heat sink

Abstract

This provides a heatsink for wireless units such as remote wireless devices. [Solution] The heat sink (200) for the wireless unit comprises a base (201) having a surface and a central vertical axis (A1) such that a first portion (202) is above a second portion (204), and a first plurality of protruding members (212) extending from the first portion (202) of the surface, the first plurality of protruding members (212) extending sufficiently along the surface over the entire first portion (202) with respect to each other and parallel to the central vertical axis (A1), and a second plurality of protruding members (214) extending from the second portion (204) of the surface, uniformly spaced along the first portion (202), with at least part or some of the protruding members extending along the surface and angled with respect to the first plurality of protruding members (212).

Description

Technical Field

[0001] Embodiments of the present specification relate to a heat sink, and more particularly, to a heat sink for a wireless unit such as a remote wireless device.

Background Art

[0002] The proper operation of modern electronic devices often requires a way to dissipate the heat generated by the electronic components of the device. Therefore, the thermal management of electronic devices becomes increasingly important. For example, in 3G mobile communication technology, remote radio units (RRUs) are widely used to convert optical signals into radio frequency signals and perform signal amplification. The RRU can be placed on a cell tower and, during operation, generates an excessive amount of heat and thus may have increasing thermal requirements. Sufficient cooling is required to maintain the reliability and functionality of the RRU and increase the lifespan of the RRU.

[0003] Heat sink devices, or heat sinks, are often used to dissipate heat in devices containing electronic components such as RRUs. A heat sink is generally a passive heat exchanger device that functions to regulate the temperature of an electronic and / or mechanical device by absorbing heat and dispersing it away from the device to the surroundings. The heat sink transfers heat from the heat-generating component to air (or a liquid coolant), enabling the heat to dissipate away from the device.

[0004] Although there are various configurations of heat sinks, there is still a need for a heat sink having a structure that is efficient in heat dissipation and has other beneficial features.

Summary of the Invention

[0005] As part of developing the embodiments described herein, one or more problems have been identified. In particular, electronic devices, such as processing units like RRUs, are often generally constrained in terms of size and have thermal demands that increase over time. At the same time, wind-driven acoustical noise, which can be generated by heatsinks coupled to electronic devices, also becomes a problem, for example, due to the effects of the geometric uniformity and size of existing heatsinks.

[0006] Conventional heatsinks generally have fins that extend uniformly vertically along the base of the heatsink. RRUs can be exposed to ambient winds traveling from different directions and at different speeds. When wind travels over an RRU with a heatsink or another object, cavities between the cooling fins of the heatsink can cause high-pitch whistling noise. The frequency of the whistling noise is within the range that is audible to humans and animals, raising environmental and health concerns. Furthermore, remote radio products are directly exposed to the environment and are therefore affected by atmospheric wind conditions, which can lead to an expansion of certain acoustic frequencies that act as an obstacle to nearby resolution.

[0007] Various existing heatsinks are implemented to address either thermal performance or wind-induced acoustic noise (or other concerns), rather than addressing both thermal performance and noise generation.

[0008] Accordingly, embodiments of this disclosure provide a heatsink that simultaneously improves thermal performance and provides attenuation / reduction of wind-induced acoustic noise. The heatsinks provided herein are a unique natural convection heatsink structure / system, which are also referred to as hybrid heatsinks or interchangeably heatsinks. The heatsinks are optimized to operate with less noise than existing heatsinks and are therefore sometimes referred to as silent hybrid heatsinks.

[0009] A part of the present disclosure provides a heat sink for a wireless unit, comprising a base having a surface and a central longitudinal axis, the surface comprising a first portion and a second portion arranged along the central longitudinal axis such that the first portion is above the second portion. The heat sink also comprises a first plurality of protruding members and a second plurality of protruding members, interchangeably also called fins. Thus, the heat sink comprises a first plurality of protruding members extending from the first portion of the surface, wherein the protruding members from the first plurality of protruding members elongate along the surface over the entire first portion, parallel to each other and with respect to the central longitudinal axis, and the first plurality of protruding members are uniformly spaced apart along the first portion. The heat sink further comprises a second plurality of protruding members extending from a second portion of the surface, wherein at least part or some of the second plurality of protruding members are arranged to extend straight along the surface and be angled relative to the first plurality of protruding members.

[0010] Therefore, the heatsink is constructed from two main structural parts, namely a first part having fins or protruding members as in a conventional heatsink, and a second part having fins angled relative to the fins in the first part, and having channels extending through it. The fins in the second part may form two separate sets of fins, with the fins in one set angled inward and upward relative to the fins in the other set, i.e., inward and upward from the lower left corner of the second part, and inward and upward from the lower right corner of the second part. The first part, with fins as may be found in a conventional setting, works to provide thermal cooling, while the second part works to cool and reduce noise that may be generated by the heatsink during operation. Thus, the first and second parts work together to improve or maximize the performance of the analog components, while reducing the impact of the analog components on the digital components and providing more cooling potential to the digital components. The provided implementation configuration allows for a reduction in heatsink weight, improved acoustic attenuation, and facilitates fan airflow.

