Computing device and circuit board

Abstract

The embodiment of the present application provides a kind of computing device and circuit board.The computing device includes housing, first circuit board and second circuit board, first circuit board is connected with housing;Second circuit board includes first rigid part, flexible part and second rigid part, first rigid part, flexible part and at least part of second rigid part are arranged along the height direction of housing and are sequentially connected, first rigid part is connected with first circuit board, and second rigid part is connected with housing.The computing device provided by the embodiment of the present application can have better compatibility and maintainability.

Description

Technical Field

[0001] This application relates to the field of computing technology, and more particularly to a computing device and a circuit board. Background Technology

[0002] With the rapid development of big data, cloud computing, and artificial intelligence (AI), the demand for computing performance from servers has increased dramatically.

[0003] Servers consist of a motherboard and expansion cards, which can be riser cards, hard drives, or network cards, and are electrically connected to the motherboard. Expansion cards and motherboards can be electrically connected via connectors. However, when the thickness of the server motherboard changes, expansion cards become difficult to adapt to different motherboards, resulting in poor compatibility. Expansion cards can also be electrically connected to the motherboard via cables. When the thickness of the server motherboard changes, the cable length can be adjusted to allow the expansion card to be adapted to different motherboards, resulting in higher compatibility. However, cables present challenges in assembly and maintenance, making maintenance difficult. Furthermore, the large wire diameter of cables can obstruct airflow, leading to poor heat dissipation in the computing device.

[0004] In related technologies, computing devices struggle to achieve both good compatibility and maintainability. Utility Model Content

[0005] This application provides a computing device and a circuit board, which can have both good compatibility and maintainability.

[0006] In a first aspect, embodiments of this application provide a computing device, including a housing, a first circuit board, and a second circuit board. The first circuit board is connected to the housing. The second circuit board includes a first rigid part, a flexible part, and a second rigid part. The first rigid part, the flexible part, and at least a portion of the second rigid part are arranged along the height direction of the housing and connected in sequence. The first rigid part is connected to the first circuit board, and the second rigid part is connected to the housing.

[0007] The computing device provided in this application embodiment comprises a housing, a first circuit board, and a second circuit board. The first circuit board is connected to the housing, and the housing provides support for the first circuit board. The second circuit board includes a first rigid part, a flexible part, and a second rigid part. The first rigid part, the flexible part, and the second rigid part are arranged along the height direction of the housing and connected sequentially. The first rigid part is connected to the first circuit board, and the second rigid part is connected to the housing. The flexible part can be bent. When the thickness of the first circuit board changes, the degree of bending of the flexible part is changed, thereby changing the distance between the first rigid part and the first circuit board to adapt to first circuit boards of different thicknesses, enabling the computing device to have good compatibility. When assembling the second circuit board and the first circuit board, the first rigid part is simply connected to the first circuit board, making the assembly and maintenance of the first and second circuit boards relatively simple.

[0008] In one possible implementation, the computing device provided in this application includes a second circuit board comprising a flexible layer and a rigid layer. The flexible layer includes a central flexible segment and a first flexible segment and a second flexible segment located on either side of the central flexible segment, the central flexible segment forming a flexible portion. The first rigid portion includes a first flexible segment and a rigid layer laminated on both sides of the first flexible segment. The second rigid portion includes a second flexible segment and a rigid layer laminated on both sides of the second flexible segment. The flexible layer extends through the first rigid portion, the flexible portion, and the second rigid portion. The areas where the flexible portion connects to the first rigid portion and the second rigid portion do not require insertion or soldering, resulting in lower signal transmission loss.

[0009] In one possible implementation, the computing device provided in this application embodiment has a flexible layer comprising multiple alternating layers of a first conductive layer and a flexible dielectric layer; and a rigid layer comprising multiple alternating layers of a second conductive layer and a rigid dielectric layer; the dielectric constant of the flexible dielectric layer is less than that of the rigid dielectric layer, and the loss factor of the flexible dielectric layer is less than that of the rigid dielectric layer. Therefore, the signal transmission loss in the flexible layer is less than the signal transmission loss in the rigid layer, resulting in lower signal transmission loss while maintaining a lower cost for the second circuit board.

[0010] In one possible implementation, the computing device provided in this application embodiment has a rigid dielectric layer substrate comprising glass fiber cloth and resin impregnated in the glass fiber cloth, and / or a flexible dielectric layer substrate comprising polytetrafluoroethylene.

[0011] In one possible implementation, the computing device provided in this application embodiment has a second circuit board with a first via and a second via. The first via passes through a first flexible segment and a rigid layer corresponding to the first flexible segment, and the second via passes through a second flexible segment and a rigid layer corresponding to the second flexible segment. Since the rigid layer is laminated on both sides of the flexible layer, the number of layers of the second circuit board through which the first and second vias pass is relatively small, making the processing of the second circuit board simpler.

