Abstract:
There is provided an electronic device that includes a housing including six sides at right angles to each other, a first side of the six sides including an opening, a first backplane arranged on a second side so as to oppose to the opening, a second backplane arranged on a third side adjacent to the second side, a circuit board which is inserted toward the first backplane through the opening to be coupled with both of the first backplane and the second backplane with use of a plurality of connectors, the circuit board including a specified corner, and a guide. The guide is configured to shift the circuit board toward the second backplane while the specified corner slides with contacting a portion of the guide which is arranged on a fourth side of the six sides opposed to the third side.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2011-057108, filed on Mar. 15, 2011, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The embodiments discussed herein are related to an electronic device and a connection structure for circuit board. 
       BACKGROUND 
       [0003]    In electronic devices such as servers and communication devices, daughter boards, which are circuit boards removably mounted in housings, have connectors concentrated at the front ends of the daughter boards in a direction in which the daughter boards are inserted. With this structure, since signal wires are routed through backplanes, which are boards disposed on surfaces of the housings toward which the daughter boards are inserted, the length of signal paths is increased. Also with this structure, the density of wiring on the daughter boards is increased, thereby increasing the number of daughter boards used in an electronic device and, accordingly, increasing the cost of the electronic devices. 
         [0004]    In order to overcome these drawbacks, connectors are provided on a plurality of edges of the daughter board. When the daughter board has connectors on the plurality of edges thereof, the backplanes, which are boards on the housing side, are provided corresponding to the edges of the daughter board where the connectors are disposed. 
         [0005]    When an electronic device has a plurality of backplanes connected to the plurality of edges of a daughter board as described above, the length of wiring on the daughter board from electronic components to the connectors may be decreased. This is useful for high-speed communication of a large number of signals. The above-described electronic device also allows the density of wiring on the daughter board to be decreased. 
         [0006]    Specifically, the above-described connection structure uses a three-dimensional mounting structure in which backplanes are disposed on both side surfaces of the daughter board, or uses a structure in which a daughter board having been inserted into a housing is moved perpendicularly to the plane of the daughter board to connect the connectors on the backplane and the daughter board to each other. These connectors are disposed so as to be engageable in a direction perpendicular to the plane of the daughter board. 
         [0007]    Japanese Laid-open Patent Publications No. 2006-164627, No. 50-119282, and No. 2002-223085 are examples of related art. 
       SUMMARY 
       [0008]    According to an aspect of the invention, an electronic device includes a housing including six sides at right angles to each other, a first side of the six sides including an opening, a first backplane arranged on a second side of the six sides, the first backplane being arranged so as to oppose to the opening, a second backplane arranged on a third side of the six sides, the third side being adjacent to the second side, a circuit board which is inserted toward the first backplane through the opening to be coupled with both of the first backplane and the second backplane with use of a plurality of connectors, the circuit board including a specified corner, and a guide configured to shift the circuit board toward the second backplane while the specified corner slides with contacting a portion of the guide, the guide being arranged on a fourth side of the six sides, the fourth side being opposed to the third side. 
         [0009]    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. 
         [0010]    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 
         [0011]      FIG. 1  is an exploded perspective view of an electronic device according to a first embodiment with part of the electronic device omitted. 
           [0012]      FIG. 2  is a perspective view of a housing of the electronic device according to the first embodiment with part of the housing omitted. 
           [0013]      FIGS. 3A to 3E  are explanatory diagrams illustrating an example of an assembly process of the electronic device according to the first embodiment. 
           [0014]      FIGS. 4A to 4C  are explanatory diagrams illustrating the example of the assembly process of the electronic device according to the first embodiment. 
           [0015]      FIG. 5  is an exploded perspective view of an electronic device according to a second embodiment with part of the electronic device omitted. 
           [0016]      FIG. 6  is a perspective view of a housing of the electronic device according to the second embodiment with part of the housing of the electronic device omitted. 
