Ultrathin vapor chamber with rhombic wire mesh type wick

Abstract

The invention discloses an ultrathin vapor chamber with a rhombic wire mesh type wick, and the wick is formed by weaving high-precision copper wires in a crossed manner, so that a dense rhombic net structure is formed. By means of the characteristic that fluid flow resistance in the connecting line direction of the vertexes of the two acute angles of the rhombus is small, a liquid working medium can be effectively promoted to rapidly flow back to the evaporation end under the capillary pressure effect, and therefore the quality of the working medium participating in phase-change heat exchange within unit time is improved, and the circulation rate of a working medium transmission loop is increased; therefore, the overall heat exchange performance of the vapor chamber is obviously enhanced. According to the ultrathin vapor chamber with the rhombic wire mesh type wick, the preparation process is compatible with the existing commercial ultrathin vapor chamber technology, sintering integration of the ultrathin vapor chamber and a lower shell plate of the vapor chamber can be achieved, and due to the characteristic, the overall thickness of the vapor chamber can be further reduced. And the urgent demand of the current miniaturized electronic equipment on an efficient and ultra-thin heat dissipation solution is met.

Description

Technical Field

[0001] The invention relates to the technical field of electronic device thermal management, in particular to an ultra-thin heat spreader with a diamond-shaped wire mesh liquid wick. Background Art

[0002] With the rapid development of semiconductor technology, the integration and power density of electronic devices continue to rise, which puts more stringent requirements on heat dissipation technology. As an efficient heat dissipation method based on phase change heat transfer, vapor chamber technology has attracted widespread attention due to its excellent heat dissipation performance. The vapor chamber achieves efficient heat transfer through the internal gas-liquid circulation phase change heat transfer mechanism. In the vapor chamber, the liquid working fluid in the capillary wick at the evaporation end absorbs the heat from the heat source and undergoes an evaporation phase change to form steam. The steam flows rapidly to the condensation end in the vacuum cavity and undergoes a condensation phase change. After releasing heat, it is converted into a liquid working fluid, and then flows back to the evaporation end driven by the capillary pressure of the wick, completing the entire gas-liquid cycle.

[0003] However, with the trend of pursuing lighter and thinner electronic devices, the demand for ultra-thin vapor chambers is becoming increasingly urgent. Ultra-thin vapor chambers, especially those with a thickness of less than 0.4 mm, have great application potential in the field of heat dissipation. However, ultra-thin vapor chambers in the prior art still face many challenges in design. Among them, the flow resistance of steam in the ultra-thin vacuum cavity increases sharply as the thickness of the steam cavity decreases, becoming a key factor hindering the smooth circulation of gas and liquid. This increase in flow resistance not only limits the rapid diffusion and condensation efficiency of steam, but also seriously restricts the overall heat transfer performance of the ultra-thin vapor chamber.

[0004] Therefore, how to effectively reduce the flow resistance of steam in the ultra-thin heat spreader and optimize the liquid wick structure to promote the smooth reflux of the liquid working fluid has become an important research direction to improve the heat transfer performance of the ultra-thin heat spreader and meet the heat dissipation needs of modern electronic devices. Summary of the invention

[0005] The present invention proposes an innovative solution to the problem of limited heat transfer performance of ultra-thin vapor chambers due to large flow resistance of the working fluid during heat dissipation: an ultra-thin vapor chamber with a diamond-shaped wire mesh liquid wick. This design utilizes the characteristic of small flow resistance in the direction of the line connecting the two acute angle vertices of the diamond, effectively promoting the rapid reflux of the liquid working fluid under the action of capillary pressure, thereby increasing the mass of the working fluid participating in phase change heat transfer per unit time, accelerating the circulation of the working fluid transmission circuit, and ultimately achieving a significant improvement in the overall heat transfer performance of the vapor chamber.

[0006] To achieve the above technical objectives, the present invention provides a solution: an ultra-thin heat spreader with a diamond wire mesh type liquid wick, characterized in that it includes: an upper shell of the heat spreader, a lower shell of the heat spreader, a liquid wick and a liquid working medium, the lower shell of the heat spreader serves as an evaporation copper plate, has a concave groove structure, and is formed by a stamping process; the liquid wick is formed by cross-weaving a plurality of copper wires, is arranged at the bottom of the concave groove of the lower shell of the heat spreader, and is fixed by a sintering process; the upper shell of the heat spreader serves as a condensation copper plate, forms an integral structure with a support column, is formed by an etching process, and is welded to the lower shell by edge sealing to form a closed cavity structure; the liquid working medium is filled in the cavity, and ethanol, acetone, deionized water, etc. can be selected, and the liquid working medium flows back to the evaporation end in the diamond wire mesh type liquid wick.

[0007] 2. The ultra-thin vapor chamber of the diamond-shaped wire mesh liquid-absorbing core according to claim 1 is characterized in that a heat source is arranged on the lower shell of the vapor chamber, and a cold source is arranged on the upper shell of the vapor chamber.

[0008] 3. The ultra-thin heat spreader of the diamond wire mesh type liquid absorbent core according to claim 1, characterized in that the liquid absorbent core is a diamond wire mesh type, and the acute vertex angle θ of the diamond mesh is 30°-80°.

