Patent Description:
Many types of electrical/electronic component generate heat during operation. In particular, electrical computer components such as motherboards, central processing units (CPUs), and memory modules may dissipate substantial amounts of heat when in use. Heating of the electrical components to high temperatures can cause damage, affect performance or cause a safety hazard. Accordingly, substantial efforts have been undertaken to find efficient, high performance systems for cooling electrical components effectively and safely.

To date, cooling of electrical components has typically been achieved through air cooling, for example via fans. However, it is difficult to achieve even cooling of electrical components through the use of air cooling. Furthermore, the recent increased performance of heat generating components has meant that it is difficult to provide sufficient cooling via air cooling, which limits the peak performance of such devices.

A further type of cooling system uses liquid cooling. Although different liquid cooling assemblies have been demonstrated, in general the electrical components are immersed in a coolant liquid so as to provide a large surface area for heat exchange between the heat generating electrical components and the coolant.

<CIT> discloses a cooling apparatus and a direct cooling impingement module, along with a method of fabrication thereof. The cooling apparatus and direct impingement cooling module include a manifold structure and a jet orifice plate for injecting coolant onto a surface to be cooled. The jet orifice plate, which includes a plurality of jet orifices for directing coolant at the surface to be cooled, is a unitary plate configured with a plurality of jet orifice structures. Each jet orifice structure projects from a lower surface of the jet orifice plate towards the surface to be cooled, and includes a respective jet orifice. The jet orifice structures are spaced to define coolant effluent removal regions therebetween which facilitate removal of coolant effluent from over a centre region of the electronic component being cooled to a peripheral region thereof, thereby reducing pressure drop across the jet orifice plate.

<CIT> discloses a jet impingement cooling system for an electronic device comprising: a housing; a substrate to be cooled located in the housing which substrate is arranged to be in thermal contact with the device to be cooled and which has a surface pattern thereon; a fluid inlet to the housing; at least one fluid outlet from the housing; and at least one nozzle in fluid connection with the fluid inlet for directing a jet of fluid at a portion of the substrate, wherein that the surface pattern defines at least one channel and the jet is aligned with the pattern such that at least a portion of the jet is incident on at least a portion of the channel such that the flow of the fluid from the jet is subsequently confined by the channel.

<CIT> discloses a modular microjet cooler. The modular microjet cooler may be attached to a packaged heat generating device that is mounted on a printed circuit board. The modular microjet cooler has an inlet allowing supply fluid to be directed through microjet nozzles toward an impingement surface on the packaged device. The modular microjet cooler also has one or more outlets that allow exhaust fluid to be removed. The modular microjet cooler is attached to the device after it has been packaged. Further, the modular microjet cooler may be attached to the packaged device either before or after it is mounted to the printed circuit board.

Against this background, there is provided a nozzle arrangement in accordance with claim <NUM>. There is further provided a cooling module in accordance with claim <NUM>. Further features of the invention are detailed in the dependent claims and herein.

According to the present disclosure, there is provided a nozzle arrangement for direct cooling of an electronic component, comprising: a nozzle for discharging liquid coolant; and a mount configured to disperse the liquid coolant, the mount further configured to be coupled with the electronic component; wherein the nozzle is coupled to the mount such that, in use, the liquid coolant is discharged from the nozzle through the mount and dispersed by the mount; wherein the mount is configured to be releasably coupled with the electronic component.

Preferably, the mount is configured for, in use, discharging the liquid coolant onto the electronic component.

Preferably, the mount is configured for, in use, dispersing the liquid coolant over a surface of the electronic component.

Preferably, the mount comprises an aperture for discharging liquid coolant.

Preferably, the mount comprises a plurality of grooves for dispersing liquid coolant.

Preferably, the plurality of grooves diverge from the aperture.

Preferably, the mount is configured to be coupled directly with the electronic component.

Preferably, the mount is configured to be coupled with the electronic component via a snap-fit connection.

Preferably, the mount comprises two or more resilient flanges, a distal end of each resilient flange comprising a hook.

Preferably, the mount is a unitary element.

