Capillary wick and vapor chamber

Abstract

The utility model provides a capillary wick and a vapor chamber, which belong to the field of thermal management and are used for solving the problems of low critical contact angle and low wicking speed of the capillary wick in the prior art. Each group of flow guide components comprises a plurality of rhombic micro-columns which are arranged at intervals along a second direction perpendicular to the first direction, the rhombic micro-columns of two adjacent groups of flow guide components are alternately arranged, and a connecting line between two acute angles of the rhombic micro-columns is parallel to the first direction; compared with a capillary core with the same height h, the same equivalent width w and the same area fraction f, the novel capillary core can provide more uniform wicking power, so that the wicking speed of the surface of the micro-column structure is improved, and the spontaneous wicking critical contact angle of the micro-column structure is increased.

Description

Technical Field

[0001] This utility model belongs to the field of thermal management, and in particular relates to a capillary liquid absorption core and a heat spreader. Background Technology

[0002] As microelectronic devices become increasingly miniaturized and powerful, efficient heat dissipation has become a pressing issue in thermal management. To address this problem, researchers have designed a vapor chamber as a heat dissipation device. Its working process involves a working liquid absorbing heat at the heat source end and evaporating into vapor. The vapor then flows to the condenser end of the vapor chamber due to the pressure difference, where it condenses into liquid and releases heat. The working liquid then returns to the evaporation end through a capillary wick to begin the next cycle.

[0003] The specific working principle of a capillary wick is as follows: Initially, the capillary wick is filled with liquid working fluid, and the liquid surface shapes at the condensing and evaporating ends are consistent, with no pressure difference between the two ends. When the capillary wick operates, the liquid working fluid at the evaporating end absorbs heat and evaporates, causing a change in the curvature of the liquid interface, while the curvature of the liquid interface at the condensing end remains unchanged. Therefore, a pressure difference is generated between the condensing and evaporating ends of the capillary wick, thereby realizing the transport of the working fluid from the condensing end to the evaporating end. The ability of the capillary wick to "pump" liquid has a significant impact on the equivalent thermal conductivity and temperature range of the vapor chamber. The faster the capillary wick "pumps" liquid, the easier it is to replenish the working fluid at the evaporating end, allowing the evaporating end to remove more heat more quickly. Therefore, the equivalent thermal conductivity of the vapor chamber is improved, and the temperature range is expanded. Currently, there are two main technical solutions for manufacturing capillary wicks in vapor chambers: 1. Capillary wicks obtained by sintering metal powder or metal mesh, such as... Figure 1 As shown; 2. Capillary wicks with micropillar structures on their surfaces, such as regularly arranged circular micropillar capillary wicks and regularly arranged square micropillar capillary wicks, such as... Figure 2 As shown; and other micropillar array structures mentioned in the published invention patent WO2022033289A1. However, regardless of the type of capillary wick, the critical contact angle for spontaneous wicking is far below 90 degrees. Among them, the maximum critical wicking contact angle obtained experimentally for regularly arranged circular and square micropillar capillary wicks is only 48±3 degrees. In the research of relevant scholars, it was found that the maximum critical contact angle for spontaneous wicking of porous media formed by stacked particles is only 55±6 degrees. In addition, the wicking speed of the two existing capillary wick design schemes is not high enough, thus limiting the temperature range and heat transfer efficiency of the heat spreader. The experimentally measured height h=34.34μm and equivalent width w=17.50μm (see schematic diagram to ensure that the liquid volume on the surface of the micropillar structure and in the equivalent groove per unit length is the same). Figure 3 The wicking coefficient D(y) of a regularly arranged circular micropillar capillary wick, calculated using the formula: w = b + a * c / (a ​​+ c)), is... 2=D*t, where y is the wicking distance, t is the wicking time, and D is the wicking coefficient. The wicking coefficient reflects the velocity of the transported liquid; the larger D is, the faster the liquid is transported. (The value is 2.56 mm.) 2 The wicking coefficient D of a regularly arranged square micropillar capillary wick with a height h = 37.17 μm and an equivalent width w = 16.50 μm is 2.31 mm. 2 / s, which is far lower than the wicking coefficient D: 8.793-9.491mm for trenches with similar height h and equivalent width w. 2 / s. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a capillary wick and a heat spreader to solve the problems of low critical contact angle and low wicking speed of the capillary wick in the prior art.

