Abstract:
An electronic apparatus includes: a first connector; a second connector; a first electronic unit connectable to the first connector; a second electronic unit connectable to the second connector; and a printed circuit board that includes the first connector and the second connector between a first extended center line toward a unit board of the first electronic unit and a second extended center line toward a unit board of the second electronic unit on a first side of the printed circuit board when the first and second electronic units are connected to the first and second connectors, respectively.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of PCT/JP2008/063355, filed on Jul. 25, 2008, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     The embodiment discussed herein is related to an electronic apparatus. 
     BACKGROUND 
     There is known an electronic apparatus which includes: a backplane provided with plural connectors; and plural electronic units respectively connected to the connectors. The electronic unit has a unit board on which electronic parts are mounted. The unit board and the backplane are electrically connected to each other, whereby signals and electricity are supplied to the electronic parts mounted on the unit board. For example, there is known a technique of connecting electronic units each having a different shape factor to the backplane efficiently within a given space (See Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2004-503890). 
     Since the plural electronic units are connected to the backplane, so that the great ratio of the backplane is occupied in the whole electronic apparatus. Thus, even if the electronic unit is able to be connected efficiently in the limited space, the whole electronic apparatus might be large when the backplane is large. The upsizing of an electronic apparatus causes the degradation of the cooling efficiency, the increase in the production cost with the upsizing of the housing or the cooling fan, and the increase in its weight. 
     SUMMARY 
     An electronic apparatus discussed herein includes: a first connector; a second connector; a first electronic unit connectable to the first connector; a second electronic unit connectable to the second connector; and a printed circuit board that includes the first connector and the second connector between a first extended center line toward a unit board of the first electronic unit and a second extended center line toward a unit board of the second electronic unit on a first side of the printed circuit board when the first and second electronic units are connected to the first and second connectors, respectively. 
     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 a server; 
         FIG. 2  is a front view of a unit system; 
         FIG. 3  is a perspective view of the unit system; 
         FIG. 4  is a perspective view of the unit system when viewed from its back; 
         FIG. 5  is a view of the connection between the backplane and unit boards; 
         FIG. 6  is a view of the connection between the backplane and the unit boards; 
         FIG. 7  is a view of the connection between the backplane and the unit boards; 
         FIGS. 8A and 8B  are explanatory views of detachment of the connector; 
         FIG. 9  is an explanatory view of the unit; 
         FIGS. 10A and 10B  are comparative views of a unit system according to a second embodiment and a unit system having a structure different from that of the unit system according to the second embodiment; 
         FIGS. 11A and 11B  are comparative views of a unit system according to the second embodiment and the unit system having a structure different from that of the unit system according to the second embodiment; 
         FIG. 12  is an explanatory view of a unit system according to a third embodiment; 
         FIGS. 13A and 13B  are comparative views of a unit system according to a fourth embodiment and a unit system having a structure different from that of the unit system according to a fourth embodiment; and 
         FIGS. 14A and 14B  are comparative views of a unit system according to a fifth embodiment and a unit system having a structure different from that of the unit system according to the fifth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The embodiments according to the present invention will be explained with reference to the accompanying drawings as follows. 
     An electronic apparatus according to an example of the embodiments will be explained. A server  1  will be explained as an example of an electronic apparatus.  FIG. 1  is a perspective view of the server  1 . The server  1  includes: a frame  100 ; a backplane (printed circuit board)  10  held in the frame  100 , units  20 ,  30 , and  40  electrically connected to the backplane  10 . Additionally,  FIG. 1  illustrates the state where a side board provided at the side of the frame  100  is removed. 
     The units  20 ,  30 , and  40  each include a unit board mounting electronic parts such as a microprocessor, memory, a hard disk, and a heat sink. The backplane  10  is provided for supplying a signal and electricity to the units  20 ,  30 , and  40 . The units  20 ,  30 , and  40  can be attached to or detached from the backplane  10 . The units  40  are arranged on a lower rack  110  and on a upper rack of the frame  100 . The units  20  and  30  are arranged on a middle rack  120 . The units  20  and  30  are connected to a middle portion of the backplane  10 . The units  40  are arranged in the upper and lower sides to sandwich units  20  and  30 . The frame  100  is provided at its bottom portion with casters  180  for moving and with stoppers  182  for prevention of the moving. 
