COOLING SYSTEM, COOLING STRUCTURE AND ELECTRONIC DEVICE AND METHODS FOR MANUFACTURING OR OPERATING A COOLING SYSTEM, COOLING STRUCTURE AND ELECTRONIC DEVICE - Patent application

Abstract

The electronic device includes a heat source and a heat distribution structure coupled to the heat source for distributing heat generated by the heat source during operation of the electronic device.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 035,025, filed June 5, 2020, U.S. Application No. 17 / 033,518, filed September 25, 2020, U.S. Application No. 16 / 728,812, filed December 27, 2019, and U.S. Application No. 16 / 914,294, filed June 27, 2020. The contents of these earlier applications are incorporated herein by reference in their entireties.

[0002] Field The example concerns the cooling concept of electronic devices. [Background technology]

[0003] Modern computing systems, especially those with very small feature sizes, draw significant power and generate large amounts of heat. Heat buildup can damage electronic components, so heat dissipation is a key concern in system design.

[0004] Emerging trends in electronic devices are changing the expected performance and form factor of devices, as devices and systems are expected to have increased performance and functionality while having a relatively thin profile. However, increased performance and / or functionality causes increased thermal challenges for devices and systems. Inadequate cooling can result in reduced device performance, reduced device life, and slower data throughput. [Brief description of the drawings]

[0005] Some examples of apparatus and / or methods are now described, by way of example only, and with reference to the accompanying drawings, in which: [Figure 1a] 1 shows a schematic cross-sectional view of an electronic device. [Figure 1b] 1 shows a schematic cross-sectional view of an electronic device. [Figure 1c]1 shows a schematic plan view of a cooling system for an electronic device. [Figure 1d] 1 shows a schematic cross-sectional view of an electronic device. [Figure 1e] 1 shows a schematic cross-sectional view of an electronic device. [Figure 1f] 1 shows a schematic cross-sectional view of an electronic device. [Figure 1g] 1 shows a flow chart of a method for manufacturing an electronic device. [Figure 1h] 1 shows a flow chart of a method of operating an electronic device. [Figure 2a] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 2b] 1 shows a schematic cross-sectional view of an electronic device. [Figure 2c] 1 shows a schematic plan view of a cooling system for an electronic device. [Figure 2d] 1 illustrates possible thicknesses of various components of an electronic device. [Figure 2e] 1 shows a schematic cross-sectional view of an electronic device. [Figure 2f] 1 shows a schematic plan view of a cooling system for an electronic device. [Figure 2g] 1 shows a flow chart of a method of operating an electronic device. [Figure 3a] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 3b] FIG. 2 shows a schematic cross-sectional view of a cooling system with a smaller steam chest and a mini-blower. [Figure 3c] 1 shows a schematic plan view of a cooling system for an electronic device. [Figure 3d] FIG. 13 illustrates the effect of air flow on a steam chest. [Figure 3e] 1 shows a schematic diagram of the effect of air flow on a steam chest. [Figure 3f] FIG. 13 is a schematic diagram of the mini blower integration. [Figure 3g] 1 is a schematic diagram of airflow through an electronic device. [Figure 3h] 1 is a schematic diagram of airflow through an electronic device. [Figure 3i]1 shows a schematic plan view of a cooling system for an electronic device. [Figure 3j] 1 shows a schematic plan view of a cooling system for an electronic device. [Figure 3k] 1 shows a schematic diagram of the resistor-capacitor (RC) network used in the case study. [Figure 3l] This is one of the graphs showing the transient response to various parameters. [Figure 3m] This is one of the graphs showing the transient response to various parameters. [Figure 3n] This is one of the graphs showing the transient response to various parameters. [Figure 3o] This is one of the graphs showing the transient response to various parameters. [Figure 3p] 1 shows a flow chart of a method for cooling an electronic device. [Figure 3q] 1 is a schematic cross-sectional view of a cooling system for an electronic device. [Figure 3r] 1 shows an illustration of the effect of predictive workload determination. [Figure 3s] 1 shows an illustration of the effect of predictive workload determination. [Figure 3t] 1 shows an illustration of the effect of predictive workload determination. [Figure 3u] 1 shows a flowchart of a method of operating a computing device. [Figure 4a] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4b] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4c] 1 shows a schematic plan view of a cooling system for an electronic device. [Figure 4d] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4e] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4f] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4g] 1 is a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4h] 1 is a schematic cross-sectional view of a cooling system for an electronic device. [Figure 4i] FIG. 13 is a graph showing junction temperature over time. [Figure 4j] FIG. 1 shows temperature difference over time. [Figure 4k] 1 shows a flow chart of a method of operating an electronic device. [Figure 5a] 1 shows a schematic cross-sectional view of a cooling structure for an electronic device. [Figure 5b] 1 shows a schematic cross-sectional view of a cooling structure for an electronic device. [Figure 5c] 1 shows a schematic bottom view of a cooling structure for an electronic device. [Figure 5d] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 5e] 1 shows a schematic cross-sectional view of a cooling system for an electronic device. [Figure 5f] 1 shows a schematic cross-sectional view of a cooling structure for an electronic device. [Figure 5g] 1 is a schematic cross-sectional view of a cooling structure for an electronic device. [Figure 5h] 1 shows a schematic bottom view of a cooling structure for an electronic device. [Figure 5i] 1 is a schematic cross-sectional view of a cooling structure for an electronic device. [Figure 5j] 1 shows a schematic bottom view of a cooling structure for an electronic device. [Figure 5k] 1 shows a schematic cross-sectional view of an electronic device. [Figure 5l] 1 shows a flow chart of a method for forming a cooling structure. [Figure 6a] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6b] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6c] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6d] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6e] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6f] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6g] 1 shows a schematic cross-sectional view of an electronic device. [Figure 6h] 1 shows a schematic cross-sectional view of a portion of a layered heat spreader. [Figure 6i] 1 is a schematic cross-sectional view of a cover for an electronic device. [Figure 6j] 1 shows a schematic diagram of a cover for an electronic device. [Figure 7a] 1 shows a simplified diagram of an example stack for a mobile device. [Figure 7b] FIG. 1 is a diagram showing an example of a two-tier steam chamber device. [Figure 7c] 1 shows another example of a two-tier steam chamber device. [Figure 7d] 1 shows another example of a two-tier steam chamber device. [Figure 7e] 1 shows another example of a two-tier steam chamber device. [Figure 7f] 1 shows another example of a two-tier steam chamber device. [Figure 7g] 1 shows a simplified diagram of an example of a mobile device stack having an air gap between the cooling solution and the top layer. [Figure 7h] 1 shows a simplified diagram of an example of a mobile device stack having an air gap between the cooling solution and the top layer. [Figure 7i] FIG. 2 illustrates an exemplary relationship between the thermal conductivity of air and pressure. [Figure 7j] 1 illustrates an exemplary hot spot for a single tier cooling system. [Figure 7k] 1 illustrates an exemplary hot spot for a two-tier cooling system. [Figure 7l] FIG. 13 illustrates exemplary performance differences for copper heat plate, single level vapor chamber, and dual level vapor chamber cooling devices. [Figure 7m] FIG. 13 shows exemplary performance differences for vacuum and aerogel-based two-layer vapor chamber devices. [Figure 7n] FIG. 1 is a flow diagram illustrating an exemplary process for manufacturing a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7o]1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7p] 1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7q] 1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7r] 1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7s] 1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7t] 1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7u] 1 illustrates exemplary steps during a manufacturing process for a dual tier steam chest cooling device according to examples of the present disclosure. [Figure 7v] FIG. 1 is a diagram showing an example of a built-in two-tier steam chamber device. [Figure 7w] 1 illustrates an exemplary hot spot for a single tier cooling system. [Figure 7x] 1 illustrates an exemplary hot spot for an embedded dual level cooling system. [Figure 7y] FIG. 1 illustrates an exemplary performance difference for a single level steam chest system and a recessed dual level steam chest cooling system. [Figure 7z] 1 is an exemplary illustration of a processor in accordance with one example. [Figure 7aa] FIG. 1 illustrates computing systems arranged in a point-to-point (PtP) configuration according to an example embodiment. [Figure 8a] FIG. 1 is a simplified block diagram of a steam chest and attachment enabling system according to an example of the present disclosure. [Figure 8b] FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8c] FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8d]FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8e] FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8f] FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8g] FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8h] FIG. 2 is a simplified block diagram of a partial view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8i] FIG. 2 is a simplified block diagram of a partial view of a steam chest according to an example of the present disclosure. [Figure 8j] FIG. 2 is a simplified diagram of a partial perspective view of a system for enabling a steam chest according to an example of the present disclosure. [Figure 8k] FIG. 1 is a simplified block diagram of a steam chest and attachment enabling system according to an example of the present disclosure. [Figure 8l] FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 8m] FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 8n] FIG. 2 is a simplified diagram of a partial view of a steam chest and attachment enabling system according to an example of the present disclosure. [Figure 8o] FIG. 2 is a simplified diagram of a partial view of a steam chest and attachment enabling system according to an example of the present disclosure. [Figure 8p] FIG. 2 is a simplified diagram of a partial view of a steam chest and attachment enabling system according to an example of the present disclosure. [Figure 8q] FIG. 2 is a simplified diagram of a partial view of a steam chest and attachment enabling system according to an example of the present disclosure. [Figure 8r] FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 8s]FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 8t] FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 8u] FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 8v] FIG. 2 is a simplified block diagram of a partial view of a system enabling steam chest and attachment means according to an example of the present disclosure. [Figure 9a] FIG. 1 is a block diagram of the internal components of a portable computing system, such as a laptop computer. [Figure 9b] FIG. 9b is a diagram of a heat transfer assembly that may be used instead of or together with the assembly of FIG. 9a. [Figure 9c] FIG. 13 is a perspective view of an alternative heat transfer assembly. [Figure 9d] FIG. 13 is an alternative view of the steam chest. [Figure 9e] FIG. 2 is a top view of the heat transfer assembly. [Figure 9f] FIG. [Figure 9g] FIG. 2 is a perspective view of an in-situ steam chamber having a heat sink. [Figure 9h] FIG. 2 is an in situ side view of a planar steam chest. [Figure 9i] FIG. 13 is a side view of the steam chest bend. [Figure 9j] FIG. 2 is a cutaway perspective view of the steam chest. [Figure 9k] A detailed view of the starburst structural support pattern on the steam chest. [Figure 9l] FIG. 2 is a perspective view of a support column in a steam chamber. [Figure 9m] A perspective view of a columnar starburst pattern. [Figure 9n] FIG. 2 is an in situ side view of the steam chest. [Figure 9o] FIG. [Figure 9p] FIG. 2 is a side view of the steam chest. [Figure 9q] FIG. 13 is a plan view of selective removal of a portion of the wick. [Figure 9r] FIG. 2 is a cross-sectional side view of the steam chest. [Figure 9s] FIG. 2 is a perspective view of heat transfer from an evaporator to a condenser. [Figure 9t] FIG. 2 is a cross-sectional side view of the steam chest with selected portions of the wick removed. [Figure 9u] 1 is an illustration of a bottom plate, which may also be called an evaporator plate. [Figure 9v] A diagram of a patched wick. [Figure 9w] 1 is an illustration of a top plate, which may also be referred to as a condenser plate. [Figure 9x] A diagram of the completed steam chamber. [Figure 9y] 1 is a flow chart of a method. [Figure 9z] FIG. 1 is a block diagram of a processor that may have two or more cores, may have an integrated memory controller, and may have integrated graphics, in accordance with one or more examples of the present specification. [Figure 9aa] FIG. 1 is a block diagram of a computer architecture according to one or more examples of the present specification. [Figure 9ab] FIG. 1 is a block diagram of a computer architecture according to one or more examples of the present specification. [Figure 9ac] FIG. 1 is a block diagram of a computer architecture according to one or more examples of the present specification. [Figure 9ad] FIG. 1 is a block diagram of a computer architecture according to one or more examples of the present specification. [Figure 9ae] FIG. 2 is a block diagram of components of a computing platform. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Some examples are described in more detail with reference to the enclosed drawings. However, other possible examples are not limited to the features of these examples described in detail. Other examples may include modifications of those features, as well as equivalents and alternatives to those features. Furthermore, the terms used herein to describe certain examples should not limit other possible examples.

[0007] Throughout the description of the figures, the same or similar reference numbers refer to the same or similar elements and / or features, which may be identical or may be implemented in modified form while providing the same or similar functionality. The thickness of lines, layers and / or areas in the figures may also be exaggerated for clarity.

[0008] If two elements A and B are combined with "or", this is understood to disclose all possible combinations, i.e. only A, only B, as well as A and B, unless expressly defined otherwise in individual cases. As alternative expressions of the same combinations "at least one of A and B" or "A and / or B" may also be used. This applies equally to combinations of more than two elements.

[0009] Where singular forms such as "a", "an" and "the" are used and the use of only a single element is not explicitly or implicitly defined as required, further examples may use several elements to implement the same functionality. Hereinafter, where functionality implemented using multiple elements is described, there are also examples of implementing the same functionality using a single element or a single processing entity. It is further understood that the terms "comprise", "including", "having" and / or "having", when used, describe the presence of specified features, integers, steps, operations, processes, elements, components and / or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, processes, elements, components and / or groups thereof.

[0010] 1a is a schematic diagram of an electronic device. The electronic device 100 comprises a heat source 110 and a steam chamber 120 coupled to the heat source 110 for distributing heat generated by the heat source 110 during operation of the electronic device. By coupling the steam chamber to the heat source of the electronic device, heat generated by the heat source can be dissipated faster from the heat source.

[0011] The vapor chamber 120 may be thermally coupled directly or indirectly to the heat source 110 through a thermal interface material (TIM) (e.g., thermal grease, thermally conductive paste, or liquid metal). The TIM may improve the thermal contact between the vapor chamber 120 and the heat source 110. For example, a metal plate (e.g., a cold plate or pedestal) may be disposed between the heat source 110 and the vapor chamber 120, or the vapor chamber 120 may be directly coupled to the heat source 110 through a thermal interface material. The metal plate may be a copper plate, an aluminum plate, or a plate made of other suitable metals or alloys. For example, the VC 120 may be in contact with the heat source 110, except for the intermediate TIM.

[0012] The thermal interface material can compensate for unevenness in the back surface of the heat source 110 and / or the surface of the vapor chamber 120 to allow good thermal contact across the entire back surface of the heat source 110. The thermal interface material can include a maximum thickness of up to 0.25 mm (or up to 0.2 mm, or up to 0.15 mm).

[0013] Two elements may be thermally coupled if only a thermally conductive material is located between them. A material may be thermally conductive if it has a thermal conductivity of at least 100 W / mK. Two elements may be directly thermally coupled if they are in contact with each other or in contact with each other except for an intervening TIM.

[0014] The heat source 110 may comprise or may be a semiconductor die configured to generate heat (e.g., waste heat) during operation. The waste heat may be generated automatically during operation of the semiconductor die. An integrated circuit may be implemented on the semiconductor die. The semiconductor die may be a bare die having an uncovered backside or a packaged semiconductor die having a backside covered by a packaging material (e.g., a mold or other material).

[0015] Heat source 110 may be or may include a processor (e.g., a CPU, microcontroller, digital signal processor, or graphics processing unit GPU), a transmitter, a receiver, a transceiver, a power supply, and / or a voltage converter, or other integrated circuit.

[0016] The electronic device may be a tablet, a laptop, a notebook, a mobile phone, a computer (eg, a personal computer or a server), or other electronic device.

[0017] A cooling system for an electronic device may include all elements (e.g., cold plates), structures (e.g., guiding structures for air flow) and / or components (e.g., vapor chests, heat pipes and / or fans) that help actively or passively distribute or dissipate heat generated by heat source 110.

[0018] Further details, optional features and aspects are mentioned in connection with the examples described below.

[0019] 1b is a schematic diagram of an electronic device. The electronic device may be implemented similarly to the electronic device described in connection with FIG. 1a. A thermal interface material 130 is disposed between the vapor chest 120 and the heat source 110. Furthermore, the stack of the heat source 110, the TIM 130 and the vapor chest 120 is disposed inside an enclosure or chassis 140 of the electronic device. An air gap is located between the vapor chest 120 and the chassis 140 of the electronic device, such that the temperature of the chassis 140 remains below a temperature limit (e.g., a skin temperature limit).

[0020] Further details, optional features, and aspects are mentioned in connection with one or more examples described above or below.

[0021] Figure 1c is a schematic diagram of an electronic device. The electronic device may be implemented similarly to the electronic device described in connection with Figure 1a or 1b. The heat source is mounted on a circuit board 150 (e.g., a motherboard), and the vapor chest 120 is thermally coupled to a heat sink 180 through a heat pipe 160. The heat sink is disposed adjacent to a fan 170, which is configured to blow air through or over the heat sink 180.

[0022] FIG. 1c may show an example of a cooling system with a heat sink, a heat pipe and a vapor chamber in a tablet.

[0023] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0024] Fig. 1d is a schematic diagram of an electronic device. The electronic device may be implemented similarly to the electronic device described in relation to Fig. 1a, 1b or 1c. The heat source 110 is disposed between the vapor chamber 120 and a circuit board 150 (e.g., a printed circuit board PCB). The circuit board 150 may carry the heat source 110 and the vapor chamber 120 and may be connected to an enclosure 140. This may provide a resilient stack.

[0025] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0026] FIG. 1e is a schematic diagram of an electronic device. The electronic device may be implemented similarly to the electronic device described in connection with FIG. 1a or FIG. 1c. Heat source 110 is a semiconductor die on a packaging substrate that forms a semiconductor device (e.g., a CPU). The semiconductor device is mounted to a circuit board (e.g., a motherboard). Heat may be dissipated from heat source 110 through vapor chamber 120 and heat pipe 160 to an area of ​​the heat pipe proximate to fan 170.

[0027] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0028] FIG. 1f is a schematic diagram of an electronic device. The electronic device may be implemented similarly to the electronic device described in connection with FIG. 1a. The vapor chamber 120 may be integrated into the heat distribution configuration between the heat sink 180 and the pedestal. The pedestal is thermally coupled to the backside of the semiconductor die of the heat source 110 through a TIM. The semiconductor die (e.g., a CPU) is attached to a substrate (e.g., a CPU substrate) that is attached to a socket. Interconnects are disposed between the semiconductor die and the substrate and between the substrate and the socket. The semiconductor die, substrate, and socket may form a semiconductor device that is mounted to a circuit board 150 (e.g., a system PCB). The semiconductor device may be secured to the circuit board through a connecting structure (e.g., a load plate) that may engage at an edge region of the substrate. The circuit board is connected to the enclosure 140 of the electronic device. A fan may be disposed near the heat sink 180 to blow air through or over the heat sink 180.

[0029] The example of Figure 1f can show a thermal solution for a bare die CPU package.

[0030] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0031] 1g shows a flow chart of a method for manufacturing an electronic device. The method 185 includes thermally coupling 186 a heat distribution structure to a heat source.

[0032] The heat distribution structure may be a vapor chamber (or a heat pipe or a metal plate).

[0033] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0034] FIG. 1h is a flow chart of a method of operating an electronic device.

[0035] The method 190 includes operating a heat source 191 and distributing 192 heat generated by the heat source during operation with a heat distribution structure.

[0036] The heat distribution structure may be a steam chest (or a heat pipe or a metal plate). Additionally, the method may include blowing air along a surface of the heat distribution structure by at least one ventilation.

[0037] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0038] Some examples relate to a cooling system comprising a heat distribution structure coupled to a heat source for distributing heat generated by the heat source. The cooling system further comprises at least one ventilation device having a main blow direction, the at least one ventilation device being arranged such that the main blow direction is directed toward the heat distribution structure. The heat distribution structure may include at least one of a vapor chamber or a heat pipe. The at least one ventilation device may be a fan, a blower, a mini-blower, or a blower-fan.

[0039] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0040] 2a is a schematic diagram of a cooling system 200 for an electronic device 100. The cooling system 200 comprises a steam chest 120 configured to be coupled to a heat source 110 of the electronic device 100. Furthermore, the cooling system 200 comprises a fan 170 with a main blowing direction. The fan 170 is positioned such that the main blowing direction is directed towards the steam chest 120.

[0041] By blowing air towards the steam chamber, the surface temperature of the steam chamber can be significantly reduced, thus improving the cooling efficiency and / or cooling capacity and / or cooling speed of the steam chamber.

[0042] The steam chest 120 may be configured to be thermally coupled directly or indirectly to the heat source 110 by a thermal interface material. For example, a metal plate (e.g., a cold plate) may be disposed between the heat source 110 and the steam chest 120, or the steam chest 120 may be directly coupled to the heat source 110 through a thermal interface material.

[0043] The fan 170 may be configured to blow air along the surface of the steam chamber 120. The fan 170 may also be referred to as or be a blower or blower fan. The fan 170 may be positioned in close proximity to or adjacent to an edge of the steam chamber 120. For example, the fan may be positioned and / or configured such that at least 50% (or at least 80% or at least 90%) of the airflow caused by the fan flows along the surface of the steam chamber. For example, the fan 170 may be configured to generate an airflow with a mean air velocity of at least 0.25 m / s (or at least 0.4 m / s or at least 0.5 m / s) and / or up to 1 m / s (or up to 0.7 m / s or up to 0.5 m / s). In this way, the cooling efficiency and / or cooling capacity and / or cooling rate of the steam chamber may be significantly improved, while additional power consumption may be kept low.

[0044] The main blow direction may be the direction in which most of the air is blown by the fan 170, or the direction in which the fan 170 is configured to blow most of the air. The fan 170 may be configured to blow more air in the main blow direction than in other directions.

[0045] The fan 170 may be positioned within the electronic device such that more air is blown towards the steam chamber 120 than anywhere else. For example, the main blow direction is towards the steam chamber 120.

[0046] The main blow direction of the fan 170 may be substantially perpendicular to the rotation axis of the fan. For example, the angle between the main blow direction and the rotation axis may be at most 100° and at least 80°. The main air intake direction of the fan 170 may be substantially parallel to the rotation axis of the fan 170. For example, the angle between the main air intake direction and the rotation axis may be at most 10°.

[0047] A small fan may be sufficient to significantly reduce the surface temperature of the steam chest 120. For example, the fan 170 may include maximum dimensions of no more than 50 mm (or up to 40 mm, or up to 30 mm) in terms of height, length and width. The fan 170 may be a single outlet fan.

[0048] Fan 170 may be positioned and / or configured to blow air into a gap extending from vapor chamber 120 to an opposing component of VC 120 (e.g., a portion of an electronic device enclosure and / or the back of a screen of an electronic device). The gap may be less than 0.5 mm (or less than 0.4 mm, or less than 0.3 mm).

[0049] Electronic device 100 may further include a circuit board configured to carry a heat source. Fan 170 may be configured to blow air into a gap extending from the circuit board to a portion of the electronic device enclosure and / or a back surface of the electronic device screen. For example, fan 170 may be positioned and / or configured such that a portion of the air is blown into a gap between steam chamber 120 and the electronic device enclosure or the back surface of the electronic device screen, and another portion of the air is blown into a gap between the circuit board and the electronic device enclosure or the back surface of the electronic device screen.

[0050] The cooling system 200 may further include a guide structure (or one or more guide elements) configured to guide the air flow caused by the fan 170 along a surface of the steam chest 120. The guide structure may be disposed on a surface of the steam chest, a part of the enclosure of the electronic device, and / or on the backside of the screen of the electronic device. The main structure of the guide structure may include or be made of plastic, the material of that part of the enclosure, or a gasket material. The guide structure may include a gasket material for sealing a gap between the guide structure and an opposing element. For example, the guide structure may be integrally formed in or attached to a part of the enclosure, and the gasket material may seal a gap between the guide structure and the steam chest 120. The guide structure may completely surround the steam chest, except for one or more air intake openings and one or more air outlet openings.

[0051] In contrast to cooling concepts in which heat is transferred to a heat sink cooled by a fan, the fan 170 of the cooling system 200 described above blows air into the vapor chamber. In other words, the fan 170 is placed in front of the heat source with respect to the direction of air movement. Thus, a heat sink does not have to be placed adjacent to the fan 170 or directly adjacent to the housing of the fan 170. By using the fan 170 according to the above concept, the electronic device can be implemented without a heat sink. In this way, weight and / or space can be saved.

[0052] The steam chest 120 may be disposed along the air flow path between the fan and the air outlet. The fan 170 may be configured to generate a flow of air from the air intake through the fan 170 to a surface of the steam chest 120 and from the surface of the steam chest 120 to the air outlet.

[0053] The steam chest 120 may be implemented as described above or below. For example, the steam chest 120 may have a maximum dimension of at least 150 mm (or at least 200 mm or at least 250 mm).

[0054] The fan 170 may be laterally disposed to the side of the steam chest 120. For example, the vertical extent of the fan 170 may overlap the vertical extent of the steam chest 120. In this manner, very thin electronic devices may be made possible.

[0055] For example, the cooling system 200 may be implemented within an electronic device 100 that includes a heat source 110. For example, the electronic device may include a thickness of up to 8 mm (or up to 10 mm, up to 9 mm, or up to 7 mm).

[0056] Electronic device 100 may be implemented without a heat pipe and / or without a heat sink for fan 170. Fan 170 may improve cooling sufficiently such that a heat pipe or heat sink may not be necessary.

[0057] Electronic device 100 may include a thermal design power of up to 10 W (or up to 12 W, or up to 15 W) and / or at least 5 W (or at least 6 W, or at least 7 W). Fan 170 may improve cooling sufficiently such that a thermal design power of up to 15 W may be possible without implementing other active cooling elements. For example, electronic device 100 may include only passive cooling elements other than the single fan 170.

[0058] The electronic device 100 may include an enclosure with one or more intake openings proximate to a fan configured to draw air from outside the electronic device through the one or more intake openings. For example, the one or more intake openings may be located in a back or side portion of a cover of a tablet or laptop.

[0059] A graphite sheet may be attached to a portion of the enclosure within electronic device 100 (eg, the back cover and / or the display panel).

[0060] The heat source 110 may comprise or may be a semiconductor die configured to generate heat (e.g., waste heat) during operation. This waste heat may be generated automatically during operation of the semiconductor die. An integrated circuit may be implemented on the semiconductor die. The semiconductor die may be a bare die having an uncovered backside, or a packaged semiconductor die having a backside covered by a packaging material (e.g., a mold or other material).

[0061] Heat source 110 may be or may include a processor (e.g., a CPU, microcontroller, digital signal processor, or graphics processing unit GPU), a transmitter, a receiver, a transceiver, a power supply, and / or a voltage converter, or other integrated circuit.

[0062] The electronic device may be a tablet, a laptop, a notebook, a mobile phone, a computer (eg, a personal computer or a server), or other electronic device.

[0063] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0064] FIG. 2b shows a schematic cross-sectional view of an electronic device. The electronic device may be implemented similarly to the electronic device described in connection with FIG. 2a. A thermal interface material 130 is disposed between the vapor chamber 120 and the heat source 110. The heat source 110 is mounted on a PCB 150. Furthermore, the stack including the PCB 150, the heat source 110, the TIM 130, and the vapor chamber 120 is located inside an enclosure or chassis 140 of the electronic device. The enclosure 140 includes a back cover (e.g., a cover of a tablet) on the back side and an LCD screen 210 on the front side of the electronic device. An air gap is located between the vapor chamber 120 and the LCD screen 210 of the electronic device so that the temperature at the outer surface remains below a temperature limit (e.g., a skin temperature limit). A fan 170 is located next to the vapor chamber 120 in the electronic device. The fan 170 is positioned and configured such that an air blow direction 272 (e.g., a main blow direction) is directed toward the vapor chamber 120. The fan 170 has air intakes at the top and bottom and an air outlet at the side. The fan 170 blows air into the gap between the steam chest 120 and the LCD screen.

[0065] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0066] 2c shows a schematic plan view of a cooling system for an electronic device. The electronic device can be implemented similarly to the electronic device described in relation to FIG. 2b. The outlet from the fan 170 in the airflow direction 272 (e.g., main blow direction) is directed towards the vapor chamber 120 (e.g., a thin copper / water structure). No heat sink or fin-like structure is attached to the fan 170.

[0067] Figure 2c may show an example of a cooling system with a fan and vapor chamber in a tablet. The tablet may be implemented with a vapor chamber but without a heat sink and heat pipes. For example, Figure 2c may be a top view of the device shown in Figure 2b.

[0068] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0069] FIG. 2d shows possible thicknesses of various components of the electronic device. The liquid crystal display LCD may include a laminate including a glass layer, an adhesive layer (e.g., OCA), touch and Super Retardation Film (SRF), an adhesive layer (e.g., OCA), and a panel. A graphite sheet is attached to the back side of the LCD. Furthermore, there is a gap between the LCD and the vapor chamber. The vapor chamber is thermally coupled to the CPU through a metal plate (e.g., copper plate) and a TIM. The CPU is attached to the PCB. There is a gap between the PCB and the graphite sheet, which is attached to the back cover of the electronic device (e.g., the A-cover of a tablet).