           [0017]      FIGS. 7A to 7E  are explanatory diagrams illustrating an example of an assembly process of the electronic device according to the second embodiment. 
           [0018]      FIGS. 8A to 8C  are explanatory diagrams illustrating the example of the assembly process of the electronic device according to the second embodiment. 
           [0019]      FIGS. 9A and 9B  are respectively an exploded perspective view and a perspective view of an electronic device in which a plurality of daughter boards are mounted with part of the electronic device omitted. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0020]    Preliminary Consideration 
         [0021]    In the structure, described in the background, in which the backplanes are disposed on both sides of the daughter board, a specific engagement method is required to realize three-dimensional mounting. There is also a problem with the structure in which the daughter board is moved perpendicularly to the plane of the daughter board to connect the connectors of the backplanes and the daughter board to each other. With this structure, separate operations are required in order to align the connectors with each other for connection and to move the daughter board. 
         [0022]    An embodiment of an electronic device and a connection structure for a circuit board according to the present invention will be described in detail below with reference to the drawings. The present embodiment does not limit the disclosed technology. 
       First Embodiment 
       [0023]      FIG. 1  is an exploded perspective view of an electronic device according to a first embodiment with part of the electronic device omitted.  FIG. 2  is a perspective view of a housing of the electronic device according to the first embodiment with part of the housing omitted. An electronic device  1  illustrated in  FIG. 1  includes a housing  2  and a daughter board  3  that is mounted in the housing  2 . The housing  2  has a front portion  2 A, a rear surface portion  2 B, a first side surface portion  2 C, a second side surface portion  2 D, a top surface portion (not illustrated), and a bottom surface portion (not illustrated). The front portion  2 A is defined by an opening portion  11 . The rear surface portion  2 B opposes the front portion  2 A. The first side surface portion  2 C is adjacent to the rear surface portion  2 B. The second side surface portion  2 D is adjacent to the rear surface portion  2 B and opposes the first side surface portion  2 C. 
         [0024]    A first backplane  12  is disposed on the rear surface portion  2 B. The first backplane  12  includes two first connectors  13  disposed thereon as an example. Each of the first connectors  13  is a straight connector having an engagement surface  13 A on the front surface portion thereof. A second backplane  14  is disposed on the first side surface portion  2 C. The second backplane  14  includes three second connectors  15  disposed thereon as an example. Each of the second connectors  15  is a right-angle connector having an engagement surface  15 A on the side surface portion thereof. 
         [0025]    The daughter board  3  includes two straight third connectors  21  disposed on a leading end area  3 A side thereof. The third connectors  21  are engaged with the first connectors  13  of the first backplane  12 . The daughter board  3  also includes three right-angle fourth connectors  22  disposed on a first side surface portion  3 B side thereof. The fourth connectors  22  are engaged with the second connectors  15  of the second backplane  14 . 
         [0026]    The housing  2  has guide rails  16  disposed therein on the first side surface portion  2 C and the second side surface portion  2 D thereof. The guide rails  16  contact a lower surface of the daughter board  3  inserted through the opening portion  11 , and hold the daughter board  3  such that the daughter board  3  is slidable relative to the guide rails  16 . The guide rails  16  hold the daughter board  3  such that the daughter board  3  is perpendicular to the rear surface portion  2 B, the first side surface portion  2 C, and the second side surface portion  2 D while the first connectors  13 , the third connectors  21 , the second connectors  15 , and the fourth connectors  22  are horizontally disposed. 
         [0027]    A guide mechanism  17  is provided on the second side surface portion  2 D inside the housing  2 . The guide mechanism  17  guides the daughter board  3  inserted through the opening portion  11  into the housing  2 . The guide mechanism  17  contacts a side surface portion  3 C of the daughter board  3  and guides the daughter board  3  held on the guide rails  16  in a direction in which the daughter board  3  is inserted into the housing  2 . When this insertion direction is the X-direction, a horizontal direction of the plane of the daughter board  3  that is directed toward the first side surface portion  2 C and perpendicular to the X-direction is the Y-direction. 
