Electronic device and connection structure for circuit board

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.

CROSS-REFERENCE TO RELATED APPLICATION

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

The embodiments discussed herein are related to an electronic device and a connection structure for circuit board.

BACKGROUND

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.

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.

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.

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.

SUMMARY

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.

DESCRIPTION OF EMBODIMENTS

Preliminary Consideration

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.

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

FIG. 1is an exploded perspective view of an electronic device according to a first embodiment with part of the electronic device omitted.FIG. 2is a perspective view of a housing of the electronic device according to the first embodiment with part of the housing omitted. An electronic device1illustrated inFIG. 1includes a housing2and a daughter board3that is mounted in the housing2. The housing2has a front portion2A, a rear surface portion2B, a first side surface portion2C, a second side surface portion2D, a top surface portion (not illustrated), and a bottom surface portion (not illustrated). The front portion2A is defined by an opening portion11. The rear surface portion2B opposes the front portion2A. The first side surface portion2C is adjacent to the rear surface portion2B. The second side surface portion2D is adjacent to the rear surface portion2B and opposes the first side surface portion2C.

A first backplane12is disposed on the rear surface portion2B. The first backplane12includes two first connectors13disposed thereon as an example. Each of the first connectors13is a straight connector having an engagement surface13A on the front surface portion thereof. A second backplane14is disposed on the first side surface portion2C. The second backplane14includes three second connectors15disposed thereon as an example. Each of the second connectors15is a right-angle connector having an engagement surface15A on the side surface portion thereof.

The daughter board3includes two straight third connectors21disposed on a leading end area3A side thereof. The third connectors21are engaged with the first connectors13of the first backplane12. The daughter board3also includes three right-angle fourth connectors22disposed on a first side surface portion3B side thereof. The fourth connectors22are engaged with the second connectors15of the second backplane14.

The housing2has guide rails16disposed therein on the first side surface portion2C and the second side surface portion2D thereof. The guide rails16contact a lower surface of the daughter board3inserted through the opening portion11, and hold the daughter board3such that the daughter board3is slidable relative to the guide rails16. The guide rails16hold the daughter board3such that the daughter board3is perpendicular to the rear surface portion2B, the first side surface portion2C, and the second side surface portion2D while the first connectors13, the third connectors21, the second connectors15, and the fourth connectors22are horizontally disposed.

A guide mechanism17is provided on the second side surface portion2D inside the housing2. The guide mechanism17guides the daughter board3inserted through the opening portion11into the housing2. The guide mechanism17contacts a side surface portion3C of the daughter board3and guides the daughter board3held on the guide rails16in a direction in which the daughter board3is inserted into the housing2. When this insertion direction is the X-direction, a horizontal direction of the plane of the daughter board3that is directed toward the first side surface portion2C and perpendicular to the X-direction is the Y-direction.

The guide mechanism17has a guide groove member30that is provided on the second side surface portion2D. The guide groove member30has a guide groove31formed therein. The second side surface portion3C of the daughter board3inserted through the opening portion11contacts the guide groove31while sliding in the guide groove31. The guide groove31guides the daughter board3from the start of insertion to the completion of mounting via following positions: a linear movement start position30A, a parallel movement start position30B, a parallel movement end position30C, and a linear movement end position30D.

A linear movement of the daughter board3in the X-direction in the guide groove31starts at the linear movement start position30A when the daughter board3is slid. At the parallel movement start position30B, the linear movement of the daughter board3in the X-direction started from the linear movement start position30A is stopped, and parallel movement of the daughter board3in the guide groove31in a diagonal direction toward the first side surface portion2C side starts. At the parallel movement end position30C, the parallel movement of the daughter board3in a diagonal direction toward the first side surface portion2C side is complete, and the linear movement of the daughter board3in the X-direction in the guide groove31restarts. At the linear movement end position30D, the linear movement of the daughter board3in the X-direction in the guide groove31is complete.

The guide groove31includes a first guide groove31A, a second guide groove31B, and a third guide groove31C. The second guide groove31B is continuous with the first guide groove31A, and the third guide groove31C is continuous with the second guide groove31B. The first guide groove31A guides the daughter board3between the linear movement start position30A and the parallel movement start position30B.