[0011] The heatsink according to embodiments of this disclosure provides an effective way to both attenuate / break up wind-induced acoustic noise and improve the thermal performance of the heatsink system without reducing the thermal potential for cooling critical analog components, thereby improving the thermal performance of the digital components of the equipment employing the heatsink. The heatsink has robust flow control by having additional flow paths on the side inlets of the heatsink structure, which reduces the effect of possible flow obstructions. Furthermore, the side access inlets for the heatsink allow for further extended cooling from outdoor wind fluctuations.

[0012] Next, embodiments will be described in more detail with reference to the enclosed drawings. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram shows a portion of a conventional heatsink and schematically illustrates the generation of whistling noise due to wind. [Figure 2] This diagram shows a front view of a conventional heatsink. [Figure 3] This figure shows a front view of the heat sink according to the disclosed embodiment. [Figure 4] This figure shows a front view of a conventional heatsink (A), a front view of a heatsink (B) with an alternative configuration, and a front view of a heatsink (C) according to an embodiment of the present disclosure. [Figure 5] This is another figure showing a front view of a heat sink according to an embodiment of the disclosure. [Figure 6] This figure shows a perspective side view of a heat sink according to the embodiment of this disclosure. [Figure 7] Figure 6 shows a perspective view of the fin portion of the heatsink, illustrating the angle of inclination of the fin portion due to the channels formed within the fins. [Figure 8A] Figure 6 schematically shows the shape of the channels extending through the fins in the heatsink, and the shapes of the upper and lower parts of the central channel (Figures 8A and 8B, respectively) and the shape of the side channels (Figure 8C). [Figure 8B] Figure 6 schematically shows the shape of the channels extending through the fins in the heatsink, and the shapes of the upper and lower parts of the central channel (Figures 8A and 8B, respectively) and the shape of the side channels (Figure 8C). [Figure 8C] Figure 6 schematically shows the shape of the channels extending through the fins in the heatsink, and the shapes of the upper and lower parts of the central channel (Figures 8A and 8B, respectively) and the shape of the side channels (Figure 8C). [Figure 9A] This figure schematically shows the airflow path through a conventional heatsink (Figure 9A) and the airflow path through a heatsink according to the embodiment of the present disclosure (Figure 9B). [Figure 9B]This figure schematically shows the airflow path through a conventional heatsink (Figure 9A) and the airflow path through a heatsink according to the embodiment of the present disclosure (Figure 9B). [Figure 10] This figure shows a perspective side view of a heat sink according to the embodiment of this disclosure. [Figure 11] This figure shows a perspective view of an example of a heat sink in panels A and B according to an embodiment of the present disclosure. [Figure 12] This figure shows another perspective view of the heatsink shown in Figure 11. [Modes for carrying out the invention]

[0014] Embodiments of this specification relate to a heat sink, also called a hybrid heat sink, having a base having a first upper portion and a second lower portion, wherein the configuration of fins extending from the first portion differs from the configuration of fins extending along the second portion. These two structural parts of the heat sink allow for both improved thermal performance of the heat sink and attenuation / reduction of acoustic noise caused by wind that may be generated in the heat sink.

[0015] FIG. 1 schematically shows how whistling noise can be generated in a heat sink 100, such as in a conventional natural convection heat sink. This heat sink can be a passive heat sink where the buoyancy of hot air alone causes an air flow generated across the heat sink. As shown in FIG. 1, since the wind 104 travels over the protruding members or fins 106 and 108, such as cooling fins or simply fins, of the heat sink 100, the flow of the wind 104 is split over the first fin 106 and the second fin 108, thereby causing vortices 110. When the vortices 110 hit the second fin 108, pressure fluctuations 112 can be brought about. If the pressure fluctuations 112 are caused by wind having a certain wind speed, the pressure fluctuations 112 can cause an acoustic feedback loop 114, thereby causing whistling noise. This noise is audible to humans, animals, and birds and can thus be a significant limiting factor during the use of heat sinks such as the heat sink 100.

[0016] FIG. 2 shows a front view of a conventional heat sink 100 and shows fins 103 extending on the surface of the base 101 along the vertical axis A of the base 101 of the heat sink 100. The heat sink 100 can be, for example, a natural convection heat sink. During use, the heat sink 100 can be disposed in the vertical direction, and the gravity g (vertical force) is shown in FIG. 2 for the purpose of illustration. The fins 103 in the conventional heat sink 100 are uniformly spaced along the base 101 such that the fins 103 form parallel rows of fins along the base 101.

[0017] For example, in conventional heat sinks, such as the heat sink 100 shown in Figure 2, heat may be diffused with a high degree of efficiency from a heat source, such as a high-density heat source, through a standard linear fin structure. In this case, the high-density heat source needs to diffuse heat downward so that it is cooled more efficiently. However, this has a detrimental effect on the cooling potential of components located lower down along the heat dispersion path, such as digital components. To improve the conditions for lower components (e.g., digital components) and still to utilize at least partially the strength of conventional heat sink structures, a heat sink structure according to embodiments of the present disclosure is provided herein. The heat sink comprises a base having a surface and a central longitudinal axis, the base comprising a first portion and a second portion arranged along the central longitudinal axis such that the first portion is above the second portion. The heat sink further comprises a first plurality of protruding members extending from a first portion of the surface, wherein the protruding members from the first plurality of protruding members extend sufficiently along the surface over the entire first portion or over the first portion, parallel to each other and to the central longitudinal axis, and the first plurality of protruding members are uniformly spaced apart along the first portion. The heat sink also comprises a second plurality of protruding members extending from a second portion of the surface, wherein at least part or some of the protruding members of the second plurality of protruding members extend straight along the surface and are configured to be angled with respect to the first plurality of protruding members.

