Abstract:
An electronic device includes: a support member; an electronic component stacked over the support member with a plurality of connections therebetween; and a refrigerant pipe through which a refrigerant passes, the refrigerant pipe being provided between at least some connections among the plurality of connections. A method for manufacturing an electric device includes: stacking an electronic component over a support member with a plurality of connections therebetween; and providing a refrigerant pipe, through which a refrigerant passes, between at least some connections among the plurality of connections.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2013-137437 filed on Jun. 28, 2013, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The embodiments discussed herein are related to an electronic device and a method for manufacturing the electronic device. 
     BACKGROUND 
     An electronic device is known including a support member, an electronic component mounted on the support member, and a cooling device that is in contact with the electronic component on the side of the electronic component that is opposite to the side facing the support member. In such an electronic device, the cooling device is deemed to be capable of cooling the electronic component. 
     However, in the electronic device described above, the cooling device is in contact with the electronic component on the side of the electronic component that is opposite to the side facing the support member. Accordingly, there is a concern that the cooling performance of the electronic component on the side facing the support member is low compared with the cooling performance of the electronic component on the side that is opposite to the side facing the support member. 
     The following are reference documents: 
     [Document 1] Japanese Laid-open Patent Publication No. 2001-53206, 
     [Document 2] Japanese National Publication of International Patent Publication No. 2003-533057, and 
     [Document 3] Japanese Laid-open Patent Publication No. 2012-149819. 
     SUMMARY 
     According to an aspect of the invention, an electronic device includes: a support member; an electronic component stacked over the support member with a plurality of connections therebetween; and a refrigerant pipe through which a refrigerant passes, the refrigerant pipe being provided between at least some connections among the plurality of connections. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an electronic device; 
         FIG. 2  is a longitudinal section of the electronic device; 
         FIG. 3  is a perspective view of a refrigerant pipe; 
         FIG. 4  is a first explanatory drawing illustrating a manufacturing process of the electronic device; 
         FIG. 5  is a second explanatory drawing illustrating the manufacturing process of the electronic device; 
         FIG. 6  is a third explanatory drawing illustrating the manufacturing process of the electronic device; 
         FIG. 7  is a cross-sectional view taken along the line VII-VII of  FIG. 5 ; 
         FIG. 8  is an exploded perceptive view illustrating a first modification of the electronic device; 
         FIG. 9  is a longitudinal section illustrating a second modification of the electronic device; 
         FIG. 10  is a longitudinal section illustrating a third modification of the electronic device; 
         FIG. 11  is a perspective view of a refrigerant pipe according to the third modification; and 
         FIG. 12  is a longitudinal section illustrating a fourth modification of the electronic device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, the embodiments of a technique disclosed in the present application will be described. 
     As illustrated in  FIG. 1 , an electronic device  10  according to the present embodiment includes a substrate  20 , an integrated circuit  30  (a semiconductor chip), and a flow path unit  40 . 
     The substrate  20  is an example of a support member and is formed in a square shape in planar view. A wiring pattern (not shown) is formed on the substrate  20 . As illustrated in  FIG. 2 , a plurality of pads  22  is formed on the surface of the substrate  20 . The plurality of pads  22  are aligned in an array and are connected to the wiring pattern (not shown) described above. 
     The integrated circuit  30  (a large scale integration or LSI circuit) is an example of an electronic component and is formed in a flat plate-like square shape in planar view. The integrated circuit  30  includes a silicon layer  31  and a circuit layer  32 . The circuit layer  32  is an example of a heating part and generates heat. A plurality of bumps  34  that are arranged in an array are provided on the circuit layer  32  at a position that corresponds to the position of the plurality of pads  22 . The plurality of bumps  34  are an example of a plurality of connections. The integrated circuit  30 , in which the circuit layer  32  faces the substrate  20 , is stacked on the substrate  20  with the plurality of bumps  34  therebetween. Furthermore, the circuit layer  32  is connected to the plurality of pads  22  with the plurality of bumps  34  therebetween. An underfill resin  36  is filled in the gaps between the substrate  20  and the integrated circuit  30 . 
