Cable backboard device

Abstract

Provided in the embodiments of the present disclosure is a cable backboard device, comprising: at least one first circuit board and at least one second circuit board, wherein the first circuit board comprises a first board-edge connector, a first chip, and a first in-board connector; the second circuit board comprises a second board-edge connector; the first board-edge connector and the second board-edge connector are in pluggable connection, so that the first circuit board and the second circuit board are in perpendicular mutual plug-in connection; and a first board-edge crimping connector is electrically connected to the first chip through a printed circuit board (PCB) transmission line, a first board-edge direct lead-out connector is electrically connected to the first in-board connector through a flexible cable, and the first in-board connector is electrically connected to the first chip.

Description

Cable backplane assembly

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on Chinese patent application CN202310785582.8, filed on June 29, 2023, with the invention name “Cable Backplane Device”, and claims the priority of the patent application, and all the disclosed contents thereof are incorporated into this application by reference. Technical Field

[0003] The embodiments of the present disclosure relate to the field of communications, and in particular, to a cable backplane device. Background Art

[0004] In communication systems, the backplane is a crucial component of communication equipment, typically consisting of a multilayer printed circuit board (PCB) and connectors. With the continuous advancement of communication system technology and the demand for higher capacity, high-speed signals in the backplane are becoming increasingly dense, with ever-increasing signal transmission rates. Consequently, the size of the boards is also increasing. However, high-speed signal transmission losses in PCBs are significant, causing the integrity of the high-speed signal to inherently degrade as the signal travels further along the channel. This phenomenon is known as link loss. Therefore, minimizing link loss in high-speed signals on PCBs has become a key issue in high-speed system design.

[0005] Compared to PCB backplanes, cable backplanes have a link loss that is approximately one-quarter that of PCB backplanes. Furthermore, cable backplanes offer excellent high-speed signal transmission characteristics, leading some existing systems to replace traditional backplanes with cable assemblies. However, packaging large numbers of cable assemblies is difficult, and cable management is a limiting factor in these systems.

[0006] In summary, how to effectively reduce the link loss of high-speed signal transmission and perform reasonable cable management is a problem that needs to be solved now.

[0007] Summary of the Invention

[0008] The embodiments of the present disclosure provide a cable backplane device to at least solve the problems in the related art of large link loss and difficulty in cable management when high-speed signals are transmitted through the backplane.

[0009] According to one embodiment of the present disclosure, a cable backplane device is provided, comprising: at least one first circuit board and at least one second circuit board, wherein the first circuit board comprises a first board edge connector, a first chip, and a first intra-board connector; the second circuit board comprises a second board edge connector; the first board edge connector comprises a first board edge crimp connector and a first board edge straight-out connector; the first board edge connector and the second board edge connector are pluggable to enable the first circuit board and the second circuit board to be vertically plugged and interconnected; the first board edge crimp connector is electrically connected to the first chip via a printed circuit board PCB transmission line, the first board edge straight-out connector is electrically connected to the first intra-board connector via a flexible cable, and the first intra-board connector is electrically connected to the first chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a schematic structural diagram of a cable backplane device according to an embodiment of the present disclosure;

[0011] FIG2 is a schematic diagram of the positional relationship between the first tray and the first circuit board according to an embodiment of the present disclosure;

[0012] FIG3 is a schematic diagram of the positional relationship between the second tray and the second circuit board according to an embodiment of the present disclosure;

[0013] FIG4 is a schematic diagram of one-to-many circuit board interconnection according to an embodiment of the present disclosure;

[0014] FIG5 is a schematic diagram of many-to-many circuit board interconnection according to an embodiment of the present disclosure;

[0015] FIG6 is a schematic diagram of the positional relationship of the cable backplane device in the backplane architecture according to an embodiment of the present disclosure;

[0016] Among them, 100-first circuit board, 110-first chip, 132-first board edge press-fit connector, 131-first board edge straight-out connector, 120-first intra-board connector, 101-first PCB transmission line, 121-first flexible cable bundle, 200-second circuit board, 210-second chip, 232-second board edge press-fit connector, 231-second board edge straight-out connector, 220-second intra-board connector, 201-second PCB transmission line, 221-second flexible cable bundle, 300-first tray, 400-second tray, 010-center backplane, 020-backplane connector. DETAILED DESCRIPTION

[0017] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and in combination with the embodiments.

