Patent Publication Number: US-9841246-B2

Title: Dual material vapor chamber and upper shell thereof

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a vapor chamber and in particular to a dual material vapor chamber and an upper shell thereof, which are used for an electronic heat source. 
     Description of Prior Art 
     While the operating speeds of the electronic components increase continuously, the heat generated increase accordingly. To effectively solve the problem of the large amount of heat generated, the vapor chamber with excellent heat transfer performance has been widely used in the industry. However, the traditional vapor chamber still needs improvements in heat transfer efficiency, manufacturing cost, and manufacturing simplification. 
     The traditional vapor chamber mainly comprises an upper shell and a lower shell. The upper and lower shells are both made of copper. Firstly, the internal spaces of the upper and lower shells are individually provided with wick structures. Then, the upper and lower shells are welded together correspondingly. Next, a working fluid is filled into the internal spaces of the upper and lower shells. Finally, the manufacturing processes of degas and sealing are fulfilled. 
     However, the traditional vapor chamber has the effect of heat transfer, but it suffers the following problems in practical use. The upper and lower shells are both made of copper, which cause a heavy weight of the whole vapor chamber. Also, the material cost of copper is many times as high as that of aluminum; consequently, the manufacturing cost of the traditional vapor chamber has not been reduced effectively. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide a dual material vapor chamber and an upper shell thereof, which can reduce the total weight and material cost of the whole vapor chamber and simplify the packing combination between the upper shell and the copper lower shell. 
     In order to achieve the above objective, the present invention provides a dual material vapor chamber comprising an upper shell, a copper lower shell, and a working fluid. The upper shell comprises an aluminum substrate and a plurality of aluminum fins. The aluminum substrate has an outer surface and an inner wall formed on the opposite side of the outer surface. The aluminum fins individually extend from the outer surface and are formed integrally. A copper deposition layer is coated on the inner wall. The copper lower shell is sealed to the upper shell correspondingly. A chamber is formed between the upper shell and the copper lower shell. The working fluid is filled in the chamber. 
     In order to achieve the above objective, the present invention also provides an upper shell of a dual material vapor chamber. The upper shell comprises an aluminum substrate and a plurality of aluminum fins. The aluminum substrate has an outer surface and an inner wall formed on the opposite side of the outer surface. The aluminum fins individually extend from the outer surface and formed integrally. A copper deposition layer is coated on the inner wall. 
     The present invention also has the following effects. By means of excellent hydrophobic property of the copper deposition layer, a good circulation of the internal working fluid can be achieved. By means of the disposition of the nickel deposition layer, the adhering force of the copper deposition layer to the inner wall can be enhanced. The fluid stagnation structure can destroy the cohesion of water molecules; thus, the water molecules which are attached to the fluid stagnation structure after condensation will not gather and flow such that all water molecules can completely drop onto the heated section of the lower shell. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
         FIG. 1  is a cross-sectional view of an upper shell of the present invention; 
         FIG. 2  is a cross-sectional view of the upper shell of  FIG. 1  coated with a copper deposition layer; 
         FIG. 3  is an exploded cross-sectional view of the dual material vapor chamber of the present invention; 
         FIG. 4  is a cross-sectional assembled view of the dual material vapor chamber of the present invention; 
         FIG. 5  is a perspective assembled view of the dual material vapor chamber of the present invention; 
         FIG. 6  is a local enlarged view of the dual material vapor chamber of the present invention during operation; and 
         FIG. 7  is a cross-sectional view of the upper shell according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The detailed description and technical details of the present invention will be explained below with reference to accompanying figures. However, the accompanying figures are only for reference and explanation, but not to limit the scope of the present invention. 
     Please refer to  FIGS. 1-5 . The present invention provides a dual material vapor chamber and an upper shell thereof. The dual material vapor chamber comprises an upper shell  10 , a copper lower shell  20 , and a working fluid  30 . 