[0018] Therefore, in a heat sink constructed using a combination of conventional fins and angled fins in a conventional configuration, an angled fin structure, sometimes referred to as a delta part or section, is configured to alter the heat transfer dynamics in both the conduction path and the air flow path. Thus, less heat is transferred downward in the heat sink because more heat is conducted to the sides, where it is dissipated with higher efficiency, due to the improved inflow properties of the cooler air and not just the lower part in a conventional heat sink, but the overall larger inlet area, the lower plus the side surfaces as inlets. Since less heat is conducted downward as much as in the existing system, the lower part generally becomes cooler, thereby reducing the influence from analog components on digital components. In embodiments of this specification, this lower part can be further extended by forming channels or cuts in the fins of the lower part, as will be described in more detail below with reference to FIGS. 4 (Panel C), 5, 6, 9B, 10, 1, and 12.

[0019] FIG. 3 shows a front view of a hybrid heat sink 200 according to an embodiment of the present disclosure. The heat sink 200 includes a base plate or base 201 having a surface and a central longitudinal axis A1. Since the surface coincides with the base 201 in FIG. 3, it is not separately labeled herein and includes a first portion 202 and a second portion 204 disposed along the central longitudinal axis A1 such that the first portion 202 is above the second portion 204. The heat sink 200 also includes a first plurality of protruding members or fins 212 and a second plurality of protruding members or fins 21 . The first plurality of protruding members 212 and the second plurality of protruding members 214 can be plates, such as metal plates, having a uniform height over their entire length. The first plurality of protruding members 212 have the same length. The protruding members from the second plurality of protruding members 214 can have different lengths, as shown in FIG. 3.

[0020] The first portion 202, having a plurality of first protruding members 212, works to provide a thermal cooling effect. The second portion 204, having a plurality of second protruding members 214, is configured to reduce or attenuate acoustic noise that may be generated by wind or other air movement.

[0021] The first plurality of protruding members 212 extend from the first portion 202 of the surface, and the protruding members from the first plurality of protruding members 212 extend sufficiently along the surface over the entire first portion 202 or over the first portion 202, parallel to each other and parallel to the longitudinal axes of the heat sink 200, such as the central longitudinal axis A1. The protruding members from the first plurality of protruding members 212 may extend along the surface substantially parallel to each other, i.e., their protruding members are parallel or parallel within some angular intervals, such as within angular intervals due to manufacturing variations, tolerances, and inaccuracies. The first plurality of protruding members 212 are substantially straight (i.e., straight or straight within some angular intervals, such as within intervals due to manufacturing variations, tolerances, and inaccuracies) and uniformly spaced along the first portion 202. As shown in Figure 3, the first set of protruding members 212 extend along the surface in parallel rows in the same manner as or similar to the protruding members 103 of the conventional heat sink 100 in Figure 2.

[0022] The second set of protruding members 214 extend from the second portion 204 of the surface. As shown in Figure 3, at least part or some of the protruding members of the second set of protruding members 214 are configured to extend straight along the surface and be angled relative to the first set of protruding members 212. The protruding members from the second set of protruding members 214 may be in the form of elongated plates, the surfaces of which are perpendicular to the surface of the base 201, and which are positioned on the second portion 204 of the surface in an angled manner relative to the first set of protruding members 212.

[0023] For example, there may be a space between the second set of protruding members 214 and the first set of protruding members 202 along the horizontal axis B1. This space may be infinitesimally small. Alternatively, some or all of the protruding members from the first set of protruding members 212 may extend further along the second portion 204 of the base 201 in an angled setting, such that each also forms a projection of the second set of protruding members 214.

[0024] In the embodiment, the first plurality of protruding members 212 and the second plurality of protruding members 214 are perpendicular to the surface of the base 201. As an example, a number of protruding members is shown in Figure 3. The heat sink 200, and other heat sinks according to embodiments of the present disclosure, may include any preferred number of protruding members from the first protruding members 212 and any preferred number of protruding members from the second plurality of protruding members 214.

[0025] As further shown in Figure 3, the second set of protruding members 214 comprises two sets of protruding members, shown on the left and right sides, respectively, angled inward and upward relative to each other, i.e., toward the central longitudinal axis A1. In Figure 3, the fins in one set extend along the base 201 such that the fins are inclined inward and upward from the left side of the base 201, and the fins in the other set extend along the base 201 such that the fins are inclined or tilted inward and upward from the right side of the base 201. It should be noted that the protruding members of the second portion 204 can also be considered to extend outward and downward away from the part of the central longitudinal axis A1 that extends through the second portion 204.

[0026] The second portion 204 of the surface of the base 201 comprises a third portion 206 and a fourth portion 208. The third plurality of protruding members 216 extend from and along the third portion 206, and the fourth plurality of protruding members 218 extend from and along the fourth portion 208, with the third plurality of protruding members 216 and the fourth plurality of protruding members 218 being angled inward and upward with respect to each other.

