Substrate assembly

Abstract

A substrate assembly according to the present invention comprises: a substrate (10) which has a first surface (10a) facing a first direction and a second surface (10b) facing the direction opposite to the first direction on the reverse side of the first surface, and to which an optical transceiver (30) is fixed, the optical transceiver having a first electrical interface (31a1) and a heat dissipation section (31a2) and being fixed to the substrate with the first electrical interface and the heat dissipation section facing the direction opposite to the first direction and arranged in a direction intersecting the first direction; and a first heat dissipation mechanism (50) which is fixed to the substrate and has a first portion (51a) that is adjacent to the heat dissipation section in the first direction and thermally connected to the heat dissipation section when the optical transceiver is fixed to the substrate, wherein a heat conductive member (47) is interposed between the heat dissipation section and the first portion.

Description

Board Assembly

[0001] The present invention relates to a substrate assembly.

[0002] 2. Description of the Related Art Conventionally, a small optical transceiver described in Patent Document 1 is known as an optical transceiver used in a network switching device (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-27147

[0004] In a network switch device that realizes co-packaged optics (CPO), a switch application specific integrated circuit (ASIC) and a plurality of optical transceivers are mounted on a board.

[0005] As communication traffic increases, in this type of network switch device, not only the amount of heat generated by the switch ASIC but also the amount of heat generated by the optical transceiver tends to increase.

[0006] Therefore, one of the objects of the present invention is to provide an improved new board assembly, for example, as a board assembly including a board on which an optical transceiver is mounted, which enables more efficient heat dissipation from the optical transceiver.

[0007] The substrate assembly of the present invention comprises a substrate having a first surface facing a first direction and a second surface opposite to the first surface facing the opposite direction to the first direction, and having an optical transceiver fixed thereto, the optical transceiver having a first electrical interface and a heat dissipation portion, and being fixed to the substrate with the first electrical interface and the heat dissipation portion facing the opposite direction to the first direction and aligned in a direction intersecting the first direction; and a first heat dissipation mechanism fixed to the substrate, the first portion being adjacent to the heat dissipation portion in the first direction and thermally connected to the heat dissipation portion when the optical transceiver is fixed to the substrate, and a thermally conductive member being interposed between the heat dissipation portion and the first portion.

[0008] In the substrate assembly, a housing portion for housing the thermally conductive member may be provided between the heat dissipation portion and the first portion.

[0009] In the substrate assembly, the thermally conductive member may be interposed in a state of contact with both the heat dissipation portion and the first portion.

[0010] In the substrate assembly, a housing portion for housing the thermally conductive member may be provided between the heat dissipation portion and the first portion, and the height of the housing portion may be smaller than the thickness of the thermally conductive member in an uncompressed state.

[0011] In the substrate assembly, the thermally conductive member may include a synthetic resin material and be flexible.

[0012] In the substrate assembly, the optical transceiver may have a body fixed to the substrate and having the first portion, and a plurality of optical fibers may extend from the body on the side opposite the heat dissipation portion.

[0013] In the substrate assembly, the first heat dissipation mechanism may have a second portion adjacent to the first portion and aligned with the substrate in a direction intersecting the first direction.

[0014] In the substrate assembly, the first heat dissipation mechanism may have a third portion adjacent to the first portion and penetrating the substrate in the first direction.

[0015] In the substrate assembly, the third portion may be provided on the substrate.

[0016] In the substrate assembly, the third portion may be provided separately from the substrate.

[0017] In the substrate assembly, the first heat dissipation mechanism may include a heat transport mechanism that transports heat by a coolant.

[0018] In the substrate assembly, the first heat dissipation mechanism may include a heat sink.

[0019] The substrate assembly may have a semiconductor integrated circuit mounted on the first surface.

[0020] In the substrate assembly, the semiconductor integrated circuit may be provided with a second heat dissipation mechanism on the opposite side of the substrate when the semiconductor integrated circuit is mounted on the substrate.

[0021] In the substrate assembly, the optical transceiver may be fixed to the substrate with the heat dissipation portion located on the opposite side of the first electrical interface from the semiconductor integrated circuit.

[0022] The board assembly may be configured such that a plurality of optical transceivers can be fixed to the board as the optical transceiver.

[0023] In the substrate assembly, the optical transceivers may be arranged along a side of the substrate.

[0024] In the substrate assembly, the multiple optical transceivers may be arranged along four sides of the substrate, and a semiconductor integrated circuit may be mounted on the first surface at a position farther from each of the sides than the optical transceivers.

[0025] The board assembly may include a fixing mechanism for fixing the optical transceiver to the board.

[0026] In the substrate assembly, the fixing mechanism may be shared by a plurality of optical transceivers as the optical transceiver.

[0027] In the board assembly, the fixing mechanism may detachably fix the optical transceiver to the board.

[0028] In the substrate assembly, the fixing mechanism may include a first member fixed to the substrate and a second member removably fixed to the first member and pressing the optical transceiver toward the substrate.

[0029] In the substrate assembly, the optical transceiver may have a body fixed to the substrate and having the first portion, a plurality of optical fibers extending from the side of the body opposite the heat dissipation portion, and the second member may have openings through which the optical fibers pass.

[0030] The substrate assembly may include a second electrical interface fixed to the substrate and electrically connected to the first electrical interface, and a positioning mechanism for positioning the first electrical interface and the second electrical interface.

[0031] The board assembly may include a socket attached to the board and having a second electrical interface electrically connected to the first electrical interface.

[0032] The substrate assembly may include a flexible thermally conductive member between the first portion and the heat dissipation portion.

[0033] The substrate assembly may be mounted on an integrated substrate capable of mounting a plurality of the substrate assemblies.

