CN217719576U - Three-dimensional flat pulsating heat pipe device for radiating and cooling high-power chip - Google Patents

Abstract

The utility model discloses a towards high-power chip heat dissipation refrigerated three-dimensional dull and stereotyped pulsating heat pipe device is applied to heat dissipation cooling technical field, include: the substrate, the first cover plate and the second cover plate; the base plate is arranged between the first cover plate and the second cover plate; two side surfaces of the base plate are provided with micro channels which are staggered with each other; the microchannels are radially arranged and distributed around the heat source joint position; the micro-channels on the two side surfaces are communicated through vertical holes; and working media are filled in the micro-channel. The utility model provides a towards high-power chip heat dissipation refrigerated three-dimensional dull and stereotyped pulsating heat pipe device can satisfy quick low temperature start, the temperature uniformity is good, the heat transfer rate is high, can guarantee again that simple structure, compactness are strong.

Description

Three-dimensional flat pulsating heat pipe device for radiating and cooling high-power chip

Technical Field

The utility model relates to a heat dissipation cooling technology field, more specifically the utility model relates to a towards high-power chip heat dissipation refrigerated three-dimensional dull and stereotyped pulsating heat pipe device that says so.

Background

With the trend of high power and miniaturization of electronic devices, problems such as heat accumulation, uneven heat distribution, local hot spots, etc. are frequent. In the field of electronic chips, the current heat flux density is about 100W/cm²With the development of information technology, the average heat flux density of the chip can reach 500W/cm²Local hot spot heat flow density even up to 1000W/cm²! Generally, the safety temperature of the chip is not allowed to exceed 85 ℃ at most, otherwise, the chip cannot operate stably, and even safety accidents occur. In order to solve the increasingly complex and severe heat dissipation problem of high heat flux density chips, it is important to develop an effective heat dissipation means. This is both a challenge and an opportunity for advanced thermal management.

The pulsating heat pipe, originally proposed by Akachi, a japanese scientist in 1990, has been proven to be a new type of efficient passive heat transfer device over decades of development. Besides utilizing the phase change latent heat related to the traditional heat pipe, the pulsating heat pipe can also carry out sensible heat transfer through self-excited oscillation of the vapor/liquid plug, thereby greatly improving the heat transfer efficiency of the pulsating heat pipe.

At present, researches on heat dissipation of the pulsating heat pipe mainly focus on two-dimensional pipe type and plate type heat pipes, the heat transfer direction of the pulsating heat pipe is limited to plane conduction, temperature distribution is uneven easily, and the requirements of heat dissipation working conditions of high heat flux, high temperature uniformity and complex and variable space in the future are difficult to meet. In order to increase the degree of freedom of Heat Transfer, there are scholars (Jie Qu, jianteng Zhao, zhonghao Rao. Experimental in the thermal conduction on thermal performance of multi-layer three-dimensional pulsating Heat pipes [ J ]. Internal Journal of Heat & Mass Transfer,115 (2017) 810-819.) considering that bending a two-dimensional tube pulsating Heat pipe into a multi-layer three-dimensional pulsating Heat pipe shows superior performance to a two-dimensional pulsating Heat pipe at high power, but has disadvantages of poor compact Heat Transfer and Heat dissipation from a miniaturized chip; in addition, a three-dimensional Flat pulsating Heat pipe with microchannels machined on both sides is proposed by a scholars (Thompson S M, lu H, ma H. Thermal spraying with Flat-Plate annealing Heat pipes [ J ]. Journal of Thermophysics & Heat Transfer,29 (2015) 338-345.) and experimental studies are carried out, and the results show that although the Heat Transfer performance can be improved compared with the copper Plate, the problems of difficult starting and large temperature difference of the cold end and the hot end exist.