     As illustrated in  FIG. 1 , the flow path unit  40  includes a first hollow member  41 , a second hollow member  42 , and a plurality of refrigerant pipes  43 . The first hollow member  41  and the second hollow member  42  have a hollow shape and are formed so as to be symmetrical with each other about a line. The first hollow member  41  includes a long plate-shaped first fixing plate  44  and a recessed first connection member  45 . The first fixing plate  44  closes an opening of the first connection member  45  having the recessed shape (see the lowest figure of  FIG. 5  also). Similarly, the second hollow member  42  includes a long plate-shaped second fixing plate  46  and a recessed second connection member  47 . The second fixing plate  46  closes an opening of the second connection member  47  having the recessed shape. 
     A cylindrical first connection port  48  and a cylindrical second connection port  49  are formed in the first connection member  45  and the second connection member  47 , respectively. The inside of the first connection port  48  is in communication with the internal space of the first hollow member  41  and the inside of the second connection port  49  is in communication with the internal space of the second hollow member  42 . Furthermore, the internal space of the first hollow member  41  is in communication with the internal space of the second hollow member  42  through the plurality of refrigerant pipes  43 . 
     Each of the refrigerant pipes  43  is, as described later, formed of a single hollow fiber (see  FIG. 3  also) and extends in a linear manner between the first hollow member  41  and the second hollow member  42 . Moreover, the plurality of refrigerant pipes  43  are disposed between the substrate  20  and the integrated circuit  30 . As illustrated in  FIG. 2 , the plurality of bumps  34 , which are arranged in an array, form a plurality of bump groups  35  that are arranged in a plurality of rows (see  FIG. 6  also). 
     Moreover, in the state in which the substrate  20  and the integrated circuit  30  are stacked together, the plurality of refrigerant pipes  43  that are embedded in the underfill resin  36  are provided between the plurality of bump groups  35 . As an example, in the present embodiment, a plurality of (two as an example) refrigerant pipes  43  each formed of a single pipe are provided between the plurality of bump groups  35  that form a plurality of rows. The plurality of refrigerant pipes  43  are provided so as to be in contact with a surface  30 A (a surface of the circuit layer  32 ), which is the surface of the integrated circuit  30  on the substrate  20  side. 
     Moreover, as illustrated in  FIG. 1 , in the electronic device  10 , hoses  51  and  52  are connected to the first connection port  48  and second connection port  49 , respectively. Furthermore, a refrigerant that is supplied from an external refrigerant supply device (not shown) to the first connection port  48  through the hose  51  flows through the plurality of refrigerant pipes  43  via the internal space of the first hollow member  41 . 
     Furthermore, the refrigerant that has passed through the plurality of refrigerant pipes  43  is conveyed to the second connection port  49  through the internal space of the second hollow member  42  and is returned to the external refrigerant supply device from the second connection port  49  via the hose  52 . The refrigerant is circulated between the external refrigerant supply device and the plurality of refrigerant pipes  43  in the above described manner. Furthermore, the refrigerant passing through the plurality of refrigerant pipes  43  allows heat to be exchanged between the refrigerant and the circuit layer  32  illustrated in  FIG. 2 ; accordingly the circuit layer  32  is cooled. Note that a coolant, which is an example of the refrigerant, is used. 
     A method for manufacturing the electronic device  10  described above will be described next. 
     First, as illustrated in the upper figure of  FIG. 4 , the first fixing plate  44  and the second fixing plate  46  are stacked together such that a plurality of holes  53  formed in the first fixing plate  44  and a plurality of holes  53  formed in the second fixing plate  46  are in communication with one another. Then, a sewing machine mechanism  60  sews a needle thread  71  through and sews a bobbin thread  72  along the first fixing plate  44  and the second fixing plate  46 . A single hollow fiber, which will become the refrigerant pipes  43  (see  FIGS. 1 and 3 ) described above, is used for the needle thread  71 . A synthetic fiber such as, for example, nylon (a registered trademark), polyethylene, or polyester is used for the hollow fiber. 
     The sewing machine mechanism  60  includes a sewing needle  62  having a needle hole  61 , a bobbin  63  around which the bobbin thread  72  is wound, and a rotary hook  64  that rotates around the bobbin  63 . The bobbin  63  is rotated in the direction of an arrow R 1  to feed the bobbin thread  72  from the bobbin  63 . Furthermore, the sewing needle  62 , the needle hole  61  of which is threaded with the needle thread  71 , sequentially passes through the plurality of holes  53 . The rotary hook  64  rotates in the direction of an arrow R 2 , which is a direction opposite to the rotating direction of the bobbin  63 , the needle thread  71  is formed into a loop  73 , and the bobbin thread  72  is inserted through the loop  73  of the needle thread  71 . 