[0034] According to the present invention, for example, a new and improved substrate assembly can be provided that allows for more efficient heat dissipation from an optical transceiver.

[0035] FIG. 1 is an exemplary and schematic perspective view of a switch device according to a first embodiment. FIG. 2 is an exemplary and schematic plan view of the switch device according to the first embodiment. FIG. 3 is an exemplary and schematic side view of a portion of the switch device according to the first embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. FIG. 5 is an exemplary and schematic plan view of a portion of the switch device according to the first embodiment, illustrating a state before an optical transceiver is mounted, a state after the optical transceiver is mounted, and a state after the optical transceiver is attached. FIG. 6 is an exemplary and schematic cross-sectional view of a portion of a switch device according to a second embodiment. FIG. 7 is an enlarged view of part VII of FIG. 6, illustrating a state before assembly. FIG. 8 is an enlarged view of part VII of FIG. 6, illustrating a state after assembly. FIG. 9 is an exemplary and schematic cross-sectional view of a portion of a switch device according to a third embodiment. FIG. 10 is an exemplary and schematic cross-sectional view of a portion of a switch device according to a fourth embodiment. FIG. 11 is an enlarged cross-sectional view of a modified example of the embodiment, taken at a position equivalent to part VII of FIG. 6, illustrating a state after assembly. Fig. 12 is an enlarged cross-sectional view of a modification different from Fig. 11 of the embodiment at a position equivalent to part VII of Fig. 6, showing a state after assembly. Fig. 13 is an exemplary and schematic perspective view of a switch device of a fifth embodiment. Fig. 14 is an exemplary and schematic plan view of the switch device of the fifth embodiment. Fig. 15 is an exemplary and schematic side view of the switch device of the fifth embodiment. Fig. 16 is an exemplary and schematic cross-sectional view of a portion of the switch device of a sixth embodiment.

[0036] Hereinafter, several exemplary embodiments of the present invention will be disclosed. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by these configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0037] The following embodiments have similar configurations. Therefore, according to the configurations of each embodiment, similar actions and effects based on the similar configurations can be obtained. Furthermore, in the following, similar configurations are given similar reference numerals, and duplicated descriptions may be omitted.

[0038] In each drawing, an arrow X indicates the X direction, an arrow Y indicates the Y direction, and an arrow Z indicates the Z direction. The X direction, Y direction, and Z direction intersect with each other and are perpendicular to each other.

[0039] [First embodiment] Fig. 1 is a perspective view of a switch device 100A (100) according to a first embodiment. Fig. 2 is a plan view of the switch device 100. Fig. 3 is a side view of a portion of the switch device 100 as viewed in the Y direction as indicated by arrow III in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2.

[0040] 1, the switch device 100 is mounted on a motherboard 200. In this embodiment, only one switch device 100 is mounted on the motherboard 200, but multiple switch devices 100 may be mounted on the motherboard 200. The motherboard 200 is an example of an integrated board.

[0041] 1 and 2 , the switch device 100 includes a substrate 10, a switch ASIC 20, a plurality of optical transceivers 30, a heat sink 21 for the switch ASIC 20, a fixing mechanism 40 for fixing the optical transceivers 30 to the substrate 10, and a heat dissipation mechanism 50 for the optical transceivers 30. Of the components of the switch device 100, the substrate 10, the fixing mechanism 40, and the heat dissipation mechanism 50 are referred to as a substrate assembly. The substrate assembly can be mounted on a motherboard 200.

[0042] As shown in FIG. 2, the substrate 10 has a square (quadrilateral) shape. Also, as shown in FIG. 4, the substrate 10 has a plate-like shape that intersects with the Z direction and extends perpendicularly thereto, and includes a surface 10a facing the Z direction and a surface 10b opposite the surface 10a and facing in the opposite direction of the Z direction. The surfaces 10a and 10b intersect with the Z direction and extend perpendicularly thereto. The substrate 10 is, for example, a printed wiring board. The Z direction is an example of a first direction of the substrate 10 and may also be referred to as the thickness direction of the substrate 10. The surface 10a is an example of a first surface, and the surface 10b is an example of a second surface.

[0043] Each of the optical transceivers 30 shown in FIGS. 1 to 4 receives an optical signal transmitted through an optical fiber 32 and outputs an electrical signal corresponding to the optical signal. The electrical signal output from the optical transceiver 30 is input to the switch ASIC 20 via a socket 43 (see FIG. 4) and conductors provided on the substrate 10. The optical transceiver 30 includes a photodiode array (not shown) as a plurality of light-receiving units for receiving the optical signal. Each of the optical transceivers 30 also receives an electrical signal from the switch ASIC 20 via conductors provided on the substrate 10 and the socket 43 and outputs an optical signal corresponding to the electrical signal. The optical signal output from the optical transceiver 30 is coupled to the optical fiber 32 and transmitted through the optical fiber 32. The optical transceiver 30 includes, for example, a VCSEL array (not shown, VCSEL: vertical cavity surface emitting laser) as a plurality of light-emitting units for outputting the optical signal.

[0044] As shown in Fig. 2, multiple optical transceivers 30 are arranged along each side 10c of the substrate 10. In this embodiment, as shown in Fig. 4, each optical transceiver 30 is mounted so as to cover the corresponding side 10c. In other words, when viewed from the opposite side in the Z direction, each optical transceiver 30 is arranged so as to straddle the side 10c, and has a portion located inside the side 10c and a portion located outside the side 10c. This has the advantages of making it easier to avoid interference between the optical fiber 32 extending from the optical transceiver 30 and other components, such as the switch ASIC 20 and heat sink 21, mounted on the substrate 10, and allowing the substrate 10 to be made smaller.

