Cooling device for a system on a chip

Abstract

A cooling apparatus for a system-on-a-chip includes a plurality of cooling units including a first side to be coupled to the system-on-a-chip, each cooling unit spaced apart from other cooling units to define a gap between adjacent cooling units, and a interposer coupled to a second side of the plurality of cooling units, the interposer including a flexible joint enabling relative movement of adjacent cooling units.

Description

Background Technology

[0001] Electronic printed circuit boards (PCBs), integrated circuits, and systems-on-a-chip (SoCs) (such as those used in computers or other electronic systems) typically have boards on which electronic components are mounted. These electronic components can generate significant heat due to power consumption. This heat is dissipated from the components and the board to ensure proper functioning of the components and to prevent damage to any part of the SoC and the entire electronic system. Attached Figure Description

[0002] Figure 1A and Figure 1B This is a side view of an example of a system-on-a-chip component including cooling equipment; Figure 2 This is a side view of an example of a system-on-a-chip component including cooling equipment; Figure 3 This is a side view of an example of a system-on-a-chip component including cooling equipment; Figure 4A and Figure 4B This is a side view of an example of a system-on-a-chip component including cooling equipment; Figures 5 to 8 This is a top view of an example of an interlayer with a flexible joint; Figure 9 A cross-sectional side view of an example of a flexible joint in an interlayer is shown; Figure 10 These are examples of methods for manufacturing, assembling, and installing cooling equipment.

[0003] Figure 11 The diagram illustrates the situation based on Figure 10 The method is used for cooling equipment during the manufacturing process.

[0004] It will be appreciated that these drawings are illustrative representations for purposes of explanation. The purpose of providing the drawings is to illustrate embodiments, and it is clearly understood that the drawings are not intended to limit the scope of the claims. Detailed Implementation

[0005] Various techniques can be used to remove heat from a System-on-a-Chip (SOC). For example, heat can be transferred to the ambient air simply through convection. However, the amount of heat transferred using this method may be relatively low. To enhance the effectiveness of convective cooling, a fan can be added to force airflow over the component. A heat sink or heat transfer plate can be attached to the component to further enhance heat dissipation by conducting heat from the heat source to a large surface area from which heat can dissipate into the air. The heat sink can be a sheet of solid material with high thermal conductivity, such as metal, having multiple fins extending from a base attached to the SOC. The fins increase the surface area of ​​the heat sink, thereby increasing the amount of heat that can be carried away by convection as air or other fluids flow over the heat sink and through the fins. For even better heat dissipation, a liquid cooling system can be used.

[0006] Liquid-cooled systems may include pumps or compressors, cooling manifolds including fluid passages, and radiators. The cooling manifolds may be connected to the state-of-the-art (SOC) to allow heat transfer from cooling plates to the cooling fluid. The compressor pumps the cooling fluid through the manifold passages and through pipes or conduits that deliver the fluid to radiators located away from the SOC. In some cases, the radiator may include a compressor for active cooling of the cooling fluid.

[0007] Thermal interface materials (TIMs) can be positioned between a System-on-a-Chip (SOC) and a heatsink or cooling manifold to improve thermal conductivity and heat transfer between them. Many materials can be used as TIMs, including thermal grease, polymer-based TIMs, carbon-based TIMs, and metal-based TIMs. Metal-based TIMs can have the highest thermal conductivity and low thermal contact resistance, and therefore provide optimal heat transfer from the SOC to the heatsink or cooling manifold. These metal-based TIMs can include silver sintered paste, gallium-based liquid metals, solder, or TIMs that include gold, silver, or copper bonding interfaces.

[0008] Some thermal immersion membranes (TIMs), including metal-based TIMs such as silver sintered paste, can rigidly bond heat sinks or cooling manifolds directly to a surface-mount organic charge (SOC). As the SOC heats up during use, temperature differences and variations in coefficients of thermal expansion between the SOC, TIM, and heat sink or cooling manifold can create stress on the TIM and SOC. In larger SOCs, this stress can lead to cracking of the SOC or TIM and / or detachment of the TIM from the SOC, heat sink, or cooling manifold. Therefore, when the SOC size exceeds approximately 20 mm × 20 mm, lower-rigidity TIMs, such as thermal grease, two-phase materials, or polymer-based TIMs, are typically used. However, as mentioned above, these TIMs can have lower thermal conductivity than metal-based TIMs (such as silver sintered paste). Therefore, solutions that allow the use of rigid TIMs on larger SOCs are desirable.

[0009] Now for reference Figure 1A and Figure 1BA typical arrangement of a SOC assembly 100 is shown before and after it heats up during use. The SOC assembly includes an SOC 102 bonded to a heat sink 104 via a TIM 106. The SOC 102 may include processing components 108 mounted to a substrate 110 (e.g., an organic or inorganic substrate). Figure 1A As shown, due to manufacturing defects, the substrate 110 and SOC 102 as a whole may be slightly convex, while the lower surface of the heat sink 104 may be substantially flat. It should be understood that the figures are not drawn to scale, and the curvature shown in the SOC is exaggerated for clarity. The TIM 106 can be applied when the SOC 102 and heat sink 104 are "cold" (e.g., at room temperature). For example, as the SOC 102 heats up during use, and heat is transferred to the heat sink 104 through the TIM 106, the SOC 102, TIM 106, and heat sink 104 undergo thermal expansion. Temperature rise during operation of the SOC can cause changes in the SOC shape. For example, as... Figure 1B As shown, as SOC 102 heats up, the amount of bending in the convex SOC 102 can decrease, and SOC 102 can become less convex or even concave. When using hot grease or a two-phase TIM material, this may cause the thickness of TIM 106 to increase more at the center than at the edges. This may cause SOC 102 to straighten or become concave. Heat sink 104 can be stiffer than SOC 102 and can resist bending along with SOC 102. This may impose significant stress on SOC 102 with a rigid TIM (such as a metallic TIM), which may lead to cracks in substrate 110 and / or cracks or peeling in TIM 106. The difference in the coefficients of thermal expansion between heat sink 104, SOC 102, and TIM 106 may further contribute to these stresses.