[0018] It should be noted that the terms "first", "second", etc. in the description and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0019] With the continuous development of communication system technology, the demand for large-capacity communication systems requires that high-speed signals in the backplane become increasingly dense, the size of single boards becomes larger and larger, and the signal transmission rate becomes higher and higher. However, high-speed signals have large transmission losses in PCBs, and link loss has become a bottleneck in high-speed system design. As a result, the constraints on circuit board design, processing, and board grade are becoming increasingly stringent.

[0020] In the backplane system architecture of the related art, the circuit boards are connected vertically to each other through at least one set of orthogonal connectors, that is, at least one set of plug-in male and female connectors. The pins of the male and female connectors are both rotated 90°, and the connector insertion loss is relatively large. In addition, the high-speed signal transmission on the board uses an internal PCB transmission line, which not only has high requirements on the board material and processing capabilities, but also has large PCB transmission line losses. As the rate increases, the link loss is increasingly unable to meet the requirements. In traditional cable backplanes, high-speed signal transmission basically all needs to pass through cables, so a large number of cables need to be designed and managed, and therefore it is difficult to package a large number of cable assemblies. Cable management is a limiting factor in this type of system.

[0021] Compared with the existing backplane system, the cable backplane device of the present application uses both board-edge crimp connectors and straight-out cable connectors on at least one single board, that is, part of the high-speed signal is transmitted through the PCB transmission line inside the board, and part is transmitted through the cable. The cable loss is significantly better than the PCB transmission line, which can not only improve the signal integrity (SI) performance of the high-speed channel, but also reduce the pressure of PCB channel loss, thereby reducing the board grade or the number of routing layers to reduce costs. Moreover, the straight-out cable connector does not contact the circuit board, and the size of the circuit board can be reduced accordingly, thereby solving the cost or problems caused by the excessive size of the single board. In addition, compared with the traditional cable backplane, the cable solution adopted in this proposal only exists inside each single board, and the number only covers part of the high-speed signals on the single board, so cable management is relatively simple.

[0022] The cable backplane device provided by the embodiment of the present disclosure adopts an interconnection scheme that uses a mixture of traditional PCB transmission lines and cables in the daughter card (circuit board). Compared with the traditional single-board routing, the cable loss is lower, the number of layers and size of the circuit board can be reduced, the board grade constraints are relaxed, and only some high-speed signals are transmitted by cables, which reduces the difficulty of cable management. In the actual implementation process, signals are exchanged between different circuit boards, and the method of signal interaction is not restricted. Specifically, part of the signal is transmitted through the PCB transmission line, and part of the signal is transmitted through the cable. The transmission method used by the specific different signals can be controlled by the control device or the signal transmission method can be set before the transmission begins. Afterwards, the cable backplane device provided by the embodiment of the present disclosure can be used to transmit the signal in the set manner.

[0023] An embodiment of the present disclosure provides a cable backplane device, comprising: at least one first circuit board and at least one second circuit board, wherein the first circuit board comprises a first board edge connector, a first chip, and a first intra-board connector; the second circuit board comprises a second board edge connector; the first board edge connector comprises a first board edge crimp connector and a first board edge straight-out connector; the first board edge connector and the second board edge connector are pluggable to enable the first circuit board and the second circuit board to be vertically plugged and interconnected; the first board edge crimp connector is electrically connected to the first chip through a printed circuit board PCB transmission line, the first board edge straight-out connector is electrically connected to the first intra-board connector through a flexible cable, and the first intra-board connector is electrically connected to the first chip.

[0024] In actual implementation, the first intra-board connector is electrically connected to the first chip by interconnecting the first intra-board connector with the first circuit board through pins, and then electrically connecting the first intra-board connector to the pins of the first chip through the PCB transmission lines within the board.

[0025] FIG1 is a schematic diagram of the structure of a cable backplane device according to an embodiment of the present disclosure. As shown in FIG1 , the cable backplane device has an orthogonal system architecture, including a first circuit board 100 and a second circuit board 200, the first circuit board and the second circuit board being arranged perpendicular to each other. The first circuit board 100 and the second circuit board 200 can serve as a pair of vertically interleaved single boards in the aforementioned backplane-less orthogonal system architecture.