         [0028]    The guide mechanism  17  has a guide groove member  30  that is provided on the second side surface portion  2 D. The guide groove member  30  has a guide groove  31  formed therein. The second side surface portion  3 C of the daughter board  3  inserted through the opening portion  11  contacts the guide groove  31  while sliding in the guide groove  31 . The guide groove  31  guides the daughter board  3  from the start of insertion to the completion of mounting via following positions: a linear movement start position  30 A, a parallel movement start position  30 B, a parallel movement end position  30 C, and a linear movement end position  30 D. 
         [0029]    A linear movement of the daughter board  3  in the X-direction in the guide groove  31  starts at the linear movement start position  30 A when the daughter board  3  is slid. At the parallel movement start position  30 B, the linear movement of the daughter board  3  in the X-direction started from the linear movement start position  30 A is stopped, and parallel movement of the daughter board  3  in the guide groove  31  in a diagonal direction toward the first side surface portion  2 C side starts. At the parallel movement end position  30 C, the parallel movement of the daughter board  3  in a diagonal direction toward the first side surface portion  2 C side is complete, and the linear movement of the daughter board  3  in the X-direction in the guide groove  31  restarts. At the linear movement end position  30 D, the linear movement of the daughter board  3  in the X-direction in the guide groove  31  is complete. 
         [0030]    The guide groove  31  includes a first guide groove  31 A, a second guide groove  31 B, and a third guide groove  31 C. The second guide groove  31 B is continuous with the first guide groove  31 A, and the third guide groove  31 C is continuous with the second guide groove  31 B. The first guide groove  31 A guides the daughter board  3  between the linear movement start position  30 A and the parallel movement start position  30 B. 
         [0031]    The first guide groove  31 A guides the daughter board  3  so as to prevent the fourth connectors  22  from interfering with the second connectors  15  in the linear movement in the X-direction. The second guide groove  31 B guides the daughter board  3  between the parallel movement start position  30 B and the parallel movement end position  30 C. The second guide groove  31 B makes the daughter board  3  sliding toward the first backplane  12  undergo the parallel movement in a sliding manner from the second side surface portion  2 D toward the first side surface portion  2 C. As a result, the daughter board  3  is guided to a position in which engagement surfaces  22 A of the fourth connectors  22  to be engaged with the second connectors  15  oppose the engagement surfaces  15 A of the second connectors  15 . Likewise, the daughter board  3  is guided to a position in which engagement surfaces  21 A of the third connectors  21  to be engaged with the first connectors  13  oppose the engagement surfaces  13 A of the first connectors  13 . 
         [0032]    The third guide groove  31 C guides the daughter board  3  between the parallel movement end position  30 C and the linear movement end position  30 D. The third guide groove  31 C makes the daughter board  3  restart the linear movement in the X-direction. By doing this, the third connectors  21  are engaged with the first connectors  13 , and the fourth connectors  22  are engaged with the second connectors  15 . Thus, the daughter board  3  is guided by the first guide groove  31 A, the second guide groove  31 B, and the third guide groove  31 C to be connected to the first side surface portion  2 C and the first backplane  12  with a single operation. The distance between the parallel movement end position  30 C to the linear movement end position  30 D is equal to or greater than the moving distance of the third connectors  21  between a position at which engagement of the third connectors  21  with the first connectors  13  starts and a position at which the engagement of third connectors  21  with the first connectors  13  is complete. 
