Conformal cooling assembly with substrate fluid-proofing for multi-die electronic assemblies

Abstract

A compliant cooling assembly for polycrystalline electronic components such as printed circuit boards and integrated circuits addresses and resolves several challenges and problems associated with managing heat generated by multiple chips using liquid-cooled cold plates and dielectric immersion cooling. The compliant cooling assembly includes a compliant cooling module comprising: an inlet channel and an outlet channel; and a filling portion configured to allow a cooling fluid to pass through it, thereby promoting direct fluid contact with heat-generating components attached to a substrate of the electronic component. The compliant cooling assembly also includes: a fastener for attaching the compliant cooling module to the substrate; and a fluid barrier disposed between the substrate and the filling portion. The fluid barrier is adapted to minimize, suppress, or prevent the cooling fluid from penetrating the substrate and being absorbed by the substrate.

Description

Technical Field

[0001] This case relates to a fluid-resistant compliant cooling assembly for substrates used in polycrystalline electronic components. Prior Technology

[0002] Processing units used in wireless communication devices, computer systems, and automated industrial manufacturing are becoming smaller, faster, and more powerful every year. These advancements have prompted designers and integrators to rely on electronic components to perform additional and more complex computing tasks and functions. Consequently, in industries such as high-performance computing, the demand for central processing units (CPUs), graphics processing units (GPUs), and other types of processing units utilizing high-performance, multi-functional, and multitasking electronic components continues to grow at an extremely rapid pace.

[0003] In an increasingly digital world, to meet the growing demand for more powerful, multifunctional, and multitasking electronic components, a popular technology is the use of multiple chips in a single electronic component. Traditionally, each electronic component in a processing unit contains a single chip to perform the specific functions of the processing unit (e.g., processing core, memory, I / O, power management, etc.), while emerging processing units now consist of multiple chips formed on each electronic component within the processing unit. Each chip in the electronic component can be optimized to perform the individual functions of the processing unit, so that when used together, all chips provide improved processing performance compared to traditional single-chip electronic components.

[0004] With this paradigm shift in the structure and performance of electronic components, new challenges have emerged in implementation. Some of these challenges fall under the category of thermal management. Without proper thermal management, multiple chips on a single electronic component are prone to overheating, which can lead to decreased computing performance, shortened lifespan, or complete failure of the semiconductor chips.

[0005] A common technique for managing heat generated by electronic components involves the use of liquid-cooled cold plates. A liquid-cooled cold plate typically comprises a plate made of a thermally conductive material (usually metal) with channels or pathways for the flow of cooling fluid through it. The flat surface of the plate is in thermal contact with the heat-generating component (e.g., a semiconductor die) via a thermal interface material (TIM). Heat flows out of the component, through the TIM, diffuses through the plate via conduction, and is carried away by the liquid coolant flowing through the internal channels or pathways of the cold plate.

[0006] While traditional liquid-cooled cold plates are highly effective at cooling many electronic components today, they face challenges in the paradigm shift from monocrystalline to polycrystalline electronic components, particularly in capless polycrystalline components. These challenges may include, for example, uneven grain height, semiconductor grain bowing, and localized hot spots. In such cases, the cold plate may no longer effectively cool multiple semiconductor grains because its flat surface may lose uniform contact across the heat-generating surface, thus limiting its ability to dissipate heat (especially from localized hot spots) into the flowing coolant.

[0007] As the industry shifts towards polycrystalline electronic components, a more efficient thermal management solution is needed to address the key challenges of cooling polycrystalline electronic components. More specifically, there is a significant need for a cooling device for polycrystalline electronic components that provides cooling adaptable to the varying heights and shapes of heat-generating components. Summary of the Invention

[0008] Generally, specific embodiments of the present invention provide a compliant cooling assembly for polycrystalline electronic components such as printed circuit boards and integrated circuits, which addresses and solves the challenges and problems described above associated with managing heat generated by multiple chips using conventional liquid-cooled cold plates. The compliant cooling assembly includes a compliant cooling module, fasteners, and a fluid barrier. The compliant cooling module includes an inlet channel, an outlet channel, and a filling section. The inlet and outlet channels are configured to allow cooling fluid to flow through the filling section, allowing direct contact between the cooling fluid and at least one heat-generating component of a substrate attached to the electronic component. The fasteners attach the compliant cooling module to the substrate. The fluid barrier is disposed between the substrate and the filling section and is configured to minimize, suppress, or prevent cooling fluid from penetrating the substrate within the filling section and being absorbed by the substrate.

[0009] More specifically, a specific embodiment of the present invention provides an apparatus for cooling an electronic component, the electronic component comprising a substrate and at least one heat-generating element attached to the surface of the substrate. The apparatus includes a compliant cooling module having a first wall and one or more sidewalls, wherein the one or more sidewalls are connected to the first wall to define a fluid filling portion. The fluid filling portion is partially surrounded and enclosed by the first wall and the one or more sidewalls, and is open on the side of the filling portion opposite to the first wall. The apparatus also includes: a fastener disposed between the substrate and the one or more sidewalls of the compliant cooling module, the fastener securingly attaching the one or more sidewalls of the compliant cooling module to the surface of the substrate such that the one or more sidewalls and the open side of the filling portion substantially surround and enclose the heat-generating element, and a portion of the surface of the substrate to which the heat-generating element is attached. Multiple heat-generating elements may also be attached to the substrate and surrounded by the sidewalls, the first wall, and the filling portion.

[0010] A fluid barrier is disposed between one or more sidewalls and a portion of the surface of a substrate substantially surrounded and enclosed by the filling portion. The fluid barrier restricts, inhibits, or prevents direct contact between cooling fluid pumped through the filling portion and a portion of the surface of the substrate substantially surrounded and enclosed by the sidewalls and the open sides of the filling portion.

[0011] The compliant cooling module further includes at least one inlet channel fluidly connected to the filling section and at least one outlet channel also fluidly connected to the filling section. Both the inlet and outlet channels are configured to allow cooling fluid to enter the compliant cooling module via the inlet channel, flow through and across the filling section to directly contact at least one heat-generating element, and then exit the compliant cooling module via the outlet channel. As the cooling fluid passes through the filling section, the direct contact between the cooling fluid and the heat-generating element in the filling section allows the cooling fluid to absorb at least some of the heat generated by the heat-generating element that is to be absorbed by the cooling fluid and discharged from the compliant cooling module via the outlet channel.

[0012] In one use case, a plurality of semiconductor dies are mounted on a printed circuit board (PCB). According to one specific embodiment of the invention, the compliant cooling module is secured to the PCB and configured to facilitate direct compliant fluid contact between the pressurized coolant and the plurality of semiconductor dies, thereby achieving heat exchange to minimize thermal resistance and reduce the operating temperature of the PCB. Preferably, but not necessarily, the cooling flow system is re-entrant (i.e., it circulates in and out of the cooling module).