[0026] As shown in Figure 1, the first circuit board includes at least the following components: a first chip 110, a first board edge crimp connector 132, a first board edge straight-out connector 131, a first intra-board connector 120, a first PCB transmission line 101, and a first flexible cable bundle 121. The chip on each circuit board is electrically connected via a PCB transmission line or an intra-board connector, a flexible cable, and an edge-board connector. The first and second circuit boards are connected via edge-board connectors to achieve signal transmission between the chips on the two boards. With the cable backplane system having the above structure, when performing high-speed signal transmission, some loss bottleneck channels are transmitted via cables, and the number of PCB transmission lines within the circuit board is reduced. This not only reduces link loss and improves signal transmission quality, but also reduces the circuit board material or reduces the size of the circuit board, thereby reducing system costs.

[0027] In actual implementation, the first circuit board 100 includes at least one first chip 110 , and the high-speed signal of the chip needs to be distributed and interconnected to the board edge connectors of the first circuit board 100 , including the first board edge press-fit connector 132 and the first board edge direct-out connector 131 .

[0028] In actual implementation, the first board edge connector and the second board edge connector constitute a group of connectors. The first board edge connector may include a first board edge press-fit connector 132 or a first board edge straight-out connector 131, and the second board edge connector may include a second board edge press-fit connector 232 or a second board edge straight-out connector 231. The first board edge connector and the second board edge connector are pluggable and electrically connected. In the plugged state, the first board edge connector and the second board edge connector can be electrically connected, thereby realizing vertical plug-in interconnection of the first circuit board 100 and the second circuit board 200. The specific connection relationship between the board edge connectors of different circuit boards is not specifically limited.

[0029] In an exemplary embodiment, the first intra-board connector is fixedly mounted on the first circuit board by means of crimping or spring connection, and is electrically connected to the first circuit board.

[0030] In actual implementation, as shown in FIG1 , the first intra-board connector 120 can be installed on the first circuit board 100 by crimping or by direct screw mounting using a spring clip, thereby directly connecting the pins of the first intra-board connector 120 to the pins on the first circuit board 100, thereby achieving electrical connection between the first intra-board connector 120 and the first circuit board 100. In actual implementation, the end of the first intra-board connector 120 electrically connected to the first circuit board 100 can be located close to the first chip 110, thereby significantly shortening the intra-board wiring connecting the pins of the first intra-board connector 120 and the first chip 110, thereby improving the SI performance of the first circuit board 100.

[0031] In one embodiment, the first intra-board connector 120 and the first flexible cable harness 121 on the first circuit board 100 can be placed on the front or back of the circuit board, or partially on the front and partially on the back. This flexible layout solution can achieve better channel SI performance and cable management.

[0032] In an exemplary embodiment, the pins of the first board edge press-fit connector are press-fitted to the pins of the first circuit board, so that the first board edge press-fit connector is electrically connected to the first circuit board.

[0033] During the actual implementation process, the side of the first board edge press-fit connector 132 that contacts the circuit board adopts a press-fit method to realize a direct connection between the connector pins and the pins of the first circuit board 100, thereby realizing an electrical connection between the first board edge press-fit connector 132 and the first circuit board 100, and then electrically connecting with the pins of the first chip 110 through the first PCB transmission line 101 in the first circuit board 100.

[0034] In an exemplary embodiment, the first board edge connector is fixedly connected to the first circuit board.

[0035] In actual implementation, the first edge-mount connector 131 can be directly fixed to the edge of the first circuit board 100 using screws or other methods. As shown in Figure 1, the first flexible cable harness 121 includes multiple flexible cables. One end of the first flexible cable harness 121 can be soldered to the pins of the first edge-mount connector 131 to achieve an electrical connection. The other end of the first flexible cable harness 121 can be soldered to the pins of the first intra-board connector 120 to achieve an electrical connection, thereby achieving an electrical connection between the first edge-mount connector 131 and the first intra-board connector 120.

[0036] In an exemplary embodiment, the cable backplane device further includes: a first tray configured to carry and install the first circuit board, the first board edge connector, and the flexible cable, and the first board edge connector is fixedly mounted on the first tray.