[0045] 1 and 2 , the optical transceivers 30 are fixed to the substrate 10 by fixing mechanisms 40 provided on each side 10 c of the substrate 10. A total of four fixing mechanisms 40 are provided, one for each of the four sides 10 c, and are shared by the multiple (eight in this embodiment, for example) optical transceivers 30 arranged along each side 10 c. Sharing the fixing mechanism 40 between the multiple optical transceivers 30 in this manner can simplify the mounting structure of the fixing mechanism 40 to the substrate 10 and reduce the number of components, compared to when each optical transceiver 30 is fixed to the substrate 10 by its own fixing mechanism, thereby reducing the effort and cost required to manufacture the switch device 100.

[0046] 1 and 2, the switch ASIC 20 is mounted on the substrate 10 at a position away from each of the sides 10c of the substrate 10 (approximately the center of the substrate 10, for example, in this embodiment). As shown in FIG. 4, the switch ASIC 20 is mounted on the surface 10a by, for example, flip-chip mounting. The switch ASIC 20 controls the operation of each optical transceiver 30. The switch ASIC 20 is an example of a semiconductor integrated circuit.

[0047] As shown in FIG. 4 , the heat sink 21 is provided in contact with the switch ASIC 20 on the side opposite the substrate 10. The heat sink 21 is in contact with the top surface of the switch ASIC 20 and has an array of pin-shaped fins 21a protruding from the base in the Z direction. The heat sink 21 is made of a material with relatively high thermal conductivity, such as an aluminum-based metal material. With this configuration, heat generated by the switch ASIC 20 is transferred in the Z direction through the heat sink 21 and transferred to the surrounding gas, i.e., released, through heat exchange between the fins 21a and the gas surrounding the fins 21a. The heat sink 21 is an example of a second heat dissipation mechanism.

[0048] 3 and 4 , in this embodiment, as an example, the fixing mechanism 40 includes an upper member 41, an intermediate member 42, and a socket 43. These components of the fixing mechanism 40 are integrated by fasteners 46 such as screws. Among the components of the fixing mechanism 40, the intermediate member 42 and the socket 43 are shared by all of the optical transceivers 30 in the group of optical transceivers 30 arranged along the side 10 c of the substrate 10. As shown in FIG. 4 , the fixing mechanism 40 fixes the optical transceivers 30 located near the side 10 c of the substrate 10 to the substrate 10 in a state where the optical transceivers 30 are sandwiched in the thickness direction of the substrate 10 by the fixing mechanism 40.

[0049] Furthermore, to enable replacement of the optical transceiver 30 after installation, the fixing mechanism 40 detachably fixes the optical transceiver 30 to the board 10. To achieve this, in this embodiment, the components of the fixing mechanism 40 include components that are fixed to the board 10 and components that are detachable from the board 10. In this embodiment, the intermediate member 42 and the socket 43 are fixed to the board 10, and the upper member 41 is configured to be detachable from the intermediate member 42, i.e., the board 10. Specifically, as shown in FIG. 4 , the upper member 41 is attached to the intermediate member 42 by a fastener 46 configured as a removable screw. The intermediate member 42 and the socket 43 are examples of a first member, and the upper member 41 is an example of a second member.

[0050] 5 is a plan view showing a state S1 before the optical transceiver 30 is placed, a state S2 after the optical transceiver 30 is placed, and a state S3 after the optical transceiver 30 is attached. As shown in state S3 of FIG. 5 , in this embodiment, the upper member 41 is not shared by all of the optical transceivers 30 along the side 10 c, but is shared only by two adjacent optical transceivers 30 along the side 10 c. This provides advantages such as facilitating the removal of individual optical transceivers 30 while allowing for component sharing, and improving positioning accuracy by reducing the effects of bending of the fixing mechanism 40 and manufacturing variations in the components of the fixing mechanism 40 and the optical transceivers 30. However, this configuration is merely an example, and the upper member 41 may be shared by all of the optical transceivers 30 along the side 10 c.

[0051] The optical transceiver 30 has a body 31 and a plurality of optical fibers 32. In the following description, unless otherwise specified, the optical transceiver 30 will be described as being fixed to the substrate 10.

[0052] As shown in FIG. 4 , the body 31 has a surface 31a facing the opposite direction of the Z direction. The surface 31a is provided with an electrical interface 31a1 having an array of electrodes (not shown) and a heat dissipation surface 31a2. In a fixed state, the electrical interface 31a1 and the heat dissipation surface 31a2 face in opposite directions of the Z direction and are aligned substantially along the surface 10a of the substrate 10 and in a direction intersecting the side 10c of the substrate 10 (the X direction in the optical transceiver 30 shown in FIG. 4 ). A heat-generating element inside the optical transceiver 30 is aligned with the heat dissipation surface 31a2 in the Z direction. The electrical interface 31a1 is an example of a first electrical interface, and the heat dissipation surface 31a2 is an example of a heat dissipation unit.

[0053] The optical fibers 32 extend from a portion of the body 31 away from the surface 31a, specifically, from a portion on the opposite side of the heat dissipation surface 31a2 and aligned with the heat dissipation surface 31a2 in the Z direction. In the vicinity of the body 31, the optical fibers 32 extend from the body 31 in the Z direction.

[0054] A socket 43, an intermediate member 42, and an upper member 41 are mounted on the substrate 10 in this order.

[0055] The upper member 41 presses the body 31 of the optical transceiver 30 in the opposite direction to the Z direction, toward the board 10 and the socket 43. As shown in Figures 4 and 5, the upper member 41 has an opening 41a as a notch that penetrates the upper member 41 in the Z direction. A portion of the body 31 is housed in the opening 41a, and the optical fiber 32 extends through the opening 41a.

[0056] The intermediate member 42 has an opening 42a as a through-hole extending in the Z direction. The side surfaces of the opening 42a function to roughly guide the body 31 of the optical transceiver 30 in the X and Y directions when the body 31 is attached.

