Directed heat spreader and chip

Abstract

The present invention discloses a directional heat spreader and chip. Among them, the directional heat spreader includes a heat source plate and a cold source plate, the heat source plate has a hot spot area, and the hot surface of the heat source plate is provided with a super hydrophilic layer; the cold surface of the cold source plate is arranged relative to the hot surface of the heat source plate, and a phase-change heat medium is provided between the cold source plate and the heat source plate; the cold surface of the cold source plate has a non-uniform microstructure, which is used for directionally regulating the condensed droplets on the cold surface to bounce toward the hot spot area when the directional heat spreader is working, and a super hydrophobic layer is formed on the non-uniform microstructure. The directional heat spreader of the present invention has a good cooling effect on the hot spot area of ​​the heat source plate, and can improve the heat flux density of the heat spreader.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange or heat dissipation, and in particular to a directional heat spreader and a chip. Background Art

[0002] For the existing liquid wick heat sink, the liquid suction rate of the liquid wick is mm / s. The slow suction speed of the liquid wick causes the liquid condensed on the cold surface to be unable to be quickly transported to the hot surface. When the heat flux density continues to increase, the working fluid will evaporate on the hot surface, causing a sharp increase in the evaporation thermal resistance and a sharp increase in the junction temperature, that is, there are evaporation limits and capillary limits.

[0003] At present, although some heat spreaders that utilize the bouncing of condensation droplets have appeared, when the cold surface super-hydrophobic surface is not designed with a microstructure, the bounce direction of the droplets is basically perpendicular to the surface bounce, the number of droplets reaching the hot spot area is small, the volume is small, the heat absorbed is small, and the cooling effect on the hot spot area is poor. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a directional vapor chamber that has a good cooling effect on the hot spot area of ​​the heat source plate and can increase the heat flux density of the vapor chamber.

[0005] According to the first aspect of the present invention, a directional vapor chamber comprises:

[0006] A heat source plate, wherein the heat source plate has a hot spot area, and a hot surface of the heat source plate is provided with a super hydrophilic layer;

[0007] A cold source plate, wherein the cold surface of the cold source plate is arranged opposite to the hot surface of the heat source plate, and a working medium for phase change heat transfer is arranged between the cold source plate and the heat source plate; the cold surface of the cold source plate has a non-uniform microstructure, which is used for directionally regulating the condensed droplets on the cold surface to bounce toward the hot spot area when the directional heat spreader is working, and a super-hydrophobic layer is formed on the non-uniform microstructure.

[0008] According to the directional heat spreader of the first aspect of the present invention, first, compared with the existing liquid wick heat spreader, in the existing liquid wick heat spreader, the liquid wick sucks liquid at a rate of mm / s, and the suction speed is slow; while in the directional heat spreader of this embodiment, the bouncing speed of condensed droplets can reach m / s, and the transport rate of condensed liquid can be increased by three orders of magnitude, breaking through the evaporation limit and capillary limit of the existing liquid wick heat spreader. Second, compared with the existing common super-hydrophobic surface heat spreader, since the existing common super-hydrophobic surface has no microstructure, the bouncing direction of the condensed droplets is basically perpendicular to the surface bounce, the number of condensed droplets reaching the hot spot area is small, the volume is small, the heat absorbed is small, and the cooling effect on the hot spot area is poor. The directional heat spreader of this embodiment, by designing a non-uniform microstructure on the cold surface, when the directional heat spreader is working, on the one hand, the maximum size of the condensed droplets grown on the non-uniform microstructure can be limited to the micron / submicron size range, so that condensed droplets of such size are more likely to achieve fusion bounce, and the probability of bouncing is greatly increased, thereby achieving stable bouncing of condensed droplets. On the other hand, the large-scale micron / submicron condensed droplets on the non-uniform microstructure can be regulated to bounce to the hot spot area, thereby increasing the number and volume of droplets reaching the hot spot area, and being able to absorb more heat in the hot spot area faster. The condensed droplets in the hot spot area, that is, the working fluid liquid, are evenly spread and evaporated into high-temperature working fluid vapor through the super-hydrophilic layer on the heat source plate to take away the heat, thereby greatly improving the cooling effect on the hot spot area, thereby improving the heat flux density of the heat spreader.

[0009] In some embodiments, the non-uniform microstructure includes a base point region directly opposite to the hot spot region and a peripheral region distributed around the base point region and not directly opposite to the hot spot region.

[0010] In some embodiments, the single microstructure unit in the base point area is in the shape of a convex column, or in the shape of a concave pit, or partially in the shape of a convex column and partially in the shape of a concave pit, and the single microstructure unit in the peripheral area is in the shape of a convex column.

[0011] In some embodiments, when the single microstructure unit in the base point area is in the shape of a convex column, the base point area includes several first sub-ring areas from the inside to the outside, and the single microstructure unit of the same first sub-ring area is an isosceles trapezoidal prism, a triangular prism, a fan-shaped prism, a rectangular prism, a parallelogram prism, a V-shaped prism or a crescent prism, and the single microstructure shapes of different first sub-ring areas are the same or different.