     The upper shell  10  which is made of aluminum or the alloy thereof mainly comprises an aluminum substrate  11  and a plurality of aluminum fins  12 . The aluminum substrate  11  which roughly has a cuboid shape has an outer surface  111  and an inner wall  112  formed on the opposite side of the outer surface  111 . A copper deposition layer  13  may be coated on the inner wall  112  by electroplating. The aluminum fins  12  individually extend from the outer surface  111  and are formed integrally in which the aluminum fins  12  can be formed spacedly by extrusion or chipping. 
     Further, the inner wall  112  can thoroughly form a fluid stagnation structure  113  by a machining process such as sandblasting or embossing. The fluid stagnation structure  113  is a rough surface containing a plurality of particles having a surface roughness (Ra) ranging from 0.01 mm to 10 mm, preferably ranging from 0.05 mm to 3 mm. If the surface roughness (Ra) is below 0.01 mm, the fluid stagnation structure  113  cannot effectively prevent the internal working fluid  30  from flowing and gathering after condensation. If the surface roughness (Ra) is above 10 mm, the whole vapor chamber is too high to meet the use requirement of electronic components. Also, an upper connecting section  114  is formed around the perimeter of the fluid stagnation structure  113 . The copper deposition layer  13  is coated on the upper connecting section  114 ; thus, the subsequent welding process can be performed easier. 
     The copper lower shell  20  which is made of copper or the alloy thereof comprises a base plate  21 , a lower surrounding plate  22  extending and bent upward from the perimeter of the base plate  2 , and a lower connecting section  23  extending and bent transversely from the perimeter of the lower surrounding plate  22 . The copper lower shell  20  is sealed to the upper shell  10  correspondingly; a chamber A is formed between the upper shell  10  and the copper lower shell  20 . During the assembly, the surfaces of the upper connecting section  114  and the lower connecting section  23  are applied with solder and then stacked to each other and heated such that the upper shell  10  and the copper lower shell  20  are sealed together. 
     The working fluid  30  which can be pure water is filled into the chamber A through an infusion-degassing tube (not shown) to perform the processes such as degassing and sealing to complete the fabrication of the dual material vapor chamber. In the present invention, a copper deposition layer  13  is coated on the inner wall  112  of the aluminum substrate  11 . Because the hydrophobicity of the copper deposition layer  13  is superior to that of the aluminum inner wall  112 , water as a working fluid  30  can have a good effect of internal circulation. 
     Moreover, the vapor chamber of the present invention further comprises a wick structure  40 , which can be metal weaving net, porous metal sintered powder, or fiber bundles. The wick structure  40  is disposed above the base plate  21  of the copper lower shell  20 . 
     Referring to  FIG. 6 , the base plate  21  of the copper lower shell  20  is used as a heated section during operation and is placed to contact the electronic heat source (not shown). Thus, the heat generated during operation will be delivered to the base plate  21  and the working fluid  30 . Then, the liquid working fluid  30  is heated and evaporated into the vapor working fluid  30 . Due to the heat dissipation effect of the aluminum substrate  11  through the aluminum fins  12 , when the vapor working fluid  30  flows toward the inner wall  112  of the aluminum substrate  11 , it will be attached to the copper deposition layer  13  of the fluid stagnation structure  113  such that after the vapor working fluid  30  contacts the copper deposition layer  13  of the fluid stagnation structure  113 , it is condensed into many distributed water molecules. Because the fluid stagnation structure  113  can destroy the cohesion of water molecules, the water molecules attached to the fluid stagnation structure  113  after condensation will not gather and flow. In this way, all water molecules can completely drop onto the heated section (i.e., the base plate  21 ) of the lower shell. 
     Referring to  FIG. 7 , in addition to the previous embodiment, the upper shell  10  of the present invention further comprises a nickel deposition layer  14  disposed between the inner wall  112  and the copper deposition layer  13 . Thus, the adhering force of the copper deposition layer  13  to the inner wall  112  can be enhanced. 
     In summary, the dual material vapor chamber and the upper shell thereof of the present invention indeed achieves the expected objectives and overcomes the problems of the prior art. Also they are indeed novel, useful, and non-obvious to be patentable. Please examine the application carefully and grant it as a formal patent for protecting the rights of the inventor.