[0070] For example, a graphite sheet is 278.6 x 189.35 mm 2 , a display panel thickness of 0.1 mm, an A-cover thickness of 0.5 mm, and an in-plane thermal conductivity k=1350 W / mK, and a through-plane thermal conductivity k=10 W / mK.

[0071] The steam chamber is 180 x 72.65 x 0.6 mm. 2 and an in-plane thermal conductivity k=2000 W / mK, and a through-plane thermal conductivity k=10 W / mK.

[0072] The fan size is 45 x 45 x 3mm 3 , P(mmAq) may be 8, Q(CFM) may be 0.9, and P(in_H2O) may be 0.315.

[0073] For example, a high Thermal Design Power (TDP) of 9W in a 13-inch convertible laptop or tablet chassis with a Z-height of 7.94mm is achievable.

[0074] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0075] FIG. 2e shows a schematic cross-sectional view of an electronic device. The electronic device may be implemented similarly to the electronic device described in relation to FIG. 2b. The steam chest 120 is thermally coupled to the heat source 110 through a metal plate 230 (e.g., a copper Cu plate) and a TIM. Furthermore, the electronic device includes a guide structure 220 (e.g., an airflow control gasket) configured to guide the air flow caused by the fan along a surface of the steam chest 120. A portion of the guide structure 220 may be disposed along an edge of the steam chest 120. Another portion of the guide structure 220 may be disposed between the steam chest 120 and the fan 170. The guide structure 220 may include or be made of a gasket material. The enclosure 140 may include a back cover (e.g., a cover). The back cover may include one or more openings 250 used as air intakes. Furthermore, the back cover and / or the side cover may include one or more openings 250 used as air outlets.

[0076] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0077] 2f shows a schematic plan view of the cooling system of the electronic device. The electronic device may be implemented similarly to the electronic device described in relation to FIG. 2e. In addition, the electronic device includes a second fan 270. The first fan 170 and the second fan 270 are disposed on opposite sides of the steam chest 120. The guide structure 220 surrounds the steam chest 120 at the edge of the steam chest 120, except for the air intake for the first fan 170, the air intake for the second fan 270, and the air outlet 240.

[0078] Alternatively, a second fan 270 or an additional fan may be positioned near the air outlet 240 and configured to draw air from the gap above the steam chest 120 and blow the air through the air outlet 240.

[0079] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0080] Some examples relate to high thermal performance in thin and light chassis consumer electronic devices. Compared to other active cooling concepts of forced convection through heat sinks for heat dissipation, forced convection on the vapor chamber surface can be applied instead. By applying this concept, heat pipes and heat sinks can be eliminated to achieve thin and light laptops and / or tablets with a total system Z-height of 8mm or less, while the superior cooling capacity of the active cooling system compared to the passive cooling system can be maintained. An active cooling system with fan, heat pipe and heat sink design can be heavy and bulky due to copper / water heat pipes and copper heat sinks and can have limitations to fit and comply with the specifications of a thin and light system. A passively cooled fanless design can fit into a thin and light system, but can be limited by the low thermal design power (TDP) it can cool.

[0081] The use of fans to blow air along the vapor chest can eliminate heat pipes and heat sinks and / or achieve high TDP in a thin and light system.

[0082] Space savings and optimization for other components or functional assemblies in the system may be enabled. The space occupied by the heat sink may be used to enlarge the battery or to implement additional functions or components. Cycle time reductions of the system assembly cells during high volume manufacturing (HVM) may be achievable. Thinner and lighter solutions with higher performance may be possible compared to other cooling solutions used in such z-height systems.

[0083] Simulations may show that the proposed concept with a fan but without a heat sink and heat pipes may result in similar skin temperatures on the tablet's LCD or the tablet's back cover (e.g., the A-cover) compared to a system with a heat sink and heat pipes.

[0084] For example, the heat sink and heat pipes can be eliminated to accommodate other components / features in the system. A thin and lightweight system may be achievable when using the proposed concept, which may be a hybrid of a fan and a vapor chest.

[0085] The proposed concept may enable higher Thermal Design Power (TDP), cost savings, weight savings, and / or improved space consumption in xyz (e.g., by eliminating heat sinks and heat pipes). For example, a system weight (e.g., weight of an electronic device, e.g., tablet) of up to 900g (or up to 880g, or up to 850g) may be enabled.

[0086] 2g shows a flow chart of a method of operating an electronic device. The method 295 includes blowing air along a surface of the steam chamber with a fan 296. The fan is positioned such that the main blow direction is directed towards the steam chamber.

[0087] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0088] 3a shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling system 300 of the electronic device 100 comprises a heat distribution structure 320 configured to be coupled to the heat source 110 of the electronic device 100. The heat distribution structure 320 comprises a vapor chest and / or a heat pipe. Furthermore, the cooling system 300 comprises a blower 370 configured to generate an air flow along a surface of the heat distribution structure 320. The blower 370 has a maximum length and a maximum width of up to 20 mm (or up to 18 mm or up to 15 mm) and / or a maximum thickness of up to 3 mm (or up to 4 mm or up to 2.5 mm).

[0089] By using a small blower to create an air flow along the vapor chamber VC or heat pipe HP, the VC surface temperature or heat pipe surface temperature can be significantly reduced, improving the cooling efficiency. In this way, the size of the VC or HP can be reduced and / or the TDP can be increased compared to other concepts.

[0090] The blower 370 (also referred to as a mini-blower, blower fan or fan) may be arranged and / or configured to blow air (directly) towards the heat distribution structure 320, or a guiding structure may be arranged to direct the air towards the heat distribution structure 320 to create an airflow along the surface of the heat distribution structure 320. For example, at least 50% of the airflow caused by the blower 370 may flow along the surface of the heat distribution structure 370. Air is considered to flow along the surface of the heat distribution structure 370 if it flows in a gap between the surface of the heat distribution structure 370 and an opposing structure (e.g., a part of an enclosure). For example, the blower 370 may be configured to create an airflow with an average airflow velocity of at least 0.25 m / s (or at least 0.4 m / s or at least 0.5 m / s) and / or up to 1 m / s (or up to 0.7 m / s or up to 0.5 m / s). In this way, the cooling efficiency and / or cooling capacity and / or cooling rate of the steam chest can be significantly improved, while the additional power consumption can be kept low.

[0091] The blower 370 may be arranged beside the heat distribution structure 320 in the lateral direction. For example, the blower 370 may be arranged directly adjacent to the edge of the heat distribution structure 320 or may be arranged at a distance of up to 2 cm (or up to 1 cm) to the edge of the heat distribution structure 320. For example, the vertical extent of the blower 370 may overlap with the vertical extent of the heat distribution structure 320. For example, the heat distribution structure 320 may be arranged beside the blower 370 in the lateral direction and between the level of the top surface of the blower 370 and the level of the bottom surface of the blower 370 in the vertical direction. The blower 370 may have a maximum current consumption of up to 0.08 A (or up to 0.1 A, or up to 0.2 A). The blower 370 may be configured to suck air from the bottom side of the blower 370 and blow air at the top side of the blower 370. Alternatively, the blower 370 can suck air from the bottom side and / or the top side and blow air at the side between the top side and the bottom side. The blower 370 may be aligned horizontally or slightly tilted with respect to the horizontal plane. For example, the rotation axis of the blower may be perpendicular to the major surface of the heat distribution structure 320 or the major surface of the circuit board carrying the heat source 110. Alternatively, the angle between the rotation axis of the blower and the major surface of the heat distribution structure 320 or the major surface of the circuit board may be at least 75° (or at least 80° or at least 85°) and / or at most 88° (or at most 85° or at most 82°).

[0092] For example, the blower 370 may be configured to blow air into a gap extending from the heat distribution structure 320 to a component on the opposite side of the heat distribution structure 320 (e.g., a portion of an enclosure for an electronic device or the backside of a screen of an electronic device). The gap may extend across at least 50% (or at least 70% or at least 90%) of the top or bottom surface of the heat distribution structure 370. The thickness of the gap may be up to 2 mm (or up to 1.5 mm or up to 1 mm).

[0093] For example, the cooling system 300 or the electronic device 100 may further comprise one or more guiding structures configured to guide the air flow caused by the blower 370 along a surface of the heat distribution structure 320. The one or more guiding structures may be disposed on at least one of the surface of the heat distribution structure 320 or a portion of the enclosure of the electronic device. For example, the guiding structures may be integrally formed on or attached to the inner surface of the enclosure or may be attached to the surface of the heat distribution structure 320. The guiding structures may be composed of the same material as the enclosure, or may be composed of or made of a polymer, plastic, or gasket material. For example, the guiding structures may include walls up to 2 mm (or up to 1.5 mm, or up to 1 mm) in height.

[0094] In contrast to cooling concepts in which a fan is used to blow air onto or through a heat sink, the proposed blower 370 induces airflow directly at the heat distribution structure 320. Thus, a heat sink may not be located adjacent to the blower 370. There may be a heat sink used elsewhere in the electronic device, but not near the blower 370. For example, a heat sink may not be located closer than 2 cm to the blower 370 and / or may not be located between the blower 370 and the heat distribution structure 320. For example, the electronic device 100 may be implemented without a heat spreader for the blower.

[0095] The electronic device may further include a circuit board (e.g., PCB) configured to carry the heat source 110. The blower 370 may be configured to cause airflow through a gap between the circuit board and the heat distribution structure 320. The blower 370 may cause airflow through the gap between the circuit board and the heat distribution structure 320 in addition to airflow through a gap between the heat distribution structure 320 and a portion of an enclosure of the electronic device or a backside of a screen of the electronic device. For example, the circuit board may include an opening and the blower 370 may be disposed at least partially within the opening.

[0096] The heat distribution structure 320 may be a flat structure with a lateral extent significantly greater than its vertical extent. For example, the thickness of the heat distribution structure 320 may be up to 10% (or up to 5%) of the maximum lateral dimension (e.g., length or width) of the heat distribution structure 320. For example, the heat distribution structure 320 may comprise or be a vapor chamber. The VC may have a maximum dimension of at least 150 mm (or at least 200 mm or at least 220 mm). The maximum dimension may be the maximum extent in a characteristic direction of the VC. For example, the maximum dimension for a rectangular VC may be the length of the long side of the rectangle. However, the VC may have any geometric shape suitable for a particular electronic device, and the maximum dimension is the maximum distance between two points on the circumference of the VC. Thanks to the blower 370, the electronic device 100 may not require a heat pipe to move heat away from the VC. For example, the electronic device 100 may be implemented without a heat pipe.

[0097] Alternatively, the heat distribution structure 320 may include or be an array of heat pipes arranged side-by-side.

[0098] The heat distribution structure 320 may be disposed along an air flow path between the blower 370 and an air outlet. The air flow path may be a path along which air flows to the blower 370 and along which the air is blown out of the blower 370. For example, the air flow path extends from an air intake in the enclosure of the electronic device 100, through the blower 370 to the heat distribution structure 320, and from the heat distribution structure 320 to an air outlet in the enclosure of the electronic device 100.

[0099] For example, the enclosure of the electronic device 100 may include one or more intake openings proximate to the blower 370. The blower may be configured to draw air from outside the electronic device 100 through the one or more intake openings. The blower 370 may be configured to cause air to flow from the air intake, through the blower 370, to a surface of the heat distribution structure 320, and from the heat distribution structure 320 to an air outlet. The heat distribution structure 320 of the cooling system may be carried by the enclosure or chassis of the electronic device.

[0100] The blower 370 may be a first blower and the cooling system 300 may comprise one or more additional blowers or fans. The cooling system 300 may further comprise a second blower configured to generate an air flow along a surface of the heat distribution structure 320. The second blower may have a maximum length and maximum width of up to 20 mm (or up to 18 mm, or up to 15 mm) and / or a maximum thickness of up to 3 mm (or up to 4 mm, or up to 2.5 mm). The first blower 370 and the second blower may be arranged on opposite sides of the heat distribution structure 320 in the lateral direction.

[0101] The cooling system 300 may be implemented in the electronic device 100. The electronic device 100 may include the cooling system 300 and the heat source 110. The electronic device may be a low power device that uses a small blower in addition to a passive cooling concept. For example, the electronic device includes a thermal design power of up to 25 W (or up to 20 W, or up to 15 W) and / or at least 5 W (or at least 10 W, or at least 12 W).

[0102] For example, electronic device 100 may be implemented without a blower, with maximum dimensions for height, length and width of at least 20 mm (or at least 25 mm or at least 30 mm). In this way, noise generation, space consumption and / or power consumption can be kept low.

[0103] Alternatively, the electronic device 100 may further include a fan. The fan may include a maximum length and a maximum width of at least 30 mm (or at least 25 mm or at least 35 mm) and / or a maximum thickness of at least 4 mm (or at least 3.5 mm or at least 5 mm). In this way, the cooling capacity of the cooling system may be increased. The blower 370 may be located closer to the heat source 110 than the fan.

[0104] The heat source 110 may include or may be a semiconductor die configured to generate heat (e.g., waste heat) during operation. This waste heat may be generated automatically during operation of the semiconductor die. An integrated circuit may be implemented on the semiconductor die. The semiconductor die may be a bare die having an uncovered backside, or a packaged semiconductor die having a backside covered by a packaging material (e.g., a mold or other material).

[0105] Heat source 110 may be or may include a processor (e.g., a CPU, microcontroller, digital signal processor, or graphics processing unit GPU), a transmitter, a receiver, a transceiver, a power supply, and / or a voltage converter, or other integrated circuit.

[0106] The electronic device may be a tablet, a laptop, a notebook, a mobile phone, a computer (eg, a personal computer or a server), or other electronic device.

[0107] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0108] Fig. 3b shows a schematic cross-section of a cooling system for an electronic device. The electronic device may be implemented similarly to the electronic device described in relation to Fig. 3a and / or Fig. 1d. As mentioned above, one aspect of the proposed concept is to combine a vapor chamber with one or more mini-blowers. Fig. 1d is a schematic cross-section of a cooling system with a vapor chamber, and Fig. 3b is a schematic cross-section of a cooling system with a (smaller) vapor chamber and a mini-blower. In the latter case, the VC may be supported by the chassis since its temperature is now lower.

[0109] The guide structure 220 is disposed between the enclosure 140 (e.g., an outer cover) and the VC 120. The guide structure 220 can guide the air flow caused by the blower along the surface of the VC 120. The guide structure 220 can be attached to the enclosure 140 or integrally formed on the enclosure 140. The guide structure 220 can be walls arranged parallel to each other. The guide structure 220 can be a channel wall between the outer cover and the VC 120.

[0110] The first blower 370 may be positioned adjacent to an edge of a first half of the VC 120, and the second blower 372 may be positioned at an edge of a second half of the VC 120. The first blower 370 and the second blower 372 may be positioned on the same side of the VC 120.

[0111] The smaller VC 120 may allow more space for a battery compared to the implementation of FIG. 1d.

[0112] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0113] Figure 3c is a schematic plan view of a cooling system for an electronic device, which may show a top view of the electronic device described in relation to Figure 3b.

[0114] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0115] Figure 3d shows an illustration of the effect of air flow on the steam chest. Using computational fluid dynamics CFD modeling, the effect of air flow on the steam chest can be visualized, as shown in Figure 3d. Figure 3d shows an illustration of the effect of air flow on the steam chest. The improvement in heat transfer coefficient from natural convection (h=2W / m^2-K) to h=20W / m^2-K is due to the junction to ambient resistance Θ J-HP This can improve performance by a factor of 5, and even at h=5W / m^2-K can double the performance. Airflow over the VC can reduce the VC temperature significantly.

[0116] Figure 3e shows a schematic of the effect of air flow over the steam chest. Figure 3e shows the heat transfer coefficient and associated thermal resistance (1 / hA) calculated using a flow over a flat plate heat transfer correlation. It can be seen that the thermal resistance of the VC decreases very rapidly from near zero flow to slight flow (~0.7m / s). The proposed concept can use this enormous sensitivity to improve the passive VC cooling capacity by using mini blowers to provide only slight flows when needed, but turning them off when not needed.

[0117] Fig. 3f is a schematic diagram of an electronic device, which can be implemented similarly to the electronic device described in relation to Fig. 3a. The electronic device of Fig. 3f is a laptop 302 with a blower 370 integrated into an opening in the circuit board 150 carrying the heat source (e.g., the CPU).

[0118] Figure 3f may show an example of mini-blower integration. A slightly tilted blower may allow for good air intake and good airflow to the bottom channel.

[0119] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0120] FIG. 3g shows a schematic diagram of an electronic device. The electronic device may be implemented similarly to the electronic device described in relation to FIG. 3f. The laptop 302 includes a second blower 372. The first blower 370 and the second blower 372 are disposed on opposite sides of the VC 120. An air intake 352 (e.g., an opening in the chassis) is disposed adjacent to each of the two blowers. In addition, a guide structure 220 (e.g., an air channel wall) is disposed between the first blower 370 and the air outlet 354 (e.g., an opening in the chassis) and between the second blower 372 and the air outlet 354, and guides air from the blowers to the air outlet 354 along the surface of the VC 120.

[0121] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0122] Fig. 3h is a schematic diagram of an electronic device, which may be implemented similarly to the electronic device described in relation to Fig. 3g. Additionally, the laptop 302 includes a horizontal guide structure 220 extending from the VC 120 toward the blower 370 to laterally extend the gap between the VC 120 and the back cover of the laptop 302 toward the blower 370, so as to better direct air into the gap.

[0123] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0124] 3g and 3h may show schematic diagrams of airflow directions according to examples. As shown in Figs. 3f, 3g and 3h, examples may provide a computing device, such as a laptop computer or tablet computer, including a cooling system and a processing unit, such as a processor, a central processing unit or a graphics processing unit. A thermally conductive element (e.g., a VC) may be in contact with the processing unit. For example, as shown in Fig. 3h, at least one blower fan 370 may be disposed at a non-zero angle relative to a main portion of a bottom plate of a chassis of the computing device. For example, the angle of the at least one blower fan 370 relative to a main portion of a bottom plate of the chassis may be between 2° and 15°. The thermally conductive element of the cooling system may be held by the chassis of the computing device.

[0125] FIG. 3i shows a schematic plan view of a cooling system for an electronic device. The cooling system can be implemented similarly to the cooling system described in connection with FIG. 3a. In the example of FIG. 3i, the heat distribution structure is an array of heat pipes 322. Two mini blowers 370, 372 are disposed adjacent to the array of heat pipes 322 in a central region of the array of heat pipes 322. The array of heat pipes 322 is thermally coupled to the heat source 110 in the central region of the array of heat pipes 322. Two main blowers 306, 308 are disposed adjacent to the array of heat pipes 322 in opposite end regions of the array of heat pipes 322. The mini blowers 370, 372 are disposed closer to the heat source 110 (e.g., a CPU package) than the two main blowers 306, 308. The mini blowers 370, 372 are configured to blow air along the surfaces of the heat pipes of the array of heat pipes 322. In this way, the cooling efficiency of the heat pipes can be significantly improved. An array of heat pipes 322 may be less expensive than a VC. The use of mini-blowers allows for the higher efficiency of a VC or HP, and allows for a reduction in the number or size of main blowers (e.g., just two main blowers instead of four) without compromising performance.

[0126] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0127] FIG. 3j shows a schematic plan view of a cooling system for an electronic device. The cooling system can be implemented similarly to the cooling system described in connection with FIG. 3a. In the example of FIG. 3j, the heat distribution structure is a flattened-large diameter heat pipe 324. The flattened-large diameter heat pipe 324 is thermally coupled to a heat source 110 (e.g., a CPU package) at a central region of the flattened-large diameter heat pipe 324. A first blower 370 is disposed adjacent to an edge of the flattened-large diameter heat pipe 324 at a first end region of the flattened-large diameter heat pipe 324, and a second blower 372 is disposed adjacent to an edge of the flattened-large diameter heat pipe 324 at a second, opposite end region of the flattened-large diameter heat pipe 324.

[0128] The cooling system may be used for mobile systems. The outside dimension OD of the flattened large diameter heat pipe 324 may be in the range of 10 mm to 50 mm, or larger for systems with larger display sizes.

[0129] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0130] FIG. 3k is a schematic diagram of a resistive-capacitive (RC) network (e.g., MATLAB Simulink RC Network Used for Combo-Cooling Case Study) used for a case study (e.g., MATLAB Simulink RC Network Combo-Cooling Case Study). The case study demonstrates the benefits of implementing a combo-cooling technique in an otherwise passive device. The RC network includes four RC nodes (Junction-to-Sink, Sink-to-Ambient, Sink-to-Skin, and Skin-to-Ambient).

[0131] Figures 31 to 3o show diagrams of transient responses for various parameters. Junction temperature Tj, temperature at sink T-sink, and skin temperature T-skin (e.g., temperature at the outer surface of the enclosure) are shown. Figure 3l shows the passive device transient thermal response starting from time=0 as the power goes from 0 to 7 watts with purely passive cooling (i.e., combo cooling is not active). Figure 3m shows the passive device transient thermal response starting from time=0 as the power goes from 0 to 20 watts with purely passive cooling (i.e., combo cooling is not active). The time to Tj-max (maximum junction temperature) is about 7 seconds. Figure 3n shows the combo cooling transient thermal response starting from time=0 as the power goes from 0 to 20 watts. The time to Tj-max (maximum junction temperature) is about 13 seconds. Figure 3o shows the combo cooling transient thermal response starting from time=0 as the power goes from 0 to 25 watts. The time to Tj-max (maximum junction temperature) is approximately 7 seconds.

[0132] Figure 3l shows the transient PL1=7W response of a passive device without combo cooling (e.g., a TDP of 7W is the possible TDP in this segment). PL1 may be the effective long-term expected steady-state power dissipation. Note that at steady state (t=100 seconds), all temperature values ​​are within the expected limits of Tj~90°C (temperature at junction) and T-skin~47°C (temperature at skin). This indicates that this device can operate fully at its TDP with passive cooling. Figure 3m shows the transient PL2=20W response of this equivalent configuration without combo cooling (PL2=20W is the possible value for this segment). Note that at this PL2 power, this device can only provide ~7 seconds of maximum performance before becoming limited at Tj (assuming Tj-max=100°C, the maximum temperature at junction). In contrast, Figure 3n shows that if combo cooling is activated during this PL2 event (resistance from sink to ambient is momentarily reduced by half, which could be possible by turning on a mini-blower based on Figure 3e), the time at turbo, and therefore the time at maximum system performance, can be extended to nearly 13 seconds (86% longer time at turbo). Furthermore, Figure 3o shows that by using combo cooling techniques, the PL2 power can be increased to 25 watts (25% increase in PL2 power) without affecting the original time to Tj-max of ~7 seconds. These figures can demonstrate that by using combo cooling techniques during critical portions of the workload, both the time at turbo and / or turbo power can be significantly increased, thus improving the user experience and performance within the same form factor. Combining this improved thermal capability with machine learning predictions of what the user / workload is going to do next can significantly improve performance.

[0133] 3p shows a flow chart of a method for cooling an electronic device. The method 380 includes blowing 382 air along a surface of a heat distribution structure with a blower. The blower has a maximum length and width of up to 20 mm, and / or a maximum thickness of up to 3 mm.

[0134] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0135] FIG. 3q shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling system 350 comprises a heat conducting element 320. The heat conducting element 320 is adapted to cool a processing unit 360 of the electronic device 100 (e.g., a computing device). Furthermore, the cooling system 350 comprises at least one blower fan 370 for blowing air across a portion of the heat conducting element 320. Furthermore, the cooling system 350 comprises a control circuit 362 configured to activate or deactivate said at least one blower fan 370 based on a thermal load of the processing unit 360 of the computing device. The cooling efficiency of the heat conducting element may be improved by the flow of air along the heat conducting element. By activating the blower fan based on the thermal load of the processing unit, the performance under high workload conditions of the processing unit may be significantly improved. By deactivating the blower fan based on the thermal load of the processing unit, the current consumption may be reduced under low workload conditions of the processing unit.

[0136] The heat conducting element 320 (or heat conducting means) may also be referred to as a heat distribution structure. The heat conducting element 320 may include or be an array of vapor chambers or heat pipes. The heat conducting element 320 may be suitable for cooling a processing unit of a computing device. For example, the heat conducting element 320 may be a passive cooler, e.g., a structural element for passively cooling a processing unit at low heat load. The heat conducting element 320 may include at least one substantially flat major surface. The at least one blower fan 370 may be configured to blow air along the at least one substantially flat major surface of the heat conducting element 320.

[0137] The blower fan 370 (or blower or fan) may be a mini-blower. For example, the at least one blower fan 370 may have a fan diameter of up to 30 (or up to 25 mm, or up to 20 mm, or up to 17 mm, or up to 15 mm). The at least one blower fan 370 may have a fan height of up to 5 mm (or up to 4 mm, or up to 3 mm). For example, the fan height may be measured perpendicular to the blower fan diameter.

[0138] Control circuitry 362 may be configured to activate the at least one blower fan 370 when the thermal load of processing unit 360 exceeds a threshold and deactivate the at least one blower fan 370 when the thermal load of processing unit 360 falls below the threshold. For example, control circuitry 362 may be configured to operate cooling system 350 passively (e.g., electronic device fan is not active) when the thermal load of processing unit 362 falls below a threshold. For example, control circuitry 362 may be configured to activate blower fan 370 when the junction temperature of processing unit 360 is equal to or greater than a first temperature threshold and / or to deactivate blower fan 370 when the junction temperature of processing unit 360 is equal to or less than a second temperature threshold. The first temperature threshold may be equal to or different from the second temperature threshold.

[0139] The control circuitry 362 of the cooling system 350 may be configured to obtain information about the thermal load from a processing unit 360 of the computing device or from another component of the electronic device (e.g., a temperature sensor). The processing unit 360 may be configured to determine information about the thermal load of the processing unit 360 and provide said information about the thermal load to the control circuitry 362 of the cooling system 350. For example, the information about the thermal load may be based on at least one temperature measured or estimated in the computing device. The temperature may be measured by a temperature sensor integrated on the processing unit 360 or located close to the processing unit 360. Alternatively or additionally, the information about the thermal load may be based on a turbo state of the processing unit 360. Correspondingly, the processing unit 360 may be configured to determine the information about the thermal load based on at least one temperature measured or estimated in the computing device and / or based on a turbo state of the processing unit 360. Alternatively or additionally, the information about the thermal load may be predicted (e.g., the workload may be predicted), for example using machine learning. For example, the information about the thermal load may be based on a predicted evolution of the thermal load. The processing unit 360 may be configured to determine information regarding the heat load by predicting the heat load using a machine learning model.

[0140] The control circuitry 362 may be part of the processing unit 360, as shown in FIG. 3q, or may be a separate integrated circuit from the processing unit 360. For example, the control circuitry 362 and / or the processing unit 360 may be implemented using any means for processing, such as one or more processing units, one or more processing devices, processors, computers, or programmable hardware components, operable with appropriately adapted software. In other words, the described functions of the control circuitry 362 or the processing unit 360 may be implemented in software, in which case the software runs on one or more programmable hardware components. Such hardware components may include a general-purpose processor, a digital signal processor (DSP), a microcontroller, or other processing circuit.

[0141] The cooling system 350 may include one or more blower fans (e.g., mini-blowers). For example, the cooling system 350 may include two blower fans disposed on lateral sides of the heat-conducting element 320 or adjacent to the same or opposite sides of the heat-conducting element 320.

[0142] The cooling system 350 may include at least one air flow conductor (also referred to as a guiding structure or guiding element) for conducting air blown by the at least one blower fan toward the thermally conductive element.

[0143] The computing device may include a cooling system 350 and a processing unit. The thermally conductive element 320 may be in direct contact with the processing unit 360 through a TIM, or a metal plate (e.g., a cold plate) may be disposed between the thermally conductive element 320 and the processing unit 360.

[0144] For example, cooling system 350 and / or electronic device 100 may include more features than those described in connection with the cooling system and / or electronic device described in connection with FIG. 2a or FIG. 3a.

[0145] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0146] Figures 3r-3t show an illustration of the effect of predictive workload decisions. Figures 3r-3t show that predictive workload use cases may use machine learning. Combo Cooling may utilize these machine learning prediction capabilities to help determine when to start the mini-blower and when turbo power should be temporarily increased. As shown in Figures 3l-3o, the proposed concept can increase the turbo 85% of the time or the PL2 power by 25% in a small passive device.

[0147] 3u shows a flow chart of a method of operating a computing device. The method 390 includes determining 392 information about a thermal load of a processing unit and providing 394 the information about the thermal load to a control circuit of a cooling system. For example, a method for a computing device may be provided.

[0148] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0149] Some examples relate to lightweight and compact passive-active combo cooling for low power devices (e.g., giving the same or similar user experience UX as other passive cooling systems). For example, a cooling method for a lightweight mobile computer is proposed. A silent mini-blower (e.g., a blower fan) may be combined with a passive cooling system (e.g., a vapor chamber).

[0150] The result can be a cooling system that is lighter and more powerful than purely passive cooling, yet can be extremely quiet, so much so that the user may not be able to hear it. Various example cooling systems can provide more space for the battery while reducing the weight of a passive cooling system.