[0005] To achieve the above and other related objectives, this utility model provides a capillary liquid aspiration core, including a mounting plate and multiple sets of flow guiding components spaced apart on the mounting plate along a first direction; each set of flow guiding components includes multiple rhomboid micropillars spaced apart on the mounting plate along a second direction; the rhomboid micropillars of adjacent sets of flow guiding components are arranged alternately, and the line connecting the two acute angles of the rhomboid micropillars is parallel to the first direction; the first direction and the second direction are perpendicular to each other.

[0006] Optionally, the rhomboid micropillars overlap with the projection portions of the two adjacent sets of flow guiding components on a plane perpendicular to the second direction.

[0007] Optionally, the area of ​​the overlapping portion is less than half the projected area of ​​a single rhomboid micropillar on a plane perpendicular to the second direction.

[0008] Optionally, the distance between the vertex of the acute angle of the rhomboid micropillar and the vertex of the obtuse angle of the rhomboid micropillar of the adjacent flow guiding component at the acute angle, projected onto a plane perpendicular to the second direction, is g, and the distance between two sets of flow guiding components adjacent to any set of flow guiding components is c, where g = c / 2.

[0009] Optionally, the projections of the rhomboid micropillars and the two adjacent sets of flow guiding components on a plane perpendicular to the first direction do not overlap.

[0010] Optionally, the distance between the vertex of the acute angle of the rhomboid micropillar and the vertex of the obtuse angle of the rhomboid micropillar of the adjacent flow guiding component at the acute angle, projected onto a plane perpendicular to the first direction, is i, and the distance between two adjacent rhomboid micropillars of the same flow guiding component is b, i = b / 2.

[0011] Optionally, the semi-obtuse angle α of the rhomboid micropillar varies in the range of 45 degrees ≤ α < 90 degrees.

[0012] Optionally, the contact angle β between the rhomboid micropillar and the mounting plate is ≦90 degrees.

[0013] Optionally, it also includes two barriers spaced apart on the mounting plate along the second direction, and multiple sets of flow guiding components are disposed between the two barriers; a first triangular protrusion is provided on the side of the barrier near the flow guiding component.

[0014] On the other hand, this utility model also provides a heat spreader, which includes a capillary liquid absorption core as described above.

[0015] As described above, the capillary wick and heat spreader of this invention have at least the following beneficial effects: By providing multiple sets of flow guiding components spaced apart along a first direction on the mounting plate, each set of flow guiding components includes multiple rhomboid micropillars spaced apart along a second direction perpendicular to the first direction, and the rhomboid micropillars of adjacent sets of flow guiding components are arranged alternately, with the line connecting the two acute angles of the rhomboid micropillars parallel to the first direction, the wicking force provided by the micropillar structure can be obtained for wicking. Compared with capillary wicks with the same height h, equivalent width w, and equal area fraction f, the regular arrangement of circular micropillars and the arrangement of square micropillars have smaller wicking resistance. This not only reduces the difficulty of the wicking peak hitting the next row of micropillars, but also shortens the time it takes for the wicking peak to hit the next row of micropillars, thereby achieving the purpose of increasing the wicking speed on the surface of the micropillar structure. In addition, by utilizing the pinning effect of the sharp edges of the rhomboid micropillars on the liquid surface, the liquid surface can more easily completely wrap around the rhomboid micropillars of adjacent flow guiding components, thereby increasing the critical contact angle of spontaneous wicking of the capillary wick. Attached Figure Description

[0016] Figure 1 The diagram shows a structural schematic of sintered copper particles or metal mesh obtained by sintering metal powder in the prior art.

[0017] Figure 2 The diagram shows a regular arrangement of circular and square micropillars in the prior art.

[0018] Figure 3 The diagram shows a prior art structural schematic of a square micropillar structure (left) and a groove arrangement (right).

[0019] Figure 4 This diagram illustrates the process of spontaneous wicking achieved by capillary wicks with regularly arranged circular micropillars in the prior art.

[0020] Figure 5 This diagram illustrates the process of spontaneous wicking achieved by a capillary core with a regular arrangement of square micropillars in the prior art.

[0021] Figure 6 The diagram shown is a structural schematic of the heat spreader of this utility model.

[0022] Figure 7 The diagram shown is a structural schematic of the liquid-absorbing capillary core of this invention.

[0023] Figure 8 The diagram shows the process of spontaneous wicking achieved by the capillary wicks with regularly arranged rhomboid micropillars according to this invention.

[0024] Figure 9 The table shows a comparison of the wicking speeds of various common micropillar structures and the rhomboid micropillar structure of this invention.