[0009] 4. The ultra-thin vapor chamber of the diamond-shaped wire mesh liquid-absorbing core according to claim 1, characterized in that the total thickness of the vapor chamber upper shell and the vapor chamber lower shell is 0.30 mm-0.43 mm.

[0010] 5. The ultra-thin vapor chamber of the diamond-shaped wire mesh liquid-absorbing core according to claim 4, characterized in that the thickness of the concave groove structure of the lower shell of the vapor chamber is 0.15 mm.

[0011] 6. The ultra-thin heat spreader of the diamond-shaped wire mesh liquid absorbent core according to claim 4, characterized in that the thickness of the shell on the heat spreader is 0.05 mm.

[0012] 7. The ultra-thin vapor chamber of the diamond-shaped wire mesh type liquid absorbent core according to claim 1, characterized in that the direction of the line connecting the two acute angle vertices of the diamond-shaped wire mesh type liquid absorbent core is parallel to the length direction of the lower shell of the vapor chamber.

[0013] 8. The ultra-thin heat spreader of the diamond wire mesh type liquid absorbent core according to claim 1 is characterized in that the liquid working medium is any one of ethanol, acetone, and deionized water, and the liquid working medium flows back to the evaporation end along the direction of the line connecting the two acute angle vertices in the diamond wire mesh type liquid absorbent core.

[0014] 9. The ultra-thin heat spreader of the diamond-shaped wire mesh type liquid absorbent core according to claim 1, characterized in that the diameter Φ of the copper wire of the diamond-shaped wire mesh type liquid absorbent core is 0.03-0.1 mm, and the mesh number is 100-330.

[0015] After adopting the scheme of the present invention, when the chip is working and generates heat, the liquid working medium in the capillary wick at the evaporation end absorbs the heat from the lower shell and undergoes an evaporation phase change to form steam. The steam flows rapidly to the condensation end in the vacuum cavity and undergoes a condensation phase change. After releasing the heat, it is converted into a liquid working medium, and then flows back to the evaporation end driven by the capillary pressure of the wick, completing the entire gas-liquid cycle. The diamond-shaped wire mesh wick has a small flow resistance, which promotes the rapid reflux of the liquid working medium under the action of capillary pressure, thereby increasing the mass of the working medium participating in the phase change heat transfer per unit time, accelerating the circulation of the working medium transmission circuit, and realizing the improvement of the overall heat exchange performance of the heat spreader. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an exploded view of the overall structure of a specific embodiment of the present invention;

[0017] Figure 2 for Figure 1 The schematic diagram of the upper shell structure shown;

[0018] Figure 3 for Figure 1 The schematic diagram of the lower shell structure and heat source distribution shown;

[0019] Figure 4 for Figure 1 The schematic diagram of the structure of the diamond-shaped wire mesh type liquid-absorbing core shown;

[0020] Figure 5 for Figure 4 Schematic diagram of the diamond-shaped wire mesh wick pores shown.

[0021] Reference numerals:

[0022] 1. Lower shell of heat spreader; 2. Diamond wire mesh type liquid absorbent core; 3. Upper shell of heat spreader; 4. Heat source; 5. Support column; θ is the cross-weaving angle of copper wire of diamond wire mesh type liquid absorbent core. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0024] like Figure 1As shown, an ultra-thin heat spreader with a diamond-shaped wire mesh wick comprises a heat spreader lower shell 1, a heat spreader upper shell 3, a diamond-shaped wire mesh wick 2 and a liquid medium filled therein. Among them, the heat spreader lower shell 1 serves as an evaporation copper plate, has a concave groove structure, and is formed by a stamping process; the diamond-shaped wire mesh wick 2 is formed by cross-weaving of multiple copper wires, is arranged at the bottom of the concave groove of the lower shell, and is fixed by a sintering process; the heat spreader upper shell 3 serves as a condensation copper plate, forms an integral structure with the support column 5, is formed by etching, and is welded to the lower shell by edge sealing to form a closed cavity structure; the liquid medium is filled in the cavity, and ethanol, acetone, deionized water, etc. can be selected, and the liquid medium flows back to the evaporation end in the diamond-shaped wire mesh wick. The heat source is arranged in the lower shell (evaporation copper plate), and the cold source is arranged in the upper shell (condensation copper plate). The diagonal line of the acute vertex angle θ of the mesh pores of the diamond-shaped wire mesh absorbent core 2 is parallel to the length direction of the lower shell 1.

