Patent Description:
Currently, an electronic system such as a memory, a server, a router, or a switch including an electronic device with parallel backplanes usually includes several basic circuits that are connected to each other, interact with each other, and used as one circuit to provide specific functions. Most of the functional circuits are deployed and integrated on a specific module, different modules are connected to the backplanes, and electrical connections between the functional circuits are realized through the backplanes. To avoid damage caused by excessively high temperature to electronic components inside an electronic device and to ensure normal operation of the electronic device, a good heat dissipation effect needs to be achieved in the electronic device. The document <CIT> shows an apparatus, system, and method for a scalable, composite configurable backplane. The document <CIT> shows a backplane, a communication device, and a communication system. Especially, the arrangement of a number of service boards and a number of switchboards on opposite sides of vertical insertion plates is shown.

The invention is defined in the independent claim. Advantageous features are defined in the dependent claims.

This application aims to provide an electronic device with parallel backplanes, to achieve a good heat dissipation effect in the electronic device.

The electronic device includes a backplane assembly, a front inserting assembly, and a rear inserting assembly. The backplane assembly is connected to the front inserting assembly and the rear inserting assembly. The backplane assembly includes a plurality of backplanes arranged in parallel at intervals, and there is a channel between adjacent backplanes. The front inserting assembly includes a plurality of first units arranged in parallel at intervals, an arrangement direction of the first units is the same as an arrangement direction of the backplanes, and the first unit is connected to one side of the backplane. The rear inserting assembly includes a plurality of second units arranged in parallel at intervals, an arrangement direction of the second units intersects the arrangement direction of the backplanes, and each of the second units is connected to one side of the backplane that is opposite to the first unit, so that the first unit is connected to the second unit through the backplane.

That the first unit is connected to one side of the backplane specifically means that the first unit is communicatively connected to the backplane, so that a signal such as a data signal and/or a control signal can be transmitted between the first unit and the backplane. That the second unit is connected to the backplane also means that the second unit is communicatively connected to the backplane, so that a signal such as a data signal and/or a control signal can be transmitted between the second unit and the backplane. Therefore, that the first unit is connected to the second unit through the backplane means that a signal is transmitted between the first unit and the second unit through the backplane.

In some embodiments of this application, the backplane includes a substrate and a connection line disposed on the substrate. That the first unit is communicatively connected to the second unit through the backplane means that the first unit is connected to the connection line on the backplane, the second unit is connected to the connection line on the backplane, and a signal such as a data signal and/or a control signal is transmitted between the first unit and the connection line and between the connection line and the second unit. The connection line can be used to transmit an electrical signal or an optical signal. When a signal transmitted between the first unit and the backplane is an electrical signal, the connection line may be a metal cable. When a signal transmitted between the first unit and the backplane is an optical signal, the connection line may be made of a material such as an optical fiber used to transmit the optical signal.

"Arranged in parallel at intervals" mentioned in this application means that a plurality of structures are disposed side by side with a particular interval between adjacent structures. For example, "the plurality of backplanes are arranged in parallel at intervals" means that the plurality of backplanes are disposed side by side with a particular interval between adjacent backplanes; "the plurality of first units are arranged in parallel at intervals" means that the plurality of first units are disposed side by side with a particular interval between adjacent first units; and "the plurality of second units are arranged in parallel at intervals" means that the plurality of second units are disposed side by side with a particular interval between adjacent second units.

"An arrangement direction of the plurality of second units intersects the arrangement direction of the plurality of backplanes" mentioned in this application means that the arrangement direction of the second units and the arrangement direction of the backplanes are not the same direction, but form a particular angle.

The backplane assembly has a structure including the plurality of backplanes arranged in parallel at intervals and the channel between adjacent backplanes, so that an airflow on two sides of the backplane assembly can easily pass through the channel. This avoids blocking from the backplane assembly to the airflow, and achieves a good heat dissipation effect in the electronic device. In addition, the direction of the backplanes that are arranged in parallel at intervals is the same as the direction of the first units that are arranged in parallel at intervals, and the first units and the second units are connected to two opposite sides of the backplanes, respectively. Therefore, there is no need to reserve a clearance, and density of the first units and/or the second units in the electronic device can be increased. In other words, compared with the prior art, more first units and second units can be connected through the backplane assembly, and an operating capability of the electronic device can be improved.

In this application, each of the first units is connected to one side of the backplanes, and each of the second units is connected to all the backplanes, so that each of the second units can be connected to all the first units through the backplanes. When the electronic device is a memory, the first units are storage units such as hard disks, the second units are controllers, and each of the controllers can access all the hard disks.

Further, in this application, each of the backplanes is connected to all the second units. Therefore, all the second units can be connected to each of the first units through the backplanes. When the electronic device is a memory, the first units are storage units such as hard disks, the second units are controllers, and all the controllers can access a same hard disk, so that the memory can be shared by a plurality of controllers.

Further, in this application, the first units connected to adjacent backplanes are staggered in a height direction of the backplanes. Specifically, the first units connected to the adjacent backplanes are staggered in the height direction of the backplanes, so that a distance between the adjacent backplanes can be as small as possible, to reduce an area occupied by the backplane assembly.

An electronic component is disposed on the backplane, and the electronic component may be a micro switch, a memory chip, or the like used to extend functions of the backplane.

In some embodiments of this application, the backplane includes a first side and a second side opposite to the first side, the front inserting assembly is connected to the first side, and the rear inserting assembly is connected to the second side. The backplane is plate-shaped. The front inserting assembly is connected to the first side, and the rear inserting assembly is connected to the second side. Therefore, there is no need to reserve a clearance, and density of the first units and/or the second units in the electronic device is increased.

Each first side is disposed with a first connector, each second side is disposed with a second connector, a side of the first unit facing the backplane is disposed with a first connection port, and the first connection port is detachably connected to the first connector; and a side of the second unit facing the backplane is disposed with a second connection port, and the second connection port is detachably connected to the second connector. The first connector is detachably connected to the first unit, so that the first unit can be easily detachably connected to the backplane, to facilitate replacement and maintenance of the first unit. Similarly, the second connector is detachably connected to the second unit, so that the second unit can be easily detachably connected to the backplane, to facilitate replacement and maintenance of the second unit, and each of the second units can be connected to all the backplanes.

In some embodiments of this application, both the first connector and the second connector are mounted on the backplane in a through-board manner. Through-board mounting means that all pins of the first connector and the second connector need to penetrate the backplane for mounting, so that the first connector and the second connector can be stably fastened on the backplane.

