阅读说明：本技术 一种带凹穴结构的微通道均热板 (Micro-channel vapor chamber with recess structure ) 是由 潘敏强 黄平南 陈阳 刘庆云 于 2019-11-22 设计创作，主要内容包括：本发明公开了一种带凹穴结构的微通道均热板，包括底板、毛细芯和盖板，所述底板的上表面设置有凹腔，毛细芯设置于凹腔内，所述盖板的上表面加工有微通道结构，所述微通道结构的内表面两侧设置凹穴结构，底板和盖板通过焊接方式形成密闭空腔，通过抽真空注液形成带凹穴结构的微通道均热板。本发明采用带凹穴结构的微通道阵列代替常规冷凝端吸液芯结构，一方面有利于工质的传输和均匀分配，增大工质冷凝面积，缩短冷凝回流路径，实现更低的流阻和优越的抗烧干特性；另一方面，凹穴结构可以增加传热面积，产生喷射节流效应，扰动蒸汽流动，抑制冷凝液膜的形成，促进冷凝回流，增大抗烧干极限，进而提高传热效率。(The invention discloses a microchannel soaking plate with a recess structure, which comprises a bottom plate, a capillary core and a cover plate, wherein the upper surface of the bottom plate is provided with a recess, the capillary core is arranged in the recess, the upper surface of the cover plate is provided with the microchannel structure, the recess structure is arranged on two sides of the inner surface of the microchannel structure, the bottom plate and the cover plate form a closed cavity in a welding mode, and the microchannel soaking plate with the recess structure is formed by vacuumizing and injecting liquid. The micro-channel array with the recessed structure is adopted to replace a conventional condensation end liquid absorption core structure, so that on one hand, the transmission and the uniform distribution of working media are facilitated, the condensation area of the working media is increased, the condensation reflux path is shortened, and the lower flow resistance and the superior burn-dry resistance are realized; on the other hand, the cavity structure can increase the heat transfer area, generate the jet throttling effect, disturb the steam flow, inhibit the formation of a condensed liquid film, promote the condensation reflux, increase the burning resistance limit, and further improve the heat transfer efficiency.)

1. The utility model provides a take microchannel soaking board of pocket structure, its characterized in that, includes bottom plate, capillary core and apron, the upper surface of bottom plate is provided with the cavity, and the capillary core sets up in the cavity, the last surface machining of apron has the microchannel structure, the internal surface both sides of microchannel structure set up the pocket structure, and bottom plate and apron form airtight cavity through the welding mode, annotate the microchannel soaking board of liquid formation area pocket structure through the evacuation.

2. The microchannel heat spreader of claim 1, wherein the wick is a copper powder sintered, metal foam, or wire mesh structure.

3. The microchannel heat spreader of claim 1, wherein the microchannel structure is in the form of an array of a plurality of microchannels, the array comprising a linear array and a circumferential array.

4. The microchannel heat spreader of claim 1, wherein the pocket structure is a two-dimensional pocket structure comprising a plurality of pockets, the pockets having a shape comprising a rectangle, triangle, semicircle, or trapezoid.

5. The microchannel heat spreader of claim 4, wherein the plurality of cavities are symmetrically disposed on opposite sides of the inner surface of the microchannel.

6. The microchannel heat spreader of claim 1, wherein the cross-section of the microchannel is circular arc, triangular, rectangular, or trapezoidal.

7. The microchannel heat spreader of claim 1 wherein the depth of the microchannel array is equal to the depth of the cavity of the bottom plate minus the height of the capillary wick.

8. A microchannel heat spreader as in claim 1 wherein the base plate and cover plate are identical in shape.

9. The microchannel heat spreader of claim 1, wherein the bottom plate and the cover plate comprise a circular or square shape.

10. The microchannel heat spreader of claim 2, wherein the wick is a sintered copper powder wick and the copper powder particles have a size of 0.075mm to 0.150 mm.

Technical Field

The invention relates to the technical field of microelectronic devices and chip heat dissipation, in particular to a micro-channel vapor chamber with a recess structure.

Background

With the miniaturization, integration and function complication of electronic equipment, the heating power of electronic chips is higher and higher. At present, the surface average heat flux density of the electronic chip exceeds 100W/cm²And there is a continuing trend toward increasing. At the same time, high heat flux density can form "hot spots" on the surface of the electronic device, resulting in reduced performance and reliability of the electronic chip.

The soaking plate is a heat dissipation component which transfers heat through phase change, and can quickly transfer and diffuse heat flow gathered on the surface of the electronic component to a condensation surface for heat dissipation, so that the surface heat flow density of the electronic component is effectively reduced. In recent years, vapor chambers have been widely used in the field of heat dissipation technology for electronic devices and chips.

Vapor chambers are generally constructed using upper and lower housings with wick structures. The liquid absorption core structure is used as the core of the soaking plate and is the important factor in the design of the soaking plate. At present, the liquid absorption core structure of the vapor chamber mainly comprises porous metal sintering and a micro-channel array. The porous metal sintered wick has the advantages of large capillary suction force, good burn-dry resistance and the like, and is a wick structure which is applied more at present. However, the porous metal sintered wick has high flow resistance and low permeability and is often used in combination with a steam chamber and a support column, thereby causing the problems of low support strength of the vapor chamber, complex processing, high manufacturing cost and the like. In addition, the porous metal sintered wick structure is easy to deform the soaking plate in the high-temperature packaging process, so that the yield is low, and meanwhile, the shell plate is easy to deform under the action of long-time heating, so that poor contact with a chip is caused, and the like. This problem is well avoided by using microchannel wick structures. The microchannel wick structure has the advantages of small contact thermal resistance, large heat transfer area, small flow resistance, large permeability and the like by directly processing the microchannel structure on the substrate. In addition, the micro-channel structure is adopted to replace a steam cavity and a support column structure, so that the pressure resistance and heat resistance of the soaking plate can be effectively improved, and a condensation reflux path is shortened, thereby effectively improving the heat transfer capacity of the soaking plate. In recent years, with the miniaturization of electronic equipment and the progress of advanced processing technology, vapor chambers are developed towards the direction of ultrathin property, flexibility and high heat transfer performance, and microchannel liquid absorption cores have the advantages of large supporting strength, small flow resistance, large permeability and the like and are more in line with the development trend of ultrathin and flexible vapor chambers.