Preferably, the mount comprises integral attachment means for attaching the mount to the electronic component.

Preferably, the nozzle is configured to be coupled to the mount via a push-fit connection.

Preferably, the nozzle may comprise a tubular protrusion for coupling with the aperture of the mount.

According to the present disclosure, there is further provided a cooling module comprising: a container housing a plurality of heat generating components, the heat generating components comprising one or more low temperature components, median temperature components, and high temperature components; and a first nozzle arrangement according to the present disclosure, the first nozzle arrangement arranged to direct liquid coolant onto a median temperature component.

Preferably, the low temperature components generate a low heat output relative to the other components in the cooling module, the high temperature components generate a high heat output relative to the other components in the cooling module, and the median temperature components generate a medium heat output relative to the other components in the cooling module.

Preferably, the nozzle arrangement is configured to direct liquid coolant to the hottest part of a heat transmitting surface of the median temperature component.

Preferably, the cooling module further comprises: a pump configured to cause liquid coolant to flow within the container; and at least one pipe, arranged to transport liquid coolant from the pump to the nozzle arrangement; wherein the nozzle arrangement comprises a nozzle, wherein the nozzle is configured to push-fit couple to a respective end of the at least one pipe.

Preferably, the cooling module further comprises a heat sink mounted on or around a high temperature component, the heat sink comprising a volume defined by a base and a retaining wall, and a nozzle for directing liquid coolant into the volume.

Preferably, the cooling module further comprises a level of liquid coolant in the container for at least partially immersing the one or more low temperature components.

Preferably, the level of liquid coolant in the volume is higher than the level of liquid coolant in the container.

Preferably, the cooling module further comprises: a component mounted away from a base of the container; and a second nozzle arrangement according to the present disclosure, the second nozzle arrangement arranged to direct liquid coolant onto the component.

Preferably, the one or more median temperature components comprise one of a solid state drive, an input/output device, or a power supply unit.

The invention may be put into practice in a number of ways and preferred embodiments will now be described by way of example only and with reference to the accompanying drawings, in which:.

With reference to <FIG> and <FIG>, there is shown a cooling module <NUM> according to the present disclosure, comprising a nozzle arrangement <NUM> in accordance with the present disclosure. Also to be considered is <FIG>, in which there is depicted an exploded view of the cooling module <NUM> of <FIG> and <FIG>. The cooling module <NUM> may, for example, comprise a server blade assembly.

The cooling module <NUM> comprises a container <NUM> (shown without a lid), housing a plurality of electrical/electronic components. (The terms electrical and electronic are used analogously herein. ) The components may generate heat during operation. The components within the cooling module <NUM> may include components <NUM> generating a relatively low temperature, components <NUM> generating a relatively high temperature, and components <NUM> generating a relatively median temperature. The absolute heat output of each category of component is not relevant to the present disclosure. What is relevant is the heat output of each component relative to the other components in the cooling module <NUM>. Low temperature components <NUM> will fall towards the bottom of a range determined by the levels of heat generated by all of the components in the cooling module <NUM>, high temperature components <NUM> will fall towards the top of the range, and median temperature components <NUM> will fall towards the middle of the range. Median temperature components <NUM> may include, but are not limited to, solid state drives (SSDs) <NUM>, input/output devices, and power supply units.

Some low temperature components <NUM>, high temperature components <NUM>, and median temperature components <NUM> are mounted on a circuit board <NUM>, which may be a computer motherboard. In <FIG>, two such identical circuit boards <NUM> are shown within the container <NUM>.

The container <NUM> is, in operation, filled with a dielectric liquid coolant (not shown), which may be termed a primary coolant. The liquid coolant is not electrically conductive, but is normally thermally conductive and can carry heat by conduction and/or convection. The quantity of liquid coolant inside the container <NUM> (which will be referred to as the 'container coolant') is sufficient to cover or immerse the low temperature components <NUM> at least partially, but it may not necessarily fully immerse the low temperature components <NUM>. The level of liquid coolant used in operation is discussed below. A pump <NUM> causes liquid coolant to flow through pipe <NUM> and travel to a heat exchanger <NUM>. The heat exchanger <NUM> receives a secondary liquid coolant (typically water or water-based) and transfers heat from the liquid coolant within the container <NUM> to this secondary liquid coolant. The secondary liquid coolant is provided to and emerges from the heat exchanger <NUM> via interface connections <NUM>. The pump <NUM> causes the cooled primary liquid coolant to exit the heat exchanger <NUM> through pipe <NUM> to a coolant manifold <NUM>, from which it is directed through further pipes <NUM> to emerge through nozzles <NUM>, <NUM>, and <NUM>.