[0027] As shown in Figure 3, the third plurality of protruding members 216 of the third portion 206 and the fourth plurality of protruding members 218 of the fourth portion 208 extend along the surface of the second portion 204 such that the central channel 220 is formed along the central longitudinal axis A1. Note that the central longitudinal axis A1 coincides with the longitudinal axis of the base 201 (not shown), and is shown to illustrate the symmetry between the third plurality of protruding members 216 and the fourth plurality of protruding members 218 with respect to the centerline of the base surface of the heat sink 200.

[0028] The central channel 220 extends between the third and fourth protruding members 216 and 218. The central channel 220 has no protruding members and generally has an inverted trapezoidal shape, i.e., it may be a strictly trapezoid or a trapezoid with some possible small variation from a strictly trapezoidal shape, for example, it may have a trapezoidal concave side. The shape of the central channel 220 and the portion formed by the channel from the protruding members may also vary due to manufacturing variations. The shape of the central channel 220 may differ in various mounting configurations of the heatsink 200, but the general shape is still an inverted trapezoid. The vertical axis (not shown) of the central channel 220 may coincide with the central vertical axis A1. The central channel 220 may have a width of approximately 1% to 10% of the width of the base 201 at its widest part, i.e., at the top, and the width of the base 201 is measured along an axis perpendicular to the central vertical axis A1.

[0029] Furthermore, please understand that the topology of the second plurality of protruding members 214, which comprises a third plurality of protruding members 216 and a fourth plurality of protruding members 218, may differ from the topology shown in Figure 3. Additionally, the size and number of channels formed in the third plurality of protruding members 216 and the fourth plurality of protruding members 218 may vary. The number of protruding members in the first plurality of protruding members 212 and the number of protruding members in the second plurality of protruding members 214 may also vary depending on the specific mounting configuration of the heat sink 200 according to the embodiments of this disclosure.

[0030] The first portion 202 and the second portion 204 may have substantially the same length or height, as measured along the central longitudinal axis A1 of the base 201. For example, the first portion 202 may occupy about 50% of the base 201, and the second portion 204 may similarly occupy about 50% of the base 201, and the total length of the first portion 202 and the second portion 204 may be considered to be 100%. As used herein, “about” means the number itself and within 5% plus or minus of the stated number. For example, about 50% means 50 and / or any number in the range from 47.5 to 52.5, including both ends. In some implementations, the first portion 202 may occupy about 60% of the base 201, and the second portion 204 may occupy about 40% of the base 201. In some implementations, the first portion 202 may occupy approximately 40% of the base 201, and the second portion 204 may occupy approximately 60% of the base 201. The lengths of the first portion 202 and the second portion 204 may depend on the details of the equipment or device using the heatsink 200, the nature and requirements of the surrounding environment, and other factors.

[0031] Furthermore, the spacing between the protruding members of the first plurality of protruding members 212 and the protruding members of the second plurality of protruding members 214 may depend on the type of device in which the heat sink 200 is used.

[0032] Please understand that the heatsink 200 may have other components not shown herein for clarity of representation. The heatsink 200 may be coupled to a wireless unit such as an RRU, or any other device. The heatsink 200 may be used in a large-scale multiple-input multiple-output (MIMO) system.

[0033] For example, conventional heatsinks, such as the one shown in Figure 2, are known to maximize cooling for analog components, such as (high-density) power transistors, for example, for the bulk heat generated (e.g., temperatures of 100°C or about 100°C, a temperature range of 95°C to 105°C, or other temperature ranges). However, conventional heatsinks may not help cool digital components, such as printed circuit board (PCB) components, such as field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). Digital components can become hot up to about 90°C. The first and second parts of the hybrid heatsink according to embodiments of this disclosure work together to maximize the performance of the analog components while reducing the influence (by the analog components) on the digital components, as shown, for example, in Figure 3. For example, the temperature reduction of the digital components can be achieved such that the temperature is lowered by, for example, 5°C, resulting in an absolute temperature of about 85°C. In this way, the influence of the analog components on the digital components is reduced, thereby improving the thermal performance of the digital components.

[0034] Figure 4 schematically illustrates the acoustic and thermal design advancements for heat sinks. A general wind from the side of the heat sink is schematically shown with respect to panel C, but this wind description is also applicable to the heat sinks shown in panels A and B. Figure 4 shows a conventional heat sink (panel A), a heat sink with an alternative configuration (panel B), and a hybrid heat sink according to embodiments of the present disclosure (panel C). In the examples herein, the conventional heat sink may be for the prior art radio shown in Figure 2, and the alternative configuration is referred to as another prior art radio. As shown in panel B of Figure 4, the alternative configuration of the heat sink includes only fins angled with respect to the longitudinal axis of the heat sink (not shown), and longitudinal channels may be formed within the fins. Examples of heat sinks with alternative or similar configurations are described in PCT / SE2018 / 050083, which is incorporated herein by reference in its entirety. While alternative configurations may be beneficial in terms of wind-induced noise, thermal performance may be negatively affected, or even reduced, by discontinuities in the fin configuration (where the fins are divided into many smaller fins, thus losing beneficial fin areas).

