Heat transfer components, computing sub-components, and computing systems

Abstract

The present disclosure relates to heat transfer assemblies, computing subassemblies, and computing systems. One or more active elastic members integrated in the sleeve apply a compressive force to PCA components that need to be cooled. The compressive force generates and maintains thermal contact, and heat is conducted from the PCA components and into the sleeve through the thermal contact. The sleeve conducts heat (directly or indirectly) to a liquid-cooled cold plate, which is configured as a cooling frame surrounding one or more PCAs with sleeves. The sleeve optionally transfers heat from components on the PCA to the cooling frame through an intermediate heat transfer device (such as a radiator or heat pipe). Liquid flowing through the internal channels of the cooling frame convects heat away from the electronic device. The turbulence promoted by the turbulence enhancement portion including a bend and a shape change portion along the internal channel improves the efficiency of convection.

Description

Background Art

[0001] Many electronic components are designed to operate within a temperature range defined in a temperature specification. More specifically, operating temperature affects the operability and efficiency of a computing device. Excessive heat typically degrades the real-time performance of electronic components. Over time, this heat may also fatigue the component materials, which in turn may shorten the useful life of the hardware. Therefore, in large or powerful computing devices that may have a high density of heat-generating electronic components, heat management and cooling of these electronic components is an area of ​​concern. As technology advances, electronic devices continue to be configured in greater numbers and at greater densities. This type of implementation may typically exacerbate concerns (and difficulties) about maintaining operating temperatures within design specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The presently disclosed technology may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0003] Figure 1 is an exploded perspective assembly view of a liquid cooling system for a printed circuit assembly.

[0004] Figure 2 is Figure 1 The heat dissipation mechanism used in the system is along Figure 1 Schematic diagram of a partial cross section taken along line 2-2 in FIG.

[0005] Figure 3 is along Figure 1 3 is a cross-sectional end view of the printed circuit assembly and the first printed circuit board taken along line 3-3 in FIG. 1 and illustrating mechanical clearances for components providing thickness constraints for the PCA sleeve.

[0006] Figure 4A is a perspective assembly view of a PCA with a jacket, which includes PCA satisfying Figure 3 A single-layer heat transfer jacket with thickness constraints determined in .

[0007] Figure 4B Yes Figure 4A An end view of a pair of PCAs in a thermal transfer sleeve in FIG. 1 , the pair of PCAs being seated in adjacent electronic sockets of a motherboard.

[0008] Figure 4C is an end view of a possible embodiment of a thermal device, which would be, by way of example, a view of a plurality of closely spaced PCAs with sleeves, such as Figure 4A The plurality of closely spaced PCAs with sleeves will dissipate heat through the heat transfer sleeves of adjacent PCAs with sleeves, as shown in FIG.

[0009] Figure 4D is an end view of a possible second embodiment of the thermal device, as an example, the end view is relative to a higher power PCA with a sleeve, such as Figure 4A The higher power jacketed PCA, taken in section along the center line AA, is used to transfer heat to an external heat transfer device.

[0010] Figure 4E is an end view of a possible third embodiment of the thermal device, as an example, the end view is relative to a high power PCA with tall components, such as Figure 4A Taken along line AA in FIG. 1 , the high power PCA is used to transfer heat to a heat sink having a non-uniform thickness.

[0011] Figure 5A yes Figure 4A Side view of the thermal contact area between the thermal transfer sleeve and the PCA components below.

[0012] Figure 5B yes Figure 4A Side view of the thermal contact area between a heat transfer sleeve and an external heat sink or adjacent sleeve.

[0013] Fig. 6A Yes Figure 1 0026] A perspective enlarged view of a portion of the bottom edge of a cover section of a thermal transfer jacket formed with active elastic members shown as being captive at both ends.

[0014] Figure 6B Yes Figure 1 0010 is a perspective enlarged view of a portion of the bottom edge of the cover section of the thermal transfer jacket formed with active elastic members, which are shown as being initially free at the bottom end and then secured by being tucked into the hem.

[0015] Figure 7 yes Figure 1 A perspective enlarged view of a cooling frame shown in FIG. 5 with details of the duct shape changes and bends that enhance turbulence and improve cooling efficiency.

[0016] FIG. 8A to FIG. 8D Selected characteristics of the bends and cross-sections of the coolant passages are illustrated.

[0017] Fig.9A yes Figure 7 A perspective cross-sectional view of an example of a turbulence-enhanced end block duct in a cooling frame.

[0018] Fig. 9B yes Figure 7 A perspective cross-sectional view of another example of a turbulence enhanced end block conduit in a cooling frame.

[0019] Fig. 10A is a cross-sectional side view of the contact area between the sleeve or heat sink and the cooling frame slot when the conduit is made into an L-shaped bend but without a U-shaped bend or shape change.

[0020] Fig. 10B It is a cross-sectional side view of the contact area between the sleeve or heat sink and the cooling frame groove when the conduit is made into an L-shaped bend, a U-shaped bend and a shape change.

[0021] Fig.11 is capable of cooling two closely spaced rows of PCAs Figure 7 A perspective view of a dual version of the cooling frame (with a streamline overlay).

[0022] Fig.12 is a top view of a motherboard for a computing system having Fig.11 The dual cooling frame is compatible with multi-row PCA sockets.

[0023] Fig.13A A top view of the cooling frame and housing assembly for a single high power PCA.

[0024] Fig. 13B 1 is a top view assembly view of a cooling frame for a row of moderately high power, closely spaced, jacketed PCAs without heat transfer devices.

[0025] Fig. 13C A top view assembly of the cooling frame and sleeve for a row of lower power, very closely spaced, PCAs.

[0026] Fig.14A yes Figure 1 Side view of a heat transfer device.

[0027] Fig. 14B is a cross-sectional view of an example of a heat transfer device for a solid heat sink (through Fig.14A cross section DD).

[0028] Fig. 14C is a cross-sectional view of an example of a heat transfer device for a hollow heat sink (through Fig.14A cross section DD).

[0029] Fig.14D is a cross-sectional view of an example of a heat transfer device for a vapor chamber heat sink (through Fig.14A cross section DD).

[0030] FIG. 15A to FIG. 15C It is for Figure 1 Data graph of thermal model results for a cooling system with FIG. 14A to FIG. 14C Three optional heat transfer devices.

[0031] Although the technology disclosed herein is susceptible to various modifications and alternative forms, the accompanying drawings illustrate specific examples described in detail by way of example herein. However, it should be understood that the description of specific examples herein is not intended to limit the disclosed technology to the specific forms disclosed, but rather the present invention is intended to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the appended claims. DETAILED DESCRIPTION

[0032] The following illustrative examples of the claimed subject matter are disclosed. For the sake of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation, many implementation-specific decisions may be made to achieve the developer's particular goals, such as compliance with system-related constraints and business-related constraints, which will vary from implementation to implementation. Furthermore, it will be appreciated that such development work, while complex and time consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0033] As used herein, the article "a" is intended to have its ordinary meaning in the patent field, i.e., "one or more". In this article, the term "about" when applied to a value generally means within the tolerance range of the equipment used to produce the value, or in some examples, unless otherwise explicitly specified, it means plus or minus 10%, or plus or minus 5%, or plus or minus 1%. Further, the term "substantially" as used herein means, for example, most, or almost all, or all, or an amount in the range of about 51% to about 100%. In addition, the examples herein are intended to be illustrative only, and are given for discussion purposes rather than by way of limitation.

[0034] Market demands continue to drive the development of electronic devices with increased capabilities and decreased size. Increased capabilities can be provided by integrated circuits ("ICs") that consume more power than previous ICs, allowing them to perform more high-speed functions simultaneously. Reductions in size can be achieved by packaging multiple ICs more closely together on a printed circuit assembly ("PCA"), and by positioning adjacent PCAs more closely together within a device housing or enclosure. This reduction in size and the tighter orientation are both examples of increased component density. Due to each of the higher power consumption and tighter spacing, the heat generated during operation may increase.

[0035] Heat can be transferred away from undesired locations by conduction through solids or fluids, convection through fluids (i.e., liquids or gases), or thermal radiation. Alternatively, heat can be absorbed by endothermic chemical reactions (such as certain phase changes). Using these principles (alone or in conjunction with each other), many approaches to cooling and heat management for computing systems have been attempted and continue to be developed.

[0036] Generally, the removal arrangement for the problematic heat concentration takes up at least some space. In today's computing systems, (e.g., due to the general increase in component density mentioned above) space is increasingly in short supply. In addition to the total amount of available space around the PCA, the position and shape of the space may also pose a challenge. Most of the PCA space that is not occupied by IC or other electronic components may be retained as one or more "forbidden zones". Generally, forbidden zones can be used to accommodate fasteners, reinforcement features of housings, wiring of card cables, range of motion of mobile parts, gaps for test probes, and other design goals that may compete for space with temperature control measures. Therefore, as electronic devices change, previous temperature control approaches may become invalid or obsolete, thereby requiring new advances in this field.