     Furthermore, the sewing machine mechanism  60  is operated to form, in the needle thread  71 , a plurality of U-shaped turn-back portions  74  that are passed through the plurality of holes  53  in a sequential manner from the first fixing plate  44  side. At this time, gaps  76  are formed between the first fixing plate  44  and connection portions  75 , the connection portions  75  being formed between the plurality of turn-back portions  74  of the needle thread  71 . Furthermore, the bobbin thread  72  fed from the bobbin  63  is provided along the surface of the second fixing plate  46  that is the surface on the opposite side to the first fixing plate  44  and is passed through the distal end portions  74 A of the plurality of turn-back portions  74 . Then, the distal end portions  74 A of the plurality of turn-back portions  74  are fixed to the second fixing plate  46 . 
     Next, as illustrated in the lower figure of  FIG. 4 , in a state in which the distal end portions  74 A of the plurality of turn-back portions  74  are fixed to the second fixing plate  46 , the first fixing plate  44  is moved away from the second fixing plate  46 . Accordingly, the plurality of turn-back portions  74  is stretched. 
     Then, as illustrated in the top figure of  FIG. 5 , each of the plurality of holes  53  is filled with a hole filler  54 . The hole filler  54  fixes a proximal end portion  74 B and the distal end portion  74 A of the plurality of turn-back portions  74  to the first fixing plate  44  and the second fixing plate  46 , respectively. Next, a cutting tool  65  is moved along the surface of the first fixing plate  44  that is the surface on the opposite side to the second fixing plate  46 ; accordingly, the connection portions  75  of the needle thread  71  between the plurality of turn-back portions  74  are removed. Furthermore, in a similar manner, the cutting tool  65  is moved along the surface of the second fixing plate  46  that is the surface on the opposite side with respect to the first fixing plate  44 ; accordingly, the distal end portions  74 A of the plurality of turn-back portions  74  are removed. Then, as illustrated in the middle figure of  FIG. 5 , the plurality of refrigerant pipes  43  (see  FIG. 7  also) are formed from the remaining portions of the needle thread  71 . 
     Next, as illustrated in the bottom figure of  FIG. 5 , the first connection member  45  is fixed to the first fixing plate  44 . The first fixing plate  44  and the first connection member  45  form the first hollow member  41 . In a similar manner, the second connection member  47  is fixed to the second fixing plate  46 . The second fixing plate  46  and the second connection member  47  form the second hollow member  42 . Accordingly, the flow path unit  40  including the first hollow member  41 , the second hollow member  42 , and the plurality of refrigerant pipes  43  is formed. 
     Next, as illustrated in the upper left figure of  FIG. 6 , the flow path unit  40  is disposed on the substrate  20 . At this time, the plurality of pads  22  that are arranged in an array form a plurality of pad groups  23  that form a plurality of rows. The flow path unit  40  is positioned on the substrate  20  so that, in planar view, each of the pairs of refrigerant pipes  43  is positioned between the plurality of pad groups  23 , which form a plurality of rows. 
     Referring next to the upper right figure of  FIG. 6  and  FIG. 2 , in a state in which the flow path unit  40  is disposed on the substrate  20 , the integrated circuit  30  is stacked onto the substrate  20  from a side of the plurality of the refrigerant pipes  43  that is opposite to the substrate  20  side of the refrigerant pipes  43 . Then, the plurality of bumps  34  that are provided on the surface of the integrated circuit  30  that is on the substrate  20  side are connected to the plurality of pads  22 . Accordingly, each of the pairs of refrigerant pipes  43  is arranged between the plurality of bump groups  35  that are arranged in rows. 
     Next, as illustrated in the bottom left figure of  FIG. 6 , the underfill resin  36  is filled between the substrate  20  and the integrated circuit  30 . Then, as illustrated in the bottom right figure of  FIG. 6 , the hoses  51  and  52  are connected to the first connection port  48  and second connection port  49 , respectively. The fabrication of the electronic device  10  is completed in the above manner. 
     The functions and the advantageous effects of the present embodiment will be described next. 
     As illustrated in  FIG. 2 , in the electronic device  10  fabricated in the above manner, each pair of refrigerant pipes  43  is provided between the substrate  20  and the integrated circuit  30  and between the plurality of bump groups  35  that are arranged in rows. The refrigerant is passed through the refrigerant pipes  43  and heat is exchanged between the refrigerant and the integrated circuit  30 ; accordingly, the cooling performance of the integrated circuit  30  on the substrate  20  side may be obtained. 