[0010] Now for reference Figure 2 According to some examples, a SOC component 200 (e.g., an SOC module) is shown. Instead of employing a single, monolithic heatsink (e.g., heatsink 104), the SOC component 200 includes a cooling device 202 comprising multiple cooling units (e.g., heatsink modules). Figure 2 The diagram shows a microchannel manifold 204 (e.g., a silicon microchannel manifold), each microchannel manifold being bonded to the SOC 102 on a first side of the microchannel manifold 204 via a separate TIM 206. In some examples, the cooling unit may be a physical heat sink, each heat sink having multiple fins to increase the surface area of ​​the heat sink to improve convection, or as... Figure 2As shown, the cooling unit can be a liquid cooling manifold (e.g., a microchannel manifold, silicon microchannel manifold, etc.). Each microchannel manifold 204 (or other type of cooling unit) can be spaced apart from other microchannel manifolds 204, thereby allowing each microchannel manifold 204 to move relative to other microchannel manifolds 204. Because the microchannel manifolds 204 are separated from each other, when the SOC 102, microchannel manifolds 204, and TIM 206 heat up, the microchannel manifolds 204 can move toward or away from each other and / or vertically relative to each other (as shown) as the SOC 102 bends (e.g., becomes less convex) without applying excessive stress to the SOC 102 or TIM 206. Unlike Figure 1A and Figure 1B In the SOC 100 assembly (where the large monolithic heatsink 104 provides stiffness to resist bending of the SOC 102, thus generating stress at the interface), the space between the microchannel manifolds 204 allows the SOC 102 to deform with less constraint, thereby reducing interface stress. This allows rigid materials, including metal-based TIMs with high thermal conductivity, such as silver sintered paste, to be used in the TIM 206. In some examples, a rigid thermal interface material can refer to a thermal interface material with an elastic modulus higher than 15 GPa at room temperature. Therefore, in contrast to the SOC assembly 100, the SOC assembly 200 allows the use of TIMs that, despite their rigidity, have very high thermal conductivity and very low contact resistance. Furthermore, compared to... Figure 2 Conversely, as shown, in some examples, the TIM 206 may be continuous, while the microchannel manifolds 204 are separated from each other. For example, the SOC assembly 200 may include a single segment of TIM 206 bonded to two or more microchannel manifolds 204, rather than including separate segments of TIM 206 for each microchannel manifold 204. Separation of the microchannel manifolds 204 may be sufficient to reduce stress, rather than as... Figure 2 As shown, this also separates TIM 206.

[0011] In some examples, SOC component 200 may include bridging elements (e.g., connectors, distributors, common components, etc.) that connect two or more cooling units. For example, as Figure 2As shown, the bridging element is a coolant distribution manifold 208 (e.g., coolant delivery manifold, fluid distribution manifold, liquid distribution manifold, etc.) that supplies liquid to the fluid channels of each microchannel manifold 204 to which it is connected. In some examples, the bridging element or any other incompressible, non-sticky material does not extend into the gaps between the microchannel manifolds 204. The coolant distribution manifolds 208 and the microchannel manifolds 204 thus allow individual microchannel manifolds 204 to move independently relative to the other microchannel manifolds 204 (e.g., in response to thermal expansion). In some examples, hot grease or other viscous or compressible materials may be applied to fill the gaps between the microchannel manifolds 204, for example, to increase thermal conductivity between the microchannel manifolds 204. In some examples, no material may be positioned between the microchannel manifolds 204. In a SOC assembly 200 where the cooling unit is a solid, air-cooled radiator, the bridging element may be a thermally conductive structure that further conducts heat away from the cooling unit and the SOC 102. For example, the bridging element itself can be a heatsink with multiple fins to increase the surface area of ​​the bridging element and improve convection. Heat can be conducted from the SOC 102 to the cooling unit and from the cooling unit to the bridging element. Heat can be removed from both the cooling unit and the bridging element through natural convection or forced convection using a fan.

[0012] The coolant distribution manifold 208 can be coupled to the microchannel manifold 204 via a flexible seal 210 on a second side of each microchannel manifold 204, which is opposite to a first side of each microchannel manifold 204, which can be bonded to the SOC 102 via a rigid TIM 206 (such as a metal-based TIM). The flexible seal 210 can be made of an elastomer or other flexible material. The flexible seal 210 allows the microchannel manifold 204 to move relative to the coolant distribution manifold 208 without applying significant stress to the microchannel manifold 204, the flexible seal 210, or the coolant distribution manifold 208. The gap between the flexible seal 210 and the cooling unit allows each microchannel manifold 204 to move independently relative to the other microchannel manifolds 204. In some examples, a single flexible seal 210 (e.g., a gasket) can be positioned between the coolant distribution manifold 208 and all or a subset of the microchannel manifolds 204. Because the interfaces between the microchannel manifolds 204 are farther from the SOC 102 than the TIM 206, flexible materials with lower thermal conductivity than the TIM 206, such as flexible seals 210, can be used. Coolant distribution manifolds 208, connected to two or more microchannel manifolds within the microchannel manifolds 204, can improve system thermal integration, allowing heat transfer between the microchannel manifolds 204 and also improving the efficiency of coolant distribution. See below for reference. Figure 3 A to Figure 3C discusses the liquid-cooled cooling device 202 in further detail. In some examples, the coolant distribution manifold 208 may be connected to a microchannel manifold 204. Therefore, each microchannel manifold 204 may include a separate coolant distribution manifold 208.

