink according  claim 1 , wherein said driving means has a housing and said height of said upper surface of said side wall is lower than the height of an upper surface of said housing of said driving means relative to said floor of said substrate. 
     
     
       4. A heat sink comprising: 
       a substrate having a floor and a vertical side wall open in one direction;  
       a plurality of fins vertically projecting from said floor of said substrate;  
       driving means at least a part of which is supported by said substrate;  
       a fan rotated by said driving means; and  
       a plate mounted on an upper surface of said side wall and having an opening, wherein:  
       a height of said upper surface of said side wall and a height of an upper surface of said plate are lower than that of an upper surface of said driving means relative to said floor of said substrate.  
     
     
       5. A heat sink according to  claim 3 , characterized in that the opening of the plate is so large as to allow the driving means to penetrate the plate through said opening but smaller in diameter than the fan. 
     
     
       6. A heat sink according to  claim 5 , characterized in that the fan has a shape of an axial fan. 
     
     
       7. A heat sink according to  claim 4 , characterized in that the fan has a shape of an axial fan. 
     
     
       8. A heat sink comprising: 
       a substrate having a floor;  
       a plurality of fins vertically projecting from said floor of said substrate;  
       driving means at least a part of which is supported by said substrate;  
       a fan rotated by said driving means;  
       a plate having an opening; and  
       a vertical side wall structure disposed between said substrate and said plate, said vertical side wall structure being open in one direction, said plate being positioned at an upper surface of said side wall structure, said plate and said side wall structure forming a frame having a height which is lower than a height of an upper surface of said driving means relative to said floor of said substrate.  
     
     
       9. A heat sink according to  claim 8 , wherein said opening of said plate is sufficiently large to allow said driving means to penetrate said plate but smaller in diameter than said fan. 
     
     
       10. A heat sink according to  claim 8 , wherein said fan has the shape of an axial fan. 
     
     
       11. A heat sink according to  claim 9 , wherein said fan has the shape of an axial fan. 
     
     
       12. A heat sink apparatus comprising: 
       
         a heat sink apparatus substrate for being attached to a heat emitting element, and having a bottom portion with a standing wall mounted thereon;  
       
       
         a driving device supported by said substrate;  
       
       
         a fan mounted on said driving device; and  
       
       
         a cover mounted on said standing wall, wherein:  
       
       
         said driving device protrudes through an opening formed on said cover and a height of an upper surface of said fan and a height of an upper surface of said cover are lower than that of an upper surface of said driving device relative to said bottom wall.  
       
     
     
       13. A heat sink apparatus according to  claim 12 , wherein said heat sink apparatus substrate has a plurality of fins mounted thereon.  
     
     
       14. A heat sink apparatus for being mounted in an electric device in a state of contact with a heat emitting element, said apparatus comprising: 
       
         a housing including an upper wall, a lower wall and a side wall, said housing having two openings;  
       
       
         a plurality of fins provided in said housing;  
       
       
         driving device provided in said housing; and  
       
       
         a fan for being rotated by said driving device, wherein:  
       
       
         a height of an upper surface of said side wall is lower than that of an upper surface of said driving device relative to said lower wall so as to generate a smooth air flow when said heat sink apparatus is mounted in the electric device so that said upper surface of said driving device faces a plane surface in said electric device.  
       
     
     
       15. A heat sink apparatus according to  claim 14 , wherein said fan faces said plurality of fins.  
     
     
       16. A heat sink apparatus according to  claim 14 , wherein one of said two openings is an outlet opening formed in a direction normal to an axial direction of said fan.  
     
     
       17. A heat sink apparatus according to  claim 14 , wherein said fan is a centrifugal fan.  
     
     
       18. A heat sink apparatus for being mounted in an electric device in a state of contact with a heat emitting element, said apparatus comprising: 
       
         a housing having an inlet and an outlet for air;  
       
       
         a driving device provided in said housing and having a protruding portion thereof form said inlet of said housing;  
       
       
         a fan provided in said housing and for being rotated by said driving device; and  
       
       
         a plurality of fins provided in said housing, wherein:  
       
       
         said protruding portion of said driving device and a portion of said housing adjacent to said inlet are for cooperating with said plane surface in said electric device to generate a smooth air flow when said heat sink apparatus is mounted in the electric device so that said inlet is disposed apart from said plane surface.  
       
     
     
       19. A heat sink apparatus according to  claim 18 , wherein said fan faces said plurality of fins.  
     
     
       20. A heat sink apparatus according to  claim 18 , wherein said outlet is formed in a direction normal to an axial direction of said fan.  
     
     
       21. A heat sink apparatus according to  claim 18 , wherein said protruding portion of said driving device and said portion of said casing adjacent to said inlet are for cooperating with said plane surface in said electric device to generate a smooth air flow to said inlet.  
     
     
       22. A heat sink comprising: 
       
         a substrate having a floor and a vertical sidewall structure comprising a plurality of walls;  
       
       
         a driving device supported by said substrate; and  
       
       
         a fan for being rotated by said driving device, wherein:  
       
       
         a height of an entire upper surface of said side wall structure is lower than that of an upper surface of said driving device relative to said floor of said substrate.  
       