[0013] After the compliant cooling module is attached to the PCB, the heat-generating components located inside the filling section of the compliant cooling module are nominally in safe contact with the cooling fluid. However, this is typically not the case for electronic devices outside the filling section, which may be damaged by exposure to the cooling fluid. Therefore, in addition to attaching the compliant cooling module to the PCB substrate, the fastener also serves as a seal between the sidewalls of the compliant cooling module and the PCB substrate. The primary function of this seal is to protect the circuitry and electronic devices outside the filling section from the effects of fluid exposure by preventing or at least minimizing the possibility that the cooling fluid injected into the filling section could flow under the sidewalls of the compliant cooling module and damage the electronic devices outside the filling section. Preferably, but not necessarily, the fastener acting as a seal between the compliant cooling module and the PCB substrate is completely impermeable to fluid (leak-proof). In some specific instances (not necessarily all), a secondary function of the fastener may be to keep dust or other particles from the surrounding environment outside the fluid filling section.

[0014] Inside the filling section, a fluid barrier can be placed on top of the PCB substrate, surrounding the semiconductor die, to further inhibit fluid penetration into the PCB substrate located inside the filling section. This fluid barrier is used to limit fluid absorption of the PCB during prolonged exposure to pressurized fluid coolant, thereby minimizing, for example, changes in impedance; trade-offs in mechanical properties; and potential short circuits.

[0015] Using this compliant cooling assembly addresses many of the thermal management challenges described above for emerging polycrystalline electronic components. First, as is common in polycrystalline electronic components, the die surface is typically not perfectly flat in height due to the inherent variability in the die attachment process to the substrate. Unlike conventional thermal management systems that attach a flat cold plate surface to multiple different dies at varying heights, the assembly and technology of this invention support various die surface height variations without compromising the overall performance of the electronic component. Furthermore, due to variations in the solder reflow die attachment process, for example, individual dies may deflect on their die surface. This technology supports individual die deflection as well as cumulative deflection across multiple dies without affecting operating principles. By addressing the issues of non-flat die height and die deflection, the compliant technology avoids process-induced variations in thermal contact; mechanical fatigue / reduced efficiency of thermal interface materials; and stress concentration in the device (e.g., due to uneven attachment pressure on heat-generating devices). Avoiding these problems results in electronic components with more effective thermal management, longer lifespan, and higher throughput.

[0016] In another specific example, the compliant cooling module includes a plurality of impingement nozzles to facilitate more efficient cooling. As pressurized fluid passes through the impingement nozzles, these nozzles generate small cooling jets that impact the heat-generating surface at high speed and vertically. This provides high convective heat transfer capability because the thermal gradient between the high-temperature heat-generating surface and the low-temperature coolant fluid is minimized to allow for efficient heat removal. These impingement nozzles can be configured to form an array on the heat-generating surface, and specifically, can be non-uniformly configured to target locally high-heat-generating regions on the semiconductor grain. This minimizes the thermal gradient between and across the semiconductor grain, thereby reducing the peak temperature of the locally hot spot regions.

[0017] Therefore, this configuration provides an effective solution to another challenge in the thermal management of polycrystalline electronic components: hot spot management. Typically, semiconductor chips contain localized heat-generating regions, which can become thermal bottlenecks limiting or reducing overall device performance. Combined with issues of non-planar chip height and polycrystalline deflection, localized hot spots can become particularly severe when the adhesion between the flat cold plate surface and the semiconductor chip surface is uneven. If left unaddressed, these localized hot spots often limit overall device performance, reliability, and lifespan.

[0018] Therefore, the compliant cooling assembly constructed and used according to specific embodiments of the present invention is designed to provide efficient thermal management and long service life for polycrystalline electronic components by promoting direct fluid contact with the surface of heat-generating components, and to protect the substrate by suppressing fluid absorption, while avoiding common polycrystalline component defects associated with non-planar grain height, grain deflection or bending, and localized hot spots. Specific embodiments of the present invention are also well-suited for use in many automated component manufacturing processes common in the semiconductor or circuit board manufacturing industry. Simple Explanation of the Diagram

[0019] To better understand the present invention, reference is made to the accompanying drawings, in which: [Figure 1] shows a schematic diagram of a prior art liquid-cooled cold plate.

[0020] [Figure 2] shows a cross-sectional view of a prior art liquid-cooled cold plate implemented in polycrystalline electronic components.

[0021] [Figure 3] shows a flowchart illustrating a specific example of a compliant cooling assembly.

[0022] [Figure 4] A cross-sectional view showing a specific example of a compliant cooling assembly.

[0023] [Figure 5] shows a cross-sectional view of another specific example of a compliant cooling assembly, which includes direct grain impact nozzles with an uneven nozzle configuration built into the cooling module to provide better cooling for localized heat-generating hot spots.

[0024] [Figure 6] shows a cross-sectional view of a specific example of a compliant cooling assembly with direct grain impact nozzles configured to minimize the thermal gradient between different heat loads.

[0025] [Figure 7] shows a cross-sectional view of another specific example of a compliant cooling assembly, wherein the barrier used to provide fluid protection to the substrate and to secure the compliant cooling module to the substrate is the same.

[0026] [Figure 8] shows another specific example of a compliant cooling assembly, in which the fluid barrier is completed in a two-step process.

[0027] [Figure 9] shows a cross-sectional view of another specific example of a compliant cooling assembly, in which fluid barriers are placed on the vertical walls of the heat-generating components to provide some fluid protection to the substrate.

[0028] [Figure 10] shows a cross-sectional view of another specific example of a compliant cooling assembly, wherein the fastener is soldered using built-in solder traces on the substrate.

[0029] [Figure 11] shows a cross-sectional view of another specific example of a compliant cooling assembly, including solder traces for use as a fluid detection circuit system. Implementation

[0030] This invention describes the use of compliant cooling components to provide highly effective and long-life thermal management for polycrystalline electronic components.

[0031] The compliant cooling components will be described in various specific examples in the following figures. Please note that the figures are not to scale and may include enlarged features to convey important concepts.

[0032] Many electronic components comprise multiple parts, including, for example, electrical components and printed circuit boards (PCBs). These electronic components typically include thermal management hardware such as fans, heat sinks, or cold plates. Figure 1 illustrates this configuration, where an electronic component (100) includes one or more heat-generating elements or assemblies (102) mounted on a cold plate (101). The heat-generating elements or assemblies (102) may be, for example, encapsulated, covered, or exposed die devices. In some cases, for example, a liquid-cooled cold plate (101) may be mounted on a computer processor (102), which may be mounted to another component or substrate (103), such as a PCB.

[0033] Figure 2 depicts a detailed cross-section of an electronic component (200) containing multiple grains (210a to 210d) cooled by a prior art cold plate (201).

[0034] In this non-limiting example, the printed circuit board (220) has four semiconductor dies (210a to 210d) mounted thereon. The dies (210a to 210d) are attached to the PCB (220) by means of a die attachment mechanism (221), which is typically solder, padding adhesive material, or a combination thereof. Die attachment mechanisms using other materials or technologies are possible. Although the dies (210a to 210d) appear to be the same size in Figure 2, dies with different sizes and dimensions may exist in the same assembly.

[0035] Figure 2 illustrates two important phenomena that can occur in electronic components containing multiple chips. First, due to the variability in chip construction itself or chip attachment processes, the upper surfaces (212a to 212d) of the semiconductor chips (210a to 210d) may not be coplanar in height. Second, due to, for example, uneven melting of solder balls, the top surfaces of individual semiconductor chips (210a to 210d) may not be flat (e.g., bowed, deflected, concave, convex, or tilted).