[0025] Figure 10 Displayed as a representation Figure 9 A schematic diagram of the arrangement of micropillar structures of various shapes.

[0026] Figure 11 Displayed as Figure 9 Dynamic wicking curves of micropillar structures of various shapes.

[0027] Figure 12 The diagram shows experimental and simulation data (obtained from Surface Evolver simulation) of the critical contact angle of spontaneous wicking of capillary wicks arranged in regular square or regular cylindrical patterns, compared with the theoretical limit and the critical contact angle of spontaneous wicking of capillary wicks with alternating rhomboid patterns proposed in this invention.

[0028] Figure 13 This table shows a comparison of the critical contact angles of the capillary wicks obtained from Surface Evolver simulations, with each parameter arranged in an alternating diamond pattern.

[0029] Component labeling: 1. Mounting plate, 2. Rhomboid micro-pillar, 3. Enclosure, 31. First triangular protrusion, 4. Upper shell of heat spreader, 5. Ring gasket, 51. Second triangular protrusion, 52. Liquid injection hole, 6. Lower shell of heat spreader. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0031] Please refer to all the accompanying drawings below. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0032] The following embodiments are for illustrative purposes only. These embodiments can be combined and are not limited to the content shown in any single embodiment below.

[0033] It is known that spontaneous wicking of a liquid working fluid on the surface of a micropillar structure requires two conditions: 1. The liquid can completely wet a single micropillar and form a continuous sheet, a process that includes two stages: protrusion (only present in square micropillar arrays) and merging; 2. The liquid can spontaneously encounter the next set of micropillars in the flow guiding assembly. The process diagrams of spontaneous wicking of circular and square micropillars arranged in a regular pattern are shown below. Figure 4 and Figure 5 For circular micropillars (see...) Figure 4 For example, A→B→C represents the liquid surface merging stage, and C→D represents the liquid surface encountering the next group of circular microcolumns. For square microcolumns (see...),... Figure 5 For example, A→B represents the liquid surface protrusion stage. (For square micropillars, the liquid surface will be held in place by the ridges of the micropillars. However, the contact angle of the wicking liquid is often less than 90 degrees. Therefore, the liquid surface between two adjacent square micropillars in the same group of flow guiding components will move forward. At the same time, the sum of the two curvatures of the free interface is zero. Therefore, the bottom liquid contact line will definitely touch the side of the square micropillar, forming a...) Figure 5 The state of diagram B (i.e., the A→B liquid surface protrusion stage will definitely occur), B→C→D is the liquid surface merging stage, and D→E is the stage where the liquid surface encounters the next set of flow guiding components.

[0034] Please see Figure 6-7This invention provides a capillary liquid-absorbing core, comprising a mounting plate 1 and multiple sets of flow-guiding components spaced apart on the mounting plate 1 along a first direction; each set of flow-guiding components includes multiple rhomboid micropillars 2 spaced apart on the mounting plate 1 along a second direction; the rhomboid micropillars 2 of adjacent sets of flow-guiding components are arranged alternately, with the first and second directions perpendicular to each other. In this embodiment, the first direction is the wicking direction, and the second direction is perpendicular to the wicking direction. The line connecting the two acute angles of each rhomboid micropillar 2 is parallel to the first direction, and correspondingly, the line connecting the two obtuse angles of each rhomboid micropillar 2 is parallel to the second direction, thereby enabling the rhomboid micropillars 2 to guide the liquid working fluid.

[0035] Figure 8 The process of spontaneous wicking by the rhomboid alternating capillary wicks designed for this utility model is as follows: A→B→C is the liquid surface merging stage, and C→D→E is the stage where the liquid surface touches the next row of microcolumns.