[0013] As described above, in a liquid-cooled system, the cooling unit can be a microchannel manifold 204 (e.g., a silicon microchannel manifold), and the bridging element can be a coolant distribution manifold 208. Due to manufacturing limitations, it may be difficult to fabricate the channels of the coolant distribution manifold 208 (which can be made of molded thermoplastic material) to accurately supply fluid directly to the smallest microchannels of the microchannel manifold 204. Instead, the silicon microchannel manifold 204 can have several (e.g., three, four, etc.) layers of fluid channels, with the smallest, most densely packed channels in the layer closest to the SOC 102, and larger channels in the layer close to the coolant distribution manifold 208, which can include even larger fluid channels. Most heat exchange occurs in the layer closest to the SOC 102, while the other layers are used to maintain high coolant flow rates through the channels, uniform coolant temperature distribution, and low coolant pressure drops at the coolant inlet and outlet ports. Additional layers are also used to address the coefficient of thermal expansion (CTE) mismatch between the silicon microchannel manifold 204 and the coolant distribution manifold 208, which can be made of a thermoplastic material. For example, silicon has a CTE of about 3 ppm / °C, and thermoplastic materials can have a CTE in the range of 25 ppm / °C to 50 ppm / °C. Excessive temperature rise in the coolant distribution manifold 208 may create stress in the interface between the microchannel manifold 204 and the coolant distribution manifold 208, which may include a flexible seal 210 and may include an adhesive bonding layer. The layer of the microchannel manifold 204 closest to the SOC 102 may experience the highest temperature changes due to its proximity to the SOC 102, while each subsequent layer close to the coolant distribution manifold 208 may experience a gradually decreasing temperature change, thus essentially insulating the coolant distribution manifold 208 from the SOC 102. This reduces the temperature variation of the coolant distribution manifold 208, thereby minimizing the effects of CTE mismatch between the silicon microchannel manifold 204 and the coolant distribution manifold 208. Therefore, the additional silicon layer can reduce stress at the bonding interface. However, silicon is a relatively expensive material, and the additional layer increases the overall size of the cooling device 202, which may be undesirable in space-constrained electronic devices.

[0014] Now for reference Figure 3According to some examples, a SOC assembly 200 is shown. To reduce cost and the overall height of the cooling device 202, layers (or portions) of the cooling units (e.g., microchannel manifolds 204) may be replaced by an intermediary layer 209. The intermediary layer 209 is positioned between the coolant distribution manifold 208 and the microchannel manifolds 204. In some examples, all the microchannel manifolds in the microchannel manifold 204 may be coupled to a single intermediary layer 209. In other examples, less than all of the microchannel manifolds 204 may be coupled to a single intermediary layer 209. For example, the cooling device 202 may include multiple intermediary layers 209, each coupled to a subset of the microchannel manifolds 204. In some examples, a separate intermediary layer 209 coupled to each cooling unit may be present. However, it may be desirable to use a single intermediary layer 209 to couple multiple microchannel manifolds 204 together, thereby allowing for tight control of the space between the microchannel manifolds 204. For example, it may be desirable to bring the microchannel manifolds 204 very close together, such that substantially the entire surface of the SOC 102 (e.g., as shown in the image) is covered. Figure 3 The upper surface of the SOC 102 shown is covered by microchannel manifolds 204, with gaps positioned on inconspicuous portions of the surface. For example, the gap between each microchannel manifold 204 can be about 200 micrometers wide or less. Such small gaps could be difficult to maintain if each microchannel manifold 204 were individually attached to the SOC 102. Therefore, each microchannel manifold 204 can be initially attached to an interposer 209, maintaining a very small gap between the microchannel manifolds 204, and the complete cooling device 202 can be attached to the SOC 102. This also allows the cooling device 202 to be pre-assembled for installation on an existing SOC 102, for example, to replace an existing heatsink. The cooling device 202 can be manufactured and / or assembled using precision mechanics to maintain the very small gaps between the microchannel manifolds 204.

[0015] In the liquid-cooled cooling device 202, the interlayer may include fluid channels that fluidly connect the fluid channels of the coolant distribution manifold 208 to the fluid channels of the microchannel manifold 204. The interlayer 209 may be made of an epoxy molding compound and may have a CTE of approximately 7 ppm / °C. Because the interlayer 209 can have a CTE between that of the microchannel manifold 204 (e.g., 3 ppm / °C) and that of the coolant distribution manifold 208 (e.g., 25-50 ppm / °C), the interlayer 209 can provide a transition layer that reduces stress at the interface compared to a cooling device 202 where the microchannel manifold 204 and the coolant distribution manifold 208 are directly coupled. The interlayer 209 with fluid channels can replace the layers of the silicon microchannel manifold 204 with lower-cost EMC while providing the same or more efficient cooling. For example, in a cooling device 202 comprising four layers in each silicon microchannel manifold 204, the top two layers of each silicon microchannel manifold 204 can be removed and replaced by an interposer layer. A complete cooling device 202 with two silicon layers and an interposer layer can provide equivalent or improved cooling compared to a cooling device with four silicon layers. The interposer layer 209 can also be thinner than the combined thickness of the two silicon layers, resulting in a lower overall height of the cooling device 202. The interposer layer 209 can include several thin layers (e.g., thinner than the layers of the silicon microchannel manifold 204), thereby allowing fluid channels to spread from the lower layer adjacent to the microchannel manifold 204 to the layer adjacent to the coolant distribution manifold 208.

