Optoelectronic device for liquid immersion cooling

Abstract

An optoelectronic device for immersion in a liquid coolant includes a printed circuit board assembly (PCBA) having opposite sides and having an optoelectronic component coupled on one side. A lens block mounted to a side of the PCBA encloses the air chamber above the optoelectronic component. An opening defined in the lens block forms a reflective surface. The lens block has a first lens facing the opto-electronic component and opposite the reflective surface. The lens block also has a second lens facing a clip connected to the optical fiber and coupled to the lens block. A first seal seals the lens block mounted to the PCBA and separates the air chamber from the liquid coolant. An insert is disposed in the opening to protect the reflective surface, and a second seal seals the opening and the insert in the lens block. A third seal seals the hoop to the lens block.

Description

Background Art

[0001] Optoelectronic modules are used for optoelectronic communications. Some optoelectronic modules are pluggable so that the module can be inserted into and removed from a holder of a host device, such as a main computer, a switching hub, a network router, or a switch box. Optoelectronic modules typically communicate with a host device by transmitting electrical data signals to the host device and / or receiving electrical data signals from the host device. The optoelectronic module then communicates the data as an optical signal along an optical cable.

[0002] To transfer data, optoelectronic modules convert optical signals into electrical signals and electrical signals into optical signals. Typically, optical signals are transmitted through optical fibers connected to the modules, and the conversion occurs at a circuit board in the optoelectronic module. The optical interface typically supports one or more optical fibers that convey optical data to and from the optoelectronic module, and uses a lens assembly in the optical interface between the optical fibers in the module and the active optoelectronic components.

[0003] For cost reasons, optoelectronic modules are not hermetically sealed so that the light path in the module is surrounded by air for efficient light coupling. Most optical lens assemblies are designed to operate in air rather than in liquid. However, liquid cooling is an effective cooling method and is much better than cooling by air. However, if liquid enters the light path, the focal length of the optical lens assembly will change due to the difference in refractive index between air and liquid. This greatly affects the performance of the optical lens system, or even makes the optical lens assembly inoperable.

[0004] The presently disclosed subject matter is directed to overcoming or at least reducing the effects of one or more of the problems set forth above.

[0005] Public Content

[0006] The optoelectronic device disclosed herein is for immersion in a liquid coolant. The optoelectronic device includes a printed circuit board (PCB) assembly, a lens block, a clamp and a seal. The PCB assembly has a first side and a second side that are opposite, and has at least one optoelectronic component coupled to the first side. The lens block is mounted to the first side of the PCB assembly and encloses an air chamber located above the at least one optoelectronic component. The lens block defines an opening that forms a reflective surface. The clamp is connected to the optical fiber and coupled to the lens block.

[0007] For the seal, a first seal seals the lens block mounted to the PCB assembly and separates the air chamber from the liquid coolant. A second seal seals the reflective surface in the opening of the lens block relative to the liquid coolant, and a third seal seals the clamp and the lens block relative to the liquid coolant. The seal may include epoxy resin.

[0008] To seal the reflective surface in the opening, an insert or plate may be disposed in the recess adjacent to the reflective surface. The second seal may seal the insert in the opening and may form an air gap between the insert and the reflective surface.

[0009] The lens block may have at least one alignment pin adjacent to the second lens, and the clamp may have at least one hole configured to fit over the at least one alignment pin. The fourth seal may seal the at least one hole. The fifth seal may seal the machining hole and the measurement hole on the lens block.

[0010] A method of assembling an optoelectronic device for immersion in a liquid coolant is disclosed herein. The method includes coupling at least one optoelectronic component to a first side of a printed circuit board (PCB) assembly; mounting a lens block on the first side of the PCB assembly above the at least one optoelectronic component and sealing an air chamber between the lens block and the first side of the PCB assembly with a first seal relative to the liquid coolant; sealing a reflective surface formed in an opening defined on the lens block with a second seal relative to the liquid coolant; and connecting a clamp on an optical fiber to the lens block by sealing the connection of the clamp to the lens block with a third seal relative to the liquid coolant.