[0012] In some embodiments, the density distribution of microstructure units in the same first sub-ring area is the same, and the density distribution of microstructure units in different first sub-ring areas is the same or different.

[0013] In some embodiments, when a single microstructure unit in the base point region is in a pit shape, the base point region is an egg tray microstructure or a grid microstructure.

[0014] In some embodiments, when a single microstructure unit in the base point area is partially in the shape of a convex column and partially in the shape of a concave pit, the base point area includes a concave pit sub-area and a convex column sub-area, the convex column sub-area surrounds the periphery of the concave pit sub-area, or the concave pit sub-area surrounds the periphery of the convex column sub-area, or the concave pit sub-area and the convex column sub-area are alternately arranged from the inside to the outside.

[0015] In some embodiments, the peripheral area includes several second sub-ring areas distributed from the outside to the inside, and a single microstructure unit of the same second sub-ring area is an isosceles trapezoidal prism, a triangular prism, a fan-shaped prism, a rectangular prism, a parallelogram prism, a V-shaped prism or a crescent prism, and the single microstructure shapes of different second sub-ring areas are the same or different.

[0016] In some embodiments, the density distribution of microstructure units in the same second sub-ring area is the same, and the density distribution of microstructure units in different second sub-ring areas is different.

[0017] In some embodiments, the density of the microstructure units in different second sub-ring regions from outside to inside is distributed in a gradient from sparse to dense.

[0018] In some embodiments, the single microstructure unit of the peripheral area is an isosceles trapezoidal prism, wherein the upper base width of the top surface of the isosceles trapezoidal prism is 1 μm, the lower base width ranges from 5 to 10 μm, the angle ranges from 15 to 30°, and the thickness of the isosceles trapezoidal prism ranges from 5 to 10 μm.

[0019] The second aspect of the present invention also provides a chip.

[0020] A chip according to an embodiment of the second aspect of the present invention comprises a directional vapor chamber according to any one embodiment of the first aspect of the present invention and a chip body, wherein the directional vapor chamber is used for dissipating heat from the chip body.

[0021] Since the oriented heat spreader of the first aspect of the embodiment of the present invention greatly improves the cooling effect on the hot spot area, thereby increasing the heat flux density of the heat spreader, therefore, the high-temperature part of the chip body is contacted with the hot spot area of ​​the heat source plate, which can effectively dissipate the high-temperature part of the chip and meet the demand for chip miniaturization. This has important practical significance for the development of my country's chip industry.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 It is a cross-sectional schematic diagram of a directional heat spreader of the present invention.

[0025] Figure 2 It is a cross-sectional schematic diagram of another directional heat spreader of the present invention.

[0026] Figure 3 It is a schematic diagram that a single microstructure unit in the non-uniform microstructure of the present invention is an isosceles trapezoidal prism.

[0027] Figure 4 and Figure 5 A schematic diagram showing the non-uniform microstructure of the present invention using the Laplace pressure difference principle to control the bouncing direction of condensed droplets (the bouncing direction is inclined upward), wherein: Figure 4 It shows that the condensed liquid droplets generate driving force on the top surface of the isosceles trapezoidal prism. Figure 5 Illustration of condensate droplets merging and bouncing.

[0028] Figure 6a It is a schematic diagram of a non-uniform microstructure of the present invention, illustrating that the microstructure unit is an isosceles trapezoidal prism, and the density of the microstructure unit is distributed in a gradient from sparse to dense from the outside to the inside.

[0029] Figure 6b for Figure 6a Top view of the .

[0030] Figure 7 FIG. 1 is another schematic diagram of a non-uniform microstructure of the present invention, showing that the microstructure unit is an isosceles trapezoidal prism, and the density of the microstructure unit is distributed in a gradient from sparse to dense from the outside to the inside. Figure 7 The density distribution of mesostructure units and Figure 6a and Figure 6b different.

[0031] Figure 8 It is a schematic diagram that a single microstructure unit in the non-uniform microstructure of the present invention is a triangular prism.

[0032] Fig. 9 It is a schematic diagram that a single microstructure unit in the non-uniform microstructure of the present invention is a fan-shaped prism.

[0033] Fig.10 It is a schematic diagram that a single microstructure unit in the non-uniform microstructure of the present invention is a V-shaped prism.

[0034] Fig.11aThis is another schematic diagram of a non-uniform microstructure of the present invention, which shows that the microstructure unit is a rectangular prism, and the density of the microstructure unit is gradiently distributed from sparse to dense from the outside to the inside. The non-uniform microstructure uses the principle of sparseness and density to control the condensed droplets to bounce upward.

[0035] Fig.11b for Fig.11a Top view of the .

[0036] Fig.12a Schematic diagram of the growth of condensed liquid droplets in the pit microstructure in the base point area of ​​the present invention.