In some embodiments of this application, the backplane assembly further includes a fixed frame with openings on two sides, the openings face the front inserting assembly and the rear inserting assembly, respectively, and the backplane is detachably fastened in the fixed frame. The backplanes are fastened in the fixed frame, so that locations of the backplanes can be relatively stable. In addition, the backplane can be detachably fastened in the fixed frame, so that it is convenient to take the backplane out from the fixed frame. This facilitates subsequent maintenance of the backplane.

In some embodiments of this application, an inner wall of the fixed frame is disposed with a plurality of card slots arranged at intervals, and an edge of each of the backplanes is secured in corresponding card slot. The card slot is used to stably secure the backplane at a fixed location in the fixed frame, to ensure that the locations of the backplanes are relatively stable.

Further, in some embodiments of this application, a buffer member is disposed between the inner wall of the card slot and the backplane. When the electronic device is subject to an external force, the buffer member can provide a buffer for the backplane, to avoid damage to the backplane due to a relatively large force generated between the backplane and the fixed frame.

In some other embodiments of this application, the fixed frame may be made of a flexible material, so that when the electronic device is subject to an external force, the fixed frame can provide a buffer for the backplane, to avoid damage to the backplane.

Further, in some embodiments of this application, the backplane may be disposed with a hole, and holes on adjacent backplanes are connected, so that an airflow can pass through the backplanes, to implement even heat dissipation at all locations in the backplane assembly.

In some embodiments, projections of the holes on the adjacent backplanes overlap on a plane parallel to any of the backplanes. In other words, holes on the backplanes are connected in the arrangement direction of the backplanes, so that an airflow can pass through all the backplanes more smoothly.

The electronic device further includes a chassis. The backplane assembly, the front inserting assembly, and the rear inserting assembly are all accommodated in the chassis. The chassis protects the backplane assembly, the front inserting assembly, and the rear inserting assembly that are located inside the chassis.

In some embodiments of this application, the fixed frame is fastened in the chassis, so that the backplane can be stably disposed in the chassis.

Further, a heat dissipation fan is disposed on a wall of the chassis. The heat dissipation fan is located on one side of the rear inserting assembly, and an airflow generated by the heat dissipation fan sequentially passes through the rear inserting assembly, the backplane assembly, and the front inserting assembly. The heat dissipation fan is used to achieve a better heat dissipation effect.

This application further provides a storage device with parallel backplanes to achieve a good heat dissipation effect in the storage device. The storage device is a specific embodiment of the electronic device.

In some embodiments of this application, the storage device may include a plurality of backplanes arranged in parallel at intervals, a plurality of interface cards arranged in parallel at intervals, and a plurality of controllers arranged in parallel at intervals. There is a channel between adjacent backplanes. An arrangement direction of the plurality of interface cards is the same as an arrangement direction of the backplanes, the interface card is connected to one side of the backplane, and the interface card is configured to connect a hard disk. An arrangement direction of the plurality of controllers intersects the arrangement direction of the plurality of backplanes, and each of the controllers is connected to one side of the backplane that is opposite to the interface card, so that the controller is connected through the backplane to the hard disk connected to interface card.

The plurality of backplanes are arranged in parallel at intervals, so that there is a channel between adjacent backplanes, and an airflow can easily pass through the channel. This avoids blocking from the backplanes to the airflow, and achieves a good heat dissipation effect in the storage device. In addition, the direction of the backplanes that are arranged in parallel at intervals is the same as the direction of the hard disks that are arranged in parallel at intervals, and the hard disks and the controllers are connected to two opposite sides of the backplanes, respectively. Therefore, there is no need to reserve a clearance, and density of the hard disks and/or the controllers in the electronic device can be increased. Compared with the prior art, more hard disks and controllers can be connected through the backplanes, and an operating capability of the storage device can be improved.

In some embodiments of this application, each of the controllers is connected to all the backplanes. To be specific, each of the controllers can access any hard disk through the backplanes and the interface cards connected to the backplanes.

In addition, in some embodiments, each backplane can be connected to all the controllers. To be specific, the plurality of controllers can access a same hard disk through the backplanes and the interface cards connected to the backplanes, so that sharing by the plurality of controllers is implemented.

In some embodiments of this application, the interface cards connected to adjacent backplanes are staggered in a height direction of the backplanes, so that a distance between the adjacent backplanes can be as small as possible, to reduce an area occupied by the backplanes.

In some embodiments of this application, an electronic component is disposed on the backplane, and the electronic component may be a micro switch or a memory chip to extend functions of the backplane.

In some embodiments of this application, the controller includes a processor, a memory, and a power module. The processor is configured to process service data on the hard disk connected to the interface card. The memory is in signal connection to the processor, to provide a cache for the processor. The power module is electrically connected to the processor and the interface card, to provide an operating voltage for the processor and the hard disk connected to the interface card.

The hard disk includes a power conversion module, an internal control module, and a data storage module. The data storage module is configured to store data; the internal control module is configured to process a signal of the controller and manage the hard disk; and the power conversion module is electrically connected to the power module, the internal control module, and the data storage module, to convert a voltage of the power module and provide the voltage to the internal control module and the data storage module.

In some other embodiments of this application, the storage device may include a plurality of backplanes arranged in parallel at intervals, a plurality of hard disks arranged in parallel at intervals, and a plurality of controllers arranged in parallel at intervals. There is a channel between adjacent backplanes. An arrangement direction of the plurality of hard disks is the same as an arrangement direction of the backplanes, and the hard disk is directly connected to one side of the backplane. An arrangement direction of the plurality of controllers intersects the arrangement direction of the plurality of backplanes, and each of the controllers is connected to one side of the backplane that is opposite to the hard disk, so that the hard disk is connected to the controller through the backplane. Compared with the storage device in the foregoing embodiments, in this application, there is no interface card in the storage device in the foregoing embodiments, and the hard disk is directly connected to the backplane. An arrangement and locations of the plurality of hard disks in the storage device, a connection relationship between the hard disks and the backplanes, and the like are the same as an arrangement and locations of the plurality of interface cards in the storage device, and a connection relationship between the interface cards and the backplanes in the storage device in the foregoing embodiments.

To describe the technical solutions in this application more clearly, the following briefly describes the accompanying drawings for describing the embodiments. It is clear that the accompanying drawings in the following descriptions show merely some embodiments of this application. A person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

Arrows in the figures show airflow directions.