[0035] The conventional heatsink design shown in panel A of Figure 4 generates wind-induced acoustic noise (a distinct, troublesome frequency) when wind blows from the side, due to the uniformity of its structure. This necessitates a modification to the heatsink, which introduces non-uniformity to induce disordered wind movement in order to attenuate the noise generation. An example of such a modification is the alternative heatsink configuration shown in panel B of Figure 4. However, this configuration adds design complexity and reduces thermal performance.

[0036] Hybrid heatsinks, as described herein, encompass combinations of standard (or near-standard) fin configurations and angled fin configurations according to embodiments of this disclosure. Hybrid heatsink structures have structural non-uniformity that allows for disordered and unstable airflow, which attenuates potential acoustic noise throughout the heatsink. For example, the heatsink shown in panel C of Figure 4 (similar to heatsink 200 in Figure 3, but including an additional channel formed in the lower portion of the base) allows for achieving both increased thermal performance and reduced wind-induced acoustic noise. Furthermore, the hybrid structures described herein do not require modifications to the general fin geometry, which simplifies the manufacturing of the heatsink.

[0037] Figure 5 shows a front view of a heatsink 200a according to an embodiment of the present disclosure. Heatsink 200a is an example of heatsink 200 (panel C) in Figure 4. Heatsink 200a includes channels that extend through fins or protruding members in the lower portion, thereby separating some of the fins into smaller portions. The channels work to separate the movement of wind or other air movement in an extended manner due to an additional level of non-uniformity in the geometry. The channels also allow for a reduction in the weight of the heatsink.

[0038] As shown in Figure 5, the heat sink 200a comprises a base plate or base 221 having a surface and a central longitudinal axis A2. The surface is not separately labeled herein as it coincides with the base 221 in the description of Figure 5, and comprises a first portion 222 and a second portion 224 arranged along the central longitudinal axis A2 such that the first portion 222 is above the second portion 224. The heat sink 200a also comprises a first plurality of protruding members or fins 232 and a second plurality of protruding members or fins 234.

[0039] The first plurality of protruding members 232 extend from the first portion 222 of the surface, and the protruding members from the first plurality of protruding members 232 extend sufficiently along the surface over the entire first portion, parallel to each other and to the central longitudinal axis A2. The first plurality of protruding members 232 are substantially straight, i.e., straight or straight within some angular intervals, such as within intervals of about 1° to about 5°, which may be due to manufacturing variations, tolerances, and inaccuracies. The first plurality of protruding members 232 are uniformly spaced along the first portion 222. As shown in Figure 5, the first plurality of protruding members 232 extend along the surface in parallel rows, in a manner similar to the protruding members 103 of the conventional heat sink 100 in Figure 2.

[0040] The second set of protruding members 234 extend from the second portion 224 of the surface. As shown in Figure 5, at least part or some of the protruding members from the second set of protruding members 234 extend straight along the surface and are configured in an angled manner relative to the first set of protruding members 232. For example, there may be a space between the second set of protruding members 214 and the first set of protruding members 202 along the transverse axis B2. For example, a space or channel may be formed along the transverse axis B2, or approximately along the transverse axis B2 (i.e., near the transverse axis B2). The space may be infinitesimally small. Alternatively, some or all of the protruding members from the first set of protruding members 222 may extend further in an angled setting along the second portion 224 of the base 221, each also forming a projection of the second set of protruding members 234. In Figure 3, the horizontal axis B2 is shown where there is approximately a boundary between the first set of protruding members 222 and the second set of protruding members 234, and this region is marked as 223.

[0041] Similar to the heat sink 200 (Figure 3), the second portion 224 of the surface of the base 201 comprises a third portion 236 and a fourth portion 238. The third plurality of protruding members 246 extend from and along the third portion 236. The fourth plurality of protruding members 248 extend from and along the fourth portion 238. The third plurality of protruding members 246 and the fourth plurality of protruding members 248 are angled upward and inward relative to each other, that is, toward the central longitudinal axis A2 and toward each other when viewed from the side of the base 221.

[0042] As shown in Figure 5, the third plurality of protruding members 246 of the third portion 236 and the fourth plurality of protruding members 248 of the fourth portion 238 extend along the surface of the second portion 224 so that the central channel 250 is formed along the central longitudinal axis A2. Note that the central longitudinal axis A2 coincides with the longitudinal axis of the base 221 (not shown), and is shown to indicate the symmetry between the third plurality of protruding members 246 and the fourth plurality of protruding members 248 with respect to the centerline of the base surface of the heat sink 200a. The central channel 250 generally has an inverted trapezoidal shape. The exact shape of the central channel 250 may differ in various mounting configurations of the heat sink 200a, but the general shape is still an inverted trapezoid. The central channel 250 may have a width of about 1% to about 10% of the width of the base 221 at its widest part, i.e., at the top.

[0043] The spacing between the second set of protruding members 234 (i.e., between rows of fins) may depend on the spacing between the first set of protruding members 232. In embodiments, the spacing between the protruding members of the second set of protruding members 234 is smaller than the spacing between the corresponding protruding members of the first set of protruding members 232, and some of the protruding members of the second set of protruding members 234 are extensions of the corresponding protruding members of the first set of protruding members 232.