[0037] Figure 12b Schematic diagram of the fusion of condensed droplets in the pit microstructure in the base point area of ​​the present invention.

[0038] Fig.12c Schematic diagram of the enhanced bouncing of condensed droplets after fusion in the pit microstructure in the base point area of ​​the present invention.

[0039] Fig.13 Schematic diagram of a uniform microstructure that does not belong to the present invention.

[0040] Fig.14 for Figure 7 The inhomogeneous microstructure and Fig.13 Schematic diagram of the experimental results of the comparative experiment on the uniform microstructure.

[0041] Fig.15 This is a schematic diagram of another non-uniform microstructure of the present invention, wherein it is illustrated that the single microstructure unit in the peripheral area is an isosceles trapezoidal prism, and the single microstructure unit in the base point area is a pit egg tray microstructure.

[0042] Fig.16 This is a schematic diagram of another non-uniform microstructure of the present invention, wherein it is illustrated that the single microstructure units in the peripheral area are isosceles trapezoidal prisms, and the single microstructure units in the base point area are partially pits and partially isosceles trapezoidal prisms.

[0043] Fig.17 This is the grid microstructure of the base point area of ​​the present invention, wherein a single grid is a square.

[0044] Fig.18 This is the grid microstructure of the base point area of ​​the present invention, wherein a single grid is an equilateral triangle.

[0045] Fig.19 This is the grid microstructure of the base point area of ​​the present invention, wherein a single grid is a regular hexagon.

[0046] Fig. 20 Schematic diagram of the regulating effect of the non-uniform microstructure of isosceles trapezoidal prisms of different sizes on condensed droplets of the present invention.

[0047] Reference numerals:

[0048] Directed Vapor Chamber 1000

[0049] Heat source plate 1 Hot spot area A Hot surface 101 Cold source plate 2 Non-uniform microstructure 201

[0050] Base point area B Peripheral area C Capillary driving force F Upper base width W1 of the top surface of the isosceles trapezoidal prism

[0051] The lower base width of the isosceles trapezoidal prism top surface is W2 and the thickness of the isosceles trapezoidal prism is H. DETAILED DESCRIPTION

[0052] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0053] Combine the following Figures 1 to 20 The directional vapor chamber 1000 according to the embodiment of the present invention is described.

[0054] like Figure 1 and Figure 2 As shown, the directional heat spreader 1000 according to the embodiment of the first aspect of the present invention includes a heat source plate 1 and a cold source plate 2, the heat source plate 1 has a hot spot area A, and the hot surface 101 of the heat source plate 1 is provided with a super hydrophilic layer; the cold surface of the cold source plate 2 is arranged relative to the hot surface 101 of the heat source plate 1, and a phase change heat transfer working medium is provided between the cold source plate 2 and the heat source plate 1; the cold surface of the cold source plate 2 has a non-uniform microstructure 201, and a super hydrophobic layer is formed on the non-uniform microstructure 201, and the non-uniform microstructure 201 is used for directionally controlling the condensed droplets on the cold surface to bounce toward the hot spot area A when the directional heat spreader 1000 is working.

[0055] Specifically, the outer side of the heat source plate 1 (i.e., the side opposite to the heat surface 101) contacts the heat source (not shown in the figure), and the size of the contact surface between the heat source and the heat source plate 1 is smaller than the plane size of the heat source plate 1. Therefore, the temperature of the local area of ​​the heat source plate 1 facing the heat source is higher than the temperature of other parts of the heat source plate 1. That is, the high temperature of the heat source plate 1 is concentrated in the local area of ​​the heat source plate 1 facing the heat source. This local area can be considered as the hot spot area A of the heat source plate 1. In other words, the heat source plate 1 has a hot spot area A. Figure 1 and Figure 2 As shown, the hot spot area A is designed in the middle area of ​​the heat source plate 1, which is more reasonable. The hot surface 101 of the heat source plate 1 is provided with a super hydrophilic layer, which can make the working fluid liquid spread evenly and evaporate into high-temperature working fluid steam to take away heat.

[0056] The outer side of the cold source plate 2 (i.e. the side facing away from the cold surface) is in contact with a cold source (not shown in the figure), so that the cold source plate 2 is in a low temperature state, which can make the high-temperature working fluid vapor condense into small droplets on the cold surface to release heat.

[0057] The cold surface of the cold source plate 2 is arranged opposite to the hot surface 101 of the heat source plate 1, and the cold surface and the hot surface 101 are opposite to each other at a distance. A phase-change heat-transferring working medium is arranged between the cold source plate and the heat source plate. The working medium conducts heat by undergoing phase change on the hot surface 101 of the heat source plate 1 and on the cold surface of the cold source plate 2. Specifically, the super-hydrophilic layer of the hot surface 101 allows the working medium liquid to spread evenly and evaporate into high-temperature working medium vapor, taking away heat; the high-temperature working medium vapor becomes large-scale condensation droplets on the cold surface of the cold source plate 2, releasing heat; adjacent condensation droplets merge and bounce at high speed to hit the hot surface 101 of the heat source plate 1, thereby forming an "evaporation-condensation-bouncing" cycle process of the working medium.