[0037] The present disclosure describes examples of cooling systems that combine solid-state conduction with fluid convection to cool closely spaced components (ICs and other components, such as inductors) mounted to PCAs, which themselves can be arranged in high-density groups. In some disclosed examples, a thin single-layer thermally conductive jacket surrounds each PCA. One or more active elastic members can be partially integrated into the jacket to apply compressive forces on the PCA components when cooling is desired. The compressive force can create and maintain thermal contact, through which heat can be conducted away from the PCA components and into the jacket. The jacket can then conduct heat (directly or indirectly) to a liquid-cooled cold plate configured as a cooling frame. In some examples, the cooling frame surrounds one or more of the PCAs with the jacket.

[0038] The sleeve can then transfer heat from components on the PCA to the cooling frame (optionally through an intermediate heat transfer device, such as a heat sink or heat pipe). Liquid flowing through the internal channels of the cooling frame can then help transfer heat away from the electronic devices. In some systems, the coolant can flow in the fluid with minimal turbulence. However, in the disclosed embodiments, turbulence can be promoted or enhanced through the use of "turbulence enhancement sections" (or turbulence enhancing sections). As referred to herein, turbulence enhancing sections (turbulence enhancing artifacts) are "intentionally designed" bends and shape changes along the internal channels. It has been found that this increased turbulence can improve the efficiency of convection.

[0039] In some examples, the heat transfer assembly includes a heat transfer jacket and a cooling frame, the heat transfer jacket is mechanically engaged with the cooling frame, and the heat transfer jacket is thermally coupled to the cooling frame. The cooling frame defines an internal frame space, and at least a portion of the heat transfer jacket is disposed in the internal frame space. The internal frame space can also define a coolant channel, the coolant channel including a turbulence enhancement portion to intentionally introduce turbulence into the liquid flow through the coolant channel.

[0040] In other examples, a computing subassembly includes a printed circuit assembly and a heat transfer assembly. The printed circuit assembly includes a printed circuit board and a plurality of electronic components mounted to the printed circuit board. The heat transfer assembly includes a heat transfer sleeve and a cooling frame. The heat transfer sleeve encapsulates and mechanically engages the printed circuit assembly and is thermally coupled to the printed circuit assembly. The heat transfer sleeve is also mechanically engaged to the cooling frame. The cooling frame is also thermally coupled to the heat transfer sleeve and the printed circuit assembly. In addition, the cooling frame defines an internal frame space and a coolant channel, at least a portion of the heat transfer sleeve is disposed in the internal frame space, and the coolant channel includes turbulence enhancement portions that are designed to intentionally introduce turbulence into the liquid flow through the coolant channel.

[0041] In yet other examples, a computing system includes a first printed circuit board and a computing subassembly. The computing subassembly includes a cooling frame mounted to the first printed circuit board. The cooling frame defines an internal frame space and a coolant channel, the coolant channel including a turbulence enhancement portion to intentionally introduce turbulence into the liquid flow through the coolant channel. The computing subassembly further includes a plurality of sleeved printed circuit assemblies. Each sleeved printed assembly is at least partially disposed in the internal frame space; is mechanically and electronically coupled to the first printed circuit board within the internal frame space; and is thermally coupled to the coolant channel.

[0042] Now turning to the attached figure, Figure 1 1 is an exploded perspective assembly view of a liquid cooling system for a printed circuit assembly ("PCA") in the context of a portion of a computing system 100. The computing system 100 may itself be a computer or may be a portion of a computer. As used herein, a "computer" is any electronic device that includes a processor and is capable of executing a program including machine-readable instructions, including, for example, a server, a converged appliance (or hyper-converged appliance), a rack-level system, some storage arrays, etc.

[0043] The computing system 100 includes a first printed circuit board ("PCB") 101 and at least one electronic socket 102 (in Figure 31 ), the functionality of which will be discussed further below. The computing system 100 also includes a computing subassembly consisting of a cooling frame 140 and one or more sleeved printed circuit assemblies ("PCAs") 105. In the illustrated example, one sleeved PCA 105 is shown in an exploded view, itself disassembled from the rest of the computing system 100. Additional sleeved PCAs 105 (not separately indicated) are shown assembled into the computing system 100.

[0044] Those skilled in the art who have the benefit of this disclosure will appreciate that computing system 100 may include many other components and features in addition to those shown. For example, computing system 100 may include a power subsystem for providing power, a cooling subsystem for delivering and receiving coolant, and a processor-based controller for various purposes, and / or other components. These other components and features are omitted for clarity so as not to obscure the subject matter claimed below.

[0045] The sleeved PCA 105 includes a PCA 110 comprised of a second printed circuit board 111 on which a plurality of electronic components 112, 113 are mounted. In the illustrated example, the PCA 110 is a memory board, and the electronic components 112, 113 are memory modules and capacitors, respectively. More specifically, the memory module 112 is a dual in-line memory module ("DIMM"). In other examples, the memory module may be some kind of memory module other than a DIMM. The PCA 110 may include other kinds of electronic components in addition to or in place of the memory modules 112 and the capacitors 113.

[0046] For example, the PCA 110 may also include an inductor (not shown), a voltage regulator (also not shown), a controller (also not shown), etc. In some examples, the PCA 110 may be a processor board. In these examples, the electronic components may be processors or other types of electronic components for implementing the functions of the processor board. Some examples of using multiple PCAs 105 with sleeves may include PCAs 105 with sleeves in which the PCAs 110 are configured to perform different functions. In such examples, one or more of the PCAs 105 with sleeves may include a PCA 110 that is a memory board, and one or more of the PCAs 105 with sleeves may include a PCA 110 that is a processor board.

[0047] In addition, the sleeved PCA 105 includes a heat transfer sleeve, which in the illustrated example includes a first cover 121 and a second cover 122. The first cover 121 and the second cover 122 each include a plurality of active elastic members 123, the form and function of which will be described below with reference to 4A to 6B More fully described. In the illustrated example, the first cover 121 and the second cover 122 are each formed of a single layer of material having a thermal conductivity of at least 350 W / m / K and a thickness of at most 0.25 mm. However, other examples may use more than one layer of material (provided that the spacing specifications are met), materials with different thermal conductivities, and materials with different thicknesses.

[0048] The first cover 121 and the second cover 122 are opposed to each other and mechanically engaged in a manner described more fully below to enclose the PCA 110. Thus, the first cover 121 covers at least a first portion of a first side of the PCA 110, and the second cover 122 covers at least a second portion of a second side of the PCA 110. When enclosing the PCA 110, the thermal transfer sleeve is mechanically engaged with and thermally coupled to the PCA 110.

[0049] As used herein, "thermally coupling" two objects means providing a thermally conductive path between the objects that allows heat to be conducted between the objects. Two objects are considered to be thermally coupled if any of the following is true: (1) the two objects are in contact with each other (either directly or via a thermal interface material ("TIM")), (2) both objects are thermally coupled to a heat transfer device (or to a chain of thermally coupled heat transfer devices), or (3) the heat transfer coefficient between the two objects is 10 W·m -2 ·K -1 or larger. A TIM may be a relatively thin, thermally conductive, and flexible (easily deformable) material placed between two devices at their thermal interface to improve heat transfer rates by filling air gaps that would otherwise exist between the devices due to surface roughness and / or misalignment. Common examples of TIMs include thermal gap pads, thermal grease, and thermal glue.

[0050] Figure 1 The example also includes an optional pair of heat transfer devices 130. When used, the heat transfer devices 130 facilitate heat transfer from the sleeved PCA 105 to the cooling frame 140. FIG. 14A to FIG. 14D Additional details are provided regarding the heat transfer device 130. In the illustrated example, the heat transfer device 130 is a heat sink, but other types of heat transfer devices may be used in other examples. Some examples may omit the heat transfer device entirely. Several such examples are discussed below.

[0051] As will be described in further detail below, the thermal transfer device 130 is thermally coupled and mechanically engaged with the sleeved PCA 105 without being mechanically fastened or otherwise attached to the sleeved PCA 105. In examples using the thermal transfer device 130, the cooling frame 140 defines corresponding mounting slots for the thermal transfer device 130 and the sleeved PCA(s) 105, although this is not described in detail herein. Figure 1 However, this Fig. 13C , and discussed with reference to this figure.

[0052] A "heat transfer device" may be any heat-conducting device configured to receive heat from one solid body via conduction (contact) and transfer heat to a second solid body via conduction (contact). Examples of heat transfer devices include, but are not limited to, heat pipes, vapor chambers, heat sinks (such as solid metal rods or strips), cooling tubes, and the like. A "heat pipe" refers to a specific type of heat transfer device that includes a housing (container) having walls surrounding a sealed internal passage containing a working fluid and a wick, such that the fluid transfers heat between different zones of the device through a cycle of evaporation and condensation.