[0036] Comparing the spontaneous wicking process diagrams of capillary wicks with a regular arrangement of circular / square micropillars and those of the capillary wicks with alternating rhomboid micropillars of this invention, it can be seen that when the liquid working fluid encounters the micropillars of the next set of flow guiding components, there are always rhomboid micropillars 2 on the surface of the alternating rhomboid micropillars in the liquid front direction. Compared to the surface of capillary wicks with a regular arrangement of circular / square micropillars, the wicking peak can obtain the uninterrupted wicking force provided by the micropillar structure. Furthermore, the rhomboid micropillars 2 alternating arrangement capillary wicks proposed in this invention have the same height h, equivalent width w, and equal area fraction f (e.g., ...). Figure 7 As shown, the area fraction f = (A1 + A2 + A3 + A4 + A5) / A0 = a * a * tanα / [(a + b) * (a * tanα + c)], where a is the length of the short diagonal of the rhombic micropillar 2, b is the minimum distance between two adjacent rhombic micropillars 2 in the same group of flow guiding components, c is the minimum distance between two adjacent rhombic micropillars 2 along the wicking direction (first direction), and A0-A5 represent the areas indicated by the arrows at the end of the red boxes. Capillary cores with regularly arranged circular micropillars and capillary cores with regularly arranged square micropillars have smaller wicking resistance. This change can not only reduce the difficulty of the wicking peak hitting the next row of micropillars, but also shorten the time of the wicking peak hitting the next row of micropillars, thereby achieving the purpose of increasing the wicking speed on the surface of the micropillar structure.

[0037] Compared to circular or square micropillars, the rhomboid micropillars 2 in this invention utilize sharp edges to pin the liquid surface, making it easier for the liquid to completely envelop the entire row of pillars. Specifically, the liquid surface is pinned by the sharp edges at the acute angles of the rhomboid micropillars 2. However, since the contact angle of the wicking liquid is often less than 90 degrees, the liquid surface in the middle of the micropillars will move forward. In addition, because the distance between the contact lines of the liquid on both sides of the acute angle of the rhomboid micropillars 2 is very small (depending on the processing accuracy, ideally it is 0), the design of the rhomboid micropillars 2 makes it easier for the liquid to completely envelop the adjacent rhomboid micropillars 2 of the guiding components compared to circular and square micropillars (i.e., easier to complete). Figure 8 During the liquid surface merging stage from A to B to C, the critical contact angle of spontaneous wicking by the capillary wick is increased.

[0038] like Figure 9-11 As shown, Figure 9 This table compares the wicking velocities of various common micropillar structures with the rhombic micropillar 2 structure of this invention. "Circle-regular" represents a regularly arranged circular micropillar capillary wick; "Square-regular" represents a regularly arranged square micropillar capillary wick; "Square-staggered" represents alternating square micropillars; "Diamond-regular" represents a regularly arranged rhombic micropillar 2 capillary wick; "Diamond-staggered" represents alternating rhombic micropillar 2 capillary wicks; and "Groove" represents a grooved capillary wick. Additionally, α=75 degrees represents a rhombic micropillar 2 with a semi-obtuse angle of 75 degrees, and α=80 degrees represents a rhombic micropillar 2 with a semi-obtuse angle of 80 degrees. γ represents the surface tension of the liquid working fluid, μ represents the dynamic viscosity of the liquid working fluid, D is the wicking coefficient, w is the equivalent width of the groove, and (μ*D) / (γ*h) is the dimensionless wicking coefficient, representing the magnitude of the wicking velocity.

[0039] Figure 10 express Figure 9 A schematic diagram of the arrangement of micropillar structures of various shapes. Figure 11 express Figure 9 Dynamic wicking curves of various shapes in the image.

[0040] exist Figure 9 There are some differences in the height of the samples. To better evaluate the wicking velocity of the capillary wick, we performed dimensionless processing on the wicking coefficient, through... Figure 9-11 As can be seen from the comparison of the dimensionless wicking coefficient (μ*D) / (γ*h), it is found that the capillary wick with alternating rhomboid micropillars proposed in this invention has a significantly improved wicking speed compared to other capillary wick configurations.

[0041] like Figure 12-13 As shown, Figure 12Experimental and simulation data (obtained from Surface Evolver simulation) of the critical contact angle for spontaneous wicking of capillary wicks arranged in regular square / regular cylindrical patterns, and the theoretical limit (theoretical formula: cosθ). c = (1-f) / (rf), where The critical contact angle, It is an area fraction. A comparison diagram showing the surface roughness of the micropillar structure and the critical contact angle of spontaneous wicking of the alternating rhomboid capillary wicks proposed in this invention. Figure 12 As shown, the Surface Evolver simulation data for the spontaneous wicking critical contact angle of capillary wicks arranged in regular square prisms / regular cylinders are in high agreement with the experimental data. Meanwhile, Figure 12 This also clearly demonstrates that the alternating rhomboid capillary wicks proposed in this invention exhibit a significantly improved spontaneous wicking critical contact angle compared to traditional regular square / cylindrical arrangements, and are closer to the theoretical limit. Furthermore, Figure 13 The data on the spontaneous wicking critical contact angle of the alternating rhomboid capillary wicks of the present invention, obtained through Surface Evolver simulation under a wider range of parameter conditions, are presented.

