Patent Publication Number: US-2023160646-A1

Title: Immersion heat dissipation structure

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to a heat dissipation structure, and more particularly to an immersion heat dissipation structure. 
     BACKGROUND OF THE DISCLOSURE 
     An immersion cooling technology is performed by directly immersing heat-generating components (such as servers and disk arrays) in a cooling fluid that is non-electrically conductive, so that heat generated by operations of the heat-generating components can be removed by evaporation of the cooling fluid. However, how heat can be more effectively dissipated through the immersion cooling technology is still one of the issues that needs to be solved in the related field. 
     SUMMARY OF THE DISCLOSURE 
     In response to the above-referenced technical inadequacy, the present disclosure provides an immersion heat dissipation structure. 
     In one aspect, the present disclosure provides an immersion heat dissipation structure, which includes a porous metal heat dissipation material, an integrated heat spreader, and a thermal interface material. The porous metal heat dissipation material has a porosity greater than 8%. The porous metal heat dissipation material and the integrated heat spreader have the thermal interface material arranged therebetween so that a thermal connection is formed therebetween, and a connection surface of the porous metal heat dissipation material and a connection surface of the thermal interface material have a sealing layer arranged therebetween. The sealing layer seals a plurality of open pores formed on the connection surface of the porous metal heat dissipation material, and a thickness of the sealing layer is less than 0.1 mm. 
     In certain embodiments, the sealing layer is a film layer formed by one of a steaming process, blocking with an organosilicon compound, filling with a passivation solution, blocking with an immobilization material, a physical vapor deposition process, or a chemical vapor deposition process. 
     In certain embodiments, the thermal interface material is made of silicone grease, silica gel, epoxy resin, or metal. 
     In another aspect, the present disclosure provides an immersion heat dissipation structure, which includes a porous metal heat dissipation material, an integrated heat spreader, and a thermal interface material. The porous metal heat dissipation material has a porosity greater than 8%. The porous metal heat dissipation material and the integrated heat spreader have the thermal interface material arranged therebetween so that a thermal connection is formed therebetween. A plurality of open pores are formed on a connection surface of the porous metal heat dissipation material, and at least one of the plurality of open pores is filled with a sealing material to fill at least a part of the at least one of the plurality of open pores. 
     In certain embodiments, the sealing material is formed by forming a sealing layer on the connection surface of the porous metal heat dissipation material, and filling the sealing material forming the sealing layer into the at least one of the plurality of open pores. 
     In certain embodiments, the sealing material is formed by forming a sealing layer on the connection surface of the porous metal heat dissipation material, removing the sealing layer by a chemical process or a mechanical process, and leaving a remaining part of the sealing material of the sealing layer in the open pore. 
     In yet another aspect, the present disclosure provides an immersion heat dissipation structure, which includes a porous metal heat dissipation material, an integrated heat spreader, and a thermal interface material. The porous metal heat dissipation material has a porosity greater than 8%. The porous metal heat dissipation material and the integrated heat spreader have the thermal interface material arranged therebetween so that a thermal connection is formed therebetween. A connection surface of the porous metal heat dissipation material is a processed surface having a porosity less than 8% that is formed by processing. 
     In certain embodiments, the connection surface of the porous metal heat dissipation material is the processed surface having the porosity less than 8% that is formed by sandblasting, grinding, or polishing. 
     In certain embodiments, the connection surface of the porous metal heat dissipation material is the processed surface having the porosity less than 8% that is formed by chemical etching or acid etching. 
     Therefore, in the immersion heat dissipation structure provided by the present disclosure, by virtue of “the porous metal heat dissipation material having the porosity greater than 8%”, “the porous metal heat dissipation material and the integrated heat spreader having the thermal interface material arranged therebetween so that the thermal connection is formed therebetween”, “the connection surface of the porous metal heat dissipation material and the connection surface of the thermal interface material having the sealing layer arranged therebetween, the sealing layer sealing the plurality of open pores formed on the connection surface of the porous metal heat dissipation material and the thickness of the sealing layer being less than 0.1 mm”, “the at least one of the plurality of open pores formed on the connection surface of the porous metal heat dissipation material being filled with the sealing material to fill at least a part of the at least one of the plurality of open pores”, or “the connection surface of the porous metal heat dissipation material being the processed surface having the porosity less than 8% that is formed by processing,” an air bubble generation in an area of the porous metal heat dissipation material of the immersion heat dissipation structure provided by the embodiments of the present disclosure can be effectively increased, and the connection property and the thermal conductivity between the thermal interface material and the porous metal heat dissipation material can be effectively increased, thereby further improving the thermal transmittance of the immersion heat dissipation structure. 