In descriptions of this application, it should be noted that terms "mounting" and "connection" should be interpreted in a broad sense unless otherwise expressly specified and limited. For example, a connection may be a fixed connection, a detachable connection, or an integrated connection. Alternatively, a connection may be a mechanical connection or an electrical connection, or may mean mutual communication. Alternatively, a connection may be a direct connection, or an indirect connection through an intermediate medium, or may be a connection between two elements or an interaction relationship between two elements. A person of ordinary skill in the art may interpret specific meanings of the foregoing terms in this application according to specific cases.

As shown in <FIG>, this application provides an electronic device with parallel backplanes. The electronic device includes a backplane assembly <NUM>, a front inserting assembly <NUM>, and a rear inserting assembly <NUM>. The front inserting assembly <NUM> and the rear inserting assembly <NUM> are located on two sides of the backplane assembly <NUM>, respectively. The backplane assembly <NUM> is connected to the front inserting assembly <NUM> and the rear inserting assembly <NUM>, so that a data signal and/or a control signal is transmitted between the front inserting assembly <NUM> and the rear inserting assembly <NUM>.

The backplane assembly <NUM> includes a plurality of backplanes <NUM> arranged in parallel at intervals. The backplane <NUM> is plate-shaped, a plurality of backplanes <NUM> are disposed in parallel, and an arrangement direction of the backplanes <NUM> and a plane on which the backplanes <NUM> are located form an angle. In an embodiment of this application, the arrangement direction of the plurality of backplanes <NUM> is perpendicular to the plane on which the backplanes <NUM> are located. In other words, a line of centers of the plurality of backplanes <NUM> is perpendicular to the plane on which the backplanes <NUM> are located. That the plurality of backplanes <NUM> are arranged in parallel at intervals means that the plurality of backplanes <NUM> are disposed side by side with a particular interval between adjacent backplanes <NUM> and there is a channel <NUM> between the adjacent backplanes <NUM>. The front inserting assembly <NUM> and the rear inserting assembly <NUM> are located at two ends of an airflow direction in the channel <NUM>, respectively. The channel <NUM> is disposed between the adjacent backplanes <NUM>, so that an airflow can smoothly pass through the two sides of the backplane assembly <NUM> through the channel <NUM>. This avoids blocking from the backplanes <NUM> to the airflow, and achieves a good heat dissipation effect in the electronic device. Compared with a manner in which a through-hole is disposed on the backplane <NUM> to implement air ventilation and heat dissipation between the front inserting assembly <NUM> and the rear inserting assembly <NUM> on the two sides of the backplane <NUM> through the through-hole on the backplane <NUM>, in this manner, no through-hole needs to be disposed on the backplane <NUM>, and therefore a difficulty in manufacturing the backplane <NUM> is reduced. In addition, the following problem does not arise: The airflow between the front inserting assembly <NUM> and the rear inserting assembly <NUM> is blocked by the backplane <NUM> and a heat dissipation effect is poor because a quantity of functional units in the front inserting assembly <NUM> and/or the rear inserting assembly <NUM> increases, an area occupied by the backplanes <NUM> after the front inserting assembly <NUM> and/or the rear inserting assembly <NUM> are connected to the backplanes <NUM> is increased, and a size of the through-hole on the backplane <NUM> needs to be decreased.

The backplane <NUM> includes a substrate and a connection line disposed on the substrate, so that the front inserting assembly <NUM> is connected to the rear inserting assembly <NUM> through the connection line. In this application, the front inserting assembly <NUM> is communicatively connected to the rear inserting assembly <NUM>. To be specific, after the front inserting assembly <NUM> and the rear inserting assembly <NUM> are connected through the connection line, information such as data information and/or control information can be transmitted between the front inserting assembly <NUM> and the rear inserting assembly <NUM> through the transmission line. In this application, the connection line may be a metal cable, to transmit an electrical signal carrying information such as data information and/or control information. In some embodiments, the connection line may alternatively be an optical fiber or the like used to transmit an optical signal, to transmit an optical signal carrying information such as data information and/or control information. In this embodiment, the backplane <NUM> is a rectangular PCB board, and the connection line may be a metal cable. It may be understood that the backplane <NUM> in this application may alternatively be in any shape. This is not limited herein. In some embodiments of this application, various electronic components may be further disposed on an outer surface of the backplane <NUM> to extend functions of the backplane <NUM>. For example, the electronic component may be disposed with a micro switch. The micro switch is used to control connection of a connection line on which the micro switch is located. Alternatively, the electronic component may be a micro storage chip or the like. The storage chip stores manufacturing information of a backplane <NUM> on which the storage chip is located, to facilitate subsequent maintenance and replacement.

The backplane <NUM> includes a first side <NUM> and a second side <NUM> opposite to the first side <NUM>. The front inserting assembly <NUM> is connected to the first side <NUM>, and the rear inserting assembly <NUM> is connected to the second side <NUM>. The front inserting assembly <NUM> and the rear inserting assembly <NUM> are usually connected to the backplane <NUM> through connectors, and the connectors are usually mounted on the backplane <NUM> in a through-board manner. To be specific, pins of the connectors need to penetrate the backplane. In the prior art, the front inserting assembly <NUM> and the rear inserting assembly <NUM> are usually fastened on two sides of the backplane <NUM> in a thickness direction of the backplane <NUM>. As a result, in the prior art, to ensure stable and effective mounting of the front inserting assembly <NUM> and the rear inserting assembly <NUM> on the backplane <NUM>, a clearance needs to be reserved when the front inserting assembly <NUM> and the rear inserting assembly <NUM> are connected to the backplane <NUM>. However, in this application, the front inserting assembly <NUM> and the rear inserting assembly <NUM> are located on two sides of the backplane <NUM> in a non-thickness direction of the backplane <NUM>. Therefore, there is no need to reserve a clearance for the front inserting assembly <NUM> and the rear inserting assembly <NUM>, and density of first units <NUM> and/or second units <NUM> in the electronic device can be increased.

A first connector <NUM> and a second connector <NUM> are connected to the backplane <NUM>. Specifically, the first connector <NUM> is connected to the first side <NUM>, and the second connector <NUM> is connected to the second side <NUM>. Each of the backplanes <NUM> can be connected to one or more first connectors <NUM> disposed at intervals and one or more second connectors <NUM> disposed at intervals. A plurality of first connectors <NUM> are disposed at intervals along an extension direction of the first side <NUM>, and a plurality of second connectors <NUM> are disposed at intervals along an extension direction of the second side <NUM>.

