TWI858855B - Vapor chamber structure - Google Patents

Abstract

A vapor chamber structure includes an aluminum upper plate, an aluminum lower plate, a working fluid and multiple micron-sized recesses. The aluminum upper plate has a first side and a second side. The aluminum lower plate has a third side and a fourth side. The aluminum upper plate and the aluminum lower plates are correspondingly mated with each other to define an airtight chamber. The working fluid is filled in the airtight chamber. The micron-sized recesses are directly formed on a surface of the third side. The micron-sized recesses are upward raised and/or downward recessed from the surface of the third side in the form of multiple small puddles so as to enhance the boiling efficiency of the working fluid in the airtight chamber and promote liquid-vapor circulation performance of the entire vapor chamber. In addition, when used in a low-temperature environment, the vapor chamber structure prevents the working fluid in the airtight chamber from freezing.

Description

Temperature balancing plate structure

A heat balancing plate structure, especially a heat balancing plate structure that is thin and can prevent the working fluid from freezing in a low temperature environment.

Vapor chamber is a common heat conducting element. It provides a method of rapid heat conduction through the principle of two-phase flow. There is a working fluid (water, refrigerant, methanol, acetone, liquid ammonia, etc.) inside the vapor chamber. The main material of the vapor chamber shell is usually copper or stainless steel. Because the working fluid inside it conducts heat through a phase change latent heat mechanism, its conductivity reaches 10000c/w. Its superconductivity is well used in electronics, aviation, military industry, petrochemical and other industries.

In recent years, the heat flux density of chip packaging has become higher and higher. When the chip power consumption can reach 1000W, the heat flux density is 250W/cm2, and the chip has hot spot problems, the thermal resistance requirements of VC are more stringent. How to reduce the thermal resistance inside the VC is the main focus of two-phase flow product design.

When the power of the heat source is higher, a larger or larger heat dissipation module with a temperature averaging plate is required to dissipate heat. However, if such heat dissipation modules are made of copper and stainless steel, the overall weight is very heavy, and it is easy to cause compression and cracking damage on the PCB board or chip. In addition, the use environment must be considered. In a low-temperature environment, the internal working fluid must be selected to be able to start and work in a low-temperature environment, and it must be prevented from freezing. What is more important is that the temperature change cycle of the application environment causes the internal working fluid to freeze, resulting in the expansion of the temperature averaging plate shell material and cracking.

How to increase the boiling speed of the internal working fluid in the temperature plate to reduce the evaporation thermal resistance, and how to increase the ease of evaporation of bubbles from the capillary structure to achieve good heat exchange are the top priorities of the industry.

Therefore, in order to effectively solve the above problems, the main purpose of the present invention is to provide a temperature balancing plate structure that is light in weight, has good structural strength, and can be used in low-temperature environments without causing freezing of the internal working fluid, and can also increase the boiling rate of the internal working fluid to reduce the evaporation thermal resistance.

To achieve the above-mentioned purpose, the present invention provides a temperature-averaging plate structure, which has an aluminum upper plate, an aluminum lower plate, a working fluid, and a plurality of micrometer-level grooves; the aluminum upper plate has a first side and a second side; the aluminum lower plate has a third side and a fourth side; the aluminum upper and lower plates are correspondingly covered to form an airtight chamber and filled with a working fluid, and the micrometer-level grooves are directly formed on the surface of the third side with a plurality of small water pools in an upward convex or downward concave configuration, so as to enhance and speed up the boiling efficiency of the working fluid in the airtight chamber, increase the overall vapor-liquid circulation efficiency, and prevent the working fluid from freezing in a low-temperature environment.

11: Aluminum upper plate

111: First side

112: Second side

12: Aluminum lower plate

121: Third side

122: Fourth side

123: Evaporation area

13: Airtight chamber

14: Micron-grade grooves

14a: ribs

15: Support body

Figure 1 is a three-dimensional exploded view of the first embodiment of the temperature balancing plate structure of the present invention; Figure 2 is a combined cross-sectional view of the first embodiment of the temperature balancing plate structure of the present invention; Figure 3 is another three-dimensional exploded view of the first embodiment of the temperature balancing plate structure of the present invention.