[0016] like Figure 3 As shown, the interposer 209 is bonded to each microchannel manifold in the microchannel manifold 204, for example, with an adhesive. If the interposer 209 is rigid, this could lead to results similar to those discussed above with respect to Figure 1. A rigid interposer 209 can resist the ability of the microchannel manifolds 204 to move relative to each other when the SOC 102 deforms due to thermal stress. If the TIM 206 is also rigid, this could create stress at the interface between the microchannel manifold 204 and the SOC 102. For example, as... Figure 3 As shown, when SOC 102 deforms, TIM 206 may be uneven or missing in some areas and may be subjected to stresses that could lead to fracture. It should be understood that... Figure 3 It is not drawn to scale, and the curvature is exaggerated to show its effect. Furthermore, although a single segment of TIM 206 is shown between SOC 102 and all microchannel manifolds 204, deformation of SOC 102 would produce a similar effect even if each microchannel manifold 204 were connected to SOC 102 via a separate segment of TIM 206.

[0017] Now for reference Figure 4AAccording to some examples, a SOC component 200 with a cooling device 302 is shown. Apart from those shown and described, the cooling device 302 may be substantially similar to... Figure 3 The cooling device 202 is shown. Unlike the relatively rigid interlayer 209 of the cooling device 202, the cooling device 302 includes an interlayer 309 having a flexible joint 311 in the region between the microchannel manifolds 204. (Refer to the above text) Figure 2 As the SOC 102 deforms, the flexible joint 311 allows the microchannel manifolds 204 to move relative to each other and substantially independently. Because the microchannel manifolds 204 are separated from each other, and the interposer 309 includes the flexible joint 311, the microchannel manifolds 204 can move relative to each other as the SOC 102 deforms (e.g., becomes less bulging) without applying excessive stress to the SOC 102 or TIM 206. Therefore, the SOC assembly 200 allows the use of a TIM that, despite its rigidity, has very high thermal conductivity and very low contact resistance. In some examples, the TIM 206 may be continuous, while the microchannel manifolds 204 are separated from each other. For example, the SOC assembly 200 may include a single segment of TIM 206 bonded to two or more microchannel manifolds 204, rather than a separate segment of TIM 206 for each microchannel manifold 204. The separation of the microchannel manifold 204 is sufficient to reduce stress without separating the TIM 206. Therefore, with Figure 3 Compared to the intermediate layer 209, the intermediate layer 309 can provide minimal resistance to the movement of the microchannel manifolds 204 relative to each other. However, because the intermediate layer 309 still connects the microchannel manifolds 204 together, the microchannel manifolds 204 can be precisely positioned and connected to the intermediate layer 309 to maintain a tightly controlled gap between the microchannel manifolds 204 (e.g., a gap of about 200 micrometers or less). The flexible connector 311 can be in the form of, for example, a partial or full cut in the intermediate layer 309, or a combination of partial and full cuts.

[0018] Intermediate layer 309 allows the cooling device 302 to be fully assembled before being mounted onto the SOC 102. It may also help to bring the microchannel manifolds 204 very close together, making virtually the entire surface of the SOC 102 (e.g., as shown) Figure 2The upper surface of the SOC 102 shown is covered by cooling units, with gaps positioned on inconspicuous portions of the surface. For example, the gap between each microchannel manifold 204 can be about 200 micrometers wide or less. Such small gaps could be difficult to maintain if each microchannel manifold 204 were individually attached to the SOC 102. Therefore, each microchannel manifold 204 can first be attached to the interposer 309, maintaining a very small gap between the microchannel manifolds 204 aligned with the flexible connector 311, and then the microchannel manifolds can be attached to the coolant distribution manifold 208 to form a complete cooling device 302, which can then be attached to the SOC 102. This also allows the cooling device 302 to be pre-assembled for installation on an existing SOC 102, for example, to replace an existing radiator. The cooling device 202 can be manufactured and / or assembled using precision mechanics to maintain the very small gaps between the microchannel manifolds 204.

[0019] Figure 4B An example of a cooling device 202 in a liquid-cooled SOC assembly 200 is shown. The cooling unit is shown as a microchannel manifold 204, where microchannels 249 extend through the microchannel manifold to transport fluid near the surface of the SOC 102. The microchannels are fluidly coupled to fluid channels 316 in the junction portion 313 of the interposer 309. Fluid channels 316 are also fluidly coupled to fluid channels 247 in a coolant distribution manifold 208. A liquid coolant (e.g., water, oil) can be supplied to the inlet 212 of the coolant distribution manifold 208 and travel through fluid channels 247 and 316 to the microchannels 249, where the coolant can absorb heat from the SOC 102. The coolant can then return to the coolant distribution manifold 208 and exit from the outlet 213. The coolant can then be cooled by a radiator and / or a refrigeration unit and recirculated back to the inlet 212. Figure 4B As shown, the fluid passage 316 does not extend through the flexible joint 311, but instead returns coolant from each microchannel manifold 204 to the coolant distribution manifold 208. Although the fluid passages 316 in the joint are shown in series, with coolant from the outlet side of the first joint 313 being delivered to the inlet side of the second joint 313, in other examples, the fluid passages 316 may be arranged in series, with the coolant supplied to the inlet 212 being diverted and supplied to each microchannel manifold 204 individually before being delivered to the outlet 213.

