CN110658595B - Flexible liquid cooling assembly for high-power pluggable connector - Google Patents

Abstract

The liquid cooled assembly includes two or more cooling subassemblies and a flexible interconnect assembly. Two or more cooling subassemblies are configured to cool two or more corresponding pluggable connector cages, each cooling subassembly including (i) a thermally conductive plate for coupling to a corresponding pluggable connector cage, and (ii) a liquid conducting channel having an inlet and an outlet for flowing a cooling liquid. The flexible interconnect assembly is configured to convey cooling fluid to and from an inlet of the cooling subassembly and to mechanically support the cooling subassembly while allowing the cooling subassembly to move relative to each other.

Description

Flexible liquid cooling assembly for high-power pluggable connector

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional patent application 62/690,987 filed on 28/6/2018, the disclosure of which is incorporated herein by reference.

Technical Field

The present invention relates generally to removing heat from pluggable electrical connectors, and more particularly to liquid cooling of pluggable electrical connectors.

Background

Electronic assemblies may employ devices that are capable of removing heat from an assembled electronic device. For example, U.S. patent application publication 2017/0135246 describes an apparatus and method for cooling electronic components. An apparatus includes a connector and an electronic component inserted into the connector. The electronic component contacts the heat sink, wherein the heat sink moves in an upward direction when the electronic component is inserted into the connector. As the radiator moves upward, the soft thermal pad located between the radiator and the liquid-cooled tubes/pipes compresses. When compressed, the thermal pad is in contact with the heat sink and the liquid cooled tube/pipe. Heat is then transferred from the electronic component through the heat sink, through the thermal pad, through the coolant tube, and into the liquid contained within the liquid coolant tube.

As another example, U.S. patent No. 9,786,578 describes a memory module cooling system that includes a liquid-cooled manifold assembly and a heat sink assembly rotatably attached to the liquid-cooled manifold assembly about an axis perpendicular to the memory module. The liquid cooled manifold assembly includes a manifold, a liquid inlet, and a liquid outlet. The heat sink assembly includes a base in thermal contact with the thermal conduit, and a heat sink in thermal contact with the thermal conduit, the heat sink configured to thermally engage the memory module. In some embodiments, thermal bonding is maintained between multiple adjacent memory modules as a particular heat sink assembly is rotated away from an associated memory module.

Disclosure of Invention

One embodiment of the present invention provides a liquid cooling assembly including two or more cooling subassemblies and a flexible interconnect assembly. Two or more cooling subassemblies are configured to cool two or more respective pluggable connector cages, each cooling subassembly including (i) a thermally conductive plate for coupling to a respective pluggable connector cage, and (ii) a liquid conducting channel having an inlet and an outlet for flowing a cooling liquid. The flexible interconnect assembly is configured to convey cooling fluid to and from an inlet of the cooling subassembly and to mechanically support the cooling subassembly while allowing the cooling subassembly to move relative to each other.

In some embodiments, the flexible interconnect assembly is configured to convey cooling fluid in series between the inlet and outlet of two or more cooling subassemblies.

In some embodiments, the flexible interconnect assembly includes tubes configured to convey a cooling fluid and to be interwoven with one another.

In one embodiment, the flexible interconnect assembly allows the cooling subassemblies to move vertically relative to each other through the tubes that are interwoven with each other.

In another embodiment, the flexible interconnect assembly includes a flexible interconnect hose configured to convey a cooling fluid.

In some embodiments, the flexible interconnect assembly allows for vertical movement of the cooling subassemblies relative to each other.

In some embodiments, the flexible interconnect assembly is configured to prevent vertical movement due to insertion or removal of a cable into or out of one of the pluggable connector cages from affecting the other of the pluggable connector cages.

In one embodiment, the flexible interconnect assembly and the two or more cooling subassemblies are attached to each other by screws.

There is also provided, in accordance with an embodiment of the present invention, a method of manufacturing, including attaching two or more respective cooling subassemblies to two or more pluggable connector cages for cooling the two or more respective pluggable connector cages, each cooling subassembly including (i) a thermally conductive plate for coupling to the respective pluggable connector cage, and (ii) a liquid conducting channel having an inlet and an outlet for flowing a cooling liquid. Coupling a flexible interconnect assembly to the two or more cooling subassemblies, wherein the flexible interconnect assembly is configured to convey cooling fluid to and from an inlet of the cooling subassemblies and to mechanically support the cooling subassemblies while allowing the cooling subassemblies to move relative to each other.