Therefore, how to realize the aims of meeting the requirements of quick low-temperature start, good temperature uniformity and high heat transfer rate and ensuring simple structure and strong compactness can become the pursuit of cumin in the field of advanced heat management of electronic chips.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a towards the three-dimensional dull and stereotyped pulsating heat pipe device of high-power chip heat dissipation refrigerated can satisfy quick low temperature start, the temperature uniformity is good, the heat transfer rate is high, can guarantee again that simple structure, compactness are strong.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip comprises: the substrate, the first cover plate and the second cover plate; the base plate is arranged between the first cover plate and the second cover plate; two side surfaces of the base plate are provided with micro channels which are staggered with each other; the microchannels are radially arranged and distributed around the heat source joint position; the micro-channels on the two side surfaces are communicated through vertical holes; and working media are filled in the micro-channel.

Further, the substrate, the first cover plate and the second cover plate are combined by means of bonding, brazing, molecular diffusion welding, induction welding and the like.

Optionally, in the above three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, the substrate is provided with a fixing hole; and dividing the substrate into four areas by taking diagonal connecting lines of the four fixing holes on the side surface of the substrate and extension lines of the boundary lines of the four sides as boundary lines, wherein the processing range of the micro-channel on each surface occupies the union part of two diagonal areas and rectangular areas determined by the four fixing holes.

Optionally, in the above three-dimensional flat pulsating heat pipe device oriented to high-power chip heat dissipation and cooling, the middle rectangular region defined by the four fixing holes is provided with the double-layer microchannels which are vertically staggered, and the regions outside the middle rectangular region are provided with the equal-diameter or variable-diameter microchannels which are approximately complementary and radially distributed around, and the whole body is in a three-dimensional radial shape with the center diffusing to the edge.

Optionally, in the above three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, the front and back microchannels are communicated through a vertical hole at one end having a converging long straight channel, and are externally connected with a pumping/filling metal pipe, so as to pump vacuum and fill working medium into the microchannels.

Optionally, in the above three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, the fluid working medium is one of deionized water, acetone, HFE7X00, R113, R134a, R1233zd, and R1336 mzz.

Optionally, in the above three-dimensional flat pulsating heat pipe device oriented to heat dissipation and cooling of a high-power chip, a liquid pumping/filling pipe is further included; and the liquid pumping/filling pipe is connected with the vertical hole on the micro-channel.

Optionally, in the above three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, a heat dissipation fin is further included; the radiating fins are fixedly connected with the base plate in a welding mode.

Optionally, in the above three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, a heat dissipation fan is further included; the heat radiation fan is arranged above or on the side of the heat radiation fin through the mounting seat.

Optionally, in the above three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, the fixing hole attaches the first cover plate to the heat source through a spring bolt or attaches the second cover plate to the heat source through a spring bolt.

Optionally, in the three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, the microchannels are of a single equivalent diameter or are arranged in a variable diameter manner.

Further, the equivalent diameter D of the microchannel needs to satisfy the following formula:

wherein g is gravitational acceleration ρ_lAnd ρ_gRespectively representing the densities of the liquid working medium and the vapor working medium, and sigma represents the surface tension of the working medium.

Optionally, in the above three-dimensional flat pulsating heat pipe device oriented to heat dissipation and cooling of a high-power chip, heat-conducting silicone grease is applied between the first cover plate and the heat source or between the second cover plate and the heat source.

It is to be understood that: one side of the plate pulsating heat pipe is provided with a micro-channel covering the universe, although the phenomenon that heat is rapidly dissipated and cooled to the periphery can be presented theoretically, the heat is affected by the on-way resistance inside the micro-channel and the local resistance at a corner, in practical application, the working medium is difficult to completely reach the periphery for heat dissipation, and only local pulsation is performed in a plurality of micro-channels close to a heat source. This has caused a lot of microchannels and heat radiating area's waste on the one hand, and on the other hand also can make whole radiating effect worsen, and the heat source temperature risees, seriously influences electronic chip's safe temperature operation.