     In particular, the integrated circuit  30  includes the circuit layer  32  that generates heat and is stacked on the substrate  20  with the circuit layer  32  side of integrated circuit  30  on the substrate  20  side. Moreover, the plurality of refrigerant pipes  43  are provided on the circuit layer  32  side of the integrated circuit  30 . Accordingly, the heat generating circuit layer  32  may be efficiently cooled by the refrigerant passing through the plurality of refrigerant pipes  43 . 
     Moreover, the refrigerant pipes  43  are provided so as to be in contact with the surface  30 A of the integrated circuit  30  that is the surface on the substrate  20  side, in other words, the refrigerant pipes  43  are provided so as to be in contact with the surface of the circuit layer  32 . Accordingly, the efficiency of heat exchange between the refrigerant passing through the refrigerant pipes  43  and the circuit layer  32  may be further improved and, as a result, the heat generating circuit layer  32  may be cooled in a further efficient manner. 
     Furthermore, since the refrigerant pipes  43  are hollow fibers, thin and inexpensive refrigerant pipes  43  may be formed. Moreover, since the refrigerant pipes  43  are each a single pipe, the refrigerant pipes  43  may be disposed between the plurality of bumps  34  even if the spaces between the plurality of bumps  34  are narrow, for example. 
     Modifications of the present embodiment will be described next. In the embodiment described above, as illustrated in  FIG. 2 , the plurality of refrigerant pipes  43  are disposed between the plurality of bump groups  35  that form the plurality of rows. However, the refrigerant pipes  43  do not have to be provided between some of the bump groups  35  among the plurality of bump groups  35  that form the plurality of rows. Furthermore, the plurality of refrigerant pipes  43  may be provided only between some of the bumps  34  among the plurality of bumps  34 . 
     Furthermore, as illustrated in  FIG. 8 , the plurality of refrigerant pipes  43  may be provided so as to wind through some of the pads  22  among the plurality of pads  22 . Accordingly, the refrigerant pipes  43  may be provided between the bumps  34  among the plurality of bumps  34  that correspond to the plurality of pads  22 . Furthermore, the plurality of refrigerant pipes  43  may be formed in a winding manner so as to be provided between all of the plurality of bumps  34  or may be formed such that the plurality of refrigerant pipes  43  only wind through some of the bumps  34  among the plurality of bumps  34 . 
     When the refrigerant pipes  43  wind around in the above described manner, the length of each of the refrigerant pipes  43  may be increased; accordingly, the cooling area per refrigerant pipe  43  may be increased. Note that the refrigerant pipes  43  may be formed in a winding manner in advance by molding. Alternatively, the refrigerant pipes  43  may be made to extend in a winding manner by adhering the refrigerant pipes  43  to the substrate  20  with an adhesive or the like and by bending the refrigerant pipes  43  from the adhered point. 
     Furthermore, in the embodiment described above, as illustrated in  FIG. 2 , the plurality of (two as an example) refrigerant pipes  43  each formed of a single pipe are provided between the plurality of bump groups  35  that form the plurality of rows. However, as illustrated in  FIG. 9 , a single piece of refrigerant pipe  43  formed of a single pipe may be provided between the plurality of bump groups  35  that form the plurality of roles. 
     Furthermore, a single piece of refrigerant pipe  43  formed of a single pipe may be provided between some of the bump groups  35  among the plurality of bump groups  35 , and a plurality of refrigerant pipes  43  each formed of a single pipe may be provided between some of the remaining bump groups  35  among the plurality of bump groups  35 . 
     Furthermore, in the embodiment described above, each of the plurality of refrigerant pipes  43  is a single pipe. However, as illustrated in  FIGS. 10 and 11 , each of the plurality of refrigerant pipes  43  may be, for example, a plurality of single pipes (as an example, three single pipes in the present modification), which are formed of hollow fibers, stranded together. Configured as such, the mechanical strength of each refrigerant pipe  43 , which is formed of single pipes stranded together, may be secured. 
     Furthermore, in the embodiment described above, a single-layered integrated circuit  30  is mounted on the substrate  20 ; however, as illustrated in  FIG. 12 , integrated circuits  30 , which are examples of the electronic component, may be mounted on the substrate  20  three-dimensionally, in other words, stacked and mounted in three dimensions. 