     These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The described embodiments may be better understood by reference to the following description and the accompanying drawings, in which: 
         FIG.  1    is a schematic side view of an immersion heat dissipation structure according to a first embodiment of the present disclosure; 
         FIG.  2    is a schematic side view of an immersion heat dissipation structure according to a second embodiment of the present disclosure; 
         FIG.  3    is a schematic side view of an immersion heat dissipation structure according to a third embodiment of the present disclosure; and 
         FIG.  4    is a schematic side view of an immersion heat dissipation structure according to a fourth embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a”, “an”, and “the” includes plural reference, and the meaning of “in” includes “in” and “on”. Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure. 
     The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first”, “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like. 
     First Embodiment 
     Reference is made to  FIG.  1   , which illustrates an immersion heat dissipation structure according to a first embodiment of the present disclosure. As shown in  FIG.  1   , the immersion heat dissipation structure provided by the first embodiment of the present disclosure includes, roughly from top to bottom, a porous metal heat dissipation material  10 , a thermal interface material  20 , and an integrated heat spreader  30 . 
     In the present embodiment, the porous metal heat dissipation material  10  can be a porous copper heat dissipation material formed by sintering copper powder, and can be immersed in a two-phase coolant (such as an electronic fluorinated liquid), so that a number of air bubbles formed by evaporation of the two-phase coolant can be greatly increased, thereby greatly enhancing a heat dissipation effect. Moreover, the porous metal heat dissipation material  10  of the present embodiment has a porosity greater than 8%, such that the number of air bubbles formed by evaporation of the two-phase coolant can be greatly increased. 
     In the present embodiment, the integrated heat spreader  30  can be used to contact a heat-generating component, and the porous metal heat dissipation material  10  and the integrated heat spreader  30  have the thermal interface material  20  arranged therebetween, so that a thermal connection between the integrated heat spreader  30  and the porous metal heat dissipation material  10  is increased, thereby improving thermal transmittance from the integrated heat spreader  30  to the porous metal heat dissipation material  10 . 
     In the present embodiment, the thermal interface material  20  can be made of silicone grease, silica gel, epoxy resin, or metal. Moreover, in order to enhance the thermal connection between the integrated heat spreader  30  and the porous metal heat spreader  10 , so as to prevent a poor connection between the thermal interface material  20  and the porous metal heat dissipation material  10  occurring in the presence of tiny open pores, a connection surface  11  of the porous metal heat dissipation material  10  and a connection surface  21  of the thermal interface material  20  have a sealing layer  15  arranged therebetween. In addition, the sealing layer  15  is used to seal a plurality of open pores  110  formed on the connection surface  11  of the porous metal heat dissipation material  10 , so that a connection property and a thermal conductivity between the thermal interface material  20  and the porous metal heat dissipation material  10  can be increased through the sealing layer  15 , thereby further improving the thermal transmittance. 
     Furthermore, in the present embodiment, in order to further improve the connection property and the thermal transmittance between the thermal interface material  20  and the porous metal heat dissipation material  10  through the sealing layer  15 , the sealing layer  15  is a film layer having a thickness of less than 0.1 mm. Moreover, the sealing layer  15  can be formed by one of a steaming process, blocking with an organosilicon compound, filling with a passivation solution, blocking with an immobilization material, a physical vapor deposition process, or a chemical vapor deposition process. 
     It should be noted that that the open pores are exaggeratedly enlarged in  FIG.  1    for a better understanding of the present disclosure. 
     Second Embodiment 
     Reference is made to  FIG.  2   , which illustrates an immersion heat dissipation structure according to a second embodiment of the present disclosure. The immersion heat dissipation structure of the second embodiment is substantially the same as that of the first embodiment, and differences therebetween are described below. 