Referring to <FIG> again, in some embodiments of this application, the first connectors <NUM> on adjacent backplanes <NUM> are staggered in the extension direction of the first side <NUM>. In other words, orthographic projections of the first connectors <NUM> on the adjacent backplanes <NUM> do not overlap in the arrangement direction of the backplanes <NUM>. It may be understood that, in some embodiments of this application, the first connectors <NUM> on the adjacent backplanes <NUM> may alternatively be disposed adjacently. In other words, orthographic projections of the first connectors <NUM> on the adjacent backplanes <NUM> may alternatively overlap in the arrangement direction of the backplanes <NUM>.

Referring to <FIG>, the front inserting assembly <NUM> includes a plurality of first units <NUM> arranged in parallel at intervals. An arrangement direction of the first units <NUM> is the same as the arrangement direction of the backplanes <NUM>, and each of the first units <NUM> is connected to one backplane <NUM>. That the first unit <NUM> is connected to one side of the backplane <NUM> specifically means that the first unit <NUM> is communicatively connected to the backplane <NUM>, so that a signal can be transmitted between the first unit <NUM> and the backplane <NUM>. In this embodiment, the first unit <NUM> is plate-shaped, each first unit <NUM> is disposed with a first connection port on the side facing the backplane, and the first connection port is detachably connected to the first connector <NUM>, so that the first unit <NUM> can be easily detachably connected to the backplane <NUM>, to facilitate replacement and maintenance of the first unit <NUM>. In some embodiments of this application, the first units <NUM> connected to the adjacent backplanes <NUM> are staggered in the extension direction of the first side <NUM>. Specifically, the first units <NUM> connected to the adjacent backplanes <NUM> are staggered in a height direction of the backplanes <NUM>, so that a distance between the adjacent backplanes <NUM> can be as small as possible, to reduce an area occupied by the backplane assembly <NUM>. In an embodiment of this application, the height direction of the backplanes <NUM> is the extension direction of the first side <NUM> and the second side <NUM>. Because the first connectors <NUM> on the adjacent backplanes <NUM> are staggered, the first units <NUM> connected to the two adjacent backplanes <NUM> are staggered. In this embodiment, each of the backplanes <NUM> is connected to one of the first connectors <NUM>, so that only one of the first units <NUM> is connected to each backplane <NUM>. It may be understood that, in other embodiments of this application, when each backplane <NUM> is connected to a plurality of first connectors <NUM> disposed at intervals, each backplane <NUM> may be connected to the plurality of first units <NUM>, and the first units <NUM> are disposed at intervals, so that there is a gap between adjacent first units <NUM>, and an airflow can pass through the gap to achieve a good heat dissipation effect.

Referring to <FIG>, the rear inserting assembly <NUM> includes a plurality of second units <NUM> arranged in parallel at intervals. Specifically, an arrangement direction of the plurality of second units <NUM> intersects the arrangement direction of the plurality of backplanes <NUM>. In other words, the arrangement direction of the plurality of second units <NUM> and the arrangement direction of the plurality of backplanes <NUM> form a particular angle. In an embodiment of this application, the arrangement direction of the plurality of second units <NUM> is perpendicular to the arrangement direction of the plurality of backplanes <NUM>. Each of the second units <NUM> is connected to one side of the backplane <NUM> that is opposite to the first unit <NUM>. That the second unit <NUM> is connected to one side of the backplane <NUM> that is opposite to the first unit <NUM> specifically means that the second unit <NUM> is communicatively connected to the backplane <NUM>, so that a signal can be transmitted between the second unit <NUM> and the backplane <NUM>. The first unit <NUM> and the second unit <NUM> are connected through the backplane <NUM>, so that the first unit <NUM> and the second unit <NUM> can communicate with each other for transmission of a signal including but not limited to a data signal and/or a control signal. In an embodiment of this application, the second unit <NUM> is plate-shaped, the second unit <NUM> is disposed with a second connection port on the side facing the backplane <NUM>, and the second connection port is detachably connected to the second connection connector <NUM>, so that the second unit <NUM> can be easily detachably connected to the backplane <NUM>, to facilitate replacement and maintenance of the second unit <NUM>. In this application, each backplane <NUM> is connected to a plurality of second connectors <NUM> disposed at intervals, so that each backplane <NUM> can be connected to the plurality of second units <NUM> through the second connectors <NUM>, and the second units <NUM> are disposed at intervals, so that there is a gap between adjacent second units <NUM>, and an airflow can pass through the gap to achieve a good heat dissipation effect.

In some embodiments of this application, each of the first units <NUM> is connected to one side of one backplane <NUM>, and each of the second units <NUM> is connected to all the backplanes <NUM>, so that each of the second units <NUM> can be connected to all the first units <NUM> through the backplanes <NUM>. When the electronic device with parallel backplanes is a memory, the first units <NUM> may be storage units such as hard disks, and the second units <NUM> may be controllers, and each of the controllers can access all hard disks. The hard disks may be various types of hard disks, such as a solid state drive (Solid State Drives, SSD), a hybrid hard drive (Hybrid Hard Drive, HHD), and a conventional hard disk drive (Hard Disk Drive, HDD). Specifically, a plurality of second connection ports are disposed at intervals on a side of each of the second units <NUM> that faces the backplanes <NUM>, and each of the second connection ports corresponds to one backplane <NUM> and is connected to a second connector <NUM> on the backplane <NUM>, so that each of the second units <NUM> is communicatively connected to all the backplanes <NUM>. It may be understood that, in other embodiments of this application, each second unit <NUM> may alternatively be communicatively connected to some backplanes <NUM>, so that all the second units <NUM> can be communicatively connected to some first units <NUM> through the backplanes <NUM>. Specifically, second connection ports corresponding to second connectors <NUM> on several corresponding backplanes <NUM> in the backplane assembly <NUM> are disposed on a side of each of the second units <NUM> that faces the backplanes <NUM>, and each of the second connection ports is connected to a second connector <NUM> on a corresponding backplane <NUM>, so that each of the second units <NUM> is connected to several backplanes <NUM> in the backplane assembly <NUM>.