[0058] The cold surface of the cold source plate 2 has a non-uniform microstructure 201, which is used to directionally control the condensed droplets on the cold surface to bounce in the direction of the hot spot area A to the hot spot area A when the directional heat spreader 1000 is working. It should be emphasized that by designing the non-uniform microstructure 201 on the cold surface, when the directional heat spreader 1000 is working, on the one hand, the maximum size of the condensed droplets grown on the non-uniform microstructure 201 can be limited to the micron / submicron size range, so that the condensed droplets of such size are more likely to achieve fusion bounce, and the probability of bouncing is greatly increased, thereby achieving stable bouncing of the condensed droplets. On the other hand, the large-scale micron / submicron condensed droplets on the non-uniform microstructure 201 can be controlled to bounce in a concentrated manner to the hot spot area A. In this way, the number of condensed droplets reaching the hot spot area A of the heat source plate 1 is greatly increased, and the heat of the hot spot area A can be absorbed faster and more. The condensed droplets in the hot spot area A, that is, the working fluid liquid, are evenly spread and evaporated into high-temperature working fluid vapor through the super-hydrophilic layer on the heat source plate 1, taking away the heat, thereby greatly improving the cooling effect on the hot spot area A. A super-hydrophobic layer is formed on the non-uniform microstructure 201, that is, the super-hydrophobic layer covers the entire cold surface, which makes it easier for the condensed liquid droplets to separate from the non-uniform microstructure 201 after fusion, which is conducive to achieving high-stability bouncing of the condensed liquid droplets.

[0059] The working principle of the directional bouncing of the non-uniform microstructure 201 is described below by way of example.

[0060] Figure 4 and Figure 5 A schematic diagram of using the Laplace differential pressure principle to control the bouncing direction of the condensed droplets (the bouncing direction is tilted) is shown. When a single microstructure unit in the non-uniform microstructure 201 selects a convex columnar isosceles trapezoidal prism (such as Figure 3 shown), then Figure 4 Shows Figure 3 the top surface of an isosceles trapezoidal prism (the top surface is an isosceles trapezoid). When high-temperature working fluid vapor condenses on the top surface of the isosceles trapezoidal prism to form condensate droplets, since different positions of the same condensate droplet have different contact widths with the top surface of the isosceles trapezoidal prism, the contact width of the condensate droplet at x1 on the top surface is δ1, and the contact width at x2 on the top surface is δ2, δ1 < δ2, resulting in the radius of curvature of the condensate droplet at x1 being smaller than that at x2, that is, r1 < r2. According to the Laplace equation, the pressure difference of the condensate droplet at x1 is greater than that at x2, that is, ΔP1 > ΔP2, and then a driving force is generated in the direction from the larger pressure difference to the smaller pressure difference( Figure 4 shows that the direction of this driving force is to the right in Figure 5 , that is, along the direction of increasing width of the isosceles trapezoid). Therefore, as Figure 5 shows, on the surface with an isosceles trapezoidal prism, when two condensate droplets fuse and bounce, they are driven by the driving force to the right, and the fused condensate droplet will bounce obliquely upward to the upper right. Thus, according to the different positions relative to the hot spot area A on the cold surface, non-uniform microstructures 201 for directional regulation can be arranged (for example, as Figure 6a-Figure 6b , Figure 7 shows), so that when the directional heat spreader 1000 works, the non-uniform microstructures 201 can directionally regulate the large-scale micron / sub-micron condensate droplets on the cold surface to bounce towards the hot spot area A in the direction of the hot spot area A.

[0061] By the same principle, a single microstructure unit in the non-uniform microstructure 201 can also select a triangular prism (as Figure 8 shows), a sector prism (as Fig. 9 shows), a parallelogram prism (not shown in the figure), a V-shaped prism (as Fig.10 shows) or a crescent prism (not shown in the figure) and other convex columns, but not limited to this. As long as the top surface of the convex column can generate a driving force similar to that generated by the above Laplace pressure difference when the condensate droplets merge and bounce, it can be used to regulate the condensate droplets to bounce in the inclined upward direction.