Drawings

The invention will be more fully understood from the following detailed description of embodiments of the invention taken together with the accompanying drawings, in which:

FIG. 1 is an isometric view of a liquid-cooled connector cage assembly according to one embodiment of the present invention;

FIG. 2 is an isometric view of an interleaved tube liquid cooling assembly according to an embodiment of the invention; and

FIG. 3 is a flow chart that schematically illustrates a method of manufacturing the liquid-cooled connector cage assembly of FIG. 2, in accordance with an embodiment of the present invention.

Detailed Description

SUMMARY

Pluggable connector cages for high-end electronic cards, such as network adapters, are necessary for high-speed data transmission (e.g., 100 Gb/sec) and, therefore, need to operate reliably at high electrical power, e.g., each on the order of several watts or more. A high-end network adapter may include a plurality of receptacle modules that are closely grouped together in one or more multi-cage connector cages, such as in a multi-cage quad small form-factor pluggable (QSFP) cage. Each jack module typically includes temperature sensitive semiconductor devices, such as lasers and amplifiers, that require cooling. At high data rates, air cooling methods may be inadequate, and in particular, the very limited space between cards within a unit may challenge the applicability of effective air cooling methods.

Thus, liquid cooling may be sought. However, liquid-cooled solutions may also be limited in applicability due to the limited space available. For example, liquid-cooled solutions may require hoses and tubes to supply cooling liquid to each of the plurality of connector cages on the card, which is impractical for integration in a plurality of electronic cards that are densely stacked together.

A possible solution to reducing the number of hoses is to use a single cold plate (e.g., a liquid-cooled, thermally conductive plate) that is attached to a multi-cage connector cage that houses several jack modules, one in each cage. Unfortunately, when hot plugging a cable connector (i.e., either plugged into or unplugged from the jack module), the mechanical forces mediated by the shared cold plate may result in an unacceptable temporary loss of thermo-mechanical contact between the thermally conductive plate and the adjacent jack module, which may cause damage or degradation to the temperature sensitive semiconductor devices inside the jack module. Furthermore, it is possible at least in principle to: this heat exchange also causes mechanical movement due to the sharing of the cold plate, which can interrupt the flow of data through the adjacent receptacle module.

One particular reason that such thermomechanical contact loss may occur in the multi-cage QSFP connector cage socket module is that the top surface of the QSFP connector cage moves up and down during insertion and extraction, thereby moving its cold plate. Movement of the rigid cold plate causes the top surfaces of adjacent ones of the multi-cage QSFP connector cages to similarly move and lose thermomechanical contact with the respective jack modules within each cage.

When two or more single cages are used on the card instead of the multi-cage connector cage, isolation of vertical motion also remains as long as two or more single cages share a single flexible liquid cooled assembly. In the following description, the two types of connector cages used are referred to as "connector cage assemblies".

To overcome the transient breaking of the thermo-mechanical contacts due to heat exchange, liquid-cooled solutions may include a flexible mediating material, such as a thermal pad, between the cold plate and the respective heat sink of the multi-cage connector cage (i.e., one for each cage). However, the thermal pad significantly increases the thermal impedance between the cage and the cold plate, which reduces the heat dissipation performance of the liquid-cooled thermal solution. Furthermore, the thermal pad may increase the overall thickness of the thermal solution, which may not be possible with limited spacing between cards.

Embodiments of the invention described hereinafter provide an inherently flexible liquid cooled assembly and a method of designing an inherently flexible liquid cooled assembly to remove heat from a connector cage assembly, such as a multi-cage QSFP connector cage assembly. The disclosed intrinsically flexible liquid cooled assembly maintains good thermo-mechanical contact with each individual connector cage of the connector cage assembly while avoiding thermo-mechanical contact disconnection of adjacent pluggable connector cages when heat exchange occurs.

In some embodiments, the disclosed flexible cooling assembly comprises: (a) Two or more cooling subassemblies for cooling two or more respective receptacle module pluggable connector cages, each cooling subassembly including (i) a thermally conductive plate for coupling to a respective receptacle module pluggable connector cage, and (ii) a liquid-conducting channel having an inlet and an outlet for flowing a cooling liquid, and (b) a flexible interconnect assembly configured to convey the cooling liquid to and from the inlet of the cooling subassembly, and to mechanically support the cooling subassemblies while allowing the cooling subassemblies to move relative to one another. In one embodiment, the flexible liquid cooled assembly is configured to cool two or more respective pluggable connector cages by passing cooling liquid in series between the inlet and outlet of the two or more cooling subassemblies.