     Next, a unit system  90  will be described. The unit system  90  includes: the backplane  10 ; and the units  20 ,  30 , and  40  connected to the backplane.  FIG. 2  is a front view of the unit system  90 .  FIG. 3  is a perspective view of the unit system  90 .  FIG. 4  is a perspective view of the unit system  90  when viewed from its back. Additionally, units connected to the back surface of the backplane  10  are omitted in  FIGS. 2 to 4 . 
     The units  20  include a unit (electronic units)  20   a  and  20   b . The units  30  include units  30   a  to  30   c . The units  40  include units  40   a  to  40   d . The units  20 ,  30 ,  40  are connected to the same side of the backplane  10 . The units  40   a  and  40   b  are connected at the upper portion of the backplane  10 . The units  40   c  and  40   d  are connected at the lower portion of the backplane  10 . The units  20   a ,  20   b , and  30   a  to  30   c  are connected at the middle portion of the backplane  10 . 
     Each thickness of the units  30   a  to  30   c  connected at the middle portion of the backplane  10  is smaller than each of that of the units  20   a  and  20   b . Also, the units  20   a ,  20   b ,  30   a  to  30   c , and  40   a  to  40   d  each have a unit board as will be described below. 
     The units  20   a ,  20   b , and  30   a  to  30   c  are respectively provided with handles  29   a ,  29   b , and  39   a  to  39   c  for respectively attaching to and detaching from the units  20   a ,  20   b , and  30   a  to  30   c  to/from the backplane  10 . 
     The units  40   a  and  40   b  face the same direction and are connected to the backplane  10 , as illustrated in  FIGS. 2 to 4 . Also, the units  40   c  and  40   d  are connected to the backplane  10  with faced the same direction. Further, the units  40   a  to  40   d  are connected to the backplane  10  with the units  40   a  and  40   b  and the unit  40   c  and  40   d  facing oppositely to each other. 
     The units  20   a  and  20   b  are arranged at the most outside of the middle portion of the backplane  10  and face oppositely to each other. 
     Next, the unit boards will be described.  FIGS. 5 to 7  are views of the connection between the backplane  10  and the unit boards. Additionally, unit boards of the units connected to the back side of the backplane  10  are illustrated in  FIGS. 5 to 7 . Electronic parts mounted on each unit board is omitted in  FIGS. 5 to 7 . 
     As illustrated in  FIGS. 5 to 7 , the unit  20   a ,  20   b ,  30   a  to  30   c , and  40   a  to  40   d  have the unit boards  21   a ,  21   b ,  31   a  to  31   c , and  41   a  to  41   d , respectively. These unit boards  21   a ,  21   b ,  31   a  to  31   c ,  41   a  to  41   d  are provided at their given surfaces with connectors  23   a ,  23   b ,  33   a  to  33   c , and  43   a  to  43   d , respectively. The connectors  23   a ,  23   b ,  33   a  to  33   c , and  43   a  to  43   d  ensure the electrical connection between the backplane  10  and the unit boards  21   a ,  21   b ,  31   a  to  31   c , and  41   a  to  41   d , respectively. 
     Plural connectors are provided in one unit board. Also, the backplane  10  is provided with plural connectors corresponding to the connectors provided in the unit boards. Handles  19  are respectively provided at the sides of the backplane  10 . 
     The connectors provided in the backplane  10  are electrically connected to the connectors respectively provided in the unit boards, thereby supplying the signals and electricity to the electronic parts mounted on the unit boards. The electronic parts are mounted on given surfaces of the unit boards  21   a ,  21   b ,  31   a  to  31   c , and  41   a  to  41   d . These electronic parts generate heat when the electricity is supplied thereto. 
     The connector provided in the unit board is mounted on the same surface on which the electronic parts are mounted. The surface on which the electronic parts are mounted is referred to as mounting surface. Additionally, when the electronic parts are mounted on both surfaces of the unit board, the electronic part having a high profile mounted on the surface is referred to as a mounting surface. 
     As illustrated in  FIG. 7 , the mounting surface of the unit board  31   a  oppositely faces mounting faces of the unit board  31   b  and  31   c.    
     Next, a brief description will be given of attachment and detachment of the connector provided in the backplane  10  and the connector provided in the unit board.  FIGS. 8A and 8B  are explanatory views of the attachment and detachment of the connectors. 
       FIG. 8A  is an enlarged view around the connector  33   a  provided in the unit board  31   a . As illustrated in  FIG. 8A , the connector  33   a  is connected to connector  13   a  provided in the backplane  10 .  FIG. 8B  illustrates the state that the connector  33   a  is detached from the connector  13   a.    