[0062] Fig.11a and Fig.11b show another method of regulating the bouncing direction of condensate droplets (the bouncing direction is inclined upward) using the principle of density. For a superhydrophobic surface with non-uniform microstructures 201, the density of the non-uniform microstructures 201 will affect the contact angle of the surface. For example, when a single microstructure unit in the non-uniform microstructures 201 selects a convex columnar rectangular prism (as Fig.11a and Fig.11bAs shown), the non-uniform microstructure 201 has a super-hydrophobic surface and the density of the microstructure units is generally distributed in a gradient from sparse to dense from the outside to the inside. The sparser the non-uniform microstructure 201, the worse the surface wettability and the larger the contact angle; the denser the non-uniform microstructure 201, the better the surface wettability and the smaller the contact angle. Therefore, from the outside to the inside of the non-uniform microstructure 201, the density distribution of the microstructure units changes from sparse to dense. For the two droplets that are merging and bouncing, the bouncing direction of the droplets is no longer vertically upward due to the different contact angles, but is offset. The bouncing direction is: the fused condensed droplets bounce from the sparse area to the dense area in a roughly parabolic shape. Therefore, in the heat spreader of the first aspect of the embodiment of the present invention, by reasonably designing the density of the microstructure units of the non-uniform microstructure 201, the condensed droplets can hit the hot spot area A during the bouncing process, so that the large-scale micron / submicron condensed droplets on the cold surface can be directionally regulated to bounce to the hot spot area A in the direction of the hot spot area A.

[0063] From the description of the above two principles, it can be known that in the directional vapor chamber 1000 of the embodiment of the first aspect of the present invention, the non-uniform microstructure 201 includes a base point area B directly opposite to the hot spot area A and a peripheral area C distributed outside the base point area B and not directly opposite to the hot spot area A. For the base point area B, the condensed liquid droplets can bounce upward at an angle, but the landing point of the condensed liquid droplets on the heat source plate 11 is still located in the hot spot area A, and for the peripheral area C, the condensed liquid droplets can bounce upward at an angle, and the landing point of the condensed liquid droplets on the heat source plate 11 is still located in the hot spot area A.

[0064] Of course, with regard to the bouncing direction of the condensation droplets in the base area B, in addition to designing a convex columnar microstructure to achieve the inclined bouncing of the condensation droplets, a concave pit microstructure can also be designed to achieve the vertical bouncing of the condensation droplets, that is, the condensation droplets in the base area B can bounce vertically.

[0065] The following is an explanation of the principle of vertical bounce of the pit microstructure: by designing a micrometer-scale thin-walled pit microstructure (refer to Fig.12a , Figure 12b and Fig.12c ), so that the condensate droplets can only grow in each individual pit of the thin-walled pit microstructure instead of growing on the sidewall top surface of the individual pit. When the condensate droplets grow to a size comparable to the pit size, they can be considered to be well grown condensate droplets (such as Fig.12a As shown in the figure), the grown condensed droplets in two adjacent pits merge (as shown in the figure). Figure 12b As shown in the figure, due to the existence of the thin wall (i.e., the side wall of a single pit), the internal flow direction of the fused condensed droplets will be induced to be away from the surface, and the thin wall will provide the droplets with a capillary driving force F away from the surface. Under the action of this capillary driving force F, the fused droplets will bounce off the cold surface at high speed like a bow and arrow (as shown in the figure). Fig.12c As shown), the vertical bounce of the condensed droplets, i.e., vertical bounce, is achieved.

[0066] The following is an example of a comparison experiment of a group of non-uniform microstructures 201 and uniform microstructures in regulating the bouncing of condensed liquid droplets in a desired direction, to demonstrate the significant effect of the non-uniform microstructure 201 of this embodiment.

[0067] In this comparative experiment, the non-uniform microstructure 201 (reference Figure 7 ) in a single microstructure unit and a uniform microstructure (ref. Fig.13 ) are all isosceles trapezoidal prisms, and the base length of the isosceles trapezoid is 5 μm. From the experimental results, it can be seen that Fig.14 As shown, the expected direction bounce ratio of the condensation droplets on the non-uniform microstructure 201 is significantly higher than the expected direction bounce ratio of the condensation droplets on the uniform microstructure.

[0068] According to the directional heat spreader 1000 of the embodiment of the first aspect of the present invention, first, compared with the existing liquid wick heat spreader, in the existing liquid wick heat spreader, the liquid wick sucks liquid at a rate of mm / s, and the suction speed is slow; while in the directional heat spreader 1000 of this embodiment, the bouncing speed of the condensed droplets can reach m / s, and the transport rate of the condensed liquid can be increased by three orders of magnitude, breaking through the evaporation limit and capillary limit of the existing liquid wick heat spreader. Second, compared with the existing common super-hydrophobic surface heat spreader, since the existing common super-hydrophobic surface has no microstructure, the bouncing direction of the condensed droplets is basically perpendicular to the surface bouncing, the number of condensed droplets reaching the hot spot area A is small, the volume is small, the heat absorbed is small, and the cooling effect on the hot spot area A is poor. The directional heat spreader 1000 of this embodiment, by designing a non-uniform microstructure 201 on the cold surface, when the directional heat spreader 1000 is working, on the one hand, the maximum size of the condensed droplets grown on the non-uniform microstructure 201 can be limited to the micron / submicron size range, so that the condensed droplets of this size It is easier to achieve fusion bounce, and the probability of bounce is greatly increased, thereby achieving stable bounce of condensed droplets. On the other hand, the large-scale micron / submicron condensed droplets on the non-uniform microstructure 201 can be regulated to bounce to the hot spot area A, thereby increasing the number and volume of droplets reaching the hot spot area A, and absorbing more heat from the hot spot area A faster. The condensed droplets in the hot spot area A, i.e., the working fluid liquid, are evenly spread and evaporated into high-temperature working fluid steam through the super-hydrophilic layer on the heat source plate 1 to take away the heat, thereby greatly improving the cooling effect on the hot spot area A, and then increasing the heat flux density of the heat spreader.