[0020] Figures 5 to 8 An example of an intermediary layer 309 is shown, wherein the intermediary layer has ten junction portions 313 to be connected to ten microchannel manifolds 204. Figures 5 to 8 The example interlayer 309 shown includes various flexible joint designs that can produce different levels of flexibility and structural support. Figure 5In the example interlayer 309, a flexible joint 311 is positioned between each of the ten joint portions 313 (also referred to as interlayer tiles, tile portions, etc.). The flexible joint 311 includes both a through-cut portion 315 and a partial-cut portion 317. The through-cut portion 315 extends all the way through the interlayer 309, while the partial-cut portion 317 is a channel or slot that does not extend all the way through the interlayer 309. The through-cut portion 315 provides no resistance to the movement of the microchannel manifold 204 relative to each other. When the various joint portions 313 are joined together, the partial-cut portion 317 provides relatively little resistance to the movement of the microchannel manifold 204 relative to each other (e.g., compared to an interlayer without cut portions). Figure 5 As shown, each joint 313 includes fluid channels 316 for fluidly connecting a coolant distribution manifold to a microchannel manifold cooling unit. The interlayer 309 includes through-cut portions 315 between the channels 316 and interruptions 319 at the intersection of the vertical and horizontal through-cut portions 315, such that the channels 316 are fluid-sealed. The flexible joint 311 can be broadly described as having a smaller cross-sectional area in a plane extending longitudinally through the flexible joint 311 than the cross-sectional area of ​​the adjacent joint 313 along a parallel plane. In other words, the thickness of the interlayer 309 at or within the flexible joint 311 (i.e., the thickness of the interlayer 309) is smaller than the cross-sectional area of ​​the adjacent joint 313 along a parallel plane. Figures 5 to 8 The page shown can be less than the thickness of the intermediary layer 309 at the adjacent joint portion 313. Figure 6 The intermediate layer 309 similarly includes ten joint portions 313, but does not include horizontal flexible joints 311. Instead, the intermediate layer 309 includes four vertical flexible joints 311 in the form of uninterrupted through cuts. Therefore, the intermediate layer 309 may have compliance (e.g., flexibility) about a vertical axis (as shown in the image). Figure 6 (as shown), but may not have significant compliance around a horizontal axis (e.g.) Figure 6 (As shown). For example, when the SOC 102 to which the cooling device 302 is connected is expected to bend primarily around a single known axis, the interposer layer 309 can be used in the cooling device 302. For example, as... Figure 1A and Figure 1B As shown, SOC 102 bends around an axis that extends into the page. If SOC 102 also does not bend around a horizontal (as shown) axis, then Figure 6 The intermediate layer 309 can be arranged such that a flexible joint 311 extends into the page parallel to the bending axis. If the SOC 102 also does not bend around a horizontal axis, a flexible joint extending parallel to the horizontal axis may not be included. In addition... Figure 7 The intermediate layer 309 does not include the portion of the cutout 317. Figure 7 The intermediary layer 309 is basically similar to Figure 5 Intermediate layer 309. Conversely, the flexible joint 311 is in the form of through cuts that do not extend to the edge of the intermediate layer 309, thus leaving a solid edge portion 312 at the edge. Further, the horizontal flexible joint 311 includes interruptions between fluid channels 316, but not interruptions at the intersection of the vertical flexible joint 311 and the horizontal flexible joint 311. Due to the absence of partial cut portions 317, Figure 7 The intermediary layer may be inferior to Figure 5 The intermediate layer is flexible, but the solid edge portion 312 can be more flexible than... Figure 5 The cut portion 317 of the intermediate layer 309 more firmly connects the joint portion 313 together. Figure 8 The intermediate layer 309 includes flexible joints 311, which are in the form of partially cut slots 321 that do not fully extend through the intermediate layer 309. Because the slots 321 do not fully extend through the intermediate layer 309, they can extend to the edge of the intermediate layer 309 while the mating portions 313 remain connected. The slots 321 provide flexibility while maintaining a high degree of strength in connecting the mating portions 313, which is higher than... Figure 5 The partial cut of the intermediate layer 309, part 317, is also higher than that of the intermediate layer 309. Figures 6 to 8 The diagram shows a flexible joint 311 that includes a through-cut portion 319.

[0021] Now for reference Figure 9Several cross-sectional views of flexible connectors 311a-311h are shown. As described above, flexible connector 311 may also include a through-cut portion 315 along the length of connector 311. In some examples, flexible connector 311 may be cut into a flat interposer 309 using a laser, saw, milling cutter, or planer. In other examples, flexible connector 311 may be molded into a flat interposer 309. For example, a layered molding process, such as a molding interconnect substrate fabrication process, may be used to form flexible connector 311. Alternatively, flexible connector 311 may be molded into interposer 309. Flexible connector 311a includes: two straight partial cuts 323 (also referred to as slots) extending beyond the centerline of interposer 309 on a first side of interposer 309; and a straight partial cut 323 extending beyond the centerline of interposer 309 on the other side of interposer 309 and positioned between the two straight partial cuts 323 on the first side. Partial cuts 323 extend parallel to each other along the interposer layer 309 to form a flexible joint 311a. Flexible joint 311b includes: three straight partial cuts 323 extending beyond the centerline of the interposer layer 309 on a first side; and two straight partial cuts 323 extending beyond the centerline of the interposer layer 309 on the other side and positioned between the three straight partial cuts 323 on the first side. Flexible joint 311c includes one straight partial cut 323 on each side of the interposer layer 309 and is aligned with the partial cuts 323 on the opposite side. Flexible joint 311d includes: one straight partial cut 323 extending beyond the centerline of the interposer layer 309 on a first side; and one straight partial cut 323 extending beyond the centerline of the interposer layer 309 on the other side and offset from the straight partial cut 323 on the first side.