[0053] Return to Figure 1 , the computing system 100 also includes a cooling frame 140. The cooling frame 140 mechanically engages the first printed circuit board 101. The first printed circuit board 101 can be referred to as a "host board" in the sense that the board "carries" the PCA 105 with the sleeve. The mechanical engagement of the cooling frame 110 with the first printed circuit board 101 can be achieved using any suitable technique known in the art. Some examples can attach the cooling frame 140 to the first printed circuit board 101 using fasteners such as screws (not shown). Other examples can attach the cooling frame 140 to the first printed circuit board 101 by bonding or adhering. Still other examples can use other techniques.

[0054] The cooling frame 140 defines at least one PCA slot 120 and an internal frame space 141. In the illustrated example, the internal frame space 141 is substantially rectangular in shape with the cooling frame 140. Other examples not illustrated may employ other geometries for the outer contours of the cooling frame 140 and the internal frame space 141. Similarly, in some examples, the geometry of the outer contour of the cooling frame 140 may be different from the geometry of the internal frame space 141. The internal frame space 141 surrounds the electronic socket 102 on the first printed circuit board 101. The electronic socket 102 is part of the (multiple) PCA slots 120, as discussed further below, and the sleeved PCA 105 is aligned with the (multiple) electronic sockets 102 in the PCA slots 120.

[0055] The cooling frame 140 also defines coolant passages that include turbulence enhancers that intentionally introduce turbulence into the flow of liquid through the coolant passages. Figure 1 is shown in and will be referred to below Figure 2 , Figure 7 as well as Fig.9A and Fig. 9B Discussed in more detail. Figure 1 In the example shown, there is a first joint 142 and a second joint 147, through which liquid coolant enters and leaves the coolant channel, respectively. In the illustrated example, the first joint 142 is assembled to the inlet (not shown) and the second joint 147 is assembled to the outlet (also not shown). However, in other examples (not shown), the functions of the inlet and outlet can be reversed. Identification as an inlet and an outlet can be determined based on implementation-specific considerations. Therefore, in an example not shown, the first joint 142 can be assembled to the outlet and the second joint 147 can be assembled to the inlet.

[0056] Each of the heat transfer device 130, the first cover 121, the second cover 122, and the cooling frame 140 is made of one or more thermally conductive materials. The first cover 121 and the second cover 122 are made of thermally conductive materials. For the purposes of this disclosure, an object, device, or assembly (which may include multiple different bodies that are thermally coupled and may include multiple different materials) is "thermally conductive" between two thermal interfaces if any of the following is true: (1) the heat transfer coefficient between the thermal interfaces is 10 W·m at any temperature between 0° C. and 100° C. -2 ·K -1 or greater, (2) the object is a continuous piece of material whose thermal conductivity (usually expressed as k, λ, or κ) between two interfaces at any temperature between 0°C and 100°C is 1 W·m -1 ·K -1 or greater, (3) the object is a heat pipe, a vapor chamber, a continuous copper body, or a continuous aluminum body. The thermal conductivity is greater than 1 W·m between 0°C and 100°C. -1 ·K -1 Examples of materials include almost all metals and their alloys (e.g., copper, aluminum, gold, etc.), some plastics (e.g., TC compounds, D series thermally conductive plastics), and many other materials.

[0057] The heat transfer device 130, the first cover 121, the second cover 122 and the cooling frame 140 can all be made of the same material or different materials. For example, the cooling frame 140 can be made by injection molding of a thermally conductive plastic, while the heat transfer device 130, the first cover 121 and the second cover 122 can be stamped from a sheet of metal or metal alloy (such as copper). Factors such as cost and weight may be considered when selecting materials.

[0058] Typically, it will be desirable that at least some of these components (such as heat transfer device 130, first cover 121 and second cover 122) be made of one or more materials that are not only thermally conductive but also highly thermally conductive. An object, device, or assembly (which may include multiple different bodies that are thermally coupled and may include multiple different materials) is "highly thermally conductive" as that term is used herein between two thermal interfaces if any of the following is true: (1) the heat transfer coefficient between the thermal interfaces is 1000 W·m at any temperature between 0°C and 100°C; -2 ·K -1 or greater, (2) the object is a continuous piece of material whose thermal conductivity (usually expressed as k, λ, or κ) between two interfaces at any temperature between 0°C and 100°C is 100 W·m -1 ·K -1 or greater, (3) the object is a heat pipe, a heat sink, a continuous copper body, or a continuous aluminum body. The thermal conductivity is 100 W·m between 0°C and 100°C. -1 ·K -1 Examples of materials that are 100 Å or larger include certain types of copper, aluminum, silver, and gold.

[0059] Figure 2 is Figure 1 A schematic diagram of a heat dissipation mechanism 200 for use in a system of FIG. 1 is shown, wherein like parts have like reference numerals. Figure 2 It is along Figure 1 A top partial cross-sectional view taken along line 2-2 in FIG. Some portions of computing system 100 (including Figure 1 Some parts shown in FIG. 1 are still not shown for the sake of clarity so as not to obscure the reference Figure 2 Content of the discussion. One such part is the cooling frame 140. In place of the cooling frame 140, a schematic representation 200 of the coolant channels defined by the cooling frame 140 is shown.

[0060] A PCA 105 (only one is shown) with a sleeve has been used with an electronic socket 102 (also in Figure 1 ) is mounted to the first printed circuit board 101 (in Figure 1). As can be seen here, each thermal transfer sleeve 235 (only one is indicated) mechanically engages the PCA 110 (only one is indicated) by making direct physical contact with one or more of the electronic components 112, 113 (only one of each is indicated). The physical contact also establishes a direct thermal coupling between the PCA 110 and the thermal transfer sleeve 235.

[0061] Note also the relationship between the sleeved PCA 105 and the heat transfer devices 130 (only one is indicated) which are mounted to the cooling frame 140 ( Figure 1 ). In the illustrated example, the heat transfer device 130 is positioned only between the sleeved PCA 105, and not between the sleeved PCA 105 and the cooling frame 140. As shown, the heat transfer device 130 physically contacts the heat transfer sleeve 235. Again, this physical contact establishes a mechanical engagement between the heat transfer device 130 and the heat transfer sleeve 235, and also establishes a thermal coupling. Similarly, the heat transfer device 130 and the cooling frame 140 ( Figure 1 Direct physical contact between the heat transfer device 130 and the cooling frame 140 (shown in Figure 1) also thermally couples the heat transfer device 130 to the cooling frame 140. However, in the example shown herein, the heat transfer device 130 is not attached or attached to the PCA 105 with the sleeve in any way.

[0062] Thus, the electronic components 112, 113 of the sleeved PCA 105 are thermally coupled to the cooling frame 140 ( Figure 1 ). The coolant flows through the coolant channels, as indicated by broad arrows 208. Because the cooling frame 140 is made of a thermally conductive material, it transfers heat from the electronic components 112, 113 to the coolant. Note that the cooling frame 140 is thermally coupled to the coolant as the coolant circulates through the coolant channels due to direct physical contact with the walls of the coolant channels.

[0063] More specifically, with the sleeved PCA 105 mechanically engaged with the cooling frame 104, heat from the electronic components 112, 113 is transferred into the coolant through the thermal coupling provided by the heat transfer sleeve 235 and the cooling frame 140, as indicated by arrow 210. With the sleeved PCA 105 physically engaged with the heat transfer device 130, heat is transferred from the heat of the electronic components 112, 113 into the heat transfer device 130 through the thermal coupling provided by the heat transfer sleeve 235, as indicated by arrow 212. The transferred heat then migrates through the heat transfer device 130 to the ends where the heat transfer device is mechanically engaged and thermally coupled to the cooling frame 140. The heat is then transferred into the coolant through the cooling frame, as indicated by arrow 214.

[0064] The coolant circulates through the coolant channels under pressure from a closed-loop cooling subsystem (not shown). The coolant is heated as it circulates through the coolant channels, circulates away from the computing system 100 to be cooled, and then circulates again to the computing system 100. Thus, the heat generated by the electronic components 112, 113 is managed and dissipated, allowing the computing system 100 to operate within specifications to improve the operability and efficiency of the computing system 100.

[0065] Several aspects of the mechanical engagement of the sleeved PCA 105 with the first printed circuit board 101 and the positioning of the PCA 105 will now be described. Figure 3 It is along Figure 1 A cross-sectional end view of the printed circuit assembly and the first printed circuit board taken along line 3-3 in FIG. Figure 3 Also shown are some of the mechanical clearances for the components that set the thickness constraints for the heat transfer sleeve in this particular example. Note again that for clarity, Figure 3 Some aspects of computing system 100 are omitted. For example, heat transfer device 130 is not shown.

[0066] The electronic socket 102 is attached to the first printed circuit board 101 in any suitable manner known in the art. The second printed circuit board 111 includes a plurality of edge connectors 300, such as gold finger connectors. Other examples (not shown) may use other types of connectors. The edge connector 300 is part of an electronic circuit (not shown) that includes the electronic components 112, 113 and other components of the PCA 110 through which the PCA 110 performs its intended function. To this end, as previously discussed, the PCA 110 may include electronic devices other than those already discussed, such as an inductor 305 and a thyristor 310. The electronic circuit may be implemented using, for example, surface traces and / or conductive layers of the first printed circuit board 101. Similarly, the electronic socket 102 is a portion of the electronic circuit of the first printed circuit 101, which portion may be implemented using surface traces and / or conductive layers (not shown).