The first guide groove31A guides the daughter board3so as to prevent the fourth connectors22from interfering with the second connectors15in the linear movement in the X-direction. The second guide groove31B guides the daughter board3between the parallel movement start position30B and the parallel movement end position30C. The second guide groove31B makes the daughter board3sliding toward the first backplane12undergo the parallel movement in a sliding manner from the second side surface portion2D toward the first side surface portion2C. As a result, the daughter board3is guided to a position in which engagement surfaces22A of the fourth connectors22to be engaged with the second connectors15oppose the engagement surfaces15A of the second connectors15. Likewise, the daughter board3is guided to a position in which engagement surfaces21A of the third connectors21to be engaged with the first connectors13oppose the engagement surfaces13A of the first connectors13.

The third guide groove31C guides the daughter board3between the parallel movement end position30C and the linear movement end position30D. The third guide groove31C makes the daughter board3restart the linear movement in the X-direction. By doing this, the third connectors21are engaged with the first connectors13, and the fourth connectors22are engaged with the second connectors15. Thus, the daughter board3is guided by the first guide groove31A, the second guide groove31B, and the third guide groove31C to be connected to the first side surface portion2C and the first backplane12with a single operation. The distance between the parallel movement end position30C to the linear movement end position30D is equal to or greater than the moving distance of the third connectors21between a position at which engagement of the third connectors21with the first connectors13starts and a position at which the engagement of third connectors21with the first connectors13is complete.

The side surface portion3C of the daughter board3has a protruding portion41that protrudes at a position in a rearward direction of the daughter board3, for example, at a position spaced away from a leading end portion3D by a distance equal to the distance between the linear movement start position30A and the parallel movement start position30B. When the leading end portion3D of the side surface portion3C of the daughter board3reaches the parallel movement start position30B in the second guide groove31B, the protruding portion41reaches the linear movement start position30A in the first guide groove31A. The protruding portion41assists the daughter board3in undergoing the parallel movement in a sliding manner toward the first side surface portion2C side as the protruding portion41enters the first guide groove31A. The protruding portion41protrudes from the surface of the side surface portion3C by a dimension L1. L1is equal to the distance of movement L2in Y-direction, by which the daughter board3undergoes the parallel movement in the second guide groove31B from the second side surface portion2D side toward the first side surface portion2C side (seeFIG. 3A).

Next, a method of assembling the electronic device1according to the first embodiment will be described.FIGS. 3A to 3EandFIGS. 4A to 4Care explanatory diagrams illustrating an example of an assembly process of the electronic device1according to the first embodiment. The daughter board3is inserted into the housing2through the opening portion11. The daughter board3is guided into the housing2as illustrated inFIG. 3Awhile the side surface portion3C of the daughter board3slides in the first guide groove31A. The daughter board3is guided into the housing2in the X-direction through the first guide groove31A. In so doing, the daughter board3is held on the guide rails16formed on the first side surface portion2C and the second side surface portion2D. As a result, the daughter board3is held perpendicularly to the first backplane12and the second backplane14while the first connectors13, the third connectors21, the second connectors15, and the fourth connectors22are horizontally disposed.

As illustrated inFIGS. 3B and 4A, the daughter board3undergoes the linear movement in the X-direction on the guide rails16until the leading end portion3D of the side surface portion3C thereof reaches the parallel movement start position30B through the first guide groove31A. When the leading end portion3D of the side surface portion3C of the daughter board3reaches the parallel movement start position30B, the protruding portion41located in a rearward direction of the daughter board3enters the first guide groove31A. As illustrated inFIG. 3C, when the leading end portion3D of the side surface portion3C of the daughter board3moves beyond the parallel movement start position30B and enters the second guide groove31B, the parallel movement of the daughter board3starts in a diagonal direction toward the first side surface portion2C side. As the protruding portion41enters the first guide groove31A, the protruding portion41interferes with the first guide groove31A. This interference assists the daughter board3in undergoing the parallel movement such that the daughter board3smoothly undergoes the parallel movement in a diagonal direction toward the first side surface portion2C side.

As illustrated inFIG. 3D, when the leading end portion3D of the side surface portion3C of the daughter board3reaches the parallel movement end position30C in the second guide groove31B, the parallel movement of the daughter board3in a diagonal direction toward the first side surface portion2C side is complete. As a result, as illustrated inFIG. 4B, the daughter board3is guided to a position at which the engagement surfaces21A of the third connectors21and the engagement surfaces13A of the first connectors13oppose each other, and the engagement surfaces22A of the fourth connectors22and the engagement surfaces15A of the second connectors15oppose each other.