[0012] In one possible implementation, the computing device provided in this application includes a first flexible dielectric layer and a second flexible dielectric layer. The first flexible dielectric layer is located in the middle region along the stacking direction of the flexible layers; the second flexible dielectric layer is located on both sides of the first flexible dielectric layer along the stacking direction of the flexible layers. The dielectric constant of the first flexible dielectric layer is smaller than that of the second flexible dielectric layer, and the loss factor of the first flexible dielectric layer is smaller than that of the second flexible dielectric layer. This further reduces the cost of the second circuit board, and when a signal is transmitted from the rigid layer to the flexible layer along the first or second via, the loss factor increases in a stepwise manner, and the dielectric constant also increases in a stepwise manner, avoiding interference from abrupt changes in the dielectric constant and loss factor on signal transmission.

[0013] In one possible implementation, the computing device provided in this application embodiment has a first flexible dielectric layer substrate comprising polytetrafluoroethylene and a second flexible dielectric layer substrate comprising polyimide.

[0014] In one possible implementation, the computing device provided in this application embodiment has a second rigid part connected to a housing, and the position of the second rigid part relative to the housing along the height direction is changeable. Therefore, the second circuit board can be compatible with more first circuit boards of varying thicknesses, further increasing the compatibility of the computing device.

[0015] In one possible implementation, the computing device provided in this application further includes multiple function cards. Each function card has a first connector, and a second rigid portion has multiple second connectors, with the first and second connectors corresponding to each other. The first rigid portion has a third connector, and a first circuit board has a fourth connector, with the third and fourth connectors interlocking. Therefore, the flexible portion does not affect the electrical connection between the second circuit board and other circuit boards, simplifying the assembly and maintenance of the computing device.

[0016] Secondly, embodiments of this application provide a circuit board, which is the second circuit board described above. The circuit board includes a first rigid part, a flexible part, and a second rigid part, and the first rigid part, the flexible part, and at least a portion of the second rigid part are connected in sequence.

[0017] Thirdly, embodiments of this application provide a circuit board including a flexible layer and a rigid layer laminated on both sides of the flexible layer, wherein the dielectric constant of the flexible layer is less than the dielectric constant of the rigid layer, and the loss factor of the flexible layer is less than the loss factor of the rigid layer. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a computing device provided in an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the structure of the motherboard module in the computing device provided in the embodiments of this application;

[0020] Figure 3 This is a schematic diagram of the structure of a function card module in a computing device provided in an embodiment of this application;

[0021] Figure 4 This is an exploded view of a function card module in a computing device provided in an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the structure of the second circuit board in the computing device provided in the embodiments of this application;

[0023] Figure 6 This is a schematic diagram of the connection between the first circuit board and the second circuit board in a computing device provided in an embodiment of this application;

[0024] Figure 7 A cross-sectional schematic diagram of the second circuit board in a computing device provided in an embodiment of this application;

[0025] Figure 8 This is another cross-sectional schematic diagram of the second circuit board in the computing device provided in the embodiments of this application;

[0026] Figure 9 Another cross-sectional schematic diagram of the second circuit board in the computing device provided in the embodiments of this application;

[0027] Figure 10 Impedance curve of the second circuit board in the computing device provided in the embodiments of this application.

[0028] Explanation of reference numerals in the attached figures:

[0029] 10-Computing devices;

[0030] 100 - Housing;

[0031] 110 - Bottom shell;

[0032] 111-Base plate;

[0033] 112-Side panel; 1121-First side panel; 1122-Second side panel; 1123-Third side panel; 1124-Fourth side panel;

[0034] 200-Hard disk module;

[0035] 300-fan module;

[0036] 310-Fan;

[0037] 400-Motherboard Module;

[0038] 410 - First circuit board; 411 - Fourth connector; 420 - Processor; 430 - Memory; 440 - Heatsink;

[0039] 500-Function Card Module;

[0040] 510 - Function card; 511 - First connector;

[0041] 520 - Second circuit board; 520a - First mounting hole;

[0042] 521 - Second connector; 522 - Third connector; 523 - First rigid part; 524 - Flexible part;

[0043] 525 - Second rigid part; 5251 - Rigid part body; 5252 - Extension part;

[0044] 526 - Flexible layer; 526a - Intermediate flexible segment; 526b - First flexible segment; 526c - Second flexible segment;

[0045] 5261 - First conductive layer; 5262 - Flexible dielectric layer; 5262a - First flexible dielectric layer; 5262b - Second flexible dielectric layer;

[0046] 527 - Rigid layer; 5271 - Second conductive layer; 5272 - Rigid dielectric layer;

[0047] 5281 - First via; 5282 - Second via;

[0048] 530 - Mounting bracket; 531 - Bottom wall; 532 - Side wall; 532a - Second mounting hole;

[0049] L - Stacking direction; X - Length direction; Y - Width direction; Z - Height direction. Detailed Implementation

[0050] The terminology used in the implementation section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. The implementation of the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0051] This application provides a computing device that can have both good compatibility and maintainability.