         [0033]    The side surface portion  3 C of the daughter board  3  has a protruding portion  41  that protrudes at a position in a rearward direction of the daughter board  3 , for example, at a position spaced away from a leading end portion  3 D by a distance equal to the distance between the linear movement start position  30 A and the parallel movement start position  30 B. When the leading end portion  3 D of the side surface portion  3 C of the daughter board  3  reaches the parallel movement start position  30 B in the second guide groove  31 B, the protruding portion  41  reaches the linear movement start position  30 A in the first guide groove  31 A. The protruding portion  41  assists the daughter board  3  in undergoing the parallel movement in a sliding manner toward the first side surface portion  2 C side as the protruding portion  41  enters the first guide groove  31 A. The protruding portion  41  protrudes from the surface of the side surface portion  3 C by a dimension L 1 . L 1  is equal to the distance of movement L 2  in Y-direction, by which the daughter board  3  undergoes the parallel movement in the second guide groove  31 B from the second side surface portion  2 D side toward the first side surface portion  2 C side (see  FIG. 3A ). 
         [0034]    Next, a method of assembling the electronic device  1  according to the first embodiment will be described.  FIGS. 3A to 3E  and  FIGS. 4A to 4C  are explanatory diagrams illustrating an example of an assembly process of the electronic device  1  according to the first embodiment. The daughter board  3  is inserted into the housing  2  through the opening portion  11 . The daughter board  3  is guided into the housing  2  as illustrated in  FIG. 3A  while the side surface portion  3 C of the daughter board  3  slides in the first guide groove  31 A. The daughter board  3  is guided into the housing  2  in the X-direction through the first guide groove  31 A. In so doing, the daughter board  3  is held on the guide rails  16  formed on the first side surface portion  2 C and the second side surface portion  2 D. As a result, the daughter board  3  is held perpendicularly to the first backplane  12  and the second backplane  14  while the first connectors  13 , the third connectors  21 , the second connectors  15 , and the fourth connectors  22  are horizontally disposed. 
         [0035]    As illustrated in  FIGS. 3B and 4A , the daughter board  3  undergoes the linear movement in the X-direction on the guide rails  16  until the leading end portion  3 D of the side surface portion  3 C thereof reaches the parallel movement start position  30 B through the first guide groove  31 A. When the leading end portion  3 D of the side surface portion  3 C of the daughter board  3  reaches the parallel movement start position  30 B, the protruding portion  41  located in a rearward direction of the daughter board  3  enters the first guide groove  31 A. As illustrated in  FIG. 3C , when the leading end portion  3 D of the side surface portion  3 C of the daughter board  3  moves beyond the parallel movement start position  30 B and enters the second guide groove  31 B, the parallel movement of the daughter board  3  starts in a diagonal direction toward the first side surface portion  2 C side. As the protruding portion  41  enters the first guide groove  31 A, the protruding portion  41  interferes with the first guide groove  31 A. This interference assists the daughter board  3  in undergoing the parallel movement such that the daughter board  3  smoothly undergoes the parallel movement in a diagonal direction toward the first side surface portion  2 C side. 
         [0036]    As illustrated in  FIG. 3D , when the leading end portion  3 D of the side surface portion  3 C of the daughter board  3  reaches the parallel movement end position  30 C in the second guide groove  31 B, the parallel movement of the daughter board  3  in a diagonal direction toward the first side surface portion  2 C side is complete. As a result, as illustrated in  FIG. 4B , the daughter board  3  is guided to a position at which the engagement surfaces  21 A of the third connectors  21  and the engagement surfaces  13 A of the first connectors  13  oppose each other, and the engagement surfaces  22 A of the fourth connectors  22  and the engagement surfaces  15 A of the second connectors  15  oppose each other. 
         [0037]    As illustrated in  FIG. 3E , the leading end portion  3 D of the side surface portion  3 C of the daughter board  3  enters the third guide groove  31 C and reaches the linear movement end position  30 D as the daughter board  3  undergoes the linear movement in the X-direction. As illustrated in  FIG. 4C , when the leading end portion  3 D of the daughter board  3  reaches the linear movement end position  30 D, the third connectors  21  are engaged with the first connectors  13 , and the fourth connectors  22  are engaged with the second connectors  15 . As a result, with a single insertion operation performed by a user, the daughter board  3  is mounted perpendicularly to the first backplane  12  and the second backplane  14 . 