As illustrated inFIG. 3E, the leading end portion3D of the side surface portion3C of the daughter board3enters the third guide groove31C and reaches the linear movement end position30D as the daughter board3undergoes the linear movement in the X-direction. As illustrated inFIG. 4C, when the leading end portion3D of the daughter board3reaches the linear movement end position30D, the third connectors21are engaged with the first connectors13, and the fourth connectors22are engaged with the second connectors15. As a result, with a single insertion operation performed by a user, the daughter board3is mounted perpendicularly to the first backplane12and the second backplane14.

In the first embodiment, with a single insertion operation, the daughter board3is guided through the guide groove31to a position at which the engagement surfaces21A of the third connectors21and the engagement surfaces13A of the first connectors13oppose each other, and the engagement surfaces22A of the fourth connectors22and the engagement surfaces15A of the second connectors15oppose each other. In the electronic device1, the daughter board3is mounted perpendicularly to the first backplane12and the second backplane14by engaging the third connectors21with the first connectors13and engaging the fourth connectors22with the second connectors15. As a result, in the first embodiment, a work burden in mounting the daughter board3in a direction perpendicular to the first backplane12and the second backplane14may be reduced. In addition, in the electronic device1according to the first embodiment, the non-uniform density of wiring on the daughter board3is suppressed. This allows the number of daughter boards3to be mounted to be decreased.

In the above-described first embodiment, the daughter board3is caused to undergo the parallel movement in a diagonal direction toward the first side surface portion2C side through the guide groove31of the guide groove member30. Alternatively, a guide protruding portion may be formed instead of the guide groove31, and the daughter board3may have a guide recess portion in the side surface portion3C thereof. In this case, the guide protruding portion slides in the guide recess portion so as to cause the daughter board3to undergo the parallel movement in a diagonal direction toward the first side surface portion2C side.

Alternatively, in the above-described first embodiment, the guide mechanism17may use a guide surface that allows the side surface portion3C of the daughter board3to slide along the guide surface so as to cause the daughter board3to undergo the parallel movement in a diagonal direction toward the first side surface portion2C side without use of the guide groove31or the guide protruding portion.

In the above-described first embodiment, the guide groove member30having the guide groove31is disposed on the second side surface portion2D. Instead, the guide groove31may be directly formed in the second side surface portion2D.

In the above-described first embodiment, the protruding portion41formed on the side surface portion3C of the daughter board3enters the first guide groove31A so as to assist the parallel movement of the daughter board3as the protruding portion41interferes with the guide groove31. Alternatively, formation of the protruding portion41may be omitted.

In the above-described first embodiment, the guide groove member30exemplifies the guide mechanism17. Alternatively, a lever member may be pivotally disposed on the second side surface portion2D instead of the guide groove member30so as to cause the daughter board3to undergo the parallel movement toward the first side surface portion2C side. An embodiment in this case will be described below as a second embodiment.

Second Embodiment

FIG. 5is an exploded perspective view of an electronic device1A according to a second embodiment with part of the electronic device1A omitted.FIG. 6is a perspective view of a housing2aof the electronic device1A according to the second embodiment with part of the housing2aomitted. Components similar to those of the electronic device1according to the first embodiment are denoted by the same reference signs in order to omit duplicate descriptions of structures and operations thereof.

A main difference between the electronic device1A illustrated inFIG. 5and the electronic device1illustrated inFIG. 1is that, in the electronic device1A, the guide mechanism17provided on the second side surface portion2D uses a lever member50instead of the guide groove member30. The lever member50is pivotally disposed on one of the guide rails16formed on the second side surface portion2D. The lever member50has a base member51, a lever portion52, a guide portion53, and a fulcrum54. The lever portion52is formed in a front end portion of the base member51. The guide portion53is formed in a rear end portion of the base member51. The lever portion52and the guide portion53are pivotable about the fulcrum54.

The guide portion53of the lever member50guides a daughter board3ain the X-direction into the housing2awhile allowing the side surface portion3C of the daughter board3ainserted through the opening portion11to slide along the guide portion53. The daughter board3ais disposed perpendicularly to the first backplane12and the second backplane14while the first connectors13, the third connectors21, the second connectors15, and the fourth connectors22are horizontally disposed.