[0151] Other active or passive cooling may be used to cool the CPU (Central Processing Unit). In active cooling, the heat may be transferred to a heat exchanger and a blower or blowers may be used to cool the heat exchanger. In passive cooling, the heat may be split (distributed) over a large area, for example with a vapor chamber. The heat may be passively transferred to the outside air by radiation, conduction, and light convection (or thermal radiation). Active cooling may be powerful, but requires a blower, which causes noise and requires space. This may lead to a smaller battery volume and capacity. In some cases, a vapor chamber may be combined with a blower. In other systems, a large fan may be combined with a vapor chamber, and the vapor chamber is attached to a heat sink. Such a concept may be really thick and not usable in a laptop. A similar concept may also be used in laptops with a large but thin fan. This concept may be thin, but noisy, and the blower may take up a lot of battery space. Even though passive cooling is silent, large heat distributors require a lot of (lateral) space and can be heavy.

[0152] Examples could employ the proposed concept by reducing the size of the steam chest, reducing the size of the active blower, and / or using the system in a passive cooling mode under low heat loads.

[0153] For example, the size of the vapor chamber may be reduced, since the outer area of ​​the VC is often less efficient. This may reduce the overall weight of the device and give more battery space. The cooling capacity of the VC can be increased by adding a mini-blower (i.e., a blower fan with a fan diameter of up to 30 mm) to cool the VC. The mini-blower may be so quiet that it can be considered noiseless. This thermal solution may be 100% passively cooled when the thermal load is low, such as at idle or at a low power workload. However, during periods of high thermal load, such as at a PL2 (e.g., short-term maximum power mode) workload, the mini-blower may be turned on to assist with power dissipation.

[0154] One objective in computing device design may be to reduce the weight of devices in the low power category. This may be achieved by providing a thermal concept with reduced weight. Another objective may be to increase battery capacity. The concepts presented in this disclosure may increase available battery space. With such a user-friendly and noiseless CPU cooling solution, the adoption in the low power (e.g., <15W) category may increase.

[0155] Below are some examples of mini blowers that can be used with the embodiments. The first example mini blower has dimensions of 15mm x 15mm x 3mm, a maximum speed of 13800 rounds per minute (rpm), a maximum air flow of 0.17 CFM (cubic feet per minute), a maximum air pressure (inch H20) of 0.154, a voltage of 3.0V, a current of 0.05A, and a maximum noise of 30.0 (dB-a) at 0.3 meters. The second example mini blower has dimensions of 15mm x 15mm x 3mm, a maximum speed of 14500 rpm, a maximum air flow of 0.28 CFM, a maximum air pressure (inch H20) of 0.075, a voltage of 3.0V, a current of 0.05A, and a maximum noise of 31.0 (dB-a) at 0.3 meters. The third example of a mini blower has dimensions of 17mm x 17mm x 3mm, a maximum speed of 12000 rpm, a maximum air flow of 0.23 CFM, a maximum air pressure (in. H20) of 0.182, a voltage of 3.0V, a current of 0.05A, and a maximum noise of 26.5 (dB-a) at 0.3 meters. 1 CFM = 1.7 cubic meters per hour = 0.47 l / s.

[0156] The table below gives examples of possible noise levels. [Table 1]

[0157] The noise level of a laptop may be around 40-45 dB. For example, a laptop based on the proposed concept may produce a maximum noise level of up to 40 dB (or up to 30 dB).

[0158] The weight of electronic devices can be significantly reduced based on the proposed concept. For example, it may be possible to reduce the VC size from 150mm x 250mm to 100mm x 200mm (i.e., only 25mm per side), which may reduce the total mass of the device (e.g., laptop) from 1000g to 910g. By reducing the VC size from 150mm x 250mm to 100mm x 200mm (1 inch per side), the VC mass can be reduced by more than 40% (e.g., 46.7%) and the total mass of the device by more than 5% or more than 8% (e.g., 9.0%). A significantly lighter steam chest may be less expensive, which may mean a lower bill of materials (BOM) for the device.

[0159] As shown in this disclosure, even a weak airflow can significantly improve the VC heat exchange. The presented concept can be comparable to a passive cooling system since the weak airflow can be operated by a nearly silent mini-blower. The weak airflow can allow the size of the VC to be reduced or minimized, which can lead to a lighter and cheaper device, giving more space for the battery, thereby increasing the battery life. The air gap between the VC and the chassis, which may be needed to isolate the skin to lower the skin temperature, can now be used as a heat transfer channel. This may not increase the overall thickness, but may improve the overall stiffness since the VC and the chassis can be combined by air channel walls. The presented concept may differ from hybrid cooling, since it may not use a "full power" fan. The presented concept may be an active cooling system using a fan, but is nearly silent like a passive cooling system. Thus, the presented concept may be referred to as "passive-active combo cooling."

[0160] In an example, the vapor chamber is combined with a mini-blower. In addition to combining these two concepts, additional system-level design optimizations may be proposed, such as really thin channeling, to increase the convection on the VC surface very effectively over instantaneous time periods. The mini-blower may be used only in the case of high-power turbos, otherwise the device may be completely passive. The proposed concept can use workload and user forecast information to adapt the cooling strategy, which may be different from other active cooling concepts.

[0161] The example also has a reduced fan size and may be more efficient than a hyperbaric design, even without the use of heat exchange fins. This is because the heat exchanger may have a small surface area and requires a really high blow to transfer the heat. Furthermore, the heat transfer through the fins may be less efficient than the heat transfer from the VC skin. The proposed concept may eliminate the heat exchanger (fins) and utilize the large surface area of ​​the VC. The heat exchange performed in the example may not require a high blow, so the fan size can be reduced. In other systems, a 2 heat pipe HP active cooling solution may be used, with a fin area of ​​9mm x 18mm x 70mm x 2 = 22680mm. 2 , which is roughly the same as the reduced VC area per side. Additionally, the high pressure design may be intended as the primary means of cooling from the start. Combo cooling may only be utilized during turbo events to increase power / turbo duration, and then revert to passive cooling.

[0162] The assembly and integration examples described above and below may be merely examples, as the final design may further depend on details such as package thermal design power (TDP), VC dimensions, etc. In various examples, mini blowers are positioned on both sides to blow low airflows on both sides of the VC through air channels (conductive sections). For example, the cooling system may include two blower fans positioned on each lateral side of the heat conducting element. The cooling system may include at least one airflow conductive section for conducting air blown by the at least one blower fan towards the heat conducting element. The heat conducting element may have at least one substantially flat major surface (e.g., a surface without ridges and providing at least 30% of the surface area of ​​the heat conducting element). The at least one blower fan may be positioned to blow air across the at least one substantially flat major surface.

[0163] In some other cooling systems, an additional fan may be used in an active cooling system to cool the board. In such a system, the heat may be transferred by a heat exchanger without channeling in the chassis. Channeling in the chassis may not be effective in active cooling because it should be relatively tall and therefore the heat exchanger may be good. Such a cooling system may be used in high power systems with a TDP of 45W or more for the CPU and additional TDP for the graphics processing unit (GPU). On the other hand, the proposed concept example is targeted at a computing device with a TDP of 15W or less with a small 15mm x 15mm fan for ultimate thermal case cooling.

[0164] Examples of the present disclosure can provide a combo active-passive cooling system with a vapor chamber and blower fan, which can make it possible to build a cooling system that is smaller and lighter than other passive systems, has the same or even slightly higher TDP, and has a similar user experience as a purely passive cooling system.

[0165] 4a shows a schematic cross-sectional view of a cooling system of an electronic device 100. The cooling system 400 comprises a first heat distribution structure 320 configured to be coupled to a heat source 110. Furthermore, the cooling system 400 comprises a thermal electric cooler (TEC) 410 and a second heat distribution structure 420. A first surface of the thermoelectric cooler 410 is thermally coupled to the first heat distribution structure 320 and a second surface of the thermoelectric cooler 410 is thermally coupled to the second heat distribution structure 420.

[0166] By implementing a TEC between two heat distribution structures, heat can be transferred very quickly from one heat distribution structure to the other, thus improving the cooling of the heat source.

[0167] The thickness of the thermoelectric cooler 410 may be up to 3 mm (or up to 2.5 mm, or up to 2 mm, e.g., 1.5 mm to 2 mm). In this way, the stack height can be kept low and thin electronic devices may be possible.

[0168] Thermoelectric cooler TEC 410 can use the Peltier effect to generate a heat flux at the junction of two different types of materials (e.g., n-type and p-type semiconductor materials). When operated as a cooler, a voltage can be applied across the TEC, resulting in a temperature difference between the two opposite sides of the TEC.

[0169] The first heat distribution structure 320 may be a planar structure with a lateral extent significantly greater than its vertical extent. For example, the thickness of the first heat distribution structure 320 may be up to 10% (or up to 5%) of the maximum lateral dimension (e.g., length or width) of the first heat distribution structure 320. The thickness of the thermoelectric cooler 410 may be greater than the thickness of the first heat distribution structure 320. The first heat distribution structure 320 may be up to 1 mm (or up to 0.8 mm, or up to 0.6 mm, e.g., 0.5 mm) thick. The first heat distribution structure 320 may be a metal plate (e.g., a cold plate) or a vapor chamber.

[0170] The second heat distribution structure 420 may be a planar structure having a lateral extent significantly greater than its vertical extent. For example, the thickness of the second heat distribution structure 420 may be at most 10% (or at most 5%) of the maximum lateral dimension (e.g., length or width) of the second heat distribution structure 420. The second heat distribution structure 420 may be a metal plate (e.g., a cold plate) or a vapor chest.

[0171] For example, the distance between the first heat distribution structure 320 and the second heat distribution structure 420 may be at most 3 mm (or at most 2.5 mm, or at most 2 mm). In this manner, the stack height can be kept low and thin electronic devices may be enabled.

[0172] An adhesive (eg, a thermally conductive adhesive) and / or a TIM may be used to attach and thermally couple the TEC 410 to the first heat distribution structure 320 and the second heat distribution structure 420 to the TEC 410.

[0173] The cooling system 400 may further include a (first) heat pipe disposed adjacent to the thermoelectric cooler 410 on the first heat distribution structure 320. For example, a side of the heat pipe may be in contact with a side of the TEC 410, or there may be a small gap (e.g., up to 5 mm, or up to 2 mm) between the heat pipe and the TEC 410. The thickness of the heat pipe may be up to 3 mm (or up to 2.5 mm, or up to 2 mm).

[0174] The (first) heat pipe may be thermally coupled to the first heat distribution structure 320 in an area opposite the center of the heat source 110. For example, the thermoelectric cooler 410 may be positioned closer to the edge of the first heat distribution structure 320 than the heat pipe in at least one direction. The heat pipe may be used continuously to cool the area of ​​the first heat distribution structure 320 closer to the heat source 110, while the TEC 410 may only be activated for additional cooling when needed (e.g., at high heat source workload conditions).

[0175] The heat pipes may extend to a fan of the cooling system 400. For example, an evaporator region of the heat pipe (e.g., a first end region) may be thermally coupled to the first heat distribution structure 320, and an evaporator region of the heat pipe (e.g., a second end region) may be located proximate or adjacent to the fan.

[0176] The heat pipe may be disposed between the first heat distribution structure 320 and the second heat distribution structure 420. For example, a first surface of the heat pipe may be thermally coupled to the first heat distribution structure 320 and a second surface of the heat pipe may be thermally coupled to the second heat distribution structure 420. The heat pipe and TEC 410 may be vertically disposed or sandwiched between the first heat distribution structure 320 and the second heat distribution structure 420.

[0177] Alternatively, the second heat distribution structure 420 may extend laterally only over a portion of the first heat distribution structure 320, thereby sandwiching the TEC 410 between the first and second heat distribution structures 320 and disposing the first heat pipe laterally on the first heat distribution structure 320 beside the second heat distribution structure 420. For example, the thickness of the thermoelectric cooler 410 may be less than the thickness of the first heat pipe. The thickness of the heat pipe is greater than the thickness of the first heat distribution 320 and / or greater than the distance between the first heat distribution 320 and the second heat distribution structure 420. By having the second heat distribution structure 420 extend only over the TEC 410, but not the heat pipe, the overall vertical dimension of the stack can be reduced (e.g., as shown in FIG. 4d).

[0178] In addition, the cooling system 400 may further include a second heat pipe. The first heat pipe may be disposed between the thermoelectric cooler 410 and the second heat pipe in the lateral direction (e.g., as shown in FIG. 4b). For example, the side of the first heat pipe may be in contact with the side of the second heat pipe, or there may be a small gap (e.g., up to 5 mm or up to 2 mm) between the first heat pipe and the second heat pipe. The second heat pipe may be disposed between the first heat distribution structure 320 and the second heat distribution structure 420. For example, a first surface of the second heat pipe may be thermally coupled to the first heat distribution structure 320, and a second surface of the second heat pipe may be thermally coupled to the second heat distribution structure 420. The first heat pipe, the second heat pipe, and the TEC 410 may be disposed or sandwiched between the first heat distribution structure 320 and the second heat distribution structure 420 in the vertical direction.

[0179] In addition, the cooling system 400 may further include a third heat pipe. The third heat pipe may be thermally coupled to the second heat distribution structure 420. The third heat pipe may be laterally spaced apart from the first heat distribution structure 320 (e.g., as shown in FIG. 4d). Alternatively, the third heat pipe may be replaced with a metal plate (e.g., a cold plate), a heat exchanger, VC, or other types of heat spreading materials for heat transfer.

[0180] The electronic device 100 may include a cooling system 400 and a heat source 110. The electronic device 100 may be configured (e.g., by a control circuit) to activate and / or deactivate the thermoelectric cooler based on one or more device parameters. The one or more device parameters may indicate a junction temperature of the heat source, a state of charge of the electronic device, a workload of the heat source 110 or the electronic device 100, and / or a thermal load of the heat source 110 or the electronic device 100. In this manner, cooling capacity and / or efficiency may be increased by activating the TEC as needed. On the other hand, the TEC may be disabled when less cooling is sufficient to reduce power consumption. For example, if the electronic device 100 is a mobile device (e.g., a laptop, tablet, or mobile phone), the TEC 410 may not be continuously activated for at least one minute (or at least 40 seconds, or at least 30 seconds) when the electronic device 100 is battery powered (e.g., not charging). In this manner, power consumption may be kept low while the electronic device 100 is battery powered. Electronic device 100 may be configured to operate TEC 410 such that the operating current of TEC 410 is at least 10% (or at least 20%) and / or at most 30% (or at most 40% or at most 25%) of the maximum current of TEC 410. In this manner, the TEC can be operated under efficient operating conditions.

[0181] The distance or gap between the second heat distribution structure 420 and a portion of the enclosure of the electronic device 100 or the back of the screen of the electronic device 100 may be at most 2 mm (or at most 1.5 mm, or at most 1 mm, e.g., between 0.5 mm and 1 mm). If there is a gap between the heat distribution structure and the enclosure, the temperature of the enclosure (e.g., the skin temperature) can be significantly reduced.

[0182] Alternatively, the second heat distribution structure 420 may be thermally coupled to a portion of the enclosure of the electronic device 100. In this manner, the cooling capacity of the heat distribution structure 420 may be increased as heat may be transferred from the second heat distribution structure 420 to the portion of the enclosure. For example, a thermal pad may be disposed on the portion of the enclosure to thermally couple the second heat distribution structure 420 to the portion of the enclosure (e.g., as shown in FIG. 4e).

[0183] For example, heat source 110 (eg, a CPU) may include a thermal design power of at least 15 W (or at least 25 W or at least 40 W) if a heat pipe is used in addition to TEC 410.

[0184] Alternatively, if the electronic device is implemented without a heat pipe and / or without a fan, the heat source 110 (e.g., a CPU) may include a thermal design power of up to 15 W (or up to 12 W, or up to 10 W). For example, the electronic device may be implemented with purely passive cooling supported by a TEC.

[0185] The heat source 110 may include or be a semiconductor die configured to generate heat (e.g., waste heat) during operation. The waste heat may be generated automatically during operation of the semiconductor die. An integrated circuit may be implemented on the semiconductor die. The semiconductor die may be a bare die having an uncovered backside, or a packaged semiconductor die having a backside covered by a packaging material (e.g., a mold or other material).

[0186] Heat source 110 may be or may include a processor (e.g., a CPU, microcontroller, digital signal processor, or graphics processing unit GPU), a transmitter, a receiver, a transceiver, a power supply, and / or a voltage converter, or other integrated circuit.

[0187] The electronic device 100 may be a tablet, a laptop, a notebook, a mobile phone, a computer (eg, a personal computer or a server), or other electronic device.

[0188] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0189] FIG. 4b shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in connection with FIG. 4a. The first heat distribution structure 320 is implemented as a first metal plate (first cold plate), and the second heat distribution structure 420 is implemented as a second metal plate (second cold plate). The first heat distribution structure 320 is disposed on a semiconductor package (e.g., a SOC package) including a substrate 404 and a semiconductor die 402. The semiconductor package is attached to a circuit board 150 (e.g., a motherboard). The first heat pipe 430, the second heat pipe 440, and the TEC 410 are disposed on a surface of the first heat distribution structure 320, and the second heat distribution structure 420 is disposed on the first heat pipe 430, the second heat pipe 440, and the TEC 410. Heat may be transferred from the semiconductor die 402 directly through the first cold plate to the heat pipes, and indirectly through the TEC 410 and the second cold plate to the heat pipes.

[0190] For example, a TEC 410 may be introduced into the system design to improve the transient response. The TEC 410 may be used for instantaneous response behavior to spread the SOC power transient. The die 402 may generate heat and may be a hot spot area, but the size of the die is smaller than the SOC package. As shown in FIG. 4b, a first cold plate may cover the entire SOC area to dissipate the SOC die heat.

[0191] For example, the TEC 410 is in direct contact (e.g., through a TIM) with a first cold plate, which may be similar to the heat pipe 430. The TEC 410 partially uses the first cold plate. Other areas of the first cold plate are still covered by the heat pipe. The Tj temperature may be monitored, and if the Tj temperature rises rapidly, which may indicate an increase in SOC power transient, the TEC 410 can instantly cool the SOC and transfer power to the second cold plate and from the second cold plate to the heat pipe 430. The first cold plate can transfer much or most of the power to the heat pipe area (the area thermally coupled to the first and second heat pipes). Both the TEC 410 and the first cold plate can work together to transfer power to the heat pipe. As a result, both normal power and transient high power can be transferred to the heat pipe.

[0192] For example, two heat pipes with uncompressed diameter φ8, compressed thickness 1.8 mm, a first cold plate of 0.5 mm, a cooling capacity of 10.1 W and a TEC of 1.2 COP can be used.

[0193] For example, one side of the TEC 410 can cool the SOC and the other side needs to be cooled. A second cold plate may be pressed against the TEC 410, transferring the TEC heat to the heat pipe area. The second cold plate may allow the heat pipe to be quickly put into operation mode.

[0194] If a proper TEC module, system stackup and / or SW control mechanism can ensure that the TEC 410 responds immediately with low power consumption, the TEC 410 can release more SOC performance. The control mechanism may be integrated with DTT tuning (dynamic tuning technology).

[0195] The proposed cooling system may reduce or minimize the transient temperature rise and instantly transfer the SOC generated power to the heat pipe region.

[0196] The TEC 410 may be enabled only at certain times when the Tj temperature rises rapidly. The TEC 410 may be disabled almost all the time to save power and avoid skin temperature rise. In this stack, the second cold plate may occupy a Z height of 0.5 mm. Simulations may show that the second cold plate area has a higher temperature on both sides. Thus, with this stack and the selected TEC 410, an additional space of 0.2-0.3 mm (e.g., a gap between the second cold plate and the cover) may be implemented to ensure that the skin temperature remains low.

[0197] The example of FIG. 4b may be a cooling system for an electronic device with a fan (eg an actively cooled notebook).

[0198] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0199] 4c shows a schematic plan view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in relation to FIG. 4b. A first heat pipe 430 and a second heat pipe 440 extend from a first cold plate to a heat sink 180. The first heat pipe 430 and the second heat pipe 440 may be thermally coupled to the heat sink 180. Additionally, a fan 170 is disposed adjacent to the heat sink 180. The fan 180 is configured to blow air through or over the heat sink 180.

[0200] Various additional components of the electronic device may be disposed on the circuit board 150 .

[0201] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0202] FIG. 4d shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in relation to FIG. 4b. However, the second heat distribution structure 420 is disposed above the TEC 410, but not above the first heat pipe 430 and the second heat pipe 440. The thickness of the TEC 410 is smaller than the thickness of the first heat pipe 430 and the second heat pipe 440. In this way, the height of the entire stack can be reduced. A third heat pipe 442 is thermally coupled to the second heat distribution structure 420. The third heat pipe 442 is laterally spaced apart from the first heat distribution structure 320. There is a gap between the enclosure 450 (e.g., C cover or D cover) of the electronic device and the second heat distribution structure 420. In this way, the surface temperature of the enclosure can be kept low.

[0203] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0204] FIG. 4e is a schematic cross-sectional view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in relation to FIG. 4d. However, the thickness of the TEC 410 is greater than the thickness of the first heat pipe 430 and the second heat pipe 440. Furthermore, instead of implementing a third heat pipe, the second heat distribution structure 420 is thermally coupled to the enclosure 450 (e.g., D-cover) via a thermal pad 452. In this way, the cooling capacity can be improved. The thermal pad 452 may include a thermally conductive adhesive or TIM, or any other material suitable for thermally coupling the second heat distribution structure 420 to the enclosure 450.

[0205] The first heat distribution structure 320 may be a cold plate (eg, a first cold plate) and the second heat distribution structure 420 may be a cold plate (eg, a second cold plate).

[0206] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0207] Fig. 4f shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in relation to Fig. 4e. However, the second heat distribution structure 420 is not thermally coupled to the enclosure 450. There is a gap between the enclosure 450 of the electronic device and the second heat distribution structure 420. In this way, the surface temperature of the enclosure can be kept low.

[0208] The first heat distribution structure 320 may be a cold plate (eg, a first cold plate) and the second heat distribution structure 420 may be a cold plate (eg, a second cold plate).

[0209] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0210] FIG. 4g shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in connection with FIG. 4a. The cooling system of FIG. 4g may be a passive cooling system without a fan. The first heat distribution structure 320 is implemented as a first metal plate (first cold plate), and the second heat distribution structure 420 is implemented as a second metal plate (second cold plate). The first heat distribution structure 320 is disposed on top of a semiconductor package (e.g., a SOC package) including a substrate 404 and a semiconductor die 402 (e.g., the die may have a length of 10.6 mm or any other length). The semiconductor package is attached to a circuit board 150 (e.g., a motherboard). The TEC 410 is disposed on a surface of the first heat distribution structure 320, and the second heat distribution structure 420 is disposed on top of the TEC 410. Heat may be transferred from the semiconductor die 402 to the second cold plate through the first cold plate and the TEC 410. There is a gap between the enclosure 450 (eg, a D-cover) of the electronic device and the second heat distribution structure 420.

[0211] The example of Fig. 4g may be a cooling system for a fan-less low-power SOC. An electronic device (e.g., a passively cooled notebook) may have a TDP of up to 12W (or up to 10W).

[0212] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0213] FIG. 4h is a schematic cross-sectional view of a cooling system for an electronic device. The cooling system may be implemented similarly to the cooling system described in connection with FIG. 4a. The cooling system of FIG. 4g may be a passive cooling system without a fan. The first heat distribution structure is implemented as a first metal plate (first cold plate), and the second heat distribution structure 420 is implemented as a second metal plate (second cold plate). A portion of the first heat distribution structure is disposed above a semiconductor package (e.g., a SOC package) including a substrate 404 and a semiconductor die 402 (e.g., the die may have a length of 10.6 mm or any other length). The semiconductor package is attached to a circuit board 150 (e.g., a motherboard). The first heat distribution structure comprises a first portion 426 thermally coupled to the semiconductor package 402 and a second portion 428 thermally coupled to the first portion 426. The second portion 428 of the first heat distribution structure is disposed laterally next to the semiconductor package 402 in the lateral direction. The semiconductor package 402 is disposed vertically between the first portion 426 and the second portion 428 of the first heat distribution structure. The TEC 410 is disposed on a surface of the second portion 428 of the first heat distribution structure, and the second heat distribution structure 420 is disposed above the TEC 410. The vertical extent of the thermoelectric cooler 410 overlaps with the vertical extent of the semiconductor package 402. In this way, a very thin electronic device may be made possible. Heat may be transferred from the semiconductor die 402 to the second cold plate through the first cold plate and the TEC 410. There is a gap between the enclosure 450 (e.g., a D-cover) of the electronic device and the second heat distribution structure 420.

[0214] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0215] Simulations may show that systems with TEC may reach maximum junction temperature Tj later than systems without TEC. TEC may be placed closer to the die to better help sustain transient power. Figure 4i shows junction temperature over time. Simulations may be based on a system as shown in Figure 4b. Two heat pipes (e.g., uncompressed diameter φ8, 1.8mm), a 0.5mm cold plate, and a TEC (e.g., 10.1W cooling capacity, 1.2COP) may be used. The configuration of the thermal solution may affect the total turbo budget. With changes in different systems, the sustained and transient capabilities of the thermal solution may vary. Simulation results show that the system with the TEC solution may reach 100 degrees after 18 seconds while the other design (without TEC) may reach 100 degrees after 11 seconds. TEC may slow down the Tj temperature rise and increase the turbo time by 7 seconds. TEC may lower the risk of Tj throttling. FIG. 4j shows the temperature difference over time, corresponding to the diagram shown in FIG. 4i.

[0216] 4k shows a flowchart of a method for cooling an electronic device. The method 490 includes activating 492 a thermoelectric cooler based on device parameters of the electronic device. A first surface of the thermoelectric cooler is thermally coupled to a first heat distribution structure and a second surface of the thermoelectric cooler is thermally coupled to a second heat distribution structure. The first heat distribution structure is coupled to a heat source.

[0217] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0218] Some examples relate to dynamic heat spreading solutions by enabling a Thermal Electronic Cooler (TEC) on a personal computer PC.

[0219] As customers demand higher performance, the CPU may need to increase the power limit for PL1 (for sustained performance) and PL2 (for burst performance). However, the time the CPU can spend in high performance mode at PL2 may be less than 10 seconds. This is because other thermal solutions may have difficulty immediately transferring the CPU generated power to thermal solutions such as heat pipes and fin cold point areas. As a result, the Tj temperature of the CPU is reached quickly, which triggers CPU throttling, which reduces CPU performance. It may become increasingly important to transfer the transient power and minimize the transient temperature rise. Sustaining the system-on-chip SOC performance may be challenging for system and thermal design.

[0220] Cold plates, vapor chambers, heat pipes and fans may be used for thermal spreading. Heat from the die is first transferred to the cold plate or vapor chamber, then to the heat pipes, and finally to the fins, which are then cooled by the fan. The closer to the die, the more effective the thermal solution may be.

[0221] Increasing the thickness of the cold plate (e.g., metal plate) may improve heat spreading and increase the thermal capacity. However, it increases the z-height and may affect the performance of the heat pipe. The size of the cold plate may be very small, like the SOC size. As a result, the thermal capacity may be low and may not support PL2 transient power significantly. In some designs, a vapor chamber may be used instead of the cold plate. The heat spreading and thermal capacity may be better compared to the cold plate. The response speed may be faster and the thermal capacity may be better at slightly higher PL2 power, but the vapor chamber may affect the heat pipe response time and may be more costly. The heat pipe may increase the z-height and may only increase the maximum heat transfer carrying capacity (Qmax), but the response time may not be improved. The fan may be located away from the CPU die area. Early activation may be required. The response speed may be the slowest of the mentioned solutions since it is located the furthest from the SOC die.

[0222] Thermoelectric cooler TEC may be able to respond instantly within 1 second. Thus, it can be used for transient response Tj temperature rise. It may also have high capacity to support high transient power. It may be controlled by software SW algorithm to balance heat dissipation and power consumption. TEC response time may be the fastest thermal solution. It may instantly transfer SOC generated power to the cold point of heat pipe. TEC may increase system thermal capacity to sustain PL1 or PL2 longer. TEC may reduce or minimize transient temperature rise and also can make SOC sustain PL2 longer and even power above PL2 to maximize CPU performance. TEC may be integrated into dynamic tuning concept (e.g. Dynamic Tuning Technology DTT).

[0223] According to one aspect of the proposed concept, a TEC may be implemented in PC systems to support high transient power to unlock higher SOC performance. The same approach may also be applied to desktop computers and notebooks.

[0224] Other SOC heat spreading solutions use cold plates and heat pipes to transfer the SOC generated power, then cool the heat pipes with fans and fins, but the SOC generated power may not be transferred to the heat pipes instantly due to slow response times. Fans and fins may be largely ineffective in less than ~10 seconds. SOC transient performance may be greatly affected by the distance between the heat spreading components and the SOC die. Components closest to the SOC die may be most useful for transient response. For example, thicker cold plates and better TIM materials may be used to improve transient performance.

[0225] The TEC may have some limitations (e.g., efficiency, power consumption, thickness, etc.), for example, a notebook system may have limited space and power supply. Thus, a suitable TEC may be selected for system integration. Since the power consumption of the TEC may be quite high, it may not be possible to rely on the TEC alone to cool the SOC in a notebook system. Working the TEC and heat pipes together may be a good choice to transfer the SOC heat. Thus, the cooling capacity of the TEC may be selected to be lower than the SOC PL1 power.