[0052] The computing device can be a server, such as a high-density server, tower server, or rack server. Among them, rack servers can be configured with different function cards according to different needs, which has the advantages of high flexibility and wide applicability.

[0053] The following section uses a rack server as an example to illustrate the specific structure of the computing device 10.

[0054] Figure 1 A schematic diagram of the structure of a computing device provided in an embodiment of this application.

[0055] See Figure 1 As shown, the computing device 10 provided in this application includes a housing 100. The housing 100 can be a cuboid structure, and the housing 100 has a length direction X, a width direction Y, and a height direction Z.

[0056] The housing 100 may include a bottom shell 110 and a top cover (not shown in the figure). The bottom shell 110 includes a bottom plate 111 and side plates 112 surrounding the periphery of the bottom plate. The side plates 112 include a first side plate 1121, a second side plate 1122, a third side plate 1123, and a fourth side plate 1124 connected end to end. The four side plates 112 and the bottom plate 111 form a receiving cavity. The first side plate 1121 and the third side plate 1123 are arranged opposite each other along the length direction X, and the second side plate 1122 and the fourth side plate 1124 are arranged opposite each other along the width direction Y.

[0057] The receiving cavity is used to house various components in the computing device 10, such as the hard disk module 200, fan module 300, motherboard module 400, and function card module 500. Figure 1 In the embodiment shown, the hard disk module 200, fan module 300, motherboard module 400 and function card module 500 can be arranged sequentially along the length direction X in the receiving cavity.

[0058] The following describes the various modules in the computing device 10. The motherboard module 400 can be disposed in the middle area of ​​the bottom shell 110 along the length direction X.

[0059] Figure 2 This is a schematic diagram of the structure of the motherboard module in the computing device provided in the embodiments of this application.

[0060] See Figure 2 As shown, the motherboard module 400 includes a first circuit board 410, a processor 420, memory 430, and other electronic components. The first circuit board 410 is the motherboard, and it can be mounted on the base plate 111 of the housing 100 using fasteners. Multiple processors 420 are mounted on the first circuit board 410. Figure 2 The diagram schematically shows two processors 420 arranged along the width direction Y. Each processor 420 has multiple memory modules 430 on both sides along the width direction Y. The memory modules 430 can be arranged at intervals along the width direction Y. The memory modules 430 are electrically connected to the processors 420 through internal traces of the first circuit board 410. A heatsink 440 may also be mounted on the processors 420.

[0061] The specific structure of function card module 500 will be described below. Please continue reading... Figure 1 As shown, the function card module 500 can be disposed at one end near the third side plate 1123 along the length direction X.

[0062] Figure 3 This is a schematic diagram of the structure of a function card module in a computing device provided in an embodiment of this application; Figure 4 This is an exploded view of a function card module in a computing device provided in an embodiment of this application. Figure 3 The mounting bracket 530 is obscured by the function card 510 and the second circuit board 520.

[0063] See Figure 3 and Figure 4 As shown, the function card module 500 includes multiple function cards 510, in Figure 3 and Figure 4 The diagram schematically illustrates two function cards 510, which can be PCIe (Peripheral Component Interconnect Express) cards. The function card module 500 also includes a second circuit board 520, which can be a riser card. Each function card 510 has a first connector 511, and the second circuit board 520 has multiple second connectors 521, which can be arranged along the height direction Z. The second connectors 521 can be connectors or gold fingers. The first connector 511 on each function card 510 plugs into the multiple second connectors 521 on the second circuit board 520, so that all function cards 510 are connected to and electrically connected to the second circuit board 520.

[0064] The second circuit board 520 has a third connector 522, which can be a connector or a gold finger. The first circuit board 410 has a fourth connector 411. Figure 2 The third connector 522 and the fourth connector 411 are inserted into each other, so that the second circuit board 520 is electrically connected to the first circuit board 410, thereby making the multiple function cards 510 electrically connected to the first circuit board 410. The second circuit board 520 is placed vertically along the height direction Z, and the multiple second connectors 521 are arranged at intervals along the height direction Z. When the function cards 510 are inserted into the second circuit board 520, the multiple function cards 510 are arranged along the height direction Z.