[0067] The PCA 110, and thus the sleeved PCA 105, is mounted to the first printed circuit board 101 by inserting the edge connector 300 into the electronic socket 102. This insertion electrically connects the electronic circuitry (not shown) of the sleeved PCA 105 to the electronic circuitry of the first printed circuit board 101. As disclosed above, the electronic socket 102 is positioned first in the Figure 1141. Thus, when assembled in this manner, the sleeved PCA 105 is at least partially disposed within the interior frame space 141. As will be discussed below, the process of inserting the sleeved PCA 105 into the electronic receptacle 102 is accompanied by insertion into a cooling frame slot (not shown) defined by the cooling frame 140.

[0068] The additional sleeved PCA 105 is shown in dashed lines to reflect the assembly with the first printed circuit board 101 to illustrate certain dimensional features of the assembly. Closely spaced PCA arrays (such as DIMM groups) impose multiple constraints on the design of temperature control measures. The space between PCAs, and the space between the PCA array and adjacent devices on the host board may decrease with each technology generation (e.g., as density increases). In addition to being small in size, these spaces may be inconveniently shaped. Size or shape constraints may hinder the adaptability of existing temperature control approaches.

[0069] Still reference Figure 3 , the socket for PCA 110 has a center-to-center spacing S on the host board cc . S cc It can be less than 9 mm, or less than 8 mm, 7 mm or 6 mm. cc It may be nominally 7.5 + / - 0.2 mm. The height of the component 112 on the PCA 110 will occupy S cc The first printed circuit board 111 may have a thickness of, for example, 0.78 mm, 1.57 mm, or 2.36 mm. Each side of the PCA 110 may also have high components that increase the H t >2.5mm to the width of PCA 110. Examples of tall components include some integrated circuits ("ICs") such as power management ICs ("PMICs"), and some non-chip electrical components such as capacitors and inductors. If tall components are mounted on two sides of PCA 110 that are directly opposite each other, the minimum gap C2 between the outer surfaces of PCA 110 when PCA 110 is placed in socket 102 may be less than 2mm, or even less than 1.5mm.

[0070] If the temperature control measure is to use a solid-state element in thermal contact with component 112, the high component is not the only component that limits the temperature control design. Solid-state temperature control elements (such as heat transfer devices) can also be preferably connected to the height H. s Short components < 1.2 mm (e.g. some types of memory chips) and medium height H mThe different heights of components 112 result in different gaps C1 (maximum), C2 (minimum), and one or more intermediate gaps C3 (depending on the design) at different locations in the space between the outer surfaces of PCA 110.

[0071] Variations in the gaps and their locations may preclude some temperature control design approaches. For example, if the minimum gap C2 occurs at the bottom of the PCA (closest to the socket interface) and the maximum gap C1 occurs at the top, a tight-fitting conductive sleeve that is assembled separately and pushed down onto the PCA(s) 110 may be easy to design and implement. In contrast, if there is an "overhang" (taller components over shorter components), a "push-down" sleeve design may be limited by the need to make thermal contact with the lower, short components on the PCA while avoiding stressing the higher, tall components on the PCA during installation. Alternatives (such as hinged clamshells and two-piece sleeves that introduce heat transfer elements laterally from opposite sides of the PCA) may perform more reliably for overhanging PCAs because the tight-fitting sections of the short components will never be pushed or pulled onto the tall components.

[0072] FIG. 4A to FIG. 4E Various aspects of an example of a sleeved PCA 400 are shown in greater detail, as well as how the active elastic member 423 can be modified to accommodate varying design constraints. Figure 4A , note that Figure 4A The above reference is shown in Figure 3 The edge connector 300 discussed above and defining the printed circuit assembly interface 408. The thermal transfer sleeve 420 includes a snap-on closure 404 that secures the first cover 421 and the second cover 422 together when being Figure 4A The snap-on closure 404 includes a lip 406 ( Figure 4C 406, which is a pair of tabs 404a on the first cover 421 and the second cover 422, which snap into a pair of grooves 404b in the lip 407 of the second cover 422 when the first cover 421 and the second cover 422 are connected together. This makes the lip 407 overlap with the lip 406, as shown in FIG. Figure 4C as shown in .

[0073] Still reference Figure 4A The PCA 400 with sleeve also includes an optional plurality of pull tabs 424 attached to the lip 407 of the second cover 422. The pull tabs 424 can be used to Figure 4BThe PCA 400 with the sleeve is removed from the first printed circuit board 401 and the cooling frame by inserting it into the electronic socket 402 in the manner shown in FIG. 4. The pull tabs 424 can be made of a flexible material so that they can be bent. For example, they can be bent when the computing system is placed in a tray (not shown) and inserted into a rack (also not shown) or other enclosure. Some examples (such as Figure 1 ) the pull tab 424 may be omitted.

[0074] Likewise Figure 4A As best shown in FIG. 4 , the PCA 400 with sleeve includes a plurality of active elastic members 423. In some examples (not shown), only one of the first cover 421 and the second cover 422 includes a plurality of active elastic members 423. However, in the example shown here, each of the first cover 421 and the second cover 422 includes a plurality of active elastic members 423. This may be FIG. 4B to FIG. 4E As can be seen in the figure, each active elastic member 423 is integral with the first cover 421 or the second cover 422, in the sense that the active elastic member and the first cover or the second cover are formed of a single piece. Each of the first cover 421 and the second cover 422 is made of a single layer of material having a thermal conductivity of at least 350 W / m / K and a thickness of at most 0.25 mm. However, other examples may use materials with different thermal conductivities and materials with different thicknesses.

[0075] Return to Figure 4B , in the first configuration, the Figure 4A 4. A pair of sleeved PCAs 411 (only one is shown) are shown in a thermal transfer sleeve 420 (only one is shown) in FIG. 4. More specifically, the sleeved PCAs 400 are placed in adjacent electronic sockets 402 of a first printed circuit board 401. The first printed circuit board 402 may be referred to as a "host board" in the sense that the board "carries" the sleeved PCAs 400. Note that a heat sink 430 is used between the two sleeved PCAs 400. The sleeved PCAs 400 are oriented vertically relative to gravity, and the first printed circuit board 401 is oriented horizontally. This is their nominal orientation in operation, although other examples may use different orientations.

[0076] When the sleeved PCA 400 is inserted into the electronic receptacle 402, the movable spring member 423 is compressed inwardly relative to the centerline 418 of each sleeved PCA 400 by the surrounding components. Figure 4BIn the example of FIG. 4 , the compression of the active elastic member 423 is caused by the mechanical engagement of the heat transfer sleeve 420 with the heat transfer device 430 and the distance between the two sleeved PCAs 400. Note that in the example without the heat transfer device 430, such compression can similarly be caused by the mechanical engagement and associated distance with the adjacent sleeved PCA 400, heat transfer device or cooling frame. Such an example FIG. 13A to FIG. 13C and discussed further below.

[0077] More technically, when the sleeved PCA 400 is inserted, the active elastic member 423 is elastically displaced from its resting position. As used herein, an active elastic member can be "elastically displaced" if it elastically deforms in response to its contact surface being displaced inwardly by up to (a) 2 mm, or (b) to a point where it is flush with the planar portion (the portion from which the active elastic member extends). An active elastic member is "elastically deformed" if the deformation caused by the displacement is not permanent, and the active elastic member substantially returns to its original configuration when the force causing the displacement is removed.

[0078] The compression described above allows the sleeved PCA 400 to be "squeezed" into the cooling frame 140 ( Figure 1 ), heat transfer device 430, and as described above with reference Figure 3 The other PCA 400 with sleeves discussed above is limited to the available space. Once the PCA 400 with sleeves is Figure 4B As shown in the arrangement, the compressed movable elastic member 423 applies a compressive force Fs of at least about 45N. Figure 4C and Figure 4D As used herein, the term "about" recognizes that precision with respect to a value may be difficult to achieve due to tolerances and errors in manufacturing, changes in material properties over time, and other similar considerations.

[0079] The compression of the active elastic member 423 when the PCA 400 with the sleeve is inserted into the electronic socket 402, and the above reference Figure 3 The gaps described above help establish most of the aforementioned thermal coupling. For example, compression ensures physical engagement between the electronic components 412, 413 and the heat transfer sleeve 420, and thus ensures thermal coupling. The gaps described above ensure that the active elastic member 423 is compressed and the heat transfer sleeve 420 physically engages the adjacent cooling frame 140 ( Figure 1 ), heat transfer device 430, and / or PCA 400 with sleeve, as appropriate. Again, this physical engagement also establishes thermal coupling between all of these parts of the heat transfer assembly and the entire computing system.

