Patent Publication Number: US-2015068707-A1

Title: Electronic component cooling apparatus

Description:
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2013-186248, filed on Sep. 9, 2013, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present invention relates to a cooling apparatus for cooling an electronic component such as a semiconductor component that generates heat. 
     BACKGROUND ART 
     With the recent increase of the amount of heat generated from a semiconductor component such as large scale integration (LSI), cases of adopting a cooling system using a refrigerant such as water have increased. In a typical cooling apparatus, a cold plate is brought into contact with a semiconductor component to absorb heat, and the heat is transferred by a refrigerant such as water passing through the cold plate via piping. 
       FIG. 8  illustrates a cooling apparatus that includes a cold plate  201 , piping  202 , couplers  204  for coupling with external piping, and a coupler fixing block  203  for fixing the couplers  204 . According to this cooling apparatus, in a state where a refrigerant in the cooling apparatus is separated from a flow path of an external refrigerant by the couplers  204 , the refrigerant is confined in the cold plate  201 , the piping  202 , the coupler fixing block  203 , and the couplers  204  that constitute a flow path of the refrigerant in the cooling apparatus. At this time, when a temperature of the refrigerant increases due to an increase of an ambient temperature or the like, pressure in the flow path rapidly increases because the refrigerant such as water is not compressed to be deformed. Consequently, a defect such as breakage of the couplers  204  occurs. 
     As countermeasures against the defect, for example, Japanese Laid-open Patent Publication No. 2006-59903 discloses a refrigerant system provided with a tank including an air layer or a pressure regulating valve for releasing pressure when fixed pressure is applied. 
       FIG. 9  illustrates a sectional structure of a cooling apparatus with a pressure reduction tank  206  added to the cooling apparatus illustrated in  FIG. 8 , from the view taken along the line D-D′ in  FIG. 8  . The pressure reduction tank  206  includes an air layer  207  therein. When the refrigerant expands due to a temperature increase or the like to enter into the tank, pressure is reduced by the air layer  207 .  FIG. 10  illustrates a sectional structure of a cooling apparatus with a pressure regulating valve  208  from the view taken along the line D-D′ in  FIG. 8 . The pressure regulating valve  208  functions to reduce pressure increase of the refrigerant. 
     However, installation of the pressure reduction tank  206  illustrated in  FIG. 9  causes projection of a tank unit from the cooling apparatus. As a result, an outer shape of the apparatus is enlarged to cause a problem such as interference with installation of the apparatus. In addition, air of the air layer  207  in the tank gradually blends into the refrigerant such as water to cause a problem such as reduction of an effect over a long term. On the other hand, when the pressure regulating valve  208  illustrated in  FIG. 10  is installed, a failure may not be avoided because the pressure regulating valve  208  operates mechanically. When there is a failure in the pressure regulating valve  208 , the refrigerant such as water may leak to seriously affect a semiconductor component. 
     SUMMARY 
     The present invention has been developed in view of the aforementioned problems, and the object of the invention is to provide an inexpensive and highly reliable electronic component cooling apparatus that includes a pressure increase reduction function of a refrigerant such as water. 
     According to the present invention, a cooling apparatus includes cooling unit including a flow path through which a refrigerant flows, opening/closing unit included in the flow path for confining the refrigerant, and pressure reduction unit disposed in at least a part of an inner wall of the flow path. 
     According to the present invention, it is possible to provide an inexpensive and highly reliable electronic component cooling apparatus that includes a pressure increase reduction function of a refrigerant such as water. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary features and advantages of the present invention will become apparent from the following detailed description when taken with the accompanying drawings in which: 
         FIG. 1  is a diagram illustrating a structure of an electronic component cooling apparatus according to an exemplary embodiment of the present invention; 
         FIG. 2  is a diagram illustrating a specific structure of the electronic component cooling apparatus according to the exemplary embodiment of the present invention; 
         FIG. 3  is a diagram illustrating a sectional structure of the electronic component cooling apparatus according to the exemplary embodiment of the present invention; 
         FIG. 4  is a diagram illustrating a sectional structure of the electronic component cooling apparatus according to the exemplary embodiment of the present invention; 
         FIG. 5  is a diagram illustrating a sectional structure of the electronic component cooling apparatus according to the exemplary embodiment of the present invention; 
         FIG. 6  is a diagram illustrating a sectional structure of the electronic component cooling apparatus according to the exemplary embodiment of the present invention; 
         FIG. 7  is a diagram illustrating a sectional structure of the electronic component cooling apparatus according to the exemplary embodiment of the present invention; 
         FIG. 8  is a diagram illustrating a structure of an existing electronic component cooling apparatus; 
         FIG. 9  is a diagram illustrating a sectional structure of the existing electronic component cooling apparatus that includes a pressure reduction tank; and 
         FIG. 10  is a diagram illustrating a sectional structure of the existing electronic component cooling apparatus that includes a pressure regulating valve. 
     