[0065] Please continue reading Figure 4As shown, the function card module 500 also includes a mounting bracket 530, which includes a bottom wall 531 and a side wall 532 connected to the bottom wall 531. The bottom wall 531 can be connected to the bottom plate 111 of the housing 100, and the side wall 532 can be connected to the side plate 112 of the housing 100. The second circuit board 520 has a first mounting hole 520a, and the side wall 532 of the mounting bracket 530 has a second mounting hole 532a. Fasteners can be inserted into the first mounting hole 520a and the second mounting hole 532a to connect the second circuit board 520 to the side wall 532 of the mounting bracket 530. Thus, the function card 510 and the second circuit board 520 can be fixed to the housing 100 through the mounting bracket 530.

[0066] Please continue reading Figure 1 As shown, the hard disk module 200 can be positioned along the length direction X at one end near the first side panel 1121. The hard disk module 200 includes multiple hard disks, which are electrically connected to the first circuit board 410. The hard disks are used to store applications and data. A fan module 300 can be positioned between the hard disk module 200 and the motherboard module 400. The fan module 300 can include multiple fans 310, which are arranged along the width direction Y, with the airflow direction of the fans 310 being the length direction X. When the fans 310 are running, they can provide heat dissipation for the hard disk module 200, the motherboard module 400, and the function card module 500.

[0067] In different computing devices 10, the thickness of the first circuit board 410 (i.e., the dimension of the first circuit board 410 along the height direction Z) is different. In this embodiment of the application, a flexible part is provided in the second circuit board 520 so that the second circuit board 520 can be adapted to different first circuit boards 410.

[0068] Figure 5 This is a schematic diagram of the structure of the second circuit board in the computing device provided in the embodiments of this application; Figure 6 This is a schematic diagram of the connection between the first circuit board and the second circuit board in a computing device provided in an embodiment of this application.

[0069] See Figures 3 to 6 As shown, the second circuit board 520 includes a first rigid part 523, a flexible part 524, and a second rigid part 525. The first rigid part 523, the flexible part 524, and at least a portion of the second rigid part 525 are arranged along the height direction Z of the housing 100 and connected in sequence. The first rigid part 523 is connected to the first circuit board 410, and the second rigid part 525 is connected to the housing 100.

[0070] The flexible portion 524 can be a flexible printed circuit board (FPCB), and both the first rigid portion 523 and the second rigid portion 525 can be circuit boards. One end of the flexible portion 524 is electrically connected to the first rigid portion 523. The second rigid portion 525 includes a rigid portion body 5251 and an extension portion 5252. The extension portion 5252 is connected to the rigid portion body 5251 and is arranged along the length direction X with the rigid portion body 5251. The first rigid portion 523, the flexible portion 524, and the rigid portion body 5251 are arranged along the height direction Z. The other end of the flexible portion 524 is electrically connected to the rigid portion body 5251.

[0071] The third connector 522 can be disposed at one end of the first rigid part 523 away from the second rigid part 525. The third connector 522 is electrically connected to the first rigid part 523 and is plugged into the fourth connector 411 on the first circuit board 410.

[0072] A first mounting hole 520a can be provided on the second rigid part 525. Fasteners are inserted into the first mounting hole 520a and the second mounting hole 532a of the mounting bracket 530 to connect the second rigid part 525 to the side wall 532 of the mounting bracket 530. A second connector 521 is provided on the extension 5252 of the second rigid part 525. The first connectors 511 on the plurality of function cards 510 are inserted one-to-one with the second connectors 521 on the second rigid part 525 to electrically connect the plurality of function cards 510 to the second circuit board 520.

[0073] Thus, the function card 510 is electrically connected to the first circuit board 410 in sequence through the second rigid part 525, the flexible part 524 and the first rigid part 523 on the second circuit board 520.

[0074] The dimension of the first circuit board 410 along the height direction Z is the thickness of the first circuit board 410. When the configuration of the computing device 10 is different, the number of layers of the first circuit board 410 is different, resulting in different thicknesses of the first circuit board 410. As a result, the distance between the fourth connector 411 of the first circuit board 410 and the bottom plate 111 of the housing 100 is also different, which also results in different distances between the insertion points of the third connector 522 and the fourth connector 411 on the second circuit board 520 and the bottom plate 111 of the housing 100.

[0075] By providing a flexible portion 524 on the second circuit board 520, the flexible portion 524 can be bent. When the thickness of the first circuit board 410 changes, the degree of bending of the flexible portion 524 is changed, thereby changing the distance between the first rigid portion 523 and the base plate 111 to adapt to first circuit boards 410 of different thicknesses. Thus, the second circuit board 520 can be compatible with first circuit boards 410 of different thicknesses, enabling the computing device 10 to have better compatibility.