[0036] These two important phenomena are illustrated in the various examples in Figure 2. The semiconductor dies (210a) and (210b) do not exhibit any bending, but their upper surfaces (212a) and (212b) are positioned at different heights above the PCB (220). The difference in die height can vary, for example, from 50 to 925 micrometers (this may be the case in the case of polycrystalline stacks).

[0037] Furthermore, semiconductor dies (210c) and (210d) are positioned at the same centerline height above the PCB (220), but exhibit die deflection. Semiconductor die (210c) exhibits a concave die deflection, while semiconductor die (210d) exhibits an apical die deflection. The difference in die deflection can vary by 10 or 100 micrometers, for example, in the range of 10 to 500 micrometers. It should be noted that the die deflection is not limited to the die deflection depicted herein; throughout the die, the concave surface may not be upward or downward, and the center of the concave surface may not be at that center. In fact, die deflection can occur in any of an infinite number of different shapes, sizes, and orientations.

[0038] These semiconductor chips are typically heat-generating components, and the heat generated by these chips must be properly managed to avoid overheating. Overheating of semiconductor chips can cause a variety of problems, including but not limited to: thermally induced stress; reduced lifespan; compromised device performance; device failure; and padding material failure.

[0039] The overheating temperature of a given semiconductor die is influenced by a variety of factors, but particularly by the semiconductor material itself. Semiconductor dies are typically made of silicon (Si) or gallium nitride (GaN). Silicon is known to overheat at temperatures as low as 100°C to 125°C. Gallium nitride is known to overheat at temperatures as low as 200°C to 250°C. To prevent semiconductor dies from overheating (and other heat-related failures), the heat generated by the heat-generating elements must be removed before the component reaches its overheating temperature. Typically, this is achieved by attaching conductive heat sinks or liquid-cooled plates to the heat-generating elements.

[0040] Referring again to Figure 2, the liquid-cooled cold plate (201), which includes an internal channel (202), an inlet conduit (203), and an outlet conduit (204), is a typical semiconductor cooling mechanism. The lower surface (207) of the cold plate is mounted to the top surface (212a to 212d) of the semiconductor chips (210a to 210d) using a thermal interface material or a TIM (211) and some kind of fastener (not shown). Heat from the heat-generating semiconductor chips (210a to 210d) is conducted to the liquid-cooled cold plate (201) via the TIM (211). The heat diffuses throughout the cold plate (201), and the cooling fluid (205) entering through the inlet conduit (203) travels through the internal channel or passage (202) to pick up the heat absorbed by the cold plate from the semiconductor chips (210a to 210d). The heated fluid (206) is then discharged through the outlet conduit (204) and cooled by individual heat exchangers (not shown), such as cooling towers, air or fan heat exchangers with radiators, cooler circuits or thermosiphons. The heated fluid then returns to the inlet conduit (203) to absorb and carry away more heat.

[0041] TIM (211) is particularly important for the operation of the cold plate. TIM promotes heat conduction at the interface between the solid surfaces (212) and (207). In the absence of TIM, micro-gaps can form between the two surfaces. Since air is a very poor thermal conductor, micro-gaps can interrupt the smooth flow of heat from the top surface (212) of the semiconductor grains (210a to 210d) to the lower surface (207) of the cold plate (201).

[0042] Although TIM (approximately 1 to 10 W / mK) has a higher thermal conductivity than air (approximately 0.015 W / mK), it still has a moderate thermal conductivity compared to, for example, a cold plate (201), which is typically made of conductive metals such as aluminum (approximately 200 W / mK) or copper (approximately 350 W / mK). Therefore, despite filling the microscopic gaps, heat loss still occurs when TIM is applied. This is evidenced by the efforts of system designers and integrators to minimize the thickness of TIM and optimize its thermal properties. TIM thickness can range from approximately 100 to 500 micrometers, or even lower, such as 10 to 50 micrometers, under special circumstances.

[0043] Observing Figure 2 again, the non-flat grain height and the bent and deflected grain surface pose challenges to the application of TIM in polycrystalline modules. Because the mounting surface (207) of the cold plate is flat, different TIM thicknesses must be used to attach the cold plate (207) to the upper surface of the semiconductor grain (212). In practice, the TIM thickness across different semiconductor grains can vary by 100 or 1000 micrometers. Because the thickness of the TIM is 10 to 100 micrometers, the thermal efficiency of each TIM can differ by 100% or more. Since the temperature gradient across the TIM varies proportionally with the TIM thickness, and the thermal efficiency of the TIM varies proportionally with the temperature gradient, extreme variations in the TIM thickness can significantly reduce the ability of the liquid-cooled cold plate to absorb and remove heat.

[0044] Additional problems can arise from two phenomena associated with the manufacturing and operation of polycrystalline electronic components. First, semiconductor grains inherently exhibit non-uniform heat generation, which creates hot spots on the semiconductor regardless of TIM thickness. Second, if the TIM thickness at one point is greater than at another, this will tend to make the point with the thicker TIM hotter than the less thicker TIM, regardless of the non-uniform heat generation pattern. Both phenomena can independently lead to overheating. Of course, when both phenomena occur simultaneously, this is the worst-case scenario in terms of heat generation and thermal management.

[0045] In Figure 2, for example, the top surface of a semiconductor die (210d) can inherently have a higher local temperature (i.e., a hot spot) at its center (245). Because the temperature at the hot spot location will always be higher than the rest of the surface, the hot spot location will approach and exceed the overheating temperature of the semiconductor material at a lower power level than other surface locations that do not generate as much heat. Furthermore, the thicker the TIM at a location on the surface of the semiconductor die, the higher the power density will be at that location, and the higher power density can cause hot spots to form at that location on the surface of the semiconductor die. In Figure 2, if the semiconductor die (210d) has an upwardly concave deflection shape at its center (245), the center (245) of the concave surface will be the thickest point of the TIM system. Therefore, the center (245) of the semiconductor die (210d) is more likely to have the highest local temperature relative to other locations above it, and is therefore more likely to reach or exceed overheating at a lower power level than other surface locations. The highest power density will be directly adjacent to the center (245).

[0046] The ultimate phenomenon of grain height variability involves potential stress concentration on the semiconductor grain (210). To minimize the TIM thickness and thus limit the thermal gradient across the TIM layer, a cold plate is typically clamped to a heat-generating device to ensure that the TIM is in close contact and completely covers the semiconductor surface (212). If the vertex of the top surface of a bent semiconductor grain (such as semiconductor grain (210c) in Figure 2) lies on a horizontal plane above the height of the top surfaces of all other grains, stress concentration of the self-clamping force may occur at the vertex of the top surface (212c) of the semiconductor grain (210c).

[0047] Furthermore, if the pressure applied to each component of the TIM is uneven, certain areas of the TIM may dry out or crack over time. In particular, with the thermal cycling of these heated components, TIM degradation may occur more rapidly, leading to a decline in thermal management efficiency over time and severely impacting the lifespan of electronic components.