[0057] The socket 43 is mounted on the surface 10a of the substrate 10 and supports the body 31 of the optical transceiver 30. The socket 43 is provided with an electrical interface 43a and an opening 43b.

[0058] The electrical interface 43a faces and contacts the electrical interface 31a1 provided on the body 31 of the optical transceiver 30 and includes conductors 43a1 electrically connected to each of the multiple electrodes provided on the electrical interface 31a1. The conductors 43a1 may be configured, for example, as contact terminals with elastically expandable pins extending in the Z direction. The conductors 43a1 are electrically connected to conductors (not shown) on the substrate 10. Each electrode of the electrical interface 31a1 of the optical transceiver 30 is electrically connected to a conductor of the switch ASIC 20 via the conductors 43a1 of the electrical interface 43a of the socket 43 and the conductors of the substrate 10. Providing a socket 43 with the electrical interface 43a provides the advantage of more easily constructing a configuration that ensures the required positioning accuracy of the multiple electrodes compared to, for example, providing the electrical interface 43a directly on the substrate 10. The electrical interface 43a is an example of a second electrical interface.

[0059] The opening 43b exposes the heat dissipation surface 31a2 provided on the body 31 of the optical transceiver 30 in the opposite direction to the Z direction. The opening 43b is provided, for example, as a through-hole or a notch that penetrates the socket 43 in the Z direction.

[0060] The heat dissipation mechanism 50 dissipates heat generated in the optical transceiver 30. The heat dissipation mechanism 50 includes a lower member 51 and a heat sink 52. At least the lower member 51 of the heat dissipation mechanism 50 may be configured to function as part of the fixing mechanism 40. The heat dissipation mechanism 50 is an example of a first heat dissipation mechanism.

[0061] The lower member 51 is located on the opposite side of the socket 43 from the intermediate member 42. The lower member 51 has a first portion 51a accommodated in the opening 43b and a second portion 51b aligned with the substrate 10 in a direction intersecting the Z direction. The lower member 51 is thermally connected to the heat dissipation surface 31a2 of the optical transceiver 30 and transfers heat generated by the optical transceiver 30. The lower member 51 is made of a material with relatively high thermal conductivity, such as an aluminum-based metal material. The lower member 51 is fixed to the substrate 10 or the fixing mechanism 40 by fasteners such as screws, adhesives, or the like. The lower member 51 may also be referred to as a heat transfer member. In this specification, two members being thermally connected means that the two members are in a state in which heat can be transferred.

[0062] The first portion 51a is adjacent to the heat dissipation surface 31a2 and thermally connected to the heat dissipation surface 31a2 via a flexible heat conduction member 47. Providing the heat conduction member 47 has the advantages of suppressing a decrease in the efficiency of heat conduction from the heat dissipation surface 31a2 to the first portion 51a due to a gap between the heat dissipation surface 31a2 and the first portion 51a caused by manufacturing variations or differences in the thermal expansion coefficients of the components, and suppressing excessive pressing force between the heat dissipation surface 31a2 and the first portion 51a.

[0063] The thermal conductive member 47 contains a synthetic resin material, which provides elasticity, flexibility, and flexibility. This allows the thermal conductive member 47 to contact and adhere to both the heat dissipation surface 31a2 and the first portion 51a. The thermal conductive member 47 is interposed between the heat dissipation surface 31a2 and the first portion 51a in an elastically compressed state. Specifically, the thermal conductive member 47 may be primarily made of a synthetic resin material such as acrylic resin or silicone resin and may contain a thermally conductive filler such as boron nitride, aluminum nitride, or alumina. The thermal conductive member 47 may also include a thin graphite film sandwiched between layers of a synthetic resin material such as polyethylene terephthalate or polyimide. The thermal conductive member 47 may also be made of a thermally conductive rubber material. The rubber material may be primarily made of silicone or acrylic and may contain a thermally conductive filler such as boron nitride, aluminum nitride, alumina, or nanodiamond. However, the heat conducting member 47 is not limited to these, and may have other structures that are elastic, flexible, and pliable.

[0064] The second portion 51b is integral with the first portion 51a and thermally connected to the first portion 51a. The second portion 51b extends from the first portion 51a in the direction opposite to the Z direction, i.e., in the thickness direction of the substrate 10, at a position aligned in a direction intersecting the Z direction with respect to the substrate 10 (the X direction in the case of the lower member 51 shown in FIG. 4).

[0065] The lower member 51 contacts the heat sink 52 on the side opposite the heat dissipation surface 31a2 of the substrate 10 and is thermally connected to the heat sink 52. The heat sink 52 has a plurality of arrayed, pin-shaped fins 52a protruding from the base in the opposite direction of the Z direction. The heat sink 52 is made of a material with relatively high thermal conductivity, such as an aluminum-based metal material. The heat sink 52 is fixed to the lower member 51 by fasteners such as screws, soldering, adhesive bonding, or the like. The lower member 51 and the heat sink 52 may be integrated into a single member. The heat sink 52 may also be referred to as a heat transfer member or a heat dissipation member.

[0066] With the lower member 51 and heat sink 52 configured as described above, heat generated in the optical transceiver 30 is transferred from the heat dissipation surface 31a2 to the lower member 51 and the heat sink 52 in the opposite direction of the Z direction, and is transferred to the surrounding gas through heat exchange between the fins 52a and the gas around the fins 52a, i.e., is released. Note that the switch device 100 may be provided with an electric fan, and may be configured so that the airflow generated by the operation of the electric fan acts on the heat sink 52.