According to the technical scheme, compared with the prior art, the utility model discloses a three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip, which can ensure that the micro-channel on each surface can be effectively utilized; compared with the traditional flat pulsating heat pipe, the double-layer staggered micro-channel is adopted, the number of the micro-channels in a unit area is increased, the dependence on gravity in the operation process is reduced, and the double-sided micro-channels are communicated with each other, and the arc smooth transition is adopted at the corner of the micro-channels, so that the working medium can be automatically adjusted according to the operation working condition, the working medium in the circulation loop is ensured to be alternately updated in time, the local dry-up phenomenon is avoided, and the heat transfer limit of the flat pulsating heat pipe is effectively improved; two layers of microchannels are arranged right above heat sources such as a power chip in a staggered mode, waste heat generated by the microchannels can be further absorbed, the microchannels are integrally in a three-dimensional radial shape with the center diffused to the edge, a rapid heat transmission path from a point to a surface to a body is formed, heat can be conveniently and uniformly distributed from the periphery, and temperature uniformity is improved; on the premise of meeting the local high heat flow density heat dissipation requirement, the overall size can be adjusted according to the actual requirement (for example, heat dissipation of high heat flow density components such as high-performance computer chips, military radar laser equipment, electronic devices in the aerospace field and the like), the capillary core sintering process of the traditional heat pipe is not needed, the pumping/filling is integrated, the processing is convenient, and the application scene of the heat pipe is greatly widened.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic perspective exploded view of embodiment 1 of the present invention;

FIG. 2 is a schematic view of the processing and layout of micro-channels on the front and back sides of the embodiment 1 of the present invention;

FIG. 3 is a schematic view of the processing and layout of micro-channels on the front and back sides of the embodiment 2 of the present invention;

FIG. 4 is a schematic view of the processing and layout of micro-channels on the front and back sides of embodiment 3 of the present invention;

FIG. 5 is a schematic view of the processing and layout of micro-channels on the front and back sides of the embodiment 4 of the present invention;

FIG. 6 is a schematic diagram of an apparatus for heat dissipation and cooling of a heat source such as a power chip using the technical solution mentioned in the technology of the embodiment of the present application;

in the figure: 1. the heat pipe comprises a first cover plate, a base plate, a second cover plate, a fixing hole, a micro channel, a liquid pumping/filling pipe, a heat source, a three-dimensional flat pulsating heat pipe, a spring bolt and a radiating fin, wherein the first cover plate is 2, the base plate is 3, the second cover plate is 4, the fixing hole is 5, the micro channel is 6, the liquid pumping/filling pipe is 7, the three-dimensional flat pulsating heat pipe is 8, the spring bolt is 9, and the radiating fin is 10.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

Embodiment 1 discloses a three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip. As shown in fig. 1, the basic configuration of the three-dimensional flat pulsating heat pipe includes: the silicon/copper/aluminum base plate 2 with the micro-channel 5, the first cover plate 1 and the second cover plate 3 which have the same area with the base plate 2 and are tightly attached to form the closed micro-channel 5, and the liquid pumping/filling pipe 6 are processed by CNC numerical control processing or a precision etching method. They are combined by means of bonding, brazing, molecular diffusion welding, induction welding, and the like. One surface of the three-dimensional flat pulsating heat pipe is tightly attached to heat sources such as a power chip, and the other surface of the three-dimensional flat pulsating heat pipe can be selectively additionally provided with fins for heat dissipation.