[0080] The design of the active elastic member 423 may be modified to accommodate different designs of configurations and arrangements of the PCA 400 with the sleeve. Figure 4C is an end view of a possible implementation of a thermal device, which would be, by way of example, an end view of several closely spaced PCAs 400 with sleeves, such as Figure 4A The plurality of closely spaced PCAs with sleeves will dissipate heat through the heat transfer sleeves of adjacent PCAs with sleeves, as shown in FIG. Figure 4D is an end view of a possible second embodiment of the thermal device, which would be, by way of example, an end view of a higher power, sleeved PCA 400, such as Figure 4A The higher power jacketed PCA, taken in section along the center line AA, is used to transfer heat to an external heat transfer device. Figure 4E is an end view of a possible third embodiment of a thermal device, which would be, by way of example, an end view of a high power housing PCA 400 with tall components, such as Figure 4A Taken along line AA in FIG. 1 , the high power PCA is used to transfer heat to a heat sink having a non-uniform thickness.

[0081] Figure 5A yes Figure 4A 4 is a side view of a thermal contact area 516 between a thermal transfer sleeve 420 and the electronic components 412, 413 beneath the PCA 410. The electronic components 412, 413 are shown in dashed lines and the thermal contact area is indicated by shading. Figure 5B yes Figure 4A The heat transfer sleeve is connected to an external heat sink (not shown) or an adjacent heat transfer sleeve (also not shown) Figure 5B 5 and 6). A side view of the thermal contact area 535 between the two (shown in FIG. 5 ). Again, the thermal contact area is indicated by shading.

[0082] Return to Figure 4A , the first cover 421 defines a first pair of tabs 481, and the second cover 422 defines a second pair of tabs 482 (only one is shown). When the first cover 421 and the second cover 422 are closed and snapped together, the two pairs of tabs define a pair of tabs 583, one of which is in the Figure 5A and Figure 5B When the PCA 400 with the sleeve is inserted into the electronic socket 402, the tab 583 slides into the cooling frame slot of the cooling frame, as will be described below with reference to Fig. 13C Note that in this example, one of the tabs 482 fits over one of the tabs 481. This relationship is part of the snap fit described above, where the first cover 421 and the second cover 422 snap fit together to form the heat transfer sleeve 420. However, in some examples, this may be omitted.

[0083] Now turning to the movable elastic member 123, Fig. 6A and Figure 6B It shows that first Figure 1 Selected details of the construction of the movable elastic member 123 are depicted in FIG. Fig. 6A First of all, Figure 1 6 is a perspective enlarged view of a portion of the bottom edge 600 of the first cover 121 formed with a thermal transfer sleeve 135 of active elastic members 123, which are bound at both ends. The active elastic members 135 are created by removing material from the first cover 121 on each side of what will become the active elastic members 123. Flexures 626 and openings 627 are then created. Figure 6B Yes Figure 1 , a perspective enlarged view of a portion of the bottom edge of the cover section of the heat transfer jacket formed with active elastic members 123, which are initially free at the bottom end 600 and then secured by being tucked into the optional hem 629.

[0084] As mentioned above, in the illustrated example, the movable elastic member 123 applies an elastic force F of at least 45N. s . Fig. 6A and Figure 6B Pictured Figure 1 The two embodiments of the movable elastic member 123 are first shown in FIG. Fig. 6A The movable elastic member 623a in the second cover 622a includes a flexure 626 at the bottom thereof and defines an opening 627 therein. The thickness T of the second cover 622a is j At most 0.25mm. Figure 6B In the embodiment, the movable elastic member 623b in the second cover member 622b also includes a flexible portion 626. However, the movable elastic member 623b also includes a lower protrusion 628 extending from the flexure 626, which is inserted into the hem 629 during manufacturing.

[0085] The amount of elastic force applied can be controlled by managing the implementation specifics of any given example. Fig. 6A and Figure 6B , such as material selection, material thickness T j The details such as the length of the movable elastic member 623, the total length and width of the opening 627, and the length and width of the opening 627 relative to the length and width of the movable elastic member 623 may affect the elastic force F. s In some examples, different movable elastic members 623 may apply different elastic forces F sFor example, the various movable elastic members can be set to different sizes or defined with openings of different sizes to adapt to the applied elastic force F s Other examples may include applying substantially the same elastic force F to all s The movable elastic part.

[0086] Thus, various examples of the claimed subject matter may employ the application of a varying elastic force F s The movable elastic member 123 is not limited to an elastic force F of at least about 45N. s Thus, some examples may implement applying a certain elastic force F in the range of about 55N to about 65N. s Still other examples may implement a certain elastic force F applied in a wider range of about 45N to 75N. s The movable elastic member 123 is provided.

[0087] Furthermore, by way of example and illustration, the active elastic member 123 disclosed herein is only one means for thermally coupling the electronic components of the PCA to an external heat transfer structure. Such an external heat transfer structure may include, for example, a cooling frame 140, a heat transfer device 130, and other PCAs 105 with sleeves as disclosed herein. Other examples not shown may employ structures equivalent to the active elastic member 123 that perform the described functions.

[0088] Now go to first Figure 1 Details of the cooling frame 140 are shown in FIG. Figure 7 is a perspective, enlarged view of cooling frame 140 in the context of heat transfer assembly 700 . Figure 7 Details of intentionally designed turbulence enhancements are illustrated, including shape changes and bends that enhance turbulence and improve cooling efficiency. The cooling frame 140 includes a first end block 743 and a second end block 745 connected by a first side rail 744 and a second side rail 746. As mentioned above, the cooling frame 140 can be manufactured as a single piece, or can be manufactured in multiple pieces and then assembled.

[0089] As also discussed above, the directionality of coolant flow through the coolant channels is not important to the functionality of the heat transfer assembly 700. For convenience, some portions of the cooling frame 140 will be referred to as the "inlet" or "inlet side" or the like, while other portions will be referred to as the "outlet" or "outlet side" or the like. However, the illustrated example exhibits bilateral symmetry about line 702, such that the inlet / outlet functionality can be reversed. Therefore, it should be understood that this is merely for convenience, and in other examples, even those having the same structure, the labeling may be reversed. On the other hand, not all examples necessarily exhibit bilateral symmetry as the illustrated example.

[0090] The first end block 743, the first side rail 744, the second end block 745, and the second side rail 746 cooperate to define a coolant passage. Figure 7 The three parts of the coolant channel are shown in FIG. The end block inlet conduit 753 defined by the first end block 743 is shown in section 7A, and the side rail outlet conduit 704 is shown in section Figure 7 B. The first end block 743 also defines an end block outlet conduit (not shown) that is similar in shape to the end block inlet conduit 753. The second side rail 746 defines a similar side rail inlet conduit (not shown), and the second end block 745 can define a similar second end block conduit (also not shown), although they can be different in other examples. In the illustrated example, the side rail outlet conduit has the same design and characteristics as the side rail inlet conduit 704. However, the second end block conduit (not shown) is a straight extension from the side rail inlet conduit to the side rail outlet conduit 704. A portion of the second end block conduit 755 is shown in phantom.

[0091] Turbulence occurs in coolant flows in cold plates and similar structures, and conventionally, attempts have been made to design channels and conduits through which the coolant may flow to minimize and / or mitigate the amount of turbulence. However, it has been found that turbulence in coolant flows can improve heat transfer, or even impede flow very well. Thus, an example of the presently claimed subject matter is a turbulence enhancer that promotes or enhances turbulence in a fluid flow. The illustrated example includes two different turbulence enhancers, namely, a conduit shape change and a bend.

[0092] More specifically, in the illustrated example, the inlet 705 and outlet 706, like the first joint 142 and the second joint 147, have circular cross-sections, such as section 708 taken along line AA through the second joint 147. The second end block conduit (although not shown) also has a circular cross-section, such as section 708. The side rail inlet conduit (not shown) and the side rail outlet conduit 704 have elliptical cross-sections, such as section 709. Thus, the coolant flow transitions from the circular end block inlet conduit 753 to the elliptical side rail inlet conduit, to the circular second end block conduit, to the elliptical side rail outlet conduit 704, and to the circular end block outlet conduit 757. Each transition from a circular cross-section to an elliptical cross-section and from an elliptical cross-section to a circular cross-section intentionally introduces turbulence into the coolant flow.

[0093] The illustrated example also uses several turbulence enhancers, which include bends in the coolant conduits to enhance turbulence. In the illustrated example, discussion of the bends and their enhanced associated turbulence will focus on Figure 7 The U-shaped bend 751 and the L-shaped bend 752 shown first in FIG. Fig. 8A and Figure 8B , respectively. However, these principles can also be extrapolated to other bends in other locations in the coolant channel. When the liquid conduit is curved, the introduction of turbulence caused depends in part on the ratio of the radius of the bend to the conduit diameter. At the same input flow rate, a sharper bend results in more turbulence. If the circular inlet has a diameter D, then Fig. 8A The radius R of the U-bend 751 shown in FIG. u Less than 1.5D, and Figure 8C The L-shaped bend radius R of the L-shaped bend 752 shown in FIG. l Less than 1.2 D. These are relatively sharp bends and therefore enhance turbulence.