[0069] In some embodiments, the non-uniform microstructure 201 includes a base point region B directly opposite to the hot spot region A and a peripheral region C distributed outside the base point region B and not directly opposite to the hot spot region A. It can be understood that the microstructure at the base point region B can make the condensed liquid droplets bounce vertically or tilted to the hot spot region A, and the microstructure at the peripheral region C can make the condensed liquid droplets bounce tilted to the hot spot region A, thereby achieving the condensed liquid droplets on the non-uniform microstructure 201 to bounce to the hot spot region A in a concentrated manner.

[0070] In some embodiments, a single microstructure unit in the base point region B is convex column-shaped (refer to Figure 1 , Figure 6a and Figure 7 , isosceles trapezoids represent convex columns), or pit-shaped (reference Figure 2 and Fig.15 , the circle represents the pit), or partly convex and partly concave (ref. Fig.16 , isosceles trapezoids represent convex pillars, and circles represent concave pits), and the single microstructure unit in the peripheral area C is convex columnar (ref. Figure 1 and Figure 2 ). It can be understood that, since the base point area B is directly opposite to the hot spot area A, the condensed liquid droplets in the base point area B may bounce obliquely upward when bouncing, but the landing point of the condensed liquid droplets on the heat source plate 11 is still located in the hot spot area A (refer to Figure 1 ), or it can be a bounce in the vertical cold surface direction (i.e. vertically upward) (refer to Figure 2 ); therefore, a single microstructure unit in the base area B can be in the shape of a convex column, a concave pit, or partially in the shape of a convex column and partially in the shape of a concave pit. The condensed droplets in the peripheral area C can only bounce upward at an angle but not vertically upward, therefore, a single microstructure unit in the peripheral area C should be in the shape of a convex column. Thus, by rationally designing the microstructure units of the base area B and the microstructure units of the peripheral area C, a highly stable directional bounce of the condensed droplets by the non-uniform microstructure 201 can be achieved, so that the large-scale micron / submicron condensed droplets on the cold surface are concentrated and bounced toward the hot spot area A to the hot spot area A, thereby greatly improving the cooling effect on the hot spot area A, and then increasing the heat flux density of the heat spreader.

[0071] In some embodiments, when a single microstructure unit in the base point region B is in the shape of a convex column, the base point region B includes a plurality of first sub-ring regions from the inside to the outside, and a single microstructure unit in the same first sub-ring region is an isosceles trapezoidal prism (refer to Figure 3 ), triangular prism (reference Figure 8 ), fan-shaped prism (reference Fig. 9 ), rectangular prism (reference Fig.11a ), parallelogram prism (not shown), V-shaped prism (refer to Fig.10) or a crescent prism (not shown in the figure), and the individual microstructure shapes of different first sub-ring areas are the same or different. It can be understood that since the hot spot area A has a certain area, and the size of the individual microstructure unit is in the micron level, which is very small, a number of first sub-ring areas that are surrounded from the inside to the outside can be designed in the range of the base point area B. The individual microstructure units of the same first sub-ring area can be isosceles trapezoidal prisms, triangular prisms, fan-shaped prisms, rectangular prisms, parallelogram prisms, V-shaped prisms or crescent prisms, but are not limited to this. The individual microstructure shapes of different first sub-ring areas can be the same, for example, the microstructure units in the base point area B are isosceles trapezoidal prisms or rectangular prisms. The shapes of individual microstructures in different first sub-ring areas may also be different. For example, the shape of individual microstructure units in one circle of first sub-ring areas is an isosceles trapezoidal prism, and the shape of individual microstructure units in another circle of first sub-ring areas is a fan-shaped prism. By arranging two or more combinations of microstructure units in the base point area B, structural anisotropy can be formed, thereby giving play to the advantages of the transport capacity of surfaces of different shapes for condensed droplets and enhancing the surface's ability to regulate the direction of droplet bouncing.

[0072] In some embodiments, the density distribution of microstructure units in the same first sub-ring area is the same, so that the condensed droplets on the same first sub-ring area can be evenly distributed, which is conducive to the fusion and bounce of the condensed droplets. The density distribution of microstructure units in different first sub-ring areas can be the same, and the condensed droplets in the base point area B can also be regulated to bounce upward to the hot spot area A. The density distribution of microstructure units in different first sub-ring areas can also be different. Since the density of microstructure units at different positions on the base point area B is different, the microstructure array of the base point area B itself can be combined with the different microstructure unit densities to regulate the droplet bounce, which can further improve the directional regulation of the condensed droplets.