However, current microchannel wick structures are relatively simple and are mostly straight channel array structures. The straight channel array structure liquid absorption core has smooth and gentle inner surface, when steam is condensed on the inner surface of the channel by cooling, a layer of liquid film is easily formed on the surface to prevent the steam from directly contacting with the condensing plate, so that the heat transfer resistance of the microchannel condensing plate is increased, and the heat exchange capacity is reduced. In addition, when steam is cooled on the inner surface of the channel to form liquid drops, the inner surface of the straight channel is gentle and has large surface tension, so that the steam is not easy to drop and flow back to the evaporation end, the burn-out limit of the soaking plate is further reduced, and the overall heat dissipation performance of the soaking plate is reduced.

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention provides the micro-channel soaking plate with the recess structures, and the recess structures are arranged on the two side surfaces in the micro-channel, so that the fluid boundary layer can be effectively damaged, the fluid flow is disturbed, the formation of a condensed liquid film is inhibited, and the heat transfer is effectively promoted. Meanwhile, a low-temperature detention area can be formed by a recess structure in the microchannel, so that condensation and backflow of steam are promoted, and higher heat transfer capacity and superior burn-dry resistance are realized.

The invention adopts the following technical scheme:

the utility model provides a take microchannel soaking plate of pocket structure, includes bottom plate, capillary core and apron, the upper surface of bottom plate is provided with the cavity, and the capillary core sets up in the cavity, the upper surface processing of apron has the microchannel structure, the internal surface both sides of microchannel structure set up the pocket structure, and bottom plate and apron form airtight cavity through the welding mode, annotate the microchannel soaking plate of liquid formation area pocket structure through the evacuation.

The capillary core is in a copper powder sintering, foam metal or wire mesh structure.

The microchannel structure is in the form of an array consisting of a plurality of microchannels, and the array form comprises a linear array and a circumferential array.

The recess structure is a two-dimensional recess structure, the recess structure comprises a plurality of recesses, and the shape of each recess comprises a rectangle, a triangle, a semicircle or a trapezoid.

The plurality of recesses are symmetrically distributed on two sides of the inner surface of the microchannel.

The cross section of the micro-channel is arc-shaped, triangular, rectangular or trapezoidal.

The depth of the microchannel array is equal to the depth of the cavity of the bottom plate minus the height of the capillary wick.

The bottom plate and the cover plate are the same in shape.

The shape of the bottom plate and the cover plate comprises a circle or a square.

When the capillary core is a copper powder sintered liquid absorbing core, the particle size of copper powder particles is 0.075mm-0.150 mm.

The invention has the beneficial effects that:

(1) the invention adopts the microchannel wick structure to replace the traditional porous metal sintered wick structure, on one hand, the microchannel structure is beneficial to the transmission and uniform distribution of working medium steam, the channel wall also expands the condensing area of the working medium, shortens the path of liquid condensation reflux, and realizes lower flow resistance and superior burn-dry resistance; on the other hand, the micro-channel structure is also used as an upper shell plate supporting column and a lower shell plate supporting column, and the metal sintered liquid absorption core structure with more holes has higher strength and can ensure that the soaking plate is tightly attached to the chip under the action of long-time heating;

(2) according to the vapor chamber, the concave structures are processed on two side surfaces in the micro-channel, so that on one hand, a fluid boundary layer can be damaged to cause fluid disturbance, the formation of a condensed liquid film is inhibited, the convective heat transfer capability between steam and the condensed plate is enhanced, and the heat transfer performance of the vapor chamber is improved; on the other hand, the insertion of the recess structure can cause the formation of a low-temperature retention area (as shown in fig. 6 and fig. 7), thereby enhancing the condensation effect (condensation enhancement point) of steam at the recess, promoting the condensation reflux of the liquid working medium and enhancing the burn-out resistance of the soaking plate;

(3) the micro-channel vapor chamber is added with a cavity structure, so that the heat transfer area can be effectively increased, meanwhile, the injection effect is generated at the inlet of the cavity, the throttling effect is generated at the outlet, the two effects effectively promote the formation of secondary flow, further the flow resistance of steam is reduced, the convection heat transfer coefficient of the steam is improved, and finally the temperature equalization and heat dissipation performance of the vapor chamber are effectively improved;

(4) the micro-channel soaking plate with the recessed structure has the advantages of high supporting strength, small flow resistance, good temperature equalizing performance and high heat transfer efficiency, and is more in line with the development trend of ultrathin and flexible soaking plates;

(5) the micro-channel soaking plate with the recessed structure is convenient to manufacture, low in processing cost and convenient for large-scale production and manufacturing of products.

Drawings

FIG. 1 is a schematic view showing the structure of a microchannel soaking plate with a cavity structure according to example 1 of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a schematic view of the cover plate of FIG. 1;

FIG. 4 is a schematic structural view of embodiment 2 of the present invention;

FIG. 5 is a schematic top view of a cover plate according to embodiment 2 of the present invention;

FIG. 6 is a graph showing the heat dissipation temperature distribution of the micro-channel vapor chamber of example 1 of the present invention;

fig. 7 is a heat dissipation flow velocity distribution diagram of embodiment 1 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited to these examples.