The disclosed flexible liquid cooled assembly is configured to isolate relative (e.g., vertical) motion between each of the multiple cage connector cages when heat exchange occurs. The height of the flexible interconnect assembly above the card surface does not exceed a given predetermined value in order to comply with existing specifications that provide very limited space between cards inside the unit.

In some embodiments, the flexibility of the disclosed cooling assembly is achieved by the cooling assembly including interconnects, such as tubes (pipes), that are interwoven with one another. The interwoven interconnects transfer the cooling fluid to a series of firmly attached individual heat conducting plates. The disclosed interwoven arrangement provides mechanical flexibility (e.g., elasticity) that prevents vertical movement of adjacent connector cages when heat exchange occurs in one of the connector cages sharing the interwoven cooling assembly.

In general, embodiments of the invention encompass various types of connector cages (e.g., SFP, DD-SFP, SFP +, QSFP +, DD-QSFP, etc.) and various mechanical designs of the disclosed liquid-cooled assemblies, where such mechanical designs may include different mechanical solutions to prevent unintended relative (e.g., vertical) mechanical movement and resulting disconnection of data traffic during heat exchange. For example, the design may use a resilient element such as a spring and/or a soft element such as a soft liquid interconnect (e.g., a silicone rubber interconnect hose with silicone rubber not reinforced or reinforced, for example, by interweaving with wires).

The disclosed liquid cooled component solutions, such as interleaved pipe layouts, may enable the development of network adapters capable of maintaining data traffic at higher data rates with higher corresponding electrical power.

Flexible liquid cooling assembly for high-power pluggable connector

FIG. 1 is an isometric view of a liquid-cooled connector cage assembly 10 according to one embodiment of the present invention. The connector cage assembly 10 may be part of a network element, such as a packet switch, that requires a large number of densely packed pluggable connector cages to input and/or output a large amount of data traffic.

Each such pluggable connector cage 14 is configured to receive a receptacle module 44 that includes a heat-sensitive photonic element such as an optoelectronic transducer (e.g., a semiconductor laser and a photodiode). The primary heat source is a semiconductor laser (e.g., VCSEL or other laser source). Each such receptacle module 44 (or the pluggable connector cage itself) may also include electronic components, such as a transimpedance amplifier that amplifies the photodiode output. Photonic and electronic devices in a given cage can consume between a few watts to over ten watts of electrical power, so densely packed connector cages need to each effectively cool the receptacle modules 44 that they receive.

As seen, for example, the liquid-cooled connector cage assembly 10 mounted on the card 12 includes five individual pluggable connector cages 14 packaged together. The liquid-cooled connector cage assembly 10 also includes a flexible cooling assembly 100, the flexible cooling assembly 100 including, for example, four cooling subassemblies 50 coupled to a flexible interconnect assembly 200. As can be seen, each cooling subassembly 50 includes a thermally conductive plate 16. The cooling subassemblies 50 are fluidly connected, e.g., in-line fluidly connected, by a flexible interconnect assembly 200, as illustrated in fig. 2.

Each pluggable connector cage 14 includes a receptacle 30, the receptacle 30 may receive a receptacle module 44, the receptacle module 44 further receiving a cable plug 15 having electrical contacts and/or optical interconnects 17. During hot plugging, i.e., when the plug 15 is inserted or removed, the top surface of the corresponding connector cage temporarily moves up and down in the vertical direction 33. Unless isolated, this vertical movement causes the top surfaces of adjacent connector cages to similarly move, which may cause an unacceptable momentary interruption in the cooling of adjacent receptacle modules 44 (not shown).

Each of the five connector cages 14 has a heat sink plate 22 attached to the top surface of the connector cage. Each thermally conductive plate 16 of the cooling subassembly 50 of the flexible cooling assembly 100 is directly attached to the top surface of each of the four heat spreader plates 22 (of the five). The fifth heat sink plate of the particular connector cage assembly shown in fig. 1 will receive cooling (not shown) from the adjacent cooling assembly.

In general, the number of cages per connector cage assembly and the number of cooling subassemblies per flexible cooling assembly are each determined by engineering considerations and each may vary independently of each other according to a particular design.

Each cooling subassembly 50 also includes a C-shaped copper conduit 18 for flowing a cooling fluid that is embedded in the corresponding heat-conducting plate 16 for cooling the corresponding connector cage 14. As can be seen, each conduit 18 has an inlet 19 and an outlet 29 for the flow of cooling liquid. The thicknesses of the heat dissipation plate 22 and the heat conductive plate 16 are limited due to the limited space between the cards inside the unit.