[0022] The flexible connector 311e includes channels 322 on each side of the interposer 309. Each channel 322 includes a vertical portion 324 extending beyond the centerline of the interposer 309 and a horizontal portion 325 extending from the end of the respective vertical portion 324 toward the vertical portion 324 of the other channel 322. The horizontal portions 325 overlap in the horizontal direction. Since forming the shape of the channels 322 using machining processes can be challenging, a molding interconnect substrate fabrication process can be used to form the channels 322. A layer of epoxy molding compound and metal (e.g., copper) traces can be formed, wherein the metal traces form the shape of the channels. The metal traces can then be chemically etched to remove the metal material, thereby leaving the channels 322 in the epoxy molding compound.

[0023] Flexible connector 311f includes: two straight partial cuts 323 on a first side of interposer 309, but not extending beyond the centerline of interposer 309; and a straight partial cut 323 on the other side of interposer 309, but not extending beyond the centerline of interposer 309, and positioned between the two straight partial cuts 323 on the first side. Flexible connector 311g includes: a pyramidal partial cut 327 on the first side of interposer 309, extending beyond the centerline of interposer 309 and gradually narrowing with increasing depth; and a pyramidal partial cut 327 on the other side of interposer 309, extending beyond the centerline of interposer 309, gradually narrowing with increasing depth, and offset from the straight partial cut 323 on the first side. Flexible connector 311h includes a single through cut 331 extending completely through interposer 309. A high-temperature flexible strip 329 connects the two joint portions 313. Each of these flexible joints 311 reduces the resistance to movement of the joint portions 313 relative to each other, thereby reducing the resistance to movement of the microchannel manifold 204 relative to each other when it is connected to the joint portions 313.

[0024] Now for reference Figure 10 An example of a method 400 for manufacturing, assembling and installing cooling equipment is shown. Figure 11 Further illustration shows the operation of method 400 performed for manufacturing, assembling, and installing example cooling device 302. At operation 402 of method 400, an interposer layer (e.g., interposer layer 309) is manufactured having a mating portion separated by a flexible connector. Interposer layer 309 can be molded using molding interconnect substrate technology, injection molded, or machined. For example, flexible connector 311 may include channels or slots cut using a laser, saw, milling cutter, or planer. Alternatively, flexible connector 311 may be molded into interposer layer 309. Fluid channels (e.g., such as...) Figures 5 to 8The fluid channel 316 shown can also be molded or cut into the interposer 309. At operation 404 of method 400, a cooling unit (e.g., a microchannel manifold 204 as shown in FIG. 4) is coupled to a joint portion 313 of the interposer 309. A layer of adhesive 333 can be applied to each joint portion 313 of the interposer, each microchannel manifold 204, or both the microchannel manifold 204 and the joint portion 313. Each microchannel manifold 204 can be separated from other cooling units by a gap 211. The width of the gap 211 can be approximately 200 micrometers or less. When the flexible joint 311 between adjacent joint portions 313 is a channel or slot, the gap 211 can be substantially aligned with the flexible joint 311. For example, a plane extending through the gap 211 can also extend longitudinally through the flexible joint 311. Microchannel manifold 204 may be a microchannel manifold having microchannels (e.g., a silicon microchannel manifold), and when microchannel manifold 204 is coupled to interposer 309, the microchannels are fluidly coupled to the channels of interposer 309. At operation 406 of method 400, interposer 309 is coupled to a bridging element (e.g., coolant distribution manifold 208 as shown in FIG. 4) to form a complete cooling device (e.g., cooling device 302 as shown in FIG. 4). In some examples, interposer 309 may be coupled to coolant distribution manifold 208 via flexible seal 210. In some examples, interposer 309 may be coupled to coolant distribution manifold 208 via adhesive bonding layer. Coolant distribution manifold 208 includes fluid channels that are fluidly coupled to the fluid channels of interposer 309 when interposer 309 is coupled to coolant distribution manifold 208.