[0076] In one possible implementation, the position of the second rigid part 525 relative to the housing 100 along the height direction Z can be changed.

[0077] For example, at least one of the first mounting hole 520a and the second mounting hole 532a can be an elongated hole extending along the height direction Z. When the position of the second rigid part 525 relative to the side wall 532 of the mounting bracket 530 changes along the height direction Z, a portion of the first mounting hole 520a and the second mounting hole 532a can still be aligned. Fasteners are inserted into the first mounting hole 520a and the second mounting hole 532a to connect the second rigid part 525 and the mounting bracket 530.

[0078] Therefore, when the bending amount of the flexible part 524 cannot meet the requirements of the thickness variation of the first circuit board 410, the second rigid part 525 can be moved along the height direction Z to compensate, so that the second circuit board 520 can be compatible with more first circuit boards 410 of different thicknesses, further increasing the compatibility of the computing device 10.

[0079] Compared to setting up a cable to connect the first circuit board and the second circuit board, with both ends of the cable plugged into the first circuit board and the second circuit board respectively, in this embodiment of the application, when assembling the second circuit board 520 and the first circuit board 410, the third connector 522 and the fourth connector 411 can be plugged in, making the assembly and maintenance of the first circuit board 410 and the second circuit board 520 simpler.

[0080] The thickness of the second circuit board 520 is the dimension of the second circuit board 520 along the width direction Y. The thickness of the flexible part 524 is less than or equal to the thickness of the first rigid part 523 or the second rigid part 525 in the second circuit board 520. The flexible part 524 makes the projected area along the first direction X smaller. Compared with the cable, the flexible part 524 has less obstruction to the airflow of the fan 310, which makes the heat dissipation of the computing device 10 better.

[0081] The computing device 10 provided in this application embodiment comprises a housing 100, a first circuit board 410, and a second circuit board 520. The first circuit board 410 is connected to the housing 100, and the housing 100 provides support for the first circuit board 410. The second circuit board 520 includes a first rigid portion 523, a flexible portion 524, and a second rigid portion 525. The first rigid portion 523, the flexible portion 524, and the second rigid portion 525 are arranged along the height direction Z of the housing 100 and connected sequentially. The first rigid portion 523 is connected to the first circuit board 410, and the second rigid portion 525 is connected to the housing 100. The flexible portion 524 can be bent. When the thickness of the first circuit board 410 changes, the bending degree of the flexible portion 524 is changed, thereby changing the distance between the first rigid portion 523 and the first circuit board 410 to adapt to first circuit boards 410 of different thicknesses, so that the computing device 10 can have better compatibility. When assembling the second circuit board 520 with the first circuit board 410, the first rigid part 523 can be connected to the first circuit board 410, making the assembly and maintenance of the first circuit board 410 and the second circuit board 520 relatively simple.

[0082] Figure 7 This is a cross-sectional schematic diagram of the second circuit board in the computing device provided in an embodiment of this application.

[0083] See Figure 7 As shown, in one possible implementation, the second circuit board 520 includes a flexible layer 526 and a rigid layer 527. The flexible layer 526 includes a middle flexible segment 526a and a first flexible segment 526b and a second flexible segment 526c located on both sides of the middle flexible segment 526a. The middle flexible segment 526a forms a flexible portion 524. The first rigid portion 523 includes a first flexible segment 526b and a rigid layer 527 laminated on both sides of the first flexible segment 526b. The second rigid portion 525 includes a second flexible segment 526c and a rigid layer 527 laminated on both sides of the second flexible segment 526c.

[0084] The second circuit board 520 has a multi-layered laminated structure. In this embodiment, the flexible layer 526 is located in the middle region along the lamination direction L, and the rigid layers 527 are located on both sides of the flexible layer 526 along the lamination direction L. The lamination direction L is the thickness direction of the second circuit board 520. In this embodiment, the thickness direction of the second circuit board 520 is consistent with the width direction Y of the housing 100.

[0085] The flexible layer 526 includes a first flexible segment 526b, an intermediate flexible segment 526a, and a second flexible segment 526c. When the second circuit board 520 is assembled in the housing 100, the first flexible segment 526b, the intermediate flexible segment 526a, and the second flexible segment 526c are arranged sequentially along the height direction Z. Among them, the intermediate flexible segment 526a located in the middle region is the aforementioned flexible portion 524.

[0086] A first flexible segment 526b and a rigid layer 527 laminated on both sides of the first flexible segment 526b form a first rigid part 523, and a second flexible segment 526c and a rigid layer 527 laminated on both sides of the second flexible segment 526c form a second rigid part 525.