The copper tubes 18 serially cool the connector cage 14 by cooling the liquid flowing inside the tubes 18. The cooling fluid enters the tube 18 via an inlet 32 and exits via an outlet 34. As can be seen, the tubes 18 extend beyond the cooling plate 16 in a direction opposite the jacks 30 and are interconnected in a flexible interconnect assembly 200 to produce the disclosed flexible cooling assembly 100. The flexible interconnect assembly 200 utilizes the available space in other densely packed cards that do not have the more spacious space for thermal solutions. In particular, the flexible interconnect assembly 200 is positioned by design at approximately the same height as the connector cage 14 to conform to the available space between the cards.

In the embodiment described below in fig. 2, the flexible interconnect assembly is implemented by interweaving tubes 18. However, the flexible interconnect assembly 200 may include other solutions, such as the use of springs and/or soft interconnect hoses that isolate relative (e.g., vertical) motion.

The isometric view shown in fig. 1 was chosen purely for conceptual clarity. In the illustrated embodiment, the flexible interconnect assembly 200 is placed at the rear of the cooling subassembly 50. In other designs, the disclosed solution may have different forms and locations, such as a flexible component located on top of the cooling subassembly 50 if there is space available between the cards. In general, the liquid conducting channel for flowing the cooling liquid, such as the pipe 18, can be implemented in an alternative manner to the pipe. For example, it may be implemented as a closed channel or other lumen formed within the plate 16. Elements that are not mandatory for understanding the disclosed mechanical isolation techniques, such as electrical components and interconnects, are omitted from the figures for simplicity of representation.

Interweaving pipe liquid cooling assembly for high-power pluggable connector

FIG. 2 is an isometric view of an interleaved tube liquid cooling assembly 110 according to one embodiment of the invention. The cooling assembly 110 includes a flexible interwoven interconnect assembly of tubes 220 which are laterally positioned out of the thermally conductive plates 16 in a direction opposite the receptacles 30 of the connector cage 14. The interwoven interconnect assembly 220 is a more general conceptual embodiment of the flexible interconnect assembly 200 depicted in fig. 1.

In the illustrated embodiment, the copper tubes 18 serially cool the connector cage 14 by cooling the liquid flowing inside the tubes 18. As can be seen, each conduit 18 has an inlet 19 and an outlet 29 for the flow of cooling liquid. Generally, the cooling scheme may involve parallel cooling of at least a portion of the connector cage 14. As can be seen, the tube 18 extends beyond the thermally conductive plate 16 in the opposite direction to the receptacle 30 and is interconnected by U-shaped conduits 20a and 20b which are interwoven with one another. U-shaped tubes 20a and 20b have respective apertures 40a and 40b between successive ones of the longitudinal portions of tubes 20a and 20 b. The apertures 40a and 40b are maximized by the interleaved design of the tubes 20a and 20 b. The maximized aperture (i.e., maximized lengths 40a and 40 b) maximizes the flexibility required for the interleaved interconnect assembly 220, and this flexibility enables each pluggable cage 14 to independently move vertically.

In one embodiment, the tubes 20a and 20b are made of copper. In other embodiments, the conduits 20a and 20b may be made of another resilient material or made of a flexible material (e.g., silicone rubber), whichever material is found to isolate the conduits 20a and 20b from vertical movement of each cooling subassembly 50.

FIG. 3 is a flow chart that schematically illustrates a method of manufacturing the interwoven tubes of the liquid-cooled connector cage assembly 110 of FIG. 2, in accordance with one embodiment of the present invention. The process begins at manufacturing step 82 with receiving a connector cage assembly (e.g., a "box" of cages packaged together), each heat sink plate 22 being attached to the top surface of each respective connector cage 14 of the cage assembly. Next, at a multi-cage connector cage attachment step 82, the prepared connector cage assembly with the connector cage 14 and the plate 22 is attached (e.g., welded) to the card 12.

The manufacturing process is run generally in parallel, and at receiving step 84, the manufactured interleaved tube cooling assembly 220 is received. Step 84 may include visually inspecting the cooling assembly 220 and/or testing the cooling assembly 220 for leaks. Next, at a liquid cooling assembly step 86, hoses of flexible material, such as natural or synthetic rubber, that absorb cold plate movement during heat exchange are coupled to the inlet 32 and outlet 34 of the cooling assembly 110.