[0048] In summary, for polycrystalline electronic components similar to those shown in Figure 2, the variability in device die geometry, manufacturing, and attachment processes to printed circuit boards presents various challenges when attempting to reduce heat using liquid-cooled cold plates. Alternative cooling components that address these challenges will enable efficient and long-life operation of polycrystalline electronic components.

[0049] Figure 3 shows a linear flowchart illustrating, as an example, the main steps performed by a compliant cooling assembly constructed and used according to a specific embodiment of the present invention. As shown in Figure 3, the first step (step 301) involves placing an electronic assembly comprising multiple heat-generating components onto a substrate. In step 302, a fluid-blocking mechanism or barrier is placed on the substrate to prevent fluid penetration into the substrate. Examples of fluid-blocking mechanisms and barriers include, but are not limited to, coatings, metal films, non-permeable polymer films, reactive dry film adhesives, pressure-sensitive adhesives, liners, seals, or any combination thereof. Next, in step 303, a compliant cooling module similar to the compliant cooling module 400 shown in Figure 4 is attached to the substrate using an attachment mechanism. Non-limiting examples of attachment mechanisms include screws, elastic washers, adhesive materials, chemical bonds, welds, brazing, spring clips, solder, or any combination thereof. At step 304, pressurized coolant (typically supplied from an external source in the electronic system) enters the compliant cooling module, flows through the chambers (or filling sections) in the compliant cooling module to flow above the heat-generating element, and thereby absorbs and removes heat from the heat-generating element when the pressurized coolant is discharged from the other end of the compliant cooling module (step 305).

[0050] Although the flowchart in Figure 3 illustrates a specific sequence and number of steps, it should be noted that the sequence and number of steps performed by different specific embodiments of the invention may differ from those shown in the examples illustrated in Figure 3, depending on the specific application and requirements. For example, the heat-generating element may first be placed on the substrate using a padding material, at which point a mask is applied to deposit a fluid barrier, such that the fluid barrier is confined by the heat-generating element. This step may be followed by attaching the compliant cooling module to the substrate using fasteners. In another embodiment, a fluid barrier may be deposited first, followed by attachment of the heat-generating element using a padding material and then fasteners. The entire substrate may be fluid-proof, or only certain portions may be fluid-proof. When a compliant cooling module is present, fasteners may be applied simultaneously with the coating providing the fluid barrier, especially when, for example, the same adhesive material is used for both the fluid barrier and the fasteners. Of course, other steps and technical sequences are also possible, thereby giving the compliant cooling assembly potential supply chain flexibility to be integrated into different steps of the process.

[0051] Figure 4 illustrates, as an example, a compliant cooling assembly constructed according to a specific embodiment of the present invention. As shown in Figure 4, a substrate (220), such as a printed circuit board (sometimes simply referred to as a "PCB"), has at least one heat-generating element (210), such as a semiconductor die, disposed thereon. In a non-limiting example, there are four heat-generating elements. The heat-generating elements (210) are disposed on the substrate (220) by means of a padding material (221) (whether it is solder, adhesive or other material or a combination thereof). The tops of the semiconductor die (210) may or may not have different heights and shapes. The compliant cooling module (400) is attached by fasteners (402) to enclose a portion of the substrate (220) and the semiconductor die (210), thereby forming a seal. A fluid barrier (422) is disposed on the substrate to prevent the substrate located inside the inner wall of the compliant cooling module from being exposed to the fluid.

[0052] In operation, pressurized cooling fluid (405) enters the compliant cooling module (400) through at least one first inlet conduit (403), passing through the outer boundary (440) of the compliant cooling module (400). The fluid then exits the compliant cooling module (400) through at least one first outlet conduit (413), passing through the inner boundary (441) of the compliant cooling module (400). The fluid then comes into direct contact with the heat-generating element (210) in the fluid filling section (407), which is located between the inner boundary (441) of the compliant cooling module (400) and the substrate (220) and the heat-generating element (210) carried on the substrate (220). The fluid absorbs heat from the heat-generating element (210) as it passes through the fluid filling section. The heated fluid then re-enters the compliant cooling module (400) through at least one second inlet conduit (414), crossing the inner boundary (441) of the compliant cooling module (400). Finally, the fluid exits through at least one second outlet conduit (404), crossing the outer boundary (440) of the compliant cooling module (400). In some specific instances, the heated fluid (406) may be cooled via an individual heat exchanger, such as a cooling tower, cooler loop, or thermosiphon, after which the heated fluid returns to at least one first inlet conduit (403).

[0053] It should be noted that in the operation of this specific example of the compliant cooling assembly, a thermal interface material may not be required. Because the fluid exits the cooling module and compliantly contacts the heat-generating element directly, there is no solid-solid interface requiring gap filling. Due to this fact, the thermal challenges of the TIM (including variable total TIM thickness, localized hot spot TIM thickness, and TIM thermal cycling) on ​​polycrystalline electronic components are mitigated. Furthermore, with the fastener (402) used to attach the cooling module (400) to the substrate (220), the mechanical challenges of the assembly, including stress concentration, uneven TIM stress, and potential TIM degradation, are also mitigated. These properties contribute to an efficient and durable thermal management system for polycrystalline electronic components.

[0054] Cooling fluids may include, for example, water, water-glycol mixtures, dielectric fluids, mineral oils, ammonia, etc. It should be understood that the term "fluid proofing" in this context does not necessarily mean that the fluid barrier is completely impermeable to the cooling fluid, or that it prevents 100% of the cooling fluid from contacting the substrate. In fact, it should be understood that even when the barrier is properly positioned, a certain amount of cooling fluid can still pass through the barrier to reach the substrate and / or be absorbed by the substrate. The barrier is sufficient to prevent at least some of the cooling fluid from contacting the substrate, and thus, depending on the application, to limit or reduce the substrate's exposure to the cooling fluid to an acceptable level. However, it should also be understood that in some specific embodiments of the invention, the fluid barrier can actually provide a complete barrier to the fluid, such that no cooling fluid can pass through the barrier and reach the substrate.

[0055] The substrate can be made of a variety of materials, such as metals (e.g., copper-molybdenum, copper, nickel-plated copper, etc.), epoxy-based plastics (e.g., FR-4 / 5, G-10 / 11), or other polymers or composite materials. When using a metal substrate, the substrate typically exhibits good fluid resistance characteristics and allows for minimal fluid resistance.

[0056] However, in many plastics and epoxy resins, as is common in PCBs, there is a slight tendency for fluid absorption over time when exposed to pressurized and heated fluids. If fluid barriers are not implemented in these substrates, fluid absorption can lead to phenomena such as changes in circuit board impedance, mechanical variations, or, in extreme cases, short circuits. Other phenomena are also possible. Compared to substrates such as metal substrates, epoxy-based substrates will require more significant fluid barriers.