The above-mentioned purpose of the present invention and its structural and functional characteristics will be explained according to the preferred embodiments of the attached drawings.

Please refer to Figures 1, 2, and 3, which are three-dimensional exploded and assembled diagrams of the temperature balancing plate structure of the present invention. As shown in the figure, the temperature balancing plate structure of the present invention includes: an aluminum upper plate 11, an aluminum lower plate 12, a working fluid 2, and a plurality of micron-grade grooves 14; the aluminum upper plate 11 has a first side 111 and a second side 112, and the first and second sides 111 and 112 are respectively arranged on the upper and lower sides of the aluminum upper plate 11.

The aluminum lower plate 12 has a third side 121 and a fourth side 122. The third and fourth sides 121, 122 are respectively arranged on the upper and lower sides of the aluminum lower plate 12. The third side 121 of the aluminum lower plate 12 has an evaporation area 123. The fourth side 122 is in contact with at least one heat source (not shown in the figure) corresponding to the evaporation area 123 for heat conduction. The aluminum upper and lower plates 11, 12 are correspondingly covered, that is, the second side 112 of the aluminum upper plate 11 and the fourth side 122 of the aluminum lower plate 12 are correspondingly covered to form an airtight chamber 13 and filled with a working fluid (not shown in the figure).

The micron-level grooves 14 are 200-300um wide and 30-50um deep. The micron-level grooves 14 are directly formed in the evaporation area 123 on the surface of the third side 121 by convex upward or concave downward (using negative or positive engraving) to form a plurality of small water pools (pits, pools, holes, ponds) to form a plurality of small spaces that can accommodate liquids, so as to accelerate the boiling speed and improve the boiling efficiency of the working fluid 2 in the airtight chamber 13, greatly increasing the overall vapor-liquid circulation efficiency.

The micron-scale grooves 14 are rectangular, rhombus, square, circular, trapezoidal, triangular and other geometric shapes, and the micron-scale grooves 14 can be arranged equidistantly or unequally, or adjacently or non-adjacently, non-connected or closely connected.

The plurality of supporting bodies 15 are columnar structures which can be independent (two ends are connected to the second side and the third side respectively) or directly protrude upward from the third side, and one end of the protrusion is connected to the second side 112 of the aluminum upper plate 11. In addition, the supporting body 15 can be selectively connected to or staggered with the micron-level grooves 14.

Referring to FIG. 3 , the micrometer-scale grooves 14 are located on the third side 121, and a plurality of ribs 14a protrude in the lateral and longitudinal directions of the third side 121, and the ribs 14a are staggered to form the micrometer-scale grooves 14; or the ribs 14a directly protrude from the third side 121 and form the micrometer-scale grooves 14 in a circumferential manner (such as a small circle or a small rectangular frame or a small closed area formed in other forms of geometric shapes) (as shown in FIG. 3 ). ; or the micron-level grooves 14 are formed by directly recessing a plurality of pits on the third side 121, and the ribs 14a or pits are formed by directly removing material or embossing on the surface of the third side 121. The micron-level grooves 14 can be processed by traditional processing or non-traditional processing. The traditional processing is a lathe, a milling machine, a plating machine, a grinder, a punching machine, a press, etc. The non-traditional processing is laser processing, discharge processing, etching processing, 3D printing, etc.

And for the main evaporation area 123 directly corresponding to the heat source (not shown in the figure), the micron-level grooves 14 are arranged in a denser manner to improve the efficiency of pool boiling, and the remaining parts outside the main evaporation area 123 can be arranged with the micron-level grooves 14 in an equidistant or non-equidistant manner.