At a securing step 88, the interwoven tube cooling assembly 220 is secured to the plate 22 on top of the connector cage 14, for example, by using screws to secure each heat-conducting plate 16 to a corresponding heat-dissipating plate 22. Finally, at an assembly step 90, the liquid cooled assembled card 12 is installed into the system (i.e., into a unit of a card enclosure similar to the card 12).

The flow chart of fig. 3 is obtained by way of example. Such an assembly process typically includes many steps and processes that have been omitted for clarity. For example, details such as the type of hose connectors used to couple the plastic hoses to the inlet 32 and outlet 34 of the cooling assembly 110 are omitted.

Although the embodiments described herein primarily address thermal solution connector cage assemblies used in high-end network adapters and other network elements, the methods and systems described herein may also be used to cool other types of connector cage assemblies operating under hot-swapping conditions, such as those used in medical mode.

It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. Documents incorporated by reference in this patent application are to be considered an integral part of the application and, unless any term is defined in these incorporated documents in a manner that conflicts with the definitions explicitly or implicitly set forth in the specification, only the definitions in the specification should be considered.

Claims (14)

1. A liquid cooling assembly comprising:

two or more sockets mounted side-by-side and configured to receive a corresponding two or more plugs, the sockets including heat-generating electronic components;

two or more cooling subassemblies for removing at least some heat from the respective two or more sockets, each cooling subassembly comprising (i) a thermally conductive plate for coupling to a respective socket, and (ii) a liquid conducting channel having an inlet and an outlet for flowing a coolant to cool the thermally conductive plate; and

a flexible interconnect assembly configured to (a) convey the cooling liquid to and from an inlet of the cooling subassembly, and (b) mechanically support the cooling subassembly while allowing the two or more receptacles mounted side-by-side to move relative to each other.

2. The liquid cooling assembly of claim 1, wherein the flexible interconnect assembly is configured to convey the cooling liquid in series between the inlet and the outlet of the two or more cooling subassemblies.

3. The liquid cooling assembly of claim 1, wherein the flexible interconnect assembly comprises tubes configured to convey the cooling liquid and to be interlaced with one another.

4. The liquid cooling assembly of claim 3 wherein said flexible interconnect assembly allows said side-by-side mounted sockets to move vertically relative to each other through said interleaved tubes.

5. The liquid cooling assembly of claim 1, wherein the flexible interconnect assembly comprises a soft interconnect hose configured to convey the cooling liquid.

6. The liquid cooling assembly of claim 1, wherein the flexible interconnect assembly allows vertical movement of the side-by-side mounted sockets relative to each other.

7. The liquid cooling assembly of claim 1, wherein the flexible interconnect assembly is configured to prevent vertical movement due to insertion or removal of a cable from one of the sockets from affecting the other of the sockets.

8. The liquid cooling assembly of claim 1, wherein the flexible interconnect assembly and the two or more cooling subassemblies are attached to each other by screws.

9. A method of manufacturing a liquid cooled component comprising:

attaching two or more respective cooling subassemblies to two or more receptacles for removing at least some heat from the respective two or more receptacles, each cooling subassembly comprising (i) a thermally conductive plate for coupling to a respective receptacle, and (ii) a liquid conducting channel having an inlet and an outlet for flowing a coolant to cool the thermally conductive plate; and

coupling a flexible interconnect assembly to the two or more cooling subassemblies, the flexible interconnect assembly being configured to (i) convey the cooling liquid to and from an inlet of the cooling subassemblies and (ii) mechanically support the cooling subassemblies while allowing the cooling subassemblies to move relative to each other.

10. The method of manufacturing of claim 9, wherein cooling the socket comprises passing the cooling fluid in series between the inlet and the outlet of the two or more cooling subassemblies.

11. The method of manufacturing of claim 9, wherein coupling the flexible interconnect assembly includes coupling tubes that are interwoven with one another.

12. The method of manufacturing of claim 11, wherein allowing the cooling subassemblies to move vertically relative to each other through the flexible interconnect assembly includes interweaving tubes of the flexible interconnect assembly with each other.

13. The method of manufacturing of claim 9, wherein coupling the flexible interconnect assembly comprises coupling a flexible interconnect hose.

14. The method of manufacturing of claim 9, wherein coupling the flexible interconnect assembly includes attaching the flexible interconnect assembly and the two or more cooling subassemblies to one another using screws.

Images