         [0038]    In the first embodiment, with a single insertion operation, the daughter board  3  is guided through the guide groove  31  to a position at which the engagement surfaces  21 A of the third connectors  21  and the engagement surfaces  13 A of the first connectors  13  oppose each other, and the engagement surfaces  22 A of the fourth connectors  22  and the engagement surfaces  15 A of the second connectors  15  oppose each other. In the electronic device  1 , the daughter board  3  is mounted perpendicularly to the first backplane  12  and the second backplane  14  by engaging the third connectors  21  with the first connectors  13  and engaging the fourth connectors  22  with the second connectors  15 . As a result, in the first embodiment, a work burden in mounting the daughter board  3  in a direction perpendicular to the first backplane  12  and the second backplane  14  may be reduced. In addition, in the electronic device  1  according to the first embodiment, the non-uniform density of wiring on the daughter board  3  is suppressed. This allows the number of daughter boards  3  to be mounted to be decreased. 
         [0039]    In the above-described first embodiment, the daughter board  3  is caused to undergo the parallel movement in a diagonal direction toward the first side surface portion  2 C side through the guide groove  31  of the guide groove member  30 . Alternatively, a guide protruding portion may be formed instead of the guide groove  31 , and the daughter board  3  may have a guide recess portion in the side surface portion  3 C thereof. In this case, the guide protruding portion slides in the guide recess portion so as to cause the daughter board  3  to undergo the parallel movement in a diagonal direction toward the first side surface portion  2 C side. 
         [0040]    Alternatively, in the above-described first embodiment, the guide mechanism  17  may use a guide surface that allows the side surface portion  3 C of the daughter board  3  to slide along the guide surface so as to cause the daughter board  3  to undergo the parallel movement in a diagonal direction toward the first side surface portion  2 C side without use of the guide groove  31  or the guide protruding portion. 
         [0041]    In the above-described first embodiment, the guide groove member  30  having the guide groove  31  is disposed on the second side surface portion  2 D. Instead, the guide groove  31  may be directly formed in the second side surface portion  2 D. 
         [0042]    In the above-described first embodiment, the protruding portion  41  formed on the side surface portion  3 C of the daughter board  3  enters the first guide groove  31 A so as to assist the parallel movement of the daughter board  3  as the protruding portion  41  interferes with the guide groove  31 . Alternatively, formation of the protruding portion  41  may be omitted. 
         [0043]    In the above-described first embodiment, the guide groove member  30  exemplifies the guide mechanism  17 . Alternatively, a lever member may be pivotally disposed on the second side surface portion  2 D instead of the guide groove member  30  so as to cause the daughter board  3  to undergo the parallel movement toward the first side surface portion  2 C side. An embodiment in this case will be described below as a second embodiment. 
       Second Embodiment 
       [0044]      FIG. 5  is an exploded perspective view of an electronic device  1 A according to a second embodiment with part of the electronic device  1 A omitted.  FIG. 6  is a perspective view of a housing  2   a  of the electronic device  1 A according to the second embodiment with part of the housing  2   a  omitted. Components similar to those of the electronic device  1  according to the first embodiment are denoted by the same reference signs in order to omit duplicate descriptions of structures and operations thereof. 
         [0045]    A main difference between the electronic device  1 A illustrated in  FIG. 5  and the electronic device  1  illustrated in  FIG. 1  is that, in the electronic device  1 A, the guide mechanism  17  provided on the second side surface portion  2 D uses a lever member  50  instead of the guide groove member  30 . The lever member  50  is pivotally disposed on one of the guide rails  16  formed on the second side surface portion  2 D. The lever member  50  has a base member  51 , a lever portion  52 , a guide portion  53 , and a fulcrum  54 . The lever portion  52  is formed in a front end portion of the base member  51 . The guide portion  53  is formed in a rear end portion of the base member  51 . The lever portion  52  and the guide portion  53  are pivotable about the fulcrum  54 . 