[0094] like FIG. 8A to FIG. 8C As seen in , in the end block entry duct 853, the U-shaped bend 851 is in a first plane, while the L-shaped bend is in a second plane orthogonal to the first plane. The turbulence caused by the consecutive orthogonal bends is more evenly distributed on the duct than when the U-shaped bend 851 and the L-shaped bend 852 are in the same plane. The distribution of convection on the duct in two orthogonal directions may be the reason for the significant improvement in cooling efficiency. However, once the coolant passes the bends, the turbulence decreases with the distance from the last bend. Therefore, if the turbulence patterns from the two bends interact additively, the bends should be close together. In a modeled example, Fig. 8A The distance S between the two bends 852 and 853 is shown inB It is approximately 2.5 times the diameter D of the catheter. It is generally believed that it is more desirable for the two bends 852, 853 to be closer rather than farther apart. In various embodiments, the distance S between the two bends 852, 853 is B About two to three times the diameter D.

[0095] In one example, the first side rail 744 and the second side rail 746 are formed by flattening an 8 mm copper tube until Fig.8D The aspect ratio h / w shown in is approximately three. The circular inlet 705, outlet 706, end block inlet conduit 753 and end block outlet conduit 757 each have a diameter D=8 mm. Therefore, although the shape of the conduit changes from circular to elliptical, the cross-sectional area of ​​the conduit remains approximately the same:

[0096]

[0097] Where L = hw, such as Fig.8D Maintaining the cross-sectional area throughout the shape change can mitigate undesirable drops in liquid pressure and velocity that may be caused by enhanced turbulence in the bend.

[0098] Fig.9A and Fig. 9B A more detailed illustration Figure 7 The first end block 743, the end block introduction conduit 753 and the end block lead-out conduit 757 are two different embodiments. Fig.9A and Fig. 9B In each of the chambers 900, the coolant 920 engages in several bends in the chamber 900, which are not as described above with reference to FIG. 8A to FIG. 8C The one in question is strictly defined by the walls of the conduit. FIG. 8A to FIG. 8C Like the design of the coolant conduit shown in , these bends also enhance turbulence in the flow of the coolant.

[0099] Fig.9A yes Figure 7 10 is a perspective cross-sectional view of an example of an end block conduit with enhanced turbulence in a cooling frame of FIG. The first end block 743a defines a chamber 900 on both the inlet and outlet sides in which a pair of guides 905 are disposed that define an inlet 705a and, in turn, a top channel 910 and a bottom channel 915. The terms "top" and "bottom" are used when the cooling frame 140a is in its nominal use orientation (which is in FIG. Fig.9A and Fig. 9B ) is defined relative to the gravitational field.

[0100] Coolant, represented by arrows 920 (only two are indicated), enters chamber 900 under pressure through inlet 705a and flows as indicated by arrows 920. More specifically, the flow of coolant 920 is redirected by the rear of chamber 900 into top channel 910 and bottom channel 915, whereupon the coolant flows into side rail inlet conduits 925. The coolant is then circulated through first side rail 744, second end block 745, and second side rail 746 (all of which are in Figure 7 ), the coolant 920 returns to the first end block 743a. The coolant 920 then enters the extraction chamber 900 through the top channel 910 and the bottom channel 915, whereupon the coolant is redirected into the outlet 708a.

[0101] Fig. 9B yes Figure 7 A perspective cross-sectional view of another example of a turbulence enhanced end block conduit in a cooling frame of FIG. Fig.9A Compared with the inlet 705a in the first end block 743b, the inlet 705b is located relatively lower on the first end block 743b. Furthermore, the first end block 743b defines the chamber 900 on both the introduction side and the lead-out side of the end block 743b. A plurality of guides 905 are provided in the chamber 900 to define a plurality of channels 925. Fig.9A The further guide 905 does not define the inlet 705b in this example.

[0102] Coolant 920 enters the inlet chamber 900 under pressure through the inlet 705b and is redirected and flows as indicated by arrow 920. The coolant 920 is redirected by the rear of the chamber 900 into the channel 915 defined by the guide 905, whereupon the coolant flows into the side rail inlet conduit 925. After circulating through the first side rail 744, the second end block 745, and the second side rail 746 (all of which are in Figure 7 After that, the coolant 920 returns to the first end block 743b. The coolant 920 then enters the extraction chamber 900 through channels 930 (only one is shown), whereupon the coolant is redirected into the outlet 708b.

[0103] Now return to Figure 7 The first end block 743 and the second end block 745 each define a plurality of cooling frame slots 748 and 749. The cooling frame slots 748 and 749 and the electronic socket 402 ( Figure 4B ) defines the PCA slot, such as Figure 1 One or more PCAs 400 with sleeves are inserted into electronic sockets 402. Figure 4B These electronic sockets are arranged in the same manner as discussed above but not in the Figure 7 The insertion includes placing Figure 5A and Figure 5B The tabs 583 shown in FIG. 5 are inserted into the cooling frame slots 748, 749 of the cooling frame 740. Mechanical engagement and thermal coupling between the sleeved PCA 400 and the cooling frame 740 is thereby established at the point of insertion into the cooling frame slots 748, 749. FIG. 4C to FIG. 4E In the case of heat transfer devices 430 in the embodiment of the present invention, these heat transfer devices can be inserted into separate cooling frame slots between the PCA 400 with sleeves and the structure of the corresponding end blocks 743, 745, as will be referred to in Fig. 13C discussed.

[0104] The turbulence enhancer results in increased turbulence, which in turn increases the efficiency of heat transfer into the coolant and thereby reduces the thermal contact area relative to laminar flow to achieve the same heat transfer. Fig. 10A and Fig. 10B The sleeved PCA 1005 and thermal transfer device 1030 are each shown inserted into an electronics socket 1002 mounted to a first printed circuit board 1001 and a cooling frame socket 1048 . Fig. 10A is the thermal contact area A between the sleeve or heat transfer device 1030 and the cooling frame slot 1048 when the conduit is made into an L-shaped bend, but without a U-shaped bend or shape change. L Cross-sectional side view. Fig. 10B The thermal contact area A between the sleeve or heat transfer device 1030 and the cooling frame groove 1048 when the conduit is formed into an L-shaped bend, a U-shaped bend and a shape change portion. T Note the difference in thermal contact area between the two.

[0105] Fig.11 Another example of forming two cooling frames and heat transfer assemblies back to back is illustrated. More specifically, Fig.11 is capable of cooling two closely spaced rows of PCAs Figure 7 1140a, 1140b). A perspective view of a dual version of the cooling frame 740 (with a streamline overlay). The cooling frame 1140 includes first end blocks 1143a, 1143b and a middle block 1145. The middle block 1145 can generally be thought of as two joined second end blocks 1145a, 1145b. Note the single middle block conduit 1107 portion of the coolant flow path 1150, with the flow of coolant represented by arrows 1107 from both sides 1140a, 1140b flowing in that portion. Each of the first end blocks 1143a, 1143b receives coolant through a respective first fitting 1142a, 1142b and discharges coolant through a respective second fitting 1147a, 1147b.

[0106] The cooling frame 1140 is shown mounted to the first printed circuit board 1101. Each cooling frame side 1140a, 1140b is defined as described above with reference to Figure 1 The corresponding internal frame spaces 1141a, 1141b discussed above for the cooling frame 140. Although not shown for clarity, multiple electronic sockets (such as Figure 4B The electronic socket 402 shown in FIG. 1 is mounted to the first printed circuit board 1101 within the internal frame spaces 1141a, 1141b.

[0107] Each of the end blocks 1143a, 1143b also defines a respective plurality of cooling frame slots 1149a, 1149b, as does the intermediate block 1145, also as described above with reference to Figure 7 4. Then, a sleeved PCA such as the sleeved PCA 400 shown in FIG. 4 can be inserted into the cooling frame sockets 1149a, 1149b and the electronic sockets (not shown), where, in operation, they are cooled as described above. Note that neither the end blocks 1143a, 1143b nor the middle block 1145 define a slot for inserting a heat transfer device. Therefore, Fig.11 The examples do not employ a heat transfer device.

[0108] Fig.12 is a top view of a motherboard 1200 for a computing system having Fig.11 More specifically, in addition to the cooling frame 1140, the first printed circuit board 1201 used as the motherboard includes several arrays of PCA socket arrays 1271 (only one is indicated). Note the socket array 1271 disposed within the internal frame space of the cooling frame 1100. In addition, the first printed circuit board includes a processor socket 1272, a voltage regulator socket 1273, a storage socket 1274, and an expansion socket 1275. Note that many of these features are implementation specific, and other examples may include other structures in addition to or in place of those shown.