[0042] In summary, the rhomboid alternating capillary wicks designed in this invention offer a larger critical wicking contact angle and a faster wicking velocity compared to existing regularly arranged circular / square micropillars. The larger critical contact angle expands the range of liquid working fluids that can be selected. The faster wicking velocity allows for higher critical heat flux densities for nucleate boiling, and for vapor chambers, it results in higher equivalent thermal conductivity and a higher capillary limit, significantly broadening the temperature range applicable to vapor chambers.

[0043] In this embodiment, the rhomboid micropillars 2 overlap with the projected portions of two adjacent sets of flow guiding components on a plane perpendicular to the second direction. Thus, a portion of the rhomboid micropillars 2 in each set of flow guiding components is inserted into the groove between two adjacent rhomboid micropillars 2. This allows the liquid working medium to contact the rhomboid micropillars 2 of the next set of flow guiding components before it has completely flowed out of the groove formed between two adjacent rhomboid micropillars 2 in that set of flow guiding components. The sharp edges of the rhomboid micropillars 2 pin the liquid surface of the working medium, making it easier for the liquid surface to completely envelop the rhomboid micropillars 2, further improving the wicking speed. Preferably, the area of ​​the overlapping portion is less than half the projected area of ​​a single rhomboid micropillar 2 on a plane perpendicular to the second direction. That is, when the acute angle of the rhomboid micropillar 2 of each set of flow guiding components is inserted into the groove between two adjacent rhomboid micropillars 2, the vertex of the acute angle does not exceed the line connecting the vertices of the two obtuse angles of the rhomboid micropillar 2 of the other set of flow guiding components. This ensures that the rhomboid micropillars 2 do not connect end-to-end.

[0044] like Figure 7-8As shown, the distance between the vertex of the acute angle of the rhomboid micropillar 2 and the vertex of the obtuse angle of the rhomboid micropillar 2 of the adjacent flow guiding component at the acute angle, projected onto a plane perpendicular to the second direction, is g; the distance between two sets of flow guiding components adjacent to any set of flow guiding components is c; where g = c / 2, further ensuring that the capillary liquid core can obtain a greater core suction speed.

[0045] The projections of the rhomboid micropillar 2 and the two adjacent sets of flow guiding components onto a plane perpendicular to the first direction do not overlap. That is, as shown... Figure 7 As shown, the length a (the line connecting the two obtuse angles) of the short diagonal of each rhomboid micropillar 2 is less than the minimum distance b (the line connecting the obtuse angles of the two adjacent rhomboid micropillars 2 in the same group of flow guiding components), which can increase the width of the groove, giving the liquid working fluid a wider flow channel and making it easier to process.

[0046] like Figure 6-7 As shown, the distance between the vertex of the acute angle of the rhomboid micropillar 2 and the vertex of the obtuse angle of the rhomboid micropillar 2 of the adjacent flow guiding component at the acute angle, when projected onto a plane perpendicular to the first direction, is i; the distance between two adjacent rhomboid micropillars 2 of the same group of flow guiding components is b, where i = b / 2. This ensures that the liquid working fluid can contact the rhomboid micropillars 2 of the next group of flow guiding components more quickly, while also enabling the liquid working fluid to have a wider flow channel.

[0047] In this embodiment, the range of the semi-obtuse angle α of the rhomboid micropillar 2 is 45 degrees ≤ α < 90 degrees, specifically 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, and 85 degrees. With the length 'a' of the short diagonal of a single rhomboid micropillar 2 in the capillary wick, the minimum distance 'b' between two adjacent rhomboid micropillars 2 in the same group of flow guiding components, and the minimum distance 'c' between two adjacent rhomboid micropillars 2 along the wicking direction (first direction) remaining constant, the larger the semi-obtuse angle α of the rhomboid micropillar 2, the larger the critical contact angle for wicking.

[0048] In this embodiment, the contact angle β between the rhomboid micropillar 2 and the mounting plate 1 is ≦90 degrees, that is, the rhomboid micropillar 2 and the mounting plate 1 are arranged vertically or in an inverted pyramid shape, so that the liquid working medium can reach the connection between the rhomboid micropillar 2 and the mounting plate 1, which is beneficial to the wicking of the liquid working medium on the surface of the micropillar structure.