[0044] In the heat sink 200a, channels 252a, 252b, 252c, and 252d, collectively referred to as channel 252, are formed in a second plurality of protruding members 234, as shown in Figure 5. Channels 252a and 252b are formed in a third plurality of protruding members 246, and channels 252c and 252d are formed in a fourth plurality of protruding members 248. Channel 252 is formed such that some of the protruding members of the second plurality of protruding members 234 may not have channels extending through them. In some implementations, all of the protruding members of the second plurality of protruding members 234 may have channels extending through them. Channels may be formed through the entire surface of the protruding member such that the lower part of the channel is formed by the surface of the base 221.

[0045] As shown in Figure 5, channels 252a and 252b in the third set of protruding members 246 are formed such that channels 252a and 252b extend along a line that is slightly angled to the left with respect to the central vertical axis A2 in Figure 5. Similarly, channels 252c and 252d are formed in the fourth set of protruding members 248 such that channels 252c and 252d extend along a line that is slightly angled to the right with respect to the central vertical axis A2 in Figure 5. Channels 252a and 252b are formed symmetrically or substantially symmetrically with respect to channels 252c and 252d.

[0046] The configuration of the second set of multiple protruding members or fins 234, and the configuration of channels formed in the second set of multiple protruding members, enables efficient airflow through the heat sink 200a.

[0047] It should be understood that the topology of the second plurality of protruding members 224, comprising a third plurality of protruding members 246 and a fourth plurality of protruding members 248, may differ from the topology shown in Figure 5. Furthermore, the size and number of channels formed in the third plurality of protruding members 246 and the fourth plurality of protruding members 248 may vary, as the embodiments of this specification are not limited in this respect. The number of protruding members in the first plurality of protruding members 232 and the number of protruding members in the second plurality of protruding members 234 may also vary depending on the specific mounting configuration of the hybrid heatsink according to the embodiments of this disclosure.

[0048] Therefore, the heatsink 200 for the wireless unit provided herein is A base 201 having a surface and a central longitudinal axis A1, wherein the surface comprises a first portion 202 and a second portion 204 arranged along the central longitudinal axis A1 such that the first portion 202 is above the second portion 204. A heat sink comprises a first plurality of protruding members 212 extending from the first portion 202 of the surface, wherein the protruding members from the first plurality of protruding members 212 extend sufficiently along the surface over the entire first portion 202, parallel to each other and with respect to the central longitudinal axis A1, and the first plurality of protruding members 212 are uniformly spaced apart along the first portion 202. The heat sink further comprises a second plurality of protruding members 214 extending from a second portion 204 of the surface, wherein at least part or some of the protruding members of the second plurality of protruding members 214 are configured to extend straight along the surface and be angled relative to the first plurality of protruding members 212.

[0049] The second portion 204 may have a plurality of channels 252, 352 formed through at least some of the second plurality of protruding members 214.

[0050] Multiple channels may extend along axes that form acute angles with respect to the central vertical axis A1.

[0051] One or more of the multiple channels 252 may be configured in a trapezoidal shape, where the lower part is narrower than the upper part of the one or more channels.

[0052] A first section 202 for cooling analog components may be configured above a second section 204, thereby reducing the influence of the analog components on the digital components and thereby improving the thermal performance of the digital components.

[0053] The second portion 204 of the surface may comprise a third portion 206 and a fourth portion 208, and the second plurality of protruding members 214 comprises a third plurality of protruding members 216 extending from the third portion 206 of the second surface and a fourth plurality of protruding members 218 extending from the fourth portion 208 of the second surface, the third plurality of protruding members 216 and the fourth plurality of protruding members 218 being angled inward and upward with respect to each other.

[0054] The multiple channels 252 may include a central channel extending between the third and fourth multiple protruding members. The central channel may have an axis that coincides with the central longitudinal axis.

[0055] Figure 6 shows a perspective side view of a heat sink 300 according to an embodiment of the present disclosure. The heat sink 300 is an example of the heat sink 200 of Figure 3 and is therefore not described in detail herein. As shown in Figure 6, the hybrid heat sink 300 has a base 301 having a surface having a first upper portion 302 and a second lower or lower portion 304. A first plurality of protruding members 312 having a setting similar to that of a conventional heat sink extend from the first portion 302. A second plurality of protruding members 314 extend from the second portion 304, with channels 350 and 352 formed in the protruding members 314. As shown in Figure 6, the surfaces of the first plurality of protruding members 232 and the second plurality of protruding members 234 may be perpendicular to the surface of the base 221.

[0056] The boundary between the first set of protruding members 312 and the second set of protruding members 314 is indicated by a line 313, but please note that the change in the shape of the protruding members from the first part to the second part may be continuous. In other words, a straight protruding member (in the first part) may gradually become angled towards the end of the first part, and that protruding member begins to become part of the second part.

[0057] Channel 350 is a central channel between the projection member of the third portion 306 and the projection member of the fourth portion 308 of the second portion 304. The central channel 305 may be symmetrical with respect to the central longitudinal axis A3 of the base 301. Channel 352 comprises channels 352a, 352b, 352c, and 352d, where channels 352a and 352b are formed in the (third) projection member of the third portion 306, and channels 352c and 352d are formed in the (fourth) projection member of the fourth portion 308. The five channels, including the central channel 350, are merely examples shown in Figure 6, as any preferred number of channels or cuts, e.g., fewer than 5 or more than 5, may be formed through the fins of the second portion 304.