         [0046]    The guide portion  53  of the lever member  50  guides a daughter board  3   a  in the X-direction into the housing  2   a  while allowing the side surface portion  3 C of the daughter board  3   a  inserted through the opening portion  11  to slide along the guide portion  53 . The daughter board  3   a  is disposed perpendicularly to the first backplane  12  and the second backplane  14  while the first connectors  13 , the third connectors  21 , the second connectors  15 , and the fourth connectors  22  are horizontally disposed. 
         [0047]    The lever portion  52  of the lever member  50  is pressed by the leading end portion  3 D of the side surface portion  3 C of the daughter board  3   a  in accordance with the linear movement in the X-direction of the daughter board  3   a , which has been inserted from the opening portion  11 . The lever portion  52  pivots about the fulcrum  54  toward the second side surface portion  2 D side in accordance with a pressing operation performed by the leading end portion  3 D. In addition, the guide portion  53  of the lever member  50  pivots about the fulcrum  54  toward the first side surface portion  2 C side as the lever portion  52  pivots toward the second side surface portion  2 D side. The guide portion  53  presses the side surface portion  3 C of the daughter board  3   a  in a diagonal direction toward the first side surface portion  2 C side as the guide portion  53  pivots toward the first side surface portion  2 C side. As a result, in accordance with the pressing operation, the guide portion  53  causes the daughter board  3   a  to undergo a parallel movement to a position at which the engagement surfaces  21 A of the third connectors  21  and the engagement surfaces  13 A of the first connectors  13  oppose each other, and the engagement surfaces  22 A of the fourth connectors  22  and the engagement surfaces  15 A of the second connectors  15  oppose each other. 
         [0048]    In addition, the lever portion  52  of the lever member  50  causes the daughter board  3   a  to undergo a parallel movement in a diagonal direction toward the first side surface portion  2 C side in accordance with the pressing operation performed by the leading end portion  3 D of the daughter board  3   a . The lever portion  52  is brought out of contact with the leading end portion  3 D of the daughter board  3   a  at a timing at which the parallel movement of the daughter board  3   a  toward the first side surface portion  2 C side is complete. The daughter board  3   a  undergoes a linear movement in the X-direction into the housing  2   a  from a position at which the engagement surfaces  21 A of the third connectors  21  and the engagement surfaces  13 A of the first connectors  13  oppose each other, and the engagement surfaces  22 A of the fourth connectors  22  and the engagement surfaces  15 A of the second connectors  15  oppose each other. As a result, the daughter board  3   a  is mounted perpendicularly to the first backplane  12  and the second backplane  14  by engaging the third connectors  21  with the first connectors  13  and engaging the fourth connectors  22  with the second connectors  15 . 
         [0049]    Next, a method of assembling the electronic device  1 A according to the second embodiment will be described.  FIGS. 7A to 7E  and  FIGS. 8A to 8C  are explanatory diagrams illustrating an example of an assembly process of the electronic device  1 A according to the second embodiment. The daughter board  3   a  is inserted into the housing  2   a  by the user. The daughter board  3   a  is inserted into the housing  2   a  in the X-direction as illustrated in  FIG. 7A  while the side surface portion  3 C thereof slides from the opening portion  11  along the lever member  50  on the second side surface portion  2 D side. In so doing, the daughter board  3   a  is held on the guide rails  16  formed on the first side surface portion  2 C and the second side surface portion  2 D in the housing  2   a . As a result, the daughter board  3   a  is held perpendicularly to the first backplane  12  and the second backplane  14  while the first connectors  13 , the third connectors  21 , the second connectors  15 , and the fourth connectors  22  are horizontally disposed. 