[0067] 2, 4, and 5, the heat dissipation surface 31a2 is located on the opposite side of the electrical interface 31a1 from the switch ASIC 20. This arrangement has the following advantages: for example, the length of the conductor between the electrical interface 31a1 and the switch ASIC 20 can be shortened, making it easier to ensure the required transmission characteristics of the electrical signal; and, since interference between the first heat dissipation mechanism and the conductor can be avoided, it is easier to obtain the required heat dissipation performance from the optical transceiver 30.

[0068] The positioning mechanism 48a shown in FIG. 5 positions the intermediate member 42 and the upper member 41 in a direction intersecting the Z direction. The positioning mechanism 48b positions the socket 43 and the optical transceiver 30 in a direction intersecting the Z direction. The positioning mechanism 48c positions the board 10 and the socket 43 in a direction intersecting the Z direction. The positioning mechanisms 48a to 48c are each formed of a member having pins or holes into which the pins are inserted. Each of the positioning mechanisms 48a to 48c is provided at two locations spaced apart from each other. Of these, the two positioning mechanisms 48b are provided so that the electrical interface 43a is positioned between the two positioning mechanisms 48b. This facilitates more accurate positioning of the electrodes of the electrical interface 31a1 (see FIG. 4) of the optical transceiver 30 and the conductors 43a1 of the electrical interface 43a of the socket 43.

[0069] As described above, this embodiment provides a novel and improved board assembly that can more efficiently dissipate heat generated by the optical transceiver 30 while avoiding interference with other components using the heat dissipation mechanism 50. Furthermore, in this embodiment, the optical transceiver 30 is disposed facing one side of the board 10, and the heat dissipation mechanism 50 is disposed facing the other side of the board 10 or outside the side 10c of the board 10. This advantageously increases the packaging density of the optical transceivers 30 by avoiding interference with the heat dissipation mechanism 50. Furthermore, since the optical fibers 32 can be drawn out from the optical transceivers 30 in a direction intersecting the surface of the board 10, the switch device 100 can be prevented from increasing in size along the surface of the board 10. Furthermore, this advantageously increases the degree of freedom in the routing direction of the optical fibers 32, thereby making it easier to avoid interference with other components such as the ASIC 20. Furthermore, since interference with the optical transceiver 30 can be avoided, the degree of freedom in the placement and structure of the heat dissipation mechanism 50 can be increased, and advantages are obtained such as making it easier to improve the heat dissipation efficiency of the heat dissipation mechanism 50 and making the heat dissipation mechanism 50 more compact, regardless of whether the cooling method of the heat dissipation mechanism 50 is water-cooled or air-cooled.

[0070] Furthermore, in this embodiment, a heat conduction member 47 is interposed between the heat dissipation surface 31a2 (heat dissipation portion) of the optical transceiver 30 and the first portion 51a of the heat dissipation mechanism 50 (first heat dissipation mechanism). If the heat conduction member 47 were not present, the thermal resistance between the heat dissipation surface 31a2 and the first portion 51a would be high, potentially reducing the heat dissipation performance of the heat dissipation mechanism 50. In this regard, this embodiment allows heat generated in the optical transceiver 30 to be more efficiently conducted to the first portion 51a, i.e., the heat dissipation mechanism 50, via the heat conduction member 47, and to be more efficiently dissipated from the heat dissipation mechanism 50.

[0071] Furthermore, in a configuration in which multiple optical transceivers 30 are arranged along the side 10c of the substrate 10, as in the present embodiment, the smaller the width of the optical transceivers 30 along the side 10c, the more optical transceivers 30 can be mounted. In the configuration of this embodiment, for example, optical transceivers 30 with a width of 10 mm or less or 8 mm or less can be mounted. In this case, optical transceivers 30 with a transmission capacity of, for example, 200 Gb / s or more, 400 Gb / s or more, or 800 Gb / s or more can be mounted.

[0072] Second Embodiment FIG. 6 is a cross-sectional view of a part of a switch device 100B (100) according to a second embodiment, taken at the same position as in FIG.

[0073] 6 , in this embodiment, a through-hole 10d is formed in the substrate 10, penetrating the substrate 10 in the Z direction, and the second portion 51b penetrates the through-hole 10d in the Z direction. The second portion 51b is an example of a third portion provided separately from the substrate 10. Note that, in this embodiment as well, as in the first embodiment, a heat sink 52 may be provided that is adjacent to the lower member 51 in the opposite direction to the Z direction and thermally connected to the lower member 51.

[0074] 6 , in this embodiment, a storage section 60 for the heat conductive member 47 is provided between the heat dissipation surface 31a2 and the first portion 51a. The storage section 60 is configured as a recess recessed in the opposite direction of the Z direction from an end surface 51c of the first portion 51a in the Z direction. The end surface 51c intersects with the Z direction and expands perpendicularly to the Z direction, and is in contact with the heat dissipation surface 31a2 around the periphery of the storage section 60. Note that the end surface 51c and the heat dissipation surface 31a2 do not necessarily have to be in contact around the entire periphery of the storage section 60.

[0075] 7 and 8 are enlarged views of part VII in Fig. 6. Fig. 7 shows the state before the optical transceiver 30 is mounted on the board 10, in other words, the state before the body 31 of the optical transceiver 30, the heat conductive member 47, and the first part 51a of the heat dissipation mechanism 50 are assembled. Fig. 8 shows the state after the optical transceiver 30 is mounted on the board 10, in other words, the state after the body 31 of the optical transceiver 30, the heat conductive member 47, and the first part 51a of the heat dissipation mechanism 50 are assembled.