[0011] The foregoing summary is not intended to summarize each potential implementation or every aspect of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 An exploded view of an optoelectronic device of the present disclosure is illustrated.

[0013] Figure 2 The diagram shows the arrangement in the housing Figure 1 A three-dimensional diagram of an optoelectronic device.

[0014] Figure 3 A more detailed illustration Figure 1 Exploded diagram of .

[0015] Figure 4 A cross-sectional view of a lens block, a printed circuit board, and a sealing device of the present disclosure is illustrated. DETAILED DESCRIPTION

[0016] Figure 1 An optoelectronic device 50 of the present disclosure is illustrated, and the optoelectronic device 50 is used to transmit and / or receive optical signals in an optical network and to communicate with a host device (not shown) via electrical signals. In general, the optoelectronic device 50 of the present disclosure can be a board mounted optical assembly (BOA), an optical engine, or a pluggable optoelectronic module for fiber optic communications. For example, the optoelectronic device 50 can be a four small form factor pluggable (QSFP+ / QSFP-DD) type active cable or an optical transceiver.

[0017] The optoelectronic device 50 includes a cable 56, a lens block 70, and a printed circuit board assembly (PCBA) 80. As discussed in more detail below, at least a portion of the optoelectronic device 50 can be immersed in a liquid coolant used in a liquid cooling system of a data center. Different liquid coolants can be used. For example, water can be used in a single-phase immersion cooling system. Alternatively, oil can be used in a two-phase immersion cooling system, where the evaporated oil is condensed by a condenser.

[0018] The cable 56 can be an optical patch cable or another type of cable. In this example, one end of the cable 56 has an optical connector 57 that can be placed outside the liquid coolant to connect to other transceivers / systems. The other end of the cable 56 is connected to the lens block 70 with an optical fiber assembly 60. The optical fiber assembly 60 has an internal connector 62, a fiber array 64, and a clamp 66.

[0019] The PCBA 80 includes an edge connector 58 and has an optical circuit 90 mounted in the PCBA 80. The edge connector 58 can be electrically connected to a host device (not shown) such as a router, switch, etc. that uses the device 50. The lens block 70 is mounted on the PCBA 80 and is positioned adjacent to the optical circuit 90, which is attached to the PCBA 80. The clamp 66 is connected to the lens block 70, and the clamp 68 can be attached to the lens block 70 to hold the clamp 66 in place. The clamp 68 is designed and used to ensure the accuracy of the alignment.

[0020] Typically, the optical circuit 90 includes one or more active optoelectronic components such as a transmitter (laser) and / or a receiver (diode), as well as other necessary components (e.g., amplifier, digital signal processor, etc.). The lens block 70 mounted to the PCBA 80 adjacent to the optical circuit 90 can route the optical signals of the active optoelectronic components to and from the optical fibers of the fiber array 64 and the cables 56.

[0021] During operation, the outgoing electrical data signals travel from the host device (not shown) through the electronic connector 58. The optical circuit 90 on the PCBA 80 optimizes these electrical data signals before passing them along the conductive traces (not shown) to the transmitter, which converts these electrical data signals into optical data signals before transmitting them through the lens block 70, the fiber array 64 to the fiber optic communication cable 56. In this way, the host device (not shown) in which the optoelectronic device 50 can be located can communicate with a remote system. The transmitter of the optical circuit 90 can be an array of optical transmitters, such as a vertical cavity surface emitting laser (VCSEL) or similar device.

[0022] In some embodiments, the optical circuit 90 also includes one or more receivers, such as diodes, that allow optical signals from the cable 56 to be received and processed. In this case, incoming optical signals traveling along the cable 56 are coupled by the fiber array 64 and the clamp 66 to the lens block 70, which routes the optical signals to one or more receivers of the optical circuit 90 on the PCBA 80. The optical circuit 90 converts the optical signals into electrical signals before passing them along conductive traces (not shown) to the edge connector 58. In this way, a host device (not shown) in which the optoelectronic device 50 can be positioned can communicate with a remote system.