[0109] FIG. 13A to FIG. 13C Several examples with different numbers of sleeved PCAs and heat transfer devices are depicted. Each of the cooling frames 1340a, 1340b, 1340c defines a respective coolant channel 1350a, 1350b, 1350c shown in dashed lines. Second end block conduits 1370a, 1370b, 1370c are also shown. Portions of the coolant channels 1350a, 1350b, 1350c defined by the respective first end blocks 1343a, 1343b, 1343c may include, for example, Fig.9A and Fig. 9BThe chambers, guides and channels discussed, although these are not shown. Note also the steps 1355 in the side rails of the cooling frames 1340a, 1340b, 1340c, these steps also enhance turbulence in the coolant flow.

[0110] Fig.13A 1 is a top view assembly of a cooling frame 1340a and heat transfer sleeve 1320 for a single high power PCA 1310a. A first end block 1343a defines a first cooling frame slot 1348a, and a second end block 1345a defines a second cooling frame slot 1349a, into which the PCA 1310a and heat transfer sleeve 1320 are inserted. This example is particularly useful where the PCA 1310a consumes a large amount of power, and therefore generates a relatively large amount of power, thereby requiring a dedicated heat transfer assembly. Note that no heat transfer device is present in view of the direct thermal coupling of the PCA 1310a with the sleeve.

[0111] Fig. 13B is a top view of a cooling frame 1340b for a row of moderately high power, closely spaced, sleeved PCAs 1305b without heat transfer devices. The first end block 1343b defines a plurality of first cooling frame slots 1348b (only one indicated), and the second end block 1345b defines a plurality of second cooling frame slots 1349b (only one indicated) into which the PCAs 1310b and heat transfer sleeves 1320 are inserted. Note again that there is no heat transfer device present.

[0112] Fig. 13C 1340c and PCAs 1305c with sleeves for a row of lower power, but very closely spaced PCAs 1310c. A first end block 1343c defines a plurality of first cooling frame slots 1348c (only one indicated), and a second end block 1345c defines a plurality of second cooling frame slots 1349c (only one indicated). In this example, the PCAs 1310c and heat transfer sleeves 1320 are not inserted into the cooling frame slots 1348c, 1349c. The PCAs 1310c are simply inserted into sockets (not shown). Instead, as shown, heat transfer devices 1330 are inserted into the cooling frame slots 1348c, 1349c.

[0113] Also note that in Fig. 13C13. In the example of FIG. 13, a heat transfer device 1330 is present. Inserting the heat transfer device 1330 into the cooling frame slots 1353, 1354 (only one of each is identified) establishes physical engagement and thermal coupling with the sleeved PCA 1305c. Such insertion also establishes physical engagement and thermal coupling between the heat transfer device 1330 and the cooling frame 1340c. Thus, the insertion thermally couples the PCA 1035c to the first end block 1343c and the second end block 1345c.

[0114] Those skilled in the art having the benefit of this disclosure will appreciate that there are still further variations in the number of jacketed PCAs, the number of heat transfer devices, and combinations thereof that may be configured with a cooling frame as disclosed herein. These numbers and configurations will be implementation specific, depending on the amount of heat generated by the jacketed PCAs and the design constraints for mitigating or handling that heat. Thus, the various examples of the subject matter claimed below are not limited to the number of jacketed PCAs and heat transfer devices shown in the illustrated examples, nor to the configurations shown.

[0115] Where a heat transfer device is used, various examples may accommodate variations in the design of the heat transfer device. Heat sinks placed between the sleeved PCAs may perform both thermal and mechanical functions. Thermally, these heat sinks diffuse heat transported through the heat transfer sleeve from adjacent PCA components. Mechanically, these heat sinks compress the active elastic members of the heat transfer sleeve against the PCA components.

[0116] The socket spacing on the motherboard, combined with the PCA substrate thickness and the location and height of the PCA components, sets an upper limit on the heat sink thickness (see, for example, Figure 3 ). This upper limit may vary with location over the length and width of the heat sink. Also, the range of available heat sink materials is constrained by the amount of heat to be dissipated within a limited thickness. Finally, the heat sink must be stiff enough to sustain the compression of the active elastic member over many years of service life without deformation; this may impose a lower limit on thickness.

[0117] Fig.14A yes Figure 1 14. A side view of a heat transfer device 1430 is shown. The heat transfer device 1430 is a heat sink in this example. The heat transfer device 1430 includes cutouts or notches 1431 to accommodate the contours of certain electronic components (not shown) of a sleeved PCA (also not shown) to which the heat transfer device 1430 is to be physically engaged and thermally coupled. The heat transfer device 1430 also includes an end taper 1432 and an end tab 1433 by which the heat transfer device 1430 engages a cooling frame slot (not shown) of a cooling frame (also not shown).

[0118] Fig. 14Bis an example of a heat transfer device 1430b that is a solid heat sink. Fig.14A More specifically, the heat transfer device 1430 is a solid heat sink, and still more specifically, is Fig.14A 1430b. Note that only a portion of the heat transfer device 1430b is shown. The heat transfer device 1430b has a solid body with T-shaped portions in the end tabs 1433 and the end tapers 1432 (not shown). T thickness, and has T between the two B thickness.

[0119] Body thickness T to dissipate sufficient heat and provide sufficient stiffness for reliable uniform elastic loading B It can be 2-5 mm, such as 3.5 mm. In some examples, this thickness may be too wide to fit between tall components on adjacent sleeved PCAs. If only a limited area on the PCA (e.g., less than 50% or less than 25%) is occupied by tall components, the tightest space can be filled by recesses (e.g., Fig.14A The cutouts or notches 1431) or steps (e.g., end tabs 1433) on the upper portion of the housing are accommodated so that overall heat dissipation and rigidity are minimally compromised.

[0120] For example, the tab thickness T T It can be as thin as 0.1-0.2 mm, but it may only occupy a small portion of the total area of ​​the heat sink. Additionally or alternatively, the recess or tab can be located close to the cooling frame slot, where the stiffness of the recess or tab is enhanced by the slot wall and any heat accumulation is convected away by the liquid flowing through the cooling block. However, if the desired recess or tab occupies too large a proportion of the area of ​​the heat sink, or is in a position that is not conducive to heat accumulation, a material with higher conductivity (or a more complex structure, such as a heat sink) can be used with a smaller body thickness T. B Provides desired heat dissipation and stiffness.

[0121] Fig. 14C is through Fig.14A 1430c. In this example, the body of the heat transfer device 1430c between the end tabs 1433 and the end cone (not shown) defines an air pocket or space 1436. The air pocket 1435 is open to the surrounding atmosphere through the bottom of the heat transfer device 1430c.

[0122] Because the hollow interior 1436 is air, gas or vacuum, rather than a highly thermally conductive material, the heat sink weighs less than Fig.14AThe cost of the hollow heat sink may also be less than its solid counterpart if the manufacturing cost of the hollow example does not completely offset the material savings. The thickness T of the wall surrounding the hollow interior 1436 W,H Preferably sufficient to provide the necessary rigidity and heat dissipation.

[0123] Fig.14D is an example of a heat transfer device 1430d for a vapor chamber heat sink (via Fig.14A DD). In this example, the vapor chamber functions as a flattened heat pipe. More specifically, between the end taper (not shown) and the end tab 1433, the body of the heat transfer device 1430d defines a vapor chamber including a vapor core 1437 and a wicking layer 1438. The vapor chamber is closed and isolated from the surrounding atmosphere.

[0124] The vapor core 1437 (which may optionally extend into thinned areas such as tabs) is filled with a thermal phase change material and lined with a very thin (<0.2 mm) wicking layer 1438. The phase change material is at the "thermal interface" (the thermal contact area between the sleeve and the heat sink, Figure 5B The gas expands and travels through the core 1437 to the "cold interface" (the thermal contact area between the cooling frame and the heat sink, Fig. 10A Area A L or Fig. 10B Area A T ). Here, the gas condenses back into liquid and travels along the wicking layer 1438 back to the hot interface.

[0125] The effective thermal conductivity of the vapor chamber depends in part on its size, but can be equal to or exceed 10 kW / m / K at sizes similar to the heat sinks described herein. In contrast, the thermal conductivity of the copper wall is 0.3-0.4 kW / m / K; therefore, the phase change material in the core 1437 does most of the heat dissipation. The copper wall only needs to provide sufficient rigidity to load the active elastic member into the adjacent heat transfer sleeve. The thickness T of the copper wall surrounding the vapor chamber core 1437 is W,V It may be 0.4-0.6 mm, for example 0.5 mm.

[0126] FIG. 14B to FIG. 14D The three heat sinks shown in the figure are compared in a thermal model of a temperature control system for a tightly packed PCA array. The system includes a cooling frame and a PCA with a sleeve and heat sink. For the modeled heat sink, the wall material is copper and the body thickness is T B is 3.5 mm, and the tab thickness T T It is 0.15mm.