[0087] In the fabrication of the second circuit board 520, a flexible layer 526 is first fabricated. After determining the area within the flexible layer 526 designated as the flexible portion 524 (the middle flexible segment 526a), this area is then avoided. Next, rigid layers 527 are laminated onto both sides of the flexible layer 526. The rigid layers 527 support and protect the first flexible segment 526b and the second flexible segment 526c. In other words, the fabrication process of the second circuit board 520 is identical to that of existing circuit boards, except for the need to shield the middle flexible segment 526a. Therefore, the fabrication process of the second circuit board 520 is simple.

[0088] The flexible layer 526 penetrates the first rigid portion 523, the flexible portion 524, and the second rigid portion 525. The flexible layer 526 is electrically connected to the rigid layers 527 located on both sides of the flexible layer 526. Thus, the first rigid portion 523, the flexible portion 524, and the second rigid portion 525 can be electrically connected through the flexible layer 526. In the above-mentioned method of using an FPC to electrically connect the first rigid portion 523 and the second rigid portion 525, the FPC is either welded to the first rigid portion 523 and the second rigid portion 525 or plugged in. Plug-in or welded connections result in greater signal loss during transmission in the second circuit board 520. However, in this embodiment, the flexible layer 526 penetrates the first rigid portion 523, the flexible portion 524, and the second rigid portion 525. The areas where the flexible portion 524 connects to the first rigid portion 523 and the areas where the flexible portion 524 connects to the second rigid portion 525 do not require plugging or welding, resulting in less signal loss during transmission.

[0089] Please continue reading Figure 7 As shown, the flexible layer 526 includes multiple alternating layers of a first conductive layer 5261 and a flexible dielectric layer 5262. Figure 7 The diagram schematically illustrates three flexible dielectric layers 5262 and two first conductive layers 5261. The rigid layer 527 comprises multiple alternating layers of second conductive layers 5271 and rigid dielectric layers 5272. Figure 7 In this structure, the rigid layers 527 located on both sides of the flexible layer 526 along the stacking direction L each include two second conductive layers 5271 and two rigid dielectric layers 5272. The dielectric constant of the flexible dielectric layer 5262 is less than that of the rigid dielectric layer 5272, and the loss factor of the flexible dielectric layer 5262 is less than that of the rigid dielectric layer 5272.

[0090] The substrate of the rigid dielectric layer 5272 can be a substrate used in conventional circuit board manufacturing processes. For example, the substrate of the rigid dielectric layer 5272 can be an epoxy fiberglass cloth substrate (FR-4), which includes fiberglass cloth, resin, and additives. The fiberglass cloth provides mechanical strength and dimensional stability, the resin (e.g., epoxy resin) impregnates the fiberglass cloth to provide electrical insulation and adhesion, and the additives give FR-4 flame-retardant properties. The second conductive layer 5271 can be made of a metal with good conductivity (e.g., copper). The second conductive layer 5271 and the rigid dielectric layer 5272 are alternately disposed and laminated to form the rigid layer 527.

[0091] The first conductive layer 5261 and the flexible dielectric layer 5262 are alternately disposed and laminated to form the flexible layer 526. The first conductive layer 5261 may also be made of a metal with good conductivity (e.g., copper). The substrate of the flexible dielectric layer 5262 is flexible, and the first conductive layer 5261 is also flexible, so that the flexible layer 526 can be bent.

[0092] The signal loss α during transmission on a circuit board mainly comes from two parts: one part is conductor loss α. c The other part is the dielectric loss α d , where α=α c +α d .

[0093] Conductor loss α c This refers to the loss generated by the first conductive layer 5261 or the second conductive layer 5271. Conductor loss α c The calculation can be performed using the following formula:

[0094]

[0095] in, Let f be the surface resistance, f be the operating frequency (in Hz), and μ0 = 4π × 10⁻⁶. -7 H / m is the permeability of free space, and σ is the electrical conductivity of a conductor (unit: S / m; the conductivity of copper is approximately 5.8 × 10⁻⁶). 7 S / m), Z0 is the characteristic impedance of the stripline (in Ω), W is the width of the center conductor (in m), and t is the thickness of the center conductor (in m).

[0096] Both the first conductive layer 5261 and the second conductive layer 5271 are made of copper, therefore their losses are similar. Thus, the loss difference between the flexible layer 526 and the rigid layer 527 mainly originates from the flexible dielectric layer 5262 and the rigid dielectric layer 5272.

[0097] Dielectric loss α d The following formula can be used for calculation:

[0098]

[0099] Where, ε r ′ ρ is the relative permittivity of the substrate, tanδ is the loss factor, and c = 3 × 10⁻⁶. 8 m / s is the speed of light, ε r " The dielectric constant is the equivalent relative permittivity. The dielectric constant and loss factor of FR-4 vary depending on the composition, ranging from 3.8 to 4.5, and from 0.005 to 0.025.