[0037] Figure 2 is a schematic diagram illustrating the positional relationship between the first tray and the first circuit board according to an embodiment of the present disclosure. As shown in Figure 2 , the first board edge connector 131 can be fixed to the edge of the first tray 300, that is, it does not contact the first circuit board 100. The first tray 300 is a structural component that supports the first circuit board 100, the first board edge connector 131, cables, etc.

[0038] In actual implementation, the first board-edge connector can be directly fixedly connected to the first circuit board, or it can be located outside the first circuit board, for example, on a first tray. The first tray can also support flexible cables, thereby reducing the area of ​​the first circuit board. Furthermore, the first circuit board can also be mounted on the first tray. In actual implementation, each first circuit board can correspond to a first tray to meet different application scenarios and functional requirements.

[0039] In one embodiment, the board-edge connector can be fixed to the edge of the tray, without contacting the circuit board. Electrical connection to the circuit board is achieved via a cable, which can reduce the size of the circuit board. This not only reduces the size of the board (circuit board) and saves costs, but also solves problems caused by oversized boards in some systems.

[0040] In an exemplary embodiment, one end of the flexible cable is soldered to the pins of the first board edge connector, and the other end of the flexible cable is soldered to the pins of the first intra-board connector.

[0041] As shown in FIG1 , the second circuit board includes at least the following components: a second chip 210, a second board-edge press-fit connector 232, a second board-edge straight-out connector 231, a second intra-board connector 220, a second PCB transmission line 201, and a second flexible cable harness 221. The second intra-board connector 220 is electrically connected to the second circuit board 200.

[0042] During actual implementation, the end of the second on-board connector 220 electrically connected to the second circuit board 200 can be set close to the second chip 210, so that the on-board wiring interconnecting the pins of the second on-board connector 220 and the second chip 210 can be shortened to a large extent, thereby improving the SI performance of the second circuit board 200.

[0043] In one embodiment, the second intra-board connector 220 and the second cable harness 221 on the second circuit board 200 can be placed on the front or back of the circuit board, or partially on the front and partially on the back. This flexible layout solution can achieve better channel SI performance and cable management.

[0044] In an exemplary embodiment, the second board edge connector includes a second board edge press-fit connector, and the second circuit board includes a second chip; the second board edge press-fit connector is electrically connected to the second chip via a PCB transmission line.

[0045] In actual implementation, the second board edge press-fit connector 232 is electrically connected to the second circuit board 200 and the second chip 210 .

[0046] In an exemplary embodiment, the second board edge connector also includes a second board edge straight-out connector, and the second circuit board also includes a second intra-board connector; the second board edge straight-out connector is electrically connected to the second intra-board connector through a flexible cable, and the second intra-board connector is electrically connected to the second chip.

[0047] In actual implementation, the second intra-board connector is electrically connected to the second chip by interconnecting the second intra-board connector with the second circuit board through pins, and then electrically connecting the second intra-board connector with the pins of the second chip through the PCB transmission lines within the board.

[0048] In actual implementation, when the first circuit board includes a first board edge crimp connector and a first board edge straight-out connector, for the cable backplane device provided in the embodiment of the present disclosure, the second board edge connector of the second circuit board may include one of the second board edge crimp connector and the second board edge straight-out connector, or both.

[0049] In an exemplary embodiment, the pins of the second board-edge press-fit connector are press-fitted to the pins of the second circuit board, thereby electrically connecting the second board-edge press-fit connector to the second circuit board. In actual implementation, as shown in Figure 1, the second board-edge straight-out connector 231 can be fixed to the edge of the second circuit board 200. The second board-edge straight-out connector 231 is electrically connected to the second on-board connector 120 via the second flexible cable harness 221.

[0050] In an exemplary embodiment, the cable backplane device further includes: a second tray configured to carry and install the second circuit board, the second board edge connector, and the flexible cable, and the second board edge connector is fixedly mounted on the second tray.

[0051] Figure 3 is a schematic diagram illustrating the positional relationship between the second tray and the second circuit board according to an embodiment of the present disclosure. As shown in Figure 3, the second board edge connector 231 can be fixed to the side of the second tray 400 without contacting the second circuit board 200. The second tray 400 is a structural component that supports the second circuit board 200, the second board edge connector 231, cables, etc.