[0049] The capillary wick in this embodiment also includes two barriers 3 spaced apart on the mounting plate 1 along the second direction, and multiple sets of flow guiding components are arranged between the two barriers 3; a first triangular protrusion 31 is provided on the side of the barrier 3 near the flow guiding components. The shape of the first triangular protrusion 31 is the shape of half a rhomboid micropillar 2 formed by cutting along the connection between the two acute angles of the rhomboid micropillar 2, thereby reducing the influence of edge effect on the wicking of liquid inside the capillary wick.

[0050] Please see Figure 6 In another aspect, this utility model also provides a heat spreader, including a capillary wick as described in any of the preceding claims, and further including an upper heat spreader shell 4, an annular gasket 5, and a lower heat spreader shell 6. The annular gasket 5 is disposed between the upper heat spreader shell 4 and the lower heat spreader shell 6, for connecting the upper heat spreader shell 4 and the lower heat spreader shell 6. The annular gasket 5 can be connected to the upper heat spreader shell 4 and the lower heat spreader shell 6 by adhesive bonding, which is not shown in this embodiment. It serves to increase the thickness of the heat spreader and to connect and seal the upper and lower shells. The inner side of the annular gasket 5 is also provided with second triangular protrusions 51 at intervals in the second direction. The shape of the second triangular protrusions 51 is the same as the structure of the first triangular protrusions 31 on the enclosure 3, which also serves to reduce the influence of edge effect on the wicking of liquid inside the capillary wick. An injection hole 52 is provided on one end sidewall of the annular gasket 5 for filling or removing liquid working medium into the heat spreader. Capillary wicks are respectively provided on the inner sides of the upper heat spreader shell 4 and the lower heat spreader shell 6. In use, the lower shell 6 of the heat exchanger plate can be used as the evaporation end, and the upper shell 4 of the heat exchanger plate can be used as the condensation end, thereby achieving the function of heat dissipation.

[0051] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0052] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A capillary liquid-absorbing core, characterized in that, Includes a mounting plate and multiple sets of flow guiding assemblies spaced apart on the mounting plate along a first direction; Each group of the flow guiding components includes a plurality of rhomboid micropillars spaced apart on the mounting plate along the second direction; the rhomboid micropillars of two adjacent groups of the flow guiding components are arranged alternately, and the line connecting the two acute angles of the rhomboid micropillars is arranged parallel to the first direction; the first direction and the second direction are arranged perpendicularly.

2. The capillary liquid-absorbing core according to claim 1, characterized in that: The rhomboid micropillars overlap with the projection portions of the two adjacent sets of flow guiding components on a plane perpendicular to the second direction.

3. The capillary liquid-absorbing core according to claim 1, characterized in that: The area of ​​the overlapping portion is less than half the projected area of ​​a single rhomboid micropillar on a plane perpendicular to the second direction.

4. A capillary liquid-absorbing core according to claim 2, characterized in that: The distance between the vertex of the acute angle of the rhomboid micropillar and the vertex of the obtuse angle of the rhomboid micropillar of the adjacent flow guiding component, projected onto a plane perpendicular to the second direction, is g. The distance between two sets of flow guiding components arranged adjacent to any one of the sets of flow guiding components is c, and g = c / 2.

5. A capillary liquid-absorbing core according to claim 2, characterized in that: The projections of the rhomboid micropillars and the two adjacent sets of flow guiding components on a plane perpendicular to the first direction do not overlap.

6. A capillary liquid-absorbing core according to claim 5, characterized in that: The distance between the vertex of the acute angle of the rhombic micropillar and the vertex of the obtuse angle of the rhombic micropillar of the adjacent flow guiding component, projected onto a plane perpendicular to the first direction, is i. The distance between two adjacent rhomboid micropillars of the same group of flow guiding components is b, i = b / 2.

7. A capillary liquid-absorbing core according to claim 1, characterized in that: The range of the semi-obtuse angle α of the rhomboid micropillar is 45 degrees ≤ α < 90 degrees.

8. A capillary liquid-absorbing core according to claim 1, characterized in that: The contact angle β between the rhomboid micropillar and the mounting plate is ≦90 degrees.

9. A capillary absorbent core according to claim 1, characterized in that: It also includes two barriers spaced apart on the mounting plate along a second direction, and multiple sets of the flow guiding components are disposed between the two barriers; a first triangular protrusion is provided on the side of the barrier near the flow guiding component.

10. A heat spreader, characterized in that, Including a capillary absorbent core as described in any one of claims 1-9.

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