     The direction is so defined as to insert the connector  33   a  to the connector  13   a . For example, it is impossible to detach the unit board  31   a  as illustrated in  FIG. 8A  and reverse the unit board  31   a  to insert the connector  31   a  into the connector  13   a . Additionally, this applies to the other connectors provided in backplane  10 . 
     As described above, the units  20   a  and  20   b  each being thicker than the units  30   a  to  30   c  are arranged in the most outside of the middle portion of the backplane  10 . Moreover, the unit  20   a  and  20   b  face oppositely to each other, and the mounting surfaces face the outside of the backplane  10 , as illustrated in  FIG. 5  to  FIG. 7 . The unit  20   a  and the unit  30   a  adjacent to the unit  20   a  can be closely arranged and connected to the backplane  10  while preventing interference of the units  20   a  and  30   a . This configuration also applies to the unit  20   b  and the unit  30   c  adjacent to the unit  20   b . Therefore, the unit system  90  can be downsized, whereby the frame  100  can be downsized. Also, the connectors of the backplane  10  connected to the unit boards  21   a  and  21   b  can be arranged closely to another connector adjacent to these connectors of the backplane  10 . This can downsize the backplane  10 . 
     The units  20   a ,  20   b , and  40   a  to  40   d  protrude from the backplane  10 . Hence, in a case where a cooling fan (not illustrated) is provided within the frame  100 , there is little resistances against the ventilation caused by the backplane  10  at the portions protruding from the backplane  10 . This can cool the units efficiently. Therefore, the cooling efficiency improves. 
     Next, air openings provided in the unit will be explained.  FIGS. 9A to 9C  are explanatory views of the unit  20   b .  FIG. 9A  is a perspective view of the unit  20   b  when viewed from its right side.  FIG. 9  B is a perspective view of the unit  20   b  when viewed from its left side.  FIG. 9C  is a perspective view of the unit  20   b  when viewed from its rear side. 
     The unit  20   b  is provided at its front with a front panel  27   b   1  made of a metal. The front panel  27   b   1  has a fence-shape and is provided with plural air openings  28   b   1 . Likewise, a top panel  27   b   2  is provided with plural air openings  28   b   2 . A back panel  27   b   5  is also provided with two air openings  28   b   5 . Side panels  27   b   3  and  27   b   4  are not provided with a air opening. The air openings  28   b   1 ,  28   b   2  and  28   b   5  function to introduce the ventilation by the cooling fan into the unit  20   b  and to exhaust therefrom. Also, as illustrated in  FIG. 4 , the air openings  28   b   5  formed in the back panel  27   b   5  protrude from the backplane  10 , thereby introducing the ventilation into the unit  20   b . Accordingly, cooling efficiency improves. 
     Next, a unit system  90   a  according to a second embodiment will be described.  FIGS. 10A and 10B  are comparative views of a unit system according to a second embodiment and a unit system having a structure different from that of the unit system according to the second embodiment.  FIG. 10A  is a side view of the unit system  90   x .  FIG. 10B  is a side views of the unit system  90   a . Additionally, each member is simplified in  FIGS. 10A and 10B . 
     As illustrated in  FIG. 10A , a unit  50   ax  is connected to a backplane  10   x  through a connector  15   ax  provided in the backplane  10   x  and a connector  53   ax  provided in the unit board  51   ax . These structures apply for the unit  70   ax.    
     As illustrated in  FIG. 10A , the units  50   ax  and  70   ax  face the same direction in the lengthwise direction with respect to the backplane  10   x  and are connected thereto. That is, the connectors  15   ax  and  17   ax , which are respectively connected to the connectors  53   ax  and  73   ax , face the same direction. For this reason, the backplane  10   x  is upsized by a space S corresponding to the height of the unit  70   ax.    
     On the other hand, units  50   a  and  70   a  face oppositely to each other in the lengthwise direction with respect to the backplane  10   a  and are connected to the backplane  10   a , as illustrated in  FIG. 10B . That is, the connectors  15   a  and  17   a , which are respectively connected to the connectors  53   a  and  73   a , face oppositely to each other. For this reason, the connector  15   a  and  17   a  can be closely arranged on the backplane  10   a . Accordingly, as compared with the unit system  90   x , the backplane  10   a  according to the second embodiment can be downsized. In addition, the backplane  10   a  is downsized as illustrated in  FIG. 10B , both units  50   a  and  70   a  protrude from the backplane  10   a . This improves the cooling efficiencies of the units  50   a  and  70   a.    