[0052] In the embodiment of the present disclosure, the number of first circuit boards 100 may be at least one, and the number of second circuit boards 200 may also be at least one. FIG4 is a schematic diagram of a one-to-many circuit board interconnection according to an embodiment of the present disclosure, and FIG5 is a schematic diagram of a many-to-many circuit board interconnection according to an embodiment of the present disclosure. The orthogonal system architecture of the embodiment of the present application is applicable to one-to-one circuit board interconnection, one-to-many circuit board interconnection as shown in FIG4, and many-to-many circuit board interconnection as shown in FIG5.

[0053] In the above embodiments, whether it is a one-to-one circuit board interconnection, a one-to-many circuit board interconnection, or a many-to-many circuit board interconnection, the first circuit board 100 and the second circuit board 200 are vertically plugged in and interconnected, and the vertical plug-in interconnection between the first circuit board 100 and the second circuit board 200 is achieved through a connector.

[0054] In one embodiment, the first board edge crimp connector 132 can be plugged into the second board edge crimp connector 232 or the second board edge straight-out connector 231, and the first board edge straight-out connector 131 can also be plugged into the second board edge crimp connector 232 or the second board edge straight-out connector 231.

[0055] In one embodiment, the number of first board edge crimp connectors 132 and first board edge straight-out connectors 131 on the first circuit board 100 is not necessarily the same. Similarly, the number of second board edge crimp connectors 232 and second board edge straight-out connectors 231 on the second circuit board 200 is not necessarily the same.

[0056] In one embodiment, the first circuit board 100 utilizes both a first board-edge press-fit connector 132 and a first board-edge direct-connector 131, while the second circuit board 200 also utilizes both a second board-edge press-fit connector 232 and a second board-edge direct-connector 231. Alternatively, the first circuit board 100 utilizes both the first board-edge press-fit connector 132 and the first board-edge direct-connector 131, while the second circuit board 200 utilizes only one of the second board-edge press-fit connector 232 or the second board-edge direct-connector 231. Alternatively, the second circuit board 200 utilizes both the second board-edge press-fit connector 232 and the second board-edge direct-connector 231, while the first circuit board 100 utilizes only one of the first board-edge press-fit connector 132 or the first board-edge direct-connector 131. Specifically, in a pair of orthogonally pluggable boards, such as the first circuit board 100 and the second circuit board 200, at least one of the boards includes both board-edge connectors, meaning that the board includes both PCB and cable channel types.

[0057] The cable backplane device provided by the embodiments of the present disclosure can also be used in traditional backplane architectures. FIG6 is a schematic diagram illustrating the positional relationship of the cable backplane device according to the embodiments of the present disclosure in a backplane architecture. As shown in FIG6 , the first circuit board 100 is connected to the backplane connector 020 on the center backplane 010 via the board-edge press-fit connector 132 and the board-edge direct-connector 131, thereby vertically plugging and electrically connecting the first circuit board 100 to the center backplane 010. Similarly, the second circuit board 200 is connected to the backplane connector 020 of the center backplane 010 via the board-edge connector, thereby vertically plugging and electrically connecting the second circuit board 200 to the center backplane 010. Signals on the first and second circuit boards 100, 200 are then interconnected via PCB transmission lines within the center backplane 010. In actual implementation, there may be multiple first and second circuit boards 100, 200, with at least one circuit board containing both press-fit and direct-connect cable edge connectors, i.e., the circuit board contains both PCB and cable channel types.

[0058] In the actual implementation process, in any possible backplane architecture, applications in which only PCB transmission lines can be used inside the daughter card board (circuit board) or cables can be used for high-speed signal transmission, thereby reducing link loss and improving SI performance, or reducing the size of the board to meet system requirements, or reducing the board grade and saving system costs, etc., all fall within the scope of protection of the embodiments of the present disclosure.

[0059] In summary, the cable backplane device provided by the embodiment of the present disclosure, compared to existing backplane systems, uses both board-edge crimp connectors and straight-out cable connectors on at least one board. That is, a portion of the high-speed signal is transmitted through the PCB transmission line within the board, and a portion is transmitted through the cable. Since the cable loss is significantly better than the PCB transmission line, it can not only improve the high-speed channel SI performance and reduce the PCB channel loss pressure, but also reduce the board grade, reduce the size of the board, and even reduce the number of routing layers, thereby reducing costs. In addition, compared to traditional cable backplanes, the cable solution used by the cable backplane device of the embodiment of the present disclosure only exists within each board, and the number only covers a portion of the high-speed signals on the board, so cable management is relatively simple.