     In the present embodiment, in order to enhance the thermal transmittance from the integrated heat spreader  30  to the porous metal heat dissipation material  10 , the connection surface  11  of the porous metal heat dissipation material  10  and the connection surface  21  of the thermal interface material  20  have the sealing layer  15  arranged therebetween. Moreover, a sealing material  151  forming the sealing layer  15  is filled in at least one of the plurality of open pores  110  formed on the connection surface  11  of the porous metal heat dissipation material  10 , so that the connection property and the thermal conductivity between the thermal interface material  20  and the porous metal heat dissipation material  10  can be increased through the sealing layer  15 , thereby further improving the thermal transmittance. 
     Third Embodiment 
     Reference is made to  FIG.  3   , which illustrates an immersion heat dissipation structure according to a third embodiment of the present disclosure. The immersion heat dissipation structure of the third embodiment is substantially the same as that of the first embodiment, and differences therebetween are described below. 
     In the present embodiment, in order to enhance the thermal connection between the integrated heat spreader  30  and the porous metal heat dissipation material  10 , at least one of the plurality of open pores  110  formed on the connection surface  110  of the porous metal heat dissipation material  10  is filled with the sealing material  151  to fill at least a part of the at least one of the plurality of open pores  110 . Moreover, the sealing material  151  is formed by forming the sealing layer  15  on the connection surface  11  of the porous metal heat dissipation material  10  (as shown in  FIG.  2   ), removing the sealing layer  15  formed on the connection surface  11  by a chemical process or a mechanical process, and leaving a remaining part of the sealing material  151  of the sealing layer  15  in the open pore  110 . Therefore, the connection property and the thermal conductivity between the thermal interface material  20  and the porous metal heat dissipation material  10  can be increased through the sealing material  151  left in the open pore  110 , thereby further improving the thermal transmittance. 
     Fourth Embodiment 
     Reference is made to  FIG.  4   , which illustrates an immersion heat dissipation structure according to a fourth embodiment of the present disclosure. The immersion heat dissipation structure of the fourth embodiment is substantially the same as that of the first embodiment, and differences therebetween are described below. 
     In the present embodiment, in order to enhance the thermal connection between the integrated heat spreader  30  and the porous metal heat dissipation material  10 , the connection surface  11  of the porous metal heat dissipation material  10  is a processed surface having a porosity less than 8% that is formed by processing. Therefore, the connection property and the thermal conductivity between the thermal interface material  20  and the porous metal heat dissipation material  10  can be increased through the processed surface having the porosity less than 8%, thereby further improving the thermal transmittance. 
     Moreover, in the present embodiment, the connection surface  11  of the porous metal heat dissipation material  10  can be the processed surface having the porosity less than 8% that is formed by mechanical processing, such as sandblasting, grinding, and polishing. 
     In addition, in the present embodiment, the connection surface  11  of the porous metal heat dissipation material  10  can be the processed surface having the porosity less than 8% that is formed by chemical etching or acid etching. 
     Beneficial Effects of the Embodiments 
     In conclusion, in the immersion heat dissipation structure provided by the present disclosure, by virtue of “the porous metal heat dissipation material  10  having the porosity greater than 8%”, “the porous metal heat dissipation material  10  and the integrated heat spreader  30  having the thermal interface material  20  arranged therebetween so that the thermal connection is formed therebetween”, “the connection surface  11  of the porous metal heat dissipation material  10  and the connection surface  21  of the thermal interface material  20  having the sealing layer  15  arranged therebetween, the sealing layer  15  sealing the plurality of open pores  110  formed on the connection surface  11  of the porous metal heat dissipation material  10 , and the thickness of the sealing layer being less than 0.1 mm”, “the at least one of the plurality of open pores  110  formed on the connection surface  11  of the porous metal heat dissipation material  10  being filled with the sealing material  151  to fill at least a part of the at least one of the plurality of open pores  110 ”, or “the connection surface  11  of the porous metal heat dissipation material  10  being the processed surface having the porosity less than 8% that is formed by processing,” an air bubble generation in an area of the porous metal heat dissipation material  10  of the immersion heat dissipation structure provided by the embodiments of the present disclosure can be effectively increased, and the connection property and the thermal conductivity between the thermal interface material  20  and the porous metal heat dissipation material  10  can be effectively increased, thereby further improving the thermal transmittance of the immersion heat dissipation structure. 
     The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. 
     The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope.