Cold plate with split counterflow passages

Abstract

A localized cooling device includes a first plate with a contact surface configured to be in contact with one or more heat- generating components, and a second plate arranged in parallel with the first plate. A first fluid passage and a second fluid passage receive fluid from a same inlet and provide fluid to a same outlet. A first fluid path through the first fluid passage and a second fluid path through the second fluid passage are sandwiched between the first plate and the second plate, and the first fluid path and the second fluid path are in opposite directions.

Description

COLD PLATE WITH SPLIT COUNTERFLOW PASSAGESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Serial No. 63 / 661,134, filed June 18, 2024 and entitled “COLD PLATE WITH SPLIT COUNTERFLOW PASSAGES,” the entire contents of which is incorporated herein by reference.BACKGROUND

[0002] The present disclosure relates to localized cooling and, more particularly, to a cold plate with split counterflow passages.

[0003] Electronic devices of different types used in different applications can generate heat. When the electronic devices are enclosed or otherwise unable to dissipate a significant amount of the generated heat to the ambient environment, an approach to preventing overheating of the electronic devices can involve localized cooling. A liquid cold plate is an exemplary localized cooling device that facilitates heat transfer between electronic devices in contact with the cold plate and liquid flowing in a fluid channel within the cold plate.SUMMARY

[0004] According to one or more embodiments, a localized cooling device includes a first plate with a contact surface configured to be in contact with or proximate one or more heat-generating electronics; a second plate spaced apart from the first plate; and a first fluid passage and a second fluid passage configured to receive fluid from a same inlet and configured to provide fluid to a same outlet, wherein: at least a portion of the first fluid passage and at least a portion of the second fluid passage are between the first plate and the second plate, and the at least a portion of the first fluid passage and the at least a portion of the second fluid passage are configured to provide fluid flow in opposite directions.

[0005] According to one or more embodiments, a method of manufacturing a localized cooling device includes configuring a first plate to contact one or more heatgenerating electronics; arranging a second plate spaced apart from the first plate; andarranging a first fluid passage and a second fluid passage such that at least a portion of the first fluid passage and at least a portion of the second fluid passage are between the first plate and the second plate, and the at least a portion of the first fluid passage and the at least a portion of the second fluid passage are configured to provide fluid flow in opposite directions.

[0006] The foregoing has outlined some of the pertinent features of the disclosed subject matter. These features are merely illustrative.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like reference character. For purposes of clarity, not every component may be labeled in every drawing. The drawings are not necessarily drawn to scale, with emphasis instead being placed on illustrating various aspects of the techniques and devices described herein.

[0008] FIG. 1A is a perspective view of an exemplary cold plate including bifurcated counterflow passages according to some embodiments;

[0009] FIG. IB shows a contact surface of the exemplary cold plate of FIG. 1A;

[0010] FIG. 2 is a view of the exemplary cold plate of FIG. 1A without an outgoing passage housing;

[0011] FIG. 3 A is a perspective view of an exemplary cold plate illustrating flow in one of the bifurcated counterflow passages according to some embodiments;

[0012] FIG. 3B is a perspective view of the exemplary cold plate of FIG. 3A illustrating flow in the other of the bifurcated counterflow passages according to some embodiments;

[0013] FIG. 3C is a perspective view of the exemplary cold plate of FIG. 3 A illustrating flow in both of the bifurcated counterflow passages according to some embodiments; and

[0014] FIG. 4 illustrates bifurcated counterflow of coolant in an exemplary cold plate according to some embodiments.DETAILED DESCRIPTION

[0015] Reference will now be made to the drawings to describe the present disclosure in detail. It will be understood that the drawings and exemplified embodiments are not limited to the details thereof. Modifications may be made without departing from the spirit and scope of the disclosed subject matter.

[0016] Electronic components generate heat that cannot sufficiently be dissipated to the environment in some applications. Localized cooling of such electronic components can ensure that an overheat condition is not reached and the system continues to operate. A cold plate is an exemplary device that facilitates localized cooling. A conventional cold plate has an inlet on one side, an outlet on another side, and a passage which is a channel for coolant from the inlet to the outlet. The coolant is introduced into the cold plate via the inlet and the coolant flows through the channel within the cold plate to the outlet. When the cold plate is arranged in contact with one or more heat-generating electronic components, the coolant can absorb heat from the electronic components as it flows through the channel between the inlet and outlet.

[0017] In some applications, a long coolant channel may be needed. One such application is a curing application that involves a lighting module. The lighting module may include an array of light emitters (e.g., solid state light emitting diodes (LEDs)) arranged in a line. The lighting module may be used to cure ink, adhesive, resin, or another material. An elongated conventional cold plate with a long channel may prove ineffective in cooling the light module, because the coolant, which absorbs heat from LEDs closer to the inlet, may be too hot by the time it reaches LEDs closer to the outlet of the cold plate to undergo heat transfer with those LEDs. While a lighting module is discussed for explanatory purposes, the techniques described herein can be applied to other applications, such as cooling other types of electronics, for example.

[0018] According to some embodiments, bifurcated counterflow passages are used for the flow of the coolant within the cold plate. The inventors recognized that introducing fresh coolant (i.e., coolant that has not undergone heat exchange with any electronic components) on opposite sides of the cold plate facilitates initiating heat absorption from electronic components on both ends of a lighting module with equal effectiveness. According to some embodiments, based on the arrangement of thepassages, by the time the coolant has absorbed heat from several LEDs and is less effective for heat exchange, it reaches LEDs that have already been cooled by coolant flow in the opposite direction, according to the counterflow arrangement. Thus, not only are all the LEDs of the light module cooled effectively by the bifurcated counterflowing coolant but a uniform temperature is also achieved for all the LEDs of the light module. That is, thermal equilibrium may be achieved for the entire cold plate as compared with conventional designs with a similar flow rate and pressure drop that have fewer flow paths within the cold plate.

[0019] In some embodiments, additional flow paths may be concentrated in one or more areas with relatively higher thermal load in order to achieve the thermal equilibrium for the entire cold plate. For example, for use with a system that is expected to have the highest heat output in a region, the cold plate may be designed to include additional flow paths in such a region. Based on the additional cooling provided in the region by the additional flow paths, a uniform temperature may be achieved with the cold plate.

[0020] While bifurcated counterflow passages are detailed for explanatory purposes, a multi-split design is contemplated according to additional or alternate embodiments. The multi- split design may be implemented via a split into three or more passages at one level (e.g., at or near the inlet) or via a hierarchical multi-split scheme in which passages are split into two or more paths and then one or more of those passages are further split at a next hierarchical level. For example, a passage at an inlet may be split into four passages, with each routed to a different side or area of the cold plate to begin cooling a different side or area of a device coupled to the cold plate.

[0021] Whether bifurcated or additionally split, the multi-split passages may result in reduced fluid velocity within the passages as compared with the volumetric flow rate of the fluid (coolant) at the inlet. The split into two or more passages may increase heat absorbed per unit volume of the fluid and reduce pressure drop of the fluid through the cold plate. By controlling volumetric flow rate at the inlet and a configuration of the splits of the passages, pressure drop of the fluid as it traverses the paths and / or heat absorbed per unit volume of fluid within the paths may be controlled.

[0022] FIG. 1A is a perspective view of an exemplary cold plate 100 of a localized cooling device including bifurcated counterflow passages 105 according tosome embodiments. As shown, the cold plate 100 includes an inlet 110 through which coolant (e.g., cold water, another fluid) is introduced and an outlet 120 through which spent coolant is removed from the cold plate 100. A contact plate 130 is shown to have a contact surface 135 that can be arranged in contact with or otherwise proximate the LEDs or other components to be cooled. A cover plate 140 is parallel with and arranged above the contact plate 130, according to the orientation shown in FIG. 1A, such that the contact plate 130 and the cover plate 140 sandwich portions of the passages 105 that facilitate heat transfer between coolant flowing in the passages 105 and components in contact with the contact surface 135. That is, fluid paths A-l, A-2, B-l, B-2 (FIG. 3C) within the passages 105 are sandwiched or disposed between the contact plate and cover plate such as between a first side 101 and a second side 102 of the contact plate 130 and cover plate 140 (shown in FIG. 2). In alternate embodiments, the fluid paths may be integrally formed in the contact plate 130 and / or cover plate 140 rather than in separate passages 105, or partially integrally formed and partially in separated passages 105. In some embodiments, the turns at ends of the system may be provided in the body of the assembly or by connected piping / tubing at suitable interfaces.

[0023] Referring to FIG. 1A, the fluid paths through the two passages 105 may be in opposite directions such that there is a counterflow of fluid (cold water or other coolant) in the passages 105, according to some embodiments, and will be discussed further in relation to FIGS. 3A-3C. An outgoing passage housing 145 may be used to cool additional components (e.g., printed circuit board assembly (PCBA)) arranged to contact the outgoing passage housing 145. The housing may be for portions of the two passages that as described in further detail herein combine at a combiner.

[0024] FIG. IB shows a contact surface 135 of the exemplary cold plate 100 of FIG. 1A. A portion of the contact surface 135 is enlarged. This portion is shown in contact with three exemplary FED modules 150 of a light module for explanatory purposes. The slots 160 and holes 165 may be used to mount additional FED modules 150 along the length of the cold plate 100. However, the techniques described herein are not limited to the manner in which FED modules or other electronics are mounted.

[0025] FIG. 2 shows the exemplary cold plate 100 of FIG. 1A without the outgoing passage housing 145 to illustrate components within housing 145. Apassage 105 from the inlet 110 is bifurcated by a splitter 210 into two counterflowing passages 105, as further discussed with reference to FIGs. 3A and 3B. These counterflowing passages 105 are recombined at a combiner 220 that can direct spent coolant in both passages 105 to the outlet 120.

[0026] FIGs. 3 A - 3C illustrate the two counterflowing paths of the coolant through the cold plate 100 according to some embodiments. FIGs. 3 A and 3B each illustrate flow in one of the bifurcated passages 105 for explanatory purposes, while FIG. 3C illustrates coolant flow in both bifurcated passages 105 and shows the counterflow according to some embodiments.

[0027] FIG. 3A is a perspective view of an exemplary cold plate 100 illustrating flow in one of the bifurcated counterflow passages 105 according to some embodiments. The cold plate 100 is shown without a cover plate 140 or outgoing passage housing 145 to expose the segments of the passages 105 that are in contact with the contact plate 130. A solid arrow is used to indicate coolant coming into the cold plate 100 via the inlet 110. At the splitter 210, coolant in one of the bifurcated passages 105 is indicated with a dashed arrow. As shown, the coolant traverses the length of the contact plate 130 (left to right according to the orientation shown in FIG. 3 A) and is then directed along the length of the contact plate 130 in the opposite direction (right to left) before being directed up, away from the surface of the contact plate 130, and to the combiner 220, which channels the coolant to the outlet 120.

[0028] FIG. 3B is a perspective view of the exemplary cold plate 100 of FIG. 3A illustrating flow in the other of the bifurcated counterflow passages 105 according to some embodiments. Again, a solid arrow is used to indicate coolant flow via the inlet 110 to the splitter 210. An arrow with alternating dashes and dots is used to indicate the flow of coolant from the splitter 210 through another bifurcated passage 105, different from the flow of coolant in the passage 105 shown by the dashed arrows in FIG. 3A. The coolant in this path traverses the length of the contact plate 130 (right to left according to the orientation shown in FIG. 3B) and is then directed along the length of the contact plate 130 in the opposite direction (left to right) before being directed up, away from the surface of the contact plate 130, and to the combiner 220, which channels the coolant to the outlet 120 along with the coolant indicated by dashed arrows in FIG. 3A.

[0029] FIG. 3C illustrates coolant flow in both bifurcated passages 105. An enlarged view is provided of the segments of the passages 105 that are in contact withthe contact plate 130, and labels are added to indicate the initial path and subsequent path in the flow of the coolant through the passages 105. Specifically, the initial path traversed by the coolant in each of the bifurcated passages 105 is labeled using “A” and the subsequent path traversed by the coolant is labeled using “B.” As discussed with reference to FIG. 3A, for one of the bifurcated passages 105 (with flow path indicated by the dashed arrow), the initial traversal for the coolant flow is from left to right (labeled “A-l”) and the subsequent traversal is from right to left (labeled “B-l”). As discussed with reference to FIG. 3B, for the other bifurcated passage 105 (indicated by the alternating dash and dot), the initial flow path of the coolant is from right to left (labeled “A-2”) and the subsequent traversal of the coolant is from left to right (labeled “B-2”).

[0030] Thus, initially, the coolant flows from left to right in the path labeled “A-l” and from right to left in the path labeled “A-2.”. This counterflow of coolant in the A-l and A-2 paths means that LEDs 150 at the opposite ends of the array are cooled by fresh coolant based on the bifurcation at the splitter 210. Subsequently, the coolant flows from right to left in the path labeled “B-l” and also from left to right in the path labeled “B-2.” This counterflowing coolant in the B-l and B-2 paths encounters already -cooled LEDs 150 that were cooled by flow in the A-l and A-2 paths. That is, the LEDs 150 or other electronic devices on the ends that are cooled by coolant at its lowest temperature (i.e., fresh introduced coolant) traversing paths A- 1 and A-2 then encounter coolant at its highest temperature (i.e., coolant that has undergone thermal heat exchange with every LED 150 or other electronic device) traversing paths B-l and B-2. This results in all of the LEDs 150 of the array or other electronic devices having a more uniform temperature as compared with a configuration in which only paths A-l and A-2 were traversed, for example. The coolant in the B-l and B-2 paths meets at the combiner 220 for flow to the outlet 120.

[0031] FIG. 4 illustrates bifurcated counterflow of coolant in an exemplary cold plate 100 according to some embodiments. One bifurcated flow path is indicated in white while the other is indicated in black. As shown, coolant from the inlet 110 is split by a splitter 210 into two passages 105 that traverse the length of the plates 130, 140 of the cold plate 100 in opposite directions. The passages 105 come back together at the combiner 220 to direct spent coolant to the outlet 120. The portions of the passages 105 that are in contact with the contact plate 130 each traverse the length of the contact plate 130 twice. The bifurcated flow enters the portions of the passages105 that are in contact with the contact plate 130 in opposite directions, as detailed with reference to FIGs. 3A-3C. The second pass of coolant in each of the bifurcated passages 105 results in uniform temperature of the LEDs 150 or other electronic devices.

[0032] As shown, in some embodiments, a first fluid path through a first fluid passage extends from a first side of a first plate and a second plate to a second side of the first plate and the second plate then back to the first side, and a second fluid path through the second fluid passage extends from the second side to the first side then back to the second side. In some embodiments, the one or more heat-generating electronics (e.g., exemplary LED modules 150 shown in FIG. IB) have a longest dimension and the first fluid passage and second fluid passage may receive fluid flowing in opposite directions parallel to the longest dimension. The fluid passages may be configured to provide fluid flow in opposite directions.

[0033] According to some embodiments, a method of manufacturing a localized cooling device may be provided. The method may include: configuring a first plate to contact one or more heat-generating components; arranging a second plate in parallel with the first plate; and arranging a first fluid passage and a second fluid passage such that a first fluid path through the first fluid passage and a second fluid path through the second fluid passage are sandwiched between the first plate and the second plate, and the first fluid path and the second fluid path are in opposite directions. The method may include arranging one or more elements as described herein. The method may include housing portions of the first fluid passage and the second fluid passage that combine at the combiner within a housing.

[0034] Examples:

[0035] Embodiments may include the following exemplary aspects and may include any suitable combination of the features described herein.

[0036] (1) A localized cooling device comprising: a first plate with a contact surface configured to be in contact with one or more heat-generating electronics; a second plate arranged spaced apart from the first plate (e.g., in parallel); and a first fluid passage and a second fluid passage configured to receive fluid from a same inlet and configured to provide fluid to a same outlet, wherein: at least a portion of (a first fluid path through) the first fluid passage and at least a portion of (a second fluid path through) the second fluid passage are between the first plate and the second plate, and the at least a portion of the (first fluid path through) the first fluid passage and the atleast a second portion of the (second fluid path through) the second fluid passage are configured to provide flow in opposite directions.

[0037] (2) The localized cooling device of aspect (1), wherein the first fluid path through the first fluid passage extends from a first side of the first plate and the second plate to a second side of the first plate and the second plate then back to the first side.

[0038] (3) The localized cooling device of aspect (2), wherein the second fluid path through the second fluid passage extends from the second side to the first side then back to the second side.

[0039] (4) The localized cooling device of aspect (1), further comprising a splitter configured to split an inlet passage from the inlet into the first fluid passage and the second fluid passage.

[0040] (5) The localized cooling device of aspect (1), further comprising a combiner configured to combine the first fluid passage and the second fluid passage into an outlet passage to the outlet.

[0041] (6) The localized cooling device of aspect (5), further comprising a housing for portions of the first fluid passage and the second fluid passage that combine at the combiner.

[0042] (7) The localized cooling device of aspect (1), wherein the one or more heat-generating electronics have a longest dimension and the first fluid passage and second fluid passage receive fluid flowing in opposite directions parallel to the longest dimension.