     
     
       23. A heat sink according to  claim 22 , wherein the fan has a shape of an axial fan.  
     
     
       24. A heat sink according to  claim 22 , wherein said driving device has a housing which includes said upper surface of said driving device.  
     
     
       25. A heat sink comprising: 
       
         a substrate having a floor and a vertical sidewall;  
       
       
         a driving device supported by said substrate;  
       
       
         a fan for being rotated by said driving device; and  
       
       
         a plate mounted on an upper surface of said sidewall and having an opening, wherein:  
       
       
         a height of said upper surface of said side wall and a height of an upper surface of said plate are lower than that of an upper surface of said driving device relative to said floor of said substrate.  
       
     
     
       26. A heat sink according to  claim 25 , wherein the opening of the plate has a size which is large enough to allow the driving device to penetrate the plate through said opening but which is smaller than the fan.  
     
     
       27. A heat sink according to  claim 26 , wherein the fan has a shape of an axial fan.  
     
     
       28. A heat sink according to  claim 25 , wherein the fan has a shape of an axial fan.  
     
     
       29. A heat sink comprising: 
       
         a substrate having a floor;  
       
       
         a driving device supported by said substrate;  
       
       
         a fan for being rotated by said driving device;  
       
       
         a plate having an opening;  
       
       
         a vertical side wall structure disposed between said substrate and said plate, wherein:  
       
       
         said plate is positioned at an upper surface of said side wall structure, and said plate and said side wall structure form a frame having a height which is lower than a height of an upper surface of said driving device relative to said floor of said substrate.  
       
     
     
       30. A heat sink according to  claim 29 , wherein said opening of said plate has a size which is large enough to allow said driving device to penetrate said plate but which is smaller than said fan.  
     
     
       31. A heat sink according to  claim 29 , wherein said fan has the shape of an axial fan.  
     
     
       32. A heat sink according to  claim 30 , wherein said fan has the shape of an axial fan.  
     
     
       33. A heat sink apparatus comprising: 
         a heat sink substrate including a bottom wall, a plurality of side walls mounted on each of the sides of said bottom wall except for one side, said bottom wall and a plurality of side walls being formed integrally in a one - piece structure;    
       
         a cover providing a first opening by being mechanically mounted on an edge portion of said side walls and being formed with a second opening therein;  
       
       
         a motor supported by said heat sink substrate and being disposed adjacent to said second opening;  
       
       
         a centrifugal fan for being rotated by said motor; and  
       
       
         a plurality of fins provided on said bottom wall of said heat sink substrate, wherein:  
       
       
         an air flow generated by said centrifugal fan passes from said second opening to said first opening.  
       
     
     
       34. A heat sink apparatus according to  claim 33 , wherein said motor protrudes from said second opening.  
     
     
       35. A heat sink comprising: 
       
         a substrate having a floor and a vertical side wall open in one direction;  
       
       
         a plurality of fins vertically projecting from said floor of said substrate;  
       
       
         a driving device at least a part of which is supported by said floor of said substrate; and  
       
       
         a fan for being rotated by said driving device, wherein:  
       
       
         a height of an upper surface of said side wall is lower than that of an upper surface of said driving device relative to said floor of said substrate.  
       
     
     
       36. A heat sink according to  claim 35 , characterized in that the fan has a shape of an axial fan.  
     
     
       37. A heat sink according to  claim 35 , wherein said driving device has a housing which includes said upper surface of said driving device.  
     
     
       38. A heat sink comprising: 
       
         a substrate having a floor and a vertical sidewall open in one direction;  
       
       
         a plurality of fins vertically projecting from said floor of said substrate;  
       
       
         a driving device at least a part of which is supported by said substrate;  
       
       
         a fan for being rotated by said driving device; and  
       
       
         a plate mounted on an upper surface of said sidewall and having an opening, wherein:  
       
       
         a height of said upper surface of said side wall and a height of an upper surface of said plate are lower than that of an upper surface of said driving device relative to said floor of said substrate.  
       
     
     
       39. A heat sink according to  claim 37 , wherein the opening of the plate has a size which is large enough to allow the driving device to penetrate the plate through said opening but which is smaller in diameter than the fan.  
     
     
       40. A heat sink according to  claim 39 , wherein the fan has a shape of an axial fan.  
     
     
       41. A heat sink according to  claim 38 , wherein the fan has shape of an axial fan.  
     
     
       42. A heat sink comprising: 
       
         a substrate having a floor;  
       
       
         a plurality of fins vertically projecting from said floor of said substrate;  
       
       
         a driving device at least a part of which is supported by said substrate;  
       
       
         a fan for being rotated by said driving device;  
       
       
         a plate having an opening; and  
       
       
         a vertical side wall structure disposed between said substrate and said plate, said vertical side wall structure being open in one direction, said plate being positioned at an upper surface of said side wall structure, said plate and said side wall structure forming a frame having a height which is lower than a height of an upper surface of said driving device relative to said floor of said substrate.  
       
     
     
       43. A heat sink according to  claim 42 , wherein said opening of said plate has a size which is large enough to allow said driving device to penetrate said plate but which is smaller in diameter than said fan.  
     
     
       44. A heat sink according to  claim 43 , wherein said fan has the shape of an axial fan.  
     
     
       45. A heat sink according to  claim 43 , wherein said fan has the shape of an axial fan.