As shown in fig. 2, the four diagonal connecting lines of the fixing holes on one surface of the substrate 2 and the extension lines of the 4 boundary lines are used as boundary lines to divide the substrate into four regions, and the machining range of the micro-channel on one surface only occupies the union part of the two diagonal regions and the rectangular regions defined by the four fixing holes. From one side, the middle rectangular area defined by the four fixing holes is internally provided with parallel dense micro-channels which are arranged and distributed, the areas outside the middle rectangular area are regularly and orderly arranged and distributed in a radial manner to the periphery, one end of each fixing hole is repeatedly and flexibly connected by a smooth small circular arc, and the other end of each fixing hole is a long straight collecting channel formed by connecting the outermost micro-channels at the two sides. From the whole, the two-layer micro-channels are vertically distributed in a staggered manner in the middle rectangular area determined by the four fixing holes, the middle of the middle rectangular area is separated by a material with a certain thickness, the number of the micro-channels in a unit area is obviously increased, waste heat generated by heat sources such as a power chip and the like can be further absorbed, the rapid low-temperature starting is realized, and the micro-channels with equal diameters or variable diameters are distributed in an approximately complementary manner in a radiation manner to the periphery outside the area, so that the internal working medium can be distributed over the whole area of the three-dimensional flat pulsating heat pipe, a rapid three-dimensional transmission path from a point to the surface to the body is formed, the heat can be conveniently and uniformly distributed from the periphery simultaneously, and the temperature uniformity is improved. The width of the micro-channel is 1mm, the depth is 1mm, the surface tension can be ensured to occupy the dominant position, and working media are filled in the micro-channel to form vapor/liquid plugs which are distributed at random intervals. The little channel of positive and negative is having the one end that collects the long straight channel and is passing through the vertical hole and communicating to here external pump/liquid filling pipe carries out the evacuation and fills and annotates the working medium to little channel inside. The embodiment does not relate to the capillary core sintering process of the traditional heat pipe, can realize pumping/filling integration, and has the advantages of simple processing and manufacturing and convenient operation.

Embodiment 2 is an improvement and a supplement to embodiment 1, and as shown in fig. 3, repeated parts are not repeated. Except that the depth of the microchannel 5 gradually transits from 1mm to 2mm at the rectangular boundary defined by the four fixing holes, and the width is kept constant. This means that in example 2, the four fixing holes define a central rectangular area within which vertically staggered double-layered 1 x 1mm microchannels are located, and outside the central rectangular area defined by the four fixing holes, approximately complementary 1 x 2mm microchannels radially arranged around. In the transition region, the Young-Laplace equation can deduce that due to the difference of hydraulic diameters, the steam/liquid plug can be acted by the acting force of moving from a small section to a large section, namely, a micro-pump effect is generated, the circulation of working media can be promoted, and the flat-plate pulsating heat pipe can be started as early as possible. Meanwhile, the pipe diameter difference can also enhance disturbance, destroy a boundary layer and enhance heat transfer.

The basic configuration and the micro-channel layout of embodiment 3 are the same as those of embodiment 1, and the repeated descriptions are omitted. Except that microchannels with width of 2mm and depth of 1mm are processed on the front and back sides, as shown in fig. 4. Accordingly, the smaller the number of microchannels per unit area, the weaker the unbalanced driving force provided, but the greater the microchannel cross-sectional size, the more desirable the reduction of the pulsating resistance of the internal vapor/liquid plug.

Embodiment 4 is an improvement and a supplement to embodiment 3, as shown in fig. 5, and repeated descriptions are omitted. Except that the depth of the microchannel 5 gradually transits from 1mm to 2mm at the rectangular boundary defined by the four fixing holes, and the width is kept constant. This means that in example 4, the four fastening holes define a central rectangular area with vertically staggered double-layered 2 x 1mm microchannels, and an outer area with approximately complementary circumferentially radially disposed 2 x 2mm microchannels. The purpose of such improvement is the same as in example 2, i.e., reduction in starting power and improvement in heat transfer performance.