[0023] Figure 2 One embodiment of an optoelectronic device 50 is illustrated and includes a housing 52 for enclosing a fiber optic assembly 60 , a lens block 70 , a PCBA 80 , and an optical circuit 90 . Figure 2 The optoelectronic device 50 shown may be fixedly attached to the cable 56, and thus the optoelectronic device 50 may represent one end of an "active cable". The other end of the cable 56 may include another optoelectronic module (not shown) attached to the other end of the communication cable 56, or may include an optoelectronic module such as Figure 1 The housing 52 may have any standard form factor and may include one or more housings that attach together and enclose the internal components of the device 50. The electronic connector 58 exposed on the housing 52 may be plugged into a router, switch, or similar device.

[0024] The optical circuit 90 is embedded inside the housing 52 of the device 50 to perform electrical-optical conversion. The optical fiber assembly 60 connects the optical fiber of the cable 56 to the optical circuit 90 inside the housing 52. The optical fiber assembly 60 is permanently attached inside the housing 52, which results in a protected optical interface. The optical fiber cable 56 is connected to the optical fiber assembly 60 and extends from the device 50 for connection to a remote system with another device 50.

[0025] As an alternative to an active cable, the communication cable 56 may instead be detachably connected to the optoelectronic device 50, in which case the optoelectronic device 50 may be used as a stand-alone module. For example, the communication cable 56 may be a fiber optic ribbon cable, and the communication cable 56 may be terminated at both ends thereof with a multi-fiber push-on (MPO) type connector. The optoelectronic device 50 may include a corresponding MPO type connector configured to be pluggably connected to the MPO type connector of the cable.

[0026] In either case, the communication cable 56 of the device 50 can be a multi-channel fiber optic communication cable including a plurality of optical fibers. The optoelectronic device 50 can be configured to transmit and receive optical signals at various data rates per second and wavelengths known and used in the art. The optoelectronic device 50 can be configured to support various communication protocols known and used in the art, and the optoelectronic device 50 can conform to any suitable form factor.

[0027] The optoelectronic device 50 may include a pull tab 54 operably connected to a release slider (not labeled), and the pull tab 54 and the release slider may be used together to insert the optoelectronic device 50 into a holder of a host device (not shown) and remove the optoelectronic device 50 from the holder. The housing 52 of the optoelectronic device 50 is not hermetically sealed so that liquid coolant can reach the PCBA 80 and circuit 90 within the device 50. However, the optical path within the device 50 is preferably surrounded by air for effective optical coupling.

[0028] With a general understanding of the optoelectronic device 50 of the present disclosure, additional details of the steering device 50 are discussed. Figure 3 An exploded detail view of the fiber optic assembly 60 (fiber array 64 and clamp 66), clamp 68, lens block 70, and PCBA 80 is shown. Figure 4 A cross-sectional view of the lens block 70 mounted on the PCBA 80 is shown.

[0029] The fiber optic assembly 60, lens block 70, PCBA 80 and optical circuit 90 have a seal 100 that allows the components to be fully immersed in a liquid cooling system for dissipating the generated heat into the surrounding liquid. The seal 100 does not affect the optical performance of the lens block 70 and still allows the device 50 to be connected to other transceivers / systems outside the liquid using optical jumper cables (56).

[0030] The clamp 66 on the fiber array 64 is installed in the lens block 70 and aligned using the alignment pin 78. A seal or gasket 120 can seal the clamp 66 inside the side pocket 77 of the lens block 70, or a seal or gasket 120' as shown in dashed outline can be provided outside the side pocket 77 to cover and seal around the opening of the clamp 66 in the side pocket 77. Under the protection of the gasket 120 / 120', the optical lens 76 in the side pocket 77 of the lens block 70 can communicate with the optical fiber of the clamp 66 without interference from the liquid coolant. The hole of the clamp 66 for the pin 78 is sealed by a seal 122 at the end of the clamp 66.