Further, in this application, each of the backplanes <NUM> is connected to all the second units <NUM>. Therefore, all the second units <NUM> can be communicatively connected to each of the first units <NUM> through the backplanes <NUM> for transmission of a data signal and/or a control signal. When the electronic device with parallel backplanes is a memory, the first units <NUM> are storage units such as hard disks, the second units <NUM> are controllers, and all the controllers can access a same hard disk, so that the memory can be shared by a plurality of controllers. In the embodiment shown in <FIG>, there are four controllers, so that the memory can be shared by the four controllers. The controllers are PCB boards or control chips having control circuits. The hard disks may be various types of hard disks, such as a solid state drive (Solid State Drives, SSD), a hybrid hard drive (Hybrid Hard Drive, HHD), and a conventional hard disk drive (Hard Disk Drive, HDD). Specifically, the second unit <NUM> is orthogonal to the backplane <NUM>, and a length of the second unit <NUM> is greater than or equal to a length of the backplane assembly <NUM> in the arrangement direction of the backplanes <NUM>, so that the second unit <NUM> intersects each of the backplanes <NUM> and is connected at a location at which the second unit <NUM> intersects the backplane <NUM>. In this way, each of the backplanes <NUM> can be connected to all the second units <NUM>. In an embodiment of this application, several second connectors <NUM> are disposed at intervals on a side of each of the backplanes <NUM> that faces the second unit <NUM> and along the extension direction of the first side <NUM>, and the second units <NUM> are one-to-one connected to the second connectors <NUM>, so that each of the backplanes <NUM> is connected to all the second units <NUM>. It may be understood that, in some embodiments of this application, each of the backplanes <NUM> may alternatively be connected to several second units <NUM> in the rear inserting assembly <NUM>. In other words, each of the backplanes <NUM> is not connected to all the second units <NUM> in the rear inserting assembly <NUM>. In this way, the second unit <NUM> can be connected to a corresponding first unit <NUM> through the backplanes <NUM>. For example, there are three backplanes <NUM> in the backplane assembly <NUM>, and the three backplanes <NUM> are a backplane A, a backplane B, and a backplane C. The rear inserting assembly <NUM> has three second units <NUM>, and the three second units <NUM> are a second unit D, a second unit E, and a second unit F. The backplane A is connected to the second unit D, the backplane B is connected to the second unit D and the second unit E, and the backplane C is connected to the second unit F and the second unit E.

Referring to <FIG>, in some embodiments of this application, the backplane <NUM> may be disposed with a hole <NUM>, and holes <NUM> on adjacent backplanes <NUM> are connected, so that an airflow can pass through all the backplanes <NUM>, to implement even heat dissipation at all locations in the backplane assembly <NUM>.

Further, in some embodiments, projections of the holes <NUM> on the adjacent backplanes <NUM> overlap on a plane parallel to any of the backplanes <NUM>. In other words, holes <NUM> on the backplanes <NUM> are connected in the arrangement direction of the backplanes <NUM>, so that an airflow can pass through all the backplanes <NUM> more smoothly. It may be understood that, in other embodiments of this application, the holes <NUM> on the adjacent backplanes <NUM> are staggered in the arrangement direction of the backplanes <NUM>. In other words, projections of the holes <NUM> on the adjacent backplanes <NUM> do not overlap on a plane parallel to any of the backplanes <NUM>.

Referring to <FIG> and <FIG>, in this application, the backplane assembly <NUM> further includes a fixed frame <NUM> with openings on two sides. The openings face the front inserting assembly <NUM> and the rear inserting assembly <NUM>, respectively. The backplane <NUM> is detachably fastened in the fixed frame <NUM>. The backplanes <NUM> are fastened in the fixed frame <NUM>, so that locations of the backplanes <NUM> can be relatively stable. In addition, the backplane <NUM> can be detachably fastened in the fixed frame <NUM>, so that it is convenient to take the backplane <NUM> out from the fixed frame <NUM>. This facilitates subsequent maintenance of the backplane <NUM>.

In some embodiments of this application, the fixed frame <NUM> is a cuboid frame. Specifically, the cuboid frame is a cuboid frame surrounded by four square plates. In this embodiment, two opposite inner wall surfaces <NUM> of the cuboid frame are disposed with a plurality of card slots <NUM> arranged at intervals, and an edge of each of the backplanes <NUM> is secured in a corresponding card slot <NUM>. The card slot <NUM> is used to stably secure the backplane <NUM> at a fixed location in the fixed frame <NUM>, to ensure that the locations of the backplanes <NUM> are relatively stable. In some embodiments of this application, the card slot <NUM> may be a sliding slot extending in a direction from the first side <NUM> to the second side <NUM>, and the backplane <NUM> can be inserted into the card slot <NUM> along the card slot <NUM> from an opening on one side of the fixed frame <NUM>. It may be understood that, in other embodiments of this application, the card slot <NUM> may alternatively be a groove disposed on the inner wall <NUM> of the fixed frame <NUM>, and the backplane <NUM> is disposed with a corresponding protrusion, so when the backplane <NUM> is fastened on the fixed frame <NUM>, the protrusion on the backplane <NUM> is inserted into the groove.

The fixed frame <NUM> may be made of various materials such as metal and plastic. In some embodiments of this application, the fixed frame <NUM> may be made of a flexible material such as plastic, so that when the electronic device is subject to an external force, the fixed frame <NUM> can provide a buffer for the backplane <NUM> to avoid damage to the backplane <NUM>.

Further, referring to <FIG>, in some embodiments of this application, a buffer member <NUM> is disposed between the inner wall of the card slot <NUM> and the backplane <NUM>. The buffer member <NUM> is used to fill in a gap between the backplane <NUM> and the inner wall of the card slot <NUM>, so that the backplane and the fixed frame <NUM> are connected more stably. In addition, when the electronic device is subject to an external force, the buffer member <NUM> can provide a buffer for the backplane <NUM>, to avoid damage to the backplane <NUM> due to a relatively large force generated between the backplane <NUM> and the fixed frame <NUM>. In this embodiment, the buffer member <NUM> is a rubber member.

Referring to <FIG> again, the electronic device with parallel backplanes further includes a chassis <NUM>. The front inserting assembly <NUM>, the rear inserting assembly <NUM>, and the backplane assembly <NUM> are all accommodated in the chassis <NUM>. The chassis <NUM> protects the front inserting assembly <NUM>, the rear inserting assembly <NUM>, and the backplane assembly <NUM> that are located inside the chassis <NUM>. In addition, in this embodiment, the fixed frame <NUM> is fastened in the chassis <NUM>, so that the backplane <NUM> can be stably disposed in the chassis <NUM>.