         [0050]    When the daughter board  3   a  is inserted into the housing  2   a  in the X-direction, the daughter board  3   a  undergoes a linear movement in the X-direction on the guide rails  16  as illustrated in  FIG. 7B . As illustrated in  FIG. 8A , the leading end portion  3 D of the side surface portion  3 C of the daughter board  3   a  presses the lever portion  52  of the lever member  50  as the daughter board  3   a  undergoes the linear movement in the X-direction. The lever portion  52  of the lever member  50  pivots about the fulcrum  54  toward the second side surface portion  2 D side in accordance with the pressing operation performed by the daughter board  3   a . The guide portion  53  of the lever member  50  pivots toward the first side surface portion  2 C side as the lever portion  52  undergoes the pivotal movement toward the second side surface portion  2 D side. 
         [0051]    A rear end portion of the daughter board  3   a  starts the parallel movement in a diagonal direction toward the first side surface portion  2 C in accordance with the pivotal movement of the guide portion  53  of the lever member  50  toward the first side surface portion  2 C side. The lever portion  52  of the lever member  50  is brought out of contact with the leading end portion  3 D of the daughter board  3   a  at a timing at which the parallel movement of the daughter board  3   a  toward the first side surface portion  2 C side is complete as illustrated in  FIGS. 7C and 7D . The lever portion  52  stops the pivotal movement toward the second side surface portion  2 D side when the lever portion  52  is brought out of contact with the leading end portion  3 D of the daughter board  3   a . When the lever portion  52  stops the pivotal movement toward the second side surface portion  2 D side, the guide portion  53  also stops the pivotal movement toward the first side surface portion  2 C side. As a result, as illustrated in  FIG. 8B , the daughter board  3   a  is guided to a position at which the engagement surfaces  21 A of the third connectors  21  and the engagement surfaces  13 A of the first connectors  13  oppose each other, and the engagement surfaces  22 A of the fourth connectors  22  and the engagement surfaces  15 A of the second connectors  15  oppose each other. 
         [0052]    The daughter board  3   a  undergoes the linear movement in the X-direction while the pivotal movement of the guide portion  53  toward the first side surface portion  2 C side is stopped. As illustrated in  FIGS. 7E and 8C , the third connectors  21  of the daughter board  3   a  are engaged with the first connectors  13 , and the fourth connectors  22  of the daughter board  3   a  are engaged with the second connectors  15 . As a result, the daughter board  3   a  is mounted perpendicularly to the first backplane  12  and the second backplane  14 . 
         [0053]    In the second embodiment, the lever portion  52  of the lever member  50  pivots toward the second side surface portion  2 D side in accordance with the linear movement of the leading end portion  3 D of the daughter board  3   a  in the X-direction caused with a single insertion operation. The guide portion  53  of the lever member  50  pivots toward the first side surface portion  2 C side as the lever portion  52  undergoes a pivotal movement. The guide portion  53  causes the daughter board  3   a  to undergo the parallel movement in a diagonal direction toward the first side surface portion  2 C side as the guide portion  53  undergoes the pivotal movement toward the first side surface portion  2 C side. By doing this, the daughter board  3   a  is guided to the position at which the engagement surfaces  21 A of the third connectors  21  and the engagement surfaces  13 A of the first connectors  13  oppose each other, and the engagement surfaces  22 A of the fourth connectors  22  and the engagement surfaces  15 A of the second connectors  15  oppose each other. In the electronic device  1 A, the daughter board  3   a  is mounted perpendicularly to the first backplane  12  and the second backplane  14  by engaging the first connectors  13  with the third connectors  21  and engaging the second connectors  15  with the fourth connectors  22 . As a result, in the second embodiment, a work burden in mounting the daughter board  3   a  perpendicularly to the first backplane  12  and the second backplane  14  may be reduced. 