[0100] Therefore, by selecting a substrate for the flexible dielectric layer 5262 with a loss factor and dielectric constant both less than FR-4, the signal transmission loss in the flexible layer 526 is reduced compared to the signal transmission loss in the rigid layer 527. Consequently, at the first rigid portion 523 and the second rigid portion 525, high-speed signals are transmitted in the flexible layer 526, while low-speed signals and power supply signals are transmitted in the rigid layer 527. At the flexible portion 524, low-speed signals and power supply signals also converge in the flexible layer 526 for transmission. This results in lower signal transmission loss while maintaining a lower cost for the second circuit board 520.

[0101] In one possible implementation, the substrate of the flexible dielectric layer 5262 comprises polytetrafluoroethylene (PTFE). PTFE is flexible and has good toughness; therefore, using PTFE for the flexible dielectric layer 5262 can reduce the possibility of damage to the flexible portion 524 due to bending. The dielectric constant of PTFE is approximately 2.1, which is less than that of FR-4, and the loss factor of PTFE is approximately 0.004, which is also less than that of FR-4. Therefore, using PTFE to prepare the flexible dielectric layer 5262 results in lower signal transmission loss in the flexible layer 526 while reducing the possibility of damage to the flexible portion 524. It is understood that other additives can also be added to PTFE to prepare the flexible dielectric layer.

[0102] Figure 8 This is another cross-sectional schematic diagram of the second circuit board in the computing device provided in the embodiments of this application.

[0103] See Figure 8As shown, in the computing device 10 where the thickness of the first circuit board 410 remains unchanged but the signal transmission quality requirements are high, the entire body of the second circuit board 520 can be composed of a flexible layer 526 and a rigid layer 527 laminated on both sides of the flexible layer 526. The rigid layer 527 can protect the flexible layer 526, and the substrate of the flexible dielectric layer 5262 of the flexible layer 526 includes polytetrafluoroethylene, which makes the signal transmission loss in the second circuit board 520 smaller.

[0104] Please continue reading Figure 7 As shown, the second circuit board 520 has a first via 5281 and a second via 5282. The first via 5281 passes through the first flexible segment 526b and the rigid layer 527 corresponding to the first flexible segment 526b. The second via 5282 passes through the second flexible segment 526c and the rigid layer 527 corresponding to the second flexible segment 526c.

[0105] A metal layer (e.g., a copper layer) is plated on the inner wall of the first via 5281. The number of first vias 5281 can be set according to the specific requirements of the second circuit board 520. The first via 5281 passes through the first flexible segment 526b and the rigid layer 527 corresponding to the first flexible segment 526b to electrically connect the first conductive layer 5261 in the first flexible segment 526b and the second conductive layer 5271 in the rigid layer 527. The second via 5282 passes through the second flexible segment 526c and the rigid layer 527 corresponding to the second flexible segment 526c to electrically connect the first conductive layer 5261 in the second flexible segment 526c and the second conductive layer 5271 in the rigid layer 527. Thus, signals can be transmitted between the first rigid part 523, the flexible part 524, and the second rigid part 525.

[0106] Since the rigid layer 527 is laminated on both sides of the flexible layer 526, the number of layers of the second circuit board 520 through which the first via 5281 and the second via 5282 pass is relatively small, making the processing of the second circuit board 520 simpler.

[0107] Figure 9 This is another cross-sectional schematic diagram of the second circuit board in the computing device provided in the embodiments of this application.

[0108] See Figure 9As shown, in one possible implementation, the flexible dielectric layer 5262 includes a first flexible dielectric layer 5262a and a second flexible dielectric layer 5262b. The first flexible dielectric layer 5262a is located in the middle region along the stacking direction L of the flexible layers 526; the second flexible dielectric layer 5262b is located on both sides of the first flexible dielectric layer 5262a along the stacking direction L of the flexible layers 526. The dielectric constant of the first flexible dielectric layer 5262a is smaller than the dielectric constant of the second flexible dielectric layer 5262b, and the loss factor of the first flexible dielectric layer 5262a is smaller than the loss factor of the second flexible dielectric layer 5262b.

[0109] The substrate of the first flexible dielectric layer 5262a can be PTFE, and the substrate of the second flexible dielectric layer 5262b can be polyimide (PI). The cost of PI is less than that of PTFE, thereby reducing the cost of the second circuit board 520.