[0058] As shown in Figure 6, some of the protruding members of the third portion 306, which have a central channel 350 extending through it, have corresponding, symmetrically arranged protruding members of the fourth portion 308, which also have a central channel 350 extending through it.

[0059] As shown in Figure 6, the central channel 350 extending between the protruding member of the third portion 306 and the protruding member of the fourth portion 308 may generally have an inverted trapezoidal shape, and the sides of the channel are concave such that the upper portion 350a of the channel 350 has the shape shown in the example in Figure 8A, and the lower portion 350b of the channel 350 has the shape shown in the example in Figure 8B. Examples of the shapes of each channel 352, which may be the same or nearly the same shape and size, are shown in Figure 8C. Thus, one or more of the multiple channels 252, 352 may be configured in a trapezoidal shape, with the lower part being narrower than the upper part of one or more channels. The length of the channel 352, as measured along the central longitudinal axis A3 of the base 301, may range from about 5 mm to about 200 mm, or from about 5 mm to about 100 mm or about 70 mm. Note that the shapes of channels 350a, 350b, and 352 in Figures 8A, 8B, and 8C are shown at approximately the same scale for comparison.

[0060] In the example shown in Figure 6, channels 350 and 352 are formed in the protruding member of the second portion 304 such that the edges of the portions of the protruding member forming the channels are straight. However, it should be noted that the edges may be rounded or may have other shapes.

[0061] As shown in Figure 6, some of the protruding members do not have channels formed through them. Thus, the five protruding members in the upper left corner of the third section 306, collectively marked with reference number 360, do not have channels. Protruding member 362 has a channel 352a extending through it, and the widest upper part of the channel 352a is formed within the protruding member 362.

[0062] As further shown in Figure 6, channel 350 may be configured such that channel 350 extends at an acute angle with respect to the central vertical axis A3 of base 301. For example, as shown for channel 352a, the vertical axis 355 of channel 352a extends at an acute angle with respect to the central vertical axis A3.

[0063] The channel 352a may be formed through at least some of the protruding members from the protruding member 316, so that the resulting portion of the protruding member generally has a trapezoidal shape. Some of the protruding members may be divided into two or three (or other number, depending on the mounting configuration) parts by the channel formed through them. The side edges of the resulting portions may be beveled as shown in Figure 6. As shown in Figure 7, for example, for a portion of the fin or protruding member 364 (also shown in Figure 6), a certain angle α is formed between an axis a1 passing through the (right) side of the protruding member 364 and an axis a2 passing through the lower edge of the protruding member 364 disposed on the surface of the base 301. The angle α can range from about 10° to about 60°. In some embodiments, the angle α may be about 33°, but it should be noted that the angle α may have other values.

[0064] As described above, the heat sink 200 according to embodiments of the present disclosure has structural non-uniformity, and thereby disorderly and unstable airflow, which attenuates possible acoustic noise throughout the heat sink. The efficiency of acoustic noise reduction can be improved, for example, by having a channel formed in its lower portion, as shown in Figure 4 (Panel C), Figures 5 and 6. Figures 9A and 9B schematically show the airflow path through a conventional heat sink (Figure 9A) and the airflow path through a hybrid heat sink according to embodiments of the present disclosure (Figure 9B). Figures 9A and 9B show general airflow from the side, the bulk airflow over each heat sink, and the relative flow structure. As shown in Figure 9A for a conventional heat sink, shown as heat sink 100 (shown in Figure 2) as an example, air can pass through the heat sink 100 with essentially no change in airflow direction.

[0065] In contrast, for heat sink 200, shown as heat sink 200a (shown in Figure 5) as an example, as shown in Figure 9B, the direction of air entering heat sink 200a through the side opening (provided by a channel formed through a protruding member in the lower portion of heat sink 200a) is altered as the wind / air passes through the channel, as indicated by arrow 905. The resulting disordered and unstable airflow reduces the acoustic noise that may be generated in heat sink 200a. Thus, heat sink 200a has robust flow control by having an additional flow path above the side inlet of heat sink 200a, which reduces the effect of possible flow obstruction. Furthermore, the side access inlet for heat sink 200a allows for extended cooling from outdoor wind fluctuations or other air movement. Due to the specific structure of heat sink 200a, the direction of air entering heat sink 200a through the side of heat sink 200a is also altered to some extent in the upper portion of heat sink 200a (907). In this way, both the heat transfer capacity and noise reduction capability of the heatsink are improved.

[0066] Figure 10 shows another example of a heatsink 200 according to an embodiment of the present disclosure, such as a heatsink 1000 having a base 1001 and a first portion 1002 and a second portion 1004 on the surface of the base 1001. The heatsink 1000 is similar to heatsink 200a (Figure 5) and heatsink 300 (Figure 6), except that the channels extend through the protruding members such that the edges of the portions of the protruding members of the second portion 1004 are rounded. In this example, the second portion 1004 comprises a third portion 1006 and a fourth portion 1008, with channels 1050 (central channel), 1052a, 1052bm, 1052c, and 1052d extending through at least some of the protruding members of the third portion 1006 and the fourth portion 1008.