[0226] Efficiency can be an important factor for system design. The operating current and maximum temperature difference can be considered to obtain a higher Coefficient of Performance (COP). If the maximum temperature difference is less than about 30°C and the operating current is 10-30% of the TEC maximum current, a COP higher than 1.0 can be achieved. A suitable TEC with a higher COP can save significant power.

[0227] For example, a notebook system may not have much space to integrate a TEC, but the TEC may share the SOC space with the heat pipe. A TEC module smaller than 1.0 mm may be used. The operating temperature of the TEC may be selected such that the operating temperature of the hot side is higher than the heat pipe temperature (e.g., 55 degrees). Thus, once the TEC is enabled, it can work together with a second cold plate (as shown in Figure 4b) to transfer heat to the heat pipe.

[0228] Software SW control algorithms and policies may be used to improve or optimize power consumption and improve performance. The policies may manage platform power, enable / disable the TEC, and / or adjust current at different operating conditions. For example, the TEC can be enabled at significant Tj temperature rise conditions for a certain time (e.g., 10-30 seconds) to ensure PL2 performance. The TEC can also cool the inside of the system during charging and low workload conditions to obtain higher system thermal capacity.

[0229] 5a shows a schematic cross-sectional view of a cooling structure for an electronic device. The cooling structure 500 comprises a heat distribution structure 320 configured to spread heat generated by a heat source 110 from a central region (or center region) to an edge region of the heat distribution structure 320. The heat distribution structure 320 is configured to be thermally coupled to the heat source 110 at the central region on a first side of the heat distribution structure 320. Furthermore, the cooling structure 500 comprises a border 510 disposed on the heat distribution structure 320. The border 510 surrounds the central region of the heat distribution structure 320 on the first side of the heat distribution structure 320.

[0230] By providing a boundary around the central region, a cavity can be created for the heat source. Any TIM placed between the heat source and the cooling structure during thermal coupling between the two cannot escape or leak from the cavity, ensuring good long-term contact between the heat source and the cooling structure. Additionally, the boundary can aid in dissipation of heat from the heat source.

[0231] The heat distribution structure 320 may be configured to be coupled to the heat source 110 by having a central area large enough to accommodate the heat source. The heat distribution structure 320 may have a planar surface in the central area. In this way, a heat source 110 (e.g., a semiconductor die or a semiconductor package) having a flat surface can be easily thermally coupled to the heat distribution structure 320. The first side of the heat distribution structure 320 may be a planar surface except for the boundary 510, or may include additional structures outside the central area that protrude from the level of the central area.

[0232] The boundary 510 (also called a sidewall or frame) may have any geometric shape, so long as it protrudes from and surrounds the central region of the heat distribution structure 320. For example, since the heat source 110 may be thin (e.g., a semiconductor die or a semiconductor package), the boundary 510 may protrude from the surface of the central region by at most 1 mm (or at most 0.8 mm or 0.5 mm). For example, the region surrounded by the boundary 510 may include a maximum dimension of at most 30 mm (or at most 40 mm, or at most 20 mm, or at most 15 mm) and / or at least 10 mm (or at least 15 mm, or at least 20 mm) in terms of length and width. The boundary 510 may form a wall that laterally surrounds the central region. The wall may extend perpendicular to the surface of the central region, and the angle between the surface of the central region and the wall may be at most 110° (or at most 100°).

[0233] The boundary 510 may be integrally formed with the heat distribution structure 320 on a first side of the heat distribution structure 320. For example, the heat distribution structure 320 may include or be a vapor chamber, and the boundary 510 may be integrally formed on a surface of the chamber wall. Alternatively, the boundary 510 may be attached (e.g., glued or soldered) to or formed (e.g., deposited) on the first side of the heat distribution structure 320.

[0234] The thermal distribution structure 320 may also be referred to as a thermal bus or thermal bus structure. The thermal distribution structure 320 may include a thermal conductivity of at least 100 W / mK (or at least 500 W / mK, at least 1000 W / mK, or at least 1500 W / mK) in at least one direction from a center region to an edge region. For example, the thermal distribution structure 320 may be or include a vapor chamber, a plurality of heat pipes (e.g., embedded in a metal plate), or a metal plate (e.g., a copper plate or an aluminum plate). For example, the thermal distribution structure 320 may include a thickness of up to 4 mm (or up to 3 mm, up to 2.5 mm, or up to 2 mm). The thermal distribution structure 320 may have maximum dimensions for length and width of at least 60 mm (or at least 80 mm or at least 100 mm) and / or up to 150 mm (or up to 120 mm or up to 100 mm).

[0235] The edge region of the heat distribution structure 320 may extend along an edge of the heat distribution structure, for example, the boundary 510 is located on a first side of the heat distribution structure 320 in the lateral direction, between the edge region and the central region.

[0236] The cooling structure 500 may further comprise a seal ring attached to the interface. The seal ring may be configured to seal a gap between the interface and a carrier structure of the heat source 110. The carrier structure may be a packaging substrate of a semiconductor die, or a circuit board on which the heat source 110 is attached, or another structure. In this way, a sealed cavity for the heat source 110 may be obtained. For example, the TIM used to thermally couple the heat source 110 and the heat distribution structure 320 may not be able to escape the sealed cavity.

[0237] The cooling structure 500 may further include a heat sink attached to a second side of the heat distribution structure 320. The heat sink may be attached (e.g., glued or soldered) to the second side of the heat distribution structure 320. For example, a TIM may be disposed between the heat sink and the heat distribution structure 320 to improve thermal coupling. The heat sink may include fins on a side opposite the heat distribution structure 320.

[0238] The CPU TIM may be held in place and ensure good contact with the CPU through the CPU die cavity. Additionally, heat from the CPU die may be spread through the vapor chamber base so that the heat enters the entire heat sink base and not just the small area that contacts the CPU die. In this way, the heat can be dissipated more efficiently to the surroundings. The thermal bus can be made of heat pipes, copper, or other good thermally conductive materials depending on the power level.

[0239] The heat source 110 may include or be a semiconductor die configured to generate heat (e.g., waste heat) during operation. The waste heat may be generated automatically during operation of the semiconductor die. An integrated circuit may be implemented on the semiconductor die. The semiconductor die may be a bare die having an uncovered backside, or a packaged semiconductor die having a backside covered by a packaging material (e.g., a mold or other material).

[0240] Heat source 110 may be or may include a processor (e.g., a CPU, microcontroller, digital signal processor, or graphics processing unit GPU), a transmitter, a receiver, a transceiver, a power supply, and / or a voltage converter, or other integrated circuit.

[0241] The electronic device 100 may be a tablet, a laptop, a notebook, a mobile phone, a computer (eg, a personal computer or a server), or other electronic device.

[0242] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0243] FIG. 5b shows a schematic cross-sectional view of a cooling structure for an electronic device. The cooling structure may be implemented similarly to the cooling structure described in connection with FIG. 5a. The heat distribution structure 320 (thermal bus) is a vapor chamber. The vapor chamber comprises a boundary 510 laterally surrounding a central region on a first side of the vapor chamber. The surface and boundary of the vapor chamber in the central region together enclose a recess or cavity for accommodating a heat source. For example, the heat source may be a CPU, and the recess may be a cavity for the CPU die. The boundary may have vertical sidewalls adjacent to the central region, a horizontal top surface, and an inclined surface extending from the top surface to a surface of an edge region of the vapor chamber. Additionally, a seal ring (e.g., a gasket material) is attached to the top of the boundary. The seal ring may seal the cavity after coupling the cooling structure with the heat source. The second side of the vapor chamber may be used as a heat sink base for mounting a heat sink.

[0244] FIG. 5b may show an example of a thermal bus with or being a vapor chamber. A different heat sink or similar (e.g., a metallic heat sink, a heat pipe, another vapor chamber, a liquid cooling system, or a TEC) may be carried by the thermal bus or attached to the top surface of the thermal bus. The thermal bus may be attached to a bare die CPU. Heat spreading may be better than with an IHS (Integrated Heat Spreader). A CPU die cavity with a seal ring may be used to eliminate TIM leakage. The thermal bus may not be integrated into the CPU package. The thermal bus may be flexible, removable, or customized.

[0245] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0246] 5c is a schematic bottom view of a cooling structure for an electronic device, which may represent the bottom view of the cooling structure described in relation to FIG.

[0247] Figure 5c may show the use of a thermal bus with a bare die package and heat sink assembly. A CPU cavity on the thermal bus may be able to hold the CPU TIM in place, especially in the case of liquid metal TIM, and can ensure good contact between the thermal bus and the CPU die surface. Additionally, a thermal path through the side of the CPU die may slightly improve cooling.

[0248] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0249] FIG. 5d shows a schematic cross-sectional view of a cooling system for an electronic device. The cooling structure may be implemented similarly to the cooling structure described in connection with FIG. 1f and / or FIG. 5a. A vapor chamber is integrated between the heat sink 180 and the semiconductor die 402. The vapor chamber is thermally coupled to the backside of the semiconductor die 402 through a TIM. The semiconductor die (e.g., a CPU) is mounted on a substrate (e.g., a CPU substrate) that is mounted on a socket 506. Interconnects are disposed between the semiconductor die 402 and the substrate 404, and between the substrate 404 and the socket 506. The semiconductor die 402, the substrate 404, and the socket 506 may form a semiconductor device mounted on a circuit board 150 (e.g., a system PCB). The semiconductor device may be secured to the circuit board through a connection structure 508 (e.g., a load plate) that may engage at an edge region of the substrate. The circuit board 150 is connected to an enclosure 140 of the electronic device. A fan may be positioned near the heat sink 180 to blow air through or over the heat sink 180 .

[0250] For example, the vapor chest may be a heat distribution structure 320 of a cooling structure as described in relation to Figures 5a and / or 5b.

[0251] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0252] 5e is a schematic cross-sectional view of a cooling structure for an electronic device. The cooling structure may be implemented similarly to the cooling structure described in connection with FIG. 5a. The heat distribution structure 320 comprises a heat sink 180 attached to an upper side of the heat distribution structure 320. The lower side of the heat distribution structure 320 is thermally coupled to the heat source 110. In addition, a fan 170 is attached to the top of the heat sink 180. The heat source 110, as well as the heat distribution structure 320, the heat sink 180 and the fan 170 are carried by the circuit board 150.

[0253] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0254] FIG. 5f is a schematic cross-sectional view of a cooling structure for an electronic device. FIG. 5f may show an enlarged cross-section of a portion of the cooling structure of FIG. 5e. A heat sink 180 is thermally coupled to an upper side of the heat distribution structure 320 by a TIM layer. A cavity wall (e.g., a boundary) is disposed on an underside of the heat distribution structure 320, laterally surrounding a semiconductor die 402 that is thermally coupled to the heat distribution structure 320 by the TIM. The die 402 is attached to a substrate 404, which is attached to a socket 506. The socket 506 is attached to a circuit board 150.

[0255] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0256] Fig. 5g is a schematic cross-sectional view of a cooling structure for an electronic device. The cooling structure may be implemented similarly to the cooling structure described in relation to Fig. 5a and / or Fig. 5b. In comparison with Fig. 5b, the heat distribution structure 320 is realized by a number of heat pipes embedded in a metal plate. The heat pipes are arranged parallel to each other. The heat pipes extend from a first edge region of the heat distribution structure 320 on one side to a second end region of the heat distribution structure 320 on the opposite side.

[0257] 5g may show an example of a thermal bus with heat pipes. The upper side of the heat distribution structure 320 may provide a thermal bus base for mounting a heat sink.

[0258] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0259] Fig. 5h is a schematic bottom view of the cooling structure of an electronic device, which may represent the bottom view of the cooling structure described in relation to Fig. 5g.

[0260] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0261] Fig. 5i shows a schematic cross-sectional view of a cooling structure for an electronic device. The cooling structure may be implemented similarly to the cooling structure described in relation to Fig. 5a and / or Fig. 5b. In comparison with Fig. 5b, the heat distribution structure 320 is implemented by a metal plate (e.g., a cold plate).

[0262] 5i can show an example of a thermal bus concept with a metal plate. The top surface of the thermal distribution structure 320 can provide a thermal bus base for mounting a heat sink.

[0263] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0264] Fig. 5j shows a schematic bottom view of a cooling structure for an electronic device, which may represent the bottom view of the cooling structure described in relation to Fig. 5i.

[0265] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0266] 5k shows a schematic cross-sectional view of an electronic device. The electronic device 580 comprises a semiconductor die 402 and a cooling structure comprising a heat distribution structure 320 configured to spread heat caused by the semiconductor die 402 from a central region to an edge region of the heat distribution structure 320. The heat distribution structure 320 is thermally coupled to the semiconductor die 402 at a central region on a first side of the heat distribution structure 320. Additionally, the bare semiconductor die 402 is directly thermally coupled to the heat distribution structure 320 through a thermal interface material.

[0267] By directly bonding the bare die to the heat distribution structure (e.g., the vapor chest), the stack height can be made very low and / or heat transfer can be improved, thus enabling very thin devices to be used.

[0268] For example, the heat distribution structure 320 may be a vapor chamber, and the distance between the backside of the semiconductor die 402 and the vapor chamber cavity may be at most 1 mm (or at most 0.8 mm or at most 0.6 mm, e.g., 0.1 mm TIM and 0.5 mm VC chamber walls).

[0269] For example, the semiconductor die 402 may be or include a central processing unit, a graphics processing unit, or another microprocessor. The semiconductor die 402 may include a thermal design power and / or maximum power consumption of at least 60 W (or at least 100 W, at least 120 W, or at least 150 W). For example, if the heat distribution structure 320 is simply a metal plate, the semiconductor die 402 may include a thermal design power and / or maximum power consumption of at least 60 W and / or up to 100 W. If the heat distribution structure 320 includes multiple heat pipes, the semiconductor die 402 may include a thermal design power and / or maximum power consumption of at least 90 W and / or up to 140 W. If the heat distribution structure 320 includes a vapor chamber, the semiconductor die 402 may include a thermal design power and / or maximum power consumption of at least 120 W (or at least 140 W or at least 160 W).

[0270] The thermal interface material may be thermal grease or liquid metal. The thermal interface material may compensate for non-uniformities in the backside of the semiconductor die 402 and / or the surface of the heat distribution structure 320 to enable good thermal contact across the entire backside of the semiconductor die 402. The thermal interface material may include a maximum thickness of up to 0.25 mm (or up to 0.2 mm or up to 0.15 mm).

[0271] The cooling structure may be implemented as described in connection with FIG. 5a and / or may comprise a heat distribution structure 320 as described in one of the examples described above or below.

[0272] For example, the heat distribution structure 320 may include a boundary and a seal ring attached to the boundary. The seal ring can seal a gap between the boundary and a packaging substrate of the semiconductor die 402.

[0273] Additionally, the electronic device 580 may include a circuit board. The semiconductor die 402 may be disposed on the circuit board.

[0274] Additionally, the electronic device 580 may include a fan configured to blow air towards a heat sink mounted on the thermal distribution structure 320 .

[0275] The electronic device 100 may be a tablet, a laptop, a notebook, a mobile phone, a computer (eg, a personal computer or a server), or other electronic device.

[0276] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0277] 51 is a flow chart of a method of forming a cooling structure. The method 590 includes providing 592 a heat distribution structure configured to spread heat generated by a heat source from a central region to an edge region of the heat distribution structure. The heat distribution structure is configured to be thermally coupled to the heat source at the central region on a first side of the heat distribution structure. Additionally, the method 590 includes forming or attaching 594 a boundary on the heat distribution structure. The boundary surrounds the central region of the heat distribution structure on the first side of the heat distribution structure.

[0278] Additionally, the method 590 may include attaching a heat sink to a second side of the heat distribution structure.

[0279] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0280] Some examples relate to split stack thermal solutions with a thermal bus for a bare die CPU. For example, a thermal bus (e.g., VC, an array of heat pipes, or a metal plate) may be used to improve the contact between the thermal solution and the bare die, which may result in higher performance of the silicon. The thermal bus may provide a bridge between the die and the heat sink. A seal ring may be incorporated to prevent leakage of the TIM (e.g., as shown in Figure 5c). The thermal bus may provide flexibility to mount different heat sink thermal solutions depending on the silicon performance goals and cost. The performance of the thermal solution may improve with better contact, resulting in higher performance.

[0281] For example, a bare die can be implemented with a high performance thermal solution attached directly. A thermal bus may act like an adapter between the bare die and the heat sink. The thermal bus can provide adequate contact with the die as well as better heat spreading from the die to the heat sink than an IHS. The thermal bus can be made of different materials such as aluminum, copper and can embed heat pipes or vapor chambers (for example, as shown in Figure 5c). A sealing ring can prevent TIM leakage. Heat sinks of various types and sizes with material selection can be attached to the thermal bus. This flexibility can provide options for different performance levels, system stack-ups, and costs. Simulations can show that an implementation with a VC and a flat heat sink (flat backside) for thermal bus use but without a pedestal can provide improved cooling compared to a vapor chamber heat sink with a pedestal. If liquid metal is used as the TIM instead of thermal grease, the cooling performance can be further improved. The use of a thermal bus can improve the temperature differential between the junction temperature and the ambient temperature by more than 10% when the CPU TIM is thermal grease and by more than 15% when the CPU TIM is liquid metal.

[0282] Other desktop CPUs with IHS (Integrated Heat Spreader) may run into bottlenecks using heat pipes and vapor chambers to achieve high performance. Some solutions may require pedestals to make proper contact with the silicon die and avoid interference with adjacent components around the silicon and loading mechanism. Pedestals may reduce the efficiency of heat spreading from the die to the heat sink base. Such solutions may not effectively remove heat from the silicon die, which may result in reduced performance. Also, the increased cost and reduced flexibility of component placement around the silicon due to additional components such as pedestals may be undesirable.

[0283] Some examples relate to cooling systems that include a heat distribution structure thermally coupled to a heat source within an enclosure of an electronic device, the heat distribution structure extending from an interior of the enclosure to an exterior of the enclosure.

[0284] The heat distribution structure may be a layered heat spreader or vapor chamber, heat pipe or metal plate. The layered heat spreader may be or include a graphite sheet, a graphene sheet, or a metal foil. The enclosure may have an opening, and the heat distribution structure extends from the interior through the opening to the exterior.

[0285] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0286] 6a shows a schematic cross-sectional view of an electronic device 100. The electronic device 100 comprises an enclosure 140 and a layered heat spreader 610 thermally coupled to a heat source 110 within the enclosure 140. The layered heat spreader 610 extends from an interior of the enclosure 140 to an exterior of the enclosure 140.

[0287] By using a layered heat transfer structure extending from the inside to the outside of the device, heat can be transferred from the inside to the outside efficiently, and thus the cooling capacity of the electronic device can be significantly increased.

[0288] The layered heat spreader 610 may be a thin layer or layers of a material or compound with high thermal conductivity. The layered heat spreader 610 may include a lateral extent that is significantly greater than the thickness. For example, the length and / or width may be at least 100 times (or at least 500 times or at least 1000 times) greater than the maximum or average thickness of the layered heat spreader 610. For example, the maximum or average thickness of the layered heat spreader 610 may be at most 1 mm (or at most 0.6 mm, or at most 0.2 mm). The layered heat spreader 610 may be flexible, bendable, and / or elastically deformable to a sufficient degree to be able to extend from the interior to the exterior of the device. The layered heat spreader 610 may have a thermal conductivity of at least 100 W / mK (or at least 500 W / mK or at least 1000 W / mK) in at least one direction along the layered heat spreader 610. The layered heat spreader 610 may have isotropic or anisotropic thermal conductivity depending on the materials used. For example, the layered heat spreader 610 may include one or more graphite sheets, or one or more metal foils (e.g., aluminum foil or copper foil).

[0289] Enclosure 140 (or chassis) may be the housing or part of the housing of electronic device 100. For example, enclosure 140 may include a back cover, a side cover, and / or a front cover of the electronic device. For example, enclosure 140 may include a back cover with side cover parts of a tablet or cell phone, and the front side may be covered with a touch screen. The touch screen may be identified as part of enclosure 140 or may be connected to enclosure 140 and form part of the housing of electronic device 100 at the front side of electronic device 100.

[0290] The enclosure 140 may include an opening (e.g., a slot or slit) and the layered heat spreader 610 may extend from the inside to the outside through the opening. The opening may be implemented in a portion of the enclosure 140 located on the back of the electronic device 100 or on a side of the electronic device 100, or between a back portion (e.g., a back cover) and a side portion of the enclosure 140. The opening may include a length of at least 290 mm (or at least 5 cm, at least 20 cm, at least 10 cm, or at least 15 cm) and / or a width of up to 2 mm (or up to 1.5 mm, or up to 1 mm).

[0291] Depending on the mounting, integration or connection of the layered heat spreader 610 externally, the layered heat spreader 610 may be repeatedly deformed in the opening and / or in the area outside the electronic device. To protect the layered heat spreader 610 from damage due to repeated deformation, one or more additional layers may be attached to the layered heat spreader 610, at least in the area of ​​the opening. For example, the layered heat spreader 610 may be covered by a protective layer in the area of ​​the opening. The protective layer may be a plastic or metal layer (e.g., an aluminum layer or a nickel-titanium-alloy layer) or may include plastic or metal. The protective layer may be attached to the layered heat spreader 610 by an adhesive. The protective layer may cover the layered heat spreader 610 from at least 5 mm before the opening to at least 5 mm after the opening, or may cover the layered heat spreader 610 only in the opening. Additionally or alternatively, a protective layer may cover layered heat spreader 610 in areas outside of electronic device 100 that are user accessible to protect layered heat spreader 610 from damage.

[0292] Furthermore, the protective layer may be covered by a cover layer in the area of ​​the opening. The cover layer may be a microfiber layer or may include a microfiber material. The cover layer may further protect the layered heat spreader 610. The cover layer may be implemented in addition to or instead of the protective layer. Additionally or alternatively, the cover layer may cover the protective layer or the layered heat spreader 610 in an area outside the electronic device 100 that is accessible to the user to protect the layered heat spreader 610 from damage and / or to protect the user from contacting the layered heat spreader 610 when the layered heat spreader 610 becomes hot.

[0293] The layered heat spreader 610 may be thermally coupled to the heat source 110 directly (e.g., via a thermally conductive adhesive or TIM) or indirectly with a heat distribution structure therebetween. The heat distribution structure may be thermally coupled to the heat source 110 on a first side, and the layered heat spreader 610 may be thermally coupled to a second side of the heat distribution structure. The heat distribution structure may include or be at least one of a metal plate, a heat pipe, or a vapor chamber. The heat distribution structure may include a thickness of up to 4 mm (or up to 3 mm, up to 2.5 mm, or up to 2 mm). For example, the heat distribution structure may include maximum dimensions in terms of length and width of at least 60 mm (or at least 100 mm, or at least 150 mm).

[0294] An outer portion of the layered heat spreader 610 that extends outside the enclosure 140 may be attached to an outer surface of the enclosure. The outer portion of the layered heat spreader 610 may be covered by a protective layer and / or a cover layer and / or a soft cover.

[0295] For example, electronic device 100 may further include a kickstand connected to enclosure 140. An outer portion of layered heat spreader 610 may extend between enclosure 140 and the kickstand. For example, the outer portion of layered heat spreader 610 may be attached to enclosure 140 behind the kickstand or may be attached to the kickstand (e.g., on the back of the kickstand). In this manner, layered heat spreader 610 may be protected from damage in the space between enclosure 140 and the kickstand. Additionally, a user is less likely to grab in the space between enclosure 140 and the kickstand.

[0296] Additionally or alternatively, a portion of the layered heat spreader 610 disposed outside the enclosure 140 can extend along the back side of the keyboard. For example, a portion of the layered heat spreader 610 may be sandwiched between the keyboard and a protective layer and / or a cover layer and / or a soft cover.

[0297] The layered heat spreader 610 may extend within the electronic device 100 from an opening in the enclosure to a vicinity of one or more heat sources of the electronic device 100 that are thermally coupled to the layered heat spreader 610. For example, a portion of the layered heat spreader 610 disposed within the enclosure extends toward the heat source 110 between the enclosure 140 and the battery of the electronic device 100.

[0298] The heat source 110 may comprise or may be a semiconductor die configured to generate heat (e.g., waste heat) during operation. This waste heat may be generated automatically during operation of the semiconductor die. An integrated circuit may be implemented on the semiconductor die. The semiconductor die may be a bare die having an uncovered backside, or a packaged semiconductor die having a backside covered by a packaging material (e.g., a mold or other material).

[0299] Heat source 110 may be or may include a processor (e.g., a CPU, microcontroller, digital signal processor, or graphics processing unit GPU), a transmitter, a receiver, a transceiver, a power supply, and / or a voltage converter, or other integrated circuit.

[0300] The electronic device 100 may be a tablet, a mobile phone, a removable electronic device, or other electronic device.

[0301] The integration of layered heat spreader 610 may enable significant improvements in the cooling capabilities of low power devices having passive cooling systems. For example, electronic device 100 may include a thermal design power of at most 25 W (or at most 20 W, at most 15 W, or at most 30 W) and / or at least 5 W (or at least 10 W or at least 15 W). Electronic device 100 may also be implemented without a fan (e.g., as a passively cooled device).

[0302] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0303] FIG. 6b shows a schematic cross-sectional view of an electronic device. The electronic device can be implemented similarly to the electronic device described in connection with FIG. 6a. The vapor chamber 120 includes or is thermally coupled to a pedestal on a first side of the vapor chamber 120. The pedestal may be a metal part integrally formed in the chamber wall on the first side of the vapor chamber 120 or may be a metal plate attached to the chamber wall of the vapor chamber 120. The pedestal is thermally coupled to the backside of the semiconductor package 602 (or semiconductor die) via a TIM. The semiconductor package is attached to a substrate 404, which is attached to a circuit board 150 (e.g., PCB). The circuit board 150 is connected to an enclosure 140 (e.g., back cover) of the electronic device. A first portion 612 of the layered heat spreader is attached to a second side of the vapor chamber 120 and extends from the vapor chamber 120 to an opening 604 in the enclosure 140. The second portion 614 of the layered heat spreader is attached to an inner surface of the enclosure 140 and extends from between the enclosure 140 and the circuit board 150 to the opening 604. The third portion 616 of the layered heat spreader is attached to an underside of the kickstand 640 and extends from the kickstand 640 to the opening 604. In this manner, heat may be transferred from the first portion 612 of the layered heat spreader to the second and third portions 614 and 616 of the layered heat spreader, or from the first and second portions 612 and 614 of the layered heat spreader to the third portion 616 of the layered heat spreader (e.g., depending on the temperature distribution along the layered heat spreader).

[0304] Additionally, a kickstand hinge 642 may be configured to allow the kickstand to be opened and closed. The kickstand hinge 642 is located near the opening 604. Additionally, a battery is disposed within the electronic device.

[0305] The enclosure 140 comprises a back cover and integrally formed side walls of a housing for an electronic device. The front of the housing is formed by a cover glass and a display 620 (e.g., a touch screen).

[0306] Layered heat spreader 610 may be implemented with graphite sheets. For example, a first graphite sheet may extend from between enclosure 140 and circuit board 150 through opening 604 to kickstand 640. A second graphite sheet may extend from vapor chamber 120 to the first graphite sheet and is thermally coupled (e.g., by a thermally conductive adhesive) to the first graphite sheet.

[0307] For example, a synthetic graphite sheet spread may extend from the top of the thermal solution to the kickstand 640 and may be secured by fabric from the external contacts.

[0308] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0309] FIG. 6c is a schematic cross-sectional view of an electronic device. The electronic device can be implemented similarly to the electronic device described in connection with FIG. 6a. The vapor chamber 120 includes or is thermally coupled to a pedestal on a first side of the vapor chamber 120. The pedestal may be a metal part integrally formed in the chamber wall on the first side of the vapor chamber 120 or may be a metal plate attached to the chamber wall of the vapor chamber 120. The pedestal is thermally coupled to the backside of the semiconductor package 602 (or semiconductor die) via a TIM. The semiconductor package is attached to a substrate 404, which is attached to a circuit board 150 (e.g., PCB). The circuit board 150 is connected to an enclosure 140 (e.g., back cover) of the electronic device. A first portion 612 of the layered heat spreader is attached to a second side of the vapor chamber 120 and extends from the vapor chamber 120 to an opening 604 in the enclosure 140. A second portion 614 of the layered heat spreader 610 is attached to an outer cover 670 (e.g., a soft cover) of the electronic device. The second portion of the layered heat spreader 610 extends along the cover 670 from the opening 604 to a portion located between the keyboard 650 and the cover 670.

[0310] The enclosure 140 comprises a back cover and an integrally formed side wall of a housing for an electronic device. The front of the housing is formed by a cover glass and a display 620 (e.g., a touch screen). An opening is located at the edge between the back cover and the side wall.