Further, a heat dissipation fan <NUM> is disposed on a wall of the chassis <NUM>. The heat dissipation fan <NUM> is used to achieve a better heat dissipation effect. The heat dissipation fan <NUM> is located on one side of the rear inserting assembly <NUM>, and an airflow, as shown by an arrow in <FIG>, sequentially passes through the rear inserting assembly <NUM>, the backplane assembly <NUM>, and the front inserting assembly <NUM>, to dissipate heat of the rear inserting assembly <NUM>, the backplane assembly <NUM>, and the front inserting assembly <NUM>.

In this application, the backplane assembly <NUM> has a structure including the plurality of backplanes <NUM> arranged in parallel at intervals and the channel <NUM> between adjacent backplanes <NUM>, so that an airflow for heat dissipation can easily pass through the channel <NUM>. This avoids blocking from the backplanes <NUM> to the airflow for heat dissipation, and avoids impact of density of the first units 21and/or the second units <NUM> in the electronic device with parallel backplanes on the airflow for heat dissipation. Compared with a manner in the prior art in which a through-hole is disposed on a backplane in an electronic device for heat dissipation, in this embodiment, an air ventilation effect in the electronic device is better, and a better heat dissipation effect is achieved in the electronic device. In addition, the first units <NUM> and the second units <NUM> are disposed on the first sides <NUM> and the second sides <NUM> of the backplanes <NUM>, respectively, and therefore there is no need to reserve a clearance for the first units <NUM> and the second units <NUM> on the two sides of the backplanes <NUM>. In this way, as many first units <NUM> and second units <NUM> as possible can be connected through the backplanes <NUM>, density of the first units <NUM> and/or the second units <NUM> in the electronic device can be increased, and the following prior-art problem does not arise: A heat dissipation effect in the electronic device is poor because the density of the first units <NUM> and/or the second units <NUM> in the electronic device is increased and a size of the through-hole for heat dissipation on the backplane <NUM> needs to be decreased.

The electronic device may be a storage device, a server, a switch, a router, or the like. The electronic device is to be described in some specific embodiments below.

Referring to <FIG>, in some embodiments of this application, an electronic device is a storage device. The storage device includes a backplane <NUM>, a hard disk <NUM>, and a controller <NUM>. The backplane <NUM> is an embodiment of the backplane <NUM> in the electronic device shown in <FIG>, the hard disk <NUM> is an embodiment of the first unit <NUM> in the electronic device shown in <FIG>, and the controller <NUM> is an embodiment of the second unit <NUM> in the electronic device shown in <FIG>. The hard disk <NUM> and the controller <NUM> are communicatively connected through the backplane <NUM>, so that a data signal and/or a control signal is/are transmitted between the hard disk <NUM> and the controller <NUM>. For example, in a data read/write scenario shown in <FIG>, when a client needs to obtain data in the hard disk <NUM>, the client sends a data reading instruction to the controller <NUM>. After receiving the data reading instruction, the controller <NUM> sends a data obtaining instruction to the hard disk <NUM> through the backplane <NUM>, to obtain the specified data from the hard disk <NUM>. The specified data is sent to the controller <NUM> through the backplane <NUM>, and then the specified data is sent to the client through the controller <NUM>. When the client needs to store data into the hard disk <NUM>, the client sends a data writing instruction to the controller <NUM>, where the data writing instruction carries the to-be-stored data. After receiving the data writing instruction, the controller <NUM> obtains the to-be-stored data from the data writing instruction, and sends, through the backplane <NUM>, the to-be-stored data to the hard disk <NUM> for storage.

Referring to <FIG>, in another embodiment of this application, a client sends a data reading instruction or a data writing instruction to the controller <NUM> over a cloud network. After the controller <NUM> receives the data reading instruction over the cloud network and obtains data from the corresponding hard disk <NUM>, the controller <NUM> sends the data to the client over the cloud network. After the controller <NUM> receives the data writing instruction over the cloud network, the controller <NUM> obtains to-be-stored data from the data wiring instruction and stores the to-be-stored data in the corresponding hard disk <NUM>.

It should be noted that in scenarios shown in <FIG>, interaction between one client, one controller <NUM>, and one hard disk <NUM> is merely used as an example for description. However, this should not constitute a limitation on an application scenario in the embodiments of this application. In an actual data read/write scenario, a plurality of clients, a plurality of controllers <NUM>, and a plurality of hard disks <NUM> may be included. For example, referring to <FIG>, in some embodiments of this application, a connection structure of the controller <NUM>, the hard disk <NUM>, and the backplane <NUM> in the storage device is the same as a connection structure of the second unit <NUM>, the first unit <NUM>, and the backplane <NUM> in <FIG>, and there may be a plurality of controllers <NUM>, backplanes <NUM>, and hard disks <NUM>. The plurality of backplanes <NUM> are arranged in parallel at intervals, and there is a channel <NUM> between adjacent backplanes <NUM>. The plurality of hard disks <NUM> are arranged in parallel at intervals. An arrangement direction of the hard disks is the same as an arrangement direction of the backplanes <NUM>, and each hard disk <NUM> is connected to one side of the backplane <NUM>. The plurality of controllers <NUM> are arranged in parallel at intervals. An arrangement direction of the controller intersects the arrangement direction of the backplanes <NUM>. Specifically, the controller <NUM> and the backplane <NUM> are disposed orthogonally or disposed at a particular angle. In addition, each of the controllers <NUM> is connected to one side of the backplane <NUM> that is opposite to the hard disk <NUM>, so that the hard disk <NUM> is connected to the controller <NUM> through the backplane <NUM>.

The plurality of backplanes <NUM> are arranged in parallel at intervals, so that there is a channel <NUM> between adjacent backplanes <NUM>, and an airflow can easily pass through the channel. This avoids blocking from the backplanes <NUM> to the airflow, and achieves a good heat dissipation effect in the storage device. In addition, the direction of the backplanes <NUM> that are arranged in parallel at intervals is the same as the direction of the hard disks <NUM> that are arranged in parallel at intervals, and the hard disks <NUM> and the controllers <NUM> are connected to two opposite sides of the backplanes <NUM>, respectively. Therefore, there is no need to reserve a clearance, and density of the hard disks <NUM> and/or the controllers <NUM> in the electronic device can be increased. Compared with the prior art, more hard disks <NUM> and controllers <NUM> can be connected through the backplanes <NUM>, and an operating capability of the storage device can be improved.