[0031] All holes 79 of the lens block 70 are also sealed by seals (124, 126, 128). Some of these holes 79 are machining holes and measurement holes used to manufacture and handle the lens block 70 during manufacturing and assembly, so these holes 79 have seals 124, 128 for sealing them after manufacturing and assembly. The top opening 74 in the lens block 70 includes a reflective surface 75, which is used to reflect light between the opposite lens 71 and lens 76 on the lens block 70. The top opening or top recess 74 is sealed with a seal 126. In order to protect the reflective surface 75 from contamination and to create an air gap close to the reflective surface 75, an insert 130 is added in the opening 74 between the surface 75 and the seal 126. (Although the insert 130 shown in the figure is plate-shaped, the insert 130 can have other shapes.) This leaves some air between the insert 130 and the reflective surface 75, which can ensure that the light in the lens block 70 is fully reflected when it is incident on the reflective surface 75.

[0032] The lens block 70 has a base 72 bonded to the PCBA 80 by an annular seal or gasket 110, and any gaps between the base 72 and the PCBA 80 are sealed with a gasket 120 to prevent liquid coolant from entering the air chamber or space 713 between the lower side 73 of the lens block 70 and the top surface of the PCBA 80. Therefore, during manufacturing and assembly, the air chamber 713 may include entrapped air. The gasket or seal 120 prevents liquid coolant from entering the air chamber 713, thereby affecting the performance of one or more active optoelectronic components 92, such as transmitters, receivers, and any of integrated circuits, chips, and other circuits disposed on the PCBA 80 and positioned below the lens block 70.

[0033] The heat generated by one or more active optoelectronic components 92 is transferred to the liquid coolant C through the thermally conductive material in the PCBA80. In order to improve heat transfer, the PCBA80 may include: a recessed groove 82 located on one side, which is used to accommodate one or more active optoelectronic components 92; and an opposite recessed groove 84 located on the other side of the PCBA80. The recessed groove 82 with the lens block 70 on the side of the PCBA80 is connected to the air chamber 713 enclosed by the lens block 70. The grooves 82 and 84 can bring the surrounding liquid coolant C closer to the one or more active optoelectronic components 92 to be cooled. In addition, one or more metal heat sinks or thermal vias 86 can be added in the PCBA80 between the grooves 82 and 84 for better heat dissipation of the components 92. These heat sinks or thermal vias 86 may contain copper. As Figure 3As shown in , any other electronic components 94 on the PCBA 80 that are not mounted below the lens block 70 are protected by the enclosure 140 to isolate these electronic components 94 from the surrounding liquid coolant.

[0034] The seals 110, 120, 122, 124, 126, 128 disclosed above may include epoxy resin, sealant, elastomeric seal, or a combination thereof. The encapsulation 140 may also be epoxy resin, sealant, elastomeric seal, or a combination thereof. In order to ensure the reliability of the provided seal, the seals 120, 122, 124, 126, 128 may be made of various types of materials.

[0035] The sealing device 100 disclosed above can isolate the entire optical lens system and components outside the lens block 70 from the liquid coolant, which can effectively prevent the coolant in the liquid system from entering the optical path, thereby preventing the coolant from affecting the optical path and components, thereby cooling the optical circuit 90 in the liquid cooling system.

[0036] The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived by the applicant. It will be understood that the features described above according to any embodiment or aspect of the disclosed subject matter may be utilized alone or in combination with any other described features in any other embodiment or aspect of the disclosed subject matter with the benefit of the present disclosure.

Claims

1. A photovoltaic device for immersion in a liquid coolant, the photovoltaic device comprising: a printed circuit board (PCB) assembly having opposing first and second sides and having at least one optoelectronic component coupled to the first side; a lens block mounted to the first side of the PCB assembly and enclosing an air chamber above the at least one optoelectronic component, the lens block defining an opening forming a reflective surface; a clamp connected to the optical fiber and coupled to the lens block; as well as a first seal that seals the lens block mounted to the PCB assembly and separates the air chamber from the liquid coolant; a second seal that seals the reflective surface in the opening of the lens block relative to the liquid coolant; as well as A third seal seals the clamp and the lens block from the liquid coolant.

2. The optoelectronic device according to claim 1, wherein: The lens block comprises: a first lens facing the at least one optoelectronic component and opposite the reflective surface; and A second lens is opposite the reflective surface and faces the collar.