[0311] For example, FIG. 6c may show a 12.3 inch tablet device. The graphite spreads from the top of the thermal solution to an added attachment (e.g., a keyboard). For example, a synthetic graphite sheet spreads from the top of the thermal solution to the keyboard on a soft cover. For example, the soft cover is attached to the tablet and cannot be removed.

[0312] Compared to a tablet with the same thermal solution except for graphite cross spreading, the cooling capacity for the SOC can be improved by 15% or more. For example, a SOC with a TDP of 10.5W can be used instead of a SOC with a TDP of 9W.

[0313] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0314] Fig. 6d shows a schematic cross-sectional view of an electronic device. The cover can be implemented similarly to the cover described in relation to Fig. 6i. The cover comprises a laminar carrier 692 (e.g., a soft cover) attached to a first side of the laminar heat spreader 610. A keyboard 650 is attached to a first portion of the laminar heat spreader 610 on a second side of the laminar heat spreader 610. An electronic device (e.g., a tablet) can be attached to a second portion of the laminar heat spreader 610 on a second side of the laminar heat spreader 610.

[0315] In comparison to the implementation shown in FIG. 6c, the layered heat spreader 610 is part of the cover and does not extend into the interior of the electronic device, so that the electronic device can be removed from the cover.

[0316] For example, FIG. 6d may show a 12.3 inch tablet device. The graphite is spread on a soft cover (e.g., the soft cover is removable). For example, a synthetic graphite sheet spread may be placed on the soft cover along with a keyboard. The tablet may be easily removed from the soft cover.

[0317] Compared to a tablet with the same thermal solution but without the soft cover with graphite cross spreading, the cooling capacity for the SOC can be improved by 10% or more. For example, a SOC with a TDP of 10W can be used instead of a SOC with a TDP of 9W.

[0318] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0319] 6e is a schematic diagram of an electronic device that may be implemented similarly to the electronic device described in connection with FIG 6b. A layered heat spreader 610 extends from the vapor chamber 120 to the underside of the kickstand 640.

[0320] For example, Figure 6e can show a 12.3 inch tablet device. The graphite extends from the top of the thermal solution to the kickstand.

[0321] Compared to a tablet with the same thermal solution but with the lateral spread of graphite, the cooling capacity for the SOC can be improved by over 20%. For example, instead of a SOC with a 9W TDP, a SOC with an 11W TDP can be used.

[0322] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0323] Fig. 6f is a schematic diagram of an electronic device that can be implemented similarly to the electronic device described in relation to Fig. 6e. Additionally, the layered heat spreader 610 is covered by a protective and / or cover layer 644 on the back side of the kickstand 640.

[0324] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0325] FIG. 6g shows a schematic diagram of an electronic device. The electronic device can be implemented similarly to the electronic device described in relation to FIG. 6e. FIG. 6g shows a detailed cross-section of a portion of the enclosure including an opening 604. The enclosure includes a recess for the kickstand such that the back of the electronic device is substantially flat when the kickstand is closed. The opening 604 is located at the edge of the recess between a portion of the enclosure that forms the bottom of the recess and a portion of the enclosure that forms a portion of the back of the electronic device where a portion of the back of the electronic device is flush with the kickstand 640 when the kickstand 640 is closed.

[0326] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0327] Figure 6h is a schematic cross-sectional view of a portion of a layered heat spreader 610. The layered heat spreader 610 may be integrated into an electronic device such as described in connection with Figure 6a or into a cover such as described in connection with Figure 6i.

[0328] The layered heat spreader 610 may be a graphite sheet, and a portion of the layered heat spreader 610 (e.g., a functional zone (working zone)) or the entire layered heat spreader 610 may be covered by a protective layer 694 and a cover layer 696. The cover layer 696 may be a microfiber layer (e.g., Alcantra).

[0329] The implementation shown in FIG. 6h can be used to avoid damage due to repeated deformation. For example, the spreading mechanism can include a graphite sheet with a thickness of about 0.1 mm with a conductivity >700 W / mK, which is joined in the functional zone with a protective layer of a maximum thickness of 0.15 mm, which can be either Nitinol (e.g., nickel-titanium alloy) or a thin plastic layer (e.g., polypropylene). This is used for example for the hinge, and this area is covered with a microfiber material (e.g., Alcantra) that can provide durability and stain resistance. The protective layer can protect the spreader from physical damage and also ensure that hot surfaces do not come into contact with the user.

[0330] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0331] 6i shows a schematic cross-sectional view of a cover for an electronic device. Cover 690 comprises a layered heat spreader 610 having a thermal conductivity of at least 100 W / mK in at least one direction. Cover 690 further comprises a layered carrier 692. Layered heat spreader 610 is attached to layered carrier 692.

[0332] By implementing a layered heat spreader in a cover for an electronic device, cooling of the electronic device can be improved, thus reducing current consumption and / or increasing the maximum time available to operate in high performance mode.

[0333] The layered heat spreader 610 may be a thin layer or layers of a material or compound with high thermal conductivity. The layered heat spreader 610 may include a lateral extent that is significantly greater than the thickness. For example, the length and / or width may be at least 100 times (or at least 500 times or at least 1000 times) greater than the maximum or average thickness of the layered heat spreader 610. For example, the maximum or average thickness of the layered heat spreader 610 may be at most 1 mm (or at most 0.6 mm, or at most 0.2 mm). The layered heat spreader 610 may be flexible, bendable, and / or elastically deformable to a sufficient extent to allow the cover 690 to be repeatedly opened and closed. The layered heat spreader 610 may have a thermal conductivity of at least 100 W / mK (or at least 500 W / mK or at least 1000 W / mK) in at least one direction along the layered heat spreader 610. For example, the layered heat spreader 610 may include one or more graphite sheets, one or more graphene sheets, or one or more metal foils (eg, aluminum foil or copper foil).

[0334] The layered carrier 692 may cover the entire surface on the first side of the layered heat spreader 610. The layered carrier 692 may include one or more layers. For example, the layered carrier 692 may include a protective layer and / or a cover layer. For example, the layered heat spreader 610 may be covered by a protective layer of the layered carrier 692. The protective layer may be a plastic (e.g., polypropylene) or a metal layer (e.g., an aluminum layer or a nickel-titanium-alloy layer), or may be a plastic or a metal (e.g., an aluminum or a nickel-titanium-alloy). The protective layer may be attached to the layered heat spreader 610 by an adhesive.

[0335] Additionally, the protective layer may be covered by a cover layer of the layered carrier 692. The cover layer may be a microfiber layer or may include a microfiber material. The cover layer may be implemented in addition to or instead of the protective layer.

[0336] The layered heat spreader 610 may be uncovered in the contact areas intended to contact the back surface of the electronic device 100. A second protective and / or cover layer may be attached to a second side of the layered heat spreader 610, opposite the layered carrier 692, in areas outside the contact areas. For example, the layered heat spreader 610 may be covered everywhere except in the contact areas.

[0337] The cover 690 may further include a keyboard connectable to the electronic device 100. For example, a portion of the layered heat spreader 610 may extend between the layered carrier 692 and the keyboard.

[0338] The cover 690 may be a hard cover or a soft cover. The cover 690 may removably house the electronic device 100. The electronic device 100 may be a tablet or a mobile phone.

[0339] The proposed soft cover can provide an opportunity for inductive charging space for the keyboard and can also be used for the smart cover.

[0340] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0341] FIG. 6j shows a schematic diagram of a cover for the electronic device. Cover 690 may be implemented similarly to the cover described in connection with FIG. 6i. Cover 690 is a soft cover that is removable from the electronic device. The layered heat spreader of cover 690 is a graphite sheet that may be completely covered on both sides by a cover layer or may be uncovered in the contact area that contacts the backside of electronic device 100.

[0342] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0343] Some examples relate to cross spreading thermal techniques to improve performance potentially by 20-30% in various handheld devices. From generation to generation, the total system power and power density of SoCs are increasing at significant rates. The challenge is to design thin and light systems that improve or maximize SoC performance. These challenges are multiplied for small form factor devices such as tablets, which are becoming smaller and smaller. For tablets, the display power and its temperature can play a major role in meeting ergonomic limitations.

[0344] According to one aspect, heat may be transferred from the top of the thermal solution (e.g. HP or VC) to the kickstand of the tablet or to additional accessories such as a keyboard KB or soft cover. In this way, the skin temperature, which is an important parameter, can be reduced. The performance of the tablet can be significantly improved if the heat diffusion can be extended from the top of the thermal solution to the kickstand or an extended additional cover or keyboard.

[0345] For example, a thermal solution can spread heat from the top of the thermal attachment to the other side. A thin layer of synthetic graphite can be applied to transfer heat from the thermal attachment to a kickstand or additional accessories, lowering the temperature of the display and back cover without impacting the weight. This can help significantly increase the thermal budget.

[0346] The proposed concept also allows for protection of the graphite sheet against damage due to repeated opening and closing of the kickstand. Furthermore, the proposed thermal solution may not compromise the space available for PCB, battery and / or other components.

[0347] The proposed concept may enable improved performance. Furthermore, cooler skin temperatures may be achievable for thin form factor FF devices, and therefore ergonomic comfort requirements related to skin temperature may be improved.

[0348] During the design of thermal solutions for thin form factor devices, it can be difficult to meet ergonomic limitations of skin temperature. More emphasis may be placed on spreading heat under the display as well as on the back cover. The back cover can have a larger surface area with less resistance to heat spreading compared to the display. The proposed cooling concept can cross spread heat from the top of the thermal attachment (e.g., VC) to cooler areas, bringing the skin temperature within ergonomic limits and improving the performance of the system.

[0349] Tablets may often use passive (cooling) systems based on the principles of natural conduction and convection, where weight, stack and performance may be the primary driving factors for the customer.

[0350] Due to the thin form factor design, the air gap between the thermal solution and the display, and between the PCB and the back cover, can be significantly reduced, which can cause problems in skin cooling. By adding a layer of graphite on top of the thermal solution, the temperature of the top of the thermal solution can be reduced (e.g., in the case of a vapor chamber system, the temperature of the condenser section can be reduced), which can increase the ΔT and heat transfer. Furthermore, it can reduce the hot spot temperature of the display and improve performance.

[0351] Computer systems may utilize vapor chambers for thermal cooling of a processor or a chip package that includes a processor (e.g., a system-on-chip (SoC) that includes a central processing unit (CPU), a graphics processing unit (GPU), and / or another type of processor). Vapor chambers may utilize phase change phenomena within the chamber to spread heat and reduce junction temperatures. In thin mobile devices, current vapor chamber designs may result in higher than desired temperatures on the exterior surfaces of the device due to the relatively thin vertical stack dimensions. In some cases, throttling of the processor may be required to reduce such temperatures. However, this also reduces computational performance within the device.

[0352] In certain computing devices, such as mobile computing devices (e.g., laptops, cell phones, tablets), thin and light designs may be highly desirable. The sustained performance of these systems may be limited by the "skin" temperature limit (e.g., about 45-46C), while the "turbo" performance (e.g., heavy computation scenarios) may be limited by the junction temperature (e.g., about 100C) of the chip package (e.g., a system-on-chip (SoC) or other type of chip that includes a processor unit such as a central processing unit (CPU) or a graphics processing unit (GPU)). Due to the thinner vertical stack height of these devices, the "skin" may heat up beyond its limit (e.g., thermal design power (TDP)) before reaching the junction temperature (Tj) limit for sustained workloads. As used herein, "skin" may refer to the outer layer of a vertical device stack, e.g., the top glass layer or back cover layer of a mobile device (e.g., cell phone or tablet). Additionally, sustained performance may refer to performance during long-term expected steady-state power consumption (e.g., PL1), and turbo performance may refer to performance during short-term maximum power consumption (e.g., PL2).

[0353] Additionally, in thinner devices, skin hot spots may be less dependent on the type of heat spreader (e.g., copper vs. heat pipe vs. vapor chamber) on the chip package because in thinner devices, heat can travel toward the skin regardless of spread. Skin heating can be avoided by providing a thermal air gap between the thermal solution on top of the chip package and the skin (e.g., glass / back cover). However, a thicker air gap increases the stack (i.e., overall height) of the system and can increase Tj, which reduces the turbo performance capability of the package.

[0354] Vapor chambers can be used as an effective solution in passive device junction temperature cooling. Vapor chambers can utilize the phase change phenomenon in the chamber to spread the heat and reduce the junction temperature (Tj). However, in some designs, the skin temperature (Tskin) can be nearly the same as other solutions such as copper spreaders or heat pipes.

[0355] Thus, examples of the present disclosure include a two-tier vapor chamber (2T-VC) structure that may provide one or more benefits over current cooling solutions, including the reduction of skin hot spots. A two-tier vapor chamber design may include two layers or tiers: (1) a thin vacuum layer (e.g., about 0.1-0.2 mm thick) in the upper region of the vapor chamber and (2) a second layer below the vacuum layer where liquid charging is utilized. The two regions may be separated by a thin copper layer. In some examples, the upper layer may be filled with an insulating material that is less thermally conductive than air (e.g., aerogel) rather than a vacuum. The upper chamber of the 2T-VC structure may help reduce the skin temperature and increase the sustainment capability (PL1 limit) of the system (in some cases by about 15-20%). In examples using aerogel insulating material in the upper chamber, the PL1 performance may be increased by 13% compared to copper plate solutions and 11% compared to other vapor chamber structures. Furthermore, for short bursts (e.g., about 5-10 seconds), the turbo performance of products with 2T-VC structure can be increased by about 15-20% compared with mainstream copper spreader solutions, and can remain almost the same as other steam chamber structures.

[0356] Some examples relate to a cooling system that includes a first portion coupled to a heat source to distribute heat generated by the heat source and a second portion coupled to the first portion to prevent heat from being distributed outside the second portion.

[0357] For example, the first portion may be a sealed first cavity and the second portion of the steam chest may be a sealed second cavity of the steam chest.

[0358] Further details, optional features, and aspects are set forth in connection with one or more of the examples described above or below.

[0359] FIG. 7a shows a simplified diagram of an example stack 7100 for a mobile device. The example stack 7100 includes an upper layer 7102, a thermal solution 7104, a chip package 7106, a printed circuit board (PCB) 7108, and a lower layer 7110. The stack 7100 may include additional layers than those shown. The upper layer 7102 and the lower layer 7110 may be outer layers of the device. The upper layer 7102 may be formed of or include glass or other suitable material and provide an outer layer interface with a user, while the lower layer may be formed of or include metal, plastic, or other suitable material for packaging a mobile device. The PCB 7108 may be formed of an electrically insulating material and may include one or more traces or other electrical components. The PCB 7108 may house one or more chip packages (e.g., 7106) that include a processor, memory, or other computer components. In the illustrated example, the chip package 7106 includes one or more processors (e.g., a CPU or GPU). In some cases, the chip package 7106 is a system-on-chip (SoC).

[0360] The thermal solution 7104 removes heat generated by the chip package 7106 during operation. In some systems, the thermal solution 7104 may include a single level vapor chamber, heat pipe, or heat sink. However, in certain examples of the present disclosure, the thermal solution 7104 includes a dual level vapor chamber design as described herein. As illustrated, the thermal solution 7104 removes heat from the chip package 7106, but some of the heat may dissipate from the thermal solution 7104 into the air gap between the thermal solution 7104 and the top layer 7102, increasing the temperature of the top layer 7102. The temperature within the top layer 7102 may be referred to herein as the skin temperature (Tskin), and the temperature at the junction between the chip package 7106 and the thermal solution 7104 may be referred to as the junction temperature (Tj).

[0361] In some systems (e.g., thin / light form factor devices like laptops or tablets, or high performance computer systems like gaming systems), the sustained power capability may be limited by the skin temperature. As an example, the skin temperature limit for these systems may be about 45-48C, and the junction temperature limit may be about 100C. A common solution to reduce the skin temperature is to provide an air gap between the thermal solution 7104 and the top layer 7102 (because air has a low conductivity of about 0.026 W / mK). The total air gap in the stack is made up of two components: one is required to maintain the nominal air gap due to the mechanical tolerances of the internal components, and the other is the thermal requirement to meet the skin temperature limit (i.e., the air gap insulates the heat from the thermal solution 7104 and reduces the skin temperature). Although the air gap provides an insulating layer and may trap heat, a thicker air gap may undesirably increase the stack thickness, increasing the junction temperature and reducing the turbo performance capability of the chip package. In some cases, the PL1 performance limit of a device may be due to Tskin and may be less dependent on the type of thermal solution, while the PL2 limit may be due to junction temperature and may depend primarily on the effectiveness of the thermal solution used.

[0362] FIG. 7b illustrates an example of a two-tier steam chamber device 7200. In particular, FIG. 7b illustrates a cross-sectional view of the device. The exemplary device 7200 includes two tiers 7210, 7220. The first tier 7210 includes a sealed cavity 7211 defined by walls 7212, 7213. In some examples, the walls 7212, 7213 may be metal (e.g., copper, titanium, aluminum, alloys, or other thermally conductive metals). The first tier 7210 also includes a support structure 7214 that is in contact with and perpendicular to the walls 7212, 7213 and may provide structural support for the cavity 7211. The support structure 7214 may be made of metal, plastic, graphite, or any other suitable material for providing structural support to the cavity 7211. Additionally, the support structure 7214 may be shaped or positioned in another manner not illustrated in FIG. 7b.

[0363] Cavity 7211 may be evacuated such that its internal pressure is less than ambient pressure. For example, in some examples, cavity 7211 is evacuated to a vacuum pressure or near vacuum pressure, such as a pressure less than 0.1 Torr (e.g., 0.05-0.1 Torr). In other examples, cavity 7211 is filled with a thermally insulating material, such as aerogel, that has a lower thermal conductivity than air. The vacuum or thermally insulating material in cavity 7211 may provide thermal insulation from other layers in the device stack (e.g., top layer 7102 in FIG. 7a), which may reduce skin temperatures and provide one or more benefits as described above or elsewhere herein.

[0364] The second tier 7220 of the device 7200 includes a sealed cavity 7221 defined by walls 7213, 7222. In the illustrated example, the wall 7222 is flat so that it may be placed in close proximity to (or coupled via a thermal interface material (TIM)) the chip package to cool it. The walls 7212, 7213 may be flat in some areas, as shown in FIG. 7b, or may have another shape. In certain examples, the components within the cavity 7221 may function as a vapor chamber, whereby a liquid within the cavity 7221 is heated by the chip package through the wall 7222, evaporates into vapor, and then condenses as heat is dissipated from the vapor to the wall 7213.

[0365] In the illustrated example, the interior surface of cavity 7221 (i.e., the interior surfaces of walls 7213, 7222) includes a wick material 7224. Wick material 7224 may include sintered metal (e.g., copper) or another type of material. Exemplary wick material 7224 includes two regions 7224a, 7224b. Region 7224a may be considered an evaporation / evaporator wick (e.g., may be the region of the wick where evaporation of liquid occurs), while region 7224b may be considered a condensation / condenser wick (e.g., may be the region of the wick where condensation (and flow as indicated by arrows in FIG. 7b) of liquid occurs). In some examples, regions 7224a, 7224b may both be sintered metal, but may have different structures or porosities.

[0366] For example, in some instances, region 7224a may include a coarse graded mesh (e.g., 40-70%, e.g., about 50-60% porosity), while region 7224b may include a fine graded mesh (e.g., 30-50%, e.g., about 40-45% porosity). The coarse graded mesh not only creates additional liquid-vapor interfaces for liquid evaporation, but also disrupts the temperature gradient in the liquid film, reducing the thermal resistance of the saturated wicking structure and increasing the evaporation rate across the interface. Thus, the total heat flux of the vapor chamber may be given by:

number

number

[0367] In the illustrated example, cavity 7221 also includes support structures 7228 that may provide structural support to cavity 7221. Support structures 7228 may be formed similarly to structures 7214 in cavity 7211, or may be formed in a different manner.

[0368] In the illustrated example, the cross-sectional areas of both cavities 7211, 7221 are rectangular. However, the cross-sectional areas of cavities 7211, 7221 may be shaped in another manner (e.g., as shown in FIG. 3A or FIG. 4A). Furthermore, in the illustrated example, the cross-sectional areas of cavities 7211, 7221 are substantially similar. However, the cross-sectional areas of cavities 7211, 7221 may be different (e.g., as shown in FIGS. 7c-7d).

[0369] 7c-7d show another example of a two-tier steam chamber device 7300. In particular, FIG. 7c shows a cross-sectional view of the device, and FIG. 7d shows a top view of the device. Similar to device 7200, the exemplary device 7300 includes two tiers 7310, 7320. The first tier 7310 includes a sealed cavity 7311 defined by walls 7312, 7313. In some examples, the walls 7312, 7313 may be metal (e.g., copper, titanium, aluminum, alloys, or other thermally conductive metals). The first tier 7310 also includes a support structure 7314 that is in contact with and perpendicular to the walls 7312, 7313 and may provide structural support for the cavity 7311. The support structure 7314 may be made of metal, plastic, graphite, or any other suitable material for providing structural support to the cavity 7311. Additionally, the support structures 7314 may be shaped or positioned in other ways not shown in FIG. 7c.

[0370] Cavity 7311 may be evacuated such that its internal pressure is less than ambient pressure. For example, in some examples, cavity 7311 is evacuated to a vacuum pressure or near vacuum pressure, such as a pressure less than 0.1 Torr (e.g., 0.05-0.1 Torr). In other examples, cavity 7311 is filled with a thermally insulating material, such as an aerogel, that has a lower thermal conductivity than air. The vacuum or thermally insulating material in cavity 7311 may provide thermal insulation from other layers in the device stack (e.g., top layer 7102 of FIG. 7a), which may reduce skin temperatures and provide one or more benefits as described above or elsewhere herein.

[0371] The second tier 7320 of the device 7300 includes a sealed cavity 7321 defined by walls 7313, 7322. In the illustrated example, wall 7322 is flat so that it may be placed in close proximity to (or coupled via a TIM) the chip package to cool the chip package. The walls 7312, 7313 may be flat in some areas, as shown in FIG. 7c, or may have another shape. In certain examples, the components within cavity 7321 may function as a vapor chamber, whereby liquid within cavity 7321 is heated by the chip package through wall 7322, evaporates into vapor, and then condenses as heat is dissipated from the vapor to wall 7313.

[0372] In the illustrated example, the interior surface of cavity 7321 (i.e., the interior surfaces of walls 7313, 7322) includes a wick material 7324. Wick material 7324 may include sintered metal (e.g., copper) or another type of material. Exemplary wick material 7324 includes two regions 7324a, 7324b. Region 7324a may be considered an evaporation / evaporator wick (e.g., may be the region of the wick where evaporation of liquid occurs), while region 7324b may be considered a condensation / condenser wick (e.g., may be the region of the wick where condensation (and flow as indicated by arrows in FIG. 7c) of liquid occurs). In some examples, regions 7324a, 7324b may both be sintered metal, but may have different structures or porosities. For example, in some instances, region 7324a may include a coarse graded mesh (e.g., about 50-60% porosity), while region 7324b may include a fine graded mesh (e.g., about 40-45% porosity).

[0373] In the illustrated example, the cross-sectional area of ​​the first cavity 7311 is trapezoidal and the cross-sectional area of ​​the second cavity 7321 is rectangular. However, the cross-sectional areas of the cavities 7311, 7321 may be shaped in other ways. Furthermore, in the illustrated example, the cross-sectional area of ​​the cavity 7311 is smaller than the cross-sectional area of ​​the cavity 7321.

[0374] 7e-7f show another example of a two-tier steam chamber device 7400. In particular, FIG. 7e shows a cross-sectional view of the device, and FIG. 7f shows a top view of the device. Similar to devices 7200 and 7300, the exemplary device 7400 includes two tiers 7410, 7420. The first tier 7410 includes a sealed cavity 7411 defined by walls 7412, 7413. In some examples, the walls 7412, 7413 may be metal (e.g., copper, titanium, aluminum, alloys, or other thermally conductive metals). The first tier 7410 also includes a support structure 7414 that is in contact with and perpendicular to the walls 7412, 7413 and may provide structural support for the cavity 7411. The support structure 7414 may be made of metal, plastic, graphite, composite material (e.g., carbon fiber), or any other suitable material for providing structural support to the cavity 7411. Additionally, the support structures 7414 may be shaped or positioned in other ways not shown in FIG. 7e.

[0375] Cavity 7411 may be evacuated such that its internal pressure is less than ambient pressure. For example, in some examples, cavity 7411 is evacuated to a vacuum pressure or near vacuum pressure, such as a pressure less than 0.1 Torr (e.g., 0.05-0.1 Torr). In other examples, cavity 7411 is filled with a thermally insulating material, such as an aerogel, that has a lower thermal conductivity than air. The vacuum or thermally insulating material in cavity 7411 may provide thermal insulation from other layers in the device stack (e.g., top layer 7102 of FIG. 7a), which may reduce skin temperatures and provide one or more benefits as described above or elsewhere herein.

[0376] The second tier 7420 of the device 7400 includes a sealed cavity 7421 defined by walls 7413, 7422. In the illustrated example, the wall 7422 is flat so that it may be placed in close proximity to (or coupled via a TIM) the chip package to cool the chip package. The walls 7412, 7413 may be flat in some areas, as shown in FIG. 7e, or may have another shape. In certain examples, the components within the cavity 7421 may function as a vapor chamber, whereby a liquid within the cavity 7421 is heated by the chip package through the wall 7422, evaporates into vapor, and then condenses as heat is dissipated from the vapor to the wall 7413.

[0377] In the illustrated example, the interior surface of cavity 7421 (i.e., the interior surfaces of walls 7413, 7422) includes a wick material 7424. The wick material 7424 may include a sintered metal (e.g., copper) or another type of material. The exemplary wick material 7424 includes two regions 7424a, 7424b. Region 7424a may be considered an evaporation / evaporator wick (e.g., may be the region of the wick where evaporation of the liquid occurs), while region 7424b may be considered a condensation / condenser wick (e.g., may be the region of the wick where condensation (and flow as indicated by the arrows in FIG. 7e) of the liquid occurs). In some examples, regions 7424a, 7424b may both be sintered metal, but may have different structures or porosities. For example, in some instances, region 7424a may include a coarse graded mesh (e.g., about 50-60% porosity), while region 7424b may include a fine graded mesh (e.g., about 40-45% porosity).

[0378] In the illustrated example, cavity 7421 also includes support structures 7428 that may provide structural support to cavity 7421. Support structures 7428 may be formed similarly to structures 7414 in cavity 7411, or may be formed in a different manner.

[0379] In the illustrated example, the cross-sectional areas of the cavities 7411, 7421 are rectangular. However, the cross-sectional areas of the cavities 7411, 7421 may be shaped in other ways. Furthermore, in the illustrated example, the cross-sectional area of ​​the cavity 7411 is smaller than the cross-sectional area of ​​the cavity 7421.

[0380] In some examples, the two-tier device may be used in a passive cooling configuration where no other heat exchanger is used for cooling. However, in other examples, the two-tier device may be used in an active cooling configuration where a heat exchanger (e.g., a fan) is used to aid in further cooling. For example, an open area across the vacuum chamber on the two-tier device may act to cool the vapor to a saturated liquid or sub-cooled vapor, while a heat exchanger (e.g., 7430) may be attached to the back of the vapor chamber used for active cooling as a condenser. For example, in the illustrated example, the heat exchanger 7430 is located proximate to the vapor chamber of tier 7420. In particular, the heat exchanger 7430 is located proximate to an outer portion of the exterior surface of the wall 7422. In some examples, the heat exchanger may be located in an area of ​​the outer surface of the wall 7422 that is outside of the area of ​​the wall 7422 to which the chip package may be bonded (e.g., may be vertically below the area of ​​the upper layer 7410). The heat exchanger 7430 may be located in other areas of the device 7400 in other examples.

[0381] 7g-7h show simplified diagrams of an example of an exemplary mobile device stack having an air gap between the cooling solution and the top layer. The stack may include additional layers than those shown (e.g., one or more of the layers described in the following examples). Referring to FIG. 7g, an exemplary mobile device stack 7500 includes a top layer 7502, a cooling device 7504, a chip package 7506, and a PCB 7508, all of which may be similar to the top layer 7102, the thermal solution 7104, the chip package 7106, and the PCB 7108, respectively, of FIG. 7a. In the example shown in FIG. 7g, the cooling device 7504 is either a copper plate or a single tier vapor chamber cooling device.

[0382] 7h, an exemplary mobile device stack 7510 includes a top layer 7512, a cooling device 7514, a chip package 7516, and a PCB 7518, all of which may be similar to top layer 7102, thermal solution 7104, chip package 7106, and PCB 7108, respectively, of FIG. 7a. In the example shown in FIG. 7h, the cooling device 7514 is a two-tier steam chest device, which may be formed similarly to the exemplary devices described above with respect to FIGS. 7b, 7c-7d, and 7e-7f, or elsewhere herein.