[0057] Referring again to Figure 4, a fluid barrier (422) may be deposited on a substrate (220) and bounded by a fastener (402) and a heat-generating element liner material (221) or a heat-generating element (210). Depending on the required level of fluid resistance for the application, the fluid barrier (422) may comprise a liquid-based sealant, such as silicone resin; it may also comprise a liquid-based adhesive, such as epoxy resin or glue. The fluid barrier (422) may also comprise a combination of such or other liquid-based sealants and adhesives. For example, the fluid barrier (422) may comprise the same adhesive used in the liner material (221). The fluid barrier (422) may comprise a high-temperature adhesive near the heat-generating element (210) and a low-temperature adhesive near the fastener (402). The adhesive may be thermally activated, UV activated, pressure activated, or another activation method or a combination thereof. The fluid barrier (422) may also comprise a compliant coating made of one or a combination of the materials mentioned above. Of course, other fluid barriers are possible.

[0058] In some configurations, hydrophobic surfactants can be applied in conjunction with adhesive or sealant materials. This allows fluids to repel water from the surface of interest. The surfactant can be applied directly to the substrate to expel any trace amounts of liquid passing through the fluid barrier, or it can be applied to a fluid barrier subjected to pressurized fluid. Other configurations are possible. It should be noted that hydrophobic surfactants or anti-fluid materials are typically not applied to the actual grain heat transfer surface.

[0059] The fastener (402) between the compliant cooling module (400) and the substrate (220) can serve as both an attachment mechanism and a seal to help protect external components of the compliant cooling module. This fastener can take many forms. For example, it can be an elastic gasket compressed by means of a fastener (not shown). The fastener can be a liquid adhesive or epoxy resin, which may be the same as or different from the fluid barrier. It can also be a solder material. Like the fluid barrier, this can depend on various specific application factors, such as: fluid pressure and temperature; substrate material; cooling module material; fluid type; the arrangement of heat-generating samples on the substrate; and the size and shape of the substrate. Other factors can also be important. Furthermore, as discussed in more detail below, the fastener can actually be located between the compliant cooling module and the fluid barrier without directly contacting the substrate.

[0060] The compliant cooling module (400) can also take many forms. While typical thermal management hard systems for heat-generating devices are made of high thermal conductivity metals, the compliant cooling assembly constructed according to specific embodiments of the invention can be made of a variety of different materials. Because the cooling assembly does not rely on the diffusion or conduction of heat throughout the plate to be removed by the internal channels, it can be made of materials with lower thermal conductivity for potential cost savings, increased service life due to reduced corrosion problems, and environmental benefits. The module can be made of high conductivity metals (copper, aluminum), low conductivity metals (steel, copper-molybdenum, invar steel), polymers, composites, etc. Because the compliant cooling module promotes direct contact between the fluid and the heat-generating element, its thermal properties are not a primary concern.

[0061] The first inlet conduit (403) and the second outlet conduit (404) can take many forms. In some cases, they can be fluid fittings, such as barbed fittings, compression fittings, welded tubing, push-fit fittings, threaded fittings, or other materials. In other cases, the conduit can be attached to a fluid manifold or distributor.

[0062] In some other specific instances, the heat-generating element (210) may have heat transfer enhancement features, such as fins, passages, or pins, disposed thereon and within the external periphery of the compliant cooling module. Such heat transfer enhancement features may allow for increased surface area, localized fluid flow effects such as turbulence, or a combination thereof. The increased surface area and turbulence allow for increased heat transfer by means of closer contact between the fluid and the heat-generating element (210).

[0063] Summarizing Figures 3 and 4, a compliant cooling assembly is presented in a specific example. In a substrate in which multiple heat-generating components are housed, the compliant cooling module is attached to the substrate via fasteners to facilitate direct fluid contact between the coolant fluid and the heat-generating elements contained within its external periphery. Fluid barriers are disposed on the substrate to prevent fluid penetration into the substrate.

[0064] Figures 5 through 11 illustrate other specific examples of compliant cooling components. Of course, other specific examples are possible, but Figures 5 through 11 are intended to show representative samples of possible implementations for a variety of possible situations.

[0065] Figure 5 shows a specific example of a variation of the compliant cooling module (500). Cooling fluid (405) enters the cooling module (500) through at least one first inlet conduit (503), crosses the outer boundary (540) of the cooling module (500), and enters the intermediate reservoir (508). At this stage, the fluid has not yet left the compliant cooling module (500). The fluid then crosses the inner boundary (541) of the cooling module (500) through a first set of outlet conduits (513), now a plurality of outlet conduits. The fluid that has left the compliant cooling module (500) and entered the fluid filling section (507) carries away heat from the heat-generating component (210) by means of direct fluid contact with the heat-generating device (210). The fluid can then re-enter the compliant cooling module (500) through at least one second inlet conduit (514), crossing the inner boundary (541) of the cooling module (500). The fluid then exits the compliant cooling module (500) via at least one second outlet conduit (504), wherein the heated fluid (406) is then cooled via individual heat exchangers, such as cooling towers, cooler loops, fans and radiators or thermosiphons, before returning to the inlet conduit (503). Of course, the same coolant need not return to the compliant cooling module. The compliant cooling module is attached to the substrate (220) using fasteners (502), and a fluid barrier (522) is disposed on the substrate (220). The compliant cooling module may also be attached to the fluid barrier (522) via fasteners (502) instead of the substrate.

[0066] In some specific examples of Figure 5, the first set of outlet conduits (513) may be impingement nozzles that generate microjets (531) to impinge on the upper surface (212) of the heat-generating element (210). Microjet cooling is a highly efficient convective heat transfer mechanism that promotes extremely high heat transfer per unit area by means of boundary layer suppression using high-speed jets directed vertically toward the heat transfer surface (212). This method provides compliant cooling on polycrystalline modules using a single compliant cooling module. Heat transfer is typically quantified by heat transfer coefficients, where microjet cooling can produce heat transfer coefficients in the range of 50,000 to 400,000 W / m²-℃ for single-phase operation (see approximately 1,000 to 5,000 W / m²-℃ for cold plates and approximately 10,000 to 30,000 W / m²-℃ for microchannel cold plates). By utilizing single-phase microjet cooling in the compliant cooling module (500), extremely efficient thermal management of the heat-generating component (210) can be achieved.

[0067] Figure 6 shows a possible specific example of the first set of outlet conduits (513) along a cross-section taken along part AA of a compliant cooling module similar to that of Figure 5 with impingement nozzles. Because the heat-generating element (210) requires the most thermal management, this configuration shown in Figure 6 preferably delivers fluid to the heat-generating element, rather than areas of the substrate where little or no heat generation occurs. The impingement nozzles (513) can be arranged in an array (601) at intervals (603) to remove heat. Each heat-generating element may have a different size, different heat load, or different heat load distribution across the surface. Therefore, the impingement nozzle array (601) can be individually customized for each heat-generating element to provide the most effective thermal management in the areas where the most effective thermal management is required. Furthermore, within a single heat-generating element, there may be hot spots with higher heat generation, where better fluid delivery can be implemented to provide more effective thermal management. For example, Figure 2 illustrates a hot spot (245) with high heat production in the middle of the rightmost heat-generating element (210d). In Figure 6, a dense array of nozzles (604) can target the hot spot with high heat production to minimize the heat gradient within the heat-generating element, in addition to minimizing the heat gradient across the heat-generating element.

[0068] As shown in Figure 6, the possibilities for impact nozzle arrays are diverse, including nozzle arrays with different nozzle sizes, different nozzle spacings, different numbers of nozzles, different array sizes, and different array layouts. Other geometric configurations are also possible.

