Abstract:
In the invention, a finger board is bent like a “letter V”, and a thickness adjustment plate is provided between the finger boards of modules to be able to move, thereby being able to adjust the height of a finger. Such a configuration enables to increase the contact pressure of the finger by increasing the height of the finger when the finger is inserted, and when the finger is detached, reduce the contact pressure by reducing the height of the finger. This accordingly provides a shield chassis of suppressing any possible noise with no loss of insertability/removability.

Description:
CLAIM OF PRIORITY 
     The present application claims priority from Japanese application serial no. JP2007-158150, filed on Jun. 15, 2007, the content of which is hereby incorporated by reference into this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a chassis of an electronic device handling high-speed signals and a canister to be housed in the chassis of the electronic device, and also relates to a packaging method of suppressing any noise emission (ElectroMagnetic Compatibility: EMC). 
     2. Description of Related Art 
     Electronic devices handling high-speed digital signals emission noise due to clock signals and data signals showing a change in synchronization with the clock signals. This noise emission affects television receivers, radios, and others, and thus is under the control of standards institutions and nations in terms of measurement method and amount of emission. The standards institutions include CISPR (International Special Committee on Radio Interference), VCCI (Voluntary Control Council for Interference), and FCC (Federal Communications Commission), for example. 
     For the purpose of suppressing such noise emission, the electronic devices are of the shield configuration with the chassis made of conductor. The issue here is that the chassis is formed with a slot to enable easy insertion and removal of a hard disk canister and a printed wiring board. When this slot is inserted with a canister or a printed wiring board, a structural gap is created between the canister and another canister or between the printed wiring board and another printed wiring board. In consideration thereof, Patent Document 1 (JP-A-2003-152359) describes the configuration of filling such a gap between canisters by providing a conductive finger of the spring configuration to each of the canisters. 
     SUMMARY OF THE INVENTION 
     The problem with such a configuration of Patent Document 1, i.e., a conductive finger of the spring configuration is provided for filling a gap between canisters, is that the contact portion between the conductors will show a change of impedance depending on the state of contact. Due to the resulting variation of impedance, the shielding effects cannot be of the sufficient level. As to the contact pressure of the portion of the spring, lower is better for the insertability and removability of the canister. 
     In consideration thereof, for increasing the insertability and removability of the portions of the canisters, there is a possibility of reducing the height of the spring to reduce the contact pressure. With such height reduction, the handling such as the insertability and removability is indeed increased but the contact portion is increased in impedance, thereby failing to achieve the sufficient level of shielding effect. On the other hand, when the contact pressure is increased by increasing the height of the spring, the contact portion is reduced in impedance so that the shielding characteristics can be of the sufficient level. However, the handling such as the insertability and removability is reduced, thereby leading to the risk of damage to the components and the chassis. 
     As such, to study the possibility of filling the gap using the finger as measures against EMI (Electromagnetic Interference), there thus needs to optimize the pressure of the spring, and the optimization problematically requires a long time. Moreover, processing and attachment of the finger also requires the accuracy, thereby resulting in the increase of cost. 
     In consideration thereof, the invention proposes to reduce noise emission without loss of operability by providing, to modules such as canister and printed circuit that are insertable/removable, a finger that can establish a low-impedance gap connection between the modules when it is attached, and reduce the contact pressure when it is detached. 
     The general outline of typical aspects of the invention of this application is briefly given as below. 
     1. In the invention, an insertable/removable module is of the configuration including a conductive finger of the spring configuration, and a mechanism for adjusting the height of the finger. In the configuration, when the finger is attached, the height of the finger is increased, and when the finger is detached, the height of the finger is reduced. 
     2. In order to achieve the object above, in the invention, an insertable/removable module is provided with a conductive finger of the spring configuration that is connected with the module at least at a portion. The module is of the configuration with which, when the module is inserted/removed into/from the finger, the amount of movement of the module is converted into the movement in a direction vertical to the direction of insertion/removal. 
     3. In the configuration with which the amount of movement of the module in the direction of insertion/removal is converted into the movement in a direction vertical thereto, the finger is fixed to one side of the module so as to be tapered, and from the side opposite to the fixed side, a thin plate is so inserted as to be able to move. 
     4. Also in the configuration with which the amount of movement of the module in the direction of insertion/removal is converted into the movement in a direction vertical thereto, the finger is fixed to one side of the module like an arc, and the side opposite to the fixed side is allowed to move in the direction of insertion/removal. 
     5. The module configuration characterized by including: a canister; an attachment/detachment mechanism connected to the canister to be able to move forward and backward with respect to a first surface of the canister; and a first conductive member connected to a second surface of the canister adjacent to the first surface thereof. The first conductive member is provided to at least partially move forward and backward with respect to the second surface in response to the attachment/detachment mechanism moving forward and backward with respect to the first surface. 