[0025] In this embodiment, the lower shell 1 of the heat spreader is used as an evaporation copper plate, adopts a concave groove structure, is prepared by stamping and forming, and has a thickness of 0.15mm; the diamond wire mesh type liquid absorbent core 2 is formed by cross-weaving a plurality of copper wires, the wire mesh pores are diamond-shaped, the side length of the diamond pores is 0.041mm, and the acute angle θ is 60°. The copper wire diameter Φ of the woven liquid absorbent core is 0.036mm, the mesh number is 330, and the thickness is 0.072mm. It is arranged at the bottom of the concave groove of the lower shell 1 of the heat spreader and is fixed to the bottom of the lower shell 1 of the heat spreader by a sintering process; The shell 3 on the board serves as a condensation copper plate with a thickness of 0.05mm and an integral structure with the support column 5. The diameter of the support column 5 is 0.54mm, the height is 0.13mm, the array spacing is 1.5mm, and it is formed by an etching process. It is sealed with the lower shell 1 of the heat spreader by the edge and welded to form a cavity. The closed chamber is 12mm long, 6mm wide and 0.202mm deep. The lower shell 1 of the heat spreader and the upper shell 3 of the heat spreader are both made of oxygen-free copper material. Deionized water is used as the liquid working medium, and the heat source 4 is arranged at one end of the length direction of the lower shell 1 of the heat spreader.

[0026] Specifically, when the chip is working, heat is generated, and the liquid working medium in the diamond wire mesh type liquid absorbent core 2 at the evaporation end absorbs the heat from the lower shell 1 of the heat spreader and undergoes an evaporation phase change to form steam, which takes away the heat through the liquid-gas phase change and cools the chip. The steam flows quickly to the upper shell 3 of the heat spreader in the vacuum cavity and undergoes a condensation phase change. After releasing the heat, it is converted into a liquid working medium, and then flows back to the evaporation end of the diamond wire mesh type liquid absorbent core 2 under the capillary pressure of the diamond wire mesh type liquid absorbent core 2, completing the entire gas-liquid cycle, achieving cyclic heat dissipation, and high heat dissipation efficiency. The present invention adopts a diamond wire mesh type liquid absorbent core design to reduce the reflux resistance of the liquid working medium, increase the mass of the working medium participating in the phase change heat transfer per unit time, and speed up the circulation speed of the working medium transmission circuit. These improvements jointly improve the overall heat exchange performance of the heat spreader, so that the heat dissipation efficiency is improved. At the same time, the ultra-thin design of the present invention also meets the needs of modern electronic equipment for miniaturization and lightweight heat dissipation components.

[0027] The present invention optimizes the liquid wick structure and adopts a diamond wire mesh design to reduce the reflux resistance of the liquid working medium inside the heat spreader, thereby effectively improving the overall heat transfer performance of the heat spreader.

[0028] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ultra-thin heat spreader with a diamond-shaped wire mesh wick, characterized in that: include: The upper shell of the heat spreader, the lower shell of the heat spreader, the liquid wick and the liquid working medium, the lower shell of the heat spreader serves as an evaporation copper plate, has a concave groove structure, and is formed by a stamping process; the liquid wick is formed by cross-weaving of multiple copper wires, is arranged at the bottom of the concave groove of the lower shell of the heat spreader, and is fixed by a sintering process; the upper shell of the heat spreader serves as a condensation copper plate, forms an integral structure with the support column, is formed by etching process, and is sealed and welded with the lower shell by edge sealing to form a closed cavity structure; the liquid working medium is filled in the cavity, and ethanol, acetone, deionized water, etc. can be selected, and the liquid working medium flows back to the evaporation end in the diamond wire mesh liquid wick.

2. The ultra-thin heat spreader of the diamond-shaped wire mesh type liquid wick according to claim 1, characterized in that: A heat source is arranged on the lower shell of the heat spreader, and a cold source is arranged on the upper shell of the heat spreader.

3. The ultra-thin heat spreader of the diamond-shaped wire mesh type liquid wick according to claim 1, characterized in that: The liquid absorbent core is a diamond mesh type, and the acute vertex angle θ of the diamond mesh is 30°-80°.

4. The ultra-thin vapor chamber of the diamond-shaped wire mesh type liquid wick according to claim 1, characterized in that: The total thickness of the upper shell of the heat spreader and the lower shell of the heat spreader is 0.30 mm-0.43 mm.

5. The ultra-thin heat spreader of the diamond-shaped wire mesh type liquid wick according to claim 4, characterized in that: The thickness of the concave groove structure of the lower shell of the heat spreader is 0.15 mm.

6. The ultra-thin heat spreader of the diamond-shaped wire mesh type liquid wick according to claim 4, characterized in that: The thickness of the shell on the heat spreader is 0.05 mm.

7. The ultra-thin vapor chamber of the diamond-shaped wire mesh type liquid wick according to claim 1, characterized in that: The direction of the line connecting the two acute angle vertices of the diamond-shaped wire mesh type liquid absorbent core is parallel to the length direction of the lower shell of the heat spreader.

8. The ultra-thin vapor chamber of the diamond-shaped wire mesh type liquid wick according to claim 1, characterized in that: The liquid working medium is any one of ethanol, acetone and deionized water, and the liquid working medium flows back to the evaporation end along the direction of the line connecting the two acute angle vertices in the diamond-shaped wire mesh type liquid absorption core.

9. The ultra-thin vapor chamber of the diamond-shaped wire mesh type liquid wick according to claim 1, characterized in that: The copper wire diameter Φ of the diamond-shaped wire mesh liquid-absorbing core is 0.03-0.1 mm, and the mesh number is 100-330.

Images