[0069] Figure 7 illustrates another specific example of a compliant cooling assembly, in which the fastener (702) and the fluid barrier (722) are completed in a single step. In this specific example, the fluid barrier (722) and the fastener (702) can be implemented using a liquid adhesive material such as an epoxy resin with low water absorption. This allows for a streamlined assembly process for the compliant cooling assembly by using the same material to implement both mechanisms.

[0070] Figure 8 illustrates another specific example of a compliant cooling assembly in which the fluid barrier is completed in a two-step process. The fluid barrier (823), such as a metal film, a non-permeable polymer film, or other highly fluid-resistant material, can be placed on the substrate (220) using an adhesive (822) or a deposition process. The adhesive (822) can be a liquid adhesive as described in Figure 7, or it can be a reactive dry film adhesive or a pressure-sensitive adhesive. The use of a fluid barrier (823) with a reactive dry film adhesive or a pressure-sensitive adhesive (822) is well-suited for die-cutting processes and simplifies the process without requiring the heat, UV, or other start-up technologies required by many liquid adhesives. If necessary, a secondary liquid adhesive can be used to fill any gaps created between the die-cut fluid barrier (823) and the grain pad (821), the heat-generating element (210), and the fasteners (802). Alternatively, the fluid barrier (823) may extend such that the fastener (802) attaches the compliant cooling module (400) to the fluid barrier (823), which is attached to the substrate (220). Again, it should be noted that the figures are not to scale; in some embodiments, the fluid barrier (823) may be as thin as 0.001 to 0.005”, while the typical thickness of a heat-generating semiconductor grain may be about 0.010 to 0.030”.

[0071] In each of the specific examples shown so far, the fluid barrier has been defined by the heat-generating element liner material (221). However, in some specific examples, it is preferable to integrate the fluid barrier into the wall of the heat-generating element (210). Figure 9 illustrates this specific example, where the fluid barrier (922) is defined by the heat-generating element (210), which extends above the liner material (221). This can be done, for example, in an embodiment where a predetermined volume of sealant is deposited onto a substrate inside the periphery of the container, and the sealant is melted and flowed to create a uniform layer surrounding the heat-generating element (210) up to a specified height. In some cases, the fluid barrier (922) may extend upward and contact the wall of the heat-generating surface (210) above the height of a typical anti-fluid layer. In other cases, for example, the fluid barrier may protrude onto the upward surface of the heat-generating element (210). It is worth noting that the grain pad (221) and the fluid barrier (922) can be applied simultaneously to simplify the manufacturing process.

[0072] Figure 10 illustrates another specific example of a compliant cooling assembly, in which alternative fasteners (1002) are present. In this specific example, the substrate (220) includes pre-fabricated copper and / or solder traces (1024) for attachment to the compliant cooling module (400). In this configuration, the assembly can undergo a solder reflow process, in which solder from the solder traces (1024) melts. The molten solder forms a bond (1002) between the substrate (220) and the cooling module (400). This allows for strong attachment bonding (1002) built into the substrate (220) during the design process, enabling fastening procedures compatible with current substrate manufacturing processes, such as automated liquid dispensing equipment or automated pick-and-place machines and solder reflow assembly equipment.

[0073] Other trace functionality can also be incorporated into polycrystalline cooling components. For example, in Figure 11, two substrate traces (1125) can be positioned close to each other on the outer surface of the substrate, with an electrically insulating material (e.g., substrate material (220)) between them. When these traces are positioned within the periphery of a compliant cooling module (400) and extend through a fluid barrier (1122), they can be implemented as a fluid detection device. That is, when a conductive fluid (e.g., water) fills the filling portion (407) bounded by the compliant cooling module (400) and the substrate (220) (or the fluid barrier (1122)), adjacent traces that are normally open-circuit connected can form a closed circuit. This can be used as a telemetry or diagnostic tool to determine whether fluid is present within the component without visual inspection.

[0074] Furthermore, similar adjacent traces (1126) can also be placed on the periphery of the compliant cooling module (400). Their operating principle will be similar, but their functionality will be reversed. For example, by bridging the insulating gaps between them with fluid and closing the circuit, these traces (1126) can be used to generate an electrical signal indicating that fluid has flowed out of the compliant cooling module (400), indicating a leak or failure in a fastener (1102), fluid barrier (1122), or other aspect of the component. This contributes to the formation of an integrated, compact assembly that provides compliant cooling to multiple heat-generating elements (210) while having built-in fault reporting capabilities.

[0075] The compliant cooling assembly constructed according to specific embodiments of the present invention can be used with many types and a wide variety of heat-generating electronic components. The heat-generating electronic component is constructed such that at least one heat-generating element is mounted on a substrate. However, typically, the heat-generating electronic component is constructed having multiple heat-generating elements attached to the surface of the substrate, as illustrated in Figures 4 to 7 and Figures 9 to 11. As shown in the figures and as described in detail above, the compliant cooling assembly of the present invention includes a compliant cooling module attached to a substrate via fasteners, and the surface of the substrate is fluid-proof via a fluid barrier disposed between the surface of the substrate and the filling portion. The compliant cooling module receives cooling fluid from a pressurized source via at least one first inlet conduit, exits the cooling module via at least one first outlet conduit, flows through the filling portion, and thus comes into direct fluid contact with at least one heat-generating element. The cooling fluid re-enters the cooling module via at least one second inlet conduit and then exits via at least one second outlet conduit.

[0076] As should be apparent from Figures 4 through 11 regarding its physical geometry and structure, in some specific instances, the compliant cooling module includes a top wall, one or more side walls, a fluid filling section, at least one inlet channel, and at least one outlet channel. Perhaps best illustrated in Figure 8, for example, it will be observed that the compliant cooling module (400) includes a top wall (440), two side walls (442a and 442b), a fluid filling section (407), an inlet channel (405), and an outlet channel (406). Since the illustration in Figure 8 only shows a cross-sectional view of the compliant cooling assembly of the present invention, it should be understood that the compliant cooling module (400) has two additional side walls, which are not shown in Figure 8 for ease of understanding. However, it should be understood that the compliant cooling module (400) may have only one side wall, or any number of side walls, depending on the overall shape of the compliant cooling assembly. For example, the overall shape of a compliant cooling component can be cylindrical (requiring only one circumferential sidewall), triangular (three sidewalls), trapezoidal (four sidewalls), or hexagonal (eight sidewalls), to name just a few possible overall shapes and corresponding numbers of sidewalls.