[0076] As shown in FIG. 7 , in this embodiment, the accommodation portion 60 is a recess recessed from the end surface 51 c to a substantially constant depth (height H). The heat conduction member 47 has a substantially constant thickness T1 greater than the height H in a free state where no external forces other than gravity or atmospheric pressure act on it. The heat conduction member 47 is accommodated in the accommodation portion 60, extending in a direction intersecting the Z direction and substantially perpendicular to the Z direction. As shown in FIG. 8 , after the body 31, the heat conduction member 47, and the first portion 51 a are assembled, the heat conduction member 47 is elastically compressed in the Z direction between the body 31 and the first portion 51 a, resulting in a thickness T2 (= H<T1) of the heat conduction member 47 that is smaller than T1. The thickness T1 is the thickness when the heat conduction member 47 is not compressed by the two members sandwiching the heat conduction member 47, i.e., the body 31 and the lower member 51. The thickness T1 is, for example, the thickness in an uncompressed state before the switch device 100 is assembled (before the thermal conductive member 47 is attached), or the thickness in an uncompressed state when the board assembly is released from the assembled state, i.e., disassembled, after the board assembly is assembled (after the thermal conductive member 47 is attached). In this case, the disassembly may be immediately after the assembly, or may be after a relatively long time, such as several years, has passed since the assembly.

[0077] If the thermal conduction member 47 is made of an elastic material such as an elastomer, the thermal conduction member 47 is elastically compressed in the Z direction approximately uniformly at each position in a direction intersecting the Z direction. The compression ratio R [%] of the thermal conduction member 47 during assembly can be defined by the following formula (1): R = (T1 - H) / T1 × 100 (1). The thermal conduction efficiency of the thermal conduction member 47 increases as the surface pressure acting on both surfaces (contact surfaces) in the thickness direction increases. When the surface pressure exceeds a threshold, the thermal conduction efficiency is approximately saturated. Based on extensive research by the inventors, it has been found that, from this perspective, the compression ratio R is preferably 15% or more, more preferably 20% or more, and even more preferably 25% or more. Furthermore, the higher the compression rate R, the stronger the repulsive force of the heat conduction member 47, which in turn increases the stress generated in the heat conduction member 47, the body 31, the lower member 51, and ultimately in the fasteners that connect the optical transceiver 30 and the heat dissipation mechanism 50. From the viewpoint of preventing the stress from becoming excessive, it has been found that the compression rate R is preferably 45% or less, more preferably 40% or less, and even more preferably 35% or less.

[0078] Furthermore, if the area of ​​the optical transceiver 30 exposed to the housing 60 is A1 and the area of ​​the heat conduction member 47 in contact with the exposed surface is A2, the contact rate Rc [%] of the heat conduction member 47 with the optical transceiver 30 can be defined as follows: Rc = A2 / A1 × 100 (2) The larger the contact area of ​​the heat conduction member 47 with the optical transceiver 30, the higher the thermal conduction efficiency of the heat conduction member 47. Based on extensive research by the inventors, it has been found that, from this perspective, the contact rate Rc is preferably 15% or more, more preferably 30% or more, and even more preferably 50% or more. The area A1 may be the cross-sectional area of ​​the housing 60 in a direction perpendicular to the compression direction (Z direction) of the heat conduction member 47.

[0079] In this embodiment, too, heat generated in the optical transceiver 30 is transferred and released from the heat dissipation surface 31a2 in the opposite direction to the Z direction in the lower member 51. This embodiment also provides the same effects as the first embodiment.

[0080] Furthermore, according to this embodiment, a housing 60 for the heat conduction member 47 is provided, and the compression ratio R of the heat conduction member 47 can be appropriately set by setting the thicknesses T1 and T2 of the heat conduction member 47 and the height H of the housing 60. This configuration, for example, makes it easier to set the efficiency of heat conduction by the heat conduction member 47 to a required value or higher. This makes it easier to more reliably release heat generated in the optical transceiver 30. Furthermore, it is possible to prevent excessive stress from occurring in each part of the switch device 100 due to the compressive repulsive force of the heat conduction member 47. This prevents deformation or damage to these parts.

[0081] Third Embodiment FIG. 9 is a cross-sectional view of a part of a switch device 100C (100) according to a third embodiment, taken at the same position as in FIG.

[0082] As shown in FIG. 9 , in this embodiment, an inlay 10e is provided on the substrate 10, penetrating the substrate 10 in the Z direction. The inlay 10e is made of a material with relatively high thermal conductivity, such as a copper-based metal material. The inlay 10e is aligned with and in contact with a first portion 51a of the lower member 51 in the Z direction, and is thermally connected to the first portion 51a. The inlay 10e constitutes part of the heat dissipation mechanism 50 and is an example of a third portion provided on the substrate 10. The inlay 10e may also be referred to as a heat transfer member or a heat dissipation member. Note that, in this embodiment, a heat sink 52 may be provided adjacent to the inlay 10e in the opposite Z direction and thermally connected to the inlay 10e.

[0083] In this embodiment, too, the heat generated in the optical transceiver 30 is transferred from the heat dissipation surface 31a2 to the lower member 51 and the inlay 10e in the opposite direction of the Z axis, and then dissipated. This embodiment also provides the same effects as the first embodiment.

[0084] Fourth Embodiment FIG. 10 is a cross-sectional view of a part of a switch device 100D (100) according to a fourth embodiment, taken at the same position as in FIG.

[0085] As shown in FIG. 10 , in this embodiment, a through via 10f is provided in the substrate 10, penetrating the substrate 10 in the Z direction. The through via 10f is made of a material with relatively high thermal conductivity, such as a copper-based metal material. The through via 10f may be solid or hollow. If hollow, the through via 10f may be a plated layer. The through via 10f is aligned with and in contact with a first portion 51a of the lower member 51 in the Z direction and is thermally connected to the first portion 51a. The through via 10f constitutes part of the heat dissipation mechanism 50 and is an example of a third portion provided on the substrate 10. The through via 10f may also be referred to as a heat transfer member or a heat dissipation member. Note that, in this embodiment, a heat sink 52 may be provided adjacent to the through via 10f in the opposite direction to the Z direction and thermally connected to the through via 10f.