[0067] Please be aware that heatsink 1000, and other heatsinks described herein, have other components that may not be shown. Therefore, Figure 10 further shows that heatsink 1000 includes mounting ports, such as a front mounting port 1015, a side mounting port 1017, and other ports (not shown), for attaching or mounting heatsink 1000 to an object, such as a wireless unit, e.g., an RRU, or another device or equipment for which heat is generated by its electronic components. The object may be placed in any outdoor or indoor environment.

[0068] In the embodiments described herein, it should be understood that the height of the protruding members may be the same throughout the heat sink 200. Furthermore, due to factors such as manufacturing constraints, some of the protruding members may have different heights, which does not affect the thermal and noise reduction efficiency of the heat sink.

[0069] Figure 11 shows two examples of heatsinks according to the embodiments of this specification, where the heatsink on the left (panel A) is similar to the heatsink 1000 in Figure 10, and the heatsink on the right (panel B) is similar to the heatsink 300 in Figure 6. Figure 12 shows another perspective view of the heatsink in Figure 11. The heatsink on the left (panel A) is similar to the heatsink 1000 in Figure 10, and the heatsink on the right (panel B) is similar to the heatsink 300 in Figure 6.

[0070] An exemplary embodiment is summarized below. A1. A base having a surface and a central vertical axis, wherein the surface comprises a first portion and a second portion arranged along the central vertical axis such that the first portion is above the second portion, A plurality of first protruding members extending from a first portion of the surface, wherein the protruding members from the plurality of first protruding members extend along the surface parallel to each other and to the central longitudinal axis, and the plurality of first protruding members are uniformly spaced apart along the first portion, A second plurality of protruding members extending from a second portion of the surface, wherein the protruding members from the second plurality of protruding members are extended along the surface and angled with respect to the first plurality of protruding members. Equipped with a heatsink.

[0071] A2. The second part of the surface comprises a third part and a fourth part, The second set of protruding members comprises a third set of protruding members extending from a third portion of the second surface and a fourth set of protruding members extending from a fourth portion of the second surface, wherein the third set of protruding members and the fourth set of protruding members are angled inward and upward relative to each other. A heat sink as described in Embodiment A1.

[0072] A3. The second part has a plurality of channels formed through at least some of the second plurality of protruding members, A heat sink according to Embodiment A2.

[0073] A4. The heat sink according to embodiment A3, wherein multiple channels extend along axes that form an acute angle with respect to the central longitudinal axis.

[0074] A5. The heat sink according to Embodiment A3 or Embodiment A4, wherein the multiple channels include a central channel extending between a third and a fourth set of protruding members.

[0075] A6. The heat sink according to embodiment A5, wherein the central channel has an axis that coincides with the central vertical axis.

[0076] It will be understood that the above description and accompanying drawings represent non-limiting examples of the apparatus taught herein. Therefore, the apparatus and techniques taught herein are not limited by the above description and accompanying drawings. Instead, the embodiments herein are limited only by the following claims and their legal equivalents.

Claims

1. A heat sink (200) for a wireless unit, wherein the heat sink (200) is A base (201) having a surface and a central vertical axis (A1), wherein the surface comprises a first portion (202) and a second portion (204) arranged along the central vertical axis (A1) such that the first portion (202) is above the second portion (204), A first plurality of protruding members (212) extending from the first portion (202) of the surface, wherein the protruding members from the first plurality of protruding members (212) extend sufficiently along the surface over the entire first portion (202) parallel to each other and to the central vertical axis (A1), and the first plurality of protruding members (212) are uniformly spaced apart along the first portion (202), A second plurality of protruding members (214) extending from the second portion (204) of the surface, wherein at least part or some of the protruding members of the second plurality of protruding members (214) are configured to extend straight along the surface and be angled with respect to the first plurality of protruding members (212) A heatsink (200) equipped with [a specific feature].

2. The second portion (204) has a plurality of channels (252, 352) formed through at least some of the second plurality of protruding members (214), The heat sink according to claim 1.

3. The heat sink according to claim 2, wherein the plurality of channels (252) extend along axes that form an acute angle with respect to the central vertical axis (A1).

4. The heat sink according to claim 2 or 3, wherein one or more of the plurality of channels (252) are configured in a trapezoidal shape, with the lower part being narrower than the upper part of the one or more channels.

5. The heat sink according to any one of claims 1 to 4, wherein the first portion (202) for cooling analog components is configured above the second portion (204), thereby reducing the influence of the analog components on the digital components, and thereby improving the thermal performance of the digital components.

6. The second portion (204) of the surface comprises a third portion (206) and a fourth portion (208), The second plurality of protruding members (214) comprises a third plurality of protruding members (216) extending from the third portion (206) of the second surface and a fourth plurality of protruding members (218) extending from the fourth portion (208) of the second surface, wherein the third plurality of protruding members (216) and the fourth plurality of protruding members (218) are angled inward and upward with respect to each other. A heat sink according to any one of claims 1 to 5.

7. The heat sink according to any one of claims 2 to 5 and 6, wherein the plurality of channels (252) comprises a central channel extending between the third plurality of protruding members and the fourth plurality of protruding members.

8. The heat sink according to claim 7, wherein the central channel has an axis that coincides with the central vertical axis.

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