       FIG. 11A  is a top plan view of the unit system  90   x .  FIG. 11B  is a top plan view of the unit system  90   a . Additionally, each member is simplified in  FIGS. 11A and 11B . 
     As illustrated in  FIG. 11A , the units  50   ax  and  50   bx  are thicker than units  60   ax  and  60   bx . Also, the units  50   ax ,  50   bx ,  60   ax , and  60   bx  respectively include unit boards  51   ax ,  51   bx ,  61   ax , and  61   bx . Electronic parts  55   ax ,  55   bx ,  65   ax , and  65   bx  are mounted on given surfaces of the unit boards  51   ax ,  51   bx ,  61   ax  and  61   bx , respectively. The units  50   ax ,  50   bx ,  60   ax  and  60   bx  face the same direction. That is, the mounting surfaces of the unit boards  51   ax ,  51   bx ,  61   ax , and  61   bx  face the same direction. 
     The unit board  51   bx  of the unit  50   bx , which is arranged at the most outside of the backplane  10   x , faces the outside of the backplane  10   x . However, the unit board  51   ax  of the unit  50   ax , which is arranged at the most outside of the backplane  10   x  and arranged at the opposite side of the unit  50   bx , faces the inner side of the backplane  10   x . For this reason, the connector  53   ax  is considerably spaced by the space S corresponding to the thickness of the unit  50   ax  from the adjacent connector  63   ax . Thus, the connectors  15   ax  and  16   ax  have to be spaced from each other by the space S. Accordingly, the backplane  10   x  upsizes. 
     On the other hand, the units  50   a  and  60   a  and the units  50   b  and  60   b  oppositely face each other, as illustrated in  FIG. 11B . The units  50   a  and  50   b  are respectively arranged at the most outsides of the backplane  10   a , and face the outside of the backplane  10   a . That is, the mounting surfaces of the unit boards  51   a  and  51   b  respectively provided in the units  50   a  and  50   b  faces the outside of the backplane  10   a.    
     Therefore, the connectors  15   a  and  16   a  are closely arranged without the interference of the units  50   a  and  60   a . For this reason, the backplane  10   a  can be downsized. As a result, the cooling efficiency also improves. 
     Next, a unit system  90   b  according to a third embodiment will be described.  FIG. 12  is an explanatory view of the unit system  90   b  according to the third embodiment. 
     Units  50   a   1  and  50   a   2  are diagonally arranged at the corners of the backplane  10 . Units  70   a   1  and  70   a   2  are diagonally arranged at the other corners of the backplane  10 . Additionally, the units  50   a   1  and  50   a   2  have the same structure, and the units  70   a   1  and  70   a   2  have the same structure. The unit  50   a   1 ,  50   a   2 ,  70   a   1  and  70   a   2  respectively have the unit boards  51   a   1 ,  51   a   2 ,  71   a   1  and  71   a   2 . The unit board  51   a   1 ,  51   a   2 ,  71   a   1  and  71   a   2  are provided with connectors  53   a   1 ,  53   a   2 ,  73   a   1  and  73   a   2 , respectively. 
     Also, plural units as not illustrated are connected to the backplane  10   b  between the units  50   a   1  and  70   a   2  and in addition to between units  70   a   1  and unit  50   a   2 . 
     The upsides of the units  50   a   1  and  70   a   1  face oppositely to each other. Likewise, the upsides of the units  70   a   2  and  50   a   2  face oppositely to each other. The lateral sides of the units  50   a   1  and  70   a   2  face oppositely to each other rightwardly and leftwardly. Also, the units  70   a   1  and  50   a   2  face oppositely to each other rightwardly and leftwardly. In this way, the upsides, downsides, left sides, and right sides of the units  50   a   1 ,  50   a   2 ,  70   a   1  and  70   a   2  face oppositely to each other. Accordingly, the connectors  53   a   1 ,  53   a   2 ,  73   a   1  and  73   a   2  can be closely arranged. Consequently, the backplane  10   b  can be downsized. 
     Also, the units  50   a   1 ,  50   a   2 ,  70   a   1  and  70   a   2  protrude from the backplane  10   b , as illustrated in  FIG. 12 . This permits air to be efficiently sent to the units  50   a   1 ,  50   a   2 ,  70   a   1 , and  70   a   2 . This result improves the cooling efficiencies of the units  50   a   1 ,  50   a   2 ,  70   a   1 , and  70   a   2 . 