[0025] At operation 408 of method 400, the cooling device 302 is coupled to the SOC (e.g., SOC 102 shown in FIG. 4). Operation 408 may include applying TIM 206 to one or both of the SOC 102 or the microchannel manifold 204, thereby positioning the cooling device 302 on the SOC 102 and curing the TIM 206. As mentioned above, a rigid TIM 206, such as silver sintering paste, can be used because the flexible interposer 309 allows the cooling units to move relative to each other. A mask can be applied to the SOC 102 such that each portion of the TIM 206 is separated when the TIM 206 is applied. During testing, a strip is used to simulate the interposer 309 to determine the effect of the flexible joint 311 in the interposer 309. In the first test setup, the tape is bonded to each microchannel manifold in the microchannel manifold 204 and at each end to a reinforcing frame coupled to the SOC 102 to simulate a rigid interposer 309 that does not allow the microchannel manifold 204 to adhere to the surface of the SOC 102. In the second test setup, the tape is bonded to each microchannel manifold in the microchannel manifold 204 but not to the reinforcing frame to simulate an interposer 309 with a flexible connector, thereby allowing the microchannel manifold 204 to adhere to the surface of the SOC 102. The bonding line thickness of the TIM 206 for each test setup is measured at different locations on the surface of the SOC 102. The standard deviation of the bonding line thickness measurement in the first test setup, representing a cooling device 202 with a rigid interposer 309, is determined to be 175 micrometers. In the second test setup (which represents a cooling device 302 with an interposer 309 having a flexible connector 311), the same measurement has a standard deviation of 21 micrometers. Therefore, the test setup of the cooling device 302 with the intermediate layer 309 having the flexible joint 311 has a more consistent and controllable joint line thickness, which indicates that the cooling of the SOC 102 can be more tightly controlled and consistent across the entire surface of the SOC 102.

[0026] In one aspect, a cooling device for a system-on-a-chip is provided. The cooling device includes a plurality of cooling units, each including a first side to be coupled to the system-on-a-chip, each cooling unit being spaced apart from the other cooling units to define gaps between adjacent cooling units. The cooling device further includes an interposer layer coupled to a second side of the plurality of cooling units, the interposer layer including flexible joints that allow relative movement of adjacent cooling units.

[0027] In some examples, flexible joints separate two tile portions of the interlayer, with adjacent cooling units each connected to one of the two tile portions that have a gap between them.

[0028] In some examples, the thickness of the interlayer at the flexible joint is less than the thickness of the interlayer at the adjacent tile portion.

[0029] In some examples, the flexible joint includes a flexible strip extending across a channel between two tile sections.

[0030] In some examples, the flexible joint includes channels or slots in the interlayer.

[0031] In some examples, the first cooling unit of the plurality of cooling units is a microchannel manifold including a first plurality of fluid channels, and the interlayer includes a second plurality of fluid channels fluidly connected to the first plurality of fluid channels.

[0032] In some examples, the cooling device includes a coolant distribution manifold that includes a third plurality of fluid channels fluidly connected to a second plurality of fluid channels.

[0033] In some examples, multiple cooling units are connected to the interlayer via adhesive.

[0034] In some examples, the flexible joint includes a first slot in a first surface of the interposer and a second slot in a second surface of the interposer, the second slot extending parallel to and close to the first slot.

[0035] On the other hand, a cooling device for a system-on-a-chip is provided. The cooling device includes a plurality of cooling units, each including a first side to be coupled to the system-on-a-chip, each cooling unit being spaced apart from the other cooling units to define gaps between adjacent cooling units, and each cooling unit including a fluid microchannel. The cooling device further includes an interposer layer coupled to a second side of the plurality of cooling units, the interposer layer including flexible joints enabling relative movement of adjacent cooling units, and a first plurality of fluid channels fluidly coupled to the microchannels of each cooling unit.

[0036] In some examples, the first plurality of fluid channels in the interlayer do not extend through the flexible joint.

[0037] In some examples, the cooling device includes a coolant distribution manifold that includes a second plurality of fluid channels fluidly connected to a first plurality of fluid channels.

[0038] In another aspect, a cooling device for a system-on-a-chip is provided. The cooling device includes a coolant delivery manifold including a first plurality of fluid channels and an interposer layer coupled to the coolant delivery manifold. The interposer layer includes: a first segment including a second plurality of fluid channels fluidly coupled to the first plurality of fluid channels; a second segment including a third plurality of fluid channels fluidly coupled to the first plurality of fluid channels; and a flexible connector connecting the first segment and the second segment. The cooling device further includes: a first cooling unit coupled to the first segment of the interposer layer and including a fourth plurality of fluid channels fluidly coupled to the second plurality of fluid channels; and a second cooling unit spaced apart from the first cooling unit to define a gap therebetween. The second cooling unit is coupled to the second segment of the interposer layer and includes a fifth plurality of fluid channels fluidly coupled to the third plurality of fluid channels.

[0039] In some examples, the flexible joint includes channels or slots in the surface of the interlayer, wherein the thickness of the interlayer at the flexible joint is less than the thickness of the interlayer at the first or second segment.

[0040] In some examples, the first and second cooling units are silicon microchannel manifolds, and the interlayer comprises an epoxy molding compound.

[0041] It should be noted that certain paragraphs of this disclosure may refer to terms relating to devices, surfaces or sides of devices, operating modes, transmission chains, antennas, etc., such as "first" and "second," to identify or distinguish them from one another. These terms are not intended to associate entities (e.g., first device and second device) merely in time or in sequence, although in some cases such relationships may be included. These terms also do not limit the number of possible entities (e.g., devices) that can operate in the system or environment.

[0042] While this specification contains specific implementation details, these should not be construed as limiting the scope of claims, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, although features may be described as functioning in certain combinations, and even initially claimed in this way, features from a claimed combination may be removed from that combination in some cases, and the claimed combination may be for sub-combinations or variations thereof.

[0043] As used herein with respect to structural features (e.g., descriptions of shape, size, orientation, direction, relative position, etc.), the terms “approximately,” “about,” “substantially,” and similar terms are intended to cover minor structural variations that may result from processes such as manufacturing or assembly, and are intended to have a broad meaning consistent with usage generally accepted by one of ordinary skill in the art to which this disclosure pertains. Unless otherwise stated, the terms “approximately,” “about,” “around,” “substantially,” etc., are used to indicate plus or minus ten percent when referring to numerical values.