[0086] In this embodiment, the heat generated in the optical transceiver 30 is transferred from the heat dissipation surface 31a2 to the lower member 51 and the through-via 10f in the opposite direction of the Z axis, and then dissipated. This embodiment also provides the same effects as the first embodiment.

[0087] 11 and 12 are cross-sectional views showing modified examples of the accommodation unit 60. As illustrated in Fig. 11, the accommodation unit 60 may be configured with a recess recessed in the Z direction from the heat dissipation surface 31a2 and a recess recessed in the opposite direction from the end surface 51c in the Z direction. As illustrated in Fig. 12, the accommodation unit 60 may be configured with only a recess recessed in the Z direction from the heat dissipation surface 31a2. These modified examples also provide the same effects as the accommodation unit 60 of the second embodiment (Fig. 8).

[0088] Fifth Embodiment Fig. 13 is a perspective view of a switch device 100E (100) according to a fifth embodiment, Fig. 14 is a plan view of the switch device 100E (100), and Fig. 15 is a side view of the switch device 100E (100).

[0089] 13 to 15, in this embodiment, the heat dissipation mechanism 50 has a heat pipe 53 that transports heat by a refrigerant between a lower member 51 and a heat sink 52. The heat pipe 53 is heated in the lower member 51 and turns into a gas, and transports heat from the lower member 51 to the heat sink 52, and is cooled in the heat sink 52 and turns into a liquid, and returns to the lower member 51. The heat pipe 53 is an example of a heat transport mechanism.

[0090] By providing the heat pipe 53, for example, it is possible to dissipate heat from a location where it is easier to dissipate heat, which is advantageous in that it is possible to cool the optical transceiver 30 more efficiently.

[0091] The heat pipe 53 may be thermally connected to the heat sink 52 of the switch ASIC 20. In this case, the heat sink 52 can be shared between the switch ASIC 20 and the optical transceiver 30, thereby reducing the number of components, which has the advantage of reducing manufacturing effort and costs, for example.

[0092] Sixth Embodiment Figure 16 is a cross-sectional view of a portion of a switch device 100F (100) according to a sixth embodiment, taken at the same position as in Figure 4. In this embodiment, the heat conduction member 47 is a thermally conductive grease. The grease may be primarily made of, for example, silicone, ester, ether, or poly-alpha olefin, and may contain a thermally conductive filler such as boron nitride, aluminum nitride, alumina, or nanodiamond. Even when the heat conduction member 47 is a semi-solid liquid such as grease, the same effects as those of the above embodiments can be achieved.

[0093] It is known that when the thermal conductive member 47 is grease, its thermal conductivity is higher in a compressed state than in an uncompressed state. Therefore, in this embodiment, the body 31 of the optical transceiver 30 is provided with a protrusion 31a3 that is inserted into the recessed housing 60. During assembly of the switch device 100, the protrusion 31a3 compresses the thermal conductive member 47 within the housing 60. To ensure that the thermal conductive member 47 (grease) is compressed within the housing 60, the clearance between the outer circumferential surface of the protrusion 31a3 and the inner circumferential surface of the housing 60 is set large enough to prevent leakage of the compressed thermal conductive member 47. In this configuration, the tip surface of the protrusion 31a3 serves as the heat dissipation surface 31a2. The protrusion 31a3 may also be referred to as an insertion portion inserted into the housing 60 or a pressing portion that presses the thermal conductive member 47.

[0094] When the volume of the accommodation portion 60 is V0, before assembling the switch device 100, the heat conduction member 47 having a volume V1 (<V0) in an uncompressed state is accommodated in the accommodation portion 60. Then, when assembling the switch device 100, the protrusion 31a3 is accommodated in the accommodation portion 60, and the volume V2 of the heat conduction member 47 sandwiched between the protrusion 31a3 and the accommodation portion 60 is made smaller than the volume V1, i.e., the heat conduction member 47 is compressed.

[0095] In this case, the compression rate R [%] of the thermal conductive member 47 during assembly can be defined as follows: R = (V1 - V2) / V2 × 100 (3) According to intensive research by the inventors, it has been found that, from the viewpoint of further increasing thermal conductivity, the compression rate R is preferably 5% or more, more preferably 10% or more, and even more preferably 15% or more. Furthermore, the higher the compression rate R, the more likely the thermal conductive member 47 is to leak from the clearance, and the stronger the repulsive force of the thermal conductive member 47. As a result, the stress generated in the thermal conductive member 47, the body 31, the lower member 51, and ultimately in the fasteners connecting the optical transceiver 30 and the heat dissipation mechanism 50 increases. From the viewpoint of suppressing leakage from the clearance while preventing the stress from becoming excessive, it has been found that the compression ratio R is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less.

[0096] This embodiment also achieves the same effects as the other embodiments including the thermally conductive member 47. The configuration of the switch device 100 when the thermally conductive member 47 is grease is not limited to the above embodiment. For example, instead of the protruding portion 31a3, a separate member from the optical transceiver 30 may be provided as the insertion portion or pressing portion described above, which contacts (preferably comes into close contact with) the surface of the lower member 51 of the optical transceiver 30 in the assembled state. An example of this is the configuration in FIG. 16 , in which the protruding portion 31a3 is separated from the optical transceiver 30 and made into a separate member. The separate member may be made of a material with a higher thermal conductivity than the body 31 of the optical transceiver 30. In this configuration, the separate member can also be considered to constitute part of the thermally conductive member.

[0097] While the above describes exemplary embodiments of the present invention, the above embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be appropriately modified and implemented.