The micron-level groove 14 is provided with a capillary structure layer (not shown in the figure). The capillary structure layer is a sintered powder body or a woven mesh or a fiber body, and is arranged on the micron-level groove 14 and tightly bonded by welding, diffusion bonding or sintering.

The present invention mainly uses aluminum as the main material for the upper and lower plates of the temperature equalizing plate, further solving the problem derived from the traditional copper or stainless steel materials being too heavy. In addition, the material properties of the aluminum material can prevent the internal working fluid of the temperature equalizing plate from freezing when used in a low-temperature environment.

When the aluminum lower plate is heated, the working fluid in liquid state will be converted into steam and diffuse upwards. Due to the setting of the micron-level grooves, small puddles (multiple small pits or multiple small water pits) are formed, dividing the large area where the original aluminum lower plate and the working fluid are in contact into multiple small areas. These small areas can increase the acceleration or rapid boiling of water in the small "core points" of the working fluid in the aluminum lower plate after heating (nucleate boiling phenomenon), and the bubbles generated by the evaporation of the working fluid can quickly break away and evaporate, forming the phenomenon of pool boiling and flow boiling, increasing The two-phase working fluid in the airtight chamber changes dramatically. The difference between the structure of the temperature averaging plate in this case and the conventional temperature averaging plate is that the structure of the temperature averaging plate in this case has boiling phase changes such as pool boiling, film boiling, and flow boiling at the same time, which can accelerate the heat transfer phenomenon of the two-phase flow change, so that the temperature averaging plate can immediately or instantly provide a temperature averaging effect. Compared with the conventional traditional evaporation and film boiling heat transfer efficiency provided only by the capillary structure, the present invention can also provide a kind of ability to produce dramatic phase changes and increase latent heat exchange compared to the conventional temperature averaging plate.

11: Aluminum upper plate

111: First side

112: Second side

12: Aluminum lower plate

121: Third side

122: Fourth side

14: Micron-grade grooves

14a: ribs

15: Support body

Claims (8)

A temperature equalizing plate structure includes: an aluminum upper plate having a first side and a second side; an aluminum lower plate having a third side and a fourth side. The aluminum upper and lower plates are correspondingly covered to form an airtight chamber filled with a working fluid, and a plurality of micron-level grooves. The micron-level grooves are directly recessed downward on the surface of the third side and have a plurality of small spaces that can accommodate liquid. The micron-level grooves are densely arranged to improve the boiling efficiency of the working fluid in the airtight chamber and increase the overall vapor-liquid circulation efficiency. In addition, the configuration of the aluminum upper and lower plates makes the temperature equalizing plate light in weight, good in structural strength, and can be used in low-temperature environments to prevent the internal working fluid from freezing. As described in item 1 of the patent application, the heat balancing plate structure, wherein the micron-level grooves are in a rectangular, diamond, square, circular, trapezoidal, triangular or other composite shapes. The temperature equalizing plate structure described in item 1 of the patent application scope further comprises a plurality of supporting bodies, which are protruded upward from the third side and connected to the second side of the aluminum upper plate. The supporting bodies and the micron-level grooves can be selectively connected or staggered. As described in item 1 of the patent application, the micron-level groove can be processed by traditional processing or non-traditional processing. The traditional processing is lathe, milling machine, plating machine, grinder, punching machine, press machine, etc. The non-traditional processing is laser processing, discharge processing, etching processing, 3D printing, etc. The temperature equalizing plate structure as described in Item 1 of the patent application, wherein the micron-scale grooves further have a sintered powder layer or a woven mesh layer. As described in item 1 of the patent application, the temperature equalizing plate structure, wherein the micron-level grooves have a width of 200-300um and a depth of 30~50um. As described in item 1 of the patent application, the heat spreader structure, wherein the micrometer-level grooves are formed by a plurality of ribs extending horizontally and vertically on the third side and interlaced with each other. As described in item 1 of the patent application, the third side of the aluminum lower plate has an evaporation area, and the fourth side corresponding to the evaporation area is in contact with at least one heat source.

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