     6. The module configuration of the fifth aspect is also characterized by further including a first member between the canister and the first conductive member. The first member is connected to the attachment/detachment mechanism, and is provided to move forward and backward with respect to the first surface in response to the attachment/detachment mechanism moving forward and backward with respect to the first surface. 
     7. The module configuration of the fifth or sixth aspect is also characterized by further including a second conductive member connected to a third surface that is adjacent to both the first and second surfaces of the canister. 
     8. The module configuration of any one of the fifth to seventh aspects is also characterized in that the first conductive member is partially protruding to an underside of a surface opposing the canister. 
     9. The module configuration of the fifth aspect is also characterized in that the first conductive member is connected also to the attachment/detachment mechanism. 
     10. The module configuration of the ninth aspect is also characterized in that the first conductive member has a curved portion between a portion connected with the canister and a portion connected with the attachment/detachment mechanism. 
     11. An electronic device including a chassis carrying therein a plurality of module configurations. The module configurations are each characterized by including: a canister; an attachment/detachment mechanism connected to the canister to be able to move forward and backward with respect to a first surface of the canister; and a first conductive member connected to a second surface of the canister adjacent to the first surface thereof. The first conductive member is provided to at least partially come in contact with any adjacent module configuration by moving forward and backward with respect to the second surface in response to the attachment/detachment mechanism moving forward and backward with respect to the first surface. 
     12. The electronic device of the eleventh aspect is also characterized by further including a second conductive member provided to come in contact with the chassis through a connection with a third surface that is adjacent to both the first and second surfaces of the canister. 
     13. The electronic device of the twelfth aspect is also characterized by further including a third conductive member provided to come in contact with the chassis through a connection with a fourth surface that is adjacent to both the first and second surfaces of the canister, and is different from the third surface. 
     14. The electronic device of any one of the eleventh to thirteenth aspects is also characterized in that the attachment/detachment mechanism is provided with a lug for engagement with a hole formed to the chassis. 
     These and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing the configuration of a server device implementing the invention; 
         FIG. 2  is a diagram showing the configuration of a canister of the invention; 
         FIG. 3  is a diagram showing the configuration of a chassis of the main body of the server device; 
         FIGS. 4A and 4B  are each a diagram showing the mechanism of the canister of the invention; 
         FIG. 5  shows the simulation result of HDD (Hard Disk Drive) resonance; 
         FIGS. 6A and 6B  are each a noise spectrum of the 3m method used for measuring the effects of the invention; 
         FIG. 7  is another diagram showing the configuration of the canister of the invention; 
         FIG. 8  is another diagram showing the configuration of the server device implementing the invention; 
         FIG. 9  is another diagram showing the mechanism of the canister of the invention; and 
         FIGS. 10A and 10B  are each still another diagram showing the mechanism of the canister of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the invention, moreover, it is preferable to attach a mechanism and a finger onto two surfaces of a module being vertical to a surface to/from which the finger is inserted/removed. The mechanism is the one for converting the amount of movement of the module in the direction of insertion/removal into the movement in the direction vertical thereto. 
     First Embodiment 
     In the below, a first embodiment of the invention is described by referring to  FIGS. 1 to 6B  with an example of a server. 
       FIG. 1  is a schematic diagram showing the configuration of a server of the invention mounted with a RAID hard disk (HDD) array. In  FIG. 1 , a server chassis  1000  is so configured as to accommodate therein a canister  1010  with a hard disk housed therein. The canister  1010  is provided with an attachment/detachment mechanism  1020  for insertion/removal of the canister. The attachment/detachment mechanism  1020  is formed with a lug  1022  at the lower portion thereof for insertion into the body, attachment/detachment thereto/therefrom, and locking therewith. The canister  1010  is connected with a finger attachment plate  1030  that is conductive, has the spring characteristics, and is low in electrical resistance. This finger attachment plate  1030  is attached with a finger  1032  that is also conductive, has the spring characteristics, and is low in electrical resistance. Between the finger attachment plate  1030  and the canister  1010 , a thickness adjustment plate  1034  is so sandwiched as to be able to move in the lateral direction on the surface of the canister  1010  attached with the finger, i.e., move forward and backward when viewed from the surface from which the canister is exposed. The thickness adjustment plate  1034  is fixed by the attachment/detachment mechanism  1020  and a pin using connection rods  1026  and  1028 . 
       FIG. 2  shows the configuration of the canister  1010 . The canister  1010  is provided with a connector  1212 , and when the canister is inserted to the further depth, the canister  1010  is allowed to exchange electric signals with a platter attached to the server chassis  1000 . The finger attachment plate  1030  is connected with the canister  1010  on one side  1230  thereof. The connection portion of the side  1230  is electrically low in impedance, and the finger attachment plate  1030  is connected with the canister  1010  with a low resistance. The other side of the finger attachment plate  1030  is attached with the conductive finger  1032 . The finger  1032  is electrically connected to an adjacent canister or to the server chassis  1000  on the broad surface as a result of the portion of this finger being deformed. 