     Next, a unit system  90   c  according to a fourth embodiment will be described.  FIG. 13  are comparative views of a unit system  90   c  according to a fourth embodiment and a unit system  90   x   1  having a structure different from that of the unit system according to the fourth embodiment.  FIG. 13A  is a top view of the unit system  90   x   1 .  FIG. 13B  is a top view of the unit system  90   c.    
     As illustrated in  FIGS. 13A and 13B , the backplane  10   c  of the unit system  90   c  and the backplane  10   x   1  of the unit system  90   c  are substantially identical to each other in size. Ten units  70   ax  to  70   jx  facing the same direction are connected to the backplane  10   x   1 , as illustrated in  FIG. 13A . Since the units  70   ax  to  70   jx  face the same direction, the distances between the adjacent connectors provided in the backplane  10   x   1  are equal. 
     In contrast, as illustrated in  FIG. 13B , eleven units  70   a  to  70   k  are connected to the unit system  90   c . The units  70   a  to  70   e  and the units  70   f  to  70   k  face oppositely to each other. That is, the units  70   a  to  70   e  face the same direction, whereas the units  70   f  to  70   k  face the opposite direction. Also, the units  70   a  and  70   k  arranged the most outside of the backplane  10   c  face the outside of the backplane  10   c . Also, the units  70   a  and  70   d  protrude from the backplane  10   c.    
     Also, adjacent units  70   e  and  70   f  face oppositely to each other. Accordingly, the connectors  17   e  and  17   f  can be closely provided in the backplane  10   c . Thus, the space between the connectors  73   e  and  73   f  are smaller than that between the connectors  73   e  and  73   d , and that between the connectors  73   f  and  73   g . For this reason, connectors can be densely arranged in the backplane  10   c.    
     In contrast, since connectors  17   ax  to  17   jx  provided in the unit system  90   x   1  are arranged at equal intervals, an eleventh connector  17   kx  cannot be provided in the backplane  10   x   1 . Thus, only ten units can be connected to the backplane  10   x   1  at the maximum. 
     In other words, in a case where ten units are connected in the unit system  90   c , the size of the backplane  10   c  can be made further smaller than the size of backplane  10   x   1 . 
     Next, a unit system  90   d  according to a fifth embodiment will be described.  FIGS. 14A and 14B  are comparative views of a unit system  90   d  according to the fifth embodiment and a unit system having a structure different from that of the unit system  90   d  according to the fifth embodiment.  FIG. 14A  is a top view of the unit system  90   x   2  having a structure different from that of the unit system  90   d .  FIG. 14B  is a top view of the unit system  90   d.    
     As illustrated in  FIG. 14A , six units  80   ax  to  80   fx  are connected to the backplane  10   x   2 . Also, all the units  80   ax  to  80   fx  face the same direction. For this reason, the distances between the adjacent connectors provided in the backplane  10   x   2  are equal. 
     On the other hand, as illustrated in  FIG. 14B , six units  80   a  to  80   f  are connected to the backplane  10   d . When the thicknesses of the units  80   ex  and  80  are compared, the unit  80   e  is thicker than the unit  80   ex , as illustrated in  FIGS. 14A and 14B . Also, the backplanes  10   x   2  and  10   d  are substantially identical to each other in size. 
     In the unit system  90   d  according to the fifth embodiment, the units  80   a  to  80   c  and the units  80   d  to  80   f  face oppositely to each other. Also, the units  80   a  and  80   f  are arranged at the most outside of the backplane  10  and are connected thereto. Also, as illustrated in  FIG. 14B , the units  80   c  and  80   d  face oppositely to each other. Specifically, the mounting surface of the unit board  81   c  and the mounting surface of the unit board  81   d  do not face each other and face oppositely to each other. Accordingly, the space between the connectors  83   c  and  83   d  is smaller than that of the connectors  83   c  and  83   b , and that of the connectors  83   d  and  83   e.    
     Thus, as compared with the backplane  10   x   2 , the same number of the units  80   a  to  80   f  can be connected to the backplane  10   d  substantially identical to the backplane  10   x   2  in size, and the units  80   a  to  80   f  each being thicker than each that of the units  80   ax  and  80   fx . In other words, in a case where units identical to each other, the backplane  10   d  can be further downsized. 
     Although the embodiment of the present inventions has been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the sprit and scope of the invention. 
     In the above embodiments, a server is explained as an example. However, the present invention can be applicable to a router or switching equipment.