The cooling module <NUM> is typically a rack-mounted module, and the components within the container <NUM> are preferably at least part of a computer server circuitry, for instance comprising a motherboard and associated components. The cooling module <NUM> may therefore have a height of <NUM> rack unit (1U, corresponding with <NUM>) or an integer number of rack units. The cooling module <NUM> may be configured for installation or installed in a corresponding rack, housing multiple such cooling modules (one, some, or all of which may have different internal construction from cooling module <NUM> disclosed herein). In this configuration, the secondary liquid coolant may be shared between cooling modules in a series or parallel arrangement. A plenum chamber and/or manifold may be provided in the rack to allow this. Other components may be provided in the rack for efficient and safe (such as power regulators, one or more pumps or similar devices).

First heat sinks <NUM> may be mounted on the high temperature components <NUM> (visible in <FIG>). Each heat sink <NUM> may comprise: a base made up of a mount <NUM> and a planar substrate <NUM> fixed to the mount <NUM>; a retaining wall <NUM> attached to the planar substrate <NUM>; projections <NUM> (shown in the form of pins); and fixing screws <NUM>, which attach the substrate <NUM> to the mount <NUM>. In this way, the planar substrate <NUM> sits directly on the high temperature component <NUM> and transfers heat from the high temperature component <NUM> to a volume defined by a base (the planar substrate <NUM>) and the retaining wall <NUM>, in which the projections <NUM> are provided.

The liquid coolant is delivered to each first heat sink <NUM> via a nozzle <NUM>. The nozzle <NUM> is arranged to direct coolant perpendicular to the plane of the substrate <NUM>. This forces the jet or flow of the liquid coolant directly into the volume defined by the substrate <NUM> and retaining wall <NUM> of the first heat sink <NUM>. As a consequence, heat dissipation is improved. This is especially the case in comparison with a system where the coolant is directed to flow over the heat sink, in a direction parallel to the plane of the heat sink substrate, such as in an air cooled system.

The nozzle <NUM> delivers the coolant directly in the centre of the volume defined by substrate <NUM> and retaining wall <NUM>. In this example, the centre of that volume corresponds with the hottest part of the area of the substrate <NUM>, which is adjacent to (and directly on) the high temperature component <NUM>. This provides a contraflow, such that the coldest coolant is directed to contact the hottest area of each first heat sink <NUM>. The coolant moves out radially from the hottest part, towards the retaining wall <NUM>. Sufficient coolant is pumped via nozzle <NUM> into the volume such that it overflows the retaining wall <NUM> and collects with the container coolant.

The retaining wall <NUM> acting as a side wall enables different levels of coolant. The coolant within the volume of each first heat sink <NUM> is at a relatively high level, whereas the coolant in the container <NUM>, which at least partially immerses the low temperature components <NUM>, is at a lower level. This allows significantly less liquid coolant to be used than in other similar systems that cover all components at the same height.

A number of benefits are thereby realised. Firstly, since less dielectric coolant is being used and this coolant can be expensive, costs can be significantly reduced. Dielectric liquid coolants are typically very heavy. By using less liquid coolant, the cooling module <NUM> can be more straightforward to install and/or lift. Also, installing the cooling module <NUM> can require less infrastructure. In addition, the cooling module <NUM> is easier to handle than similar systems using significantly more primary liquid coolant. The level of the primary liquid coolant within the majority of the container <NUM> is not close to the top of the container. As a result, spillages during maintenance or exchange of components are less likely. The risk of leakage is also reduced.

The retaining wall <NUM> creates a weir effect. The coolant in the container <NUM> at a relatively low level cools the low temperature components <NUM> that, in the absence of a liquid coolant, would usually be cooled by air. It is not necessary for low temperature components <NUM> to be fully immersed in liquid coolant.

A second heat sink <NUM> may be provided to cool a power supply unit. The second heat sink <NUM> may comprise a volume defined by a base (not shown) and a retaining wall <NUM> as per the first heat sink, with a nozzle <NUM> discharging liquid coolant into the volume. The second heat sink <NUM> may therefore result in a similar weir effect, with liquid coolant overflowing the retaining wall <NUM> and collecting with the container coolant.

The median temperature components <NUM> require a lesser degree of cooling than the high temperature components <NUM>, and therefore may not warrant the additional cost, complexity, and space associated with a first or second heat sink <NUM>,<NUM>. Nevertheless, as median temperature components <NUM> generate more heat than low temperature components <NUM>, it would be advantageous to provide the median temperature components <NUM> with a greater degree of cooling than is achieved through immersive cooling alone. Additional cooling may be provided to one of more of the median temperature components <NUM> by discharging liquid coolant directly onto the respective medium temperature components <NUM>.

A nozzle arrangement <NUM> as illustrated in <FIG> may be used to direct liquid coolant onto a median temperature component <NUM>. The nozzle arrangement <NUM> may generally comprise a mount <NUM> (shown in further detail in <FIG>) coupled to a nozzle <NUM>.

The mount <NUM> may comprise a generally planar element <NUM> having a first side <NUM> and an opposing second side <NUM>. An aperture <NUM> may be provided in the planar element <NUM>, through which liquid coolant may be discharged. The first side <NUM> of the planar element <NUM> may comprise dispersing means for dispersing liquid coolant discharged through the aperture <NUM>. For example, the first side of the planar element <NUM> may be provided with a plurality of grooves <NUM> diverging from the aperture <NUM>.

Two or more arms <NUM> may extend from generally opposing edges of the planar element <NUM>. The arms <NUM> may extend generally parallel to the plane of the planar element <NUM>. The arms <NUM> may have first and second sides <NUM>,<NUM> in common with the first and second sides <NUM>,<NUM> of the planar element <NUM>.

The mount <NUM> may further comprise attachment means <NUM> for attaching the mount <NUM> to a median temperature component <NUM>. Preferably, the mount may comprise integral attachment means <NUM>, such that the mount <NUM> is a unitary element. Preferably, the attachment means <NUM> may be configured to provide a releasable attachment to a median temperature component <NUM>. In particular, the attachment means <NUM> may be configured to provide a snap-fit connection. For example, a resilient flange <NUM> may extend from a distal end of each arm <NUM>. The resilient flange <NUM> may extend from the first side <NUM> of the arm <NUM>, in a direction generally perpendicular to the plane of the planar element <NUM>. A distal end of each flange <NUM> may be provided with a hook <NUM>, which may extend from the flange <NUM> in a direction generally parallel to the arm <NUM>, towards a proximal end of the arm <NUM>.

The sizing of the mount <NUM> may be bespoke to each median temperature component <NUM>, to ensure a good fit. Alternatively, the mount <NUM> may be adjustable, for example by making the arms <NUM> telescopic.

The nozzle <NUM> may be configured to be releasably coupled to the pipe <NUM>, to provide a supply of liquid coolant to the nozzle <NUM>. This may be via a push-fit connection. For example, a first tubular protrusion <NUM> extending from the nozzle <NUM> may be configured to fit inside the pipe <NUM>, as shown in <FIG>. Alternatively, the first tubular protrusion <NUM> may be configured such that the pipe <NUM> fits inside the first tubular protrusion <NUM>.

The nozzle <NUM> may further be configured to be releasably coupled to the mount <NUM>, such as via a push-fit connection. For example, a second tubular protrusion <NUM> extending from the nozzle <NUM> may be configured to provide a push-fit connection when inserted into the aperture <NUM> in mount <NUM>. In an alternative embodiment, the nozzle <NUM> may be permanently coupled to the mount <NUM>. For example, the nozzle <NUM> and the mount <NUM> may be formed as a unitary part.

The nozzle arrangement <NUM> enables the liquid coolant to be delivered directly to a median temperature component <NUM>. Additionally, the nozzle arrangement enables the liquid coolant to be delivered to a localised area of the median temperature component <NUM>. The positioning of the mount <NUM> on a surface of the median temperature component <NUM> may be optimised such that the aperture <NUM> is located over an area of the median temperature component <NUM> having the maximum heat generation. Such optimisation of the positioning of the mount <NUM> may advantageously increase the efficiently of the cooling provided by the nozzle arrangement <NUM>.

Some components in the cooling module <NUM> may be mounted away from a base of the container <NUM> (not shown), for example mounted higher up on a circuit board or mounted on a mezzanine circuit board. The location of such components may mean that they cannot be cooled by immersive cooling in the container coolant. Instead, the nozzle arrangement <NUM> may advantageously be employed to cool such components.

By utilising push- and snap-fit connections, which do not require tools, the nozzle arrangement <NUM> may be fitted and removed straightforwardly. Consequently, replacing a circuit board <NUM> (which may comprise one or more median temperature components <NUM>) or other median temperature components <NUM> in the cooling module <NUM> may be easy and quick. The nozzle <NUM> may further be provided with an earth point <NUM>, which can be coupled to an earth or ground point, to eliminate static build up in the pipe <NUM> and nozzle <NUM>.

To assemble the nozzle arrangement <NUM>, the nozzle <NUM> may be coupled to the pipe <NUM> by inserting the first tubular protrusion <NUM> into the pipe <NUM> and may further be coupled to the mount <NUM> by inserting the second tubular protrusion <NUM> of the nozzle <NUM> into the aperture <NUM> of the mount <NUM>.

Nozzle arrangements <NUM> may be coupled respectively to selected median temperature components <NUM> in a cooling module <NUM>. In particular, the mount <NUM> of the nozzle arrangement <NUM> may be directly coupled to the median temperature component <NUM> via the attachment means <NUM>. The positioning of the mount <NUM> on a surface of the median temperature component <NUM> may be optimised such that the aperture <NUM> of the mount <NUM> is located over an area of the surface of the median temperature component <NUM> which generates the most heat. Examples of positions of the mount <NUM> on a median temperature component <NUM> are shown in <FIG>.

In operation, the pump <NUM> may draw liquid coolant from the container <NUM> and drive it through the heat exchanger <NUM>, via coolant manifold <NUM>, to pipes <NUM>, from which it may be discharged by respective nozzles <NUM>,<NUM>,<NUM>. Nozzles <NUM>,<NUM> may discharge liquid coolant into first and second heat sinks <NUM>,<NUM> to cool high temperature components <NUM>. Liquid coolant overflowing the heat sinks <NUM>,<NUM> may collect with the container coolant, which may be used to cool low temperature components <NUM> via immersive cooling.

Nozzles <NUM> may discharge liquid coolant directly onto the median temperature component <NUM>. In particular, due to the positioning of the mount <NUM> on the median temperature component <NUM>, liquid coolant may be discharged onto the hottest region of the surface of the median temperature component <NUM>. Liquid coolant discharged through the nozzle <NUM> may be dispersed over the surface of the median temperature component <NUM> by the plurality of grooves <NUM> diverging from the aperture <NUM> on the first side <NUM> of the planar element <NUM>. The resulting flow path of the liquid coolant is shown by arrows <NUM> in <FIG>. The dispersed liquid coolant may cascade over the edges of the median temperature component <NUM> and collect with the container coolant.

Claim 1:
A nozzle arrangement (<NUM>) for direct liquid cooling of an electronic component comprising:
a nozzle (<NUM>) for discharging liquid coolant; and
a mount (<NUM>) configured to disperse the liquid coolant, the mount further configured to be coupled with the electronic component; wherein
the nozzle is coupled to the mount such that, in use, the liquid coolant is discharged from the nozzle through the mount and dispersed by the mount; wherein
the mount is configured to be releasably coupled with the electronic component.