     The canister  1010  is attached with the attachment/detachment mechanism  1020  using a pivot pin  1224  for insertion/removal of the canister. This attachment/detachment mechanism  1020  is of the cantilever configuration by the pivot pin  1224 , and can perform insertion/removal and locking with ease using a lug  1022 . The attachment/detachment mechanism  1020  is attached with the two connection rods  1026  and  1028  using connection pins  1226  and  1228 , respectively. When the attachment/detachment mechanism  1020  is tilted forward, i.e., when the canister is detached, the connection rods  1026  and  1028  are also moved forward, and when the attachment/detachment mechanism  1020  is moved backward to be back in position, i.e., when the canister is attached, the connection rods  1026  and  1028  are also moved backward. The connection rods  1026  and  1028  are respectively formed with oval-shaped holes  1256  and  1258 , and are attached to the thickness adjustment plate  1034  by connection pins  1227  and  1229  being inserted through the holes, respectively. The size of the oval-shaped holes determines the movement amount of the thickness adjustment plate  1034  when the attachment/detachment mechanism  1020  is tilted, and by extension, adjusts the degree of opening and closing of the finger attachment plate  1030 . Note here that this thickness adjustment plate  1034  is attached at the position sandwiched between the canister  1010  and the finger attachment plate  1030 . 
       FIG. 3  shows the configuration of the server chassis  1000 . On the front surface of the chassis  1000 , slots  1312  are formed for attachment of the eight canisters  1010  each for use with a hard disk. The slots are each attached with a guide  1314  for allowing individual insertion/removal of the canister  1010 . The slots are each formed with a hole  1316  at the front portion thereof, and the hole  1316  is latched with the lug  1022  of the canister, thereby enabling insertion, attachment/detachment, and locking. The finger  1318  connected to the chassis establishes an electrical connection between the eighth canister  1010  and the server chassis  1000 . 
       FIGS. 4A and 4B  are each a diagram showing the operation of the attachment/detachment mechanism, and the state of opening/closing of the finger.  FIGS. 4A and 4B  each show a schematic cross-sectional view viewed from above of the canister of  FIG. 2  cut along a line A-A′.  FIG. 4A  specifically shows the state in which the canister  1010  is attached to the server chassis  1000 . The finger attachment plate  1030  is fixed to the canister  1010  on one side thereof. The finger attachment plate  1030  is bent to look like an inverted letter V, and into the space formed between the canister due to the bending, the thickness adjustment plate  1034  is inserted. The thickness adjustment plate  1034  is connected to the connection rod  1026  via the connection pin  1227 , and then is connected to the attachment/detachment mechanism  1020 , thereby configuring the crank mechanism. This accordingly changes the semicircular movement of the attachment/detachment mechanism  1020  into the forward-and-backward movement in the direction of insertion/removal. In the connection rod  1026 , the hole for insertion of the connection pin  1227  is of an oval figure long in the forward-and-backward direction, thereby optimizing the amount of movement of the thickness adjustment plate  1034 . In such a mechanism, the bent finger attachment plate  1030  can be changed in angle of opening/closure when the thickness adjustment plate  1034  moves in the forward-and-backward direction. In  FIG. 4A  example, by the thickness adjustment plate  1034  being pushed into the further depth, the opening angle between the finger attachment plate  1030  and the canister is increased so that the finger  1032  comes in contact with the adjacent canister with a high contact pressure.  FIG. 4B  shows the state at the time of detachment. As shown in  FIG. 4B , because the attachment/detachment mechanism  1020  is pulled toward the front, the thickness adjustment plate  1034  follows the movement, i.e., is pulled out toward the front, so that the opening angle between the finger attachment plate  1030  and the canister is reduced. Accordingly, the contact pressure with the adjacent canister is reduced, or the finger  1032  does not come in contact with the adjacent canister, thereby being able to reduce the force at the time of detachment. 
     With a server mounted with a RAID hard disk (HDD) array to which the invention is applied, for example, transfer of the hard disk is sometimes performed by SATA (Serial Advanced Technology Attachment) or SAS interface (Serial-Attachment Small Computer System Interface). Such SATA and SAS interface are currently used for transmission at the high-speed 3 GHz.  FIG. 5  shows the simulation result of the propagation distribution of an electromagnetic field when SATA interface signals are directed from a connector to the printed circuit mounted on a hard disk. When the signals are transmitted at 3 GHz, the electromagnetic waves have the wavelength of about 100 mm in the air. Because the wavelength is almost the same as the lateral length of the 3.5 hard disk, this causes such resonance of showing two intensive distribution of the electromagnetic field in the lateral length. When the chassis is in such a resonance state, the electromagnetic noise is considerably increased.  FIGS. 6A and 6B  each show the result of measurement of, with the 3m method, the radio field intensity of the server mounted with an RAID hard disk (HDD) array.  FIG. 6A  specifically shows the result of noise measurement in the state that the space around a canister is not filled. Similarly to the simulation result, if the space around the canister is not filled, the canister with a hard disk therein itself serves as an antenna, thereby emitting strong noise at 3 GHz.  FIG. 6B  shows the configuration of the invention, and shows the result of noise measurement in the state that the space around the canister is filled. Although noise emission of some level is observed, the effects of noise reduction of about 10 dB are achieved by the invention. 