Further, in some embodiments, each of the controllers <NUM> is connected to all the backplanes <NUM>. In other words, each of the controllers <NUM> can access any hard disk <NUM> through the backplanes <NUM>. In some embodiments, each of the backplanes <NUM> can be connected to all the controllers <NUM>, so that a plurality of controllers <NUM> can access a same hard disk <NUM>, so that connections of the plurality of controllers are implemented. Therefore, in this application, the controllers <NUM> and the hard disks <NUM> may be deployed in a centralized storage architecture or distributed storage architectures. When the controllers <NUM> and the hard disks <NUM> are deployed in the centralized storage architecture, one piece of data is stored in one of the plurality of hard disks <NUM>. In an embodiment of this application, when a piece of data is stored in one hard disk <NUM>, because a plurality of controllers <NUM> can access the same hard disk <NUM>, a user that communicates with any controller <NUM> can obtain data from the same hard disk <NUM> or write data into the same hard disk <NUM>. For example, in an embodiment, video data is written into a hard disk A, and a controller A, a controller B, and a controller C are all connected to the hard disk A through backplanes. In this case, all of the controller A, the controller B, and the controller C can read the video data information from the hard disk A. This means that a user can obtain the video data from the hard disk A through any one of the controller A, the controller B, or the controller C. When the controllers <NUM> and the hard disks <NUM> are deployed in the distributed storage architectures, one piece of data may be divided into a plurality of small pieces of data, a check code corresponding to each small piece of data is generated, and each small piece of data and the corresponding check code are separately stored in a plurality of hard disks. In this application, because each controller <NUM> can be communicatively connected to all the backplanes <NUM> to access any hard disk <NUM> through the backplanes <NUM>, any controller <NUM> can fan out an instruction to the plurality of hard disks <NUM> through the backplanes <NUM>, to obtain small pieces of data from the plurality of hard disks <NUM>, and can combine the small pieces of data obtained from the plurality of hard disks <NUM> into the complete data. Alternatively, one piece of data may be divided into a plurality of pieces of data and separately written the plurality of pieces of data into the plurality of hard disks <NUM>. For example, video data of a user A is divided into video data <NUM>, video data <NUM>, and video data <NUM>, and check codes, a check code <NUM>, a check code <NUM>, and a check code <NUM>, corresponding to the video data <NUM>, the video data <NUM> and the video data <NUM> are generated, respectively. Then, the video data <NUM> and the check code <NUM> are stored in a hard disk <NUM>, the video data <NUM> and the check code <NUM> are stored in a hard disk <NUM>, and the video data <NUM> and the check code <NUM> are stored in a hard disk <NUM>. When a controller needs to read the video data, the controller may send a data reading instruction, and fan out the instruction to the hard disk <NUM>, the hard disk <NUM>, and the hard disk <NUM> through the backplanes, to obtain the video data <NUM>, the video data <NUM>, the video data <NUM>, the check code <NUM>, the check code <NUM>, and the check code <NUM> from the three hard disks. Then, the controller processes, for example, combines, the video data <NUM>, the video data <NUM>, the video data <NUM>, the check code <NUM>, the check code <NUM>, and the check code <NUM>, to finally obtain the video data.

Referring to <FIG> and <FIG>, in some embodiments of this application, the controller <NUM> is detachably connected to the backplane <NUM> through a fourth connector <NUM>, and the hard disk <NUM> is detachably connected to the backplane <NUM> through a third connector <NUM>, so that a user can flexibly configure a connection relationship between the hard disk <NUM> and the controller <NUM> based on a use requirement, and obtain different storage architectures. The third connector <NUM> is an embodiment of the first connector <NUM> in the electronic device, and the fourth connector <NUM> is an embodiment of the second connector <NUM> in the electronic device shown in <FIG>. The fourth connector <NUM> and the controller <NUM> may be two independent components, or the fourth connector <NUM> may be a part of the controller <NUM>. The third connector <NUM> and the hard disk <NUM> may also be two independent components, or the third connector <NUM> may be a part of the hard disk <NUM>. The fourth connector <NUM> and the controller <NUM> may be two independent components. In other words, the fourth connector <NUM> and the controller <NUM> can also be detachably connected, to facilitate replacement of the fourth connector when the fourth connector <NUM> is damaged. The third connector <NUM> and the hard disk <NUM> can be two independent components. In other words, the third connector <NUM> and the hard disk <NUM> can also be detachably connected, to facilitate replacement of the third connector when the third connector <NUM> is damaged. Specifically, one end of the third connector <NUM> and one end of the fourth connector <NUM> are mounted on the backplane <NUM> in a through-board manner, and the other ends each have a plug-in interface. The controller <NUM> has a plug corresponding to the plug-in interface on the fourth connector <NUM> and is connected to the fourth connector <NUM> in a plugging manner. Similarly, the hard disk <NUM> has a plug corresponding to the plug-in interface on the third connector <NUM>, and is connected to the third connector <NUM> in a plugging manner. It may be understood that, in other embodiments of this application, the fourth connector <NUM> and the controller <NUM> or the third connector <NUM> and the hard disk <NUM> may alternatively be connected in a fixed manner.

In this application, a connection between the third connector <NUM> and the hard disk <NUM> may be a direct connection, or an indirect connection through an intermediate medium. Referring to <FIG>, if the third connector <NUM> is directly connected to the hard disk <NUM>, a signal can be directly transmitted from the hard disk <NUM> to the third connector <NUM>. Referring to <FIG>, a difference between the embodiments shown in <FIG> and the embodiment shown in <FIG> lies in: The third connector <NUM> is indirectly connected to the hard disk <NUM>. Specifically, an interface card <NUM> (IO Card) providing an input/output (Input/Output, I/O) interface is alternatively connected between the third connector <NUM> and the hard disk <NUM>, the interface card <NUM> is directly connected to the third connector <NUM>, and is connected to the backplane <NUM> through the third connector <NUM>. Then, the hard disk <NUM> is connected to the interface card <NUM>, and is indirectly connected to the third connector <NUM> through the interface card <NUM>. In this embodiment, the interface card <NUM> is a specific embodiment of the first unit <NUM> in the electronic device in <FIG>. Locations and an arrangement of a plurality of interface cards <NUM> in the storage device, a connection manner between the interface cards and the backplanes, and the like are the same as locations and an arrangement of the hard disks <NUM> in the storage device and a connection manner between the hard disks and the backplanes in the embodiment shown in <FIG>. In addition, in this embodiment, the interface card <NUM> is connected to the hard disk <NUM>. It may be understood that, in some embodiments of this application, the hard disk <NUM> may be a part of the storage device. In some other embodiments of this application, the hard disk <NUM> may alternatively be an external structure of the storage device, to facilitate replacement of the hard disk <NUM>. For example, the storage device in this embodiment is connected to an external hard disk array, where the external hard disk array includes hard disks <NUM> disposed in an array. The hard disk array is connected to an I/O interface of the interface card <NUM> through a cable, so that the external disk array is connected to the storage device. When a hard disk <NUM> needs to be replaced, only the cable connecting the hard disk array and the I/O interface of the interface card <NUM> needs to be removed from the I/O interface, and a new disk array is mounted.