[0383] In the examples shown in Figures 7g-7h, the space between the chip package and the top layer may be the same. However, the total thickness of the cooling device may be different. For example, in one example, air gap 7503 may have a thickness of about 0.8 mm and cooling device 7504 may have a thickness of about 0.5 mm, while air gap 7513 may have a thickness of about 0.5 mm and cooling device 7514 may have a thickness of about 0.8 mm (A+B in Figure 7h). The thickness of each layer of the two-tier cooling device (i.e., thicknesses A and B in Figure 7h) may be the same or different. For example, in the above example, each layer of the two-tier cooling device may be about 0.4 mm. In some examples, the two-tier cooling device may be formed such that the bottom layer has a total thickness of 0.4 mm (i.e., thickness A in Figure 7h) and the top layer has a top metal wall thickness of 0.2 mm and a cavity thickness of 0.2 mm. Thus, in some instances, the increase in thickness of the dual tier cooling device may be compensated for by a decrease in the thickness of the air gap, so that the overall stack height may remain the same as with conventional cooling techniques.

[0384] Simulation and Testing In the following model, the vacuum is modeled as a low conductivity object for radiation. The conductivity value depends on the exhaust pressure maintained in the chamber before the liquid charging phase. In the modeling used herein, the conductivity value is taken to be 0.005 W / mK to 0.001 W / mK based on an exhaust range of 0.05 to 0.1 Torr air pressure, while the emissivity is taken to be 0.9 to capture radiation in the vacuum. FIG. 7i is a chart 7600 showing an example of the relationship between thermal conductivity of air and pressure. In some examples, the exhaust pressure for the upper level cavity may be selected in the example exhaust pressure range 7602 shown in FIG. 7i.

[0385] The following exemplary device stack is used in the models described below. The exemplary stack layers are listed in Tables 1-2 in vertical order, with the first item listed being the top layer of the stack and the last item listed being the bottom layer of the stack. As shown in Tables 1-2, the total stack thickness is the same in each case, but the thicknesses of the top air gap and cooling device are different.

[0386] [Table 2] [Table 3]

[0387] The simulation results shown in Table 3 are based on PL1=7W (TDP) and PL2=10W (1CT) over 5 seconds. Thermal simulations were performed for three different thermal solutions: (A) 0.5mm copper plate with 0.8mm air gap, (B) 0.5mm single-tier vapor chamber (VC) device with 0.8mm air gap, (C) 0.8mm double-tier VC (2T-VC) with 0.5mm air gap, and (D) 0.8mm 2T-VC with 0.5mm air gap, but with a 15% reduction in the area of ​​the top-tier vacuum chamber from (C). [Table 4]

[0388] As shown in Table 3, the PL1 capability of the copper plate is slightly lower than that of the single-layer VC of the same size and thickness because the system is limited by the skin temperature. However, the Tj is reduced by about 18C for the single-layer VC, spreading the hot spots on its surface and reducing the top cover temperature of the VC by about 0.4C. In the case of the first 2T-VC (C), the skin temperature is reduced by about 3C due to the resistance caused by the vacuum layer in the heat transfer path from the 2T-VC to the skin, which helps to increase the PL1 limit by ~15% compared to the copper plate and the single-layer VC. Turning to the second 2T-VC (D), the increase in Tj can be mitigated by system optimization, for example, by providing thicker graphite below the PCB and / or using a vacuum chamber only above the core area (e.g., reducing the vacuum size by 15%).

[0389] Figures 7j-7k show examples of hot spots for single and dual tier cooling devices, respectively. As shown in Figures 7j-7k, the hot spot associated with the chip package (relative center of the chart) is reduced, so the main hot spot location is shifted to the lower right side of the chart (indicated by the dotted line). Here, heat is dissipated from the LED panel instead of the chip package. In the shown example, the PL1 capability is increased by approximately 20-25%.

[0390] Figure 71 is a chart 7800 showing an example of the performance difference for a copper heat plate device ("Cu" in the figure), a single tier steam chamber device ("VC" in the figure), and a two tier steam chamber cooling device ("2T-VC" in the figure). As shown, the 5 second PL2 capacity is nearly the same for the single tier VC and 2T-VC configurations, and increased by about 23% compared to the copper plate configuration (e.g., due to better capacitance of phase change in the steam chamber).

[0391] FIG. 7m is a chart 7900 showing an example of the performance difference between a vacuum and aerogel based dual level steam chamber device. Table 4 also shows such a performance difference based on aerogel properties of k=0.017 W / mK and e=0.9 (GORE data). [Table 5]

[0392] In some examples, the aerogel conductivity can be in the range of 0.016-0.018 W / mK, so the thermal resistance can be smaller for the aerogel-based 2T-VC compared to the vacuum-based 2T-VC, but still greater than air. As shown, the top glass temperature is 41.9C for the aerogel-based 2T-VC compared to 40.5C for the vacuum-based 2T-VC. The PL1 performance of the aerogel-based 2T-VC is increased by 13% compared to the copper plate and 11% compared to the single layer VC.

[0393] In some examples, the walls of each level may be constructed of different metals. In some examples, the top wall of the device (e.g., 212 in FIG. 7b) may be the same metal as the lower level walls (e.g., 213, 222 in FIG. 7b). However, in other examples, the top wall of the device (e.g., 212 in FIG. 7b) may be a different metal than the lower level walls (e.g., 213, 222 in FIG. 7b). The choice of metal may depend on implementation details, including cost or thickness constraints. Table 5 below shows example junction temperatures (Tj), skin temperatures (Tskin), device thicknesses, and relative costs. As shown, the use of titanium in certain walls may provide a lower overall device thickness and lower Tj, but at a higher cost and higher Tskin. In other examples, another type of metal, such as aluminum or an alloy, may be used. [Table 6]

[0394] FIG. 7n is a flow diagram illustrating an example process 71000 for manufacturing a dual-level steam chest cooling device according to an example of the present disclosure, and FIGS. 7o-7r illustrate example steps during the manufacturing process 71000. This example process may include additional or different operations, and the operations may be performed in the order shown or in a different order. In some cases, one or more of the operations illustrated in FIG. 7n are implemented as a process that includes multiple operations, sub-processes, or other types of routines. In some cases, the operations may be combined, performed in a different order, performed in parallel, repeated sequentially or otherwise repeated, or performed in a different manner.

[0395] In 71002, metal is extruded to form a device including a first cavity defined (at least in part) by a first wall and a second wall, and a second cavity defined (at least in part) by a second wall and a third wall. For example, with reference to Figures 7o-7p, extrusion device 71100 includes a first cavity 71102 and a second cavity 71104. The first cavity 71102 is defined by walls 71106 and 71108, and the second cavity is defined by walls 71108 and 71100. Although a particular cross-sectional profile is shown in Figure 7p, other cross-sectional profiles (e.g., those shown in Figures 7b, 7d, and 7f) may be extruded.

[0396] At 71004, the extruded device is cut into a desired shape. For example, referring to the example shown in Fig. 7q (top view of device 71100), device 71110 is cut into the shape shown. Cutting can be done using a laser cutting process in some examples.

[0397] At 71006, the cavity of the device is partially sealed, for example by friction welding. For example, referring to the example shown in Figure 7r, device 71100 is welded along dashed line 71112 to partially seal the cavity of the device.

[0398] At 71008, a support structure device is inserted into the first cavity of the device. The support structure device can be formed of plastic, graphite, metal, composite material (e.g., carbon fiber) or other types of materials. As an example, the support structure device can be formed similar to the exemplary support structure device 7110 shown in FIG. 7s, which can be inserted into the top cavity of the cut and welded device 71100 shown in FIG. 7r.

[0399] At 71010, a wick material is inserted into the second cavity of the device. The wick material may include sintered metal, copper fiber, or other types of wick material. In some cases, the wick material may be formed on a pre-assembled wick structure that is to be inserted into the cut and welded extruded device. For example, the wick material may be formed on a pre-assembled structure similar to the example device 71130 shown in FIG. 7t, which may be inserted into the bottom cavity of the cut and welded device 71100 shown in FIG. 7r. In some cases, additional preparation steps (e.g., heating) may be required to prepare the wick material once the device 71130 is inserted.

[0400] At 71012, the top and bottom cavities of the device are prepared and sealed. In some cases, the preparation of the top cavity may include aerogel insertion or air evacuation (to create a vacuum), while the preparation of the bottom cavity may include the insertion of a liquid used in a vapor chamber. Once the cavities are prepared, they may be completely sealed by further friction welding. For example, referring to the example shown in FIG. 7u, the device 71100 may be welded along dotted line 71114 to completely seal the cavity of the device. Following the sealing process, the device may be tested, inspected, and / or quality checked prior to use (e.g., mounting in a device stack for cooling chip packages).

[0401] FIG 7v illustrates an example of an embedded two-tier steam chamber device 71200. In particular, FIG 7v illustrates a cross-sectional view of the device 71200. Similar to the device 400 of FIG 7e, the exemplary device 71200 includes two tiers 71210, 71220. However, the enclosed cavity 71211 of the tier 71210 is disposed within the cavity 712211 of the tier 71220, while the cavity 411 is outside the cavity 7421 of the exemplary device 7400.

[0402] The sealed cavity 71211 is defined by walls 71212, 71213. In some examples, the walls 71212, 7213 may be metal (e.g., copper, titanium, aluminum, alloys, or other thermally conductive metals). The sealed cavity includes a support structure 71214 that is in contact with and perpendicular to the walls 71212, 71213 and may provide structural support for the cavity 712111. The support structure 71214 may be made of metal, plastic, graphite, a composite material (e.g., carbon fiber) or any other suitable material for providing structural support to the cavity 71211. Additionally, the support structure 71214 may be shaped or positioned in another manner not shown in FIG. 7v.

[0403] Cavity 71211 may be evacuated such that its internal pressure is lower than the ambient pressure (e.g., the pressure within cavity 71221 or outside device 71200). For example, in some examples, cavity 71211 is evacuated to a vacuum pressure or near vacuum pressure, such as a pressure less than 0.1 Torr (e.g., 0.05 to 0.1 Torr). In other examples, cavity 71211 is filled with a thermally insulating material, such as an aerogel, that has a lower thermal conductivity than air. The vacuum or thermally insulating material within cavity 71211 may provide thermal insulation from other layers in the device stack (e.g., top layer 7102 of FIG. 7a), which may reduce skin temperatures and provide one or more benefits as described above or elsewhere herein.

[0404] The second level 71220 of the device 71200 includes a sealed cavity 71221 defined by walls 71213, 71222. In the illustrated example, the walls 71222 are flat so that they may be placed in close proximity to (or coupled via a TIM) the chip package to cool the chip package. The walls 71212, 71213 may be flat in some areas, as shown in FIG. 7v, or may have another shape. In certain examples, the components within the cavity 71221 may function as a vapor chamber, whereby liquid within the cavity 71221 is heated by the chip package through the walls 71222, evaporates into vapor, and then condenses as heat is dissipated from the vapor to the walls 71213.

[0405] In the illustrated example, the interior surface of cavity 71221 (i.e., the interior surfaces of walls 71213, 71222) includes a wick material 71224. The wick material 71224 may include sintered metal (e.g., copper) or another type of material. The exemplary wick material 71224 includes two regions 71224a, 71224b. Region 71224a may be considered an evaporation / evaporator wick (e.g., may be the region of the wick where evaporation of the liquid occurs), while region 71224b may be considered a condensation / condenser wick (e.g., may be the region of the wick where condensation (and flow as indicated by the arrows in FIG. 7v) of the liquid occurs). In some examples, regions 71224a, 71224b may both be sintered metal, but may have different structures or porosities. For example, in some instances, region 71224a may include a coarse graded mesh (e.g., about 50-60% porosity), while region 71224b may include a fine graded mesh (e.g., about 40-45% porosity).

[0406] In the illustrated example, cavity 71221 also includes support structures 71228 that can provide structural support to cavity 71221. Support structures 71228 may be formed similarly to structures 71214 in cavity 71211, or may be formed in a different manner.

[0407] In the illustrated example, the cross-sectional areas of cavities 71211, 71221 are rectangular. However, the cross-sectional areas of cavities 71211, 71221 may be shaped in other ways. Furthermore, in the illustrated example, the cross-sectional area of ​​cavity 71211 is smaller than the cross-sectional area of ​​cavity 71221.

[0408] Figures 7w-7x show examples of hot spots for a single tier and embedded dual tier cooling system, respectively. As shown in Figures 7w-7x, the hot spot associated with the chip package (relative center of the chart) is reduced, so the primary hot spot location is shifted (as shown by the dotted oval). In the examples shown, the PL1 capacity is increased by approximately 15-20%.

[0409] A recessed structure as shown in Figure 7v can be utilized to obtain one or more of the advantages of the two tier device described above while maintaining a similar or the same stack height as the single tier cooling device. Exemplary simulation results for the two scenarios are shown in Table 6. [Table 7]

[0410] FIG. 7y shows an example of the performance difference between a single tier steam chest device ("1-VC" in the figure) and a buried two tier steam chest cooling device ("2T-VC" in the figure). As shown, the 5 second PL2 capacity is almost the same for the single tier VC and buried 2T-VC configurations.

[0411] A process similar to that described above with respect to Figures 7v-7x can be used to fabricate an embedded dual-tier VC device.

[0412] 7z-7aa are block diagrams of example computer architectures that may be used in accordance with the embodiments disclosed herein. For example, in some examples, a dual-tier steam chamber device as described above may be used to cool a chip package such as an SoC (e.g., processor core 71500 of FIG. 7z, or one or both of processors 71670, 71680 of FIG. 7aa) that includes one or more sides shown in FIG. 7z-7aa. In some examples, the computer architecture may be implemented within a mobile device system, such as a mobile phone or a tabletop computer system. Other computer architecture designs known in the art for processors and computing systems may also be used. In general, suitable computer architectures for the embodiments disclosed herein may include, but are not limited to, the configurations shown in FIG. 7z-7aa.

[0413] FIG. 7z is an exemplary diagram of a processor according to one example. The processor 71500 is an example of a type of hardware device that can be used in connection with the implementations described above. The processor 71500 may be any type of processor, such as a microprocessor, an embedded processor, a digital signal processor (DSP), a network processor, a multi-core processor, a single-core processor, or other device for executing code. Although only one processor 71500 is shown in FIG. 7z, a processor element may alternatively include two or more of the processors 71500 shown in FIG. 7z. The processor 71500 may be a single-threaded core, or, in at least one example, the processor 71500 may be multi-threaded in that it may include two or more hardware thread contexts (or "logical processors") per core.

[0414] FIG. 7z also illustrates memory 71502 coupled to the processor 71500 according to an example. Memory 71502 may be any of a wide variety of memories (including various layers of a memory hierarchy) known or available to those skilled in the art. Such memory elements may include, but are not limited to, random access memory (RAM), read only memory (ROM), logic blocks of a field programmable gate array (FPGA), erasable programmable read only memory (EPROM), and electrically erasable programmable ROM (EEPROM).

[0415] The processor 71500 may execute any type of instruction related to an algorithm, process, or operation described herein. In general, the processor 71500 may transform elements or items (e.g., data) from one state or thing to another state or thing.

[0416] The code 71504 may be one or more instructions executed by the processor 71500 and may be stored in the memory 71502, or may be stored in software, hardware, firmware, or any suitable combination thereof, or may be stored in any other internal or external component, device, element, or object, as appropriate, based on specific needs. In one example, the processor 71500 may follow the program sequence of instructions shown by the code 71504. Each instruction enters the front-end logic 71506 and is processed by one or more decoders 71508. The decoder may generate as its output a micro-operation, such as a fixed-width micro-operation in a predetermined format, or may generate other instructions, micro-instructions, or control signals that reflect the original code instruction. The front-end logic 71506 also includes register renaming logic 71510 and scheduling logic 71512, which generally allocate resources and queue operations corresponding to the instructions for execution.

[0417] The processor 71500 may also include execution logic 71514 having a set of execution units 71516a, 71516b, 71516n, etc. Some examples may include several execution units dedicated to a particular function or set of functions. Other examples may include only one execution unit, or one execution unit capable of performing a particular function. The execution logic 71514 performs the operations specified by the code instructions.

[0418] After completing execution of the operations specified by the code instructions, the back-end logic 71518 may retire the instructions of the code 71504. In one example, the processor 71500 tolerates out-of-order execution but requires in-order retirement of instructions. The retirement logic 71520 may take various known forms (e.g., a reorder buffer, etc.). In this manner, the processor 71500 is transformed during execution of the code 71504 with respect to at least the outputs generated by the decoder, the hardware registers and tables utilized by the register renaming logic 71510, and any registers (not shown) modified by the execution logic 71514.

[0419] Although not shown in FIG. 7z, a processing element may include other elements on a chip with the processor 71500. For example, a processing element may include memory control logic along with the processor 71500. A processing element may include input / output control logic and / or may include input / output control logic integrated with the memory control logic. A processing element may also include one or more caches. In some examples, non-volatile memory (such as flash memory or fuses) may also be included on a chip with the processor 71500.

[0420] 7aa illustrates a computing system 71600 arranged in a point-to-point (PtP) configuration, according to one example. In particular, FIG. 7aa illustrates a system in which a processor, memory, and input / output devices are interconnected by several point-to-point interfaces. In general, one or more of the computing systems described herein may be configured in the same or similar manner as computing system 71500.

[0421] The processors 71670 and 71680 may include integrated memory controller logic (MC) 71672 and 71682 to communicate with the memory elements 71632 and 71634, respectively. In the alternative, the memory controller logic 71672 and 71682 may be discrete logic separate from the processors 71670 and 71680. The memory elements 71632 and / or 71634 may store various data used by the processors 71670 and 71680 in accomplishing the operations and functions outlined herein.

[0422] Processors 71670 and 71680 may be any type of processor, such as those described in connection with other figures. Processors 71670 and 71680 may exchange data via a point-to-point (PtP) interface 71650 using point-to-point (PtP) interface circuits 71678 and 71688, respectively. Processors 71670 and 71680 may exchange data with a chipset 71690 via individual point-to-point interfaces 71652 and 71654 using point-to-point interface circuits 71676, 71686, 71694, and 71698, respectively. Chipset 71690 may also exchange data with a coprocessor 71638, such as a high performance graphics circuit, a machine learning accelerator, or other coprocessor 71638, via an interface 71639, which may be a PtP interface circuit. In another example, any or all of the PtP links shown in FIG. 7aa may be implemented as multi-drop buses rather than PtP links.

[0423] The chipset 71690 may communicate with the bus 71620 via an interface circuit 71696. The bus 71620 may have one or more devices communicating therethrough, such as a bus bridge 71618 and an input / output device 71616. Through the bus 71610, the bus bridge 71618 may communicate with other devices, such as a user interface 71612 (such as a keyboard, mouse, touch screen, or other input device), a communication device 71626 (such as a modem, network interface device, or other type of communication device capable of communicating over a computer network 71660), audio I / O device 71616, and / or a data storage device 71628. The data storage device 71628 may store code 71630, which may be executed by the processor 71670 and / or 71680. In another example, any portion of the bus architecture may be implemented with one or more PtP links.

[0424] The computer system illustrated in Figure 7aa is a schematic diagram of an example computer system that may be utilized to implement various examples discussed herein. It will be appreciated that the various components of the system illustrated in Figure 7aa may be combined in a system-on-chip (SoC) architecture or any other suitable configuration capable of achieving the functionality and features of the examples and implementations provided herein.

[0425] Although some of the systems and solutions described and illustrated herein have been described as including or relating to multiple elements, not all elements explicitly illustrated or described may be utilized in every alternative implementation of the disclosure. Additionally, one or more of the elements described herein may be located external to the system, and in other instances, an element may be included within or as part of one or more of the other described elements or other elements not described in the illustrated implementation. Additionally, an element may be combined with other components and may be used for alternative or additional purposes in addition to those described herein.

[0426] In some examples, a system includes a chip package and a cooling device coupled to the chip package. The chip package includes one or more processors, and the cooling device includes a first cavity defined at least in part by a first metal wall and a second metal wall, and a second cavity defined at least in part by a flat third metal wall and the second metal wall. An internal pressure of the first cavity is lower than an ambient pressure outside the sealed first cavity. The second cavity includes a liquid disposed therein and a wick material coupled to an interior surface of the third wall, and the chip package is positioned such that it is coupled to the flat third metal wall of the cooling device.

[0427] Moreover, it should be understood that the above-described examples are non-limiting examples provided merely for purposes of illustrating certain principles and features, and do not necessarily limit or restrict potential examples of the concepts described herein. For example, a variety of different examples can be realized using various combinations of the features and components described herein, including combinations realized through various implementations of the components described herein. Other implementations, features, and details should be understood from the contents of this specification.

[0428] While the present disclosure has been described with respect to certain implementations and generally associated methods, modifications and permutations of these implementations and methods will be apparent to those of ordinary skill in the art. For example, the actions described herein can be performed in an order different from that described and still achieve desirable results. By way of example, the processes depicted in the accompanying figures do not necessarily require the particular order depicted, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous. Additionally, other user interface layouts and functionality may be supported. Other variations are within the scope of the following claims.

[0429] In general, one aspect of the subject matter described herein may be embodied in a method and instructions performed that include or cause the actions of identifying a sample including software code, generating a control flow graph for each of a plurality of functions included in the sample, and identifying features in each of the functions that correspond to instances of a set of control flow fragment types. The identified features may be used to generate a Feature Set for the sample from the identified features.

[0430] These and other examples may each optionally include one or more of the following features: The features identified for each function may be combined to generate a concatenated string for the sample, and a feature set may be generated from the concatenated string. A string may be generated for each function, each string describing a respective feature identified for that function. Combining features may include identifying calls in a particular function of the plurality of functions to another function of the plurality of functions, and replacing a portion of the string of the particular function that references the other function with the contents of the string of the other function. Identifying features may include abstracting each string of the function such that only features of a set of control flow fragment types are described in the string. The set of control flow fragment types may include memory accesses by the function and function calls by the function. Identifying features may include identifying instances of memory accesses by each function, and identifying instances of function calls by each function. A feature set may identify each feature identified for each function. The feature set may be an n-graph.

[0431] Further, each of these and other examples may optionally include one or more of the following features: A feature set may be provided for use in classifying the sample. For example, classifying the sample may include clustering the sample with other samples based on the sample's corresponding features. Classifying the sample may further include determining a set of features associated with the cluster of samples. Classifying the sample may also include determining whether to classify the sample as malware and / or whether the sample is likely to be one of one or more families of malware. Identifying the features may include abstracting each of the control flow graphs such that only features of a set of control flow fragment types are described in the control flow graph. A plurality of samples including the sample may be received. In some cases, the plurality of samples may be received from a plurality of sources. The feature set may identify a subset of features identified in the control flow graph of the sample's function. The subset of features may correspond to memory accesses and function calls in the sample code.

[0432] Although the specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or what may be claimed, but rather as descriptions of features specific to particular examples of particular inventions. Certain features described in the specification in the context of separate examples may also be implemented in combination in a single example. Conversely, various features described in the context of a single example may be implemented separately in multiple examples or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations, and may even be initially claimed as such, one or more features from a claimed combination may, in some cases, be excised from such combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0433] Similarly, although the figures show operations in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown, or sequentially, or that all of the illustrated operations be performed, to achieve desired results. In certain situations, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the above examples should not be understood as requiring such separation in all examples, and it should be understood that the program components and systems described may generally be integrated together in a single software product or packaged in multiple software products.

[0434] The following detailed description describes example devices, methods, and systems that may be relevant to enabling steam chests and attachment means.

[0435] The terms "above," "below," "below," "between," and "on" as used herein can refer to the relative position of a layer or component with respect to another layer or component. For example, a layer or component disposed above or below another layer or component may be in direct contact with the other layer or component, or there may be one or more intervening layers or components. Furthermore, a layer or component disposed between two layers or components may be in direct contact with the two layers or components, or there may be one or more intervening layers or components. In contrast, a first layer or component that is "directly" "on" a second layer or component is in direct contact with the second layer or component. Similarly, unless expressly stated otherwise, a feature disposed between two features may be in direct contact with the adjacent feature, or there may be one or more intervening layers.

[0436] Implementations of the examples disclosed herein may be formed or performed on a substrate, such as a non-semiconductor substrate or semiconductor substrate. In some implementations, the non-semiconductor substrate may be silicon dioxide, or an interlayer dielectric composed of silicon dioxide, silicon nitride, titanium oxide, and other transition metal oxides. Although some examples of materials from which the non-semiconductor substrate may be formed are described herein, any material that may serve as a foundation upon which a non-semiconductor device may be built is within the spirit and scope of the examples disclosed herein. In some implementations, the semiconductor substrate (e.g., a semiconductor die) may be a crystalline substrate formed using bulk silicon or a silicon-on-insulator substructure. In other implementations, the semiconductor substrate may be formed using alternative materials that may or may not be combined with silicon, including, but not limited to, germanium, indium antimonide, lead telluride, indium arsenide, indium phosphide, gallium arsenide, indium arsenide gallium antimonide, or other combinations of III-V or IV materials. In other examples, the substrate may be a flexible substrate, including 2D materials such as graphene and molybdenum disulfide, organic materials such as pentacene, transparent oxides such as indium gallium zinc oxide poly / amorphous (low temperature dep) III-V semiconductors and germanium / silicon, and other non-silicon based flexible substrates. Although some examples of materials from which the substrate may be formed are described herein, any material that may serve as a foundation upon which a semiconductor device may be built is within the spirit and scope of the examples disclosed herein.

[0437] In the detailed description, reference is made to the accompanying drawings which form a part hereof, in which like numerals indicate like parts and in which possible examples are shown by way of illustration. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description should not be construed in a limiting sense. For purposes of this disclosure, the phrase "A and / or B" means (A), (B) or (A and B). In this disclosure, the phrase "A, B, and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C). In this disclosure, reference to "one example" or "one example" means that a particular feature, structure, or characteristic described in connection with that example is included in at least one example. Appearances of the phrase "in one example" or "in one example" do not necessarily all refer to the same example. Appearances of the phrases "for example," "in one example," or "in one example" are not necessarily all referring to the same example.

[0438] Referring to FIG. 8a, FIG. 8a is a simplified block diagram of an electronic device 8102 configured with a steam chest and attachment means, according to an example of the present disclosure. In one example, the electronic device 8102 may include one or more electronic components 8106. For example, as shown in FIG. 8a, the electronic device 8102 includes electronic components 8106a-8106d. The electronic component 8106a may include a heat source 8108a and a steam chest 8110a. The steam chest 8110a can be coupled to the heat source 8108a using a steam chest fastening means 8112. The electronic component 8106b may include a steam chest 8110b. The steam chest 8110b can be coupled to the electronic component 8106b using a steam chest fastening means 8112. The electronic component 8106c may include heat sources 8108b and 8108c, and a steam chest 8110c. The vapor chamber 8110c can be coupled to the electronic component 8106c using a vapor chamber fastening means 8112. The vapor chamber 8110c can be thermally coupled to a heat source 8108c. The heat source 8108b can be uncoupled to the vapor chamber. The electronic element 8106d can include a heat source 8108d and a vapor chamber 8110d. The vapor chamber 8110d can be above the heat source 8108d and coupled to the electronic component 8106d using a vapor chamber fastening means 8112. Each of the heat sources 8108a-8108d can be a heat generating device (e.g., a processor, a logic unit, a field programmable gate array (FPGA), a chipset, an integrated circuit (IC), a graphics processor, a graphics card, a battery, a memory, or some other type of heat generating device).

[0439] Each of the steam chambers 8110a-8110d can include one or more braided column structures and / or one or more braided wick structures. To create the steam chamber, the columns and / or wicks in the steam chamber can be made using braided fibers, where fiber strands are woven together. In a particular example, the braided fibers are braided copper fibers. In another example, the braided fibers are braided titanium fibers or some other braided thermally conductive fiber material. The fiber strands in the braided fibers help provide a capillary path for the liquid in the steam chamber and help provide support for the top and bottom plates of the steam chamber. Using braided fibers can help reduce the manufacturing time of the steam chamber by using pre-made columns and wicks that include fiber strands. Additionally, the braided fibers help reduce the weight of the columns to the steam chamber.

[0440] Each of the steam chambers 8110a-8110d may be coupled to an electronic component (e.g., steam chamber 8110b coupled to electronic component 8106b) and / or an electronic element (e.g., steam chamber 8110a coupled to heat source 8108a) using steam chamber fastening means 8112. For example, as shown in FIG. 8a, steam chamber 8110a is coupled to heat source 8108a using two steam chamber fastening means 8112, steam chamber 8110b is coupled to electronic component 8106b using four steam chamber fastening means 8112, steam chamber 8110c is coupled to electronic component 8106c using two steam chamber fastening means 8112, and steam chamber 8110d is coupled to electronic component 8106d using three steam chamber fastening means 8112.

[0441] Each of the steam chest fastening means 8112 may be a helical washer that may help limit the maximum axial load and prevent over tightening. Due to the design of the steam chest fastening means 8112, when the steam chest is fastened to the electronic components (e.g., electronic component 8106b) and / or electronic elements (e.g., heat source 8108a), the steam chest fastening means 8112 will begin to yield once the required load is achieved. Additionally, the configuration of the steam chest fastening means 8112 may be tolerant to accommodating variations in flatness of the electronic components and / or electronic elements. In one example, the outer edge of the steam chest fastening means 8112 may be soldered to the steam chest in a dimple, cavity, recess, etc., to help reduce the thickness, or Z-stack height, of the system. The terms "Z-stack height", "Z-height", "Z-position", etc. refer to the height along the (x, y, z) coordinate axes or the "Z" axis of a Cartesian coordinate system.