    
    
     EXEMPLARY EMBODIMENT 
     Next, the exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.  FIG. 1  is a diagram illustrating a structure of an electronic component cooling apparatus according to the exemplary embodiment of the present invention. The cooling apparatus is provided with cooling unit  10  including a flow path  11  through which a refrigerant flows and configured to cool an electronic component, opening/closing unit  12  included in the flow path  11  for confining the refrigerant, and pressure reduction unit  13  disposed in at least a part of an inner wall of the flow path  11 . The refrigerant is supplied from external piping  14 , and discharged to the external piping  14 . 
       FIG. 2  is a diagram illustrating a specific structure of the cooling apparatus according to the exemplary embodiment. The cooling apparatus includes a cold plate  101  that is cooling unit, piping  102  through which a refrigerant such as water flows, couplers  104  connected to external piping to supply and discharge the refrigerant, and a coupler fixing block  103  for fixing the couplers  104 . A flow path through which the refrigerant flows is disposed inside the cold plate  101 . The cold plate  101  comes into contact with an electronic component such as a semiconductor component to absorb heat. Metal piping, for example, can be used for the piping  102 . 
     By causing the cold plate  101  to come into contact with a semiconductor component  105 , the cold plate  101  absorbs heat of the semiconductor component  105 . The refrigerant flowing through the flow path in the cold plate  101  flows through a flow path constituted by the piping  102 , the coupler fixing block  103 , and the couplers  104 . Thereby, the absorbed heat is transferred to the outside. 
     The coupler  104 , which includes an opening/closing unit  107  inside, can supply or discharge the refrigerant to or from the flow path through the external piping when connected to the external piping. Further, the coupler  104  can confine the refrigerant in the flow path when separated from the external piping. The opening/closing unit  107  may be a mechanism incorporated in the coupler  104 . 
       FIG. 3  is a diagram illustrating a sectional structure of the coupler fixing block  103  of the cooling apparatus according to the exemplary embodiment from the view taken along the line A-A′ in  FIG. 2 .  FIG. 4  is a diagram illustrating a sectional structure of the coupler fixing block  103  and surroundings thereof of the cooling apparatus according to the exemplary embodiment from the vies taken along the line B-B′ in  FIG. 2 . As illustrated in  FIGS. 3 and 4 , pressure reduction unit  106  is disposed in an inner wall of the refrigerant flow path of the coupler fixing block  103 . In the coupler  104  illustrated in  FIG. 4 , the opening/closing unit  107  is omitted. 
     The pressure reduction unit  106  may be formed into a sheet-shaped structure, and may contract in a thickness direction by pressure of the refrigerant. The pressure reduction unit  106  may be composed of a low-elastic soft resin layer such as silicon resin and rubber material including an independent bubble structure. 
     The pressure reduction unit  106  may be installed in an inner wall of the flow path of the piping  102  or in an inner wall of the flow path of the coupler  104 .  FIG. 5  illustrates a structure where the pressure reduction unit  106  is disposed in the inner wall of the flow path of the piping  102  in the section taken along the line B-B′ illustrated in  FIG. 2 .  FIG. 6  illustrates a structure where the pressure reduction unit  106  is disposed in the inner wall of the flow path of the coupler  104  in the section taken along the line B-B′ illustrated in  FIG. 2 . In the coupler  104  illustrated in  FIGS. 5 and 6 , the opening/closing unit  107  is omitted. 
     The pressure reduction unit  106  may be installed in at least a part of the inner wall of the respective flow path of the coupler fixing block  103 , the piping  102 , or the coupler  104 . The pressure reduction unit  106  may be fixed to the inner wall of the respective flow path of the coupler fixing block  103 , the piping  102 , or the coupler  104  using adhesive or the like. 
     As illustrated in  FIG. 7 , the pressure reduction unit  106  may be installed in an inner wall of the flow path of the cold plate  101 .  FIG. 7  illustrates a structure where the pressure reduction unit  106  is disposed in the inner wall of the flow path of the cold plate  101  in the section taken along the line C-C′ illustrated in  FIG. 2 . To efficiently transmit, to the refrigerant, heat absorbed at the cold plate  101  from the semiconductor component  105 , it is preferable that at least a part of the inner wall of the flow path of the cold plate  101  at a side contacting with the semiconductor component  105  directly comes into contact with the refrigerant. 
     When the coupler  104  is separated from the external piping, the flow path of the cooling apparatus is filled with the refrigerant by the opening/closing unit  107 , and the refrigerant is confined in the flow path. In this state, when a temperature of the refrigerant increases due to an increase of an ambient temperature or the like, internal pressure increases because the refrigerant such as water is not compressed to be deformed. The increase of the internal pressure is accompanied by deformation and contraction of the pressure reduction unit  106 . As a result, the pressure increase in the cooling apparatus can be reduced. 
     The low-elastic soft resin layer of the pressure reduction unit  106 , which is made of silicon resin or rubber material including an independent bubble structure, is inexpensive. Further, operation of the pressure reduction is highly reliable because it is performed by deformation and contraction accompanying with the pressure increase. 
     According to the exemplary embodiment, it is possible to provide an inexpensive and highly reliable electronic component cooling apparatus that includes a pressure increase reduction function of a refrigerant such as water. The cooling apparatus according to the exemplary embodiment can be widely used for cooling not only an electronic component but also components that generate heat. 
     The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these exemplary embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present invention is not intended to be limited to the exemplary embodiments described herein but is to be accorded the widest scope as defined by the limitations of the claims and equivalents. 
     Further, it is noted that the inventor&#39;s intent is to retain all equivalents of the claimed invention even if the claims are amended during prosecution. 
       10  Cooling unit 
       11  Flow path 
       12  Opening/closing unit 
       13  Pressure reduction unit 
       14  External piping 
       101 ,  201  Cold plate 
       102 ,  202  Piping 
       103 ,  203  Coupler fixing block 
       104 ,  204  Coupler 
       105 ,  205  Semiconductor component 
       106  Pressure reduction unit 
       107  Opening/closing unit 
       206  Pressure reduction tank 
       207  Air layer 
       208  Pressure regulating valve