     Each integrated circuit  30  is arranged so that the circuit layer  32  faces the substrate  20 . Furthermore, the plurality of bumps  34 , which are an example of the plurality of first connections, are provided between the substrate  20  and the integrated circuit  30  of the lowermost layer (the lower layer in the present case) among the plurality of integrated circuits  30 . Similarly, a plurality of bumps  84 , which are an example of the plurality of second connections, are provided between the plurality of integrated circuits  30 . Furthermore, an underfill resin  86 , similar to the underfill resin  36  filled into the gap between the integrated circuit  30  and the substrate  20 , is filled into the gaps between the plurality of integrated circuits  30 . 
     Furthermore, the integrated circuit  30  of the lower layer among the plurality of integrated circuits  30  is provided with through-electrodes  88 . The plurality of bumps  34  and the plurality of bumps  84  are connected through the through-electrodes  88 . Furthermore, the refrigerant pipes  43 , which are examples of a first refrigerant pipe, are each provided between the plurality of bumps  34 , and refrigerant pipes  93 , which are examples of a second refrigerant pipe, are provided between the plurality of bumps  84 . Similar to the refrigerant pipes  43 , the refrigerant flows through the refrigerant pipes  93 , and the refrigerant pipes  93  are in contact with the surface  30 A of the integrated circuit  30  of the upper layer on the substrate  20  side (the surface of the circuit layer  32 ). 
     Configured as such, the refrigerant is passed through each of the refrigerant pipes  43  and  93 . Since heat is exchanged between the refrigerant and the integrated circuits  30 , the circuit layer  32  of each integrated circuit  30  may be cooled individually. In particular, the cooling performance of the circuit layer  32  of the integrated circuit  30  of the lower layer may be obtained even if a plurality of integrated circuits  30  is mounted three-dimensionally. 
     Note that in the modification illustrated in  FIG. 12 , among the plurality of integrated circuits  30  that are mounted three-dimensionally, the integrated circuit  30  of a first layer (the lower layer) may be regarded as an example of a support member, and the integrated circuit  30  of the layer that is provided above the first layer may be regarded as an example of the electronic component. 
     Furthermore, in the modification illustrated in  FIG. 12 , the integrated circuit  30  may be stacked in three or more layers. Furthermore, the refrigerant pipes  43  may be provided only between some of the bumps  34  among the plurality of bumps  34 , and further, the refrigerant pipes  93  may be provided only between some of the bumps  84  among the plurality of bumps  84 . Furthermore, the plurality of integrated circuits  30  may be mounted on the substrate  20  after the integrated circuits  30  have been stacked together; alternatively, the integrated circuits  30  may be stacked onto the substrate  20  in order from the integrated circuit  30  of the lower layer to the integrated circuit  30  of the upper layer. 
     Furthermore, in the embodiment described above, the electronic device  10  includes the substrate  20 , the plurality of bumps  34 , and the integrated circuit  30  as examples of the support member, the plurality of connections, and the electronic component, respectively. However, the embodiment described above may be applied to other electronic devices having a support member other than the substrate  20 , connections other than the plurality of bumps  34 , and an electronic component other than the integrated circuit  30 . Furthermore, the electronic component of such electronic devices may be, in its entirety, a heating part. 
     Furthermore, in the embodiment described above, each of the refrigerant pipes  43  is formed of, as an example, a hollow fiber. However, each refrigerant pipe  43  may be a component other than the hollow fiber. Moreover, a fluid other than the coolant may be employed as the refrigerant. 
     Furthermore, the plurality of modifications described above may be also applied to the method for manufacturing the electronic device  10  described above. 
     Furthermore, in the embodiment described above, the refrigerant is supplied from the external refrigerant supply device to the first connection port  48  through the hose  51 , and the refrigerant is returned to the external refrigerant supply device from the second connection port  49  through the hose  52 . However, the refrigerant may be supplied from the external refrigerant supply device to the second connection port  49  through the hose  52 , and the refrigerant may be returned to the external refrigerant supply device from the first connection port  48  through the hose  51 . 
     Furthermore, as illustrated in the lower figure of  FIG. 4 , in the method for manufacturing the electronic device  10  according to the present embodiment, the first fixing plate  44  is moved apart from the second fixing plate  46 . However, the second fixing plate  46  may be moved apart from the first fixing plate  44 , alternatively, the first fixing plate  44  and the second fixing plate  46  may be moved apart from each other. 
     Furthermore, among the plurality of modifications described above, those that are capable of being combined with each other may be combined and implemented as appropriate. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiment of the present invention has been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.