The lever portion52of the lever member50is pressed by the leading end portion3D of the side surface portion3C of the daughter board3ain accordance with the linear movement in the X-direction of the daughter board3a, which has been inserted from the opening portion11. The lever portion52pivots about the fulcrum54toward the second side surface portion2D side in accordance with a pressing operation performed by the leading end portion3D. In addition, the guide portion53of the lever member50pivots about the fulcrum54toward the first side surface portion2C side as the lever portion52pivots toward the second side surface portion2D side. The guide portion53presses the side surface portion3C of the daughter board3ain a diagonal direction toward the first side surface portion2C side as the guide portion53pivots toward the first side surface portion2C side. As a result, in accordance with the pressing operation, the guide portion53causes the daughter board3ato undergo a parallel movement to a position at which the engagement surfaces21A of the third connectors21and the engagement surfaces13A of the first connectors13oppose each other, and the engagement surfaces22A of the fourth connectors22and the engagement surfaces15A of the second connectors15oppose each other.

In addition, the lever portion52of the lever member50causes the daughter board3ato undergo a parallel movement in a diagonal direction toward the first side surface portion2C side in accordance with the pressing operation performed by the leading end portion3D of the daughter board3a. The lever portion52is brought out of contact with the leading end portion3D of the daughter board3aat a timing at which the parallel movement of the daughter board3atoward the first side surface portion2C side is complete. The daughter board3aundergoes a linear movement in the X-direction into the housing2afrom a position at which the engagement surfaces21A of the third connectors21and the engagement surfaces13A of the first connectors13oppose each other, and the engagement surfaces22A of the fourth connectors22and the engagement surfaces15A of the second connectors15oppose each other. As a result, the daughter board3ais mounted perpendicularly to the first backplane12and the second backplane14by engaging the third connectors21with the first connectors13and engaging the fourth connectors22with the second connectors15.

Next, a method of assembling the electronic device1A according to the second embodiment will be described.FIGS. 7A to 7EandFIGS. 8A to 8Care explanatory diagrams illustrating an example of an assembly process of the electronic device1A according to the second embodiment. The daughter board3ais inserted into the housing2aby the user. The daughter board3ais inserted into the housing2ain the X-direction as illustrated inFIG. 7Awhile the side surface portion3C thereof slides from the opening portion11along the lever member50on the second side surface portion2D side. In so doing, the daughter board3ais held on the guide rails16formed on the first side surface portion2C and the second side surface portion2D in the housing2a. As a result, the daughter board3ais held perpendicularly to the first backplane12and the second backplane14while the first connectors13, the third connectors21, the second connectors15, and the fourth connectors22are horizontally disposed.

When the daughter board3ais inserted into the housing2ain the X-direction, the daughter board3aundergoes a linear movement in the X-direction on the guide rails16as illustrated inFIG. 7B. As illustrated inFIG. 8A, the leading end portion3D of the side surface portion3C of the daughter board3apresses the lever portion52of the lever member50as the daughter board3aundergoes the linear movement in the X-direction. The lever portion52of the lever member50pivots about the fulcrum54toward the second side surface portion2D side in accordance with the pressing operation performed by the daughter board3a. The guide portion53of the lever member50pivots toward the first side surface portion2C side as the lever portion52undergoes the pivotal movement toward the second side surface portion2D side.

A rear end portion of the daughter board3astarts the parallel movement in a diagonal direction toward the first side surface portion2C in accordance with the pivotal movement of the guide portion53of the lever member50toward the first side surface portion2C side. The lever portion52of the lever member50is brought out of contact with the leading end portion3D of the daughter board3aat a timing at which the parallel movement of the daughter board3atoward the first side surface portion2C side is complete as illustrated inFIGS. 7C and 7D. The lever portion52stops the pivotal movement toward the second side surface portion2D side when the lever portion52is brought out of contact with the leading end portion3D of the daughter board3a. When the lever portion52stops the pivotal movement toward the second side surface portion2D side, the guide portion53also stops the pivotal movement toward the first side surface portion2C side. As a result, as illustrated inFIG. 8B, the daughter board3ais guided to a position at which the engagement surfaces21A of the third connectors21and the engagement surfaces13A of the first connectors13oppose each other, and the engagement surfaces22A of the fourth connectors22and the engagement surfaces15A of the second connectors15oppose each other.