[0077] The top portions of the sidewalls (442a and 442b) are joined to the peripheral edge of the top wall (440) to define the boundary surrounding the fluid filling portion (407). Thus, the fluid filling portion (407) is partially surrounded and enclosed by the top wall (440) and the sidewalls (442a and 442b). However, the bottom side of the fluid filling portion (407) of the compliant cooling module (400), that is, the side of the fluid filling portion (407) opposite to the top wall (440), is open because the compliant cooling module (400) itself does not have a wall on the bottom side of the fluid filling portion (407) opposite to the top wall (440). Therefore, the bottom of the compliant cooling module (400) remains open until the bottom portions of the sidewalls (442a and 442b) of the compliant cooling module are fastened to the substrate (220) using fasteners (802) to complete the construction of the compliant cooling assembly. When the compliant cooling module (400) is fastened to the substrate (220) using fasteners (802), all sidewalls, including the open sides of the sidewalls (442a and 442b) and the fluid filling portion (407), substantially surround and enclose the heat-generating element 210 and a portion of the surface of the substrate to which the heat-generating element (210) is attached. Due to the presence of the inlet channel (405) and outlet channel (406) extending through the top wall (440) of the compliant cooling module (400), the fluid filling portion (407) is considered to be "substantially surrounded and enclosed" and not completely surrounded and enclosed.

[0078] Although this description refers to the wall opposite the open side of the filling section as the "top" wall, it should be recognized and understood that the top wall is not always "above" the substrate and the heat-generating element. Therefore, the "top wall" referred to in this description can actually be below, to the right, or to the left of the substrate and the heat-generating element, depending on the final placement and orientation of the electronic components and compliant cooling components in the assembled processing unit. It should also be understood that, depending on the requirements of a particular processing unit, in some specific instances, the inlet and outlet channels may be positioned and extend through the sidewalls of the compliant cooling module rather than the top wall, without departing from the scope of the invention.

[0079] As previously described and illustrated in Figures 5 and 6, the compliant cooling module (400) can be configured to provide better fluid delivery to certain heat-generating elements (210) or portions of heat-generating elements (210) to minimize localized hot spots. The compliant cooling module may also include impingement nozzles to promote particularly high heat transfer between the fluid and the heat-generating elements. The compliant cooling assembly of the present invention provides an efficient option for thermal management of substrates containing multiple different heat-generating elements, particularly polycrystalline devices with non-planar grain heights, grain deflection or bending, and high-heat-generating localized hot spots. These features and advantages also tend to improve the lifespan of electronic components using these features and advantages.

[0080] Compliant cooling components offer alternatives to existing thermal management technologies such as liquid-cooled cold plates and dielectric immersion cooling. Liquid-cooled cold plates in polycrystalline modules can present thermal and mechanical challenges such as variable thermal interface material layer thickness, stress concentration, increased risk of TIM degradation due to uneven TIM pressure, and unpredictable hotspots. Meanwhile, dielectric immersion cooling is a potentially more expensive cooling method, less efficient in managing heat, and can be environmentally unfriendly depending on the immersion coolant used, often resulting in polycrystalline modules with short lifespans and poor performance in high-power-density applications. While fluid-proof solutions similar to those disclosed and advocated herein may be of interest for immersion cooling technology, immersion cooling may require the entire PCB to be fluid-proof, which is process-intensive and costly, and may still be difficult to achieve sufficient performance using certain hardware components (such as optical connectors). For applications requiring power-intensive processing units, specific examples of the present invention providing localized fluid protection represent a more efficient, durable, and environmentally friendly solution.

[0081] The scope of this invention is not limited to the specific examples described herein. In fact, various other examples and modifications of the invention, other than those described herein, will be apparent to those skilled in the art from the foregoing description and drawings. Therefore, such other examples and modifications are intended to fall within the scope of this invention. Furthermore, although this invention has been described herein in the context of a specific purpose, a specific setting, and a specific implementation, those skilled in the art will recognize that its effectiveness is not limited thereto and that the invention can be advantageously implemented in any number of settings for any number of purposes. Therefore, the claims set forth below should be interpreted in light of the full scope and spirit of the invention as described herein.

[0082] 100: Electronic Components

[0083] 101: Cold Plate

[0084] 102: Heat-generating elements or components / Computer processor

[0085] 103: Another component or substrate

[0086] 200: Electronic Components

[0087] 201: Previous technology cold plate

[0088] 202: Internal passage or pathway

[0089] 203: Inlet catheter

[0090] 204: Outlet conduit

[0091] 205: Cooling fluid

[0092] 206: Heating fluid

[0093] 207: Lower surface

[0094] 210: Heat-generating element

[0095] 210a: Semiconductor die

[0096] 210b: Semiconductor die

[0097] 210c: Semiconductor die

[0098] 210d: Semiconductor grain

[0099] 211: Thermal Interface Materials

[0100] 212: Upper surface

[0101] 212a: Upper surface

[0102] 212b: Upper surface

[0103] 212c: Upper surface

[0104] 212d: Upper surface

[0105] 220: Printed Circuit Board / Substrate

[0106] 221: Grain attachment mechanism / padding material

[0107] 245: Center

[0108] 301: Steps

[0109] 302: Steps

[0110] 303: Steps

[0111] 304: Steps

[0112] 305: Steps

[0113] 400: Compliant Cooling Module

[0114] 402: Fasteners

[0115] 403: First inlet catheter

[0116] 404: Second outlet catheter

[0117] 405: Cooling fluid / inlet channel

[0118] 406: Heated fluid / outlet channel

[0119] 407: Fluid filling part

[0120] 413: First outlet conduit

[0121] 414: Second inlet catheter

[0122] 422:Fluid barrier

[0123] 440: Outer boundary / top wall

[0124] 441: Inner Boundary

[0125] 442a: Sidewall

[0126] 442b: Sidewall

[0127] 500: Compliant Cooling Module

[0128] 502: Fasteners

[0129] 503: First inlet catheter

[0130] 504: Second outlet conduit

[0131] 507: Fluid filling part

[0132] 508: Intermediate Storage

[0133] 513: Outlet conduit / impact nozzle

[0134] 514: Second inlet catheter

[0135] 522:Fluid barrier

[0136] 531: Microjets

[0137] 540: Outer boundary

[0138] 541: Inner Boundary

[0139] 601: Impact Nozzle Array

[0140] 603: Interval

[0141] 604: Nozzle

[0142] 702: Fasteners

[0143] 722:Fluid barrier

[0144] 802: Fasteners

[0145] 821: Grain Pad

[0146] 822: Adhesive

[0147] 823:Fluid barrier

[0148] 922:Fluid barrier

[0149] 1002: Alternative Fasteners

[0150] 1024: Solder traces

[0151] 1102: Fasteners

[0152] 1122:Fluid barrier

[0153] 1125: Substrate traces

[0154] 1126: Traces

Claims

1. An electronic component comprising: a substrate; at least two heat-generating elements attached to a surface of the substrate, the at least two heat-generating elements having an upper surface not entirely in the same plane; a cooling module comprising a reservoir configured to receive pressurized cooling fluid, a first wall, and one or more sidewalls connected to the first wall to define a fluid-filled portion, the fluid-filled portion being partially surrounded and enclosed by the first wall and the one or more sidewalls, the fluid-filled portion being further open on a side face of the fluid-filled portion opposite to the first wall, the cooling module further comprising a plurality of impact nozzles fluidly connecting the reservoir to the first wall of the fluid-filled portion; A fastener is disposed between the substrate and the one or more sidewalls, the fastener securely attaching the one or more sidewalls of the cooling module to the surface of the substrate, such that the first wall, the one or more sidewalls and the open side of the fluid filling portion substantially surround and enclose the at least two heat-generating elements and a portion of the surface of the substrate, wherein the at least two heat-generating elements are attached to the surface. The plurality of impact nozzles are configured to receive the pressurized cooling fluid from the reservoir, and are configured to increase the velocity of the pressurized cooling fluid to transform it into a plurality of high-speed microjet streams of pressurized cooling fluid. These high-speed microjet streams are also configured to guide the pressurized cooling fluid through the fluid filling section and directly impact the upper surface of the at least two heat-generating elements at high speed and perpendicular to the first wall of the fluid filling section. The reservoir, the plurality of impact nozzles, and the fluid filling section are configured to receive the liquid phase of the pressurized cooling fluid and to allow the pressurized cooling fluid to pass through the plurality of impact nozzles, flow through the fluid filling section, and directly impact the upper surface of the heat-generating elements without causing a phase change. The pressurized cooling fluid remains liquid after impacting the upper surface of the heat-generating elements.