[0442] As used herein, the term "when" may be used to indicate the temporal nature of an event. For example, the phrase "event 'A' occurs when event 'B' occurs" means that event 'A' may occur before, during, or after event 'B' occurs, but is nevertheless associated with the occurrence of event 'B'. For example, if event A occurs in response to the occurrence of event B, or in response to a signal indicating that event B has occurred, is occurring, or will occur in the future, then event 'A' occurs when event B occurs. References in this disclosure to "one example" or "an example" mean that a particular feature, structure, or characteristic described in connection with that example is included in at least one example. Appearances of the phrases "in one example" or "in an example" do not necessarily all refer to the same example.

[0443] For purposes of describing certain exemplary technologies, the following basic information may be considered as a basis for properly describing the present disclosure. End users have more media and communication options than ever before. Currently, many prominent technology trends are ongoing (e.g., more computing elements, more online video services, more Internet traffic, more complex processing, etc.), and these trends are changing the expected performance and form factor of devices. This is because devices and systems are expected to have improved performance and functionality while having a relatively thin profile. However, the improvement in performance and / or functionality causes an increase in thermal challenges for devices and systems. For example, in some devices, it may be difficult to cool certain heat sources. One way to cool a heat source is to use a vapor chamber. The vapor chamber may be a planar heat pipe that includes a sealed hollow vessel, a working fluid, and a closed-loop capillary recirculation system. The vapor chamber works on the principle of liquid phase change, which helps to increase heat transfer.

[0444] A vapor chamber can be made of upper and lower copper plates with an internal wick structure. When heat is applied to the vapor chamber from a heat source, the water or other fluid in the vapor chamber boils and turns into a gas, which moves to the cooler area of ​​the vapor chamber. From the cooler area of ​​the vapor chamber, the heat is dissipated where it condenses back into a liquid. The heat is dissipated through an external heat exchanger, heat pipe, or some other thermal system to dissipate the heat. The evaporation and condensation of the water creates a pumping action that moves the water or other fluid (and thus the heat) from the area of ​​the heat source to other areas of the vapor chamber. There are various types of wick structures that can be used in a vapor chamber, but vapor chambers are often classified as powder or mesh. In either case, the powder or mesh lined copper plates are surfaced to allow the water to flow within the area of ​​the vapor chamber. Typically, copper columns are used throughout the vapor chamber to support the plates that act as the top and bottom of the vapor chamber.

[0445] The columns may be pillar-like structures that are attached to the top and / or bottom plates by a sintering process. This requires high sintering times, as the sintering process generally takes a relatively long time and must be done slowly, increasing the manufacturing time of the steam chamber. In addition, the process of forged or sintered columns adds weight to the steam chamber, as the columns may be relatively thick copper blocks.

[0446] A vapor chamber can act to efficiently move heat within a thermal system, similar to a heat pipe, rather than actually dissipating heat to the environment. Typical thermal conductivity of a vapor chamber can range from 3000 to 10000 W / mK. However, the cost of a vapor chamber can be relatively high due to the multiple steps involved in the vapor chamber manufacturing process (e.g., wick sintering, pillar sintering, edge welding, liquid filling, and vacuum sealing, after cutting the plates as needed).

[0447] For example, thin steam chambers are manufactured using a two-plate approach. Here, two copper plates of 0.1-0.2 mm thickness with a wick attached to the copper plate are placed one on top of the other, separated by a column. These columns provide mechanical strength to the steam chamber, as well as capillary action for the liquid to return to the heat source. The columns are made of powdered copper sintered onto a thin plate, then both plates are sprayed or filled with copper powder or mesh and sintered. This forms a capillary pathway for the fluid on the top and bottom plates. These columns can be made as a corrugated sheet of the column or from powdered copper sintered to one of the plates. The corrugated sheet of the column adds weight to the steam chamber, and the powdered copper columns increase the manufacturing time due to the long sintering operation.

[0448] The sintering process takes about 24 hours, which can be a relatively long time for a mass production manufacturing process. This also increases the cost and manufacturing time of the steam chest. In general, the cost of a steam chest can be broken down as follows: material is about 25% of the total cost, labor is about 25% of the total cost, manufacturing is about 20% of the total cost, depreciation and other factors are about 15% of the total cost, and yield loss is about 15% of the total cost. Yield loss is due to flatness variations, leaks, cosmetic issues (e.g., dents and bends), brazing issues, etc. Yield loss can be about 20% of the total cost for a 1 mm steam chest and about 30% of the total cost for a 0.6 mm steam chest. What is needed is a means, system, apparatus, method, etc. that helps reduce the manufacturing time of the steam chest and also helps reduce the weight of the steam chest.

[0449] Also, while steam chests are increasingly being used as passive cooling systems in mobile products, the manufacturing tolerances of steam chests are so large that the bond lines of the steam chest can be unloaded or unevenly loaded or overloaded which can cause poor thermal performance and crack the structure bonded to the steam chest. In some instances, a separate soldered pedestal is used to help secure the steam chest to the printed circuit board (PCB) and / or above the heat source. A separate soldered pedestal is not a good solution as it can increase the thickness of the die area and therefore the overall thickness of the device. Furthermore, the tolerances of the soldered pedestal are not tight, often ±0.05mm after milling and ±0.10mm after soldering. The pedestal cannot be milled after soldering because milling would destroy the weak mesh and skin bond of the steam chest. Additionally, due to tolerance variations, all parts must be measured manually, which is an expensive process and can result in low yields that are not suitable for mass production. The pedestal can also increase stiffness locally, further tightening the required tolerances. Additionally, separate soldered components between the heat source and the vapor chamber can degrade thermal performance. In some instances, there may be tall components between the PCB and the screw attachment. In these instances, the pedestal and the standoff support frame must be different elements, which further worsens the Z tolerance, which can be approximately ±0.20 mm. What is needed is a means, system, apparatus, method, etc., of fastening the vapor chamber to the PCB that can help limit the maximum axial load and prevent over-tightening.

[0450] A system that allows for a steam chest and attachment means, as outlined in FIG. 8a, can solve these problems (and others). In one example, a steam chest with a braided structure helps reduce steam chest costs by reducing manufacturing time. Fiber strands can be used to create the braided column structure(s) and / or braided wick structure(s) of the steam chest. The braided column structure(s) and / or braided wick structure(s) can be attached to the top and bottom plates of the steam chest. The braided column structure(s) and / or braided wick structure(s) can be prefabricated prior to the steam chest manufacturing process, thereby reducing steam chest manufacturing time. The steam chest can also be bonded to the PCB using a spiral washer that helps limit the maximum axial load and prevent damage from over tightening. Due to the design of the washer, the washer begins to yield when the required load is achieved. Additionally, the configuration of the washer can accommodate flatness variations.

[0451] In one example, the wick and columns in the steam chamber can be made using copper fibers, where copper fiber strands are braided together to create the steam chamber. In some examples, titanium fiber strands are braided together or other thermally conductive fiber materials are braided together. This braided structure can be brazed to the top and bottom plates of the steam chamber. The term "brazed" includes attaching the fiber braided strands to the top plate of the steam chamber through welding, soldering, sintering of the copper fiber strands. In other examples, the pillar structure can be manufactured through a punching process, a forging process, a molding process, or a metal etching process. The fiber strands can provide capillary passages for the steam chamber and add rigidity to the top and bottom plates, helping to prevent the steam chamber from collapsing.

[0452] The use of braided copper fibers can help reduce the manufacturing time of the steam chamber by using columns and wicks that are already available in the form of fiber braids. In addition, the braided copper fibers help reduce the weight of the copper columns. Also, the fiber-wick structure shows better thermal performance compared to sintered and composite wick structures.

[0453] More specifically, the column and wick structures can be made in the form of fiber braids. For the columns, the fiber braids can be pre-made before the steam chamber is manufactured and then cut to the required height, depending on the thickness of the steam chamber. The fiber braids can then be placed between the two plates of the steam chamber and brazed together. The fiber braids can be made into long strands and cut into smaller elements as needed. This helps to reduce the manufacturing time of the steam chamber, because during mass production, the fiber braids can be cut to the desired height, depending on the thickness of the steam chamber. Also, the capillary performance of the fiber braid-based heat pipe can work better than that of composite or sintered heat pipes.

[0454] In another example, an integrated column and wick structure can be made by weaving copper fiber strands using knitting concepts or through a process similar to that done in weaving cloth. During the weaving process, knots can be put in place to act as columns. This process can integrate the column and wick together and eliminate the sintering process involved in bonding the copper column to the wick. In yet another example, perforated copper pillars can be achieved through various manufacturing techniques such as chemical etching, stamping, forging, and / or punching operations in one of the plates of the steam chamber.

[0455] The steam chest may be coupled to an electronic component (e.g., electronic component 8106b), an electronic element (e.g., heat source 8108a), a PCB, a motherboard, etc. using a steam chest fastening means (e.g., steam chest fastening means 8112). The steam chest fastening means may be configured to limit the maximum axial load and help prevent over-tightening. The steam chest fastening means may be a spiral washer with a notch to mitigate the effects of high normal loads and high tightening torques. The notch may be located at a transition area between a central portion of the steam chest fastening means and an outer portion of the steam chest fastening means. In a particular example, the central portion may include a threaded boss that receives a threaded attachment means and the outer portion may include a flange that is soldered to the steam chest. The cutout may be radial or curved. If the cutout is curved, it may help prevent screw / thread failure during over-tightening. For example, if the notch is curved, once the maximum tightening moment is reached it will begin to lift to reduce the load, which the screw boss can help prevent screw / thread failure.

[0456] In the specific example of a 0.20 mm and 0.40 mm copper washer construction of the steam chest fastener, the nominal axial target deformation is 0.25 mm, which leads to a minimum allowable deformation of 0.05 mm and a maximum deformation of 0.45 mm. The difference between the minimum and maximum forces is 0.5 Newtons (or about 0.112 lbf) for the 0.20 mm thickness and 2 Newtons (or about 0.45 lbf) for the 0.40 mm thickness. Thus, the variable force range is about ten percent (10%) of the total axial screw force. The 0.30 mm thickness gives a total package load of about 8 lbf (or about 35.59 Newtons) to about 9 lbf (or about 40.03 Newtons) for the four screws, with the maximum load being about 10 lbf (or about 44.48 Newtons). The ultimate moment for the M1.2 threads is slightly over 30 Newton-mm, which is relatively easy to achieve in normal cases, and the above configuration of the steam chest fixing means may help prevent that moment from being achieved. Overtightening to 25 Newton-mm may cause some permanent deformation to the steam chest fixing means, which may reduce the axial load by approximately 30%.

[0457] The steam chest fastening means is not limited to use only with steam chests. Similar elastic, plastic, or other materials having the above configuration as the steam chest fastening means can be milled or stamped into a heat pipe, cold plate, any other thermal element, or other component. If the steam chest fastening means is used with a cold plate, a separate leaf spring is not required. This allows more freedom for the board design, since the screw location for the cold plate can be determined relatively freely and does not need to be at the end of the leaf spring.

[0458] In one example, electronic device 8102 is intended to include a computer, a personal digital assistant (PDA), a laptop or electronic notebook, a cellular phone, an iPhone, a tablet, an IP phone, a network element, a network appliance, a server, a router, a switch, a gateway, a bridge, a load balancer, a processor, a module, or any other device, component, element, or object, including a heat source. Electronic device 8102 may include any suitable hardware, software, component, module, or object that facilitates its operation, as well as suitable interfaces for receiving, transmitting, and / or otherwise communicating data or information in a network environment. This may include suitable algorithms and communication protocols that enable the effective exchange of data or information. Electronic device 8102 may include virtual elements.

[0459] With regard to internal structure, the electronic device 8102 may include memory elements for storing information used in operation. The electronic device 8102 may hold information in any suitable memory element (e.g., random access memory (RAM), read only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), application specific integrated circuit (ASIC), etc.), software, hardware, firmware, or any other suitable component, device, element, or object, as appropriate, based on specific needs. Any of the memory items discussed herein should be construed as being encompassed by the broad term "memory element." Additionally, the information used, tracked, transmitted, or received may be provided in any database, register, queue, table, cache, control list, or other storage structure, all of which may be referenced in any suitable time frame. Any such storage options may also be included in the broad term "memory element" as used herein. In certain example implementations, the functionality may be realized by logic encoded on one or more tangible media (e.g., embedded logic provided in an ASIC, digital signal processor (DSP) instructions, software (potentially including object code and source code) executed by a processor or other similar machine), and the media may include non-transitory computer-readable media. In some of these examples, memory elements may store data used for operations described herein. This includes memory elements that may store software, logic, code, or processor instructions executed to perform an activity or operation.

[0460] In addition, the heat source 8104 may be or include one or more processors capable of executing software or algorithms. In one example, a processor may transform an element or item (e.g., data) from one state or thing to another. In another example, activities may be performed using fixed or programmable logic (e.g., software / computer instructions executed by a processor), and the heat elements identified herein may be some type of programmable processor, programmable digital logic (e.g., field programmable gate array (FPGA), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)), or ASIC that includes digital logic, software, code, electronic instructions, or any suitable combination thereof. Any of the potential processing elements, modules, and machines described herein should be construed as being encompassed by the broad term "processor."

[0461] The electronic device 8102 may be a standalone device or may communicate with the cloud service 8116 and / or one or more network elements 8118 using a network 8120. The network 8120 represents a series of interconnected communication paths points or nodes for transmitting and receiving packets of information. The network 8120 provides a communication interface between the nodes and may be configured as any local area network (LAN), virtual local area network (VLAN), wide area network (WAN), wireless local area network (WLAN), metropolitan area network (MAN), intranet, extranet, virtual private network (VPN), and any other suitable architecture or system that facilitates communication in a network environment, or any suitable combination thereof, including wired and / or wireless communication.

[0462] In the network 8120, network traffic including packets, frames, signals, data, etc. may be transmitted and received according to any suitable communication messaging protocol. Suitable communication messaging protocols may include a layered scheme such as the Open Systems Interconnection (OSI) model, or any derivative or variation thereof (e.g., Transmission Control Protocol / Internet Protocol (TCP / IP), User Datagram Protocol / IP (UDP / IP)). Messages over the network may be created according to various network protocols (e.g., Ethernet, InfiniBand, OmniPath, etc.). Additionally, wireless signal communication may be provided over a cellular network. Appropriate interfaces and infrastructure may be provided to enable communication with the cellular network.

[0463] The term "packet" as used herein refers to a unit of data that may be routed between a source node and a destination node on a packet-switched network. A packet includes a source network address and a destination network address. These network addresses may be Internet Protocol (IP) addresses in the TCP / IP messaging protocol. The term "data" as used herein refers to any type of binary, numeric, audio, video, text, or script data, or any type of source or object code, or any other suitable information in any suitable format, that may be communicated from one point to another in an electronic device and / or network.

[0464] Referring to FIG. 8b, FIG. 8b is a simplified block diagram of a portion of a steam chamber 8110e. The steam chamber 8110e may include a bottom plate 8124 and one or more columns 8126. The columns 8126 are pillar or column-like structures that help provide mechanical strength to the steam chamber 8110e as well as provide capillary action for liquids within the steam chamber 8110e. The columns 8126 may be made of braided copper, braided titanium, or some other braided material that may help provide mechanical strength to the steam chamber 8110e as well as provide capillary action for liquids within the steam chamber 8110e. In one example, multiple columns 8126 may be arranged in a grid-like pattern, for example, as shown in FIG. 8b. In some examples, one or more support columns 8128 may be added to provide additional support. The support columns 8128 may be non-braided fiber columns that provide additional support for the steam chamber 8110e. In other examples, the multiple columns 8126 and optionally the one or more support columns 8128 may be arranged according to design constraints and / or other factors.

[0465] 8c, which is a simplified block diagram of a cutaway side view of a portion of a steam chest 8110e. The steam chest 8110e may include a bottom plate 8124 and one or more columns 8126. In some examples, one or more support columns 8128 may be added to provide additional support to the steam chest 8110e.

[0466] Referring to Fig. 8d, Fig. 8d is a simplified block diagram of a portion of a steam chest 8110e. The steam chest 8110e may include a top plate 8130. In some examples, instead of a bottom plate 8124 including one or more columns 8126 as shown in Figs. 8b and 8c, one or more columns 8126 may be on the top plate 8130. Additionally, the top plate 8130 may include one or more support columns 8128 to provide additional support to the steam chest 8110e.

[0467] Referring to FIG. 8e, FIG. 8e is a simplified block diagram of a steam chamber 8110e. The steam chamber 8110e may include a bottom plate 8124, one or more columns 8126, and a top plate 8130. The steam chamber 8110e may be created by fastening the bottom plate 8124 to the top plate 8130. In one example, the bottom plate 8124 is fastened to the top plate 8130 using a brazing process, a soldering process, a sintering process, or using a direct punching, molding, or forging method. In some examples, one or more support columns 8128 may be added to provide additional support to the steam chamber 8110e.

[0468] Referring to Figure 8f, Figure 8f is a simplified block diagram of a portion of a steam chest 8110f. The steam chest 8110f may include a bottom plate 8124 and a wick 8132. The wick 8132 may be made using copper fibers woven together with copper fiber strands, titanium fibers woven together with titanium fibers, or some other conductive fiber strands woven together. In other examples, the wick 8132 may be made from a mesh structure.

[0469] Referring to FIG. 8g, FIG. 8g is a simplified block diagram of a portion of the steam chest 8110f. As shown in FIG. 8g, a plurality of columns 8126 may be secured to the wick 8132. In one example, the plurality of columns 8126 are secured to the wick 8132 by attaching fiber braided strands, such as by welding, soldering, sintering, or the like, copper fiber strands to the top plate of the steam chest. In some examples, the wick 8132 is configured as a fine mesh structure, which may be a woven structure, with the weave acting as pillars. In some examples, one or more support columns 8128 may be added to provide additional support.

[0470] Referring to Fig. 8h, Fig. 8h is a simplified block diagram of a portion of a steam chamber 8110f. The steam chamber 8110f may include a top plate 8130 and a wick 8132. In some examples, instead of a bottom plate 8124 including one or more columns 8126 as shown in Fig. 8g, the one or more columns 8126 may be on the top plate 8130. Additionally, the top plate 8130 may include one or more support columns 8128 to provide additional support to the steam chamber 8110f.

[0471] Referring to FIG. 8i, FIG. 8i is a simplified block diagram of a steam chamber 8110f. The steam chamber 8110f may include a bottom plate 8124, one or more columns 8126, a top plate 8130, a wick 8132, and a fluid 8134. The fluid 8134 may be water. The steam chamber 8110f may be created by fastening the bottom plate 8124 to the top plate 8130. The columns 8126 may help provide mechanical strength to the steam chamber 8110f as well as capillary action for the liquid inside the steam chamber 8110f. In some examples, one or more support columns 8128 may be added to provide additional support to the steam chamber 8110f.

[0472] In one example, at the hot interface of the steam chamber 8110f (e.g., the area where the outer wall of the bottom plate 8124 is proximate to the heat source), the fluid 8134 turns to steam by absorbing heat from the bottom plate 8124. The steam then travels through the steam chamber 8110f to the cooler interface (e.g., the top plate 8130) where it condenses back into the fluid 8134, releasing heat to the cooler interface. The fluid 8134 then returns to the hot interface via capillary action, centrifugal force, gravity, etc., and the cycle repeats.

[0473] Referring to FIG. 8j, FIG. 8j is a simplified block diagram of a portion of a fiber braid 8164. The fiber braid 8164 may include fiber strands 8136. The fiber strands 8136 may be braided copper fibers, braided titanium fibers, or other braided thermally conductive fiber material. In one example, the fiber strands 8136 are braided or woven together to create the fiber braid 8164. The fiber braid 8164 may be brazed to the bottom and / or top of the steam chest to create one or more columns 8126 and / or one or more wicks 8132, as shown in FIGS. 8e and 8i. The fiber strands 8136 in the fiber braid 8164 provide capillary paths for fluid in the steam chest and help add support to the top and bottom plates of the steam chest. The fiber braid 8164 may help reduce the weight of the columns 8126 and / or wicks 8132. Also, using fiber strands 8136 to create a fiber wick structure for column 8126 and / or wick 8132 allows for better thermal performance compared to sintered and composite wick structures. Additionally, using fiber braid 8164 can help reduce manufacturing time of the steam chamber by using already available wicks and columns in the form of fiber braid 8164. For example, fiber braid 8164 can be created prior to manufacturing of the steam chamber and then cut to the required height depending on the thickness of the steam chamber.

[0474] Referring to Fig. 8k, Fig. 8k is a simplified block diagram of a steam chest 8110e. In one example, one or more steam chest fastening means 8112 may be secured to the steam chest 8110e. The steam chest fastening means 8112 may include a flange 8148 and one or more spring arms 8150. The flange 8148 may be soldered to the steam chest 8110e.

[0475] Referring to Fig. 8l, Fig. 8l is a simplified block diagram of a steam chest 8110e above a heat source 8108. As shown in Fig. 8l, one or more steam chest fastening means 8112 may be secured to the steam chest 8110e. The steam chest fastening means 8112 may include a flange 8148 and one or more spring arms 8150.

[0476] The heat source 8108 can be on a substrate 8142, which can be secured to a PCB 8146 using a solder ball grid array 8144. A thermal interface material (TIM) 8140 can be on the heat source 8108. If a gap exists between the vapor chamber 8110e and the TIM 8140 when the vapor chamber 8110e is secured to the PCB 8146, a pedestal 8138 can be configured to close the gap. The pedestal 8138 can be used to add rigidity to the vapor chamber 8110e and help provide uniform pressure from the vapor chamber 8110e to the heat source 8108. A riser 8152 can extend from the PCB 8146 to help couple the vapor chamber 8110e above the heat source 8108. The riser 8152 can take into account the height of the solder ball grid array 8144, the substrate 8142, the heat source 8108, the TIM 8140, and the pedestal 8138, if present. A mounting means 8154 can be used to mate with the steam chamber fastening means 8112 to help secure the steam chamber 8110e above the heat source 8108.

[0477] Referring to Fig. 8m, Fig. 8m is a simplified block diagram of a portion of an electronic device including a steam chamber 8110e above a heat source 8108. As shown in Fig. 8m, a steam chamber fastening means 8112 can be used to secure the steam chamber 8110e above the heat source 8108. The steam chamber fastening means 8112 may include a flange 8148 and one or more spring arms 8150. The flange 8148 may be coupled to the steam chamber 8110e.

[0478] The TIM 8140 may be between the heat source 8108 and the vapor chamber 8110e. If there is a gap between the vapor chamber 8110e and the TIM 8140, the pedestal 8138 may be configured to close the gap. The heat source 8108 may be on a substrate 8142, which may be secured to a PCB 8146 using a solder ball grid array 8144. The vapor chamber fastening means 8112 may be coupled to the vapor chamber 8110e, and the attachment means 8154 may extend through the PCB 8146 and couple to the vapor chamber fastening means 8112 to help secure the vapor chamber 8110e above the heat source 8108. The riser 8152 may extend from the PCB 8146 to the vapor chamber fastening means 8112 (more specifically, the spring arm 8150 of the vapor chamber fastening means 8112) and to the perimeter attachment means 8154. The riser 8152 can take into account the height of the solder ball grid array 8144, the substrate 8142, the heat source 8108, the TIM 8140, and the pedestal 8138, if the pedestal 8138 is present.

[0479] 8n and 8o, which are simplified diagrams of a steam chest fastening means 8112a. The steam chest fastening means 8112a may include a flange 8148 and a plurality of spring arms 8150. For example, as shown in Figs. 8n and 8o, the steam chest fastening means 8112a includes four spring arms 8150. The spring arms 8150 may extend from the flange 8148 to a central portion 8156 of the steam chest fastening means 8112a. The central portion 8156 may include an attachment mechanism that allows the attachment means 8154 to couple with the steam chest fastening means 8112a. For example, if the attachment means 8154 is a screw or threaded fastener, the central portion 8156 may include threads that allow the attachment means 8154 to be screwed or sewn to the central portion 8156 and couple with the steam chest fastening means 8112a.

[0480] 8p and 8q, which are simplified diagrams of a steam chest fastening means 8112b. The steam chest fastening means 8112b may include a flange 8148 and a plurality of spring arms 8150. For example, as shown in Figs. 8p and 8q, the steam chest fastening means 8112b includes three spring arms 8150. The spring arms 8150 may extend from the flange 8148 to a central portion 8156 of the steam chest fastening means 8112b. The central portion 8156 may include an attachment mechanism that allows the attachment means 8154 to couple with the steam chest fastening means 8112b. If the attachment means 8154 is a screw or threaded fastener, the central portion 8156 may include threads that allow the attachment means 8154 to be screwed or sewn to the central portion 8156 and to couple with the steam chest fastening means 8112b.

[0481] Referring to Fig. 8r, Fig. 8r is a simplified diagram of an exemplary stress field for steam chest fastening means 8112b. When attachment means 8154 is coupled to steam chest fastening means 8112b, a force extends from attachment means 8154 to center portion 8156 and spring arm 8150. Spring arm 8150 is configured to bend, flex, rotate, etc. to absorb a portion of the force and help prevent the force from reaching flange 8148 and the steam chest including steam chest fastening means 8112b.

[0482] 8s and 8t, which are simplified block diagrams illustrating a portion of an electronic device 8102a. The electronic device 8102a may include a chassis 8158, a PCB 8146, and a steam chamber 8110f. The steam chamber fastening means 8112d may be coupled to the attachment means 8154a and aid in fastening the steam chamber 8110f to the PCB 8146. In one example, the attachment means 8154a is a threaded screw, a bolt, or other threaded attachment means. As shown in FIG. 8s and 8t, the steam chamber fastening means 8112d may include a flange 8148, a spring arm 8150, and a central portion 8156a. The central portion 8156a may include threads 8160 that allow the attachment means 8154a to be screwed or sewn into the central portion 8156a of the steam chamber fastening means 8112d.

[0483] 8u and 8v, which are simplified block diagrams illustrating a portion of electronic device 8102b. Electronic device 8102b may include chassis 8158, PCB 8146, and steam chamber 8110g. As shown in Figs. 8u and 8v, steam chamber fastening means 8112e may include flange 8148, spring arm 8150, and central portion 8156. Central portion 8156 may include threaded insert 8162. In one example, threaded insert 8162 may be soldered or otherwise secured to central portion 8156.

[0484] The steam chamber fastening means 8112e can be coupled to the mounting means 8154b and aid in fastening the steam chamber 8110g to the PCB 8146. In one example, the mounting means 8154b is a threaded screw, bolt, or other threaded mounting means. The threaded insert 8162 may include threads 8160 that allow the mounting means 8154b to be screwed or threaded into the threaded insert 8162 of the steam chamber fastening means 8112e and aid in fastening the steam chamber 8110g to the PCB 8146.

[0485] Although the present disclosure has been described in detail with respect to specific arrangements and configurations, the configurations and arrangements of these examples may be significantly altered without departing from the scope of the present disclosure. Additionally, specific components may be combined, separated, removed, or added based on specific needs and implementations. Additionally, while the steam chest 8110 and steam chest fastening means 8112 are illustrated with reference to specific elements and operations, these elements and operations may be replaced by any suitable architecture, protocol, and / or process that achieves the intended functionality of the steam chest 8110 and steam chest fastening means 8112.

[0486] Particular examples described herein provide an electronic device that can be configured to include a steam chest and a mounting means for the steam chest. The steam chest can include one or more columns, at least a portion of which include a fiber braid and one or more wicks. At least one wick can also include a fiber braid. The columns can be brazed to a top plate or a bottom plate of the steam chest. The steam chest can be secured above a heat source with a steam chest fastening means that can include a spring arm. The spring arm can bend, curve, rotate, etc. to absorb some of the force when the steam chest is secured above the heat source.

[0487] The present disclosure may repeat reference numerals and / or letters in the various embodiments. This repetition is for simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed. Different embodiments may have different advantages, and no particular advantage is necessarily claimed for any embodiment.

[0488] In large desktop systems where space is plentiful, heat dissipation can be achieved via a simple heat sink and fan above the processor and graphics processing unit (GPU), which may be sufficient to remove excess heat and protect the system.

[0489] But in smaller portable systems, such as laptop and tablet computers, "z-space" (space along the "z-axis", in other words, the thickness of the device) is usually at a premium. When a user first picks up a device, the first thing they almost always notice is its size and weight. So system designers are under pressure to create thinner and lighter devices. Such lighter and thinner devices require more advanced and integrated thermal solutions.

[0490] The steam chest can form part of an elaborate, integrated heat dissipation solution. The steam chest has a (usually) conductive outer casing, such as copper. The steam chest includes a sealed cavity (chamber) that may be evacuated of air during manufacture to form a vacuum chamber. Within the chamber is placed an evaporative fluid, such as deionized water or some other fluid, which may be selected for its non-corrosiveness and high specific heat. The chamber may also include columns that provide structural support and help ensure that the chamber does not collapse easily.