[0043] (8) A method of manufacturing a localized cooling device, the method comprising: configuring a first plate to contact one or more heat-generating electronics; arranging a second plate spaced apart from the first plate; arranging a first fluid passage and a second fluid passage such that at least a portion of (a first fluid path through) the first fluid passage and at least a portion of (a second fluid path through) the second fluid passage are between the first plate and the second plate, and the first fluid path and the second fluid path are configured to provide fluid flow in opposite directions.

[0044] (9) The method of aspect (8), wherein arranging the first fluid passage includes the at least a portion of (the first fluid path through) the first fluid passage extending from a first side of the first plate and the second plate to a second side of the first plate and the second plate then back to the first side.

[0045] (10) The method of aspect (9), wherein arranging the second fluid passage includes the at least a portion of (the second fluid path through) the second fluid passage extending from the second side to the first side then back to the second side.

[0046] (11) The method of aspect (8), further comprising arranging a splitter to split an inlet passage from an inlet into the first fluid passage and the second fluid passage.

[0047] (12) The method of aspect (8), further comprising arranging a combiner to combine the first fluid passage and the second fluid passage into an outlet passage to an outlet.

[0048] (13) The method of aspect (12), further comprising housing portions of the first fluid passage and the second fluid passage that combine at the combiner within a housing.

[0049] Various aspects of the embodiments described above may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

[0050] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both,” of the elements so conjoined, e.g., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, e.g., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0051] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0052] As used herein in the specification and in the claims, the phrase, “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently, “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, ,and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0053] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0054] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0055] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0056] The word “exemplary” is used herein to mean serving as an example, instance, or illustration. Any embodiment, implementation, process, feature, etc., described herein as exemplary should therefore be understood to be an illustrativeexample and should not be understood to be a preferred or advantageous example unless otherwise indicated.

[0057] Having thus described several aspects of at least one embodiment, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the spirit and scope of the principles described herein. Accordingly, the foregoing description and drawings are by way of example only.

Claims

CLAIMSWhat is claimed is:

1. A localized cooling device comprising: a first plate with a contact surface configured to be in contact with or proximate one or more heat- generating electronics; a second plate spaced apart from the first plate; and a first fluid passage and a second fluid passage configured to receive fluid from a same inlet and configured to provide fluid to a same outlet, wherein: at least a portion of the first fluid passage and at least a portion of the second fluid passage are between the first plate and the second plate, and the at least a portion of the first fluid passage and the at least a portion of the second fluid passage are configured to provide fluid flow in opposite directions.

2. The localized cooling device according to claim 1, wherein the at least a portion of the first fluid passage extends from a first side of the first plate and the second plate to a second side of the first plate and the second plate then back to the first side.

3. The localized cooling device according to claim 2, wherein the at least a portion of the second fluid passage extends from the second side to the first side then back to the second side.

4. The localized cooling device according to claim 1, further comprising a splitter configured to split an inlet passage from an inlet into the first fluid passage and the second fluid passage.

5. The localized cooling device according to claim 1, further comprising a combiner configured to combine the first fluid passage and the second fluid passage into an outlet passage to the outlet.

6. The localized cooling device according to claim 5, further comprising a housing for portions of the first fluid passage and the second fluid passage that combine at the combiner.

7. The localized cooling device according to claim 1, wherein the one or more heat-generating electronics have a longest dimension and the first fluid passage and second fluid passage receive fluid flowing in opposite directions parallel to the longest dimension.

8. A method of manufacturing a localized cooling device, the method comprising: configuring a first plate to contact one or more heat- generating electronics; arranging a second plate spaced apart from the first plate; and arranging a first fluid passage and a second fluid passage such that at least a portion of the first fluid passage and at least a portion of the second fluid passage are between the first plate and the second plate, and the at least a portion of the first fluid passage and the at least a portion of the second fluid passage are configured to provide fluid flow in opposite directions.

9. The method according to claim 8, wherein arranging the first fluid passage includes the at least a portion of the first fluid passage extending from a first side of the first plate and the second plate to a second side of the first plate and the second plate then back to the first side.

10. The method according to claim 9, wherein arranging the second fluid passage includes the at least a portion of the second fluid passage extending from the second side to the first side then back to the second side.

11. The method according to claim 8, further comprising arranging a splitter to split an inlet passage from an inlet into the first fluid passage and the second fluid passage.

12. The method according to claim 8, further comprising arranging a combiner to combine the first fluid passage and the second fluid passage into an outlet passage to an outlet.

13. The method according to claim 12, further comprising housing portions of the first fluid passage and the second fluid passage that combine at the combiner within a housing.

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