2. The electronic assembly of claim 1, wherein the upper surfaces of the at least two heat-generating elements are located at at least two different heights above the surface of the substrate.

3. The electronic assembly of claim 1, wherein the upper surface of the at least two heat-generating elements is bowed, deflected, concave, convex or inclined.

4. The electronic assembly of claim 1, wherein a first vertex of a first upper surface of a first heat-generating element is located on a first horizontal plane, and a second vertex of a second upper surface of a second heat-generating element is located on a second horizontal plane, the first plane being closer to the surface of the substrate than the second horizontal plane.

5. The electronic component of claim 1, wherein the upper surfaces of two of the at least two heat-generating elements attached to the substrate have different geometries.

6. The electronic component of claim 1, wherein the plurality of impact nozzles are configured to form an impact nozzle array, the impact nozzle array being disposed above at least one of the at least two heat-generating elements.

7. The electronic component of claim 6, wherein the plurality of impact nozzles are configured to form at least two impact nozzle arrays, comprising a first impact nozzle array and a second impact nozzle array, the first impact nozzle array being disposed above a first heat-generating element and the second impact nozzle array being disposed above a second heat-generating element.

8. The electronic component of claim 7, wherein the size of the impact nozzles of the first impact nozzle array is different from the size of the impact nozzles of the second impact nozzle array.

9. The electronic component of claim 7, wherein the spacing between the impact nozzles of the first impact nozzle array is different from the spacing between the impact nozzles of the second impact nozzle array.

10. The electronic component of claim 7, wherein the number of impact nozzles in the first impact nozzle array is different from the number of impact nozzles in the second impact nozzle array.

11. The electronic component of claim 7, wherein the size of the first array is larger than the size of the second array.

12. The electronic component of claim 7, wherein the layout of the first array differs from the layout of the second array.

13. The electronic component of claim 7, wherein the density of the impact nozzles of the first impact nozzle array is greater than the density of the impact nozzles of the second impact nozzle array, such that the first cooling efficiency delivered to one of the first heat-generating elements is greater than the second cooling efficiency delivered to one of the second heat-generating elements.

14. The electronic component of claim 1, wherein the plurality of impact nozzles in the first wall of the fluid filling portion are unevenly disposed on the first wall of the fluid filling portion for targeting a localized high-heat region on one or more of the at least two heat-generating elements attached to the substrate.

15. An electronic component comprising: a substrate; a heat-generating element attached to a surface of the substrate, the heat-generating element having an upper surface having a height variation relative to the surface of the substrate; a cooling module comprising a reservoir configured to receive pressurized cooling fluid, a first wall, and one or more sidewalls connected to the first wall to define a fluid-filled portion, the fluid-filled portion being partially surrounded and enclosed by the first wall and the one or more sidewalls, the fluid-filled portion being further open on a side face of the fluid-filled portion opposite to the first wall, the cooling module further comprising a plurality of impact nozzles fluidly connecting the reservoir to the first wall of the fluid-filled portion; A fastener is disposed between the substrate and the one or more sidewalls, the fastener securely attaching the one or more sidewalls of the cooling module to the surface of the substrate, such that the first wall, the one or more sidewalls and the open side of the fluid filling portion substantially surround and enclose the heat-generating element and a portion of the surface of the substrate, wherein the heat-generating element is attached to the surface of the substrate. The plurality of impact nozzles are configured to receive the pressurized cooling fluid from the reservoir, and are configured to increase the velocity of the pressurized cooling fluid to transform it into a plurality of high-speed micro-jet streams of pressurized cooling fluid. These high-speed micro-jet streams are also configured to guide the flow of the plurality of high-speed micro-jet streams of pressurized cooling fluid through the fluid filling section and directly impact the upper surface of the heat-generating element at high speed and perpendicular to the first wall of the fluid filling section. The reservoir, the plurality of impact nozzles, and the fluid filling section are configured to receive the liquid phase of the pressurized cooling fluid, allowing it to pass through the plurality of impact nozzles, flow through the fluid filling section, and directly impact the upper surface of the heat-generating element without causing a phase change. The pressurized cooling fluid remains liquid after impacting the upper surface of the heat-generating element.

16. The electronic component of claim 15, wherein the upper surface of the heat-generating element is bowed, deflected, concave, convex, or inclined relative to the surface of the substrate.

17. The electronic assembly of claim 15, wherein the distance between one or more locations of the upper surface of the heat-generating element and the surface of the substrate is different from the distance between one or more other locations of the upper surface of the heat-generating element and the surface of the substrate.

18. The electronic component of claim 15, wherein the upper surface of the heat-generating element attached to the substrate has a non-perfectly flat shape.

19. The electronic component of claim 15, wherein the plurality of impact nozzles are configured to form an impact nozzle array, the impact nozzle array being disposed above the heat-generating element.

20. The electronic component of claim 19, wherein the plurality of impact nozzles are configured to form at least two impact nozzle arrays, comprising a first impact nozzle array and a second impact nozzle array, the first impact nozzle array being disposed above a first portion of one of the heat-generating elements, and the second impact nozzle array being disposed above a second portion of one of the heat-generating elements.

21. The electronic component of claim 20, wherein the size of the impact nozzles of the first impact nozzle array is different from the size of the impact nozzles of the second impact nozzle array.

22. The electronic component of claim 20, wherein the spacing between the impact nozzles of the first impact nozzle array is different from the spacing between the impact nozzles of the second impact nozzle array.

23. The electronic component of claim 20, wherein the number of impact nozzles in the first impact nozzle array is different from the number of impact nozzles in the second impact nozzle array.

24. The electronic component of claim 20, wherein the size of the first array is larger than the size of the second array.

25. The electronic component of claim 20, wherein the layout of the first array differs from the layout of the second array.

26. The electronic component of claim 20, wherein the density of the impact nozzles of the first impact nozzle array is greater than the density of the impact nozzles of the second impact nozzle array, such that the first cooling efficiency delivered to the first portion of the heat-generating element is greater than the second cooling efficiency delivered to the second portion of the heat-generating element.

27. The electronic component of claim 15, wherein the plurality of impact nozzles in the first wall of the fluid filling portion are unevenly disposed on the first wall of the fluid filling portion for aiming at a localized high-heat region on the heat-generating element attached to the substrate.

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