The daughter board3aundergoes the linear movement in the X-direction while the pivotal movement of the guide portion53toward the first side surface portion2C side is stopped. As illustrated inFIGS. 7E and 8C, the third connectors21of the daughter board3aare engaged with the first connectors13, and the fourth connectors22of the daughter board3aare engaged with the second connectors15. As a result, the daughter board3ais mounted perpendicularly to the first backplane12and the second backplane14.

In the second embodiment, the lever portion52of the lever member50pivots toward the second side surface portion2D side in accordance with the linear movement of the leading end portion3D of the daughter board3ain the X-direction caused with a single insertion operation. The guide portion53of the lever member50pivots toward the first side surface portion2C side as the lever portion52undergoes a pivotal movement. The guide portion53causes the daughter board3ato undergo the parallel movement in a diagonal direction toward the first side surface portion2C side as the guide portion53undergoes the pivotal movement toward the first side surface portion2C side. By doing this, the daughter board3ais guided to the position at which the engagement surfaces21A of the third connectors21and the engagement surfaces13A of the first connectors13oppose each other, and the engagement surfaces22A of the fourth connectors22and the engagement surfaces15A of the second connectors15oppose each other. In the electronic device1A, the daughter board3ais mounted perpendicularly to the first backplane12and the second backplane14by engaging the first connectors13with the third connectors21and engaging the second connectors15with the fourth connectors22. As a result, in the second embodiment, a work burden in mounting the daughter board3aperpendicularly to the first backplane12and the second backplane14may be reduced.

In the above-described first and second embodiments, the first backplane12and the second backplane14are respectively disposed on the rear surface portion2B and the first side surface portion2C in the housing2or2a. Alternatively, for example, two backplanes may be disposed on the rear surface portion2B and the second side surface portion2D, on the top surface portion and the first side surface portion2C, on the top surface portion and the second side surface portion2D, on the bottom surface portion and the first side surface portion2C, on the bottom surface portion and the second side surface portion2D, or the like.

In the above-described first and second embodiments, one daughter board3or3ais perpendicularly mounted to the first backplane12and the second backplane14. Similar advantages are obtainable when a plurality of daughter boards3or3aare mounted to the first backplane12and second backplane14.FIGS. 9A and 9Bare respectively an exploded perspective view and a perspective view of an electronic device1B in which a plurality of daughter boards3are mounted with part of the electronic device1B omitted. A plurality of daughter board3amay similarly be mounted in a housing of an electronic device. For convenience of explanation, components similar to those of the electronic device1illustrated inFIG. 1are 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 portion2D and the guide mechanism17are omitted fromFIGS. 9A and 9B. The electronic device1B illustrated inFIGS. 9A and 9Buses the guide mechanism17(not illustrated) to sequentially mount the daughter boards3perpendicularly to the first backplane12and the second backplane14. The electronic device1B allows the plurality of daughter boards3to be easily mounted to the first backplane12and the second backplane14. In order to electrically connect the daughter boards3to each other, a jumper61may be used to connect the daughter boards3to each other.

In the above-described embodiments, when the daughter board3or3ais inserted into the housing2or2a, the daughter board3or3ais caused to undergo the linear movement in the X-direction while occurrence of a situation in which the fourth connectors22interfere with the second connectors15is avoided, and the daughter board3or3ais caused to undergo the parallel movement in a diagonal direction toward the first side surface portion2C side. The daughter board3or3ahaving undergone the parallel movement is again caused to undergo the linear movement in the X-direction. As a result, engagement of the third connectors21of the daughter board3or3awith the first connectors13and engagement of the fourth connectors22of the daughter board3or3awith the second connectors15simultaneously 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 board3or3ais 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 boards3or3aare mounted.

In the above-described first and second embodiments, the daughter board3or3ais perpendicularly mounted to the first backplane12and the second backplane14. By doing this, occurrence of a situation in which connectors to be engaged with those of the daughter board3or3aare concentrated in the rear surface portion2B of the first backplane12is avoidable. This may decrease the number of connectors mounted on the first backplane12on the rear surface portion2B side opposing the opening portion11, and accordingly, a space in which a vent hole is disposed may be allocated in the rear surface portion2B. As a result, cooling air flows from the opening portion11to the vent hole of the rear surface portion2B in a certain direction, that is, in the X-direction, and accordingly, cooling efficiency may be improved.