[0073] In some embodiments, when a single microstructure unit in the base point region B is in the shape of a pit, the base point region B is an egg tray microstructure (refer to Fig.15 ) or grid microstructure (reference Figures 17 to 19 ). It can be understood that, on the one hand, by designing the base point area B into an egg tray microstructure or a grid microstructure, the condensed liquid droplets can be confined in the corresponding pits, and the condensed liquid droplets can bounce vertically when bouncing.

[0074] Preferably, the shape of a single microstructure unit of the grid microstructure is preferably a square (refer to Fig.17 ), triangle (reference Fig.18 ) or a regular hexagon (reference Fig.19 ), which can achieve dense paving of the grid, which is beneficial for the condensation droplets in the base point area to grow only in each single pit.

[0075] In some embodiments, when a single microstructure unit in the base point region B is partially convex-column-shaped and partially concave-shaped, the base point region B includes a concave sub-region and a convex column sub-region, and the convex column sub-region surrounds the periphery of the concave sub-region (not shown in the figure), or the concave sub-region surrounds the periphery of the convex column region (refer to Fig.16 ), or the pit sub-areas and the convex pillar sub-areas are arranged alternately from the inside to the outside (not shown in the figure). In this way, the condensed liquid droplets in the base point area B can be directed to bounce, so that the condensed liquid droplets in the base point area B bounce to the hot spot area A in a concentrated manner.

[0076] In some embodiments, the peripheral area C includes several second sub-ring areas distributed from outside to inside, and the single microstructure unit of the same second sub-ring area is an isosceles trapezoidal prism, a triangular prism, a fan-shaped prism, a rectangular prism, a parallelogram prism, a V-shaped prism or a crescent prism, and the single microstructure shapes of different second sub-ring areas are the same or different. It can be understood that since the peripheral area C has a certain area, and the size of the single microstructure unit is in the micron level, the size is very small, therefore, several second sub-ring areas from outside to inside can be designed in the range of the peripheral area C, and the single microstructure unit of the same second sub-ring area can be an isosceles trapezoidal prism, a triangular prism, a fan-shaped prism, a rectangular prism, a parallelogram prism, a V-shaped prism or a crescent prism, but is not limited to this. The single microstructure shapes of different second sub-ring areas can be the same, for example, the microstructure unit in the peripheral area C is an isosceles trapezoidal prism or a rectangular prism. The shapes of individual microstructures in different second sub-ring areas may also be different. For example, the shape of individual microstructure units in one circle of second sub-ring areas is an isosceles trapezoidal prism, and the shape of individual microstructure units in another circle of second sub-ring areas is a fan-shaped prism. By arranging two or more combinations of microstructure units in the peripheral area C, structural anisotropy can be formed, thereby giving play to the advantages of the transport capacity of surfaces of different shapes for condensed droplets and enhancing the surface's ability to regulate the direction of droplet bouncing.

[0077] In some embodiments, the density distribution of the microstructure units in the same second sub-ring area is the same, so that the condensed droplets on the same first sub-ring area can be evenly distributed, which is conducive to the fusion and bounce of the condensed droplets. The density distribution of the microstructure units in different second sub-ring areas is different, and the microstructure array of the peripheral area C itself can be combined with the microstructure unit density gradient to further improve the directional control effect on the condensed droplets.

[0078] In some embodiments, the density of the microstructure units in different second sub-ring areas from the outside to the inside is distributed in a gradient from sparse to dense. According to the above-mentioned use of the density principle to control the bouncing direction of the condensed droplets, it can be known that for the two droplets that merge and bounce, the bounce direction of the droplets is no longer vertically upward due to the different contact angles, but is offset. The bouncing direction is: the fused condensed droplets bounce from the sparse area to the dense area in a roughly parabolic shape. Therefore, in the heat spreader of the first aspect of the embodiment of the present invention, through the reasonable design of the density of the microstructure units in the peripheral area C, the condensed droplets can hit the hot spot area A during the bouncing process, thereby further improving the directional regulation of the condensed droplets.

[0079] In some embodiments, a single microstructure unit in the peripheral region C is an isosceles trapezoidal prism, wherein the upper base width W1 of the top surface of the isosceles trapezoidal prism is 1 μm, the lower base width W2 is in the range of 5 to 10 μm, the angle between the two oblique sides is in the range of 15 to 30°, and the thickness H of the isosceles trapezoidal prism is in the range of 5 to 10 μm. Experiments have shown that when a single microstructure unit in the peripheral region of a non-uniform microstructure adopts an isosceles trapezoidal prism of this size range, the proportion of condensed droplets bouncing in the expected direction is high. The following is a set of experimental data to illustrate the regulating effect of the isosceles trapezoidal prism surfaces of different sizes on the droplet bouncing direction, such as Fig. 20 As shown in the figure, the width of the lower base of the top surface of the isosceles trapezoidal prism has three sizes, namely 2.5μm, 5μm, and 10μm. From the proportion of condensed droplets bouncing in the expected direction, it can be found that the isosceles trapezoidal prism non-uniform microstructure can effectively control the direction of droplet bouncing, so that the droplets bounce in the expected direction.