         [0054]    In the above-described first and second embodiments, the first backplane  12  and the second backplane  14  are respectively disposed on the rear surface portion  2 B and the first side surface portion  2 C in the housing  2  or  2   a . Alternatively, for example, two backplanes may be disposed on the rear surface portion  2 B and the second side surface portion  2 D, on the top surface portion and the first side surface portion  2 C, on the top surface portion and the second side surface portion  2 D, on the bottom surface portion and the first side surface portion  2 C, on the bottom surface portion and the second side surface portion  2 D, or the like. 
         [0055]    In the above-described first and second embodiments, one daughter board  3  or  3   a  is perpendicularly mounted to the first backplane  12  and the second backplane  14 . Similar advantages are obtainable when a plurality of daughter boards  3  or  3   a  are mounted to the first backplane  12  and second backplane  14 .  FIGS. 9A and 9B  are respectively an exploded perspective view and a perspective view of an electronic device  1 B in which a plurality of daughter boards  3  are mounted with part of the electronic device  1 B omitted. A plurality of daughter board  3   a  may similarly be mounted in a housing of an electronic device. For convenience of explanation, components similar to those of the electronic device  1  illustrated in  FIG. 1  are denoted by the same reference signs in order to omit duplicate descriptions of structures and operations thereof. Also for convenience of explanation, the top and bottom surface portions are omitted. In addition, the second side surface portion  2 D and the guide mechanism  17  are omitted from  FIGS. 9A and 9B . The electronic device  1 B illustrated in  FIGS. 9A and 9B  uses the guide mechanism  17  (not illustrated) to sequentially mount the daughter boards  3  perpendicularly to the first backplane  12  and the second backplane  14 . The electronic device  1 B allows the plurality of daughter boards  3  to be easily mounted to the first backplane  12  and the second backplane  14 . In order to electrically connect the daughter boards  3  to each other, a jumper  61  may be used to connect the daughter boards  3  to each other. 
         [0056]    In the above-described embodiments, when the daughter board  3  or  3   a  is inserted into the housing  2  or  2   a , the daughter board  3  or  3   a  is caused to undergo the linear movement in the X-direction while occurrence of a situation in which the fourth connectors  22  interfere with the second connectors  15  is avoided, and the daughter board  3  or  3   a  is caused to undergo the parallel movement in a diagonal direction toward the first side surface portion  2 C side. The daughter board  3  or  3   a  having undergone the parallel movement is again caused to undergo the linear movement in the X-direction. As a result, engagement of the third connectors  21  of the daughter board  3  or  3   a  with the first connectors  13  and engagement of the fourth connectors  22  of the daughter board  3  or  3   a  with the second connectors  15  simultaneously occur. That is, in the above-described embodiments, compared to the related-art structure in which connectors are engaged with each other by moving a daughter board in a direction perpendicular to a surface portion of the daughter board, the connectors are engaged with each other without a work space in which the daughter board  3  or  3   a  is moved in the perpendicular direction. As a result, in the above-described embodiments, the work space is not required, thereby allowing the size of the electronic device to be decreased by decreasing a distance between positions at which the daughter boards  3  or  3   a  are mounted. 
         [0057]    In the above-described first and second embodiments, the daughter board  3  or  3   a  is perpendicularly mounted to the first backplane  12  and the second backplane  14 . By doing this, occurrence of a situation in which connectors to be engaged with those of the daughter board  3  or  3   a  are concentrated in the rear surface portion  2 B of the first backplane  12  is avoidable. This may decrease the number of connectors mounted on the first backplane  12  on the rear surface portion  2 B side opposing the opening portion  11 , and accordingly, a space in which a vent hole is disposed may be allocated in the rear surface portion  2 B. As a result, cooling air flows from the opening portion  11  to the vent hole of the rear surface portion  2 B in a certain direction, that is, in the X-direction, and accordingly, cooling efficiency may be improved. 
         [0058]    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 embodiments of the present inventions have 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.