[0044] As used herein, the term "connection" and its variations mean that two components are directly or indirectly connected to each other. Such a connection can be static (e.g., permanent or fixed) or movable (e.g., removable or detachable). This connection can be achieved by: two components being directly connected to each other; two components being connected to each other by means of a single intermediate component or any additional, interconnected intermediate component; or two components being connected to each other by means of an intermediate component integrally formed with one of the two components as a single whole. If "connection" or its variations are modified by an additional term (e.g., direct connection), the general definition of "connection" provided above is modified by the common linguistic meaning of the additional term (e.g., "direct connection" means the connection of two components without any single intermediate component), resulting in a narrower definition than the general definition of "connection" provided above. Such connections can be mechanical, electrical, or fluid.

[0045] References to the location of components in this document (e.g., "top", "bottom", "upper", "middle", "lower", "above", "below", "vertical", "horizontal", etc.) are used only to describe the orientation of the various components in the figures. It should be noted that the orientation of the various components may differ according to other examples, and such variations are intended to be covered by this disclosure.

[0046] Regarding the use of virtually any plural and / or singular terms in this document, those skilled in the art can convert from plural to singular and / or from singular to plural depending on the context and / or application. For clarity, various singular / plural permutations may be explicitly described herein.

[0047] For purposes of illustration and description, the foregoing description of illustrative examples has been presented. It is not intended to be exhaustive or limiting regarding the precise forms disclosed, and modifications and variations are possible, or may be derived from practice of the disclosed examples, in light of the foregoing teachings. The scope of the claimed subject matter is intended to be defined by the appended claims and their equivalents.

Claims

1. A cooling device for a system-on-a-chip, the cooling device comprising: Multiple cooling units, the multiple cooling units including a first side to be coupled to the system-on-a-chip, each cooling unit being spaced apart from other cooling units to define a gap between adjacent cooling units; as well as An intermediary layer is attached to a second side of the plurality of cooling units, the intermediary layer including a flexible joint that allows the adjacent cooling units to move relative to each other.

2. The cooling device according to claim 1, wherein, The flexible joint separates the two tile portions of the intermediate layer, and each adjacent cooling unit is connected to one of the two tile portions having the gap between them.

3. The cooling device according to claim 2, wherein, The thickness of the intermediary layer at the flexible joint is less than the thickness of the intermediary layer at the adjacent tile portion.

4. The cooling device according to claim 2, wherein, The flexible joint includes a flexible strip extending across a channel between the two tile portions.

5. The cooling device according to claim 1, wherein, The flexible joint includes channels or slots in the intermediate layer.

6. The cooling device according to claim 1, wherein, The first cooling unit of the plurality of cooling units is a microchannel manifold including a first plurality of fluid channels, and wherein the interlayer includes a second plurality of fluid channels fluidly connected to the first plurality of fluid channels.

7. The cooling device of claim 6, further comprising a coolant distribution manifold, the coolant distribution manifold including a third plurality of fluid channels fluidly connected to the second plurality of fluid channels.

8. The cooling device according to claim 1, wherein, The plurality of cooling units are connected to the intermediate layer by an adhesive.

9. The cooling device according to claim 1, wherein, The flexible joint includes a first slot in a first surface of the intermediary layer and a second slot in a second surface of the intermediary layer, the second slot extending parallel to and close to the first slot.

10. A cooling device for a system-on-a-chip, the cooling device comprising: Multiple cooling units, each including a first side to be coupled to the system-on-chip, each cooling unit being spaced apart from the other cooling units to define gaps between adjacent cooling units, each cooling unit including a fluid microchannel; and An intermediary layer is attached to a second side of the plurality of cooling units, the intermediary layer including a flexible joint that allows the adjacent cooling units to move relative to each other, and a first plurality of fluid channels fluidly connected to the microchannels of each cooling unit.

11. The cooling device according to claim 10, wherein, The first plurality of fluid channels in the intermediary layer do not extend through the flexible joint.

12. The cooling apparatus of claim 11, further comprising a coolant distribution manifold, the coolant distribution manifold including a second plurality of fluid channels fluidly connected to the first plurality of fluid channels.

13. A cooling device for a system-on-a-chip, the cooling device comprising: A coolant delivery manifold, the coolant delivery manifold including a first plurality of fluid passages; An intermediary layer, connected to the coolant delivery manifold, the intermediary layer comprising: A first section, the first section including a second plurality of fluid channels fluidly connected to the first plurality of fluid channels; The second section includes a third plurality of fluid channels fluidly connected to the first plurality of fluid channels; and A flexible joint, wherein the flexible joint connects the first segment and the second segment; A first cooling unit, the first cooling unit being coupled to the first segment of the intermediate layer, and including a fourth plurality of fluid channels fluidly coupled to the second plurality of fluid channels; and A second cooling unit, spaced apart from the first cooling unit to define a gap between the first and second cooling units, is connected to a second segment of the intermediate layer and includes a fifth plurality of fluid channels fluidly connected to the third plurality of fluid channels.

14. The cooling device according to claim 13, wherein, The flexible joint includes channels or slots in the surface of the intermediary layer, wherein the thickness of the intermediary layer at the flexible joint is less than the thickness of the intermediary layer at the first segment or the second segment.

15. The cooling device according to claim 13, wherein, The first cooling unit and the second cooling unit are silicon microchannel manifolds, and the interlayer comprises an epoxy resin molding compound.

Images