The I/O interface may be an interface that may be connected to a host server, such as a fiber channel (Fiber Channel, FC) interface, an internet small computer system interface (Internet Small Computer System Interface, ISCSI), or an infiniband (Infiniband, IB) interface, or may be an interface that is connected to a rear hard disk <NUM>, such as a <NUM>/<NUM> serial attached small computer system interface (Serial Attached SCSI). In addition, in other embodiments of this application, based on an actual requirement, other structures can be connected to the backplane <NUM> through the interface of the interface card <NUM> and communicatively connected to the controller <NUM>. In an embodiment of this application, the third connector <NUM> is a Gen-Z 4C connector, and the fourth connector <NUM> is an orthogonal enterprise and data center SSD form factor (Enterprise Data Center SSD Form Factor, EDSFF) female elbow. Both the third connector <NUM> and the fourth connector <NUM> are mounted on the backplane <NUM> in a through-board manner, so that the third connector <NUM> is stably fastened on the backplane <NUM>. The fourth connector <NUM> is the orthogonal EDSFF female elbow.

The controller <NUM> is described in detail below.

Referring to <FIG>, a controller <NUM> may include a processor <NUM>. The processor <NUM> is communicatively connected to a fourth connector <NUM>. The processor may be a central processing unit (Central Processing Unit, CPU), a digital signal processor, an application-specific integrated circuit, a field-programmable gate array (Field-Programmable Gate Array, FPGA), or other programmable logic devices. This is not limited herein. The processor <NUM> is configured to implement service data transmission between the controller and a hard disk <NUM>, to obtain data stored in the hard disk <NUM> or store to-be-stored data in the hard disk <NUM>. Further, the processor may detect a connection state (connected or disconnected) between the hard disk <NUM> and a backplane <NUM>, detect whether the hard disk <NUM> is faulty, detect information about the hard disk <NUM>, and control a power supply state or a connection state of the hard disk <NUM>. Further, the controller <NUM> may include a memory <NUM> and a power module <NUM>. The memory <NUM> is connected to the processor <NUM> and is configured to provide a cache function for the processor <NUM> during communication between the processor <NUM> and the hard disk <NUM>. The power module <NUM> is electrically connected to the processor <NUM> and the fourth connector <NUM> to provide an operating voltage for the processor <NUM> and the hard disk <NUM> that is communicatively connected to the controller <NUM> through the fourth connector <NUM>, the backplane <NUM>, and a third connector <NUM>.

The hard disk <NUM> is described in detail below.

Referring to <FIG>, a hard disk <NUM> may include a power conversion module <NUM>, an internal control module <NUM>, and a data storage module <NUM>. The power conversion module <NUM> is electrically connected to a third connector <NUM>, the internal control module <NUM>, and the data storage module <NUM>. The power conversion module <NUM> is electrically connected to the third connector <NUM>, to implement electrical connection to a power module <NUM> in a controller <NUM>. The power conversion module <NUM> converts a voltage provided by the power module <NUM> in the controller <NUM> into an operating voltage suitable for the internal control module <NUM> and the data storage module <NUM>, to supply power to the internal control module <NUM> and the data storage module <NUM>. The internal control module <NUM> is configured to process a signal of the controller <NUM> and manage the hard disk <NUM>. For example, the internal control module <NUM> receives a control signal of the controller <NUM> for the hard disk <NUM>, and provides a function of reading data form the data storage module <NUM> or writing data into the data storage module <NUM>. In this embodiment, the hard disk <NUM> is directly connected to the third connector <NUM>. It may be understood that, in other embodiments, the hard disk <NUM> may be indirectly connected to the third connector <NUM>. The data storage module <NUM> is configured to store or read user data under a control of the internal control module <NUM>. In some embodiments of this application, the data storage module <NUM> may be a central processing unit (Central Processing Unit, CPU), a digital signal processor, an application-specific integrated circuit, a field-programmable gate array (Field-Programmable Gate Array, FPGA), or other programmable logic devices. This is not limited herein.

In some embodiments of this application, the electronic device may alternatively be a switch or a router. When the electronic device is a switch, the first unit <NUM> is a switching matrix card, and the second unit <NUM> is a service line card. When the electronic device with parallel backplanes is a router, the first unit <NUM> is a network board and an interface card, and the second unit <NUM> is a main control board.

Claim 1:
An electronic device with parallel backplanes, comprising a backplane assembly, a front inserting assembly (<NUM>), and a rear inserting assembly (<NUM>), wherein the backplane assembly is connected to the front inserting assembly (<NUM>) and the rear inserting assembly (<NUM>); the backplane assembly (<NUM>) comprises a plurality of backplanes (<NUM>) arranged in parallel at intervals, and there is a channel between adjacent backplanes (<NUM>); the front inserting assembly (<NUM>) comprises a plurality of first units (<NUM>) arranged in parallel at intervals, an arrangement direction of the first units is the same as an arrangement direction of the backplanes (<NUM>), and the first unit (<NUM>) is connected to one side of the backplane (<NUM>); and the rear inserting assembly (<NUM>) comprises a plurality of second units (<NUM>) arranged in parallel at intervals, an arrangement direction of the plurality of second units (<NUM>) intersects the arrangement direction of the plurality of backplanes (<NUM>), and each of the second units (<NUM>) is connected to one side of the backplane (<NUM>) that is opposite to the first unit (<NUM>), so that the first unit (<NUM>) is connected to the second unit (<NUM>) through the backplane (<NUM>), characterised in that the first units (<NUM>) connected to adjacent backplanes (<NUM>) are staggered in a height direction of the backplanes (<NUM>).