[0110] The dielectric constant of PI is approximately 3.2, falling between that of PTFE (dielectric constant approximately 2.1) and FR-4 (dielectric constant 3.8-4.5). The loss factor of PI is 0.0045, falling between that of PTFE (loss factor 0.004) and FR-4 (loss factor 0.005-0.025). Therefore, when a signal propagates from the rigid layer 527 towards the flexible layer 526 along the first via 5281 or the second via 5282, the loss factor and dielectric constant increase in a stepwise manner, preventing abrupt changes in dielectric constant and loss factor from interfering with signal transmission.

[0111] Figure 10 Impedance curve of the second circuit board in the computing device provided in the embodiments of this application.

[0112] See Figure 10 As shown, the horizontal axis represents frequency, and the vertical axis represents loss value. The two curves show the loss as a function of frequency when the second flexible dielectric layer 5262b uses two different types of polyimide. The two types of polyimide are PP_S9GN2 and PP_S10GQ. It can be seen that at a frequency of 28GHz, the loss of polyimide of type PP_S9GN2 is 0.526dB, and the loss of polyimide of type PP_S10GQ is 0.505dB. Compared with the commonly used substrates in related technologies, which have a loss of 0.9dB at 28GHz, the loss is relatively small.

[0113] It is understood that the second circuit board 520 provided in this application embodiment can also be other circuit boards in the computing device 10, such as network cards or hard drives. When the second circuit board 520 is connected to other circuit boards in the computing device 10, the second circuit board 520 can be adapted to circuit boards of different thicknesses connected to it because of the flexible part 524 provided in the second circuit board 520.

[0114] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A computing device, characterized in that, include: case; A first circuit board, which is connected to the housing; The second circuit board includes a first rigid part, a flexible part, and a second rigid part. The first rigid part, the flexible part, and at least a portion of the second rigid part are arranged along the height direction of the housing and connected in sequence. The first rigid part is connected to the first circuit board, and the second rigid part is connected to the housing.

2. The computing device according to claim 1, characterized in that, The second circuit board includes a flexible layer and a rigid layer. The flexible layer includes a central flexible segment and a first flexible segment and a second flexible segment located on both sides of the central flexible segment. The central flexible segment forms the flexible portion. The first rigid portion includes a first flexible segment and rigid layers laminated on both sides of the first flexible segment; The second rigid portion includes a second flexible segment and the rigid layer laminated on both sides of the second flexible segment.

3. The computing device according to claim 2, characterized in that, The flexible layer includes multiple alternating layers of a first conductive layer and a flexible dielectric layer; The rigid layer comprises multiple alternating layers of a second conductive layer and a rigid dielectric layer; The dielectric constant of the flexible dielectric layer is less than that of the rigid dielectric layer, and the loss factor of the flexible dielectric layer is less than that of the rigid dielectric layer.

4. The computing device according to claim 3, characterized in that, The substrate of the rigid dielectric layer includes fiberglass cloth and resin impregnated in the fiberglass cloth, and / or the substrate of the flexible dielectric layer includes polytetrafluoroethylene.

5. The computing device according to claim 2, characterized in that, The second circuit board has a first via and a second via. The first via passes through the first flexible segment and the rigid layer corresponding to the first flexible segment, and the second via passes through the second flexible segment and the rigid layer corresponding to the second flexible segment.

6. The computing device according to claim 3 or 4, characterized in that, The flexible dielectric layer includes a first flexible dielectric layer and a second flexible dielectric layer. The first flexible dielectric layer is located in the middle region along the stacking direction of the flexible layer. The second flexible dielectric layer is located on both sides of the first flexible dielectric layer along the stacking direction of the flexible layer. The dielectric constant of the first flexible dielectric layer is less than that of the second flexible dielectric layer, and the loss factor of the first flexible dielectric layer is less than that of the second flexible dielectric layer.

7. The computing device according to claim 6, characterized in that, The substrate of the first flexible dielectric layer includes polytetrafluoroethylene, and the substrate of the second flexible dielectric layer includes polyimide.

8. The computing device according to any one of claims 1 to 5, characterized in that, The second rigid part is connected to the housing, and the position of the second rigid part relative to the housing along the height direction is changeable.

9. The computing device according to claim 8, characterized in that, The computing device also includes multiple function cards, each function card having a first connector and the second rigid part having multiple second connectors, with the first connector and the second connector being connected in a one-to-one correspondence. The first rigid part has a third connector, and the first circuit board has a fourth connector, wherein the third connector is plugged into the fourth connector.

10. A circuit board, characterized in that, The circuit board is a second circuit board as described in any one of claims 1 to 9, the circuit board comprising a first rigid portion, a flexible portion and a second rigid portion, wherein the first rigid portion, the flexible portion and at least a portion of the second rigid portion are connected in sequence.

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