[0491] A portion of the vapor chamber may be placed in contact with or in close proximity to a heat generating element such as a processor, GPU, etc. This portion of the vapor chamber may be called the "hot plate," but need not be a separate or discrete plate. This portion may also be called the evaporator. The "cold plate" is the portion that is sufficiently distant from the heat plate. This section may also be called the condenser. When the hot plate is heated, the outer wall absorbs heat and transfers it to an evaporative fluid, which efficiently absorbs the heat due to its high specific heat. Once the evaporative fluid reaches its boiling point, it evaporates and spreads across the vacuum chamber, carrying the heat away from the heat plate. The heated vapor reaches one or more "cold plates," which also need not be separate or discrete plates. The cold plates absorb heat by condensation. Excess heat may be further dissipated, for example, by placing a fan at or near the condenser, which may result in excess heat being expelled from the system. Evaporation and condensation are very effective heat transfer mechanisms because they are heat-intensive activities, especially for fluids with high specific heat capacities such as deionized water.

[0492] After the heat condenses at the cold plate, wicking means are provided to return the cooled liquid towards the heat plate so that the cycle can be repeated. Various wicking means are known in the art, including, by way of illustrative and non-limiting examples, sluices that gravitationally return the fluid towards the heat plate, capillary tubes, or metal wicks that may include porous metal that collects water and returns it towards the heat plate.

[0493] Generally, substantially planar steam chests (e.g., those with length and width dimensions within about half an order of magnitude of each other) allow heat to dissipate substantially radially from the heat source, and it is common to place the heat source near the geometric center of gravity of the steam chest. A special case of a steam chest is a heat pipe, where the length is greater than about five times the width (and sometimes much greater). Heat pipes carry heat laterally along the length of the heat pipe and can be used to distribute heat from one part of a device to another. In the case of a heat pipe, the heat source may be located at or near one end of the heat pipe, which can then carry heat to the other end.

[0494] Some aspects of the present specification provide several improvements to the steam chest. These improvements can be used individually or in combination with each other to realize improved structural and operational performance in the steam chest. To simplify the present disclosure, the improvements are disclosed as separate improvements, and each improvement can be performed alone. However, this should not be interpreted to mean that the improvements must be independent of each other. For example, the steam chest and system design can be improved by simultaneously applying one, two, or more of the improvements disclosed herein. Thus, although various improvements are presented separately as individual features, these embodiments can be combined in any combination desired to realize system-level advantages.

[0495] In the first aspect, the vapor chamber can be improved by using it in combination with a heat pipe. In particular, vapor chambers are relatively expensive, and because of their cost, large vapor chambers may be limited to "high-end" laptop computers, such as gaming laptops. However, as mentioned above, planar vapor chambers generally conduct heat radially. Thus, the vapor chamber may experience "cold spots" at the ends where heat cannot be effectively reached. This problem may be exacerbated when the vapor chamber has a complex geometric shape, such as something other than a simple rectangle.

[0496] However, by using a steam chest with well-placed heat pipes, the steam chest can be made more efficient while reducing its cost. For example, the size of the steam chest can be reduced in one dimension, thus reducing its complexity and cost. Heat pipes may be placed at the edge of the reduced size steam chest, with the lateral dimension of the heat pipe extending in the direction of the reduced steam chest size. This allows the planar steam chest to better perform its function of dissipating heat in a radial direction. Once the heat reaches the edge, it can be carried away by conduction through the heat pipes. This can provide improved heat dissipation compared to planar steam chests with larger lateral dimensions of the heat pipes. Additionally, the cost of a smaller steam chest can be substantially reduced, thus realizing an economic advantage and allowing the steam chest to be used in less expensive devices that would not have previously justified the use of a steam chest.

[0497] In a second feature, which can be used separately or in conjunction with the above-mentioned embodiment, the planar steam chamber can be structurally improved. In some cases, a "super-thin" steam chamber can be used to meet aggressive "z-space" requirements. These are particularly stringent in tablets or similar small devices. To reduce the thermal impedance between the heat source and the steam chamber, mechanical fastening means can be used to keep the hot plate in close contact with the heat source. Fastening means can include, for example, mechanical bolts or other structures to hold the steam chamber "tight" against the heat source. However, especially in super-thin steam chambers, this can create mechanical stresses and cause bending or z-axis displacement of the steam chamber. Such bending can create a risk of buckling or reduce the efficiency or useful life of the steam chamber.

[0498] To help reduce such z-axis displacement, embodiments herein include an internal "starburst" structure for the steam chest, which helps structurally stiffen the chamber, prevent collapse, and provide a low-profile mounting feature.

[0499] In a third aspect, improvements can be made to the wick of the vapor chamber. These improvements can reduce the pressure loss of the vapor in the thin vapor chamber as it travels from the evaporator to the condenser, thereby improving its thermal performance. This can be accomplished, for example, by selectively removing portions of the wick to reduce the pressure loss from the evaporator to the condenser.

[0500] The overall efficiency of a steam chest is affected by many factors, including the thermal gradient between the evaporator and condenser, and the pressure loss through the steam chest. If there is a high thermal gradient, this means that heat is not being efficiently spread throughout the steam chest. Pressure loss also affects the ability of the steam to carry heat away from the evaporator to the condenser. In fact, it has been experimentally observed that there is an approximately inverse cube relationship between pressure loss in the steam chest and heat transfer efficiency. Thus, even modest improvements in pressure loss can lead to dramatic improvements in efficiency.

[0501] The pressure drop in a steam chest is inversely proportional to the available volume of the steam chest. Thus, increasing the volume of the steam chest reduces the pressure drop. However, as mentioned above, in portable computing devices, a common application for steam chests, the z-space can be relatively limited. For example, a 1 mm thick steam chest may have a 0.2 mm wick above and below, leaving a 0.2 mm gap for steam to flow, assuming a 0.2 mm wall thickness. However, if either the top or bottom portion of the wick is removed, the available flow area for steam increases locally from 0.2 mm to 0.4 mm. If both the top and bottom are removed in a particular region, the available cross-sectional area for steam flow can be as high as 0.6 mm.

[0502] Since the wick is still needed to return fluid from the condenser to the evaporator, it may not be practical to remove the entire wick. However, if a percentage of the wick is strategically removed, such as in a patch, the available cross-sectional area for vapor flow can be increased locally while providing enough wick for condensed vapor to return to the evaporator. In one illustrative example, about 30% or 45% of the wick can be removed to increase the available volume for vapor flow. In the more general case, any percentage between 15% and 70% of the wick can be removed to increase the vapor flow rate.

[0503] Removal of the wick from these regions increases the vapor flow area within the vapor chamber without increasing thickness. Once condensed, the fluid can reach the evaporator through wicks located elsewhere in the vapor chamber. This effectively increases the local thickness, and therefore the vapor flow area, of portions of the vapor chamber. Thus, a relatively thinner vapor chamber can provide thermal performance equivalent to that of a relatively thicker vapor chamber.

[0504] The three features discussed above define three broad categories of steam room improvements. For convenience, these first, second, and third categories may be referred to as "A," "B," and "C," respectively. Features A, B, and C are discussed separately below. For example, Figures 9a-9e relate to feature category A, Figures 9f-9n relate to feature category B, and Figures 9o-9v relate to feature category C.

[0505] These features are described separately below to help the reader understand each feature. However, this does not mean that these features must exist separately from each other. For example, this specification anticipates the following advantages resulting from the following combinations, as illustrative and non-limiting examples: A - Improved thermal performance in the steam room, reduced size and corresponding reduced cost. b. B - Improved planarity integrity for steam chests, including thin steam chests. c. C- Reduce pressure loss in the steam chamber, improving performance and efficiency. d. A+B - Improved thermal performance and synergistically improved planarity integrity in ultra-thin steam chambers, reducing steam chamber size and cost. e. A+C- Reducing the size of the steam chamber and reducing the pressure drop, resulting in synergistic improvement in thermal performance. f. B+C - Improve planar integrity in ultra-thin steam chest and reduce pressure loss, resulting in improved planar integrity and synergistically improved thermal performance. g. A+B+C - Ultra-thin steam chest, reduced size, synergistically improved planarity integrity, reduced pressure drop for synergistically improved thermal performance.

[0506] The system and method for providing an improved steam room will now be described in more detail with reference to the accompanying drawings. It should be noted that certain reference numbers may be repeated throughout the drawings to indicate that a particular device or block is completely or substantially consistent throughout the drawings. However, this is not intended to imply a particular relationship between the various embodiments disclosed. In certain instances, a genus of elements may be referenced by a particular reference number ("widget 10"), while individual species or instances of the genus may be referenced by a hyphenated number ("first particular widget 10-1" and "second particular widget 10-2").

[0507] Some of the following figures detail example architectures and systems for implementing the above-described embodiments. In some embodiments, one or more of the hardware components and / or instructions described above are emulated or implemented as software modules, as described in more detail below.

[0508] FIG. 9a is a block diagram of the internal components of a portable computer system 9100, such as a laptop computer. In this figure, the portable computing system 9100 includes several electronic components that provide the functionality and features of a portable computing device. These electronic components may generate heat, and in particular, a central processing unit (CPU), system on a chip (SoC), GPU, or other high powered device may generate more heat than most of the rest of the system. Thus, a vapor chamber 9104 is provided to draw heat from the heat-generating devices, such as the CPU or SoC, and expel the heat from the system.

[0509] In this illustration, the steam chamber 9104 is a large planar steam chamber having an irregular (e.g., non-rectangular) shape. The steam chamber 9104 includes an evaporator 9116 that may be located above a heat source such as a CPU. The evaporator 9116 does not need to be a discrete or separate plate, but may simply be the portion of the steam chamber 9104 closest to the heat source. The condenser of the steam chamber 9104 includes a remote area away from the evaporator 9116 where fluid begins to condense as the temperature drops.

[0510] Fans 9112-1 and 9112-2 are strategically positioned in selected portions of the steam chest 9104 to provide a heat flow 9108 that extracts heat from the steam chest 9104. This effectively transfers heat from the evaporator 9116 to the condenser portion of the steam chest 9104 where it is extracted externally to the entire system.

[0511] In many applications, vapor chambers are considered a "prime" thermal solution, especially in systems whose z-axis is constrained (i.e., thin systems). As a prime solution, vapor chambers are very effective and relatively expensive compared to some other thermal solutions. Thus, cost remains an issue when deploying vapor chambers on non-prime laptops. Size can be a cost factor for vapor chambers, so they are more common in smaller devices such as smartphones and tablet computers.

[0512] The embodiments herein reduce the relative cost by minimizing the spatial coverage of the vapor chest and by extending the effective reach of the vapor chest within the system with additional heat pipes. This design approach can result in up to 40% projected cost savings due to improved manufacturing yields and raw material cost savings. Advantageously, it can also improve the performance of heat dissipation in areas within the system that are typically considered areas that cannot be easily reached by vapor (such as corner zones). This can be solved by adding straight heat pipes to the edges of the vapor chest. Furthermore, due to the linear heat transfer characteristics of heat pipes, the embodiments of the present disclosure can realize a substantial reduction in the cost of larger, heavier vapor chests while improving overall performance.

[0513] Some existing thermal solutions use large steam chests that cover almost 40% of the interior area of ​​some systems. This is shown in the example system of Figure 9a.

[0514] In the example of a consumer gaming laptop system, the vapor chamber extends towards the right edge of the internal system base, allowing the system to have an additional fan outlet with better cooling capacity.

[0515] Both of these configurations can incur costs that exceed the desired goal. Another consideration with existing steam chests is the "dead corner" problem. Steam chests are generally designed to transfer heat in a radial direction, while heat pipes transfer heat in a linear direction. Thus, steam chests are best suited for rectangular shapes. However, in practice, the steam chest shape must fit into the existing system layout. Thus, current designs may be inadequate for efficient heat transfer.

[0516] For example, in Figure 9a, a temperature delta may be generated in the bottom right corner of the steam chest, meaning that heat cannot be transferred to this area due to the geometry of the system base. To solve this problem, an additional graphite spreader could be added, but this would increase costs.

[0517] This disclosure describes an edge-to-edge vapor chamber design for high performance laptops with fan outlets on both side edges. The design includes straight heat pipes that are arranged perpendicular to the motherboard without bends and are attached to the side edges of the vapor chamber to maximize the performance of the heat pipes. Using this approach, the size of the vapor chamber and the length of the heat pipes can be minimized without trading off performance.

[0518] Advantages of the disclosed embodiments include: 1.Reduced steam chamber costs due to reduced raw materials and lighter weight 2. Easier manufacturing, improved yield rates, and reduced costs 3.Improved performance, reduced skin temperature and improved acoustics.

[0519] FIG. 9b is a diagram of a heat transfer assembly 9200 that may be used in place of or in conjunction with the assembly of FIG. 9a.

[0520] In this example, the heat transfer assembly 9200 includes a planar steam chamber 9204, which in this case is substantially rectangular. This steam chamber can still be considered a planar steam chamber, for example because its length is at most about five times its width. This is an imprecise definition that separates steam chambers from heat pipes, but it does not apply in this case. The heat transfer assembly 9200 also includes fans 9212-1 and 9212-2, which are also strategically positioned to evacuate heat from the steam chamber 9204. At the short end of the steam chamber 9204 are two heat pipes 9220-1 and 9220-2. The heat pipes 9220 are a special case of a steam chamber. Specifically, the heat pipes 9220 have a longer dimension that is about five times greater than its shorter dimension.

[0521] A truly planar steam chest, such as one with approximately equal length and width, will radiate heat radially, resulting in heat spreading in substantially all directions. The steam chest 9204 in this illustration is not close to being perfectly planar and may therefore experience somewhat hybrid heat spreading. Heat spreads radially from the evaporator region, which may be located approximately at the geometric center of gravity of the steam chest 9204, for example. However, because the steam chest 9204 is longer than it is wide, it also experiences some lateral movement along its length dimension. This carries heat away to the edges of the steam chest 9204 at both ends, where it is transferred to the heat pipes 9220, since they are in conductive contact with the steam chest 9204. The heat pipes 9220 can then efficiently transfer the heat to the fan 9212.

[0522] Note that in this figure, the heat pipes 9220 are sealed away from the vapor chamber 9204. Thus, in this figure, there is no vapor chamber with a complex geometry, but simply a rectangle. This configuration achieves an advantage over the heat transfer system of FIG. 9a in that the vapor chamber 9204 is smaller than the vapor chamber 9104 of FIG. 9a, and therefore less expensive to manufacture. Furthermore, the heat pipes 9220 associated with the vapor chamber 9204 transfer heat more efficiently than a single large vapor chamber with a complex geometry. Thus, the heat transfer assembly 9200 of FIG. 9b is less expensive and more effective than the complex geometry vapor chamber of FIG. 9a.

[0523] FIG. 9c is a perspective view of an alternative heat transfer assembly 9300.

[0524] Heat transfer assembly 9300 is slightly different than heat transfer assembly 9200. In this case, heat transfer assembly 9300 includes a vapor chamber 9304 with two "hot plates" or evaporators 9316-1 and 9316-2. As shown, the vapor chamber 9304 is more of a square, with length and width dimensions more evenly spaced from one another. In this case, lengthwise heat pipes 9320-1 and 9320-2 carry heat away from the vapor chamber 9304. Widthwise heat pipes 9322-1 and 9322-2 then carry the heat down toward fans 9312-1 and 9312-2.

[0525] As mentioned above, heat pipes provide more linear or lateral thermal displacement, while planar vapor chambers experience more radial heat transfer. Thus, heat pipes 9320 and 9322 may be used to direct heat to specific areas away from the disclosed heat sources.

[0526] FIG. 9d is an alternative top view of the steam chamber 9404 with heat pipes 9422-1 and 9422-2. FIG. 9d shows how the effective steam zone is distributed and how the heat pipes are connected to the steam chamber. The steam chamber is connected to the heat pipes only from the side edges of the steam chamber. For simulations, this was found to be an advantageous arrangement for the heat pipes. Previous models have shown that extending the steam chamber towards the bottom edge of the lateral heat exchanger gives good temperature simulation results, but the steam in the steam chamber may not be able to diffuse sufficiently due to physical limitations of the steam chamber's internal structure. The design of the present disclosure is a balance between cost and performance.

[0527] Figure 9e is a top view of the heat transfer assembly 9500 in situ in a portable computing device. Figure 9e shows details of an exemplary vapor chest assembly design of the present disclosure and how it may be placed within a system. The example of Figure 9e shows up to a 60% reduction in vapor chest size compared to conventional designs without compromising heat spreading performance.

[0528] FIG. 9f is a perspective view of a planar steam chest 9600 that may be used in conjunction with the "starburst" structural support pattern.

[0529] Improving heat spreading in low-profile, aggressive z-height mobile systems (defined by the thickness of the motherboard and its components, which can be as little as 3mm) is often critical to maintain safe junction temperatures, reduce hot spots on the outer skin, and meet ergonomic thermal limitations. Ultra-thin vapor chambers are one option for heat dissipation in these low-profile systems. As with other heat spreading and dissipation solutions, such vapor chambers may need to be mechanically coupled to the die or other heat source to operate effectively.

[0530] Loading the steam chest to reduce the thermal impedance to the heat source can pose difficulties due to the somewhat weak, hollow nature of the steam chest. If excessively loaded, the steam chest can collapse or flex excessively, which reduces the effectiveness of the thermal interface material (TIM) or the steam chest itself. This problem is further exacerbated by reducing the overall thickness of the steam chest with aggressively thin form factors.

[0531] In certain embodiments of the present disclosure, internal structural elements are included within the vapor chamber that allow for a more rigid assembly capable of supporting thermal interface loads. Such embodiments can open new design space for low-profile mounting methods for thinner and lighter clamshell and 2-in-1 devices.

[0532] The internal structuring element may be called a "starburst" or "radial" pattern. Previous solutions include: Thermal adhesives can be used to avoid the need to maintain a load on the steam chest. However, many low pressure and low temperature cure thermal adhesives have relatively poor thermal performance. Generally, reduced thermal resistance dictates the need for the thinnest possible gap between the heat source and the thermal solution. Better thermal performance and thinner bond line adhesives are possible, but may require a load to be applied during the curing process. Some adhesives require high cure temperatures, which can impair the function of the steam chest due to thermal expansion of the working fluid inside. Stiffener plates can be soldered or attached to the vapor chamber to provide additional rigidity, but these also consume z-space that may be at a premium in low-profile systems. Additionally, stiffener plates on the condenser side of the chamber may not reduce the risk of vapor chamber collapse on the evaporator side if the attached die surface is relatively small and creates localized loads against the attached surface. Evaporator-side stiffeners may need to be placed outside of the package area to conserve z-height and therefore may have to share space with other components on the motherboard. Copper pillars can be added internally to the steam chest to help maintain separation between the evaporator and condenser sides, but primarily to improve compressive load performance versus bending and / or flexural stiffness.

[0533] FIG. 9 g is a perspective view of an in situ vapor chest 9704 with a system-on-chip 9716 thermally coupled directly or nearly directly to an evaporator 9712 and a heat sink 9708 .

[0534] 9h is an in situ illustration in a side view of a planar vapor chamber 9804. The planar vapor chamber 9804 is thermally coupled to active components 9808, which may be soldered to, for example, a motherboard or other circuit board.

[0535] 9i is an illustration in side view of bending of the steam chest. As shown, the steam chest 9904 is attached to the active component 9908. Fastening means 9912-1 and 9912-2, e.g. screws or bolts, fasten the steam chest 9904 to the active component 9908. This ensures good, intimate thermal contact and increases the efficiency of heat transfer. However, as shown, this may result in bending of the steam chest 9904.

[0536] The disclosed embodiments provide an integrated structure within the chamber that acts structurally to reinforce the chamber and prevent it from collapsing, as well as provide a low-profile mounting mechanism. The disclosed embodiments also provide benefits to devices with passive cooling, allowing higher loads to be applied to the vapor chamber due to an improved thermal interface to the die (with thinner, more consistent bond lines), mitigating deflection in the vapor chamber, and reducing the risk of interference with package stiffeners or nearby components. These advantages can reduce the required total z-budget, as formed pedestals that space the vapor chamber away from the die can be shortened or eliminated. Certain embodiments can also enable low-profile mounting methods that meet increasingly restrictive z-height targets.

[0537] Steam chests with multi-artery wicks to improve fluid transport in high power applications have been used for many years. However, such embodiments are sometimes not utilized for mobile products driven by skin temperature limitations. The artery-like wicks herein are extended beyond the heat source and integrated with each mounting location. This interface where the steam chest is attached to the system dramatically improves the stiffness above the package while facilitating proper loading.

[0538] FIG. 9j is a cut away perspective view of a steam chest 91004 employing a starburst structural support pattern.

[0539] FIG. 9k is a more detailed view of the starburst structure support pattern on the steam chest. In FIG. 9k, the steam chest 91104 includes a starburst structure support pattern 91108. The starburst structure 91108 includes attachment points 91112-1, 91112-2, 91112-3, and 91112-4. The attachment points 91112 may provide through holes through which fastening means such as screws or bolts can pass to attach the steam chest 91104 to the column.

[0540] FIG. 9l is a perspective view of the support columns within the steam chamber.

[0541] Figure 9m is a perspective view of a columnar starburst pattern.

[0542] In some applications, these structures focus on increasing the flow of fluid to the "hot zone" of the chamber or to the evaporator, and not primarily on improving the structural properties of the chamber. The disclosed embodiments introduce a radial or starburst pattern that can expand to encompass the entire package surface, not just the die. The size and shape of the arteries can balance thermal and structural performance. Individual ribs can also incorporate mounting features to improve structural integrity along the load path within the vapor chamber, such as through holes or rings around countersunk holes.

[0543] Modeling using finite element analysis (FEA) was used to compare a standard copper pillar vapor chamber to the embodiments herein. Both the copper pillar vapor chamber and the vapor chamber of the present disclosure use 200 μm thick walls with a 1 mm thick vapor cavity for a total assembly of 1.4 mm thickness. The chamber assembly may be constrained by mounting holes (or locations if no holes are present) at the four corners, and a die load of 20 pounds force (lbf) may be applied to the underside of the evaporator for modeling purposes. The baseline maximum deflection under these conditions has been shown to be 4-5 times greater for the copper pillar vapor chamber than the currently disclosed embodiments.

[0544] One possible embodiment of a lower profile mounting system utilizes the disclosed internal structure of the vapor chamber to transfer the spring force from the support plate to the top of the die through the thermal interface. Because the structure is integrated into the vapor chamber, possibly as a sintered material rather than a solid, this type of structure may be lighter overall.

[0545] It should be noted that the internal structure needs to be refined to balance both structural and thermal performance, and thus the actual shape and design of the internal structure may differ from the disclosed example.

[0546] FIG. 9n is an in situ diagram 91400 in a side view of a steam chamber 91404. This in situ view shows the advantage of the starburst pattern.

[0547] Specifically, the steam chamber 91404 is positioned above the active components 91408, and the attachment means 91412-1 and 91412-2 hold the steam chamber 91404 in intimate contact with the active components 91408 for good thermal conductivity and transfer. However, the starburst structural pattern provides less curvature in the steam chamber 91404.

[0548] Figure 9o is a top view of the steam chamber 91504. The steam chamber 91504 is simply a two part steam chamber with portions labeled part 1 91520 and part 2 91522. A hot plate 91508 is located above the active components such as the SoC.

[0549] In an additional aspect herein, the pressure loss of the vapor in the vapor chamber is reduced as it travels from the evaporator to the condenser, thereby improving its thermal performance. This is accomplished by strategically removing wicks from patches to reduce the vapor pressure loss from the evaporator to the condenser. The removal of the wick increases the vapor flow area in the vapor chamber without increasing the thickness of the vapor chamber. Once condensed, the liquid reaches the evaporator through a wick located elsewhere in the system base. A similar effect can be achieved by localized thickening in heat pipes.

[0550] 9p is a side view of the steam chamber 91604. In the illustrated side view of the steam chamber 91604, a top plate 91612 and a bottom plate 91612 are visible. An upper wick 91620 is affixed to the top plate 91612 and a lower wick 91624 is affixed to the bottom plate 91616. An active component 91608 is in intimate thermal contact with the hot plate of the steam chamber 91604. Columns 91632 help provide str...

Claims

1. A cooling system for an electronic device, comprising: a heat distribution structure coupled to a heat source of the electronic device to distribute heat generated by the heat source; At least one ventilation including a main blow direction, the at least one ventilation being arranged such that the main blow direction is directed toward the heat distribution structure; a guide structure having a plurality of channel walls between the heat distribution structure and the electronic device enclosure; having Cooling system.

2. The cooling system of claim 1 , wherein the heat distribution structure comprises at least one of a vapor chest or a heat pipe.

3. The cooling system of claim 1 or 2, wherein at least 50% of the air flow caused by the at least one ventilation flows along a surface of the heat distribution structure.

4. a heat distribution structure configured to be coupled to a heat source of an electronic device, the heat distribution structure having at least one of a vapor chest or a heat pipe; A blower configured to generate a flow of air along a surface of the heat distribution structure, the blower comprising: a maximum length and width of at most 20 mm; or Maximum thickness of at most 3mm a blower having at least one of: a guide structure having a plurality of channel walls between the heat distribution structure and the electronic device enclosure; having Cooling system.

5. The cooling system of claim 4 , wherein at least 50% of the airflow caused by the blower flows along the surface of the heat distribution structure.

6. 1. A cooling system for a computing device, the cooling system comprising: a thermally conductive element, the thermally conductive element being suitable for cooling a processing unit of the computing device; at least one blower fan for blowing air across a portion of the heat conducting element; a control circuit configured to activate or deactivate the at least one blower fan based on a thermal load of a processing unit of the computing device; a guide structure between the heat-conducting element and the back surface of the screen of the computing device; having Cooling system.

7. The cooling system of claim 6 , wherein the heat transfer element comprises a vapor chest.

8. a first heat distribution structure coupled to the heat source to distribute heat generated by the heat source; A thermoelectric cooler; a second heat distribution structure, wherein a first surface of the thermoelectric cooler is thermally coupled to the first heat distribution structure and a second surface of the thermoelectric cooler is thermally coupled to the second heat distribution structure; a heat pipe disposed adjacent to the thermoelectric cooler on the first heat distribution structure; and It has the thermoelectric cooler is located closer to an edge of the first heat distribution structure in at least one direction than the heat pipe; Cooling system.

9. A cooling system as described in claim 8, wherein the heat pipe extends to a fan of the cooling system.

10. A cooling system as described in claim 8 or 9, wherein the heat pipe is coupled to the first heat distribution structure in a region opposite the center of the heat source.

11. 11. The cooling system of claim 8, wherein a first surface of the heat pipe is thermally coupled to the first heat distribution structure and a second surface of the heat pipe is thermally coupled to the second heat distribution structure.

12. a heat distribution structure configured to spread heat generated by a heat source from a central region to an edge region of the heat distribution structure, the heat distribution structure configured to be thermally coupled to the heat source at the central region on a first side of the heat distribution structure; a boundary located on the heat distribution structure, the boundary surrounding the central region of the heat distribution structure on a first side of the heat distribution structure; Cooling system.

13. The cooling system of claim 12 , wherein the heat distribution structure has a planar surface in the central region.

14. 14. The cooling system of claim 12 or 13, wherein the boundary protrudes from the surface of the central region by at most 1 mm.

15. a heat distribution structure thermally coupled to a heat source within an enclosure for an electronic device, the heat distribution structure having a heat distribution structure extending from an interior of the enclosure to an exterior of the enclosure; 1. A cooling system comprising: the heat distribution structure is a laminar heat spreader; Cooling system.

16. 16. The cooling system of claim 15, wherein the layered heat spreader comprises a graphite sheet, a graphene sheet, or a metal foil.

17. 17. The cooling system of claim 15 or 16, wherein the enclosure comprises an opening, and the heat distribution structure extends through the opening from the interior to the exterior.

18. An electronic device comprising a cooling system according to any one of the preceding claims.

19. a semiconductor die; a cooling structure comprising a heat distribution structure configured to spread heat generated by the semiconductor die from a central region to an edge region of the heat distribution structure, the heat distribution structure being thermally coupled to the semiconductor die at the central region on a first side of the heat distribution structure; a seal ring attached to a boundary surrounding a central region of the heat distribution structure, the seal ring sealing a gap between the boundary and a packaging substrate of the semiconductor die; An electronic device having the semiconductor die is directly thermally coupled to the heat distribution structure via a thermal interface material; electronic equipment.

20. 1. A method for operating an electronic device, comprising: operating a heat source of the electronic device; distributing heat generated by the heat source during operation through a heat distribution structure; blowing air along a surface of the heat distribution structure with a fan, the vertical extent of the fan overlapping the vertical extent of the heat distribution structure; and method.

21. 1. A method for manufacturing an electronic device, comprising: thermally coupling a heat distribution structure to a heat source, the heat distribution structure configured to spread heat caused by the heat source from a central region to an edge region of the heat distribution structure, the heat distribution structure being thermally coupled to the heat source at the central region on a first side of the heat distribution structure; forming a boundary on or attached to the heat distribution structure on the first side of the heat distribution structure, the boundary surrounding the central region of the heat distribution structure; method.

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