[0127] Those of ordinary skill in the art who have the benefit of this disclosure will appreciate that other variations of the heat transfer device of the claimed subject matter may be implemented in addition to those illustrated herein. Furthermore, the selection of a variation will be implementation specific, depending on the heat generated by the sleeved PCA and the design constraints for mitigating or handling that heat. Other constraints such as performance, cost, manufacturability, etc. may also affect the selection.

[0128] FIG. 15A to FIG. 15C It is for Figure 1 Data graph of thermal model results for a cooling system with FIG. 14A to FIG. 14C 1561A, 1561B, and 1561C are regions of operation where operation is close to the limit of remaining within specification. Regions 1562A, 1562B, and 1562C are regions where operation is outside the limit of remaining within specification.

[0129] The detailed description has ended. The specific examples disclosed above are illustrative only, as the technology disclosed herein may be modified and implemented in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitation is intended to the details of construction or design shown herein except as described in the appended claims. It is therefore apparent that the specific examples disclosed above may be changed or modified, and all such variations are considered to be within the scope and spirit of the appended claims. Therefore, protection for the contents of the claims is sought herein.

Claims

1. A heat transfer assembly comprising: heat transfer sleeves; as well as a cooling frame, the heat transfer sleeve being mechanically engaged with the cooling frame and the heat transfer sleeve being thermally coupled to the cooling frame, the cooling frame defining: an internal frame space into which at least a portion of the heat transfer jacket is disposed; as well as a coolant passage including at least one turbulence enhancer for intentionally enhancing turbulence into a liquid flow through the coolant passage; The cooling frame includes a first end block, a second end block opposite to the first end block, an introduction side rail extending between the first end block and the second end block, and an exit side rail extending between the first end block and the second end block. wherein the internal frame space is defined between the first end block and the second end block and between the lead-in side rail and the lead-out side rail, and wherein the coolant channel extends from an inlet to a first portion of the first end block, from the first portion of the first end block to the introduction side rail, from the introduction side rail to the second end block, from the second end block to the exit side rail, from the exit side rail to a second portion of the first end block, and from the second portion of the first end block to an outlet.

2. The heat transfer assembly of claim 1, in, The inlet has a circular cross-section; wherein the outlet has a circular cross-section; and The coolant channel includes a section between the inlet and the outlet and having an elliptical cross section.

3. The heat transfer assembly of claim 2, wherein: A section of the coolant passage between the inlet and the outlet includes at least one turbulence enhancement portion of the coolant passage; and The at least one turbulence enhancing portion further includes a bend and a shape change portion for further enhancing turbulence of the liquid flow passing through the coolant channel.

4. The heat transfer assembly of claim 2, wherein: The coolant passage, in a section between the inlet and the outlet, comprises: a first end block channel in the first portion of the first end block and fluidly connected to the inlet; a second end block channel, the second end block channel being in the second end block, a third end block channel in the second portion of the first end block and fluidly connected to the outlet; an incoming side rail channel in the incoming side rail and in fluid communication with the first end block channel and the second end block channel; and An exit side rail channel is provided in the exit side rail and is in fluid communication with the second end block channel and the exit third end block channel.

5. The heat transfer assembly of claim 1, wherein: The heat transfer sleeve comprises: a first cover defining a first pair of tabs by which the thermal transfer sleeve is mechanically engaged and thermally coupled to the cooling frame; a second cover member opposite the first cover member and mechanically engaged with the first cover member, the second cover member defining a second pair of tabs by which the thermal transfer sleeve is mechanically engaged and thermally coupled to the cooling frame; and A first movable elastic member is integrated with the first covering member.

6. The heat transfer assembly of claim 5, wherein: The heat transfer sleeve further includes a second movable elastic member, and the second movable elastic member is integral with the second covering member.

7. The heat transfer assembly of claim 1, wherein: The heat transfer assembly also includes a heat transfer device thermally coupled to the heat transfer jacket and thermally coupled to the cooling frame.

8. The heat transfer assembly of claim 7, wherein: The heat transfer device is a heat sink.

9. A computing subcomponent comprising: A printed circuit assembly, the printed circuit assembly comprising: Printed circuit boards; and a plurality of electronic components mounted to the printed circuit board; A heat transfer assembly, the heat transfer assembly comprising: a thermal transfer sleeve encapsulating and mechanically engaging the printed circuit assembly and thermally coupled to the printed circuit assembly; and a cooling frame, the heat transfer sleeve being mechanically engaged with the cooling frame, and the heat transfer sleeve and the printed circuit assembly being thermally coupled to the cooling frame, the cooling frame defining: an internal frame space into which at least a portion of the heat transfer jacket is disposed; and a coolant passage comprising at least one turbulence enhancer for intentionally introducing turbulence into a flow of liquid passing through the coolant passage; The cooling frame includes a first end block, a second end block opposite to the first end block, an introduction side rail extending between the first end block and the second end block, and an exit side rail extending between the first end block and the second end block. wherein the internal frame space is defined between the first end block and the second end block and between the lead-in side rail and the lead-out side rail, and The coolant passage extends from an inlet to a first portion of the first end block, from the first portion of the first end block to the lead-in side rail, from the lead-in side rail to the second end block, from the second end block to the lead-out side rail, from the lead-out side rail to a second portion of the first end block, and from the second portion of the first end block to an outlet.

10. The computing subassembly of claim 9, wherein: The printed circuit assembly is a memory board.

11. The computing subassembly of claim 9, wherein: The electronic components include a plurality of dual in-line memory modules (DIMMs).

12. The computing subassembly of claim 9, wherein: The coolant channel comprises: an inlet having a circular cross-section; an outlet having a circular cross-section; and A section between the inlet and the outlet and having an elliptical cross-section.

13. The computing subassembly of claim 12, wherein: The segment includes the at least one turbulence enhancing portion of the coolant passage, and The at least one turbulence enhancing portion includes a bend and a shape change portion for enhancing turbulence of a liquid flow passing through the coolant channel.

14. The computing subassembly of claim 9, wherein: The heat transfer sleeve comprises: A first covering member, wherein the first covering member: defining a first pair of tabs, the thermal transfer sleeve being mechanically engaged and thermally coupled to the cooling frame by the first pair of tabs; thermally coupling the printed circuit assembly to the cooling frame; and covering at least a first portion of a first side of the printed circuit assembly; a second covering member, the second covering member being opposite to the first covering member and being mechanically engaged with the first covering member, and the second covering member: defining a second pair of tabs, the thermal transfer sleeve being mechanically engaged and thermally coupled to the cooling frame by the second pair of tabs; thermally coupling the printed circuit assembly to the cooling frame; and covering at least a second portion of a second side of the printed circuit assembly; and a first movable elastic member, the first movable elastic member being integral with the first cover member, the first movable elastic member being compressed against a first component of the plurality of electronic components mounted to the printed circuit assembly by engagement of the first cover member and the second cover member to mechanically engage the first cover member with the printed circuit assembly so as to: mechanically engaging the thermal transfer sleeve with the printed circuit assembly; and The printed circuit assembly is thermally coupled to the thermal transfer sleeve and the cooling frame.

15. The computing subassembly of claim 9, wherein: The computing subassembly also includes a heat transfer device thermally coupled to the heat transfer jacket and thermally coupled to the cooling frame.

16. The computing subassembly of claim 15, wherein: The heat transfer device is thermally coupled to the heat transfer sleeve by a mechanical engagement.

17. The computing subassembly of claim 15, wherein: The heat transfer device is a heat sink.

18. A computing system comprising: a first printed circuit board, the first printed circuit board comprising a socket; and The computing subassembly of claim 9, wherein the cooling frame is mounted to the first printed circuit board such that the inner frame space surrounds the socket and the printed circuit assembly is mechanically and electrically coupled to the socket of the first printed circuit board within the inner frame space.

19. The computing system of claim 18, in, The printed circuit board has length, width and thickness dimensions and comprises: a first face parallel to said length and width dimensions, a second surface parallel to and opposite to the first surface, an edge connecting the first face and the second face, and an edge connector located at an edge and configured to communicatively connect the printed circuit assembly to another electronic device; The thermal transfer sleeve includes a first cover member and a second cover member, wherein the first cover member extends along a first side of the printed circuit assembly and is mechanically and thermally coupled to the first side of the printed circuit assembly including the first side, and the second cover member extends along a second side of the printed circuit assembly and is mechanically and thermally coupled to the second side of the printed circuit assembly including the second side; Wherein, the first covering member, the second covering member, or the first covering member and the second covering member both include movable elastic members, and the movable elastic members are integrated with the first covering member and / or the second covering member, wherein each movable elastic member is pushed toward the printed circuit assembly under the action of elastic force to contact the printed circuit assembly and thermally couple the printed circuit assembly with the heat transfer sleeve.

20. The computing system of claim 19, in, The first cover and the second cover define a pair of tabs positioned at opposite ends of the thermal transfer sleeve relative to a length dimension of the printed circuit board, One of the protrusions is mechanically engaged and thermally coupled to the first end block, and the other of the protrusions is mechanically engaged and thermally coupled to the second end block.

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