     As such, with the configuration of changing the contact pressure of the finger-attachment jig for use to fill the space around the canister depending on whether the canister is attached or detached, attachment and detachment of the canister can be eased while keeping the effects of noise reduction. 
     Second Embodiment 
     A second embodiment of the invention is described by referring to  FIGS. 7 and 8 . 
     In the second embodiment, similarly to the first embodiment, exemplified is a canister with a hard disk housed therein. The second embodiment is of almost the same configuration as that of the first embodiment, but there is a difference of including a finger also at the upper and lower portions of the canister. The details of this difference will be described below. 
       FIG. 7  is a drawing showing the configuration of a canister, and  FIG. 8  is a drawing showing the state in which a canister  2010  is mounted to a server. As shown in  FIG. 7 , in the invention, additionally to the configuration of the first embodiment, a finger  2032  and a finger attachment plate  2034  are provided also to a space portion on the upper surface of the canister, thereby filling the spaces at the upper and lower portions of the canister. In the invention, a thickness adjustment plate  2034  is so configured as to enclose the upper portion of the canister like a “letter of L”, and is connected with the attachment/detachment mechanism  1020  with the crank mechanism using the connection rods  1026  and  1028 . With such a configuration, the opening/closing angle of the finger  2032  at the upper portion of the canister is changed depending on whether the canister is attached or detached. The lower portion of the canister is also provided with a fixed finger  2036 , and when the contact pressure is increased for the upper finger, the lower finger is responsively pushed against the lower portion of the chassis. With such a configuration of the second embodiment, the spaces in the four directions of the canister can be each filled with the finger of the sufficient contact pressure, thereby being able to suppress any possible noise. Note that, in the second embodiment, exemplified is the configuration of including the fingers both at the upper and lower space portions of the canister. This is surely not the only option, and the finger may be provided either to the upper or lower portion for space filling. 
     Third Embodiment 
     A third embodiment of the invention is described by referring to  FIGS. 9 to 10B . 
     In this embodiment, as shown in  FIG. 9 , a finger board  3032  is shaped like an arc, and when the attachment/detachment mechanism  1020  is put in the circular movement, the arc diameter of the finger board  3032  shows a change, thereby changing the height of the arc of the finger. With the height of the arc changed as such, the contact pressure of the finger board  3032  with the canister adjacent thereto is changed.  FIGS. 10A and 10B  are each a cross-sectional view of the finger board of  FIG. 9  cut along a line B-B′, viewed from above of the canister.  FIG. 10B  shows the state in which the canister is detached. In such a state that an attachment/detachment lever  1020  is pulled forward, the arc-shaped finger board  3032  is also pulled toward the front, thereby reducing the height of the arc and also the contact pressure. Contrarily, as shown in  FIG. 10A , when the attachment/detachment lever  1020  is pushed to fix a canister  3010  to the body, the arc-shaped finger board  3032  is pushed rearward, thereby reducing the arc diameter. In response thereto, the height of the arc is increased, and the contact pressure is increased. 
     As such, also in such a configuration of the second embodiment, the attachment/detachment of the canister can be eased by reducing the contact pressure at the time of detachment, and by increasing the contact pressure at the time of attachment, thereby favorably increasing the shielding characteristics with respect to any possible noise. Note that, in this embodiment, the finger is shaped like an arc. This is surely not restrictive, and even if the finger is shaped like an “inverted letter V”, the similar effects can be achieved, and various other shape modifications are possible without departing from the scope of the invention. 
     According to the invention, at the time of insertion of a module, a finger is expanded in the direction vertical to the direction of insertion/removal, thereby filling the space between the module and another module. At the time of detachment of the module, the finger is compressed in the direction vertical to the direction of insertion/removal, thereby ensuring the space between the module and another module. As such, when an electronic device is activated with the module inserted therein, the shielding effects are exerted so that the measures against the EMC are taken, and for detachment of the module, the module can be pulled out with ease. 
     The invention is applicable to a chassis of an electrical device such as server storage device and personal computer, and the attachment configuration of a module for mounting of the electrical device to a chassis, especially a module of a printed circuit, a hard disk, a memory, or others. 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all aspects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.