[0080] The second aspect of the present invention also provides a chip.

[0081] The chip according to the embodiment of the second aspect of the present invention comprises a directional heat spreader 1000 and a chip body according to any one embodiment of the first aspect of the present invention, and the directional heat spreader 1000 is used to dissipate heat from the chip body. Since the directional heat spreader 1000 of the embodiment of the first aspect of the present invention greatly improves the cooling effect on the hot spot area A, thereby increasing the heat flux density of the heat spreader, the high-temperature part of the chip body is brought into contact with the hot spot area A of the heat source plate 1, which can effectively dissipate heat from the high-temperature part of the chip, while meeting the demand for chip miniaturization, which has important practical significance for the development of my country's chip industry.

[0082] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0083] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A directional heat spreader, characterized in that: include: A heat source plate, wherein the heat source plate has a hot spot area, and a hot surface of the heat source plate is provided with a super hydrophilic layer; A cold source plate, wherein the cold surface of the cold source plate is arranged opposite to the hot surface of the heat source plate, and a phase-change heat-transfer working medium is arranged between the cold source plate and the heat source plate; the cold surface of the cold source plate has a non-uniform microstructure, which is used for directionally controlling the condensed droplets on the cold surface to bounce toward the hot spot area when the directional heat spreader is working, and a super-hydrophobic layer is formed on the non-uniform microstructure; the non-uniform microstructure includes a base point area directly opposite to the hot spot area and a peripheral area distributed on the periphery of the base point area and not directly opposite to the hot spot area, wherein the non-uniform microstructure is used to limit the maximum size of the condensed droplets grown on the non-uniform microstructure to be in the micron / submicron size range.

2. The directional vapor chamber according to claim 1, characterized in that: The single microstructure unit in the base point area is in the shape of a convex column, or in the shape of a concave pit, or partially in the shape of a convex column and partially in the shape of a concave pit, and the single microstructure unit in the peripheral area is in the shape of a convex column.

3. The directional vapor chamber according to claim 2, characterized in that: When the single microstructure unit in the base point area is in the shape of a convex column, the base point area includes several first sub-ring areas from the inside to the outside, and the single microstructure unit of the same first sub-ring area is an isosceles trapezoidal prism, a triangular prism, a fan-shaped prism, a rectangular prism, a parallelogram prism, a V-shaped prism or a crescent prism, and the single microstructure shapes of different first sub-ring areas are the same or different.

4. The directional vapor chamber according to claim 3, characterized in that: The density distribution of microstructure units in the same first sub-ring area is the same, and the density distribution of microstructure units in different first sub-ring areas is the same or different.

5. The directional vapor chamber according to claim 2, characterized in that: When a single microstructure unit in the base point region is in a pit shape, the base point region is an egg tray microstructure or a grid microstructure.

6. The directional vapor chamber according to claim 2, characterized in that: When a single microstructure unit in the base point area is partially in the shape of a convex column and partially in the shape of a concave pit, the base point area includes a concave pit sub-area and a convex column sub-area, the convex column sub-area surrounds the periphery of the concave pit sub-area, or the concave pit sub-area surrounds the periphery of the convex column sub-area, or the concave pit sub-area and the convex column area are alternately arranged from the inside to the outside.

7. The directional vapor chamber according to any one of claims 1 to 6, characterized in that: The peripheral area includes several second sub-ring areas distributed from the outside to the inside, and a single microstructure unit of the same second sub-ring area is an isosceles trapezoidal prism, a triangular prism, a fan-shaped prism, a rectangular prism, a parallelogram prism, a V-shaped prism or a crescent prism. The single microstructure shapes of different second sub-ring areas are the same or different.

8. The directional vapor chamber according to claim 7, characterized in that: The density distribution of microstructure units in the same second sub-ring area is the same, and the density distribution of microstructure units in different second sub-ring areas is different.

9. The directional vapor chamber according to claim 8, characterized in that: The density of the microstructure units in the different second sub-ring regions from outside to inside is distributed in a gradient from sparse to dense.

10. The directional vapor chamber according to claim 9, characterized in that: The single microstructure unit in the peripheral area is an isosceles trapezoidal prism, wherein the upper base width of the top surface of the isosceles trapezoidal prism is 1 μm, the lower base width ranges from 5 to 10 μm, the angle ranges from 15 to 30°, and the thickness of the isosceles trapezoidal prism ranges from 5 to 10 μm.

11. A chip, characterized in that: It comprises the directional heat spreader as described in any one of claims 1 to 10 and a chip body, wherein the directional heat spreader is used to dissipate heat from the chip body.

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