3. The optoelectronic device according to claim 2, wherein: The lens block includes at least one alignment pin adjacent to the second lens; and wherein the clamp includes: at least one hole, the at least one hole is configured to fit over the at least one alignment pin; and wherein the optoelectronic device also includes a fourth seal that seals the at least one hole. 4 . The optoelectronic device according to claim 3 , further comprising a fifth sealing member for sealing the processing hole and the measuring hole on the lens block.

5. The optoelectronic device according to claim 4, wherein: The first sealant, the second sealant, the third sealant, the fourth sealant, and the fifth sealant include epoxy resin.

6. The optoelectronic device of claim 1, further comprising an insert disposed in the opening adjacent to the reflective surface, the second seal sealing the insert in the opening and forming an air gap between the insert and the reflective surface.

7. The optoelectronic device of claim 1, further comprising a clamp coupled to the lens block and retaining the clamp to the lens block.

8. The optoelectronic device according to claim 1, further comprising a cable connected to the optical fiber of the clamp.

9. The optoelectronic device according to claim 1, further comprising a housing enclosing the PCB assembly, the lens block and the clamp.

10. The optoelectronic device according to claim 1, wherein: The first side of the PCB assembly defines a first concave groove having the at least one optoelectronic component, the at least one optoelectronic component is disposed on the first concave groove, and the first concave groove is in communication with the air chamber enclosed by the lens block.

11. The optoelectronic device according to claim 10, wherein: The second side of the PCB assembly defines a second concave recessed groove, the second concave recessed groove being opposite to the first concave recessed groove.

12. The optoelectronic device of claim 10, comprising a metal heat sink or thermal via disposed in the PCB assembly between the first recessed groove and the second recessed groove.

13. The optoelectronic device according to claim 1, wherein: The at least one optoelectronic component includes an optical transmitter, an optical receiver, or both.

14. The optoelectronic device according to claim 1, further comprising: at least one electronic component coupled to the PCB assembly and located outside the air chamber; as well as A fourth sealing member encapsulates the at least one electronic component.

15. The optoelectronic device according to claim 1, wherein: The first sealing member, the second sealing member, and the third sealing member include epoxy resin.

16. A method of assembling a photovoltaic device for immersion in a liquid coolant, the method comprising: coupling at least one optoelectronic component to a first side of a printed circuit board (PCB) assembly; mounting a lens block on the first side of the PCB assembly above the at least one optoelectronic component and sealing an air space between the lens block and the first side of the PCB assembly from the liquid coolant with a first seal; sealing a reflective surface formed in an opening defined in the lens block relative to the liquid coolant with a second seal; as well as The clamp on the optical fiber is connected to the lens block by sealing the connection of the clamp to the lens block from the liquid coolant with a third seal.

17. The method according to claim 16, comprising: forming the first side of the PCB assembly having a first concave recess for the at least one optoelectronic component; as well as A second side of the PCB assembly is formed having a second concave recess opposite the first concave recess.

18. The method according to claim 16, wherein: Connecting the clamp to the lens block includes fitting at least one hole in the clamp over at least one alignment pin on the lens block and sealing the fitting of the at least one hole over the at least one alignment pin with a fourth seal relative to the liquid coolant.

19. The method according to claim 16, wherein: Sealing the reflective surface from the liquid coolant with the second seal includes positioning an insert in the opening adjacent the reflective surface; sealing the insert in the opening with the second seal; And an air gap is formed between the insert and the reflective surface.

20. The method according to claim 16, wherein: Connecting the clamp to the lens block includes retaining the clamp to the lens block by coupling a clamp to the lens block.

21. The method of claim 16, further comprising enclosing the PCB assembly, the lens block, and the clamp in a housing.

22. The method of claim 16, further comprising: coupling at least one electronic component to the PCB assembly and located outside the air chamber; as well as The at least one electronic component is encapsulated with a fourth sealing member.

23. The method according to claim 16, wherein: Sealing with the first seal, sealing with the second seal, and sealing with the third seal include sealing with epoxy.

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