[0060] The present disclosure provides a cable backplane device adapted for communication system network equipment, such as routers, data center switches, etc., as a board-level interconnection architecture for realizing inter-board signal transmission. Network equipment generally includes a control unit, an interface processing unit, a switching / forwarding unit, etc. These units are connected to each other through a service bus for communication, ensuring that the messages coming from the interface processing unit can be exchanged internally to other ports. In one embodiment, the interface processing unit can be set on the backplane, and then the interconnection between the various units is realized through the backplane, that is, the backplane is used as a resource pool.

[0061] The cable backplane device provided by the embodiment of the present disclosure adopts an orthogonal system architecture without a backplane to achieve vertical insertion of a first circuit board and a second circuit board. Compared with the orthogonal system architecture with a backplane, this reduces a set of inter-board connectors, reduces the insertion loss of the system, avoids signal loss in the wiring on the backplane, and improves the high-speed performance of the system. The first circuit board and the first board edge straight-out connector are electrically connected through a first intra-board connector and a first flexible cable bundle. Compared with transmitting signals through PCB transmission lines on a single board, the cable has better high-speed performance, lower signal loss, and fewer PCB transmission lines within the circuit board. At the same time, it can reduce the circuit board material or reduce the circuit board size, reducing system costs.

[0062] The above description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will appreciate that various modifications and variations of the present disclosure are possible. Any modifications, equivalent substitutions, or improvements made within the principles of the present disclosure should be included within the scope of protection of the present disclosure.

Claims

1. A cable backplane device, comprising: at least one first circuit board and at least one second circuit board, wherein: The first circuit board includes a first board edge connector, a first chip, and a first in-board connector; the second circuit board includes a second board edge connector; the first board edge connector includes a first board edge crimping connector and a first board edge straight-out connector; The first board edge connector and the second board edge connector are pluggable and connected, so that the first circuit board and the second circuit board are vertically plugged and interconnected; The first board edge crimping connector is electrically connected to the first chip through a printed circuit board PCB transmission line, the first board edge straight-out connector is electrically connected to the first on-board connector through a flexible cable, and the first on-board connector is electrically connected to the first chip.

2. The cable backplane device according to claim 1, wherein: The second board edge connector includes a second board edge crimp connector, and the second circuit board includes a second chip; The second board edge crimp connector is electrically connected to the second chip via a PCB transmission line.

3. The cable backplane device according to claim 2, wherein: The second board edge connector further includes a second board edge straight-out connector, and the second circuit board further includes a second in-board connector; The second board edge connector is electrically connected to the second in-board connector via a flexible cable, and the second in-board connector is electrically connected to the second chip.

4. The cable backplane device according to claim 1, wherein: The first intra-board connector is fixedly mounted on the first circuit board by means of crimping or spring connection, and is electrically connected to the first circuit board.

5. The cable backplane device according to claim 1, wherein: The pins of the first board edge crimping connector are crimped to the pins of the first circuit board, so that the first board edge crimping connector is electrically connected to the first circuit board.

6. The cable backplane device according to claim 1, wherein: The first board edge connector is fixedly connected to the first circuit board.

7. The cable backplane device according to claim 1, wherein: The cable backplane device also includes: The first tray is configured to carry and install the first circuit board, the first board edge connector, and the flexible cable, and the first board edge connector is fixedly installed on the first tray.

8. The cable backplane device according to claim 2, wherein: The pins of the second board edge crimping connector are crimped to the pins of the second circuit board, so that the second board edge crimping connector is electrically connected to the second circuit board.

9. The cable backplane device according to claim 3, wherein: The cable backplane device also includes: The second tray is configured to carry and install the second circuit board, the second board edge connector, and the flexible cable, and the second board edge connector is fixedly installed on the second tray.

10. The cable backplane device according to claim 1, wherein: One end of the flexible cable is welded to a pin of the first board edge connector, and the other end of the flexible cable is welded to a pin of the first board inner connector.

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