[0098] DESCRIPTION OF SYMBOLS 10...Substrate (substrate assembly) 10a...Surface (first surface) 10b...Surface (second surface) 10c...Side 10d...Through hole 10e...Inlay (third portion) 10f...Through via (third portion) 20...Switch ASIC (semiconductor integrated circuit) 21...Heat sink (second heat dissipation mechanism) 21a...Fin 30...Optical transceiver 31...Body 31a...Surface 31a1...Electrical interface (first electrical interface) 31a2...Heat dissipation surface (heat dissipation portion) 31a3...Protrusion (inserted portion, pressing portion) 32...Optical fiber 40...Fixing mechanism (substrate assembly) 41...Upper member (second member) 41a...Opening 42...Intermediate member (first member) 42a...Opening 43...Socket (first member) 43a...Electrical interface (second electrical interface) 43a1...Conductor 43b...Opening 46...Fixing device 47...Heat conduction member 48a to 48c...Positioning mechanism 50...Heat dissipation mechanism (first heat dissipation mechanism, board assembly) 51...Lower member 51a...First portion 51b...Second portion 51c...End surface 52...Heat sink 52a...Fin 53...Heat pipe (heat transport mechanism) 60...Accommodation section 100, 100A to 100F...Switch device 200...Motherboard A1, A2...Area H...Height S1 to S3...State T1, T2...Thickness X...Direction Y...Direction Z...Direction (first direction)

Claims

1. A substrate assembly comprising: a substrate having a first surface facing a first direction and a second surface opposite the first surface facing a direction opposite to the first direction, the substrate having an optical transceiver fixed thereto, the optical transceiver having a first electrical interface and a heat dissipation portion, the optical transceiver being fixed to the substrate with the first electrical interface and the heat dissipation portion facing in the opposite direction to the first direction and aligned in a direction intersecting the first direction; and a first heat dissipation mechanism fixed to the substrate, the first portion being adjacent to the heat dissipation portion in the first direction and thermally connected to the heat dissipation portion when the optical transceiver is fixed to the substrate, a thermally conductive member being interposed between the heat dissipation portion and the first portion.

2. The board assembly according to claim 1, further comprising an accommodation portion for accommodating said thermally conductive member, said accommodation portion being provided between said heat dissipation portion and said first portion.

3. The board assembly according to claim 1, wherein the heat conductive member is interposed in contact with both the heat dissipation portion and the first portion.

4. The substrate assembly according to claim 2, wherein the height of said housing is less than the thickness of said thermally conductive member in an uncompressed state.

5. The board assembly according to any one of claims 1 to 4, wherein the heat conducting member includes a synthetic resin material and has flexibility.

6. The board assembly according to claim 1, wherein said optical transceiver has a body fixed to said board and having said first portion, and a plurality of optical fibers extend from said body on the side opposite said heat dissipation portion.

7. A substrate assembly as described in claim 1 or 6, wherein the first heat dissipation mechanism has a second portion adjacent to the first portion and aligned with the substrate in a direction intersecting the first direction.

8. The substrate assembly according to claim 1 or 6, wherein the first heat dissipation mechanism has a third portion adjacent to the first portion and penetrating the substrate in the first direction.

9. The substrate assembly of claim 8, wherein the third portion is provided on the substrate.

10. The substrate assembly of claim 8, wherein the third portion is provided separately from the substrate.

11. The substrate assembly according to claim 1, wherein the first heat dissipation mechanism comprises a heat transport mechanism that transports heat by a coolant.

12. The substrate assembly of claim 1, wherein the first heat dissipation mechanism comprises a heat sink.

13. The substrate assembly according to claim 1, wherein a semiconductor integrated circuit is mounted on the first surface.

14. The board assembly according to claim 13, wherein the semiconductor integrated circuit is provided with a second heat dissipation mechanism on a side opposite to the board when the semiconductor integrated circuit is mounted on the board.

15. The board assembly according to claim 13 or 14, wherein the optical transceiver is fixed to the board with the heat sink positioned on the opposite side of the first electrical interface from the semiconductor integrated circuit.

16. The board assembly according to claim 1, configured so that a plurality of optical transceivers can be fixed to the board as the optical transceiver.

17. The substrate assembly of claim 16, wherein the plurality of optical transceivers are arranged along an edge of the substrate.

18. The substrate assembly according to claim 17, wherein the plurality of optical transceivers are arranged along four sides of the substrate, and a semiconductor integrated circuit is mounted on the first surface at a position farther from each of the sides than the optical transceivers.

19. The board assembly of claim 1, further comprising a fixing mechanism for fixing the optical transceiver to the board.

20. The substrate assembly according to claim 19, wherein the fixing mechanism is shared by a plurality of optical transceivers as the optical transceiver.

21. The board assembly according to claim 19 or 20, wherein the fixing mechanism removably fixes the optical transceiver to the board.

22. The board assembly of claim 21, wherein the fixing mechanism comprises a first member fixed to the board, and a second member removably fixed to the first member and pressing the optical transceiver toward the board.

23. The board assembly of claim 22, wherein the optical transceiver has a body fixed to the board and having the first portion, a plurality of optical fibers extending from the side of the body opposite the heat dissipation portion, and the second member is provided with an opening through which the optical fibers pass.

24. The substrate assembly of claim 1, comprising: a second electrical interface fixed to the substrate and electrically connected to the first electrical interface; and a positioning mechanism for positioning the first electrical interface and the second electrical interface.

25. The board assembly of claim 1, further comprising a socket attached to said board and having a second electrical interface electrically connected to said first electrical interface.

26. The board assembly according to claim 1, further comprising a flexible heat-conducting member between said first portion and said heat sink.

27. The substrate assembly according to claim 1, which is mounted on an integrated substrate capable of mounting a plurality of substrate assemblies as the substrate assembly.

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