Before working, heat sources 7 such as power chips and the like are arranged in the central areas of the four fixing holes, are tightly attached to one side face of the three-dimensional flat pulsating heat pipe 8 by using spring bolts 9, and heat-conducting silicone grease is coated between the heat sources and the three-dimensional flat pulsating heat pipe to reduce contact thermal resistance. When the micro-channel works, waste heat generated by heat sources such as a power chip and the like is transmitted to working media inside the micro-channel 5 through the heat-conducting silicone grease and the metal shell. Part of liquid phase working medium is heated to evaporate and change phase to generate vapor bubbles, the vapor bubbles are fused and grown into vapor plugs under the action of internal pressure, the long liquid plugs are blocked into short liquid plugs, and the pressure difference on two sides of the liquid plugs is gradually increased along with the increase of input power until the vapor/liquid plug pulsation can be generated by overcoming flow resistance. Meanwhile, the pressure in the adjacent micro-channels is unbalanced, so that the pulsating heat transfer strength of the internal working medium is further improved, and heat is rapidly transferred to the periphery in the forms of phase change latent heat and liquid plug sensible heat. It should be noted that the flat pulsating heat pipe is only a heat transfer element having a high equivalent thermal conductivity, and if it is desired to exert its function to the maximum, the heat radiation fin 10 may be attached to the other surface on which the heat source such as the power chip is mounted. If the heat dissipation space is allowed, forced air convection can be formed by installing a heat dissipation fan above or beside the fins, so as to enhance the heat dissipation capability of the cold end, as shown in fig. 6.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed in the embodiment corresponds to the method disclosed in the embodiment, so that the description is simple, and the relevant points can be referred to the description of the method part.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of a high-power chip is characterized by comprising: the substrate, the first cover plate and the second cover plate; the base plate is arranged between the first cover plate and the second cover plate; two side surfaces of the base plate are provided with micro channels which are staggered with each other; the microchannels are radially arranged and distributed around the heat source joint position; the micro-channels on the two side surfaces are communicated through vertical holes; and working medium is filled in the micro-channel.

2. The three-dimensional flat pulsating heat pipe device for heat dissipation and cooling of high-power chips as claimed in claim 1, wherein said base plate is provided with fixing holes; and dividing the substrate into four areas by taking diagonal connecting lines of the four fixing holes on the side surface of the substrate and extension lines of the boundary lines of the four sides as boundary lines, wherein the processing range of the micro-channel on each surface occupies the union part of two diagonal areas and rectangular areas determined by the four fixing holes.

3. The three-dimensional flat pulsating heat pipe device oriented to high-power chip heat dissipation and cooling as recited in claim 2, wherein said microchannels are arranged in parallel in a central rectangular region defined by four fixing holes, and are arranged in a radial manner outside the central rectangular region.

4. The three-dimensional flat pulsating heat pipe device oriented to high power chip heat dissipation cooling of claim 1, further comprising a long straight channel, wherein the long straight channel is communicated with the outermost micro channel.

5. The device of claim 1, wherein the fluid medium is one of deionized water, acetone, HFE7X00, R113, R134a, R1233zd and R1336 mzz.

6. The three-dimensional flat pulsating heat pipe device oriented to high-power chip heat dissipation and cooling as recited in claim 1, further comprising a liquid pumping/filling pipe; the liquid pumping/filling pipe is connected with the vertical hole on the micro-channel.

7. The three-dimensional flat pulsating heat pipe device oriented to high-power chip heat dissipation and cooling as recited in claim 1, further comprising heat dissipation fins; the radiating fins are fixedly connected with the base plate in a welding mode.

8. The three-dimensional flat pulsating heat pipe device oriented to high power chip heat dissipation and cooling as recited in claim 7, further comprising a heat dissipation fan; the heat radiation fan is arranged above or on the side of the heat radiation fin through the mounting seat.

9. The three-dimensional flat pulsating heat pipe device oriented to high power chip heat dissipation and cooling as claimed in claim 2, wherein the fixing hole is used for attaching the first cover plate to the heat source through a spring bolt or attaching the second cover plate to the heat source through a spring bolt.

10. The pulsating heat pipe device as claimed in claim 9, wherein a thermally conductive silicone grease is applied between the first cover plate and the heat source or between the second cover plate and the heat source.

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